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Sample records for encode slow signals

  1. Peptide Signals Encode Protein Localization▿

    OpenAIRE

    Russell, Jay H.; Keiler, Kenneth C.

    2007-01-01

    Many bacterial proteins are localized to precise intracellular locations, but in most cases the mechanism for encoding localization information is not known. Screening libraries of peptides fused to green fluorescent protein identified sequences that directed the protein to helical structures or to midcell. These peptides indicate that protein localization can be encoded in 20-amino-acid peptides instead of complex protein-protein interactions and raise the possibility that the location of a ...

  2. Peafowl antipredator calls encode information about signalers.

    Science.gov (United States)

    Yorzinski, Jessica L

    2014-02-01

    Animals emit vocalizations that convey information about external events. Many of these vocalizations, including those emitted in response to predators, also encode information about the individual that produced the call. The relationship between acoustic features of antipredator calls and information relating to signalers (including sex, identity, body size, and social rank) were examined in peafowl (Pavo cristatus). The "bu-girk" antipredator calls of male and female peafowl were recorded and 20 acoustic parameters were automatically extracted from each call. Both the bu and girk elements of the antipredator call were individually distinctive and calls were classified to the correct signaler with over 90% and 70% accuracy in females and males, respectively. Females produced calls with a higher fundamental frequency (F0) than males. In both females and males, body size was negatively correlated with F0. In addition, peahen rank was related to the duration, end mean frequency, and start harmonicity of the bu element. Peafowl antipredator calls contain detailed information about the signaler and can potentially be used by receivers to respond to dangerous situations.

  3. Slow oscillation electrical brain stimulation during waking promotes EEG theta activity and memory encoding

    DEFF Research Database (Denmark)

    Kirov, Roumen; Weiss, Carsten; Siebner, Hartwig R

    2009-01-01

    in a marked and widespread increase in EEG theta (4-8 Hz) activity. During wake, tSOS did not enhance consolidation of memories when applied after learning, but improved encoding of hippocampus-dependent memories when applied during learning. We conclude that the EEG frequency and related memory processes......The application of transcranial slow oscillation stimulation (tSOS; 0.75 Hz) was previously shown to enhance widespread endogenous EEG slow oscillatory activity when applied during a sleep period characterized by emerging endogenous slow oscillatory activity. Processes of memory consolidation...

  4. Populations of striatal medium spiny neurons encode vibrotactile frequency in rats: modulation by slow wave oscillations.

    Science.gov (United States)

    Hawking, Thomas G; Gerdjikov, Todor V

    2013-01-01

    Dorsolateral striatum (DLS) is implicated in tactile perception and receives strong projections from somatosensory cortex. However, the sensory representations encoded by striatal projection neurons are not well understood. Here we characterized the contribution of DLS to the encoding of vibrotactile information in rats by assessing striatal responses to precise frequency stimuli delivered to a single vibrissa. We applied stimuli in a frequency range (45-90 Hz) that evokes discriminable percepts and carries most of the power of vibrissa vibration elicited by a range of complex fine textures. Both medium spiny neurons and evoked potentials showed tactile responses that were modulated by slow wave oscillations. Furthermore, medium spiny neuron population responses represented stimulus frequency on par with previously reported behavioral benchmarks. Our results suggest that striatum encodes frequency information of vibrotactile stimuli which is dynamically modulated by ongoing brain state.

  5. The you gene encodes an EGF-CUB protein essential for Hedgehog signaling in zebrafish.

    Directory of Open Access Journals (Sweden)

    Ian G Woods

    2005-03-01

    Full Text Available Hedgehog signaling is required for many aspects of development in vertebrates and invertebrates. Misregulation of the Hedgehog pathway causes developmental abnormalities and has been implicated in certain types of cancer. Large-scale genetic screens in zebrafish have identified a group of mutations, termed you-class mutations, that share common defects in somite shape and in most cases disrupt Hedgehog signaling. These mutant embryos exhibit U-shaped somites characteristic of defects in slow muscle development. In addition, Hedgehog pathway mutations disrupt spinal cord patterning. We report the positional cloning of you, one of the original you-class mutations, and show that it is required for Hedgehog signaling in the development of slow muscle and in the specification of ventral fates in the spinal cord. The you gene encodes a novel protein with conserved EGF and CUB domains and a secretory pathway signal sequence. Epistasis experiments support an extracellular role for You upstream of the Hedgehog response mechanism. Analysis of chimeras indicates that you mutant cells can appropriately respond to Hedgehog signaling in a wild-type environment. Additional chimera analysis indicates that wild-type you gene function is not required in axial Hedgehog-producing cells, suggesting that You is essential for transport or stability of Hedgehog signals in the extracellular environment. Our positional cloning and functional studies demonstrate that You is a novel extracellular component of the Hedgehog pathway in vertebrates.

  6. Encoding an Optical Signal using a Wireless Radio-Freqency Signal

    DEFF Research Database (Denmark)

    2011-01-01

    Source: US2012148252A The present invention provides a method for modulating an optical signal in a semiconductor device. A wireless radio frequency modulation signal is used to provide a time-dependent electric field in a semiconductor nanostructure region, which causes a change in the absorption...... in the semiconductor device. An optical signal propagating in the semiconductor device will be modulated in accordance with the properties of the wireless radio frequency modulation signal, thus providing a method for encoding information from a wireless radio frequency signal onto an optical carrier....

  7. Transmembrane signaling through major histocompatibility complex (MHC) encoded molecules

    International Nuclear Information System (INIS)

    Newell, M.K.

    1987-01-01

    The importance of the major histocompatibility complex (MHC) encoded molecules has traditionally been ascribed to the role these molecules play as restriction elements for T lymphocytes. This is, in order for T cell activation to occur the T cell must recognize antigen in association with MHC molecules. More controversial, however, is the potential role MHC molecules play as signal transducing receptors/acceptors to the B lymphocyte. In other words, do class II MHC molecules (Ia antigens) actively transduce a signal to the B cell which drives its differentiation into an antibody secreting cell? Two approaches to this question are described. The first involves biochemical characterization of those molecules which consistently copurify with I-A/sup k/ by two dimensional gel electrophoresis. The second approach utilizes two types of analyses: first, an examination of the biochemical changes which occur in the cell as a result of Ia ligation; and second, analysis of changes in the B cell's physiological response as a result of Ia perturbation. Molecules were examined which may couple the antigen binding event in the B lymphocyte to the antigen driven signal transduction cascade which ultimately leads to immunoglobulin secretion. In these experiments, cells were labelled with [ 32 P] and stimulated cells with phorbol myristate acetate. The membrane form of immunoglobulin was then isolated from detergent lysates of whole cells and passed over an anti-k affinity column. The eluates were analyzed by SDS-PAGE

  8. 47 CFR 11.12 - Two-tone Attention Signal encoder and decoder.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Two-tone Attention Signal encoder and decoder... SYSTEM (EAS) General § 11.12 Two-tone Attention Signal encoder and decoder. Existing two-tone Attention... Attention Signal decoder will no longer be required and the two-tone Attention Signal will be used to...

  9. Velocity estimation using recursive ultrasound imaging and spatially encoded signals

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav; Gammelmark, Kim; Jensen, Jørgen Arendt

    2000-01-01

    is subtracted yielding a new frame at every pulse emission. In this paper the method is extended to blood velocity estimation, where a new color flow mapping (CFM) image is created after every pulse emission. The underlying assumption is that the velocity is constant between two pulse emissions and the current...... estimates can therefore be used for compensation of the motion artifacts in the data acquired in the next emission. Two different transmit strategies are investigated in this paper: (a) using a single defocused active aperture in transmit, and (b) emitting with all active transmit sub-apertures at the same...... time using orthogonal spatial encoding signals. The method was applied on data recorded by an experimental system. The estimates of the blood velocity for both methods had a bias less than 3% and a standard deviation around 2% making them a feasible approach for blood velocity estimations...

  10. Optical signal processing using slow and fast light technologies

    DEFF Research Database (Denmark)

    Capmany, J.; Sales, Salvador; Xue, Weiqi

    2009-01-01

    microwave or millimeter-wave frequency bands, we present one scheme to increase the achievable RF phase shift by enhancing light slow-down or speed-up. As a real application in microwave photonics, a widely tunable microwave photonic notch filter with 100% fractional tuning range is also proposed...

  11. Signal Encoding and Telemetry Systems for Space Vehicles.

    Science.gov (United States)

    1983-05-01

    first application in which this design encoder was flown on two Brazilian Sonda III rockets. These encoders were programmed for the following operating...State University (OSU). The depletion sensing vehicles will be Sonda III rockets and will be instrumented by Northeastern University. The experiments...Preamp. Gain 400 Polarization Loss 3 dB Safety Factor 3 dB Xmtr. Power 3, 5 or 8 W RESULTS Xmtr. Power CNR at IF 3 watts 9.7 dB 5 12.0 8 14.0 Sonda III

  12. Automatic detection of slow-wave sleep and REM-sleep stages using polysomnographic ECG signals

    International Nuclear Information System (INIS)

    Khemiri, S.; Aloui, K.; Naceur, M. S.

    2011-01-01

    We describe in this paper a new approach of classifying the different sleep stages only by focusing on the polysomnographic ECG signals. We show the pre-processing technique of the ECG signals. At the same time the identifcation and elimination of the different types of artifacts which contain the signal and its reconstruction are shown. The automatic classification of the slow-deep sleep and the rapid eye movement sleep called in this work REM-sleep consists in extracting physiological indicators that characterize these two sleep stages through the polysomnographic ECG signal. In other words, this classification is based on the analysis of the cardiac rhythm during a night's sleep.

  13. Encoding of electrophysiology and other signals in MR images

    DEFF Research Database (Denmark)

    Hanson, Lars G; Lund, Torben E; Hanson, Christian G

    2007-01-01

    PURPOSE: To develop a gradient insensitive, generic technique for recording of non-MR signals by use of surplus scanner bandwidth. MATERIALS AND METHODS: Relatively simple battery driven hardware is used to transform one or more signals into radio waves detectable by the MR scanner. Similar....... CONCLUSION: The method provides relatively inexpensive sampling with inherent microsecond synchronization and it reduces gradient artifacts in physiological recordings significantly. When oversampling is employed, the method is compatible with all MR reconstruction and postprocessing techniques....

  14. Automatic real-time adjustment of pulse signal of incremental photoelectric encoder

    Science.gov (United States)

    Zhao, Changhai; Wan, Qiuhua; Lu, Xinran; Du, Yingcai

    2017-12-01

    An automatic real-time pulse signal adjustment method for the incremental photoelectric encoder was designed in this study in an effort to ensure highly precise output speed pulse signals. The original moire fringe signal of the photoelectric sensor encoder output is first converted into a voltage signal through the digital potentiometer, then the voltage signal is converted into two orthogonal sinusoidal signals through the amplifier circuit, and finally the sinusoidal signal is subdivided into 10 segments via the subdividing chip and converted into a square wave pulse signal output. The numerical size of the digital potentiometer can be adjusted according to the collected sine signal amplitude value and square wave pulse signal error, which restrains the output error within a reasonable range. Experimental results showed that in high temperature conditions, the system can reduce the peak error of the encoder output square wave signal from 3.12″ to 0.52″; in low temperature conditions, the peak error can be reduced from 4.16″ to 0.56″.

  15. Magnetic resonance imaging with nonlinear gradient fields signal encoding and image reconstruction

    CERN Document Server

    Schultz, Gerrit

    2013-01-01

    Within the past few decades magnetic resonance imaging has become one of the most important imaging modalities in medicine. For a reliable diagnosis of pathologies further technological improvements are of primary importance. This text deals with a radically new approach of image encoding: The fundamental principle of gradient linearity is challenged by investigating the possibilities of acquiring anatomical images with the help of nonlinear gradient fields. Besides a thorough theoretical analysis with a focus on signal encoding and image reconstruction, initial hardware implementations are tested using phantom as well as in-vivo measurements. Several applications are presented that give an impression about the implications that this technological advancement may have for future medical diagnostics.   Contents n  Image Reconstruction in MRI n  Nonlinear Gradient Encoding: PatLoc Imaging n  Presentation of Initial Hardware Designs n  Basics of Signal Encoding and Image Reconstruction in PatLoc Imaging n ...

  16. Ready...go: Amplitude of the FMRI signal encodes expectation of cue arrival time.

    Directory of Open Access Journals (Sweden)

    Xu Cui

    2009-08-01

    Full Text Available What happens when the brain awaits a signal of uncertain arrival time, as when a sprinter waits for the starting pistol? And what happens just after the starting pistol fires? Using functional magnetic resonance imaging (fMRI, we have discovered a novel correlate of temporal expectations in several brain regions, most prominently in the supplementary motor area (SMA. Contrary to expectations, we found little fMRI activity during the waiting period; however, a large signal appears after the "go" signal, the amplitude of which reflects learned expectations about the distribution of possible waiting times. Specifically, the amplitude of the fMRI signal appears to encode a cumulative conditional probability, also known as the cumulative hazard function. The fMRI signal loses its dependence on waiting time in a "countdown" condition in which the arrival time of the go cue is known in advance, suggesting that the signal encodes temporal probabilities rather than simply elapsed time. The dependence of the signal on temporal expectation is present in "no-go" conditions, demonstrating that the effect is not a consequence of motor output. Finally, the encoding is not dependent on modality, operating in the same manner with auditory or visual signals. This finding extends our understanding of the relationship between temporal expectancy and measurable neural signals.

  17. Slowing down as an early warning signal for abrupt climate change.

    Science.gov (United States)

    Dakos, Vasilis; Scheffer, Marten; van Nes, Egbert H; Brovkin, Victor; Petoukhov, Vladimir; Held, Hermann

    2008-09-23

    In the Earth's history, periods of relatively stable climate have often been interrupted by sharp transitions to a contrasting state. One explanation for such events of abrupt change is that they happened when the earth system reached a critical tipping point. However, this remains hard to prove for events in the remote past, and it is even more difficult to predict if and when we might reach a tipping point for abrupt climate change in the future. Here, we analyze eight ancient abrupt climate shifts and show that they were all preceded by a characteristic slowing down of the fluctuations starting well before the actual shift. Such slowing down, measured as increased autocorrelation, can be mathematically shown to be a hallmark of tipping points. Therefore, our results imply independent empirical evidence for the idea that past abrupt shifts were associated with the passing of critical thresholds. Because the mechanism causing slowing down is fundamentally inherent to tipping points, it follows that our way to detect slowing down might be used as a universal early warning signal for upcoming catastrophic change. Because tipping points in ecosystems and other complex systems are notoriously hard to predict in other ways, this is a promising perspective.

  18. Nrf2 Signaling and the Slowed Aging Phenotype: Evidence from Long-Lived Models

    Directory of Open Access Journals (Sweden)

    Danielle R. Bruns

    2015-01-01

    Full Text Available Studying long-lived animals provides novel insight into shared characteristics of aging and represents a unique model to elucidate approaches to prevent chronic disease. Oxidant stress underlies many chronic diseases and resistance to stress is a potential mechanism governing slowed aging. The transcription factor nuclear factor (erythroid-derived 2-like 2 is the “master regulator” of cellular antioxidant defenses. Nrf2 is upregulated by some longevity promoting interventions and may play a role in regulating species longevity. However, Nrf2 expression and activity in long-lived models have not been well described. Here, we review evidence for altered Nrf2 signaling in a variety of slowed aging models that accomplish lifespan extension via pharmacological, nutritional, evolutionary, genetic, and presumably epigenetic means.

  19. Quantum dot SOA input power dynamic range improvement for differential-phase encoded signals.

    Science.gov (United States)

    Vallaitis, T; Bonk, R; Guetlein, J; Hillerkuss, D; Li, J; Brenot, R; Lelarge, F; Duan, G H; Freude, W; Leuthold, J

    2010-03-15

    Experimentally we find a 10 dB input power dynamic range advantage for amplification of phase encoded signals with quantum dot SOA as compared to low-confinement bulk SOA. An analysis of amplitude and phase effects shows that this improvement can be attributed to the lower alpha-factor found in QD SOA.

  20. Signal processing issues for the exploitation of pulse-to-pulse encoding SAR transponders

    DEFF Research Database (Denmark)

    Merryman Boncori, John Peter; Schiavon, Giovanni

    2008-01-01

    -encoding point scatterers and distributed ones. A time-domain processing algorithm and a code synchronization procedure are proposed and validated on simulated data and on a European Remote Sensing Satellite-2 data set containing prototypes of such a device. The interaction of the transponder signal with terrain...

  1. The Wisdom of Networks: A General Adaptation and Learning Mechanism of Complex Systems: The Network Core Triggers Fast Responses to Known Stimuli; Innovations Require the Slow Network Periphery and Are Encoded by Core-Remodeling.

    Science.gov (United States)

    Csermely, Peter

    2018-01-01

    I hypothesize that re-occurring prior experience of complex systems mobilizes a fast response, whose attractor is encoded by their strongly connected network core. In contrast, responses to novel stimuli are often slow and require the weakly connected network periphery. Upon repeated stimulus, peripheral network nodes remodel the network core that encodes the attractor of the new response. This "core-periphery learning" theory reviews and generalizes the heretofore fragmented knowledge on attractor formation by neural networks, periphery-driven innovation, and a number of recent reports on the adaptation of protein, neuronal, and social networks. The core-periphery learning theory may increase our understanding of signaling, memory formation, information encoding and decision-making processes. Moreover, the power of network periphery-related "wisdom of crowds" inventing creative, novel responses indicates that deliberative democracy is a slow yet efficient learning strategy developed as the success of a billion-year evolution. Also see the video abstract here: https://youtu.be/IIjP7zWGjVE. © 2017 WILEY Periodicals, Inc.

  2. Bayesian estimation of the underlying bone properties from mixed fast and slow mode ultrasonic signals.

    Science.gov (United States)

    Marutyan, Karen R; Bretthorst, G Larry; Miller, James G

    2007-01-01

    We recently proposed that the observed apparent negative dispersion in bone can arise from the interference between fast wave and slow wave modes, each exhibiting positive dispersion [Marutyan et al., J. Acoust. Soc. Am. 120, EL55-EL61 (2006)]. In the current study, we applied Bayesian probability theory to solve the inverse problem: extracting the underlying properties of bone. Simulated mixed mode signals were analyzed using Bayesian probability. The calculations were implemented using the Markov chain Monte Carlo with simulated annealing to draw samples from the marginal posterior probability for each parameter.

  3. Controlling microwave signals by means of slow and fast light effects in SOA-EA structures

    DEFF Research Database (Denmark)

    Sales, Salvador; Öhman, Filip; Capmany, José

    2007-01-01

    We present a novel scheme for the control of microwave signals in the optical domain. We propose the use of alternating amplifying and absorbing sections to implement phase control by using fast and slow light effects in semiconductors. The potential benefits from the proposed semiconductor optical...... 10 GHz using commercially available components that were not optimized for this purpose. These results indicate a potential for several microwave photonic applications including the change of the direction of the radiation pattern of photonic phase-array antennas or the implementation of fast tunable...

  4. CORTICAL ENCODING OF SIGNALS IN NOISE: EFFECTS OF STIMULUS TYPE AND RECORDING PARADIGM

    Science.gov (United States)

    Billings, Curtis J.; Bennett, Keri O.; Molis, Michelle R.; Leek, Marjorie R.

    2010-01-01

    Objectives Perception-in-noise deficits have been demonstrated across many populations and listening conditions. Many factors contribute to successful perception of auditory stimuli in noise, including neural encoding in the central auditory system. Physiological measures such as cortical auditory evoked potentials can provide a view of neural encoding at the level of the cortex that may inform our understanding of listeners’ abilities to perceive signals in the presence of background noise. In order to understand signal-in-noise neural encoding better, we set out to determine the effect of signal type, noise type, and evoking paradigm on the P1-N1-P2 complex. Design Tones and speech stimuli were presented to nine individuals in quiet, and in three background noise types: continuous speech spectrum noise, interrupted speech spectrum noise, and four-talker babble at a signal-to-noise ratio of −3 dB. In separate sessions, cortical auditory evoked potentials were evoked by a passive homogenous paradigm (single repeating stimulus) and an active oddball paradigm. Results The results for the N1 component indicated significant effects of signal type, noise type, and evoking paradigm. While components P1 and P2 also had significant main effects of these variables, only P2 demonstrated significant interactions among these variables. Conclusions Signal type, noise type, and evoking paradigm all must be carefully considered when interpreting signal-in-noise evoked potentials. Furthermore, these data confirm the possible usefulness of CAEPs as an aid to understanding perception-in-noise deficits. PMID:20890206

  5. Distinct signal transductions in fast- and slow- twitch muscles upon denervation.

    Science.gov (United States)

    Gao, Hongbo; Li, Yi-Fan

    2018-02-01

    Denervation induces skeletal muscle atrophy, which primarily impairs oxidative slow twitch fibers. The underlying mechanism of this phenomenon, however, remains to be addressed. We hypothesize that denervation-induced fiber-specific atrophy may result from the distinct activities of different signaling pathways that are involved in protein synthesis and degradation in fast- and slow-twitch fibers. In this study, 1-month-old male mice were subjected to unilateral sciatic denervation for 4 days. Fast-twitch muscle extensor digitorum longus (EDL) and slow-twitch muscle soleus were collected from the denervated side and the control side of hind limbs. Total and phosphorylated protein levels of key factors of major signaling pathways in these tissues were determined using western blot assay. Our data showed that total AKT and FoxO3 protein levels were upregulated in denervated muscles as compared with control sides. Phosphorylation of AKT and FoxO3 were proportionally enhanced in denervated EDL but not soleus, indicating AKT activation drives phosphorylation of FoxO3 in EDL but not in soleus upon denervation. As a result, FoxO3-targeted atrogenes MurF1 and Atrogin1 protein abundances were reduced in denervated EDL but not altered in soleus. In consistent with this change, polyubiquitination were significantly increased in denervated soleus, but only a slight increase in ubiquitination was found in denervated EDL. Autophagy marker LC3 protein level was significantly increased in both muscle types, but in greater extent in EDL after denervation. IRS1 protein level and active ERK were reduced in both muscles upon denervation, which might contribute to the upregulation of total AKT protein level and FoxO3 abundance in EDL and soleus. Total and phosphorylated AMPK protein levels were increased in denervated soleus but not in EDL. Overall, these data reveal that the key signaling pathways that regulate protein synthesis and degradation are more sensitive in soleus than EDL

  6. The slow afterhyperpolarization: a target of β1-adrenergic signaling in hippocampus-dependent memory retrieval.

    Science.gov (United States)

    Zhang, Lei; Ouyang, Ming; Ganellin, C Robin; Thomas, Steven A

    2013-03-13

    In rodents, adrenergic signaling by norepinephrine (NE) in the hippocampus is required for the retrieval of intermediate-term memory. NE promotes retrieval via the stimulation of β1-adrenergic receptors, the production of cAMP, and the activation of both protein kinase A (PKA) and the exchange protein activated by cAMP. However, a final effector for this signaling pathway has not been identified. Among the many targets of adrenergic signaling in the hippocampus, the slow afterhyperpolarization (sAHP) is an appealing candidate because its reduction by β1 signaling enhances excitatory neurotransmission. Here we report that reducing the sAHP is critical for the facilitation of retrieval by NE. Direct blockers of the sAHP, as well as blockers of the L-type voltage-dependent calcium influx that activates the sAHP, rescue retrieval in mutant mice lacking either NE or the β1 receptor. Complementary to this, a facilitator of L-type calcium influx impairs retrieval in wild-type mice. In addition, we examined the role of NE in the learning-related reduction of the sAHP observed ex vivo in hippocampal slices. We find that this reduction in the sAHP depends on the induction of persistent PKA activity specifically in conditioned slices. Interestingly, this persistent PKA activity is induced by NE/β1 signaling during slice preparation rather than during learning. These observations suggest that the reduction in the sAHP may not be present autonomously in vivo, but is likely induced by neuromodulatory input, which is consistent with the idea that NE is required in vivo for reduction of the sAHP during memory retrieval.

  7. Can Co-Activation of Nrf2 and Neurotrophic Signaling Pathway Slow Alzheimer’s Disease?

    Directory of Open Access Journals (Sweden)

    Kelsey E. Murphy

    2017-05-01

    Full Text Available Alzheimer’s disease (AD is a multifaceted disease that is hard to treat by single-modal treatment. AD starts with amyloid peptides, mitochondrial dysfunction, and oxidative stress and later is accompanied with chronic endoplasmic reticulum (ER stress and autophagy dysfunction, resulting in more complicated pathogenesis. Currently, few treatments can modify the complicated pathogenic progress of AD. Compared to the treatment with exogenous antioxidants, the activation of global antioxidant defense system via Nrf2 looks more promising in attenuating oxidative stress in AD brains. Accompanying the activation of the Nrf2-mediated antioxidant defense system that reduce the AD-causative factor, oxidative stress, it is also necessary to activate the neurotrophic signaling pathway that replaces damaged organelles and molecules with new ones. Thus, the dual actions to activate both the Nrf2 antioxidant system and neurotrophic signaling pathway are expected to provide a better strategy to modify AD pathogenesis. Here, we review the current understanding of AD pathogenesis and neuronal defense systems and discuss a possible way to co-activate the Nrf2 antioxidant system and neurotrophic signaling pathway with the hope of helping to find a better strategy to slow AD.

  8. Cytoskeletal Signaling: Is Memory Encoded in Microtubule Lattices by CaMKII Phosphorylation?

    Science.gov (United States)

    Craddock, Travis J. A.; Tuszynski, Jack A.; Hameroff, Stuart

    2012-01-01

    Memory is attributed to strengthened synaptic connections among particular brain neurons, yet synaptic membrane components are transient, whereas memories can endure. This suggests synaptic information is encoded and ‘hard-wired’ elsewhere, e.g. at molecular levels within the post-synaptic neuron. In long-term potentiation (LTP), a cellular and molecular model for memory, post-synaptic calcium ion (Ca2+) flux activates the hexagonal Ca2+-calmodulin dependent kinase II (CaMKII), a dodacameric holoenzyme containing 2 hexagonal sets of 6 kinase domains. Each kinase domain can either phosphorylate substrate proteins, or not (i.e. encoding one bit). Thus each set of extended CaMKII kinases can potentially encode synaptic Ca2+ information via phosphorylation as ordered arrays of binary ‘bits’. Candidate sites for CaMKII phosphorylation-encoded molecular memory include microtubules (MTs), cylindrical organelles whose surfaces represent a regular lattice with a pattern of hexagonal polymers of the protein tubulin. Using molecular mechanics modeling and electrostatic profiling, we find that spatial dimensions and geometry of the extended CaMKII kinase domains precisely match those of MT hexagonal lattices. This suggests sets of six CaMKII kinase domains phosphorylate hexagonal MT lattice neighborhoods collectively, e.g. conveying synaptic information as ordered arrays of six “bits”, and thus “bytes”, with 64 to 5,281 possible bit states per CaMKII-MT byte. Signaling and encoding in MTs and other cytoskeletal structures offer rapid, robust solid-state information processing which may reflect a general code for MT-based memory and information processing within neurons and other eukaryotic cells. PMID:22412364

  9. Cytoskeletal signaling: is memory encoded in microtubule lattices by CaMKII phosphorylation?

    Directory of Open Access Journals (Sweden)

    Travis J A Craddock

    Full Text Available Memory is attributed to strengthened synaptic connections among particular brain neurons, yet synaptic membrane components are transient, whereas memories can endure. This suggests synaptic information is encoded and 'hard-wired' elsewhere, e.g. at molecular levels within the post-synaptic neuron. In long-term potentiation (LTP, a cellular and molecular model for memory, post-synaptic calcium ion (Ca²⁺ flux activates the hexagonal Ca²⁺-calmodulin dependent kinase II (CaMKII, a dodacameric holoenzyme containing 2 hexagonal sets of 6 kinase domains. Each kinase domain can either phosphorylate substrate proteins, or not (i.e. encoding one bit. Thus each set of extended CaMKII kinases can potentially encode synaptic Ca²⁺ information via phosphorylation as ordered arrays of binary 'bits'. Candidate sites for CaMKII phosphorylation-encoded molecular memory include microtubules (MTs, cylindrical organelles whose surfaces represent a regular lattice with a pattern of hexagonal polymers of the protein tubulin. Using molecular mechanics modeling and electrostatic profiling, we find that spatial dimensions and geometry of the extended CaMKII kinase domains precisely match those of MT hexagonal lattices. This suggests sets of six CaMKII kinase domains phosphorylate hexagonal MT lattice neighborhoods collectively, e.g. conveying synaptic information as ordered arrays of six "bits", and thus "bytes", with 64 to 5,281 possible bit states per CaMKII-MT byte. Signaling and encoding in MTs and other cytoskeletal structures offer rapid, robust solid-state information processing which may reflect a general code for MT-based memory and information processing within neurons and other eukaryotic cells.

  10. Rhizobial peptidase HrrP cleaves host-encoded signaling peptides and mediates symbiotic compatibility.

    Science.gov (United States)

    Price, Paul A; Tanner, Houston R; Dillon, Brett A; Shabab, Mohammed; Walker, Graham C; Griffitts, Joel S

    2015-12-08

    Legume-rhizobium pairs are often observed that produce symbiotic root nodules but fail to fix nitrogen. Using the Sinorhizobium meliloti and Medicago truncatula symbiotic system, we previously described several naturally occurring accessory plasmids capable of disrupting the late stages of nodule development while enhancing bacterial proliferation within the nodule. We report here that host range restriction peptidase (hrrP), a gene found on one of these plasmids, is capable of conferring both these properties. hrrP encodes an M16A family metallopeptidase whose catalytic activity is required for these symbiotic effects. The ability of hrrP to suppress nitrogen fixation is conditioned upon the genotypes of both the host plant and the hrrP-expressing rhizobial strain, suggesting its involvement in symbiotic communication. Purified HrrP protein is capable of degrading a range of nodule-specific cysteine-rich (NCR) peptides encoded by M. truncatula. NCR peptides are crucial signals used by M. truncatula for inducing and maintaining rhizobial differentiation within nodules, as demonstrated in the accompanying article [Horváth B, et al. (2015) Proc Natl Acad Sci USA, 10.1073/pnas.1500777112]. The expression pattern of hrrP and its effects on rhizobial morphology are consistent with the NCR peptide cleavage model. This work points to a symbiotic dialogue involving a complex ensemble of host-derived signaling peptides and bacterial modifier enzymes capable of adjusting signal strength, sometimes with exploitative outcomes.

  11. Subsecond dopamine fluctuations in human striatum encode superposed error signals about actual and counterfactual reward.

    Science.gov (United States)

    Kishida, Kenneth T; Saez, Ignacio; Lohrenz, Terry; Witcher, Mark R; Laxton, Adrian W; Tatter, Stephen B; White, Jason P; Ellis, Thomas L; Phillips, Paul E M; Montague, P Read

    2016-01-05

    In the mammalian brain, dopamine is a critical neuromodulator whose actions underlie learning, decision-making, and behavioral control. Degeneration of dopamine neurons causes Parkinson's disease, whereas dysregulation of dopamine signaling is believed to contribute to psychiatric conditions such as schizophrenia, addiction, and depression. Experiments in animal models suggest the hypothesis that dopamine release in human striatum encodes reward prediction errors (RPEs) (the difference between actual and expected outcomes) during ongoing decision-making. Blood oxygen level-dependent (BOLD) imaging experiments in humans support the idea that RPEs are tracked in the striatum; however, BOLD measurements cannot be used to infer the action of any one specific neurotransmitter. We monitored dopamine levels with subsecond temporal resolution in humans (n = 17) with Parkinson's disease while they executed a sequential decision-making task. Participants placed bets and experienced monetary gains or losses. Dopamine fluctuations in the striatum fail to encode RPEs, as anticipated by a large body of work in model organisms. Instead, subsecond dopamine fluctuations encode an integration of RPEs with counterfactual prediction errors, the latter defined by how much better or worse the experienced outcome could have been. How dopamine fluctuations combine the actual and counterfactual is unknown. One possibility is that this process is the normal behavior of reward processing dopamine neurons, which previously had not been tested by experiments in animal models. Alternatively, this superposition of error terms may result from an additional yet-to-be-identified subclass of dopamine neurons.

  12. Subsecond dopamine fluctuations in human striatum encode superposed error signals about actual and counterfactual reward

    Science.gov (United States)

    Kishida, Kenneth T.; Saez, Ignacio; Lohrenz, Terry; Witcher, Mark R.; Laxton, Adrian W.; Tatter, Stephen B.; White, Jason P.; Ellis, Thomas L.; Phillips, Paul E. M.; Montague, P. Read

    2016-01-01

    In the mammalian brain, dopamine is a critical neuromodulator whose actions underlie learning, decision-making, and behavioral control. Degeneration of dopamine neurons causes Parkinson’s disease, whereas dysregulation of dopamine signaling is believed to contribute to psychiatric conditions such as schizophrenia, addiction, and depression. Experiments in animal models suggest the hypothesis that dopamine release in human striatum encodes reward prediction errors (RPEs) (the difference between actual and expected outcomes) during ongoing decision-making. Blood oxygen level-dependent (BOLD) imaging experiments in humans support the idea that RPEs are tracked in the striatum; however, BOLD measurements cannot be used to infer the action of any one specific neurotransmitter. We monitored dopamine levels with subsecond temporal resolution in humans (n = 17) with Parkinson’s disease while they executed a sequential decision-making task. Participants placed bets and experienced monetary gains or losses. Dopamine fluctuations in the striatum fail to encode RPEs, as anticipated by a large body of work in model organisms. Instead, subsecond dopamine fluctuations encode an integration of RPEs with counterfactual prediction errors, the latter defined by how much better or worse the experienced outcome could have been. How dopamine fluctuations combine the actual and counterfactual is unknown. One possibility is that this process is the normal behavior of reward processing dopamine neurons, which previously had not been tested by experiments in animal models. Alternatively, this superposition of error terms may result from an additional yet-to-be-identified subclass of dopamine neurons. PMID:26598677

  13. Modulation of cellular signaling by herpesvirus-encoded G protein-coupled receptors

    Directory of Open Access Journals (Sweden)

    Sabrina M de Munnik

    2015-03-01

    Full Text Available Human herpesviruses are widespread infectious pathogens that have been associated with proliferative and inflammatory diseases. During viral evolution, human herpesviruses have pirated genes encoding viral G protein-coupled receptors (vGPCRs, which are expressed on infected host cells. These vGPCRs show highest homology to human chemokine receptors, which play a key role in the immune system. Importantly, vGPCRs have acquired unique properties such as constitutive activity and the ability to bind a broad range of human chemokines. This allows vGPCRs to hijack human proteins and modulate cellular signaling for the benefit of the virus, ultimately resulting in immune evasion and viral dissemination to establish a widespread and lifelong infection. Knowledge on the mechanisms by which herpesviruses reprogram cellular signaling might provide insight in the contribution of vGPCRs to viral survival and herpesvirus-associated pathologies.

  14. Robust high-resolution quantification of time signals encoded by in vivo magnetic resonance spectroscopy

    Science.gov (United States)

    Belkić, Dževad; Belkić, Karen

    2018-01-01

    This paper on molecular imaging emphasizes improving specificity of magnetic resonance spectroscopy (MRS) for early cancer diagnostics by high-resolution data analysis. Sensitivity of magnetic resonance imaging (MRI) is excellent, but specificity is insufficient. Specificity is improved with MRS by going beyond morphology to assess the biochemical content of tissue. This is contingent upon accurate data quantification of diagnostically relevant biomolecules. Quantification is spectral analysis which reconstructs chemical shifts, amplitudes and relaxation times of metabolites. Chemical shifts inform on electronic shielding of resonating nuclei bound to different molecular compounds. Oscillation amplitudes in time signals retrieve the abundance of MR sensitive nuclei whose number is proportional to metabolite concentrations. Transverse relaxation times, the reciprocal of decay probabilities of resonances, arise from spin-spin coupling and reflect local field inhomogeneities. In MRS single voxels are used. For volumetric coverage, multi-voxels are employed within a hybrid of MRS and MRI called magnetic resonance spectroscopic imaging (MRSI). Common to MRS and MRSI is encoding of time signals and subsequent spectral analysis. Encoded data do not provide direct clinical information. Spectral analysis of time signals can yield the quantitative information, of which metabolite concentrations are the most clinically important. This information is equivocal with standard data analysis through the non-parametric, low-resolution fast Fourier transform and post-processing via fitting. By applying the fast Padé transform (FPT) with high-resolution, noise suppression and exact quantification via quantum mechanical signal processing, advances are made, presented herein, focusing on four areas of critical public health importance: brain, prostate, breast and ovarian cancers.

  15. Photonic linear chirped microwave signal generation based on the ultra-compact spectral shaper using the slow light effect

    DEFF Research Database (Denmark)

    Yan, Siqi; Gao, Shengqian; Zhou, Feng

    2017-01-01

    A novel concept to generate a linear chirped microwave signal is proposed and experimentally demonstrated. The frequency to time mapping method is employed, where the photonic crystal waveguide Mach-Zehnder interferometer structure acts as the spectral shaper thanks to the slow light effect. By o....... The utilization of the slow light effect brings in significant advantages, including the ultra-small footprint of 0.096 mm(2) and simple structure to our scheme, which may be of great importance towards its potential applications. (C) 2017 Optical Society of America...

  16. Reduction of nocturnal slow-wave activity affects daytime vigilance lapses and memory encoding but not reaction time or implicit learning.

    Science.gov (United States)

    Van Der Werf, Ysbrand D; Altena, Ellemarije; Vis, José C; Koene, Teddy; Van Someren, Eus J W

    2011-01-01

    Total sleep deprivation in healthy subjects has a profound effect on the performance on tasks measuring sustained attention or vigilance. We here report how a selective disruption of deep sleep only, that is, selective slow-wave activity (SWA) reduction, affects the performance of healthy well-sleeping subjects on several tasks: a "simple" and a "complex" vigilance task, a declarative learning task, and an implicit learning task despite unchanged duration of sleep. We used automated electroencephalogram (EEG) dependent acoustic feedback aimed at selective interference with-and reduction of-SWA. In a within-subject repeated measures crossover design, performance on the tasks was assessed in 13 elderly adults without sleep complaints after either SWA-reduction or after normal sleep. The number of vigilance lapses increased as a result of SWA reduction, irrespective of the type of vigilance task. Recognition on the declarative memory task was also affected by SWA reduction, associated with a decreased activation of the right hippocampus on encoding (measured with fMRI) suggesting a weaker memory trace. SWA reduction, however, did not affect reaction time on either of the vigilance tasks or implicit memory task performance. These findings suggest a specific role of slow oscillations in the subsequent daytime ability to maintain sustained attention and to encode novel declarative information but not to maintain response speed or to build implicit memories. Of particular interest is that selective SWA reduction can mimic some of the effects of total sleep deprivation, while not affecting sleep duration. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. A macrophage inflammatory protein homolog encoded by guinea pig cytomegalovirus signals via CC chemokine receptor 1

    International Nuclear Information System (INIS)

    Penfold, Mark; Miao Zhenhua; Wang Yu; Haggerty, Shannon; Schleiss, Mark R.

    2003-01-01

    Cytomegaloviruses encode homologs of cellular immune effector proteins, including chemokines (CKs) and CK receptor-like G protein-coupled receptors (GPCRs). Sequence of the guinea pig cytomegalovirus (GPCMV) genome identified an open reading frame (ORF) which predicted a 101 amino acid (aa) protein with homology to the macrophage inflammatory protein (MIP) subfamily of CC (β) CKs, designated GPCMV-MIP. To assess functionality of this CK, recombinant GPCMV-MIP was expressed in HEK293 cells and assayed for its ability to bind to and functionally interact with a variety of GPCRs. Specific signaling was observed with the hCCR1 receptor, which could be blocked with hMIP -1α in competition experiments. Migration assays revealed that GPCMV-MIP was able to induce chemotaxis in hCCR1-L1.2 cells. Antisera raised against a GST-MIP fusion protein immunoprecipitated species of ∼12 and 10 kDa from GPCMV-inoculated tissue culture lysates, and convalescent antiserum from GPCMV-infected animals was immunoreactive with GST-MIP by ELISA assay. These results represent the first substantive in vitro characterization of a functional CC CK encoded by a cytomegalovirus

  18. Extracellular signal-regulated kinase pathway is differentially involved in beta-agonist-induced hypertrophy in slow and fast muscles.

    Science.gov (United States)

    Shi, H; Zeng, C; Ricome, A; Hannon, K M; Grant, A L; Gerrard, D E

    2007-05-01

    The molecular mechanisms controlling beta-adrenergic receptor agonist (BA)-induced skeletal muscle hypertrophy are not well known. We presently report that BA exerts a distinct muscle- and muscle fiber type-specific hypertrophy. Moreover, we have shown that pharmacologically or genetically attenuating extracellular signal-regulated kinase (ERK) signaling in muscle fibers resulted in decreases (P muscle ablated (P muscles revealed that ERK1/2 is activated to a greater extent in fast- than in slow-twitch muscles. These data indicate that ERK signaling is differentially involved in BA-induced hypertrophy in slow and fast skeletal muscles, suggesting that the increased abundance of phospho-ERK1/2 and ERK activity found in fast-twitch myofibers, compared with their slow-twitch counterparts, may account, at least in part, for the fiber type-specific hypertrophy induced by BA stimulation. These data suggest that fast myofibers are pivotal in the adaptation of muscle to environmental cues and that the mechanism underlying this change is partially mediated by the MAPK signaling cascade.

  19. Substrate-Activated Conformational Switch on Chaperones Encodes a Targeting Signal in Type III Secretion

    Directory of Open Access Journals (Sweden)

    Li Chen

    2013-03-01

    Full Text Available The targeting of type III secretion (TTS proteins at the injectisome is an important process in bacterial virulence. Nevertheless, how the injectisome specifically recognizes TTS substrates among all bacterial proteins is unknown. A TTS peripheral membrane ATPase protein located at the base of the injectisome has been implicated in the targeting process. We have investigated the targeting of the EspA filament protein and its cognate chaperone, CesAB, to the EscN ATPase of the enteropathogenic E. coli (EPEC. We show that EscN selectively engages the EspA-loaded CesAB but not the unliganded CesAB. Structure analysis revealed that the targeting signal is encoded in a disorder-order structural transition in CesAB that is elicited only upon the binding of its physiological substrate, EspA. Abrogation of the interaction between the CesAB-EspA complex and EscN resulted in severe secretion and infection defects. Additionally, we show that the targeting and secretion signals are distinct and that the two processes are likely regulated by different mechanisms.

  20. Progressive and Error-Resilient Transmission Strategies for VLC Encoded Signals over Noisy Channels

    Directory of Open Access Journals (Sweden)

    Guillemot Christine

    2006-01-01

    Full Text Available This paper addresses the issue of robust and progressive transmission of signals (e.g., images, video encoded with variable length codes (VLCs over error-prone channels. This paper first describes bitstream construction methods offering good properties in terms of error resilience and progressivity. In contrast with related algorithms described in the literature, all proposed methods have a linear complexity as the sequence length increases. The applicability of soft-input soft-output (SISO and turbo decoding principles to resulting bitstream structures is investigated. In addition to error resilience, the amenability of the bitstream construction methods to progressive decoding is considered. The problem of code design for achieving good performance in terms of error resilience and progressive decoding with these transmission strategies is then addressed. The VLC code has to be such that the symbol energy is mainly concentrated on the first bits of the symbol representation (i.e., on the first transitions of the corresponding codetree. Simulation results reveal high performance in terms of symbol error rate (SER and mean-square reconstruction error (MSE. These error-resilience and progressivity properties are obtained without any penalty in compression efficiency. Codes with such properties are of strong interest for the binarization of -ary sources in state-of-the-art image, and video coding systems making use of, for example, the EBCOT or CABAC algorithms. A prior statistical analysis of the signal allows the construction of the appropriate binarization code.

  1. Improved slow-light performance of 10 Gb/s NRZ, PSBT and DPSK signals in fiber broadband SBS.

    Science.gov (United States)

    Yi, Lilin; Jaouen, Yves; Hu, Weisheng; Su, Yikai; Bigo, Sébastien

    2007-12-10

    We have demonstrated error-free operations of slow-light via stimulated Brillouin scattering (SBS) in optical fiber for 10-Gb/s signals with different modulation formats, including non-return-to-zero (NRZ), phase-shaped binary transmission (PSBT) and differential phase-shiftkeying (DPSK). The SBS gain bandwidth is broadened by using current noise modulation of the pump laser diode. The gain shape is simply controlled by the noise density function. Super-Gaussian noise modulation of the Brillouin pump allows a flat-top and sharp-edge SBS gain spectrum, which can reduce slow-light induced distortion in case of 10-Gb/s NRZ signal. The corresponding maximal delay-time with error-free operation is 35 ps. Then we propose the PSBT format to minimize distortions resulting from SBS filtering effect and dispersion accompanied with slow light because of its high spectral efficiency and strong dispersion tolerance. The sensitivity of the 10-Gb/s PSBT signal is 5.2 dB better than the NRZ case with a same 35-ps delay. The maximal delay of 51 ps with error-free operation has been achieved. Futhermore, the DPSK format is directly demodulated through a Gaussian-shaped SBS gain, which is achieved using Gaussian-noise modulation of the Brillouin pump. The maximal error-free time delay after demodulation of a 10-Gb/s DPSK signal is as high as 81.5 ps, which is the best demonstrated result for 10-Gb/s slow-light.

  2. Lack of Critical Slowing Down Suggests that Financial Meltdowns Are Not Critical Transitions, yet Rising Variability Could Signal Systemic Risk.

    Science.gov (United States)

    Guttal, Vishwesha; Raghavendra, Srinivas; Goel, Nikunj; Hoarau, Quentin

    2016-01-01

    Complex systems inspired analysis suggests a hypothesis that financial meltdowns are abrupt critical transitions that occur when the system reaches a tipping point. Theoretical and empirical studies on climatic and ecological dynamical systems have shown that approach to tipping points is preceded by a generic phenomenon called critical slowing down, i.e. an increasingly slow response of the system to perturbations. Therefore, it has been suggested that critical slowing down may be used as an early warning signal of imminent critical transitions. Whether financial markets exhibit critical slowing down prior to meltdowns remains unclear. Here, our analysis reveals that three major US (Dow Jones Index, S&P 500 and NASDAQ) and two European markets (DAX and FTSE) did not exhibit critical slowing down prior to major financial crashes over the last century. However, all markets showed strong trends of rising variability, quantified by time series variance and spectral function at low frequencies, prior to crashes. These results suggest that financial crashes are not critical transitions that occur in the vicinity of a tipping point. Using a simple model, we argue that financial crashes are likely to be stochastic transitions which can occur even when the system is far away from the tipping point. Specifically, we show that a gradually increasing strength of stochastic perturbations may have caused to abrupt transitions in the financial markets. Broadly, our results highlight the importance of stochastically driven abrupt transitions in real world scenarios. Our study offers rising variability as a precursor of financial meltdowns albeit with a limitation that they may signal false alarms.

  3. Reciprocal Influence of Slow Waves Extracted in Intracranial Pressure, Arterial Pressure and Cerebral Blood Velocity Signals

    National Research Council Canada - National Science Library

    Cervenansky, F

    2001-01-01

    ...), and arterial blood pressure (ABP). To clarify the links, we compared two frequency methods based on coherence function to estimate the influence of ICP, ABP, and CBV on couples, respectively CBV-ABP, ICP-CBV and ICP-ABP, of slow waves...

  4. Evaluation of JPEG 2000 encoder options: human and model observer detection of variable signals in X-ray coronary angiograms.

    Science.gov (United States)

    Zhang, Yani; Pham, Binh; Eckstein, Miguel P

    2004-05-01

    Previous studies have evaluated the effect of the new still image compression standard JPEG 2000 using nontask based image quality metrics, i.e., peak-signal-to-noise-ratio (PSNR) for nonmedical images. In this paper, the effect of JPEG 2000 encoder options was investigated using the performance of human and model observers (nonprewhitening matched filter with an eye filter, square-window Hotelling, Laguerre-Gauss Hotelling and channelized Hotelling model observer) for clinically relevant visual tasks. Two tasks were investigated: the signal known exactly but variable task (SKEV) and the signal known statistically task (SKS). Test images consisted of real X-ray coronary angiograms with simulated filling defects (signals) inserted in one of the four simulated arteries. The signals varied in size and shape. Experimental results indicated that the dependence of task performance on the JPEG 2000 encoder options was similar for all model and human observers. Model observer performance in the more tractable and computationally economic SKEV task can be used to reliably estimate performance in the complex but clinically more realistic SKS task. JPEG 2000 encoder settings different from the default ones resulted in greatly improved model and human observer performance in the studied clinically relevant visual tasks using real angiography backgrounds.

  5. A human torque teno virus encodes a microRNA that inhibits interferon signaling.

    Directory of Open Access Journals (Sweden)

    Rodney P Kincaid

    Full Text Available Torque teno viruses (TTVs are a group of viruses with small, circular DNA genomes. Members of this family are thought to ubiquitously infect humans, although causal disease associations are currently lacking. At present, there is no understanding of how infection with this diverse group of viruses is so prevalent. Using a combined computational and synthetic approach, we predict and identify miRNA-coding regions in diverse human TTVs and provide evidence for TTV miRNA production in vivo. The TTV miRNAs are transcribed by RNA polymerase II, processed by Drosha and Dicer, and are active in RISC. A TTV mutant defective for miRNA production replicates as well as wild type virus genome; demonstrating that the TTV miRNA is dispensable for genome replication in a cell culture model. We demonstrate that a recombinant TTV genome is capable of expressing an exogenous miRNA, indicating the potential utility of TTV as a small RNA vector. Gene expression profiling of host cells identifies N-myc (and STAT interactor (NMI as a target of a TTV miRNA. NMI transcripts are directly regulated through a binding site in the 3'UTR. SiRNA knockdown of NMI contributes to a decreased response to interferon signaling. Consistent with this, we show that a TTV miRNA mediates a decreased response to IFN and increased cellular proliferation in the presence of IFN. Thus, we add Annelloviridae to the growing list of virus families that encode miRNAs, and suggest that miRNA-mediated immune evasion can contribute to the pervasiveness associated with some of these viruses.

  6. Injection of fully-defined signal mixtures: a novel high-throughput tool to study neuronal encoding and computations.

    Directory of Open Access Journals (Sweden)

    Vladimir Ilin

    Full Text Available Understanding of how neurons transform fluctuations of membrane potential, reflecting input activity, into spike responses, which communicate the ultimate results of single-neuron computation, is one of the central challenges for cellular and computational neuroscience. To study this transformation under controlled conditions, previous work has used a signal immersed in noise paradigm where neurons are injected with a current consisting of fluctuating noise that mimics on-going synaptic activity and a systematic signal whose transmission is studied. One limitation of this established paradigm is that it is designed to examine the encoding of only one signal under a specific, repeated condition. As a result, characterizing how encoding depends on neuronal properties, signal parameters, and the interaction of multiple inputs is cumbersome. Here we introduce a novel fully-defined signal mixture paradigm, which allows us to overcome these problems. In this paradigm, current for injection is synthetized as a sum of artificial postsynaptic currents (PSCs resulting from the activity of a large population of model presynaptic neurons. PSCs from any presynaptic neuron(s can be now considered as "signal", while the sum of all other inputs is considered as "noise". This allows us to study the encoding of a large number of different signals in a single experiment, thus dramatically increasing the throughput of data acquisition. Using this novel paradigm, we characterize the detection of excitatory and inhibitory PSCs from neuronal spike responses over a wide range of amplitudes and firing-rates. We show, that for moderately-sized neuronal populations the detectability of individual inputs is higher for excitatory than for inhibitory inputs during the 2-5 ms following PSC onset, but becomes comparable after 7-8 ms. This transient imbalance of sensitivity in favor of excitation may enhance propagation of balanced signals through neuronal networks. Finally, we

  7. Regulation of slow and fast muscle myofibrillogenesis by Wnt/beta-catenin and myostatin signaling.

    NARCIS (Netherlands)

    Tee, J.M.; van Rooijen, C.R.; Boonen, R.A.C.M.; Zivkovic, D.

    2009-01-01

    Deviation from proper muscle development or homeostasis results in various myopathic conditions. Employing genetic as well as chemical intervention, we provide evidence that a tight regulation of Wnt/beta-catenin signaling is essential for muscle fiber growth and maintenance. In zebrafish embryos,

  8. Intestinal Insulin Signaling Encodes Two Different Molecular Mechanisms for the Shortened Longevity Induced by Graphene Oxide in Caenorhabditis elegans

    Science.gov (United States)

    Zhao, Yunli; Yang, Ruilong; Rui, Qi; Wang, Dayong

    2016-04-01

    Graphene oxide (GO) has been shown to cause multiple toxicities in various organisms. However, the underlying molecular mechanisms for GO-induced shortened longevity are still unclear. We employed Caenorhabditis elegans to investigate the possible involvement of insulin signaling pathway in the control of GO toxicity and its underlying molecular mechanisms. Mutation of daf-2, age-1, akt-1, or akt-2 gene induced a resistant property of nematodes to GO toxicity, while mutation of daf-16 gene led to a susceptible property of nematodes to GO toxicity, suggesting that GO may dysregulate the functions of DAF-2/IGF-1 receptor, AGE-1, AKT-1 and AKT-2-mediated kinase cascade, and DAF-16/FOXO transcription factor. Genetic interaction analysis suggested the involvement of signaling cascade of DAF-2-AGE-1-AKT-1/2-DAF-16 in the control of GO toxicity on longevity. Moreover, intestinal RNA interference (RNAi) analysis demonstrated that GO reduced longevity by affecting the functions of signaling cascade of DAF-2-AGE-1-AKT-1/2-DAF-16 in the intestine. DAF-16 could also regulate GO toxicity on longevity by functioning upstream of SOD-3, which encodes an antioxidation system that prevents the accumulation of oxidative stress. Therefore, intestinal insulin signaling may encode two different molecular mechanisms responsible for the GO toxicity in inducing the shortened longevity. Our results highlight the key role of insulin signaling pathway in the control of GO toxicity in organisms.

  9. A General scheme for dithering multidimensional signals, and a visual instance of encoding images with limited palettes

    Directory of Open Access Journals (Sweden)

    Mohamed Attia

    2014-07-01

    Full Text Available The core contribution of this paper is to introduce a general neat scheme based on soft vector clustering for the dithering of multidimensional signals that works in any space of arbitrary dimensionality, on arbitrary number and distribution of quantization centroids, and with a computable and controllable quantization noise. Dithering upon the digitization of one-dimensional and multi-dimensional signals disperses the quantization noise over the frequency domain which renders it less perceptible by signal processing systems including the human cognitive ones, so it has a very beneficial impact on vital domains such as communications, control, machine-learning, etc. Our extensive surveys have concluded that the published literature is missing such a neat dithering scheme. It is very desirable and insightful to visualize the behavior of our multidimensional dithering scheme; especially the dispersion of quantization noise over the frequency domain. In general, such visualization would be quite hard to achieve and perceive by the reader unless the target multidimensional signal itself is directly perceivable by humans. So, we chose to apply our multidimensional dithering scheme upon encoding true-color images – that are 3D signals – with palettes of limited sets of colors to show how it minimizes the visual distortions – esp. contouring effect – in the encoded images.

  10. Modulation of cellular signaling by herpesvirus-encoded G protein-coupled receptors

    NARCIS (Netherlands)

    de Munnik, Sabrina M.; Smit, Martine J.; Leurs, Rob; Vischer, Henry F.

    2015-01-01

    Human herpesviruses (HHVs) are widespread infectious pathogens that have been associated with proliferative and inflammatory diseases. During viral evolution, HHVs have pirated genes encoding viral G protein-coupled receptors (vGPCRs), which are expressed on infected host cells. These vGPCRs show

  11. Investigating the Slow Axonal Transport of Neurofilaments: A Precursor for Optimal Neuronal Signaling

    Science.gov (United States)

    Johnson, Christopher M.

    systematically vary the number of motors in the model and attempt to identify those combinations of motors that show an agreement with the motility characteristic found from the above mentioned kymographs. By pruning the modeled data in accordance with the experimental results, our model can render an estimate of how many motors are attached to the cargo during transport. The model predicts that, on average, the total number of active motors on each neurofilament is relatively small and relatively independent of polymer length, which suggests that the motors may not be distributed uniformly along the filaments. Finally, we develop a model to explore the physiological function of axon morphology sculpted by neurofilament kinetics. Specifically, nodal constrictions are generated by slowing of neurofilaments in the internodal domain (Monsma et al., 2014), but the physiological function of these constrictions is unknown. To address this, we develop a computational model to investigate the effect of nodal constrictions on the axonal conduction velocity. For a fixed number of ion channels, we find that there is an optimal extent of nodal constriction which minimizes the internodal axon caliber that is required to achieve a given target conduction velocity, and we show that this is sensitive to the precise geometry of the axon and myelin sheath in the flanking paranodal regions. Thus axonal constrictions appear to be a biological adaptation that serves to minimize axonal volume, thereby maximizing the spatial and metabolic efficiency of these processes.

  12. Chromosome locations of genes encoding human signal transduction adapter proteins, Nck (NCK), Shc (SHC1), and Grb2 (GRB2)

    DEFF Research Database (Denmark)

    Huebner, K; Kastury, K; Druck, T

    1994-01-01

    Abnormalities due to chromosomal aberration or point mutation in gene products of growth factor receptors or in ras gene products, which lie on the same signaling pathway, can cause disease in animals and humans. Thus, it can be important to determine chromosomal map positions of genes encoding...... "adapter" proteins, which are involved in transducing signals from receptor tyrosine kinases to downstream signal recipients such as ras, because adaptor protein genes could also, logically, serve as targets of mutation, rearrangement, or other aberration in disease. Therefore, DNAs from panels of rodent...... hybridization. The NCK locus is at chromosome region 3q21, a region involved in neoplasia-associated changes; the SHC cognate locus, SHC1, is at 1q21, and the GRB2 locus is at 17q22-qter telomeric to the HOXB and NGFR loci. Both SHC1 and GRB2 are in chromosome regions that may be duplicated in some tumor types....

  13. Spatio-temporal encoding using narrow-band linear frequency modulated signals in synthetic aperture ultrasound imaging

    DEFF Research Database (Denmark)

    Gran, Fredrik; Jensen, Jørgen Arendt

    2005-01-01

    energy, the signal to noise ratio will increase. However, to focus the data properly using the STA approach, the transmitters have to be separated from each other. This is done by dividing the available spectrum into several subbands with a small overlap. Separating different transmitters can be done...... by bandpass filtering. Therefore, the separation can be done instantaneously without the need for further transmissions, unlike spatial encoding relying on Hadamard or Golay coding schemes, where several transmissions have to be made before the decoding can be done. Motion artifacts from the decoding can...

  14. The lysis cassette of bacteriophage ϕKMV encodes a signal-arrest-release endolysin and a pinholin

    OpenAIRE

    Briers, Yves; Peeters, Liesbet M; Volckaert, Guido; Lavigne, Rob

    2011-01-01

    The lysis cassette of Pseudomonas aeruginosa phage ϕKMV encodes a holin, endolysin, Rz and Rz1 in the canonical order. It has a tight organization with a high degree of overlapping genes and is highly conserved (between 96 and 100% identity at the protein level) among several other members of the “phiKMV-like viruses.” The endolysin KMV45 exhibits characteristics as expected for a signal-arrest-release (SAR) endolysin, whereas the holin KMV44 is a typical pinholin. KMV45 is initially secreted...

  15. Rapid versus slow ascending vasodilatation: intercellular conduction versus flow-mediated signalling with tetanic versus rhythmic muscle contractions.

    Science.gov (United States)

    Sinkler, Shenghua Y; Segal, Steven S

    2017-12-01

    In response to exercise, vasodilatation ascends from downstream arterioles into upstream feed arteries (FAs). We hypothesized that the signalling events underlying ascending vasodilatation variy with the intensity and duration of skeletal muscle contraction. In the gluteus maximus muscle of C57BL/6 mice, brief tetanic contraction evoked rapid onset vasodilatation (ROV) (ROV only in FAs. Blocking SK Ca and IK Ca channels attenuated ROV, implicating hyperpolarization as the underlying signal. During rhythmic twitch contractions, slow onset vasodilatation (10-15 s) in FAs remained intact following loss of ROV and was eliminated following nitric oxide synthase inhibition. Tetanic contraction initiates hyperpolarization that conducts along endothelium into FAs. Rhythmic twitch contractions stimulate FA endothelium to release nitric oxide in response to elevated shear stress secondary to metabolic dilatation of arterioles. Complementary endothelial signalling pathways for ascending vasodilatation ensure increased oxygen delivery to active skeletal muscle. In response to exercise, vasodilatation initiated within the microcirculation of skeletal muscle ascends the resistance network into upstream feed arteries (FAs) located external to the tissue. Ascending vasodilatation (AVD) is essential for reducing FA resistance that otherwise restricts blood flow into the microcirculation. In the present study, we tested the hypothesis that signalling events underlying AVD vary with the intensity and duration of muscle contraction. In the gluteus maximus muscle of anaesthetized male C57BL/6 mice (aged 3-4 months), brief tetanic contraction (100 Hz for 500 ms) evoked rapid onset vasodilatation (ROV) in FAs that peaked within 4 s. By contrast, during rhythmic twitch contractions (4 Hz), slow onset vasodilatation (SOV) of FAs began after ∼10 s and plateaued within 30 s. Selectively damaging the endothelium with light-dye treatment midway between a FA and its primary arteriole

  16. Revisiting the slow force response: the role of the PKG signaling pathway in the normal and the ischemic heart.

    Science.gov (United States)

    Castro-Ferreira, Ricardo; Neves, João Sérgio; Ladeiras-Lopes, Ricardo; Leite-Moreira, André M; Neiva-Sousa, Manuel; Almeida-Coelho, João; Ferreira-Martins, João; F Leite-Moreira, Adelino

    2014-09-01

    The myocardial response to acute stretch consists of a two-phase increase in contractility: an acute increase by the Frank-Starling mechanism and a gradual and time-dependent increase in force generated known as the slow force response (SFR). The SFR is actively modulated by different signaling pathways, but the role of protein kinase G (PKG) signaling is unknown. In this study we aim to characterize the role of the PKG signaling pathway in the SFR under normal and ischemic conditions. Rabbit papillary muscles were stretched from 92 to 100% of maximum length (Lmax) under basal conditions, in the absence (1) or presence of: a PKG agonist (2) and a PKG inhibitor (3); under ischemic conditions in the absence (4) or presence of: a PKG agonist (5); a nitric oxide (NO) donor (6) and a phosphodiesterase 5 (PDE5) inhibitor (7). Under normoxia, the SFR was significantly attenuated by inhibition of PKG and remained unaltered with PKG activation. Ischemia induced a progressive decrease in myocardial contractility after stretch. Neither the PKG agonist nor the NO donor altered the myocardial response to stretch under ischemic conditions. However, the use of a PDE5 inhibitor in ischemia partially reversed the progressive deterioration in contractility. PKG activity is essential for the SFR. During ischemia, a progressive decline in the force is observed in response to acute myocardial stretch. This dysfunctional response can be partially reversed by the use of PDE5 inhibitors. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  17. The Drosophila rolled locus encodes a MAP kinase required in the sevenless signal transduction pathway.

    OpenAIRE

    Biggs, W H; Zavitz, K H; Dickson, B; van der Straten, A; Brunner, D; Hafen, E; Zipursky, S L

    1994-01-01

    Mitogen-activated protein (MAP) kinases have been proposed to play a critical role in receptor tyrosine kinase (RTK)-mediated signal transduction pathways. Although genetic and biochemical studies of RTK pathways in Caenorhabditis elegans, Drosophila melanogaster and mammals have revealed remarkable similarities, a genetic requirement for MAP kinases in RTK signaling has not been established. During retinal development in Drosophila, the sevenless (Sev) RTK is required for development of the ...

  18. A Data Hiding Technique to Synchronously Embed Physiological Signals in H.264/AVC Encoded Video for Medicine Healthcare.

    Science.gov (United States)

    Peña, Raul; Ávila, Alfonso; Muñoz, David; Lavariega, Juan

    2015-01-01

    The recognition of clinical manifestations in both video images and physiological-signal waveforms is an important aid to improve the safety and effectiveness in medical care. Physicians can rely on video-waveform (VW) observations to recognize difficult-to-spot signs and symptoms. The VW observations can also reduce the number of false positive incidents and expand the recognition coverage to abnormal health conditions. The synchronization between the video images and the physiological-signal waveforms is fundamental for the successful recognition of the clinical manifestations. The use of conventional equipment to synchronously acquire and display the video-waveform information involves complex tasks such as the video capture/compression, the acquisition/compression of each physiological signal, and the video-waveform synchronization based on timestamps. This paper introduces a data hiding technique capable of both enabling embedding channels and synchronously hiding samples of physiological signals into encoded video sequences. Our data hiding technique offers large data capacity and simplifies the complexity of the video-waveform acquisition and reproduction. The experimental results revealed successful embedding and full restoration of signal's samples. Our results also demonstrated a small distortion in the video objective quality, a small increment in bit-rate, and embedded cost savings of -2.6196% for high and medium motion video sequences.

