WorldWideScience

Sample records for undert signal presence

  1. Trial of finger contamination reduction of the operator in nerve block treatment. Comparison of over- and under-table systems

    International Nuclear Information System (INIS)

    Saito, Hajime; Okabe, Keigo; Nakazawa, Yasuo

    2004-01-01

    Fluoroscopy-guided intervention of the lumbar spine, such as nerve block, plays an important role in the management of disc hernia patients. However, irradiation of operators' fingers remains a problem even with careful collimation and operation, especially when performed by non-radiologists. We compared the irradiation doses of under-table and over-table fluoroscopy systems, and we discuss the most advantageous method of reducing irradiation. The effectiveness and conditions of use of lead protection gloves were also evaluated. Skin dose was monitored using polymethyl methacrylate (PMMA) and an electronic dose meter. The skin doses of over- and under-table fluoroscopy were compared using C-arm fluoroscopy. Finger irradiation dose with 0.03 mmPb protection gloves was also measured. The under-table method reduced skin dose by 95% compared with the over-table method. Thicker PMMA resulted in a higher rate of irradiation reduction. Protection gloves reduced radiation dose by half, although this reduction was cancelled when automatic brightness control (ABC) was utilized. Under-tube fluoroscopy was superior to over-tube fluoroscopy in reducing irradiation to the fingers. (author)

  2. A Test for the Presence of a Signal

    OpenAIRE

    Rolke, Wolfgang A.; Lopez, Angel M.

    2006-01-01

    We describe a statistical hypothesis test for the presence of a signal based on the likelihood ratio statistic. We derive the test for a case of interest and also show that for that case the test works very well, even far out in the tails of the distribution. We also study extensions of the test to cases where there are multiple channels.

  3. Optimum FIR filter for sampled signals in presence of jitter

    Science.gov (United States)

    Cattaneo, Paolo Walter

    1996-02-01

    The requirements of the integrated readout electronics for calorimetry at high luminosity hadron colliders pose new challenges both to hardware design and to the performance of signal processing algorithms. Both aspects have been treated in detail by the FERMI(RD16) collaboration [C. Alippi et al., Nucl. Instr. and Meth. A 344 (1994) 180], from which this work has been motivated. The estimation of the amplitude of sampled signals is usually performed with a digital FIR filter, or with a more sophisticated non linear digital filter using FIR filters as building blocks [S.J. Inkinen and J. Niittylahti, Trainable FIR-order statistic hybrid filters, to be published in IEEE Trans. Circuits and Systems; H. Alexanian et al., FERMI Collaboration, Optimized digital feature extraction in the FERMI microsystem Nucl. Instr. and Meth. A 357 (1995)]. In presence of significant signal phase jitter with respect to the clock, the phase dependence of the filter output can be a major source of error. This is especially true for measurements of large amplitudes for which the effect of electronic noise becomes negligible. This paper reports on the determination of digital FIR filters that optimize the signal over noise ratio due to known jitter distributions for different filter lengths. As the presence of electronic noise is neglected, the results are mainly relevant for measurements of large signals. FERMI is a collaboration with the aim of designing integrated electronics for the read out of calorimeter detectors in particle physics experiments at hadron colliders. It includes: CERN, Geneva, Switzerland; Department of Physics and Measurement Technology, University of Linköping, Sweden; Center for Industrial Microelectronics and Materials Technology, University of Linköping, Sweden; LPNHE Universities Paris VI-VII, Paris, France; Dipartimento di Elettronica, Politecnico di Milano, Italy, Sezine INFN, Pavia, Italy; Dipartimento di Fisica Nucleare e Teorica dell'Universitá e Sezione

  4. Infrasonic detection performance in presence of nuisance signal

    Science.gov (United States)

    Charbit, Maurice; Arrowsmith, Stephen; Che, Il-young; Le Pichon, Alexis; Nouvellet, Adrien; Park, Junghyun; Roueff, Francois

    2014-05-01

    The infrasound network of the International Monitoring System (IMS) consists of sixty stations deployed all over the World by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). The IMS has been designed to reliably detect, at least by two stations, an explosion greater than 1 kiloton located anywhere on the Earth [1]. Each station is an array of at least four microbarometers with an aperture of 1 to 3 km. The first important issue is to detect the presence of the signal of interest (SOI) embedded in noise. The detector is commonly based on the property that the SOI provides coherent observations on the sensors but not the noise. The statistic of test, called F-stat [2], [5], [6] , calculated in a time cell a few seconds, is commonly used for this purpose. In this paper, we assume that a coherent source is permanently present arriving from an unknown direction of arrivals (DOA). The typical case is the presence of microbaroms or the presence of wind. This source is seen as a nuisance signal (NS). In [4], [3] authors assume that a time cell without the SOI (CH0) is available, whereas a following time cell is considered as the cell under test (CUT). Therefore the DOA and the SNR of the NS can be estimated. If the signal-to-noise ration SNR of the NS is large enough, the distribution of the F-stat under the absence of SOI is known to be a non central Fisher. It follows that the threshold can be performed from a given value of the FAR. The major drawback to keep the NS is that the NS could hide the SOI, this phenomena is similar to the leakage which is a well-known phenomena in the Fourier analysis. An other approach consists to use the DOA estimate of the NS to mitigate the NS by spatial notch filter in the frequency domain. On this approach a new algorithm is provided. To illustrate, numerical results on synthetical and real data are presented, in term of Receiver Operating Characteristic ROC curves. REFERENCES [1] Christie D.R. and Campus P., The IMS

  5. Batch-Form Solutions to Optimal Input Signal Recovery in the Presence of Noises

    Science.gov (United States)

    Lin, Ping; Phan, Minh Q.; Ketcham, Stephen A.

    2013-12-01

    This paper studies the problem of optimally recovering the input signals to a linear time-invariant system in the presence of input and measurement noises. The emphasis is on batch-form solutions which are suitable for short-duration large-domain signal propagation applications. The system, the input and measurement noise covariances, the noise-corrupted output signals are assumed known, and we seek to recover the input signals that enter the system prior to being corrupted by input noise. The input signal recovery is optimal in the sense that the optimal Kalman filter residual is correctly recovered from the given information. Various solution techniques are considered and a weighted least-squares solution is found to be the simplest and most practical in short-duration signal recovery applications.

  6. Model observer design for multi-signal detection in the presence of anatomical noise

    Science.gov (United States)

    Wen, Gezheng; Markey, Mia K.; Park, Subok

    2017-02-01

    As psychophysical studies are resource-intensive to conduct, model observers are commonly used to assess and optimize medical imaging quality. Model observers are typically designed to detect at most one signal. However, in clinical practice, there may be multiple abnormalities in a single image set (e.g. multifocal multicentric (MFMC) breast cancer), which can impact treatment planning. Prevalence of signals can be different across anatomical regions, and human observers do not know the number or location of signals a priori. As new imaging techniques have the potential to improve multiple-signal detection (e.g. digital breast tomosynthesis may be more effective for diagnosis of MFMC than mammography), image quality assessment approaches addressing such tasks are needed. In this study, we present a model observer to detect multiple signals in an image dataset. A novel implementation of partial least squares (PLS) was developed to estimate different sets of efficient channels directly from the images. The PLS channels are adaptive to the characteristics of signals and the background, and they capture the interactions among signal locations. Corresponding linear decision templates are employed to generate both image-level and location-specific scores on the presence of signals. Our results show that: (1) the model observer can achieve high performance with a reasonably small number of channels; (2) the model observer with PLS channels outperforms that with benchmark modified Laguerre-Gauss channels, especially when realistic signal shapes and complex background statistics are involved; (3) the tasks of clinical interest, and other constraints such as sample size would alter the optimal design of the model observer.

  7. Frequentist coverage properties of uncertainty intervals for weak Poisson signals in the presence of background

    Science.gov (United States)

    Coakley, K. J.; Splett, J. D.; Simons, D. S.

    2010-03-01

    We construct uncertainty intervals for weak Poisson signals in the presence of background. We consider the case where a primary experiment yields a realization of the signal plus background, and a second experiment yields a realization of the background. The data acquisition times, for the background-only experiment, Tbg, and the primary experiment, T, are selected so that their ratio, Tbg/T, varies from 1 to 25. The upper choice of 25 is motivated by an experimental study at the National Institute of Standards and Technology (NIST). The expected number of background counts in the primary experiment varies from 0.2 to 2. We construct 90% and 95% confidence intervals based on a propagation-of-errors method as well as two implementations of a Neyman procedure where acceptance regions are constructed based on a likelihood-ratio criterion that automatically determines whether the resulting confidence interval is one-sided or two-sided. In one of the implementations of the Neyman procedure due to Feldman and Cousins (FC), uncertainty in the expected background contribution is neglected. In the other implementation, we account for random uncertainty in the estimated expected background with a parametric bootstrap implementation of a method due to Conrad. We also construct minimum length Bayesian credibility intervals. For each method, we test for the presence of a signal based on the value of the lower endpoint of the uncertainty interval. In general, the propagation-of-errors method performs the worst compared to the other methods according to frequentist coverage and detection probability criteria, and sometimes produces nonsensical intervals where both endpoints are negative. The Neyman procedures generally yield intervals with better frequentist coverage properties compared to the Bayesian method except for some cases where Tbg/T = 1. In general, the Bayesian method yields intervals with lower detection probabilities compared to Neyman procedures. One of the main

  8. Contributions of AMPK and p53 dependent signaling to radiation response in the presence of metformin.

    Science.gov (United States)

    Muaddi, Hala; Chowdhury, Sanjana; Vellanki, Ravi; Zamiara, Paul; Koritzinsky, Marianne

    2013-09-01

    Metformin is commonly prescribed to treat type 2 diabetes, and has additional potential as a cancer prophylactic and therapeutic. Metformin activates AMPK that in turn can launch a p53-dependent metabolic checkpoint. Possible interactions between metformin and radiation are poorly understood. Since radiation-induced signaling also involves AMPK and p53, we investigated their importance in mediating responses to metformin and radiation. A549 cells, HCT116 cells wildtype or knockout for p53 or MEFs wildtype or double knockout for AMPKα1 and α2 were irradiated in the presence or absence of metformin. The impact of metformin on oxygen consumption and proliferation rates was determined, as well as clonogenic radiation survival. Metformin resulted in moderate radiation protection in all cell lines, irrespective of AMPK and p53. Loss of AMPK sensitized cells to the anti-proliferative effects of metformin, while loss of p53 promoted both the growth inhibitory and toxic effects of metformin. Consequently, overall cell death after radiation was similar with and without metformin irrespective of AMPK or p53 genotype. The anti-proliferative activity of metformin may confer benefit in combination with radiotherapy, and this benefit is intensified upon loss of AMPK or p53 signaling. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Direct Position Determination of Unknown Signals in the Presence of Multipath Propagation.

    Science.gov (United States)

    Du, Jianping; Wang, Ding; Yu, Wanting; Yu, Hongyi

    2018-03-17

    A novel geolocation architecture, termed "Multiple Transponders and Multiple Receivers for Multiple Emitters Positioning System (MTRE)" is proposed in this paper. Existing Direct Position Determination (DPD) methods take advantage of a rather simple channel assumption (line of sight channels with complex path attenuations) and a simplified MUltiple SIgnal Classification (MUSIC) algorithm cost function to avoid the high dimension searching. We point out that the simplified assumption and cost function reduce the positioning accuracy because of the singularity of the array manifold in a multi-path environment. We present a DPD model for unknown signals in the presence of Multi-path Propagation (MP-DPD) in this paper. MP-DPD adds non-negative real path attenuation constraints to avoid the mistake caused by the singularity of the array manifold. The Multi-path Propagation MUSIC (MP-MUSIC) method and the Active Set Algorithm (ASA) are designed to reduce the dimension of searching. A Multi-path Propagation Maximum Likelihood (MP-ML) method is proposed in addition to overcome the limitation of MP-MUSIC in the sense of a time-sensitive application. An iterative algorithm and an approach of initial value setting are given to make the MP-ML time consumption acceptable. Numerical results validate the performances improvement of MP-MUSIC and MP-ML. A closed form of the Cramér-Rao Lower Bound (CRLB) is derived as a benchmark to evaluate the performances of MP-MUSIC and MP-ML.

  10. Design and implementation of a multiband digital filter using FPGA to extract the ECG signal in the presence of different interference signals.

    Science.gov (United States)

    Aboutabikh, Kamal; Aboukerdah, Nader

    2015-07-01

    In this paper, we propose a practical way to synthesize and filter an ECG signal in the presence of four types of interference signals: (1) those arising from power networks with a fundamental frequency of 50Hz, (2) those arising from respiration, having a frequency range from 0.05 to 0.5Hz, (3) muscle signals with a frequency of 25Hz, and (4) white noise present within the ECG signal band. This was done by implementing a multiband digital filter (seven bands) of type FIR Multiband Least Squares using a digital programmable device (Cyclone II EP2C70F896C6 FPGA, Altera), which was placed on an education and development board (DE2-70, Terasic). This filter was designed using the VHDL language in the Quartus II 9.1 design environment. The proposed method depends on Direct Digital Frequency Synthesizers (DDFS) designed to synthesize the ECG signal and various interference signals. So that the synthetic ECG specifications would be closer to actual ECG signals after filtering, we designed in a single multiband digital filter instead of using three separate digital filters LPF, HPF, BSF. Thus all interference signals were removed with a single digital filter. The multiband digital filter results were studied using a digital oscilloscope to characterize input and output signals in the presence of differing sinusoidal interference signals and white noise. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Direct Position Determination of Unknown Signals in the Presence of Multipath Propagation

    Directory of Open Access Journals (Sweden)

    Jianping Du

    2018-03-01

    Full Text Available A novel geolocation architecture, termed “Multiple Transponders and Multiple Receivers for Multiple Emitters Positioning System (MTRE” is proposed in this paper. Existing Direct Position Determination (DPD methods take advantage of a rather simple channel assumption (line of sight channels with complex path attenuations and a simplified MUltiple SIgnal Classification (MUSIC algorithm cost function to avoid the high dimension searching. We point out that the simplified assumption and cost function reduce the positioning accuracy because of the singularity of the array manifold in a multi-path environment. We present a DPD model for unknown signals in the presence of Multi-path Propagation (MP-DPD in this paper. MP-DPD adds non-negative real path attenuation constraints to avoid the mistake caused by the singularity of the array manifold. The Multi-path Propagation MUSIC (MP-MUSIC method and the Active Set Algorithm (ASA are designed to reduce the dimension of searching. A Multi-path Propagation Maximum Likelihood (MP-ML method is proposed in addition to overcome the limitation of MP-MUSIC in the sense of a time-sensitive application. An iterative algorithm and an approach of initial value setting are given to make the MP-ML time consumption acceptable. Numerical results validate the performances improvement of MP-MUSIC and MP-ML. A closed form of the Cramér–Rao Lower Bound (CRLB is derived as a benchmark to evaluate the performances of MP-MUSIC and MP-ML.

  12. Presence of a functional but dispensable Nuclear Export Signal in the HTLV-2 Tax protein

    Directory of Open Access Journals (Sweden)

    Kiemer Lars

    2005-11-01

    Full Text Available Abstract Background Human T-cell leukemia virus type 1 and type 2 are related human retroviruses. HTLV-1 is the etiological agent of the Adult T-cell Leukemia/Lymphoma and of the Tropical Spastic Paraparesis/HTLV-1 Associated Myelopathy, whereas, HTLV-2 infection has not been formally associated with any T-cell malignancy. HTLV-1 and 2 genomes encode, respectively, the Tax1 and Tax2 proteins whose role is to transactivate the viral promoter. HTLV-1 and HTLV-2 Tax sequences display 28% divergence at the amino acid level. Tax1 is a shuttling protein that possesses both a non canonical nuclear import (NLS and a nuclear export (NES signal. We have recently demonstrated that Tax1 and Tax2 display different subcellular localization and that residues 90–100 are critical for this process. We investigate in the present report, whether Tax2 also possesses a functional NES. Results We first used a NES prediction method to determine whether the Tax2 protein might contain a NES and the results do suggest the presence of a NES sequence in Tax2. Using Green Fluorescent Protein-NES (GFP-NES fusion proteins, we demonstrate that the Tax2 sequence encompasses a functional NES (NES2. As shown by microscope imaging, NES2 is able to mediate translocation of GFP from the nucleus, without the context of a full length Tax protein. Furthermore, point mutations or leptomycin B treatment abrogate NES2 function. However, within the context of full length Tax2, similar point mutations in the NES2 leucine rich stretch do not modify Tax2 localization. Finally, we also show that Tax1 NES function is dependent upon the positioning of the nuclear export signal "vis-à-vis" GFP. Conclusion HTLV-2 Tax NES is functional but dispensable for the protein localization in vitro.

  13. Image restoration by Wiener filtering in the presence of signal-dependent noise.

    Science.gov (United States)

    Kondo, K; Ichioka, Y; Suzuki, T

    1977-09-01

    An optimum filter to restore the degraded image due to blurring and the signal-dependent noise is obtained on the basis of the theory of Wiener filtering. Computer simulations of image restoration using signal-dependent noise models are carried out. It becomes clear that the optimum filter, which makes use of a priori information on the signal-dependent nature of the noise and the spectral density of the signal and the noise showing significant spatial correlation, is potentially advantageous.

  14. GNSS space-time interference mitigation and attitude determination in the presence of interference signals.

    Science.gov (United States)

    Daneshmand, Saeed; Jahromi, Ali Jafarnia; Broumandan, Ali; Lachapelle, Gérard

    2015-05-26

    The use of Space-Time Processing (STP) in Global Navigation Satellite System (GNSS) applications is gaining significant attention due to its effectiveness for both narrowband and wideband interference suppression. However, the resulting distortion and bias on the cross correlation functions due to space-time filtering is a major limitation of this technique. Employing the steering vector of the GNSS signals in the filter structure can significantly reduce the distortion on cross correlation functions and lead to more accurate pseudorange measurements. This paper proposes a two-stage interference mitigation approach in which the first stage estimates an interference-free subspace before the acquisition and tracking phases and projects all received signals into this subspace. The next stage estimates array attitude parameters based on detecting and employing GNSS signals that are less distorted due to the projection process. Attitude parameters enable the receiver to estimate the steering vector of each satellite signal and use it in the novel distortionless STP filter to significantly reduce distortion and maximize Signal-to-Noise Ratio (SNR). GPS signals were collected using a six-element antenna array under open sky conditions to first calibrate the antenna array. Simulated interfering signals were then added to the digitized samples in software to verify the applicability of the proposed receiver structure and assess its performance for several interference scenarios.

  15. Restoration of mammographic images in the presence of signal-dependent noise

    Science.gov (United States)

    Aghdasi, Farzin; Ward, Rabab K.; Palcic, Branko

    1993-07-01

    We developed and implemented two locally adaptive image smoothing filters to improve the signal to noise ratio of digitized mammogram images. The application of these smoothing filters in conjunction with the deconvolution of the images results in better visualization of image details. Previous efforts in restoration of digitized mammograms have assumed a stationary image with uncorrelated white Gaussian noise. In this work we considered a more realistic case of a non-stationary image model and signal-dependent noise of photonic and film-grain origins. Both the camera blur and the MTF of the screen-film combination were considered. The camera noise may be minimized through averaging and background subtraction. The signal-dependent nature of the radiographic noise was modelled by a linear shift-invariant system and the relative strengths of various noise sources were compared. The deconvolution filter was designed to respond to the particular form of the noise in the system based on the Minimum Mean Squared Error (MMSE) criteria. Of the two smoothing filters the Bayesian estimator was found to outperform the adaptive Wiener filter. Filters were implemented in a real time processing environment using our mammographic image acquisition and analysis system.

  16. Angiotensin 2 directly increases rabbit renal brush-border membrane sodium transport: Presence of local signal transduction system

    Energy Technology Data Exchange (ETDEWEB)

    Morduchowicz, G.A.; Sheikh-Hamad, D.; Dwyer, B.E.; Stern, N.; Jo, O.D.; Yanagawa, N. (Sepulveda Veterans Administration, CA (USA))

    1991-05-01

    In the present study, the authors have examined the direct actions of angiotensin II (AII) in rabbit renal brush border membrane (BBM) where binding sites for AII exist. Addition of AII (10(-11)-10(-7) M) was found to stimulate 22Na+ uptake by the isolated BBM vesicles directly. All did not affect the Na(+)-dependent BBM glucose uptake, and the effect of AII on BBM 22Na+ uptake was inhibited by amiloride, suggesting the involvement of Na+/H+ exchange mechanism. BBM proton permeability as assessed by acridine orange quenching was not affected by AII, indicating the direct effect of AII on Na+/H+ antiport system. In search of the signal transduction mechanism, it was found that AII activated BBM phospholipase A2 (PLA) and that BBM contains a 42-kDa guanine nucleotide-binding regulatory protein (G-protein) that underwent pertussis toxin (PTX)-catalyzed ADP-ribosylation. Addition of GTP potentiated, while GDP-beta S or PTX abolished, the effects of AII on BBM PLA and 22Na+ uptake, suggesting the involvement of G-protein in AII's actions. On the other hand, inhibition of PLA by mepacrine prevented AII's effect on BBM 22Na+ uptake, and activation of PLA by mellitin or addition of arachidonic acid similarly enhanced BBM 22Na+ uptake, suggesting the role of PLA activation in mediating AII's effect on BBM 22Na+ uptake. In summary, results of the present study show a direct stimulatory effect of AII on BBM Na+/H+ antiport system, and suggest the presence of a local signal transduction system involving G-protein mediated PLA activation.

  17. Signal-to-noise ratio evaluation of magnetic resonance images in the presence of an ultrasonic motor.

    Science.gov (United States)

    Shokrollahi, Peyman; Drake, James M; Goldenberg, Andrew A

    2017-04-14

    Safe robot-assisted intervention using magnetic resonance imaging (MRI) guidance requires the precise control of assistive devices, and most currently available tools are rarely MRI-compatible. To obtain high precision, it is necessary to characterize and develop existing MRI-safe actuators for use in a high magnetic field (≥3 T). Although an ultrasonic motor (USM) is considered to be an MRI-safe actuator, and can be used in the vicinity of a high field scanner, its presence interferes with MR images. Although an MR image provides valuable information regarding the pathology of a patient's body, noise, generally of a granular type, decreases the quality of the image and jeopardizes the true evaluation of any existing pathological issues. An eddy current induced in the conductor material of the motor structure can be a source of noise when the motor is close to the isocenter of the image. We aimed to assess the effects of a USM on the signal-to-noise ratio (SNR) of MR images in a 3-T scanner. The SNR was compared for four image sequences in transverse directions for three orientations of the motor (x, y, and z) when the motor was in the "off" state. The SNR was evaluated to assess three artifact reduction methods used to minimize the motor-induced artifacts. The SNR had a range of 5-10 dB for slices close to the motor in the x and y orientations, and increased to 15-20 dB for slices far from the motor. Averaging the SNR for slices in all cases gave an SNR loss of about 10 dB. The maximum SNR was measured in the z orientation. In this case, the SNR loss was almost the same as that of other motor orientations, approximately 10 dB, but with a higher range, approximately 20-40 dB. The selection of certain scanning parameters is necessary for reducing motor-generated artifacts. These parameters include slice selection and bandwidth. In developing any MRI-compatible assisted device actuated by a USM, this study recommends the use of an approximately 3-mm slice

  18. Tissue regeneration and biomineralization in sea urchins: role of Notch signaling and presence of stem cell markers.

    Directory of Open Access Journals (Sweden)

    Helena C Reinardy

    Full Text Available Echinoderms represent a phylum with exceptional regenerative capabilities that can reconstruct both external appendages and internal organs. Mechanistic understanding of the cellular pathways involved in regeneration in these animals has been hampered by the limited genomic tools and limited ability to manipulate regenerative processes. We present a functional assay to investigate mechanisms of tissue regeneration and biomineralization by measuring the regrowth of amputated tube feet (sensory and motor appendages and spines in the sea urchin, Lytechinus variegatus. The ability to manipulate regeneration was demonstrated by concentration-dependent inhibition of regrowth of spines and tube feet by treatment with the mitotic inhibitor, vincristine. Treatment with the gamma-secretase inhibitor DAPT resulted in a concentration-dependent inhibition of regrowth, indicating that both tube feet and spine regeneration require functional Notch signaling. Stem cell markers (Piwi and Vasa were expressed in tube feet and spine tissue, and Vasa-positive cells were localized throughout the epidermis of tube feet by immunohistochemistry, suggesting the existence of multipotent progenitor cells in these highly regenerative appendages. The presence of Vasa protein in other somatic tissues (e.g. esophagus, radial nerve, and a sub-population of coelomocytes suggests that multipotent cells are present throughout adult sea urchins and may contribute to normal homeostasis in addition to regeneration. Mechanistic insight into the cellular pathways governing the tremendous regenerative capacity of echinoderms may reveal processes that can be modulated for regenerative therapies, shed light on the evolution of regeneration, and enable the ability to predict how these processes will respond to changing environmental conditions.

  19. Method for separation of a weak background signal from at the presence of a strong one in the Fourier spectroscopy

    International Nuclear Information System (INIS)

    Lib, Yu.N.; Zhukov, M.S.

    1985-01-01

    A method for solving a big signal problem in the nmr Fourier spectroscopy is described. Thus the digital filtration of a big signal is carried out, where from the droop of induced signal accumulated before the moment of memory content overflow, subtracted is a model interferogram, corresponding only to removed big signals (the model interferogram is the result of perocessing of an initial interferogram). Calculating formulae and dependences haracterizing the accumulation-subtraction process and minimal gain as compared with a common technique with scaling are given. Experimental results which confirm the method efficiency are stated

  20. Performance Analysis and Enhancements for the Music Subspace Direction-Finding Algorithm in the Presence of Wideband Signals

    Science.gov (United States)

    2014-12-01

    signals classification ( MUSIC ) subspace direction-finding algorithm are evaluated in this thesis. Additionally, two performance enhancements are...presented: one that reduces the MUSIC computational load and one that provides a method of utilizing collector motion to resolve DOA ambiguities.

  1. Noise induced regularity of porous silicon nanostructures electrochemically etched in the presence of a sub-threshold periodic signal

    Science.gov (United States)

    Roy, Tanushree; Rumandla, Sravya; Agarwal, V.; Parmananda, P.

    2017-09-01

    In the present work, regularity of the pores generated during the electrochemical etching of silicon wafer is analyzed. The wafer-electrolyte (ethanolic hydrofluoric acid) composite is placed in an electrochemical cell operated galvanostatically at a fixed (set-point) anodic current. This set-point current is subsequently perturbed by a sub-threshold periodic current signal. Numerous experiments were performed for diverse experimental configurations. Some of the experimental parameters varied were hydrofluoric concentration, set-points, and the properties of the input periodic signal (i.e., duty cycle and amplitude). The regularity of the generated pore size distribution was quantified by calculating the spatial normalized variance (NV). For certain experimental configurations, as described later, the phenomena of Periodic Stochastic Resonance (PSR) could be provoked. In PSR, enhanced regularity of the Porous Silicon nanostructures for an optimal HF concentration is observed. Consequently, the spatial NV versus the HF concentration curve exhibits a unimodal profile.

  2. Detection of a Low Power Communication Signal in the Presence of a Strong Co-Channel TV Broadcast Interference Using a Kalman Filter

    Science.gov (United States)

    2014-12-01

    Television Systems Committee AWGN additive white Gaussian noise BCH Bose-Chaudhuri-Hocquengham bps bits per second CIR channel impulse response... impulse responses (CIRs) are used both for equalization in the respective DVB-T2 receivers and in the KF to estimate the state of the DVB-T2 signal...if a communication system can operate reliably in the presence of a strong, co-channel interference, then there is no need to buy spectrum, an

  3. Menthol evokes Ca2+ signals and induces oxidative stress independently of the presence of TRPM8 (menthol receptor in cancer cells

    Directory of Open Access Journals (Sweden)

    Mustafa Nazıroğlu

    2018-04-01

    Full Text Available Menthol is a naturally occurring monoterpene alcohol possessing remarkable biological properties including antipruritic, analgesic, antiseptic, anti-inflammatory and cooling effects. Here, we examined the menthol-evoked Ca2+ signals in breast and prostate cancer cell lines. The effect of menthol (50–500 µM was predicted to be mediated by the transient receptor potential ion channel melastatin subtype 8 (TRPM8. However, the intensity of menthol-evoked Ca2+ signals did not correlate with the expression levels of TRPM8 in breast and prostate cancer cells indicating a TRPM8-independent signaling pathway. Menthol-evoked Ca2+ signals were analyzed in detail in Du 145 prostate cancer cells, as well as in CRISPR/Cas9 TRPM8-knockout Du 145 cells. Menthol (500 µM induced Ca2+ oscillations in both cell lines, thus independent of TRPM8, which were however dependent on the production of inositol trisphosphate. Results based on pharmacological tools point to an involvement of the purinergic pathway in menthol-evoked Ca2+ responses. Finally, menthol (50–500 µM decreased cell viability and induced oxidative stress independently of the presence of TRPM8 channels, despite that temperature-evoked TRPM8-mediated inward currents were significantly decreased in TRPM8-knockout Du 145 cells compared to wild type Du 145 cells. Keywords: Ca2+ oscillations, TRPM8, Menthol, Oxidative stress, Purinergic signaling

  4. Sub-Nyquist signal-reconstruction-free operational modal analysis and damage detection in the presence of noise

    Science.gov (United States)

    Gkoktsi, Kyriaki; Giaralis, Agathoklis; TauSiesakul, Bamrung

    2016-04-01

    Motivated by a need to reduce energy consumption in wireless sensors for vibration-based structural health monitoring (SHM) associated with data acquisition and transmission, this paper puts forth a novel approach for undertaking operational modal analysis (OMA) and damage localization relying on compressed vibrations measurements sampled at rates well below the Nyquist rate. Specifically, non-uniform deterministic sub-Nyquist multi-coset sampling of response acceleration signals in white noise excited linear structures is considered in conjunction with a power spectrum blind sampling/estimation technique which retrieves/samples the power spectral density matrix from arrays of sensors directly from the sub-Nyquist measurements (i.e., in the compressed domain) without signal reconstruction in the time-domain and without posing any signal sparsity conditions. The frequency domain decomposition algorithm is then applied to the power spectral density matrix to extract natural frequencies and mode shapes as a standard OMA step. Further, the modal strain energy index (MSEI) is considered for damage localization based on the mode shapes extracted directly from the compressed measurements. The effectiveness and accuracy of the proposed approach is numerically assessed by considering simulated vibration data pertaining to a white-noise excited simply supported beam in healthy and in 3 damaged states, contaminated with Gaussian white noise. Good accuracy is achieved in estimating mode shapes (quantified in terms of the modal assurance criterion) and natural frequencies from an array of 15 multi-coset devices sampling at a 70% slower than the Nyquist frequency rate for SNRs as low as 10db. Damage localization of equal level/quality is also achieved by the MSEI applied to mode shapes derived from noisy sub-Nyquist (70% compression) and Nyquist measurements for all damaged states considered. Overall, the furnished numerical results demonstrate that the herein considered sub

  5. Why Human Papillomaviruses Activate the DNA Damage Response (DDR) and How Cellular and Viral Replication Persists in the Presence of DDR Signaling.

    Science.gov (United States)

    Bristol, Molly L; Das, Dipon; Morgan, Iain M

    2017-09-21

    Human papillomaviruses (HPV) require the activation of the DNA damage response (DDR) in order to undergo a successful life cycle. This activation presents a challenge for the virus and the infected cell: how does viral and host replication proceed in the presence of a DDR that ordinarily arrests replication; and how do HPV16 infected cells retain the ability to proliferate in the presence of a DDR that ordinarily arrests the cell cycle? This raises a further question: why do HPV activate the DDR? The answers to these questions are only partially understood; a full understanding could identify novel therapeutic strategies to target HPV cancers. Here, we propose that the rapid replication of an 8 kb double stranded circular genome during infection creates aberrant DNA structures that attract and activate DDR proteins. Therefore, HPV replication in the presence of an active DDR is a necessity for a successful viral life cycle in order to resolve these DNA structures on viral genomes; without an active DDR, successful replication of the viral genome would not proceed. We discuss the essential role of TopBP1 in this process and also how viral and cellular replication proceeds in HPV infected cells in the presence of DDR signals.

  6. Features of the propagation of pseudorandom pulse signals from the shelf to deep water in the presence of gyre formation on the acoustic track

    Science.gov (United States)

    Akulichev, V. A.; Burenin, A. V.; Ladychenko, S. Yu.; Lobanov, V. B.; Morgunov, Yu. N.

    2017-08-01

    The paper discusses the results of an experiment conducted in the Sea of Japan in March 2016 on an acoustic track 194 km long in winter hydrological conditions. The most complex case of propagation of pseudorandom pulse signals from the shelf to deep water in the presence of gyre formation on the acoustic track. An analysis of the experimentally obtained pulse characteristics show that at all points, a maximum, in terms of amplitude, first arrival of acoustic energy is recorded. This is evidence that at a given depth horizon, pulses that have passed the shortest distance through a near-surface sound channel at small angles close to zero are received first. The calculation method of mean sound velocity on the track, based on the satellite data of surface temperature monitoring, is proposed. We expect that the results obtained with this method can be successfully used for the purposes of acoustic range finding and navigation.

  7. A Cross-Correlational Analysis between Electroencephalographic and End-Tidal Carbon Dioxide Signals: Methodological Issues in the Presence of Missing Data and Real Data Results

    Directory of Open Access Journals (Sweden)

    Maria Sole Morelli

    2016-10-01

    Full Text Available Electroencephalographic (EEG irreducible artifacts are common and the removal of corrupted segments from the analysis may be required. The present study aims at exploring the effects of different EEG Missing Data Segment (MDS distributions on cross-correlation analysis, involving EEG and physiological signals. The reliability of cross-correlation analysis both at single subject and at group level as a function of missing data statistics was evaluated using dedicated simulations. Moreover, a Bayesian-based approach for combining the single subject results at group level by considering each subject’s reliability was introduced. Starting from the above considerations, the cross-correlation function between EEG Global Field Power (GFP in delta band and end-tidal CO2 (PETCO2 during rest and voluntary breath-hold was evaluated in six healthy subjects. The analysis of simulated data results at single subject level revealed a worsening of precision and accuracy in the cross-correlation analysis in the presence of MDS. At the group level, a large improvement in the results’ reliability with respect to single subject analysis was observed. The proposed Bayesian approach showed a slight improvement with respect to simple average results. Real data results were discussed in light of the simulated data tests and of the current physiological findings.

  8. A cinema of presence and proximity: Gunvor Nelson's collage films and the aesthetics of the signaletic material before the electronic signal

    Directory of Open Access Journals (Sweden)

    John Sundholm

    2012-06-01

    Full Text Available This essay argues for the importance of an intersubjective and impure film theory in which the signal and the signaletic is considered as figures for approaching film. This in order to make the argument that the signaletic mode indeed enables a novel perspective on moving image history. The aesthetics of the signaletic has thus a history preceding that of electronic media, in particular when it comes to animation and experimental film. When constructing such an archaeology, however, dichotomies into sign and signal should be avoided; otherwise, the complexity of many of the films is reduced. In order to illuminate the latter point, four films by Gunvor Nelson is analyzed (both analog and digital, showing not only how both sign and signal interact but also how the aesthetics of the signal and the signaletic material is not dependant on the electronic as such.

  9. An experiment protocol for a search for radio signals of extraterrestrial intelligent origin in the presence of man-made radio frequency sources

    Science.gov (United States)

    Edelson, R. E.

    1977-01-01

    Some aspects of signal extraction in a microwave search for evidence of extraterrestrial intelligence are examined. Parametric relations are summarized which are applicable to a microwave search of constrained duration that employs FFT spectrum-analyzer receivers, with sensitivity enhancement by spectrum accumulation and detection by a threshold criterion. Three types of natural and man-made false alarms are identified, the probability of false alarm in a single data channel is computed, and the implications of false alarms for a constant-beamwidth sky survey are considered. It is shown that the key to an efficient search is the prompt and unambiguous elimination of false alarms. An experimental protocol is suggested which eliminates spurious signals primarily through procedural techniques involving antenna repointing, delayed repeated observations, and storage of particular historical parameters for suspect signals.

  10. Design of a completely model free adaptive control in the presence of parametric, non-parametric uncertainties and random control signal delay.

    Science.gov (United States)

    Tutsoy, Onder; Barkana, Duygun Erol; Tugal, Harun

    2018-03-14

    In this paper, an adaptive controller is developed for discrete time linear systems that takes into account parametric uncertainty, internal-external non-parametric random uncertainties, and time varying control signal delay. Additionally, the proposed adaptive control is designed in such a way that it is utterly model free. Even though these properties are studied separately in the literature, they are not taken into account all together in adaptive control literature. The Q-function is used to estimate long-term performance of the proposed adaptive controller. Control policy is generated based on the long-term predicted value, and this policy searches an optimal stabilizing control signal for uncertain and unstable systems. The derived control law does not require an initial stabilizing control assumption as in the ones in the recent literature. Learning error, control signal convergence, minimized Q-function, and instantaneous reward are analyzed to demonstrate the stability and effectiveness of the proposed adaptive controller in a simulation environment. Finally, key insights on parameters convergence of the learning and control signals are provided. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  11. The Mere Co-Presence: Synchronization of Autonomic Signals and Emotional Responses across Co-Present Individuals Not Engaged in Direct Interaction

    Science.gov (United States)

    Golland, Yulia; Arzouan, Yossi; Levit-Binnun, Nava

    2015-01-01

    Existing evidence suggests that in social contexts individuals become coupled in their emotions and behaviors. Furthermore, recent biological studies demonstrate that the physiological signals of interacting individuals become coupled as well, exhibiting temporally synchronized response patterns. However, it is yet unknown whether people can shape each other's responses without the direct, face-to-face interaction. Here we investigated whether the convergence of physiological and emotional states can occur among “merely co-present” individuals, without direct interactional exchanges. To this end, we measured continuous autonomic signals and collected emotional responses of participants who watched emotional movies together, seated side-by-side. We found that the autonomic signals of co-present participants were idiosyncratically synchronized and that the degree of this synchronization was correlated with the convergence of their emotional responses. These findings suggest that moment-to-moment emotional transmissions, resulting in shared emotional experiences, can occur in the absence of direct communication and are mediated by autonomic synchronization. PMID:26018597

  12. The anti-fibrotic effect of inhibition of TGFβ-ALK5 signalling in experimental pulmonary fibrosis in mice is attenuated in the presence of concurrent γ-herpesvirus infection

    Directory of Open Access Journals (Sweden)

    Natalia Smoktunowicz

    2015-09-01

    Full Text Available TGFβ-ALK5 pro-fibrotic signalling and herpesvirus infections have been implicated in the pathogenesis and exacerbation of pulmonary fibrosis. In this study we addressed the role of TGFβ-ALK5 signalling during the progression of fibrosis in a two-hit mouse model of murine γ-herpesvirus 68 (MHV-68 infection on the background of pre-existing bleomycin-induced pulmonary fibrosis. Assessment of total lung collagen levels in combination with ex vivo micro-computed tomography (µCT analysis of whole lungs demonstrated that MHV-68 infection did not enhance lung collagen deposition in this two-hit model but led to a persistent and exacerbated inflammatory response. Moreover, µCT reconstruction and analysis of the two-hit model revealed distinguishing features of diffuse ground-glass opacities and consolidation superimposed on pre-existing fibrosis that were reminiscent of those observed in acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF. Virally-infected murine fibrotic lungs further displayed evidence of extensive inflammatory cell infiltration and increased levels of CCL2, TNFα, IL-1β and IL-10. Blockade of TGFβ-ALK5 signalling attenuated lung collagen accumulation in bleomycin-alone injured mice, but this anti-fibrotic effect was reduced in the presence of concomitant viral infection. In contrast, inhibition of TGFβ-ALK5 signalling in virally-infected fibrotic lungs was associated with reduced inflammatory cell aggregates and increased levels of the antiviral cytokine IFNγ. These data reveal newly identified intricacies for the TGFβ-ALK5 signalling axis in experimental lung fibrosis, with different outcomes in response to ALK5 inhibition depending on the presence of viral infection. These findings raise important considerations for the targeting of TGFβ signalling responses in the context of pulmonary fibrosis.

  13. Ultraviolet radiation induces stress in etiolated Landoltia punctata, as evidenced by the presence of alanine, a universal stress signal: a ¹⁵N NMR study.

    Science.gov (United States)

    Monselise, E B-I; Levkovitz, A; Kost, D

    2015-01-01

    Analysis with (15) N NMR revealed that alanine, a universal cellular stress signal, accumulates in etiolated duckweed plants exposed to 15-min pulsed UV light, but not in the absence of UV irradiation. The addition of 10 mm vitamin C, a radical scavenger, reduced alanine levels to zero, indicating the involvement of free radicals. Free D-alanine was detected in (15) N NMR analysis of the chiral amino acid content, using D-tartaric acid as solvent. The accumulation of D-alanine under stress conditions presents a new perspective on the biochemical processes taking place in prokaryote and eukaryote cells. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  14. Transcription, Signaling Receptor Activity, Oxidative Phosphorylation, and Fatty Acid Metabolism Mediate the Presence of Closely Related Species in Distinct Intertidal and Cold-Seep Habitats.

    Science.gov (United States)

    Van Campenhout, Jelle; Vanreusel, Ann; Van Belleghem, Steven; Derycke, Sofie

    2015-12-03

    Bathyal cold seeps are isolated extreme deep-sea environments characterized by low species diversity while biomass can be high. The Håkon Mosby mud volcano (Barents Sea, 1,280 m) is a rather stable chemosynthetic driven habitat characterized by prominent surface bacterial mats with high sulfide concentrations and low oxygen levels. Here, the nematode Halomonhystera hermesi thrives in high abundances (11,000 individuals 10 cm(-2)). Halomonhystera hermesi is a member of the intertidal Halomonhystera disjuncta species complex that includes five cryptic species (GD1-5). GD1-5's common habitat is characterized by strong environmental fluctuations. Here, we compared the transcriptomes of H. hermesi and GD1, H. hermesi's closest relative. Genes encoding proteins involved in oxidative phosphorylation are more strongly expressed in H. hermesi than in GD1, and many genes were only observed in H. hermesi while being completely absent in GD1. Both observations could in part be attributed to high sulfide concentrations and low oxygen levels. Additionally, fatty acid elongation was also prominent in H. hermesi confirming the importance of highly unsaturated fatty acids in this species. Significant higher amounts of transcription factors and genes involved in signaling receptor activity were observed in GD1 (many of which were completely absent in H. hermesi), allowing fast signaling and transcriptional reprogramming which can mediate survival in dynamic intertidal environments. GC content was approximately 8% higher in H. hermesi coding unigenes resulting in differential codon usage between both species and a higher proportion of amino acids with GC-rich codons in H. hermesi. In general our results showed that most pathways were active in both environments and that only three genes are under natural selection. This indicates that also plasticity should be taken in consideration in the evolutionary history of Halomonhystera species. Such plasticity, as well as possible

  15. Tentacle Probes: differentiation of difficult single-nucleotide polymorphisms and deletions by presence or absence of a signal in real-time PCR.

    Science.gov (United States)

    Satterfield, Brent C; Kulesh, David A; Norwood, David A; Wasieloski, Leonard P; Caplan, Michael R; West, Jay A A

    2007-12-01

    False-positive results are a common problem in real-time PCR identification of DNA sequences that differ from near neighbors by a single-nucleotide polymorphism (SNP) or deletion. Because of a lack of sufficient probe specificity, post-PCR analysis, such as a melting curve, is often required for mutation differentiation. Tentacle Probes, cooperative reagents with both a capture and a detection probe based on specific cell-targeting principles, were developed as a replacement for 2 chromosomal TaqMan-minor groove binder (MGB) assays previously developed for Yersinia pestis and Bacillus anthracis detection. We compared TaqMan-MGB probes to Tentacle Probes for SNP and deletion detection based on the presence or absence of a growth curve. With the TaqMan-MGB Y. pestis yp48 assays, false-positive results for Yersinia pseudotuberculosis occurred at every concentration tested, and with the TaqMan-MGB B. anthracis gyrA assays, false-positive results occurred in 21 of 29 boil preps of environmental samples of near neighbors. With Tentacle Probes no false-positive results occurred. The high specificity exhibited by Tentacle Probes may eliminate melting curve analysis for SNP and deletion mutation detection, allowing the diagnostic use of previously difficult targets.