  19. Striatal Activity and Reward Relativity: Neural Signals Encoding Dynamic Outcome Valuation.

    Science.gov (United States)

    Webber, Emily S; Mankin, David E; Cromwell, Howard C

    2016-01-01

    The striatum is a key brain region involved in reward processing. Striatal activity has been linked to encoding reward magnitude and integrating diverse reward outcome information. Recent work has supported the involvement of striatum in the valuation of outcomes. The present work extends this idea by examining striatal activity during dynamic shifts in value that include different levels and directions of magnitude disparity. A novel task was used to produce diverse relative reward effects on a chain of instrumental action. Rats ( Rattus norvegicus ) were trained to respond to cues associated with specific outcomes varying by food pellet magnitude. Animals were exposed to single-outcome sessions followed by mixed-outcome sessions, and neural activity was compared among identical outcome trials from the different behavioral contexts. Results recording striatal activity show that neural responses to different task elements reflect incentive contrast as well as other relative effects that involve generalization between outcomes or possible influences of outcome variety. The activity that was most prevalent was linked to food consumption and post-food consumption periods. Relative encoding was sensitive to magnitude disparity. A within-session analysis showed strong contrast effects that were dependent upon the outcome received in the immediately preceding trial. Significantly higher numbers of responses were found in ventral striatum linked to relative outcome effects. Our results support the idea that relative value can incorporate diverse relationships, including comparisons from specific individual outcomes to general behavioral contexts. The striatum contains these diverse relative processes, possibly enabling both a higher information yield concerning value shifts and a greater behavioral flexibility.

  20. Reduction of nocturnal slow-wave activity affects daytime vigilance lapses and memory encoding but not reaction time or implicit learning

    NARCIS (Netherlands)

    van der Werf, Y.D.; Altena, E.; Vis, J.C.; Koene, T.; van Someren, E.J.W.

    2011-01-01

    Total sleep deprivation in healthy subjects has a profound effect on the performance on tasks measuring sustained attention or vigilance. We here report how a selective disruption of deep sleep only, that is, selective slow-wave activity (SWA) reduction, affects the performance of healthy

  1. Phasic Mesolimbic Dopamine Signaling Encodes the Facilitation of Incentive Motivation Produced by Repeated Cocaine Exposure

    OpenAIRE

    Ostlund, SB; LeBlanc, KH; Kosheleff, AR; Wassum, KM; Maidment, NT

    2014-01-01

    Drug addiction is marked by pathological drug seeking and intense drug craving, particularly in response to drug-related stimuli. Repeated psychostimulant administration is known to induce long-term alterations in mesolimbic dopamine (DA) signaling that are hypothesized to mediate this heightened sensitivity to environmental stimuli. However, there is little direct evidence that drug-induced alteration in mesolimbic DA function underlies this hypersensitivity to motivational cues. In the curr...

  2. Signal Reception for Space-Time Differentially Encoded Transmissions over FIR Rich Multipath Channels

    Directory of Open Access Journals (Sweden)

    Zhang Zhan

    2004-01-01

    Full Text Available With sophisticated signal and information processing algorithms, air interfaces with space-time (ST coding and multiple reception antennas substantially improve the reliability of wireless links. This paper proposes a new receiver algorithm for differential ST coded transmissions over the finite-impulse-response (FIR rich multipath fading channels. The symbol detection introduced in this paper is a deterministic subspace-based approach in a multiple-input and multiple-output (MIMO system framework. The receiver (i operates in a blind fashion without estimating the channel or its inverse and (ii is able to work with a small number of signal samples and hence can be applied in the quasistatic channels. The proposed scheme employs multiple antennas at both sides of the transceiver and exploits both the antenna diversity and the multiple constant modulus (MCM characteristics of the signaling. The receiver is able to blindly mitigate the intersymbol interference (ISI in a rich multipath propagation environment, and this has been verified through the extensive Monte Carlo simulations.

  3. Characterization of cDNA clones encoding rabbit and human serum paraoxonase: The mature protein retains its signal sequence

    Energy Technology Data Exchange (ETDEWEB)

    Hassett, C.; Richter, R.J.; Humbert, R.; Omiecinski, C.J.; Furlong, C.E. (Univ. of Washington, Seattle (United States)); Chapline, C.; Crabb, J.W. (W.Alton Jones Cell Science Center, Lake Placid, NY (United States))

    1991-10-22

    Serum paraoxonase hydrolyzes the toxic metabolites of a variety of organophosphorus insecticides. High serum paraoxonase levels appear to protect against the neurotoxic effects of organophosphorus substrates of this enzyme. The amino acid sequence accounting for 42% of rabbit paraoxonase was determined. From these data, two oligonucleotide probes were synthesized and used to screen a rabbit liver cDNA library. Human paraoxonase clones were isolated from a liver cDNA library by using the rabbit cDNA as a hybridization probe. Inserts from three of the longest clones were sequenced, and one full-length clone contained an open reading frame encoding 355 amino acids, four less than the rabbit paraoxonase protein. Amino-terminal sequences derived from purified rabbit and human paraoxonase proteins suggested that the signal sequence is retained, with the exception of the initiator methionine residue. Characterization of the rabbit and human paraoxonase cDNA clones confirms that the signal sequences are not processed, except for the N-terminal methionine residue. The rabbit and human cDNA clones demonstrate striking nucleotide and deduced amino acid similarities (greater than 85%), suggesting an important metabolic role and constraints on the evolution of this protein.

  4. Large Signal Modulation and Distortion in a Microwave Phase Shifter Based on Slow Light in a Semiconductor Waveguide

    DEFF Research Database (Denmark)

    Chen, Yaohui; Öhman, Filip; Mørk, Jesper

    2006-01-01

    We model slow/light propagation in an active semiconductor waveguide in the large modulation depth regime. Distortion from higher harmonics is countered by filtering and the regenerating properties of the device further increase the modulation depth.......We model slow/light propagation in an active semiconductor waveguide in the large modulation depth regime. Distortion from higher harmonics is countered by filtering and the regenerating properties of the device further increase the modulation depth....

  5. Automated optimization of JPEG 2000 encoder options based on model observer performance for detecting variable signals in X-ray coronary angiograms.

    Science.gov (United States)

    Zhang, Yani; Pham, Binh T; Eckstein, Miguel P

    2004-04-01

    Image compression is indispensable in medical applications where inherently large volumes of digitized images are presented. JPEG 2000 has recently been proposed as a new image compression standard. The present recommendations on the choice of JPEG 2000 encoder options were based on nontask-based metrics of image quality applied to nonmedical images. We used the performance of a model observer [non-prewhitening matched filter with an eye filter (NPWE)] in a visual detection task of varying signals [signal known exactly but variable (SKEV)] in X-ray coronary angiograms to optimize JPEG 2000 encoder options through a genetic algorithm procedure. We also obtained the performance of other model observers (Hotelling, Laguerre-Gauss Hotelling, channelized-Hotelling) and human observers to evaluate the validity of the NPWE optimized JPEG 2000 encoder settings. Compared to the default JPEG 2000 encoder settings, the NPWE-optimized encoder settings improved the detection performance of humans and the other three model observers for an SKEV task. In addition, the performance also was improved for a more clinically realistic task where the signal varied from image to image but was not known a priori to observers [signal known statistically (SKS)]. The highest performance improvement for humans was at a high compression ratio (e.g., 30:1) which resulted in approximately a 75% improvement for both the SKEV and SKS tasks.

  6. Continuous Shear Wave Signals from around a Subducted Seamount Following 2014 Mw 6.8 Slow-slip Event in the Hikurangi Subduction Margin Offshore New Zealand

    Science.gov (United States)

    Iwasaki, Y.; Mochizuki, K.; Ishise, M.; Todd, E. K.; Schwartz, S. Y.; Henrys, S. A.; Savage, M. K.; Sheehan, A.; Ito, Y.; Wallace, L.; Webb, S. C.; Zal, H. J.; Yamada, T.; Shinohara, M.

    2017-12-01

    From May 2014 to June 2015 a marine seismic and geodetic experiment was conducted at the Hikurangi subduction margin. During this experiment, a slow-slip event (SSE) with equivalent moment magnitude of Mw 6.8 occurred for two weeks starting in late September 2014, directly beneath the ocean bottom seismometer (OBS) network (Wallace et al., 2016). In this study, we used the continuous waveform data recorded by these OBSs. We calculated a cross correlation coefficient between the two horizontal components and applied a polarization analysis every 10 seconds for 30 second-long OBS waveform records. As a result, we detected the continuous arrival of S-wave signals that appeared to have started in the latter half of the SSE. This continuous signal was identified as tremor and its source location was determined by the envelope cross-correlation method (Todd et al., 2017, in prep). Our result, however, suggests that these signals occur continuously rather than as sporadic individual events, and that they last for more than two weeks. Polarization directions changed at the same time and then remained stable through the two week duration. Such stable polarized directions can only be identified during this period. Our analysis requires fewer OBS than other methods for monitoring such S-wave signals, which may enable us to detect as yet unidentified signals in the Hikurangi margin where seismic attenuation has been shown to be large. The continuous signals with a stable polarization direction were only observed at OBS stations in a limited region, which suggests that the signals were generated near the up-dip edge of the slow slip area and surrounding a subducted seamount. Sources of the continuous signals appear to have migrated from south to north . This observation is consistent with the location of individual tremors identified with envelope cross-correlation methods (Todd et al., 2017, in prep). The slow slip along the plate interface circumvented the subducted seamount

  7. Minor abnormalities of testis development in mice lacking the gene encoding the MAPK signalling component, MAP3K1.

    Directory of Open Access Journals (Sweden)

    Nick Warr

    2011-05-01

    Full Text Available In mammals, the Y chromosome is a dominant male determinant, causing the bipotential gonad to develop as a testis. Recently, cases of familial and spontaneous 46,XY disorders of sex development (DSD have been attributed to mutations in the human gene encoding mitogen-activated protein kinase kinase kinase 1, MAP3K1, a component of the mitogen-activated protein kinase (MAPK signal transduction pathway. In individuals harbouring heterozygous mutations in MAP3K1, dysregulation of MAPK signalling was observed in lymphoblastoid cell lines, suggesting a causal role for these mutations in disrupting XY sexual development. Mice lacking the cognate gene, Map3k1, are viable and exhibit the eyes open at birth (EOB phenotype on a mixed genetic background, but on the C57BL/6J genetic background most mice die at around 14.5 dpc due to a failure of erythropoiesis in the fetal liver. However, no systematic examination of sexual development in Map3k1-deficient mice has been described, an omission that is especially relevant in the case of C57BL/6J, a genetic background that is sensitized to disruptions to testis determination. Here, we report that on a mixed genetic background mice lacking Map3k1 are fertile and exhibit no overt abnormalities of testis development. On C57BL/6J, significant non-viability is observed with very few animals surviving to adulthood. However, an examination of development in Map3k1-deficient XY embryos on this genetic background revealed no significant defects in testis determination, although minor abnormalities were observed, including an increase in gonadal length. Based on these observations, we conclude that MAP3K1 is not required for mouse testis determination. We discuss the significance of these data for the functional interpretation of sex-reversing MAP3K1 mutations in humans.

  8. The lysis cassette of bacteriophage ϕKMV encodes a signal-arrest-release endolysin and a pinholin.

    Science.gov (United States)

    Briers, Yves; Peeters, Liesbet M; Volckaert, Guido; Lavigne, Rob

    2011-01-01

    The lysis cassette of Pseudomonas aeruginosa phage ϕKMV encodes a holin, endolysin, Rz and Rz1 in the canonical order. It has a tight organization with a high degree of overlapping genes and is highly conserved (between 96 and 100% identity at the protein level) among several other members of the "phiKMV-like viruses." The endolysin KMV45 exhibits characteristics as expected for a signal-arrest-release (SAR) endolysin, whereas the holin KMV44 is a typical pinholin. KMV45 is initially secreted as an inactive, membrane-anchored endolysin, which is subsequently released by membrane depolarization driven by the pinholin KMV44. The SAR domain of KMV45 is necessary for its full enzymatic activity, suggesting a refolding of the catalytic cleft upon release from the membrane. The physical proximity of the catalytic glutamic acid residue close to SAR domain suggests an alternative activation mechanism compared to the SAR endolysin of phages P1, ERA103 and 21. Expression of KMV44 leads to a quick cell lysis when paired with SAR endolysin KMV45, but not with the cytoplasmic phage λ endolysin, indicating the membrane depolarizing function of KMV44 rather than the large hole-making function characteristic of classical holins.

  9. Achievable Strength-Based Signal Detection in Quantity-Constrained PAM OOK Concentration-Encoded Molecular Communication.

    Science.gov (United States)

    Mahfuz, Mohammad Upal

    2016-10-01

    In this paper, the expressions of achievable strength-based detection probabilities of concentration-encoded molecular communication (CEMC) system have been derived based on finite pulsewidth (FP) pulse-amplitude modulated (PAM) on-off keying (OOK) modulation scheme and strength threshold. An FP-PAM system is characterized by its duty cycle α that indicates the fraction of the entire symbol duration the transmitter remains on and transmits the signal. Results show that the detection performance of an FP-PAM OOK CEMC system significantly depends on the statistical distribution parameters of diffusion-based propagation noise and intersymbol interference (ISI). Analytical detection performance of an FP-PAM OOK CEMC system under ISI scenario has been explained and compared based on receiver operating characteristics (ROC) for impulse (i.e., spike)-modulated (IM) and FP-PAM CEMC schemes. It is shown that the effects of diffusion noise and ISI on ROC can be explained separately based on their communication range-dependent statistics. With full duty cycle, an FP-PAM scheme provides significantly worse performance than an IM scheme. The paper also analyzes the performance of the system when duty cycle, transmission data rate, and quantity of molecules vary.

  10. Human cyclophilin B: A second cyclophilin gene encodes a peptidyl-prolyl isomerase with a signal sequence

    International Nuclear Information System (INIS)

    Price, E.R.; Zydowsky, L.D.; Jin, Mingjie; Baker, C.H.; McKeon, F.D.; Walsh, C.T.

    1991-01-01

    The authors report the cloning and characterization of a cDNA encoding a second human cyclosporin A-binding protein (hCyPB). Homology analyses reveal that hCyPB is a member of the cyclophilin B (CyPB) family, which includes yeast CyPB, Drosophila nina A, and rat cyclophilin-like protein. This family is distinguished from the cyclophilin A (CyPA) family by the presence of endoplasmic reticulum (ER)-directed signal sequences. hCyPB has a hydrophobic leader sequence not found in hCyPA, and its first 25 amino acids are removed upon expression in Escherichia coli. Moreover, they show that hCyPB is a peptidyl-prolyl cis-trans isomerase which can be inhibited by cyclosporin A. These observations suggest that other members of the CyPB family will have similar enzymatic properties. Sequence comparisons of the CyPB proteins show a central, 165-amino acid peptidyl-prolyl isomerase and cyclosprorin A-binding domain, flanked by variable N-terminal and C-terminal domains. These two variable regions may impart compartmental specificity and regulation to this family of cyclophilin proteins containing the conserved core domain. Northern blot analyses show that hCyPB mRNA is expressed in the Jurkat T-cell line, consistent with its possible target role in cyclosporin A-mediated immunosuppression

  11. Chromosome locations of genes encoding human signal transduction adapter proteins, Nck (NCK), Shc (SHC1), and Grb2 (GRB2)

    DEFF Research Database (Denmark)

    Huebner, K; Kastury, K; Druck, T

    1994-01-01

    -human hybrids carrying defined complements of human chromosomes were assayed for the presence of the cognate genes for NCK, SHC, and GRB2, three SH2 or SH2/SH3 (Src homology 2 and 3) domain-containing adapter proteins. Additionally, NCK and SHC genes were more narrowly localized by chromosomal in situ...... hybridization. The NCK locus is at chromosome region 3q21, a region involved in neoplasia-associated changes; the SHC cognate locus, SHC1, is at 1q21, and the GRB2 locus is at 17q22-qter telomeric to the HOXB and NGFR loci. Both SHC1 and GRB2 are in chromosome regions that may be duplicated in some tumor types.......Abnormalities due to chromosomal aberration or point mutation in gene products of growth factor receptors or in ras gene products, which lie on the same signaling pathway, can cause disease in animals and humans. Thus, it can be important to determine chromosomal map positions of genes encoding...

  12. Abnormal intraluminal signal within the pulmonary arteries on MR imaging: Differentiation between slow blood flow and thrombus using an ECG-gated; multiphasic: Spin-echo technique

    International Nuclear Information System (INIS)

    White, R.D.; Higgins, C.B.

    1986-01-01

    The authors evaluated abnormal MR imaging signal patterns in the pulmonary arteries of 22 patients with pulmonary hypertension (n = 13), pulmonary embolus (n = 4), or both (n = 5). Using multiphasic (five or six phases; 19 patients) or standard (three patients with pulmonary embolus) ECG-gated, double spin-echo techniques, they were able to differentiate between causes of such abnormal signal patterns. The pattern of slow blood flow (abnormal signal in systole with fluctuating distribution during cardiac cycle, and intensity increasing visually from first to second echo) was noted in 89% of patients with pulmonary hypertension alone or in combination with pulmonary embolism, and was characteristic of high systolic pulmonary pressures (12 of 12 patients with pressure > 80 mm Hg, vs. 3 of 5 patients with pressure 55 mm Hg vs. 5 of 7 patients with pressures <55 mm Hg). This pattern was differentiated from that of thrombus (persistent signal with fixed distribution during cardiac cycle, and little to no visible intensity change from first to second echo), which was noted in six of seven proved embolus cases. Thus, gated multiphase MR imaging shows potential for the noninvasive visualization of pulmonary embolus and the differentiation of this entity from the slow blood flow of pulmonary hypertension

  13. Expression of signal transduction system encoding genes of Yersinia pseudotuberculosis IP32953 at 28°C and 3°C.

    Directory of Open Access Journals (Sweden)

    Eveliina Palonen

    Full Text Available Yersinia pseudotuberculosis is a significant psychrotrophic food pathogen whose cold tolerance mechanisms are poorly understood. Signal transduction systems serve to monitor the environment, but no systematic investigation of their role at cold temperatures in Y. pseudotuberculosis has yet been undertaken. The relative expression levels of 54 genes predicted to encode proteins belonging to signal transduction systems in Y. pseudotuberculosis IP32953 were determined at 28°C and 3°C by quantitative real-time reverse transcription-PCR. The relative expression levels of 44 genes were significantly (p<0.05 higher at 3°C than at 28°C. Genes encoding the two-component system CheA/CheY had the highest relative expression levels at 3°C. Mutational analysis revealed that cheA is important for growth and motility at 3°C. The relative expression level of one gene, rssB, encoding an RpoS regulator, was significantly (p<0.05 lower at 3°C than at 28°C. The results suggest that several signal transduction systems might be used during growth at low temperature, and at least, CheA/CheY two-component system is important for low-temperature growth.

  14. Getting at the source of distinctive encoding effects in the DRM paradigm: evidence from signal-detection measures and source judgments.

    Science.gov (United States)

    Bodner, Glen E; Huff, Mark J; Lamontagne, Raymond W; Azad, Tanjeem

    2017-05-01

    Studying Deese-Roediger-McDermott (DRM) lists using a distinctive encoding task can reduce the DRM false memory illusion. Reductions for both distinctively encoded lists and non-distinctively encoded lists in a within-group design have been ascribed to use of a distinctiveness heuristic by which participants monitor their memories at test for distinctive-task details. Alternatively, participants might simply set a more conservative response criterion, which would be exceeded by distinctive list items more often than all other test items, including the critical non-studied items. To evaluate these alternatives, we compared a within-group who studied 5 lists by reading, 5 by anagram generation, and 5 by imagery, relative to a control group who studied all 15 lists by reading. Generation and imagery improved recognition accuracy by impairing relational encoding, but the within group did not show greater memory monitoring at test relative to the read control group. Critically, the within group's pattern of list-based source judgments provided new evidence that participants successfully monitored for distinctive-task details at test. Thus, source judgments revealed evidence of qualitative, recollection-based monitoring in the within group, to which our quantitative signal-detection measure of monitoring was blind.

  15. Expression of cAMP-responsive element binding proteins (CREBs) in fast- and slow-twitch muscles: a signaling pathway to account for the synaptic expression of collagen-tailed subunit (ColQ) of acetylcholinesterase at the rat neuromuscular junction.

    Science.gov (United States)

    Choi, Roy C Y; Chen, Vicky P; Luk, Wilson K W; Yung, Amanda W Y; Ng, Alice H M; Dong, Tina T X; Tsim, Karl W K

    2013-03-25

    The gene encoding the collagen-tailed subunit (ColQ) of acetylcholinesterase (AChE) contains two distinct promoters that drive the production of two ColQ mRNAs, ColQ-1 and ColQ-1a, in slow- and fast-twitch muscles, respectively. ColQ-1a is expressed at the neuromuscular junction (NMJ) in fast-twitch muscle, and this expression depends on trophic factors supplied by motor neurons signaling via a cAMP-dependent pathway in muscle. To further elucidate the molecular basis of ColQ-1a's synaptic expression, here we investigated the expression and localization of cAMP-responsive element binding protein (CREB) at the synaptic and extra-synaptic regions of fast- and slow-twitch muscles from adult rats. The total amount of active, phosphorylated CREB (P-CREB) present in slow-twitch soleus muscle was higher than that in fast-twitch tibialis muscle, but P-CREB was predominantly expressed in the fast-twitch muscle at NMJs. In contrast, P-CREB was detected in both synaptic and extra-synaptic regions of slow-twitch muscle. These results reveal, for the first time, the differential distribution of P-CREB in fast- and slow-twitch muscles, which might support the crucial role of cAMP-dependent signaling in controlling the synapse-specific expression of ColQ-1a in fast-twitch muscles. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. Viral Inhibition of the IFN-Induced JAK/STAT Signalling Pathway: Development of Live Attenuated Vaccines by Mutation of Viral-Encoded IFN-Antagonists

    Directory of Open Access Journals (Sweden)

    Stephen B. Fleming

    2016-06-01

    Full Text Available The interferon (IFN induced anti-viral response is amongst the earliest and most potent of the innate responses to fight viral infection. The induction of the Janus kinase/signal transducer and activation of transcription (JAK/STAT signalling pathway by IFNs leads to the upregulation of hundreds of interferon stimulated genes (ISGs for which, many have the ability to rapidly kill viruses within infected cells. During the long course of evolution, viruses have evolved an extraordinary range of strategies to counteract the host immune responses in particular by targeting the JAK/STAT signalling pathway. Understanding how the IFN system is inhibited has provided critical insights into viral virulence and pathogenesis. Moreover, identification of factors encoded by viruses that modulate the JAK/STAT pathway has opened up opportunities to create new anti-viral drugs and rationally attenuated new generation vaccines, particularly for RNA viruses, by reverse genetics.

  17. Similar activation of signal transduction pathways by the herpesvirus-encoded chemokine receptors US28 and ORF74

    DEFF Research Database (Denmark)

    McLean, Katherine A; Holst, Peter J; Martini, Lene

    2004-01-01

    The virally encoded chemokine receptors US28 from human cytomegalovirus and ORF74 from human herpesvirus 8 are both constitutively active. We show that both receptors constitutively activate the transcription factors nuclear factor of activated T cells (NFAT) and cAMP response element binding...... viral gene expression similarly. As ORF74 is a known inducer of neoplasia, these findings may have important implications for cytomegalovirus-associated pathogenicity....

  18. Electroporated Antigen-Encoding mRNA Is Not a Danger Signal to Human Mature Monocyte-Derived Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Stefanie Hoyer

    2015-01-01

    Full Text Available For therapeutic cancer vaccination, the adoptive transfer of mRNA-electroporated dendritic cells (DCs is frequently performed, usually with monocyte-derived, cytokine-matured DCs (moDCs. However, DCs are rich in danger-sensing receptors which could recognize the exogenously delivered mRNA and induce DC activation, hence influencing the DCs’ immunogenicity. Therefore, we examined whether electroporation of mRNA with a proper cap and a poly-A tail of at least 64 adenosines had any influence on cocktail-matured moDCs. We used 16 different RNAs, encoding tumor antigens (MelanA, NRAS, BRAF, GNAQ, GNA11, and WT1, and variants thereof. None of those RNAs induced changes in the expression of CD25, CD40, CD83, CD86, and CD70 or the secretion of the cytokines IL-8, IL-6, and TNFα of more than 1.5-fold compared to the control condition, while an mRNA encoding an NF-κB-activation protein as positive control induced massive secretion of the cytokines. To determine whether mRNA electroporation had any effect on the whole transcriptome of the DCs, we performed microarray analyses of DCs of 6 different donors. None of 60,000 probes was significantly different between mock-electroporated DCs and MelanA-transfected DCs. Hence, we conclude that no transcriptional programs were induced within cocktail-matured DCs by electroporation of single tumor-antigen-encoding mRNAs.

  19. Inhibition of IRE1 signaling affects the expression of genes encoded glucocorticoid receptor and some related factors and their hypoxic regulation in U87 glioma cells

    Directory of Open Access Journals (Sweden)

    Minchenko D.O.

    2016-07-01

    Full Text Available Objective. The aim of the present investigation was to examine the effect of inhibition of endoplasmic reticulum stress signaling, mediated by IRE1 (inositol requiring enzyme 1, which is a central mediator of the unfolded protein response on the expression of genes encoding glucocorticoid receptor (NR3C1 and some related proteins (SGK1, SGK3, NCOA1, NCOA2, ARHGAP35, NNT and their hypoxic regulation in U87 glioma cells for evaluation of their possible significance in the control of the glioma growth.

  20. Slow conformational changes in MutS and DNA direct ordered transitions between mismatch search, recognition and signaling of DNA repair

    Science.gov (United States)

    Sharma, Anushi; Doucette, Christopher; Biro, F. Noah; Hingorani, Manju M.

    2013-01-01

    MutS functions in mismatch repair (MMR) to scan DNA for errors, identify a target site and trigger subsequent events in the pathway leading to error removal and DNA re-synthesis. These actions, enabled by the ATPase activity of MutS, are now beginning to be analyzed from the perspective of the protein itself. This study provides the first ensemble transient kinetic data on MutS conformational dynamics as it works with DNA and ATP in MMR. Using a combination of fluorescence probes (on T. aquaticus MutS and DNA) and signals (intensity, anisotropy and resonance energy transfer), we have monitored the timing of key conformational changes in MutS that are coupled to mismatch binding and recognition, ATP binding and hydrolysis, as well as sliding clamp formation and signaling of repair. Significant findings include: (a) a slow step that follows weak initial interaction between MutS and DNA, in which concerted conformational changes in both macromolecules control mismatch recognition, (b) rapid, binary switching of MutS conformations that is concerted with ATP binding and hydrolysis, and (c) is stalled after mismatch recognition to control formation of the ATP-bound MutS sliding clamp. These rate-limiting pre- and post-mismatch recognition events outline the mechanism of action of MutS on DNA during initiation of MMR. PMID:23973435

  1. Spectral encoded optical label detection for dynamic routing of impulse radio ultra-wideband signals in metro-access networks

    DEFF Research Database (Denmark)

    Osadchiy, Alexey Vladimirovich; Yu, Xianbin; Yin, Xiaoli

    2010-01-01

    In this paper we propose and experimentally demonstrate the principle of coherent label detection for dynamic routing of wavelength division multiplexed impulse radio ultra-wideband signals by using four-tone spectral amplitude coded labels.......In this paper we propose and experimentally demonstrate the principle of coherent label detection for dynamic routing of wavelength division multiplexed impulse radio ultra-wideband signals by using four-tone spectral amplitude coded labels....

  2. Slow Meteors

    Science.gov (United States)

    Dubs, Martin; Sposetti, Stefano; Spinner, Roger; Booz, Beat

    2017-04-01

    Slow meteors are studied with video observations and spectroscopy. A comparison of their orbits and spectra points to a common origin. Although they do not belong to some meteor stream, they deserve to be studied in more detail. The present paper tries to make a first attempt to characterize the common properties of this class of meteors.

  3. Signal peptidase complex 18, encoded by SEC11A, contributes to progression via TGF-α secretion in gastric cancer.

    Science.gov (United States)

    Oue, N; Naito, Y; Hayashi, T; Takigahira, M; Kawano-Nagatsuma, A; Sentani, K; Sakamoto, N; Zarni Oo, H; Uraoka, N; Yanagihara, K; Ochiai, A; Sasaki, H; Yasui, W

    2014-07-24

    We built an in-house oligonucleotide array on which 394 genes were selected based on our Serial Analysis of Gene Expression (SAGE) data and previously reported array data and listed several genes related to cancer progression. Among these, we focused on SEC11A, which encodes the SPC18 protein. SEC11A mRNA expression was measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in gastric cancer (GC) tissue samples. Expression and distribution of SPC18 protein were investigated by immunohistochemical analysis in two independent GC cohorts (Hiroshima cohort, n=99 and Chiba cohort, n=989). To determine the effect of SPC18 on cell viability and invasiveness in vitro, MTT and Boyden chamber invasion assays were performed. To evaluate the influence of SPC18 on cell growth in vivo, GC cells were injected into severe combined immunodeficiency mice. Levels of TGF-α and EGF in media from the GC cells were measured by enzyme-linked immunosorbent assay (ELISA). Studies in human tissue revealed overexpression of SEC11A mRNA in 40% of 42 GC samples by qRT-PCR. Immunohistochemical analysis of SPC18 revealed that 26 and 20% of GC cases were SPC18-positive in the Hiroshima and Chiba cohorts, respectively. In both cohorts, the Kaplan-Meier analysis showed poorer survival in SPC18-positive GC cases than in SPC18-negative GC cases. Forced expression of SPC18 activates GC cell growth in vitro and in vivo. The levels of TGF-α in culture media from GC cells were reduced by knockdown of SPC18. These results indicate that SPC18 contributes to malignant progression through promotion of TGF-α secretion in GC.

  4. Performance analysis of spectral-phase-encoded optical code-division multiple-access system regarding the incorrectly decoded signal as a nonstationary random process

    Science.gov (United States)

    Yan, Meng; Yao, Minyu; Zhang, Hongming

    2005-11-01

    The performance of a spectral-phase-encoded (SPE) optical code-division multiple-access (OCDMA) system is analyzed. Regarding the incorrectly decoded signal (IDS) as a nonstationary random process, we derive a novel probability distribution for it. The probability distribution of the IDS is considered a chi-squared distribution with degrees of freedom r=1, which is more reasonable and accurate than in previous work. The bit error rate (BER) of an SPE OCDMA system under multiple-access interference is evaluated. Numerical results show that the system can sustain very low BER even when there are multiple simultaneous users, and as the code length becomes longer or the initial pulse becomes shorter, the system performs better.

  5. A Phylogenetic Survey on the Structure of the HIV-1 Leader RNA Domain That Encodes the Splice Donor Signal.

    Science.gov (United States)

    Mueller, Nancy; Das, Atze T; Berkhout, Ben

    2016-07-21

    RNA splicing is a critical step in the human immunodeficiency virus type 1 (HIV-1) replication cycle because it controls the expression of the complex viral proteome. The major 5' splice site (5'ss) that is positioned in the untranslated leader of the HIV-1 RNA transcript is of particular interest because it is used for the production of the more than 40 differentially spliced subgenomic mRNAs. HIV-1 splicing needs to be balanced tightly to ensure the proper levels of all viral proteins, including the Gag-Pol proteins that are translated from the unspliced RNA. We previously presented evidence that the major 5'ss is regulated by a repressive local RNA structure, the splice donor (SD) hairpin, that masks the 11 nucleotides (nts) of the 5'ss signal for recognition by U1 small nuclear RNA (snRNA) of the spliceosome machinery. A strikingly different multiple-hairpin RNA conformation was recently proposed for this part of the HIV-1 leader RNA. We therefore inspected the sequence of natural HIV-1 isolates in search for support, in the form of base pair (bp) co-variations, for the different RNA conformations.

  6. Application of Genetically Encoded Fluorescent Nitric Oxide (NO•) Probes, the geNOps, for Real-time Imaging of NO• Signals in Single Cells.

    Science.gov (United States)

    Eroglu, Emrah; Rost, Rene; Bischof, Helmut; Blass, Sandra; Schreilechner, Anna; Gottschalk, Benjamin; Depaoli, Maria R; Klec, Christiane; Charoensin, Suphachai; Madreiter-Sokolowski, Corina T; Ramadani, Jeta; Waldeck-Weiermair, Markus; Graier, Wolfgang F; Malli, Roland

    2017-03-16

    Nitric Oxide (NO•) is a small radical, which mediates multiple important cellular functions in mammals, bacteria and plants. Despite the existence of a large number of methods for detecting NO• in vivo and in vitro, the real-time monitoring of NO• at the single-cell level is very challenging. The physiological or pathological effects of NO• are determined by the actual concentration and dwell time of this radical. Accordingly, methods that allow the single-cell detection of NO• are highly desirable. Recently, we expanded the pallet of NO• indicators by introducing single fluorescent protein-based genetically encoded nitric oxide (NO•) probes (geNOps) that directly respond to cellular NO• fluctuations and, hence, addresses this need. Here we demonstrate the usage of geNOps to assess intracellular NO• signals in response to two different chemical NO•-liberating molecules. Our results also confirm that freshly prepared 3-(2-hydroxy-1-methyl-2-nitrosohydrazino)-N-methyl-1-propanamine (NOC-7) has a much higher potential to evoke change in intracellular NO• levels as compared with the inorganic NO• donor sodium nitroprusside (SNP). Furthermore, dual-color live-cell imaging using the green geNOps (G-geNOp) and the chemical Ca 2+ indicator fura-2 was performed to visualize the tight regulation of Ca 2+ -dependent NO• formation in single endothelial cells. These representative experiments demonstrate that geNOps are suitable tools to investigate the real-time generation and degradation of single-cell NO• signals in diverse experimental setups.

  7. Detection of the sulfhydryl groups in proteins with slow hydrogen exchange rates and determination of their proton/deuteron fractionation factors using the deuterium-induced effects on the 13C(beta) NMR signals.

    Science.gov (United States)

    Takeda, Mitsuhiro; Jee, JunGoo; Terauchi, Tsutomu; Kainosho, Masatsune

    2010-05-05

    A method for identifying cysteine (Cys) residues with sulfhydryl (SH) groups exhibiting slow hydrogen exchange rates has been developed for proteins in aqueous media. The method utilizes the isotope shifts of the C(beta) chemical shifts induced by the deuteration of the SH groups. The 18.2 kDa E. coli peptidyl prolyl cis-trans isomerase b (EPPIb), which was selectively labeled with [3-(13)C;3,3-(2)H(2)]Cys, showed much narrower line widths for the (13)C(beta) NMR signals, as compared to those of the proteins labeled with either [3-(13)C]Cys or (3R)-[3-(13)C;3-(2)H]Cys. The (13)C(beta) signals of the two Cys residues of EPPIb, i.e. Cys-31 and Cys-121, labeled with [3-(13)C;3,3-(2)H(2)]Cys, split into four signals in H(2)O/D(2)O (1:1) at 40 degrees C and pH 7.5, indicating that the exchange rates of the side-chain SH's and the backbone amides are too slow to average the chemical shift differences of the (13)C(beta) signals, due to the two- and three-bond isotope shifts. By virtue of the well-separated signals, the proton/deuteron fractional factors for both the SH and amide groups of the two Cys residues in EPPIb could be directly determined, as approximately 0.4-0.5 for [SD]/[SH] and 0.9-1.0 for [ND]/[NH], by the relative intensities of the NMR signals for the isotopomers. The proton NOE's of the two slowly exchanging SH's were clearly identified in the NOESY spectra and were useful for the determining the local structure of EPPIb around the Cys residues.

  8. FROM SLOW FOOD TO SLOW TOURISM

    Directory of Open Access Journals (Sweden)

    Bac Dorin Paul

    2014-12-01

    Full Text Available One of the effects of globalization is the faster pace of our lives. This rhythm can be noticed in all aspects of life: travel, work, shopping, etc. and it has serious negative effects. It has become common knowledge that stress and speed generate serious medical issues. Food and eating habits in the modern world have taken their toll on our health. However, some people took a stand and argued for a new kind of lifestyle. It all started in the field of gastronomy, where a new movement emerged – Slow Food, based on the ideas and philosophy of Carlo Petrini. Slow Food represents an important adversary to the concept of fast food, and is promoting local products, enjoyable meals and healthy food. The philosophy of the Slow Food movement developed in several directions: Cittaslow, slow travel and tourism, slow religion and slow money etc. The present paper will account the evolution of the concept and its development during the most recent years. We will present how the philosophy of slow food was applied in all the other fields it reached and some critical points of view. Also we will focus on the presence of the slow movement in Romania, although it is in a very early stage of development. The main objectives of the present paper are: to present the chronological and ideological evolution of the slow movement; to establish a clear separation of slow travel and slow tourism, as many mistake on for the other; to review the presence of the slow movement in Romania. Regarding the research methodology, information was gathered from relevant academic papers and books and also from interviews and discussions with local entrepreneurs. The research is mostly theoretical and empirical, as slow food and slow tourism are emerging research themes in academic circles.

  9. Position encoder

    International Nuclear Information System (INIS)

    Goursky, Vsevolod

    1975-01-01

    A circuitry for deriving the quotient of signal delivered by position-sensitive detectors is described. Digital output is obtained in the form of 10- to 12-bit words. Impact position may be determined with 0.25% accuracy when the dynamic range of the energy signal is less 1:10, and 0.5% accuracy when the dynamic range is 1:20. The division requires an average time of 5μs for 10-bit words

  10. Position encoder

    International Nuclear Information System (INIS)

    Goursky, V.

    1975-05-01

    This paper describes circuitry for deriving the quotient of signals delivered by position-sensitive detectors. Digital output is obtained in the form of 10 to 12 bit words. Impact position may be determined with 0.25% accuracy when the dynamic range of the energy signal is less than 1:10, and 0.5% accuracy when the dynamic range is 1:20. The division requires an average time of 5μs for 10-bit words [fr

  11. Ingredients of Huangqi decoction slow biliary fibrosis progression by inhibiting the activation of the transforming growth factor-beta signaling pathway

    Directory of Open Access Journals (Sweden)

    Du Jin-Xing

    2012-04-01

    Full Text Available Abstract Background Huangqi decoction was first described in Prescriptions of the Bureau of Taiping People's Welfare Pharmacy in Song Dynasty (AD 1078, and it is an effective recipe that is usually used to treat consumptive disease, anorexia, and chronic liver diseases. Transforming growth factor beta 1 (TGFβ1 plays a key role in the progression of liver fibrosis, and Huangqi decoction and its ingredients (IHQD markedly ameliorated hepatic fibrotic lesions induced by ligation of the common bile duct (BDL. However, the mechanism of IHQD on hepatic fibrotic lesions is not yet clear. The purpose of the present study is to elucidate the roles of TGFβ1 activation, Smad-signaling pathway, and extracellular signal-regulated kinase (ERK in the pathogenesis of biliary fibrosis progression and the antifibrotic mechanism of IHQD. Methods A liver fibrosis model was induced by ligation of the common bile duct (BDL in rats. Sham-operation was performed in control rats. The BDL rats were randomly divided into two groups: the BDL group and the IHQD group. IHQD was administrated intragastrically for 4 weeks. At the end of the fifth week after BDL, animals were sacrificed for sampling of blood serum and liver tissue. The effect of IHQD on the TGFβ1 signaling pathway was evaluated by western blotting and laser confocal microscopy. Results Decreased content of hepatic hydroxyproline and improved liver function and histopathology were observed in IHQD rats. Hepatocytes, cholangiocytes, and myofibroblasts in the cholestatic liver injury released TGFβ1, and activated TGFβ1 receptors can accelerate liver fibrosis. IHQD markedly inhibited the protein expression of TGFβ1, TGFβ1 receptors, Smad3, and p-ERK1/2 expression with no change of Smad7 expression. Conclusion IHQD exert significant therapeutic effects on BDL-induced fibrosis in rats through inhibition of the activation of TGFβ1-Smad3 and TGFβ1-ERK1/2 signaling pathways.

  12. The putative bZIP transcription factor BzpN slows proliferation and functions in the regulation of cell density by autocrine signals in Dictyostelium.

    Directory of Open Access Journals (Sweden)

    Jonathan E Phillips

    Full Text Available The secreted proteins AprA and CfaD function as autocrine signals that inhibit cell proliferation in Dictyostelium discoideum, thereby regulating cell numbers by a negative feedback mechanism. We report here that the putative basic leucine zipper transcription factor BzpN plays a role in the inhibition of proliferation by AprA and CfaD. Cells lacking BzpN proliferate more rapidly than wild-type cells but do not reach a higher stationary density. Recombinant AprA inhibits wild-type cell proliferation but does not inhibit the proliferation of cells lacking BzpN. Recombinant CfaD also inhibits wild-type cell proliferation, but promotes the proliferation of cells lacking BzpN. Overexpression of BzpN results in a reduced cell density at stationary phase, and this phenotype requires AprA, CfaD, and the kinase QkgA. Conditioned media from high-density cells stops the proliferation of wild-type but not bzpN(- cells and induces a nuclear localization of a BzpN-GFP fusion protein, though this localization does not require AprA or CfaD. Together, the data suggest that BzpN is necessary for some but not all of the effects of AprA and CfaD, and that BzpN may function downstream of AprA and CfaD in a signal transduction pathway that inhibits proliferation.

  13. The Putative bZIP Transcripton Factor BzpN Slows Proliferation and Functions in the Regulation of Cell Density by Autocrine Signals in Dictyostelium

    Science.gov (United States)

    Phillips, Jonathan E.; Huang, Eryong; Shaulsky, Gad; Gomer, Richard H.

    2011-01-01

    The secreted proteins AprA and CfaD function as autocrine signals that inhibit cell proliferation in Dictyostelium discoideum, thereby regulating cell numbers by a negative feedback mechanism. We report here that the putative basic leucine zipper transcription factor BzpN plays a role in the inhibition of proliferation by AprA and CfaD. Cells lacking BzpN proliferate more rapidly than wild-type cells but do not reach a higher stationary density. Recombinant AprA inhibits wild-type cell proliferation but does not inhibit the proliferation of cells lacking BzpN. Recombinant CfaD also inhibits wild-type cell proliferation, but promotes the proliferation of cells lacking BzpN. Overexpression of BzpN results in a reduced cell density at stationary phase, and this phenotype requires AprA, CfaD, and the kinase QkgA. Conditioned media from high-density cells stops the proliferation of wild-type but not bzpN− cells and induces a nuclear localization of a BzpN-GFP fusion protein, though this localization does not require AprA or CfaD. Together, the data suggest that BzpN is necessary for some but not all of the effects of AprA and CfaD, and that BzpN may function downstream of AprA and CfaD in a signal transduction pathway that inhibits proliferation. PMID:21760904

  14. The putative bZIP transcription factor BzpN slows proliferation and functions in the regulation of cell density by autocrine signals in Dictyostelium.

    Science.gov (United States)

    Phillips, Jonathan E; Huang, Eryong; Shaulsky, Gad; Gomer, Richard H

    2011-01-01

    The secreted proteins AprA and CfaD function as autocrine signals that inhibit cell proliferation in Dictyostelium discoideum, thereby regulating cell numbers by a negative feedback mechanism. We report here that the putative basic leucine zipper transcription factor BzpN plays a role in the inhibition of proliferation by AprA and CfaD. Cells lacking BzpN proliferate more rapidly than wild-type cells but do not reach a higher stationary density. Recombinant AprA inhibits wild-type cell proliferation but does not inhibit the proliferation of cells lacking BzpN. Recombinant CfaD also inhibits wild-type cell proliferation, but promotes the proliferation of cells lacking BzpN. Overexpression of BzpN results in a reduced cell density at stationary phase, and this phenotype requires AprA, CfaD, and the kinase QkgA. Conditioned media from high-density cells stops the proliferation of wild-type but not bzpN(-) cells and induces a nuclear localization of a BzpN-GFP fusion protein, though this localization does not require AprA or CfaD. Together, the data suggest that BzpN is necessary for some but not all of the effects of AprA and CfaD, and that BzpN may function downstream of AprA and CfaD in a signal transduction pathway that inhibits proliferation.

  15. Interdependent processing and encoding of speech and concurrent background noise.

    Science.gov (United States)

    Cooper, Angela; Brouwer, Susanne; Bradlow, Ann R

    2015-05-01

    Speech processing can often take place in adverse listening conditions that involve the mixing of speech and background noise. In this study, we investigated processing dependencies between background noise and indexical speech features, using a speeded classification paradigm (Garner, 1974; Exp. 1), and whether background noise is encoded and represented in memory for spoken words in a continuous recognition memory paradigm (Exp. 2). Whether or not the noise spectrally overlapped with the speech signal was also manipulated. The results of Experiment 1 indicated that background noise and indexical features of speech (gender, talker identity) cannot be completely segregated during processing, even when the two auditory streams are spectrally nonoverlapping. Perceptual interference was asymmetric, whereby irrelevant indexical feature variation in the speech signal slowed noise classification to a greater extent than irrelevant noise variation slowed speech classification. This asymmetry may stem from the fact that speech features have greater functional relevance to listeners, and are thus more difficult to selectively ignore than background noise. Experiment 2 revealed that a recognition cost for words embedded in different types of background noise on the first and second occurrences only emerged when the noise and the speech signal were spectrally overlapping. Together, these data suggest integral processing of speech and background noise, modulated by the level of processing and the spectral separation of the speech and noise.

  16. The CXC chemokine receptor encoded by herpesvirus saimiri, ECRF3, shows ligand-regulated signaling through Gi, Gq, and G12/13 proteins but constitutive signaling only through Gi and G12/13 proteins

    DEFF Research Database (Denmark)

    Rosenkilde, Mette M; McLean, Katherine A; Holst, Peter J

    2004-01-01

    Open reading frame 74 (ORF74) of many gamma(2)-herpesviruses encodes a CXC chemokine receptor. The molecular pharmacological profile of ORF74 from herpesvirus saimiri, ECRF3, is characterized here and compared with that of the well known ORF74 from human herpesvirus 8 (HHV8). The ECRF3 receptor b...... ligand selectivity of ECRF3 among ORF74 receptors could reflect differences in the cellular tropism of the gamma(2)-herpesviruses....

  17. Fly Photoreceptors Encode Phase Congruency.

    Directory of Open Access Journals (Sweden)

    Uwe Friederich

    Full Text Available More than five decades ago it was postulated that sensory neurons detect and selectively enhance behaviourally relevant features of natural signals. Although we now know that sensory neurons are tuned to efficiently encode natural stimuli, until now it was not clear what statistical features of the stimuli they encode and how. Here we reverse-engineer the neural code of Drosophila photoreceptors and show for the first time that photoreceptors exploit nonlinear dynamics to selectively enhance and encode phase-related features of temporal stimuli, such as local phase congruency, which are invariant to changes in illumination and contrast. We demonstrate that to mitigate for the inherent sensitivity to noise of the local phase congruency measure, the nonlinear coding mechanisms of the fly photoreceptors are tuned to suppress random phase signals, which explains why photoreceptor responses to naturalistic stimuli are significantly different from their responses to white noise stimuli.

  18. Fly Photoreceptors Encode Phase Congruency.

    Science.gov (United States)

    Friederich, Uwe; Billings, Stephen A; Hardie, Roger C; Juusola, Mikko; Coca, Daniel

    2016-01-01

    More than five decades ago it was postulated that sensory neurons detect and selectively enhance behaviourally relevant features of natural signals. Although we now know that sensory neurons are tuned to efficiently encode natural stimuli, until now it was not clear what statistical features of the stimuli they encode and how. Here we reverse-engineer the neural code of Drosophila photoreceptors and show for the first time that photoreceptors exploit nonlinear dynamics to selectively enhance and encode phase-related features of temporal stimuli, such as local phase congruency, which are invariant to changes in illumination and contrast. We demonstrate that to mitigate for the inherent sensitivity to noise of the local phase congruency measure, the nonlinear coding mechanisms of the fly photoreceptors are tuned to suppress random phase signals, which explains why photoreceptor responses to naturalistic stimuli are significantly different from their responses to white noise stimuli.

  19. Fluorescent reporter signals, EGFP and DsRed, encoded in HIV-1 facilitate the detection of productively infected cells and cell-associated viral replication levels

    Directory of Open Access Journals (Sweden)

    Kazutaka eTerahara

    2012-01-01

    Full Text Available Flow cytometric analysis is a reliable and convenient method for investigating molecules at the single cell level. Previously, recombinant human immunodeficiency virus type 1 (HIV-1 strains were constructed that express a fluorescent reporter, either enhanced green fluorescent protein or DsRed, which allow the monitoring of HIV-1-infected cells by flow cytometry. The present study further investigated the potential of these recombinant viruses in terms of whether the HIV-1 fluorescent reporters would be helpful in evaluating viral replication based on fluorescence intensity. When primary CD4+ T cells were infected with recombinant viruses, the fluorescent reporter intensity measured by flow cytometry was associated with the level of CD4 downmodulation and Gag p24 expression in infected cells. Interestingly, some HIV-1-infected cells, in which CD4 was only moderately downmodulated, were reporter-positive but Gag p24-negative. Furthermore, when the activation status of primary CD4+ T cells was modulated by T cell receptor-mediated stimulation, we confirmed the preferential viral production upon strong stimulation and showed that the intensity of the fluorescent reporter within a proportion of HIV-1-infected cells was correlated with the viral replication level. These findings indicate that a fluorescent reporter encoded within HIV-1 is useful for the sensitive detection of productively-infected cells at different stages of infection and for evaluating cell-associated viral replication at the single cell level.

  20. Systematic Design of Slow Light Waveguides

    DEFF Research Database (Denmark)

    Wang, Fengwen

    Light can propagate much slower in photonic crystal waveguides and plasmonic waveguides than in vacuum. Slow light propagation in waveguides shows broad prospects in the terabit communication systems. However, it causes severe signal distortions and displays large propagation loss. Moreover...... the same bandwidth. The first optimization formulation is further employed to design slow light metal- dielectric-metal plasmonic waveguides. It is shown that dispersionless slow light propagation is achieved in the optimized plasmonic waveguide. Further study reveals that the loss in metal can...

  1. Mutation patterns in genes encoding interferon signaling and antigen presentation: A pan-cancer survey with implications for the use of immune checkpoint inhibitors.

    Science.gov (United States)

    Budczies, Jan; Bockmayr, Michael; Klauschen, Frederick; Endris, Volker; Fröhling, Stefan; Schirmacher, Peter; Denkert, Carsten; Stenzinger, Albrecht

    2017-08-01

    Blockade of immune checkpoints has become a powerful tool in cancer medicine, which is effective across various solid cancer types and hematologic malignancies. While immunohistochemical detection of PD-L1 expression in tumor cells, immune cells, or both has been introduced as predictive biomarker in several clinical trials, shortcomings and limitations of this approach were quickly recognized. As a single biomarker is unlikely to adequately reflect the complex interplay between immune cells and cancer, various genetic determinants of therapy success, including microsatellite instability, mutational burden, and PD-L1 amplification, are being investigated. Very recent work indicates that mutations in B2M, JAK1, and JAK2 render melanoma resistant to immune checkpoint blockade, thus serving as negative response predictors. Using the TCGA dataset, we performed a pan-cancer analysis of potentially damaging mutations in key genes implicated in antigen presentation and interferon-gamma signaling and investigated associations with transcript levels of immune checkpoint genes, cytolytic activity, and mutational burden. For B2M, JAK1, and JAK2, we observed overall mutation frequencies of 1.8%, 2%, and 2.6%, respectively, and found significant associations with mutational burden. On pathway level, melanoma as well as bladder, gastric, and lung cancer were most frequently affected by putative resistance mutations with mutation rates of 27%-50% in the antigen presentation pathway and of 16%-21% in the interferon signaling pathway. Our analysis suggests that a significant number of tumors harbor mutations that may negatively interfere with immune checkpoint inhibition, or confer a higher likelihood of resistance for which a second hit is ultimately required. Since these mutations are prevalent in treatment-naïve tumors, genetic screening prior to therapy might complement current approaches at predicting response to immune checkpoint blockade. © 2017 Wiley Periodicals, Inc.

  2. Slow Light at High Frequencies in an Amplifying Semiconductor Waveguide

    DEFF Research Database (Denmark)

    Öhman, Filip; Yvind, Kresten; Mørk, Jesper

    2006-01-01

    We demonstrate slow-down of a modulated light signal in a semiconductor waveguide. Concatenated amplifying and absorbing sections simultaneously achieve both amplification and a controllable time delay at 15 GHz.......We demonstrate slow-down of a modulated light signal in a semiconductor waveguide. Concatenated amplifying and absorbing sections simultaneously achieve both amplification and a controllable time delay at 15 GHz....

  3. Lmx1a encodes a rostral set of mesodiencephalic dopaminergic neurons marked by the Wnt/B-catenin signaling activator R-spondin 2.

    Directory of Open Access Journals (Sweden)

    Elisa J Hoekstra

    Full Text Available Recent developments in molecular programming of mesodiencephalic dopaminergic (mdDA neurons have led to the identification of many transcription factors playing a role in mdDA specification. LIM homeodomain transcription factor Lmx1a is essential for chick mdDA development, and for the efficient differentiation of ES-cells towards a dopaminergic phenotype. In this study, we aimed towards a more detailed understanding of the subtle phenotype in Lmx1a-deficient (dreher mice, by means of gene expression profiling. Transcriptome analysis was performed, to elucidate the exact molecular programming underlying the neuronal deficits after loss of Lmx1a. Subsequent expression analysis on brain sections, confirmed that Nurr1 is regulated by Lmx1a, and additional downstream targets were identified, like Pou4f1, Pbx1, Pitx2, C130021l20Rik, Calb2 and Rspo2. In line with a specific, rostral-lateral (prosomer 2/3 loss of expression of most of these genes during development, Nurr1 and C130021l20Rik were affected in the SNc of the mature mdDA system. Interestingly, this deficit was marked by the complete loss of the Wnt/b-catenin signaling activator Rspo2 in this domain. Subsequent analysis of Rspo2-/- embryos revealed affected mdDA neurons, partially phenocopying the Lmx1a mutant. To conclude, our study revealed that Lmx1a is essential for a rostral-lateral subset of the mdDA neuronal field, where it might serve a critical function in modulating proliferation and differentiation of mdDA progenitors through the regulation of the Wnt activator Rspo2.

  4. Deletion of the vaccinia virus gene A46R, encoding for an inhibitor of TLR signalling, is an effective approach to enhance the immunogenicity in mice of the HIV/AIDS vaccine candidate NYVAC-C.

    Directory of Open Access Journals (Sweden)

    Beatriz Perdiguero

    Full Text Available Viruses have developed strategies to counteract signalling through Toll-like receptors (TLRs that are involved in the detection of viruses and induction of proinflammatory cytokines and IFNs. Vaccinia virus (VACV encodes A46 protein which disrupts TLR signalling by interfering with TLR: adaptor interactions. Since the innate immune response to viruses is critical to induce protective immunity, we studied whether deletion of A46R gene in a NYVAC vector expressing HIV-1 Env, Gag, Pol and Nef antigens (NYVAC-C improves immune responses against HIV-1 antigens. This question was examined in human macrophages and in mice infected with a single A46R deletion mutant of the vaccine candidate NYVAC-C (NYVAC-C-ΔA46R. The viral gene A46R is not required for virus replication in primary chicken embryo fibroblast (CEF cells and its deletion in NYVAC-C markedly increases TNF, IL-6 and IL-8 secretion by human macrophages. Analysis of the immune responses elicited in BALB/c mice after DNA prime/NYVAC boost immunization shows that deletion of A46R improves the magnitude of the HIV-1-specific CD4 and CD8 T cell immune responses during adaptive and memory phases, maintains the functional profile observed with the parental NYVAC-C and enhances anti-gp120 humoral response during the memory phase. These findings establish the immunological role of VACV A46R on innate immune responses of macrophages in vitro and antigen-specific T and B cell immune responses in vivo and suggest that deletion of viral inhibitors of TLR signalling is a useful approach for the improvement of poxvirus-based vaccine candidates.

  5. Study and realisation of a double integration charge encoder at VXI standard

    International Nuclear Information System (INIS)

    Leconte, A.

    1994-07-01

    The 16 channels charge encoder herein described equips the Phoswich scintillators which, associated with photomultiplier tubes, constitutes the first ring of the INDRA Multidetector. This 4 π Multidetector, located at GANIL at Caen, is first presented. In this encoder, two integrations are made, offering a distinction between the fast component of the signal from the detector and the slow one (decreasing times: 2,4 ns and 320ns respectively). This measurement is performed by the integration of each component within an adjustable time-gate. Apart from the two integrations, the encoder realizes the detection of the impulsion with a constant fraction discriminator, the generation of the two gates and a test function. The use of surface mounted components together with the choice of the VXI interconnection standard, also presented in this report, allowed highly integrated electronics. The encoder uses the sliding scale principle. It also includes the electronics for some programmable adjustments, the remote visualisation of important signals and the logic for the conversion. (author). 22 refs

  6. Multi-modulus algorithm based on global artificial fish swarm intelligent optimization of DNA encoding sequences.

    Science.gov (United States)

    Guo, Y C; Wang, H; Wu, H P; Zhang, M Q

    2015-12-21

    Aimed to address the defects of the large mean square error (MSE), and the slow convergence speed in equalizing the multi-modulus signals of the constant modulus algorithm (CMA), a multi-modulus algorithm (MMA) based on global artificial fish swarm (GAFS) intelligent optimization of DNA encoding sequences (GAFS-DNA-MMA) was proposed. To improve the convergence rate and reduce the MSE, this proposed algorithm adopted an encoding method based on DNA nucleotide chains to provide a possible solution to the problem. Furthermore, the GAFS algorithm, with its fast convergence and global search ability, was used to find the best sequence. The real and imaginary parts of the initial optimal weight vector of MMA were obtained through DNA coding of the best sequence. The simulation results show that the proposed algorithm has a faster convergence speed and smaller MSE in comparison with the CMA, the MMA, and the AFS-DNA-MMA.

  7. SPS slow extraction septa

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    SPS long straight section (LSS) with a series of 5 septum tanks for slow extraction (view in the direction of the proton beam). There are 2 of these: in LSS2, towards the N-Area; in LSS6 towards the W-Area. See also Annual Report 1975, p.175.

  8. The genome sequence of the protostome Daphnia pulex encodes respective orthologues of a neurotrophin, a Trk and a p75NTR: Evolution of neurotrophin signaling components and related proteins in the bilateria

    Directory of Open Access Journals (Sweden)

    Wilson Karen HS

    2009-10-01

    Full Text Available Abstract Background Neurotrophins and their Trk and p75NTR receptors play an important role in the nervous system. To date, neurotrophins, Trk and p75NTR have only been found concomitantly in deuterostomes. In protostomes, homologues to either neurotrophin, Trk or p75NTR are reported but their phylogenetic relationship to deuterostome neurotrophin signaling components is unclear. Drosophila has neurotrophin homologues called Spätzles (Spz, some of which were recently renamed neurotrophins, but direct proof that these are deuterostome neurotrophin orthologues is lacking. Trks belong to the receptor tyrosine kinase (RTK family and among RTKs, Trks and RORs are closest related. Flies lack Trks but have ROR and ROR-related proteins called NRKs playing a neurotrophic role. Mollusks have so far the most similar proteins to Trks (Lymnaea Trk and Aplysia Trkl but the exact phylogenetic relationship of mollusk Trks to each other and to vertebrate Trks is unknown. p75NTR belongs to the tumor necrosis factor receptor (TNFR superfamily. The divergence of the TNFR families in vertebrates has been suggested to parallel the emergence of the adaptive immune system. Only one TNFR representative, the Drosophila Wengen, has been found in protostomes. To clarify the evolution of neurotrophin signaling components in bilateria, this work analyzes the genome of the crustacean Daphnia pulex as well as new genetic data from protostomes. Results The Daphnia genome encodes a neurotrophin, p75NTR and Trk orthologue together with Trkl, ROR, and NRK-RTKs. Drosophila Spz1, 2, 3, 5, 6 orthologues as well as two new groups of Spz proteins (Spz7 and 8 are also found in the Daphnia genome. Searching genbank and the genomes of Capitella, Helobdella and Lottia reveals neurotrophin signaling components in other protostomes. Conclusion It appears that a neurotrophin, Trk and p75NTR existed at the protostome/deuterostome split. In protostomes, a "neurotrophin superfamily" includes

  9. Encoder designed to work in harsh environments

    Energy Technology Data Exchange (ETDEWEB)

    Toop, L.

    2007-05-15

    Dynapar has developed the Acuro AX71 absolute encoder for use on offshore or land-based oil rig operations. It provides feedback on the operation of automated systems such as draw works, racking systems, rotary tables and top drives. By ensuring that automated systems function properly, this encoder responds to a need by the oil and gas industry to keep workers safe and improve efficiency, particularly for operations in rugged situations. The encoder provides feedback from motor systems to controllers, giving information about position and speed of downhole drill bits. This newly developed encoder is better than commonly used incremental encoders which are not precise in strong electrical noise environments. Rather, the absolute encoder uses a different method of reporting to the controller. A digital signal is transmitted constantly as the device operates. It is less susceptible to noise issues. It is highly accurate, tolerant of noise and is not affected by power outages. However, the absolute encoder is generally more delicate in drilling applications with high ambient temperatures and shock levels. Dynapar addressed this issue by developing compact stainless steel housing that is useful for corrosion resistance in marine applications. The AX71 absolute encoder can withstand up to 100 G of mechanical shock and ambient temperatures of up to 60 degrees C. The encoder is ATEX certified without barriers, and offers the high resolution feedback of 4,000 counts of multiturn rotation and 16,000 counts of position. 1 fig.

  10. Slow-transit Constipation.

    Science.gov (United States)

    Bharucha, Adil E.; Philips, Sidney F.

    2001-08-01

    Idiopathic slow-transit constipation is a clinical syndrome predominantly affecting women, characterized by intractable constipation and delayed colonic transit. This syndrome is attributed to disordered colonic motor function. The disorder spans a spectrum of variable severity, ranging from patients who have relatively mild delays in transit but are otherwise indistinguishable from irritable bowel syndrome to patients with colonic inertia or chronic megacolon. The diagnosis is made after excluding colonic obstruction, metabolic disorders (hypothyroidism, hypercalcemia), drug-induced constipation, and pelvic floor dysfunction (as discussed by Wald ). Most patients are treated with one or more pharmacologic agents, including dietary fiber supplementation, saline laxatives (milk of magnesia), osmotic agents (lactulose, sorbitol, and polyethylene glycol 3350), and stimulant laxatives (bisacodyl and glycerol). A subtotal colectomy is effective and occasionally is indicated for patients with medically refractory, severe slow-transit constipation, provided pelvic floor dysfunction has been excluded or treated.

  11. Slowing Military Change

    Science.gov (United States)

    2008-10-01

    subjective. More objective measurements, such as statistics on youth crime, teenage pregnancy , drug use, literacy, and educational achievement...SLOWING MILITARY CHANGE Zhivan J. Alach October 2008 This publication is a work of the U.S. Government as defined in Title 17, United States Code...those of the author and do not necessarily reflect the official policy or position of the New Zealand Defence Force, the New Zealand Government , the

  12. Connexin 39.9 Protein Is Necessary for Coordinated Activation of Slow-twitch Muscle and Normal Behavior in Zebrafish*

    Science.gov (United States)

    Hirata, Hiromi; Wen, Hua; Kawakami, Yu; Naganawa, Yuriko; Ogino, Kazutoyo; Yamada, Kenta; Saint-Amant, Louis; Low, Sean E.; Cui, Wilson W.; Zhou, Weibin; Sprague, Shawn M.; Asakawa, Kazuhide; Muto, Akira; Kawakami, Koichi; Kuwada, John Y.

    2012-01-01

    In many tissues and organs, connexin proteins assemble between neighboring cells to form gap junctions. These gap junctions facilitate direct intercellular communication between adjoining cells, allowing for the transmission of both chemical and electrical signals. In rodents, gap junctions are found in differentiating myoblasts and are important for myogenesis. Although gap junctions were once believed to be absent from differentiated skeletal muscle in mammals, recent studies in teleosts revealed that differentiated muscle does express connexins and is electrically coupled, at least at the larval stage. These findings raised questions regarding the functional significance of gap junctions in differentiated muscle. Our analysis of gap junctions in muscle began with the isolation of a zebrafish motor mutant that displayed weak coiling at day 1 of development, a behavior known to be driven by slow-twitch muscle (slow muscle). We identified a missense mutation in the gene encoding Connexin 39.9. In situ hybridization found connexin 39.9 to be expressed by slow muscle. Paired muscle recordings uncovered that wild-type slow muscles are electrically coupled, whereas mutant slow muscles are not. The further examination of cellular activity revealed aberrant, arrhythmic touch-evoked Ca2+ transients in mutant slow muscle and a reduction in the number of muscle fibers contracting in response to touch in mutants. These results indicate that Connexin 39.9 facilitates the spreading of neuronal inputs, which is irregular during motor development, beyond the muscle cells and that gap junctions play an essential role in the efficient recruitment of slow muscle fibers. PMID:22075003

  13. Slow Food arjessa : Case Slow Food ruokakurssi Kristiinankaupungin Kansalaisopistossa

    OpenAIRE

    Mäenpää, Minna-Maria

    2015-01-01

    Opinnäytetyössäni esittelen Slow Food -järjestön toimintaa kansainvälisesti ja Slow Food -henkistä toimintaa Kristiinankaupungissa. Yhdistin teoriaosuuteen yhdessä Kristiinankaupungin kansalaisopiston ja Perunaelinkeinoalan kehittämishankkeen kanssa Kristiinankaupungissa järjestämäni Slow Food arjessa -kurssin. Tutkimuksen ongelmana oli luoda kurssikonsepti, jossa Slow Food -henkinen tiedottaminen esimerkiksi alueemme ruoantuottajista yhdistettiin varsinaiseen ruoan valmistamiseen. Keräsin tä...

  14. Go, Slow, and Whoa Foods

    Science.gov (United States)

    ... tips for seasonal health, safety and fun Go, Slow, and Whoa Foods Past Issues / Summer 2007 Table of Contents For ... Inc. 2002 Food Group GO Almost anytime foods SLOW Sometimes foods WHOA Once in a while foods Vegetables Almost ...

  15. Coaxial slow source

    International Nuclear Information System (INIS)

    Brooks, R.D.; Jarboe, T.R.

    1990-01-01

    Field reversed configurations (FRCs) are a class of compact toroid with not toroidal field. The field reversed theta pinch technique has been successfully used for formation of FRCs since their inception in 1958. In this method an initial bias field is produced. After ionization of the fill gas, the current in the coil is rapidly reversed producing the radial implosion of a current sheath. At the ends of the coil the reversed field lines rapidly tear and reconnect with the bias field lines until no more bias flux remains. At this point, vacuum reversed field accumulates around the configuration which contracts axially until an equilibrium is reached. When extrapolating the use of such a technique to reactor size plasmas two main shortcomings are found. First, the initial bias field, and hence flux in a given device, which can be reconnected to form the configuration is limited from above by destructive axial dynamics. Second, the voltages required to produce rapid current reversal in the coil are very large. Clearly, a low voltage formation technique without limitations on flux addition is desirable. The Coaxial Slow Source (CSS) device was designed to meet this need. It has two coaxial theta pinch coils. Coaxial coil geometry allows for the addition of as much magnetic flux to the annular plasma between them as can be generated inside the inner coil. Furthermore the device can be operated at charging voltages less than 10 kV and on resistive diffusion, rather than implosive time scales. The inner coil is a novel, concentric, helical design so as to allow it to be cantilevered on one end to permit translation of the plasma. Following translation off the inner coil the Annular Field Reversed Configuration would be re-formed as a true FRC. In this paper we investigate the formation process in the new parallel configuration., CSSP, in which the inner and outer coils are connected in parallel to the main capacitor bank

  16. Development of a reflective optical encoder with submicron accuracy

    Science.gov (United States)

    Ye, Guoyong; Liu, Hongzhong; Ban, Yaowen; Shi, Yongsheng; Yin, Lei; Lu, Bingheng

    2018-03-01

    Signal distortion is a key issue that limits the measurement resolution and accuracy of optical encoders. In this paper, an optical encoder based on generalized grating imaging using a two-dimensional index grating is presented. The general expression of intensity distribution for generalized grating imaging including the relative displacement between the scale grating and the reading head is derived, and the formation of the signal distortion of the optical encoder is analyzed. Then, a two-dimensional index grating, which consists of multiple grating tracks with defined offsets, is proposed to suppress the dominant third and fifth order harmonic signals. The operating principle of the two-dimensional index grating is explained in detail and a reflective optical encoder is developed. In the experiment, approximately ideal Lissajous figure of the encoder signals is obtained. Fourier analysis of the encoder signals shows that both the third and fifth order harmonic distortions are below 0.6%. Experimental results show that the interpolation error of the optical encoder is within ± 0 . 18 μm, and the accuracy is better than ± 0 . 3 μm over 255 mm travel range with a maximum variation of 0.136 μm.

  17. Time-Encoded Imagers.

    Energy Technology Data Exchange (ETDEWEB)

    Marleau, Peter; Brubaker, Erik

    2014-11-01

    This report provides a short overview of the DNN R&D funded project, Time-Encoded Imagers. The project began in FY11 and concluded in FY14. The Project Description below provides the overall motivation and objectives for the project as well as a summary of programmatic direction. It is followed by a short description of each task and the resulting deliverables.

  18. Encoders and Fault Detection

    NARCIS (Netherlands)

    Persis, Claudio De

    2003-01-01

    Monitoring large-scale systems is of fundamental importance in modern infrastructures. Many of these large-scale systems are complex interconnections of sub-components which interact by means of communication channels with limited bandwidth. Therefore the information must be encoded in order to be

  19. Neural Semantic Encoders.

    Science.gov (United States)

    Munkhdalai, Tsendsuren; Yu, Hong

    2017-04-01

    We present a memory augmented neural network for natural language understanding: Neural Semantic Encoders. NSE is equipped with a novel memory update rule and has a variable sized encoding memory that evolves over time and maintains the understanding of input sequences through read , compose and write operations. NSE can also access multiple and shared memories. In this paper, we demonstrated the effectiveness and the flexibility of NSE on five different natural language tasks: natural language inference, question answering, sentence classification, document sentiment analysis and machine translation where NSE achieved state-of-the-art performance when evaluated on publically available benchmarks. For example, our shared-memory model showed an encouraging result on neural machine translation, improving an attention-based baseline by approximately 1.0 BLEU.

  20. Study and realisation of a double integration charge encoder at VXI standard; Etude et realisation d`un codeur de charge double integration au standard VXI

    Energy Technology Data Exchange (ETDEWEB)

    Leconte, A.

    1994-07-01

    The 16 channels charge encoder herein described equips the Phoswich scintillators which, associated with photomultiplier tubes, constitutes the first ring of the INDRA Multidetector. This 4 {pi} Multidetector, located at GANIL at Caen, is first presented. In this encoder, two integrations are made, offering a distinction between the fast component of the signal from the detector and the slow one (decreasing times: 2,4 ns and 320ns respectively). This measurement is performed by the integration of each component within an adjustable time-gate. Apart from the two integrations, the encoder realizes the detection of the impulsion with a constant fraction discriminator, the generation of the two gates and a test function. The use of surface mounted components together with the choice of the VXI interconnection standard, also presented in this report, allowed highly integrated electronics. The encoder uses the sliding scale principle. It also includes the electronics for some programmable adjustments, the remote visualisation of important signals and the logic for the conversion. (author). 22 refs.

  1. Birth control - slow release methods

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007555.htm Birth control - slow release methods To use the sharing features on this page, please enable JavaScript. Certain birth control methods contain man-made forms of hormones. ...

  2. Slow and fast light in semiconductors

    Science.gov (United States)

    Sedgwick, Forrest Grant

    Slow and fast light are the propagation of optical signals at group velocities below and above the speed of light in a given medium. There has been great interest in the use of nonlinear optics to engineer slow and fast light dispersion for applications in optical communications and radio-frequency or microwave photonics. Early results in this field were primarily confined to dilute atomic systems. While these results were impressive, they had two major barriers to practical application. First, the wavelengths were not compatible with fiber optic telecommunications. More importantly, the bandwidth obtainable in these experiments was inherently low; 100 kHz or less. Within the last five years slow and fast light effects have been observed and engineered in a much wider variety of systems. In this work, we detail our efforts to realize slow and fast light in semiconductor systems. There are three primary advantages of semiconductor systems: fiber-compatible wavelengths, larger bandwidth, and simplification of integration with other optical components. In this work we will explore three different types of physical mechanisms for implementing slow and fast light. The first is electromagnetically induced transparency (EIT). In transporting this process to semiconductors, we initially turn our attention to quantum dots or "artificial atoms". We present simulations of a quantum dot EIT-based device within the context of an optical communications link and we derive results which are generally applicable to a broad class of slow light devices. We then present experimental results realizing EIT in quantum wells by using long-lived electron spin coherence. The second mechanism we will explore is coherent population oscillations (CPO), also known as carrier density pulsations (CDP). We examine for the first time how both slow and fast light may be achieved in a quantum well semiconductor optical amplifier (SOA) while operating in the gain regime. Again, we simulate the device

  3. Disorders of phonological encoding.

    Science.gov (United States)

    Butterworth, B

    1992-03-01

    Studies of phonological disturbances in aphasic speech are reviewed. It is argued that failure to test for error consistency in individual patients makes it generally improper to draw inferences about specific disorders of phonological encoding. A minimalist interpretation of available data on phonological errors is therefore proposed that involves variable loss of information in transmission between processing subsystems. Proposals for systematic loss or corruption of phonological information in lexical representations or in translation subsystems is shown to be inadequately grounded. The review concludes with some simple methodological prescriptions for future research.

  4. The Potential of/for 'Slow': Slow Tourists and Slow Destinations

    Directory of Open Access Journals (Sweden)

    J. Guiver

    2016-05-01

    Full Text Available Slow tourism practices are nothing new; in fact, they were once the norm and still are for millions of people whose annual holiday is spent camping, staying in caravans, rented accommodation, with friends and relations or perhaps in a second home, who immerse themselves in their holiday environment, eat local food, drink local wine and walk or cycle around the area. So why a special edition about slow tourism? Like many aspects of life once considered normal (such as organic farming or free-range eggs, the emergence of new practices has highlighted differences and prompted a re-evaluation of once accepted practices and values. In this way, the concept of ‘slow tourism’ has recently appeared as a type of tourism that contrasts with many contemporary mainstream tourism practices. It has also been associated with similar trends already ‘branded’ slow: slow food and cittaslow (slow towns and concepts such as mindfulness, savouring and well-being.

  5. Slow rupture of frictional interfaces

    Science.gov (United States)

    Bar Sinai, Yohai; Brener, Efim A.; Bouchbinder, Eran

    2012-02-01

    The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not completely understood. We show that slow rupture is an intrinsic and robust property of simple non-monotonic rate-and-state friction laws. It is associated with a new velocity scale cmin, determined by the friction law, below which steady state rupture cannot propagate. We further show that rupture can occur in a continuum of states, spanning a wide range of velocities from cmin to elastic wave-speeds, and predict different properties for slow rupture and ordinary fast rupture. Our results are qualitatively consistent with recent high-resolution laboratory experiments and may provide a theoretical framework for understanding slow rupture phenomena along frictional interfaces.

  6. Single echo acquisition MRI using RF encoding.

    Science.gov (United States)

    Wright, Steven M; McDougall, Mary Preston

    2009-11-01

    Encoding of spatial information in magnetic resonance imaging is conventionally accomplished by using magnetic field gradients. During gradient encoding, the position in k-space is determined by a time-integral of the gradient field, resulting in a limitation in imaging speed due to either gradient power or secondary effects such as peripheral nerve stimulation. Partial encoding of spatial information through the sensitivity patterns of an array of coils, known as parallel imaging, is widely used to accelerate the imaging, and is complementary to gradient encoding. This paper describes the one-dimensional limit of parallel imaging in which all spatial localization in one dimension is performed through encoding by the radiofrequency (RF) coil. Using a one-dimensional array of long and narrow parallel elements to localize the image information in one direction, an entire image is obtained from a single line of k-space, avoiding rapid or repeated manipulation of gradients. The technique, called single echo acquisition (SEA) imaging, is described, along with the need for a phase compensation gradient pulse to counteract the phase variation contained in the RF coil pattern which would otherwise cause signal cancellation in each imaging voxel. Image reconstruction and resolution enhancement methods compatible with the speed of the technique are discussed. MR movies at frame rates of 125 frames per second are demonstrated, illustrating the ability to monitor the evolution of transverse magnetization to steady state during an MR experiment as well as demonstrating the ability to image rapid motion. Because this technique, like all RF encoding approaches, relies on the inherent spatially varying pattern of the coil and is not a time-integral, it should enable new applications for MRI that were previously inaccessible due to speed constraints, and should be of interest as an approach to extending the limits of detection in MR imaging.

  7. Pulsar slow-down epochs

    International Nuclear Information System (INIS)

    Heintzmann, H.; Novello, M.

    1981-01-01

    The relative importance of magnetospheric currents and low frequency waves for pulsar braking is assessed and a model is developed which tries to account for the available pulsar timing data under the unifying aspect that all pulsars have equal masses and magnetic moments and are born as rapid rotators. Four epochs of slow-down are distinguished which are dominated by different braking mechanisms. According to the model no direct relationship exists between 'slow-down age' and true age of a pulsar and leads to a pulsar birth-rate of one event per hundred years. (Author) [pt

  8. Time encoded radiation imaging

    Science.gov (United States)

    Marleau, Peter; Brubaker, Erik; Kiff, Scott

    2014-10-21

    The various technologies presented herein relate to detecting nuclear material at a large stand-off distance. An imaging system is presented which can detect nuclear material by utilizing time encoded imaging relating to maximum and minimum radiation particle counts rates. The imaging system is integrated with a data acquisition system that can utilize variations in photon pulse shape to discriminate between neutron and gamma-ray interactions. Modulation in the detected neutron count rates as a function of the angular orientation of the detector due to attenuation of neighboring detectors is utilized to reconstruct the neutron source distribution over 360 degrees around the imaging system. Neutrons (e.g., fast neutrons) and/or gamma-rays are incident upon scintillation material in the imager, the photons generated by the scintillation material are converted to electrical energy from which the respective neutrons/gamma rays can be determined and, accordingly, a direction to, and the location of, a radiation source identified.

  9. Encoding the Factorisation Calculus

    Directory of Open Access Journals (Sweden)

    Reuben N. S. Rowe

    2015-08-01

    Full Text Available Jay and Given-Wilson have recently introduced the Factorisation (or SF- calculus as a minimal fundamental model of intensional computation. It is a combinatory calculus containing a special combinator, F, which is able to examine the internal structure of its first argument. The calculus is significant in that as well as being combinatorially complete it also exhibits the property of structural completeness, i.e. it is able to represent any function on terms definable using pattern matching on arbitrary normal forms. In particular, it admits a term that can decide the structural equality of any two arbitrary normal forms. Since SF-calculus is combinatorially complete, it is clearly at least as powerful as the more familiar and paradigmatic Turing-powerful computational models of Lambda Calculus and Combinatory Logic. Its relationship to these models in the converse direction is less obvious, however. Jay and Given-Wilson have suggested that SF-calculus is strictly more powerful than the aforementioned models, but a detailed study of the connections between these models is yet to be undertaken. This paper begins to bridge that gap by presenting a faithful encoding of the Factorisation Calculus into the Lambda Calculus preserving both reduction and strong normalisation. The existence of such an encoding is a new result. It also suggests that there is, in some sense, an equivalence between the former model and the latter. We discuss to what extent our result constitutes an equivalence by considering it in the context of some previously defined frameworks for comparing computational power and expressiveness.

  10. The dynamics of slow manifolds

    NARCIS (Netherlands)

    Verhulst, F.; Bakri, T.

    2006-01-01

    Invited lecture at Konferensi Nasional Matematika XIII, Semarang, 24-27 juli, 2006; to be publ. in J. Indones. Math. Soc. (2007) After reviewing a number of results from geometric singular perturbation theory, we discuss several approaches to obtain periodic solutions in a slow manifold.

  11. Noise and neuronal populations conspire to encode simple waveforms reliably

    Science.gov (United States)

    Parnas, B. R.

    1996-01-01

    Sensory systems rely on populations of neurons to encode information transduced at the periphery into meaningful patterns of neuronal population activity. This transduction occurs in the presence of intrinsic neuronal noise. This is fortunate. The presence of noise allows more reliable encoding of the temporal structure present in the stimulus than would be possible in a noise-free environment. Simulations with a parallel model of signal processing at the auditory periphery have been used to explore the effects of noise and a neuronal population on the encoding of signal information. The results show that, for a given set of neuronal modeling parameters and stimulus amplitude, there is an optimal amount of noise for stimulus encoding with maximum fidelity.

  12. Permutations as a means to encode order in word space

    OpenAIRE

    Sahlgren, Magnus; Holst, Anders; Kanerva, Pentti

    2008-01-01

    We show that sequence information can be encoded into high-dimensional fixed-width vectors using permutations of coordinates. Computational models of language often represent words with high-dimensional semantic vectors compiled from word-use statistics. A word's semantic vector usually encodes the contexts in which the word appears in a large body of text but ignores word order. However, word order often signals a word's grammatical role in a sentence and thus tells of the word's meaning. Jo...

  13. The unappreciated slowness of conventional tourism

    Directory of Open Access Journals (Sweden)

    G.R. Larsen

    2016-05-01

    Full Text Available Most tourists are not consciously engaging in ‘slow travel’, but a number of travel behaviours displayed by conventional tourists can be interpreted as slow travel behaviour. Based on Danish tourists’ engagement with the distances they travel across to reach their holiday destination, this paper explores unintended slow travel behaviours displayed by these tourists. None of the tourists participating in this research were consciously doing ‘slow travel’, and yet some of their most valued holiday memories are linked to slow travel behaviours. Based on the analysis of these unintended slow travel behaviours, this paper will discuss the potential this insight might hold for promotion of slow travel. If unappreciated and unintentional slow travel behaviours could be utilised in the deliberate effort of encouraging more people to travel slow, ‘slow travel’ will be in a better position to become integrated into conventional travel behaviour.

  14. Selecting Operations for Assembler Encoding

    Directory of Open Access Journals (Sweden)

    Tomasz Praczyk

    2010-04-01

    Full Text Available Assembler Encoding is a neuro-evolutionary method in which a neural network is represented in the form of a simple program called Assembler Encoding Program. The task of the program is to create the so-called Network Definition Matrix which maintains all the information necessary to construct the network. To generate Assembler Encoding Programs and the subsequent neural networks evolutionary techniques are used.
    The performance of Assembler Encoding strongly depends on operations used in Assembler Encoding Programs. To select the most effective operations, experiments in the optimization and the predator-prey problem were carried out. In the experiments, Assembler Encoding Programs equipped with different types of operations were tested. The results of the tests are presented at the end of the paper.

  15. The herpes simplex virus 1-encoded envelope glycoprotein B activates NF-κB through the Toll-like receptor 2 and MyD88/TRAF6-dependent signaling pathway.

    Directory of Open Access Journals (Sweden)

    Mingsheng Cai

    Full Text Available The innate immune response plays a critical role in the host defense against invading pathogens, and TLR2, a member of the Toll-like receptor (TLR family, has been implicated in the immune response and initiation of inflammatory cytokine secretion against several human viruses. Previous studies have demonstrated that infectious and ultraviolet-inactivated herpes simplex virus 1 (HSV-1 virions lead to the activation of nuclear factor kappa B (NF-κB and secretion of proinflammatory cytokines via TLR2. However, except for the envelope glycoprotein gH and gL, whether there are other determinants of HSV-1 responsible for TLR2 mediated biological effects is not known yet. Here, we demonstrated that the HSV-1-encoded envelope glycoprotein gB displays as molecular target recognized by TLR2. gB coimmunoprecipitated with TLR2, TLR1 and TLR6 in transfected and infected human embryonic kidney (HEK 293T cells. Treatment of TLR2-transfected HEK293T (HEK293T-TLR2 cells with purified gB results in the activation of NF-κB reporter, and this activation requires the recruitment of the adaptor molecules myeloid differentiation primary-response protein 88 (MyD88 and tumor necrosis factor receptor-associated factor 6 (TRAF6 but not CD14. Furthermore, activation of NF-κB was abrogated by anti-gB and anti-TLR2 blocking antibodies. In addition, the expression of interleukin-8 induced by gB was abrogated by the treatment of the human monocytic cell line THP-1 with anti-TLR2 blocking antibody or by the incubation of gB with anti-gB antibody. Taken together, these results indicate the importance and potency of HSV-1 gB as one of pathogen-associated molecular patterns (PAMPs molecule recognized by TLR2 with immediate kinetics.

  16. Deep Marginalized Sparse Denoising Auto-Encoder for Image Denoising

    Science.gov (United States)

    Ma, Hongqiang; Ma, Shiping; Xu, Yuelei; Zhu, Mingming

    2018-01-01

    Stacked Sparse Denoising Auto-Encoder (SSDA) has been successfully applied to image denoising. As a deep network, the SSDA network with powerful data feature learning ability is superior to the traditional image denoising algorithms. However, the algorithm has high computational complexity and slow convergence rate in the training. To address this limitation, we present a method of image denoising based on Deep Marginalized Sparse Denoising Auto-Encoder (DMSDA). The loss function of Sparse Denoising Auto-Encoder is marginalized so that it satisfies both sparseness and marginality. The experimental results show that the proposed algorithm can not only outperform SSDA in the convergence speed and training time, but also has better denoising performance than the current excellent denoising algorithms, including both the subjective and objective evaluation of image denoising.

  17. Whisker encoding of mechanical events during active tactile exploration

    Directory of Open Access Journals (Sweden)

    Yves eBoubenec

    2012-11-01

    Full Text Available Rats use their whiskers to extract a wealth of information about their immediate environment, such as the shape, position or texture of an object. The information is conveyed to mechanoreceptors located within the whisker follicle in the form of a sequence of whisker deflections induced by the whisker/object contact interaction. How the whiskers filter and shape the mechanical information and effectively participate in the coding of tactile features remains an open question to date. In the present article, a biomechanical model was developed that provides predictions of the whisker dynamics during active tactile exploration, amenable to quantitative experimental comparison. This model is based on a decomposition of the whisker profile into a slow, quasi-static sequence and rapid resonant small-scale vibrations. It was applied to the typical situation of a rat whisking across an object. Having derived the quasi-static sequence of whisker deformation, the resonant properties of the whisker were analyzed, taking into account the boundary conditions imposed by the whisker/surface contact. We then focused on two elementary mechanical events that are expected to trigger neural responses, namely (i the whisker/object first contact and (ii the whisker detachment from the object. Both events were found to trigger a deflection wave propagating upward to the mystacial pad at constant velocity of 3-5m/s. This yielded a characteristic mechanical signature at the whisker base, in the form of a large peak of negative curvature occurring 4ms after the event was triggered. The dependence in amplitude and lag of this mechanical signal with the main contextual parameters (such as radial or angular distance was investigated. The model was validated experimentally by comparing its predictions to high-speed video recordings of shock-induced whisker deflections performed on anesthetized rats. The consequences of these results on possible tactile encoding schemes are

  18. Mandarin speech-in-noise and tone recognition using vocoder simulations of the temporal limits encoder for cochlear implants.

    Science.gov (United States)

    Meng, Qinglin; Zheng, Nengheng; Li, Xia

    2016-01-01

    Temporal envelope-based signal processing strategies are widely used in cochlear-implant (CI) systems. It is well recognized that the inability to convey temporal fine structure (TFS) in the stimuli limits CI users' performance, but it is still unclear how to effectively deliver the TFS. A strategy known as the temporal limits encoder (TLE), which employs an approach to derive the amplitude modulator to generate the stimuli coded in an interleaved-sampling strategy, has recently been proposed. The TLE modulator contains information related to the original temporal envelope and a slow-varying TFS from the band signal. In this paper, theoretical analyses are presented to demonstrate the superiority of TLE compared with two existing strategies, the clinically available continuous-interleaved-sampling (CIS) strategy and the experimental harmonic-single-sideband-encoder strategy. Perceptual experiments with vocoder simulations in normal-hearing listeners are conducted to compare the performance of TLE and CIS on two tasks (i.e., Mandarin speech reception in babble noise and tone recognition in quiet). The performance of the TLE modulator is mostly better than (for most tone-band vocoders) or comparable to (for noise-band vocoders) the CIS modulator on both tasks. This work implies that there is some potential for improving the representation of TFS with CIs by using a TLE strategy.

  19. Logarithmically slow onset of synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Benkoe, Gil; Jensen, Henrik Jeldtoft [Institute for Mathematical Sciences, Imperial College London, 53 Prince' s Gate, South Kensington Campus, SW7 2PG, London (United Kingdom)], E-mail: g.benkoe@imperial.ac.uk, E-mail: h.jensen@imperial.ac.uk

    2010-04-23

    The transient of a synchronizing system is investigated, considering synchronization as a relaxation phenomenon. The stepwise establishment of synchronization is studied in the system of dynamically coupled maps introduced by Ito and Kaneko (2001 Phys. Rev. Lett. 88 028701, 2003 Phys. Rev. E 67 046226), where the plasticity of dynamical couplings might be relevant in the context of neuroscience. Logarithmically slow dynamics in the transient of a fully deterministic dynamical system are shown to occur.

  20. Slow extraction at the SSC

    International Nuclear Information System (INIS)

    Colton, E.P.

    1985-01-01

    Resonant slow extraction at the SSC will permit fixed-target operation. Stochastic extraction appears to be a promising technique for achieving spill times of the order of 1000 s. However, systematic sextupole error fields in the SSC dipoles must be reduced a factor of twenty from the design values; otherwise the extraction process will be perturbed or suppressed. In addition, good regulation of the SSC power supplies is essential for smooth extraction over the spill period. 10 refs., 1 fig

  1. Rapidly-Indexing Incremental-Angle Encoder

    Science.gov (United States)

    Christon, Philip R.; Meyer, Wallace W.

    1989-01-01

    Optoelectronic system measures relative angular position of shaft or other device to be turned, also measures absolute angular position after device turned through small angle. Relative angular position measured with fine resolution by optoelectronically counting finely- and uniformly-spaced light and dark areas on encoder disk as disk turns past position-sensing device. Also includes track containing coarsely- and nonuniformly-spaced light and dark areas, angular widths varying in proportion to absolute angular position. This second track provides gating and indexing signal.

  2. Peri-encoding predictors of memory encoding and consolidation.

    Science.gov (United States)

    Cohen, Noga; Pell, Liat; Edelson, Micah G; Ben-Yakov, Aya; Pine, Alex; Dudai, Yadin

    2015-03-01

    We review reports of brain activations that occur immediately prior to the onset or following the offset of to-be-remembered information and can predict subsequent mnemonic success. Memory-predictive pre-encoding processes, occurring from fractions of a second to minutes prior to event onset, are mainly associated with activations in the medial temporal lobe (MTL), amygdala and midbrain, and with enhanced theta oscillations. These activations may be considered as the neural correlates of one or more cognitive operations, including contextual processing, attention, and the engagement of distinct computational modes associated with prior encoding or retrieval. Post-encoding activations that correlate with subsequent memory performance are mainly observed in the MTL, sensory cortices and frontal regions. These activations may reflect binding of elements of the encoded information and initiation of memory consolidation. In all, the findings reviewed here illustrate the importance of brain states in the immediate peri-encoding time windows in determining encoding success. Understanding these brain states and their specific effects on memory may lead to optimization of the encoding of desired memories and mitigation of undesired ones. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. A 10 Gbit/s OCDMA system based on electric encoding and optical transmission

    Science.gov (United States)

    Li, Chuan-qi; Hu, Jin-lin; He, Dong-dong; Chen, Mei-juan; Wang, Da-chi; Chen, Yan

    2013-11-01

    An electric encoded/optical transmission system of code division multiple access (CDMA) is proposed. It encodes the user signal in electric domain, and transfers the different code slice signals via the different wavelengths of light. This electric domain encoder/decoder is compared with current traditional encoder/decoder. Four-user modulation/demodulation optical CDMA (OCDMA) system with rate of 2.5 Gbit/s is simulated, which is based on the optical orthogonal code (OCC) designed in our laboratory. The results show that the structure of electric encoding/optical transmission can encode/decode signal correctly, and can achieve the chip rate equal to the user data rate. It can overcome the rate limitation of electronic bottleneck, and bring some potential applications in the electro-optical OCDMA system.

  4. A SSVEP Stimuli Encoding Method Using Trinary Frequency-Shift Keying Encoded SSVEP (TFSK-SSVEP

    Directory of Open Access Journals (Sweden)

    Xing Zhao

    2017-06-01

    Full Text Available SSVEP is a kind of BCI technology with advantage of high information transfer rate. However, due to its nature, frequencies could be used as stimuli are scarce. To solve such problem, a stimuli encoding method which encodes SSVEP signal using Frequency Shift–Keying (FSK method is developed. In this method, each stimulus is controlled by a FSK signal which contains three different frequencies that represent “Bit 0,” “Bit 1” and “Bit 2” respectively. Different to common BFSK in digital communication, “Bit 0” and “Bit 1” composited the unique identifier of stimuli in binary bit stream form, while “Bit 2” indicates the ending of a stimuli encoding. EEG signal is acquired on channel Oz, O1, O2, Pz, P3, and P4, using ADS1299 at the sample rate of 250 SPS. Before original EEG signal is quadrature demodulated, it is detrended and then band-pass filtered using FFT-based FIR filtering to remove interference. Valid peak of the processed signal is acquired by calculating its derivative and converted into bit stream using window method. Theoretically, this coding method could implement at least 2n−1 (n is the length of bit command stimulus while keeping the ITR the same. This method is suitable to implement stimuli on a monitor and where the frequency and phase could be used to code stimuli is limited as well as implementing portable BCI devices which is not capable of performing complex calculations.

  5. Amygdala Contributions to Stimulus-Reward Encoding in the Macaque Medial and Orbital Frontal Cortex during Learning.

    Science.gov (United States)

    Rudebeck, Peter H; Ripple, Joshua A; Mitz, Andrew R; Averbeck, Bruno B; Murray, Elisabeth A

    2017-02-22

    Orbitofrontal cortex (OFC), medial frontal cortex (MFC), and amygdala mediate stimulus-reward learning, but the mechanisms through which they interact are unclear. Here, we investigated how neurons in macaque OFC and MFC signaled rewards and the stimuli that predicted them during learning with and without amygdala input. Macaques performed a task that required them to evaluate two stimuli and then choose one to receive the reward associated with that option. Four main findings emerged. First, amygdala lesions slowed the acquisition and use of stimulus-reward associations. Further analyses indicated that this impairment was due, at least in part, to ineffective use of negative feedback to guide subsequent decisions. Second, the activity of neurons in OFC and MFC rapidly evolved to encode the amount of reward associated with each stimulus. Third, amygdalectomy reduced encoding of stimulus-reward associations during the evaluation of different stimuli. Reward encoding of anticipated and received reward after choices were made was not altered. Fourth, amygdala lesions led to an increase in the proportion of neurons in MFC, but not OFC, that encoded the instrumental response that monkeys made on each trial. These correlated changes in behavior and neural activity after amygdala lesions strongly suggest that the amygdala contributes to the ability to learn stimulus-reward associations rapidly by shaping encoding within OFC and MFC. SIGNIFICANCE STATEMENT Altered functional interactions among orbital frontal cortex (OFC), medial frontal cortex (MFC), and amygdala are thought to underlie several psychiatric conditions, many related to reward learning. Here, we investigated the causal contribution of the amygdala to the development of neuronal activity in macaque OFC and MFC related to rewards and the stimuli that predict them during learning. Without amygdala inputs, neurons in both OFC and MFC showed decreased encoding of stimulus-reward associations. MFC also showed

  6. Amygdala Contributions to Stimulus–Reward Encoding in the Macaque Medial and Orbital Frontal Cortex during Learning

    Science.gov (United States)

    Averbeck, Bruno B.

    2017-01-01

    Orbitofrontal cortex (OFC), medial frontal cortex (MFC), and amygdala mediate stimulus–reward learning, but the mechanisms through which they interact are unclear. Here, we investigated how neurons in macaque OFC and MFC signaled rewards and the stimuli that predicted them during learning with and without amygdala input. Macaques performed a task that required them to evaluate two stimuli and then choose one to receive the reward associated with that option. Four main findings emerged. First, amygdala lesions slowed the acquisition and use of stimulus–reward associations. Further analyses indicated that this impairment was due, at least in part, to ineffective use of negative feedback to guide subsequent decisions. Second, the activity of neurons in OFC and MFC rapidly evolved to encode the amount of reward associated with each stimulus. Third, amygdalectomy reduced encoding of stimulus–reward associations during the evaluation of different stimuli. Reward encoding of anticipated and received reward after choices were made was not altered. Fourth, amygdala lesions led to an increase in the proportion of neurons in MFC, but not OFC, that encoded the instrumental response that monkeys made on each trial. These correlated changes in behavior and neural activity after amygdala lesions strongly suggest that the amygdala contributes to the ability to learn stimulus–reward associations rapidly by shaping encoding within OFC and MFC. SIGNIFICANCE STATEMENT Altered functional interactions among orbital frontal cortex (OFC), medial frontal cortex (MFC), and amygdala are thought to underlie several psychiatric conditions, many related to reward learning. Here, we investigated the causal contribution of the amygdala to the development of neuronal activity in macaque OFC and MFC related to rewards and the stimuli that predict them during learning. Without amygdala inputs, neurons in both OFC and MFC showed decreased encoding of stimulus–reward associations. MFC also

  7. Critical slowing down governs the transition to neuron spiking.

    Directory of Open Access Journals (Sweden)

    Christian Meisel

    2015-02-01

    Full Text Available Many complex systems have been found to exhibit critical transitions, or so-called tipping points, which are sudden changes to a qualitatively different system state. These changes can profoundly impact the functioning of a system ranging from controlled state switching to a catastrophic break-down; signals that predict critical transitions are therefore highly desirable. To this end, research efforts have focused on utilizing qualitative changes in markers related to a system's tendency to recover more slowly from a perturbation the closer it gets to the transition--a phenomenon called critical slowing down. The recently studied scaling of critical slowing down offers a refined path to understand critical transitions: to identify the transition mechanism and improve transition prediction using scaling laws. Here, we outline and apply this strategy for the first time in a real-world system by studying the transition to spiking in neurons of the mammalian cortex. The dynamical system approach has identified two robust mechanisms for the transition from subthreshold activity to spiking, saddle-node and Hopf bifurcation. Although theory provides precise predictions on signatures of critical slowing down near the bifurcation to spiking, quantitative experimental evidence has been lacking. Using whole-cell patch-clamp recordings from pyramidal neurons and fast-spiking interneurons, we show that 1 the transition to spiking dynamically corresponds to a critical transition exhibiting slowing down, 2 the scaling laws suggest a saddle-node bifurcation governing slowing down, and 3 these precise scaling laws can be used to predict the bifurcation point from a limited window of observation. To our knowledge this is the first report of scaling laws of critical slowing down in an experiment. They present a missing link for a broad class of neuroscience modeling and suggest improved estimation of tipping points by incorporating scaling laws of critical slowing

  8. Slow extraction control system of HIRFL-CSR

    International Nuclear Information System (INIS)

    Liu Wufeng; Qiao Weimin; Yuan Youjin; Mao Ruishi; Zhao Tiecheng

    2013-01-01

    For heavy-ion radiotherapy, HIRFL-CSR (Heavy Ion Research Facility in Lanzhou-Cooler Storage Ring) needs a long term uniform ion beam extraction from HIRFL-CSR main ring to high energy beam transport line to meet the requirement of heavy-ion radiotherapy's ion beam. Slow extraction control system uses the synchronous signal of HIRFL-CSR control system's timing system to realize process control. When the synchronous event data of HIRFL-CSR control system's timing system trigger controlling and changing data (frequency value, tune value, voltage value), the waveform generator will generate waveform by frequency value, tune value and voltage value, and will amplify the generated waveform by power amplifier to electrostatic deflector to achieve RF-KO slow extraction. The synchronous event receiver of slow extraction system is designed by using FPGA and optical fiber interface to keep high transmission speed and anti-jamming. HIRFL-CSR's running for heavy-ion radiotherapy and ten thousand seconds long period slow extraction experiments show that slow extraction control system is workable and can meet the requirement of heavy-ion radiotherapy's ion beam. (authors)

  9. The CUORE slow monitoring systems

    Science.gov (United States)

    Gladstone, L.; Biare, D.; Cappelli, L.; Cushman, J. S.; Del Corso, F.; Fujikawa, B. K.; Hickerson, K. P.; Moggi, N.; Pagliarone, C. E.; Schmidt, B.; Wagaarachchi, S. L.; Welliver, B.; Winslow, L. A.

    2017-09-01

    CUORE is a cryogenic experiment searching primarily for neutrinoless double decay in 130Te. It will begin data-taking operations in 2016. To monitor the cryostat and detector during commissioning and data taking, we have designed and developed Slow Monitoring systems. In addition to real-time systems using LabVIEW, we have an alarm, analysis, and archiving website that uses MongoDB, AngularJS, and Bootstrap software. These modern, state of the art software packages make the monitoring system transparent, easily maintainable, and accessible on many platforms including mobile devices.

  10. Corpuscular slow-roll inflation

    Science.gov (United States)

    Casadio, Roberto; Giugno, Andrea; Giusti, Andrea

    2018-01-01

    We show that a corpuscular description of gravity can lead to an inflationary scenario similar to Starobinsky's model without requiring the introduction of the inflaton field. All relevant properties are determined by the number of gravitons in the cosmological condensate or, equivalently, by their Compton length. In particular, the relation between the Hubble parameter H and its time derivative H ˙ required by cosmic microwave background observations at the end of inflation, as well as the (minimum) initial value of the slow-roll parameter, are naturally obtained from the Compton size of the condensate.

  11. Blowup for flat slow manifolds

    DEFF Research Database (Denmark)

    Kristiansen, Kristian Uldall

    2017-01-01

    In this paper, we present a way of extending the blowup method, in the formulation of Krupa and Szmolyan, to flat slow manifolds that lose hyperbolicity beyond any algebraic order. Although these manifolds have infinite co-dimensions, they do appear naturally in certain settings; for example, in (a......) the regularization of piecewise smooth systems by tanh, (b) a particular aircraft landing dynamics model, and finally (c) in a model of earthquake faulting. We demonstrate the approach using a simple model system and the examples (a) and (b)....

  12. Blowup for flat slow manifolds

    Science.gov (United States)

    Kristiansen, K. U.

    2017-05-01

    In this paper, we present a way of extending the blowup method, in the formulation of Krupa and Szmolyan, to flat slow manifolds that lose hyperbolicity beyond any algebraic order. Although these manifolds have infinite co-dimensions, they do appear naturally in certain settings; for example, in (a) the regularization of piecewise smooth systems by \\tanh , (b) a particular aircraft landing dynamics model, and finally (c) in a model of earthquake faulting. We demonstrate the approach using a simple model system and the examples (a) and (b).

  13. Slow electrons kill the ozone

    International Nuclear Information System (INIS)

    Maerk, T.

    2001-01-01

    A new method and apparatus (Trochoidal electron monochromator) to study the interactions of electrons with atoms, molecules and clusters was developed. Two applications are briefly reported: a) the ozone destruction in the atmosphere is caused by different reasons, a new mechanism is proposed, that slow thermal electrons are self added to the ozone molecule (O 3 ) with a high frequency, then O 3 is destroyed ( O 3 + e - → O - + O 2 ); b) another application is the study of the binding energy of the football molecule C60. (nevyjel)

  14. Premotor and Motor Cortices Encode Reward.

    Directory of Open Access Journals (Sweden)

    Pavan Ramkumar

    Full Text Available Rewards associated with actions are critical for motivation and learning about the consequences of one's actions on the world. The motor cortices are involved in planning and executing movements, but it is unclear whether they encode reward over and above limb kinematics and dynamics. Here, we report a categorical reward signal in dorsal premotor (PMd and primary motor (M1 neurons that corresponds to an increase in firing rates when a trial was not rewarded regardless of whether or not a reward was expected. We show that this signal is unrelated to error magnitude, reward prediction error, or other task confounds such as reward consumption, return reach plan, or kinematic differences across rewarded and unrewarded trials. The availability of reward information in motor cortex is crucial for theories of reward-based learning and motivational influences on actions.

  15. Epileptic interictal discharges are more frequent during NREM slow wave downstates.

    Science.gov (United States)

    Ujma, Péter Przemyslaw; Halász, Péter; Kelemen, Anna; Fabó, Dániel; Erőss, Loránd

    2017-09-29

    Epileptiform activity in various but not all epilepsy and recording types and cerebral areas is more frequent in NREM sleep, and especially during sleep periods with high-amplitude EEG slow waves. Slow waves synchronize high-frequency oscillations: physiological activity from the theta through the gamma band usually appears during scalp-positive upstates while epileptiform activity occurs at transitory phases and the scalp-negative downstate. It has been proposed that interictal discharges (IIDs) are facilitated by the high degree of neuronal firing synchrony during slow wave transitory and downstates. This would suggest that their occurrence increases as a function of slow wave synchronization, indicated by greater amplitude, steeper slopes and higher EEG signal synchronization. We investigated the occurrence of IIDs during NREM sleep slow waves in epileptic patients undergoing presurgical electrophysiological monitoring. Intracranially registered IIDs preferentially occurred during the scalp-negative downstates of frontal scalp slow waves in all subjects. IID occurrence was more frequent during larger slow waves in the pooled sample and a subset of subjects. However, slow wave slope steepness and EEG signal synchronization between two frontal scalp channels was not significantly associated with IID occurrence. Our results indicate that IIDs indeed do not occur at the same slow wave phase as physiological rhythms, but contrary to previous hypotheses their occurrence is not strongly affected by EEG synchronization. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Connecting slow earthquakes to huge earthquakes

    OpenAIRE

    Obara, Kazushige; Kato, Aitaro

    2016-01-01

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of th...

  17. Integrated Photonics Enabled by Slow Light

    DEFF Research Database (Denmark)

    Mørk, Jesper; Chen, Yuntian; Ek, Sara

    2012-01-01

    In this talk we will discuss the physics of slow light in semiconductor materials and in particular the possibilities offered for integrated photonics. This includes ultra-compact slow light enabled optical amplifiers, lasers and pulse sources.......In this talk we will discuss the physics of slow light in semiconductor materials and in particular the possibilities offered for integrated photonics. This includes ultra-compact slow light enabled optical amplifiers, lasers and pulse sources....

  18. Don't Forget the Slow Learner.

    Science.gov (United States)

    Watson, Daniel L.; Rangel, Lyle

    1989-01-01

    Advocates cooperative learning as an effective tool for reaching slow learners, by bridging the gaps between the learning styles of slow learners and the teaching requirements of the classroom, resulting in improved academic performance for both slow learners and high achievers. (SR)

  19. Deficiency of slow skeletal muscle troponin T causes atrophy of type I slow fibres and decreases tolerance to fatigue

    Science.gov (United States)

    Wei, Bin; Lu, Yingru; Jin, J-P

    2014-01-01

    The total loss of slow skeletal muscle troponin T (ssTnT encoded by TNNT1 gene) due to a nonsense mutation in codon Glu180 causes a lethal form of recessively inherited nemaline myopathy (Amish nemaline myopathy, ANM). To investigate the pathogenesis and muscle pathophysiology of ANM, we studied the phenotypes of partial and total loss of ssTnT in Tnnt1 gene targeted mice. An insertion of neomycin resistance cassette in intron 10 of Tnnt1 gene caused an approximately 60% decrease in ssTnT protein expression whereas cre-loxP-mediated deletion of exons 11–13 resulted in total loss of ssTnT, as seen in ANM muscles. In diaphragm and soleus muscles of the knockdown and knockout mouse models, we demonstrated that ssTnT deficiency resulted in significantly decreased levels of other slow fibre-specific myofilament proteins whereas fast fibre-specific myofilament proteins were increased correspondingly. Immunohistochemical studies revealed that ssTnT deficiency produced significantly smaller type I slow fibres and compensatory growth of type II fast fibres. Along with the slow fibre atrophy and the changes in myofilament protein isoform contents, ssTnT deficiency significantly reduced the tolerance to fatigue in soleus muscle. ssTnT-deficient soleus muscle also contains significant numbers of small-sized central nuclei type I fibres, indicating active regeneration. The data provide strong support for the essential role of ssTnT in skeletal muscle function and the causal effect of its loss in the pathology of ANM. This observation further supports the hypothesis that the function of slow fibres can be restored in ANM patients if a therapeutic supplement of ssTnT is achieved. PMID:24445317

  20. Analysing and Comparing Encodability Criteria

    Directory of Open Access Journals (Sweden)

    Kirstin Peters

    2015-08-01

    Full Text Available Encodings or the proof of their absence are the main way to compare process calculi. To analyse the quality of encodings and to rule out trivial or meaningless encodings, they are augmented with quality criteria. There exists a bunch of different criteria and different variants of criteria in order to reason in different settings. This leads to incomparable results. Moreover it is not always clear whether the criteria used to obtain a result in a particular setting do indeed fit to this setting. We show how to formally reason about and compare encodability criteria by mapping them on requirements on a relation between source and target terms that is induced by the encoding function. In particular we analyse the common criteria full abstraction, operational correspondence, divergence reflection, success sensitiveness, and respect of barbs; e.g. we analyse the exact nature of the simulation relation (coupled simulation versus bisimulation that is induced by different variants of operational correspondence. This way we reduce the problem of analysing or comparing encodability criteria to the better understood problem of comparing relations on processes.

  1. Does time really slow down during a frightening event?

    Directory of Open Access Journals (Sweden)

    Chess Stetson

    2007-12-01

    Full Text Available Observers commonly report that time seems to have moved in slow motion during a life-threatening event. It is unknown whether this is a function of increased time resolution during the event, or instead an illusion of remembering an emotionally salient event. Using a hand-held device to measure speed of visual perception, participants experienced free fall for 31 m before landing safely in a net. We found no evidence of increased temporal resolution, in apparent conflict with the fact that participants retrospectively estimated their own fall to last 36% longer than others' falls. The duration dilation during a frightening event, and the lack of concomitant increase in temporal resolution, indicate that subjective time is not a single entity that speeds or slows, but instead is composed of separable subcomponents. Our findings suggest that time-slowing is a function of recollection, not perception: a richer encoding of memory may cause a salient event to appear, retrospectively, as though it lasted longer.

  2. Does Time Really Slow Down during a Frightening Event?

    Science.gov (United States)

    Stetson, Chess; Fiesta, Matthew P.; Eagleman, David M.

    2007-01-01

    Observers commonly report that time seems to have moved in slow motion during a life-threatening event. It is unknown whether this is a function of increased time resolution during the event, or instead an illusion of remembering an emotionally salient event. Using a hand-held device to measure speed of visual perception, participants experienced free fall for 31 m before landing safely in a net. We found no evidence of increased temporal resolution, in apparent conflict with the fact that participants retrospectively estimated their own fall to last 36% longer than others' falls. The duration dilation during a frightening event, and the lack of concomitant increase in temporal resolution, indicate that subjective time is not a single entity that speeds or slows, but instead is composed of separable subcomponents. Our findings suggest that time-slowing is a function of recollection, not perception: a richer encoding of memory may cause a salient event to appear, retrospectively, as though it lasted longer. PMID:18074019

  3. The plant vacuole: emitter and receiver of calcium signals.

    Science.gov (United States)

    Peiter, Edgar

    2011-08-01

    This review portrays the plant vacuole as both a source and a target of Ca(2+) signals. In plants, the vacuole represents a Ca(2+) store of enormous size and capacity. Total and free Ca(2+) concentrations in the vacuole vary with plant species, cell type, and environment, which is likely to have an impact on vacuolar function and the release of vacuolar Ca(2+). It is known that cytosolic Ca(2+) signals are often generated by release of the ion from internal stores, but in very few cases has a role of the vacuole been directly demonstrated. Biochemical and electrophysical studies have provided evidence for the operation of ligand- and voltage-gated Ca(2+)-permeable channels in the vacuolar membrane. The underlying molecular mechanisms are largely unknown with one exception: the slow vacuolar channel, encoded by TPC1, is the only vacuolar Ca(2+)-permeable channel cloned to date. However, due to its complex regulation and its low selectivity amongst cations, the role of this channel in Ca(2+) signalling is still debated. Many transport proteins at the vacuolar membrane are also targets of Ca(2+) signals, both by direct binding of Ca(2+) and by Ca(2+)-dependent phosphorylation. This enables the operation of feedback mechanisms and integrates vacuolar transport systems in the wider signalling network of the plant cell. 2011 Elsevier Ltd. All rights reserved.

  4. The TTI slowness surface approximation

    KAUST Repository

    Stovas, A.

    2011-01-01

    The relation between the vertical and horizontal slownesses, better known as the dispersion relation, for a transversely isotropic media with titled symmetry axis {left parenthesis, less than bracket}TTI{right parenthesis, greater than bracket} requires solving a quartic polynomial, which does not admit a practical explicit solution to be used, for example, in downward continuation. Using a combination of perturbation theory with respect to the anelliptic parameter and Shanks transform to improve the accuracy of the expansion, we develop an explicit formula for the dispersion relation that is highly accurate for all practical purposes. It also reveals some insights into the anisotropy parameter dependency of the dispersion relation including the low impact that the anelliptic parameter has on the vertical placement of reflectors for small tilt in the symmetry angle. © 2011 Society of Exploration Geophysicists.

  5. Rapamycin slows aging in mice.

    Science.gov (United States)

    Wilkinson, John E; Burmeister, Lisa; Brooks, Susan V; Chan, Chi-Chao; Friedline, Sabrina; Harrison, David E; Hejtmancik, James F; Nadon, Nancy; Strong, Randy; Wood, Lauren K; Woodward, Maria A; Miller, Richard A

    2012-08-01

    Rapamycin increases lifespan in mice, but whether this represents merely inhibition of lethal neoplastic diseases, or an overall slowing in multiple aspects of aging is currently unclear. We report here that many forms of age-dependent change, including alterations in heart, liver, adrenal glands, endometrium, and tendon, as well as age-dependent decline in spontaneous activity, occur more slowly in rapamycin-treated mice, suggesting strongly that rapamycin retards multiple aspects of aging in mice, in addition to any beneficial effects it may have on neoplastic disease. We also note, however, that mice treated with rapamycin starting at 9 months of age have significantly higher incidence of testicular degeneration and cataracts; harmful effects of this kind will guide further studies on timing, dosage, and tissue-specific actions of rapamycin relevant to the development of clinically useful inhibitors of TOR action. © 2012 The Authors. Aging Cell © 2012 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland.

  6. Slow molecular recognition by RNA.

    Science.gov (United States)

    Gleitsman, Kristin R; Sengupta, Raghuvir N; Herschlag, Daniel

    2017-12-01

    Molecular recognition is central to biological processes, function, and specificity. Proteins associate with ligands with a wide range of association rate constants, with maximal values matching the theoretical limit set by the rate of diffusional collision. As less is known about RNA association, we compiled association rate constants for all RNA/ligand complexes that we could find in the literature. Like proteins, RNAs exhibit a wide range of association rate constants. However, the fastest RNA association rates are considerably slower than those of the fastest protein associations and fall well below the diffusional limit. The apparently general observation of slow association with RNAs has implications for evolution and for modern-day biology. Our compilation highlights a quantitative molecular property that can contribute to biological understanding and underscores our need to develop a deeper physical understanding of molecular recognition events. © 2017 Gleitsman et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  7. Traditional Procurement is too Slow

    Directory of Open Access Journals (Sweden)

    Ann Kong

    2012-11-01

    Full Text Available This paper reports on an exploratory interview survey of construction project participants aimed at identifying the reasons for the decrease in use of the traditional, lump-sum, procurement system in Malaysia. The results show that most people believe it is too slow. This appears to be in part due to the contiguous nature of the various phase and stages of the process and especially the separation of the design and construction phases. The delays caused by disputes between the various parties are also seen as a contributory factor - the most prominent cause being the frequency of variations, with design and scope changes being a particular source of discontent. It is concluded that an up scaling of the whole of the time related reward/penalty system may be the most appropriate measure for the practice in future.

  8. Hypocretin/Orexin Peptides Alter Spike Encoding by Serotonergic Dorsal Raphe Neurons through Two Distinct Mechanisms That Increase the Late Afterhyperpolarization.

    Science.gov (United States)

    Ishibashi, Masaru; Gumenchuk, Iryna; Miyazaki, Kenichi; Inoue, Takafumi; Ross, William N; Leonard, Christopher S

    2016-09-28

    Orexins (hypocretins) are neuropeptides that regulate multiple homeostatic processes, including reward and arousal, in part by exciting serotonergic dorsal raphe neurons, the major source of forebrain serotonin. Here, using mouse brain slices, we found that, instead of simply depolarizing these neurons, orexin-A altered the spike encoding process by increasing the postspike afterhyperpolarization (AHP) via two distinct mechanisms. This orexin-enhanced AHP (oeAHP) was mediated by both OX1 and OX2 receptors, required Ca(2+) influx, reversed near EK, and decayed with two components, the faster of which resulted from enhanced SK channel activation, whereas the slower component decayed like a slow AHP (sAHP), but was not blocked by UCL2077, an antagonist of sAHPs in some neurons. Intracellular phospholipase C inhibition (U73122) blocked the entire oeAHP, but neither component was sensitive to PKC inhibition or altered PKA signaling, unlike classical sAHPs. The enhanced SK current did not depend on IP3-mediated Ca(2+) release but resulted from A-current inhibition and the resultant spike broadening, which increased Ca(2+) influx and Ca(2+)-induced-Ca(2+) release, whereas the slower component was insensitive to these factors. Functionally, the oeAHP slowed and stabilized orexin-induced firing compared with firing produced by a virtual orexin conductance lacking the oeAHP. The oeAHP also reduced steady-state firing rate and firing fidelity in response to stimulation, without affecting the initial rate or fidelity. Collectively, these findings reveal a new orexin action in serotonergic raphe neurons and suggest that, when orexin is released during arousal and reward, it enhances the spike encoding of phasic over tonic inputs, such as those related to sensory, motor, and reward events. Orexin peptides are known to excite neurons via slow postsynaptic depolarizations. Here we elucidate a significant new orexin action that increases and prolongs the postspike

  9. The Slow Cycling Phenotype: A Growing Problem for Treatment Resistance in Melanoma.

    Science.gov (United States)

    Ahn, Antonio; Chatterjee, Aniruddha; Eccles, Michael R

    2017-06-01

    Treatment resistance in metastatic melanoma is a longstanding issue. Current targeted therapy regimes in melanoma largely target the proliferating cancer population, leaving slow-cycling cancer cells undamaged. Consequently, slow-cycling cells are enriched upon drug therapy and can remain in the body for years until acquiring proliferative potential that triggers cancer relapse. Here we overview the molecular mechanisms of slow-cycling cells that underlie treatment resistance in melanoma. Three main areas of molecular reprogramming are discussed that mediate slow cycling and treatment resistance. First, a low microphthalmia-associated transcription factor (MITF) dedifferentiated state activates various signaling pathways. This includes WNT5A, EGFR, as well as other signaling activators, such as AXL and NF-κB. Second, the chromatin-remodeling factor Jumonji/ARID domain-containing protein 1B (JARID1B, KDM5B ) orchestrates and maintains slow cycling and treatment resistance in a small subpopulation of melanoma cells. Finally, a shift in metabolic state toward oxidative phosphorylation has been demonstrated to regulate treatment resistance in slow-cycling cells. Elucidation of the underlying processes of slow cycling and its utilization by melanoma cells may reveal new vulnerable characteristics as therapeutic targets. Moreover, combining current therapies with targeting slow-cycling subpopulations of melanoma cells may allow for more durable and greater treatment responses. Mol Cancer Ther; 16(6); 1002-9. ©2017 AACR . ©2017 American Association for Cancer Research.

  10. Multidimensionally encoded magnetic resonance imaging.

    Science.gov (United States)

    Lin, Fa-Hsuan

    2013-07-01

    Magnetic resonance imaging (MRI) typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image reconstruction performance. Here, we propose the multidimensionally encoded (MDE) MRI to map a q-dimensional object onto a p-dimensional encoding space where p > q. MDE MRI is a theoretical framework linking imaging strategies using linear and nonlinear SEMs. Using a system of eight surface SEM coils with an eight-channel radiofrequency coil array, we demonstrate the five-dimensional MDE MRI for a two-dimensional object as a further generalization of PatLoc imaging and O-space imaging. We also present a method of optimizing spatial bases in MDE MRI. Results show that MDE MRI with a higher dimensional encoding space can reconstruct images more efficiently and with a smaller reconstruction error when the k-space sampling distribution and the number of samples are controlled. Copyright © 2012 Wiley Periodicals, Inc.

  11. Characteristics of broadband slow earthquakes explained by a Brownian model

    Science.gov (United States)

    Ide, S.; Takeo, A.

    2017-12-01

    Brownian slow earthquake (BSE) model (Ide, 2008; 2010) is a stochastic model for the temporal change of seismic moment release by slow earthquakes, which can be considered as a broadband phenomena including tectonic tremors, low frequency earthquakes, and very low frequency (VLF) earthquakes in the seismological frequency range, and slow slip events in geodetic range. Although the concept of broadband slow earthquake may not have been widely accepted, most of recent observations are consistent with this concept. Then, we review the characteristics of slow earthquakes and how they are explained by BSE model. In BSE model, the characteristic size of slow earthquake source is represented by a random variable, changed by a Gaussian fluctuation added at every time step. The model also includes a time constant, which divides the model behavior into short- and long-time regimes. In nature, the time constant corresponds to the spatial limit of tremor/SSE zone. In the long-time regime, the seismic moment rate is constant, which explains the moment-duration scaling law (Ide et al., 2007). For a shorter duration, the moment rate increases with size, as often observed for VLF earthquakes (Ide et al., 2008). The ratio between seismic energy and seismic moment is constant, as shown in Japan, Cascadia, and Mexico (Maury et al., 2017). The moment rate spectrum has a section of -1 slope, limited by two frequencies corresponding to the above time constant and the time increment of the stochastic process. Such broadband spectra have been observed for slow earthquakes near the trench axis (Kaneko et al., 2017). This spectrum also explains why we can obtain VLF signals by stacking broadband seismograms relative to tremor occurrence (e.g., Takeo et al., 2010; Ide and Yabe, 2014). The fluctuation in BSE model can be non-Gaussian, as far as the variance is finite, as supported by the central limit theorem. Recent observations suggest that tremors and LFEs are spatially characteristic

  12. Slow moving neural source in the epileptic hippocampus can mimic progression of human seizures.

    Science.gov (United States)

    Chiang, Chia-Chu; Wei, Xile; Ananthakrishnan, Arvind Keshav; Shivacharan, Rajat S; Gonzalez-Reyes, Luis E; Zhang, Mingming; Durand, Dominique M

    2018-01-24

    Fast and slow neural waves have been observed to propagate in the human brain during seizures. Yet the nature of these waves is difficult to study in a surgical setting. Here, we report an observation of two different traveling waves propagating in the in-vitro epileptic hippocampus at speeds similar to those in the human brain. A fast traveling spike and a slow moving wave were recorded simultaneously with a genetically encoded voltage sensitive fluorescent protein (VSFP Butterfly 1.2) and a high speed camera. The results of this study indicate that the fast traveling spike is NMDA-sensitive but the slow moving wave is not. Image analysis and model simulation demonstrate that the slow moving wave is moving slowly, generating the fast traveling spike and is, therefore, a moving source of the epileptiform activity. This slow moving wave is associated with a propagating neural calcium wave detected with calcium dye (OGB-1) but is independent of NMDA receptors, not related to ATP release, and much faster than those previously recorded potassium waves. Computer modeling suggests that the slow moving wave can propagate by the ephaptic effect like epileptiform activity. These findings provide an alternative explanation for slow propagation seizure wavefronts associated with fast propagating spikes.

  13. Berberine slows cell growth in autosomal dominant polycystic kidney disease cells

    Energy Technology Data Exchange (ETDEWEB)

    Bonon, Anna; Mangolini, Alessandra [Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, 44121 Ferrara (Italy); Pinton, Paolo [Department of Morphology, Surgery and Experimental Medicine, Section of General Pathology, University of Ferrara, 44121 Ferrara (Italy); Senno, Laura del [Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, 44121 Ferrara (Italy); Aguiari, Gianluca, E-mail: dsn@unife.it [Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, 44121 Ferrara (Italy)

    2013-11-22

    Highlights: •Berberine at appropriate doses slows cell proliferation in ADPKD cystic cells. •Reduction of cell growth by berberine occurs by inhibition of ERK and p70-S6 kinase. •Higher doses of berberine cause an overall cytotoxic effect. •Berberine overdose induces apoptotic bodies formation and DNA fragmentation. •Antiproliferative properties of this drug make it a new candidate for ADPKD therapy. -- Abstract: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary monogenic disorder characterized by development and enlargement of kidney cysts that lead to loss of renal function. It is caused by mutations in two genes (PKD1 and PKD2) encoding for polycystin-1 and polycystin-2 proteins which regulate different signals including cAMP, mTOR and EGFR pathways. Abnormal activation of these signals following PC1 or PC2 loss of function causes an increased cell proliferation which is a typical hallmark of this disease. Despite the promising findings obtained in animal models with targeted inhibitors able to reduce cystic cell growth, currently, no specific approved therapy for ADPKD is available. Therefore, the research of new more effective molecules could be crucial for the treatment of this severe pathology. In this regard, we have studied the effect of berberine, an isoquinoline quaternary alkaloid, on cell proliferation and apoptosis in human and mouse ADPKD cystic cell lines. Berberine treatment slows cell proliferation of ADPKD cystic cells in a dose-dependent manner and at high doses (100 μg/mL) it induces cell death in cystic cells as well as in normal kidney tubule cells. However, at 10 μg/mL, berberine reduces cell growth in ADPKD cystic cells only enhancing G{sub 0}/G{sub 1} phase of cell cycle and inhibiting ERK and p70-S6 kinases. Our results indicate that berberine shows a selected antiproliferative activity in cellular models for ADPKD, suggesting that this molecule and similar natural compounds could open new

  14. Off-resonance slow light

    Science.gov (United States)

    Shakhmuratov, R. N.; Odeurs, J.

    2008-12-01

    We consider the propagation of a light pulse in a medium with a single resonance. If the frequency of the pulse is tuned far from resonance and the pulse duration is much shorter than the lifetime of the excited state of the resonant particles in the medium (atoms in a gas, impurity ions in a solid, etc.), the group velocity of the pulse is appreciably reduced. It is shown that the slowing down of the group velocity of the pulse is accompanied with a pulse chirp, which produces a pulse broadening in time. It is proposed to use two samples in sequence with opposite chirps (up chirp and down chirp or vice versa) compensating the pulse broadening. Then the pulse can be delayed with almost no losses, distortion, and broadening. However, there is a maximum distance, beyond which the pulse experiences corruption. Pumping with an auxiliary laser beam can control the delay time of the light pulse in the medium. Conditions to eliminate the contribution of the dephasing processes in the pulse propagation are considered.

  15. Plant domestication slows pest evolution.

    Science.gov (United States)

    Turcotte, Martin M; Lochab, Amaneet K; Turley, Nash E; Johnson, Marc T J

    2015-09-01

    Agricultural practices such as breeding resistant varieties and pesticide use can cause rapid evolution of pest species, but it remains unknown how plant domestication itself impacts pest contemporary evolution. Using experimental evolution on a comparative phylogenetic scale, we compared the evolutionary dynamics of a globally important economic pest - the green peach aphid (Myzus persicae) - growing on 34 plant taxa, represented by 17 crop species and their wild relatives. Domestication slowed aphid evolution by 13.5%, maintained 10.4% greater aphid genotypic diversity and 5.6% higher genotypic richness. The direction of evolution (i.e. which genotypes increased in frequency) differed among independent domestication events but was correlated with specific plant traits. Individual-based simulation models suggested that domestication affects aphid evolution directly by reducing the strength of selection and indirectly by increasing aphid density and thus weakening genetic drift. Our results suggest that phenotypic changes during domestication can alter pest evolutionary dynamics. © 2015 John Wiley & Sons Ltd/CNRS.

  16. Role of slow oscillatory activity and slow wave sleep in consolidation of episodic-like memory in rats.

    Science.gov (United States)

    Oyanedel, Carlos N; Binder, Sonja; Kelemen, Eduard; Petersen, Kimberley; Born, Jan; Inostroza, Marion

    2014-12-15

    Our previous experiments showed that sleep in rats enhances consolidation of hippocampus dependent episodic-like memory, i.e. the ability to remember an event bound into specific spatio-temporal context. Here we tested the hypothesis that this enhancing effect of sleep is linked to the occurrence of slow oscillatory and spindle activity during slow wave sleep (SWS). Rats were tested on an episodic-like memory task and on three additional tasks covering separately the where (object place recognition), when (temporal memory), and what (novel object recognition) components of episodic memory. In each task, the sample phase (encoding) was followed by an 80-min retention interval that covered either a period of regular morning sleep or sleep deprivation. Memory during retrieval was tested using preferential exploration of novelty vs. familiarity. Consistent with previous findings, the rats which had slept during the retention interval showed significantly stronger episodic-like memory and spatial memory, and a trend of improved temporal memory (although not significant). Object recognition memory was similarly retained across sleep and sleep deprivation retention intervals. Recall of episodic-like memory was associated with increased slow oscillatory activity (0.85-2.0Hz) during SWS in the retention interval. Spatial memory was associated with increased proportions of SWS. Against our hypothesis, a relationship between spindle activity and episodic-like memory performance was not detected, but spindle activity was associated with object recognition memory. The results provide support for the role of SWS and slow oscillatory activity in consolidating hippocampus-dependent memory, the role of spindles in this process needs to be further examined. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  17. Applications of Slow Light in Telecommunications

    National Research Council Canada - National Science Library

    Boyd, Robert W; Gauthier, Daniel J; Gaeta, Alexander L

    2006-01-01

    .... Now, optical scientists are turning their attention toward developing useful applications of slow light, including controllable optical delay lines, optical buffers and true time delay methods...

  18. Electroencephalographic slow waves prior to sleepwalking episodes.

    Science.gov (United States)

    Perrault, Rosemarie; Carrier, Julie; Desautels, Alex; Montplaisir, Jacques; Zadra, Antonio

    2014-12-01

    Recent studies have suggested that the onset of sleepwalking episodes may be preceded by fluctuations in slow-wave sleep electroencephalographic characteristics. However, whether or not such fluctuations are specific to sleepwalking episodes or generalized to all sleep-wake transitions in sleepwalkers remains unknown. The goal of this study was to compare spectral power for delta (1-4 Hz) and slow delta (0.5-1 Hz) as well as slow oscillation density before the onset of somnambulistic episodes versus non-behavioral awakenings recorded from the same group of sleepwalkers. A secondary aim was to describe the time course of observed changes in slow-wave activity and slow oscillations during the 3 min immediately preceding the occurrence of somnambulistic episodes. Twelve adult sleepwalkers were investigated polysomnographically during the course of one night. Slow-wave activity and slow oscillation density were significantly greater prior to patients' somnambulistic episodes as compared with non-behavioral awakenings. However, there was no evidence for a gradual increase over the 3 min preceding the episodes. Increased slow-wave activity and slow oscillation density appear to be specific to sleepwalking episodes rather than generalized to all sleep-wake transitions in sleepwalkers. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. How can survival processing improve memory encoding?