  16. Comparing Stage Presence and Virtual Reality Presence

    Directory of Open Access Journals (Sweden)

    Sebastian Xavier Samur

    2016-05-01

    Full Text Available Reflecting on the impending release of new Head Mounted Display virtual reality (VR technologies, the article examines definitions and techniques for digital presence, and compares them with research into stage presence. It opens with an outline of definitions of digital presence, comparing them with Cormac Power’s fictional, auratic, and literal modes of presence in performance. The article then looks at techniques used in VR and on stage to achieve presence. Finally, performance examples that use virtual reality technologies are presented. The article concludes that even if the technology falls short, discourse on digital presence is useful in providing insights into presence on stage.

  17. Monitoring presence of chemical agents

    International Nuclear Information System (INIS)

    Preston, J.M.

    1984-01-01

    The specification describes a case for use with a hand-portable chemical agent detector for continuously monitoring an atmosphere for the presence of predetermined chemical agents. The detector having means for ionizing air samples and providing at an output terminal electrical signals representative of the mobility spectrum of ionized chemical vapours produced by the ionizing means. The case comprises means for defining a chamber in the case for supporting and removably enclosing the detector, means for communicating ambient atmosphere to the chamber, electrical circuit means in the case, the circuit means being adapted to be detachably connected to the detector output terminal when the detector is positioned in the chamber and being responsive to the electrical signals for producing an alarm signal when the signals detect a chemical agent concentration in the atmosphere exceeding a predetermined concentration level, and alarm means responsive to the alarm signal. (author)

  18. CesRK, a two-component signal transduction system in Listeria monocytogenes, responds to the presence of cell wall-acting antibiotics and affects beta-lactam resistance

    DEFF Research Database (Denmark)

    Kallipolitis, Birgitte H; Ingmer, Hanne; Gahan, Cormac G

    2003-01-01

    of a putative two-component signal transduction system that plays a role in the virulence and ethanol tolerance of L. monocytogenes. Here we present evidence that the response regulator, CesR, and a histidine protein kinase, CesK, which is encoded by the gene downstream from cesR, are involved in the ability...

  19. Presence of Social Presence during Disasters

    DEFF Research Database (Denmark)

    Mukkamala, Alivelu Manga; Beck, Roman

    2017-01-01

    During emergencies, affected people use social media platforms for interaction and collaboration. Social media is used to ask for help, provide moral support, and to help each other, without direct face-to-face interactions. From a social presence point of view, we analyzed Twitter messages to un...

  20. Presence Service in IMS

    OpenAIRE

    Petras, David; Baronak, Ivan; Chromy, Erik

    2013-01-01

    This paper describes the presence service, which is located in the IP multimedia subsystem. This service allows making many applications for different groups of people. The paper describes differences between a network without the service and with the service. The biggest change is an increased number of transmitted messages. The presence uses some part of the IP multimedia subsystem control layer, which is shown in communication between the user and the server. The paper deals with the numbe...

  1. Presence While Watching Movies

    Directory of Open Access Journals (Sweden)

    Tom Troscianko

    2011-05-01

    Full Text Available “Presence” is the illusion of being in a mediated experience rather than simply being an observer. It is a concept often applied to the question of realism of virtual environments. However, it is equally applicable to the act of watching a movie. A movie provides a markedly different visual environment to that given by the natural world—particularly because of frequent edits. And yet, the audience in a movie achieves high levels of presence. We investigate the relationship between presence and the optical and temporal parameters of movies. We find effects of mean shot length, colour/b&w, and 3D/2D. We find that short shots, while being unnatural, are associated with high levels of presence. We consider why such artificial stimuli should appear so real and immersive.

  2. Presence Service in IMS

    Directory of Open Access Journals (Sweden)

    David Petras

    2013-01-01

    Full Text Available This paper describes the presence service, which is located in the IP multimedia subsystem. This service allows making many applications for different groups of people. The paper describes differences between a network without the service and with the service. The biggest change is an increased number of transmitted messages. The presence uses some part of the IP multimedia subsystem control layer, which is shown in communication between the user and the server. The paper deals with the number of generated messages depending on the behaviour of the users. This is described by a mathematical model using discrete Markov chains.

  3. Capturing Online Presence

    DEFF Research Database (Denmark)

    de Bakker, Frank; Hellsten, Lina

    2013-01-01

    an important channel for CSR debate. In this paper, we present an explorative study of activist groups’ online presence via their websites and propose a combination of methods to study both the structural positioning of websites (hyperlink network analysis) and the meanings in these websites (semantic co-word...... activist networks’ online presence can provide insights into the tactics these networks apply to achieve institutional change on CSR issues. Meanwhile, we identify some notable differences between styles and word use in the two organisations’ websites. We conclude with a set of suggestions for future...

  4. The presence of ADHD

    DEFF Research Database (Denmark)

    Breining, Sanni Nørgaard

    2014-01-01

    This paper uses high quality register-data to study the spillover effects on firstborns from having a younger sibling suffering from ADHD. Using OLS and cousin fixed effects analyses it is found that the educational outcomes of healthy firstborn children are significantly reduced by the presence...

  5. Connected media and presence

    NARCIS (Netherlands)

    Kort, J.; Nefs, H.T.; Gullström, C.; Greef, T.J. de; Parnes, P.

    2013-01-01

    Effective design of shared mediated spaces, information and connectedness requires theory and practice from a range of disciplines such as found in European projects like Together Anywhere, Together Anytime (TA2) and the EIT ICT Labs Mediating Presence activity. Building on this work we continue to

  6. 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...

  7. PresenceRemote

    DEFF Research Database (Denmark)

    Sokoler, Tomas; Svensson, Marcus Sanchez

    2008-01-01

    This paper reports on our early experiences with the design of Social TV for senior citizens. Even though there seems to be a straight forward match between new interactive TV technologies on the rise and the notion of supporting social interaction amongst elderly TV viewers it is not at all clea...... for unarticulated intentions of use in our design of Social TV. The ‘PresenceRemote’ is an enhanced TV remote control making it possible for you to notice others and be noticed by peers within your local neighborhood as you watch TV....

  8. PresenceRemote

    DEFF Research Database (Denmark)

    Sokoler, Tomas; Svensson, Marcus Sanchez

    2008-01-01

    This paper reports on our early experiences with the design of Social TV for senior citizens. Even though there seems to be a straight forward match between new interactive TV technologies on the rise and the notion of supporting social interaction amongst elderly TV viewers it is not at all clea...... for unarticulated intentions of use in our design of Social TV. The ‘PresenceRemote’ is an enhanced TV remote control making it possible for you to notice others and be noticed by peers within your local neighborhood as you watch TV.......This paper reports on our early experiences with the design of Social TV for senior citizens. Even though there seems to be a straight forward match between new interactive TV technologies on the rise and the notion of supporting social interaction amongst elderly TV viewers it is not at all clear...

  9. The Impact of Blended Learning on Social Presence, Cognitive Presence, Teaching Presence, and Perceived Learning

    Science.gov (United States)

    Harrell, Kyleigh Blackwell

    2017-01-01

    The quantitative study examined how blended learning influences high school learners' social presence, cognitive presence, teacher presence, and perceived learning in comparison to online instruction. The study answered the following research questions: (a) Do differences exist among the social presence, cognitive presence, and teaching presence…

  10. Detection of Transient Signals in Doppler Spectra

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Signal processing is used to detect transient signals in the presence of noise. Two embodiments are disclosed. In both embodiments, the time series from a remote...

  11. 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

  12. 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.

  13. On the Use of Presence Measurements to Evaluate Computer Games

    DEFF Research Database (Denmark)

    Nordahl, Rolf; Korsgaard, Dannie

    2008-01-01

    measurement method is modified for use in computer game development. 39 subjects were part of the experiment, which was designed to test applicability of the adapted presence measuring method. Besides playing a game prototype, test participants were asked to press a button when a visual signal, triggered...... by an in-game event, would appear on the screen in the periphery of sight. Noting how strong the signal was is assumed to infer how strong the stimuli had to be in order to break the immersive presence. The results indicated that the adapted method with observations from the test is more useful, than...

  14. 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

  15. In The Presence of Technology

    DEFF Research Database (Denmark)

    Nortvig, Anne-Mette

    In a hybrid synchronous classroom that includes both on line and on campus students, technology plays a big part in the teaching. This paper attempts to analyse and discuss how the transparency of technology affects opportunities for the students to interact and for the teacher to be present in d...... of disembodied presence and presents different learning design experiments that have been developed in a physiotherapy e-learning program to deal with the experience of disembodied presence and to thematise the role of technology....

  16. Family presence during cardiopulmonary resuscitation.

    Science.gov (United States)

    Jabre, Patricia; Belpomme, Vanessa; Azoulay, Elie; Jacob, Line; Bertrand, Lionel; Lapostolle, Frederic; Tazarourte, Karim; Bouilleau, Guillem; Pinaud, Virginie; Broche, Claire; Normand, Domitille; Baubet, Thierry; Ricard-Hibon, Agnes; Istria, Jacques; Beltramini, Alexandra; Alheritiere, Armelle; Assez, Nathalie; Nace, Lionel; Vivien, Benoit; Turi, Laurent; Launay, Stephane; Desmaizieres, Michel; Borron, Stephen W; Vicaut, Eric; Adnet, Frederic

    2013-03-14

    The effect of family presence during cardiopulmonary resuscitation (CPR) on the family members themselves and the medical team remains controversial. We enrolled 570 relatives of patients who were in cardiac arrest and were given CPR by 15 prehospital emergency medical service units. The units were randomly assigned either to systematically offer the family member the opportunity to observe CPR (intervention group) or to follow standard practice regarding family presence (control group). The primary end point was the proportion of relatives with post-traumatic stress disorder (PTSD)-related symptoms on day 90. Secondary end points included the presence of anxiety and depression symptoms and the effect of family presence on medical efforts at resuscitation, the well-being of the health care team, and the occurrence of medicolegal claims. In the intervention group, 211 of 266 relatives (79%) witnessed CPR, as compared with 131 of 304 relatives (43%) in the control group. In the intention-to-treat analysis, the frequency of PTSD-related symptoms was significantly higher in the control group than in the intervention group (adjusted odds ratio, 1.7; 95% confidence interval [CI], 1.2 to 2.5; P=0.004) and among family members who did not witness CPR than among those who did (adjusted odds ratio, 1.6; 95% CI, 1.1 to 2.5; P=0.02). Relatives who did not witness CPR had symptoms of anxiety and depression more frequently than those who did witness CPR. Family-witnessed CPR did not affect resuscitation characteristics, patient survival, or the level of emotional stress in the medical team and did not result in medicolegal claims. Family presence during CPR was associated with positive results on psychological variables and did not interfere with medical efforts, increase stress in the health care team, or result in medicolegal conflicts. (Funded by Programme Hospitalier de Recherche Clinique 2008 of the French Ministry of Health; ClinicalTrials.gov number, NCT01009606.).

  17. Ciemat Relational Capital: Institutional Presence

    International Nuclear Information System (INIS)

    Vaquero Ortiz, E. M.; González Pineda, L. M.; Cascante Díaz, E.

    2015-01-01

    The resources in any organization for its activity development can be divided into two main groups: tangible assets and intangible assets. In recent decades there has been a recognition of the importance of the intangible assets as value generators for the development and growth of organizations. And the so called Relational Capital is among them Relational Capital arises from the relationship processes that an organization maintains with external agents. Thus, in the case of a public research institution, such as CIEMAT, it includes the relations with projects financing organizations, with partners and with customers (both public and private entities which are serviced), as well as the institutional presence understood as the participation in discussion and coordination forums (foundations, associations, committees…). This report presents a study of CIEMAT institutional presence in the year 2015.

  18. Breathing life into social presence

    DEFF Research Database (Denmark)

    Cowley, Stephen; Fester, Marie-Theres

    2018-01-01

    Whilst many studies focus on human-to-media interactions, this paper turns to how a multimodal medium influences human-to-human contact. By bringing together both radical embodied cognitive science (Chemero 2009) and dialogism (Linell 2009), the paper develops an anti-representationalist approach...... to the concept of social presence. We use an exploratory study of close friendships that maintain their interaction through the use of the mobile instant messaging service WhatsApp. In so doing, we describe texting as language-activity where people engage with each other by using resources from body, environment...... attention to this kind of heightened social presence that we choose to call “co-imagining”....

  19. 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...

  20. Determining the parameters of chirp signals using cyclostationary ...

    African Journals Online (AJOL)

    This paper deals with the problems of detecting a chirp signal of motion target against a strong undesired signal from the transmitter in radar. We use Generalized Almost- Cyclostationary (GACS) signal processing method to determine the rate and initial frequency of the chirp signal in presence of the strong undesired ...

  1. Sonic Virtuality, Environment, and Presence

    DEFF Research Database (Denmark)

    Grimshaw, Mark

    2018-01-01

    The article presents a brief introduction to the concept of sonic virtuality, a view of sound as a multi-modal, emergent perception that provides a framework that has since been used to provide an explanation of the formation of environments. Additionally, the article uses such concepts to explain...... the phenomenon of presence, not only in virtual worlds but also in actual worlds. The view put forward is that environment is an emergent perception, formed from the hypothetical modelling of salient worlds of sensory things, and it is in the environment that we feel present. The article ends with some thoughts...

  2. Family presence at resuscitation attempts.

    Science.gov (United States)

    Jaques, Helen

    UK resuscitation guidelines suggest that parents and carers should be allowed to be present during a resuscitation attempt in hospital but no guidance is available regarding family presence when resuscitation takes place out of hospital. A new research study has suggested that relatives who were offered the opportunity to witness resuscitation were less likely to develop symptoms of post-traumatic stress disorder than those who were not given the chance. This article summarises the results of this study and provides an expert commentary on its conclusions.

  3. Signal trend identification with fuzzy methods

    International Nuclear Information System (INIS)

    Reifman, J.; Tsoukalas, L. H.; Wang, X.; Wei, T. Y. C.

    1999-01-01

    A fuzzy-logic-based methodology for on-line signal trend identification is introduced. Although signal trend identification is complicated by the presence of noise, fuzzy logic can help capture important features of on-line signals and classify incoming power plant signals into increasing, decreasing and steady-state trend categories. In order to verify the methodology, a code named PROTREN is developed and tested using plant data. The results indicate that the code is capable of detecting transients accurately, identifying trends reliably, and not misinterpreting a steady-state signal as a transient one

  4. Traffic signal control enhancements under vehicle infrastructure integration systems.

    Science.gov (United States)

    2011-12-01

    Most current traffic signal systems are operated using a very archaic traffic-detection simple binary : logic (vehicle presence/non presence information). The logic was originally developed to provide input for old : electro-mechanical controllers th...

  5. Signal detection by means of orthogonal decomposition

    Science.gov (United States)

    Hajdu, C. F.; Dabóczi, T.; Péceli, G.; Zamantzas, C.

    2018-03-01

    Matched filtering is a well-known method frequently used in digital signal processing to detect the presence of a pattern in a signal. In this paper, we suggest a time variant matched filter, which, unlike a regular matched filter, maintains a given alignment between the input signal and the template carrying the pattern, and can be realized recursively. We introduce a method to synchronize the two signals for presence detection, usable in case direct synchronization between the signal generator and the receiver is not possible or not practical. We then propose a way of realizing and extending the same filter by modifying a recursive spectral observer, which gives rise to orthogonal filter channels and also leads to another way to synchronize the two signals.

  6. Promotion Signal: Proxy for a Price Cut?

    OpenAIRE

    Inman, J Jeffrey; McAlister, Leigh; Hoyer, Wayne D

    1990-01-01

    Evidence suggests that some consumers react to promotion signals without considering relative price information. We adopt Petty and Cacioppo's Elaboration Likelihood Model (ELM) to explain this behavior in terms of the ELM's peripheral route to pursuasion in which the promotion signal is taken as a cue for a price cut. Experimental results show that low need for cognition individuals react to the simple presence of a promotion signal whether or not the price of the promoted brand is reduced, ...

  7. 33 CFR 401.51 - Signaling approach to a bridge.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Signaling approach to a bridge... approach to a bridge. (a) Unless a vessel's approach has been recognized by a flashing signal, the master shall signal the vessel's presence to the bridge operator by VHF radio when it comes abreast of any of...

  8. Basic digital signal processing

    CERN Document Server

    Lockhart, Gordon B

    1985-01-01

    Basic Digital Signal Processing describes the principles of digital signal processing and experiments with BASIC programs involving the fast Fourier theorem (FFT). The book reviews the fundamentals of the BASIC program, continuous and discrete time signals including analog signals, Fourier analysis, discrete Fourier transform, signal energy, power. The text also explains digital signal processing involving digital filters, linear time-variant systems, discrete time unit impulse, discrete-time convolution, and the alternative structure for second order infinite impulse response (IIR) sections.

  9. Signal Processing and Restoration

    NARCIS (Netherlands)

    Biemond, J.; Slump, C.H.; Lagendijk, R.L.; Tolhuizen, L.M.G.M.; de With, P.H.N.

    2004-01-01

    Digital Signal Processing (DSP) concerns the theoretical and practical aspects of representing information-bearing signals in digital form and the use of processors or special purpose hardware to extract that information or to transform the signals in useful ways. Areas where digital signal

  10. Retroactive signaling in short signaling pathways.

    Directory of Open Access Journals (Sweden)

    Jacques-Alexandre Sepulchre

    Full Text Available In biochemical signaling pathways without explicit feedback connections, the core signal transduction is usually described as a one-way communication, going from upstream to downstream in a feedforward chain or network of covalent modification cycles. In this paper we explore the possibility of a new type of signaling called retroactive signaling, offered by the recently demonstrated property of retroactivity in signaling cascades. The possibility of retroactive signaling is analysed in the simplest case of the stationary states of a bicyclic cascade of signaling cycles. In this case, we work out the conditions for which variables of the upstream cycle are affected by a change of the total amount of protein in the downstream cycle, or by a variation of the phosphatase deactivating the same protein. Particularly, we predict the characteristic ranges of the downstream protein, or of the downstream phosphatase, for which a retroactive effect can be observed on the upstream cycle variables. Next, we extend the possibility of retroactive signaling in short but nonlinear signaling pathways involving a few covalent modification cycles.

  11. Signal verification can promote reliable signalling.

    Science.gov (United States)

    Broom, Mark; Ruxton, Graeme D; Schaefer, H Martin

    2013-11-22

    The central question in communication theory is whether communication is reliable, and if so, which mechanisms select for reliability. The primary approach in the past has been to attribute reliability to strategic costs associated with signalling as predicted by the handicap principle. Yet, reliability can arise through other mechanisms, such as signal verification; but the theoretical understanding of such mechanisms has received relatively little attention. Here, we model whether verification can lead to reliability in repeated interactions that typically characterize mutualisms. Specifically, we model whether fruit consumers that discriminate among poor- and good-quality fruits within a population can select for reliable fruit signals. In our model, plants either signal or they do not; costs associated with signalling are fixed and independent of plant quality. We find parameter combinations where discriminating fruit consumers can select for signal reliability by abandoning unprofitable plants more quickly. This self-serving behaviour imposes costs upon plants as a by-product, rendering it unprofitable for unrewarding plants to signal. Thus, strategic costs to signalling are not a prerequisite for reliable communication. We expect verification to more generally explain signal reliability in repeated consumer-resource interactions that typify mutualisms but also in antagonistic interactions such as mimicry and aposematism.

  12. Delayed system control in presence of actuator saturation

    Directory of Open Access Journals (Sweden)

    A. Mahjoub

    2014-09-01

    Full Text Available The paper is introducing a new design method for systems’ controllers with input delay and actuator saturations and focuses on how to force the system output to track a reference input not necessarily saturation-compatible. We propose a new norm based on the way we quantify tracking performance as a function of saturation errors found using the same norm. The newly defined norm is related to signal average power making possible to account for most common reference signals e.g. step, periodic. It is formally shown that, whatever the reference shape and amplitude, the achievable tracking quality is determined by a well defined reference tracking mismatch error. This latter depends on the reference rate and its compatibility with the actuator saturation constraint. In fact, asymptotic output-reference tracking is achieved in the presence of constraint-compatible step-like references.

  13. Signal Incongruence and its Consequences

    DEFF Research Database (Denmark)

    Vergne, Jean-Philippe; Wernicke, Maria Stokholm; Brenner, Steffen

    2018-01-01

    We draw on the signaling and infomediary literatures to examine how media evaluations of CEO overcompensation (a negative cue associated with selfishness and greed) are affected by the presence of corporate philanthropy (a positive cue associated with altruism and generosity). In line with our th...... and damage media evaluations of firms and CEOs. Taken together, these findings shed new light on the media as agents of external corporate governance for firms and open new avenues for research on executive compensation.......We draw on the signaling and infomediary literatures to examine how media evaluations of CEO overcompensation (a negative cue associated with selfishness and greed) are affected by the presence of corporate philanthropy (a positive cue associated with altruism and generosity). In line with our...... incongruence, and to infomediary and corporate governance research by showing that media disapproval can lead to lower executive compensation. We also reconcile two conflicting views on firm prosocial behavior by showing that, in the presence of incongruent cues, philanthropy can simultaneously enhance...

  14. Process and apparatus for detecting presence of plant substances

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, J.A.

    1991-04-16

    This patent describes an apparatus and process for detecting the presence of plant substances in a particular environment. It comprises: measuring the background K40 gamma ray radiation level in a particular environment with a 1.46 MeV gamma ray counter system; measuring the amount of K40 gamma ray radiation emanating from a package containing a plant substance being passed through an environment with a counter; and generating an alarm signal when the total K40 gamma ray radiation reaches a predetermined level over and above the background level.

  15. Process and apparatus for detecting presence of plant substances

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, J.A.

    1990-01-01

    Disclosed is a process for detecting the presence of plant substances in a particular environment which comprises the steps of: (1) Measuring the background K40 gamma ray radiation level in a particular environment with a 1.46 MeV gamma ray counter system; (2) measuring the amount of K40 gamma ray radiation emanating from a package containing said plant substance being passed through said environment with said counter; and (3) generating an alarm signal when the total K40 gamma ray radiation reaches a predetermined level over and above the background level. Also disclosed is the apparatus and system used to conduct the process.

  16. Process and apparatus for detecting presence of plant substances

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, J.A.

    1990-12-31

    Disclosed is a process for detecting the presence of plant substances in a particular environment which comprises the steps of: (1) Measuring the background K40 gamma ray radiation level in a particular environment with a 1.46 MeV gamma ray counter system; (2) measuring the amount of K40 gamma ray radiation emanating from a package containing said plant substance being passed through said environment with said counter; and (3) generating an alarm signal when the total K40 gamma ray radiation reaches a predetermined level over and above the background level. Also disclosed is the apparatus and system used to conduct the process.

  17. Presence in Virtual Reality Exposure Therapy Systems

    OpenAIRE

    Ling, Y.

    2014-01-01

    Experiencing anxiety is essential for virtual reality exposure therapy (VRET) to be effective in curing patients suffering from anxiety disorders. However, some patients drop out in VRET due to the lack of feeling anxiety. Presence - which refers to the feeling of being in the virtual environment - has been considered an important mechanism that leads to the experience of anxiety. Therefore, understanding the relationship between presence and anxiety and finding ways to improve presence in VR...

  18. OVERSEAS PRESENCE: Observations on a Rightsizing Framework

    National Research Council Canada - National Science Library

    2002-01-01

    ... vulnerabilities while retaining effectiveness in meeting foreign policy objectives. We reviewed reports, including those of the Accountability Review Boards,3 the Overseas Presence Advisory Panel (OPAP...

  19. Community of Inquiry: Social Presence Revisited

    Science.gov (United States)

    Kreijns, Karel; Van Acker, Frederick; Vermeulen, Marjan; Van Buuren, Hans

    2014-01-01

    Social presence is a construct that has attracted the attention of many educational scholars involved in online collaborative learning settings wherein all the dialogue is happening through text-based asynchronous and synchronous communication channels. The social presence of the learning group members is associated with the degree of…

  20. Community of inquiry: Social presence revisited

    NARCIS (Netherlands)

    Kreijns, Karel; Van Acker, Frederik; Vermeulen, Marjan; Van Buuren, Hans

    2018-01-01

    Social presence is a construct that has attracted the attention of many educational scholars involved in online collaborative learning settings wherein all the dialogue is happening through text-based asynchronous and synchronous communication channels. The social presence of the learning group

  1. creating social presence in large classes

    African Journals Online (AJOL)

    Social presence refers to the ability of students to project themselves as 'real people' in an online learning community. While it is difficult to create social presence in large classes, educational technologies can enhance the social dimension of online learning if educators relinquish the use of technology as an instrument of ...

  2. GNSS signal acquisition in harsh urban environments

    NARCIS (Netherlands)

    Wildemeersch, Matthias; Wildemeersch, Matthias; Slump, Cornelis H.; Quek, Tony Q.S.; Rabbachin, Alberto

    2013-01-01

    In urban environment, Global Navigation Satellite System (GNSS) signals are impaired by non-line-of-sight fading conditions and by the presence of potential sources of electromagnetic disturbance. This paper analyzes the impact of the wireless propagation medium and aggregate network interference by

  3. Signal sciences workshop. Proceedings

    International Nuclear Information System (INIS)

    Candy, J.V.

    1997-01-01

    This meeting is aimed primarily at signal processing and controls. The technical program for the 1997 Workshop includes a variety of efforts in the Signal Sciences with applications in the Microtechnology Area a new program at LLNL and a future area of application for both Signal/Image Sciences. Special sessions organized by various individuals in Seismic and Optical Signal Processing as well as Micro-Impulse Radar Processing highlight the program, while the speakers at the Signal Processing Applications session discuss various applications of signal processing/control to real world problems. For the more theoretical, a session on Signal Processing Algorithms was organized as well as for the more pragmatic, featuring a session on Real-Time Signal Processing

  4. Traffic signal timing manual

    Science.gov (United States)

    2008-06-01

    This report serves as a comprehensive guide to traffic signal timing and documents the tasks completed in association with its development. The focus of this document is on traffic signal control principles, practices, and procedures. It describes th...

  5. Signal sciences workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J.V.

    1997-05-01

    This meeting is aimed primarily at signal processing and controls. The technical program for the 1997 Workshop includes a variety of efforts in the Signal Sciences with applications in the Microtechnology Area a new program at LLNL and a future area of application for both Signal/Image Sciences. Special sessions organized by various individuals in Seismic and Optical Signal Processing as well as Micro-Impulse Radar Processing highlight the program, while the speakers at the Signal Processing Applications session discuss various applications of signal processing/control to real world problems. For the more theoretical, a session on Signal Processing Algorithms was organized as well as for the more pragmatic, featuring a session on Real-Time Signal Processing.

  6. Biomedical signal processing

    CERN Document Server

    Akay, Metin

    1994-01-01

    Sophisticated techniques for signal processing are now available to the biomedical specialist! Written in an easy-to-read, straightforward style, Biomedical Signal Processing presents techniques to eliminate background noise, enhance signal detection, and analyze computer data, making results easy to comprehend and apply. In addition to examining techniques for electrical signal analysis, filtering, and transforms, the author supplies an extensive appendix with several computer programs that demonstrate techniques presented in the text.

  7. Nurses' perceptions of family presence during resuscitation.

    Science.gov (United States)

    Tudor, Kelly; Berger, Jill; Polivka, Barbara J; Chlebowy, Rachael; Thomas, Beena

    2014-11-01

    Although strong evidence indicates that the presence of a patient's family during resuscitation has a positive effect on the family, the practice is still controversial and is not consistently implemented. To explore nurses' experience with resuscitation, perceptions of the benefits and risks of having a patient's family members present, and self-confidence in having family presence at their workplace. Differences in demographic characteristics and relationships between nurses' perceptions of self-confidence and perceived risks and benefits of family presence were evaluated. The study was descriptive, with a cross-sectional survey design. A convenience sample of 154 nurses working in inpatient and outpatient units at an urban hospital were surveyed. The 63-item survey included 2 previously validated scales, demographic questions, and opinion questions. Nurses' self-confidence and perceived benefit of family presence were significantly related (r = 0.54; P resuscitation events, were specialty certified, or were members of nurses' professional organizations. Barriers to family presence included fear of interference by the patient's family, lack of space, lack of support for the family members, fear of trauma to family members, and performance anxiety. Changing the practice of family presence will require strengthening current policy, identifying a team member to attend to the patient's family during resuscitation, and requiring nurses to complete education on evidence that supports family presence and changes in clinical practice. ©2014 American Association of Critical-Care Nurses.

  8. Predicting tick presence by environmental risk mapping

    Directory of Open Access Journals (Sweden)

    Arno eSwart

    2014-11-01

    Full Text Available Public health statistics recorded an increasing trend in the incidence of tick bites and erythema migrans in the Netherlands. We investigated whether the disease incidence could be predicted by a spatially explicit categorization model, based on environmental factors and a training set of tick absence-presence data. Presence and absence of Ixodes ricinus were determined by the blanket-dragging method at numerous sites spread over the Netherlands. The probability of tick presence on a 1 km by 1 km square grid was estimated from the field data using a satellite-based methodology. Expert elicitation was conducted to provide a Bayesian prior per landscape type. We applied a linear model to test a correlation between incidence of erythema migrans consultations by general practitioners in the Netherlands and the estimated probability of tick presence. Ticks were present at 252 distinct sampling coordinates and absent at 425. Tick presence was estimated for 54% percent of the total land cover. Our model has predictive power for tick presence in the Netherlands, tick bite incidence per municipality correlated significantly with the average probability of tick presence per grid. The estimated intercept of the linear model was positive and significant. This indicates that a significant fraction of the tick bite consultations could be attributed to the Ixodes ricinus population outside the resident municipality.

  9. Parametric inference of neuronal response latency in presence of a background signal

    DEFF Research Database (Denmark)

    Tamborrino, Massimiliano; Ditlevsen, Susanne; Lansky, Petr

    2013-01-01

    Neurons are commonly characterized by spontaneous generation of action potentials (spikes), which appear without any apparent or controlled stimulation. When a stimulus is applied, the spontaneous firing may prevail and hamper identification of the effect of the stimulus. Therefore, for any...... will persist even when sample size is increasing. The first question is: what is the response latency to the stimulus? Answering this question becomes even more difficult if the latency is of a complex nature, for example composed of a physically implied deterministic part and a stochastic part. This scenario...

  10. Performing Presence in the Pop Art Lab

    DEFF Research Database (Denmark)

    Strand, Dixi Louise

    2011-01-01

    This paper presents the author's entry into a virtual world, Second Life, to conduct a case study on 'presence in virtual worlds'. The object of study is not the IT platform that might provide opportunities for presence, nor the human actors that might experience presence, but what happens when...... create specific visibilities, gather appearances together and how they may lead to interest, surprise and new insights into virtual worlds as an emergent, distributed phenomenon. In conclusion, the paper proposes a set of analytical strategies that may improve our understanding of how virtual worlds...

  11. Presence Experiences - the eventalisation of urban space

    DEFF Research Database (Denmark)

    Pløger, John

    2010-01-01

    ’ and Hans Martin Gumbrecht on ‘presence-events’, I focus on subcultural and subpolitical groups trying to capture urban commercial spaces and to reverse or reveal their symbolic meaning. Using the oppositional youth group Pirate Parties, I argue that it is exactly the eventalisation and the presence quality......Cultural events are, as part of an urban development strategy, about (symbolic) representations, but for the human beings participating in the event it may include acts of in/visibility (anonymity versus expressivity) and different articulations of meaning or subjectivity in space. A particular...... and virtual qualities of presence-event spaces and the eventalisation of urban space...

  12. Optimal Signal Quality Index for Photoplethysmogram Signals

    Directory of Open Access Journals (Sweden)

    Mohamed Elgendi

    2016-09-01

    Full Text Available A photoplethysmogram (PPG is a noninvasive circulatory signal related to the pulsatile volume of blood in tissue and is typically collected by pulse oximeters. PPG signals collected via mobile devices are prone to artifacts that negatively impact measurement accuracy, which can lead to a significant number of misleading diagnoses. Given the rapidly increased use of mobile devices to collect PPG signals, developing an optimal signal quality index (SQI is essential to classify the signal quality from these devices. Eight SQIs were developed and tested based on: perfusion, kurtosis, skewness, relative power, non-stationarity, zero crossing, entropy, and the matching of systolic wave detectors. Two independent annotators annotated all PPG data (106 recordings, 60 s each and a third expert conducted the adjudication of differences. The independent annotators labeled each PPG signal with one of the following labels: excellent, acceptable or unfit for diagnosis. All indices were compared using Mahalanobis distance, linear discriminant analysis, quadratic discriminant analysis, and support vector machine with leave-one-out cross-validation. The skewness index outperformed the other seven indices in differentiating between excellent PPG and acceptable, acceptable combined with unfit, and unfit recordings, with overall F 1 scores of 86.0%, 87.2%, and 79.1%, respectively.

  13. Optimal Signal Quality Index for Photoplethysmogram Signals.

    Science.gov (United States)

    Elgendi, Mohamed

    2016-09-22

    A photoplethysmogram (PPG) is a noninvasive circulatory signal related to the pulsatile volume of blood in tissue and is typically collected by pulse oximeters. PPG signals collected via mobile devices are prone to artifacts that negatively impact measurement accuracy, which can lead to a significant number of misleading diagnoses. Given the rapidly increased use of mobile devices to collect PPG signals, developing an optimal signal quality index (SQI) is essential to classify the signal quality from these devices. Eight SQIs were developed and tested based on: perfusion, kurtosis, skewness, relative power, non-stationarity, zero crossing, entropy, and the matching of systolic wave detectors. Two independent annotators annotated all PPG data (106 recordings, 60 s each) and a third expert conducted the adjudication of differences. The independent annotators labeled each PPG signal with one of the following labels: excellent, acceptable or unfit for diagnosis. All indices were compared using Mahalanobis distance, linear discriminant analysis, quadratic discriminant analysis, and support vector machine with leave-one-out cross-validation. The skewness index outperformed the other seven indices in differentiating between excellent PPG and acceptable, acceptable combined with unfit, and unfit recordings, with overall F 1 scores of 86.0%, 87.2%, and 79.1%, respectively.

  14. Performance Analysis of Recurrence Matrix Statistics for the Detection of Deterministic Signals in Noise

    National Research Council Canada - National Science Library

    Michalowicz, Joseph V; Nichols, Jonathan M; Bucholtz, Frank

    2008-01-01

    Understanding the limitations to detecting deterministic signals in the presence of noise, especially additive, white Gaussian noise, is of importance for the design of LPI systems and anti-LPI signal defense...

  15. Robust Feature Extraction from ECG Signals Based on Nonlinear Dynamical Modeling

    National Research Council Canada - National Science Library

    Owis, Mohamed

    2001-01-01

    ...) signals to detect the presence of arrhythmia. Conventional methods of arrhythmia detection rely on observing morphological features of the signal in the time domain or after applying a certain transformation, Even though these techniques...

  16. Estimating Economic Benefits of Naval Forward Presence

    National Research Council Canada - National Science Library

    Looney, Robert

    2000-01-01

    This study extends the analysis of the economic benefits of naval crisis response enabled by forward presence undertaken by the Naval Postgraduate School for the 1997 Quadrennial Defense Review (QDR97...

  17. Presence and the utility of audio spatialization

    DEFF Research Database (Denmark)

    Bormann, Karsten

    2005-01-01

    The primary concern of this paper is whether the utility of audio spatialization, as opposed to the fidelity of audio spatialization, impacts presence. An experiment is reported that investigates the presence-performance relationship by decoupling spatial audio fidelity (realism) from task...... performance by varying the spatial fidelity of the audio independently of its relevance to performance on the search task that subjects were to perform. This was achieved by having conditions in which subjects searched for a music-playing radio (an active sound source) and having conditions in which...... supplied only nonattenuated audio was detrimental to performance. Even so, this group of subjects consistently had the largest increase in presence scores over the baseline experiment. Further, the Witmer and Singer (1998) presence questionnaire was more sensitive to whether the audio source was active...

  18. The Signal Distribution System

    CERN Document Server

    Belohrad, D; CERN. Geneva. AB Department

    2005-01-01

    For the purpose of LHC signal observation and high frequency signal distribution, the Signal Distribution System (SDS) was built. The SDS can contain up to 5 switching elements, where each element allows the user to switch between one of the maximum 8 bi-directional signals. The coaxial relays are used to switch the signals. Depending of the coaxial relay type used, the transfer bandwidth can go up to 18GHz. The SDS is controllable via TCP/IP, parallel port, or locally by rotary switch.

  19. Acoustic Signals and Systems

    DEFF Research Database (Denmark)

    2008-01-01

    The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...

  20. Olfactory Stimuli Increase Presence in Virtual Environments.

    Directory of Open Access Journals (Sweden)

    Benson G Munyan

    Full Text Available Exposure therapy (EXP is the most empirically supported treatment for anxiety and trauma-related disorders. EXP consists of repeated exposure to a feared object or situation in the absence of the feared outcome in order to extinguish associated anxiety. Key to the success of EXP is the need to present the feared object/event/situation in as much detail and utilizing as many sensory modalities as possible, in order to augment the sense of presence during exposure sessions. Various technologies used to augment the exposure therapy process by presenting multi-sensory cues (e.g., sights, smells, sounds. Studies have shown that scents can elicit emotionally charged memories, but no prior research has examined the effect of olfactory stimuli upon the patient's sense of presence during simulated exposure tasks.60 adult participants navigated a mildly anxiety-producing virtual environment (VE similar to those used in the treatment of anxiety disorders. Participants had no autobiographical memory associated with the VE. State anxiety, Presence ratings, and electrodermal (EDA activity were collected throughout the experiment.Utilizing a Bonferroni corrected Linear Mixed Model, our results showed statistically significant relationships between olfactory stimuli and presence as assessed by both the Igroup Presence Questionnaire (IPQ: R2 = 0.85, (F(3,52 = 6.625, p = 0.0007 and a single item visual-analogue scale (R2 = 0.85, (F(3,52 = 5.382, p = 0.0027. State anxiety was unaffected by the presence or absence of olfactory cues. EDA was unaffected by experimental condition.Olfactory stimuli increase presence in virtual environments that approximate those typical in exposure therapy, but did not increase EDA. Additionally, once administered, the removal of scents resulted in a disproportionate decrease in presence. Implications for incorporating the use of scents to increase the efficacy of exposure therapy is discussed.

  1. Community of inquiry: Social presence revisited

    OpenAIRE

    Kreijns, Karel; Van Acker, Frederik; Vermeulen, Marjan; Van Buuren, Hans

    2018-01-01

    Social presence is a construct that has attracted the attention of many educational scholars involved in online collaborative learning settings wherein all the dialogue is happening through text-based asynchronous and synchronous communication channels. The social presence of the learning group members is associated with the degree of participation and social interaction amongst them and, as such, is therefore considered a critical variable for learning. The Community of Inquiry (CoI) framewo...

  2. Conformational snapshots of Tec kinases during signaling.

    Science.gov (United States)

    Joseph, Raji E; Andreotti, Amy H

    2009-03-01

    The control of cellular signaling cascades is of utmost importance in regulating the immune response. Exquisitely precise protein-protein interactions and chemical modification of substrates by enzymatic catalysis are the fundamental components of the signals that alert immune cells to the presence of a foreign antigen. In particular, the phosphorylation events induced by protein kinase activity must be spatially and temporally regulated by specific interactions to maintain a normal and effective immune response. High resolution structures of many protein kinases along with supporting biochemical data are providing significant insight into the intricate regulatory mechanisms responsible for controlling cellular signaling. The Tec family kinases are immunologically important kinases for which regulatory details are beginning to emerge. This review focuses on bringing together structural insights gained over the years to develop an understanding of how domain interactions both within the Tec kinases and between the Tec kinases and other signaling molecules control immune cell function.

  3. Method of signal analysis

    International Nuclear Information System (INIS)

    Berthomier, Charles

    1975-01-01

    A method capable of handling the amplitude and the frequency time laws of a certain kind of geophysical signals is described here. This method is based upon the analytical signal idea of Gabor and Ville, which is constructed either in the time domain by adding an imaginary part to the real signal (in-quadrature signal), or in the frequency domain by suppressing negative frequency components. The instantaneous frequency of the initial signal is then defined as the time derivative of the phase of the analytical signal, and his amplitude, or envelope, as the modulus of this complex signal. The method is applied to three types of magnetospheric signals: chorus, whistlers and pearls. The results obtained by analog and numerical calculations are compared to results obtained by classical systems using filters, i.e. based upon a different definition of the concept of frequency. The precision with which the frequency-time laws are determined leads then to the examination of the principle of the method and to a definition of instantaneous power density spectrum attached to the signal, and to the first consequences of this definition. In this way, a two-dimensional representation of the signal is introduced which is less deformed by the analysis system properties than the usual representation, and which moreover has the advantage of being obtainable practically in real time [fr

  4. Nonlocal quantum information transfer without superluminal signalling and communication

    OpenAIRE

    Walleczek, Jan; Groessing, Gerhard

    2015-01-01

    It is a frequent assumption that - via superluminal information transfers - superluminal signals capable of enabling communication are necessarily exchanged in any quantum theory that posits hidden superluminal influences. However, does the presence of hidden superluminal influences automatically imply superluminal signalling and communication? The non-signalling theorem mediates the apparent conflict between quantum mechanics and the theory of special relativity. However, as a 'no-go' theore...

  5. Wnt signaling in cancer

    Science.gov (United States)

    Zhan, T; Rindtorff, N; Boutros, M

    2017-01-01

    Wnt signaling is one of the key cascades regulating development and stemness, and has also been tightly associated with cancer. The role of Wnt signaling in carcinogenesis has most prominently been described for colorectal cancer, but aberrant Wnt signaling is observed in many more cancer entities. Here, we review current insights into novel components of Wnt pathways and describe their impact on cancer development. Furthermore, we highlight expanding functions of Wnt signaling for both solid and liquid tumors. We also describe current findings how Wnt signaling affects maintenance of cancer stem cells, metastasis and immune control. Finally, we provide an overview of current strategies to antagonize Wnt signaling in cancer and challenges that are associated with such approaches. PMID:27617575

  6. Teaching and Learning Immersion and Presence

    DEFF Research Database (Denmark)

    Herbelin, Bruno; Ciger, Jan

    2008-01-01

    It is known since Socrates that people learn better by experiencing a problem by themselves and by finding a (the) solution(s) by their own. It is however not always possible to offer such freedom to students when teaching the concepts of immersion and presence in virtual environments due to the ......-presence, and observe the inherent problems liked to  communication, field of view, or latency issues. The test performed shows that such experimentation have positive pedagogical impacts, both from the learning and students motivation perspectives.......It is known since Socrates that people learn better by experiencing a problem by themselves and by finding a (the) solution(s) by their own. It is however not always possible to offer such freedom to students when teaching the concepts of immersion and presence in virtual environments due...

  7. Presence of pRI1:

    DEFF Research Database (Denmark)

    Migura, Lourdes Garcia; Hasman, Henrik; Jensen, Lars Bogø

    2009-01-01

    This study focused on the molecular characterization of a small cryptic, mobilizable plasmid (6038 bp) sequenced from an E. faecium 9631160-1 of poultry origin. Sequence analysis of pRI1 revealed seven open reading frames. pRI1 contained an IS 100% identical to ISEfa4. This insertion element...... almost identical to the repA from the pEFNP1 and pKQ10 plasmids from E. faecium was also identified. Presence of the pRI1 replication initiation gene (rep) was analyzed in a panel of 159 E. faecium isolates of human and animal origin from different European countries, of which 60 tested positive...... for the presence of pRI1-rep. Conjugation experiments verified transfer of the pRI1 together with conjugative plasmids harboring resistance to vancomycin and streptogramin. The presence of pRI1 in enterococcal isolates geographically separated and from different origin demonstrates the ability of enterococci...

  8. Digest: Context matters: the effects of light environment and female presence on the structure of wolf spider courtship displays.

    Science.gov (United States)

    Fialko, Kristina

    2018-03-31

    Does variation in the environment in which a signal is presented affect the components of a complex, ritualized animal display? Using a signal phenotype network, Rosenthal et al. (2018) find that light and female presence alter the structure of wolf spider courtship displays, providing evidence that complex signaling behaviors may be modified depending on the social and environmental context. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  9. Presence is not always in the sigular

    DEFF Research Database (Denmark)

    Nortvig, Anne-Mette

    , and the e-students can be at home and in the classroom (via videoconference) at the same time or in the classroom while also actively present on Facebook. On the basis of fieldwork and interviews in professional bachelor program in physiotherapy and with inspiration from symbolic interactionism...... and postphenomenology, this paper attempts to analyze and discuss physical and virtual presence in various e-learning designs. The paper suggests the concept of polytopic presence in order to nuance the dichotomies between same/different time and same/different place and to focus on the necessity of a didactical...

  10. Presence is not always in the Singular

    DEFF Research Database (Denmark)

    Nortvig, Anne-Mette

    -students can be at home and in the classroom (via videoconference) at the same time or in the classroom while also actively present on Facebook. On the basis of fieldwork and interviews in professional bachelor program in physiotherapy and with inspiration from symbolic interactionism and postphenomenology......, this paper attempts to analyze and discuss physical and virtual presence in various e-learning designs. The paper suggests the concept of polytopic presence in order to nuance the dichotomies between same/different time and same/different place and to focus on the necessity of a didactical consideration...

  11. Biomedical signals and systems

    CERN Document Server

    Tranquillo, Joseph V

    2013-01-01

    Biomedical Signals and Systems is meant to accompany a one-semester undergraduate signals and systems course. It may also serve as a quick-start for graduate students or faculty interested in how signals and systems techniques can be applied to living systems. The biological nature of the examples allows for systems thinking to be applied to electrical, mechanical, fluid, chemical, thermal and even optical systems. Each chapter focuses on a topic from classic signals and systems theory: System block diagrams, mathematical models, transforms, stability, feedback, system response, control, time

  12. Digital signal processing

    CERN Document Server

    O'Shea, Peter; Hussain, Zahir M

    2011-01-01

    In three parts, this book contributes to the advancement of engineering education and that serves as a general reference on digital signal processing. Part I presents the basics of analog and digital signals and systems in the time and frequency domain. It covers the core topics: convolution, transforms, filters, and random signal analysis. It also treats important applications including signal detection in noise, radar range estimation for airborne targets, binary communication systems, channel estimation, banking and financial applications, and audio effects production. Part II considers sel

  13. Geolocation of RF signals

    CERN Document Server

    Progri, Ilir

    2011-01-01

    ""Geolocation of RF Signals - Principles and Simulations"" offers an overview of the best practices and innovative techniques in the art and science of geolocation over the last twenty years. It covers all research and development aspects including theoretical analysis, RF signals, geolocation techniques, key block diagrams, and practical principle simulation examples in the frequency band from 100 MHz to 18 GHz or even 60 GHz. Starting with RF signals, the book progressively examines various signal bands - such as VLF, LF, MF, HF, VHF, UHF, L, S, C, X, Ku, and, K and the corresponding geoloca

  14. Social presence, embarrassment, and nonverbal behavior

    NARCIS (Netherlands)

    Costa, Marco; Dinsbach, A.A.; Manstead, A.S.R.; Ricci-Bitti, Pio-Enrico

    2001-01-01

    Nonverbal behaviors in response to viewing slides depicting nude males, nude females, erotic couples and neutral pictures, either alone or in the presence of two unfamiliar individuals, were studied in 22 female and 16 male university students. Participants were unaware of being videorecorded.

  15. Presence and the utility of audio spatialization

    DEFF Research Database (Denmark)

    Bormann, Karsten

    2005-01-01

    or not, while the presence questionnaire used by Slater and coworkers (see Tromp et al., 1998) was more sensitive to whether audio was fully spatialized or not. Finally, having the sound source active positively impacts the assessment of the audio while negatively impacting subjects' assessment...

  16. 31 CFR 91.3 - Recording presence.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Recording presence. 91.3 Section 91.3 Money and Finance: Treasury Regulations Relating to Money and Finance REGULATIONS GOVERNING CONDUCT IN... exists, and at such other times as may be necessary for the orderly conduct of the Government's business...

  17. 31 CFR 407.3 - Recording presence.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Recording presence. 407.3 Section 407.3 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) SECRET SERVICE... business of the Treasury Department. The property shall also be closed to the public when, in the opinion...

  18. Presence in Virtual Reality Exposure Therapy Systems

    NARCIS (Netherlands)

    Ling, Y.

    2014-01-01

    Experiencing anxiety is essential for virtual reality exposure therapy (VRET) to be effective in curing patients suffering from anxiety disorders. However, some patients drop out in VRET due to the lack of feeling anxiety. Presence - which refers to the feeling of being in the virtual environment -

  19. Leader affective presence and innovation in teams.

    Science.gov (United States)

    Madrid, Hector P; Totterdell, Peter; Niven, Karen; Barros, Eduardo

    2016-05-01

    Affective presence is a novel personality construct that describes the tendency of individuals to make their interaction partners feel similarly positive or negative. We adopt this construct, together with the input-process-output model of teamwork, to understand how team leaders influence team interaction and innovation performance. In 2 multisource studies, based on 350 individuals working in 87 teams of 2 public organizations and 734 individuals working in 69 teams of a private organization, we tested and supported hypotheses that team leader positive affective presence was positively related to team information sharing, whereas team leader negative affective presence was negatively related to the same team process. In turn, team information sharing was positively related to team innovation, mediating the effects of leader affective presence on this team output. The results indicate the value of adopting an interpersonal individual differences approach to understanding how affect-related characteristics of leaders influence interaction processes and complex performance in teams. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  20. Measurement of the dose in quartz in the presence of feldspar contamination

    DEFF Research Database (Denmark)

    Wallinga, J.; Murray, A.S.; Bøtter-Jensen, L.

    2002-01-01

    , without seriously affecting the quartz OSL signal. A single-aliquot regenerative-dose protocol is proposed which, in our samples, allows accurate measurement of the dose in quartz in the presence of feldspar contamination. The protocol also has potential use for quartz dose determination in mixed...

  1. Vibration measurement with nonlinear converter in the presence of noise

    Science.gov (United States)

    Mozuras, Almantas

    2017-10-01

    Conventional vibration measurement methods use the linear properties of physical converters. These methods are strongly influenced by nonlinear distortions, because ideal linear converters are not available. Practically, any converter can be considered as a linear one, when an output signal is very small. However, the influence of noise increases significantly and signal-to-noise ratio decreases at lower signals. When the output signal is increasing, the nonlinear distortions are also augmenting. If the wide spectrum vibration is measured, conventional methods face a harmonic distortion as well as intermodulation effects. Purpose of this research is to develop a measurement method of wide spectrum vibration by using a converter described by a nonlinear function of type f(x), where x =x(t) denotes the dependence of coordinate x on time t due to the vibration. Parameter x(t) describing the vibration is expressed as Fourier series. The spectral components of the converter output f(x(t)) are determined by using Fourier transform. The obtained system of nonlinear equations is solved using the least squares technique that permits to find x(t) in the presence of noise. This method allows one to carry out the absolute or relative vibration measurements. High resistance to noise is typical for the absolute vibration measurement, but it is necessary to know the Taylor expansion coefficients of the function f(x). If the Taylor expansion is not known, the relative measurement of vibration parameters is also possible, but with lower resistance to noise. This method allows one to eliminate the influence of nonlinear distortions to the measurement results, and consequently to eliminate harmonic distortion and intermodulation effects. The use of nonlinear properties of the converter for measurement gives some advantages related to an increased frequency range of the output signal (consequently increasing the number of equations) that allows one to decrease the noise influence on

  2. Detection the nonlinear ultrasonic signals based on modified Duffing equations

    Directory of Open Access Journals (Sweden)

    Yuhua Zhang

    Full Text Available The nonlinear ultrasonic signals, like second harmonic generation (SHG signals, could reflect the nonlinearity of material induced by fatigue damage in nonlinear ultrasonic technique which are weak nonlinear signals and usually submerged by strong background noise. In this paper the modified Duffing equations are applied to detect the SHG signals relating to the fatigue damage of material. Due to the Duffing equation could only detect the signal with specific frequency and initial phase, firstly the frequency transformation is carried on the Duffing equation which could detect the signal with any frequency. Then the influence of initial phases of to-be-detected signal and reference signal on the detection result is studied in detail, four modified Duffing equations are proposed to detect actual engineering signals with any initial phase. The relationship between the response amplitude and the total driving force is applied to estimate the amplitude of weak periodic signal. The detection results show the modified Duffing equations could effectively detect the second harmonic in SHG signals. When the SHG signals include strong background noise, the noise doesn’t change the motion state of Duffing equation and the second harmonic signal could be detected until the SNR of noisy SHG signals are −26.3, yet the frequency spectrum method could only identify when the SNR is greater than 0.5. When estimation the amplitude of second harmonic signal, the estimation error of Duffing equation is obviously less than the frequency spectrum analysis method under the same noise level, which illustrates the Duffing equation has the noise immune capacity. The presence of the second harmonic signal in nonlinear ultrasonic experiments could provide an insight about the early fatigue damage of engineering components. Keywords: Modified Duffing equations, SHG signals, Amplitude estimation, Second harmonic signal detection

  3. Signaling in symbiosis

    NARCIS (Netherlands)

    Limpens, E.H.M.; Bisseling, T.

    2003-01-01

    In recent years, the major focus in nodulation research has been on the genetic dissection of Nod-factor signaling. Components of this pathway appear to be shared with signaling processes that are induced during the formation of mycorrhiza. With the cloning of orthologs of the NIN and DMI2 genes

  4. SignalR blueprints

    CERN Document Server

    Ingebrigtsen, Einar

    2015-01-01

    This book is designed for software developers, primarily those with knowledge of C#, .NET, and JavaScript. Good knowledge and understanding of SignalR is assumed to allow efficient programming of core elements and applications in SignalR.

  5. Digital Signal Processors

    Indian Academy of Sciences (India)

    A computer controlling the motion of a satellite should acquire signals from the satellite while it is in motion, compute corrections (if required) to the trajectory and send control signals back within a specified time for effective control. Delays may be fatal to ..... emulators and system evaluation tools have facilitated concurrent.

  6. Ubiquitination in apoptosis signaling

    NARCIS (Netherlands)

    van de Kooij, L.W.

    2014-01-01

    The work described in this thesis focuses on ubiquitination and protein degradation, with an emphasis on how these processes regulate apoptosis signaling. More specifically, our aims were: 1. To increase the understanding of ubiquitin-mediated regulation of apoptosis signaling. 2. To identify the E3

  7. Second-hand signals

    DEFF Research Database (Denmark)

    Bergenholtz, Carsten

    2014-01-01

    used by various agents in their search for and assessment of products and firms. I conclude by arguing how this second‐hand nature of signals goes beyond a simple dyadic focus on senders and receivers of signals, and thus elucidates the more complex interrelations of the various types of agents...

  8. Quantum cloning without signaling

    OpenAIRE

    Gisin, Nicolas

    1998-01-01

    Perfect Quantum Cloning Machines (QCM) would allow to use quantum nonlocality for arbitrary fast signaling. However perfect QCM cannot exist. We derive a bound on the fidelity of QCM compatible with the no-signaling constraint. This bound equals the fidelity of the Bu\\v{z}ek-Hillery QCM.

  9. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2011-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  10. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2010-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  11. Optimal fault signal estimation

    NARCIS (Netherlands)

    Stoorvogel, Antonie Arij; Niemann, H.H.; Saberi, A.; Sannuti, P.

    2002-01-01

    We consider here both fault identification and fault signal estimation. Regarding fault identification, we seek either exact or almost fault identification. On the other hand, regarding fault signal estimation, we seek either $H_2$ optimal, $H_2$ suboptimal or Hinfinity suboptimal estimation. By

  12. The Construction of Presence and the Multimidiatic Stage: hegemony of an immanent presence

    Directory of Open Access Journals (Sweden)

    Juarez José Nunes

    2015-09-01

    Full Text Available In this work, we depart from the understanding that the co-presence of performers and spectators in contemporary theatre articulates itself through a focus on fiction and one that emphasizes the sensorial perception and concrete interaction. Based on a discussion of the problem of expression in Deleuze/Spinoza and on the critique of the production of meaning in Gumbrecht, we name these two modes of presence respectively emanative presence and immanent presence, with the latter becoming hegemonic in contemporary theatre. We aim to reflect on how a multimedia device, with its possibilities of intermediality, may impact on the interaction between immanence and transcendence.

  13. Neutron signal transfer analysis

    CERN Document Server

    Pleinert, H; Lehmann, E

    1999-01-01

    A new method called neutron signal transfer analysis has been developed for quantitative determination of hydrogenous distributions from neutron radiographic measurements. The technique is based on a model which describes the detector signal obtained in the measurement as a result of the action of three different mechanisms expressed by signal transfer functions. The explicit forms of the signal transfer functions are determined by Monte Carlo computer simulations and contain only the distribution as a variable. Therefore an unknown distribution can be determined from the detector signal by recursive iteration. This technique provides a simple and efficient tool for analysis of this type while also taking into account complex effects due to the energy dependency of neutron interaction and single and multiple scattering. Therefore this method provides an efficient tool for precise quantitative analysis using neutron radiography, as for example quantitative determination of moisture distributions in porous buil...

  14. Molecular and Cellular Signaling

    CERN Document Server

    Beckerman, Martin

    2005-01-01

    A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

  15. Adaptive signal processor

    Energy Technology Data Exchange (ETDEWEB)

    Walz, H.V.

    1980-07-01

    An experimental, general purpose adaptive signal processor system has been developed, utilizing a quantized (clipped) version of the Widrow-Hoff least-mean-square adaptive algorithm developed by Moschner. The system accommodates 64 adaptive weight channels with 8-bit resolution for each weight. Internal weight update arithmetic is performed with 16-bit resolution, and the system error signal is measured with 12-bit resolution. An adapt cycle of adjusting all 64 weight channels is accomplished in 8 ..mu..sec. Hardware of the signal processor utilizes primarily Schottky-TTL type integrated circuits. A prototype system with 24 weight channels has been constructed and tested. This report presents details of the system design and describes basic experiments performed with the prototype signal processor. Finally some system configurations and applications for this adaptive signal processor are discussed.

  16. Adaptive signal processor

    International Nuclear Information System (INIS)

    Walz, H.V.

    1980-07-01

    An experimental, general purpose adaptive signal processor system has been developed, utilizing a quantized (clipped) version of the Widrow-Hoff least-mean-square adaptive algorithm developed by Moschner. The system accommodates 64 adaptive weight channels with 8-bit resolution for each weight. Internal weight update arithmetic is performed with 16-bit resolution, and the system error signal is measured with 12-bit resolution. An adapt cycle of adjusting all 64 weight channels is accomplished in 8 μsec. Hardware of the signal processor utilizes primarily Schottky-TTL type integrated circuits. A prototype system with 24 weight channels has been constructed and tested. This report presents details of the system design and describes basic experiments performed with the prototype signal processor. Finally some system configurations and applications for this adaptive signal processor are discussed

  17. Black holes in the presence of dark energy

    International Nuclear Information System (INIS)

    Babichev, E O; Dokuchaev, V I; Eroshenko, Yu N

    2013-01-01

    The new, rapidly developing field of theoretical research—studies of dark energy interacting with black holes (and, in particular, accreting onto black holes)–—is reviewed. The term 'dark energy' is meant to cover a wide range of field theory models, as well as perfect fluids with various equations of state, including cosmological dark energy. Various accretion models are analyzed in terms of the simplest test field approximation or by allowing back reaction on the black-hole metric. The behavior of various types of dark energy in the vicinity of Schwarzschild and electrically charged black holes is examined. Nontrivial effects due to the presence of dark energy in the black hole vicinity are discussed. In particular, a physical explanation is given of why the black hole mass decreases when phantom energy is being accreted, a process in which the basic energy conditions of the famous theorem of nondecreasing horizon area in classical black holes are violated. The theoretical possibility of a signal escaping from beneath the black hole event horizon is discussed for a number of dark energy models. Finally, the violation of the laws of thermodynamics by black holes in the presence of noncanonical fields is considered. (reviews of topical problems)

  18. Intragroup Emotions: Physiological Linkage and Social Presence

    Science.gov (United States)

    Järvelä, Simo; Kätsyri, Jari; Ravaja, Niklas; Chanel, Guillaume; Henttonen, Pentti

    2016-01-01

    We investigated how technologically mediating two different components of emotion—communicative expression and physiological state—to group members affects physiological linkage and self-reported feelings in a small group during video viewing. In different conditions the availability of second screen text chat (communicative expression) and visualization of group level physiological heart rates and their dyadic linkage (physiology) was varied. Within this four person group two participants formed a physically co-located dyad and the other two were individually situated in two separate rooms. We found that text chat always increased heart rate synchrony but HR visualization only with non-co-located dyads. We also found that physiological linkage was strongly connected to self-reported social presence. The results encourage further exploration of the possibilities of sharing group member's physiological components of emotion by technological means to enhance mediated communication and strengthen social presence. PMID:26903913

  19. Modal Coupling in Presence of Dry Friction

    Directory of Open Access Journals (Sweden)

    Marco Claudio De Simone

    2018-02-01

    Full Text Available In this paper, we analyze the behavior of a single pad system in the presence of dry friction. The goal is to investigate the path that leads a stable mechanical system to unstable behavior. In doing so, we studied the behavior of a discrete three DOF model, a continuous model and a finite element model of the pad. The numerical results are consistent with the experimental investigation conducted on a brake disk for railway application.

  20. 'Presence' of the past in the presence (Hans Ulrich Gumbrecht, Eelco Runia)

    NARCIS (Netherlands)

    ter Schure, L

    2006-01-01

    In recent writings historian Eelco Runia (Groningen) and literary theorist Hans Ulrich Gumbrecht (Stanford) have introduced the notion of presence, a new and promising way of thinking about history. Although there are differences between the two authors, both think of presence as the antithesis of

  1. Orexin/Hypocretin Signaling.

    Science.gov (United States)

    Kukkonen, Jyrki P

    Orexin/hypocretin peptide (orexin-A and orexin-B) signaling is believed to take place via the two G-protein-coupled receptors (GPCRs), named OX 1 and OX 2 orexin receptors, as described in the previous chapters. Signaling of orexin peptides has been investigated in diverse endogenously orexin receptor-expressing cells - mainly neurons but also other types of cells - and in recombinant cells expressing the receptors in a heterologous manner. Findings in the different systems are partially convergent but also indicate cellular background-specific signaling. The general picture suggests an inherently high degree of diversity in orexin receptor signaling.In the current chapter, I present orexin signaling on the cellular and molecular levels. Discussion of the connection to (potential) physiological orexin responses is only brief since these are in focus of other chapters in this book. The same goes for the post-synaptic signaling mechanisms, which are dealt with in Burdakov: Postsynaptic actions of orexin. The current chapter is organized according to the tissue type, starting from the central nervous system. Finally, receptor signaling pathways are discussed across tissues, cell types, and even species.

  2. MR spectroscopy detection of lactate and lipid signals in the brains of healthy elderly people

    NARCIS (Netherlands)

    Sijens, PE; den Heijer, T; de Leeuw, FE; de Groot, JC; Achten, E; Heijboer, RJJ; Hofman, A; Breteler, MMB; Oudkerk, M

    2001-01-01

    Magnetic resonance spectroscopy was used to assess the presence of brain lactate and lipid signals, frequently associated with the presence of pathology, in healthy persons of 60-90 years old (n = 540). Lactate and lipid signals were observed in, respectively, 25 and 6% of women, and 18 and 2% of

  3. Bistability in biochemical signaling models.

    Science.gov (United States)

    Sobie, Eric A

    2011-09-20

    This Teaching Resource provides lecture notes, slides, and a student assignment for a two-part lecture on the principles underlying bistability in biochemical signaling networks, which are illustrated with examples from the literature. The lectures cover analog, or graded, versus digital, all-or-none, responses in cells, with examples from different types of biological processes requiring each. Rate-balance plots are introduced as a method for determining whether generic one-variable systems exhibit one or several stable steady states. Bifurcation diagrams are presented as a more general method for detecting the presence of bistability in biochemical signaling networks. The examples include an artificial toggle switch, the lac operon in bacteria, and the mitogen-activated protein kinase cascade in both Xenopus oocytes and mammalian cells. The second part of the lecture links the concepts of bistability more closely to the mathematical tools provided by dynamical systems analysis. The examples from the first part of the lecture are analyzed with phase-plane techniques and bifurcation analysis, using the scientific programming language MATLAB. Using these programs as a template, the assignment requires the students to implement a model from the literature and analyze the stability of this model's steady states.

  4. Polyphenol compounds and PKC signaling.

    Science.gov (United States)

    Das, Joydip; Ramani, Rashmi; Suraju, M Olufemi

    2016-10-01

    Naturally occurring polyphenols found in food sources provide huge health benefits. Several polyphenolic compounds are implicated in the prevention of disease states, such as cancer. One of the mechanisms by which polyphenols exert their biological actions is by interfering in the protein kinase C (PKC) signaling pathways. PKC belongs to a superfamily of serine-threonine kinase and are primarily involved in phosphorylation of target proteins controlling activation and inhibition of many cellular processes directly or indirectly. Despite the availability of substantial literature data on polyphenols' regulation of PKC, no comprehensive review article is currently available on this subject. This article reviews PKC-polyphenol interactions and its relevance to various disease states. In particular, salient features of polyphenols, PKC, interactions of naturally occurring polyphenols with PKC, and future perspective of research on this subject are discussed. Some polyphenols exert their antioxidant properties by regulating the transcription of the antioxidant enzyme genes through PKC signaling. Regulation of PKC by polyphenols is isoform dependent. The activation or inhibition of PKC by polyphenols has been found to be dependent on the presence of membrane, Ca(2+) ion, cofactors, cell and tissue types etc. Two polyphenols, curcumin and resveratrol are in clinical trials for the treatment of colon cancer. The fact that 74% of the cancer drugs are derived from natural sources, naturally occurring polyphenols or its simple analogs with improved bioavailability may have the potential to be cancer drugs in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Signal flow analysis

    CERN Document Server

    Abrahams, J R; Hiller, N

    1965-01-01

    Signal Flow Analysis provides information pertinent to the fundamental aspects of signal flow analysis. This book discusses the basic theory of signal flow graphs and shows their relation to the usual algebraic equations.Organized into seven chapters, this book begins with an overview of properties of a flow graph. This text then demonstrates how flow graphs can be applied to a wide range of electrical circuits that do not involve amplification. Other chapters deal with the parameters as well as circuit applications of transistors. This book discusses as well the variety of circuits using ther

  6. Detecting Impulses in Mechanical Signals by Wavelets

    Directory of Open Access Journals (Sweden)

    Yang W-X

    2004-01-01

    Full Text Available The presence of periodical or nonperiodical impulses in vibration signals often indicates the occurrence of machine faults. This knowledge is applied to the fault diagnosis of such machines as engines, gearboxes, rolling element bearings, and so on. The development of an effective impulse detection technique is necessary and significant for evaluating the working condition of these machines, diagnosing their malfunctions, and keeping them running normally over prolong periods. With the aid of wavelet transforms, a wavelet-based envelope analysis method is proposed. In order to suppress any undesired information and highlight the features of interest, an improved soft threshold method has been designed so that the inspected signal is analyzed in a more exact way. Furthermore, an impulse detection technique is developed based on the aforementioned methods. The effectiveness of the proposed technique on the extraction of impulsive features of mechanical signals has been proved by both simulated and practical experiments.

  7. Digital signal processing theory and practice

    CERN Document Server

    Rao, K Deergha

    2018-01-01

    The book provides a comprehensive exposition of all major topics in digital signal processing (DSP). With numerous illustrative examples for easy understanding of the topics, it also includes MATLAB-based examples with codes in order to encourage the readers to become more confident of the fundamentals and to gain insights into DSP. Further, it presents real-world signal processing design problems using MATLAB and programmable DSP processors. In addition to problems that require analytical solutions, it discusses problems that require solutions using MATLAB at the end of each chapter. Divided into 13 chapters, it addresses many emerging topics, which are not typically found in advanced texts on DSP. It includes a chapter on adaptive digital filters used in the signal processing problems for faster acceptable results in the presence of changing environments and changing system requirements. Moreover, it offers an overview of wavelets, enabling readers to easily understand the basics and applications of this po...

  8. Purinergic signalling and diabetes

    DEFF Research Database (Denmark)

    Burnstock, Geoffrey; Novak, Ivana

    2013-01-01

    The pancreas is an organ with a central role in nutrient breakdown, nutrient sensing and release of hormones regulating whole body nutrient homeostasis. In diabetes mellitus, the balance is broken-cells can be starving in the midst of plenty. There are indications that the incidence of diabetes...... molecules in purinergic signalling cascades. This signalling takes place at the level of the pancreas, where the close apposition of various cells-endocrine, exocrine, stromal and immune cells-contributes to the integrated function. Following an introduction to diabetes, the pancreas and purinergic...... signalling, we will focus on the role of purinergic signalling and its changes associated with diabetes in the pancreas and selected tissues/organ systems affected by hyperglycaemia and other stress molecules of diabetes. Since this is the first review of this kind, a comprehensive historical angle is taken...

  9. Topological signal processing

    CERN Document Server

    Robinson, Michael

    2014-01-01

    Signal processing is the discipline of extracting information from collections of measurements. To be effective, the measurements must be organized and then filtered, detected, or transformed to expose the desired information.  Distortions caused by uncertainty, noise, and clutter degrade the performance of practical signal processing systems. In aggressively uncertain situations, the full truth about an underlying signal cannot be known.  This book develops the theory and practice of signal processing systems for these situations that extract useful, qualitative information using the mathematics of topology -- the study of spaces under continuous transformations.  Since the collection of continuous transformations is large and varied, tools which are topologically-motivated are automatically insensitive to substantial distortion. The target audience comprises practitioners as well as researchers, but the book may also be beneficial for graduate students.

  10. Transmembrane Signalling: Membrane messengers

    Science.gov (United States)

    Cockroft, Scott L.

    2017-05-01

    Life has evolved elaborate means of communicating essential chemical information across cell membranes. Inspired by biology, two new artificial mechanisms have now been developed that use synthetic messenger molecules to relay chemical signals into or across lipid membranes.

  11. Ultrahigh bandwidth signal processing

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo

    2016-01-01

    Optical time lenses have proven to be very versatile for advanced optical signal processing. Based on a controlled interplay between dispersion and phase-modulation by e.g. four-wave mixing, the processing is phase-preserving, an hence useful for all types of data signals including coherent multi......-level modulation founats. This has enabled processing of phase-modulated spectrally efficient data signals, such as orthogonal frequency division multiplexed (OFDM) signa In that case, a spectral telescope system was used, using two time lenses with different focal lengths (chirp rates), yielding a spectral...... regeneratio These operations require a broad bandwidth nonlinear platform, and novel photonic integrated nonlinear platform like aluminum gallium arsenide nano-waveguides used for 1.28 Tbaud optical signal processing will be described....

  12. Acoustic MIMO signal processing

    CERN Document Server

    Huang, Yiteng; Chen, Jingdong

    2006-01-01

    A timely and important book addressing a variety of acoustic signal processing problems under multiple-input multiple-output (MIMO) scenarios. It uniquely investigates these problems within a unified framework offering a novel and penetrating analysis.

  13. Signals and systems

    CERN Document Server

    Rao, K Deergha

    2018-01-01

    This textbook covers the fundamental theories of signals and systems analysis, while incorporating recent developments from integrated circuits technology into its examples. Starting with basic definitions in signal theory, the text explains the properties of continuous-time and discrete-time systems and their representation by differential equations and state space. From those tools, explanations for the processes of Fourier analysis, the Laplace transform, and the z-Transform provide new ways of experimenting with different kinds of time systems. The text also covers the separate classes of analog filters and their uses in signal processing applications. Intended for undergraduate electrical engineering students, chapter sections include exercise for review and practice for the systems concepts of each chapter. Along with exercises, the text includes MATLAB-based examples to allow readers to experiment with signals and systems code on their own. An online repository of the MATLAB code from this textbook can...

  14. Signal Station Inspection Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Handwritten reports resulting from detailed inspections of US Army Signal Service Stations, 1871-1889. Features reported included instrument exposure and condition,...

  15. Foundations of signal processing

    CERN Document Server

    Vetterli, Martin; Goyal, Vivek K

    2014-01-01

    This comprehensive and engaging textbook introduces the basic principles and techniques of signal processing, from the fundamental ideas of signals and systems theory to real-world applications. Students are introduced to the powerful foundations of modern signal processing, including the basic geometry of Hilbert space, the mathematics of Fourier transforms, and essentials of sampling, interpolation, approximation and compression. The authors discuss real-world issues and hurdles to using these tools, and ways of adapting them to overcome problems of finiteness and localisation, the limitations of uncertainty and computational costs. Standard engineering notation is used throughout, making mathematical examples easy for students to follow, understand and apply. It includes over 150 homework problems and over 180 worked examples, specifically designed to test and expand students' understanding of the fundamentals of signal processing, and is accompanied by extensive online materials designed to aid learning, ...

  16. Traffic Signal Cycle Lengths

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — Traffic signal location list for the town of Chapel Hill. This data set includes light cycle information as well as as intersection information.The Town of Chapel...

  17. Ethereal presences in holography and photography

    Science.gov (United States)

    Richardson, M.; Byrne, Kay

    2007-02-01

    This paper examines the concept of the 'Presence of Absence' in post-mortem photography and holography, drawing upon both historical and lesser-known images as reference. To create a photographic negative one needs the presence of light to expose the light sensitive surface, be it glass, a polished plate or plastic. A hologram may also be created when a coherent light source, for example from a Laser, travels through a light sensitive material and falls upon the subject to be recorded. A holograph however, retains the optical qualities of both phase and amplitude, the memory of light. Both mediums recall, as it were, 'now absent moments', and confronts us with what is 'not there' as much as 'what is'. This paper examines the exploration of absence and presence in post-mortem photography and holography and it's a richly visceral visual language. A photonic syntax can interpret death as an elegant yet horrific aesthetic, the photograph may be beautify screened and yet obscene in its content. In essence one can be a voyeur, experiencing a mere visual whisper of the true nature of the subject. Our Victorian forefathers explored postmortem photography as an object of mourning, and at the close of the nineteenth century when Jack the Ripper had the inhabitants of White Chapel in a grip of fear, photography made its mark as a documentation of violent crime. Today, within contemporary photography, death is now presented within the confines of the 'Art Gallery', as a sensual, and at times, sensationalised art form. In exploring post-mortem imagery, both in holography and conventional photography, absence presents an aspect of death as startling in its unanimated form and detailed in its finite examination of mortality.

  18. Redox signaling in plants.

    Science.gov (United States)

    Foyer, Christine H; Noctor, Graham

    2013-06-01

    Our aim is to deliver an authoritative and challenging perspective of current concepts in plant redox signaling, focusing particularly on the complex interface between the redox and hormone-signaling pathways that allow precise control of plant growth and defense in response to metabolic triggers and environmental constraints and cues. Plants produce significant amounts of singlet oxygen and other reactive oxygen species (ROS) as a result of photosynthetic electron transport and metabolism. Such pathways contribute to the compartment-specific redox-regulated signaling systems in plant cells that convey information to the nucleus to regulate gene expression. Like the chloroplasts and mitochondria, the apoplast-cell wall compartment makes a significant contribution to the redox signaling network, but unlike these organelles, the apoplast has a low antioxidant-buffering capacity. The respective roles of ROS, low-molecular antioxidants, redox-active proteins, and antioxidant enzymes are considered in relation to the functions of plant hormones such as salicylic acid, jasmonic acid, and auxin, in the composite control of plant growth and defense. Regulation of redox gradients between key compartments in plant cells such as those across the plasma membrane facilitates flexible and multiple faceted opportunities for redox signaling that spans the intracellular and extracellular environments. In conclusion, plants are recognized as masters of the art of redox regulation that use oxidants and antioxidants as flexible integrators of signals from metabolism and the environment.

  19. Digital Signal Processing applied to Physical Signals

    CERN Document Server

    Alberto, Diego; Musa, L

    2011-01-01

    It is well known that many of the scientific and technological discoveries of the XXI century will depend on the capability of processing and understanding a huge quantity of data. With the advent of the digital era, a fully digital and automated treatment can be designed and performed. From data mining to data compression, from signal elaboration to noise reduction, a processing is essential to manage and enhance features of interest after every data acquisition (DAQ) session. In the near future, science will go towards interdisciplinary research. In this work there will be given an example of the application of signal processing to different fields of Physics from nuclear particle detectors to biomedical examinations. In Chapter 1 a brief description of the collaborations that allowed this thesis is given, together with a list of the publications co-produced by the author in these three years. The most important notations, definitions and acronyms used in the work are also provided. In Chapter 2, the last r...

  20. Email and Epistolary technologies: Presence, Intimacy, Disembodiment

    Directory of Open Access Journals (Sweden)

    Esther Milne

    2003-01-01

    Full Text Available A key problem for critical media practice is how to assess accurately the technological impact, historical significance and cultural consequences of a particular change in a communications system. Contemporary theorising about the impact of electronic, digitally networked culture is often articulated within an eschatological narrative of apocalypse and last things. The old is cast as naive and redundant while the new appears triumphant, conquering and redemptive. Washing away the sins of the old, the new technology arrives, it seems, out of nowhere. In response to such socio-technological representations, this paper argues that the dialectic between old and new communication systems is more complex than has been assumed by contemporary media theory. Rather than a narrative of radical changes, decisive shifts and abrupt breaks, the relation between epistolary and email technology reveals certain continuities. Specifically, tropes of presence and intimacy are traced through three media sites: a "virtual community" of British nineteenth-century letter writers, the postcard correspondence of an Australian First World War soldier and a twenty first century email discussion list. Mapping these sites reveals a central paradox of technological and discursive cultural practice, namely, that material signifiers can be used to produce incorporeal presence.

  1. Presence in the IP Multimedia Subsystem

    Directory of Open Access Journals (Sweden)

    Ling Lin

    2007-01-01

    Full Text Available With an ever increasing penetration of Internet Protocol (IP technologies, the wireless industry is evolving the mobile core network towards all-IP network. The IP Multimedia Subsystem (IMS is a standardised Next Generation Network (NGN architectural framework defined by the 3rd Generation Partnership Project (3GPP to bridge the gap between circuit-switched and packet-switched networks and consolidate both sides into on single all-IP network for all services. In this paper, we provide an insight into the limitation of the presence service, one of the fundamental building blocks of the IMS. Our prototype-based study is unique of its kind and helps identifying the factors which limit the scalability of the current version of the presence service (3GPP TS 23.141 version 7.2.0 Release 7 [1], which will in turn dramatically limit the performance of advanced IMS services. We argue that the client-server paradigm behind the current IMS architecture does not suite the requirements of the IMS system, which defies the very purpose of its introduction. We finally elaborate on possible avenues for addressing this problem.

  2. Family Presence During Pediatric Tracheal Intubations.

    Science.gov (United States)

    Sanders, Ronald C; Nett, Sholeen T; Davis, Katherine Finn; Parker, Margaret M; Bysani, G Kris; Adu-Darko, Michelle; Bird, Geoffrey L; Cheifetz, Ira M; Derbyshire, Ashley T; Emeriaud, Guillaume; Giuliano, John S; Graciano, Ana Lia; Hagiwara, Yusuke; Hefley, Glenda; Ikeyama, Takanari; Jarvis, J Dean; Kamat, Pradip; Krishna, Ashwin S; Lee, Anthony; Lee, Jan Hau; Li, Simon; Meyer, Keith; Montgomery, Vicki L; Nagai, Yuki; Pinto, Matthew; Rehder, Kyle J; Saito, Osamu; Shenoi, Asha N; Taekema, Hester Christianne; Tarquinio, Keiko M; Thompson, Ann E; Turner, David A; Nadkarni, Vinay M; Nishisaki, Akira

    2016-03-01

    Family-centered care, which supports family presence (FP) during procedures, is now a widely accepted standard at health care facilities that care for children. However, there is a paucity of data regarding the practice of FP during tracheal intubation (TI) in pediatric intensive care units (PICUs). Family presence during procedures in PICUs has been advocated. To describe the current practice of FP during TI and evaluate the association with procedural and clinician (including physician, respiratory therapist, and nurse practitioner) outcomes across multiple PICUs. Prospective cohort study in which all TIs from July 2010 to March 2014 in the multicenter TI database (National Emergency Airway Registry for Children [NEAR4KIDS]) were analyzed. Family presence was defined as a family member present during TI. This study included all TIs in patients younger than 18 years in 22 international PICUs. Family presence and no FP during TI in the PICU. The percentage of FP during TIs. First attempt success rate, adverse TI-associated events, multiple attempts (≥ 3), oxygen desaturation (oxygen saturation as measured by pulse oximetry <80%), and self-reported team stress level. A total of 4969 TI encounters were reported. Among those, 81% (n = 4030) of TIs had documented FP status (with/without). The median age of participants with FP was 2 years and 1 year for those without FP. The average percentage of TIs with FP was 19% and varied widely across sites (0%-43%; P < .001). Tracheal intubations with FP (vs without FP) were associated with older patients (median, 2 years vs 1 year; P = .04), lower Paediatric Index of Mortality 2 score, and pediatric resident as the first airway clinician (23%, n = 179 vs 18%, n = 584; odds ratio [OR], 1.4; 95% CI, 1.2-1.7). Tracheal intubations with FP and without FP were no different in the first attempt success rate (OR, 1.00; 95% CI, 0.85-1.18), adverse TI-associated events (any events: OR, 1.06; 95% CI, 0.85-1.30 and severe events: OR

  3. Exponential signaling gain at the receptor level enhances signal-to-noise ratio in bacterial chemotaxis.

    Directory of Open Access Journals (Sweden)

    Silke Neumann

    Full Text Available Cellular signaling systems show astonishing precision in their response to external stimuli despite strong fluctuations in the molecular components that determine pathway activity. To control the effects of noise on signaling most efficiently, living cells employ compensatory mechanisms that reach from simple negative feedback loops to robustly designed signaling architectures. Here, we report on a novel control mechanism that allows living cells to keep precision in their signaling characteristics - stationary pathway output, response amplitude, and relaxation time - in the presence of strong intracellular perturbations. The concept relies on the surprising fact that for systems showing perfect adaptation an exponential signal amplification at the receptor level suffices to eliminate slowly varying multiplicative noise. To show this mechanism at work in living systems, we quantified the response dynamics of the E. coli chemotaxis network after genetically perturbing the information flux between upstream and downstream signaling components. We give strong evidence that this signaling system results in dynamic invariance of the activated response regulator against multiplicative intracellular noise. We further demonstrate that for environmental conditions, for which precision in chemosensing is crucial, the invariant response behavior results in highest chemotactic efficiency. Our results resolve several puzzling features of the chemotaxis pathway that are widely conserved across prokaryotes but so far could not be attributed any functional role.

  4. Exponential signaling gain at the receptor level enhances signal-to-noise ratio in bacterial chemotaxis.

    Science.gov (United States)

    Neumann, Silke; Løvdok, Linda; Bentele, Kajetan; Meisig, Johannes; Ullner, Ekkehard; Paldy, Ferencz S; Sourjik, Victor; Kollmann, Markus

    2014-01-01

    Cellular signaling systems show astonishing precision in their response to external stimuli despite strong fluctuations in the molecular components that determine pathway activity. To control the effects of noise on signaling most efficiently, living cells employ compensatory mechanisms that reach from simple negative feedback loops to robustly designed signaling architectures. Here, we report on a novel control mechanism that allows living cells to keep precision in their signaling characteristics - stationary pathway output, response amplitude, and relaxation time - in the presence of strong intracellular perturbations. The concept relies on the surprising fact that for systems showing perfect adaptation an exponential signal amplification at the receptor level suffices to eliminate slowly varying multiplicative noise. To show this mechanism at work in living systems, we quantified the response dynamics of the E. coli chemotaxis network after genetically perturbing the information flux between upstream and downstream signaling components. We give strong evidence that this signaling system results in dynamic invariance of the activated response regulator against multiplicative intracellular noise. We further demonstrate that for environmental conditions, for which precision in chemosensing is crucial, the invariant response behavior results in highest chemotactic efficiency. Our results resolve several puzzling features of the chemotaxis pathway that are widely conserved across prokaryotes but so far could not be attributed any functional role.

  5. Correlation of Respiratory Signals and Electrocardiogram Signals via Empirical Mode Decomposition

    KAUST Repository

    El Fiky, Ahmed Osama

    2011-05-24

    Recently Electrocardiogram (ECG) signals are being broadly used as an essential diagnosing tool in different clinical applications as they carry a reliable representation not only for cardiac activities, but also for other associated biological processes, like respiration. However, the process of recording and collecting them has usually suffered from the presence of some undesired noises, which in turn affects the reliability of such representations.Therefore, de-noising ECG signals became a hot research field for signal processing experts to ensure better and clear representation of the different cardiac activities. Given the nonlinear and non-stationary properties of ECGs, it is not a simple task to cancel the undesired noise terms without affecting the biological physics of them. In this study, we are interested in correlating the ECG signals with respiratory parameters, specifically the lung volume and lung pressure. We have focused on the concept of de-noising ECG signals by means of signal decomposition using an algorithm called the Empirical Mode Decomposition (EMD) where the original ECG signals are being decomposed into a set of intrinsic mode functions (IMF). Then, we have provided criteria based on which some of these IMFs have been adapted to reconstruct de-noised ECG version. Finally, we have utilized de-noised ECGs as well as IMFs for to study the correlation with lung volume and lung pressure. These correlation studies have showed some clear resemblance especially between the oscillations of ECGs and lung pressures.

  6. Cellular signalling properties in microcircuits

    DEFF Research Database (Denmark)

    Toledo-Rodriguez, Maria; El Manira, Abdeljabbar; Wallén, Peter

    2005-01-01

    Molecules and cells are the signalling elements in microcircuits. Recent studies have uncovered bewildering diversity in postsynaptic signalling properties in all areas of the vertebrate nervous system. Major effort is now being invested in establishing the specialized signalling properties...

  7. VLSI signal processing technology

    CERN Document Server

    Swartzlander, Earl

    1994-01-01

    This book is the first in a set of forthcoming books focussed on state-of-the-art development in the VLSI Signal Processing area. It is a response to the tremendous research activities taking place in that field. These activities have been driven by two factors: the dramatic increase in demand for high speed signal processing, especially in consumer elec­ tronics, and the evolving microelectronic technologies. The available technology has always been one of the main factors in determining al­ gorithms, architectures, and design strategies to be followed. With every new technology, signal processing systems go through many changes in concepts, design methods, and implementation. The goal of this book is to introduce the reader to the main features of VLSI Signal Processing and the ongoing developments in this area. The focus of this book is on: • Current developments in Digital Signal Processing (DSP) pro­ cessors and architectures - several examples and case studies of existing DSP chips are discussed in...

  8. Presence of anaplastic lymphoma kinase in inflammatory breast cancer.

    Science.gov (United States)

    Robertson, Fredika M; Petricoin Iii, Emanuel F; Van Laere, Steven J; Bertucci, Francois; Chu, Khoi; Fernandez, Sandra V; Mu, Zhaomei; Alpaugh, Katherine; Pei, Jianming; Circo, Rita; Wulfkuhle, Julia; Ye, Zaiming; Boley, Kimberly M; Liu, Hui; Moraes, Ricardo; Zhang, Xuejun; Demaria, Ruggero; Barsky, Sanford H; Sun, Guoxian; Cristofanilli, Massimo

    2013-01-01

    Although Inflammatory Breast Cancer (IBC) is recognized as the most metastatic variant of locally advanced breast cancer, the molecular basis for the distinct clinical presentation and accelerated program of metastasis of IBC is unknown. Reverse phase protein arrays revealed activation of the receptor tyrosine kinase, anaplastic lymphoma kinase (ALK) and biochemically-linked downstream signaling molecules including JAK1/STAT3, AKT, mTor, PDK1, and AMPKβ in pre-clinical models of IBC. To evaluate the clinical relevance of ALK in IBC, analysis of 25 IBC patient tumors using the FDA approved diagnostic test for ALK genetic abnormalities was performed. These studies revealed that 20/25 (80%) had either increased ALK copy number, low level ALK gene amplification, or ALK gene expression, with a prevalence of ALK alterations in basal-like IBC. One of 25 patients was identified as having an EML4-ALK translocation. The generality of gains in ALK copy number in basal-like breast tumors with IBC characteristics was demonstrated by analysis of 479 breast tumors using the TGCA data-base and our newly developed 79 IBC-like gene signature. The small molecule dual tyrosine kinase cMET/ALK inhibitor, Crizotinib (PF-02341066/Xalkori®, Pfizer Inc), induced both cytotoxicity (IC50 = 0.89 μM) and apoptosis, with abrogation of pALK signaling in IBC tumor cells and in FC-IBC01 tumor xenograft model, a new IBC model derived from pleural effusion cells isolated from an ALK(+) IBC patient. Based on these studies, IBC patients are currently being evaluated for the presence of ALK genetic abnormalities and when eligible, are being enrolled into clinical trials evaluating ALK targeted therapeutics.