    Science.gov (United States)

    Luo, Meng; Geng, Haiyan

    2013-11-01

    We investigated the psychological mechanism of survival processing advantage from the perspective of false memory in two experiments. Using a DRM paradigm in combination with analysis based on signal detection theory, we were able to separately examine participants' utilization of verbatim representation and gist representation. Specifically, in Experiment 1, participants rated semantically related words in a survival scenario for a survival condition but rated pleasantness of words in the same DRM lists for a non-survival control condition. The results showed that participants demonstrated more gist processing in the survival condition than in the pleasantness condition; however, the degree of item-specific processing in the two encoding conditions did not significantly differ. In Experiment 2, the control task was changed to a category rating task, in which participants were asked to make category ratings of words in the category lists. We found that the survival condition involved more item-specific processing than did the category condition, but we found no significant difference between the two encoding conditions at the level of gist processing. Overall, our study demonstrates that survival processing can simultaneously promote gist and item-specific representations. When the control tasks only promoted either item-specific representation or gist representation, memory advantages of survival processing occurred.

  20. Theory of multisource crosstalk reduction by phase-encoded statics

    KAUST Repository

    Schuster, Gerard T.

    2011-03-01

    Formulas are derived that relate the strength of the crosstalk noise in supergather migration images to the variance of time, amplitude and polarity shifts in encoding functions. A supergather migration image is computed by migrating an encoded supergather, where the supergather is formed by stacking a large number of encoded shot gathers. Analysis reveals that for temporal source static shifts in each shot gather, the crosstalk noise is exponentially reduced with increasing variance of the static shift and the square of source frequency. This is not too surprising because larger time shifts lead to less correlation between traces in different shot gathers, and so should tend to reduce the crosstalk noise. Analysis also reveals that combining both polarity and time statics is a superior encoding strategy compared to using either polarity statics or time statics alone. Signal-to-noise (SNR) estimates show that for a standard migration image and for an image computed by migrating a phase-encoded supergather; here, G is the number of traces in a shot gather, I is the number of stacking iterations in the supergather and S is the number of encoded/blended shot gathers that comprise the supergather. If the supergather can be uniformly divided up into Q unique sub-supergathers, then the resulting SNR of the final image is, which means that we can enhance image quality but at the expense of Q times more cost. The importance of these formulas is that they provide a precise understanding between different phase encoding strategies and image quality. Finally, we show that iterative migration of phase-encoded supergathers is a special case of passive seismic interferometry. We suggest that the crosstalk noise formulas can be helpful in designing optimal strategies for passive seismic interferometry and efficient extraction of Green\\'s functions from simulated supergathers. © 2011 The Authors Geophysical Journal International © 2011 RAS.

  1. Brain Circuits Encoding Reward from Pain Relief.

    Science.gov (United States)

    Navratilova, Edita; Atcherley, Christopher W; Porreca, Frank

    2015-11-01

    Relief from pain in humans is rewarding and pleasurable. Primary rewards, or reward-predictive cues, are encoded in brain reward/motivational circuits. While considerable advances have been made in our understanding of reward circuits underlying positive reinforcement, less is known about the circuits underlying the hedonic and reinforcing actions of pain relief. We review findings from electrophysiological, neuroimaging, and behavioral studies supporting the concept that the rewarding effect of pain relief requires opioid signaling in the anterior cingulate cortex (ACC), activation of midbrain dopamine neurons, and the release of dopamine in the nucleus accumbens (NAc). Understanding of circuits that govern the reward of pain relief may allow the discovery of more effective and satisfying therapies for patients with acute or chronic pain.

  2. Covert reorganization of implicit task representations by slow wave sleep.

    Directory of Open Access Journals (Sweden)

    Juliana Yordanova

    2009-05-01

    Full Text Available There is evidence that slow wave sleep (SWS promotes the consolidation of memories that are subserved by mediotemporal- and hippocampo-cortical neural networks. In contrast to implicit memories, explicit memories are accompanied by conscious (attentive and controlled processing. Awareness at pre-sleep encoding has been recognized as critical for the off-line memory consolidation. The present study elucidated the role of task-dependent cortical activation guided by attentional control at pre-sleep encoding for the consolidation of hippocampus-dependent memories during sleep.A task with a hidden regularity was used (Number Reduction Task, NRT, in which the responses that can be implicitly predicted by the hidden regularity activate hippocampo-cortical networks more strongly than responses that cannot be predicted. Task performance was evaluated before and after early-night sleep, rich in SWS, and late-night sleep, rich in rapid eye movement (REM sleep. In implicit conditions, slow cortical potentials (SPs were analyzed to reflect the amount of controlled processing and the localization of activated neural task representations.During implicit learning before sleep, the amount of controlled processing did not differ between unpredictable and predictable responses, nor between early- and late-night sleep groups. A topographic re-distribution of SPs indicating a spatial reorganization occurred only after early, not after late sleep, and only for predictable responses. These SP changes correlated with the amount of SWS and were covert because off-line RT decrease did not differentiate response types or sleep groups.It is concluded that SWS promotes the neural reorganization of task representations that rely on the hippocampal system despite absence of conscious access to these representations.Original neurophysiologic evidence is provided for the role of SWS in the consolidation of memories encoded with hippocampo-cortical interaction before sleep. It

  3. Virally encoded 7TM receptors

    DEFF Research Database (Denmark)

    Rosenkilde, M M; Waldhoer, M; Lüttichau, H R

    2001-01-01

    expression of this single gene in certain lymphocyte cell lineages leads to the development of lesions which are remarkably similar to Kaposi's sarcoma, a human herpesvirus 8 associated disease. Thus, this and other virally encoded 7TM receptors appear to be attractive future drug targets....

  4. Encoding by synchronization in the primate striatum.

    Science.gov (United States)

    Adler, Avital; Finkes, Inna; Katabi, Shiran; Prut, Yifat; Bergman, Hagai

    2013-03-13

    Information is encoded in the nervous system through the discharge and synchronization of single neurons. The striatum, the input stage of the basal ganglia, is divided into three territories: the putamen, the caudate, and the ventral striatum, all of which converge onto the same motor pathway. This parallel organization suggests that there are multiple and competing systems in the basal ganglia network controlling behavior. To explore which mechanism(s) enables the different striatal domains to encode behavioral events and to control behavior, we compared the neural activity of phasically active neurons [medium spiny neurons (MSNs), presumed projection neurons] and tonically active neurons (presumed cholinergic interneurons) across striatal territories from monkeys during the performance of a well practiced task. Although neurons in all striatal territories displayed similar spontaneous discharge properties and similar temporal modulations of their discharge rates to the behavioral events, their correlation structure was profoundly different. The distributions of signal and noise correlation of pairs of putamen MSNs were strongly shifted toward positive correlations and these two measures were correlated. In contrast, MSN pairs in the caudate and ventral striatum displayed symmetrical, near-zero signal and noise correlation distributions. Furthermore, only putamen MSN pairs displayed different noise correlation dynamics to rewarding versus neutral/aversive cues. Similarly, the noise correlation between tonically active neuron pairs was stronger in the putamen than in the caudate. We suggest that the level of synchronization of the neuronal activity and its temporal dynamics differentiate the striatal territories and may thus account for the different roles that striatal domains play in behavioral control.

  5. Resonant absorption of the slow sausage wave in the slow continuum

    Science.gov (United States)

    Yu, D. J.; Van Doorsselaere, T.; Goossens, M.

    2017-06-01

    Aims: General analytical formulas for the damping rate by resonant absorption of slow sausage modes in the slow (cusp) continuum are derived and the resonant damping of the slow surface mode under photospheric conditions is investigated. Methods: The connection formula across the resonant layer is used to derive the damping rate for the slow sausage mode in the slow continuum by assuming a thin boundary. Results: It is shown that the effect of the resonant damping on the slow surface sausage mode in the slow continuum, which has been underestimated in previous interpretations, could be efficient under magnetic pore conditions. A simplified analytical formula for the damping rate of slow surface mode in the long wavelength limit is derived. This formula can be useful for a rough estimation of the damping rate due to resonant absorption for observational wave damping.

  6. Slow Movement/Slow University: Critical Engagements. Introduction to the Thematic Section

    Directory of Open Access Journals (Sweden)

    Maggie O'Neill

    2014-09-01

    Full Text Available This thematic section emerged from two seminars that took place at Durham University in England in November 2013 and March 2014 on the possibilities for thinking through what a change movement towards slow might mean for the University. Slow movements have emerged in relation to a number of topics: Slow food, Citta slow and more recently, slow science. What motivated us in the seminars was to explore how far these movements could help us address the acceleration and intensification of work within our own and other universities, and indeed, what new learning, research, philosophies, practices, structures and governance might emerge. This editorial introduction presents the concept of the "slow university" and introduces our critical engagements with slow. The articles presented here interrogate the potentialities, challenges, problems and pitfalls of the slow university in an era of corporate culture and management rationality. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1403166

  7. Slow-light vortices in periodic waveguides

    DEFF Research Database (Denmark)

    Sukhorukov, Andrey A.; Ha, Sangwoo; Desyatnikov, Anton S.

    2009-01-01

    We reveal that the reduction of the group velocity of light in periodic waveguides is generically associated with the presence of vortex energy flows. We show that the energy flows are gradually frozen for slow-light at the Brillouin zone edge, whereas vortices persist for slow-light states having...

  8. 49 CFR 236.813 - Speed, slow.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Speed, slow. 236.813 Section 236.813 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, slow. A speed not exceeding 20 miles per hour. ...

  9. Response of electret dosemeter to slow neutrons

    International Nuclear Information System (INIS)

    Ghilardi, A.J.P.; Pela, C.A.; Zimmerman, R.L.

    1987-01-01

    The response of electret dosemeter to slow neutrons exposure is cited, mentioning the preparation and the irradiation of dosemeter with Am-Be source. Some theory considerations about the response of electret dosemeter to slow and fast neutrons are also presented. (C.G.C.) [pt

  10. VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR

    African Journals Online (AJOL)

    Dr Obe

    1984-09-01

    Sep 1, 1984 ... VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR by. L. A. Agu. Electrical Engineering Department. University of Nigeria, Nsukka. ABSTRACT. This paper presents the scheme for a very slow speed linear machine which uses conventional laminations and with which speeds of the same low.

  11. Can fast and slow intelligence be differentiated?

    NARCIS (Netherlands)

    Partchev, I.; de Boeck, P.

    2012-01-01

    Responses to items from an intelligence test may be fast or slow. The research issue dealt with in this paper is whether the intelligence involved in fast correct responses differs in nature from the intelligence involved in slow correct responses. There are two questions related to this issue: 1.

  12. Tandem queue with server slow-down

    NARCIS (Netherlands)

    Miretskiy, D.I.; Scheinhardt, W.R.W.; Mandjes, M.R.H.

    2007-01-01

    We study how rare events happen in the standard two-node tandem Jackson queue and in a generalization, the socalled slow-down network, see [2]. In the latter model the service rate of the first server depends on the number of jobs in the second queue: the first server slows down if the amount of

  13. Copyright Protection of Color Imaging Using Robust-Encoded Watermarking

    Directory of Open Access Journals (Sweden)

    M. Cedillo-Hernandez

    2015-04-01

    Full Text Available In this paper we present a robust-encoded watermarking method applied to color images for copyright protection, which presents robustness against several geometric and signal processing distortions. Trade-off between payload, robustness and imperceptibility is a very important aspect which has to be considered when a watermark algorithm is designed. In our proposed scheme, previously to be embedded into the image, the watermark signal is encoded using a convolutional encoder, which can perform forward error correction achieving better robustness performance. Then, the embedding process is carried out through the discrete cosine transform domain (DCT of an image using the image normalization technique to accomplish robustness against geometric and signal processing distortions. The embedded watermark coded bits are extracted and decoded using the Viterbi algorithm. In order to determine the presence or absence of the watermark into the image we compute the bit error rate (BER between the recovered and the original watermark data sequence. The quality of the watermarked image is measured using the well-known indices: Peak Signal to Noise Ratio (PSNR, Visual Information Fidelity (VIF and Structural Similarity Index (SSIM. The color difference between the watermarked and original images is obtained by using the Normalized Color Difference (NCD measure. The experimental results show that the proposed method provides good performance in terms of imperceptibility and robustness. The comparison among the proposed and previously reported methods based on different techniques is also provided.

  14. Subversion of cytokine networks by virally encoded decoy receptors.

    Science.gov (United States)

    Epperson, Megan L; Lee, Chung A; Fremont, Daved H

    2012-11-01

    During the course of evolution, viruses have captured or created a diverse array of open reading frames, which encode for proteins that serve to evade and sabotage the host innate and adaptive immune responses that would otherwise lead to their elimination. These viral genomes are some of the best textbooks of immunology ever written. The established arsenal of immunomodulatory proteins encoded by viruses is large and growing, and includes specificities for virtually all known inflammatory pathways and targets. The focus of this review is on herpes and poxvirus-encoded cytokine and chemokine-binding proteins that serve to undermine the coordination of host immune surveillance. Structural and mechanistic studies of these decoy receptors have provided a wealth of information, not only about viral pathogenesis but also about the inner workings of cytokine signaling networks. © 2012 John Wiley & Sons A/S.

  15. Connecting slow earthquakes to huge earthquakes.

    Science.gov (United States)

    Obara, Kazushige; Kato, Aitaro

    2016-07-15

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes. Copyright © 2016, American Association for the Advancement of Science.

  16. Slow flow and mural thrombus in aortic diseases: Spin-echo MR findings and their differentiation

    International Nuclear Information System (INIS)

    Chung, Jin Wook; Park, Jae Hyung; Han, Man Chung

    1993-01-01

    In order to evaluate the ability of spin-echo MR imaging to differentiate slow flow from mural thrombus in aortic diseases, we reviewed the spin-echo MR images of 13 patients with intraaortic thrombus documented by CT (N=11) or aortography (N=2). Six patients had aortic aneurysms and seven had aortic dissections. Intraaortic mural thrombi were accompanied by flow-related intraluminal signal of various pattern and extents in all 13 patients. On 10 gated MR studies, slow flow regions showed ever-echo rephasing phenomenon (N=8), interslice variation of signal intensities of the intraluminal signal (N=7) and flow-related ghost artifact (N=2). However, these MR flow phenomena were obscured on two of three non-gated studies. Seven of 13 intraaortic thrombi remained hyperintense on T2-weighted second-echo images. In these circumstance, a hypointense boundary layer between slow flow and mural thrombus, which was caused by either ' boundary layer dephasing phenomenon' of slow flow or 'paramagnetic T2 shortening' of fresh clot at the edge of mural thrombus, was very useful in discriminating the area of slow flow from that of mural thrombus. Proper interpretation of spin-echo MR images may obviate the need for phase display imaging or gradient-echo imaging in differentiating slow flow and mural thrombus

  17. Process-specific analysis in episodic memory retrieval using fast optical signals and hemodynamic signals in the right prefrontal cortex

    Science.gov (United States)

    Dong, Sunghee; Jeong, Jichai

    2018-02-01

    Objective. Memory is formed by the interaction of various brain functions at the item and task level. Revealing individual and combined effects of item- and task-related processes on retrieving episodic memory is an unsolved problem because of limitations in existing neuroimaging techniques. To investigate these issues, we analyze fast and slow optical signals measured from a custom-built continuous wave functional near-infrared spectroscopy (CW-fNIRS) system. Approach. In our work, we visually encode the words to the subjects and let them recall the words after a short rest. The hemodynamic responses evoked by the episodic memory are compared with those evoked by the semantic memory in retrieval blocks. In the fast optical signal, we compare the effects of old and new items (previously seen and not seen) to investigate the item-related process in episodic memory. The Kalman filter is simultaneously applied to slow and fast optical signals in different time windows. Main results. A significant task-related HbR decrease was observed in the episodic memory retrieval blocks. Mean amplitude and peak latency of a fast optical signal are dependent upon item types and reaction time, respectively. Moreover, task-related hemodynamic and item-related fast optical responses are correlated in the right prefrontal cortex. Significance. We demonstrate that episodic memory is retrieved from the right frontal area by a functional connectivity between the maintained mental state through retrieval and item-related transient activity. To the best of our knowledge, this demonstration of functional NIRS research is the first to examine the relationship between item- and task-related memory processes in the prefrontal area using single modality.

  18. Encoding information into precipitation structures

    International Nuclear Information System (INIS)

    Martens, Kirsten; Bena, Ioana; Droz, Michel; Rácz, Zoltan

    2008-01-01

    Material design at submicron scales would be profoundly affected if the formation of precipitation patterns could be easily controlled. It would allow the direct building of bulk structures, in contrast to traditional techniques which consist of removing material in order to create patterns. Here, we discuss an extension of our recent proposal of using electrical currents to control precipitation bands which emerge in the wake of reaction fronts in A + + B – → C reaction–diffusion processes. Our main result, based on simulating the reaction–diffusion–precipitation equations, is that the dynamics of the charged agents can be guided by an appropriately designed time-dependent electric current so that, in addition to the control of the band spacing, the width of the precipitation bands can also be tuned. This makes straightforward the encoding of information into precipitation patterns and, as an amusing example, we demonstrate the feasibility by showing how to encode a musical rhythm

  19. DNA sequence variants in PPARGC1A, a gene encoding a coactivator of the ω-3 LCPUFA sensing PPAR-RXR transcription complex, are associated with NV AMD and AMD-associated loci in genes of complement and VEGF signaling pathways.

    Directory of Open Access Journals (Sweden)

    John Paul SanGiovanni

    Full Text Available Increased intake of ω-3 long-chain polyunsaturated fatty acids (LCPUFAs and use of peroxisome proliferator activator receptor (PPAR-activating drugs are associated with attenuation of pathologic retinal angiogenesis. ω-3 LCPUFAs are endogenous agonists of PPARs. We postulated that DNA sequence variation in PPAR gamma (PPARG co-activator 1 alpha (PPARGC1A, a gene encoding a co-activator of the LCPUFA-sensing PPARG-retinoid X receptor (RXR transcription complex, may influence neovascularization (NV in age-related macular degeneration (AMD.We applied exact testing methods to examine distributions of DNA sequence variants in PPARGC1A for association with NV AMD and interaction of AMD-associated loci in genes of complement, lipid metabolism, and VEGF signaling systems. Our sample contained 1858 people from 3 elderly cohorts of western European ancestry. We concurrently investigated retinal gene expression profiles in 17-day-old neonatal mice on a 2% LCPUFA feeding paradigm to identify LCPUFA-regulated genes both associated with pathologic retinal angiogenesis and known to interact with PPARs or PPARGC1A.A DNA coding variant (rs3736265 and a 3'UTR-resident regulatory variant (rs3774923 in PPARGC1A were independently associated with NV AMD (exact P = 0.003, both SNPs. SNP-SNP interactions existed for NV AMD (P<0.005 with rs3736265 and a AMD-associated variant in complement factor B (CFB, rs512559. PPARGC1A influences activation of the AMD-associated complement component 3 (C3 promoter fragment and CFB influences activation and proteolysis of C3. We observed interaction (P ≤ 0.003 of rs3736265 with a variant in vascular endothelial growth factor A (VEGFA, rs3025033, a key molecule in retinal angiogenesis. Another PPARGC1A coding variant (rs8192678 showed statistical interaction with a SNP in the VEGFA receptor fms-related tyrosine kinase 1 (FLT1, rs10507386; P ≤ 0.003. C3 expression was down-regulated 2-fold in retinas of ω-3 LCPUFA-fed mice

  20. DNA sequence variants in PPARGC1A, a gene encoding a coactivator of the ω-3 LCPUFA sensing PPAR-RXR transcription complex, are associated with NV AMD and AMD-associated loci in genes of complement and VEGF signaling pathways.

    Science.gov (United States)

    SanGiovanni, John Paul; Chen, Jing; Sapieha, Przemyslaw; Aderman, Christopher M; Stahl, Andreas; Clemons, Traci E; Chew, Emily Y; Smith, Lois E H

    2013-01-01

    Increased intake of ω-3 long-chain polyunsaturated fatty acids (LCPUFAs) and use of peroxisome proliferator activator receptor (PPAR)-activating drugs are associated with attenuation of pathologic retinal angiogenesis. ω-3 LCPUFAs are endogenous agonists of PPARs. We postulated that DNA sequence variation in PPAR gamma (PPARG) co-activator 1 alpha (PPARGC1A), a gene encoding a co-activator of the LCPUFA-sensing PPARG-retinoid X receptor (RXR) transcription complex, may influence neovascularization (NV) in age-related macular degeneration (AMD). We applied exact testing methods to examine distributions of DNA sequence variants in PPARGC1A for association with NV AMD and interaction of AMD-associated loci in genes of complement, lipid metabolism, and VEGF signaling systems. Our sample contained 1858 people from 3 elderly cohorts of western European ancestry. We concurrently investigated retinal gene expression profiles in 17-day-old neonatal mice on a 2% LCPUFA feeding paradigm to identify LCPUFA-regulated genes both associated with pathologic retinal angiogenesis and known to interact with PPARs or PPARGC1A. A DNA coding variant (rs3736265) and a 3'UTR-resident regulatory variant (rs3774923) in PPARGC1A were independently associated with NV AMD (exact P = 0.003, both SNPs). SNP-SNP interactions existed for NV AMD (Pcomplement factor B (CFB, rs512559). PPARGC1A influences activation of the AMD-associated complement component 3 (C3) promoter fragment and CFB influences activation and proteolysis of C3. We observed interaction (P ≤ 0.003) of rs3736265 with a variant in vascular endothelial growth factor A (VEGFA, rs3025033), a key molecule in retinal angiogenesis. Another PPARGC1A coding variant (rs8192678) showed statistical interaction with a SNP in the VEGFA receptor fms-related tyrosine kinase 1 (FLT1, rs10507386; P ≤ 0.003). C3 expression was down-regulated 2-fold in retinas of ω-3 LCPUFA-fed mice - these animals also showed 70% reduction in retinal NV (P

  1. KEK-IMSS Slow Positron Facility

    Science.gov (United States)

    Hyodo, T.; Wada, K.; Yagishita, A.; Kosuge, T.; Saito, Y.; Kurihara, T.; Kikuchi, T.; Shirakawa, A.; Sanami, T.; Ikeda, M.; Ohsawa, S.; Kakihara, K.; Shidara, T.

    2011-12-01

    The Slow Positron Facility at the Institute of Material Structure Science (IMSS) of High Energy Accelerator Research Organization (KEK) is a user dedicated facility with an energy tunable (0.1 - 35 keV) slow positron beam produced by a dedicated 55MeV linac. The present beam line branches have been used for the positronium time-of-flight (Ps-TOF) measurements, the transmission positron microscope (TPM) and the photo-detachment of Ps negative ions (Ps-). During the year 2010, a reflection high-energy positron diffraction (RHEPD) measurement station is going to be installed. The slow positron generator (converter/ moderator) system will be modified to get a higher slow positron intensity, and a new user-friendly beam line power-supply control and vacuum monitoring system is being developed. Another plan for this year is the transfer of a 22Na-based slow positron beam from RIKEN. This machine will be used for the continuous slow positron beam applications and for the orientation training of those who are interested in beginning researches with a slow positron beam.

  2. The cryogenic source of slow monochromatic positrons

    International Nuclear Information System (INIS)

    Meshkov, I.N.; Pavlov, V.N.; Sidorin, A.O.; Yakovenko, S.L.

    2008-01-01

    The cryogenic source of slow monochromatic positrons based on the 22 Na isotope has been designed and constructed at JINR. Positrons emitted from radioactive source 22 Na have a very broad energy spectrum up to 0.5 MeV. To generate monochromatic beam of slow positrons the solid neon is used as a moderator. The solid neon allows forming slow positron beam of the energy of 1.2 eV at the spectrum width of 1 eV. The efficiency of moderation is 1 % of total positron flux

  3. Slow light vortices in periodic waveguides

    DEFF Research Database (Denmark)

    Sukhorukov, Andrey A.; Ha, Sangwoo; Desyatnikov, Anton S.

    2009-01-01

    We reveal that the reduction of the group velocity of light in periodic waveguides is generically associated with the presence of vortex energy flows. We show that the energy flows are gradually frozen for slow-light at the Brillouin zone edge, whereas vortices persist for slow-light states having...... non-vanishing phase velocity inside the Brillouin zone. We also demonstrate that presence of vortices can be linked to the absence of slow-light at the zone edge, and present calculations illustrating these general results....

  4. Dystonia Associated with Idiopathic Slow Orthostatic Tremor

    Directory of Open Access Journals (Sweden)

    Christopher Kobylecki

    2016-02-01

    Full Text Available Background: We aimed to characterize the clinical and electrophysiological features of patients with slow orthostatic tremor.Case Report: The clinical and neurophysiological data of patients referred for lower limb tremor on standing were reviewed. Patients with symptomatic or primary orthostatic tremor were excluded. Eight patients were identified with idiopathic slow 4–8 Hz orthostatic tremor, which was associated with tremor and dystonia in cervical and upper limb musculature. Coherence analysis in two patients showed findings different to those seen in primary orthostatic tremor.Discussion: Slow orthostatic tremor may be associated with dystonia and dystonic tremor.

  5. New Methods of Stereo Encoding for FM Radio Broadcasting Based on Digital Technology

    Directory of Open Access Journals (Sweden)

    P. Stranak

    2007-12-01

    Full Text Available The article describes new methods of stereo encoding for FM radio broadcasting. Digital signal processing makes possible to construct an encoder with properties that are not attainable using conventional analog solutions. The article describes the mathematical model of the encoder, on the basis of which a specific program code for DSP was developed. The article further deals with a new method of composite clipping which does not cause impurities in the output spectrum, and at the same time preserves high separation between the left and right audio channels. The application of the new method is useful mainly where there are unwanted signal overshoots on the input of the stereo encoder, e.g., in case of signal transmission from the studio to the transmitter site through a route with psychoacoustic lossy compression of data rate.

  6. Designing waveforms for temporal encoding using a frequency sampling method

    DEFF Research Database (Denmark)

    Gran, Fredrik; Jensen, Jørgen Arendt

    2007-01-01

    In this paper a method for designing waveforms for temporal encoding in medical ultrasound imaging is described. The method is based on least squares optimization and is used to design nonlinear frequency modulated signals for synthetic transmit aperture imaging. By using the proposed design method...... are shown for both methods, wherein the common carotid artery on a 27-year-old healthy male was scanned...

  7. Role of local field potentials in encoding hand movement kinematics.

    Science.gov (United States)

    Witte, Matthias

    2011-10-01

    How the brain orchestrates the musculoskeletal system to produce complex three-dimensional movements is still poorly understood. Despite first promising results in brain-machine interfaces that translate cortical activity to control output, there is an ongoing debate about which brain signals provide richest information related to movement planning and execution. Novel results by Bansal and colleagues (2011) now suggest that neuronal spiking and local field potentials jointly encode kinematics during skilled reach and grasp movements.

  8. [Signaling network-based functional cell design].

    Science.gov (United States)

    Ju, Jianqi; Wei, Ping

    2017-03-25

    Cellular signaling networks act as the central processor to deal with environmental signals and regulate cell function, and determine cell fate. Using synthetic biology approach to engineer cell signaling networks is crucial for ultimately constructing man-made "cell machines". Cellular signaling networks can encode sophisticated cell information by processing quantitatively signaling dynamics, which enables multi-dimensional regulation of functional sub-circuits. Here, we first review the research progresses on the signaling coding mechanisms; and then elaborate the methodologies and applications of cells signaling engineering; finally, we envision that signaling-based cell engineering are important for the increasingly-complicated next generation synthetic biology.

  9. Hall effect encoding of brushless dc motors

    Science.gov (United States)

    Berard, C. A.; Furia, T. J.; Goldberg, E. A.; Greene, R. C.

    1970-01-01

    Encoding mechanism integral to the motor and using the permanent magnets embedded in the rotor eliminates the need for external devices to encode information relating the position and velocity of the rotating member.

  10. Slow and Fast Light, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to the NASA Small Business Innovation Research (SBIR) Program 2015 Phase I Solicitation S3.08: Slow and Fast Light, Torch Technologies in partnership...

  11. Experimental demonstration of spinor slow light

    Science.gov (United States)

    Lee, Meng-Jung; Ruseckas, Julius; Lee, Chin-Yuan; Kudriašov, Viačeslav; Chang, Kao-Fang; Cho, Hung-Wen; JuzeliÅ«nas, Gediminas; Yu, Ite A.

    2016-03-01

    Over the last decade there has been a continuing interest in slow and stored light based on the electromagnetically induced transparency (EIT) effect, because of their potential applications in quantum information manipulation. However, previous experimental works all dealt with the single-component slow light which cannot be employed as a qubit. In this work, we report the first experimental demonstration of two-component or spinor slow light (SSL) using a double tripod (DT) atom-light coupling scheme. The oscillations between the two components, similar to the Rabi oscillation of a two-level system or a qubit, were observed. Single-photon SSL can be considered as two-color qubits. We experimentally demonstrated a possible application of the DT scheme as quantum memory and quantum rotator for the two-color qubits. This work opens up a new direction in the slow light research.

  12. Slow and fast light in semiconductor waveguides

    DEFF Research Database (Denmark)

    Mørk, Jesper; Hansen, Per Lunnemann; Xue, Weiqi

    2010-01-01

    transparency and coherent population oscillations. While electromagnetically induced transparency has been the most important effect in realizing slowdown effects in atomic gasses, progress has been comparatively slow in semiconductors due to inherent problems of fast dephasing times and inhomogeneous...

  13. Elastic scattering of slow positrons by helium

    International Nuclear Information System (INIS)

    Amusia, M.Ya.; Cherepkov, N.A.; Chernysheva, L.V.; Shapiro, S.G.

    1976-01-01

    The s-, p-, d- and f-wave phaseshifts for elastic scattering of slow positrons by He are calculated using a simplified version of the random phase approximation with exchange, with virtual positronium formation effect taken into account. (author)

  14. Influence of tungsten fiber’s slow drift on the measurement of G with angular acceleration method

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Jie; Wu, Wei-Huang; Zhan, Wen-Ze [School of Mechanical Engineering and Electronic Information, China University of Geosciences, Wuhan 430074 (China); Xue, Chao [MOE Key Laboratory of Fundamental Physical Quantities Measurement, School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Physics and Astronomy, Sun Yat-sen University, Guangzhou 510275 (China); Shao, Cheng-Gang, E-mail: cgshao@mail.hust.edu.cn; Wu, Jun-Fei [MOE Key Laboratory of Fundamental Physical Quantities Measurement, School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Milyukov, Vadim [Sternberg Astronomical Institute, Lomonosov Moscow State University, Moscow 119992 (Russian Federation)

    2016-08-15

    In the measurement of the gravitational constant G with angular acceleration method, the equilibrium position of torsion pendulum with tungsten fiber undergoes a linear slow drift, which results in a quadratic slow drift on the angular velocity of the torsion balance turntable under feedback control unit. The accurate amplitude determination of the useful angular acceleration signal with known frequency is biased by the linear slow drift and the coupling effect of the drifting equilibrium position and the room fixed gravitational background signal. We calculate the influences of the linear slow drift and the complex coupling effect on the value of G, respectively. The result shows that the bias of the linear slow drift on G is 7 ppm, and the influence of the coupling effect is less than 1 ppm.

  15. Lipoproteins of slow-growing Mycobacteria carry three fatty acids and are N-acylated by apolipoprotein N-acyltransferase BCG_2070c.

    Science.gov (United States)

    Brülle, Juliane K; Tschumi, Andreas; Sander, Peter

    2013-10-05

    Lipoproteins are virulence factors of Mycobacterium tuberculosis. Bacterial lipoproteins are modified by the consecutive action of preprolipoprotein diacylglyceryl transferase (Lgt), prolipoprotein signal peptidase (LspA) and apolipoprotein N- acyltransferase (Lnt) leading to the formation of mature triacylated lipoproteins. Lnt homologues are found in Gram-negative and high GC-rich Gram-positive, but not in low GC-rich Gram-positive bacteria, although N-acylation is observed. In fast-growing Mycobacterium smegmatis, the molecular structure of the lipid modification of lipoproteins was resolved recently as a diacylglyceryl residue carrying ester-bound palmitic acid and ester-bound tuberculostearic acid and an additional amide-bound palmitic acid. We exploit the vaccine strain Mycobacterium bovis BCG as model organism to investigate lipoprotein modifications in slow-growing mycobacteria. Using Escherichia coli Lnt as a query in BLASTp search, we identified BCG_2070c and BCG_2279c as putative lnt genes in M. bovis BCG. Lipoproteins LprF, LpqH, LpqL and LppX were expressed in M. bovis BCG and BCG_2070c lnt knock-out mutant and lipid modifications were analyzed at molecular level by matrix-assisted laser desorption ionization time-of-flight/time-of-flight analysis. Lipoprotein N-acylation was observed in wildtype but not in BCG_2070c mutants. Lipoprotein N- acylation with palmitoyl and tuberculostearyl residues was observed. Lipoproteins are triacylated in slow-growing mycobacteria. BCG_2070c encodes a functional Lnt in M. bovis BCG. We identified mycobacteria-specific tuberculostearic acid as further substrate for N-acylation in slow-growing mycobacteria.

  16. Slow Learner Errors Analysis in Solving Fractions Problems in Inclusive Junior High School Class

    Science.gov (United States)

    Novitasari, N.; Lukito, A.; Ekawati, R.

    2018-01-01

    A slow learner whose IQ is between 71 and 89 will have difficulties in solving mathematics problems that often lead to errors. The errors could be analyzed to where the errors may occur and its type. This research is qualitative descriptive which aims to describe the locations, types, and causes of slow learner errors in the inclusive junior high school class in solving the fraction problem. The subject of this research is one slow learner of seventh-grade student which was selected through direct observation by the researcher and through discussion with mathematics teacher and special tutor which handles the slow learner students. Data collection methods used in this study are written tasks and semistructured interviews. The collected data was analyzed by Newman’s Error Analysis (NEA). Results show that there are four locations of errors, namely comprehension, transformation, process skills, and encoding errors. There are four types of errors, such as concept, principle, algorithm, and counting errors. The results of this error analysis will help teachers to identify the causes of the errors made by the slow learner.

  17. Interlinked Fast and Slow Positive Feedback Loops Drive Reliable Cell Decisions

    OpenAIRE

    Brandman, Onn; Ferrell, James E.; Li, Rong; Meyer, Tobias

    2005-01-01

    Positive feedback is a ubiquitous signal transduction motif that allows systems to convert graded inputs into decisive, all-or-none outputs. Here we investigate why the positive feedback switches that regulate polarization of budding yeast, calcium signaling, Xenopus oocyte maturation, and various other processes use multiple interlinked loops rather than single positive feedback loops. Mathematical simulations revealed that linking fast and slow positive feedback loops creates a “dual-time” ...

  18. Human gamma oscillations during slow wave sleep.

    Directory of Open Access Journals (Sweden)

    Mario Valderrama

    Full Text Available Neocortical local field potentials have shown that gamma oscillations occur spontaneously during slow-wave sleep (SWS. At the macroscopic EEG level in the human brain, no evidences were reported so far. In this study, by using simultaneous scalp and intracranial EEG recordings in 20 epileptic subjects, we examined gamma oscillations in cerebral cortex during SWS. We report that gamma oscillations in low (30-50 Hz and high (60-120 Hz frequency bands recurrently emerged in all investigated regions and their amplitudes coincided with specific phases of the cortical slow wave. In most of the cases, multiple oscillatory bursts in different frequency bands from 30 to 120 Hz were correlated with positive peaks of scalp slow waves ("IN-phase" pattern, confirming previous animal findings. In addition, we report another gamma pattern that appears preferentially during the negative phase of the slow wave ("ANTI-phase" pattern. This new pattern presented dominant peaks in the high gamma range and was preferentially expressed in the temporal cortex. Finally, we found that the spatial coherence between cortical sites exhibiting gamma activities was local and fell off quickly when computed between distant sites. Overall, these results provide the first human evidences that gamma oscillations can be observed in macroscopic EEG recordings during sleep. They support the concept that these high-frequency activities might be associated with phasic increases of neural activity during slow oscillations. Such patterned activity in the sleeping brain could play a role in off-line processing of cortical networks.

  19. Magnon Inflation: Slow Roll with Steep Potentials

    CERN Document Server

    Adshead, Peter; Burgess, C P; Hayman, Peter; Patil, Subodh P

    2016-01-01

    We find multi-scalar effective field theories (EFTs) that can achieve a slow inflationary roll despite having a scalar potential that does not satisfy the usual slow-roll condition (d V)^2 << V^2/Mp^2. They evade the usual slow-roll conditions on $V$ because their kinetic energies are dominated by single-derivative terms rather than the usual two-derivative terms. Single derivatives dominate during slow roll and so do not require a breakdown of the usual derivative expansion that underpins calculational control in much of cosmology. The presence of such terms requires some sort of UV Lorentz-symmetry breaking during inflation (besides the usual cosmological breaking). Chromo-natural inflation provides an example of a UV theory that can generate the multi-field single-derivative terms we consider, and we argue that the EFT we find indeed captures the slow-roll conditions for the background evolution for Chromo-natural inflation. We also show that our EFT can be understood as a multi-field generalization ...

  20. Shot-Noise Limited Time-Encoded Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    Sebastian Karpf

    2017-01-01

    Full Text Available Raman scattering, an inelastic scattering mechanism, provides information about molecular excitation energies and can be used to identify chemical compounds. Albeit being a powerful analysis tool, especially for label-free biomedical imaging with molecular contrast, it suffers from inherently low signal levels. This practical limitation can be overcome by nonlinear enhancement techniques like stimulated Raman scattering (SRS. In SRS, an additional light source stimulates the Raman scattering process. This can lead to orders of magnitude increase in signal levels and hence faster acquisition in biomedical imaging. However, achieving a broad spectral coverage in SRS is technically challenging and the signal is no longer background-free, as either stimulated Raman gain (SRG or loss (SRL is measured, turning a sensitivity limit into a dynamic range limit. Thus, the signal has to be isolated from the laser background light, requiring elaborate methods for minimizing detection noise. Here, we analyze the detection sensitivity of a shot-noise limited broadband stimulated time-encoded Raman (TICO-Raman system in detail. In time-encoded Raman, a wavelength-swept Fourier domain mode locking (FDML laser covers a broad range of Raman transition energies while allowing a dual-balanced detection for lowering the detection noise to the fundamental shot-noise limit.

  1. Engineering Genetically Encoded FRET Sensors

    Science.gov (United States)

    Lindenburg, Laurens; Merkx, Maarten

    2014-01-01

    Förster Resonance Energy Transfer (FRET) between two fluorescent proteins can be exploited to create fully genetically encoded and thus subcellularly targetable sensors. FRET sensors report changes in energy transfer between a donor and an acceptor fluorescent protein that occur when an attached sensor domain undergoes a change in conformation in response to ligand binding. The design of sensitive FRET sensors remains challenging as there are few generally applicable design rules and each sensor must be optimized anew. In this review we discuss various strategies that address this shortcoming, including rational design approaches that exploit self-associating fluorescent domains and the directed evolution of FRET sensors using high-throughput screening. PMID:24991940

  2. Digital Signal Processing Based Biotelemetry Receivers

    Science.gov (United States)

    Singh, Avtar; Hines, John; Somps, Chris

    1997-01-01

    This is an attempt to develop a biotelemetry receiver using digital signal processing technology and techniques. The receiver developed in this work is based on recovering signals that have been encoded using either Pulse Position Modulation (PPM) or Pulse Code Modulation (PCM) technique. A prototype has been developed using state-of-the-art digital signal processing technology. A Printed Circuit Board (PCB) is being developed based on the technique and technology described here. This board is intended to be used in the UCSF Fetal Monitoring system developed at NASA. The board is capable of handling a variety of PPM and PCM signals encoding signals such as ECG, temperature, and pressure. A signal processing program has also been developed to analyze the received ECG signal to determine heart rate. This system provides a base for using digital signal processing in biotelemetry receivers and other similar applications.

  3. Theory of carrier depletion and light amplification in active slow light photonic crystal waveguides

    DEFF Research Database (Denmark)

    Chen, Yaohui; Mørk, Jesper

    2013-01-01

    of the device is investigated. An effective rate-equation-based model is presented. It is shown that it well accounts for the three-dimensional simulation results. Simulations indicate that a slow-light-enhanced photonic crystal traveling-wave amplifier has a high small-signal modal gain and low saturation...

  4. The pde2 gene of Saccharomyces cerevisiae is allelic to rca1 and encodes a phosphodiesterase which protects the cell from extracellular cAMP.

    Science.gov (United States)

    Wilson, R B; Renault, G; Jacquet, M; Tatchell, K

    1993-07-05

    The high affinity cAMP phosphodiesterase, encoded by PDE2, is an important component of the cAMP-dependent protein kinase signaling system in Saccharomyces cerevisiae. An unexpected phenotype of pde2 mutants is sensitivity to external cAMP. This trait has been found independently for rca1 mutants and has been used to monitor the effects of cAMP on several biological processes. We demonstrate here that RCA1 is identical to PDE2. Further analysis of the phenotype of pde2 deletions reveal that exogenously added cAMP results in an increase in the internal level of cAMP. This increase slows down the rate of cell division by increasing the length of the G1 phase of the cell cycle and leads to increased cell volume. Also, cells with a disrupted PDE2 gene previously arrested by nutrient starvation rapidly lose thermotolerance when incubated with exogenous cAMP. From these observations we propose that a role of the PDE2-encoded phosphodiesterase may be to help insulate the internal cAMP pools from the external environment. This protective role might also be important in other eukaryotic organisms where cAMP is a key second messenger.

  5. Robust EPI Nyquist ghost elimination via spatial and temporal encoding.

    Science.gov (United States)

    Hoge, W Scott; Tan, Huan; Kraft, Robert A

    2010-12-01

    Nyquist ghosts are an inherent artifact in echo planar imaging acquisitions. An approach to robustly eliminate Nyquist ghosts is presented that integrates two previous Nyquist ghost correction techniques: temporal domain encoding (phase labeling for additional coordinate encoding: PLACE and spatial domain encoding (phased array ghost elimination: PAGE). Temporal encoding modulates the echo planar imaging acquisition trajectory from frame to frame, enabling one to interleave data to remove inconsistencies that occur between sampling on positive and negative gradient readouts. With PLACE, one can coherently combine the interleaved data to cancel residual Nyquist ghosts. If the level of ghosting varies significantly from image to image, however, the signal cancellation that occurs with PLACE can adversely affect SNR-sensitive applications such as perfusion imaging with arterial spin labeling. This work proposes integrating PLACE into a PAGE-based reconstruction process to yield significantly better Nyquist ghost correction that is more robust than PLACE or PAGE alone. The robustness of this method is demonstrated in the presence of magnetic field drift with an in-vivo arterial spin labeling perfusion experiment. Copyright © 2010 Wiley-Liss, Inc.

  6. Dynamical encoding of looming, receding, and focussing

    Science.gov (United States)

    Longtin, Andre; Clarke, Stephen Elisha; Maler, Leonard; CenterNeural Dynamics Collaboration

    This talk will discuss a non-conventional neural coding task that may apply more broadly to many senses in higher vertebrates. We ask whether and how a non-visual sensory system can focus on an object. We present recent experimental and modeling work that shows how the early sensory circuitry of electric sense can perform such neuronal focusing that is manifested behaviorally. This sense is the main one used by weakly electric fish to navigate, locate prey and communicate in the murky waters of their natural habitat. We show that there is a distance at which the Fisher information of a neuron's response to a looming and receding object is maximized, and that this distance corresponds to a behaviorally relevant one chosen by these animals. Strikingly, this maximum occurs at a bifurcation between tonic firing and bursting. We further discuss how the invariance of this distance to signal attributes can arise, a process that first involves power-law spike frequency adaptation. The talk will also highlight the importance of expanding the classic dual neural encoding of contrast using ON and OFF cells in the context of looming and receding stimuli. The authors acknowledge support from CIHR and NSERC.

  7. Belief Propagation for Probabilistic Slow Feature Analysis

    Science.gov (United States)

    Omori, Toshiaki; Sekiguchi, Tomoki; Okada, Masato

    2017-08-01

    Slow feature analysis (SFA) is a time-series analysis method for extracting slowly-varying latent features from multi-dimensional data. A recent study proposed a probabilistic framework of SFA using the Bayesian statistical framework. However, the conventional probabilistic framework of SFA can not accurately extract the slow feature in noisy environments since its marginal likelihood function was approximately derived under the assumption that there exists no observation noise. In this paper, we propose a probabilistic framework of SFA with rigorously derived marginal likelihood function. Here, we rigorously derive the marginal likelihood function of the probabilistic framework of SFA by using belief propagation. We show using numerical data that the proposed probabilistic framework of SFA can accurately extract the slow feature and underlying parameters for the latent dynamics simultaneously even under noisy environments.

  8. Kinetic slow mode-type solitons

    Directory of Open Access Journals (Sweden)

    K. Baumgärtel

    2005-01-01

    Full Text Available One-dimensional hybrid code simulations are presented, carried out in order both to study solitary waves of the slow mode branch in an isotropic, collisionless, medium-β plasma (βi=0.25 and to test the fluid based soliton interpretation of Cluster observed strong magnetic depressions (Stasiewicz et al., 2003; Stasiewicz, 2004 against kinetic theory. In the simulations, a variety of strongly oblique, large amplitude, solitons are seen, including solitons with Alfvenic polarization, similar to those predicted by the Hall-MHD theory, and robust, almost non-propagating, solitary structures of slow magnetosonic type with strong magnetic field depressions and perpendicular ion heating, which have no counterpart in fluid theory. The results support the soliton-based interpretation of the Cluster observations, but reveal substantial deficiencies of Hall-MHD theory in describing slow mode-type solitons in a plasma of moderate beta.

  9. Resveratrol exhibits differential protective effects on fast- and slow-twitch muscles in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Chang, Chih-Chun; Yang, Meng-Hsuan; Tung, Hung-Chun; Chang, Chieh-Yu; Tsai, Yu-Lin; Huang, Jiung-Pang; Yen, Tzung-Hai; Hung, Li-Man

    2014-01-01

    This study aimed to investigate the differential protective effect of resveratrol (RSV) on oxidative stress and metabolic signaling pathways in fast- and slow-twitch skeletal muscles of rats with diabetes. Diabetic rats were induced by streptozotocin (STZ) for 2 weeks and then administered with RSV (1, 10 and 100 μg/kg per day) for 1 week. We determined oxidative stress and protein expression by lucigenin-mediated chemiluminescence and Western immunoblot. The superoxide anion production and copper-zinc superoxide dismutase (CuZnSOD) protein level were increased in fast-twitch muscle than in slow-twitch muscle of diabetes. The Akt and glycogen synthase kinase 3 (GSK-3) phosphorylations were reduced in both fast- and slow-twitch muscles of diabetes. Oxidative stress and GSK-3 dephosphorylation were corrected by RSV treatment in both fast- and slow-twitch muscles of diabetes. Furthermore, RSV treatment downregulated CuZnSOD protein level in diabetic fast-twitch muscle. In diabetic slow-twitch muscle, RSV treatment elevated manganese SOD (MnSOD) and phosphorylated Akt protein levels and reduced acetyl-CoA carboxylase (ACC) phosphorylation. Our results suggested that fast-twitch muscle incurred more oxidative stress, whereas slow-twitch muscle altered metabolic signaling molecules activities under diabetic status. The antidiabetic effect of RSV on fast- and slow-twitch skeletal muscles was mediated by different antioxidative and metabolic signals. © 2013 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

  10. Transplanckian energy production and slow roll inflation

    International Nuclear Information System (INIS)

    Danielsson, Ulf H.

    2005-01-01

    In this paper we investigate how the energy density due to a nonstandard choice of initial vacuum affects the expansion of the universe during inflation. To do this we introduce source terms in the Friedmann equations making sure that we respect the relation between gravity and thermodynamics. We find that the energy production automatically implies a slow rolling cosmological constant. Hence we also conclude that there is no well defined value for the cosmological constant in the presence of sources. We speculate that a nonstandard vacuum can provide slow roll inflation on its own

  11. SnoVault and encodeD: A novel object-based storage system and applications to ENCODE metadata.

    Science.gov (United States)

    Hitz, Benjamin C; Rowe, Laurence D; Podduturi, Nikhil R; Glick, David I; Baymuradov, Ulugbek K; Malladi, Venkat S; Chan, Esther T; Davidson, Jean M; Gabdank, Idan; Narayana, Aditi K; Onate, Kathrina C; Hilton, Jason; Ho, Marcus C; Lee, Brian T; Miyasato, Stuart R; Dreszer, Timothy R; Sloan, Cricket A; Strattan, J Seth; Tanaka, Forrest Y; Hong, Eurie L; Cherry, J Michael

    2017-01-01

    The Encyclopedia of DNA elements (ENCODE) project is an ongoing collaborative effort to create a comprehensive catalog of functional elements initiated shortly after the completion of the Human Genome Project. The current database exceeds 6500 experiments across more than 450 cell lines and tissues using a wide array of experimental techniques to study the chromatin structure, regulatory and transcriptional landscape of the H. sapiens and M. musculus genomes. All ENCODE experimental data, metadata, and associated computational analyses are submitted to the ENCODE Data Coordination Center (DCC) for validation, tracking, storage, unified processing, and distribution to community resources and the scientific community. As the volume of data increases, the identification and organization of experimental details becomes increasingly intricate and demands careful curation. The ENCODE DCC has created a general purpose software system, known as SnoVault, that supports metadata and file submission, a database used for metadata storage, web pages for displaying the metadata and a robust API for querying the metadata. The software is fully open-source, code and installation instructions can be found at: http://github.com/ENCODE-DCC/snovault/ (for the generic database) and http://github.com/ENCODE-DCC/encoded/ to store genomic data in the manner of ENCODE. The core database engine, SnoVault (which is completely independent of ENCODE, genomic data, or bioinformatic data) has been released as a separate Python package.

  12. SnoVault and encodeD: A novel object-based storage system and applications to ENCODE metadata.

    Directory of Open Access Journals (Sweden)

    Benjamin C Hitz

    Full Text Available The Encyclopedia of DNA elements (ENCODE project is an ongoing collaborative effort to create a comprehensive catalog of functional elements initiated shortly after the completion of the Human Genome Project. The current database exceeds 6500 experiments across more than 450 cell lines and tissues using a wide array of experimental techniques to study the chromatin structure, regulatory and transcriptional landscape of the H. sapiens and M. musculus genomes. All ENCODE experimental data, metadata, and associated computational analyses are submitted to the ENCODE Data Coordination Center (DCC for validation, tracking, storage, unified processing, and distribution to community resources and the scientific community. As the volume of data increases, the identification and organization of experimental details becomes increasingly intricate and demands careful curation. The ENCODE DCC has created a general purpose software system, known as SnoVault, that supports metadata and file submission, a database used for metadata storage, web pages for displaying the metadata and a robust API for querying the metadata. The software is fully open-source, code and installation instructions can be found at: http://github.com/ENCODE-DCC/snovault/ (for the generic database and http://github.com/ENCODE-DCC/encoded/ to store genomic data in the manner of ENCODE. The core database engine, SnoVault (which is completely independent of ENCODE, genomic data, or bioinformatic data has been released as a separate Python package.

  13. Power calculation of linear and angular incremental encoders

    Science.gov (United States)

    Prokofev, Aleksandr V.; Timofeev, Aleksandr N.; Mednikov, Sergey V.; Sycheva, Elena A.

    2016-04-01

    Automation technology is constantly expanding its role in improving the efficiency of manufacturing and testing processes in all branches of industry. More than ever before, the mechanical movements of linear slides, rotary tables, robot arms, actuators, etc. are numerically controlled. Linear and angular incremental photoelectric encoders measure mechanical motion and transmit the measured values back to the control unit. The capabilities of these systems are undergoing continual development in terms of their resolution, accuracy and reliability, their measuring ranges, and maximum speeds. This article discusses the method of power calculation of linear and angular incremental photoelectric encoders, to find the optimum parameters for its components, such as light emitters, photo-detectors, linear and angular scales, optical components etc. It analyzes methods and devices that permit high resolutions in the order of 0.001 mm or 0.001°, as well as large measuring lengths of over 100 mm. In linear and angular incremental photoelectric encoders optical beam is usually formulated by a condenser lens passes through the measuring unit changes its value depending on the movement of a scanning head or measuring raster. Past light beam is converting into an electrical signal by the photo-detecter's block for processing in the electrical block. Therefore, for calculating the energy source is a value of the desired value of the optical signal at the input of the photo-detecter's block, which reliably recorded and processed in the electronic unit of linear and angular incremental optoelectronic encoders. Automation technology is constantly expanding its role in improving the efficiency of manufacturing and testing processes in all branches of industry. More than ever before, the mechanical movements of linear slides, rotary tables, robot arms, actuators, etc. are numerically controlled. Linear and angular incremental photoelectric encoders measure mechanical motion and

  14. A Novel Audio Cryptosystem Using Chaotic Maps and DNA Encoding

    Directory of Open Access Journals (Sweden)

    S. J. Sheela

    2017-01-01

    Full Text Available Chaotic maps have good potential in security applications due to their inherent characteristics relevant to cryptography. This paper introduces a new audio cryptosystem based on chaotic maps, hybrid chaotic shift transform (HCST, and deoxyribonucleic acid (DNA encoding rules. The scheme uses chaotic maps such as two-dimensional modified Henon map (2D-MHM and standard map. The 2D-MHM which has sophisticated chaotic behavior for an extensive range of control parameters is used to perform HCST. DNA encoding technology is used as an auxiliary tool which enhances the security of the cryptosystem. The performance of the algorithm is evaluated for various speech signals using different encryption/decryption quality metrics. The simulation and comparison results show that the algorithm can achieve good encryption results and is able to resist several cryptographic attacks. The various types of analysis revealed that the algorithm is suitable for narrow band radio communication and real-time speech encryption applications.

  15. Optimal Achievable Encoding for Brain Machine Interface

    Science.gov (United States)

    2017-12-22

    AFRL-RH-WP-TP-2017-0001 Optimal Achievable Encoding for Brain- Machine Interface Eduardo Chichilnisky Leland Stanford Junior...Oct 2016 – 30 Sep 2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Optimal Achievable Encoding for Brain- Machine Interface 5b...required. First, we developed novel models of retinal encoding that improve upon the state of the art, by using machine learning methods to

  16. Implementation-intention encoding in a prospective memory task enhances spontaneous retrieval of intentions.

    Science.gov (United States)

    Rummel, Jan; Einstein, Gilles O; Rampey, Hilary

    2012-01-01

    Although forming implementation intentions (Gollwitzer, 1999) has been demonstrated to generally improve prospective memory, the underlying cognitive mechanisms are not completely understood. It has been proposed that implementation-intention encoding encourages spontaneous retrieval (McDaniel & Scullin, 2010). Alternatively one could assume the positive effect of implementation-intention encoding is caused by increased or more efficient monitoring for target cues. To test these alternative explanations and to further investigate the cognitive mechanisms underlying implementation-intention benefits, in two experiments participants formed the intention to respond to specific target cues in a lexical decision task with a special key, but then had to suspend this intention during an intervening word-categorisation task. Response times on trials directly following the occurrence of target cues in the intervening task were significantly slower with implementation-intention encoding than with standard encoding, indicating that spontaneous retrieval was increased (Experiment 1). However, when activation of the target cues was controlled for, similar slowing was found with both standard and implementation-intention encoding (Experiment 2). The results imply that implementation-intention encoding as well as increased target-cue activation foster spontaneous retrieval processes.

  17. Response of electret dosemeter to slow neutrons

    International Nuclear Information System (INIS)

    Ghilardi, A.J.P.; Pela, C.A.; Zimmerman, R.L.

    1987-01-01

    The response of the electret dosemeter to exposition of slow neutrons is studied. Different external coatings are used on the dosemeter (polyethylene, alminium, polyethylene + boron, aluminium + boron) and exposure curves (with and without water) are compared. (M.A.C.) [pt

  18. Slowed ageing, welfare, and population problems.

    Science.gov (United States)

    Wareham, Christopher

    2015-10-01

    Biological studies have demonstrated that it is possible to slow the ageing process and extend lifespan in a wide variety of organisms, perhaps including humans. Making use of the findings of these studies, this article examines two problems concerning the effect of life extension on population size and welfare. The first--the problem of overpopulation--is that as a result of life extension too many people will co-exist at the same time, resulting in decreases in average welfare. The second--the problem of underpopulation--is that life extension will result in too few people existing across time, resulting in decreases in total welfare. I argue that overpopulation is highly unlikely to result from technologies that slow ageing. Moreover, I claim that the problem of underpopulation relies on claims about life extension that are false in the case of life extension by slowed ageing. The upshot of these arguments is that the population problems discussed provide scant reason to oppose life extension by slowed ageing.

  19. Analysis of the neutron slowing down equation

    International Nuclear Information System (INIS)

    Sengupta, A.; Karnick, H.

    1978-01-01

    The infinite series solution of the elementary neutron slowing down equation is studied using the theory of entire functions of exponential type and nonharmonic Fourier series. It is shown from Muntz--Szasz and Paley--Wiener theorems, that the set of exponentials ]exp(ilambda/sub n/u) ]/sup infinity//sub n/=-infinity, where ]lambda/sub n/]/sup infinity//sub n/=-infinity are the roots of the transcendental equation in slowing down theory, is complete and forms a basis in a lethargy interval epsilon. This distinctive role of the maximum lethargy change per collision is due to the Fredholm character of the slowing down operator which need not be quasinilpotent. The discontinuities in the derivatives of the collision density are examined by treating the slowing down equation in its differential-difference form. The solution (Hilbert) space is the union of a countable number of subspaces L 2 (-epsilon/2, epsilon/2) over each of which the exponential functions are complete

  20. Holographic Gratings for Slow-Neutron Optics

    Science.gov (United States)

    Klepp, Juergen; Pruner, Christian; Tomita, Yasuo; Geltenbort, Peter; Drevenšek-Olenik, Irena; Gyergyek, Saso; Kohlbrecher, Joachim; Fally, Martin

    2012-01-01

    Recent progress in the development of holographic gratings for neutron-optics applications is reviewed. We summarize the properties of gratings recorded in deuterated (poly)methylmethacrylate, holographic polymer-dispersed liquid crystals and nanoparticle-polymer composites revealed by diffraction experiments with slow neutrons. Existing and anticipated neutron-optical instrumentations based on holographic gratings are discussed.

  1. Preliminary characterization of slow growing rhizobial strains ...

    African Journals Online (AJOL)

    In this paper, we did some preliminary characterization of six slow growing rhizobial strains, isolated from Retama monosperma (L.) Boiss. root nodules sampled from 3 sites along the coast of Oran (CapeFalcon, Bousfer and MersElHadjadj) in Northwestern Algeria. Results of this study showed that all strains had a very ...

  2. Probabilistic Slow Features for Behavior Analysis

    NARCIS (Netherlands)

    Zafeiriou, Lazaros; Nicolaou, Mihalis A.; Zafeiriou, Stefanos; Nikitidis, Symeon; Pantic, Maja

    A recently introduced latent feature learning technique for time-varying dynamic phenomena analysis is the so-called slow feature analysis (SFA). SFA is a deterministic component analysis technique for multidimensional sequences that, by minimizing the variance of the first-order time derivative

  3. Learning slow features for behavior analysis

    NARCIS (Netherlands)

    Zafeiriou, Lazaros; Nicolaou, Mihalis A.; Zafeiriou, Stefanos; Nikitids, Symeon; Pantic, Maja

    2013-01-01

    A recently introduced latent feature learning technique for time varying dynamic phenomena analysis is the socalled Slow Feature Analysis (SFA). SFA is a deterministic component analysis technique for multi-dimensional sequences that by minimizing the variance of the first order time derivative

  4. A slow component of classic Stroop interference

    NARCIS (Netherlands)

    Phaf, R. Hans; Horsman, Hark H.; van der Moolen, Bas; Roos, Yvo B. W. E. M.; Schmand, Ben

    2010-01-01

    The interference in colour naming may extend beyond critical Stroop trials. This "slow'' effect was first discovered in emotional Stroop tasks, but is extended here to classical Stroop. In two experiments, meaningless coloured letter strings followed a colour word or neutral word. Student

  5. Slow evaporation method and enhancement in photoluminescence ...

    Indian Academy of Sciences (India)

    MS received 31 May 2015; accepted 1 February 2016. Abstract. The series of Bi3+ co-doped YPO4 : Eu3+ nanophosphors were successfully synthesized by the slow evaporation method. Bi3+-doped and un-doped YPO4 : Eu3+ phosphors were characterized by using powder X-ray diffraction, Fourier transform infrared ...

  6. Identification of a conserved cluster of skin-specific genes encoding secreted proteins.

    Science.gov (United States)

    Moffatt, Pierre; Salois, Patrick; St-Amant, Natalie; Gaumond, Marie-Hélène; Lanctôt, Christian

    2004-06-09

    Terminal differentiation of keratinocytes results in the formation of a cornified layer composed of cross-linked intracellular and extracellular material. Using a signal trap expression screening strategy, we have identified four cDNAs encoding secreted proteins potentially involved in this process. One of the cDNAs is identical to the short isoform of suprabasin, a recently described epidermis-specific protein, which is shown here to contain a functional secretory signal. The second cDNA, sk89, encodes a protein of 493 amino acids, rich in glycine and serine residues. The third cDNA encodes a C-terminal fragment of SK89 (amino acids 410-493). It comprises exons 13 to 18 of the sk89 locus but transcription starts at an isoform-specific exon encoding a distinct secretory signal. The fourth cDNA encodes keratinocyte differentiation-associated protein (KDAP), a precursor protein of 102 amino acids. Subcellular localization by immunofluorescence and detection of the tagged proteins by Western blotting confirmed that the four proteins are secreted. Northern analysis and in situ hybridization revealed that expression of the corresponding genes was restricted to the suprabasal keratinocytes of the epidermis. These genes encoding epidermis-specific secreted products are found in a conserved cluster on human chromosome 19q13.12 and on mouse chromosome 7A3.

  7. The ENCODE project: missteps overshadowing a success.

    Science.gov (United States)

    Eddy, Sean R

    2013-04-08

    Two clichés of science journalism have now played out around the ENCODE project. ENCODE's publicity first presented a misleading "all the textbooks are wrong" narrative about noncoding human DNA. Now several critiques of ENCODE's narrative have been published, and one was so vitriolic that it fueled "undignified academic squabble" stories that focused on tone more than substance. Neither story line does justice to our actual understanding of genomes, to ENCODE's results, or to the role of big science in biology. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Universal dynamic goniometer for rotary encoders

    Science.gov (United States)

    Smirnov, Nikolai V.; Latyev, Svjatoslav M.; Naumova, Anastasiia I.

    2017-06-01

    A novel dynamic goniometer for the accuracy of rotary encoders has been developed on the base of the method of comparison with the reference encoder. The set-up of the goniometer considers all constructive and informative characteristics of measured encoders. The novel goniometer construction uses the new compensating method of instrumental errors in automatic working process. The advantages of the dynamic goniometer in combination with an optical rotary encoder at the reduction of the measuring time and a simultaneous increase of the accuracy.

  9. Development of lead slowing down spectrometer for isotopic fissile assay

    International Nuclear Information System (INIS)

    Lee, Yong Deok; Park, Chang Je; Ahn, Sang Joon; Kim, Ho Dong

    2014-01-01

    A lead slowing down spectrometer (LSDS) is under development for analysis of isotopic fissile material contents in pyro-processed material, or spent fuel. Many current commercial fissile assay technologies have a limitation in accurate and direct assay of fissile content. However, LSDS is very sensitive in distinguishing fissile fission signals from each isotope. A neutron spectrum analysis was conducted in the spectrometer and the energy resolution was investigated from 0.1eV to 100keV. The spectrum was well shaped in the slowing down energy. The resolution was enough to obtain each fissile from 0.2eV to 1keV. The detector existence in the lead will disturb the source neutron spectrum. It causes a change in resolution and peak amplitude. The intense source neutron production was designed for ∼E12 n's/sec to overcome spent fuel background. The detection sensitivity of U238 and Th232 fission chamber was investigated. The first and second layer detectors increase detection efficiency. Thorium also has a threshold property to detect the fast fission neutrons from fissile fission. However, the detection of Th232 is about 76% of that of U238. A linear detection model was set up over the slowing down neutron energy to obtain each fissile material content. The isotopic fissile assay using LSDS is applicable for the optimum design of spent fuel storage to maximize burnup credit and quality assurance of the recycled nuclear material for safety and economics. LSDS technology will contribute to the transparency and credibility of pyro-process using spent fuel, as internationally demanded.

  10. Analysis of slow-wave activity and slow-wave oscillations prior to somnambulism.

    Science.gov (United States)

    Jaar, Olivier; Pilon, Mathieu; Carrier, Julie; Montplaisir, Jacques; Zadra, Antonio

    2010-11-01

    STUDY OBJECTIVIES: several studies have investigated slow wave sleep EEG parameters, including slow-wave activity (SWA) in relation to somnambulism, but results have been both inconsistent and contradictory. The first goal of the present study was to conduct a quantitative analysis of sleepwalkers' sleep EEG by studying fluctuations in spectral power for delta (1-4 Hz) and slow delta (0.5-1 Hz) before the onset of somnambulistic episodes. A secondary aim was to detect slow-wave oscillations to examine changes in their amplitude and density prior to behavioral episodes. twenty-two adult sleepwalkers were investigated polysomnographically following 25 h of sleep deprivation. analysis of patients' sleep EEG over the 200 sec prior to the episodes' onset revealed that the episodes were not preceded by a gradual increase in spectral power for either delta or slow delta over frontal, central, or parietal leads. However, time course comparisons revealed significant changes in the density of slow-wave oscillations as well as in very slow oscillations with significant increases occurring during the final 20 sec immediately preceding episode onset. the specificity of these sleep EEG parameters for the occurrence and diagnosis of NREM parasomnias remains to be determined.

  11. Spatial Specificity in Spatiotemporal Encoding and Fourier Imaging

    Science.gov (United States)

    Goerke, Ute

    2015-01-01

    Purpose Ultrafast imaging techniques based on spatiotemporal-encoding (SPEN), such as RASER (rapid acquisition with sequential excitation and refocusing), is a promising new class of sequences since they are largely insensitive to magnetic field variations which cause signal loss and geometric distortion in EPI. So far, attempts to theoretically describe the point-spread-function (PSF) for the original SPEN-imaging techniques have yielded limited success. To fill this gap a novel definition for an apparent PSF is proposed. Theory Spatial resolution in SPEN-imaging is determined by the spatial phase dispersion imprinted on the acquired signal by a frequency-swept excitation or refocusing pulse. The resulting signal attenuation increases with larger distance from the vertex of the quadratic phase profile. Methods Bloch simulations and experiments were performed to validate theoretical derivations. Results The apparent PSF quantifies the fractional contribution of magnetization to a voxel’s signal as a function of distance to the voxel. In contrast, the conventional PSF represents the signal intensity at various locations. Conclusion The definition of the conventional PSF fails for SPEN-imaging since only the phase of isochromats, but not the amplitude of the signal varies. The concept of the apparent PSF is shown to be generalizable to conventional Fourier- imaging techniques. PMID:26712657

  12. Retrograde signaling

    DEFF Research Database (Denmark)

    Kleine, Tatjana; Leister, Dario Michael

    2016-01-01

    The term retrograde signaling refers to the fact that chloroplasts and mitochondria utilize specific signaling molecules to convey information on their developmental and physiological states to the nucleus and modulate the expression of nuclear genes accordingly. Signals emanating from plastids...... of retrograde signaling has since been extended and revised. Elements of several 'operational' signaling circuits have come to light, including metabolites, signaling cascades in the cytosol and transcription factors. Here, we review recent advances in the identification and characterization of retrograde...

  13. LEAD SLOWING DOWN SPECTROSCOPY FOR DIRECT Pu MASS MEASUREMENTS

    International Nuclear Information System (INIS)

    Ressler, Jennifer J.; Smith, Leon E.; Anderson, Kevin K.

    2008-01-01

    The direct measurement of Pu in previously irradiated fuel assemblies is a recognized need in the international safeguards community. A suitable technology could support more timely and independent material control and accounting (MC and A) measurements at nuclear fuel storage areas, the head-end of reprocessing facilities, and at the product-end of recycled fuel fabrication. Lead slowing down spectroscopy (LSDS) may be a viable solution for directly measuring not only the mass of 239Pu in fuel assemblies, but also the masses of other fissile isotopes such as 235U and 241Pu. To assess the potential viability of LSDS, an LSDS spectrometer was modeled in MCNP5 and 'virtual assays' of nominal PWR assemblies ranging from 0 to 60 GWd/MTU burnup were completed. Signal extraction methods, including the incorporation of nonlinear fitting to account for self-shielding effects in strong resonance regions, are described. Quantitative estimates of Pu uncertainty are given for simplistic and more realistic fuel isotopic inventories calculated using ORIGEN. A discussion of additional signal-perturbing effects that will be addressed in future work, and potential signal extraction approaches that could improve Pu mass uncertainties, are also discussed

  14. Experimental study on quantitative evaluation of slow pulsatile flow of CSF with cine MRI

    International Nuclear Information System (INIS)

    Matsuda, Masao

    1991-01-01

    The present study was designed to evaluate the slow pulsatile flow of cerebrospinal fluid (CSF) quantitatively with cine MRI in phantom experiment for the clinical application. The flow phantom was constructed from a plastic tube with a narrow channel to represent the central aqueduct. The phantom was filled with water to represent the CSF. The second tube filled with stationary water was positioned beside the flow phantom and acted as a control for no-flow signal strength. The ratio of signal intensity in regions of interest for the flow phantom and the control was measured. Not only the actual velocity curve of the flowing water through the phantom but also the temporal profile of signal intensity showed two main peaks with other small peaks in one cycle. This suggested a close relationship between signal intensity of cine MRI and flow velocity. A significant correlation between the signal intensity ratio and the velocity was obtained on cine MRI pulse sequences. Cine MRI was thus found to have the ability to give quantitative information about slow pulsatile flow. The most suitable pulse sequence was fast imaging with steady state free precession pulse sequence at the flip angle between 50 and 90 degrees. This preliminary study suggests that the slow pulsatile flow of CSF passing along the aqueduct can be visualized and measured. Thus, the sequence proposed has a potential for the investigation of normal and disturbed CSF circulation and the mapping of the flow pattern in different pathological conditions. (N.K.)

  15. A Stochastic Slow Extraction Scheme For U70 Synchrotron

    CERN Document Server

    Ivanov, S

    2004-01-01

    Outcomes of a feasibility study for a low-budget sto-chastic slow extraction system in the U70 proton synchro-tron of IHEP are reported. The existing 200 MHz (spill) RF system is to be employed as a longitudinal kicker. It will be driven by a sum of a non-random RF carrier plus an additive random amplitude-modulated signal - either quadrature or in-phase, or both. A few novel solutions to be implemented in the longitudinal diffusion technique that would force protons into the conventional 3-rd order transverse extraction resonance are foreseen so as to com-ply with the technical constraints inherent in U70. Getting a-few-seconds-long and high-quality spills is assessed as being viable with the system in question.

  16. A MPEG-4 encoder based on TMS320C6416

    Science.gov (United States)

    Li, Gui-ju; Liu, Wei-ning

    2013-08-01

    Engineering and products need to achieve real-time video encoding by DSP, but the high computational complexity and huge amount of data requires that system has high data throughput. In this paper, a real-time MPEG-4 video encoder is designed based on TMS320C6416 platform. The kernel is the DSP of TMS320C6416T and FPGA chip f as the organization and management of video data. In order to control the flow of input and output data. Encoded stream is output using the synchronous serial port. The system has the clock frequency of 1GHz and has up to 8000 MIPS speed processing capacity when running at full speed. Due to the low coding efficiency of MPEG-4 video encoder transferred directly to DSP platform, it is needed to improve the program structure, data structures and algorithms combined with TMS320C6416T characteristics. First: Design the image storage architecture by balancing the calculation spending, storage space cost and EDMA read time factors. Open up a more buffer in memory, each buffer cache 16 lines of video data to be encoded, reconstruction image and reference image including search range. By using the variable alignment mode of the DSP, modifying the definition of structure variables and change the look-up table which occupy larger space with a direct calculation array to save memory space. After the program structure optimization, the program code, all variables, buffering buffers and the interpolation image including the search range can be placed in memory. Then, as to the time-consuming process modules and some functions which are called many times, the corresponding modules are written in parallel assembly language of TMS320C6416T which can increase the running speed. Besides, the motion estimation algorithm is improved by using a cross-hexagon search algorithm, The search speed can be increased obviously. Finally, the execution time, signal-to-noise ratio and compression ratio of a real-time image acquisition sequence is given. The experimental

  17. Vocabulary learning benefits from REM after slow-wave sleep.

    Science.gov (United States)

    Batterink, Laura J; Westerberg, Carmen E; Paller, Ken A

    2017-10-01

    Memory reactivation during slow-wave sleep (SWS) influences the consolidation of recently acquired knowledge. This reactivation occurs spontaneously during sleep but can also be triggered by presenting learning-related cues, a technique known as targeted memory reactivation (TMR). Here we examined whether TMR can improve vocabulary learning. Participants learned the meanings of 60 novel words. Auditory cues for half the words were subsequently presented during SWS in an afternoon nap. Memory performance for cued versus uncued words did not differ at the group level but was systematically influenced by REM sleep duration. Participants who obtained relatively greater amounts of REM showed a significant benefit for cued relative to uncued words, whereas participants who obtained little or no REM demonstrated a significant effect in the opposite direction. We propose that REM after SWS may be critical for the consolidation of highly integrative memories, such as new vocabulary. Reactivation during SWS may allow newly encoded memories to be associated with other information, but this association can include disruptive linkages with pre-existing memories. Subsequent REM sleep may then be particularly beneficial for integrating new memories into appropriate pre-existing memory networks. These findings support the general proposition that memory storage benefits optimally from a cyclic succession of SWS and REM. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Transcriptomic difference in bovine blastocysts following vitrification and slow freezing at morula stage.

    Directory of Open Access Journals (Sweden)

    Alisha Gupta

    Full Text Available Cryopreservation is known for its marked deleterious effects on embryonic health. Bovine compact morulae were vitrified or slow-frozen, and post-warm morulae were cultured to the expanded blastocyst stage. Blastocysts developed from vitrified and slow-frozen morulae were subjected to microarray analysis and compared with blastocysts developed from unfrozen control morulae for differential gene expression. Morula to blastocyst conversion rate was higher (P < 0.05 in control (72% and vitrified (77% than in slow-frozen (34% morulae. Total 20 genes were upregulated and 44 genes were downregulated in blastocysts developed from vitrified morulae (fold change ≥ ± 2, P < 0.05 in comparison with blastocysts developed from control morulae. In blastocysts developed from slow-frozen morulae, 102 genes were upregulated and 63 genes were downregulated (fold change ≥ ± 1.5, P < 0.05. Blastocysts developed from vitrified morulae exhibited significant changes in gene expression mainly involving embryo implantation (PTGS2, CALB1, lipid peroxidation and reactive oxygen species generation (HSD3B1, AKR1B1, APOA1 and cell differentiation (KRT19, CLDN23. However, blastocysts developed from slow-frozen morulae showed changes in the expression of genes related to cell signaling (SPP1, cell structure and differentiation (DCLK2, JAM2 and VIM, and lipid metabolism (PLA2R1 and SMPD3. In silico comparison between blastocysts developed form vitrified and slow-frozen morulae revealed similar changes in gene expression as between blastocysts developed from vitrified and control morulae. In conclusion, blastocysts developed form vitrified morulae demonstrated better post-warming survival than blastocysts developed from slow-frozen morulae but their gene expression related to lipid metabolism, steroidogenesis, cell differentiation and placentation changed significantly (≥ 2 fold. Slow freezing method killed more morulae than vitrification but those which survived up to

  19. 47 CFR 11.32 - EAS Encoder.

    Science.gov (United States)

    2010-10-01

    ... encoder programming shall be protected by a lock or other security measures and be configured so that... for either manual or automatic operation. (2) Inputs. The encoder shall have two inputs, one for audio... initiating the automatic generation of the simultaneous tones shall be protected to prevent accidental...

  20. Effects of diazepam on encoding processes

    NARCIS (Netherlands)

    Gorissen, M.; Eling, P.; Luijtelaar, G. van; Coenen, A.

    1995-01-01

    Benzodiazepines are known to induce amnesic effects. To specify these effects more precisely, 40 healthy volunteers were given 15 mg diazepam or placebo. Effects on a chain of encoding operations were investigated: activation of memory representations, spreading of activation, semantic encoding and

  1. Excitatory Neuronal Hubs Configure Multisensory Integration of Slow Waves in Association Cortex

    Directory of Open Access Journals (Sweden)

    Satoshi Kuroki

    2018-03-01

    Full Text Available Summary: Multisensory integration (MSI is a fundamental emergent property of the mammalian brain. During MSI, perceptual information encoded in patterned activity is processed in multimodal association cortex. The systems-level neuronal dynamics that coordinate MSI, however, are unknown. Here, we demonstrate intrinsic hub-like network activity in the association cortex that regulates MSI. We engineered calcium reporter mouse lines based on the fluorescence resonance energy transfer sensor yellow cameleon (YC2.60 expressed in excitatory or inhibitory neurons. In medial and parietal association cortex, we observed spontaneous slow waves that self-organized into hubs defined by long-range excitatory and local inhibitory circuits. Unlike directional source/sink-like flows in sensory areas, medial/parietal excitatory and inhibitory hubs had net-zero balanced inputs. Remarkably, multisensory stimulation triggered rapid phase-locking mainly of excitatory hub activity persisting for seconds after the stimulus offset. Therefore, association cortex tends to form balanced excitatory networks that configure slow-wave phase-locking for MSI. Video Abstract: : Kuroki et al. performed cell-type-specific, wide-field FRET-based calcium imaging to visualize cortical network activity induced by multisensory inputs. They observed phase-locking of cortical slow waves in excitatory neuronal hubs in association cortical areas that may underlie multisensory integration. Keywords: wide-field calcium imaging, multisensory integration, cortical slow waves, association cortex, phase locking, fluorescence resonance energy transfer, spontaneous activity, excitatory neuron, inhibitory neuron, mouse

  2. Spatio-Temporal Encoding in Medical Ultrasound Imaging

    DEFF Research Database (Denmark)

    Gran, Fredrik

    2005-01-01

    In this dissertation two methods for spatio-temporal encoding in medical ultrasound imaging are investigated. The first technique is based on a frequency division approach. Here, the available spectrum of the transducer is divided into a set of narrow bands. A waveform is designed for each band...... the signal to noise ratio and simultaneously the penetration depth so that the medical doctor can image deeper lying structures. The method is tested both experimentally and in simulation and has also evaluated for the purpose of blood flow estimation. The work presented is based on four papers which...

  3. The Arabic Diatessaron Project: Digitalizing, Encoding, Lemmatization

    Directory of Open Access Journals (Sweden)

    Giuliano Lancioni

    2016-04-01

    Full Text Available The Arabic Diatessaron Project (henceforth ADP is an international research project in Digital Humanities that aims to collect, digitalise and encode all known manuscripts of the Arabic Diatessaron (henceforth AD, a text that has been relatively neglected in scholarly research. ADP’s final goal is to provide a number of tools that can enable scholars to effectively query, compare and investigate all known variants of the text that will be encoded as far as possible in compliance with the Text Encoding Initiative (TEI guidelines. The paper addresses a number of issues involved in the process of digitalising manuscripts included in the two existing editions (Ciasca 1888 and Marmardji 1935, adding variants in unedited manuscripts, encoding and lemmatising the text. Issues involved in the design of the ADP include presentation of variants, choice of the standard text, applicability of TEI guidelines, automatic translation between different encodings, cross-edition concordances and principles of lemmatisation.

  4. Polymeric membrane studied using slow positron beam

    International Nuclear Information System (INIS)

    Hung, W.-S.; Lo, C.-H.; Cheng, M.-L.; Chen Hongmin; Liu Guang; Chakka, Lakshmi; Nanda, D.; Tung, K.-L.; Huang, S.-H.; Lee, Kueir-Rarn; Lai, J.-Y.; Sun Yiming; Yu Changcheng; Zhang Renwu; Jean, Y.C.

    2008-01-01

    A radioisotope slow positron beam has been built at the Chung Yuan Christian University in Taiwan for the research and development in membrane science and technology. Doppler broadening energy spectra and positron annihilation lifetime have been measured as a function of positron energy up to 30 keV in a polyamide membrane prepared by the interfacial polymerization between triethylenetetraamine (TETA) and trimesoyl chloride (TMC) on modified porous polyacrylonitrile (PAN) asymmetric membrane. The multilayer structures and free-volume depth profile for this asymmetric membrane system are obtained. Positron annihilation spectroscopy coupled with a slow beam could provide new information about size selectivity of transporting molecules and guidance for molecular designs in polymeric membranes

  5. A tilted transversely isotropic slowness surface approximation

    KAUST Repository

    Stovas, A.

    2012-05-09

    The relation between vertical and horizontal slownesses, better known as the dispersion relation, for transversely isotropic media with a tilted symmetry axis (TTI) requires solving a quartic polynomial equation, which does not admit a practical explicit solution to be used, for example, in downward continuation. Using a combination of the perturbation theory with respect to the anelliptic parameter and Shanks transform to improve the accuracy of the expansion, we develop an explicit formula for the vertical slowness that is highly accurate for all practical purposes. It also reveals some insights into the anisotropy parameter dependency of the dispersion relation including the low impact that the anelliptic parameter has on the vertical placement of reflectors for a small tilt in the symmetry angle. © 2012 European Association of Geoscientists & Engineers.

  6. A model for visual memory encoding.

    Directory of Open Access Journals (Sweden)

    Rodolphe Nenert

    Full Text Available Memory encoding engages multiple concurrent and sequential processes. While the individual processes involved in successful encoding have been examined in many studies, a sequence of events and the importance of modules associated with memory encoding has not been established. For this reason, we sought to perform a comprehensive examination of the network for memory encoding using data driven methods and to determine the directionality of the information flow in order to build a viable model of visual memory encoding. Forty healthy controls ages 19-59 performed a visual scene encoding task. FMRI data were preprocessed using SPM8 and then processed using independent component analysis (ICA with the reliability of the identified components confirmed using ICASSO as implemented in GIFT. The directionality of the information flow was examined using Granger causality analyses (GCA. All participants performed the fMRI task well above the chance level (>90% correct on both active and control conditions and the post-fMRI testing recall revealed correct memory encoding at 86.33 ± 5.83%. ICA identified involvement of components of five different networks in the process of memory encoding, and the GCA allowed for the directionality of the information flow to be assessed, from visual cortex via ventral stream to the attention network and then to the default mode network (DMN. Two additional networks involved in this process were the cerebellar and the auditory-insular network. This study provides evidence that successful visual memory encoding is dependent on multiple modules that are part of other networks that are only indirectly related to the main process. This model may help to identify the node(s of the network that are affected by a specific disease processes and explain the presence of memory encoding difficulties in patients in whom focal or global network dysfunction exists.

  7. A model for visual memory encoding.

    Science.gov (United States)

    Nenert, Rodolphe; Allendorfer, Jane B; Szaflarski, Jerzy P

    2014-01-01

    Memory encoding engages multiple concurrent and sequential processes. While the individual processes involved in successful encoding have been examined in many studies, a sequence of events and the importance of modules associated with memory encoding has not been established. For this reason, we sought to perform a comprehensive examination of the network for memory encoding using data driven methods and to determine the directionality of the information flow in order to build a viable model of visual memory encoding. Forty healthy controls ages 19-59 performed a visual scene encoding task. FMRI data were preprocessed using SPM8 and then processed using independent component analysis (ICA) with the reliability of the identified components confirmed using ICASSO as implemented in GIFT. The directionality of the information flow was examined using Granger causality analyses (GCA). All participants performed the fMRI task well above the chance level (>90% correct on both active and control conditions) and the post-fMRI testing recall revealed correct memory encoding at 86.33 ± 5.83%. ICA identified involvement of components of five different networks in the process of memory encoding, and the GCA allowed for the directionality of the information flow to be assessed, from visual cortex via ventral stream to the attention network and then to the default mode network (DMN). Two additional networks involved in this process were the cerebellar and the auditory-insular network. This study provides evidence that successful visual memory encoding is dependent on multiple modules that are part of other networks that are only indirectly related to the main process. This model may help to identify the node(s) of the network that are affected by a specific disease processes and explain the presence of memory encoding difficulties in patients in whom focal or global network dysfunction exists.

  8. Testing algorithms for critical slowing down

    Directory of Open Access Journals (Sweden)

    Cossu Guido

    2018-01-01

    Full Text Available We present the preliminary tests on two modifications of the Hybrid Monte Carlo (HMC algorithm. Both algorithms are designed to travel much farther in the Hamiltonian phase space for each trajectory and reduce the autocorrelations among physical observables thus tackling the critical slowing down towards the continuum limit. We present a comparison of costs of the new algorithms with the standard HMC evolution for pure gauge fields, studying the autocorrelation times for various quantities including the topological charge.

  9. SOFTWARE Manual for VMM3 Slow Control

    CERN Document Server

    Guth, Manuel

    2017-01-01

    For the New Small Wheel upgrade of the ATLAS detector a new readout chip, called VMM3(a), was developed. In order to provide this new technology to a larger community, the RD51 collaboration is integrating the VMM3 in their scalable readout system (SRS). For this purpose, a new slow control and calibration tool is necessary. This new software was developed and improved within a CERN Summer Student project.

  10. Slow movement execution in event-related potentials (P300).

    Science.gov (United States)

    Naruse, Kumi; Sakuma, Haruo; Hirai, Takane

    2002-02-01

    We examined whether slow movement execution has an effect on cognitive and information processing by measuring the P300 component. 8 subjects performed a continuous slow forearm rotational movement using 2 task speeds. Slow (a 30-50% decrease from the subject's Preferred speed) and Very Slow (a 60-80% decrease). The mean coefficient of variation for rotation speed under Very Slow was higher than that under Slow, showing that the subjects found it difficult to perform the Very Slow task smoothly. The EEG score of alpha-1 (8-10 Hz) under Slow Condition was increased significantly more than under the Preferred Condition; however, the increase under Very Slow was small when compared with Preferred. After performing the task. P300 latency under Very Slow increased significantly as compared to that at pretask. Further, P300 amplitude decreased tinder both speed conditions when compared to that at pretask, and a significant decrease was seen under the Slow Condition at Fz, whereas the decrease under the Very Slow Condition was small. These differences indicated that a more complicated neural composition and an increase in subjects' attention might have been involved when the task was performed under the Very Slow Condition. We concluded that slow movement execution may have an influence on cognitive function and may depend on the percentage of decrease from the Preferred speed of the individual.

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

    Directory of Open Access Journals (Sweden)

    Stephanie eRatté

    2015-01-01

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

  12. Dimension Reduction for Systems with Slow Relaxation

    Science.gov (United States)

    Venkataramani, Shankar C.; Venkataramani, Raman C.; Restrepo, Juan M.

    2017-05-01

    We develop reduced, stochastic models for high dimensional, dissipative dynamical systems that relax very slowly to equilibrium and can encode long term memory. We present a variety of empirical and first principles approaches for model reduction, and build a mathematical framework for analyzing the reduced models. We introduce the notions of universal and asymptotic filters to characterize `optimal' model reductions for sloppy linear models. We illustrate our methods by applying them to the practically important problem of modeling evaporation in oil spills.

  13. Encoding of coordination complexes with XML.

    Science.gov (United States)

    Vinoth, P; Sankar, P

    2017-09-01

    An in-silico system to encode structure, bonding and properties of coordination complexes is developed. The encoding is achieved through a semantic XML markup frame. Composition of the coordination complexes is captured in terms of central atom and ligands. Structural information of central atom is detailed in terms of electron status of valence electron orbitals. The ligands are encoded with specific reference to the electron environment of ligand centre atoms. Behaviour of ligands to form low or high spin complexes is accomplished by assigning a Ligand Centre Value to every ligand based on the electronic environment of ligand centre atom. Chemical ontologies are used for categorization purpose and to control different hybridization schemes. Complexes formed by the central atoms of transition metal, non-transition elements belonging to s-block, p-block and f-block are encoded with a generic encoding platform. Complexes of homoleptic, heteroleptic and bridged types are also covered by this encoding system. Utility of the encoded system to predict redox electron transfer reaction in the coordination complexes is demonstrated with a simple application. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Efficient reverse time migration with amplitude encoding

    Science.gov (United States)

    Hu, Jiangtao; Wang, Huazhong; Zhao, Lei; Shao, Yu; Wang, Meixia; Osen, Are

    2015-08-01

    Reverse time migration (RTM) is an accurate seismic imaging method for imaging the complex subsurface structure. Traditional common shot RTM suffers from low efficiency due to the large number of single shot gathers, especially for marine seismic data. Phase encoding is commonly used to reduce the computational cost of RTM. Phase encoding in the frequency domain is usually related to time shift in the time domain. Therefore, phase-encoding-based RTM needs time padding to avoid information loss which degrades the efficiency of the time-domain wavefield extrapolator. In this paper, an efficient time-domain RTM scheme based on the amplitude encoding is proposed. This scheme uses the orthogonal cosine basis as the encoding function, which has similar physical meaning to plane wave encoding (i.e. plane-wave components with different surface shooting angles). The proposed scheme can generate a qualified imaging result as well as common shot RTM but with less computational cost. Since this scheme does not need time padding, it is more efficient than the phase encoding schemes and can be conveniently implemented in the time domain. Numerical examples on the Sigsbee2a synthetic dataset demonstrate the feasibility of the proposed method.

  15. Encoded recoupling and decoupling: An alternative to quantum error-correcting codes applied to trapped-ion quantum computation

    International Nuclear Information System (INIS)

    Lidar, D.A.; Wu, L.-A.

    2003-01-01

    A recently developed theory for eliminating decoherence and design constraints in quantum computers, 'encoded recoupling and decoupling', is shown to be fully compatible with a promising proposal for an architecture enabling scalable ion-trap quantum computation [D. Kielpinski et al., Nature (London) 417, 709 (2002)]. Logical qubits are encoded into pairs of ions. Logic gates are implemented using the Soerensen-Moelmer (SM) scheme applied to pairs of ions at a time. The encoding offers continuous protection against collective dephasing. Decoupling pulses, that are also implemented using the SM scheme directly to the encoded qubits, are capable of further reducing various other sources of qubit decoherence, such as due to differential dephasing and due to decohered vibrational modes. The feasibility of using the relatively slow SM pulses in a decoupling scheme quenching the latter source of decoherence follows from the observed 1/f spectrum of the vibrational bath

  16. Differing Time of Onset of Concurrent TMS-fMRI during Associative Memory Encoding: A Measure of Dynamic Connectivity

    Directory of Open Access Journals (Sweden)

    Colin Hawco

    2017-08-01

    Full Text Available There has been a distinct shift in neuroimaging from localization of function into a more network based approach focused on connectivity. While fMRI has proven very fruitful for this, the hemodynamic signal is inherently slow which limits the temporal resolution of fMRI-only connectivity measures. The brain, however, works on a time scale of milliseconds. This study utilized concurrent transcranial magnetic stimulation (TMS-fMRI in a novel way to obtain measures of dynamic connectivity by measuring changes in fMRI signal amplitude in regions distal to the site of stimulation following differing TMS onset times. Seventeen healthy subjects completed an associative memory encoding task known to involve the DLPFC, viewing pairs of objects which could be semantically related or unrelated. Three pulses of 10 Hz repetitive TMS were applied over the left DLPFC starting either at 200, 600, or 1000 ms after stimulus onset. Associations for related pairs were better remembered than unrelated pairs in a post-scan cued recall test. Differences in neural activity were assessed across different TMS onsets, separately for related and unrelated pairs. Time specific TMS effects were observed in several regions, including those associated with higher-level processing (lateral frontal, anterior cingulate, visual areas (occipital, and regions involved in semantic processing (e.g., left mid-temporal and medial frontal. Activity in the frontal cortex was decreased at 200 ms post-stimulus for unrelated pairs, and 1000 ms post-stimulus for related pairs. This suggests differences in the timing across conditions in which the DLFPC interacts with other PFC regions, consistent with the notion that the DLPFC is facilitating extended semantic processing for related items. This study demonstrates that time-varying TMS onset inside the MRI can be used to reliably measure fast dynamic connectivity with a temporal resolution in the hundreds of milliseconds.

  17. ENCODE whole-genome data in the UCSC genome browser (2011 update)

    Science.gov (United States)

    Raney, Brian J.; Cline, Melissa S.; Rosenbloom, Kate R.; Dreszer, Timothy R.; Learned, Katrina; Barber, Galt P.; Meyer, Laurence R.; Sloan, Cricket A.; Malladi, Venkat S.; Roskin, Krishna M.; Suh, Bernard B.; Hinrichs, Angie S.; Clawson, Hiram; Zweig, Ann S.; Kirkup, Vanessa; Fujita, Pauline A.; Rhead, Brooke; Smith, Kayla E.; Pohl, Andy; Kuhn, Robert M.; Karolchik, Donna; Haussler, David; Kent, W. James

    2011-01-01

    The ENCODE project is an international consortium with a goal of cataloguing all the functional elements in the human genome. The ENCODE Data Coordination Center (DCC) at the University of California, Santa Cruz serves as the central repository for ENCODE data. In this role, the DCC offers a collection of high-throughput, genome-wide data generated with technologies such as ChIP-Seq, RNA-Seq, DNA digestion and others. This data helps illuminate transcription factor-binding sites, histone marks, chromatin accessibility, DNA methylation, RNA expression, RNA binding and other cell-state indicators. It includes sequences with quality scores, alignments, signals calculated from the alignments, and in most cases, element or peak calls calculated from the signal data. Each data set is available for visualization and download via the UCSC Genome Browser (http://genome.ucsc.edu/). ENCODE data can also be retrieved using a metadata system that captures the experimental parameters of each assay. The ENCODE web portal at UCSC (http://encodeproject.org/) provides information about the ENCODE data and links for access. PMID:21037257

  18. Hexagonal pixel detector with time encoded binary readout

    International Nuclear Information System (INIS)

    Hoedlmoser, H.; Varner, G.; Cooney, M.

    2009-01-01

    The University of Hawaii is developing continuous acquisition pixel (CAP) detectors for vertexing applications in lepton colliding experiments such as SuperBelle or ILC. In parallel to the investigation of different technology options such as MAPS or SOI, both analog and binary readout concepts have been tested. First results with a binary readout scheme in which the hit information is time encoded by means of a signal shifting mechanism have recently been published. This paper explains the hit reconstruction for such a binary detector with an emphasis on fake hit reconstruction probabilities in order to evaluate the rate capability in a high background environment such as the planned SuperB factory at KEK. The results show that the binary concept is at least comparable to any analog readout strategy if not better in terms of occupancy. Furthermore, we present a completely new binary readout strategy in which the pixel cells are arranged in a hexagonal grid allowing the use of three independent output directions to reduce reconstruction ambiguities. The new concept uses the same signal shifting mechanism for time encoding, however, in dedicated transfer lines on the periphery of the detector, which enables higher shifting frequencies. Detailed Monte Carlo simulations of full size pixel matrices including hit and BG generation, signal generation, and data reconstruction show that by means of multiple signal transfer lines on the periphery the pixel can be made smaller (higher resolution), the number of output channels and the data volume per triggered event can be reduced dramatically, fake hit reconstruction is lowered to a minimum and the resulting effective occupancies are less than 10 -4 . A prototype detector has been designed in the AMS 0.35μm Opto process and is currently under fabrication.

  19. Costs of storing colour and complex shape in visual working memory: Insights from pupil size and slow waves.

    Science.gov (United States)

    Kursawe, Michael A; Zimmer, Hubert D

    2015-06-01

    We investigated the impact of perceptual processing demands on visual working memory of coloured complex random polygons during change detection. Processing load was assessed by pupil size (Exp. 1) and additionally slow wave potentials (Exp. 2). Task difficulty was manipulated by presenting different set sizes (1, 2, 4 items) and by making different features (colour, shape, or both) task-relevant. Memory performance in the colour condition was better than in the shape and both condition which did not differ. Pupil dilation and the posterior N1 increased with set size independent of type of feature. In contrast, slow waves and a posterior P2 component showed set size effects but only if shape was task-relevant. In the colour condition slow waves did not vary with set size. We suggest that pupil size and N1 indicates different states of attentional effort corresponding to the number of presented items. In contrast, slow waves reflect processes related to encoding and maintenance strategies. The observation that their potentials vary with the type of feature (simple colour versus complex shape) indicates that perceptual complexity already influences encoding and storage and not only comparison of targets with memory entries at the moment of testing. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Both neurons and astrocytes exhibited tetrodotoxin-resistant metabotropic glutamate receptor-dependent spontaneous slow Ca2+ oscillations in striatum.

    Directory of Open Access Journals (Sweden)

    Atsushi Tamura

    Full Text Available The striatum plays an important role in linking cortical activity to basal ganglia outputs. Group I metabotropic glutamate receptors (mGluRs are densely expressed in the medium spiny projection neurons and may be a therapeutic target for Parkinson's disease. The group I mGluRs are known to modulate the intracellular Ca(2+ signaling. To characterize Ca(2+ signaling in striatal cells, spontaneous cytoplasmic Ca(2+ transients were examined in acute slice preparations from transgenic mice expressing green fluorescent protein (GFP in the astrocytes. In both the GFP-negative cells (putative-neurons and astrocytes of the striatum, spontaneous slow and long-lasting intracellular Ca(2+ transients (referred to as slow Ca(2+ oscillations, which lasted up to approximately 200 s, were found. Neither the inhibition of action potentials nor ionotropic glutamate receptors blocked the slow Ca(2+ oscillation. Depletion of the intracellular Ca(2+ store and the blockade of inositol 1,4,5-trisphosphate receptors greatly reduced the transient rate of the slow Ca(2+ oscillation, and the application of an antagonist against mGluR5 also blocked the slow Ca(2+ oscillation in both putative-neurons and astrocytes. Thus, the mGluR5-inositol 1,4,5-trisphosphate signal cascade is the primary contributor to the slow Ca(2+ oscillation in both putative-neurons and astrocytes. The slow Ca(2+ oscillation features multicellular synchrony, and both putative-neurons and astrocytes participate in the synchronous activity. Therefore, the mGluR5-dependent slow Ca(2+ oscillation may involve in the neuron-glia interaction in the striatum.

  1. Neo-Fuzzy Encoder and Its Adaptive Learning for Big Data Processing

    Directory of Open Access Journals (Sweden)

    Bodyanskiy Yevgeniy

    2017-12-01

    Full Text Available In the paper a two-layer encoder is proposed. The nodes of encoder under consideration are neo-fuzzy neurons, which are characterised by high speed of learning process and effective approximation properties. The proposed architecture of neo-fuzzy encoder has a two-layer bottle neck” structure and its learning algorithm is based on error backpropagation. The learning algorithm is characterised by a high rate of convergence because the output signals of encoder’s nodes (neo-fuzzy neurons are linearly dependent on the tuning parameters. The proposed learning algorithm can tune both the synaptic weights and centres of membership functions. Thus, in the paper the hybrid neo-fuzzy system-encoder is proposed that has essential advantages over conventional neurocompressors.

  2. In silicio search for genes encoding peroxisomal proteins in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kal, A J; Hettema, E H; van den Berg, M; Koerkamp, M G; van Ijlst, L; Distel, B; Tabak, H F

    2000-01-01

    The biogenesis of peroxisomes involves the synthesis of new proteins that after, completion of translation, are targeted to the organelle by virtue of peroxisomal targeting signals (PTS). Two types of PTSs have been well characterized for import of matrix proteins (PTS1 and PTS2). Induction of the genes encoding these matrix proteins takes place in oleate-containing medium and is mediated via an oleate response element (ORE) present in the region preceding these genes. The authors have searched the yeast genome for OREs preceding open reading frames (ORFs), and for ORFs that contain either a PTS1 or PTS2. Of the ORFs containing an ORE, as well as either a PTS1 or a PTS2, many were known to encode bona fide peroxisomal matrix proteins. In addition, candidate genes were identified as encoding putative new peroxisomal proteins. For one case, subcellular location studies validated the in silicio prediction. This gene encodes a new peroxisomal thioesterase.

  3. Generation and mnemonic encoding induce a mirror effect in the DRM paradigm.

    Science.gov (United States)

    Guntre, Raymond W; Bodner, Glen E; Azad, Tanjeem

    2007-07-01

    Encoding tasks that increase memory accuracy are appealing from both practical and theoretical perspectives. Within the Deese/Roediger-McDermott (DRM) paradigm, we found that generating list words from anagrams (relative to reading) produced a mirror effect: enhanced recognition of studied words coupled with a reduction in false recognition. Signal detection analyses suggest that the increase in correct recognition was due to enhanced item-specific encoding of the list words, whereas the reduction in false recognition was due to enhanced strategic monitoring at test (i.e., a distinctiveness heuristic), rather than to reduced relational encoding at study. Further support for a distinctiveness heuristic account was obtained using both "theme judgment" instructions and within-group conditions. In our final experiment, we replicated this mirror effect using a purely mnemonic (self-referential) encoding task, showing that extra perceptual cues are not necessary to induce participants to adopt a successful memory-improvement strategy at test.

  4. On the edge of language acquisition: inherent constraints on encoding multisyllabic sequences in the neonate brain.

    Science.gov (United States)

    Ferry, Alissa L; Fló, Ana; Brusini, Perrine; Cattarossi, Luigi; Macagno, Francesco; Nespor, Marina; Mehler, Jacques

    2016-05-01

    To understand language, humans must encode information from rapid, sequential streams of syllables - tracking their order and organizing them into words, phrases, and sentences. We used Near-Infrared Spectroscopy (NIRS) to determine whether human neonates are born with the capacity to track the positions of syllables in multisyllabic sequences. After familiarization with a six-syllable sequence, the neonate brain responded to the change (as shown by an increase in oxy-hemoglobin) when the two edge syllables switched positions but not when two middle syllables switched positions (Experiment 1), indicating that they encoded the syllables at the edges of sequences better than those in the middle. Moreover, when a 25 ms pause was inserted between the middle syllables as a segmentation cue, neonates' brains were sensitive to the change (Experiment 2), indicating that subtle cues in speech can signal a boundary, with enhanced encoding of the syllables located at the edges of that boundary. These findings suggest that neonates' brains can encode information from multisyllabic sequences and that this encoding is constrained. Moreover, subtle segmentation cues in a sequence of syllables provide a mechanism with which to accurately encode positional information from longer sequences. Tracking the order of syllables is necessary to understand language and our results suggest that the foundations for this encoding are present at birth. © 2015 John Wiley & Sons Ltd.

  5. Effects of body mass index on gastric slow wave: a magnetogastrographic study

    International Nuclear Information System (INIS)

    Somarajan, S; Cassilly, S; Obioha, C; Bradshaw, L A; Richards, W O

    2014-01-01

    We measured gastric slow wave activity simultaneously with magnetogastrogram (MGG), mucosal electromyogram (EMG) and electrogastrogram (EGG) in human subjects with varying body mass index (BMI) before and after a meal. In order to investigate the effect of BMI on gastric slow wave parameters, each subject's BMI was calculated and divided into two groups: subjects with BMI ≤ 27 and BMI > 27. Signals were processed with Fourier spectral analysis and second-order blind identification (SOBI) techniques. Our results showed that increased BMI does not affect signal characteristics such as frequency and amplitude of EMG and MGG. Comparison of the postprandial EGG power, on the other hand, showed a statistically significant reduction in subjects with BMI > 27 compared with BMI ≤ 27. In addition to the frequency and amplitude, the use of SOBI-computed propagation maps from MGG data allowed us to visualize the propagating slow wave and compute the propagation velocity in both BMI groups. No significant change in velocity with increasing BMI or meal was observed in our study. In conclusion, multichannel MGG provides an assessment of frequency, amplitude and propagation velocity of the slow wave in subjects with differing BMI categories and was observed to be independent of BMI. (paper)

  6. The Roles of Cortical Slow Waves in Synaptic Plasticity and Memory Consolidation

    Directory of Open Access Journals (Sweden)

    Daisuke Miyamoto

    2017-11-01

    Full Text Available Sleep plays important roles in sensory and motor memory consolidation. Sleep oscillations, reflecting neural population activity, involve the reactivation of learning-related neurons and regulate synaptic strength and, thereby affect memory consolidation. Among sleep oscillations, slow waves (0.5–4 Hz are closely associated with memory consolidation. For example, slow-wave power is regulated in an experience-dependent manner and correlates with acquired memory. Furthermore, manipulating slow waves can enhance or impair memory consolidation. During slow wave sleep, inter-areal interactions between the cortex and hippocampus (HC have been proposed to consolidate declarative memory; however, interactions for non-declarative (HC-independent memory remain largely uninvestigated. We recently showed that the directional influence in a slow-wave range through a top-down cortical long-range circuit is involved in the consolidation of non-declarative memory. At the synaptic level, the average cortical synaptic strength is known to be potentiated during wakefulness and depressed during sleep. Moreover, learning causes plasticity in a subset of synapses, allocating memory to them. Sleep may help to differentiate synaptic strength between allocated and non-allocated synapses (i.e., improving the signal-to-noise ratio, which may facilitate memory consolidation. Herein, we offer perspectives on inter-areal interactions and synaptic plasticity for memory consolidation during sleep.

  7. "Slow-scanning" in Ground-based Mid-infrared Observations

    Science.gov (United States)

    Ohsawa, Ryou; Sako, Shigeyuki; Miyata, Takashi; Kamizuka, Takafumi; Okada, Kazushi; Mori, Kiyoshi; Uchiyama, Masahito S.; Yamaguchi, Junpei; Fujiyoshi, Takuya; Morii, Mikio; Ikeda, Shiro

    2018-04-01

    Chopping observations with a tip-tilt secondary mirror have conventionally been used in ground-based mid-infrared observations. However, it is not practical for next generation large telescopes to have a large tip-tilt mirror that moves at a frequency larger than a few hertz. We propose an alternative observing method, a "slow-scanning" observation. Images are continuously captured as movie data, while the field of view is slowly moved. The signal from an astronomical object is extracted from the movie data by a low-rank and sparse matrix decomposition. The performance of the "slow-scanning" observation was tested in an experimental observation with Subaru/COMICS. The quality of a resultant image in the "slow-scanning" observation was as good as in a conventional chopping observation with COMICS, at least for a bright point-source object. The observational efficiency in the "slow-scanning" observation was better than that in the chopping observation. The results suggest that the "slow-scanning" observation can be a competitive method for the Subaru telescope and be of potential interest to other ground-based facilities to avoid chopping.

  8. Fifteen Years of Slow Slip and Tremor Observations at the Northern Costa Rica Subduction Zone

    Science.gov (United States)

    Schwartz, S. Y.; Dixon, T. H.; Protti, M.; González, V. M.

    2015-12-01

    Coordinated long-term geophysical observations at the northern Costa Rica seismogenic zone, facilitated by NSF's MARGINS program, have greatly expanded our understanding of its megathrust behavior. Here we review fifteen years of seismic, geodetic, ocean bottom fluid flow and pressure sensor data collected on or near the Nicoya Peninsula, above the shallow thrust interface that document a variety of slow slip behaviors. These include relatively deep (~30-40 km), large slow slip events that occur about every 2 years, smaller events that locate at more intermediate depth (10-15 km) and occur more frequently (~1 per year), and very shallow events at the toe of the margin wedge that produce no discernible GPS signal on land but are detected on seafloor pressure sensors. Most of these slow slip events at the toe are accompanied by seismic tremor. Short-term, GPS only observations might have detected a few of these slow slip events; however, the longer more diverse instrument deployment was necessary to reveal their greater complexity. This demonstrates the need for a sustained, multi-instrument deployment and off-shore instrumentation at several different subduction zones, like that proposed for the Subduction Zone Observatory (SZO), to significantly advance our understanding of slow slip at convergent boundaries. Similar instrumentation to what exists in Nicoya is presently being established in the Osa-Burica region of southern Costa Rica to capture earthquake cycle deformation there. These two installations can provide a good nucleus for a larger circum-Pacific SZO effort.

  9. Eddy current-nulled convex optimized diffusion encoding (EN-CODE) for distortion-free diffusion tensor imaging with short echo times.

    Science.gov (United States)

    Aliotta, Eric; Moulin, Kévin; Ennis, Daniel B

    2018-02-01

    To design and evaluate eddy current-nulled convex optimized diffusion encoding (EN-CODE) gradient waveforms for efficient diffusion tensor imaging (DTI) that is free of eddy current-induced image distortions. The EN-CODE framework was used to generate diffusion-encoding waveforms that are eddy current-compensated. The EN-CODE DTI waveform was compared with the existing eddy current-nulled twice refocused spin echo (TRSE) sequence as well as monopolar (MONO) and non-eddy current-compensated CODE in terms of echo time (TE) and image distortions. Comparisons were made in simulations, phantom experiments, and neuro imaging in 10 healthy volunteers. The EN-CODE sequence achieved eddy current compensation with a significantly shorter TE than TRSE (78 versus 96 ms) and a slightly shorter TE than MONO (78 versus 80 ms). Intravoxel signal variance was lower in phantoms with EN-CODE than with MONO (13.6 ± 11.6 versus 37.4 ± 25.8) and not different from TRSE (15.1 ± 11.6), indicating good robustness to eddy current-induced image distortions. Mean fractional anisotropy values in brain edges were also significantly lower with EN-CODE than with MONO (0.16 ± 0.01 versus 0.24 ± 0.02, P current-induced image distortions in DTI with a TE comparable to MONO and substantially shorter than TRSE. Magn Reson Med 79:663-672, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  10. Slow Wave Sleep and Long Duration Spaceflight

    Science.gov (United States)

    Whitmire, Alexandra; Orr, Martin; Arias, Diana; Rueger, Melanie; Johnston, Smith; Leveton, Lauren

    2012-01-01

    While ground research has clearly shown that preserving adequate quantities of sleep is essential for optimal health and performance, changes in the progression, order and /or duration of specific stages of sleep is also associated with deleterious outcomes. As seen in Figure 1, in healthy individuals, REM and Non-REM sleep alternate cyclically, with stages of Non-REM sleep structured chronologically. In the early parts of the night, for instance, Non-REM stages 3 and 4 (Slow Wave Sleep, or SWS) last longer while REM sleep spans shorter; as night progresses, the length of SWS is reduced as REM sleep lengthens. This process allows for SWS to establish precedence , with increases in SWS seen when recovering from sleep deprivation. SWS is indeed regarded as the most restorative portion of sleep. During SWS, physiological activities such as hormone secretion, muscle recovery, and immune responses are underway, while neurological processes required for long term learning and memory consolidation, also occur. The structure and duration of specific sleep stages may vary independent of total sleep duration, and changes in the structure and duration have been shown to be associated with deleterious outcomes. Individuals with narcolepsy enter sleep through REM as opposed to stage 1 of NREM. Disrupting slow wave sleep for several consecutive nights without reducing total sleep duration or sleep efficiency is associated with decreased pain threshold, increased discomfort, fatigue, and the inflammatory flare response in skin. Depression has been shown to be associated with a reduction of slow wave sleep and increased REM sleep. Given research that shows deleterious outcomes are associated with changes in sleep structure, it is essential to characterize and mitigate not only total sleep duration, but also changes in sleep stages.

  11. Quasistatic modelling of the coaxial slow source

    International Nuclear Information System (INIS)

    Hahn, K.D.; Pietrzyk, Z.A.; Vlases, G.C.

    1986-01-01

    A new 1-D Lagrangian MHD numerical code in flux coordinates has been developed for the Coaxial Slow Source (CSS) geometry. It utilizes the quasistatic approximation so that the plasma evolves as a succession of equilibria. The P=P (psi) equilibrium constraint, along with the assumption of infinitely fast axial temperature relaxation on closed field lines, is incorporated. An axially elongated, rectangular plasma is assumed. The axial length is adjusted by the global average condition, or assumed to be fixed. In this paper predictions obtained with the code, and a limited amount of comparison with experimental data are presented

  12. Hot big bang or slow freeze?

    Science.gov (United States)

    Wetterich, C.

    2014-09-01

    We confront the big bang for the beginning of the universe with an equivalent picture of a slow freeze - a very cold and slowly evolving universe. In the freeze picture the masses of elementary particles increase and the gravitational constant decreases with cosmic time, while the Newtonian attraction remains unchanged. The freeze and big bang pictures both describe the same observations or physical reality. We present a simple ;crossover model; without a big bang singularity. In the infinite past space-time is flat. Our model is compatible with present observations, describing the generation of primordial density fluctuations during inflation as well as the present transition to a dark energy-dominated universe.

  13. Lead Slowing Down Spectrometer Status Report

    International Nuclear Information System (INIS)

    Warren, Glen A.; Anderson, Kevin K.; Bonebrake, Eric; Casella, Andrew M.; Danon, Yaron; Devlin, M.; Gavron, Victor A.; Haight, R.C.; Imel, G.R.; Kulisek, Jonathan A.; O'Donnell, J.M.; Weltz, Adam

    2012-01-01

    This report documents the progress that has been completed in the first half of FY2012 in the MPACT-funded Lead Slowing Down Spectrometer project. Significant progress has been made on the algorithm development. We have an improve understanding of the experimental responses in LSDS for fuel-related material. The calibration of the ultra-depleted uranium foils was completed, but the results are inconsistent from measurement to measurement. Future work includes developing a conceptual model of an LSDS system to assay plutonium in used fuel, improving agreement between simulations and measurement, design of a thorium fission chamber, and evaluation of additional detector techniques.

  14. Counting graphene layers with very slow electrons

    Energy Technology Data Exchange (ETDEWEB)

    Frank, Ludĕk; Mikmeková, Eliška; Müllerová, Ilona [Institute of Scientific Instruments AS CR, v.v.i., Královopolská 147, 61264 Brno (Czech Republic); Lejeune, Michaël [Laboratoire de Physique de la Matière Condensée, Faculté des Sciences d' Amiens, Universite de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens Cedex 2 (France)

    2015-01-05

    The study aimed at collection of data regarding the transmissivity of freestanding graphene for electrons across their full energy scale down to the lowest energies. Here, we show that the electron transmissivity of graphene drops with the decreasing energy of the electrons and remains below 10% for energies below 30 eV, and that the slow electron transmissivity value is suitable for reliable determination of the number of graphene layers. Moreover, electrons incident below 50 eV release adsorbed hydrocarbon molecules and effectively clean graphene in contrast to faster electrons that decompose these molecules and create carbonaceous contamination.

  15. A novel method for intelligent fault diagnosis of rolling bearings using ensemble deep auto-encoders

    Science.gov (United States)

    Shao, Haidong; Jiang, Hongkai; Lin, Ying; Li, Xingqiu

    2018-03-01

    Automatic and accurate identification of rolling bearings fault categories, especially for the fault severities and fault orientations, is still a major challenge in rotating machinery fault diagnosis. In this paper, a novel method called ensemble deep auto-encoders (EDAEs) is proposed for intelligent fault diagnosis of rolling bearings. Firstly, different activation functions are employed as the hidden functions to design a series of auto-encoders (AEs) with different characteristics. Secondly, EDAEs are constructed with various auto-encoders for unsupervised feature learning from the measured vibration signals. Finally, a combination strategy is designed to ensure accurate and stable diagnosis results. The proposed method is applied to analyze the experimental bearing vibration signals. The results confirm that the proposed method can get rid of the dependence on manual feature extraction and overcome the limitations of individual deep learning models, which is more effective than the existing intelligent diagnosis methods.

  16. Using XML to encode TMA DES metadata.

    Science.gov (United States)

    Lyttleton, Oliver; Wright, Alexander; Treanor, Darren; Lewis, Paul

    2011-01-01

    The Tissue Microarray Data Exchange Specification (TMA DES) is an XML specification for encoding TMA experiment data. While TMA DES data is encoded in XML, the files that describe its syntax, structure, and semantics are not. The DTD format is used to describe the syntax and structure of TMA DES, and the ISO 11179 format is used to define the semantics of TMA DES. However, XML Schema can be used in place of DTDs, and another XML encoded format, RDF, can be used in place of ISO 11179. Encoding all TMA DES data and metadata in XML would simplify the development and usage of programs which validate and parse TMA DES data. XML Schema has advantages over DTDs such as support for data types, and a more powerful means of specifying constraints on data values. An advantage of RDF encoded in XML over ISO 11179 is that XML defines rules for encoding data, whereas ISO 11179 does not. We created an XML Schema version of the TMA DES DTD. We wrote a program that converted ISO 11179 definitions to RDF encoded in XML, and used it to convert the TMA DES ISO 11179 definitions to RDF. We validated a sample TMA DES XML file that was supplied with the publication that originally specified TMA DES using our XML Schema. We successfully validated the RDF produced by our ISO 11179 converter with the W3C RDF validation service. All TMA DES data could be encoded using XML, which simplifies its processing. XML Schema allows datatypes and valid value ranges to be specified for CDEs, which enables a wider range of error checking to be performed using XML Schemas than could be performed using DTDs.

  17. Using XML to encode TMA DES metadata

    Directory of Open Access Journals (Sweden)

    Oliver Lyttleton

    2011-01-01

    Full Text Available Background: The Tissue Microarray Data Exchange Specification (TMA DES is an XML specification for encoding TMA experiment data. While TMA DES data is encoded in XML, the files that describe its syntax, structure, and semantics are not. The DTD format is used to describe the syntax and structure of TMA DES, and the ISO 11179 format is used to define the semantics of TMA DES. However, XML Schema can be used in place of DTDs, and another XML encoded format, RDF, can be used in place of ISO 11179. Encoding all TMA DES data and metadata in XML would simplify the development and usage of programs which validate and parse TMA DES data. XML Schema has advantages over DTDs such as support for data types, and a more powerful means of specifying constraints on data values. An advantage of RDF encoded in XML over ISO 11179 is that XML defines rules for encoding data, whereas ISO 11179 does not. Materials and Methods: We created an XML Schema version of the TMA DES DTD. We wrote a program that converted ISO 11179 definitions to RDF encoded in XML, and used it to convert the TMA DES ISO 11179 definitions to RDF. Results: We validated a sample TMA DES XML file that was supplied with the publication that originally specified TMA DES using our XML Schema. We successfully validated the RDF produced by our ISO 11179 converter with the W3C RDF validation service. Conclusions: All TMA DES data could be encoded using XML, which simplifies its processing. XML Schema allows datatypes and valid value ranges to be specified for CDEs, which enables a wider range of error checking to be performed using XML Schemas than could be performed using DTDs.

  18. Slow-plasmon resonant-nanostrip antennas: Analysis and demonstration

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Beermann, J.; Boltasseva, Alexandra

    2008-01-01

    Resonant scattering by gold nanostrip antennas due to constructive interference of counterpropagating slow surface plasmon polaritons (SPPs) is analyzed, including the quasistatic limit of ultrasmall antennas, and experimentally demonstrated. The phase of slow SPP reflection by strip ends is foun...

  19. Sustainable Development of Slow Fashion Businesses: Customer Value Approach

    Directory of Open Access Journals (Sweden)

    Sojin Jung

    2016-06-01

    Full Text Available As an alternative to the prevalent fast fashion model, slow fashion has emerged as a way of enhancing sustainability in the fashion industry, yet how slow fashion can enhance profitability is still largely unknown. Based on a customer value creation framework, this study empirically tested a structural model that specified the slow fashion attributes that contribute to creating perceived customer value, which subsequently increases a consumer’s intention to buy and pay a price premium for slow fashion products. An analysis of 221 U.S. consumer data revealed that delivering exclusive product value is significantly critical in creating customer value for slow fashion, and customer value, in turn, positively affects consumers’ purchase intentions. Further analysis also revealed that different slow fashion attributes distinctively affect customer value. This provides potential strategies on which slow fashion businesses can focus to secure an economically sustainable business model, thereby continuously improving environmental and social sustainability with the slow fashion ideal.

  20. Prostaglandin regulation of gastric slow waves and peristalsis

    OpenAIRE

    Forrest, Abigail S.; Hennig, Grant W.; Jokela-Willis, Sari; Park, Chong Doo; Sanders, Kenton M.

    2009-01-01

    Gastric emptying depends on functional coupling of slow waves between the corpus and antrum, to allow slow waves initiated in the gastric corpus to propagate to the pyloric sphincter and generate gastric peristalsis. Functional coupling depends on a frequency gradient where slow waves are generated at higher frequency in the corpus and drive the activity of distal pacemakers. Simultaneous intracellular recording from corpus and antrum was used to characterize the effects of PGE2 on slow waves...

  1. Slow-light effects in photonic crystal membrane lasers

    DEFF Research Database (Denmark)

    Xue, Weiqi; Yu, Yi; Ottaviano, Luisa

    2015-01-01

    In this paper, we present a systematic investigation of photonic crystal cavity laser operating in the slow-light regime. The dependence of lasing threshold on the effect of slow-light will be particularly highlighted.......In this paper, we present a systematic investigation of photonic crystal cavity laser operating in the slow-light regime. The dependence of lasing threshold on the effect of slow-light will be particularly highlighted....

  2. Haploinsufficiency of the genes encoding the tumor suppressor Pten predisposes zebrafish to hemangiosarcoma

    NARCIS (Netherlands)

    Choorapoikayil, S.; Kuiper, R.V.; de Bruin, A.; den Hertog, J.

    2012-01-01

    PTEN is an essential tumor suppressor that antagonizes Akt/PKB signaling. The zebrafish genome encodes two Pten genes, ptena and ptenb. Here, we report that zebrafish mutants that retain a single wild-type copy of ptena or ptenb (ptena(+/-)ptenb(-/-) or ptena(-/-)ptenb(+/-)) are viable and fertile.

  3. A flow cytometric assay technology based on quantum dots-encoded beads

    International Nuclear Information System (INIS)

    Wang Haiqiao; Liu Tiancai; Cao Yuancheng; Huang Zhenli; Wang Jianhao; Li Xiuqing; Zhao Yuandi

    2006-01-01

    A flow cytometric detecting technology based on quantum dots (QDs)-encoded beads has been described. Using this technology, several QDs-encoded beads with different code were identified effectively, and the target molecule (DNA sequence) in solution was also detected accurately by coupling to its complementary sequence probed on QDs-encoded beads through DNA hybridization assay. The resolution of this technology for encoded beads is resulted from two longer wavelength fluorescence identification signals (yellow and red fluorescent signals of QDs), and the third shorter wavelength fluorescence signal (green reporting signal of fluorescein isothiocyanate (FITC)) for the determination of reaction between probe and target. In experiment, because of QDs' unique optical character, only one excitation light source was needed to excite the QDs and probe dye FITC synchronously comparing with other flow cytometric assay technology. The results show that this technology has present excellent repeatability and good accuracy. It will become a promising multiple assay platform in various application fields after further improvement

  4. Enhanced immunogenicity of DNA fusion vaccine encoding secreted hepatitis B surface antigen and chemokine RANTES

    International Nuclear Information System (INIS)

    Kim, Seung Jo; Suh, Dongchul; Park, Sang Eun; Park, Jeong-Sook; Byun, Hyang-Min; Lee, Chan; Lee, Sun Young; Kim, Inho; Oh, Yu-Kyoung

    2003-01-01

    To increase the potency of DNA vaccines, we constructed genetic fusion vaccines encoding antigen, secretion signal, and/or chemokine RANTES. The DNA vaccines encoding secreted hepatitis B surface antigen (HBsAg) were constructed by inserting HBsAg gene into an expression vector with an endoplasmic reticulum (ER)-targeting secretory signal sequence. The plasmid encoding secretory HBsAg (pER/HBs) was fused to cDNA of RANTES, generating pER/HBs/R. For comparison, HBsAg genes were cloned into pVAX1 vector with no signal sequence (pHBs), and further linked to the N-terminus of RANTES (pHBs/R). Immunofluorescence study showed the cytoplasmic localization of HBsAg protein expressed from pHBs and pHBs/R, but not from pER/HBs and pER/HBs/R at 48 h after transfection. In mice, RANTES-fused DNA vaccines more effectively elicited the levels of HBsAg-specific IgG antibodies than pHBs. All the DNA vaccines induced higher levels of IgG 2a rather than IgG 1 antibodies. Of RANTES-fused vaccines, pER/HBs/R encoding the secreted fusion protein revealed much higher humoral and CD8 + T cell-stimulating responses compared to pHBs/R. These results suggest that the immunogenicity of DNA vaccines could be enhanced by genetic fusion to a secretory signal peptide sequence and RANTES

  5. Neural markers of memory consolidation do not predict temporal estimates of encoded items

    NARCIS (Netherlands)

    Damsma, Atser; van der Mijn, Wilmar; van Rijn, Dirk

    2017-01-01

    In contrast to the paradigms used in most laboratory experiments on interval timing, everyday tasks often involve the continuous tracking of multiple intervals without an explicit starting signal. A potential explanation of this capacity is that time perception and working memory encoding are

  6. Excitation of surface plasma waves over corrugated slow-wave ...

    Indian Academy of Sciences (India)

    Abstract. A microwave propagating along vacuum–dielectric–plasma interface excites surface plasma wave (SPW). A periodic slow-wave structure placed over dielectric slows down the SPW. The phase velocity of slow SPW is sensitive to height, periodicity, number of periods, thickness and the separation between ...

  7. Slow features nonnegative matrix factorization for temporal data decomposition

    NARCIS (Netherlands)

    Zafeiriou, Lazaros; Nikitidis, Symeon; Zafeiriou, Stefanos; Pantic, Maja

    2014-01-01

    In this paper, we combine the principles of temporal slowness and nonnegative parts-based learning into a single framework that aims to learn slow varying parts-based representations of time varying sequences. We demonstrate that the proposed algorithm arises naturally by embedding the Slow Features

  8. Good, Clean, Fair: The Rhetoric of the Slow Food Movement

    Science.gov (United States)

    Schneider, Stephen

    2008-01-01

    This article outlines the origins of the Slow Food movement before examining the ways in which Slow Food rhetoric seeks to redefine gastronomy and combat the more deleterious effects of globalization. In articulating a new gastronomy, Slow Food founder Carlo Petrini attempts to reconstruct the gastronomy of Jean Anthelme Brillat-Savarin, at once…

  9. Slow Photons for Photocatalysis and Photovoltaics.

    Science.gov (United States)

    Liu, Jing; Zhao, Heng; Wu, Min; Van der Schueren, Benoit; Li, Yu; Deparis, Olivier; Ye, Jinhua; Ozin, Geoffrey A; Hasan, Tawfique; Su, Bao-Lian

    2017-05-01

    Solar light is widely recognized as one of the most valuable renewable energy sources for the future. However, the development of solar-energy technologies is severely hindered by poor energy-conversion efficiencies due to low optical-absorption coefficients and low quantum-conversion yield of current-generation materials. Huge efforts have been devoted to investigating new strategies to improve the utilization of solar energy. Different chemical and physical strategies have been used to extend the spectral range or increase the conversion efficiency of materials, leading to very promising results. However, these methods have now begun to reach their limits. What is therefore the next big concept that could efficiently be used to enhance light harvesting? Despite its discovery many years ago, with the potential for becoming a powerful tool for enhanced light harvesting, the slow-photon effect, a manifestation of light-propagation control due to photonic structures, has largely been overlooked. This review presents theoretical as well as experimental progress on this effect, revealing that the photoreactivity of materials can be dramatically enhanced by exploiting slow photons. It is predicted that successful implementation of this strategy may open a very promising avenue for a broad spectrum of light-energy-conversion technologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Pharmacological postconditioning against myocardial infarction with a slow-releasing hydrogen sulfide donor, GYY4137

    OpenAIRE

    Karwi, Qutuba; Whiteman, Matthew; Wood, Mark E.; Torregrossa, Roberta; Baxter, Gary

    2016-01-01

    Exogenous hydrogen sulfide (H2S) protects against myocardial ischemia/reperfusion injury but the mechanism of action is unclear. The present study investigated the effect of GYY4137, a slow-releasing H2S donor, on myocardial infarction given specifically at reperfusion and the signalling pathway involved. Thiobutabarbital-anesthetised rats were subjected to 30min of left coronary artery occlusion and 2h reperfusion. Infarct size was assessed by tetrazolium staining. In the first study, animal...