  9. Optimization of orthogonal adaptive waveform design in presence of compound Gaussian clutter for MIMO radar.

    Science.gov (United States)

    Reddy, B Roja; Uttarakumari, M

    2015-01-01

    In this paper, an adaptive algorithm is proposed to develop an orthogonally optimized waveforms with good correlation properties that are suitable for the detection of target in the presence of strong clutter. The joint optimization both at the transmitter and receiver is adapted based on the secondary data and clutter to maximize signal to interference noise ratio (SINR) with target and clutter knowledge. The result shows good correlation properties and better SINR and signal to clutter ratio (SCR) compared to the existing iterative algorithm. The proposed algorithm also shows improved detection even for lower SCR when implemented with GLRT.

  10. Family Presence During Resuscitation After Trauma.

    Science.gov (United States)

    Leske, Jane S; McAndrew, Natalie S; Brasel, Karen J; Feetham, Suzanne

    The purpose of this study was to examine the effects of family presence during resuscitation (FPDR) in patients who survived trauma from motor vehicle crashes (MVC) and gunshot wounds (GSW). A convenience sample of family members participated within three days of admission to critical care. Family members of 140 trauma patients (MVC n = 110, 79%; GSW n = 30, 21%) participated. Family members ranged in age from 20-84 years (M = 46, SD = 15, Mdn = 47). The majority were female (n = 112, 80%) and related to the patient as spouse (n = 46, 33%). Participating in the FPDR option reduced anxiety (t = -2.43, p =.04), reduced stress (t = -2.86, p = .005), and fostered well-being (t = 3.46, p = .001). Results demonstrate the positive initial effects of FPDR on family members of patients surviving trauma injury.

  11. Corneal autofluorescence in presence of diabetic retinopathy

    Science.gov (United States)

    Rovati, Luigi; Docchio, Franco; Azzolini, Claudio; Van Best, Jaap A.

    1998-06-01

    Recently corneal autofluorescence has been proposed as an ocular diagnostic tool for diabetic retinopathy. The method is based on the sensible increase of the natural fluorescence of corneal tissue within specific wavelength in presence of early stage of diabetic retinopathy. The main advantages of this method are that the corneal autofluorescence has been demonstrated to be not age-related and that the cornea is readily accessible to be investigated. In this study 47 insulin-dependent diabetes mellitus and 51 non-insulin- dependent diabetes mellitus patients aged 20 - 90 years have been considered. Patients were selected from the Eye Clinic of S. Raffaele Hospital. The modified Airlie House classification was used to grade the diabetic retinopathy. Corneal autofluorescence has been measured by using both a specifically designed instrument and the Fluorotron Master. Corneal autofluorescence mean value for each diabetic retinopathy measured by using both the instruments correlated with the retinopathy grade.

  12. Historical aspects of human presence in Space

    Science.gov (United States)

    Harsch, V.

    2007-02-01

    Purpose: This paper presents the development of human presence in Space from its beginnings. Study hypotheses were based on historical findings on scientific, medical, cultural, and political aspects of manned Space flight due to the different attitudes of Space minded nations and organizations. Impacts of aerospace medicine on the advances of biomedical sciences will be touched upon, as well as the historical development of aviation and Space medical achievements which are described briefly and visions for future developments are given. Methods: An overview was gained by literature-study, archives research and oral history taking. Results: Aviation Medicine evolved parallel to Man's ability to fly. War-triggered advancements in aviation brought mankind to the edge of space-equivalent conditions within a few decades of the first motor-flight, which took place in the USA in 1903 [V. Harsch, Aerospace medicine in Germany: from the very beginnings, Aviation and Space Environment Medicine 71 (2000) 447-450 [1

  13. 'Connected presence' in distributed family life

    DEFF Research Database (Denmark)

    Christensen, Toke Haunstrup

    2009-01-01

    ' use of the mobile phone in the context of modern family life, emphasizing the importance of the temporal and spatial dispersion of family members in explaining the form and content of intra-familial mediated communication. Finally, the dual role of media technologies (including the mobile phone......Concurrent with the explosive pervasion of information and communication technologies in recent years, mediated communication has gained a strong position in the daily interaction between family members. Based on the results of qualitative interviews with families in Denmark, this article shows how...... the mobile phone is used by parents and children to mediate a feeling of closeness while they are physically separated. This practice of `connected presence' is based on frequent calls and text messages between parents and children as well as between parents themselves. The article also analyses families...

  14. Transmit selection algorithms for imperfect threshold-based receive MRC in the presence of co-channel interference

    KAUST Repository

    Radaydeh, Redha Mahmoud Mesleh

    2010-01-01

    The performance of transmit antenna selection for threshold-based maximal ratio combining (MRC) diversity receivers in the presence of multiple co-channel interfering signals is studied. The impact of imperfect channel estimation of desired user signals is considered, and the effect of phase and time misalignments between desired and undesired signals is incorporated in the analysis. Precise formulation for Nakagami-m faded interfering signals is presented. The analysis is applicable for arbitrary transmit antenna selection, which is based on the receiver combined signal-to-noise ratios (SNRs) or combined signal-to-interference-plus-noise ratios (SINRs) for different transmit channels. New expressions for the distribution of combined SINR and outage probability performance are derived considering SNR-based as well as SINR-based selection algorithms. The results can be used to study the performance of different system architectures under various channel conditions when the implementation complexity is of interest. ©2010 IEEE.

  15. The contribution of adhesion signaling to lactogenesis.

    Science.gov (United States)

    Morrison, Bethanie; Cutler, Mary Lou

    2010-10-01

    The mammary gland undergoes hormonally controlled cycles of pubertal maturation, pregnancy, lactation, and involution, and these processes rely on complex signaling mechanisms, many of which are controlled by cell-cell and cell-matrix adhesion. The adhesion of epithelial cells to the extracellular matrix initiates signaling mechanisms that have an impact on cell proliferation, survival, and differentiation throughout lactation. The control of integrin expression on the mammary epithelial cells, the composition of the extracellular matrix and the presence of secreted matricellular proteins all contribute to essential adhesion signaling during lactogenesis. In vitro and in vivo studies, including the results from genetically engineered mice, have shed light on the regulation of these processes at the cell and tissue level and have led to increased understanding of the essential signaling components that are regulated in temporal and cell specific manner during lactogenesis. Recent studies suggest that a secreted matricellular protein, CTGF/CCN2, may play a role in lactogenic differentiation through binding to β1 integrin complexes, enhancing the production of extracellular matrix components and contributions to cell adhesion signaling.

  16. Honest signalling with costly gambles.

    Science.gov (United States)

    Meacham, Frazer; Perlmutter, Aaron; Bergstrom, Carl T

    2013-10-06

    Costly signalling theory is commonly invoked as an explanation for how honest communication can be stable when interests conflict. However, the signal costs predicted by costly signalling models often turn out to be unrealistically high. These models generally assume that signal cost is determinate. Here, we consider the case where signal cost is instead stochastic. We examine both discrete and continuous signalling games and show that, under reasonable assumptions, stochasticity in signal costs can decrease the average cost at equilibrium for all individuals. This effect of stochasticity for decreasing signal costs is a fundamental mechanism that probably acts in a wide variety of circumstances.

  17. Quantum signaling game

    International Nuclear Information System (INIS)

    Frackiewicz, Piotr

    2014-01-01

    We present a quantum approach to a signaling game; a special kind of extensive game of incomplete information. Our model is based on quantum schemes for games in strategic form where players perform unitary operators on their own qubits of some fixed initial state and the payoff function is given by a measurement on the resulting final state. We show that the quantum game induced by our scheme coincides with a signaling game as a special case and outputs nonclassical results in general. As an example, we consider a quantum extension of the signaling game in which the chance move is a three-parameter unitary operator whereas the players' actions are equivalent to classical ones. In this case, we study the game in terms of Nash equilibria and refine the pure Nash equilibria adapting to the quantum game the notion of a weak perfect Bayesian equilibrium. (paper)

  18. Signal integrity characterization techniques

    CERN Document Server

    Bogatin, Eric

    2009-01-01

    "Signal Integrity Characterization Techniques" addresses the gap between traditional digital and microwave curricula all while focusing on a practical and intuitive understanding of signal integrity effects within the data transmission channel. High-speed interconnects such as connectors, PCBs, cables, IC packages, and backplanes are critical elements of differential channels that must be designed using today's most powerful analysis and characterization tools.Both measurements and simulation must be done on the device under test, and both activities must yield data that correlates with each other. Most of this book focuses on real-world applications of signal integrity measurements - from backplane for design challenges to error correction techniques to jitter measurement technologies. The authors' approach wisely addresses some of these new high-speed technologies, and it also provides valuable insight into its future direction and will teach the reader valuable lessons on the industry.

  19. PKD signaling and pancreatitis

    Science.gov (United States)

    Yuan, Jingzhen; Pandol, Stephen J.

    2016-01-01

    Background Acute pancreatitis is a serious medical disorder with no current therapies directed to the molecular pathogenesis of the disorder. Inflammation, inappropriate intracellular activation of digestive enzymes, and parenchymal acinar cell death by necrosis are the critical pathophysiologic processes of acute pancreatitis. Thus, it is necessary to elucidate the key molecular signals that mediate these pathobiologic processes and develop new therapeutic strategies to attenuate the appropriate signaling pathways in order to improve outcomes for this disease. A novel serine/threonine protein kinase D (PKD) family has emerged as key participants in signal transduction, and this family is increasingly being implicated in the regulation of multiple cellular functions and diseases. Methods This review summarizes recent findings of our group and others regarding the signaling pathway and the biological roles of the PKD family in pancreatic acinar cells. In particular, we highlight our studies of the functions of PKD in several key pathobiologic processes associated with acute pancreatitis in experimental models. Results Our findings reveal that PKD signaling is required for NF-κB activation/inflammation, intracellular zymogen activation, and acinar cell necrosis in rodent experimental pancreatitis. Novel small-molecule PKD inhibitors attenuate the severity of pancreatitis in both in vitro and in vivo experimental models. Further, this review emphasizes our latest advances in the therapeutic application of PKD inhibitors to experimental pancreatitis after the initiation of pancreatitis. Conclusions These novel findings suggest that PKD signaling is a necessary modulator in key initiating pathobiologic processes of pancreatitis, and that it constitutes a novel therapeutic target for treatments of this disorder. PMID:26879861

  20. Electronic signal conditioning

    CERN Document Server

    NEWBY, BRUCE

    1994-01-01

    At technician level, brief references to signal conditioning crop up in a fragmented way in various textbooks, but there has been no single textbook, until now!More advanced texts do exist but they are more mathematical and presuppose a higher level of understanding of electronics and statistics. Electronic Signal Conditioning is designed for HNC/D students and City & Guilds Electronics Servicing 2240 Parts 2 & 3. It will also be useful for BTEC National, Advanced GNVQ, A-level electronics and introductory courses at degree level.

  1. Purinergic Signalling: Therapeutic Developments

    OpenAIRE

    Burnstock, Geoffrey

    2017-01-01

    Purinergic signalling, i.e., the role of nucleotides as extracellular signalling molecules, was proposed in 1972. However, this concept was not well accepted until the early 1990’s when receptor subtypes for purines and pyrimidines were cloned and characterised, which includes four subtypes of the P1 (adenosine) receptor, seven subtypes of P2X ion channel receptors and 8 subtypes of the P2Y G protein-coupled receptor. Early studies were largely concerned with the physiology, pharmacology and ...

  2. Genomic signal processing

    CERN Document Server

    Shmulevich, Ilya

    2007-01-01

    Genomic signal processing (GSP) can be defined as the analysis, processing, and use of genomic signals to gain biological knowledge, and the translation of that knowledge into systems-based applications that can be used to diagnose and treat genetic diseases. Situated at the crossroads of engineering, biology, mathematics, statistics, and computer science, GSP requires the development of both nonlinear dynamical models that adequately represent genomic regulation, and diagnostic and therapeutic tools based on these models. This book facilitates these developments by providing rigorous mathema

  3. TOR signalling in plants.

    Science.gov (United States)

    Rexin, Daniel; Meyer, Christian; Robaglia, Christophe; Veit, Bruce

    2015-08-15

    Although the eukaryotic TOR (target of rapamycin) kinase signalling pathway has emerged as a key player for integrating nutrient-, energy- and stress-related cues with growth and metabolic outputs, relatively little is known of how this ancient regulatory mechanism has been adapted in higher plants. Drawing comparisons with the substantial knowledge base around TOR kinase signalling in fungal and animal systems, functional aspects of this pathway in plants are reviewed. Both conserved and divergent elements are discussed in relation to unique aspects associated with an autotrophic mode of nutrition and adaptive strategies for multicellular development exhibited by plants. © 2015 Authors; published by Portland Press Limited.

  4. Tuning positive feedback for signal detection in noisy dynamic environments.

    Science.gov (United States)

    Johansson, Anders; Ramsch, Kai; Middendorf, Martin; Sumpter, David J T

    2012-09-21

    Learning from previous actions is a key feature of decision-making. Diverse biological systems, from neuronal assemblies to insect societies, use a combination of positive feedback and forgetting of stored memories to process and respond to input signals. Here we look how these systems deal with a dynamic two-armed bandit problem of detecting a very weak signal in the presence of a high degree of noise. We show that by tuning the form of positive feedback and the decay rate to appropriate values, a single tracking variable can effectively detect dynamic inputs even in the presence of a large degree of noise. In particular, we show that when tuned appropriately a simple positive feedback algorithm is Fisher efficient, in that it can track changes in a signal on a time of order L(h)=(|h|/σ)(-2), where |h| is the magnitude of the signal and σ the magnitude of the noise. Copyright © 2012. Published by Elsevier Ltd.

  5. Signaling and Accounting Information

    OpenAIRE

    Stewart C. Myers

    1989-01-01

    This paper develops a signaling model in which accounting information improves real investment decisions. Pure cash flow reporting is shown to lead to underinvestment when managers have superior information but are acting in shareholders' interests. Accounting by prespecified, "objective" rules alleviates the underinvestment problem.

  6. Analog signal isolation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Beadle, E.R.

    1992-12-31

    This paper discusses several techniques for isolating analog signals in an accelerator environment. The techniques presented here encompass isolation amplifiers, voltage-to-frequency converters (VIFCs), transformers, optocouplers, discrete fiber optics, and commercial fiber optic links. Included within the presentation of each method are the design issues that must be considered when selecting the isolation method for a specific application.

  7. Analog signal isolation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Beadle, E.R.

    1992-01-01

    This paper discusses several techniques for isolating analog signals in an accelerator environment. The techniques presented here encompass isolation amplifiers, voltage-to-frequency converters (VIFCs), transformers, optocouplers, discrete fiber optics, and commercial fiber optic links. Included within the presentation of each method are the design issues that must be considered when selecting the isolation method for a specific application.

  8. Calcium signaling in neurodegeneration

    Directory of Open Access Journals (Sweden)

    Dreses-Werringloer Ute

    2009-05-01

    Full Text Available Abstract Calcium is a key signaling ion involved in many different intracellular and extracellular processes ranging from synaptic activity to cell-cell communication and adhesion. The exact definition at the molecular level of the versatility of this ion has made overwhelming progress in the past several years and has been extensively reviewed. In the brain, calcium is fundamental in the control of synaptic activity and memory formation, a process that leads to the activation of specific calcium-dependent signal transduction pathways and implicates key protein effectors, such as CaMKs, MAPK/ERKs, and CREB. Properly controlled homeostasis of calcium signaling not only supports normal brain physiology but also maintains neuronal integrity and long-term cell survival. Emerging knowledge indicates that calcium homeostasis is not only critical for cell physiology and health, but also, when deregulated, can lead to neurodegeneration via complex and diverse mechanisms involved in selective neuronal impairments and death. The identification of several modulators of calcium homeostasis, such as presenilins and CALHM1, as potential factors involved in the pathogenesis of Alzheimer's disease, provides strong support for a role of calcium in neurodegeneration. These observations represent an important step towards understanding the molecular mechanisms of calcium signaling disturbances observed in different brain diseases such as Alzheimer's, Parkinson's, and Huntington's diseases.

  9. Quantum cloning and signaling

    International Nuclear Information System (INIS)

    Simon, C.; Weihs, G.; Zeilinger, A.

    1999-01-01

    We discuss the close connections between cloning of quantum states and superluminal signaling. We present an optimal universal cloning machine based on stimulated emission recently proposed by the authors. As an instructive example, we show how a scheme for superluminal communication based on this cloning machine fails. (Authors)

  10. Intersection auxiliary signal system

    Science.gov (United States)

    Zhang, Jian

    1995-12-01

    Many intersection accidents are related to drivers' inappropriate responses to an amber signal light, due to their misjudgment on the traffic situation and/or their aggressive behavior. To reduce intersection accidents of this nature, this paper proposes the Intersection Auxiliary Signal System (IAS). IAS can be installed at selected intersections, where information regarding signal phasing, intersection geometry and speed limit is transmitted from an ultrasonic/infra-red transmitter. An on-vehicle device receivers and processes the information, the provides the driver with explicit suggestions on the correct action to take (continue to pass or decelerate to stop), or warnings against on-going incorrect actions. IAS is expected to be more effective in suburban intersections, which are usually characterized by greater dimension, longer amber phases, and higher vehicle speeds. Both the intersection transmitters and the on-vehicle processors are expected to have simple structures and low costs. Simulation results show that IAS has a significant effect on reducing red signal violation, especially when there is no significant dilemma zones.

  11. Signalling control strength.

    Science.gov (United States)

    Westerhoff, Hans V

    2008-06-07

    Metabolic control analysis (MCA) has become what it is, largely because the special organization of living cells led to rather specific questions. These questions focused on the role of enzymes, genes, and, in subsequent generalizations, on well-defined process activities. With an emphasis on the work by Heinrich and co-workers, the theory behind MCA is summarized in a way that leads naturally to its extensions to hierarchical systems, such as gene expression and signal transduction, and to control beyond the steady state. The analysis of the control properties of signal transduction cascades is reviewed with an emphasis on the relative importance of the protein kinases and the protein phosphatases. The two types of enzyme are both important for the amplitude of signal transduction, whereas phosphatases may be more important for the later phases of signal transduction and for its duration. Novel MCA of concentrations and fluxes that vary with time is explicated. It is concluded that the clarity and operationality of concepts such as control strength (now control coefficient) plus the clear theoretical frameworks provided by Heinrich and colleagues, should enable us greatly to reduce the Babylonian confusion that could otherwise occur in the data deluges of Systems Biology.

  12. Non-linear dimensionality reduction of signaling networks

    OpenAIRE

    Ivakhno, Sergii; Armstrong, J Douglas

    2007-01-01

    Abstract Background Systems wide modeling and analysis of signaling networks is essential for understanding complex cellular behaviors, such as the biphasic responses to different combinations of cytokines and growth factors. For example, tumor necrosis factor (TNF) can act as a proapoptotic or prosurvival factor depending on its concentration, the current state of signaling network and the presence of other cytokines. To understand combinatorial regulation in such systems, new computational ...

  13. Spacetime thermodynamics in the presence of torsion

    Science.gov (United States)

    Dey, Ramit; Liberati, Stefano; Pranzetti, Daniele

    2017-12-01

    It was shown by Jacobson in 1995 that the Einstein equation can be derived as a local constitutive equation for an equilibrium spacetime thermodynamics. With the aim to understand if such thermodynamical description is an intrinsic property of gravitation, many attempts have been made so far to generalize this treatment to a broader class of gravitational theories. Here we consider the case of the Einstein-Cartan theory as a prototype of theories with nonpropagating torsion. In doing so, we study the properties of Killing horizons in the presence of torsion, establish the notion of local causal horizon in Riemann-Cartan spacetimes, and derive the generalized Raychaudhuri equation for these kinds of geometries. Then, starting with the entropy that can be associated to these local causal horizons, we derive the Einstein-Cartan equation by implementing the Clausius equation. We outline two ways of proceeding with the derivation depending on whether we take torsion as a geometric field or as a matter field. In both cases we need to add internal entropy production terms to the Clausius equation as the shear and twist cannot be taken to be 0 a priori for our setup. This fact implies the necessity of a nonequilibrium thermodynamics treatment for the local causal horizon. Furthermore, it implies that a nonzero twist at the horizon in general contributes to the Hartle-Hawking tidal heating for black holes with possible implications for future observations.

  14. Holographic space: presence and absence in time

    Science.gov (United States)

    Chang, Yin-Ren; Richardson, Martin

    2017-03-01

    In terms of contemporary art, time-based media generally refers to artworks that have duration as a dimension and unfold to the viewer over time, that could be a video, slide, film, computer-based technologies or audio. As part of this category, holography pushes this visual-oriented narrative a step further, which brings a real 3D image to invite and allow audiences revisiting the scene of the past, at the moment of recording in space and time. Audiences could also experience the kinetic holographic aesthetics through constantly moving the viewing point or illumination source, which creates dynamic visual effects. In other words, when the audience and hologram remain still, the holographic image can only be perceived statically. This unique form of expression is not created by virtual simulation; the principal of wavefront reconstruction process made holographic art exceptional from other time-based media. This project integrates 3D printing technology to explore the nature of material aesthetics, transiting between material world and holographic space. In addition, this series of creation also reveals the unique temporal quality of a hologram's presence and absence, an ambiguous relationship existing in this media.

  15. The Presence of Backpacking Tourism in Europe

    Directory of Open Access Journals (Sweden)

    Vukica Majstorović

    2013-10-01

    Full Text Available Global tourism is characterized by constant change. New forms of tourism and various types of tourist movements are emerging, while the number of tourists is constantly increasing and now it surpasses one billion. What considerably contributes to the increase in tourist traffic is low-budget travel. Backpacking is such form of travel. It is mostly present among young population that wants to travel in order to experience authentic adventures and learn about the local culture, far from typical tourist paths. Backpackers aim to see as much as possible for small amounts of money. The process of globalization has contributed to the fact that the phenomenon of backpacking is present all around the globe. In order to determine the presence of backpacking in Europe and some important characteristics of this type of travel there has been conducted a survey via the Internet. The results showed that young Europeans are informed of this way of tourist movements and they make the majority of the participants in backpacking tourism. In the years to come the number of people in the world involved in these types of journeys will grow, which will lead to the need for a more detailed analysis of backpacking worldwide.

  16. Quality Assurance in the Presence of Variability

    Science.gov (United States)

    Lauenroth, Kim; Metzger, Andreas; Pohl, Klaus

    Software Product Line Engineering (SPLE) is a reuse-driven development paradigm that has been applied successfully in information system engineering and other domains. Quality assurance of the reusable artifacts of the product line (e.g. requirements, design, and code artifacts) is essential for successful product line engineering. As those artifacts are reused in several products, a defect in a reusable artifact can affect several products of the product line. A central challenge for quality assurance in product line engineering is how to consider product line variability. Since the reusable artifacts contain variability, quality assurance techniques from single-system engineering cannot directly be applied to those artifacts. Therefore, different strategies and techniques have been developed for quality assurance in the presence of variability. In this chapter, we describe those strategies and discuss in more detail one of those strategies, the so called comprehensive strategy. The comprehensive strategy aims at checking the quality of all possible products of the product line and thus offers the highest benefits, since it is able to uncover defects in all possible products of the product line. However, the central challenge for applying the comprehensive strategy is the complexity that results from the product line variability and the large number of potential products of a product line. In this chapter, we present one concrete technique that we have developed to implement the comprehensive strategy that addresses this challenge. The technique is based on model checking technology and allows for a comprehensive verification of domain artifacts against temporal logic properties.

  17. Annual modulation of dark matter in the presence of streams

    International Nuclear Information System (INIS)

    Savage, Chris; Freese, Katherine; Gondolo, Paolo

    2006-01-01

    In addition to a smooth component of weakly interacting massive particle (WIMP) dark matter in galaxies, there may be streams of material; the effects of WIMP streams on direct detection experiments is examined in this paper. The contribution to the count rate due to the stream cuts off at some characteristic energy. Near this cutoff energy, the stream contribution to the annual modulation of recoils in the detector is comparable to that of the thermalized halo, even if the stream represents only a small portion (∼5% or less) of the local halo density. Consequently the total modulation may be quite different than would be expected for the standard halo model alone: it may not be cosinelike and can peak at a different date than expected. The effects of speed, direction, density, and velocity dispersion of a stream on the modulation are examined. We describe how the observation of a modulation can be used to determine these stream parameters. Alternatively, the presence of a dropoff in the recoil spectrum can be used to determine the WIMP mass if the stream speed is known. The annual modulation of the cutoff energy together with the annual modulation of the overall signal provide a 'smoking gun' for WIMP detection

  18. Multimodal signalling in estrildid finches

    DEFF Research Database (Denmark)

    Gomes, A. C. R.; Funghi, C.; Soma, M.

    2017-01-01

    Sexual traits (e.g. visual ornaments, acoustic signals, courtship behaviour) are often displayed together as multimodal signals. Some hypotheses predict joint evolution of different sexual signals (e.g. to increase the efficiency of communication) or that different signals trade off with each oth...

  19. Sinusoidal Representation of Acoustic Signals

    Science.gov (United States)

    Honda, Masaaki

    Sinusoidal representation of acoustic signals has been an important tool in speech and music processing like signal analysis, synthesis and time scale or pitch modifications. It can be applicable to arbitrary signals, which is an important advantage over other signal representations like physical modeling of acoustic signals. In sinusoidal representation, acoustic signals are composed as sums of sinusoid (sine wave) with different amplitudes, frequencies and phases, which is based on the timedependent short-time Fourier transform (STFT). This article describes the principles of acoustic signal analysis/synthesis based on a sinusoid representation with focus on sine waves with rapidly varying frequency.

  20. The newest digital signal processing

    International Nuclear Information System (INIS)

    Lee, Chae Uk

    2002-08-01

    This book deal with the newest digital signal processing, which contains introduction on conception of digital signal processing, constitution and purpose, signal and system such as signal, continuos signal, discrete signal and discrete system, I/O expression on impress response, convolution, mutual connection of system and frequency character,z transform of definition, range, application of z transform and relationship with laplace transform, Discrete fourier, Fast fourier transform on IDFT algorithm and FFT application, foundation of digital filter of notion, expression, types, frequency characteristic of digital filter and design order of filter, Design order of filter, Design of FIR digital filter, Design of IIR digital filter, Adaptive signal processing, Audio signal processing, video signal processing and application of digital signal processing.

  1. Presence of metabolic syndrome in football linemen.

    Science.gov (United States)

    Buell, Jackie L; Calland, Doug; Hanks, Fiona; Johnston, Bruce; Pester, Benjamin; Sweeney, Robert; Thorne, Robert

    2008-01-01

    Metabolic syndrome is a clustering of symptoms associated with abdominal obesity that demonstrates a high risk for cardiovascular disease and type II diabetes mellitus. To evaluate football linemen in National Collegiate Athletic Association Divisions I, II, and III schools for the presence of metabolic syndrome according to the American Heart Association/National Heart, Lung, and Blood Institute criteria as well as to document other related biomarkers. Cross-sectional descriptive study. Three university locations on the first full day of football camp in early morning. Of 76 football linemen, 70 were able to provide blood samples. Height, mass, blood pressure, upper-body skinfolds, and waist circumference were measured at various stations. Two small venous samples of blood were collected and analyzed in a hospital laboratory for fasting insulin, glucose, high-density lipoprotein, total cholesterol, triglycerides, C-reactive protein, and glycosylated hemoglobin. The last station was a verbal family history for cardiovascular disease and diabetes; also, athletes filled out a nutrition attitudes questionnaire. Of the 70 athletes, 34 were identified as having metabolic syndrome according to measures of blood pressure, waist circumference, fasting glucose, high-density lipoprotein, and triglycerides. The mean total cholesterol-to-high-density lipoprotein cholesterol ratio for the group was 4.95, with 32 participants displaying values higher than 5.0. Twelve volunteers had total cholesterol levels greater than 200 mmol/L, 15 had high levels of C-reactive protein, and 9 had slightly elevated levels of glycosylated hemoglobin. Although athletes might be assumed to be protected from risks of cardiovascular disease, we found a high incidence of metabolic syndrome and other associated adverse biomarkers for heart disease in collegiate football linemen. Early screening, awareness, and intervention may have favorable effects on the overall health outcomes of football linemen.

  2. Uplink Array Calibration via Power Spectra in the Presence of Phase and Delay Errors

    Science.gov (United States)

    Vilnrotter, V. A.

    2017-08-01

    In uplink array operations, alignment of the carrier phase and modulation delay from each antenna is of fundamental importance in achieving maximum array gain. The power spectrum of the combined signal can be obtained at the spacecraft and relayed to the ground for processing, or in near-Earth radar applications the echo signals from small targets can be collected and processed at the ground receiver. Expressions are derived for the power spectrum of a transmitting array of K elements in the presence of phase and delay alignment errors, and simulation results are provided to validate the theoretical results. It is shown that the power spectra are generally sensitive to errors in carrier and modulation alignment, thus enabling uplink array calibration directly from the power spectrum of the combined array signal.

  3. Variable reflectivity signal mirrors and signal response measurements

    International Nuclear Information System (INIS)

    Vine, Glenn de; Shaddock, Daniel A; McClelland, David E

    2002-01-01

    Future gravitational wave detectors will include some form of signal mirror in order to alter the signal response of the device. We introduce interferometer configurations which utilize a variable reflectivity signal mirror allowing a tunable peak frequency and variable signal bandwidth. A detector configured with a Fabry-Perot cavity as the signal mirror is compared theoretically with one using a Michelson interferometer for a signal mirror. A system for the measurement of the interferometer signal responses is introduced. This technique is applied to a power-recycled Michelson interferometer with resonant sideband extraction. We present broadband measurements of the benchtop prototype's signal response for a range of signal cavity detunings. This technique is also applicable to most other gravitational wave detector configurations

  4. Variable reflectivity signal mirrors and signal response measurements

    CERN Document Server

    Vine, G D; McClelland, D E

    2002-01-01

    Future gravitational wave detectors will include some form of signal mirror in order to alter the signal response of the device. We introduce interferometer configurations which utilize a variable reflectivity signal mirror allowing a tunable peak frequency and variable signal bandwidth. A detector configured with a Fabry-Perot cavity as the signal mirror is compared theoretically with one using a Michelson interferometer for a signal mirror. A system for the measurement of the interferometer signal responses is introduced. This technique is applied to a power-recycled Michelson interferometer with resonant sideband extraction. We present broadband measurements of the benchtop prototype's signal response for a range of signal cavity detunings. This technique is also applicable to most other gravitational wave detector configurations.

  5. A novel acoustic catheter stethoscope based acquisition and signal processing framework to extract multiple bio signals.

    Science.gov (United States)

    Adithya, Prashanth Chetlur; Sankar, Ravi; Moreno, Wilfrido A; Hart, Stuart

    2017-07-01

    In this study, a novel acoustic stethoscope based on an intravenous catheter was introduced to measure vascular pressures from a Yorkshire pig. Our hypothesis is that by means of this single device (measurement system) and by applying signal analysis and processing framework, multiple vital bio signals can be extracted. In contrast, current conventional state-of-the-art technologies use multiple devices to provide the same information. The framework used to extract these bio signals consisted of a noise cancellation technique and wavelet based source separation. The preliminary results obtained from the acquired pressure data revealed the presence of acoustic heart and respiratory pulses. Finally, the computed heart and respiratory rates were benchmarked with actual values measured using conventional devices to validate our hypothesis.

  6. Costs and constraints conspire to produce honest signaling

    DEFF Research Database (Denmark)

    Holman, Luke

    2012-01-01

    Signal costs and evolutionary constraints have both been proposed as ultimate explanations for the ubiquity of honest signaling, but the interface between these two factors is unclear. Here, I propose a pluralistic interpretation, and use game theory to demonstrate that evolutionary constraints...... that endocrine-mediated trade-offs preclude dishonesty. Several lines of evidence suggest that the realized cost of pheromone production may be nontrivial, and the antagonistic effects of juvenile hormone indicate the presence of significant evolutionary constraints. I conclude that the honesty of queen...... pheromones and other signals is likely enforced by both the cost of dishonesty and a suite of evolutionary constraints....

  7. Model-based Bayesian signal extraction algorithm for peripheral nerves

    Science.gov (United States)

    Eggers, Thomas E.; Dweiri, Yazan M.; McCallum, Grant A.; Durand, Dominique M.

    2017-10-01

    Objective. Multi-channel cuff electrodes have recently been investigated for extracting fascicular-level motor commands from mixed neural recordings. Such signals could provide volitional, intuitive control over a robotic prosthesis for amputee patients. Recent work has demonstrated success in extracting these signals in acute and chronic preparations using spatial filtering techniques. These extracted signals, however, had low signal-to-noise ratios and thus limited their utility to binary classification. In this work a new algorithm is proposed which combines previous source localization approaches to create a model based method which operates in real time. Approach. To validate this algorithm, a saline benchtop setup was created to allow the precise placement of artificial sources within a cuff and interference sources outside the cuff. The artificial source was taken from five seconds of chronic neural activity to replicate realistic recordings. The proposed algorithm, hybrid Bayesian signal extraction (HBSE), is then compared to previous algorithms, beamforming and a Bayesian spatial filtering method, on this test data. An example chronic neural recording is also analyzed with all three algorithms. Main results. The proposed algorithm improved the signal to noise and signal to interference ratio of extracted test signals two to three fold, as well as increased the correlation coefficient between the original and recovered signals by 10–20%. These improvements translated to the chronic recording example and increased the calculated bit rate between the recovered signals and the recorded motor activity. Significance. HBSE significantly outperforms previous algorithms in extracting realistic neural signals, even in the presence of external noise sources. These results demonstrate the feasibility of extracting dynamic motor signals from a multi-fascicled intact nerve trunk, which in turn could extract motor command signals from an amputee for the end goal of

  8. Biomedical signal analysis

    CERN Document Server

    Rangayyan, Rangaraj M

    2015-01-01

    The book will help assist a reader in the development of techniques for analysis of biomedical signals and computer aided diagnoses with a pedagogical examination of basic and advanced topics accompanied by over 350 figures and illustrations. Wide range of filtering techniques presented to address various applications. 800 mathematical expressions and equations. Practical questions, problems and laboratory exercises. Includes fractals and chaos theory with biomedical applications.

  9. A Low-Cost Tele-Presence Wheelchair System

    OpenAIRE

    Shen, Jiajun; Xu, Bin; Pei, Mingtao; Jia, Yunde

    2016-01-01

    This paper presents the architecture and implementation of a tele-presence wheelchair system based on tele-presence robot, intelligent wheelchair, and touch screen technologies. The tele-presence wheelchair system consists of a commercial electric wheelchair, an add-on tele-presence interaction module, and a touchable live video image based user interface (called TIUI). The tele-presence interaction module is used to provide video-chatting for an elderly or disabled person with the family mem...

  10. Plant peptide hormone signalling.

    Science.gov (United States)

    Motomitsu, Ayane; Sawa, Shinichiro; Ishida, Takashi

    2015-01-01

    The ligand-receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone-receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions. © 2015 Authors; published by Portland Press Limited.

  11. Signal analysis approach to ultrasonic evaluation of diffusion bond quality

    International Nuclear Information System (INIS)

    Thomas, Graham; Chinn, Diane

    1999-01-01

    Solid state bonds like the diffusion bond are attractive techniques for joining dissimilar materials since they are not prone to the defects that occur with fusion welding. Ultrasonic methods can detect the presence of totally unbonded regions but have difficulty sensing poor bonded areas where the substrates are in intimate contact. Standard ultrasonic imaging is based on amplitude changes in the signal reflected from the bond interface. Unfortunately, amplitude alone is not sensitive to bond quality. We demonstrated that there is additional information in the ultrasonic signal that correlates with bond quality. In our approach, we interrogated a set of dissimilar diffusion bonded samples with broad band ultrasonic signals. The signals were digitally processed and the characteristics of the signals that corresponded to bond quality were determined. These characteristics or features were processed with pattern recognition algorithms to produce predictions of bond quality. The predicted bond quality was then compared with the destructive measurement to assess the classification capability of the ultrasonic technique

  12. Artificial neural networks for classifying olfactory signals.

    Science.gov (United States)

    Linder, R; Pöppl, S J

    2000-01-01

    For practical applications, artificial neural networks have to meet several requirements: Mainly they should learn quick, classify accurate and behave robust. Programs should be user-friendly and should not need the presence of an expert for fine tuning diverse learning parameters. The present paper demonstrates an approach using an oversized network topology, adaptive propagation (APROP), a modified error function, and averaging outputs of four networks described for the first time. As an example, signals from different semiconductor gas sensors of an electronic nose were classified. The electronic nose smelt different types of edible oil with extremely different a-priori-probabilities. The fully-specified neural network classifier fulfilled the above mentioned demands. The new approach will be helpful not only for classifying olfactory signals automatically but also in many other fields in medicine, e.g. in data mining from medical databases.

  13. A Team of Instructors' Use of Social Presence, Teaching Presence, and Attitudinal Dissonance Strategies: An Animal Behaviour and Welfare MOOC

    Science.gov (United States)

    Watson, Sunnie Lee; Watson, William R.; Janakiraman, Shamila; Richardson, Jennifer

    2017-01-01

    This case study examined a team of instructors' use of social presence, teaching presence, and attitudinal dissonance in a Massive Online Open Course (MOOC) on Animal Behaviour and Welfare (ABW), designed to facilitate attitudinal learning. The study reviewed a team of six instructors' use of social presence and teaching presence by applying the…

  14. Analysis of Rhythms in Experimental Signals

    Science.gov (United States)

    Desherevskii, A. V.; Zhuravlev, V. I.; Nikolsky, A. N.; Sidorin, A. Ya.

    2017-12-01

    We compare algorithms designed to extract quasiperiodic components of a signal and estimate the amplitude, phase, stability, and other characteristics of a rhythm in a sliding window in the presence of data gaps. Each algorithm relies on its own rhythm model; therefore, it is necessary to use different algorithms depending on the research objectives. The described set of algorithms and methods is implemented in the WinABD software package, which includes a time-series database management system, a powerful research complex, and an interactive data-visualization environment.

  15. Biomedical signal and image processing

    CERN Document Server

    Najarian, Kayvan

    2012-01-01

    INTRODUCTION TO DIGITAL SIGNAL AND IMAGE PROCESSINGSignals and Biomedical Signal ProcessingIntroduction and OverviewWhat is a ""Signal""?Analog, Discrete, and Digital SignalsProcessing and Transformation of SignalsSignal Processing for Feature ExtractionSome Characteristics of Digital ImagesSummaryProblemsFourier TransformIntroduction and OverviewOne-Dimensional Continuous Fourier TransformSampling and NYQUIST RateOne-Dimensional Discrete Fourier TransformTwo-Dimensional Discrete Fourier TransformFilter DesignSummaryProblemsImage Filtering, Enhancement, and RestorationIntroduction and Overview

  16. The signaling helix: a common functional theme in diverse signaling proteins

    Directory of Open Access Journals (Sweden)

    Aravind L

    2006-09-01

    Full Text Available Abstract Background The mechanism by which the signals are transmitted between receptor and effector domains in multi-domain signaling proteins is poorly understood. Results Using sensitive sequence analysis methods we identify a conserved helical segment of around 40 residues in a wide range of signaling proteins, including numerous sensor histidine kinases such as Sln1p, and receptor guanylyl cyclases such as the atrial natriuretic peptide receptor and nitric oxide receptors. We term this helical segment the signaling (S-helix and present evidence that it forms a novel parallel coiled-coil element, distinct from previously known helical segments in signaling proteins, such as the Dimerization-Histidine phosphotransfer module of histidine kinases, the intra-cellular domains of the chemotaxis receptors, inter-GAF domain helical linkers and the α-helical HAMP module. Analysis of domain architectures allowed us to reconstruct the domain-neighborhood graph for the S-helix, which showed that the S-helix almost always occurs between two signaling domains. Several striking patterns in the domain neighborhood of the S-helix also became evident from the graph. It most often separates diverse N-terminal sensory domains from various C-terminal catalytic signaling domains such as histidine kinases, cNMP cyclase, PP2C phosphatases, NtrC-like AAA+ ATPases and diguanylate cyclases. It might also occur between two sensory domains such as PAS domains and occasionally between a DNA-binding HTH domain and a sensory domain. The sequence conservation pattern of the S-helix revealed the presence of a unique constellation of polar residues in the dimer-interface positions within the central heptad of the coiled-coil formed by the S-helix. Conclusion Combining these observations with previously reported mutagenesis studies on different S-helix-containing proteins we suggest that it functions as a switch that prevents constitutive activation of linked downstream

  17. Purinergic Signalling: Therapeutic Developments.

    Science.gov (United States)

    Burnstock, Geoffrey

    2017-01-01

    Purinergic signalling, i.e., the role of nucleotides as extracellular signalling molecules, was proposed in 1972. However, this concept was not well accepted until the early 1990's when receptor subtypes for purines and pyrimidines were cloned and characterised, which includes four subtypes of the P1 (adenosine) receptor, seven subtypes of P2X ion channel receptors and 8 subtypes of the P2Y G protein-coupled receptor. Early studies were largely concerned with the physiology, pharmacology and biochemistry of purinergic signalling. More recently, the focus has been on the pathophysiology and therapeutic potential. There was early recognition of the use of P1 receptor agonists for the treatment of supraventricular tachycardia and A 2A receptor antagonists are promising for the treatment of Parkinson's disease. Clopidogrel, a P2Y 12 antagonist, is widely used for the treatment of thrombosis and stroke, blocking P2Y 12 receptor-mediated platelet aggregation. Diquafosol, a long acting P2Y 2 receptor agonist, is being used for the treatment of dry eye. P2X3 receptor antagonists have been developed that are orally bioavailable and stable in vivo and are currently in clinical trials for the treatment of chronic cough, bladder incontinence, visceral pain and hypertension. Antagonists to P2X7 receptors are being investigated for the treatment of inflammatory disorders, including neurodegenerative diseases. Other investigations are in progress for the use of purinergic agents for the treatment of osteoporosis, myocardial infarction, irritable bowel syndrome, epilepsy, atherosclerosis, depression, autism, diabetes, and cancer.

  18. Purinergic Signalling: Therapeutic Developments

    Directory of Open Access Journals (Sweden)

    Geoffrey Burnstock

    2017-09-01

    Full Text Available Purinergic signalling, i.e., the role of nucleotides as extracellular signalling molecules, was proposed in 1972. However, this concept was not well accepted until the early 1990’s when receptor subtypes for purines and pyrimidines were cloned and characterised, which includes four subtypes of the P1 (adenosine receptor, seven subtypes of P2X ion channel receptors and 8 subtypes of the P2Y G protein-coupled receptor. Early studies were largely concerned with the physiology, pharmacology and biochemistry of purinergic signalling. More recently, the focus has been on the pathophysiology and therapeutic potential. There was early recognition of the use of P1 receptor agonists for the treatment of supraventricular tachycardia and A2A receptor antagonists are promising for the treatment of Parkinson’s disease. Clopidogrel, a P2Y12 antagonist, is widely used for the treatment of thrombosis and stroke, blocking P2Y12 receptor-mediated platelet aggregation. Diquafosol, a long acting P2Y2 receptor agonist, is being used for the treatment of dry eye. P2X3 receptor antagonists have been developed that are orally bioavailable and stable in vivo and are currently in clinical trials for the treatment of chronic cough, bladder incontinence, visceral pain and hypertension. Antagonists to P2X7 receptors are being investigated for the treatment of inflammatory disorders, including neurodegenerative diseases. Other investigations are in progress for the use of purinergic agents for the treatment of osteoporosis, myocardial infarction, irritable bowel syndrome, epilepsy, atherosclerosis, depression, autism, diabetes, and cancer.