  11. Factors Contributing Decreased Performance Of Slow Learners

    Directory of Open Access Journals (Sweden)

    Dr. L. Kannan

    2015-03-01

    Full Text Available Back ground Even experienced teaching faculty and administrators can be challenged by learners who have not able to perform up to expected need in their annual performance of their students these students are called as slow learnersStruggle learners. There should be a designed study to foster discussion about diagnosing particular problems that contribute with meeting objectives of slow learners. Methodology The study was performed on the entire current first year of Medical students were all the three internal assessments of 250 students performance is taken in to consideration for the study. This study is of cross section type.After obtaining the list of all students marks in internal examination from medical education unit supporting mentors are contacted to meet the students and confidentiality is maintained throughout the study. After obtaining informed consent a questionnaire was administered to the students by the investigator. The questionnaire contains the following sections. Section I will be on the background characteristics of the student name age sex type of family. Section II will be on the details of their learning capabilities. Section III will focus on the awareness of the slow learners in which the precipitating factors contributing to them. Results The prevalence of slow learners as low achievers were contributed to be 32.4 percentages.The performance of the students is based on combination of all three internal assessment marks including theory and practical performance. In this the students age ranges from 17 to 21 years the mean age of student was contributed to be 17.81 and majority of the students were in the age group of 18 years which contributed to be 16867.2.In the present study majority were males 13252.8 compared to females 11847.2.but when study is compared to percentage of attendance majority of the individual 15177 scored more than 50 percentage of marks have more than 80 percentage of attendance but when

  12. Encoder: a connectionist model of how learning to visually encode fixated text images improves reading fluency.

    Science.gov (United States)

    Martin, Gale L

    2004-07-01

    This article proposes that visual encoding learning improves reading fluency by widening the span over which letters are recognized from a fixated text image so that fewer fixations are needed to cover a text line. Encoder is a connectionist model that learns to convert images like the fixated text images human readers encode into the corresponding letter sequences. The computational theory of classification learning predicts that fixated text-image size makes this learning difficult but that reducing image variability and biasing learning should help. Encoder confirms these predictions. It fails to learn as image size increases but achieves humanlike visual encoding accuracy when image variability is reduced by regularities in fixation positions and letter sequences and when learning is biased to discover mapping functions based on the sequential, componential structure of text. After training, Encoder exhibits many humanlike text familiarity effects. ((c) 2004 APA, all rights reserved)

  13. Mechanisms of Memory Retrieval in Slow-Wave Sleep.

    Science.gov (United States)

    Cairney, Scott A; Sobczak, Justyna M; Lindsay, Shane; Gaskell, M Gareth

    2017-09-01

    Memories are strengthened during sleep. The benefits of sleep for memory can be enhanced by re-exposing the sleeping brain to auditory cues; a technique known as targeted memory reactivation (TMR). Prior studies have not assessed the nature of the retrieval mechanisms underpinning TMR: the matching process between auditory stimuli encountered during sleep and previously encoded memories. We carried out two experiments to address this issue. In Experiment 1, participants associated words with verbal and nonverbal auditory stimuli before an overnight interval in which subsets of these stimuli were replayed in slow-wave sleep. We repeated this paradigm in Experiment 2 with the single difference that the gender of the verbal auditory stimuli was switched between learning and sleep. In Experiment 1, forgetting of cued (vs. noncued) associations was reduced by TMR with verbal and nonverbal cues to similar extents. In Experiment 2, TMR with identical nonverbal cues reduced forgetting of cued (vs. noncued) associations, replicating Experiment 1. However, TMR with nonidentical verbal cues reduced forgetting of both cued and noncued associations. These experiments suggest that the memory effects of TMR are influenced by the acoustic overlap between stimuli delivered at training and sleep. Our findings hint at the existence of two processing routes for memory retrieval during sleep. Whereas TMR with acoustically identical cues may reactivate individual associations via simple episodic matching, TMR with nonidentical verbal cues may utilize linguistic decoding mechanisms, resulting in widespread reactivation across a broad category of memories. © Sleep Research Society 2017. Published by Oxford University Press [on behalf of the Sleep Research Society].

  14. An encyclopedia of mouse DNA elements (Mouse ENCODE).

    Science.gov (United States)

    Stamatoyannopoulos, John A; Snyder, Michael; Hardison, Ross; Ren, Bing; Gingeras, Thomas; Gilbert, David M; Groudine, Mark; Bender, Michael; Kaul, Rajinder; Canfield, Theresa; Giste, Erica; Johnson, Audra; Zhang, Mia; Balasundaram, Gayathri; Byron, Rachel; Roach, Vaughan; Sabo, Peter J; Sandstrom, Richard; Stehling, A Sandra; Thurman, Robert E; Weissman, Sherman M; Cayting, Philip; Hariharan, Manoj; Lian, Jin; Cheng, Yong; Landt, Stephen G; Ma, Zhihai; Wold, Barbara J; Dekker, Job; Crawford, Gregory E; Keller, Cheryl A; Wu, Weisheng; Morrissey, Christopher; Kumar, Swathi A; Mishra, Tejaswini; Jain, Deepti; Byrska-Bishop, Marta; Blankenberg, Daniel; Lajoie, Bryan R; Jain, Gaurav; Sanyal, Amartya; Chen, Kaun-Bei; Denas, Olgert; Taylor, James; Blobel, Gerd A; Weiss, Mitchell J; Pimkin, Max; Deng, Wulan; Marinov, Georgi K; Williams, Brian A; Fisher-Aylor, Katherine I; Desalvo, Gilberto; Kiralusha, Anthony; Trout, Diane; Amrhein, Henry; Mortazavi, Ali; Edsall, Lee; McCleary, David; Kuan, Samantha; Shen, Yin; Yue, Feng; Ye, Zhen; Davis, Carrie A; Zaleski, Chris; Jha, Sonali; Xue, Chenghai; Dobin, Alex; Lin, Wei; Fastuca, Meagan; Wang, Huaien; Guigo, Roderic; Djebali, Sarah; Lagarde, Julien; Ryba, Tyrone; Sasaki, Takayo; Malladi, Venkat S; Cline, Melissa S; Kirkup, Vanessa M; Learned, Katrina; Rosenbloom, Kate R; Kent, W James; Feingold, Elise A; Good, Peter J; Pazin, Michael; Lowdon, Rebecca F; Adams, Leslie B

    2012-08-13

    To complement the human Encyclopedia of DNA Elements (ENCODE) project and to enable a broad range of mouse genomics efforts, the Mouse ENCODE Consortium is applying the same experimental pipelines developed for human ENCODE to annotate the mouse genome.

  15. MAGNETIC RESONANCE WATER SELF-DIFFUSION TENSOR ENCODING OPTIMIZATION METHODS FOR FULL BRAIN ACQUISITION

    Directory of Open Access Journals (Sweden)

    Khader M Hasan

    2011-05-01

    Full Text Available Water diffusion tensor magnetic resonance imaging (DT-MRI is a non-invasive and sensitive modality that is becoming increasingly popular in diagnostic radiology. DT-MRI provides in vivo directional information about the organization and microdynamics of deep brain tissue that is not available by other MRI relaxationbased methods. The DT-MRI experiment involves a host of imaging and diffusion parameters that influence the efficiency (signal-to-noise ratio per unit time, accuracy, and specificity of the information sought. These parameters may include typical imaging parameters such as TE, TR, slice thickness, sampling rate, etc. The DTI relevant parameter space includes pulse duration, separation, direction, number of directions (Ne, order, sign and strength of the diffusion encoding gradient pulses. The goal of this work is to present and compare different tensor encoding strategies used to obtain the DT-MRI information for the whole brain. In this paper an evaluation of tensor encoding advantage is presented using a multi-dimensional non-parametric Bootstrap resampling method. This work also explores the relationship between different tensor encoding schemes using the analytical encoding approach. This work shows that the minimum energy optimization approach can produce uniformly distributed tensor encoding that are comparable to the icosahedral sets. The minimum condition encoding sets are not uniformly distributed and are shown to be suboptimal and related to a commonly used heuristic tensor encoding set. This work shows that the icosahedral set is the only uniformly distributed set with Ne = 6. At equal imaging time, the Bootstrap experiments show that optimal tensor encoding sets can have 6 < Ne < 24.

  16. Slow Progress in Dune (Left Front Wheel)

    Science.gov (United States)

    2005-01-01

    The left front wheel of NASA's Mars Exploration Rover Opportunity makes slow but steady progress through soft dune material in this movie clip of frames taken by the rover's front hazard identification camera over a period of several days. The sequence starts on Opportunity's 460th martian day, or sol (May 10, 2005) and ends 11 days later. In eight drives during that period, Opportunity advanced a total of 26 centimeters (10 inches) while spinning its wheels enough to have driven 46 meters (151 feet) if there were no slippage. The motion appears to speed up near the end of the clip, but that is an artifact of individual frames being taken less frequently.

  17. Slow Progress in Dune (Left Rear Wheel)

    Science.gov (United States)

    2005-01-01

    The left rear wheel of NASA's Mars Exploration Rover Opportunity makes slow but steady progress through soft dune material in this movie clip of frames taken by the rover's rear hazard identification camera over a period of several days. The sequence starts on Opportunity's 460th martian day, or sol (May 10, 2005) and ends 11 days later. In eight drives during that period, Opportunity advanced a total of 26 centimeters (10 inches) while spinning its wheels enough to have driven 46 meters (151 feet) if there were no slippage. The motion appears to speed up near the end of the clip, but that is an artifact of individual frames being taken less frequently.

  18. Slow Progress in Dune (Right Rear Wheel)

    Science.gov (United States)

    2005-01-01

    The right rear wheel of NASA's Mars Exploration Rover Opportunity makes slow but steady progress through soft dune material in this movie clip of frames taken by the rover's rear hazard identification camera over a period of several days. The wheel is largely hidden by a cable bundle. The sequence starts on Opportunity's 460th martian day, or sol (May 10, 2005) and ends 11 days later. In eight drives during that period, Opportunity advanced a total of 26 centimeters (10 inches) while spinning its wheels enough to have driven 46 meters (151 feet) if there were no slippage. The motion appears to speed up near the end of the clip, but that is an artifact of individual frames being taken less frequently.

  19. Slow Progress in Dune (Right Front Wheel)

    Science.gov (United States)

    2005-01-01

    The right front wheel of NASA's Mars Exploration Rover Opportunity makes slow but steady progress through soft dune material in this movie clip of frames taken by the rover's front hazard identification camera over a period of several days. The sequence starts on Opportunity's 460th martian day, or sol (May 10, 2005) and ends 11 days later. In eight drives during that period, Opportunity advanced a total of 26 centimeters (10 inches) while spinning its wheels enough to have driven 46 meters (151 feet) if there were no slippage. The motion appears to speed up near the end of the clip, but that is an artifact of individual frames being taken less frequently.

  20. Slow creep in soft granular packings.

    Science.gov (United States)

    Srivastava, Ishan; Fisher, Timothy S

    2017-05-14

    Transient creep mechanisms in soft granular packings are studied numerically using a constant pressure and constant stress simulation method. Rapid compression followed by slow dilation is predicted on the basis of a logarithmic creep phenomenon. Characteristic scales of creep strain and time exhibit a power-law dependence on jamming pressure, and they diverge at the jamming point. Microscopic analysis indicates the existence of a correlation between rheology and nonaffine fluctuations. Localized regions of large strain appear during creep and grow in magnitude and size at short times. At long times, the spatial structure of highly correlated local deformation becomes time-invariant. Finally, a microscale connection between local rheology and local fluctuations is demonstrated in the form of a linear scaling between granular fluidity and nonaffine velocity.

  1. Hot big bang or slow freeze?

    International Nuclear Information System (INIS)

    Wetterich, C.

    2014-01-01

    We confront the big bang for the beginning of the universe with an equivalent picture of a slow freeze — a very cold and slowly evolving universe. In the freeze picture the masses of elementary particles increase and the gravitational constant decreases with cosmic time, while the Newtonian attraction remains unchanged. The freeze and big bang pictures both describe the same observations or physical reality. We present a simple “crossover model” without a big bang singularity. In the infinite past space–time is flat. Our model is compatible with present observations, describing the generation of primordial density fluctuations during inflation as well as the present transition to a dark energy-dominated universe

  2. Hot big bang or slow freeze?

    Energy Technology Data Exchange (ETDEWEB)

    Wetterich, C.

    2014-09-07

    We confront the big bang for the beginning of the universe with an equivalent picture of a slow freeze — a very cold and slowly evolving universe. In the freeze picture the masses of elementary particles increase and the gravitational constant decreases with cosmic time, while the Newtonian attraction remains unchanged. The freeze and big bang pictures both describe the same observations or physical reality. We present a simple “crossover model” without a big bang singularity. In the infinite past space–time is flat. Our model is compatible with present observations, describing the generation of primordial density fluctuations during inflation as well as the present transition to a dark energy-dominated universe.

  3. Hot big bang or slow freeze?

    Directory of Open Access Journals (Sweden)

    C. Wetterich

    2014-09-01

    Full Text Available We confront the big bang for the beginning of the universe with an equivalent picture of a slow freeze — a very cold and slowly evolving universe. In the freeze picture the masses of elementary particles increase and the gravitational constant decreases with cosmic time, while the Newtonian attraction remains unchanged. The freeze and big bang pictures both describe the same observations or physical reality. We present a simple “crossover model” without a big bang singularity. In the infinite past space–time is flat. Our model is compatible with present observations, describing the generation of primordial density fluctuations during inflation as well as the present transition to a dark energy-dominated universe.

  4. Reflection of Slow Electrons from Solid Surface

    Science.gov (United States)

    Mustafaev, Alexander; Ainov, Matsak; Kaganovich, Igor; Demidov, Vladimir

    2013-09-01

    Given that progress of future plasma technologies depends on control of electron coefficient reflection r0, the development of methods of measurement and control of r0 is of great importance. Published experimental data on r0 for slow electrons are inconsistent and sometime give large values up to r0 ~ 0 , 8 and even higher. This talk presents a technique for r0 measurements in low pressure plasmas in the presence of transverse magnetic field. It is found that for poly-crystal surface, effective reflection coefficient can really reach value of 0.8. It is demonstrated that it is connected to additional reflection from potential barrier near the surfaces. The contribution of electron reflection from the barrier and the surface has been divided and studied. The data have been confirmed at different mono-crystal surfaces. This work was supported by DoE Fusion Energy Sciences contract DE-SC0001939 and Education Ministry of the RF.

  5. A Time-Domain Analog Spatial Compressed Sensing Encoder for Multi-Channel Neural Recording.

    Science.gov (United States)

    Okazawa, Takayuki; Akita, Ippei

    2018-01-11

    A time-domain analog spatial compressed sensing encoder for neural recording applications is proposed. Owing to the advantage of MEMS technologies, the number of channels on a silicon neural probe array has doubled in 7.4 years, and therefore, a greater number of recording channels and higher density of front-end circuitry is required. Since neural signals such as action potential (AP) have wider signal bandwidth than that of an image sensor, a data compression technique is essentially required for arrayed neural recording systems. In this paper, compressed sensing (CS) is employed for data reduction, and a novel time-domain analog CS encoder is proposed. A simpler and lower power circuit than conventional analog or digital CS encoders can be realized by using the proposed CS encoder. A prototype of the proposed encoder was fabricated in a 180 nm 1P6M CMOS process, and it achieved an active area of 0.0342 mm 2 / ch . and an energy efficiency of 25.0 pJ / ch . · conv .

  6. Impaired encoding of rapid pitch information underlies perception and memory deficits in congenital amusia.

    Science.gov (United States)

    Albouy, Philippe; Cousineau, Marion; Caclin, Anne; Tillmann, Barbara; Peretz, Isabelle

    2016-01-06

    Recent theories suggest that the basis of neurodevelopmental auditory disorders such as dyslexia or specific language impairment might be a low-level sensory dysfunction. In the present study we test this hypothesis in congenital amusia, a neurodevelopmental disorder characterized by severe deficits in the processing of pitch-based material. We manipulated the temporal characteristics of auditory stimuli and investigated the influence of the time given to encode pitch information on participants' performance in discrimination and short-term memory. Our results show that amusics' performance in such tasks scales with the duration available to encode acoustic information. This suggests that in auditory neuro-developmental disorders, abnormalities in early steps of the auditory processing can underlie the high-level deficits (here musical disabilities). Observing that the slowing down of temporal dynamics improves amusics' pitch abilities allows considering this approach as a potential tool for remediation in developmental auditory disorders.

  7. Restoring the encoding properties of a stochastic neuron model by an exogenous noise

    Directory of Open Access Journals (Sweden)

    Alessandra ePaffi

    2015-05-01

    Full Text Available Here we evaluate the possibility of improving the encoding properties of an impaired neuronal system by superimposing an exogenous noise to an external electric stimulation signal. The approach is based on the use of mathematical neuron models consisting of stochastic HH-like circuit, where the impairment of the endogenous presynaptic inputs is described as a subthreshold injected current and the exogenous stimulation signal is a sinusoidal voltage perturbation across the membrane. Our results indicate that a correlated Gaussian noise, added to the sinusoidal signal can significantly increase the encoding properties of the impaired system, through the Stochastic Resonance (SR phenomenon. These results suggest that an exogenous noise, suitably tailored, could improve the efficacy of those stimulation techniques used in neuronal systems, where the presynaptic sensory neurons are impaired and have to be artificially bypassed.

  8. Position-sensitive proportional counters using resistance-capacitance position encoding

    International Nuclear Information System (INIS)

    Kopp, M.K.; Borkowski, C.J.

    1975-12-01

    A new method was developed for encoding the position of individual photons, neutrons, or charged particles in proportional counters by using the distributed RC line characteristics of these counters. The signal processing is described and guidelines for the design and operation of these position sensitive proportional counters (PSPCs) are given. Using these guidelines, several prototypic PSPCs were constructed to improve the spatial resolution and shorten the signal processing time; for example, the intrinsic spatial uncertainty was reduced to 28 μ fwhm for alpha particles and 100 μ fwhm for low-energy x rays (2 to 6 keV). Also, the signal processing time was reduced to 0.6 μsec without seriously degrading the spatial resolution. These results have opened new fields of application of the RC position encoding method in imaging distributions of photons, charged particles, or neutrons in nuclear medicine, physics, and radiography

  9. Design and properties of position-sensitive proportional counters using resistance--capacitance position encoding

    International Nuclear Information System (INIS)

    Borkowski, C.J.; Kopp, M.K.

    1975-01-01

    The construction and signal processing methods of several experimental gas-filled, position-sensitive proportional counters (PSPCs) using resistance--capacitance (RC) position encoding are described, and guidelines for the design and operation of these counters are given. Using these guidelines, we were able to improve the spatial resolution and shorten the signal processing time; for example, the intrinsic spatial uncertainty in the position measurement was reduced to 28 μ FWHM for alpha particles and 100 μ FWHM for low-energy x rays (2--6 keV). Also, the signal processing time was reduced to 0.6 μsec without seriously degrading the spatial resolution. These results have widened the field of application of the RC position encoding method for position measurements of low-energy photons, neutrons, and charged particles in a wide variety of nuclear physics experiments, in nuclear medicine imaging, and in low-dose, medium-resolution radiography. (AIP)

  10. StrigoQuant: A genetically encoded biosensor for quantifying strigolactone activity and specificity

    KAUST Repository

    Samodelov, S. L.

    2016-11-05

    Strigolactones are key regulators of plant development and interaction with symbiotic fungi; however, quantitative tools for strigolactone signaling analysis are lacking. We introduce a genetically encoded hormone biosensor used to analyze strigolactone-mediated processes, including the study of the components involved in the hormone perception/signaling complex and the structural specificity and sensitivity of natural and synthetic strigolactones in Arabidopsis, providing quantitative insights into the stereoselectivity of strigolactone perception. Given the high specificity, sensitivity, dynamic range of activity, modular construction, ease of implementation, and wide applicability, the biosensor StrigoQuant will be useful in unraveling multiple levels of strigolactone metabolic and signaling networks.

  11. Visual working memory encoding in schizophrenia and first-degree relatives: neurofunctional abnormalities and impaired consolidation.

    Science.gov (United States)

    Stäblein, Michael; Storchak, Helena; Ghinea, Denisa; Kraft, Dominik; Knöchel, Christian; Prvulovic, David; Bittner, Robert A; Reif, Andreas; Oertel-Knöchel, Viola

    2018-03-09

    Working memory (WM) deficits in schizophrenia (SCZ) have been linked to impairments in the encoding phase that are associated with aberrant neuronal functioning. Similar abnormalities have been observed in unaffected first-degree relatives (REL) and are thus discussed as candidate endophenotypes. The process of WM consolidation - i.e. the formation of durable WM representations - is assumed to be impaired in SCZ, but no study has investigated WM consolidation and neuronal correlates of visual WM encoding in REL before. We examined whole-brain activation during the encoding phase with an event-related functional magnetic resonance imaging study design in 25 SCZ subjects, 22 REL subjects, and 25 healthy controls. Subjects performed a visual masked change detection task that assessed WM performance and consolidation. SCZ showed deficient WM performance indicating an impairment consolidation process, accompanied by broad neuronal hypoactivation, most prominently in frontal brain regions, as well as increased activity of the anterior cingulate during the encoding phase. REL showed decreased neuronal activity in the middle and medial frontal gyrus and increased activity in the precentral gyrus and insula during encoding, but no significant behavioral deficits were observed. In respect of given consolidation times, REL showed a shift from decreased frontal activity at short time intervals to increased frontal activity at longer time intervals. Findings suggest WM consolidation may be slowed in REL so that the deployment of compensatory neuronal resources during encoding is needed to assure proper WM performance. This supports the view of WM-related neuronal dysfunctions as a potential endophenotypic marker.

  12. Improved spatial localization in magnetic resonance spectroscopic imaging with two-dimensional PSF-Choice encoding.

    Science.gov (United States)

    Zhang, Shelley HuaLei; Maier, Stephan E; Panych, Lawrence P

    2018-03-03

    Magnetic resonance spectroscopic imaging (MRSI), under low-spatial resolution settings, often suffers signal contamination from neighboring voxels due to ringing artifacts. Spatial localization can be improved by constraining the point-spread-function (PSF). Here the effectiveness of the two-dimensional PSF-Choice technique in providing improved spatial localization for MRSI is demonstrated. The PSF-Choice technique constrains the PSF to a desired shape by manipulating the weighting of RF excitation pulse throughout phase-encode steps. Based on a Point REsolved SpectroScopy (PRESS)-type sequence, PSF-Choice encoding was implemented along two dimensions to excite a two-dimensional Gaussian profile, by replacing the usual RF excitation pulse with a train of pulses that is modified at each phase-encoding step. The method was proven mathematically, and demonstrated experimentally in phantoms containing prostate relevant metabolic compounds of choline, creatine and citrate. Using a dedicated prostate-mimicking spectroscopy phantom surrounded by oil, it was found that there is significantly less signal contamination from oil for PSF-Choice encoding compared with standard phase encoding. In particular, with standard phase encoding, there was a significant difference (p = 0.014) between ratios of Choline + Creatine to Citrate for voxels well within the phantom compared to voxels within the phantom but near the boundary with oil. The ratios in boundary voxels were also significantly different (p = 0.035) from reference values obtained using the prostate phantom with no oil present. In contrast, no significant differences were found in comparisons of these ratios when encoding with PSF-Choice. The PSF-Choice scheme applied along two dimensions produces MR spectroscopic images with substantially reduced truncation artifacts and spectral contamination. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Precursory slow crustal deformation before short-term slow slip event in January 2006, recorded at Shingu borehole station southern Kii Peninsula

    Science.gov (United States)

    Fukuda, M.; Sagiya, T.

    2007-12-01

    In January 2006, a deep low frequency tremor activity and an associated short-term slow slip event occurred in the eastern Kii Peninsula and this coupled activity migrated to the northeast at a rate of 10km/day. We are monitoring crustal deformation at Shingu borehole station in the southeastern Kii peninsula. The Shingu borehole site is located about 100km landward from the Nankai Trough axis, and close to the epicenter of the 1944 Tonankai Earthquake. The borehole is 500 m deep and is equipped with an integrated multi-component borehole monitoring system developed by Ishii et al. (2002), consisting of 6 strain sensors (4 in horizontal, 2 in vertical), 2 pendulum tilt sensors, a magnetic direction finder, and a quartz thermometer. Each signal is originally recorded with a sampling frequency of 50 Hz. We decimated the original data into hourly data, which we decomposed into tidal response, barometric response, smoothed trend and random noise component by applying BAYTAP-G software [Tamura et al., 1991]. In the trend component from November 2005 to March 2006, we did not found deformation signal at the time of the Jan. 2006 tremor event. However, we found three significant slow strain changes from the processed records. Two of them coincide with the occurrence of the tremor activities in the southern Kii Peninsula, and are characterized by N-S contraction (0.019-0.031 ppm) and E-W extension (0.025-0.038 ppm). These are the first evidence of the short-term slow slip event in this area. The third change is characterized by NW-SE extension (0.026 ppm), N-S contraction (0.012 ppm), E-W extension (0.022 ppm), and southwestward tilting (0.23 micro rad). It occurred from December 29, 2005 to January 2, 2006, just before the tremor and slip event in January 2006, but was not accompanied by any tremor activity. We conducted a series of inversion analysis to infer the source of this possible slow slip event. We assumed that the slow slip event was caused by a reverse fault

  14. Enhanced double patterning decomposition using lines encoding

    Directory of Open Access Journals (Sweden)

    Khaled M. Soradi

    2016-09-01

    Full Text Available Double patterning photolithography (DPL is considered one of the best solutions used for enabling 32 nm/22 nm technology. In this paper, we propose a new technique for double patterning post decomposition conflict resolution. The algorithm is based on lines positions encoding followed by code pattern matching. Experimental results show that the usage of encoded patterns decreases the time needed for pattern matching and increases the matching accuracy. The overall manual problem solution time is reduced to about 1%.

  15. W-band radio-over-fiber propagation of two optically encoded wavelength channels

    Science.gov (United States)

    Eghbal, Morad Khosravi; Shadaram, Mehdi

    2018-01-01

    We propose a W-band wavelength-division multiplexing (WDM)-over-optical code-division multiple access radio-over-fiber system. This system offers capacity expansion by increasing the working frequency to millimeter wave region and by introducing optical encoding and multiwavelength multiplexing. The system's functionality is investigated by software modeling, and the results are presented. The generated signals are data modulated at 10 Gb/s and optically encoded for two wavelength channels and transmitted with a 20-km length of fiber. The received signals are optically decoded and detected. Also, encoding has improved the bit error rate (BER) versus the received optical power margin for the WDM setting by about 4 dB. In addition, the eye-diagram shows that the difference between received optical power levels at the BER of 10-12 to 10-3 is about 1.3% between two encoded channels. This method of capacity improvement is significantly important for the next generation of mobile communication, where millimeter wave signals will be widely used to deliver data to small cells.

  16. Nonmotor regions encode path-related information during movements.

    Science.gov (United States)

    Breault, Macauley S; Sacre, Pierre; Johnson, Jacob J; Kerr, Matthew; Johnson, Matthew D; Bulacio, Juan; Gonzalez-Martinez, Jorge; Sarma, Sridevi V; Gale, John T

    2017-07-01

    Sensorimotor control and the involvement of motor brain regions has been extensively studied, but the role nonmotor brain regions play during movements has been overlooked. This is particularly due to the difficulty of recording from multiple regions in the brain during motor control. In this study, we utilize stereoelectroencephalography (SEEG) recording techniques to explore the role nonmotor brain areas have on the way we move. Nine humans were implanted with SEEG depth electrodes for clinical purposes, which rendered access to local field potential (LFP) activity in deep and peripheral nonmotor structures. Participants performed fast and slow arm reaching movements using a robotic manipulandum. In this study, we explored whether neural activity in a given nonmotor brain structure correlated to movement path metrics including: path length, path deviation, and path speed. Statistical analysis revealed correlations between averaged neural activity in middle temporal gyrus, supramarginal gyrus, and fusiform gyrus and our path metrics both within and across the subjects. Furthermore, we split trials across subjects into two groups: one group consisted of trials with high values of each path metric and the other with low values. We then found significant differences in LFP power in specific frequency bands (e.g. beta) during movement between each group. These results suggest that nonmotor regions may dynamically encode path-related information during movement.

  17. Synthesis and structure-activity relationship of the first nonpeptidergic inverse agonists for the human cytomegalovirus encoded chemokine receptor US28

    NARCIS (Netherlands)

    Hulshof, Janneke W; Casarosa, Paola; Menge, Wiro M P B; Kuusisto, Leena M S; van der Goot, Henk; Smit, Martine J; de Esch, Iwan J P; Leurs, Rob

    2005-01-01

    US28 is a human cytomegalovirus (HCMV) encoded G-protein-coupled receptor that signals in a constitutively active manner. Recently, we identified 1 [5-(4-(4-chlorophenyl)-4-hydroxypiperidin-1-yl)-2,2-diphenylpentanenitrile] as the first reported nonpeptidergic inverse agonist for a viral-encoded

  18. Dynamic encoding of speech sequence probability in human temporal cortex.

    Science.gov (United States)

    Leonard, Matthew K; Bouchard, Kristofer E; Tang, Claire; Chang, Edward F

    2015-05-06

    Sensory processing involves identification of stimulus features, but also integration with the surrounding sensory and cognitive context. Previous work in animals and humans has shown fine-scale sensitivity to context in the form of learned knowledge about the statistics of the sensory environment, including relative probabilities of discrete units in a stream of sequential auditory input. These statistics are a defining characteristic of one of the most important sequential signals humans encounter: speech. For speech, extensive exposure to a language tunes listeners to the statistics of sound sequences. To address how speech sequence statistics are neurally encoded, we used high-resolution direct cortical recordings from human lateral superior temporal cortex as subjects listened to words and nonwords with varying transition probabilities between sound segments. In addition to their sensitivity to acoustic features (including contextual features, such as coarticulation), we found that neural responses dynamically encoded the language-level probability of both preceding and upcoming speech sounds. Transition probability first negatively modulated neural responses, followed by positive modulation of neural responses, consistent with coordinated predictive and retrospective recognition processes, respectively. Furthermore, transition probability encoding was different for real English words compared with nonwords, providing evidence for online interactions with high-order linguistic knowledge. These results demonstrate that sensory processing of deeply learned stimuli involves integrating physical stimulus features with their contextual sequential structure. Despite not being consciously aware of phoneme sequence statistics, listeners use this information to process spoken input and to link low-level acoustic representations with linguistic information about word identity and meaning. Copyright © 2015 the authors 0270-6474/15/357203-12$15.00/0.

  19. Construction report of the PF slow-positron source. 1

    International Nuclear Information System (INIS)

    Enomoto, Atsushi; Kurihara, Toshikazu; Kobayashi, Hitoshi

    1993-12-01

    The slow positron source utilizing the electron beam of the 2.5 GeV electron beam accelerator which is the synchrotron radiation injector is being constructed. The outline of the project and the present state of construction are reported. As of November, 1993, by injecting the electron beam of about 10 W to the targets for producing positrons, the slow positrons of 4 x 10 4 e + /s has been obtained in the laboratory. Finally, with the electron beam of 30 kW, it is aimed at to obtain the slow positron beam of 2 x 10 9 e + /s. In the slow positron source, the electron beam from the 2.5 GeV linear accelerator is used as the primary beam. This beam is led to the target with electromagnets. Radiation shields were strengthened, and the electrostatic lens system was attached to efficiently extract and send out slow positrons. The conveying system for slow positrons is explained. Primary electron beam, target and moderator for producing slow positrons, the change to continuous current of pulsed slow positron beam and the heightening of luminance of slow positron beam, and the experiment on the utilization of slow positron beam, and the control system for positron conveyance path are reported. (K.I.)

  20. FIR Filter Implementation Based on the RNS with Diminished-1 Encoded Channel

    Directory of Open Access Journals (Sweden)

    Dragana Uros Zivaljevic

    2013-03-01

    Full Text Available A technique, based on the residue number system (RNS with diminished-1 encoded channel, has being used for implementing a finite impulse response (FIR digital filter. The proposed RNS architecture of the filter consists of three main blocks: forward and reverse converter and arithmetic processor for each channel. Architecture for residue to binary (reverse convertor with diminished-1 encoded channel has been proposed. Besides, for all RNS channels, the systolic design is used for the efficient  realization of FIR filter. A numerical example illustrates the principles of diminished-1 residue arithmetic, signal processing, and decoding for FIR filters.

  1. Signal detection

    International Nuclear Information System (INIS)

    Tholomier, M.

    1985-01-01

    In a scanning electron microscope, whatever is the measured signal, the same set is found: incident beam, sample, signal detection, signal amplification. The resulting signal is used to control the spot luminosity with the observer cathodoscope. This is synchronized with the beam scanning on the sample; on the cathodoscope, the image in secondary electrons, backscattered electrons,... of the sample surface is reconstituted. The best compromise must be found between a register time low enough to remove eventual variations (under the incident beam) of the nature of the observed phenomenon, and a good spatial resolution of the image and a signal-to-noise ratio high enough. The noise is one of the basic limitations of the scanning electron microscope performance. The whose measurement line must be optimized to reduce it [fr

  2. Manchester encoder-decoder for optical data communication links.

    Science.gov (United States)

    Al-Sammak, A J; Al-Ruwaihi, K; Al-Kooheji, I

    1992-04-20

    A new encoder-decoder (CODEC) design of a Manchester coding scheme suitable for optical data communication links is presented. The design is simple and uses off-the-shelf digital electronic components and subsystems. The CODEC can be used for high data rate transmissions, typical of opticalfiber systems and local area networks. The decoder is insensitive to variations in the clock rates within the range of +/-33%, whereas the encoder, which is a simple XOR logic gate, is not affected by clock variations. During high-frequency operation (e.g., at 100 MHz), the CODEC can be operated at a wide range of frequencies (from 66.6 to 133.3 MHz) without modification to the CODEC circuitry. Furthermore, the CODEC can be made to operate at any data rate by a simple change of a single capacitor or a single resistor in the decoder circuit. The CODEC was built in the laboratory by using transistor-transistor logicintegrated circuits. It was experimentally found that with this decoder the transmitted data, as well as the cloc, can be recovered from the Manchester coded signal without being affected by clock variations within the designed range.

  3. Neural Encoding of Auditory Features during Music Perception and Imagery.

    Science.gov (United States)

    Martin, Stephanie; Mikutta, Christian; Leonard, Matthew K; Hungate, Dylan; Koelsch, Stefan; Shamma, Shihab; Chang, Edward F; Millán, José Del R; Knight, Robert T; Pasley, Brian N

    2017-10-27

    Despite many behavioral and neuroimaging investigations, it remains unclear how the human cortex represents spectrotemporal sound features during auditory imagery, and how this representation compares to auditory perception. To assess this, we recorded electrocorticographic signals from an epileptic patient with proficient music ability in 2 conditions. First, the participant played 2 piano pieces on an electronic piano with the sound volume of the digital keyboard on. Second, the participant replayed the same piano pieces, but without auditory feedback, and the participant was asked to imagine hearing the music in his mind. In both conditions, the sound output of the keyboard was recorded, thus allowing precise time-locking between the neural activity and the spectrotemporal content of the music imagery. This novel task design provided a unique opportunity to apply receptive field modeling techniques to quantitatively study neural encoding during auditory mental imagery. In both conditions, we built encoding models to predict high gamma neural activity (70-150 Hz) from the spectrogram representation of the recorded sound. We found robust spectrotemporal receptive fields during auditory imagery with substantial, but not complete overlap in frequency tuning and cortical location compared to receptive fields measured during auditory perception. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. Encoding of reward expectation by monkey anterior insular neurons.

    Science.gov (United States)

    Mizuhiki, Takashi; Richmond, Barry J; Shidara, Munetaka

    2012-06-01

    The insula, a cortical brain region that is known to encode information about autonomic, visceral, and olfactory functions, has recently been shown to encode information during reward-seeking tasks in both single neuronal recording and functional magnetic resonance imaging studies. To examine the reward-related activation, we recorded from 170 single neurons in anterior insula of 2 monkeys during a multitrial reward schedule task, where the monkeys had to complete a schedule of 1, 2, 3, or 4 trials to earn a reward. In one block of trials a visual cue indicated whether a reward would or would not be delivered in the current trial after the monkey successfully detected that a red spot turned green, and in other blocks the visual cue was random with respect to reward delivery. Over one-quarter of 131 responsive neurons were activated when the current trial would (certain or uncertain) be rewarded if performed correctly. These same neurons failed to respond in trials that were certain, as indicated by the cue, to be unrewarded. Another group of neurons responded when the reward was delivered, similar to results reported previously. The dynamics of population activity in anterior insula also showed strong signals related to knowing when a reward is coming. The most parsimonious explanation is that this activity codes for a type of expected outcome, where the expectation encompasses both certain and uncertain rewards.

  5. Encoder-decoder optimization for brain-computer interfaces.

    Directory of Open Access Journals (Sweden)

    Josh Merel

    2015-06-01

    Full Text Available Neuroprosthetic brain-computer interfaces are systems that decode neural activity into useful control signals for effectors, such as a cursor on a computer screen. It has long been recognized that both the user and decoding system can adapt to increase the accuracy of the end effector. Co-adaptation is the process whereby a user learns to control the system in conjunction with the decoder adapting to learn the user's neural patterns. We provide a mathematical framework for co-adaptation and relate co-adaptation to the joint optimization of the user's control scheme ("encoding model" and the decoding algorithm's parameters. When the assumptions of that framework are respected, co-adaptation cannot yield better performance than that obtainable by an optimal initial choice of fixed decoder, coupled with optimal user learning. For a specific case, we provide numerical methods to obtain such an optimized decoder. We demonstrate our approach in a model brain-computer interface system using an online prosthesis simulator, a simple human-in-the-loop pyschophysics setup which provides a non-invasive simulation of the BCI setting. These experiments support two claims: that users can learn encoders matched to fixed, optimal decoders and that, once learned, our approach yields expected performance advantages.

  6. Evidence for a Mechanism Encoding Audiovisual Spatial Separation

    Directory of Open Access Journals (Sweden)

    Emily Orchard-Mills

    2011-10-01

    Full Text Available Auditory and visual spatial representations are produced by distinct processes, drawing on separate neural inputs and occurring in different regions of the brain. We tested for a bimodal spatial representation using a spatial increment discrimination task. Discrimination thresholds for synchronously presented but spatially separated audiovisual stimuli were measured for base separations ranging from 0° to 45°. In a dark anechoic chamber, the spatial interval was defined by azimuthal separation of a white-noise burst from a speaker on a movable robotic arm and a checkerboard patch 5° wide projected onto an acoustically transparent screen. When plotted as a function of base interval, spatial increment thresholds exhibited a J-shaped pattern. Thresholds initially declined, the minimum occurring at base separations approximately equal to the individual observer's detection threshold and thereafter rose log-linearly according to Weber's law. This pattern of results, known as the ‘dipper function’, would be expected if the auditory and visual signals defining the spatial interval converged onto an early sensory filter encoding audiovisual space. This mechanism could be used to encode spatial separation of auditory and visual stimuli.

  7. Frequency encoded optical assessment of human retinal physiology

    Science.gov (United States)

    Leitgeb, Rainer A.; Michaely, Roland; Bachmann, Adrian; Lassner, Theo; Blatter, Cedric

    2008-02-01

    We demonstrate in-vivo functional imaging of the human retina with Fourier domain optical coherence tomography employing frequency encoding of an excitation pattern. The principle is based on projecting a modulated rectangular pattern across the foveal region and acquiring a time series of B-Scans at the same vertical position across the pattern. The idea is to modulate the excitation with a frequency that is distinct from the heartbeat and irregular motion artifacts. Fourier analysis of the time series at each transverse position in the B-scan series allows assessing the retinal response as change in the FDOCT reflectivity signal exactly at the pattern modulation frequency. We observe a change in retinal reflectivity within the region of the outer segment photoreceptor layer exactly at the pattern modulation frequency.

  8. Toward standardization of slow earthquake catalog -Development of database website-

    Science.gov (United States)

    Kano, M.; Aso, N.; Annoura, S.; Arai, R.; Ito, Y.; Kamaya, N.; Maury, J.; Nakamura, M.; Nishimura, T.; Obana, K.; Sugioka, H.; Takagi, R.; Takahashi, T.; Takeo, A.; Yamashita, Y.; Matsuzawa, T.; Ide, S.; Obara, K.

    2017-12-01

    Slow earthquakes have now been widely discovered in the world based on the recent development of geodetic and seismic observations. Many researchers detect a wide frequency range of slow earthquakes including low frequency tremors, low frequency earthquakes, very low frequency earthquakes and slow slip events by using various methods. Catalogs of the detected slow earthquakes are open to us in different formats by each referring paper or through a website (e.g., Wech 2010; Idehara et al. 2014). However, we need to download catalogs from different sources, to deal with unformatted catalogs and to understand the characteristics of different catalogs, which may be somewhat complex especially for those who are not familiar with slow earthquakes. In order to standardize slow earthquake catalogs and to make such a complicated work easier, Scientific Research on Innovative Areas "Science of Slow Earthquakes" has been developing a slow earthquake catalog website. In the website, we can plot locations of various slow earthquakes via the Google Maps by compiling a variety of slow earthquake catalogs including slow slip events. This enables us to clearly visualize spatial relations among slow earthquakes at a glance and to compare the regional activities of slow earthquakes or the locations of different catalogs. In addition, we can download catalogs in the unified format and refer the information on each catalog on the single website. Such standardization will make it more convenient for users to utilize the previous achievements and to promote research on slow earthquakes, which eventually leads to collaborations with researchers in various fields and further understanding of the mechanisms, environmental conditions, and underlying physics of slow earthquakes. Furthermore, we expect that the website has a leading role in the international standardization of slow earthquake catalogs. We report the overview of the website and the progress of construction. Acknowledgment: This

  9. Ultrashort Phenomena in Biochemistry and Biological Signaling

    Science.gov (United States)

    Splinter, Robert

    2014-11-01

    In biological phenomena there are indications that within the long pulse-length of the action potential on millisecond scale, there is additional ultrashort perturbation encoding that provides the brain with detailed information about the origin (location) and physiological characteristics. The objective is to identify the mechanism-of-action providing the potential for encoding in biological signal propagation. The actual molecular processes involved in the initiation of the action potential have been identified to be in the femtosecond and pico-second scale. The depolarization process of the cellular membrane itself, leading to the onset of the actionpotential that is transmitted to the brain, however is in the millisecond timeframe. One example of the femtosecond chemical interaction is the photoresponse of bacteriorhodopsin. No clear indication for the spatial encoding has so far been verified. Further research will be required on a cellular signal analysis level to confirm or deny the spatial and physiological encoding in the signal wave-trains of intercellular communications and sensory stimuli. The pathological encoding process for cardiac depolarization is however very pronounced and validated, however this electro-chemical process is in the millisecond amplitude and frequency modulation spectrum.

  10. KOGNAC : Efficient encoding of large knowledge graphs

    NARCIS (Netherlands)

    Urbani, Jacopo; Dutta, Sourav; Gurajada, Sairam; Weikum, Gerhard

    2016-01-01

    Many Web applications require efficient querying of large Knowledge Graphs (KGs). We propose KOGNAC, a dictionary-encoding algorithm designed to improve SPARQL querying with a judicious combination of statistical and semantic techniques. In KOGNAC, frequent terms are detected with a frequency

  11. Phenotypic and Molecular Characterization of Plasmid- Encoded ...

    African Journals Online (AJOL)

    Purpose: To investigate the distribution of plasmid-encoded extended spectrum beta-lacatamases (ESBLs) in Lahore, Pakistan using different phenotypic and molecular methods. Methods: Escherichia coli and Klebsiella spp were obtained over a period of nineteen months (June 2007 to December 2008). Both were tested ...

  12. in rice encoding a flavin monooxygenase

    Indian Academy of Sciences (India)

    Cloning, characterization and expression of OsFMO(t) in rice encoding a flavin monooxygenase. Jicai Yi, Lanna Liu, Youpei Cao, Jiazuo Li and Mantong Mei. J. Genet. 92, 471–480. Figure 1. Examples of PCR analysis of the presence of the genes for HPT and GUS in transgenic plants. Genomic DNA of putative.

  13. RNAi suppressors encoded by pathogenic human viruses

    NARCIS (Netherlands)

    de Vries, Walter; Berkhout, Ben

    2008-01-01

    RNA silencing or RNAi interference (RNAi) serves as an innate antiviral mechanism in plants, fungi and animals. Human viruses, like plant viruses, encode suppressor proteins or RNAs that block or modulate the RNAi pathway. This review summarizes the mechanisms by which pathogenic human viruses

  14. Visual Memory : The Price of Encoding Details

    NARCIS (Netherlands)

    Nieuwenstein, Mark; Kromm, Maria

    2017-01-01

    Studies on visual long-term memory have shown that we have a tremendous capacity for remembering pictures of objects, even at a highly detailed level. What remains unclear, however, is whether encoding objects at such a detailed level comes at any cost. In the current study, we examined how the

  15. Slow-roll approximation in loop quantum cosmology

    International Nuclear Information System (INIS)

    Luc, Joanna; Mielczarek, Jakub

    2017-01-01

    The slow-roll approximation is an analytical approach to study dynamical properties of the inflationary universe. In this article, systematic construction of the slow-roll expansion for effective loop quantum cosmology is presented. The analysis is performed up to the fourth order in both slow-roll parameters and the parameter controlling the strength of deviation from the classical case. The expansion is performed for three types of the slow-roll parameters: Hubble slow-roll parameters, Hubble flow parameters and potential slow-roll parameters. An accuracy of the approximation is verified by comparison with the numerical phase space trajectories for the case with a massive potential term. The results obtained in this article may be helpful in the search for the subtle quantum gravitational effects with use of the cosmological data.

  16. Traits, States, and encoding speed: support for a top-down view of neuroticism/state relations.

    Science.gov (United States)

    Robinson, Michael D; Clore, Gerald L

    2007-02-01

    Recent theories suggest that trait neuroticism gains its pernicious power particularly among individuals less capable of making distinctions concerning present reality. Four studies, involving 272 undergraduates, sought to provide some basic, assessment-related support for such theories in the context of individual differences in choice reaction time, which reflect abilities to make distinctions at encoding. Studies 1-3 focused on somatic symptoms, whereas Study 4 focused on neurotic behaviors and negative affect. As predicted, neuroticism consistently interacted with categorization speed in predicting these dependent measures. Specifically, neuroticism/outcome relations were robust among individuals slow to make distinctions at encoding; by contrast, neuroticism did not predict the dependent measures among individuals fast to make distinctions. Such data reinforce suggestions that neuroticism is particularly pernicious among individuals less capable of making distinctions at encoding.

  17. Supervised Learning in Spiking Neural Networks for Precise Temporal Encoding.

    Science.gov (United States)

    Gardner, Brian; Grüning, André

    2016-01-01

    Precise spike timing as a means to encode information in neural networks is biologically supported, and is advantageous over frequency-based codes by processing input features on a much shorter time-scale. For these reasons, much recent attention has been focused on the development of supervised learning rules for spiking neural networks that utilise a temporal coding scheme. However, despite significant progress in this area, there still lack rules that have a theoretical basis, and yet can be considered biologically relevant. Here we examine the general conditions under which synaptic plasticity most effectively takes place to support the supervised learning of a precise temporal code. As part of our analysis we examine two spike-based learning methods: one of which relies on an instantaneous error signal to modify synaptic weights in a network (INST rule), and the other one relying on a filtered error signal for smoother synaptic weight modifications (FILT rule). We test the accuracy of the solutions provided by each rule with respect to their temporal encoding precision, and then measure the maximum number of input patterns they can learn to memorise using the precise timings of individual spikes as an indication of their storage capacity. Our results demonstrate the high performance of the FILT rule in most cases, underpinned by the rule's error-filtering mechanism, which is predicted to provide smooth convergence towards a desired solution during learning. We also find the FILT rule to be most efficient at performing input pattern memorisations, and most noticeably when patterns are identified using spikes with sub-millisecond temporal precision. In comparison with existing work, we determine the performance of the FILT rule to be consistent with that of the highly efficient E-learning Chronotron rule, but with the distinct advantage that our FILT rule is also implementable as an online method for increased biological realism.

  18. Slow positron beam at the JINR, Dubna

    Directory of Open Access Journals (Sweden)

    Horodek Paweł

    2015-12-01

    Full Text Available The Low Energy Positron Toroidal Accumulator (LEPTA at the Joint Institute for Nuclear Research (JINR proposed for generation of positronium in flight has been adopted for positron annihilation spectroscopy (PAS. The positron injector generates continuous slow positron beam with positron energy range between 50 eV and 35 keV. The radioactive 22Na isotope is used. In distinction to popular tungsten foil, here the solid neon is used as moderator. It allows to obtain the beam intensity of about 105 e+/s width energy spectrum characterized by full width at half maximum (FWHM of 3.4 eV and a tail to lower energies of about 30 eV. The paper covers the characteristic of variable energy positron beam at the LEPTA facility: parameters, the rule of moderation, scheme of injector, and transportation of positrons into the sample chamber. Recent status of the project and its development in the field of PAS is discussed. As an example, the measurement of the positron diffusion length in pure iron is demonstrated.

  19. A slow gravity compensated atom laser

    DEFF Research Database (Denmark)

    Kleine Büning, G.; Will, J.; Ertmer, W.

    2010-01-01

    We report on a slow guided atom laser beam outcoupled from a Bose–Einstein condensate of 87Rb atoms in a hybrid trap. The acceleration of the atom laser beam can be controlled by compensating the gravitational acceleration and we reach residual accelerations as low as 0.0027 g. The outcoupling...... mechanism allows for the production of a constant flux of 4.5×106 atoms per second and due to transverse guiding we obtain an upper limit for the mean beam width of 4.6 μm. The transverse velocity spread is only 0.2 mm/s and thus an upper limit for the beam quality parameter is M 2=2.5. We demonstrate...... the potential of the long interrogation times available with this atom laser beam by measuring the trap frequency in a single measurement. The small beam width together with the long evolution and interrogation time makes this atom laser beam a promising tool for continuous interferometric measurements....

  20. Predictors of slow colonic transit in children.

    Science.gov (United States)

    Ridha, Zainab; Quinn, Rakesh; Croaker, Geoffrey David Hain

    2015-02-01

    Slow transit constipation (STC) and functional fecal retention (FFR) are two forms of severe intractable constipation in childhood diagnosed by nuclear transit studies (NTS). This retrospective study aims to identify the predicting factors for STC and FFR by looking at the association with neuropsychiatric disorders (NPD), obesity, family history of constipation and atopic disease. A retrospective chart review was conducted on children with intractable constipation referred for NTS between 1st April 2003 and 1st April 2014. Comparisons were made between STC, FFR and normal transit patients with regards to NPD, obesity (BMI z score >95th percentile), family history of constipation in first and second-degree relatives and atopic disease which included food allergy, asthma and eczema. Between 2003 and 2014, 97 patients were referred for a NTS. Out of 36 patients with NPD, 21 (58.3 %) had STC and 13 (36.1 %) had FFR (p < 0.05). 15.8 % of patients with constipation were obese, compared to 6.4 % in the general Australian paediatric population (p < 0.05). There was no significant association between constipation and atopic disease or family history. Neuropsychiatric disorders, in particular autism, are useful predictors of STC and FFR in children. Obesity may be associated with a higher risk of developing chronic constipation.

  1. Phosphoinositide signaling.

    Science.gov (United States)

    Boss, Wendy F; Im, Yang Ju

    2012-01-01

    "All things flow and change…even in the stillest matter there is unseen flux and movement." Attributed to Heraclitus (530-470 BC), from The Story of Philosophy by Will Durant. Heraclitus, a Greek philosopher, was thinking on a much larger scale than molecular signaling; however, his visionary comments are an important reminder for those studying signaling today. Even in unstimulated cells, signaling pathways are in constant metabolic flux and provide basal signals that travel throughout the organism. In addition, negatively charged phospholipids, such as the polyphosphorylated inositol phospholipids, provide a circuit board of on/off switches for attracting or repelling proteins that define the membranes of the cell. This template of charged phospholipids is sensitive to discrete changes and metabolic fluxes-e.g., in pH and cations-which contribute to the oscillating signals in the cell. The inherent complexities of a constantly fluctuating system make understanding how plants integrate and process signals challenging. In this review we discuss one aspect of lipid signaling: the inositol family of negatively charged phospholipids and their functions as molecular sensors and regulators of metabolic flux in plants.

  2. Simulation and Comparison Between Slow and Fast FH/BPSK Spread Spectrum Using Matlab

    Directory of Open Access Journals (Sweden)

    Sanaa Said Kadhim

    2018-02-01

    Full Text Available This paper investigates the properties and applications of Frequency Hopping Spread Spectrum (FHSS.  FHSS is radio communication technique by which the sender of information sends the data on a radio channel, which changes the frequency of transmission based on a predetermined sequence of code. The FHSS has many advantages over traditional modulation methods, it can overcome fading, multipath channels and interferences. Hence the interception becomes difficult. This security feature makes FHSS more preferable for  military applications. At the receiver side, the signal is demodulated by the same carrier signal for which frequency changes by the same code sequences used by the sender. This paper presents two types of FHSS, slow and fast. The  simulation procedures of both types were  implemented and applied on   Frequency Hopping /Binary Phase Shift Keying (FH/BPSK spread spectrum system using MATLAB. The simulation sequences for fast and slow frequency hopping is the same in number  and frequencies of spreading carriers and both used BPSK traditional modulation type. The  comparison  results  based on their power spectral density   show that the fast frequency hopping is more resistive to noise the slow one.

  3. PRINCIPLES OF SLOW TRAVEL APPLIED TO TOURIST LEISURE CONTEMPORARY

    OpenAIRE

    Bauer, Rafael Chequer; Netto, Alexandre Panosso

    2014-01-01

    The article shows the concept of Slow Travel, a travel’s modality based in a new perspective of touristic use considering a slowdown style. In this way, the paper analyses the context of growing and development about Slow Travel, including its ideological matrix based in industrial revolution’s contestation, specially about the acceleration noted at contemporary society and its application inside the leisure and travel universes. At least, shows the main characteristics of Slow Travel, and it...

  4. Fast wave current drive above the slow wave density limit

    International Nuclear Information System (INIS)

    McWilliams, R.; Sheehan, D.P.; Wolf, N.S.; Edrich, D.

    1989-01-01

    Fast wave and slow wave current drive near the mean gyrofrequency were compared in the Irvine Torus using distinct phased array antennae of similar principal wavelengths, frequencies, and input powers. The slow wave current drive density limit was measured for 50ω ci ≤ω≤500ω ci and found to agree with trends in tokamaks. Fast wave current drive was observed at densities up to the operating limit of the torus, demonstrably above the slow wave density limit

  5. Adaptation of slow myofibers: the effect of sustained BDNF treatment of extraocular muscles in infant nonhuman primates.

    Science.gov (United States)

    Willoughby, Christy L; Fleuriet, Jérome; Walton, Mark M; Mustari, Michael J; McLoon, Linda K

    2015-06-01

    We evaluated promising new treatment options for strabismus. Neurotrophic factors have emerged as a potential treatment for oculomotor disorders because of diverse roles in signaling to muscles and motor neurons. Unilateral treatment with sustained release brain-derived neurotrophic factor (BDNF) to a single lateral rectus muscle in infant monkeys was performed to test the hypothesis that strabismus would develop in correlation with extraocular muscle (EOM) changes during the critical period for development of binocularity. The lateral rectus muscles of one eye in two infant macaques were treated with sustained delivery of BDNF for 3 months. Eye alignment was assessed using standard photographic methods. Muscle specimens were analyzed to examine the effects of BDNF on the density, morphology, and size of neuromuscular junctions, as well as myofiber size. Counts were compared to age-matched controls. No change in eye alignment occurred with BDNF treatment. Compared to control muscle, neuromuscular junctions on myofibers expressing slow myosins had a larger area. Myofibers expressing slow myosin had larger diameters, and the percentage of myofibers expressing slow myosins increased in the proximal end of the muscle. Expression of BDNF was examined in control EOM, and observed to have strongest immunoreactivity outside the endplate zone. We hypothesize that the oculomotor system adapted to sustained BDNF treatment to preserve normal alignment. Our results suggest that BDNF treatment preferentially altered myofibers expressing slow myosins. This implicates BDNF signaling as influencing the slow twitch properties of EOM.

  6. Non-Invasive Optical Biosensor for Probing Cell Signaling

    OpenAIRE

    Fang, Ye

    2007-01-01

    Cell signaling mediated through a cellular target is encoded by spatial and temporal dynamics of downstream signaling networks. The coupling of temporal dynamics with spatial gradients of signaling activities guides cellular responses upon stimulation. Monitoring the integration of cell signaling in real time, if realized, would provide a new dimension for understanding cell biology and physiology. Optical biosensors including resonant waveguide grating (RWG) biosensor manifest a physiologica...

  7. The Persistence of a Slow Manifold with Bifurcation

    DEFF Research Database (Denmark)

    Kristiansen, Kristian Uldall; Palmer, P.; Robert, M.

    2012-01-01

    his paper considers the persistence of a slow manifold with bifurcation in a slow-fast two degree of freedom Hamiltonian system. In particular, we consider a system with a supercritical pitchfork bifurcation in the fast space which is unfolded by the slow coordinate. The model system is motivated...... by tethered satellites. It is shown that an almost full measure subset of a neighborhood of the slow manifold's normally elliptic branches persists in an adiabatic sense. We prove this using averaging and a blow-up near the bifurcation....

  8. Threshold Characteristics of Slow-Light Photonic Crystal Lasers

    DEFF Research Database (Denmark)

    Xue, Weiqi; Yu, Yi; Ottaviano, Luisa

    2016-01-01

    The threshold properties of photonic crystal quantum dot lasers operating in the slow-light regime are investigated experimentally and theoretically. Measurements show that, in contrast to conventional lasers, the threshold gain attains a minimum value for a specific cavity length. The experimental...... results are explained by an analytical theory for the laser threshold that takes into account the effects of slow light and random disorder due to unavoidable fabrication imperfections. Longer lasers are found to operate deeper into the slow-light region, leading to a trade-off between slow-light induced...

  9. Characterization and functional analysis of a slow-cycling subpopulation in colorectal cancer enriched by cell cycle inducer combined chemotherapy.

    Science.gov (United States)

    Wu, Feng-Hua; Mu, Lei; Li, Xiao-Lan; Hu, Yi-Bing; Liu, Hui; Han, Lin-Tao; Gong, Jian-Ping

    2017-10-03

    The concept of cancer stem cells has been proposed in various malignancies including colorectal cancer. Recent studies show direct evidence for quiescence slow-cycling cells playing a role in cancer stem cells. There exists an urgent need to isolate and better characterize these slow-cycling cells. In this study, we developed a new model to enrich slow-cycling tumor cells using cell-cycle inducer combined with cell cycle-dependent chemotherapy in vitro and in vivo . Our results show that Short-term exposure of colorectal cancer cells to chemotherapy combined with cell-cycle inducer enriches for a cell-cycle quiescent tumor cell population. Specifically, these slow-cycling tumor cells exhibit increased chemotherapy resistance in vitro and tumorigenicity in vivo . Notably, these cells are stem-cell like and participate in metastatic dormancy. Further exploration indicates that slow-cycling colorectal cancer cells in our model are less sensitive to cytokine-induced-killer cell mediated cytotoxic killing in vivo and in vitro . Collectively, our cell cycle inducer combined chemotherapy exposure model enriches for a slow-cycling, dormant, chemo-resistant tumor cell sub-population that are resistant to cytokine induced killer cell based immunotherapy. Studying unique signaling pathways in dormant tumor cells enriched by cell cycle inducer combined chemotherapy treatment is expected to identify novel therapeutic targets for preventing tumor recurrence.

  10. Effects of distinctive encoding on correct and false memory: a meta-analytic review of costs and benefits and their origins in the DRM paradigm.

    Science.gov (United States)

    Huff, Mark J; Bodner, Glen E; Fawcett, Jonathan M

    2015-04-01

    We review and meta-analyze how distinctive encoding alters encoding and retrieval processes and, thus, affects correct and false recognition in the Deese-Roediger-McDermott (DRM) paradigm. Reductions in false recognition following distinctive encoding (e.g., generation), relative to a nondistinctive read-only control condition, reflected both impoverished relational encoding and use of a retrieval-based distinctiveness heuristic. Additional analyses evaluated the costs and benefits of distinctive encoding in within-subjects designs relative to between-group designs. Correct recognition was design independent, but in a within design, distinctive encoding was less effective at reducing false recognition for distinctively encoded lists but more effective for nondistinctively encoded lists. Thus, distinctive encoding is not entirely "cost free" in a within design. In addition to delineating the conditions that modulate the effects of distinctive encoding on recognition accuracy, we discuss the utility of using signal detection indices of memory information and memory monitoring at test to separate encoding and retrieval processes.

  11. Virus-encoded chemokine receptors--putative novel antiviral drug targets

    DEFF Research Database (Denmark)

    Rosenkilde, Mette M

    2005-01-01

    as such a paramount role in the antiviral immune responses. It is therefore not surprising that viruses have found ways to exploit and subvert the chemokine system by means of molecular mimicry. By ancient acts of molecular piracy and by induction and suppression of endogenous genes, viruses have utilized chemokines...... and their receptors to serve a variety of roles in viral life-cycle. This review focuses on the pharmacology of virus-encoded chemokine receptors, yet also the family of virus-encoded chemokines and chemokine-binding proteins will be touched upon. Key properties of the virus-encoded receptors, compared...... to their closest endogenous homologs, are interactions with a wider range of chemokines, which can act as agonists, antagonists and inverse agonists, and the exploitation of many signal transduction pathways. High constitutive activity is another key property of some--but not all--of these receptors. The chemokine...

  12. Molecular cloning and characterization of cDNA encoding fibrinolytic enzyme-3 from earthworm Eisenia foetida.

    Science.gov (United States)

    Dong, Guo-Qing; Yuan, Xiao-Ling; Shan, Ya-Jun; Zhao, Zhen-Hu; Chen, Jia-Pei; Cong, Yu-Wen

    2004-04-01

    The earthworm fibrinolytic enzyme-3 (EFE-3, GenBank accession No: AY438622), from the earthworm Eisenia foetida, is a component of earthworm fibrinolytic enzymes. In this study, cDNA encoding the EFE-3 was cloned by RT-PCR. The cDNA contained an open reading frame of 741 nucleotides, which encoded a deduced protein of 247 amino acid residues, including signal sequences. EFE-3 showed a high degree of homology to earthworm (Lumbricus rebullus) proteases F-III-1, F-III-2, and bovine trypsin. The recombinant EFE-3 was expressed in E. coli as inclusion bodies, and the gene encoding the native form of EFE-3 was expressed in COS-7 cells in the medium. Both the refolding product of inclusion bodies and the secreted protease could dissolve the artificial fibrin plate.

  13. Duration of inhibition of ventral tegmental area dopamine neurons encodes a level of conditioned fear.

    Science.gov (United States)

    Mileykovskiy, Boris; Morales, Marisela

    2011-05-18

    It is widely accepted that midbrain dopamine (DA) neurons encode actual and expected reward values by phasic alterations in firing rate. However, how DA neurons encode negative events in the environment is still unclear because some DA neurons appear to be depressed and others excited by aversive stimuli. Here, we show that exposing fear-conditioned rats to stimuli predicting electrical shock elicited three types of biphasic responses, each of which contained an inhibitory pause, in neurochemically identified ventral tegmental area (VTA) DA neurons. The duration of the inhibitory pause in these responses of VTA DA neurons was in direct proportion to the increase in respiratory rate reflecting the level of conditioned fear. Our results suggest that the duration of inhibition of VTA DA neurons encodes negative emotional values of signals predicting aversive events in the environment.

  14. Rapid identification of slow healing wounds.

    Science.gov (United States)

    Jung, Kenneth; Covington, Scott; Sen, Chandan K; Januszyk, Michael; Kirsner, Robert S; Gurtner, Geoffrey C; Shah, Nigam H

    2016-01-01

    Chronic nonhealing wounds have a prevalence of 2% in the United States, and cost an estimated $50 billion annually. Accurate stratification of wounds for risk of slow healing may help guide treatment and referral decisions. We have applied modern machine learning methods and feature engineering to develop a predictive model for delayed wound healing that uses information collected during routine care in outpatient wound care centers. Patient and wound data was collected at 68 outpatient wound care centers operated by Healogics Inc. in 26 states between 2009 and 2013. The dataset included basic demographic information on 59,953 patients, as well as both quantitative and categorical information on 180,696 wounds. Wounds were split into training and test sets by randomly assigning patients to training and test sets. Wounds were considered delayed with respect to healing time if they took more than 15 weeks to heal after presentation at a wound care center. Eleven percent of wounds in this dataset met this criterion. Prognostic models were developed on training data available in the first week of care to predict delayed healing wounds. A held out subset of the training set was used for model selection, and the final model was evaluated on the test set to evaluate discriminative power and calibration. The model achieved an area under the curve of 0.842 (95% confidence interval 0.834-0.847) for the delayed healing outcome and a Brier reliability score of 0.00018. Early, accurate prediction of delayed healing wounds can improve patient care by allowing clinicians to increase the aggressiveness of intervention in patients most at risk. © 2015 by the Wound Healing Society.

  15. Automated selective disruption of slow wave sleep.

    Science.gov (United States)

    Ooms, Sharon J; Zempel, John M; Holtzman, David M; Ju, Yo-El S

    2017-04-01

    Slow wave sleep (SWS) plays an important role in neurophysiologic restoration. Experimentally testing the effect of SWS disruption previously required highly time-intensive and subjective methods. Our goal was to develop an automated and objective protocol to reduce SWS without affecting sleep architecture. We developed a custom Matlab™ protocol to calculate electroencephalogram spectral power every 10s live during a polysomnogram, exclude artifact, and, if measurements met criteria for SWS, deliver increasingly louder tones through earphones. Middle-aged healthy volunteers (n=10) each underwent 2 polysomnograms, one with the SWS disruption protocol and one with sham condition. The SWS disruption protocol reduced SWS compared to sham condition, as measured by spectral power in the delta (0.5-4Hz) band, particularly in the 0.5-2Hz range (mean 20% decrease). A compensatory increase in the proportion of total spectral power in the theta (4-8Hz) and alpha (8-12Hz) bands was seen, but otherwise normal sleep features were preserved. N3 sleep decreased from 20±34 to 3±6min, otherwise there were no significant changes in total sleep time, sleep efficiency, or other macrostructural sleep characteristics. This novel SWS disruption protocol produces specific reductions in delta band power similar to existing methods, but has the advantage of being automated, such that SWS disruption can be performed easily in a highly standardized and operator-independent manner. This automated SWS disruption protocol effectively reduces SWS without impacting overall sleep architecture. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Heterodyne detection using spectral line pairing for spectral phase encoding optical code division multiple access and dynamic dispersion compensation.