  19. Generation of earthquake signals

    International Nuclear Information System (INIS)

    Kjell, G.

    1994-01-01

    Seismic verification can be performed either as a full scale test on a shaker table or as numerical calculations. In both cases it is necessary to have an earthquake acceleration time history. This report describes generation of such time histories by filtering white noise. Analogue and digital filtering methods are compared. Different methods of predicting the response spectrum of a white noise signal filtered by a band-pass filter are discussed. Prediction of both the average response level and the statistical variation around this level are considered. Examples with both the IEEE 301 standard response spectrum and a ground spectrum suggested for Swedish nuclear power stations are included in the report

  20. Signal Processing for Communications

    CERN Document Server

    Prandoni, Paolo

    2008-01-01

    Taking a novel, less classical approach to the subject, the authors have written this book with the conviction that signal processing should be fun. Their treatment is less focused on the mathematics and more on the conceptual aspects, allowing students to think about the subject at a higher conceptual level, thus building the foundations for more advanced topics and helping students solve real-world problems. The last chapter pulls together the individual topics into an in-depth look at the development of an end-to-end communication system. Richly illustrated with examples and exercises in ea

  1. Phonocardiography Signal Processing

    CERN Document Server

    Abbas, Abbas K

    2009-01-01

    The auscultation method is an important diagnostic indicator for hemodynamic anomalies. Heart sound classification and analysis play an important role in the auscultative diagnosis. The term phonocardiography refers to the tracing technique of heart sounds and the recording of cardiac acoustics vibration by means of a microphone-transducer. Therefore, understanding the nature and source of this signal is important to give us a tendency for developing a competent tool for further analysis and processing, in order to enhance and optimize cardiac clinical diagnostic approach. This book gives the

  2. Transmembrane Signaling Proteoglycans

    DEFF Research Database (Denmark)

    Couchman, John R

    2010-01-01

    and their glycosaminoglycan chains is matched by diverse functions. However, all assume roles as coreceptors, often working alongside high-affinity growth factor receptors or adhesion receptors such as integrins. Other common themes are an ability to signal through their cytoplasmic domains, often to the actin cytoskeleton......, and linkage to PDZ protein networks. Many transmembrane proteoglycans associate on the cell surface with metzincin proteases and can be shed by them. Work with model systems in vivo and in vitro reveal roles in growth, adhesion, migration, and metabolism. Furthermore, a wide range of phenotypes for the core...

  3. Synthesis, photophysical and metal ion signalling behaviour of mono

    Indian Academy of Sciences (India)

    Unknown

    Fluorescence decay behaviour of the systems suggests a through-space nature of PET. The systems exhi- bit off–on fluorescence signalling in the aprotic media in the presence of several metal ions, some of which are well known for their fluorescence quenching abilities. Diazacrown derivative, II, appears to be a somewhat ...

  4. DNA Damage Signaling Instructs Polyploid Macrophage Fate in Granulomas

    DEFF Research Database (Denmark)

    Herrtwich, Laura; Nanda, Indrajit; Evangelou, Konstantinos

    2016-01-01

    granuloma-resident macrophages formed via modified cell divisions and mitotic defects and not, as previously thought, by cell-to-cell fusion. TLR2 signaling promoted macrophage polyploidy and suppressed genomic instability by regulating Myc and ATR. We propose that, in the presence of persistent...

  5. Acquisition of GNSS signals in urban interference environment

    NARCIS (Netherlands)

    Wildemeersch, Matthias; Wildemeersch, Matthias; Slump, Cornelis H.; Rabbachin, Alberto

    2014-01-01

    In urban environment Global Navigation Satellite System (GNSS) signals are impaired by strong fading and by the presence of several potential sources of interference that can severely affect the acquisition. The work presented here evaluates the acquisition performance for the most common

  6. Multiscale Signal Analysis and Modeling

    CERN Document Server

    Zayed, Ahmed

    2013-01-01

    Multiscale Signal Analysis and Modeling presents recent advances in multiscale analysis and modeling using wavelets and other systems. This book also presents applications in digital signal processing using sampling theory and techniques from various function spaces, filter design, feature extraction and classification, signal and image representation/transmission, coding, nonparametric statistical signal processing, and statistical learning theory. This book also: Discusses recently developed signal modeling techniques, such as the multiscale method for complex time series modeling, multiscale positive density estimations, Bayesian Shrinkage Strategies, and algorithms for data adaptive statistics Introduces new sampling algorithms for multidimensional signal processing Provides comprehensive coverage of wavelets with presentations on waveform design and modeling, wavelet analysis of ECG signals and wavelet filters Reviews features extraction and classification algorithms for multiscale signal and image proce...

  7. Hedgehog: an unusual signal transducer

    NARCIS (Netherlands)

    Bijlsma, Maarten F.; Spek, C. Arnold; Peppelenbosch, Maikel P.

    2004-01-01

    Hedgehog proteins are of pivotal importance for development and maintenance of tissue patterns in adult organisms. Despite the role of Hedgehogs in differentiation and tumorigenesis, signal transduction of Hedgehog remains a relatively uncharted area of signalling biochemistry. For proper Hedgehog

  8. Biological signals classification and analysis

    CERN Document Server

    Kiasaleh, Kamran

    2015-01-01

    This authored monograph presents key aspects of signal processing analysis in the biomedical arena. Unlike wireless communication systems, biological entities produce signals with underlying nonlinear, chaotic nature that elude classification using the standard signal processing techniques, which have been developed over the past several decades for dealing primarily with standard communication systems. This book separates what is random from that which appears to be random, and yet is truly deterministic with random appearance. At its core, this work gives the reader a perspective on biomedical signals and the means to classify and process such signals. In particular, a review of random processes along with means to assess the behavior of random signals is also provided. The book also includes a general discussion of biological signals in order to demonstrate the inefficacy of the well-known techniques to correctly extract meaningful information from such signals. Finally, a thorough discussion of recently ...

  9. Two-dimensional signal analysis

    CERN Document Server

    Garello, René

    2010-01-01

    This title sets out to show that 2-D signal analysis has its own role to play alongside signal processing and image processing.Concentrating its coverage on those 2-D signals coming from physical sensors (such as radars and sonars), the discussion explores a 2-D spectral approach but develops the modeling of 2-D signals and proposes several data-oriented analysis techniques for dealing with them. Coverage is also given to potential future developments in this area.

  10. Confidence versus Performance as an Indicator of the Presence of Alternative Conceptions and Inadequate Problem-Solving Skills in Mechanics

    Science.gov (United States)

    Potgieter, Marietjie; Malatje, Esther; Gaigher, Estelle; Venter, Elsie

    2010-01-01

    This study investigated the use of performance-confidence relationships to signal the presence of alternative conceptions and inadequate problem-solving skills in mechanics. A group of 33 students entering physics at a South African university participated in the project. The test instrument consisted of 20 items derived from existing standardised…

  11. Astrocytes in endocannabinoid signalling.

    Science.gov (United States)

    Navarrete, Marta; Díez, Adolfo; Araque, Alfonso

    2014-10-19

    Astrocytes are emerging as integral functional components of synapses, responding to synaptically released neurotransmitters and regulating synaptic transmission and plasticity. Thus, they functionally interact with neurons establishing tripartite synapses: a functional concept that refers to the existence of communication between astrocytes and neurons and its crucial role in synaptic function. Here, we discuss recent evidence showing that astrocytes are involved in the endocannabinoid (ECB) system, responding to exogenous cannabinoids as well as ECBs through activation of type 1 cannabinoid receptors, which increase intracellular calcium and stimulate the release of glutamate that modulates synaptic transmission and plasticity. We also discuss the consequences of ECB signalling in tripartite synapses on the astrocyte-mediated regulation of synaptic function, which reveal novel properties of synaptic regulation by ECBs, such as the spatially controlled dual effect on synaptic strength and the lateral potentiation of synaptic efficacy. Finally, we discuss the potential implications of ECB signalling for astrocytes in brain pathology and animal behaviour. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  12. Critical nodes in signalling pathways

    DEFF Research Database (Denmark)

    Taniguchi, Cullen M; Emanuelli, Brice; Kahn, C Ronald

    2006-01-01

    Physiologically important cell-signalling networks are complex, and contain several points of regulation, signal divergence and crosstalk with other signalling cascades. Here, we use the concept of 'critical nodes' to define the important junctions in these pathways and illustrate their unique role...

  13. Presence and Learning in a Community of Inquiry

    Science.gov (United States)

    Maddrell, Jennifer A.; Morrison, Gary R.; Watson, Ginger S.

    2017-01-01

    The community of inquiry (CoI) framework suggests social presence, teaching presence, and cognitive presence are essential elements to foster successful educational experiences in computer-mediated distance learning environments. Although thousands of CoI-based articles have been published, those critical of the framework and related research…

  14. Detection of signals in noise

    CERN Document Server

    Whalen, Anthony D; Declaris, Nicholas

    1971-01-01

    Detection of Signals in Noise serves as an introduction to the principles and applications of the statistical theory of signal detection. The book discusses probability and random processes; narrowband signals, their complex representation, and their properties described with the aid of the Hilbert transform; and Gaussian-derived processes. The text also describes the application of hypothesis testing for the detection of signals and the fundamentals required for statistical detection of signals in noise. Problem exercises, references, and a supplementary bibliography are included after each c

  15. Signals and systems for dummies

    CERN Document Server

    Wickert, Mark

    2013-01-01

    Getting mixed signals in your signals and systems course? The concepts covered in a typical signals and systems course are often considered by engineering students to be some of the most difficult to master. Thankfully, Signals & Systems For Dummies is your intuitive guide to this tricky course, walking you step-by-step through some of the more complex theories and mathematical formulas in a way that is easy to understand. From Laplace Transforms to Fourier Analyses, Signals & Systems For Dummies explains in plain English the difficult concepts that can trip you up

  16. Machine intelligence and signal processing

    CERN Document Server

    Vatsa, Mayank; Majumdar, Angshul; Kumar, Ajay

    2016-01-01

    This book comprises chapters on key problems in machine learning and signal processing arenas. The contents of the book are a result of a 2014 Workshop on Machine Intelligence and Signal Processing held at the Indraprastha Institute of Information Technology. Traditionally, signal processing and machine learning were considered to be separate areas of research. However in recent times the two communities are getting closer. In a very abstract fashion, signal processing is the study of operator design. The contributions of signal processing had been to device operators for restoration, compression, etc. Applied Mathematicians were more interested in operator analysis. Nowadays signal processing research is gravitating towards operator learning – instead of designing operators based on heuristics (for example wavelets), the trend is to learn these operators (for example dictionary learning). And thus, the gap between signal processing and machine learning is fast converging. The 2014 Workshop on Machine Intel...

  17. [Progress on Hedgehog signaling transduction].

    Science.gov (United States)

    Tang, Ying; Cheng, Steven

    2014-08-25

    Hedgehog (Hh) signaling pathway plays an important role during embryonic development and pattern formation. Disruption of Hh pathway results in various developmental disorders and increasing cancer incidence. Here we provide a comprehensive review of the pathway members, focusing on how mammalian Hh regulates the Gli family of transcription factors through its downstream members, the so-called "canonical signaling pathway". Hh signaling pathway is highly conserved among species, and primary cilia plays an important role as a "signaling center" during vertebrate signal transduction. Further, in the past few years, numerous studies have shown that Hh signal can also be transduced through Gli-independent ways collectively referred to as "non-canonical signaling pathways", which can be subdivided into two modules: (i) those not requiring Smo and (ii) those downstream of Smo that do not require Gli transcription factors. Thus, we review the rapid progress on canonical and non-canonical Hh pathways.

  18. Measuring signal generators theory & design

    CERN Document Server

    Rybin, Yuriy K

    2014-01-01

    The book brings together the following issues: Theory of deterministic, random and discrete signals reproducible in oscillatory systems of generators; Generation of periodic signals with a specified spectrum, harmonic distortion factor and random signals with specified probability density function and spectral density; Synthesis of oscillatory system structures; Analysis of oscillatory systems with non-linear elements and oscillation amplitude stabilization systems; It considers the conditions and criteria of steady-state modes in signal generators on active four-pole elements with unidirectional and bidirectional transmission of signals and on two-pole elements; analogues of Barkhausen criteria; Optimization of oscillatory system structures by harmonic distortion level, minimization of a frequency error and set-up time of the steady state mode; Theory of construction of random signal generators; Construction of discrete and digital signal generators; Practical design of main units of generators; Practical bl...

  19. [Signal Processing Suite Design

    Science.gov (United States)

    Sahr, John D.; Mir, Hasan; Morabito, Andrew; Grossman, Matthew

    2003-01-01

    Our role in this project was to participate in the design of the signal processing suite to analyze plasma density measurements on board a small constellation (3 or 4) satellites in Low Earth Orbit. As we are new to space craft experiments, one of the challenges was to simply gain understanding of the quantity of data which would flow from the satellites, and possibly to interact with the design teams in generating optimal sampling patterns. For example, as the fleet of satellites were intended to fly through the same volume of space (displaced slightly in time and space), the bulk plasma structure should be common among the spacecraft. Therefore, an optimal, limited bandwidth data downlink would take advantage of this commonality. Also, motivated by techniques in ionospheric radar, we hoped to investigate the possibility of employing aperiodic sampling in order to gain access to a wider spatial spectrum without suffering aliasing in k-space.

  20. Analysis of sEMG signals using discrete wavelet transform for muscle fatigue detection

    Science.gov (United States)

    Flórez-Prias, L. A.; Contreras-Ortiz, S. H.

    2017-11-01

    The purpose of the present article is to characterize sEMG signals to determine muscular fatigue levels. To do this, the signal is decomposed using the discrete wavelet transform, which offers noise filtering features, simplicity and efficiency. sEMG signals on the forearm were acquired and analyzed during the execution of cyclic muscular contractions in the presence and absence of fatigue. When the muscle fatigues, the sEMG signal shows a more erratic behavior of the signal as more energy is required to maintain the effort levels.

  1. Creating and measuring social presence in online graduate nursing courses.

    Science.gov (United States)

    Mayne, Linda A; Wu, Qiang

    2011-01-01

    The literature has shown that social presence is one of the most significant factors in building a sense of community in online education. This pilot study examines the outcomes of integrating social presence strategies into an online graduate nursing course and lays the groundwork for a larger study into dimensions of social presence and student satisfaction. Using a two-group comparison design, the results demonstrate that the purposeful incorporation of specific social presence techniques had a positive impact on student perceptions of social presence and group interaction as well as online learning expectations.

  2. Wavelet analysis for nonstationary signals

    International Nuclear Information System (INIS)

    Penha, Rosani Maria Libardi da

    1999-01-01

    Mechanical vibration signals play an important role in anomalies identification resulting of equipment malfunctioning. Traditionally, Fourier spectral analysis is used where the signals are assumed to be stationary. However, occasional transient impulses and start-up process are examples of nonstationary signals that can be found in mechanical vibrations. These signals can provide important information about the equipment condition, as early fault detection. The Fourier analysis can not adequately be applied to nonstationary signals because the results provide data about the frequency composition averaged over the duration of the signal. In this work, two methods for nonstationary signal analysis are used: Short Time Fourier Transform (STFT) and wavelet transform. The STFT is a method of adapting Fourier spectral analysis for nonstationary application to time-frequency domain. To have a unique resolution throughout the entire time-frequency domain is its main limitation. The wavelet transform is a new analysis technique suitable to nonstationary signals, which handles the STFT drawbacks, providing multi-resolution frequency analysis and time localization in a unique time-scale graphic. The multiple frequency resolutions are obtained by scaling (dilatation/compression) the wavelet function. A comparison of the conventional Fourier transform, STFT and wavelet transform is made applying these techniques to: simulated signals, arrangement rotor rig vibration signal and rotate machine vibration signal Hanning window was used to STFT analysis. Daubechies and harmonic wavelets were used to continuos, discrete and multi-resolution wavelet analysis. The results show the Fourier analysis was not able to detect changes in the signal frequencies or discontinuities. The STFT analysis detected the changes in the signal frequencies, but with time-frequency resolution problems. The wavelet continuos and discrete transform demonstrated to be a high efficient tool to detect

  3. The role of presence in virtual reality exposure therapy.

    Science.gov (United States)

    Price, Matthew; Anderson, Page

    2007-01-01

    A growing body of literature suggests that virtual reality is a successful tool for exposure therapy in the treatment of anxiety disorders. Virtual reality (VR) researchers posit the construct of presence, defined as the interpretation of an artificial stimulus as if it were real, to be a presumed factor that enables anxiety to be felt during virtual reality exposure therapy (VRE). However, a handful of empirical studies on the relation between presence and anxiety in VRE have yielded mixed findings. The current study tested the following hypotheses about the relation between presence and anxiety in VRE with a clinical sample of fearful flyers: (1) presence is related to in-session anxiety; (2) presence mediates the extent that pre-existing (pre-treatment) anxiety is experienced during exposure with VR; (3) presence is positively related to the amount of phobic elements included within the virtual environment; (4) presence is related to treatment outcome. Results supported presence as a factor that contributes to the experience of anxiety in the virtual environment as well as a relation between presence and the phobic elements, but did not support a relation between presence and treatment outcome. The study suggests that presence may be a necessary but insufficient requirement for successful VRE.

  4. Understanding the neurospecificity of Prion protein signaling.

    Science.gov (United States)

    Schneider, Benoit; Pietri, Mathea; Pradines, Elodie; Loubet, Damien; Launay, Jean-Marie; Kellermann, Odile; Mouillet-Richard, Sophie

    2011-01-01

    The cellular prion protein PrP(C) is the normal counterpart of the scrapie prion protein PrP(Sc), the main component of the infectious agent of transmissible spongiform encephalopathies (TSEs). It is a ubiquitous cell-surface glycoprotein, abundantly expressed in neurons, which constitute the targets of TSE pathogenesis. The presence of PrP(C) at the surface of neurons is an absolute requirement for the development of prion diseases and corruption of PrP(C) function(s) within an infectious context emerges as a proximal cause for PrP(Sc)-induced neurodegeneration. Experimental evidence gained over the past decade indicates that PrP(C) has the capacity to mobilize promiscuous signal transduction cascades that, notably, contribute to cell homeostasis. Beyond ubiquitous effectors, much data converge onto a neurospecificity of PrP(C) signaling, which may be the clue to neuronal cell demise in prion disorders. In this article, we highlight the requirement of PrP(C) for TSEs-associated neurodegeneration and review the current knowledge of PrP(C)-dependent signal transduction in neuronal cells and its implications for PrP(Sc)-mediated neurotoxicity.

  5. Interleukin 4 signals through two related pathways.

    Science.gov (United States)

    Pernis, A; Witthuhn, B; Keegan, A D; Nelms, K; Garfein, E; Ihle, J N; Paul, W E; Pierce, J H; Rothman, P

    1995-08-15

    The interleukin 4 (IL-4) signaling pathway involves activation, by tyrosine phosphorylation, of two distinct substrates, a signal-transducing factor (STF-IL4) and the IL-4-induced phosphotyrosine substrate (4PS). It is not known whether the IL-4-mediated activation of these substrates occurs via related or distinct signaling pathways. We report that 32D cells, an IL-3-dependent myeloid progenitor cell line in which no phosphorylated 4PS is found, activate high levels of STF-IL4 in response to IL-4. Consistent with the known requirement for 4PS or insulin receptor substrate 1 (IRS-1) in IL-4-mediated mitogenesis, activation of STF-IL4 in 32D cells is not sufficient for IL-4-inducible c-myc expression. In addition, we have examined the ability of 32D cells transfected with different truncation mutants of the human IL-4 receptor to activate Jak-3 kinase and STF-IL4 in response to human IL-4. As in the case of 4PS/IRS-1, we have found that activation of both Jak-3 and STF-IL4 requires the presence of the IL-4 receptor region comprising aa 437-557. The finding that the same region of the IL-4 receptor is required for the induction of both 4PS/IRS-1 and STF-IL4 suggests that the IL-4-stimulated activation of these two substrates might involve common factors.

  6. Signaling pathways in a Citrus EST database

    Directory of Open Access Journals (Sweden)

    Angela Mehta

    2007-01-01

    Full Text Available Citrus spp. are economically important crops, which in Brazil are grown mainly in the State of São Paulo. Citrus cultures are attacked by several pathogens, causing severe yield losses. In order to better understand this culture, the Millenium Project (IAC Cordeirópolis was launched in order to sequence Citrus ESTs (expressed sequence tags from different tissues, including leaf, bark, fruit, root and flower. Plants were submitted to biotic and abiotic stresses and investigated under different development stages (adult vs. juvenile. Several cDNA libraries were constructed and the sequences obtained formed the Citrus ESTs database with almost 200,000 sequences. Searches were performed in the Citrus database to investigate the presence of different signaling pathway components. Several of the genes involved in the signaling of sugar, calcium, cytokinin, plant hormones, inositol phosphate, MAPKinase and COP9 were found in the citrus genome and are discussed in this paper. The results obtained may indicate that similar mechanisms described in other plants, such as Arabidopsis, occur in citrus. Further experimental studies must be conducted in order to understand the different signaling pathways present.

  7. To hold her hand: family presence during patient resuscitation.

    Science.gov (United States)

    Atwood, Denise A

    2008-01-01

    Family presence at the bedside during resuscitation is an important component of the patient's care. Many families report feeling that their presence at such a time is helpful to both them and the patient. Some studies suggest that family presence may reduce the chance of legal action regarding the patient's outcome because it decreases the mystery surrounding the level of effort undertaken to save the patient's life. However, many facilities are reluctant to allow family presence during resuscitation typically because of the belief that family presence will somehow disrupt the providers' ability to conduct the resuscitation. This article explores the background behind this issue and the studies done to date on family presence and makes suggestions for adopting policies allowing family presence during resuscitation.

  8. Ridge Regression Signal Processing

    Science.gov (United States)

    Kuhl, Mark R.

    1990-01-01

    The introduction of the Global Positioning System (GPS) into the National Airspace System (NAS) necessitates the development of Receiver Autonomous Integrity Monitoring (RAIM) techniques. In order to guarantee a certain level of integrity, a thorough understanding of modern estimation techniques applied to navigational problems is required. The extended Kalman filter (EKF) is derived and analyzed under poor geometry conditions. It was found that the performance of the EKF is difficult to predict, since the EKF is designed for a Gaussian environment. A novel approach is implemented which incorporates ridge regression to explain the behavior of an EKF in the presence of dynamics under poor geometry conditions. The basic principles of ridge regression theory are presented, followed by the derivation of a linearized recursive ridge estimator. Computer simulations are performed to confirm the underlying theory and to provide a comparative analysis of the EKF and the recursive ridge estimator.

  9. Evolution of Hormone Signaling Networks in Plant Defense.

    Science.gov (United States)

    Berens, Matthias L; Berry, Hannah M; Mine, Akira; Argueso, Cristiana T; Tsuda, Kenichi

    2017-08-04

    Studies with model plants such as Arabidopsis thaliana have revealed that phytohormones are central regulators of plant defense. The intricate network of phytohormone signaling pathways enables plants to activate appropriate and effective defense responses against pathogens as well as to balance defense and growth. The timing of the evolution of most phytohormone signaling pathways seems to coincide with the colonization of land, a likely requirement for plant adaptations to the more variable terrestrial environments, which included the presence of pathogens. In this review, we explore the evolution of defense hormone signaling networks by combining the model plant-based knowledge about molecular components mediating phytohormone signaling and cross talk with available genome information of other plant species. We highlight conserved hubs in hormone cross talk and discuss evolutionary advantages of defense hormone cross talk. Finally, we examine possibilities of engineering hormone cross talk for improvement of plant fitness and crop production.

  10. Model of multicomponent micro-Doppler signal in environment MatLab

    Directory of Open Access Journals (Sweden)

    Kucheryavenko Alexander

    2017-01-01

    Full Text Available The article illustrates the problem of measuring the speed glider component targets in the presence of a turboprop effect of the reflected signal in a pulse-Doppler radar, proposed a model turboprop signal component and an algorithm for its suppression

  11. The signal function of thematically (In)congruent ambient scents in a retail environment

    NARCIS (Netherlands)

    Schifferstein, H.N.J.; Blok, S.T.

    2002-01-01

    An odor emitted by an object signals the presence of that object and may draw attention to it. Can odors that are not actually emitted by an object also function as a signal? We investigated whether the degree of thematic congruency between an ambient odor and a magazine affected magazine sales in a

  12. In Vivo Lactate Editing in the Presence of Inhomogeneous B1 Fields

    Science.gov (United States)

    Reddy, R.; Subramanian, V. H.; Clark, B. J.; Leigh, J. S.

    The flip-angle dependence of a recently proposed lactate-editing sequence is analyzed. Spin-spin coupling is shown to affect the flip-angle dependence of the excitation. In the presence of spin-spin coupling, the edited signal is shown to have a sin 11 θ dependence. Irrespective of the flip angle, the sequence does not pass uncoupled spins. When the third pulse has a phase of zero with respect to the first pulse, the sequence suppresses the lactate signal and passes only uncoupled spins with a flip-angle dependence of sin 7 θ. The flip-angle dependence of this sequence is compared with that of the most widely used editing sequences. Even when used with a surface coil, the sequence retains its editing capabilities. This is demonstrated by obtaining lactate spectra from a rat brain and a pig heart.

  13. MR signal in the sacroiliac joint space in spondyloarthritis: a new sign

    Energy Technology Data Exchange (ETDEWEB)

    Laloo, Frederiek; Herregods, N.; Verstraete, K.; Jans, L. [Ghent University Hospital, Department of Radiology and Medical Imaging, Gent (Belgium); Varkas, G.; Elewaut, D.; Bosch, F. van den [Ghent University Hospital, Department of Rheumatology, Gent (Belgium); Jaremko, J.L. [University of Alberta Hospital, Department of Radiology and Diagnostic Imaging, Edmonton, Alberta (Canada); Baraliakos, X. [Ruhr-University Bochum, Rheumazentrum Ruhrgebiet, Herne (Germany)

    2017-05-15

    To determine the diagnostic value of MR signal within the sacroiliac (SI) joint space in spondyloarthritis (SpA). A retrospective analysis of MRIs of SI joints was performed in 363 patients, aged 16-45 years, clinically suspected of sacroiliitis. Intra-articular SI joint MR signals were categorized as normal, high T1 signal, fluid signal, ankylosis or vacuum phenomenon (VP). These MRI findings were correlated with the final diagnosis, according to the ASAS criteria. Sensitivity, specificity, and positive and negative likelihood ratios (LR) and predictive values were calculated. Presence of intra-articular high T1 signal, fluid signal and ankylosis had a specificity of 95.8 %, 95.3 % and 99.5 % for SpA. High T1 signal, fluid signal and ankylosis were present in 38.4 %, 19.2 % and 17.9 % of SpA patients and in 4.2 %, 4.7 % and 0.5 % of patients without SpA, resulting in LR+ of 9.0, 4.1 and 37.9, respectively. VP was present in 13.2 % of SpA patients and in 20.8 % of patients without SpA, resulting in an LR+ of 0.6. Presence of high T1 signal, fluid signal and ankylosis within the SI joint on MRI have high specificity for SpA. High T1 signal is the most sensitive MRI feature within the SI joint for SpA. (orig.)

  14. Steganography in arrhythmic electrocardiogram signal.

    Science.gov (United States)

    Edward Jero, S; Ramu, Palaniappan; Ramakrishnan, S

    2015-08-01

    Security and privacy of patient data is a vital requirement during exchange/storage of medical information over communication network. Steganography method hides patient data into a cover signal to prevent unauthenticated accesses during data transfer. This study evaluates the performance of ECG steganography to ensure secured transmission of patient data where an abnormal ECG signal is used as cover signal. The novelty of this work is to hide patient data into two dimensional matrix of an abnormal ECG signal using Discrete Wavelet Transform and Singular Value Decomposition based steganography method. A 2D ECG is constructed according to Tompkins QRS detection algorithm. The missed R peaks are computed using RR interval during 2D conversion. The abnormal ECG signals are obtained from the MIT-BIH arrhythmia database. Metrics such as Peak Signal to Noise Ratio, Percentage Residual Difference, Kullback-Leibler distance and Bit Error Rate are used to evaluate the performance of the proposed approach.

  15. Phylogenetic signal in diatom ecology: perspectives for aquatic ecosystems biomonitoring.

    Science.gov (United States)

    Keck, François; Rimet, Frédéric; Franc, Alain; Bouchez, Agnés

    2016-04-01

    Diatoms include a great diversity of taxa and are recognized as powerful bioindicators in rivers. However using diatoms for monitoring programs is costly and time consuming because most of the methodologies necessitate species-level identification. This raises the question of the optimal trade-off between taxonomic resolution and bioassessment quality. Phylogenetic tools may form the bases of new, more efficient approaches for biomonitoring if relationships between ecology and phylogeny can be demonstrated. We estimated the ecological optima of 127 diatom species for 19 environmental parameters using count data from 2119 diatom communities sampled during eight years in eastern France. Using uni- and multivariate analyses, we explored the relationships between freshwater diatom phylogeny and ecology (i.e., the phylogenetic signal). We found a significant phylogenetic signal for many of the ecological optima that were tested, but the strength of the signal varied significantly from one trait to another. Multivariate analysis also showed that the multidimensional ecological niche of diatoms can be strongly related to phylogeny. The presence of clades containing species that exhibit homogeneous ecology suggests that phylogenetic information can be useful for aquatic biomonitoring. This study highlights the presence of significant patterns of ecological optima for freshwater diatoms in relation to their phylogeny. These results suggest the presence of a signal above the species level, which is encouraging for the development of simplified methods for biomonitoring survey.

  16. Unmixing binocular signals

    Directory of Open Access Journals (Sweden)

    Sidney R Lehky

    2011-08-01

    Full Text Available Incompatible images presented to the two eyes lead to perceptual oscillations in which one image at a time is visible. Early models portrayed this binocular rivalry as involving reciprocal inhibition between monocular representations of images, occurring at an early visual stage prior to binocular mixing. However, psychophysical experiments found conditions where rivalry could also occur at a higher, more abstract level of representation. In those cases, the rivalry was between image representations dissociated from eye-of-origin information, rather than between monocular representations from the two eyes. Moreover, neurophysiological recordings found the strongest rivalry correlate in inferotemporal cortex, a high-level, predominantly binocular visual area involved in object recognition, rather than early visual structures. An unresolved issue is how can the separate identities of the two images be maintained after binocular mixing in order for rivalry to be possible at higher levels? Here we demonstrate that after the two images are mixed, they can be unmixed at any subsequent stage using a physiologically plausible nonlinear signal-processing algorithm, non-negative matrix factorization, previously proposed for parsing object parts during object recognition. The possibility that unmixed left and right images can be regenerated at late stages within the visual system provides a mechanism for creating various binocular representations and interactions de novo in different cortical areas for different purposes, rather than inheriting then from early areas. This is a clear example how nonlinear algorithms can lead to highly non-intuitive behavior in neural information processing.

  17. 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)

  18. Volcanic signals in oceans

    KAUST Repository

    Stenchikov, Georgiy L.

    2009-08-22

    Sulfate aerosols resulting from strong volcanic explosions last for 2–3 years in the lower stratosphere. Therefore it was traditionally believed that volcanic impacts produce mainly short-term, transient climate perturbations. However, the ocean integrates volcanic radiative cooling and responds over a wide range of time scales. The associated processes, especially ocean heat uptake, play a key role in ongoing climate change. However, they are not well constrained by observations, and attempts to simulate them in current climate models used for climate predictions yield a range of uncertainty. Volcanic impacts on the ocean provide an independent means of assessing these processes. This study focuses on quantification of the seasonal to multidecadal time scale response of the ocean to explosive volcanism. It employs the coupled climate model CM2.1, developed recently at the National Oceanic and Atmospheric Administration\\'s Geophysical Fluid Dynamics Laboratory, to simulate the response to the 1991 Pinatubo and the 1815 Tambora eruptions, which were the largest in the 20th and 19th centuries, respectively. The simulated climate perturbations compare well with available observations for the Pinatubo period. The stronger Tambora forcing produces responses with higher signal-to-noise ratio. Volcanic cooling tends to strengthen the Atlantic meridional overturning circulation. Sea ice extent appears to be sensitive to volcanic forcing, especially during the warm season. Because of the extremely long relaxation time of ocean subsurface temperature and sea level, the perturbations caused by the Tambora eruption could have lasted well into the 20th century.

  19. Fundamentals of statistical signal processing

    CERN Document Server

    Kay, Steven M

    1993-01-01

    A unified presentation of parameter estimation for those involved in the design and implementation of statistical signal processing algorithms. Covers important approaches to obtaining an optimal estimator and analyzing its performance; and includes numerous examples as well as applications to real- world problems. MARKETS: For practicing engineers and scientists who design and analyze signal processing systems, i.e., to extract information from noisy signals — radar engineer, sonar engineer, geophysicist, oceanographer, biomedical engineer, communications engineer, economist, statistician, physicist, etc.

  20. Queen signaling in social wasps

    DEFF Research Database (Denmark)

    van Zweden, Jelle Stijn; Bonckaert, Wim; Wenseleers, Tom

    2014-01-01

    , thereby arguing against fast evolution of signals as a result of a queen-worker arms race ensuing from queen control. Lastly, levels of worker reproduction in these species correspond well with their average colony kin structures, as predicted by the queen signaling hypothesis but not the queen control...... hypothesis. Altogether, this correlative yet comprehensive analysis provides compelling evidence that honest signaling explains levels of reproductive division of labor in social wasps....

  1. Semi-classical signal analysis

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2012-09-30

    This study introduces a new signal analysis method, based on a semi-classical approach. The main idea in this method is to interpret a pulse-shaped signal as a potential of a Schrödinger operator and then to use the discrete spectrum of this operator for the analysis of the signal. We present some numerical examples and the first results obtained with this method on the analysis of arterial blood pressure waveforms. © 2012 Springer-Verlag London Limited.

  2. Wnt signaling in the early sea urchin embryo.

    Science.gov (United States)

    Kumburegama, Shalika; Wikramanayake, Athula H

    2008-01-01

    Wnt signaling regulates a remarkably diverse array of cellular and developmental events during animal embryogenesis and homeostasis. The crucial role that Wnt signaling plays in regulating axial patterning in early embryos has been particularly striking. Recent work has highlighted the conserved role that canonical Wnt signaling plays in patterning the animal-vegetal (A-V) axis in sea urchin and sea anemone embryos. In sea urchin embryos, the canonical Wnt signaling pathway is selectively turned on in vegetal cells as early as the 16-cell stage embryo, and signaling through this pathway is required for activation of the endomesodermal gene regulatory network. Loss of nuclear beta-catenin signaling animalizes the sea urchin embryo and blocks pattern formation along the entire A-V axis. Nuclear entry of beta-catenin into vegetal cells is regulated cell autonomously by maternal information that is present at the vegetal pole of the unfertilized egg. Analysis of Dishevelled (Dsh) regulation along the A-V axis has revealed the presence of a cytoarchitectural domain at the vegetal pole of the unfertilized sea urchin egg. This vegetal cortical domain appears to be crucial for the localized activation of Dsh at the vegetal pole, but the precise mechanisms are unknown. The elucidation of how Dsh is selectively activated at the vegetal cortical domain is likely to provide important insight into how this enigmatic protein is regulated during canonical Wnt signaling. Additionally, this information will shed light on the origins of embryonic polarity during animal evolution. This chapter examines the roles played by the canonical Wnt signaling pathway in the specification and patterning of the A-V axis in the sea urchin. These studies have led to the identification of a novel role for canonical Wnt signaling in regulating protein stability, and continued studies of Wnt signaling in this model system are likely to reveal additional roles for this pathway in regulating early

  3. Exciton dissociation in the presence of phonons: A reduced hierarchy equations of motion approach

    International Nuclear Information System (INIS)

    Yao, Yao; Yang, Wenchao; Zhao, Yang

    2014-01-01

    Combining the reduced hierarchy equations of motion (HEOM) approach with the Wigner-function formalism, we investigate nonperturbatively exciton dissociation under the influence of a phonon bath in an organic heterojunction. The exciton is modeled by an electron-hole pair with the electron moving in the presence of both an external electric field and the Coulomb attraction potential from the hole. In the absence of a phonon bath, calculated HEOM results reproduce those from the Onsager-Braun theory in weak electric fields. In the presence of a phonon bath, substantial deviations from the Onsager-Braun theory are found, signaling phonon-induced quantum effects. Furthermore, time evolution of the spatial current distribution is examined, and an initial spike followed by a polarity change of the transient photocurrent have been recovered

  4. Effective Biopotential Signal Acquisition: Comparison of Different Shielded Drive Technologies

    Directory of Open Access Journals (Sweden)

    Yanbing Jiang

    2018-02-01

    Full Text Available Biopotential signals are mainly characterized by low amplitude and thus often distorted by extraneous interferences, such as power line interference in the recording environment and movement artifacts during the acquisition process. With the presence of such large-amplitude interferences, subsequent processing and analysis of the acquired signals becomes quite a challenging task that has been reported by many previous studies. A number of software-based filtering techniques have been proposed, with most of them being able to minimize the interferences but at the expense of distorting the useful components of the target signal. Therefore, this study proposes a hardware-based method that utilizes a shielded drive circuit to eliminate extraneous interferences on biopotential signal recordings, while also preserving all useful components of the target signal. The performance of the proposed method was evaluated by comparing the results with conventional hardware and software filtering methods in three different biopotential signal recording experiments (electrocardiogram (ECG, electro-oculogram (EOG, and electromyography (EMG on an ADS1299EEG-FE platform. The results showed that the proposed method could effectively suppress power line interference as well as its harmonic components, and it could also significantly eliminate the influence of unwanted electrode lead jitter interference. Findings from this study suggest that the proposed method may provide potential insight into high quality acquisition of different biopotential signals to greatly ease subsequent processing in various biomedical applications.

  5. Signal generation in gas detectors

    International Nuclear Information System (INIS)

    Stillman, A.

    1993-01-01

    This tutorial describes the generation of electrical signals in gas detectors. Ionization of the gas by the passage of charged particles generates these signals. Starting with the Bethe-Bloch equation, the treatment is a general introduction to the production of ion-pairs in gas devices. I continue with the characterization of the ionization as an electrical signal, and calculate the signal current in a simple example. Another example demonstrates the effect of space charge on the design of a detector. The AGS Booster ionization profile monitor is a model for this calculation

  6. Signal generation in gas detectors

    Energy Technology Data Exchange (ETDEWEB)

    Stillman, A.

    1993-11-01

    This tutorial describes the generation of electrical signals in gas detectors. Ionization of the gas by the passage of charged particles generates these signals. Starting with the Bethe-Bloch equation, the treatment is a general introduction to the production of ion-pairs in gas devices. I continue with the characterization of the ionization as an electrical signal, and calculate the signal current in a simple example. Another example demonstrates the effect of space charge on the design of a detector. The AGS Booster ionization profile monitor is a model for this calculation.

  7. Virtual Vertical Aircraft Signal Training

    National Research Council Canada - National Science Library

    Norling, William

    1998-01-01

    .... Advances in virtual environments may provide a cost effective solution to the current live helicopter operations method of training, provided technical issues associated with hand and wand signal...

  8. Signal anomaly detection and characterization

    International Nuclear Information System (INIS)

    Morgenstern, V.M.; Upadhyaya, B.R.; Gloeckler, O.

    1988-08-01

    As part of a comprehensive signal validation system, we have developed a signal anomaly detector, without specifically establishing the cause of the anomaly. A signal recorded from process instrumentation is said to have an anomaly, if during steady-state operation, the deviation in the level of the signal, its root-mean-square (RMS) value, or its statistical distribution changes by a preset value. This deviation could be an unacceptable increase or a decrease in the quantity being monitored. An anomaly in a signal may be characterized by wideband or single-frequency noise, bias error, pulse-type error, nonsymmetric behavior, or a change in the signal bandwidth. Various signatures can be easily computed from data samples and compared against specified threshold values. We want to point out that in real processes, pulses can appear with different time widths, and at different rates of change of the signal. Thus, in characterizing an anomaly as a pulse-type, the fastest pulse width is constrained by the signal sampling interval. For example, if a signal is sampled at 100 Hz, we will not be able to detect pulses occurring at kHz rates. Discussion with utility and Combustion Engineering personnel indicated that it is not practical to detect pulses having a narrow time width. 9 refs., 11 figs., 8 tabs

  9. Pragmatic circuits signals and filters

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Signals and Filters is built around the processing of signals. Topics include spectra, a short introduction to the Fourier series, design of filters, and the properties of the Fourier transform. The focus is on signals rather than power. But the treatment is still pragmatic. For example, the author accepts the work of Butterworth and uses his results to design filters in a fairly methodical fashion. This third of three volumes finishes with a look at spectra by showing how to get a spectrum even if a signal is not periodic. The Fourier transform provides a way of dealing wi

  10. [Family presence during cardiopulmonary resuscitation and other invasive procedures].

    Science.gov (United States)

    Prati, Gabriele; Monti, Massimo

    2010-01-01

    Family presence during patient cardiopulmonary resuscitation and other invasive procedures has been discussed and debated since the early 1990s. Although family presence was nor a well-practiced phenomenon, nor generally accepted, since the early to mid 1990s many American professional organizations have endorsed the idea of family presence. The aim of this study is to identify the policies, preferences, and practices of critical care and emergency personnel for having patients' families present during medical procedures and cardiopulmonary resuscitation. A total of 378 nurses and medical workers filled out a 10-item survey. Among the respondents, nurses tended to disagree more with family presence in comparison to physician. Critical care unit personnel tended to disagree more with family presence in comparison to emergency department personnel and especially pre-hospital care personnel. While 83% of participants disagree with family presence during cardiopulmonary resuscitation, 67% of participant endorse the view that family presence may foster collaboration between family members and staff members. Overall, 92% of participants worked on units without written policies allowing family presence. Training programs aimed at disseminating knowledge about the relational aspects of health care and the development of written policies or guidelines for family presence during medical procedures are recommended.

  11. An analysis of signal processing algorithm performance for cortical intrinsic optical signal imaging and strategies for algorithm selection.

    Science.gov (United States)

    Turley, J A; Zalewska, K; Nilsson, M; Walker, F R; Johnson, S J

    2017-08-03

    Intrinsic Optical Signal (IOS) imaging has been used extensively to examine activity-related changes within the cerebral cortex. A significant technical challenge with IOS imaging is the presence of large noise, artefact components and periodic interference. Signal processing is therefore important in obtaining quality IOS imaging results. Several signal processing techniques have been deployed, however, the performance of these approaches for IOS imaging has never been directly compared. The current study aims to compare signal processing techniques that can be used when quantifying stimuli-response IOS imaging data. Data were gathered from the somatosensory cortex of mice following piezoelectric stimulation of the hindlimb. The effectiveness of each technique to remove noise and extract the IOS signal was compared for both spatial and temporal responses. Careful analysis of the advantages and disadvantages of each method were carried out to inform the choice of signal processing for IOS imaging. We conclude that spatial Gaussian filtering is the most effective choices for improving the spatial IOS response, whilst temporal low pass and bandpass filtering produce the best results for producing temporal responses when periodic stimuli are an option. Global signal regression and truncated difference also work well and do not require periodic stimuli.

  12. Non-linear dimensionality reduction of signaling networks

    Science.gov (United States)

    Ivakhno, Sergii; Armstrong, J Douglas

    2007-01-01

    Background Systems wide modeling and analysis of signaling networks is essential for understanding complex cellular behaviors, such as the biphasic responses to different combinations of cytokines and growth factors. For example, tumor necrosis factor (TNF) can act as a proapoptotic or prosurvival factor depending on its concentration, the current state of signaling network and the presence of other cytokines. To understand combinatorial regulation in such systems, new computational approaches are required that can take into account non-linear interactions in signaling networks and provide tools for clustering, visualization and predictive modeling. Results Here we extended and applied an unsupervised non-linear dimensionality reduction approach, Isomap, to find clusters of similar treatment conditions in two cell signaling networks: (I) apoptosis signaling network in human epithelial cancer cells treated with different combinations of TNF, epidermal growth factor (EGF) and insulin and (II) combination of signal transduction pathways stimulated by 21 different ligands based on AfCS double ligand screen data. For the analysis of the apoptosis signaling network we used the Cytokine compendium dataset where activity and concentration of 19 intracellular signaling molecules were measured to characterise apoptotic response to TNF, EGF and insulin. By projecting the original 19-dimensional space of intracellular signals into a low-dimensional space, Isomap was able to reconstruct clusters corresponding to different cytokine treatments that were identified with graph-based clustering. In comparison, Principal Component Analysis (PCA) and Partial Least Squares – Discriminant analysis (PLS-DA) were unable to find biologically meaningful clusters. We also showed that by using Isomap components for supervised classification with k-nearest neighbor (k-NN) and quadratic discriminant analysis (QDA), apoptosis intensity can be predicted for different combinations of TNF, EGF

  13. Non-linear dimensionality reduction of signaling networks

    Directory of Open Access Journals (Sweden)

    Ivakhno Sergii

    2007-06-01

    Full Text Available Abstract Background Systems wide modeling and analysis of signaling networks is essential for understanding complex cellular behaviors, such as the biphasic responses to different combinations of cytokines and growth factors. For example, tumor necrosis factor (TNF can act as a proapoptotic or prosurvival factor depending on its concentration, the current state of signaling network and the presence of other cytokines. To understand combinatorial regulation in such systems, new computational approaches are required that can take into account non-linear interactions in signaling networks and provide tools for clustering, visualization and predictive modeling. Results Here we extended and applied an unsupervised non-linear dimensionality reduction approach, Isomap, to find clusters of similar treatment conditions in two cell signaling networks: (I apoptosis signaling network in human epithelial cancer cells treated with different combinations of TNF, epidermal growth factor (EGF and insulin and (II combination of signal transduction pathways stimulated by 21 different ligands based on AfCS double ligand screen data. For the analysis of the apoptosis signaling network we used the Cytokine compendium dataset where activity and concentration of 19 intracellular signaling molecules were measured to characterise apoptotic response to TNF, EGF and insulin. By projecting the original 19-dimensional space of intracellular signals into a low-dimensional space, Isomap was able to reconstruct clusters corresponding to different cytokine treatments that were identified with graph-based clustering. In comparison, Principal Component Analysis (PCA and Partial Least Squares – Discriminant analysis (PLS-DA were unable to find biologically meaningful clusters. We also showed that by using Isomap components for supervised classification with k-nearest neighbor (k-NN and quadratic discriminant analysis (QDA, apoptosis intensity can be predicted for different

  14. Non-linear dimensionality reduction of signaling networks.

    Science.gov (United States)

    Ivakhno, Sergii; Armstrong, J Douglas

    2007-06-08

    Systems wide modeling and analysis of signaling networks is essential for understanding complex cellular behaviors, such as the biphasic responses to different combinations of cytokines and growth factors. For example, tumor necrosis factor (TNF) can act as a proapoptotic or prosurvival factor depending on its concentration, the current state of signaling network and the presence of other cytokines. To understand combinatorial regulation in such systems, new computational approaches are required that can take into account non-linear interactions in signaling networks and provide tools for clustering, visualization and predictive modeling. Here we extended and applied an unsupervised non-linear dimensionality reduction approach, Isomap, to find clusters of similar treatment conditions in two cell signaling networks: (I) apoptosis signaling network in human epithelial cancer cells treated with different combinations of TNF, epidermal growth factor (EGF) and insulin and (II) combination of signal transduction pathways stimulated by 21 different ligands based on AfCS double ligand screen data. For the analysis of the apoptosis signaling network we used the Cytokine compendium dataset where activity and concentration of 19 intracellular signaling molecules were measured to characterise apoptotic response to TNF, EGF and insulin. By projecting the original 19-dimensional space of intracellular signals into a low-dimensional space, Isomap was able to reconstruct clusters corresponding to different cytokine treatments that were identified with graph-based clustering. In comparison, Principal Component Analysis (PCA) and Partial Least Squares - Discriminant analysis (PLS-DA) were unable to find biologically meaningful clusters. We also showed that by using Isomap components for supervised classification with k-nearest neighbor (k-NN) and quadratic discriminant analysis (QDA), apoptosis intensity can be predicted for different combinations of TNF, EGF and insulin. Prediction

  15. Phosphorylation site dynamics of early T-cell receptor signaling

    DEFF Research Database (Denmark)

    Chylek, Lily A; Akimov, Vyacheslav; Dengjel, Jörn

    2014-01-01

    a systems-level understanding of how these components cooperate to control signaling dynamics, especially during the crucial first seconds of stimulation. Here, we used quantitative proteomics to characterize reshaping of the T-cell phosphoproteome in response to TCR/CD28 co-stimulation, and found...... that diverse dynamic patterns emerge within seconds. We detected phosphorylation dynamics as early as 5 s and observed widespread regulation of key TCR signaling proteins by 30 s. Development of a computational model pointed to the presence of novel regulatory mechanisms controlling phosphorylation of sites...

  16. Multifrequency OFDM SAR in Presence of Deception Jamming

    Directory of Open Access Journals (Sweden)

    Schuerger Jonathan

    2010-01-01

    Full Text Available Orthogonal frequency division multiplexing (OFDM is considered in this paper from the perspective of usage in imaging radar scenarios with deception jamming. OFDM radar signals are inherently multifrequency waveforms, composed of a number of subbands which are orthogonal to each other. While being employed extensively in communications, OFDM has not found comparatively wide use in radar, and, particularly, in synthetic aperture radar (SAR applications. In this paper, we aim to show the advantages of OFDM-coded radar signals with random subband composition when used in deception jamming scenarios. Two approaches to create a radar signal by the jammer are considered: instantaneous frequency (IF estimator and digital-RF-memory- (DRFM- based reproducer. In both cases, the jammer aims to create a copy of a valid target image via resending the radar signal at prescribed time intervals. Jammer signals are derived and used in SAR simulations with three types of signal models: OFDM, linear frequency modulated (LFM, and frequency-hopped (FH. Presented results include simulated peak side lobe (PSL and peak cross-correlation values for random OFDM signals, as well as simulated SAR imagery with IF and DRFM jammers'-induced false targets.

  17. Smoke Signal or Smoke Screen?

    DEFF Research Database (Denmark)

    Vergne, Jean-Philippe; Wernicke, Georg; Brenner, Steffen

    This paper explains the amount of disapproval faced by firms that overpay their CEO by integrating signaling and categorization theories. We argue that, in contexts characterized by intense scrutiny, ambivalent signals sent by firms suspend categorization by stakeholders, leading to further disap...

  18. Signals in Communication Engineering History

    Science.gov (United States)

    Consonni, Denise; Silva, Magno T. M.

    2010-01-01

    This paper is a study of various electric signals, which have been employed throughout the history of communication engineering in its two main landmarks: the telegraph and the telephone. The signals are presented in their time and frequency domain representations. The historical order has been followed in the presentation: wired systems, spark…

  19. Cellular semiotics and signal transduction

    DEFF Research Database (Denmark)

    Bruni, Luis Emilio

    2007-01-01

    (s)" in signal transduction; i.e.: how specificity is determined, how ubiquitous signals or messengers convey specific information, how undesired cross-talk is avoided, how redundancy integrates the system. This chapter proposes a basic conceptual toolbox for interpreting empirical data that deals...

  20. Hippo signalling directs intestinal fate

    DEFF Research Database (Denmark)

    le Bouteiller, Marie Catherine M; Jensen, Kim Bak

    2015-01-01

    Hippo signalling has been associated with many important tissue functions including the regulation of organ size. In the intestinal epithelium differing functions have been proposed for the effectors of Hippo signalling, YAP and TAZ1. These are now shown to have a dual role in the intestinal epit...

  1. Signals and systems with MATLAB

    CERN Document Server

    Yang, Won Young; Song, Ik H; Cho, Yong S

    2009-01-01

    Covers some of the theoretical foundations and mathematical derivations that can be used in higher-level related subjects such as signal processing, communication, and control, minimizing the mathematical difficulty and computational burden. This book illustrates the usage of MATLAB and Simulink for signal and system analysis and design.

  2. Signaling a Change of Heart

    DEFF Research Database (Denmark)

    Schumacher, Gijs

    2011-01-01

    introduced welfare state retrenchment measures. Social Democrats can win votes and join coalitions by shifting rightwards. In contrast, they can pursue policy objectives by shifting leftwards. To communicate these shifts, in other words, ‘changes of heart’, parties send signals to voters and other parties...... after having signalled ‘a change of heart’....

  3. Intracellular signal modulation by nanomaterials.

    Science.gov (United States)

    Hussain, Salik; Garantziotis, Stavros; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Baeza-Squiban, Armelle; Boland, Sonja

    2014-01-01

    A thorough understanding of the interactions of nanomaterials with biological systems and the resulting activation of signal transduction pathways is essential for the development of safe and consumer friendly nanotechnology. Here we present an overview of signaling pathways induced by nanomaterial exposures and describe the possible correlation of their physicochemical characteristics with biological outcomes. In addition to the hierarchical oxidative stress model and a review of the intrinsic and cell-mediated mechanisms of reactive oxygen species (ROS) generating capacities of nanomaterials, we also discuss other oxidative stress dependent and independent cellular signaling pathways. Induction of the inflammasome, calcium signaling, and endoplasmic reticulum stress are reviewed. Furthermore, the uptake mechanisms can be of crucial importance for the cytotoxicity of nanomaterials and membrane-dependent signaling pathways have also been shown to be responsible for cellular effects of nanomaterials. Epigenetic regulation by nanomaterials, effects of nanoparticle-protein interactions on cell signaling pathways, and the induction of various cell death modalities by nanomaterials are described. We describe the common trigger mechanisms shared by various nanomaterials to induce cell death pathways and describe the interplay of different modalities in orchestrating the final outcome after nanomaterial exposures. A better understanding of signal modulations induced by nanomaterials is not only essential for the synthesis and design of safer nanomaterials but will also help to discover potential nanomedical applications of these materials. Several biomedical applications based on the different signaling pathways induced by nanomaterials are already proposed and will certainly gain a great deal of attraction in the near future.

  4. A Serpentine Way to Signaling

    Indian Academy of Sciences (India)

    IAS Admin

    tude inside the cells, leading to activation of effectors molecules. Effectors are protein molecules that bind to DNA and cause. Figure 1. Simplified diagram of a signal transduction cas- cade. A signal transduction cascade represents the route of transfer of information from outside to inside the cell. There are many molecules.

  5. Presence capture cameras - a new challenge to the image quality

    Science.gov (United States)

    Peltoketo, Veli-Tapani

    2016-04-01

    Commercial presence capture cameras are coming to the markets and a new era of visual entertainment starts to get its shape. Since the true presence capturing is still a very new technology, the real technical solutions are just passed a prototyping phase and they vary a lot. Presence capture cameras have still the same quality issues to tackle as previous phases of digital imaging but also numerous new ones. This work concentrates to the quality challenges of presence capture cameras. A camera system which can record 3D audio-visual reality as it is has to have several camera modules, several microphones and especially technology which can synchronize output of several sources to a seamless and smooth virtual reality experience. Several traditional quality features are still valid in presence capture cameras. Features like color fidelity, noise removal, resolution and dynamic range create the base of virtual reality stream quality. However, co-operation of several cameras brings a new dimension for these quality factors. Also new quality features can be validated. For example, how the camera streams should be stitched together with 3D experience without noticeable errors and how to validate the stitching? The work describes quality factors which are still valid in the presence capture cameras and defines the importance of those. Moreover, new challenges of presence capture cameras are investigated in image and video quality point of view. The work contains considerations how well current measurement methods can be used in presence capture cameras.

  6. Presence of chaperones during pelvic examinations in southeast ...

    African Journals Online (AJOL)

    Objectives: To assess the opinions, attitude, and preferences of Nigerian women to the presence of chaperones during pelvic examinations. Materials and Methods: A cross‑sectional survey of first time gynecology clinic attendees on their opinions, attitudes, and preferences with respect to the presence of chaperones ...

  7. Privacy implications of presence sharing in mobile messaging applications

    NARCIS (Netherlands)

    Buchenscheit, Andreas; Könings, Bastian; Neubert, Andreas; Schaub, Florian; Schneider, Matthias; Kargl, Frank

    2014-01-01

    Mobile messaging applications, such as WhatsApp, provide a free alternative for mobile texting on smartphones. Mobile messengers typically also share presence information about users to indicate when a user is online. We investigated the privacy implications of such presence updates, using WhatsApp

  8. Effect of plant cover on presence of Black Francolin (Francolinus ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-06-21

    Jun 21, 2010 ... factors threatening the populations of these birds in Khouzestan Province, southwestern Iran. Using plot sampling, this study aims to investigate different vegetative factors including plant species, percentage of species presence and dominant plant cover height on francolin presence. Sampling was.

  9. Increasing Social Presence in Online Learning through Small Group Discussions

    Science.gov (United States)

    Akcaoglu, Mete; Lee, Eunbae

    2016-01-01

    Social presence is difficult to achieve, but an imperative component of online learning. In this study, we investigated the effect of group size on students' perceptions of social presence in two graduate-level online courses, comparing small group versus whole class discussions. Our results indicated that when in small group discussions, students…

  10. Attitudes towards parental presence at induction of anaesthesia

    African Journals Online (AJOL)

    induction of anaesthesia,~Many paediatric anaesthetists today would agree that parental presence at induction is ... personal attitudes to parental presence, perceived benefits for the child and parent, and negative ... the X2 goodness of fit test for a single sample to compare the number of respondents who disagreed with ...

  11. Online Interactions and Social Presence in Online Learning

    Science.gov (United States)

    Lee, Sang Joon; Huang, Kun

    2018-01-01

    The community of inquiry framework identified three essential elements of cognitive, social, and teaching presences for a successful online learning experience. Among them, social presence is key for developing personal relationships and enhancing collaboration and critical discourse in online courses. This study examined whether providing more…

  12. Signal processing for radiation detectors

    CERN Document Server

    Nakhostin, Mohammad

    2018-01-01

    This book provides a clear understanding of the principles of signal processing of radiation detectors. It puts great emphasis on the characteristics of pulses from various types of detectors and offers a full overview on the basic concepts required to understand detector signal processing systems and pulse processing techniques. Signal Processing for Radiation Detectors covers all of the important aspects of signal processing, including energy spectroscopy, timing measurements, position-sensing, pulse-shape discrimination, and radiation intensity measurement. The book encompasses a wide range of applications so that readers from different disciplines can benefit from all of the information. In addition, this resource: * Describes both analog and digital techniques of signal processing * Presents a complete compilation of digital pulse processing algorithms * Extrapolates content from more than 700 references covering classic papers as well as those of today * Demonstrates concepts with more than 340 origin...

  13. Signal focusing through active transport

    Science.gov (United States)

    Godec, Aljaž; Metzler, Ralf

    2015-07-01

    The accuracy of molecular signaling in biological cells and novel diagnostic devices is ultimately limited by the counting noise floor imposed by the thermal diffusion. Motivated by the fact that messenger RNA and vesicle-engulfed signaling molecules transiently bind to molecular motors and are actively transported in biological cells, we show here that the random active delivery of signaling particles to within a typical diffusion distance to the receptor generically reduces the correlation time of the counting noise. Considering a variety of signaling particle sizes from mRNA to vesicles and cell sizes from prokaryotic to eukaryotic cells, we show that the conditions for active focusing—faster and more precise signaling—are indeed compatible with observations in living cells. Our results improve the understanding of molecular cellular signaling and novel diagnostic devices.

  14. Endocannabinoid signaling and synaptic function

    Science.gov (United States)

    Castillo, Pablo E.; Younts, Thomas J.; Chávez, Andrés E.; Hashimotodani, Yuki

    2012-01-01

    Endocannabinoids are key modulators of synaptic function. By activating cannabinoid receptors expressed in the central nervous system, these lipid messengers can regulate several neural functions and behaviors. As experimental tools advance, the repertoire of known endocannabinoid-mediated effects at the synapse, and their underlying mechanism, continues to expand. Retrograde signaling is the principal mode by which endocannabinoids mediate short- and long-term forms of plasticity at both excitatory and inhibitory synapses. However, growing evidence suggests that endocannabinoids can also signal in a non-retrograde manner. In addition to mediating synaptic plasticity, the endocannabinoid system is itself subject to plastic changes. Multiple points of interaction with other neuromodulatory and signaling systems have now been identified. Synaptic endocannabinoid signaling is thus mechanistically more complex and diverse than originally thought. In this review, we focus on new advances in endocannabinoid signaling and highlight their role as potent regulators of synaptic function in the mammalian brain. PMID:23040807

  15. Piezoelectric extraction of ECG signal

    Science.gov (United States)

    Ahmad, Mahmoud Al

    2016-11-01

    The monitoring and early detection of abnormalities or variations in the cardiac cycle functionality are very critical practices and have significant impact on the prevention of heart diseases and their associated complications. Currently, in the field of biomedical engineering, there is a growing need for devices capable of measuring and monitoring a wide range of cardiac cycle parameters continuously, effectively and on a real-time basis using easily accessible and reusable probes. In this paper, the revolutionary generation and extraction of the corresponding ECG signal using a piezoelectric transducer as alternative for the ECG will be discussed. The piezoelectric transducer pick up the vibrations from the heart beats and convert them into electrical output signals. To this end, piezoelectric and signal processing techniques were employed to extract the ECG corresponding signal from the piezoelectric output voltage signal. The measured electrode based and the extracted piezoelectric based ECG traces are well corroborated. Their peaks amplitudes and locations are well aligned with each other.

  16. Aberrant Signaling Pathways in Glioma

    International Nuclear Information System (INIS)

    Nakada, Mitsutoshi; Kita, Daisuke; Watanabe, Takuya; Hayashi, Yutaka; Teng, Lei; Pyko, Ilya V.; Hamada, Jun-Ichiro

    2011-01-01

    Glioblastoma multiforme (GBM), a WHO grade IV malignant glioma, is the most common and lethal primary brain tumor in adults; few treatments are available. Median survival rates range from 12–15 months. The biological characteristics of this tumor are exemplified by prominent proliferation, active invasiveness, and rich angiogenesis. This is mainly due to highly deregulated signaling pathways in the tumor. Studies of these signaling pathways have greatly increased our understanding of the biology and clinical behavior of GBM. An integrated view of signal transduction will provide a more useful approach in designing novel therapies for this devastating disease. In this review, we summarize the current understanding of GBM signaling pathways with a focus on potential molecular targets for anti-signaling molecular therapies

  17. "Being there" and remembering it: Presence improves memory encoding.

    Science.gov (United States)

    Makowski, Dominique; Sperduti, Marco; Nicolas, Serge; Piolino, Pascale

    2017-08-01

    Few studies have investigated the link between episodic memory and presence: the feeling of "being there" and reacting to a stimulus as if it were real. We collected data from 244 participants after they had watched the movie Avengers: Age of Ultron. They answered questions about factual (details of the movie) and temporal memory (order of the scenes) about the movie, as well as their emotion experience and their sense of presence during the projection. Both higher emotion experience and sense of presence were related to better factual memory, but not to temporal order memory. Crucially, the link between emotion and factual memory was mediated by the sense of presence. We interpreted the role of presence as an external absorption of the attentional focus toward the stimulus, thus enhancing memory encoding. Our findings could shed light on the cognitive processes underlying memory impairments in psychiatric conditions characterized by an altered sense of reality. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Applying advanced digital signal processing techniques in industrial radioisotopes applications

    International Nuclear Information System (INIS)

    Mahmoud, H.K.A.E.

    2012-01-01

    Radioisotopes can be used to obtain signals or images in order to recognize the information inside the industrial systems. The main problems of using these techniques are the difficulty of identification of the obtained signals or images and the requirement of skilled experts for the interpretation process of the output data of these applications. Now, the interpretation of the output data from these applications is performed mainly manually, depending heavily on the skills and the experience of trained operators. This process is time consuming and the results typically suffer from inconsistency and errors. The objective of the thesis is to apply the advanced digital signal processing techniques for improving the treatment and the interpretation of the output data from the different Industrial Radioisotopes Applications (IRA). This thesis focuses on two IRA; the Residence Time Distribution (RTD) measurement and the defect inspection of welded pipes using a gamma source (gamma radiography). In RTD measurement application, this thesis presents methods for signal pre-processing and modeling of the RTD signals. Simulation results have been presented for two case studies. The first case study is a laboratory experiment for measuring the RTD in a water flow rig. The second case study is an experiment for measuring the RTD in a phosphate production unit. The thesis proposes an approach for RTD signal identification in the presence of noise. In this approach, after signal processing, the Mel Frequency Cepstral Coefficients (MFCCs) and polynomial coefficients are extracted from the processed signal or from one of its transforms. The Discrete Wavelet Transform (DWT), Discrete Cosine Transform (DCT), and Discrete Sine Transform (DST) have been tested and compared for efficient feature extraction. Neural networks have been used for matching of the extracted features. Furthermore, the Power Density Spectrum (PDS) of the RTD signal has been also used instead of the discrete

  19. Laser signals' nonlinear change in fatty acids

    CERN Document Server

    Ghelmez-Dumitru, M; Piscureanu, M; Sterian, A

    2003-01-01

    Previous works showed that thin layers of fatty acids and fatty acid-cholesterol mixtures behaved as optical liquid crystals, even at low incident laser power. The paper presents an experimental and computer study of laser signals, emergent from such samples, in presence of fluctuations. The optical emergent laser beams' features at different incident parameters were experimentally determined for different type (c.w. and pulsed) lasers, as for example helium-neon and Nd sup 3 sup + glass lasers. The results were correlated with the amount of cholesterol in mixtures and with their response in external electric field. These measurements are in all cases affected by fluctuations. We developed some computer-based procedures, by using the TableCurve3D from Jandel Scientific software and equations Runge-Kutta in MATLAB for taking into account these fluctuations.

  20. Stripping potentiometric analysis: application to determination of metallic cations in presence of uranium

    International Nuclear Information System (INIS)

    Pereira-Ramos, J.P.; Chivot, J.; Sarantopoulos, F.; Godard, R.

    1984-01-01

    Potentiometric stripping analysis consists of a potentiostatic deposition step of trace elements and a subsequent stripping step. The trace metals are simultaneously reduced at a rotating electrode, the working electrode being a mercury film coated glassy carbon electrode; the amalgamated metals are then re-oxidized with an oxidizing agent. The analytical signal of this method is the time required for complete re-oxidation. Influence of different parameters on the analytical signal is studied by using mercury (II) ions as oxidizing agent in 5.10 -4 M H 2 SO 4 aqueous solution. Here, we point out the main characteristics of the potentiometric stripping analysis under the same experimental conditions. The reproductibility ranges are comprised between 0.5% to 1.5% and the detection limit for cadmium (II) is estimated to be 2.10 -10 M with a plating time of 300 seconds. Small quantities, as 10 -7 M Cd 2+ , Pb 2+ and Zn 2+ are simultaneously determined in presence of U (VI) ions (UO 2 2+ ) with an accuracy of 0.5% for Cd 2+ and Zn 2+ , and 4.5% for Pb 2+ . Compared to well-known electrochemical techniques, potentiometric stripping analysis appears to be a performing method for trace analysis in a wide range of media: this method permits the analysis of elements in presence of species more concentrated and being able to oxidize the trace elements [fr

  1. Showing Off in Humans: Male Generosity as a Mating Signal

    Directory of Open Access Journals (Sweden)

    Wendy Iredale

    2008-07-01

    Full Text Available We examined people's charity contributions while in the presence of an observer of the same sex, opposite sex, or no observer. Inspired by costly signaling theory, we hypothesized that men would be more generous in the presence of a potential mate. Men and women played a number of experimental games in which they could earn money. On completion of these games participants were asked what percentage of their earned money they would be willing to donate to charity. Our results show that men contribute more to charity when observed by a member of the opposite sex than by a member of the same sex or no observer. Conversely, female charity donations did not significantly vary across the three observer conditions. Findings support the notion that men's generosity might have evolved as a mating signal.

  2. Quorum Quenching Revisited—From Signal Decays to Signalling Confusion

    Directory of Open Access Journals (Sweden)

    Kok-Gan Chan

    2012-04-01

    Full Text Available In a polymicrobial community, while some bacteria are communicating with neighboring cells (quorum sensing, others are interrupting the communication (quorum quenching, thus creating a constant arms race between intercellular communication. In the past decade, numerous quorum quenching enzymes have been found and initially thought to inactivate the signalling molecules. Though this is widely accepted, the actual roles of these quorum quenching enzymes are now being uncovered. Recent evidence extends the role of quorum quenching to detoxification or metabolism of signalling molecules as food and energy source; this includes “signalling confusion”, a term coined in this paper to refer to the phenomenon of non-destructive modification of signalling molecules. While quorum quenching has been explored as a novel anti-infective therapy targeting, quorum sensing evidence begins to show the development of resistance against quorum quenching.

  3. Signal transduction by growth factor receptors: signaling in an instant

    DEFF Research Database (Denmark)

    Dengjel, Joern; Akimov, Vyacheslav; Blagoev, Blagoy

    2007-01-01

    -out by mass spectrometry-based proteomics has allowed exciting views on the very early events in signal transduction. Activation profiles of regulated phosphorylation sites on epidermal growth factor receptor and downstream signal transducers showed different kinetics within the first ten seconds......Phosphorylation-based signaling events happening within the first minute of receptor stimulation have so far only been analyzed by classical cell biological approaches like live-cell microscopy. The development of a quench flow system with a time resolution of one second coupled to a read...... of stimulation. This new technique opens the perspectives for accurate analysis of rapid cellular processes and will help to establish models describing signal initiation at the plasma membrane....

  4. MHC signaling during social communication

    Science.gov (United States)

    Ruff, James S.; Nelson, Adam C.; Kubinak, Jason L.; Potts, Wayne K.

    2016-01-01

    The major histocompatibility complex (MHC) has been known to play a critical role in immune recognition since the 1950s. It was a surprise, then, in the 1970s when the first report appeared indicating MHC might also function in social signaling and in mate choice. Since this seminal discovery, MHC signaling has been found throughout vertebrates and its known functions have expanded beyond mate choice to include a suite of behaviors from kin-biased cooperation, parent-progeny recognition to pregnancy block. The widespread occurrence of MHC in social signaling has revealed conserved behavioral-genetic mechanisms that span vertebrates and includes humans. The identity of the signal’s chemical constituents and the receptors responsible for the perception of the signal have remained elusive, but recent advances have enabled the identification of the key components of the behavioral circuit. In this chapter we organize recent findings from the literature and discuss them in relation to four non-mutually exclusive models wherein MHC functions as a signal of (i) individuality, (ii) relatedness, (iii) genetic compatibility and (iv) quality. We also synthesize current mechanistic studies, showing how knowledge about the molecular basis of MHC signaling can lead to elegant and informative experimental manipulations. Finally, we discuss current evidence relating to the primordial functions of the MHC, including the possibility that its role in social signaling may be ancestral to its central role in adaptive immunity. PMID:22399386

  5. Baird's beaked whale echolocation signals.

    Science.gov (United States)

    Baumann-Pickering, Simone; Yack, Tina M; Barlow, Jay; Wiggins, Sean M; Hildebrand, John A

    2013-06-01

    Echolocation signals from Baird's beaked whales were recorded during visual and acoustic shipboard surveys of cetaceans in the California Current ecosystem and with autonomous, long-term recorders in the Southern California Bight. The preliminary measurement of the visually validated Baird's beaked whale echolocation signals from towed array data were used as a basis for identifying Baird's signals in the autonomous recorder data. Two distinct signal types were found, one being a beaked whale-like frequency modulated (FM) pulse, the other being a dolphin-like broadband click. The median FM inter-pulse interval was 230 ms. Both signal types showed a consistent multi-peak structure in their spectra with peaks at ~9, 16, 25, and 40 kHz. Depending on signal type, as well as recording aspect and distance to the hydrophone, these peaks varied in relative amplitude. The description of Baird's echolocation signals will allow for studies of their distribution and abundance using towed array data without associated visual sightings and from autonomous seafloor hydrophones.

  6. Microsystem for signal processing applications

    Science.gov (United States)

    Frankenstein, B.; Froehlich, K.-J.; Hentschel, D.; Reppe, G.

    2005-05-01

    Acoustic monitoring of technological processes requires methods that eliminate noise as much as possible. Sensor-near signal evaluation can contribute substantially. Frequently, a further necessity exists to integrate the measuring technique in the monitored structure. The solution described contains components for analog preprocessing of acoustic signals, their digitization, algorithms for data reduction, and digital communication. The core component is a digital signal processor (DSP). Digital signal processors perform the algorithms necessary for filtering, down sampling, FFT computation and correlation of spectral components particularly effective. A compact, sensor-near signal processing structure was realized. It meets the Match-X standard, which as specified by the German Association for Mechanical and Plant Engineering (VDMA) for development of micro-technical modules, which can be combined to applicaiton specific systems. The solution is based on AL2O3 ceramic components including different signal processing modules as ADC, as well as memory and power supply. An arbitrary waveform generator has been developed and combined with a power amplifier for piezoelectric transducers in a special module. A further module interfaces to these transducers. It contains a multi-channel preamplifier, some high-pass filters for analog signal processing and an ADC-driver. A Bluetooth communication chip for wireless data transmission and a DiscOnChip module are under construction. As a first application, the combustion behavior of safety-relevant contacts is monitored. A special waveform up to 5MHz is produced and sent to the monitored object. The resulting signal form is evaluated with special algorithms, which extract significant parameters of the signal, and transmitted via CAN-bus.

  7. Noise reduction in intracranial pressure signal using causal shape manifolds.

    Science.gov (United States)

    Rajagopal, Abhejit; Hamilton, Robert B; Scalzo, Fabien

    2016-07-01

    We present the Iterative/Causal Subspace Tracking framework (I/CST) for reducing noise in continuously monitored quasi-periodic biosignals. Signal reconstruction of the basic segments of the noisy signal (e.g. beats) is achieved by projection to a reduced space on which probabilistic tracking is performed. The attractiveness of the presented method lies in the fact that the subspace, or manifold, is learned by incorporating temporal, morphological, and signal elevation constraints, so that segment samples with similar shapes, and that are close in time and elevation, are also close in the subspace representation. Evaluation of the algorithm's effectiveness on the intracranial pressure (ICP) signal serves as a practical illustration of how it can operate in clinical conditions on routinely acquired biosignals. The reconstruction accuracy of the system is evaluated on an idealized 20-min ICP recording established from the average ICP of patients monitored for various ICP related conditions. The reconstruction accuracy of the ground truth signal is tested in presence of varying levels of additive white Gaussian noise (AWGN) and Poisson noise processes, and measures significant increases of 758% and 396% in the average signal-to-noise ratio (SNR).

  8. Advanced optical signal processing of broadband parallel data signals

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Hu, Hao; Kjøller, Niels-Kristian

    2016-01-01

    Optical signal processing may aid in reducing the number of active components in communication systems with many parallel channels, by e.g. using telescopic time lens arrangements to perform format conversion and allow for WDM regeneration.......Optical signal processing may aid in reducing the number of active components in communication systems with many parallel channels, by e.g. using telescopic time lens arrangements to perform format conversion and allow for WDM regeneration....

  9. Fast digitizing and digital signal processing of detector signals

    International Nuclear Information System (INIS)

    Hannaske, Roland

    2008-01-01

    A fast-digitizer data acquisition system recently installed at the neutron time-of-flight experiment nELBE, which is located at the superconducting electron accelerator ELBE of Forschungszentrum Dresden-Rossendorf, is tested with two different detector types. Preamplifier signals from a high-purity germanium detector are digitized, stored and finally processed. For a precise determination of the energy of the detected radiation, the moving-window deconvolution algorithm is used to compensate the ballistic deficit and different shaping algorithms are applied. The energy resolution is determined in an experiment with γ-rays from a 22 Na source and is compared to the energy resolution achieved with analogously processed signals. On the other hand, signals from the photomultipliers of barium fluoride and plastic scintillation detectors are digitized. These signals have risetimes of a few nanoseconds only. The moment of interaction of the radiation with the detector is determined by methods of digital signal processing. Therefore, different timing algorithms are implemented and tested with data from an experiment at nELBE. The time resolutions achieved with these algorithms are compared to each other as well as to reference values coming from analog signal processing. In addition to these experiments, some properties of the digitizing hardware are measured and a program for the analysis of stored, digitized data is developed. The analysis of the signals shows that the energy resolution achieved with the 10-bit digitizer system used here is not competitive to a 14-bit peak-sensing ADC, although the ballistic deficit can be fully corrected. However, digital methods give better result in sub-ns timing than analog signal processing. (orig.)

  10. Seismic signals from Dust Devils on Mars

    Science.gov (United States)

    Kenda, Balthasar; Lognonné, Philippe; Spiga, Aymeric; Kawamura, Taichi; Kedar, Sharon; Banerdt, Bruce; Lorenz, Ralph

    2016-10-01

    We modeled the long-period seismic signals generated by Dust Devils and convective vortices on Mars. To characterize the source term, we used Large-Eddy Simulations with a spatial resolution of 50 m that resolve large turbulent and convective structures of the Martian atmosphere. The corresponding surface pressure fluctuations induce a quasi-static ground displacement and thus a tilt of the surface, which over weak soils can be detected by sensitive seismometers, as shown in terrestrial field experiments. Typical convective vortices on Mars have core-pressure drops of 2-5 Pa and generate tilt accelerations of 10-20 nm/s2 over a regolith halfspace, and of a few nm/s2 in the presence of a layer of harder rock at shallow depth. This signals are strong enough to be detected by the Very-Broad Band seismometer of the InSight/SEIS experiment up to a distance of several tens of meters from the vortex. The results of numerical simulations are compared to meteorological data from previous mission to Mars, and they give estimates of the encounter frequencies, showing how convective vortices will be routinely detected during the central hours of the day. A joint analysis of meteorological and seismic data will permit to distinguish atmospheric episodes from internal seimic sources and to investigate the structure and the elastic properties of the near surface at the InSight landing site.

  11. NO signaling in retinal bipolar cells.

    Science.gov (United States)

    Agurto, A; Vielma, A H; Cadiz, B; Couve, E; Schmachtenberg, O

    2017-08-01

    Nitric oxide (NO) is a neuromodulator involved in physiological and pathological processes in the retina. In the inner retina, a subgroup of amacrine cells have been shown to synthesize NO, but bipolar cells remain controversial as NO sources. This study correlates NO synthesis in dark-adapted retinas, through labeling with the NO marker DAF-FM, with neuronal nitric oxide synthase (nNOS) and inducible NOS expression, and presence of the NO receptor soluble guanylate cyclase in bipolar cells. NO containing bipolar cells were morphologically identified by dialysis of DAF fluorescent cells with intracellular dyes, or by DAF labeling followed by immunohistochemistry for nNOS and other cellular markers. DAF fluorescence was observed in all types of bipolar cells that could be identified, but the most intense DAF fluorescence was observed in bipolar cells with severed processes, supporting pathological NO signaling. Among nNOS expressing bipolar cells, type 9 was confirmed unequivocally, while types 2, 3a, 3b, 4, 5, 7, 8 and the rod bipolar cell were devoid of this enzyme. These results establish specific bipolar cell types as NO sources in the inner retina, and support the involvement of NO signaling in physiological and pathological processes in the inner retina. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. ESR signals of irradiated insects

    International Nuclear Information System (INIS)

    Ukai, Mitsuko; Kameya, Hiromi; Imamura, Taro; Miyanoshita, Akihiro; Todoriki, Setsuko; Shimoyama, Yuhei

    2009-01-01

    Analysis of irradiated insects using Electron Spin Resonance (ESR) spectroscopy was reported. The insects were maize weevil, red flour beetle, Indian meal moth and cigarette beetle that are hazardous to crops. The ESR spectra were consisted of a singlet at g=2 and a sextet centered at the similar g-value. The singlet signal is due to an organic free radical. The sextet signal is attributable to the hyperfine interactions from Mn 2+ ions. Upon irradiation, new signals were not detected. The relaxation times, T 1 and T 2 , showed no variations before and after irradiation. (author)

  13. Ultrasound imaging using coded signals

    DEFF Research Database (Denmark)

    Misaridis, Athanasios

    coded excitation can be used for increasing the frame rate. The work includes both simulated results using Field II, and experimental results based on measurements on phantoms as well as clinical images. Initially a mathematical foundation of signal modulation is given. Pulse compression based...... is described. Application of coded excitation in array imaging is evaluated through simulations in Field II. The low degree of the orthogonality among coded signals for ultrasound systems is first discussed, and the effect of mismatched filtering in the cross-correlation properties of the signals is evaluated...... emissions. Finally, a novel coding technique which uses pulse train excitation is presented....

  14. Statistical theory of signal detection

    CERN Document Server

    Helstrom, Carl Wilhelm; Costrell, L; Kandiah, K

    1968-01-01

    Statistical Theory of Signal Detection, Second Edition provides an elementary introduction to the theory of statistical testing of hypotheses that is related to the detection of signals in radar and communications technology. This book presents a comprehensive survey of digital communication systems. Organized into 11 chapters, this edition begins with an overview of the theory of signal detection and the typical detection problem. This text then examines the goals of the detection system, which are defined through an analogy with the testing of statistical hypotheses. Other chapters consider

  15. Subjective Evaluation of Audiovisual Signals

    Directory of Open Access Journals (Sweden)

    F. Fikejz

    2010-01-01

    Full Text Available This paper deals with subjective evaluation of audiovisual signals, with emphasis on the interaction between acoustic and visual quality. The subjective test is realized by a simple rating method. The audiovisual signal used in this test is a combination of images compressed by JPEG compression codec and sound samples compressed by MPEG-1 Layer III. Images and sounds have various contents. It simulates a real situation when the subject listens to compressed music and watches compressed pictures without the access to original, i.e. uncompressed signals.

  16. EUROmediCAT signal detection

    DEFF Research Database (Denmark)

    Given, Joanne E; Loane, Maria; Luteijn, Johannes Michiel

    2016-01-01

    AIMS: To evaluate congenital anomaly (CA)-medication exposure associations produced by the new EUROmediCAT signal detection system and determine which require further investigation. METHODS: Data from 15 EUROCAT registries (1995-2011) with medication exposures at the chemical substance (5th level...... persisted after data validation, a literature review was conducted for prior evidence of human teratogenicity. RESULTS: Thirteen out of 27 CA-medication exposure signals, based on 389 exposed cases, passed data validation. There was some prior evidence in the literature to support six signals (gastroschisis...

  17. On Generalized Fractional Differentiator Signals

    Directory of Open Access Journals (Sweden)

    Hamid A. Jalab

    2013-01-01

    Full Text Available By employing the generalized fractional differential operator, we introduce a system of fractional order derivative for a uniformly sampled polynomial signal. The calculation of the bring in signal depends on the additive combination of the weighted bring-in of N cascaded digital differentiators. The weights are imposed in a closed formula containing the Stirling numbers of the first kind. The approach taken in this work is to consider that signal function in terms of Newton series. The convergence of the system to a fractional time differentiator is discussed.

  18. Terminality implies non-signalling

    Directory of Open Access Journals (Sweden)

    Bob Coecke

    2014-12-01

    Full Text Available A 'process theory' is any theory of systems and processes which admits sequential and parallel composition. `Terminality' unifies normalisation of pure states, trace-preservation of CP-maps, and adding up to identity of positive operators in quantum theory, and generalises this to arbitrary process theories. We show that terminality and non-signalling coincide in any process theory, provided one makes causal structure explicit. In fact, making causal structure explicit is necessary to even make sense of non-signalling in process theories. We conclude that because of its much simpler mathematical form, terminality should be taken to be a more fundamental notion than non-signalling.

  19. Performance analysis of chaotic and white watermarks in the presence of common watermark attacks

    International Nuclear Information System (INIS)

    Mooney, Aidan; Keating, John G.; Heffernan, Daniel M.

    2009-01-01

    Digital watermarking is a technique that aims to embed a piece of information permanently into some digital media, which may be used at a later stage to prove owner authentication and attempt to provide protection to documents. The most common watermark types used to date are pseudorandom number sequences which possess a white spectrum. Chaotic watermark sequences have been receiving increasing interest recently and have been shown to be an alternative to the pseudorandom watermark types. In this paper the performance of pseudorandom watermarks and chaotic watermarks in the presence of common watermark attacks is performed. The chaotic watermarks are generated from the iteration of the skew tent map, the Bernoulli map and the logistic map. The analysis focuses on the watermarked images after they have been subjected to common image distortion attacks. The capacities of each of these images are also calculated. It is shown that signals generated from lowpass chaotic signals have superior performance over the other signal types analysed for the attacks studied.

  20. Presence and biofeedback in first-person perspective computer games

    DEFF Research Database (Denmark)

    Grimshaw-Aagaard, Mark Nicholas

    2019-01-01

    . Following the line taken by presence theorists, I differentiate between immersion, an objective measure such that computer game technology can be less or more immersive, and presence, a subjective, human response to that technology. The third section looks at current possibilities for biofeedback...... in relation to sound design for first-person perspective computer games; in line with the first section, biofeedback devices are treated as an immersive technology. I close the chapter by suggesting ways in which sound design in such games might make use of biofeedback to enhance the perception of presence...

  1. A Note on optimal estimation in the presence of outliers

    Directory of Open Access Journals (Sweden)

    John N. Haddad

    2017-06-01

    Full Text Available Haddad, J. 2017. A Note on optimal estimation in the presence of outliers. Lebanese Science Journal, 18(1: 136-141. The basic estimation problem of the mean and standard deviation of a random normal process in the presence of an outlying observation is considered. The value of the outlier is taken as a constraint imposed on the maximization problem of the log likelihood. It is shown that the optimal solution of the maximization problem exists and expressions for the estimates are given. Applications to estimation in the presence of outliers and outlier detection are discussed and illustrated through a simulation study and analysis of trade data

  2. Manipulating Bodily Presence Affects Cross-Modal Spatial Attention: A Virtual-Reality-Based ERP Study.

    Science.gov (United States)

    Harjunen, Ville J; Ahmed, Imtiaj; Jacucci, Giulio; Ravaja, Niklas; Spapé, Michiel M

    2017-01-01

    Earlier studies have revealed cross-modal visuo-tactile interactions in endogenous spatial attention. The current research used event-related potentials (ERPs) and virtual reality (VR) to identify how the visual cues of the perceiver's body affect visuo-tactile interaction in endogenous spatial attention and at what point in time the effect takes place. A bimodal oddball task with lateralized tactile and visual stimuli was presented in two VR conditions, one with and one without visible hands, and one VR-free control with hands in view. Participants were required to silently count one type of stimulus and ignore all other stimuli presented in irrelevant modality or location. The presence of hands was found to modulate early and late components of somatosensory and visual evoked potentials. For sensory-perceptual stages, the presence of virtual or real hands was found to amplify attention-related negativity on the somatosensory N140 and cross-modal interaction in somatosensory and visual P200. For postperceptual stages, an amplified N200 component was obtained in somatosensory and visual evoked potentials, indicating increased response inhibition in response to non-target stimuli. The effect of somatosensory, but not visual, N200 enhanced when the virtual hands were present. The findings suggest that bodily presence affects sustained cross-modal spatial attention between vision and touch and that this effect is specifically present in ERPs related to early- and late-sensory processing, as well as response inhibition, but do not affect later attention and memory-related P3 activity. Finally, the experiments provide commeasurable scenarios for the estimation of the signal and noise ratio to quantify effects related to the use of a head mounted display (HMD). However, despite valid a-priori reasons for fearing signal interference due to a HMD, we observed no significant drop in the robustness of our ERP measurements.

  3. Performance of the split-symbol moments SNR estimator in the presence of inter-symbol interference

    Science.gov (United States)

    Shah, B.; Hinedi, S.

    1989-01-01

    The Split-Symbol Moments Estimator (SSME) is an algorithm that is designed to estimate symbol signal-to-noise ratio (SNR) in the presence of additive white Gaussian noise (AWGN). The performance of the SSME algorithm in band-limited channels is examined. The effects of the resulting inter-symbol interference (ISI) are quantified. All results obtained are in closed form and can be easily evaluated numerically for performance prediction purposes. Furthermore, they are validated through digital simulations.