    Science.gov (United States)

    Yang, Yi; Foster, Mark; Khurgin, Jacob B; Cooper, A Brinton

    2012-07-30

    A novel coherent optical code-division multiple access (OCDMA) scheme is proposed that uses spectral line pairing to generate signals suitable for heterodyne decoding. Both signal and local reference are transmitted via a single optical fiber and a simple balanced receiver performs sourceless heterodyne detection, canceling speckle noise and multiple-access interference (MAI). To validate the idea, a 16 user fully loaded phase encoded system is simulated. Effects of fiber dispersion on system performance are studied as well. Both second and third order dispersion management is achieved by using a spectral phase encoder to adjust phase shifts of spectral components at the optical network unit (ONU).

  17. The carboxyl terminus of human cytomegalovirus-encoded 7 transmembrane receptor US28 camouflages agonism by mediating constitutive endocytosis

    DEFF Research Database (Denmark)

    Waldhoer, Maria; Casarosa, Paola; Rosenkilde, Mette M

    2003-01-01

    US28 is one of four 7 transmembrane (7TM) chemokine receptors encoded by human cytomegalovirus and has been shown to both signal and endocytose in a ligand-independent, constitutively active manner. Here we show that the constitutive activity and constitutive endocytosis properties of US28...... that the cytoplasmic tail domain of US28 per se regulates receptor endocytosis, independent of the signaling ability of the core domain of US28. The constitutive endocytic property of the US28 c-tail was transposable to other 7TM receptors, the herpes virus 8-encoded ORF74 and the tachykinin NK1 receptor (ORF74-US28...

  18. Implicit false memory in the DRM paradigm: effects of amnesia, encoding instructions, and encoding duration.

    Science.gov (United States)

    Van Damme, Ilse; d'Ydewalle, Géry

    2009-09-01

    Recent studies with the Deese/Roediger-McDermott (Deese 1959; Roediger & McDermott, 1995) paradigm have revealed that amnesic patients do not only show impaired veridical memory, but also diminished false memory for semantically related lure words. Due to the typically used explicit retrieval instructions, however, this finding may reflect problems at encoding, at recollection, or both. Therefore, the present experiments examined implicit as well as explicit false memory in patients suffering from Korsakoff's syndrome and controls. In Experiment 1, encoding instructions either focused on remembering individual list words, or on discovering semantic relationships among the words. In Experiment 2, different presentation durations were used. Results emphasize the distinction between automatic and intentional retrieval: Korsakoff patients' veridical and false memory scores were diminished when explicit recollection was required, but not when memory was tested implicitly. Encoding manipulations only significantly affected veridical memory: Priming was reduced with thematic encoding, and explicit retrieval was facilitated when given more study time.

  19. Slow GABAA mediated synaptic transmission in rat visual cortex

    Directory of Open Access Journals (Sweden)

    Sceniak Michael P

    2008-01-01

    Full Text Available Abstract Background Previous reports of inhibition in the neocortex suggest that inhibition is mediated predominantly through GABAA receptors exhibiting fast kinetics. Within the hippocampus, it has been shown that GABAA responses can take the form of either fast or slow response kinetics. Our findings indicate, for the first time, that the neocortex displays synaptic responses with slow GABAA receptor mediated inhibitory postsynaptic currents (IPSCs. These IPSCs are kinetically and pharmacologically similar to responses found in the hippocampus, although the anatomical specificity of evoked responses is unique from hippocampus. Spontaneous slow GABAA IPSCs were recorded from both pyramidal and inhibitory neurons in rat visual cortex. Results GABAA slow IPSCs were significantly different from fast responses with respect to rise times and decay time constants, but not amplitudes. Spontaneously occurring GABAA slow IPSCs were nearly 100 times less frequent than fast sIPSCs and both were completely abolished by the chloride channel blocker, picrotoxin. The GABAA subunit-specific antagonist, furosemide, depressed spontaneous and evoked GABAA fast IPSCs, but not slow GABAA-mediated IPSCs. Anatomical specificity was evident using minimal stimulation: IPSCs with slow kinetics were evoked predominantly through stimulation of layer 1/2 apical dendritic zones of layer 4 pyramidal neurons and across their basal dendrites, while GABAA fast IPSCs were evoked through stimulation throughout the dendritic arborization. Many evoked IPSCs were also composed of a combination of fast and slow IPSC components. Conclusion GABAA slow IPSCs displayed durations that were approximately 4 fold longer than typical GABAA fast IPSCs, but shorter than GABAB-mediated inhibition. The anatomical and pharmacological specificity of evoked slow IPSCs suggests a unique origin of synaptic input. Incorporating GABAA slow IPSCs into computational models of cortical function will help

  20. Head movements quadruple the range of speeds encoded by the insect motion vision system in hawkmoths.

    Science.gov (United States)

    Windsor, Shane P; Taylor, Graham K

    2017-10-11

    Flying insects use compensatory head movements to stabilize gaze. Like other optokinetic responses, these movements can reduce image displacement, motion and misalignment, and simplify the optic flow field. Because gaze is imperfectly stabilized in insects, we hypothesized that compensatory head movements serve to extend the range of velocities of self-motion that the visual system encodes. We tested this by measuring head movements in hawkmoths Hyles lineata responding to full-field visual stimuli of differing oscillation amplitudes, oscillation frequencies and spatial frequencies. We used frequency-domain system identification techniques to characterize the head's roll response, and simulated how this would have affected the output of the motion vision system, modelled as a computational array of Reichardt detectors. The moths' head movements were modulated to allow encoding of both fast and slow self-motion, effectively quadrupling the working range of the visual system for flight control. By using its own output to drive compensatory head movements, the motion vision system thereby works as an adaptive sensor, which will be especially beneficial in nocturnal species with inherently slow vision. Studies of the ecology of motion vision must therefore consider the tuning of motion-sensitive interneurons in the context of the closed-loop systems in which they function. © 2017 The Author(s).

  1. Dual dimensionality reduction reveals independent encoding of motor features in a muscle synergy for insect flight control.

    Science.gov (United States)

    Sponberg, Simon; Daniel, Thomas L; Fairhall, Adrienne L

    2015-04-01

    What are the features of movement encoded by changing motor commands? Do motor commands encode movement independently or can they be represented in a reduced set of signals (i.e. synergies)? Motor encoding poses a computational and practical challenge because many muscles typically drive movement, and simultaneous electrophysiology recordings of all motor commands are typically not available. Moreover, during a single locomotor period (a stride or wingstroke) the variation in movement may have high dimensionality, even if only a few discrete signals activate the muscles. Here, we apply the method of partial least squares (PLS) to extract the encoded features of movement based on the cross-covariance of motor signals and movement. PLS simultaneously decomposes both datasets and identifies only the variation in movement that relates to the specific muscles of interest. We use this approach to explore how the main downstroke flight muscles of an insect, the hawkmoth Manduca sexta, encode torque during yaw turns. We simultaneously record muscle activity and turning torque in tethered flying moths experiencing wide-field visual stimuli. We ask whether this pair of muscles acts as a muscle synergy (a single linear combination of activity) consistent with their hypothesized function of producing a left-right power differential. Alternatively, each muscle might individually encode variation in movement. We show that PLS feature analysis produces an efficient reduction of dimensionality in torque variation within a wingstroke. At first, the two muscles appear to behave as a synergy when we consider only their wingstroke-averaged torque. However, when we consider the PLS features, the muscles reveal independent encoding of torque. Using these features we can predictably reconstruct the variation in torque corresponding to changes in muscle activation. PLS-based feature analysis provides a general two-sided dimensionality reduction that reveals encoding in high dimensional

  2. Dual dimensionality reduction reveals independent encoding of motor features in a muscle synergy for insect flight control.

    Directory of Open Access Journals (Sweden)

    Simon Sponberg

    2015-04-01

    Full Text Available What are the features of movement encoded by changing motor commands? Do motor commands encode movement independently or can they be represented in a reduced set of signals (i.e. synergies? Motor encoding poses a computational and practical challenge because many muscles typically drive movement, and simultaneous electrophysiology recordings of all motor commands are typically not available. Moreover, during a single locomotor period (a stride or wingstroke the variation in movement may have high dimensionality, even if only a few discrete signals activate the muscles. Here, we apply the method of partial least squares (PLS to extract the encoded features of movement based on the cross-covariance of motor signals and movement. PLS simultaneously decomposes both datasets and identifies only the variation in movement that relates to the specific muscles of interest. We use this approach to explore how the main downstroke flight muscles of an insect, the hawkmoth Manduca sexta, encode torque during yaw turns. We simultaneously record muscle activity and turning torque in tethered flying moths experiencing wide-field visual stimuli. We ask whether this pair of muscles acts as a muscle synergy (a single linear combination of activity consistent with their hypothesized function of producing a left-right power differential. Alternatively, each muscle might individually encode variation in movement. We show that PLS feature analysis produces an efficient reduction of dimensionality in torque variation within a wingstroke. At first, the two muscles appear to behave as a synergy when we consider only their wingstroke-averaged torque. However, when we consider the PLS features, the muscles reveal independent encoding of torque. Using these features we can predictably reconstruct the variation in torque corresponding to changes in muscle activation. PLS-based feature analysis provides a general two-sided dimensionality reduction that reveals encoding in

  3. Dual Dimensionality Reduction Reveals Independent Encoding of Motor Features in a Muscle Synergy for Insect Flight Control

    Science.gov (United States)

    Sponberg, Simon; Daniel, Thomas L.; Fairhall, Adrienne L.

    2015-01-01

    What are the features of movement encoded by changing motor commands? Do motor commands encode movement independently or can they be represented in a reduced set of signals (i.e. synergies)? Motor encoding poses a computational and practical challenge because many muscles typically drive movement, and simultaneous electrophysiology recordings of all motor commands are typically not available. Moreover, during a single locomotor period (a stride or wingstroke) the variation in movement may have high dimensionality, even if only a few discrete signals activate the muscles. Here, we apply the method of partial least squares (PLS) to extract the encoded features of movement based on the cross-covariance of motor signals and movement. PLS simultaneously decomposes both datasets and identifies only the variation in movement that relates to the specific muscles of interest. We use this approach to explore how the main downstroke flight muscles of an insect, the hawkmoth Manduca sexta, encode torque during yaw turns. We simultaneously record muscle activity and turning torque in tethered flying moths experiencing wide-field visual stimuli. We ask whether this pair of muscles acts as a muscle synergy (a single linear combination of activity) consistent with their hypothesized function of producing a left-right power differential. Alternatively, each muscle might individually encode variation in movement. We show that PLS feature analysis produces an efficient reduction of dimensionality in torque variation within a wingstroke. At first, the two muscles appear to behave as a synergy when we consider only their wingstroke-averaged torque. However, when we consider the PLS features, the muscles reveal independent encoding of torque. Using these features we can predictably reconstruct the variation in torque corresponding to changes in muscle activation. PLS-based feature analysis provides a general two-sided dimensionality reduction that reveals encoding in high dimensional

  4. Dynamics of the slowing segmentation clock reveal alternating two-segment periodicity.

    Science.gov (United States)

    Shih, Nathan P; François, Paul; Delaune, Emilie A; Amacher, Sharon L

    2015-05-15

    The formation of reiterated somites along the vertebrate body axis is controlled by the segmentation clock, a molecular oscillator expressed within presomitic mesoderm (PSM) cells. Although PSM cells oscillate autonomously, they coordinate with neighboring cells to generate a sweeping wave of cyclic gene expression through the PSM that has a periodicity equal to that of somite formation. The velocity of each wave slows as it moves anteriorly through the PSM, although the dynamics of clock slowing have not been well characterized. Here, we investigate segmentation clock dynamics in the anterior PSM in developing zebrafish embryos using an in vivo clock reporter, her1:her1-venus. The her1:her1-venus reporter has single-cell resolution, allowing us to follow segmentation clock oscillations in individual cells in real-time. By retrospectively tracking oscillations of future somite boundary cells, we find that clock reporter signal increases in anterior PSM cells and that the periodicity of reporter oscillations slows to about ∼1.5 times the periodicity in posterior PSM cells. This gradual slowing of the clock in the anterior PSM creates peaks of clock expression that are separated at a two-segment periodicity both spatially and temporally, a phenomenon we observe in single cells and in tissue-wide analyses. These results differ from previous predictions that clock oscillations stop or are stabilized in the anterior PSM. Instead, PSM cells oscillate until they incorporate into somites. Our findings suggest that the segmentation clock may signal somite formation using a phase gradient with a two-somite periodicity. © 2015. Published by The Company of Biologists Ltd.

  5. Configural face encoding and spatial frequency information.

    Science.gov (United States)

    Boutet, Isabelle; Collin, Charles; Faubert, Jocelyn

    2003-10-01

    Configural relations and a critical band of spatial frequencies (SFs) in the middle range are particularly important for face recognition. We report the results of four experiments in which the relationship between these two types of information was examined. In Experiments 1, 2A, and 2B, the face inversion effect (FIE) was used to probe configural face encoding. Recognition of upright and inverted faces and nonface objects was measured in four conditions: a no-filter condition and three SF conditions (low, medium, and high frequency). We found significant FIEs of comparable magnitudes for all frequency conditions. In Experiment 3, discrimination of faces on the basis of either configural or featural modifications was measured under the same four conditions. Although the ability to discriminate configural modifications was superior in the medium-frequency condition, so was the ability to discriminate featural modifications. We conclude that the band of SF that is critical for face recognition does not contribute preferentially to configural encoding.

  6. Bacillus caldolyticus prs gene encoding phosphoribosyldiphosphate synthase

    DEFF Research Database (Denmark)

    Krath, Britta N.; Hove-Jensen, Bjarne

    1996-01-01

    The prs gene, encoding phosphoribosyl-diphosphate (PRPP) synthase, as well as the flanking DNA sequences were cloned and sequenced from the Gram-positive thermophile, Bacillus caldolyticus. Comparison with the homologous sequences from the mesophile, Bacillus subtilis, revealed a gene (gca......D) encoding N-acetylglucosamine-l-phosphate uridyltransferase upstream of prs, and a gene homologous to ctc downstream of prs. cDNA synthesis with a B. caldolyticus gcaD-prs-ctc-specified mRNA as template, followed by amplification utilising the polymerase chain reaction indicated that the three genes are co......-transcribed. Comparison of amino acid sequences revealed a high similarity among PRPP synthases across a wide phylogenetic range. An E. coli strain harbouring the B. caldolyticus prs gene in a multicopy plasmid produced PRPP synthase activity 33-fold over the activity of a haploid B. caldolyticus strain. B. caldolyticus...

  7. Storing data encoded DNA in living organisms

    Science.gov (United States)

    Wong,; Pak C. , Wong; Kwong K. , Foote; Harlan, P [Richland, WA

    2006-06-06

    Current technologies allow the generation of artificial DNA molecules and/or the ability to alter the DNA sequences of existing DNA molecules. With a careful coding scheme and arrangement, it is possible to encode important information as an artificial DNA strand and store it in a living host safely and permanently. This inventive technology can be used to identify origins and protect R&D investments. It can also be used in environmental research to track generations of organisms and observe the ecological impact of pollutants. Today, there are microorganisms that can survive under extreme conditions. As well, it is advantageous to consider multicellular organisms as hosts for stored information. These living organisms can provide as memory housing and protection for stored data or information. The present invention provides well for data storage in a living organism wherein at least one DNA sequence is encoded to represent data and incorporated into a living organism.

  8. Nucleic acid compositions and the encoding proteins

    Science.gov (United States)

    Preston, III, James F.; Chow, Virginia; Nong, Guang; Rice, John D.; St. John, Franz J.

    2014-09-02

    The subject invention provides at least one nucleic acid sequence encoding an aldouronate-utilization regulon isolated from Paenibacillus sp. strain JDR-2, a bacterium which efficiently utilizes xylan and metabolizes aldouronates (methylglucuronoxylosaccharides). The subject invention also provides a means for providing a coordinately regulated process in which xylan depolymerization and product assimilation are coupled in Paenibacillus sp. strain JDR-2 to provide a favorable system for the conversion of lignocellulosic biomass to biobased products. Additionally, the nucleic acid sequences encoding the aldouronate-utilization regulon can be used to transform other bacteria to form organisms capable of producing a desired product (e.g., ethanol, 1-butanol, acetoin, 2,3-butanediol, 1,3-propanediol, succinate, lactate, acetate, malate or alanine) from lignocellulosic biomass.

  9. An Intensional Concurrent Faithful Encoding of Turing Machines

    Directory of Open Access Journals (Sweden)

    Thomas Given-Wilson

    2014-10-01

    Full Text Available The benchmark for computation is typically given as Turing computability; the ability for a computation to be performed by a Turing Machine. Many languages exploit (indirect encodings of Turing Machines to demonstrate their ability to support arbitrary computation. However, these encodings are usually by simulating the entire Turing Machine within the language, or by encoding a language that does an encoding or simulation itself. This second category is typical for process calculi that show an encoding of lambda-calculus (often with restrictions that in turn simulates a Turing Machine. Such approaches lead to indirect encodings of Turing Machines that are complex, unclear, and only weakly equivalent after computation. This paper presents an approach to encoding Turing Machines into intensional process calculi that is faithful, reduction preserving, and structurally equivalent. The encoding is demonstrated in a simple asymmetric concurrent pattern calculus before generalised to simplify infinite terms, and to show encodings into Concurrent Pattern Calculus and Psi Calculi.

  10. Rapid chemical shift encoding with single-acquisition single-slab 3D GRASE.

    Science.gov (United States)

    Kim, Hahnsung; Kim, Dong-Hyun; Sohn, Chul-Ho; Park, Jaeseok

    2017-11-01

    To investigate the feasibility of chemical shift encoded, single-slab 3D GRASE for rapid fat-water separation within a single acquisition. The proposed method incorporates signal-to-noise-ratio-optimal chemical shift encoding into single-slab 3D GRASE with variable flip angles. Chemical shift induced phase information was encoded in succession to different positions in k-space by inserting phase encoding blips between adjacent lobes of the oscillating readout gradients. To enhance imaging efficiency, signal prescription-based variable flip angles were used in the long refocusing pulse train. After echo-independent phase correction, missing signals in k-echo space were interpolated using convolution kernels that span over all echoes. Fat-water separation in a single acquisition was performed using both multi-echo fast spin echo and GRASE as compared to conventional multiacquisition fast spin echo with echo shifts. The proposed single-slab 3D GRASE shows superior performance in accurately delineating cartilage structures compared to its counterpart, multi-echo 3D fast spin echo. Compared with multiacquisition fast spin echo with three echo shifts (63 min), the proposed method substantially speeds up imaging time (7 min), and achieves 0.6 mm isotropic resolution in knee imaging with reduced artifacts and noise. We successfully demonstrated the feasibility of rapid chemical shift encoding and separation using the proposed, single-acquisition single-slab 3D GRASE for high resolution isotropic imaging within clinically acceptable time. Magn Reson Med 78:1852-1861, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  11. Audio Cartography: Visual Encoding of Acoustic Parameters

    OpenAIRE

    Kornfeld, A.; Schiewe, J.; Dykes, J.

    2011-01-01

    Our sonic environment is the matter of subject in multiple domains which developed individual means of its description. As a result, it lacks an established visual language through which knowledge can be connected and insights shared. We provide a visual communication framework for the systematic and coherent documentation of sound in large-scale environments. This consists of visual encodings and mappings of acoustic parameters into distinct graphic variables that present plausible solutions...

  12. Toward Chemical Implementation of Encoded Combinatorial Libraries

    DEFF Research Database (Denmark)

    Nielsen, John; Janda, Kim D.

    1994-01-01

    The recent application of "combinatorial libraries" to supplement existing drug screening processes might simplify and accelerate the search for new lead compounds or drugs. Recently, a scheme for encoded combinatorial chemistry was put forward to surmount a number of the limitations possessed by...... by existing methodologies. Here we detail the synthesis of several matrices and the necessary chemistry to implement the conceptual scheme. In addition, we disclose how this novel technology permits a controlled ′dendritic" display of the chemical libraries....

  13. Reducing Black Carbon May Be the Fastest Strategy for Slowing ...

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Reducing Black Carbon May Be the Fastest Strategy for Slowing Climate Change. Reducing Black Carbon May Be the Fastest Strategy for Slowing Climate Change. IGSD/INECE Climate Briefing Note June 2009. A drastic reduction of black-carbon emissions could ...

  14. Experimental determination of the slow-neutron wavelength distribution

    DEFF Research Database (Denmark)

    Lebech, Bente; Mikke, K.; Sledziewska-Blocka, D.

    1970-01-01

    Different experiments for determining the slow-neutron wavelength distribution in the region 227-3 meV have been carried out, and the results compared. It is concluded that the slow-neutron wave-length distribution can be determined accurately by elastic scattering on a pure incoherent or a pure ...

  15. Dynamics of slow and fast systems on complex networks

    Indian Academy of Sciences (India)

    .35(green), 0.5(blue). Region 2, where = 0 corre- sponds to AD. are coupled to form the network, the emergent frequency may depend also on the number of slow systems m. ... slow (red) systems, while fast (green) systems show large.

  16. Slow Release Of Reagent Chemicals From Gel Matrices

    Science.gov (United States)

    Debnam, William J.; Barber, Patrick G.; Coleman, James

    1988-01-01

    Procedure developed for slow release of reagent chemicals into solutions. Simple and inexpensive and not subject to failure of equipment. Use of toothpaste-type tube or pump dispenser conceivably provides more controlled technique for storage and dispensation of gel matrix. Possible uses include controlled, slow release of reagents in chemical reactions, crystal growth, space-flight experiments, and preformed gel medications from packets.

  17. The Localizing Value Of Focal Delta Slowing In Temporal Lobe ...

    African Journals Online (AJOL)

    Slow wave EEG had a higher marginal probability than neuropsychological assessment of predicting the focus, and was equally effective as other investigative methods. Conclusion These results suggest that focal temporal delta slowing is useful in the localization of epileptogenic foci. There was no discordance with the ...

  18. The Geometry of Slow Manifolds near a Folded Node

    NARCIS (Netherlands)

    Desroches, M.; Krauskopf, B.; Osinga, H.M.

    2008-01-01

    This paper is concerned with the geometry of slow manifolds of a dynamical system with one fast and two slow variables. Specifically, we study the dynamics near a folded-node singularity, which is known to give rise to so-called canard solutions. Geometrically, canards are intersection curves of

  19. Optogenetic monitoring of synaptic activity with genetically encoded voltage indicators

    Directory of Open Access Journals (Sweden)

    Ryuichi Nakajima

    2016-08-01

    Full Text Available The age of genetically encoded voltage indicators has matured to the point that changes in membrane potential can now be observed optically in vivo. Improving the signal size and speed of these voltage sensors has been the primary driving forces during this maturation process. As a result, there is a wide range of probes using different voltage detecting mechanisms and fluorescent reporters. As the use of these probes transitions from optically reporting membrane potential in single, cultured cells to imaging populations of cells in slice and/or in vivo, a new challenge emerges – optically resolving the different types of neuronal activity. While improvements in speed and signal size are still needed, optimizing the voltage range and the subcellular expression (ie., soma only of the probe are becoming more important. In this review, we will examine the ability of recently developed probes to report synaptic activity in slice and in vivo. The VSFP family of voltage sensors, ArcLight, ASAP-1, and the rhodopsin family of probes are all good at reporting changes in membrane potential, but all have difficulty distinguishing subthreshold depolarizations from action potentials and detecting neuronal inhibition when imaging populations of cells. Finally, we will offer a few possible ways to improve the optical resolution of the various types of neuronal activities.

  20. Na, K-ATPase as signaling transducer

    OpenAIRE

    Li, Juan

    2007-01-01

    It is now generally agreed that Na,K-ATPase (NKA), in addition to its role in the maintenance of Na+ and K+ gradients across the cell membrane, is a signal transducer. Our group has identified a novel signaling pathway where NKA interact with IP3R to form a signaling microdomain. Ouabain, a specific ligand of NKA, activates this pathway, triggers slow Ca2+ oscillations and activates NF-κB. In current study, the molecular mechanisms and some important downstream effects of NK...

  1. The intersubject and intrasubject reproducibility of FMRI activation during three encoding tasks: implications for clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, Greg S. [Virginia Commonwealth University, Department of Radiology, Richmond, VA (United States); Tomaszewski Farias, Sarah [University of California at Davis, Department of Neurology, Sacramento (United States); Buonocore, Michael H. [University of California at Davis, Department of Radiology, Sacramento (United States); Yonelinas, Andrew P. [University of California at Davis, Department of Psychology, Davis (United States)

    2006-07-15

    The goal of the present study was to evaluate the inter- and intrasubject reproducibility of FMRI activation for three memory encoding tasks previously used in the context of presurgical functional mapping. The primary region of interest (ROI) was the medial temporal lobe (MTL). Comparative ROIs included the inferior frontal and fusiform gyri which are less affected by susceptibility-induced signal losses than the MTL regions. Eighteen subjects were scanned using three memory encoding paradigms: word-pair, pattern, and scene encoding. Nine subjects underwent repeat scanning. Intersubject reproducibility of FMRI activation was evaluated by examining the percent of subjects who showed activation within a given ROI and the range to which individual laterality indices (LIs) varied from the mean. Intrasubject test-retest reproducibility was evaluated by examining the LI test-retest correlation, the average difference between LIs from two separate imaging sessions, and concordance ratios of activation volumes (R{sub volume} and R{sub overlap}). For scene encoding the reproducibility of activation volume and LIs within the MTL were as good as or better than the reproducibility within the fusiform and inferior frontal ROIs. For pattern encoding and word-pair encoding, the reproducibility of activation volume and LIs within the MTL tended to be worse compared to the fusiform and inferior frontal ROIs. The differences in FMRI reproducibility appeared more dependent on the task than the susceptibility effects. The results of this study suggest that FMRI-based assessment of the neural substrates of memory using a scene encoding task may be a useful clinical tool. (orig.)

  2. The intersubject and intrasubject reproducibility of FMRI activation during three encoding tasks: implications for clinical applications

    International Nuclear Information System (INIS)

    Harrington, Greg S.; Tomaszewski Farias, Sarah; Buonocore, Michael H.; Yonelinas, Andrew P.

    2006-01-01

    The goal of the present study was to evaluate the inter- and intrasubject reproducibility of FMRI activation for three memory encoding tasks previously used in the context of presurgical functional mapping. The primary region of interest (ROI) was the medial temporal lobe (MTL). Comparative ROIs included the inferior frontal and fusiform gyri which are less affected by susceptibility-induced signal losses than the MTL regions. Eighteen subjects were scanned using three memory encoding paradigms: word-pair, pattern, and scene encoding. Nine subjects underwent repeat scanning. Intersubject reproducibility of FMRI activation was evaluated by examining the percent of subjects who showed activation within a given ROI and the range to which individual laterality indices (LIs) varied from the mean. Intrasubject test-retest reproducibility was evaluated by examining the LI test-retest correlation, the average difference between LIs from two separate imaging sessions, and concordance ratios of activation volumes (R volume and R overlap ). For scene encoding the reproducibility of activation volume and LIs within the MTL were as good as or better than the reproducibility within the fusiform and inferior frontal ROIs. For pattern encoding and word-pair encoding, the reproducibility of activation volume and LIs within the MTL tended to be worse compared to the fusiform and inferior frontal ROIs. The differences in FMRI reproducibility appeared more dependent on the task than the susceptibility effects. The results of this study suggest that FMRI-based assessment of the neural substrates of memory using a scene encoding task may be a useful clinical tool. (orig.)

  3. An Extremely Slow Motion Servo Control Technique Used in the Hubble Space Telescope's Star Selector Servo Subsystem

    Science.gov (United States)

    Madni, Asad M.; Jumper, Mike

    1997-02-01

    A state-of-the-art, slow motion dual axis servo control system used on the Hubble Space Telescope's Star Selector Subsystem is presented. It utilizes optical encoders with integral DC torque motors to provide precise, digital rate control over a range of 0.5 arcseconds/second (0.0333 revolution/day) to 16,384 arcseconds/second (0.759 revolution/minute) and 21-bit absolute-position words to an accuracy of 2.0 arcseconds peak-to-peak. In the finetracking mode the system provides position tracking to the order of 0.1 microradian.

  4. Spatially dynamic recurrent information flow across long-range dorsal motor network encodes selective motor goals.

    Science.gov (United States)

    Yoo, Peter E; Hagan, Maureen A; John, Sam E; Opie, Nicholas L; Ordidge, Roger J; O'Brien, Terence J; Oxley, Thomas J; Moffat, Bradford A; Wong, Yan T

    2018-03-08

    Performing voluntary movements involves many regions of the brain, but it is unknown how they work together to plan and execute specific movements. We recorded high-resolution ultra-high-field blood-oxygen-level-dependent signal during a cued ankle-dorsiflexion task. The spatiotemporal dynamics and the patterns of task-relevant information flow across the dorsal motor network were investigated. We show that task-relevant information appears and decays earlier in the higher order areas of the dorsal motor network then in the primary motor cortex. Furthermore, the results show that task-relevant information is encoded in general initially, and then selective goals are subsequently encoded in specifics subregions across the network. Importantly, the patterns of recurrent information flow across the network vary across different subregions depending on the goal. Recurrent information flow was observed across all higher order areas of the dorsal motor network in the subregions encoding for the current goal. In contrast, only the top-down information flow from the supplementary motor cortex to the frontoparietal regions, with weakened recurrent information flow between the frontoparietal regions and bottom-up information flow from the frontoparietal regions to the supplementary cortex were observed in the subregions encoding for the opposing goal. We conclude that selective motor goal encoding and execution rely on goal-dependent differences in subregional recurrent information flow patterns across the long-range dorsal motor network areas that exhibit graded functional specialization. © 2018 Wiley Periodicals, Inc.

  5. Functional magnetic resonance imaging using non-Fourier, spatially selective radiofrequency encoding.

    Science.gov (United States)

    Yoo, S S; Guttmann, C R; Panych, L P

    1999-04-01

    A new method for functional magnetic resonance imaging (fMRI) employing non-Fourier encoding using spatially selective radiofrequency (RF) excitation is presented. The method uses manipulation of spatially selective RF pulses to encode spins in the slice-select direction. The method has several advantages over standard multislice approaches. It provides a simple means for monitoring irregularly distributed sections throughout a volume without the need to encode the whole volume. It offers the potential for increased signal-to-noise ratio if an appropriate basis is used for encoding. With a unique design of excitation pulses, it also appears possible to significantly reduce in-flow effects. An interleaved echo-planar imaging (EPI) sequence was adapted for non-Fourier encoding in the slice-select direction and was implemented on a conventional 1.5-Telsa system. The method was then used for functional mapping of the visual and motor areas where significant reduction of in-flow effect was demonstrated. This approach can be adapted to other imaging sequences that are used for fMRI, such as single-shot EPI.

  6. Fragments of a larger whole: retrieval cues constrain observed neural correlates of memory encoding.

    Science.gov (United States)

    Otten, Leun J

    2007-09-01

    Laying down a new memory involves activity in a number of brain regions. Here, it is shown that the particular regions associated with successful encoding depend on the way in which memory is probed. Event-related functional magnetic resonance imaging signals were acquired while subjects performed an incidental encoding task on a series of visually presented words denoting objects. A recognition memory test using the Remember/Know procedure to separate responses based on recollection and familiarity followed 1 day later. Critically, half of the studied objects were cued with a corresponding spoken word, and half with a corresponding picture. Regardless of cue, activity in prefrontal and hippocampal regions predicted subsequent recollection of a word. Type of retrieval cue modulated activity in prefrontal, temporal, and parietal cortices. Words subsequently recognized on the basis of a sense of familiarity were at study also associated with differential activity in a number of brain regions, some of which were probe dependent. Thus, observed neural correlates of successful encoding are constrained by type of retrieval cue, and are only fragments of all encoding-related neural activity. Regions exhibiting cue-specific effects may be sites that support memory through the degree of overlap between the processes engaged during encoding and those engaged during retrieval.

  7. ARA-PEPs: a repository of putative sORF-encoded peptides in Arabidopsis thaliana.

    Science.gov (United States)

    Hazarika, Rashmi R; De Coninck, Barbara; Yamamoto, Lidia R; Martin, Laura R; Cammue, Bruno P A; van Noort, Vera

    2017-01-17

    Many eukaryotic RNAs have been considered non-coding as they only contain short open reading frames (sORFs). However, there is increasing evidence for the translation of these sORFs into bioactive peptides with potent signaling, antimicrobial, developmental, antioxidant roles etc. Yet only a few peptides encoded by sORFs are annotated in the model organism Arabidopsis thaliana. To aid the functional annotation of these peptides, we have developed ARA-PEPs (available at http://www.biw.kuleuven.be/CSB/ARA-PEPs ), a repository of putative peptides encoded by sORFs in the A. thaliana genome starting from in-house Tiling arrays, RNA-seq data and other publicly available datasets. ARA-PEPs currently lists 13,748 sORF-encoded peptides with transcriptional evidence. In addition to existing data, we have identified 100 novel transcriptionally active regions (TARs) that might encode 341 novel stress-induced peptides (SIPs). To aid in identification of bioactivity, we add functional annotation and sequence conservation to predicted peptides. To our knowledge, this is the largest repository of plant peptides encoded by sORFs with transcript evidence, publicly available and this resource will help scientists to effortlessly navigate the list of experimentally studied peptides, the experimental and computational evidence supporting the activity of these peptides and gain new perspectives for peptide discovery.

  8. Slow slip events in the early part of the earthquake cycle

    Science.gov (United States)

    Voss, Nicholas K.; Malservisi, Rocco; Dixon, Timothy H.; Protti, Marino

    2017-08-01

    In February 2014 a Mw = 7.0 slow slip event (SSE) took place beneath the Nicoya Peninsula, Costa Rica. This event occurred 17 months after the 5 September 2012, Mw = 7.6, earthquake and along the same subduction zone segment, during a period when significant postseismic deformation was ongoing. A second SSE occurred in the middle of 2015, 21 months after the 2014 SSE and 38 months after the earthquake. The recurrence interval for Nicoya SSEs was unchanged by the earthquake. However, the spatial distribution of slip for the 2014 event differed significantly from previous events, having only deep ( 40 km) slip, compared to previous events, which had both deep and shallow slip. The 2015 SSE marked a return to the combination of deep plus shallow slip of preearthquake SSEs. However, slip magnitude in 2015 was nearly twice as large (Mw = 7.2) as preearthquake SSEs. We employ Coulomb Failure Stress change modeling in order to explain these changes. Stress changes associated with the earthquake and afterslip were highest near the shallow portion of the megathrust, where preearthquake SSEs had significant slip. Lower stress change occurred on the deeper parts of the plate interface, perhaps explaining why the deep ( 40 km) region for SSEs remained unchanged. The large amount of shallow slip in the 2015 SSE may reflect lack of shallow slip in the prior SSE. These observations highlight the variability of aseismic strain release rates throughout the earthquake cycle.Plain Language SummaryWe analyzed small signals in continuous GPS time series. By averaging many GPS measurements over a day, we are able to get very precise measurements of the motion of the ground. We found two events in the Nicoya Peninsula of Costa Rica where the GPS changed direction and began moving toward the oceanic trench in the opposite direction of subduction plate motion. These events are called slow slip events and have been found in other regions such as Cascadia, Alaska, Japan, and New Zealand. In

  9. Nucleic acids encoding phloem small RNA-binding proteins and transgenic plants comprising them

    Science.gov (United States)

    Lucas, William J.; Yoo, Byung-Chun; Lough, Tony J.; Varkonyi-Gasic, Erika

    2007-03-13

    The present invention provides a polynucleotide sequence encoding a component of the protein machinery involved in small RNA trafficking, Cucurbita maxima phloem small RNA-binding protein (CmPSRB 1), and the corresponding polypeptide sequence. The invention also provides genetic constructs and transgenic plants comprising the polynucleotide sequence encoding a phloem small RNA-binding protein to alter (e.g., prevent, reduce or elevate) non-cell autonomous signaling events in the plants involving small RNA metabolism. These signaling events are involved in a broad spectrum of plant physiological and biochemical processes, including, for example, systemic resistance to pathogens, responses to environmental stresses, e.g., heat, drought, salinity, and systemic gene silencing (e.g., viral infections).

  10. Concurrent Codes: A Holographic-Type Encoding Robust against Noise and Loss.

    Directory of Open Access Journals (Sweden)

    David M Benton

    Full Text Available Concurrent coding is an encoding scheme with 'holographic' type properties that are shown here to be robust against a significant amount of noise and signal loss. This single encoding scheme is able to correct for random errors and burst errors simultaneously, but does not rely on cyclic codes. A simple and practical scheme has been tested that displays perfect decoding when the signal to noise ratio is of order -18dB. The same scheme also displays perfect reconstruction when a contiguous block of 40% of the transmission is missing. In addition this scheme is 50% more efficient in terms of transmitted power requirements than equivalent cyclic codes. A simple model is presented that describes the process of decoding and can determine the computational load that would be expected, as well as describing the critical levels of noise and missing data at which false messages begin to be generated.

  11. Enhancement of sleep slow waves: underlying mechanisms and practical consequences.

    Directory of Open Access Journals (Sweden)

    Michele eBellesi

    2014-10-01

    Full Text Available Even modest sleep restriction, especially the loss of sleep slow wave activity, is invariably associated with slower EEG activity during wake, the occurrence of local sleep in an otherwise awake brain, and impaired performance due to cognitive and memory deficits. Recent studies not only confirm the beneficial role of sleep in memory consolidation, but also point to a specific role for sleep slow waves. Thus, the implementation of methods to enhance sleep slow waves without unwanted arousals or lightening of sleep could have significant practical implications. Here we first review the evidence that it is possible to enhance sleep slow waves in humans using transcranial direct-current stimulation and transcranial magnetic stimulation. Since these methods are currently impractical and their safety is questionable, especially for chronic long-term exposure, we then discuss novel data suggesting that it is possible to enhance slow waves using sensory stimuli. We consider the physiology of the K-complex, a peripheral evoked slow wave, and show that, among different sensory modalities, acoustic stimulation is the most effective in increasing the magnitude of slow waves, likely through the activation of non-lemniscal ascending pathways to the thalamo-cortical system. In addition, we discuss how intensity and frequency of the acoustic stimuli, as well as exact timing and pattern of stimulation, affect sleep enhancement. Finally, we discuss automated algorithms that read the EEG and, in real-time, adjust the stimulation parameters in a closed-loop manner to obtain an increase in sleep slow waves and avoid undesirable arousals. In conclusion, while discussing the mechanisms that underlie the generation of sleep slow waves, we review the converging evidence showing that acoustic stimulation is safe and represents an ideal tool for slow wave sleep enhancement.

  12. On Kinetic Slow Modes, Fluid Slow Modes, and Pressure-balanced Structures in the Solar Wind

    International Nuclear Information System (INIS)

    Verscharen, Daniel; Chen, Christopher H. K.; Wicks, Robert T.

    2017-01-01

    Observations in the solar wind suggest that the compressive component of inertial-range solar-wind turbulence is dominated by slow modes. The low collisionality of the solar wind allows for nonthermal features to survive, which suggests the requirement of a kinetic plasma description. The least-damped kinetic slow mode is associated with the ion-acoustic (IA) wave and a nonpropagating (NP) mode. We derive analytical expressions for the IA-wave dispersion relation in an anisotropic plasma in the framework of gyrokinetics and then compare them to fully kinetic numerical calculations, results from two-fluid theory, and magnetohydrodynamics (MHD). This comparison shows major discrepancies in the predicted wave phase speeds from MHD and kinetic theory at moderate to high β . MHD and kinetic theory also dictate that all plasma normal modes exhibit a unique signature in terms of their polarization. We quantify the relative amplitude of fluctuations in the three lowest particle velocity moments associated with IA and NP modes in the gyrokinetic limit and compare these predictions with MHD results and in situ observations of the solar-wind turbulence. The agreement between the observations of the wave polarization and our MHD predictions is better than the kinetic predictions, which suggests that the plasma behaves more like a fluid in the solar wind than expected.

  13. Unexpected diversity of slow lorises (Nycticebus spp.) within the Javan pet trade: implications for slow loris taxonomy

    NARCIS (Netherlands)

    Nekaris, K.A.I.; Jaffe, S.

    2007-01-01

    Since the 1950s, Sundaland (Borneo, Java, Sumatra and their surrounding islands) was thought to be inhabited by a single slow loris species, the greater slow loris Nycticebus coucang. Early taxonomies as well as recent morphological and genetic studies, however, point to at least three species

  14. Analog Integrated Circuit Design for Spike Time Dependent Encoder and Reservoir in Reservoir Computing Processors

    Science.gov (United States)

    2018-01-01

    nonlinear function was modeled [50] with three fabricated analog multipliers (AD633) [51] and multiple operational amplifiers (op- amp ) (AD712) [52...output signals of these electronic circuit are usually limited to several hundred nanovolts. An op- amp with a finite gain of 109 is normally required to...Op- AMPs ) are not necessary. This project resulted in the design of an agile analog integrated circuit implementation of a spike-time encoding

  15. Excitatory Neuronal Hubs Configure Multisensory Integration of Slow Waves in Association Cortex.

    Science.gov (United States)

    Kuroki, Satoshi; Yoshida, Takamasa; Tsutsui, Hidekazu; Iwama, Mizuho; Ando, Reiko; Michikawa, Takayuki; Miyawaki, Atsushi; Ohshima, Toshio; Itohara, Shigeyoshi

    2018-03-13

    Multisensory integration (MSI) is a fundamental emergent property of the mammalian brain. During MSI, perceptual information encoded in patterned activity is processed in multimodal association cortex. The systems-level neuronal dynamics that coordinate MSI, however, are unknown. Here, we demonstrate intrinsic hub-like network activity in the association cortex that regulates MSI. We engineered calcium reporter mouse lines based on the fluorescence resonance energy transfer sensor yellow cameleon (YC2.60) expressed in excitatory or inhibitory neurons. In medial and parietal association cortex, we observed spontaneous slow waves that self-organized into hubs defined by long-range excitatory and local inhibitory circuits. Unlike directional source/sink-like flows in sensory areas, medial/parietal excitatory and inhibitory hubs had net-zero balanced inputs. Remarkably, multisensory stimulation triggered rapid phase-locking mainly of excitatory hub activity persisting for seconds after the stimulus offset. Therefore, association cortex tends to form balanced excitatory networks that configure slow-wave phase-locking for MSI. VIDEO ABSTRACT. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  16. Cued memory reactivation during slow-wave sleep promotes explicit knowledge of a motor sequence.

    Science.gov (United States)

    Cousins, James N; El-Deredy, Wael; Parkes, Laura M; Hennies, Nora; Lewis, Penelope A

    2014-11-26

    Memories are gradually consolidated after initial encoding, and this can sometimes lead to a transition from implicit to explicit knowledge. The exact physiological processes underlying this reorganization remain unclear. Here, we used a serial reaction time task to determine whether targeted memory reactivation (TMR) of specific memory traces during slow-wave sleep promotes the emergence of explicit knowledge. Human participants learned two 12-item sequences of button presses (A and B). These differed in both cue order and in the auditory tones associated with each of the four fingers (one sequence had four higher-pitched tones). Subsequent overnight sleep was monitored, and the tones associated with one learned sequence were replayed during slow-wave sleep. After waking, participants demonstrated greater explicit knowledge (p = 0.005) and more improved procedural skill (p = 0.04) for the cued sequence relative to the uncued sequence. Furthermore, fast spindles (13.5-15 Hz) at task-related motor regions predicted overnight enhancement in procedural skill (r = 0.71, p = 0.01). Auditory cues had no effect on post-sleep memory performance in a control group who received TMR before sleep. These findings suggest that TMR during sleep can alter memory representations and promote the emergence of explicit knowledge, supporting the notion that reactivation during sleep is a key mechanism in this process. Copyright © 2014 Cousins et al.

  17. Multiscale analysis of slow-fast neuronal learning models with noise.

    Science.gov (United States)

    Galtier, Mathieu; Wainrib, Gilles

    2012-11-22

    This paper deals with the application of temporal averaging methods to recurrent networks of noisy neurons undergoing a slow and unsupervised modification of their connectivity matrix called learning. Three time-scales arise for these models: (i) the fast neuronal dynamics, (ii) the intermediate external input to the system, and (iii) the slow learning mechanisms. Based on this time-scale separation, we apply an extension of the mathematical theory of stochastic averaging with periodic forcing in order to derive a reduced deterministic model for the connectivity dynamics. We focus on a class of models where the activity is linear to understand the specificity of several learning rules (Hebbian, trace or anti-symmetric learning). In a weakly connected regime, we study the equilibrium connectivity which gathers the entire 'knowledge' of the network about the inputs. We develop an asymptotic method to approximate this equilibrium. We show that the symmetric part of the connectivity post-learning encodes the correlation structure of the inputs, whereas the anti-symmetric part corresponds to the cross correlation between the inputs and their time derivative. Moreover, the time-scales ratio appears as an important parameter revealing temporal correlations.

  18. Inverse problems in cancellous bone: estimation of the ultrasonic properties of fast and slow waves using Bayesian probability theory.

    Science.gov (United States)

    Anderson, Christian C; Bauer, Adam Q; Holland, Mark R; Pakula, Michal; Laugier, Pascal; Bretthorst, G Larry; Miller, James G

    2010-11-01

    Quantitative ultrasonic characterization of cancellous bone can be complicated by artifacts introduced by analyzing acquired data consisting of two propagating waves (a fast wave and a slow wave) as if only one wave were present. Recovering the ultrasonic properties of overlapping fast and slow waves could therefore lead to enhancement of bone quality assessment. The current study uses Bayesian probability theory to estimate phase velocity and normalized broadband ultrasonic attenuation (nBUA) parameters in a model of fast and slow wave propagation. Calculations are carried out using Markov chain Monte Carlo with simulated annealing to approximate the marginal posterior probability densities for parameters in the model. The technique is applied to simulated data, to data acquired on two phantoms capable of generating two waves in acquired signals, and to data acquired on a human femur condyle specimen. The models are in good agreement with both the simulated and experimental data, and the values of the estimated ultrasonic parameters fall within expected ranges.

  19. Signal Processing

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Signal processing techniques, extensively used nowadays to maximize the performance of audio and video equipment, have been a key part in the design of hardware and software for high energy physics detectors since pioneering applications in the UA1 experiment at CERN in 1979

  20. [Demography: can growth be slowed down?].

    Science.gov (United States)

    1990-01-01

    The UN Fund for Population Activities report on the status of world population in 1990 is particularly unsettling because it indicates that fertility is not declining as rapidly as had been predicted. The world population of some 5.3 billion is growing by 90-100 million per year. 6 years ago the growth rate appeared to be declining everywhere except in Africa and some regions of South Asia. Hopes that the world population would stabilize at around 10.2 billion by the end of the 21st century now appear unrealistic. Some countries such as the Philippines, India, and Morocco which had some success in slowing growth in the 1960s and 70s have seen a significant deceleration in the decline. Growth rates in several African countries are already 2.7% per year and increasing. It is projected that Africa's population will reach 1.581 billion by 2025. Already there are severe shortages of arable land in some overwhelmingly agricultural countries like Rwanda and Burundi, and malnutrition is widespread on the continent. Between 1979-81 and 1986- 87, cereal production declined in 25 African countries out of 43 for which the Food and Agriculture Organization has data. The urban population of developing countries is increasing at 3.6%/year. It grew from 285 million in 1950 to 1.384 billion today and is projected at 4.050 billion in 2050. Provision of water, electricity, and sanitary services will be very difficult. From 1970-88 the number of urban households without portable water increased from 138 million to 215 million. It is not merely the quality of life that is menaced by constant population growth, but also the very future of the earth as a habitat, because of the degradation of soils and forests and resulting global warming. 6-7 million hectares of agricultural land are believed to be lost to erosion each year. Deforestation is a principal cause of soil erosion. Each year more than 11 million hectares of tropical forest and forested zones are stripped, in addition to some

  1. Improving slowness estimate stability and visualization using limited sensor pair correlation on seismic arrays

    Science.gov (United States)

    Gibbons, Steven J.; Näsholm, S. P.; Ruigrok, E.; Kværna, T.

    2018-04-01

    Seismic arrays enhance signal detection and parameter estimation by exploiting the time-delays between arriving signals on sensors at nearby locations. Parameter estimates can suffer due to both signal incoherence, with diminished waveform similarity between sensors, and aberration, with time-delays between coherent waveforms poorly represented by the wave-front model. Sensor-to-sensor correlation approaches to parameter estimation have an advantage over direct beamforming approaches in that individual sensor-pairs can be omitted without necessarily omitting entirely the data from each of the sensors involved. Specifically, we can omit correlations between sensors for which signal coherence in an optimal frequency band is anticipated to be poor or for which anomalous time-delays are anticipated. In practice, this usually means omitting correlations between more distant sensors. We present examples from International Monitoring System seismic arrays with poor parameter estimates resulting when classical f-k analysis is performed over the full array aperture. We demonstrate improved estimates and slowness grid displays using correlation beamforming restricted to correlations between sufficiently closely spaced sensors. This limited sensor-pair correlation (LSPC) approach has lower slowness resolution than would ideally be obtained by considering all sensor-pairs. However, this ideal estimate may be unattainable due to incoherence and/or aberration and the LSPC estimate can often exploit all channels, with the associated noise-suppression, while mitigating the complications arising from correlations between very distant sensors. The greatest need for the method is for short-period signals on large aperture arrays although we also demonstrate significant improvement for secondary regional phases on a small aperture array. LSPC can also provide a robust and flexible approach to parameter estimation on three-component seismic arrays.

  2. Data from ‘Critical Slowing Down as a Personalized Early Warning Signal for Depression’

    Directory of Open Access Journals (Sweden)

    Jolanda J Kossakowski

    2017-02-01

    Full Text Available We present a dataset of a single (N = 1 participant diagnosed with major depressive disorder, who completed 1478 measurements over the course of 239 consecutive days in 2012 and 2013. The experiment included a double-blind phase in which the dosage of anti-depressant medication was gradually reduced. The entire study looked at momentary affective states in daily life before, during, and after the double-blind phase. The items, which were asked ten times a day, cover topics like mood, physical condition and social contacts. Also, depressive symptoms were measured on a weekly basis using the Symptom Checklist Revised (SCL-90-R. The data are suitable for various time-series analyses and studies in complex dynamical systems.

  3. Slowing down as an early warning signal for abrupt climate change

    NARCIS (Netherlands)

    Dakos, V.; Scheffer, M.; Nes, van E.H.; Brovkin, V.; Petoukhov, V.; Held, H.

    2008-01-01

    In the Earth's history, periods of relatively stable climate have often been interrupted by sharp transitions to a contrasting state. One explanation for such events of abrupt change is that they happened when the earth system reached a critical tipping point. However, this remains hard to prove for

  4. ChIP-seq guidelines and practices of the ENCODE and modENCODE consortia

    Science.gov (United States)

    Landt, Stephen G.; Marinov, Georgi K.; Kundaje, Anshul; Kheradpour, Pouya; Pauli, Florencia; Batzoglou, Serafim; Bernstein, Bradley E.; Bickel, Peter; Brown, James B.; Cayting, Philip; Chen, Yiwen; DeSalvo, Gilberto; Epstein, Charles; Fisher-Aylor, Katherine I.; Euskirchen, Ghia; Gerstein, Mark; Gertz, Jason; Hartemink, Alexander J.; Hoffman, Michael M.; Iyer, Vishwanath R.; Jung, Youngsook L.; Karmakar, Subhradip; Kellis, Manolis; Kharchenko, Peter V.; Li, Qunhua; Liu, Tao; Liu, X. Shirley; Ma, Lijia; Milosavljevic, Aleksandar; Myers, Richard M.; Park, Peter J.; Pazin, Michael J.; Perry, Marc D.; Raha, Debasish; Reddy, Timothy E.; Rozowsky, Joel; Shoresh, Noam; Sidow, Arend; Slattery, Matthew; Stamatoyannopoulos, John A.; Tolstorukov, Michael Y.; White, Kevin P.; Xi, Simon; Farnham, Peggy J.; Lieb, Jason D.; Wold, Barbara J.; Snyder, Michael

    2012-01-01

    Chromatin immunoprecipitation (ChIP) followed by high-throughput DNA sequencing (ChIP-seq) has become a valuable and widely used approach for mapping the genomic location of transcription-factor binding and histone modifications in living cells. Despite its widespread use, there are considerable differences in how these experiments are conducted, how the results are scored and evaluated for quality, and how the data and metadata are archived for public use. These practices affect the quality and utility of any global ChIP experiment. Through our experience in performing ChIP-seq experiments, the ENCODE and modENCODE consortia have developed a set of working standards and guidelines for ChIP experiments that are updated routinely. The current guidelines address antibody validation, experimental replication, sequencing depth, data and metadata reporting, and data quality assessment. We discuss how ChIP quality, assessed in these ways, affects different uses of ChIP-seq data. All data sets used in the analysis have been deposited for public viewing and downloading at the ENCODE (http://encodeproject.org/ENCODE/) and modENCODE (http://www.modencode.org/) portals. PMID:22955991

  5. Bubble masks for time-encoded imaging of fast neutrons.

    Energy Technology Data Exchange (ETDEWEB)

    Brubaker, Erik; Brennan, James S.; Marleau, Peter; Nowack, Aaron B.; Steele, John T.; Sweany, Melinda; Throckmorton, Daniel J.

    2013-09-01

    Time-encoded imaging is an approach to directional radiation detection that is being developed at SNL with a focus on fast neutron directional detection. In this technique, a time modulation of a detected neutron signal is inducedtypically, a moving mask that attenuates neutrons with a time structure that depends on the source position. An important challenge in time-encoded imaging is to develop high-resolution two-dimensional imaging capabilities; building a mechanically moving high-resolution mask presents challenges both theoretical and technical. We have investigated an alternative to mechanical masks that replaces the solid mask with a liquid such as mineral oil. Instead of fixed blocks of solid material that move in pre-defined patterns, the oil is contained in tubing structures, and carefully introduced air gapsbubblespropagate through the tubing, generating moving patterns of oil mask elements and air apertures. Compared to current moving-mask techniques, the bubble mask is simple, since mechanical motion is replaced by gravity-driven bubble propagation; it is flexible, since arbitrary bubble patterns can be generated by a software-controlled valve actuator; and it is potentially high performance, since the tubing and bubble size can be tuned for high-resolution imaging requirements. We have built and tested various single-tube mask elements, and will present results on bubble introduction and propagation as a function of tubing size and cross-sectional shape; real-time bubble position tracking; neutron source imaging tests; and reconstruction techniques demonstrated on simple test data as well as a simulated full detector system.

  6. Prostaglandin regulation of gastric slow waves and peristalsis

    Science.gov (United States)

    Forrest, Abigail S.; Hennig, Grant W.; Jokela-Willis, Sari; Park, Chong Doo; Sanders, Kenton M.

    2009-01-01

    Gastric emptying depends on functional coupling of slow waves between the corpus and antrum, to allow slow waves initiated in the gastric corpus to propagate to the pyloric sphincter and generate gastric peristalsis. Functional coupling depends on a frequency gradient where slow waves are generated at higher frequency in the corpus and drive the activity of distal pacemakers. Simultaneous intracellular recording from corpus and antrum was used to characterize the effects of PGE2 on slow waves in the murine stomach. PGE2 increased slow-wave frequency, and this effect was mimicked by EP3, but not by EP2, receptor agonists. Chronotropic effects were due to EP3 receptors expressed by intramuscular interstitial cells of Cajal because these effects were not observed in W/WV mice. Although the integrated chronotropic effects of EP3 receptor agonists were deduced from electrophysiological experiments, no clear evidence of functional uncoupling was observed with two-point electrical recording. Gastric peristalsis was also monitored by video imaging and spatiotemporal maps to study the impact of chronotropic agonists on propagating contractions. EP3 receptor agonists increased the frequency of peristaltic contractions and caused ectopic sites of origin and collisions of peristaltic waves. The impact of selective regional application of chronotropic agonists was investigated by use of a partitioned bath. Antral slow waves followed enhanced frequencies induced by stimulation of the corpus, and corpus slow waves followed when slow-wave frequency was elevated in the antrum. This demonstrated reversal of slow-wave propagation with selective antral chronotropic stimulation. These studies demonstrate the impact of chronotropic agonists on regional intrinsic pacemaker frequency and integrated gastric peristalsis. PMID:19359421

  7. Prostaglandin regulation of gastric slow waves and peristalsis.

    Science.gov (United States)

    Forrest, Abigail S; Hennig, Grant W; Jokela-Willis, Sari; Park, Chong Doo; Sanders, Kenton M

    2009-06-01

    Gastric emptying depends on functional coupling of slow waves between the corpus and antrum, to allow slow waves initiated in the gastric corpus to propagate to the pyloric sphincter and generate gastric peristalsis. Functional coupling depends on a frequency gradient where slow waves are generated at higher frequency in the corpus and drive the activity of distal pacemakers. Simultaneous intracellular recording from corpus and antrum was used to characterize the effects of PGE(2) on slow waves in the murine stomach. PGE(2) increased slow-wave frequency, and this effect was mimicked by EP(3), but not by EP(2), receptor agonists. Chronotropic effects were due to EP(3) receptors expressed by intramuscular interstitial cells of Cajal because these effects were not observed in W/W(V) mice. Although the integrated chronotropic effects of EP(3) receptor agonists were deduced from electrophysiological experiments, no clear evidence of functional uncoupling was observed with two-point electrical recording. Gastric peristalsis was also monitored by video imaging and spatiotemporal maps to study the impact of chronotropic agonists on propagating contractions. EP(3) receptor agonists increased the frequency of peristaltic contractions and caused ectopic sites of origin and collisions of peristaltic waves. The impact of selective regional application of chronotropic agonists was investigated by use of a partitioned bath. Antral slow waves followed enhanced frequencies induced by stimulation of the corpus, and corpus slow waves followed when slow-wave frequency was elevated in the antrum. This demonstrated reversal of slow-wave propagation with selective antral chronotropic stimulation. These studies demonstrate the impact of chronotropic agonists on regional intrinsic pacemaker frequency and integrated gastric peristalsis.

  8. Evaluating standard terminologies for encoding allergy information.

    Science.gov (United States)

    Goss, Foster R; Zhou, Li; Plasek, Joseph M; Broverman, Carol; Robinson, George; Middleton, Blackford; Rocha, Roberto A

    2013-01-01

    Allergy documentation and exchange are vital to ensuring patient safety. This study aims to analyze and compare various existing standard terminologies for representing allergy information. Five terminologies were identified, including the Systemized Nomenclature of Medical Clinical Terms (SNOMED CT), National Drug File-Reference Terminology (NDF-RT), Medication Dictionary for Regulatory Activities (MedDRA), Unique Ingredient Identifier (UNII), and RxNorm. A qualitative analysis was conducted to compare desirable characteristics of each terminology, including content coverage, concept orientation, formal definitions, multiple granularities, vocabulary structure, subset capability, and maintainability. A quantitative analysis was also performed to compare the content coverage of each terminology for (1) common food, drug, and environmental allergens and (2) descriptive concepts for common drug allergies, adverse reactions (AR), and no known allergies. Our qualitative results show that SNOMED CT fulfilled the greatest number of desirable characteristics, followed by NDF-RT, RxNorm, UNII, and MedDRA. Our quantitative results demonstrate that RxNorm had the highest concept coverage for representing drug allergens, followed by UNII, SNOMED CT, NDF-RT, and MedDRA. For food and environmental allergens, UNII demonstrated the highest concept coverage, followed by SNOMED CT. For representing descriptive allergy concepts and adverse reactions, SNOMED CT and NDF-RT showed the highest coverage. Only SNOMED CT was capable of representing unique concepts for encoding no known allergies. The proper terminology for encoding a patient's allergy is complex, as multiple elements need to be captured to form a fully structured clinical finding. Our results suggest that while gaps still exist, a combination of SNOMED CT and RxNorm can satisfy most criteria for encoding common allergies and provide sufficient content coverage.

  9. The ENCODE (ENCyclopedia Of DNA Elements) Project.

    Science.gov (United States)

    2004-10-22

    The ENCyclopedia Of DNA Elements (ENCODE) Project aims to identify all functional elements in the human genome sequence. The pilot phase of the Project is focused on a specified 30 megabases (approximately 1%) of the human genome sequence and is organized as an international consortium of computational and laboratory-based scientists working to develop and apply high-throughput approaches for detecting all sequence elements that confer biological function. The results of this pilot phase will guide future efforts to analyze the entire human genome.

  10. Theory of neutron slowing down in nuclear reactors

    CERN Document Server

    Ferziger, Joel H; Dunworth, J V

    2013-01-01

    The Theory of Neutron Slowing Down in Nuclear Reactors focuses on one facet of nuclear reactor design: the slowing down (or moderation) of neutrons from the high energies with which they are born in fission to the energies at which they are ultimately absorbed. In conjunction with the study of neutron moderation, calculations of reactor criticality are presented. A mathematical description of the slowing-down process is given, with particular emphasis on the problems encountered in the design of thermal reactors. This volume is comprised of four chapters and begins by considering the problems

  11. Slow Food: por um alimento bom, limpo e justo

    OpenAIRE

    Porazzi, Fabiele

    2012-01-01

    REVIEW:PETRINI, Carlo. Slow Food: princípios da nova gastronomia. Trad. de Renata Lúcia Botina. São Paulo: Editora Senac, 2009. 245 p. RESEÑA:PETRINI, Carlo. Slow Food: princípios da nova gastronomia. Trad. de Renata Lúcia Botina. São Paulo: Editora Senac, 2009. 245 p. http://dx.doi.org/10.5007/1807-1384.2012v9n1p384 RESENHA:PETRINI, Carlo. Slow Food: princípios da nova gastronomia. Trad. de Renata Lúcia Botina. São Paulo: Editora Senac, 2009. 245 p.

  12. Slow light invisibility, teleportation, and other mysteries of light

    CERN Document Server

    Perkowitz, Sidney

    2011-01-01

    Slow Light is a popular treatment of today's astonishing breakthroughs in the science of light. Even though we don't understand light's quantum mysteries, we can slow it to a stop and speed it up beyond its Einsteinian speed limit, 186,000 miles/sec; use it for quantum telecommunications; teleport it; manipulate it to create invisibility; and perhaps generate hydrogen fusion power with it. All this is lucidly presented for non-scientists who wonder about teleportation, Harry Potter invisibility cloaks, and other fantastic outcomes. Slow Light shows how the real science and the fantasy inspire

  13. Dual beam encoded extended fractional Fourier transform security ...

    Indian Academy of Sciences (India)

    This paper describes a simple method for making dual beam encoded extended fractional Fourier transform (EFRT) security holograms. The hologram possesses different stages of encoding so that security features are concealed and remain invisible to the counterfeiter. These concealed and encoded anticounterfeit ...

  14. Dual beam encoded extended fractional Fourier transform security ...

    Indian Academy of Sciences (India)

    Abstract. This paper describes a simple method for making dual beam encoded ex- tended fractional Fourier transform (EFRT) security holograms. The hologram possesses different stages of encoding so that security features are concealed and remain invisible to the counterfeiter. These concealed and encoded ...

  15. Ongoing slow oscillatory phase modulates speech intelligibility in cooperation with motor cortical activity.

    Directory of Open Access Journals (Sweden)

    Takayuki Onojima

    Full Text Available Neural oscillation is attracting attention as an underlying mechanism for speech recognition. Speech intelligibility is enhanced by the synchronization of speech rhythms and slow neural oscillation, which is typically observed as human scalp electroencephalography (EEG. In addition to the effect of neural oscillation, it has been proposed that speech recognition is enhanced by the identification of a speaker's motor signals, which are used for speech production. To verify the relationship between the effect of neural oscillation and motor cortical activity, we measured scalp EEG, and simultaneous EEG and functional magnetic resonance imaging (fMRI during a speech recognition task in which participants were required to recognize spoken words embedded in noise sound. We proposed an index to quantitatively evaluate the EEG phase effect on behavioral performance. The results showed that the delta and theta EEG phase before speech inputs modulated the participant's response time when conducting speech recognition tasks. The simultaneous EEG-fMRI experiment showed that slow EEG activity was correlated with motor cortical activity. These results suggested that the effect of the slow oscillatory phase was associated with the activity of the motor cortex during speech recognition.

  16. Hollow core photonic bandgap fiber with microfluid-infiltrated air holes for slow-light propagation

    Science.gov (United States)

    Ren, Liyong; Liang, Jian; Yun, Maojin

    2012-10-01

    Slow light plays an important role in the fields of all-optical signal processing and integration photonics. It has shown many potential applications, such as realizing optical delay lines or buffers, enhancing linear and nonlinear light-matter interactions, as well as increasing the sensitivity of the interferometers and transducers. In this paper, hollow-core photonic bandgap fibers made from high index glasses are designed by infiltrating microfluid into the air-holes to tailor the fiber dispersion for slow-light propagation under low pulse distortion. In such a fiber made from Si material, group index ng~8 is obtained with a bandwidth up to 30 nm, where the group index fluctuation is restricted in ±10 % of the ng, while ng~6 is obtained with a bandwidth over 100 nm when the chalcogenide material is selected instead. Such a ±10 % criterion determines a regarded flatland region accordingly, and in this region the group velocity dispersion can be negligible. It is found that for the same fiber length the slow-light time delay in the photonic bandgap fiber is much larger as compared with that in the single mode fiber. This kind of photonic bandgap fiber may have many potential applications in short-distance fiber communications and delay lines.