  4. Dynamic time warping and machine learning for signal quality assessment of pulsatile signals

    International Nuclear Information System (INIS)

    Li, Q; Clifford, G D

    2012-01-01

    In this work, we describe a beat-by-beat method for assessing the clinical utility of pulsatile waveforms, primarily recorded from cardiovascular blood volume or pressure changes, concentrating on the photoplethysmogram (PPG). Physiological blood flow is nonstationary, with pulses changing in height, width and morphology due to changes in heart rate, cardiac output, sensor type and hardware or software pre-processing requirements. Moreover, considerable inter-individual and sensor-location variability exists. Simple template matching methods are therefore inappropriate, and a patient-specific adaptive initialization is therefore required. We introduce dynamic time warping to stretch each beat to match a running template and combine it with several other features related to signal quality, including correlation and the percentage of the beat that appeared to be clipped. The features were then presented to a multi-layer perceptron neural network to learn the relationships between the parameters in the presence of good- and bad-quality pulses. An expert-labeled database of 1055 segments of PPG, each 6 s long, recorded from 104 separate critical care admissions during both normal and verified arrhythmic events, was used to train and test our algorithms. An accuracy of 97.5% on the training set and 95.2% on test set was found. The algorithm could be deployed as a stand-alone signal quality assessment algorithm for vetting the clinical utility of PPG traces or any similar quasi-periodic signal. (paper)

  5. Separating astrophysical sources from indirect dark matter signals

    Science.gov (United States)

    Siegal-Gaskins, Jennifer M.

    2015-01-01

    Indirect searches for products of dark matter annihilation and decay face the challenge of identifying an uncertain and subdominant signal in the presence of uncertain backgrounds. Two valuable approaches to this problem are (i) using analysis methods which take advantage of different features in the energy spectrum and angular distribution of the signal and backgrounds and (ii) more accurately characterizing backgrounds, which allows for more robust identification of possible signals. These two approaches are complementary and can be significantly strengthened when used together. I review the status of indirect searches with gamma rays using two promising targets, the Inner Galaxy and the isotropic gamma-ray background. For both targets, uncertainties in the properties of backgrounds are a major limitation to the sensitivity of indirect searches. I then highlight approaches which can enhance the sensitivity of indirect searches using these targets. PMID:25304638

  6. Subcellular Organization of GPCR Signaling.

    Science.gov (United States)

    Eichel, Kelsie; von Zastrow, Mark

    2018-02-01

    G protein-coupled receptors (GPCRs) comprise a large and diverse class of signal-transducing receptors that undergo dynamic and isoform-specific membrane trafficking. GPCRs thus have an inherent potential to initiate or regulate signaling reactions from multiple membrane locations. This review discusses emerging insights into the subcellular organization of GPCR function in mammalian cells, focusing on signaling transduced by heterotrimeric G proteins and β-arrestins. We summarize recent evidence indicating that GPCR-mediated activation of G proteins occurs not only from the plasma membrane (PM) but also from endosomes and Golgi membranes and that β-arrestin-dependent signaling can be transduced from the PM by β-arrestin trafficking to clathrin-coated pits (CCPs) after dissociation from a ligand-activated GPCR. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Automobile Crash Sensor Signal Processor

    Science.gov (United States)

    1973-11-01

    The crash sensor signal processor described interfaces between an automobile-installed doppler radar and an air bag activating solenoid or equivalent electromechanical device. The processor utilizes both digital and analog techniques to produce an ou...

  8. Endothelial signaling in leukocyte transmigration

    NARCIS (Netherlands)

    Hordijk, Peter

    2003-01-01

    Leukocyte transendothelial migration is a multistep process coordinated by chemokine receptors, integrins and cell adhesion molecules. The interaction between leukocytes and endothelial cells is accompanied by bidirectional signaling in both cell types, which is initiated following formation of

  9. Invariants of DNA genomic signals

    Science.gov (United States)

    Cristea, Paul Dan A.

    2005-02-01

    For large scale analysis purposes, the conversion of genomic sequences into digital signals opens the possibility to use powerful signal processing methods for handling genomic information. The study of complex genomic signals reveals large scale features, maintained over the scale of whole chromosomes, that would be difficult to find by using only the symbolic representation. Based on genomic signal methods and on statistical techniques, the paper defines parameters of DNA sequences which are invariant to transformations induced by SNPs, splicing or crossover. Re-orienting concatenated coding regions in the same direction, regularities shared by the genomic material in all exons are revealed, pointing towards the hypothesis of a regular ancestral structure from which the current chromosome structures have evolved. This property is not found in non-nuclear genomic material, e.g., plasmids.

  10. Dopamine signaling: target in glioblastoma

    Czech Academy of Sciences Publication Activity Database

    Bartek, Jiří; Hodný, Zdeněk

    2014-01-01

    Roč. 5, č. 5 (2014), 1116-1117 ISSN 1949-2553 Institutional support: RVO:68378050 Keywords : Dopamine signaling * glioblastoma * MAPK Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.359, year: 2014

  11. Digital storage of repeated signals

    International Nuclear Information System (INIS)

    Prozorov, S.P.

    1984-01-01

    An independent digital storage system designed for repeated signal discrimination from background noises is described. The signal averaging is performed off-line in the real time mode by means of multiple selection of the investigated signal and integration in each point. Digital values are added in a simple summator and the result is recorded the storage device with the volume of 1024X20 bit from where it can be output on an oscillograph, a plotter or transmitted to a compUter for subsequent processing. The described storage is reliable and simple device on one base of which the systems for the nuclear magnetic resonapce signal acquisition in different experiments are developed

  12. Signal transforms in dynamic measurements

    CERN Document Server

    Layer, Edward

    2015-01-01

    This book is devoted to the analysis of measurement signals which requires specific mathematical operations like Convolution, Deconvolution, Laplace, Fourier, Hilbert, Wavelet or Z transform which are all presented in the present book. The different problems refer to the modulation of signals, filtration of disturbance as well as to the orthogonal signals and their use in digital form for the measurement of current, voltage, power and frequency are also widely discussed. All the topics covered in this book are presented in detail and illustrated by means of examples in MathCad and LabVIEW. This book provides a useful source for researchers, scientists and engineers who in their daily work are required to deal with problems of measurement and signal processing and can also be helpful to undergraduate students of electrical engineering.    

  13. Nuclear Receptor Signaling Atlas (NURSA)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Nuclear Receptor Signaling Atlas (NURSA) is designed to foster the development of a comprehensive understanding of the structure, function, and role in disease...

  14. Forward Military Presence: A Matter of Strategic Culture

    National Research Council Canada - National Science Library

    Basham, Steven L

    2007-01-01

    .... The research within this paper offers for consideration the possibility that United States policy toward forward military presence is guided by a developing strategic culture based upon an underlying...

  15. presence of pathogenic yeasts and fungi on schools playing ...

    African Journals Online (AJOL)

    BSN

    GROUNDS: DANGER POSED TO PUBLIC ... inhibit bacterial growth as recommended by Cheesbrough ( 1984). The media \\\\ere prepared in the ... reduced light for the presence or absence of capsules. If present the size of the capsule is noted.

  16. Gridded Species Distribution, Version 1: Global Amphibians Presence Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Amphibians Presence Grids of the Gridded Species Distribution, Version 1 is a reclassified version of the original grids of amphibian species distribution...

  17. Attitude and practice of birth attendants regarding the presence of ...

    African Journals Online (AJOL)

    Attitude and practice of birth attendants regarding the presence of male partner at delivery in Nigeria. Abiodun Adeniran, Kikelomo Adesina, Abiodun Aboyeji, Olayinka Balogun, Peace Adeniran, Adegboyega Fawole ...

  18. Tele-Presence: Bringing the Operator Back in the Loop

    National Research Council Canada - National Science Library

    Erp, van, Jan B; Duistermaat, Maaike; Jansen, Chris; Groen, Eric; Hoedemaeker, Marieka

    2006-01-01

    .... A recent concept (which we call tele-presence) to tackle this problem is to design man-machine interfaces that allow operators to optimally use their perceptual motor system in order to relieve the cognitive system...

  19. Hand Tool Manipulation and Self-Presence in VR

    National Research Council Canada - National Science Library

    Badler, Norman

    1999-01-01

    The objective was to purchase Virtual Reality and associated computing equipment to enable the investigation of full body avatar control and self-presence using both fine motion hand manipulation plus...

  20. Presence and biofeedback in first-person perspective computer games

    DEFF Research Database (Denmark)

    Grimshaw-Aagaard, Mark Nicholas

    2019-01-01

    in relation to sound design for first-person perspective computer games; in line with the first section, biofeedback devices are treated as an immersive technology. I close the chapter by suggesting ways in which sound design in such games might make use of biofeedback to enhance the perception of presence...... – before suggesting future directions. Following the chapter's introduction, I present a definition of sound on which I base the ideas presented in the following sections. The second section of the chapter deals with the elusive nature of presence and presents my thoughts on worlds and environments...... of the perception of presence. In step with the series 'breadth first' approach, the chapter presents the reader with an overview of current thinking on sound and immersion/presence before delving into biofeedback in the context of sound design for virtual worlds – such as first-person perspective computer games...

  1. Selective response of dopamine in the presence of ascorbic acid ...

    African Journals Online (AJOL)

    Selective response of dopamine in the presence of ascorbic acid and uric acid at gold nanoparticles and multi-walled carbon nanotubes grafted with ethylene diamine tetraacetic acid modified electrode.

  2. Beskidt undertøj hænger man da i vinduet - en undersøgelse af grænserne mellem det private og offentlige på Facebook

    OpenAIRE

    Hilstrøm, Anna Louise

    2013-01-01

    This project concerns the discursive trends related to the criticism of over-sharing and thus the lack of privacy on Facebook. Phenomena such as mediatization and remediation are used to show the context of contemporary perception and use of Facebook and thus the criticisms pivotal to the debate. This leads to an examination of themes such as media-specific panics, perceptions of online and offline activities, and youth as a social construct. Using a questionnaire survey conducted on Facebook...

  3. Wnt signaling in limb organogenesis

    OpenAIRE

    Geetha-Loganathan, Poongodi; Nimmagadda, Suresh; Scaal, Martin

    2008-01-01

    Secreted signaling molecules of the Wnt family have been found to play a central role in controlling embryonic development of a wide range of taxa from Hydra to humans. The most extensively studied Wnt signaling pathway is the canonical Wnt pathway, which controls gene expression by stabilizing β-catenin, and regulates a multitude of developmental processes. More recently, noncanonical Wnt pathways, which are β-catenin-independent, have been found to be important developmental regulators. Und...

  4. Cytonemes as specialized signaling filopodia

    OpenAIRE

    Kornberg, Thomas B.; Roy, Sougata

    2014-01-01

    Development creates a vast array of forms and patterns with elegant economy, using a small vocabulary of pattern-generating proteins such as BMPs, FGFs and Hh in similar ways in many different contexts. Despite much theoretical and experimental work, the signaling mechanisms that disperse these morphogen signaling proteins remain controversial. Here, we review the conceptual background and evidence that establishes a fundamental and essential role for cytonemes as specialized filopodia that t...

  5. RET Signaling in Prostate Cancer.

    Science.gov (United States)

    Ban, Kechen; Feng, Shu; Shao, Longjiang; Ittmann, Michael

    2017-08-15

    Purpose: Large diameter perineural prostate cancer is associated with poor outcomes. GDNF, with its coreceptor GFRα1, binds RET and activates downstream pro-oncogenic signaling. Because both GDNF and GFRα1 are secreted by nerves, we examined the role of RET signaling in prostate cancer. Experimental Design: Expression of RET, GDNF, and/or GFRα1 was assessed. The impact of RET signaling on proliferation, invasion and soft agar colony formation, perineural invasion, and growth in vivo was determined. Cellular signaling downstream of RET was examined by Western blotting. Results: RET is expressed in all prostate cancer cell lines. GFRα1 is only expressed in 22Rv1 cells, which is the only line that responds to exogenous GDNF. In contrast, all cell lines respond to GDNF plus GFRα1. Conditioned medium from dorsal root ganglia contains secreted GFRα1 and promotes transformation-related phenotypes, which can be blocked by anti-GFRα1 antibody. Perineural invasion in the dorsal root ganglion assay is inhibited by anti-GFRα antibody and RET knockdown. In vivo , knockdown of RET inhibits tumor growth. RET signaling activates ERK or AKT signaling depending on context, but phosphorylation of p70S6 kinase is markedly increased in all cases. Knockdown of p70S6 kinase markedly decreases RET induced transformed phenotypes. Finally, RET is expressed in 18% of adenocarcinomas and all three small-cell carcinomas examined. Conclusions: RET promotes transformation associated phenotypes, including perineural invasion in prostate cancer via activation of p70S6 kinase. GFRα1, which is secreted by nerves, is a limiting factor for RET signaling, creating a perineural niche where RET signaling can occur. Clin Cancer Res; 23(16); 4885-96. ©2017 AACR . ©2017 American Association for Cancer Research.

  6. Neurotransmitter signaling in white matter.

    Science.gov (United States)

    Butt, Arthur M; Fern, Robert F; Matute, Carlos

    2014-11-01

    White matter (WM) tracts are bundles of myelinated axons that provide for rapid communication throughout the CNS and integration in grey matter (GM). The main cells in myelinated tracts are oligodendrocytes and astrocytes, with small populations of microglia and oligodendrocyte precursor cells. The prominence of neurotransmitter signaling in WM, which largely exclude neuronal cell bodies, indicates it must have physiological functions other than neuron-to-neuron communication. A surprising aspect is the diversity of neurotransmitter signaling in WM, with evidence for glutamatergic, purinergic (ATP and adenosine), GABAergic, glycinergic, adrenergic, cholinergic, dopaminergic and serotonergic signaling, acting via a wide range of ionotropic and metabotropic receptors. Both axons and glia are potential sources of neurotransmitters and may express the respective receptors. The physiological functions of neurotransmitter signaling in WM are subject to debate, but glutamate and ATP-mediated signaling have been shown to evoke Ca(2+) signals in glia and modulate axonal conduction. Experimental findings support a model of neurotransmitters being released from axons during action potential propagation acting on glial receptors to regulate the homeostatic functions of astrocytes and myelination by oligodendrocytes. Astrocytes also release neurotransmitters, which act on axonal receptors to strengthen action potential propagation, maintaining signaling along potentially long axon tracts. The co-existence of multiple neurotransmitters in WM tracts suggests they may have diverse functions that are important for information processing. Furthermore, the neurotransmitter signaling phenomena described in WM most likely apply to myelinated axons of the cerebral cortex and GM areas, where they are doubtless important for higher cognitive function. © 2014 Wiley Periodicals, Inc.

  7. Sentiment analysis for PTSD signals

    CERN Document Server

    Kagan, Vadim; Sapounas, Demetrios

    2013-01-01

    This book describes a computational framework for real-time detection of psychological signals related to Post-Traumatic Stress Disorder (PTSD) in online text-based posts, including blogs and web forums. Further, it explores how emerging computational techniques such as sentiment mining can be used in real-time to identify posts that contain PTSD-related signals, flag those posts, and bring them to the attention of psychologists, thus providing an automated flag and referral capability.

  8. The role of presence in virtual reality exposure therapy

    OpenAIRE

    Price, Matthew; Anderson, Page

    2006-01-01

    A growing body of literature suggests that virtual reality is a successful tool for exposure therapy in the treatment of anxiety disorders. Virtual reality (VR) researchers posit the construct of presence, defined as the interpretation of an artificial stimulus as if it were real, to be a presumed factor that enables anxiety to be felt during virtual reality exposure therapy (VRE). However, a handful of empirical studies on the relation between presence and anxiety in VRE have yielded mixed f...

  9. Bet 3: effect of family presence on paediatric trauma resuscitation.

    Science.gov (United States)

    2011-11-01

    A short cut review was performed to assess the effect of the presence of family members on the efficiency of paediatric trauma resuscitation. Two studies with a total of 999 patients were included. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses are tabulated. The clinical bottom line is that the presence of the patient's family does not adversely affect the outcome of paediatric trauma resuscitation.

  10. Landau Levels in the Presence of Topological Defects

    OpenAIRE

    Marques, G. de A.; Furtado, Claudio; Bezerra, V. B.; Moraes, Fernando

    2000-01-01

    We study the Landau levels associated with electrons moving in a magnetic field in the presence of a continuous distribution of disclinations, a magnetic screw dislocation and a dispiration. We focus on the influence of these topological defects on the spectrum of the electron(or hole) in a magnetic field in the framework of the geometric theory of defects in solids of Katanaev and Volovich. The presence of the defects breaks the degeneracy of the Landau levels in different ways depending on ...

  11. Social Injustice from The Presence of the Bauxite Mining Companies

    OpenAIRE

    Fatmawati Fatmawati; Salfius Seko

    2016-01-01

    This study aims to examine the forms of social injustice by the presence of mining companies and local residents in the Tayan Hilir, Sanggau. This study used a qualitative approach accomplished through a descriptive method, and which was then analyzed using qualitative analysis to describe the form of social injustice for society by the presence of mining companies. Results of the study explained that point on begins the social injustice originated from government policies that tend to favor ...

  12. Ion Acoustic Waves in the Presence of Electron Plasma Waves

    DEFF Research Database (Denmark)

    Michelsen, Poul; Pécseli, Hans; Juul Rasmussen, Jens

    1977-01-01

    Long-wavelength ion acoustic waves in the presence of propagating short-wavelength electron plasma waves are examined. The influence of the high frequency oscillations is to decrease the phase velocity and the damping distance of the ion wave.......Long-wavelength ion acoustic waves in the presence of propagating short-wavelength electron plasma waves are examined. The influence of the high frequency oscillations is to decrease the phase velocity and the damping distance of the ion wave....

  13. The implementation of time and presence contol information system

    OpenAIRE

    Poličnik, Mojca

    2009-01-01

    When implement new information system we are often confronted with various problems (fear of new information system, poor project design,...) Diploma talks about implementation of time and presence control information system to industrial company. The first four chapters describe the main mudules of time and presence control information system. The fifth chapter contains general informations about implementation of information system. In the sixth chapter describes the process of implemen...

  14. Sensor Data Fusion for Accurate Cloud Presence Prediction Using Dempster-Shafer Evidence Theory

    Directory of Open Access Journals (Sweden)

    Jesse S. Jin

    2010-10-01

    Full Text Available Sensor data fusion technology can be used to best extract useful information from multiple sensor observations. It has been widely applied in various applications such as target tracking, surveillance, robot navigation, signal and image processing. This paper introduces a novel data fusion approach in a multiple radiation sensor environment using Dempster-Shafer evidence theory. The methodology is used to predict cloud presence based on the inputs of radiation sensors. Different radiation data have been used for the cloud prediction. The potential application areas of the algorithm include renewable power for virtual power station where the prediction of cloud presence is the most challenging issue for its photovoltaic output. The algorithm is validated by comparing the predicted cloud presence with the corresponding sunshine occurrence data that were recorded as the benchmark. Our experiments have indicated that comparing to the approaches using individual sensors, the proposed data fusion approach can increase correct rate of cloud prediction by ten percent, and decrease unknown rate of cloud prediction by twenty three percent.

  15. Resuscitation team perceptions of family presence during CPR.

    Science.gov (United States)

    Zavotsky, Kathleen Evanovich; McCoy, Jon; Bell, Ginette; Haussman, Kristen; Joiner, Jennifer; Marcoux, Kelly Keefe; Magarelli, Karen; Mahoney, Kathleen; Maldonado, Linda; Mastro, Kari A; Milloria, Amy; Tamburri, Linda M; Tortajada, Dawn

    2014-01-01

    The literature supports family presence during cardiopulmonary resuscitation (CPR) and its many perceived benefits for patients and their families. It also suggests that, overall, health care professionals are supportive of this practice. There have not been any published studies to date that have looked at the perception of family presence from the multidisciplinary resuscitation or code team's perspective. The purpose of this study was to describe the multidisciplinary care provider's understanding and perceived barriers of family presence during CPR in an academic medical center. This study is a quantitative, exploratory, descriptive study that utilized survey methodology. The sample included all members of an urban academic medical center's resuscitation response team. The study findings reveal that, overall, code team members feel that family members should be allowed to remain at the bedside during CPR but that challenges exist including education deficits and mixed feelings that may result from family presence; the study participants caring for neonates and children were more favorable to family presence during CPR than their adult counterparts. Barriers remain related to family presence during resuscitation. Education is needed for all members of the health care team to facilitate collaborative changes in resuscitation practices. Education should include information regarding institutional policies, methods for incorporating family members into the code process, and interventions to support the psychosocial needs of family members.

  16. Spatial Downscaling of Alien Species Presences Using Machine Learning

    Directory of Open Access Journals (Sweden)

    Ioannis N. Daliakopoulos

    2017-07-01

    Full Text Available Spatially explicit assessments of alien species environmental and socio-economic impacts, and subsequent management interventions for their mitigation, require large scale, high-resolution data on species presence distribution. However, these data are often unavailable. This paper presents a method that relies on Random Forest (RF models to distribute alien species presence counts at a finer resolution grid, thus achieving spatial downscaling. A bootstrapping scheme is designed to account for sub-setting uncertainty, and subsets are used to train a sufficiently large number of RF models. RF results are processed to estimate variable importance and model performance. The method is tested with an ~8 × 8 km2 grid containing floral alien species presence and several potentially exploratory indices of climatic, habitat, land use, and soil property covariates for the Mediterranean island of Crete, Greece. Alien species presence is aggregated at 16 × 16 km2 and used as a predictor of presence at the original resolution, thus simulating spatial downscaling. Uncertainty assessment of the spatial downscaling of alien species' occurrences was also performed and true/false presences and absences were quantified. The approach is promising for downscaling alien species datasets of larger spatial scale but coarse resolution, where the underlying environmental information is available at a finer resolution. Furthermore, the RF architecture allows for tuning toward operationally optimal sensitivity and specificity, thus providing a decision support tool for designing a resource efficient alien species census.

  17. Hedgehog signalling in foregut malignancy.

    Science.gov (United States)

    Watkins, D N; Peacock, C D

    2004-09-15

    Hedgehog (Hh) signalling mediates axial patterning and stem cell fate in development. This is mediated by Sonic, Desert and Indian Hedgehogs whose morphogen gradients determine the level of signalling in recipient tissues. Aberrant, cell autonomous, ligand-dependent Hh signalling has recently been demonstrated in small cell lung cancer (SCLC), as well as in upper gastrointestinal malignancies arising from pancreas, esophagus and stomach. These tumors lack mutations in the Hh receptor PATCHED, identifying a mechanism of pathway activation distinct from Gorlin's syndrome associated neural and skin tumors. We believe that this phenomenon represents a conserved mechanism for establishing niche-independent stem cell fates in cancer which is essential for malignant transformation and metastasis. Specific inhibition of Hh signalling by the naturally occurring plant alkaloid cyclopamine provides the opportunity for pharmacologic assessment of the role of Hh signalling in these tumors. Cyclopamine inhibits growth of SCLC and a wide range of foregut derived malignancies both in vitro and in vivo. This demonstrates an ongoing requirement for Hh signalling in these highly lethal and aggressive tumors. A novel therapeutic strategy is proposed using pharmacologic targeting of Hh dependent tumors with high potency pathway antagonists.

  18. Insulin Signaling and Heart Failure

    Science.gov (United States)

    Riehle, Christian; Abel, E. Dale

    2016-01-01

    Heart failure is associated with generalized insulin resistance. Moreover, insulin resistant states such as type 2 diabetes and obesity increases the risk of heart failure even after adjusting for traditional risk factors. Insulin resistance or type 2 diabetes alters the systemic and neurohumoral milieu leading to changes in metabolism and signaling pathways in the heart that may contribute to myocardial dysfunction. In addition, changes in insulin signaling within cardiomyocytes develop in the failing heart. The changes range from activation of proximal insulin signaling pathways that may contribute to adverse left ventricular remodeling and mitochondrial dysfunction to repression of distal elements of insulin signaling pathways such as forkhead (FOXO) transcriptional signaling or glucose transport which may also impair cardiac metabolism, structure and function. This article will review the complexities of insulin signaling within the myocardium and ways in which these pathways are altered in heart failure or in conditions associated with generalized insulin resistance. The implications of these changes for therapeutic approaches to treating or preventing heart failure will be discussed. PMID:27034277

  19. Metabolites in vertebrate Hedgehog signaling.

    Science.gov (United States)

    Roberg-Larsen, Hanne; Strand, Martin Frank; Krauss, Stefan; Wilson, Steven Ray

    2014-04-11

    The Hedgehog (HH) signaling pathway is critical in embryonic development, stem cell biology, tissue homeostasis, chemoattraction and synapse formation. Irregular HH signaling is associated with a number of disease conditions including congenital disorders and cancer. In particular, deregulation of HH signaling has been linked to skin, brain, lung, colon and pancreatic cancers. Key mediators of the HH signaling pathway are the 12-pass membrane protein Patched (PTC), the 7-pass membrane protein Smoothened (SMO) and the GLI transcription factors. PTC shares homology with the RND family of small-molecule transporters and it has been proposed that it interferes with SMO through metabolites. Although a conclusive picture is lacking, substantial efforts are made to identify and understand natural metabolites/sterols, including cholesterol, vitamin D3, oxysterols and glucocorticoides, that may be affected by, or influence the HH signaling cascade at the level of PTC and SMO. In this review we will elaborate the role of metabolites in HH signaling with a focus on oxysterols, and discuss advancements in modern analytical approaches in the field. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. SignalPlant: an open signal processing software platform.

    Science.gov (United States)

    Plesinger, F; Jurco, J; Halamek, J; Jurak, P

    2016-07-01

    The growing technical standard of acquisition systems allows the acquisition of large records, often reaching gigabytes or more in size as is the case with whole-day electroencephalograph (EEG) recordings, for example. Although current 64-bit software for signal processing is able to process (e.g. filter, analyze, etc) such data, visual inspection and labeling will probably suffer from rather long latency during the rendering of large portions of recorded signals. For this reason, we have developed SignalPlant-a stand-alone application for signal inspection, labeling and processing. The main motivation was to supply investigators with a tool allowing fast and interactive work with large multichannel records produced by EEG, electrocardiograph and similar devices. The rendering latency was compared with EEGLAB and proves significantly faster when displaying an image from a large number of samples (e.g. 163-times faster for 75  ×  10(6) samples). The presented SignalPlant software is available free and does not depend on any other computation software. Furthermore, it can be extended with plugins by third parties ensuring its adaptability to future research tasks and new data formats.

  1. Presence of third molars in orthodontic patients from northern Greece

    Directory of Open Access Journals (Sweden)

    Barka G

    2012-05-01

    Full Text Available Georgia Barka,1 Georgios Tretiakov,1 Theodosios Theodosiou,2 Ioulia Ioannidou-Marathiotou31School of Dentistry, 2Biostatistics, Department of Informatics, School of Natural Sciences, 3Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, GreeceObjective: The purpose of the present study was to investigate the frequency of presence of third molar teeth and their distribution in each jaw and each side, according to sex, in a group of orthodontic patients with permanent dentition from northern Greece.Methods: The sample included panoramic radiographs from 220 patients with permanent dentition (mean age 13.62 ± 1.81. The Χ2 test was used to assess the relationships between the variables, and the Fisher's exact test was used in cases where the expected frequencies in each cell were <5.Results: The frequency of third molar presence was 79.1%, and 20.9% was the frequency of third molar agenesis. Intersexual differences in the number of third molars was not statistically significant. There was a correlation between the distribution of third molars on the right and the left side (Fisher's exact test = 100.788; P = 0. The two sides showed the same tendency toward the presence or absence of third molars. A correlation was also found between the distribution of maxillary and mandibular third molars (Fisher's exact test = 24.372; P = 0. In each jaw, the presence or absence of third molars was highly related to the number of third molars found in the other jaw.Conclusion: The present results showed that in this orthodontic group of northern Greek patients, presence accounted for 79.1% and agenesis for 20.9%. No significant difference was found between the frequencies of third molar presence on the left and right sides in either the maxilla or mandible.Keywords: third molars, presence, orthodontic population, Greeks

  2. Determination of mutated genes in the presence of wild-type DNA by using molecular beacons as probe

    Science.gov (United States)

    Zhang, Yonghua; Ai, Junjie; Gu, Qiaorong; Gao, Qiang; Qi, Honglan; Zhang, Chengxiao

    2017-03-01

    Low-abundance mutations in the presence of wild-type DNA can be determined using molecular beacon (MB) as probe. A MB is generally used as DNA probe because it can distinguish single-base mismatched target DNA from fully matched target DNA. However, the probe can not determine low-abundance mutations in the presence of wild-type DNA. In this study, this limitation is addressed by enhancing the stability of unpaired base-containing dsDNA with a hydrogen-bonding ligand, which was added after hybridization of the MB to the target DNA. The ligand formed hydrogen bonds with unpaired bases and stabilized the unpaired base-containing dsDNA if target DNA is mutated one. As a result, more MBs were opened by the mutant genes in the presence of the ligand and a further increase in the fluorescence intensity was obtained. By contrast, fluorescence intensity did not change if target DNA is wild-type one. Consequent increase in the fluorescence intensity of the MB was regarded as a signal derived from mutant genes. The proposed method was applied in synthetic template systems to determine point mutation in DNA obtained from PCR analysis. The method also allows rapid and simple discrimination of a signal if it is originated in the presence of mutant gene or alternatively by a lower concentration of wild gene.

  3. Bystander signaling via oxidative metabolism

    Directory of Open Access Journals (Sweden)

    Sawal HA

    2017-08-01

    Full Text Available Humaira Aziz Sawal,1 Kashif Asghar,2 Matthias Bureik,3 Nasir Jalal4 1Healthcare Biotechnology Department, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, 2Basic Sciences Research, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan; 3Health Science Platform, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China; 4Health Science Platform, Department of Molecular and Cellular Pharmacology, Tianjin University, Tianjin, China Abstract: The radiation-induced bystander effect (RIBE is the initiation of biological end points in cells (bystander cells that are not directly traversed by an incident-radiation track, but are in close proximity to cells that are receiving the radiation. RIBE has been indicted of causing DNA damage via oxidative stress, besides causing direct damage, inducing tumorigenesis, producing micronuclei, and causing apoptosis. RIBE is regulated by signaling proteins that are either endogenous or secreted by cells as a means of communication between cells, and can activate intracellular or intercellular oxidative metabolism that can further trigger signaling pathways of inflammation. Bystander signals can pass through gap junctions in attached cell lines, while the suspended cell lines transmit these signals via hormones and soluble proteins. This review provides the background information on how reactive oxygen species (ROS act as bystander signals. Although ROS have a very short half-life and have a nanometer-scale sphere of influence, the wide variety of ROS produced via various sources can exert a cumulative effect, not only in forming DNA adducts but also setting up signaling pathways of inflammation, apoptosis, cell-cycle arrest, aging, and even tumorigenesis. This review outlines the sources of the bystander effect linked to ROS in a cell, and provides methods of investigation for researchers who would like to

  4. Liquid Argon TPC Signal Formation, Signal Processing and Hit Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Baller, Bruce [Fermilab

    2017-03-11

    This document describes the early stage of the reconstruction chain that was developed for the ArgoNeuT and MicroBooNE experiments at Fermilab. These experiments study accelerator neutrino interactions that occur in a Liquid Argon Time Projection Chamber. Reconstructing the properties of particles produced in these interactions requires knowledge of the micro-physics processes that affect the creation and transport of ionization electrons to the readout system. A wire signal deconvolution technique was developed to convert wire signals to a standard form for hit reconstruction, to remove artifacts in the electronics chain and to remove coherent noise.

  5. Comparison of Student and Instructor Perceptions of Social Presence

    Directory of Open Access Journals (Sweden)

    Kathleen Mathieson

    2014-05-01

    Full Text Available As enrollment in online courses continues to grow and online education is increasingly recognized as an established instructional mode, the unique challenges posed by this learning environment should be addressed. A primary challenge for virtual educators is developing social presence such that participants feel a sense of human connection with each other. Accomplishing this within learning management systems (LMS that are often restrictive can be difficult. Prior research has established a relationship between student perceptions of social presence and satisfaction, but little research has included perceptions of instructors. This study compares student and instructor perceptions of social presence and the importance placed on social connections. While students and instructors reported high levels of social presence, students reported significantly lower levels than instructors. In particular, students found the LMS more impersonal than instructors and were less comfortable participating in LMS activities than instructors. Students had less desire for social connections with other students and instructors, and reported having less time available for such connections. Strategies to facilitate social presence, including offering social networking opportunities outside the LMS, are discussed in light of these differences in perceptions between students and instructors.

  6. Spatial Downscaling of Alien Species Presences using Machine Learning

    Science.gov (United States)

    Daliakopoulos, Ioannis N.; Katsanevakis, Stelios; Moustakas, Aristides

    2017-07-01

    Large scale, high-resolution data on alien species distributions are essential for spatially explicit assessments of their environmental and socio-economic impacts, and management interventions for mitigation. However, these data are often unavailable. This paper presents a method that relies on Random Forest (RF) models to distribute alien species presence counts at a finer resolution grid, thus achieving spatial downscaling. A sufficiently large number of RF models are trained using random subsets of the dataset as predictors, in a bootstrapping approach to account for the uncertainty introduced by the subset selection. The method is tested with an approximately 8×8 km2 grid containing floral alien species presence and several indices of climatic, habitat, land use covariates for the Mediterranean island of Crete, Greece. Alien species presence is aggregated at 16×16 km2 and used as a predictor of presence at the original resolution, thus simulating spatial downscaling. Potential explanatory variables included habitat types, land cover richness, endemic species richness, soil type, temperature, precipitation, and freshwater availability. Uncertainty assessment of the spatial downscaling of alien species’ occurrences was also performed and true/false presences and absences were quantified. The approach is promising for downscaling alien species datasets of larger spatial scale but coarse resolution, where the underlying environmental information is available at a finer resolution than the alien species data. Furthermore, the RF architecture allows for tuning towards operationally optimal sensitivity and specificity, thus providing a decision support tool for designing a resource efficient alien species census.

  7. Neural responses to multimodal ostensive signals in 5-month-old infants.

    Directory of Open Access Journals (Sweden)

    Eugenio Parise

    Full Text Available Infants' sensitivity to ostensive signals, such as direct eye contact and infant-directed speech, is well documented in the literature. We investigated how infants interpret such signals by assessing common processing mechanisms devoted to them and by measuring neural responses to their compounds. In Experiment 1, we found that ostensive signals from different modalities display overlapping electrophysiological activity in 5-month-old infants, suggesting that these signals share neural processing mechanisms independently of their modality. In Experiment 2, we found that the activation to ostensive signals from different modalities is not additive to each other, but rather reflects the presence of ostension in either stimulus stream. These data support the thesis that ostensive signals obligatorily indicate to young infants that communication is directed to them.

  8. Faster but Less Careful Prehension in Presence of High, Rather than Low, Social Status Attendees.

    Directory of Open Access Journals (Sweden)

    Carlo Fantoni

    Full Text Available Ample evidence attests that social intention, elicited through gestures explicitly signaling a request of communicative intention, affects the patterning of hand movement kinematics. The current study goes beyond the effect of social intention and addresses whether the same action of reaching to grasp an object for placing it in an end target position within or without a monitoring attendee's peripersonal space, can be moulded by pure social factors in general, and by social facilitation in particular. A motion tracking system (Optotrak Certus was used to record motor acts. We carefully avoided the usage of communicative intention by keeping constant both the visual information and the positional uncertainty of the end target position, while we systematically varied the social status of the attendee (a high, or a low social status in separated blocks. Only thirty acts performed in the presence of a different social status attendee, revealed a significant change of kinematic parameterization of hand movement, independently of the attendee's distance. The amplitude of peak velocity reached by the hand during the reach-to-grasp and the lift-to-place phase of the movement was larger in the high rather than in the low social status condition. By contrast, the deceleration time of the reach-to-grasp phase and the maximum grasp aperture was smaller in the high rather than in the low social status condition. These results indicated that the hand movement was faster but less carefully shaped in presence of a high, but not of a low social status attendee. This kinematic patterning suggests that being monitored by a high rather than a low social status attendee might lead participants to experience evaluation apprehension that informs the control of motor execution. Motor execution would rely more on feedforward motor control in the presence of a high social status human attendee, vs. feedback motor control, in the presence of a low social status attendee.

  9. Biomedical signal and image processing.

    Science.gov (United States)

    Cerutti, Sergio; Baselli, Giuseppe; Bianchi, Anna; Caiani, Enrico; Contini, Davide; Cubeddu, Rinaldo; Dercole, Fabio; Rienzo, Luca; Liberati, Diego; Mainardi, Luca; Ravazzani, Paolo; Rinaldi, Sergio; Signorini, Maria; Torricelli, Alessandro

    2011-01-01

    Generally, physiological modeling and biomedical signal processing constitute two important paradigms of biomedical engineering (BME): their fundamental concepts are taught starting from undergraduate studies and are more completely dealt with in the last years of graduate curricula, as well as in Ph.D. courses. Traditionally, these two cultural aspects were separated, with the first one more oriented to physiological issues and how to model them and the second one more dedicated to the development of processing tools or algorithms to enhance useful information from clinical data. A practical consequence was that those who did models did not do signal processing and vice versa. However, in recent years,the need for closer integration between signal processing and modeling of the relevant biological systems emerged very clearly [1], [2]. This is not only true for training purposes(i.e., to properly prepare the new professional members of BME) but also for the development of newly conceived research projects in which the integration between biomedical signal and image processing (BSIP) and modeling plays a crucial role. Just to give simple examples, topics such as brain–computer machine or interfaces,neuroengineering, nonlinear dynamical analysis of the cardiovascular (CV) system,integration of sensory-motor characteristics aimed at the building of advanced prostheses and rehabilitation tools, and wearable devices for vital sign monitoring and others do require an intelligent fusion of modeling and signal processing competences that are certainly peculiar of our discipline of BME.

  10. 300 Area signal cable study

    International Nuclear Information System (INIS)

    Whattam, J.W.

    1994-01-01

    This report was prepared to discuss the alternatives available for removing the 300 Area overhead signal cable system. This system, installed in 1969, has been used for various monitoring and communication signaling needs throughout the 300 Area. Over the years this cabling system has deteriorated, has been continually reconfigured, and has been poorly documented to the point of nonreliability. The first step was to look at the systems utilizing the overhead signal cable that are still required for operation. Of the ten systems that once operated via the signal cable, only five are still required; the civil defense evacuation alarms, the public address (PA) system, the criticality alarms, the Pacific Northwest Laboratory Facilities Management Control System (FMCS), and the 384 annunciator panel. Of these five, the criticality alarms and the FMCS have been dealt with under other proposals. Therefore, this study focused on the alternatives available for the remaining three systems (evacuation alarms, PA system, and 384 panel) plus the accountability aid phones. Once the systems to be discussed were determined, then three alternatives for providing the signaling pathway were examined for each system: (1) re-wire using underground communication ducts, (2) use the Integrated Voice/Data Telecommunications System (IVDTS) already installed and operated by US West, and (3) use radio control. Each alternative was developed with an estimated cost, advantages, and disadvantages. Finally, a recommendation was provided for the best alternative for each system

  11. EGFR Signaling in Liver Diseases

    Directory of Open Access Journals (Sweden)

    Karin Komposch

    2015-12-01

    Full Text Available The epidermal growth factor receptor (EGFR is a transmembrane receptor tyrosine kinase that is activated by several ligands leading to the activation of diverse signaling pathways controlling mainly proliferation, differentiation, and survival. The EGFR signaling axis has been shown to play a key role during liver regeneration following acute and chronic liver damage, as well as in cirrhosis and hepatocellular carcinoma (HCC highlighting the importance of the EGFR in the development of liver diseases. Despite the frequent overexpression of EGFR in human HCC, clinical studies with EGFR inhibitors have so far shown only modest results. Interestingly, a recent study has shown that in human HCC and in mouse HCC models the EGFR is upregulated in liver macrophages where it plays a tumor-promoting function. Thus, the role of EGFR in liver diseases appears to be more complex than what anticipated. Further studies are needed to improve the molecular understanding of the cell-specific signaling pathways that control disease development and progression to be able to develop better therapies targeting major components of the EGFR signaling network in selected cell types. In this review, we compiled the current knowledge of EGFR signaling in different models of liver damage and diseases, mainly derived from the analysis of HCC cell lines and genetically engineered mouse models (GEMMs.

  12. Dialkylresorcinols as bacterial signaling molecules.

    Science.gov (United States)

    Brameyer, Sophie; Kresovic, Darko; Bode, Helge B; Heermann, Ralf

    2015-01-13

    It is well recognized that bacteria communicate via small diffusible molecules, a process termed quorum sensing. The best understood quorum sensing systems are those that use acylated homoserine lactones (AHLs) for communication. The prototype of those systems consists of a LuxI-like AHL synthase and a cognate LuxR receptor that detects the signal. However, many proteobacteria possess LuxR receptors, yet lack any LuxI-type synthase, and thus these receptors are referred to as LuxR orphans or solos. In addition to the well-known AHLs, little is known about the signaling molecules that are sensed by LuxR solos. Here, we describe a novel cell-cell communication system in the insect and human pathogen Photorhabdus asymbiotica. We identified the LuxR homolog PauR to sense dialkylresorcinols (DARs) and cyclohexanediones (CHDs) instead of AHLs as signals. The DarABC synthesis pathway produces the molecules, and the entire system emerged as important for virulence. Moreover, we have analyzed more than 90 different Photorhabdus strains by HPLC/MS and showed that these DARs and CHDs are specific to the human pathogen P. asymbiotica. On the basis of genomic evidence, 116 other bacterial species are putative DAR producers, among them many human pathogens. Therefore, we discuss the possibility of DARs as novel and widespread bacterial signaling molecules and show that bacterial cell-cell communication goes far beyond AHL signaling in nature.

  13. Optical time-lens signal processing

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen

    2014-01-01

    This paper describes the use of optical time lenses for optical signal processing of advanced optical data signals. Examples given include 1.28 Tbaud Nyquist channel serial-to-parallel conversion and spectral magnification of OFDM signals.......This paper describes the use of optical time lenses for optical signal processing of advanced optical data signals. Examples given include 1.28 Tbaud Nyquist channel serial-to-parallel conversion and spectral magnification of OFDM signals....

  14. Mathematical model for classification of EEG signals

    Science.gov (United States)

    Ortiz, Victor H.; Tapia, Juan J.

    2015-09-01

    A mathematical model to filter and classify brain signals from a brain machine interface is developed. The mathematical model classifies the signals from the different lobes of the brain to differentiate the signals: alpha, beta, gamma and theta, besides the signals from vision, speech, and orientation. The model to develop further eliminates noise signals that occur in the process of signal acquisition. This mathematical model can be used on different platforms interfaces for rehabilitation of physically handicapped persons.

  15. Robust Stabilization of Jet Engine Compressor In The Presence of ...

    African Journals Online (AJOL)

    In this work, first we modify the Moore and Grietzer three-state model for compressors to include disturbance (noise signals) and then use the method of integrator backstepping, coupled with saturation functions to develop robust controllers for the stabilization of the compressor. Also, we develop robust observers for ...

  16. Primary structure of the signal peptide of tropoelastin b.

    Science.gov (United States)

    Karr, S R; Foster, J A

    1981-06-25

    Elastin is a major protein of compliant connective tissue and is characterized by an amino acid composition abundant in nonpolar residues. The soluble precursor to elastin tropoelastin, is extractable in organic solvents and possesses an extensive clustering of nonpolar amino acid residues in the immediate NH2-terminal region (Foster, J. A., Shapiro, R., Voynow, P., Crombie, G., Faris, B., and Franzblau, C. (1975) Biochemistry 14, 857-864). It was, therefore, of special interest to determine whether tropoelastin requires a hydrophobic signal peptide for vectorial transport of the nascent polypeptide. The possibility that the initial tropoelastin translation product possesses a short signal peptide was examined in a cell-free translation system. Total RNA, isolated from aortae of 1-day-old chicks, was translated in an mRNA-dependent reticulocyte lysate translation assay. The translation products were then immunoprecipitated and subjected to automated radiosequencing. Comparison of the NH2-terminal sequence of tropoelastin b synthesized in the cell-free system versus that synthesized in organ culture demonstrated the presence of a signal peptide 24 amino acid residues in length. The signal peptide sequence is as follows: Met-Arg-Gln-Ala-Ala-Ala-Pro-Leu-Leu-Pro-Gly-Val-Leu-Leu-Leu-Phe-Ser-Ile-Leu-Pro -Ala-Ser-Gln-Gln. The preponderance of hydrophobic amino acid residues as well as the polar residues adjacent to the initiator methionine and the carboxyl termini found in the signal peptide is similar to that reported for other secreted proteins.