  17. Ongoing slow oscillatory phase modulates speech intelligibility in cooperation with motor cortical activity.

    Science.gov (United States)

    Onojima, Takayuki; Kitajo, Keiichi; Mizuhara, Hiroaki

    2017-01-01

    Neural oscillation is attracting attention as an underlying mechanism for speech recognition. Speech intelligibility is enhanced by the synchronization of speech rhythms and slow neural oscillation, which is typically observed as human scalp electroencephalography (EEG). In addition to the effect of neural oscillation, it has been proposed that speech recognition is enhanced by the identification of a speaker's motor signals, which are used for speech production. To verify the relationship between the effect of neural oscillation and motor cortical activity, we measured scalp EEG, and simultaneous EEG and functional magnetic resonance imaging (fMRI) during a speech recognition task in which participants were required to recognize spoken words embedded in noise sound. We proposed an index to quantitatively evaluate the EEG phase effect on behavioral performance. The results showed that the delta and theta EEG phase before speech inputs modulated the participant's response time when conducting speech recognition tasks. The simultaneous EEG-fMRI experiment showed that slow EEG activity was correlated with motor cortical activity. These results suggested that the effect of the slow oscillatory phase was associated with the activity of the motor cortex during speech recognition.

  18. Hippocampal slow oscillation: a novel EEG state and its coordination with ongoing neocortical activity.

    Science.gov (United States)

    Wolansky, Trish; Clement, Elizabeth A; Peters, Steven R; Palczak, Michael A; Dickson, Clayton T

    2006-06-07

    State-dependent EEG in the hippocampus (HPC) has traditionally been divided into two activity patterns: theta, a large-amplitude, regular oscillation with a bandwidth of 3-12 Hz, and large-amplitude irregular activity (LIA), a less regular signal with broadband characteristics. Both of these activity patterns have been linked to the memory functions subserved by the HPC. Here we describe, using extracellular field recording techniques in naturally sleeping and urethane-anesthetized rats, a novel state present during deactivated stages of sleep and anesthesia that is characterized by a prominent large-amplitude and slow frequency (sink-source alternations in stratum lacunosum-moleculare of CA1. This, along with correlated slow oscillatory field and multiunit activity in superficial entorhinal cortex suggests that the hippocampal SO may be coordinated with slow neocortical activity through input arriving via the temporo-ammonic pathway. This novel state may present a favorable milieu for synchronization-dependent synaptic plasticity within and between hippocampal and neocortical ensembles.

  19. Drosophila egghead encodes a beta 1,4-mannosyltransferase predicted to form the immediate precursor glycosphingolipid substrate for brainiac

    DEFF Research Database (Denmark)

    Wandall, Hans H; Pedersen, Johannes W; Park, Chaeho

    2002-01-01

    The neurogenic Drosophila genes brainiac and egghead are essential for epithelial development in the embryo and in oogenesis. Analysis of egghead and brainiac mutants has led to the suggestion that the two genes function in a common signaling pathway. Recently, brainiac was shown to encode a UDP...

  20. Slow slip phenomena in Cascadia from 2007 and beyond: a review

    Science.gov (United States)

    Gomberg, Joan; ,

    2010-01-01

    Recent technological advances combined with more detailed analyses of seismologic and geodetic observations have fundamentally changed our understanding of the ways in which tectonic stresses arising from plate motions are accommodated by slip on faults. The traditional view that relative plate motions are accommodated by a simple cycle of stress accumulation and release on “locked” plate-boundary faults has been revolutionized by the serendipitous discovery and recognition of the significance of slow-slip phenomena, mostly in the deeper reaches of subduction zones. The Cascadia subduction zone, located in the Pacific Northwest of the conterminous United States and adjacent Canada, is an archetype of exploration and learning about slow-slip phenomena. These phenomena are manifest as geodetically observed aseismic transient deformations accompanied by a previously unrecognized class of seismic signals. Although secondary failure processes may be involved in generating the seismic signals, the primary origins of both aseismic and seismic phenomena appear to be episodic fault slip, probably facilitated by fluids, on a plate interface that is critically stressed or weakened. In Cascadia, this transient slip evolves more slowly and over more prolonged durations relative to the slip in earthquakes, and it occurs between the 30- and 40-km-depth contours of the plate interface where information was previously elusive. Although there is some underlying organization that relaxes nearly all the accrued plate-motion stresses along the entirety of Cascadia, we now infer that slow slip evolves in complex patterns indicative of propagating stress fronts. Our new understanding provides key constraints not only on the region where the slow slip originates, but also on the probable characteristics of future megathrust earthquakes in Cascadia. Herein, we review the most significant scientific issues and progress related to understanding slow-slip phenomena in Cascadia and

  1. V123 Beam Synchronous Encoder Module

    International Nuclear Information System (INIS)

    Kerner, T.; Conkling, C. R.; Oerter, B.

    1999-01-01

    The V123 Synchronous Encoder Module transmits events to distributed trigger modules and embedded decoders around the RHIC rings where they are used to provide beam instrumentation triggers [1,2,3]. The RHIC beam synchronous event link hardware is mainly comprised of three VMEbus board designs, the central input modules (V201), and encoder modules (V123), and the distributed trigger modules (V124). Two beam synchronous links, one for each ring, are distributed via fiberoptic and fanned out via twisted wire pair cables. The V123 synchronizes with the RF system clock derived from the beam bucket frequency and a revolution fiducial pulse. The RF system clock is used to create the beam synchronous event link carrier and events are synchronized with the rotation fiducial. A low jitter RF clock is later recovered from this carrier by phase lock loops in the trigger modules. Prioritized hardware and software triggers fill up to 15 beam event code transmission slots per revolution while tracking the ramping RF acceleration frequency and storage frequency. The revolution fiducial event is always the first event transmitted which is used to synchronize the firing of the abort kicker and to locate the first bucket for decoders distributed about the ring

  2. Slow manifold and Hannay angle in the spinning top

    Energy Technology Data Exchange (ETDEWEB)

    Berry, M V [H H Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Shukla, P [Department of Physics, Indian Institute of Technology, Kharagpur (India)

    2011-01-15

    The spin of a top can be regarded as a fast variable, coupled to the motion of the axis which is slow. In pure precession, the rotation of the axis round a cone (without nutation), can be considered as the result of a reaction from the fast spin. The resulting restriction of the total state space of the top is an illustrative example, at graduate-student level, of the general dynamical concept of the slow manifold. For this case, the slow manifold can be calculated exactly, and expanded as a series of reaction forces (of magnetic type) in powers of slowness, corresponding to a modified precession frequency. The forces correspond to a series for the Hannay angle for the fast motion, describing the location of a point on the top.

  3. Human Growth Hormone (HGH): Does It Slow Aging?

    Science.gov (United States)

    Healthy Lifestyle Healthy aging Human growth hormone is described by some as the key to slowing the aging ... about proven ways to improve your health. Remember, healthy lifestyle choices — such as eating a healthy diet and ...

  4. Slow light enhancement and limitations in periodic media

    DEFF Research Database (Denmark)

    Grgic, Jure

    Properties of periodic dielectric media have attracted a big interest in the last two decades due to numerous exciting physical phenomena that cannot occur in homogeneous media. Due to their strong dispersive properties, the speed of light can be significantly slowed down in periodic structures....... When light velocity is much smaller than the speed of light in a vacuum, we describe this phenomena as slow light. In this thesis, we analyze important properties of slow light enhancement and limitations in periodic structures. We analyze quantitatively and qualitatively different technologies...... and significant structures with numerical and analytical methods. By analyzing different structures, we show very general properties for limitation and enhancement in the slow light regime. Inherent imperfections of fabricated structures such as a material loss and structural disorder have a strong influence...

  5. On the use of slow light for enhancing waveguide properties

    DEFF Research Database (Denmark)

    Mørk, Jesper; Nielsen, Torben Roland

    2010-01-01

    On the basis of a general analysis of waveguides containing a dispersive material, we identify conditions under which slow-light propagation may enhance the gain, absorption, or phase change. The enhancement is shown to depend on the slow-light mechanism and the translational symmetry of the wave...... of the waveguide. A combination of material and waveguide dispersion may strongly enhance the control of light speed, e.g., using electromagnetically induced transparency in quantum dots embedded in a photonic crystal waveguide.......On the basis of a general analysis of waveguides containing a dispersive material, we identify conditions under which slow-light propagation may enhance the gain, absorption, or phase change. The enhancement is shown to depend on the slow-light mechanism and the translational symmetry...

  6. Critical slowing down and error analysis in lattice QCD simulations

    International Nuclear Information System (INIS)

    Schaefer, Stefan; Sommer, Rainer; Virotta, Francesco

    2010-09-01

    We study the critical slowing down towards the continuum limit of lattice QCD simulations with Hybrid Monte Carlo type algorithms. In particular for the squared topological charge we find it to be very severe with an effective dynamical critical exponent of about 5 in pure gauge theory. We also consider Wilson loops which we can demonstrate to decouple from the modes which slow down the topological charge. Quenched observables are studied and a comparison to simulations of full QCD is made. In order to deal with the slow modes in the simulation, we propose a method to incorporate the information from slow observables into the error analysis of physical observables and arrive at safer error estimates. (orig.)

  7. Critical slowing down and error analysis in lattice QCD simulations

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Stefan [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Sommer, Rainer; Virotta, Francesco [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2010-09-15

    We study the critical slowing down towards the continuum limit of lattice QCD simulations with Hybrid Monte Carlo type algorithms. In particular for the squared topological charge we find it to be very severe with an effective dynamical critical exponent of about 5 in pure gauge theory. We also consider Wilson loops which we can demonstrate to decouple from the modes which slow down the topological charge. Quenched observables are studied and a comparison to simulations of full QCD is made. In order to deal with the slow modes in the simulation, we propose a method to incorporate the information from slow observables into the error analysis of physical observables and arrive at safer error estimates. (orig.)

  8. Compounding of slow-release niacinamide capsules: feasibility and characterization.

    Science.gov (United States)

    Radojkovic, Branko; Milić, Jela; Calija, Bojan

    2012-01-01

    The purpose of this study was to assess the feasibility of extemporaneous compounding of slow-release oral dosage form of niacinamide and to evaluate its release kinetics. The model formulation (preparation) was developed in the form of powder-filled hard gelatin capsules. Two slow-release preparations with different ratios of hypromellose have been prepared and evaluated in comparison with an immediate-release preparation. The dissolution tests were performed as per United States Pharmacopoeia requirements: Type I Apparatus, over 7 hours. Both slow-release preparations, containing 40% and 60% v/v hypromellose, respectively, have showed slow release kinetics. The dissolution profiles were significantly different, with similarity factor f2niacinamide capsules can be successfully compounded using hypromellose as a sole release rate modifier, and that the release mechanism is comparable to hydrophilic polymer matrix-based systems.

  9. Very Slow Speed Axial Motion Reluctance Motor | Agu | Nigerian ...

    African Journals Online (AJOL)

    Abstract. This paper presents the scheme for a very slow speed linear machine which uses conventional laminations and with which speeds of the same low order as that of the screw-thread motor can be obtained.

  10. Damping of Slow Magnetoacoustic Waves in an Inhomogeneous ...

    Indian Academy of Sciences (India)

    Aschwanden. 2004b; Nakariakov 2003). In this paper, we will study the dissipation of slow MHD waves in an inhomogeneous, compressible, and low-β coronal loop plasma through viscosity and thermal conduction. The paper is organized as follows.

  11. Preparation and characterization of Slow Release Formulations of ...

    African Journals Online (AJOL)

    alginate beads and characterize the resulting slow release formulations (SRFs) using scanning electron microscopy (SEM), and Fourier Transform infrared spectroscopy (FTIR). Two sets of formulations were made by extrusion into 0.25 M calcium ...

  12. Population Suppression of Subterranean Termites by Slow-Acting Toxicants

    Science.gov (United States)

    Nan-Yao Su; Rudolf H. Scheffrahn

    1991-01-01

    Historic background and the concept of slow-acting toxicants for population suppression of subterranean termites are reviewed. Information needed for development of bait-toxicants and studies needed to generate such information are summarized.

  13. Cortical deactivation induced by visual stimulation in human slow-wave sleep

    DEFF Research Database (Denmark)

    Born, Alfred Peter; Law, Ian; Lund, Torben E

    2002-01-01

    It has previously been demonstrated that sleeping and sedated young children respond with a paradoxical decrease in the blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signal in the rostro-medial occipital visual cortex during visual stimulation...... visual stimulation in spontaneously sleeping adult volunteers. In five sleeping volunteers fMRI studies confirmed a robust signal decrease during stimulation in the rostro-medial occipital cortex. A similar relative decrease at the same location was found during visual stimulation...... and polysomnographically verified slow-wave sleep in a separate group of six subjects using H(2)(15)O PET measures of the regional cerebral blood flow (rCBF). This decrease was more rostro-dorsal compared to the relative rCBF increase along the calcarine sulcus found during visual stimulation in the awake state...

  14. Negative base encoding in optical linear algebra processors

    Science.gov (United States)

    Perlee, C.; Casasent, D.

    1986-01-01

    In the digital multiplication by analog convolution algorithm, the bits of two encoded numbers are convolved to form the product of the two numbers in mixed binary representation; this output can be easily converted to binary. Attention is presently given to negative base encoding, treating base -2 initially, and then showing that the negative base system can be readily extended to any radix. In general, negative base encoding in optical linear algebra processors represents a more efficient technique than either sign magnitude or 2's complement encoding, when the additions of digitally encoded products are performed in parallel.

  15. Exploring carrier dynamics in semiconductors for slow light

    DEFF Research Database (Denmark)

    Mørk, Jesper; Xue, Weiqi; Chen, Yaohui

    2009-01-01

    We give an overview of recent results on slow and fast light in active semiconductor waveguides. The cases of coherent population oscillations as well as electromagnetically induced transparency are covered, emphasizing the physics and fundamental limitations.......We give an overview of recent results on slow and fast light in active semiconductor waveguides. The cases of coherent population oscillations as well as electromagnetically induced transparency are covered, emphasizing the physics and fundamental limitations....

  16. Perceptions of the Slow Food Cultural Trend among the Youth

    OpenAIRE

    Lelia Voinea; Anca Atanase; Ion Schileru

    2016-01-01

    As they become increasingly aware of the importance of healthy eating and of the serious food imbalance caused by the overconsumption of industrial, ultra-processed and superorganoleptic food, consumers are now beginning to turn their attention to food choices guaranteeing both individual health and also of the environment . Thus, in recent years we are witnessing the rise of a cultural trend ‒ Slow Food. Slow Food has become an international movement that advocates for satisfying culinary pl...

  17. Hunting for shallow slow-slip events at Cascadia

    Science.gov (United States)

    Tan, Y. J.; Bletery, Q.; Fan, W.; Janiszewski, H. A.; Lynch, E.; McCormack, K. A.; Phillips, N. J.; Rousset, B.; Seyler, C.; French, M. E.; Gaherty, J. B.; Regalla, C.

    2017-12-01

    The discovery of slow earthquakes at subduction zones is one of the major breakthroughs of Earth science in the last two decades. Slow earthquakes involve a wide spectrum of fault slip behaviors and seismic radiation patterns, such as tremor, low-frequency earthquakes, and slow-slip events. The last of these are particularly interesting due to their large moment releases accompanied by minimal ground shaking. Slow-slip events have been reported at various subduction zones ; most of these slow-slip events are located down-dip of the megathrust seismogenic zone, while a few up-dip cases have recently been observed at Nankai and New Zealand. Up-dip slow-slip events illuminate the structure of faulting environments and rupture mechanisms of tsunami earthquakes. Their possible presence and location at a particular subduction zone can help assess earthquake and tsunami hazard for that region. However, their typical location distant from the coast requires the development of techniques using offshore instrumentation. Here, we investigate the absolute pressure gauges (APG) of the Cascadia Initiative, a four year amphibious seismic experiment, to search for possible shallow up-dip slow-slip events in the Cascadia subduction zone. These instruments are collocated with ocean bottom seismometers (OBS) and located close to buoys and onshore GPS stations, offering the opportunity to investigate the utility of multiple datasets. Ultimately, we aim to develop a protocol to analyze APG data for offshore shallow slow-slip event detections and quantify uncertainties, with direct applications to understanding the up-dip subduction interface system in Cascadia.

  18. Temporal Heterogeneity and the Value of Slowness in Robotic Systems

    Science.gov (United States)

    2015-11-01

    seasonal changes. Contrast this to the more common agricultural robotics approach, where larger machines conduct these operations periodically rather than...Abstract— Robot teaming is a well-studied area, but little research to date has been conducted on the fundamental benefits of heterogeneous...aspect of robot ecosystems consisting of fast and slow robots (SlowBots) working together, including the bio-inspiration for such systems. I

  19. Apparatus for laser slowing and cooling of molecules

    Science.gov (United States)

    2016-10-09

    SECURITY CLASSIFICATION OF: This is the final report for our DURIP grant entitled "Apparatus for Laser Slowing and cooling of Molecules". We have... cooling of a new molecular species, TlF. We have also successfully acquired and assembled the parts for a custom laser system, which produces long...Distribution Unlimited UU UU UU UU 09-10-2016 1-Sep-2012 31-Aug-2014 Final Report: Apparatus for laser slowing and cooling of molecules The views

  20. Slow and fast light in semiconductor structures: physics and applications

    DEFF Research Database (Denmark)

    Mørk, Jesper; Nielsen, Torben Roland; Xue, Weiqi

    We discuss the physics and applications of slow light in semiconductor waveguides. In particular we introduce methods for enhancing the degree of light speed control considering both electromagnetically induced transparency as well as coherent population oscillations.......We discuss the physics and applications of slow light in semiconductor waveguides. In particular we introduce methods for enhancing the degree of light speed control considering both electromagnetically induced transparency as well as coherent population oscillations....

  1. Global expression analysis of nucleotide binding site-leucine rich repeat-encoding and related genes in Arabidopsis

    Science.gov (United States)

    Tan, Xiaoping; Meyers, Blake C; Kozik, Alexander; West, Marilyn AL; Morgante, Michele; St Clair, Dina A; Bent, Andrew F; Michelmore, Richard W

    2007-01-01

    Background Nucleotide binding site-leucine rich repeat (NBS-LRR)-encoding genes comprise the largest class of plant disease resistance genes. The 149 NBS-LRR-encoding genes and the 58 related genes that do not encode LRRs represent approximately 0.8% of all ORFs so far annotated in Arabidopsis ecotype Col-0. Despite their prevalence in the genome and functional importance, there was little information regarding expression of these genes. Results We analyzed the expression patterns of ~170 NBS-LRR-encoding and related genes in Arabidopsis Col-0 using multiple analytical approaches: expressed sequenced tag (EST) representation, massively parallel signature sequencing (MPSS), microarray analysis, rapid amplification of cDNA ends (RACE) PCR, and gene trap lines. Most of these genes were expressed at low levels with a variety of tissue specificities. Expression was detected by at least one approach for all but 10 of these genes. The expression of some but not the majority of NBS-LRR-encoding and related genes was affected by salicylic acid (SA) treatment; the response to SA varied among different accessions. An analysis of previously published microarray data indicated that ten NBS-LRR-encoding and related genes exhibited increased expression in wild-type Landsberg erecta (Ler) after flagellin treatment. Several of these ten genes also showed altered expression after SA treatment, consistent with the regulation of R gene expression during defense responses and overlap between the basal defense response and salicylic acid signaling pathways. Enhancer trap analysis indicated that neither jasmonic acid nor benzothiadiazole (BTH), a salicylic acid analog, induced detectable expression of the five NBS-LRR-encoding genes and one TIR-NBS-encoding gene tested; however, BTH did induce detectable expression of the other TIR-NBS-encoding gene analyzed. Evidence for alternative mRNA polyadenylation sites was observed for many of the tested genes. Evidence for alternative splicing

  2. Global expression analysis of nucleotide binding site-leucine rich repeat-encoding and related genes in Arabidopsis

    Directory of Open Access Journals (Sweden)

    St Clair Dina A

    2007-10-01

    Full Text Available Abstract Background Nucleotide binding site-leucine rich repeat (NBS-LRR-encoding genes comprise the largest class of plant disease resistance genes. The 149 NBS-LRR-encoding genes and the 58 related genes that do not encode LRRs represent approximately 0.8% of all ORFs so far annotated in Arabidopsis ecotype Col-0. Despite their prevalence in the genome and functional importance, there was little information regarding expression of these genes. Results We analyzed the expression patterns of ~170 NBS-LRR-encoding and related genes in Arabidopsis Col-0 using multiple analytical approaches: expressed sequenced tag (EST representation, massively parallel signature sequencing (MPSS, microarray analysis, rapid amplification of cDNA ends (RACE PCR, and gene trap lines. Most of these genes were expressed at low levels with a variety of tissue specificities. Expression was detected by at least one approach for all but 10 of these genes. The expression of some but not the majority of NBS-LRR-encoding and related genes was affected by salicylic acid (SA treatment; the response to SA varied among different accessions. An analysis of previously published microarray data indicated that ten NBS-LRR-encoding and related genes exhibited increased expression in wild-type Landsberg erecta (Ler after flagellin treatment. Several of these ten genes also showed altered expression after SA treatment, consistent with the regulation of R gene expression during defense responses and overlap between the basal defense response and salicylic acid signaling pathways. Enhancer trap analysis indicated that neither jasmonic acid nor benzothiadiazole (BTH, a salicylic acid analog, induced detectable expression of the five NBS-LRR-encoding genes and one TIR-NBS-encoding gene tested; however, BTH did induce detectable expression of the other TIR-NBS-encoding gene analyzed. Evidence for alternative mRNA polyadenylation sites was observed for many of the tested genes. Evidence for

  3. Global expression analysis of nucleotide binding site-leucine rich repeat-encoding and related genes in Arabidopsis.

    Science.gov (United States)

    Tan, Xiaoping; Meyers, Blake C; Kozik, Alexander; West, Marilyn A L; Morgante, Michele; St Clair, Dina A; Bent, Andrew F; Michelmore, Richard W

    2007-10-23

    Nucleotide binding site-leucine rich repeat (NBS-LRR)-encoding genes comprise the largest class of plant disease resistance genes. The 149 NBS-LRR-encoding genes and the 58 related genes that do not encode LRRs represent approximately 0.8% of all ORFs so far annotated in Arabidopsis ecotype Col-0. Despite their prevalence in the genome and functional importance, there was little information regarding expression of these genes. We analyzed the expression patterns of approximately 170 NBS-LRR-encoding and related genes in Arabidopsis Col-0 using multiple analytical approaches: expressed sequenced tag (EST) representation, massively parallel signature sequencing (MPSS), microarray analysis, rapid amplification of cDNA ends (RACE) PCR, and gene trap lines. Most of these genes were expressed at low levels with a variety of tissue specificities. Expression was detected by at least one approach for all but 10 of these genes. The expression of some but not the majority of NBS-LRR-encoding and related genes was affected by salicylic acid (SA) treatment; the response to SA varied among different accessions. An analysis of previously published microarray data indicated that ten NBS-LRR-encoding and related genes exhibited increased expression in wild-type Landsberg erecta (Ler) after flagellin treatment. Several of these ten genes also showed altered expression after SA treatment, consistent with the regulation of R gene expression during defense responses and overlap between the basal defense response and salicylic acid signaling pathways. Enhancer trap analysis indicated that neither jasmonic acid nor benzothiadiazole (BTH), a salicylic acid analog, induced detectable expression of the five NBS-LRR-encoding genes and one TIR-NBS-encoding gene tested; however, BTH did induce detectable expression of the other TIR-NBS-encoding gene analyzed. Evidence for alternative mRNA polyadenylation sites was observed for many of the tested genes. Evidence for alternative splicing was

  4. Beneficial Effects of Slow Steaming in Bulk Freight Markets

    Directory of Open Access Journals (Sweden)

    Sarah Boone

    2017-12-01

    Full Text Available Slow steaming has recently been adopted into normal practice by many maritime shipping companies for the fuel and monetary savings it offers. The practice also offers savings in Greenhouse Gas (GHG emissions. With regulations coming into play such as the 2020 sulfur cap, slow steaming may be the least costly option for some maritime companies to adjust their operations. While some have accepted the new practice, there are still companies and vessels that see this exercise as a loss of revenue due to the extra time it takes to deliver goods to their destination. This paper reviews how the method of rating ships by their GHG emissions per nautical mile can be directly related to slow steaming. We propose that ships with poor ratings (E, F, G find mandatory regulations to slow steam or improve their CO2 output in some way. Those with superior ratings (A, B, C, D would benefit from incentives packages tied to their implementation of slow steaming practices. It will also examine how slow steaming benefits maritime businesses both economically and environmentally to find ways to lower their emissions and discusses the possible chain reaction that may occur if these eco-friendly shipping practices are observed.

  5. A New Quantum Gray-Scale Image Encoding Scheme

    Science.gov (United States)

    Naseri, Mosayeb; Abdolmaleky, Mona; Parandin, Fariborz; Fatahi, Negin; Farouk, Ahmed; Nazari, Reza

    2018-02-01

    In this paper, a new quantum images encoding scheme is proposed. The proposed scheme mainly consists of four different encoding algorithms. The idea behind of the scheme is a binary key generated randomly for each pixel of the original image. Afterwards, the employed encoding algorithm is selected corresponding to the qubit pair of the generated randomized binary key. The security analysis of the proposed scheme proved its enhancement through both randomization of the generated binary image key and altering the gray-scale value of the image pixels using the qubits of randomized binary key. The simulation of the proposed scheme assures that the final encoded image could not be recognized visually. Moreover, the histogram diagram of encoded image is flatter than the original one. The Shannon entropies of the final encoded images are significantly higher than the original one, which indicates that the attacker can not gain any information about the encoded images. Supported by Kermanshah Branch, Islamic Azad University, Kermanshah, IRAN

  6. Promoter analysis of the fish gene of slow/cardiac-type myosin heavy chain implicated in specification of muscle fiber types.

    Science.gov (United States)

    Kinoshita, Shigeharu; Ceyhun, Saltuk Bugrahan; Md, Asaduzzamann; Siddique, Bhuiyan Sharmin; Akolkar, Dadasaheb B; Asakawa, Shuichi; Watabe, Shugo

    2018-04-01

    Vertebrate skeletal muscles consist of heterogeneous tissues containing various types of muscle fibers, where specification of the fiber type is crucial for muscle development. Fish are an attractive experimental model to study the mechanisms of such fiber type specification because of the separated localization of slow and fast muscles in the trunk myotome. We examined regulation of expression of the torafugu gene of slow/cardiac-type myosin heavy chain, MYH M5 , and isolated an operational promoter in order to force its tissue-specific expression across different fish species via the transgenic approach in zebrafish and medaka. This promoter activity was observed in adaxial cell-derived superficial slow muscle fibers under the control of a hedgehog signal. We also uncovered coordinated expression of MYH M5 and Sox6b, which is an important transcriptional repressor for specification of muscle fiber types and participates in hedgehog signaling. Sequence comparison in the 5'-flanking region identified three conserved regions, CSR1-CSR3, between torafugu MYH M5 and its zebrafish ortholog. Analysis of deletion mutants showed that CSR1 significantly stimulates gene expression in slow muscle fibers. In contrast, deletion of CSR3 resulted in ectopic expression of a reporter gene in fast muscle fibers. CSR3 was found to contain a putative Sox family protein-binding site. These results indicate that the dual mechanism causing inhibition in fast muscle fibers and activation in slow muscle fibers is essential for slow muscle fiber-specific gene expression in fish.

  7. How many positions can we perceptually encode, one or many?

    Science.gov (United States)

    Hess, R F; Barnes, G; Dumoulin, S O; Dakin, S C

    2003-06-01

    Here we show that our sensitivity for discriminating relative position across the visual field is limited. In experiment 1 we show that we are much worse at detecting a texture defined by the relative position of elements within an array than would be expected if we had access to multiple estimates of relative position across the visual field. In experiment 2 we show that human performance is impaired for positional judgments when there is uncertainty as to which of a number of possible elements is misaligned. This impairment is greater than one would expect from an ideal observer model and greater than that found for a comparable task involving orientation. It is consistent with positional thresholds being determined by only one estimate of relative position. In experiment 3 we estimate the number of suprathreshold positional signals that can be pooled at the same time across the visual field using a standard summation variance paradigm. The results suggest that the human visual system is limited to one estimate of position, but additional estimates can be built up serially over time; however, this process is slow and probably cognitive in nature. These experiments taken as a whole suggest that only one estimate of relative position (i.e. relative to a predefined reference) at a time is accessible at the perceptual level.

  8. Critical slowing down associated with regime shifts in the US housing market

    Science.gov (United States)

    Tan, James Peng Lung; Cheong, Siew Siew Ann

    2014-02-01

    Complex systems are described by a large number of variables with strong and nonlinear interactions. Such systems frequently undergo regime shifts. Combining insights from bifurcation theory in nonlinear dynamics and the theory of critical transitions in statistical physics, we know that critical slowing down and critical fluctuations occur close to such regime shifts. In this paper, we show how universal precursors expected from such critical transitions can be used to forecast regime shifts in the US housing market. In the housing permit, volume of homes sold and percentage of homes sold for gain data, we detected strong early warning signals associated with a sequence of coupled regime shifts, starting from a Subprime Mortgage Loans transition in 2003-2004 and ending with the Subprime Crisis in 2007-2008. Weaker signals of critical slowing down were also detected in the US housing market data during the 1997-1998 Asian Financial Crisis and the 2000-2001 Technology Bubble Crisis. Backed by various macroeconomic data, we propose a scenario whereby hot money flowing back into the US during the Asian Financial Crisis fueled the Technology Bubble. When the Technology Bubble collapsed in 2000-2001, the hot money then flowed into the US housing market, triggering the Subprime Mortgage Loans transition in 2003-2004 and an ensuing sequence of transitions. We showed how this sequence of couple transitions unfolded in space and in time over the whole of US.

  9. Prosocial Signalling

    DEFF Research Database (Denmark)

    Kahsay, Goytom Abraha

    signalling can cause reverse price reactions resembling the crowding-out of pre-existing motives for prosocial behavior seen in situations of volunteering and charitable giving. Using a unique combination of questionnaire and purchase panel data, it presents evidence of such reputation-driven reverse price...... reactions in the Danish market for organic milk. The second paper proposes a self-image model to account consumers’ behaviour under PWYW. It finds that when a good’s fixed price is lower than an exogenously given threshold fair value, PWYW can lead to a lower utility, which may lead to lower purchase rate...

  10. Neurons in the barrel cortex turn into processing whisker and odor signals: a cellular mechanism for the storage and retrieval of associative signals.

    Science.gov (United States)

    Wang, Dangui; Zhao, Jun; Gao, Zilong; Chen, Na; Wen, Bo; Lu, Wei; Lei, Zhuofan; Chen, Changfeng; Liu, Yahui; Feng, Jing; Wang, Jin-Hui

    2015-01-01

    Associative learning and memory are essential to logical thinking and cognition. How the neurons are recruited as associative memory cells to encode multiple input signals for their associated storage and distinguishable retrieval remains unclear. We studied this issue in the barrel cortex by in vivo two-photon calcium imaging, electrophysiology, and neural tracing in our mouse model that the simultaneous whisker and olfaction stimulations led to odorant-induced whisker motion. After this cross-modal reflex arose, the barrel and piriform cortices connected. More than 40% of barrel cortical neurons became to encode odor signal alongside whisker signal. Some of these neurons expressed distinct activity patterns in response to acquired odor signal and innate whisker signal, and others encoded similar pattern in response to these signals. In the meantime, certain barrel cortical astrocytes encoded odorant and whisker signals. After associative learning, the neurons and astrocytes in the sensory cortices are able to store the newly learnt signal (cross-modal memory) besides the innate signal (native-modal memory). Such associative memory cells distinguish the differences of these signals by programming different codes and signify the historical associations of these signals by similar codes in information retrievals.

  11. Effects of load and maintenance duration on the time course of information encoding and retrieval in working memory: from perceptual analysis to post-categorization processes.

    Science.gov (United States)

    Pinal, Diego; Zurrón, Montserrat; Díaz, Fernando

    2014-01-01

    information encoding, maintenance, and retrieval; these are supported by brain activity in a network of frontal, parietal and temporal regions. Manipulation of WM load and duration of the maintenance period can modulate this activity. Although such modulations have been widely studied using the event-related potentials (ERP) technique, a precise description of the time course of brain activity during encoding and retrieval is still required. Here, we used this technique and principal component analysis to assess the time course of brain activity during encoding and retrieval in a delayed match to sample task. We also investigated the effects of memory load and duration of the maintenance period on ERP activity. Brain activity was similar during information encoding and retrieval and comprised six temporal factors, which closely matched the latency and scalp distribution of some ERP components: P1, N1, P2, N2, P300, and a slow wave. Changes in memory load modulated task performance and yielded variations in frontal lobe activation. Moreover, the P300 amplitude was smaller in the high than in the low load condition during encoding and retrieval. Conversely, the slow wave amplitude was higher in the high than in the low load condition during encoding, and the same was true for the N2 amplitude during retrieval. Thus, during encoding, memory load appears to modulate the processing resources for context updating and post-categorization processes, and during retrieval it modulates resources for stimulus classification and context updating. Besides, despite the lack of differences in task performance related to duration of the maintenance period, larger N2 amplitude and stronger activation of the left temporal lobe after long than after short maintenance periods were found during information retrieval. Thus, results regarding the duration of maintenance period were complex, and future work is required to test the time-based decay theory predictions.

  12. Encoding technique for high data compaction in data bases of fusion devices

    International Nuclear Information System (INIS)

    Vega, J.; Cremy, C.; Sanchez, E.; Portas, A.; Dormido, S.

    1996-01-01

    At present, data requirements of hundreds of Mbytes/discharge are typical in devices such as JET, TFTR, DIII-D, etc., and these requirements continue to increase. With these rates, the amount of storage required to maintain discharge information is enormous. Compaction techniques are now essential to reduce storage. However, general compression techniques may distort signals, but this is undesirable for fusion diagnostics. We have developed a general technique for data compression which is described here. The technique, which is based on delta compression, does not require an examination of the data as in delayed methods. Delta values are compacted according to general encoding forms which satisfy a prefix code property and which are defined prior to data capture. Several prefix codes, which are bit oriented and which have variable code lengths, have been developed. These encoding methods are independent of the signal analog characteristics and enable one to store undistorted signals. The technique has been applied to databases of the TJ-I tokamak and the TJ-IU torsatron. Compaction rates of over 80% with negligible computational effort were achieved. Computer programs were written in ANSI C, thus ensuring portability and easy maintenance. We also present an interpretation, based on information theory, of the high compression rates achieved without signal distortion. copyright 1996 American Institute of Physics

  13. Non-invasive Optical Biosensor for Probing Cell Signaling

    Directory of Open Access Journals (Sweden)

    Ye Fang

    2007-10-01

    Full Text Available Cell signaling mediated through a cellular target is encoded by spatial andtemporal dynamics of downstream signaling networks. The coupling of temporal dynamicswith spatial gradients of signaling activities guides cellular responses upon stimulation.Monitoring the integration of cell signaling in real time, if realized, would provide a newdimension for understanding cell biology and physiology. Optical biosensors includingresonant waveguide grating (RWG biosensor manifest a physiologically relevant andintegrated cellular response related to dynamic redistribution of cellular matters, thusproviding a non-invasive means for cell signaling study. This paper reviews recentprogresses in biosensor instrumentation, and theoretical considerations and potentialapplications of optical biosensors for whole cell sensing.

  14. Encoding !-tensors as !-graphs with neighbourhood orders

    Directory of Open Access Journals (Sweden)

    David Quick

    2015-11-01

    Full Text Available Diagrammatic reasoning using string diagrams provides an intuitive language for reasoning about morphisms in a symmetric monoidal category. To allow working with infinite families of string diagrams, !-graphs were introduced as a method to mark repeated structure inside a diagram. This led to !-graphs being implemented in the diagrammatic proof assistant Quantomatic. Having a partially automated program for rewriting diagrams has proven very useful, but being based on !-graphs, only commutative theories are allowed. An enriched abstract tensor notation, called !-tensors, has been used to formalise the notion of !-boxes in non-commutative structures. This work-in-progress paper presents a method to encode !-tensors as !-graphs with some additional structure. This will allow us to leverage the existing code from Quantomatic and quickly provide various tools for non-commutative diagrammatic reasoning.

  15. Radiofrequency encoded angular-resolved light scattering

    DEFF Research Database (Denmark)

    Buckley, Brandon W.; Akbari, Najva; Diebold, Eric D.

    2015-01-01

    The sensitive, specific, and label-free classification of microscopic cells and organisms is one of the outstanding problems in biology. Today, instruments such as the flow cytometer use a combination of light scatter measurements at two distinct angles to infer the size and internal complexity...... of cells at rates of more than 10,000 per second. However, by examining the entire angular light scattering spectrum it is possible to classify cells with higher resolution and specificity. Current approaches to performing these angular spectrum measurements all have significant throughput limitations...... Encoded Angular-resolved Light Scattering (REALS), this technique multiplexes angular light scattering in the radiofrequency domain, such that a single photodetector captures the entire scattering spectrum from a particle over approximately 100 discrete incident angles on a single shot basis. As a proof...

  16. Measurement strategy for spatially encoded photonic qubits

    International Nuclear Information System (INIS)

    Solis-Prosser, M. A.; Neves, L.

    2010-01-01

    We propose a measurement strategy which can, probabilistically, reproduce the statistics of any observable for spatially encoded photonic qubits. It comprises the implementation of a two-outcome positive operator-valued measure followed by a detection in a fixed transverse position, making the displacement of the detection system unnecessary, unlike previous methods. This strategy generalizes a scheme recently demonstrated by one of us and co-workers, restricted to measurement of observables with equatorial eigenvectors only. The method presented here can be implemented with the current technology of programmable multipixel liquid-crystal displays. In addition, it can be straightforwardly extended to high-dimensional qudits and may be a valuable tool in optical implementations of quantum information protocols with spatial qubits and qudits.

  17. Ultrathin Nonlinear Metasurface for Optical Image Encoding.

    Science.gov (United States)

    Walter, Felicitas; Li, Guixin; Meier, Cedrik; Zhang, Shuang; Zentgraf, Thomas

    2017-05-10

    Security of optical information is of great importance in modern society. Many cryptography techniques based on classical and quantum optics have been widely explored in the linear optical regime. Nonlinear optical encryption in which encoding and decoding involve nonlinear frequency conversions represents a new strategy for securing optical information. Here, we demonstrate that an ultrathin nonlinear photonic metasurface, consisting of meta-atoms with 3-fold rotational symmetry, can be used to hide optical images under illumination with a fundamental wave. However, the hidden image can be read out from second harmonic generation (SHG) waves. This is achieved by controlling the destructive and constructive interferences of SHG waves from two neighboring meta-atoms. In addition, we apply this concept to obtain gray scale SHG imaging. Nonlinear metasurfaces based on space variant optical interference open new avenues for multilevel image encryption, anticounterfeiting, and background free image reconstruction.

  18. Estuary-ocean connectivity: fast physics, slow biology.

    Science.gov (United States)

    Raimonet, Mélanie; Cloern, James E

    2017-06-01

    Estuaries are connected to both land and ocean so their physical, chemical, and biological dynamics are influenced by climate patterns over watersheds and ocean basins. We explored climate-driven oceanic variability as a source of estuarine variability by comparing monthly time series of temperature and chlorophyll-a inside San Francisco Bay with those in adjacent shelf waters of the California Current System (CCS) that are strongly responsive to wind-driven upwelling. Monthly temperature fluctuations inside and outside the Bay were synchronous, but their correlations weakened with distance from the ocean. These results illustrate how variability of coastal water temperature (and associated properties such as nitrate and oxygen) propagates into estuaries through fast water exchanges that dissipate along the estuary. Unexpectedly, there was no correlation between monthly chlorophyll-a variability inside and outside the Bay. However, at the annual scale Bay chlorophyll-a was significantly correlated with the Spring Transition Index (STI) that sets biological production supporting fish recruitment in the CCS. Wind forcing of the CCS shifted in the late 1990s when the STI advanced 40 days. This shift was followed, with lags of 1-3 years, by 3- to 19-fold increased abundances of five ocean-produced demersal fish and crustaceans and 2.5-fold increase of summer chlorophyll-a in the Bay. These changes reflect a slow biological process of estuary-ocean connectivity operating through the immigration of fish and crustaceans that prey on bivalves, reduce their grazing pressure, and allow phytoplankton biomass to build. We identified clear signals of climate-mediated oceanic variability in this estuary and discovered that the response patterns vary with the process of connectivity and the timescale of ocean variability. This result has important implications for managing nutrient inputs to estuaries connected to upwelling systems, and for assessing their responses to changing

  19. Encoding of aversion by dopamine and the nucleus accumbens

    Directory of Open Access Journals (Sweden)

    James Edgar Mccutcheon

    2012-09-01

    Full Text Available Adaptive motivated behavior requires rapid discrimination between beneficial and harmful stimuli. Such discrimination leads to the generation of either an approach or rejection response, as appropriate, and enables organisms to maximize reward and minimize punishment. Classically, the nucleus accumbens (NAc and the dopamine projection to it are considered an integral part of the brain’s reward circuit, i.e., they direct approach and consumption behaviors and underlie positive reinforcement. This reward-centered framing ignores important evidence about the role of this system in encoding aversive events. One reason for bias towards reward is the difficulty in designing experiments in which animals repeatedly experience punishments; another is the challenge in dissociating the response to an aversive stimulus itself from the reward/relief experienced when an aversive stimulus is terminated. Here, we review studies that employ techniques with sufficient time resolution to measure responses in ventral tegmental area (VTA and NAc to aversive stimuli as they are delivered. We also present novel findings showing that the same stimulus – intraoral infusion of sucrose – has differing effects on NAc shell dopamine release depending on the prior experience. Here, for some rats, sucrose was rendered aversive by explicitly pairing it with malaise in a conditioned taste aversion paradigm. Thereafter, sucrose infusions led to a suppression of dopamine with a similar magnitude and time course to intra-oral infusions of a bitter quinine solution. The results are discussed in the context of regional differences in dopamine signaling and the implications of a pause in phasic dopamine release within the NAc shell. Together with our data, the emerging literature suggests an important role for differential phasic dopamine signaling in aversion versus reward.

  20. Encoding and Decoding Models in Cognitive Electrophysiology.

    Science.gov (United States)

    Holdgraf, Christopher R; Rieger, Jochem W; Micheli, Cristiano; Martin, Stephanie; Knight, Robert T; Theunissen, Frederic E

    2017-01-01

    Cognitive neuroscience has seen rapid growth in the size and complexity of data recorded from the human brain as well as in the computational tools available to analyze this data. This data explosion has resulted in an increased use of multivariate, model-based methods for asking neuroscience questions, allowing scientists to investigate multiple hypotheses with a single dataset, to use complex, time-varying stimuli, and to study the human brain under more naturalistic conditions. These tools come in the form of "Encoding" models, in which stimulus features are used to model brain activity, and "Decoding" models, in which neural features are used to generated a stimulus output. Here we review the current state of encoding and decoding models in cognitive electrophysiology and provide a practical guide toward conducting experiments and analyses in this emerging field. Our examples focus on using linear models in the study of human language and audition. We show how to calculate auditory receptive fields from natural sounds as well as how to decode neural recordings to predict speech. The paper aims to be a useful tutorial to these approaches, and a practical introduction to using machine learning and applied statistics to build models of neural activity. The data analytic approaches we discuss may also be applied to other sensory modalities, motor systems, and cognitive systems, and we cover some examples in these areas. In addition, a collection of Jupyter notebooks is publicly available as a complement to the material covered in this paper, providing code examples and tutorials for predictive modeling in python. The aim is to provide a practical understanding of predictive modeling of human brain data and to propose best-practices in conducting these analyses.

  1. Shell-encoded Au nanoparticles with tunable electroactivity for specific dual disease biomarkers detection.

    Science.gov (United States)

    Zhao, Yuan; Yang, Yaxin; Sun, Yali; Cui, Linyan; Zheng, Fangjie; Zhang, Jiru; Song, Qijun; Xu, Chuanlai

    2018-01-15

    The exploration of electroactive labelling with tailorable and strong differential pulse voltammetry (DPV) responses is of great importance in accurate and sensitive screening of a panel of biomarkers related to cancer. Herein, shell-encoded gold nanoparticles (Au NPs) are fabricated and give rise to shell species-dominated DPV peak potentials. Two independent DPV peaks appear at -0.08V for Au@Cu 2 O core-shell NPs and 0.26V for Au@Ag core-shell NPs. Shell-encoded Au NPs drastically exhibit shell thickness-tunable amplified peak currents. The non-interfering and amplified DPV responses enable shell-encoded Au NPs to be an alternative electrochemical signal amplifier for dual screening of carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP). The limits of detection (LODs) are calculated to be 1.8pg/mL for CEA and 0.3pg/mL for AFP. In comparison to the parallel single-analyte assays, shell-encoded Au NPs engineered electrochemical aptasensors offer multiplexing capability and show significant prospects in biomedical research and early diagnosis of diseases. Copyright © 2017. Published by Elsevier B.V.

  2. Optical image encryption method based on incoherent imaging and polarized light encoding

    Science.gov (United States)

    Wang, Q.; Xiong, D.; Alfalou, A.; Brosseau, C.

    2018-05-01

    We propose an incoherent encoding system for image encryption based on a polarized encoding method combined with an incoherent imaging. Incoherent imaging is the core component of this proposal, in which the incoherent point-spread function (PSF) of the imaging system serves as the main key to encode the input intensity distribution thanks to a convolution operation. An array of retarders and polarizers is placed on the input plane of the imaging structure to encrypt the polarized state of light based on Mueller polarization calculus. The proposal makes full use of randomness of polarization parameters and incoherent PSF so that a multidimensional key space is generated to deal with illegal attacks. Mueller polarization calculus and incoherent illumination of imaging structure ensure that only intensity information is manipulated. Another key advantage is that complicated processing and recording related to a complex-valued signal are avoided. The encoded information is just an intensity distribution, which is advantageous for data storage and transition because information expansion accompanying conventional encryption methods is also avoided. The decryption procedure can be performed digitally or using optoelectronic devices. Numerical simulation tests demonstrate the validity of the proposed scheme.

  3. Mnemons: encoding memory by protein super-assembly

    Directory of Open Access Journals (Sweden)

    Fabrice Caudron

    2015-02-01

    Full Text Available Memory is mainly understood as the recollection of past events. The human brain and its simplest unit, the synapse, belong to the places in which such memories are physically stored. From an experimental point of view, memory can be tested in humans by recall. However, in other organisms, memory is reflected in its use by individuals to learn about and adapt their behavior to their environment. Under this criterion, even unicellular organisms are able to learn from their environments and show the ability to adapt their responses to repeating stimuli. This indicates that they are able to keep track of their histories and use these traces to elaborate adapted responses, making these traces akin to memory encodings. Understanding these phenomena may even help us to dissect part of the rather complex molecular orchestration happening in our synapses. When exposed unsuccessfully to mating pheromone, i.e. when mating does not happen, budding yeast cells become refractory to the mating signal. This refractory state is restricted to the mother cell and not inherited by the daughter cells, even though it is stable for most if not the entire life span of the mother cell. Interestingly, both stability and asymmetric segregation of the acquired state are explained by the molecular mechanism underlying its establishment, which shows important analogies and distinctions to prions. Here we discuss these similarities and differences

  4. Characterization of a cDNA encoding cottonseed catalase.

    Science.gov (United States)

    Ni, W; Turley, R B; Trelease, R N

    1990-06-21

    A 1.7 kb cDNA clone was isolated from our lambda gt11 library constructed from poly(A) RNA of 24-h-old cotyledons. The cDNA encodes a full-length catalase peptide (492 amino acid residues). The calculated molecular mass is 56,800, similar to that determined for purified enzyme (57,000 SDS-PAGE). Among higher plant catalases, this cotton catalase shows the highest amino acid sequence identity (85%) to the subunit of homotetrameric maize CAT 1, a developmental counterpart to the homotetrameric CAT A isoform of cotton seeds. Comparison of sequences from cotton, sweet potato, maize CAT 1, and yeast with bovine catalase revealed that the amino acid residues and regions that are involved in catalytic activity and/or required to maintain basic catalase structure, are highly conserved. The C-terminus region, which has the lowest nucleotide sequence identity between plant and mammalian catalases, does not terminate with a tripeptide, S-K/R/H-L, a putative targeting signal for peroxisomal proteins.

  5. CDNA encoding a polypeptide including a hevein sequence

    Science.gov (United States)

    Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

    1995-03-21

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  6. Encoding visual information in retinal ganglion cells with prosthetic stimulation

    Science.gov (United States)

    Freeman, Daniel K.; Rizzo, Joseph F., III; Fried, Shelley I.

    2011-06-01

    Retinal prostheses aim to restore functional vision to those blinded by outer retinal diseases using electric stimulation of surviving retinal neurons. The ability to replicate the spatiotemporal pattern of ganglion cell spike trains present under normal viewing conditions is presumably an important factor for restoring high-quality vision. In order to replicate such activity with a retinal prosthesis, it is important to consider both how visual information is encoded in ganglion cell spike trains, and how retinal neurons respond to electric stimulation. The goal of the current review is to bring together these two concepts in order to guide the development of more effective stimulation strategies. We review the experiments to date that have studied how retinal neurons respond to electric stimulation and discuss these findings in the context of known retinal signaling strategies. The results from such in vitro studies reveal the advantages and disadvantages of activating the ganglion cell directly with the electric stimulus (direct activation) as compared to activation of neurons that are presynaptic to the ganglion cell (indirect activation). While direct activation allows high temporal but low spatial resolution, indirect activation yields improved spatial resolution but poor temporal resolution. Finally, we use knowledge gained from in vitro experiments to infer the patterns of elicited activity in ongoing human trials, providing insights into some of the factors limiting the quality of prosthetic vision.

  7. cDNA encoding a polypeptide including a hevein sequence

    Energy Technology Data Exchange (ETDEWEB)

    Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

    2000-07-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  8. Digitally programmable signal generator

    International Nuclear Information System (INIS)

    Priatko, G.J.; Kaskey, J.A.

    1988-01-01

    A digitally programmable signal generator (DPSG) includes a first memory from which data is written into a second memory formed of n banks. Each bank includes four memories and a multiplexer, the banks being read once during each time frame, the read-out bits being multiplexed and fed out serially in synchronism with a plurality of clock pulses occuring during a time frame. The resulting serial bit streams may be fed in parallel to a digital-to-analog converter. The DPSG can be used in applications such as Atomic Vapor Laser Isotope Separation (AVLIS) to create an optimal match between the process laser's spectral profile and that of the vaporized material, optical telecommunications, non-optical telecommunication in the microwave and radio spectrum, radar, electronic countermeasures, high speed computer interconnects, local area networks, high definition video transport and the multiplexing of large quantities of slow digital memory into high speed data streams. This invention extends the operation of DPSGs into the GHz range. (author)

  9. Traffic characterization and modeling of wavelet-based VBR encoded video

    Energy Technology Data Exchange (ETDEWEB)

    Yu Kuo; Jabbari, B. [George Mason Univ., Fairfax, VA (United States); Zafar, S. [Argonne National Lab., IL (United States). Mathematics and Computer Science Div.

    1997-07-01

    Wavelet-based video codecs provide a hierarchical structure for the encoded data, which can cater to a wide variety of applications such as multimedia systems. The characteristics of such an encoder and its output, however, have not been well examined. In this paper, the authors investigate the output characteristics of a wavelet-based video codec and develop a composite model to capture the traffic behavior of its output video data. Wavelet decomposition transforms the input video in a hierarchical structure with a number of subimages at different resolutions and scales. the top-level wavelet in this structure contains most of the signal energy. They first describe the characteristics of traffic generated by each subimage and the effect of dropping various subimages at the encoder on the signal-to-noise ratio at the receiver. They then develop an N-state Markov model to describe the traffic behavior of the top wavelet. The behavior of the remaining wavelets are then obtained through estimation, based on the correlations between these subimages at the same level of resolution and those wavelets located at an immediate higher level. In this paper, a three-state Markov model is developed. The resulting traffic behavior described by various statistical properties, such as moments and correlations, etc., is then utilized to validate their model.

  10. Spiking neural circuits with dendritic stimulus processors : encoding, decoding, and identification in reproducing kernel Hilbert spaces.

    Science.gov (United States)

    Lazar, Aurel A; Slutskiy, Yevgeniy B

    2015-02-01

    We present a multi-input multi-output neural circuit architecture for nonlinear processing and encoding of stimuli in the spike domain. In this architecture a bank of dendritic stimulus processors implements nonlinear transformations of multiple temporal or spatio-temporal signals such as spike trains or auditory and visual stimuli in the analog domain. Dendritic stimulus processors may act on both individual stimuli and on groups of stimuli, thereby executing complex computations that arise as a result of interactions between concurrently received signals. The results of the analog-domain computations are then encoded into a multi-dimensional spike train by a population of spiking neurons modeled as nonlinear dynamical systems. We investigate general conditions under which such circuits faithfully represent stimuli and demonstrate algorithms for (i) stimulus recovery, or decoding, and (ii) identification of dendritic stimulus processors from the observed spikes. Taken together, our results demonstrate a fundamental duality between the identification of the dendritic stimulus processor of a single neuron and the decoding of stimuli encoded by a population of neurons with a bank of dendritic stimulus processors. This duality result enabled us to derive lower bounds on the number of experiments to be performed and the total number of spikes that need to be recorded for identifying a neural circuit.

  11. Subdivision Error Analysis and Compensation for Photoelectric Angle Encoder in a Telescope Control System

    Directory of Open Access Journals (Sweden)

    Yanrui Su

    2015-01-01

    Full Text Available As the position sensor, photoelectric angle encoder affects the accuracy and stability of telescope control system (TCS. A TCS-based subdivision error compensation method for encoder is proposed. Six types of subdivision error sources are extracted through mathematical expressions of subdivision signals first. Then the period length relationships between subdivision signals and subdivision errors are deduced. And the error compensation algorithm only utilizing the shaft position of TCS is put forward, along with two control models; Model I is that the algorithm applies only to the speed loop of TCS and Model II is applied to both speed loop and position loop. Combined with actual project, elevation jittering phenomenon of the telescope is discussed to decide the necessity of DC-type subdivision error compensation. Low-speed elevation performance before and after error compensation is compared to help decide that Model II is preferred. In contrast to original performance, the maximum position error of the elevation with DC subdivision error compensation is reduced by approximately 47.9% from 1.42″ to 0.74″. The elevation gets a huge decrease in jitters. This method can compensate the encoder subdivision errors effectively and improve the stability of TCS.

  12. Episodic Memory Encoding Interferes with Reward Learning and Decreases Striatal Prediction Errors

    Science.gov (United States)

    Braun, Erin Kendall; Daw, Nathaniel D.

    2014-01-01

    Learning is essential for adaptive decision making. The striatum and its dopaminergic inputs are known to support incremental reward-based learning, while the hippocampus is known to support encoding of single events (episodic memory). Although traditionally studied separately, in even simple experiences, these two types of learning are likely to co-occur and may interact. Here we sought to understand the nature of this interaction by examining how incremental reward learning is related to concurrent episodic memory encoding. During the experiment, human participants made choices between two options (colored squares), each associated with a drifting probability of reward, with the goal of earning as much money as possible. Incidental, trial-unique object pictures, unrelated to the choice, were overlaid on each option. The next day, participants were given a surprise memory test for these pictures. We found that better episodic memory was related to a decreased influence of recent reward experience on choice, both within and across participants. fMRI analyses further revealed that during learning the canonical striatal reward prediction error signal was significantly weaker when episodic memory was stronger. This decrease in reward prediction error signals in the striatum was associated with enhanced functional connectivity between the hippocampus and striatum at the time of choice. Our results suggest a mechanism by which memory encoding may compete for striatal processing and provide insight into how interactions between different forms of learning guide reward-based decision making. PMID:25378157

  13. Episodic memory encoding interferes with reward learning and decreases striatal prediction errors.

    Science.gov (United States)

    Wimmer, G Elliott; Braun, Erin Kendall; Daw, Nathaniel D; Shohamy, Daphna

    2014-11-05

    Learning is essential for adaptive decision making. The striatum and its dopaminergic inputs are known to support incremental reward-based learning, while the hippocampus is known to support encoding of single events (episodic memory). Although traditionally studied separately, in even simple experiences, these two types of learning are likely to co-occur and may interact. Here we sought to understand the nature of this interaction by examining how incremental reward learning is related to concurrent episodic memory encoding. During the experiment, human participants made choices between two options (colored squares), each associated with a drifting probability of reward, with the goal of earning as much money as possible. Incidental, trial-unique object pictures, unrelated to the choice, were overlaid on each option. The next day, participants were given a surprise memory test for these pictures. We found that better episodic memory was related to a decreased influence of recent reward experience on choice, both within and across participants. fMRI analyses further revealed that during learning the canonical striatal reward prediction error signal was significantly weaker when episodic memory was stronger. This decrease in reward prediction error signals in the striatum was associated with enhanced functional connectivity between the hippocampus and striatum at the time of choice. Our results suggest a mechanism by which memory encoding may compete for striatal processing and provide insight into how interactions between different forms of learning guide reward-based decision making. Copyright © 2014 the authors 0270-6474/14/3414901-12$15.00/0.

  14. Delay-Encoded Harmonic Imaging (DE-HI) in Multiplane-Wave Compounding.

    Science.gov (United States)

    Gong, Ping; Song, Pengfei; Chen, Shigao

    2017-04-01

    The development of ultrafast ultrasound imaging brings great opportunities to improve imaging technologies such as shear wave elastography and ultrafast Doppler imaging. In ultrafast imaging, several tilted plane or diverging wave images are coherently combined to form a compounded image, leading to trade-offs among image signal-to-noise ratio (SNR), resolution, and post-compounded frame rate. Multiplane wave (MW) imaging is proposed to solve this trade-off by encoding multiple plane waves with Hadamard matrix during one transmission event (i.e. pulse-echo event), to improve image SNR without sacrificing the resolution or frame rate. However, it suffers from stronger reverberation artifacts in B-mode images compared to standard plane wave compounding due to longer transmitted pulses. If harmonic imaging can be combined with MW imaging, the reverberation artifacts and other clutter noises such as sidelobes and multipath scattering clutters should be suppressed. The challenge, however, is that the Hadamard codes used in MW imaging cannot encode the 2 nd harmonic component by inversing the pulse polarity. In this paper, we propose a delay-encoded harmonic imaging (DE-HI) technique to encode the 2 nd harmonic with a one quarter period delay calculated at the transmit center frequency, rather than reversing the pulse polarity during multiplane wave emissions. Received DE-HI signals can then be decoded in the frequency domain to recover the signals as in single plane wave emissions, but mainly with improved SNR at the 2 nd harmonic component instead of the fundamental component. DE-HI was tested experimentally with a point target, a B-mode imaging phantom, and in-vivo human liver imaging. Improvements in image contrast-to-noise ratio (CNR), spatial resolution, and lesion-signal-to-noise ratio ( l SNR) have been achieved compared to standard plane wave compounding, MW imaging, and standard harmonic imaging (maximal improvement of 116% on CNR and 115% on l SNR as compared

  15. Modular verification of chemical reaction network encodings via serializability analysis

    Science.gov (United States)

    Lakin, Matthew R.; Stefanovic, Darko; Phillips, Andrew

    2015-01-01

    Chemical reaction networks are a powerful means of specifying the intended behaviour of synthetic biochemical systems. A high-level formal specification, expressed as a chemical reaction network, may be compiled into a lower-level encoding, which can be directly implemented in wet chemistry and may itself be expressed as a chemical reaction network. Here we present conditions under which a lower-level encoding correctly emulates the sequential dynamics of a high-level chemical reaction network. We require that encodings are transactional, such that their execution is divided by a “commit reaction” that irreversibly separates the reactant-consuming phase of the encoding from the product-generating phase. We also impose restrictions on the sharing of species between reaction encodings, based on a notion of “extra tolerance”, which defines species that may be shared between encodings without enabling unwanted reactions. Our notion of correctness is serializability of interleaved reaction encodings, and if all reaction encodings satisfy our correctness properties then we can infer that the global dynamics of the system are correct. This allows us to infer correctness of any system constructed using verified encodings. As an example, we show how this approach may be used to verify two- and four-domain DNA strand displacement encodings of chemical reaction networks, and we generalize our result to the limit where the populations of helper species are unlimited. PMID:27325906

  16. Modular verification of chemical reaction network encodings via serializability analysis.

    Science.gov (United States)

    Lakin, Matthew R; Stefanovic, Darko; Phillips, Andrew

    2016-06-13

    Chemical reaction networks are a powerful means of specifying the intended behaviour of synthetic biochemical systems. A high-level formal specification, expressed as a chemical reaction network, may be compiled into a lower-level encoding, which can be directly implemented in wet chemistry and may itself be expressed as a chemical reaction network. Here we present conditions under which a lower-level encoding correctly emulates the sequential dynamics of a high-level chemical reaction network. We require that encodings are transactional, such that their execution is divided by a "commit reaction" that irreversibly separates the reactant-consuming phase of the encoding from the product-generating phase. We also impose restrictions on the sharing of species between reaction encodings, based on a notion of "extra tolerance", which defines species that may be shared between encodings without enabling unwanted reactions. Our notion of correctness is serializability of interleaved reaction encodings, and if all reaction encodings satisfy our correctness properties then we can infer that the global dynamics of the system are correct. This allows us to infer correctness of any system constructed using verified encodings. As an example, we show how this approach may be used to verify two- and four-domain DNA strand displacement encodings of chemical reaction networks, and we generalize our result to the limit where the populations of helper species are unlimited.

  17. Frame Synchronization of High-Speed Vision Sensors with Respect to Temporally Encoded Illumination in Highly Dynamic Environments

    Directory of Open Access Journals (Sweden)

    Koichi Hashimoto

    2013-03-01

    Full Text Available The authors propose a Manchester Encoding inspired illumination modulation strategy to properly index the temporally-aligned vision frames, which are successfully synchronized by the LED reference signal. Based on signal normalization, Manchester Encoded reference signals carry temporal information owing to serial communication and thus can timestamp the output vision frame. Both simulated and experimental results show satisfactory robustness to various disturbances, such as dynamic targets, fluctuant optical intensity, and unfixed cameras, etc. The 1,000 Hz vision sensor is locked to 500 Hz temporally modulated LED illumination with only 24 μs jitters. This result is believed to be applicable to low-cost wireless vision sensor network.

  18. Signal replication in a DNA nanostructure

    Science.gov (United States)

    Mendoza, Oscar; Houmadi, Said; Aimé, Jean-Pierre; Elezgaray, Juan

    2017-01-01

    Logic circuits based on DNA strand displacement reaction are the basic building blocks of future nanorobotic systems. The circuits tethered to DNA origami platforms present several advantages over solution-phase versions where couplings are always diffusion-limited. Here we consider a possible implementation of one of the basic operations needed in the design of these circuits, namely, signal replication. We show that with an appropriate preparation of the initial state, signal replication performs in a reproducible way. We also show the existence of side effects concomitant to the high effective concentrations in tethered circuits, such as slow leaky reactions and cross-activation.

  19. Perceptions of the Slow Food Cultural Trend among the Youth

    Directory of Open Access Journals (Sweden)

    Lelia Voinea

    2016-11-01

    Full Text Available As they become increasingly aware of the importance of healthy eating and of the serious food imbalance caused by the overconsumption of industrial, ultra-processed and superorganoleptic food, consumers are now beginning to turn their attention to food choices guaranteeing both individual health and also of the environment . Thus, in recent years we are witnessing the rise of a cultural trend ‒ Slow Food. Slow Food has become an international movement that advocates for satisfying culinary pleasure, protects biological and cultural diversity, spread taste education, links "green" producers to consumers and believes that gastronomy intersects with politics, agriculture and ecology. Slow Food proposes a holistic approach to food problem, where the economic, sociocultural and environmental aspects are interlinked, being pursued as part of an overall strategy. In order to highlight the manner in which the principles of this cultural trend are perceived by the representatives of the new generation of consumers in Romania, exploratory research marketing was conducted among the students in the second year of the master’s program Quality Management, Expertise and Consumer Protection, from the Faculty of Business and Tourism from the Buchares t University of Economic Studies . The results of this research have shown an insufficient knowledge of Slow Food phenomenon and, especially, the Slow Food network activity in Romania. To show that the Slow Food type of food is a healthier option towards which the future consumer demand should be guided, especially those belonging to the younger generation, an antithetical comparative analysis of the nutritional value of two menus was performed: a suggestive one for the Slow Food feeding style and other one, specific to the fast food style. Slow Food style was considered antithetical to the fast food because many previous studies have shown a preference of the young for the fast-food type products, despite the

  20. Design of 10Gbps optical encoder/decoder structure for FE-OCDMA system using SOA and opto-VLSI processors.

    Science.gov (United States)

    Aljada, Muhsen; Hwang, Seow; Alameh, Kamal

    2008-01-21

    In this paper we propose and experimentally demonstrate a reconfigurable 10Gbps frequency-encoded (1D) encoder/decoder structure for optical code division multiple access (OCDMA). The encoder is constructed using a single semiconductor optical amplifier (SOA) and 1D reflective Opto-VLSI processor. The SOA generates broadband amplified spontaneous emission that is dynamically sliced using digital phase holograms loaded onto the Opto-VLSI processor to generate 1D codewords. The selected wavelengths are injected back into the same SOA for amplifications. The decoder is constructed using single Opto-VLSI processor only. The encoded signal can successfully be retrieved at the decoder side only when the digital phase holograms of the encoder and the decoder are matched. The system performance is measured in terms of the auto-correlation and cross-correlation functions as well as the eye diagram.