  17. [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.

  18. Presence of Phlebotomus perniciosus Atypical Form in Algeria

    Directory of Open Access Journals (Sweden)

    Kamel Eddine Benallal

    2017-04-01

    Full Text Available Background: Phlebotomus perniciosus and Phlebotomus longicuspis are two phlebotomine sand fly species morphologically similar and differing in males only by the shape of the copulatory valves which are bifurcated in P. perniciosus, tip long and tapered in P. longicuspis.Methods: A count of the median coxite setae was carried out on 208 specimens from the collections of Dedet and of Parrot, identified previously as P. longicuspis and on 38 P. perniciosus male sand flies captured during the year 2012–2013, in order to seek the presence of atypical P. perniciosus form.Results: The analysis revealed the presence of 33/246 (13% atypical P. perniciosus previously confused with P. longicuspis species and whose distribution is mainly located in the semi-arid and arid bioclimatic regions.Conclusion: This study proved for the first time the presence of atypical form of P. perniciosus in Algeria.

  19. Recurrent corneal ulceration in presence of synthetic microfibrils

    Directory of Open Access Journals (Sweden)

    Barsam A

    2011-06-01

    Full Text Available A Barsam1, N Patel1, H Laganowski2, HD Perry31Moorfields Eye Hospital, London, UK; 2Department of Ophthalmology, Queen Mary's Hospital, Sidcup, Kent, UK; 3Ophthalmic Consultants of Long Island, Nassau University, Long Island, NY, USAAbstract: Recurrence of microbial keratitis in the presence of protozoal infection is very rare and infrequently reported unless predisposing factors are present. The association of recurrent microbial keratitis and synthetic microfibrils has never previously been reported to our knowledge. This single interventional case study describes the clinical course and treatment of a contact lens wearer who was treated for Acanthamoeba keratitis with superinfection from bacterial organisms in the presence of synthetic microfibrils. The presence of synthetic fibrils on a corneal ulcer base may act as a nidus for pathological organisms and interfere with normal corneal healing. This may result in infection recurrence and the growth of resistant opportunistic organisms.Keywords: Acanthamoeba, microbial keratitis, cornea ulcer, contact lens infection, synthetic microfibrils

  20. Ozonation of deciduous wood in the presence of hydrogen peroxide

    Science.gov (United States)

    Mamleeva, N. A.; Kharlanov, A. N.; Fionov, A. V.; Lunin, V. V.

    2011-10-01

    The kinetic curves of the dependence of ozone specific absorption ( Q r, sp ) upon aspen wood ozonation in the presence and absence of hydrogen peroxide are obtained. It is established that the rate of ozone and Q r, sp absorption increase in the O3/H2O2 system. It is demonstrated by ESR, IR, and UV spectroscopy of diffuse reflection that wood ozonation in the O3/H2O2 system results in the destruction of lignin aromatic and quinoid structures. The ozonation process in the presence of H2O2 is accompanied by destruction of the carbohydrate component of the lignocarbohydrate complex. We conclude that O3/H2O2 can be used in the deep delignification of wood. It is shown that the presence of hydrogen peroxide upon ozonation increases the efficiency of the process, allowing its duration and total ozone consumption to be reduced.

  1. Robust image authentication in the presence of noise

    CERN Document Server

    2015-01-01

    This book addresses the problems that hinder image authentication in the presence of noise. It considers the advantages and disadvantages of existing algorithms for image authentication and shows new approaches and solutions for robust image authentication. The state of the art algorithms are compared and, furthermore, innovative approaches and algorithms are introduced. The introduced algorithms are applied to improve image authentication, watermarking and biometry.    Aside from presenting new directions and algorithms for robust image authentication in the presence of noise, as well as image correction, this book also:   Provides an overview of the state of the art algorithms for image authentication in the presence of noise and modifications, as well as a comparison of these algorithms, Presents novel algorithms for robust image authentication, whereby the image is tried to be corrected and authenticated, Examines different views for the solution of problems connected to image authentication in the pre...

  2. Visual Realism and Presence in a Virtual Reality Game

    DEFF Research Database (Denmark)

    Hvass, Jonatan Salling; Larsen, Oliver Stevns; Vendelbo, Kasper Bøgelund

    2017-01-01

    Virtual Reality (VR) has finally entered the homes of consumers, and a large number of the available applications are games. This paper presents a between-subjects study (n=50) exploring if vi-sual realism (polygon count and texture resolution) affects pres-ence during a scenario involving gameplay......, graphics, and controls that, contrary to much existing research, resemble commercially available VR games. The results suggest that participants exposed to a higher degree of visual realism experienced a stronger sensa-tion of presence, as assessed by means of self-reports, and phys-iological measures...... revealed that higher visual realism also was accompanied by stronger fear responses which may be indicative of stronger presence....

  3. Environmental predictors of ice seal presence in the Bering Sea.

    Directory of Open Access Journals (Sweden)

    Jennifer L Miksis-Olds

    Full Text Available Ice seals overwintering in the Bering Sea are challenged with foraging, finding mates, and maintaining breathing holes in a dark and ice covered environment. Due to the difficulty of studying these species in their natural environment, very little is known about how the seals navigate under ice. Here we identify specific environmental parameters, including components of the ambient background sound, that are predictive of ice seal presence in the Bering Sea. Multi-year mooring deployments provided synoptic time series of acoustic and oceanographic parameters from which environmental parameters predictive of species presence were identified through a series of mixed models. Ice cover and 10 kHz sound level were significant predictors of seal presence, with 40 kHz sound and prey presence (combined with ice cover as potential predictors as well. Ice seal presence showed a strong positive correlation with ice cover and a negative association with 10 kHz environmental sound. On average, there was a 20-30 dB difference between sound levels during solid ice conditions compared to open water or melting conditions, providing a salient acoustic gradient between open water and solid ice conditions by which ice seals could orient. By constantly assessing the acoustic environment associated with the seasonal ice movement in the Bering Sea, it is possible that ice seals could utilize aspects of the soundscape to gauge their safe distance to open water or the ice edge by orienting in the direction of higher sound levels indicative of open water, especially in the frequency range above 1 kHz. In rapidly changing Arctic and sub-Arctic environments, the seasonal ice conditions and soundscapes are likely to change which may impact the ability of animals using ice presence and cues to successfully function during the winter breeding season.

  4. Environmental predictors of ice seal presence in the Bering Sea.

    Science.gov (United States)

    Miksis-Olds, Jennifer L; Madden, Laura E

    2014-01-01

    Ice seals overwintering in the Bering Sea are challenged with foraging, finding mates, and maintaining breathing holes in a dark and ice covered environment. Due to the difficulty of studying these species in their natural environment, very little is known about how the seals navigate under ice. Here we identify specific environmental parameters, including components of the ambient background sound, that are predictive of ice seal presence in the Bering Sea. Multi-year mooring deployments provided synoptic time series of acoustic and oceanographic parameters from which environmental parameters predictive of species presence were identified through a series of mixed models. Ice cover and 10 kHz sound level were significant predictors of seal presence, with 40 kHz sound and prey presence (combined with ice cover) as potential predictors as well. Ice seal presence showed a strong positive correlation with ice cover and a negative association with 10 kHz environmental sound. On average, there was a 20-30 dB difference between sound levels during solid ice conditions compared to open water or melting conditions, providing a salient acoustic gradient between open water and solid ice conditions by which ice seals could orient. By constantly assessing the acoustic environment associated with the seasonal ice movement in the Bering Sea, it is possible that ice seals could utilize aspects of the soundscape to gauge their safe distance to open water or the ice edge by orienting in the direction of higher sound levels indicative of open water, especially in the frequency range above 1 kHz. In rapidly changing Arctic and sub-Arctic environments, the seasonal ice conditions and soundscapes are likely to change which may impact the ability of animals using ice presence and cues to successfully function during the winter breeding season.

  5. Cytokinin signaling during root development.

    Science.gov (United States)

    Bishopp, Anthony; Help, Hanna; Helariutta, Ykä

    2009-01-01

    The cytokinin class of phytohormones regulates division and differentiation of plant cells. They are perceived and signaled by a phosphorelay mechanism similar to those observed in prokaryotes. Research into the components of phosphorelay had previously been marred by genetic redundancy. However, recent studies have addressed this with the creation of high-order mutants. In addition, several new elements regulating cytokinin signaling have been identified. This has uncovered many roles in diverse developmental and physiological processes. In this review, we look at these processes specifically in the context of root development. We focus on the formation and maintenance of the root apical meristem, primary and secondary vascular development, lateral root emergence and development, and root nodulation. We believe that the root is an ideal organ with which to investigate cytokinin signaling in a wider context.

  6. Neural networks in signal processing

    International Nuclear Information System (INIS)

    Govil, R.

    2000-01-01

    Nuclear Engineering has matured during the last decade. In research and design, control, supervision, maintenance and production, mathematical models and theories are used extensively. In all such applications signal processing is embedded in the process. Artificial Neural Networks (ANN), because of their nonlinear, adaptive nature are well suited to such applications where the classical assumptions of linearity and second order Gaussian noise statistics cannot be made. ANN's can be treated as nonparametric techniques, which can model an underlying process from example data. They can also adopt their model parameters to statistical change with time. Algorithms in the framework of Neural Networks in Signal processing have found new applications potentials in the field of Nuclear Engineering. This paper reviews the fundamentals of Neural Networks in signal processing and their applications in tasks such as recognition/identification and control. The topics covered include dynamic modeling, model based ANN's, statistical learning, eigen structure based processing and generalization structures. (orig.)

  7. The Dynamics of Costly Signaling

    Directory of Open Access Journals (Sweden)

    Elliott O. Wagner

    2013-04-01

    Full Text Available Costly signaling is a mechanism through which the honesty of signals can be secured in equilibrium, even in interactions where communicators have conflicting interests. This paper explores the dynamics of one such signaling game: Spence’s model of education. It is found that separating equilibria are unlikely to emerge under either the replicator or best response dynamics, but that partially communicative mixed equilibria are quite important dynamically. These mixtures are Lyapunov stable in the replicator dynamic and asymptotically stable in the best response dynamic. Moreover, they have large basins of attraction, in fact larger than those of either pooling or separating equilibria. This suggests that these mixtures may play significant, and underappreciated, roles in the explanation of the emergence and stability of information transfer.

  8. Ocean circulation generated magnetic signals

    DEFF Research Database (Denmark)

    Manoj, C.; Kuvshinov, A.; Maus, S.

    2006-01-01

    Conducting ocean water, as it flows through the Earth's magnetic field, generates secondary electric and magnetic fields. An assessment of the ocean-generated magnetic fields and their detectability may be of importance for geomagnetism and oceanography. Motivated by the clear identification...... of ocean tidal signatures in the CHAMP magnetic field data we estimate the ocean magnetic signals of steady flow using a global 3-D EM numerical solution. The required velocity data are from the ECCO ocean circulation experiment and alternatively from the OCCAM model for higher resolution. We assume...... of the magnetic field, as compared to the ECCO simulation. Besides the expected signatures of the global circulation patterns, we find significant seasonal variability of ocean magnetic signals in the Indian and Western Pacific Oceans. Compared to seasonal variation, interannual variations produce weaker signals....

  9. Notch Signaling and Brain Tumors

    DEFF Research Database (Denmark)

    Stockhausen, Marie; Kristoffersen, Karina; Poulsen, Hans Skovgaard

    2011-01-01

    Human brain tumors are a heterogenous group of neoplasms occurring inside the cranium and the central spinal cord. In adults and children, astrocytic glioma and medulloblastoma are the most common subtypes of primary brain tumors. These tumor types are thought to arise from cells in which Notch...... signaling plays a fundamental role during development. Recent findings have shown that Notch signaling is dysregulated, and contributes to the malignant potential of these tumors. Growing evidence point towards an important role for cancer stem cells in the initiation and maintenance of glioma...... and medulloblastoma. In this chapter we will cover the present findings of Notch signaling in human glioma and medulloblastoma and try to create an overall picture of its relevance in the pathogenesis of these tumors....

  10. Wavelets and multiscale signal processing

    CERN Document Server

    Cohen, Albert

    1995-01-01

    Since their appearance in mid-1980s, wavelets and, more generally, multiscale methods have become powerful tools in mathematical analysis and in applications to numerical analysis and signal processing. This book is based on "Ondelettes et Traitement Numerique du Signal" by Albert Cohen. It has been translated from French by Robert D. Ryan and extensively updated by both Cohen and Ryan. It studies the existing relations between filter banks and wavelet decompositions and shows how these relations can be exploited in the context of digital signal processing. Throughout, the book concentrates on the fundamentals. It begins with a chapter on the concept of multiresolution analysis, which contains complete proofs of the basic results. The description of filter banks that are related to wavelet bases is elaborated in both the orthogonal case (Chapter 2), and in the biorthogonal case (Chapter 4). The regularity of wavelets, how this is related to the properties of the filters and the importance of regularity for t...

  11. Hedgehog signaling in the stomach.

    Science.gov (United States)

    Konstantinou, Daniel; Bertaux-Skeirik, Nina; Zavros, Yana

    2016-12-01

    The Hedgehog (Hh) signaling pathway not only plays a key part in controlling embryonic development, but in the adult stomach governs important cellular events such as epithelial cell differentiation, proliferation, gastric disease, and regeneration. In particular, Sonic Hedgehog (Shh) signaling has been well studied for its role in gastric physiology and pathophysiology. Shh is secreted from the gastric parietal cells and contributes to the regeneration of the epithelium in response to injury, or the development of gastritis during Helicobacter pylori infection. Dysregulation of the Shh signaling pathway leads to the disruption of gastric differentiation, loss of gastric acid secretion and the development of cancer. In this chapter, we will review the most recent findings that reveal the role of Shh as a regulator of gastric physiology, regeneration, and disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Multichannel Coding of Applause Signals

    Directory of Open Access Journals (Sweden)

    Jeroen Breebaart

    2007-08-01

    Full Text Available We develop a parametric multichannel audio codec dedicated to coding signals consisting of a dense series of transient-type events. These signals of which applause is a typical example are known to be problematic for such audio codecs. The codec design is based on preservation of both timbre and transient-type event density. It combines a very low complexity and a low parameter bit rate (0.2 kbps. In a formal listening test, we compared the proposed codec to the recently standardised MPEG Surround multichannel codec, with an associated parameter bit rate of 9 kbps. We found the new codec to have a significantly higher audio quality than the MPEG Surround codec for the two multichannel applause signals under test. Though this seems promising, the technique presented is not fully mature, for example, because issues related to integration of the proposed codec in the MPEG Surround codec were not addressed.

  13. Multichannel Coding of Applause Signals

    Science.gov (United States)

    Hotho, Gerard; van de Par, Steven; Breebaart, Jeroen

    2007-12-01

    We develop a parametric multichannel audio codec dedicated to coding signals consisting of a dense series of transient-type events. These signals of which applause is a typical example are known to be problematic for such audio codecs. The codec design is based on preservation of both timbre and transient-type event density. It combines a very low complexity and a low parameter bit rate (0.2 kbps). In a formal listening test, we compared the proposed codec to the recently standardised MPEG Surround multichannel codec, with an associated parameter bit rate of 9 kbps. We found the new codec to have a significantly higher audio quality than the MPEG Surround codec for the two multichannel applause signals under test. Though this seems promising, the technique presented is not fully mature, for example, because issues related to integration of the proposed codec in the MPEG Surround codec were not addressed.

  14. Humanin signal for Alzheimer's disease.

    Science.gov (United States)

    Matsuoka, Masaaki

    2011-01-01

    Despite a bulk of evidence supporting the idea that increased neurotoxic insults lead to Alzheimer's disease (AD), the possibility still remains that insufficiency of an endogenous defense system contributes to the disease progression. Humanin is a bioactive peptide that is likely to inhibit both neuronal death and dysfunction only related to AD by binding to a Humanin receptor on the cell-surface and by activating a STAT3-mediated signal, preventing the onset of dementia. A couple of recent studies presented evidence suggesting that the Humanin signal is decreased in neurons of AD patients. If this is the case, the restoration or activation of the Humanin signal in neurons may change the course of AD.

  15. Studies on Presence: prolegomena for the research on performative practices

    Directory of Open Access Journals (Sweden)

    Gilberto Icle

    2011-05-01

    Full Text Available This text presents a few notes about the manner through which the Studies on Presence define and delimit themselves from an epistemological point of view. It presents the university context of the research to which this perspective belongs and the self-referential mode of studying performative practices. It also discusses presence in the work of performers and its relation to meaning in order to delimit a field of problematisation on the inadequacy of interpretation as the only wayfor having access to knowledge. We propose, from Michel Foucault and Hans Ulrich Gumbrecht, other modes of research on performative practices.

  16. Dynamic modeling of presence of occupants using inhomogeneous Markov chains

    DEFF Research Database (Denmark)

    Andersen, Philip Hvidthøft Delff; Iversen, Anne; Madsen, Henrik

    2014-01-01

    on inhomogeneous Markov chains with where the transition probabilities are estimated using generalized linear models with polynomials, B-splines, and a filter of passed observations as inputs. For treating the dispersion of the data series, a hierarchical model structure is used where one model is for low presence......Occupancy modeling is a necessary step towards reliable simulation of energy consumption in buildings. This paper outlines a method for fitting recordings of presence of occupants and simulation of single-person to multiple-persons office environments. The method includes modeling of dependence...

  17. Radiation polymerisation of cyclohexyl acrylate in presence of cyclohexanol

    International Nuclear Information System (INIS)

    Roger, R.; Rao, M.H.; Rao, K.N.

    1986-01-01

    Radiation polymerisation of cyclohexyl acrylate in presence of cyclohexanol has been studied at various dose rates. The dose rate exponent determined approx. 0.66 indicates the possibility of the existence of the chain transfer to cyclohexanol. GPC chromatogram shows the presence of the low molecular weight polymer suppressing the high molecular weight fraction. These results suggest that the origin of the low molecular weight polymer could be through free radical initiation. High molecular weight fraction which is due to ionic initiation is suppressed completely indicating the possibility of cyclohexanol acting as a chain transfer agent for ions. (author)

  18. Enforcing Transferable Permit Systems in the Presence of Market Power

    International Nuclear Information System (INIS)

    Chavez, C.A.; Stanlund, J.K.

    2003-01-01

    We derive an enforcement strategy for a transferable permit system in the presence of market power that achieves complete compliance in a cost-effective manner. We show that the presence of a firm with market influence makes designing an enforcement strategy more difficult than enforcing a perfectly competitive system. We also re-consider the suggestion that a firm with market influence should be allocated permits so that it chooses to not participate in the permit market. When enforcement and its costs are taken into account, that suggestion does not hold except in a very special case

  19. Is Host Ectoparasite Load Related to Echeneid Fish Presence?

    International Nuclear Information System (INIS)

    Mucientes, G.R.; Queiroz, N.; Queiroz, N.; Pierce, S.J.; Pierce, S.J.; Sazima, I.; Brunnschweiler, J.M.

    2008-01-01

    This study used field data of echeneid and ectoparasitic associations with free-swimming whale sharks (Rhincodon typus) and captured mako sharks (Isurus oxyrinchus) to test whether (1) echeneid presence was positively correlated with ectoparasitic presence; and (2) the number of ectoparasitic was negatively correlated with the number of echeneid fish. Data from whale and mako sharks do not support the first hypothesis whereas data from mako sharks yields support for the second hypothesis. The results indicate that echeneids do regulate the number of ectoparasitic on at least some host species, but these benefits may be contingent on the echeneid species.

  20. Is Host Ectoparasite Load Related to Echeneid Fish Presence?

    Directory of Open Access Journals (Sweden)

    Gonzalo R. Mucientes

    2008-01-01

    Full Text Available This study used field data of echeneid and ectoparasite associations with free-swimming whale sharks (Rhincodon typus and captured mako sharks (Isurus oxyrinchus to test whether (1 echeneid presence was positively correlated with ectoparasite presence; and (2 the number of ectoparasites was negatively correlated with the number of echeneid fish. Data from whale and mako sharks do not support the first hypothesis whereas data from mako sharks yields support for the second hypothesis. The results indicate that echeneids do regulate the number of ectoparasites on at least some host species, but these benefits may be contingent on the echeneid species.

  1. Hydrogenolytic cleavage of naphthylmethyl ethers in the presence of sulfides.

    Science.gov (United States)

    Adero, Philip O; Jarois, Dean R; Crich, David

    2017-09-08

    With the aid of a series of model thioether or thioglycoside containing polyols protected with combinations of benzyl ethers and 2-naphthylmethyl ethers it is demonstrated that the latter are readily cleaved selectively under hydrogenolytic conditions in the presence of the frequently catalyst-poisoning sulfides. These results suggest the possibility of employing 2-naphthylmethyl ethers in place of benzyl ethers in synthetic schemes when hydrogenolytic deprotection is anticipated in the presence of thioether type functionality. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. A combined segmenting and non-segmenting approach to signal quality estimation for ambulatory photoplethysmography

    International Nuclear Information System (INIS)

    Wander, J D; Morris, D

    2014-01-01

    Continuous cardiac monitoring of healthy and unhealthy patients can help us understand the progression of heart disease and enable early treatment. Optical pulse sensing is an excellent candidate for continuous mobile monitoring of cardiovascular health indicators, but optical pulse signals are susceptible to corruption from a number of noise sources, including motion artifact. Therefore, before higher-level health indicators can be reliably computed, corrupted data must be separated from valid data. This is an especially difficult task in the presence of artifact caused by ambulation (e.g. walking or jogging), which shares significant spectral energy with the true pulsatile signal. In this manuscript, we present a machine-learning-based system for automated estimation of signal quality of optical pulse signals that performs well in the presence of periodic artifact. We hypothesized that signal processing methods that identified individual heart beats (segmenting approaches) would be more error-prone than methods that did not (non-segmenting approaches) when applied to data contaminated by periodic artifact. We further hypothesized that a fusion of segmenting and non-segmenting approaches would outperform either approach alone. Therefore, we developed a novel non-segmenting approach to signal quality estimation that we then utilized in combination with a traditional segmenting approach. Using this system we were able to robustly detect differences in signal quality as labeled by expert human raters (Pearson’s r = 0.9263). We then validated our original hypotheses by demonstrating that our non-segmenting approach outperformed the segmenting approach in the presence of contaminated signal, and that the combined system outperformed either individually. Lastly, as an example, we demonstrated the utility of our signal quality estimation system in evaluating the trustworthiness of heart rate measurements derived from optical pulse signals. (paper)

  3. Signals, systems, transforms, and digital signal processing with Matlab

    CERN Document Server

    Corinthios, Michael

    2009-01-01

    Continuous-Time and Discrete-Time Signals and SystemsIntroductionContinuous-Time SignalsPeriodic FunctionsUnit Step FunctionGraphical Representation of FunctionsEven and Odd Parts of a FunctionDirac-Delta ImpulseBasic Properties of the Dirac-Delta ImpulseOther Important Properties of the ImpulseContinuous-Time SystemsCausality, StabilityExamples of Electrical Continuous-Time SystemsMechanical SystemsTransfer Function and Frequency ResponseConvolution and CorrelationA Right-Sided and a Left-Sided FunctionConvolution with an Impulse and Its DerivativesAdditional Convolution PropertiesCorrelation FunctionProperties of the Correlation FunctionGraphical InterpretationCorrelation of Periodic FunctionsAverage, Energy and Power of Continuous-Time SignalsDiscrete-Time SignalsPeriodicityDifference EquationsEven/Odd DecompositionAverage Value, Energy and Power SequencesCausality, StabilityProblemsAnswers to Selected ProblemsFourier Series ExpansionTrigonometric Fourier SeriesExponential Fourier SeriesExponential versus ...

  4. DMPD: Signal integration between IFNgamma and TLR signalling pathways in macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16920490 Signal integration between IFNgamma and TLR signalling pathways in macroph...tml) (.csml) Show Signal integration between IFNgamma and TLR signalling pathways in macrophages. PubmedID 1...6920490 Title Signal integration between IFNgamma and TLR signalling pathways in

  5. Signal processing for cognitive radios

    CERN Document Server

    Jayaweera, Sudharman K

    2014-01-01

    This book covers power electronics, in depth, by presenting the basic principles and application details, and it can be used both as a textbook and reference book.  Introduces the specific type of CR that has gained the most research attention in recent years: the CR for Dynamic Spectrum Access (DSA). Provides signal processing solutions to each task by relating the tasks to materials covered in Part II. Specialized chapters then discuss specific signal processing algorithms required for DSA and DSS cognitive radios  

  6. PSpice for digital signal processing

    CERN Document Server

    Tobin, Paul

    2007-01-01

    PSpice for Digital Signal Processing is the last in a series of five books using Cadence Orcad PSpice version 10.5 and introduces a very novel approach to learning digital signal processing (DSP). DSP is traditionally taught using Matlab/Simulink software but has some inherent weaknesses for students particularly at the introductory level. The 'plug in variables and play' nature of these software packages can lure the student into thinking they possess an understanding they don't actually have because these systems produce results quicklywithout revealing what is going on. However, it must be

  7. Genomic Signals of Reoriented ORFs

    Directory of Open Access Journals (Sweden)

    Paul Dan Cristea

    2004-01-01

    Full Text Available Complex representation of nucleotides is used to convert DNA sequences into complex digital genomic signals. The analysis of the cumulated phase and unwrapped phase of DNA genomic signals reveals large-scale features of eukaryote and prokaryote chromosomes that result from statistical regularities of base and base-pair distributions along DNA strands. By reorienting the chromosome coding regions, a “hidden” linear variation of the cumulated phase has been revealed, along with the conspicuous almost linear variation of the unwrapped phase. A model of chromosome longitudinal structure is inferred on these bases.

  8. Signal processing for remote sensing

    CERN Document Server

    Chen, CH

    2007-01-01

    Written by leaders in the field, Signal Processing for Remote Sensing explores the data acquisitions segment of remote sensing. Each chapter presents a major research result or the most up to date development of a topic. The book includes a chapter by Dr. Norden Huang, inventor of the Huang-Hilbert transform who, along with and Dr. Steven Long discusses the application of the transform to remote sensing problems. It also contains a chapter by Dr. Enders A. Robinson, who has made major contributions to seismic signal processing for over half a century, on the basic problem of constructing seism

  9. Digital signal processing for NDT

    International Nuclear Information System (INIS)

    Georgel, B.

    1994-01-01

    NDT begins to adapt and use the most recent developments of digital signal and image processing. We briefly sum up the main characteristics of NDT situations (particularly noise and inverse problem formulation) and comment on techniques already used or just emerging (SAFT, split spectrum, adaptive learning network, noise reference filtering, stochastic models, neural networks). This survey is focused on ultrasonics, eddy currents and X-ray radiography. The final objective of end users (availability of automatic diagnosis systems) cannot be achieved only by signal processing algorithms. A close cooperation with other techniques such as artificial intelligence has therefore to be implemented. (author). 20 refs

  10. Multichannel Coding of Applause Signals

    OpenAIRE

    Jeroen Breebaart; Steven van de Par; Gerard Hotho

    2007-01-01

    We develop a parametric multichannel audio codec dedicated to coding signals consisting of a dense series of transient-type events. These signals of which applause is a typical example are known to be problematic for such audio codecs. The codec design is based on preservation of both timbre and transient-type event density. It combines a very low complexity and a low parameter bit rate (0.2 kbps). In a formal listening test, we compared the proposed codec to the recently standardised MPEG Su...

  11. Notch Signaling and Brain Tumors

    DEFF Research Database (Denmark)

    Stockhausen, Marie; Kristoffersen, Karina; Poulsen, Hans Skovgaard

    2011-01-01

    Human brain tumors are a heterogenous group of neoplasms occurring inside the cranium and the central spinal cord. In adults and children, astrocytic glioma and medulloblastoma are the most common subtypes of primary brain tumors. These tumor types are thought to arise from cells in which Notch...... signaling plays a fundamental role during development. Recent findings have shown that Notch signaling is dysregulated, and contributes to the malignant potential of these tumors. Growing evidence point towards an important role for cancer stem cells in the initiation and maintenance of glioma...

  12. The Pseudomonas Quinolone Signal (PQS)

    DEFF Research Database (Denmark)

    Sams, Thomas; Baker, Ysobel; Hodgkinson, James

    2015-01-01

    Pseudomonas aeruginosa is an opportunistichuman pathogen that routinely appears near the top ofpublic health threat lists worldwide. P. aeruginosa causes in-fections by secreting a wealth of exceptionally active exo-products, leading to tissue damage. The synthesis of manyof these virulence factors...... is now known to be under the con-trol of the quorum sensing (QS) system. Over the last15 years, the Pseudomonas quinolone signal (PQS) has beenfound to play a crucial role in QS by linking the two seg-ments (las and rhl) of the P. aeruginosa N-acylhomoserinelactone-dependent QS signaling pathways. Herein...

  13. Chaotic signals in digital communications

    CERN Document Server

    Eisencraft, Marcio; Suyama, Ricardo

    2013-01-01

    Chaotic Signals in Digital Communications combines fundamental background knowledge with state-of-the-art methods for using chaotic signals and systems in digital communications. The book builds a bridge between theoretical works and practical implementation to help researchers attain consistent performance in realistic environments. It shows the possible shortcomings of the chaos-based communication systems proposed in the literature, particularly when they are subjected to non-ideal conditions. It also presents a toolbox of techniques for researchers working to actually implement such system

  14. Signal recovery in imaging photoplethysmography

    International Nuclear Information System (INIS)

    Holton, Benjamin D; Mannapperuma, Kavan; Lesniewski, Peter J; Thomas, John C

    2013-01-01

    Imaging photoplethysmography is an emerging technique for the extraction of biometric information from people using video recordings. The focus is on extracting the cardiac heart rate of the subject by analysing the luminance of the colour video signal and identifying periodic components. Advanced signal processing is needed to recover the information required. In this paper, independent component analysis (ICA), principal component analysis, auto- and cross-correlation are investigated and compared with respect to their effectiveness in extracting the relevant information from video recordings. Results obtained are compared with those recorded by a modern commercial finger pulse oximeter. It is found that ICA produces the most consistent results. (paper)

  15. Signal recovery in imaging photoplethysmography.

    Science.gov (United States)

    Holton, Benjamin D; Mannapperuma, Kavan; Lesniewski, Peter J; Thomas, John C

    2013-11-01

    Imaging photoplethysmography is an emerging technique for the extraction of biometric information from people using video recordings. The focus is on extracting the cardiac heart rate of the subject by analysing the luminance of the colour video signal and identifying periodic components. Advanced signal processing is needed to recover the information required. In this paper, independent component analysis (ICA), principal component analysis, auto- and cross-correlation are investigated and compared with respect to their effectiveness in extracting the relevant information from video recordings. Results obtained are compared with those recorded by a modern commercial finger pulse oximeter. It is found that ICA produces the most consistent results.

  16. Subgraph detection using graph signals

    KAUST Repository

    Chepuri, Sundeep Prabhakar

    2017-03-06

    In this paper we develop statistical detection theory for graph signals. In particular, given two graphs, namely, a background graph that represents an usual activity and an alternative graph that represents some unusual activity, we are interested in answering the following question: To which of the two graphs does the observed graph signal fit the best? To begin with, we assume both the graphs are known, and derive an optimal Neyman-Pearson detector. Next, we derive a suboptimal detector for the case when the alternative graph is not known. The developed theory is illustrated with numerical experiments.

  17. Signal processing systems for nuclear reactor

    International Nuclear Information System (INIS)

    Hirano, Kazuo.

    1981-01-01

    Purpose: To carry out the works signal processing, in a nuclear power plant, automatically. Constitution: Neutron flux signal from reactor instruments is inputted into a reactivity meter, and processes in accordance with reactor characteristic equations and, as the result, outputted as a reactivity signal rho. The signal rho, as well as the neutron flux signal and temperature signal are inputted together to a pen recorder and recorded on a record chart. While on the other hand, these signals are inputted into a signal processor, together with a range-switching signal from the reactivity meter and with a control-rod-position signal n from other instrument. In the signal processor, the differentiation and integration values such as Δrho/(n 1 -n 2 ) and ΣΔrho of the control element are conducted automatically. The results are indicated on a graphic display. (J.P.N.)

  18. Electrochemical monitoring of the interaction between anticancer drug and DNA in the presence of antioxidant.

    Science.gov (United States)

    Muti, Merve; Muti, Mihrican

    2018-02-01

    The aim of this work is to find out the effect of antioxidant onto the interaction of DNA-anticancer drug, daunorubicin. Daunorubicin (DNR) is an anti-cancer drug which is used for the treatment of certain cancers including the treatment of leukemia. The treatments of patients, who suffer from cancer, become generally complicated if they take some antioxidant-containing supplement during chemotherapy. In this study, the interaction performance between DNR and DNA was investigated both in the presence and absence of antioxidant, caffeic acid, as the first time in the literature. Interaction performances were evaluated by observing both guanine (1.0V) and DNR (0.5V) oxidation signal in the same potential window. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Performance Evaluation of Underwater Wireless Optical Communications Links in the Presence of Different Air Bubble Populations

    KAUST Repository

    Oubei, Hassan M.

    2017-03-16

    We experimentally evaluate the performance of underwater wireless optical communication (UWOC) links in the presence of different air bubbles. Air bubbles of different sizes and densities are generated by using an air pipe in conjunction with a submersible water pump of variable flow rate that help break up large bubbles into smaller bubbles. Received signal intensity measurements show that bubbles significantly degrade the performance of UWOC links. Large bubbles completely obstruct the optical beam and cause a deep fade. However, as the bubble size decreases, the level of deep fade also decreases because the optical beam is less susceptible to complete obstruction and more light reaches the detector. We also show that beam expansion could help mitigate the performance degradation due to the deep fade caused by air bubbles scatters in the channel.

  20. Wideband Direction of Arrival Estimation in the Presence of Unknown Mutual Coupling

    Directory of Open Access Journals (Sweden)

    Weixing Li

    2017-02-01

    Full Text Available This paper investigates a subarray based algorithm for direction of arrival (DOA estimation of wideband uniform linear array (ULA, under the presence of frequency-dependent mutual coupling effects. Based on the Toeplitz structure of mutual coupling matrices, the whole array is divided into the middle subarray and the auxiliary subarray. Then two-sided correlation transformation is applied to the correlation matrix of the middle subarray instead of the whole array. In this way, the mutual coupling effects can be eliminated. Finally, the multiple signal classification (MUSIC method is utilized to derive the DOAs. For the condition when the blind angles exist, we refine DOA estimation by using a simple approach based on the frequency-dependent mutual coupling matrixes (MCMs. The proposed method can achieve high estimation accuracy without any calibration sources. It has a low computational complexity because iterative processing is not required. Simulation results validate the effectiveness and feasibility of the proposed algorithm.

  1. Reception of Multiple Telemetry Signals via One Dish Antenna

    Science.gov (United States)

    Mukai, Ryan; Vilnrotter, Victor

    2010-01-01

    A microwave aeronautical-telemetry receiver system includes an antenna comprising a seven-element planar array of receiving feed horns centered at the focal point of a paraboloidal dish reflector that is nominally aimed at a single aircraft or at multiple aircraft flying in formation. Through digital processing of the signals received by the seven feed horns, the system implements a method of enhanced cancellation of interference, such that it becomes possible to receive telemetry signals in the same frequency channel simultaneously from either or both of two aircraft at slightly different angular positions within the field of view of the antenna, even in the presence of multipath propagation. The present system is an advanced version of the system described in Spatio- Temporal Equalizer for a Receiving-Antenna Feed Array NPO-43077, NASA Tech Briefs, Vol. 34, No. 2 (February 2010), page 32. To recapitulate: The radio-frequency telemetry signals received by the seven elements of the array are digitized, converted to complex baseband form, and sent to a spatio-temporal equalizer that consists mostly of a bank of seven adaptive finite-impulse-response (FIR) filters (one for each element in the array) plus a unit that sums the outputs of the filters. The combination of the spatial diversity of the feedhorn array and the temporal diversity of the filter bank affords better multipath suppression performance than is achievable by means of temporal equalization alone. The FIR filter bank adapts itself in real time to enable reception of telemetry at a low bit error rate, even in the presence of frequency-selective multipath propagation like that commonly found at flight-test ranges. The combination of the array and the filter bank makes it possible to constructively add multipath incoming signals to the corresponding directly arriving signals, thereby enabling reductions in telemetry bit-error rates.

  2. Dysprosium (holmium) determination in the presence of erbium and dysprosium (holmium, erbium) determination in the presence of cerium

    International Nuclear Information System (INIS)

    Tolubara, A.I.; Kochubej, A.I.; Usatenko, Yu.I.

    1978-01-01

    Effect of salicylic acid upon complex formation in the systems REE - boronsulfoalizarinate, REE - oxine and REE - boronsulfoalizarinate - oxine is investigated. Comparison of optical characteristics of the above systems in the absence and in the presence of salicylic acid is carried out. It is established that in all the cases the effect of salicylic acid depends both on the nature of REE and the ratio of all the components of the system. Under certain conditions the given dependence is observed only for erbium complexes. Extraction-photometric methods of dysprosium and holmium determination in the presence of equal erbium amounts, as well as holmium and erbium determination in the presence of cerium equal amounts is developed

  3. Presence of lupus anticoagulant in an asymptomatic Nigerian ...

    African Journals Online (AJOL)

    Method:A 25 year old \\'healthy\\' male Nigerian was screened for the presence of any coagulation abnormality using the KCT, PT and platelet count; after volunteering for his plasma to be used in the preparation of normal pooled plasma in a study. Results: He was discovered to have a prolonged KCT, PT and normal platelet ...

  4. Reactivity and resizing of gold nanorods in presence of Cu

    Indian Academy of Sciences (India)

    Wintec

    Reactivity of gold nanorods, in presence of cupric ions, was probed in an attempt to understand the chemistry of anisotropic particles. The reaction progresses through a series of intermediates. It can be arrested at any stage to get nanorods of desired dimension and therefore, can be .... among the low index planes of gold.

  5. Solitary drift waves in the presence of magnetic shear

    International Nuclear Information System (INIS)

    Meiss, J.D.; Horton, W.

    1982-07-01

    The two-component fluid equations describing electron drift and ion acoustic waves in a nonuniform magnetized plasma are shown to possess nonlinear two-dimensional solitary wave solutions. In the presence of magnetic shear, radiative shear damping is exponentially small in L/sub s//L/sub n/ for solitary drift waves, in contrast to linear waves

  6. Inadvertent presence of genetically modified elements in maize food ...

    African Journals Online (AJOL)

    owner

    2013-07-31

    Jul 31, 2013 ... assess the maize food products in the Kenyan market for the presence of genetic elements from GMOs. This was done by testing various maize food products, including grains from open air markets, relief food, maize seeds from seed companies and processed food sampled from various supermarkets in ...

  7. 1. Association between Presence of Haptoglobin Phenotypes and ...

    African Journals Online (AJOL)

    RICHY

    1. Medical Journal of Zambia, Vol. 42, No. 1: 1- 6 (2015). ABSTRACT. Objectives: The aim of the study was to investigate the association between presence of haptoglobin phenotypes and hypertension in indigenous Zambian patients attending outpatient medical clinic at the University. Teaching Hospital in Lusaka, Zambia.

  8. Origin of Ancient Canary Islanders Guanches: presence of Atlantic ...

    African Journals Online (AJOL)

    Present paper HLA genes partial data and presence of abundant old Iberian language scripts (which show an easy translation proposal by using Basque) in Fuerteventura and also in Lanzarote and El Hierro Islands suggest that a present day dogma of a hypothetically North African single origin should be changed.

  9. Inadvertent presence of genetically modified elements in maize food ...

    African Journals Online (AJOL)

    Kenya has a biosafety law and has tested genetically modified (GM) maize under confinement and containment, but has neither released nor commercialized any GM crop. This study assessed various maize food products from the Kenyan farms and markets for the inadvertent presence of GMOs. It assessed the possibility ...

  10. Clustering Binary Data in the Presence of Masking Variables

    Science.gov (United States)

    Brusco, Michael J.

    2004-01-01

    A number of important applications require the clustering of binary data sets. Traditional nonhierarchical cluster analysis techniques, such as the popular K-means algorithm, can often be successfully applied to these data sets. However, the presence of masking variables in a data set can impede the ability of the K-means algorithm to recover the…

  11. Ultrafast Grignard addition reactions in the presence of water

    DEFF Research Database (Denmark)

    Osztrovszky, Gyorgyi; Holm, Torkil; Madsen, R.

    2010-01-01

    The addition of allylmagnesium bromide and benzylmagnesium chloride to carbonyl compounds was investigated in the presence of protic reagents such as water and the rate of carbonyl addition was found to be comparable to the rate of protonation by the reagent....

  12. Women's Presence In The Judiciary Of Goiás

    Directory of Open Access Journals (Sweden)

    Christiane de Holanda Camilo

    2017-02-01

    Full Text Available This paper makes a qualitative and quantitative analysis of the feminization of the phenomenon in the State Judiciary of the State of Goiás, specifically observing this phenomenon for the presence of magistrates in the exercise of judges function in different indentation according to access criteria , promotion and removal.

  13. Presence of nitrites, nitrates, nitrosamines in the eggs of Intensively ...

    African Journals Online (AJOL)

    In this study, the presence and concentrations of nitrosamines and their precursors (nitrates and nitrites) in raw table eggs obtained from four layer-farms in Abeokuta, were analysed. Nitrosamines are highly toxic and carcinogenic group of chemicals that have the potential to be formed in the body through a process called ...

  14. Multiple imputation in the presence of high-dimensional data.

    Science.gov (United States)

    Zhao, Yize; Long, Qi

    2016-10-01

    Missing data are frequently encountered in biomedical, epidemiologic and social research. It is well known that a naive analysis without adequate handling of missing data may lead to bias and/or loss of efficiency. Partly due to its ease of use, multiple imputation has become increasingly popular in practice for handling missing data. However, it is unclear what is the best strategy to conduct multiple imputation in the presence of high-dimensional data. To answer this question, we investigate several approaches of using regularized regression and Bayesian lasso regression to impute missing values in the presence of high-dimensional data. We compare the performance of these methods through numerical studies, in which we also evaluate the impact of the dimension of the data, the size of the true active set for imputation, and the strength of correlation. Our numerical studies show that in the presence of high-dimensional data the standard multiple imputation approach performs poorly and the imputation approach using Bayesian lasso regression achieves, in most cases, better performance than the other imputation methods including the standard imputation approach using the correctly specified imputation model. Our results suggest that Bayesian lasso regression and its extensions are better suited for multiple imputation in the presence of high-dimensional data than the other regression methods. © The Author(s) 2013.

  15. Optimal schemes to detect the presence of insect species.

    NARCIS (Netherlands)

    Zonneveld, C.; Longcore, T; Mulder, C.

    2003-01-01

    Survey protocols to detect the presence of particular species should be organized to make optimal use of available resources. Current protocols mostly deal with this problem intuitively, but the problem can also be addressed with mathematical modeling. To this aim, we used a model that describes the

  16. Oral Candidiasis: A Tool For The Detection Of Presence And ...

    African Journals Online (AJOL)

    This objectives of the study were to determine the prevalence of HIV infection in children using oral thrush as a marker of disease presence and to find out the relationship of CD4 count with oral candidiasis in HIV-infected children. The study group consisted of 108 children aged 18 months to 5 years presenting with oral ...

  17. Assessment of microbiological status and presence of antibiotic ...

    African Journals Online (AJOL)

    February to March, n=95) and towards the end of the rainy season (April to May, n=91). Total bacterial count (TBC) and Coliform counts (TCC) were established and used as indicators of microbial contamination of the milk. Presence of antibiotic ...

  18. The presence of a primary male caregiver affects children's ...

    African Journals Online (AJOL)

    This study aimed to determine whether the presence or absence of a primary male caregiver influences a child's language skills. A language test was administered to 342 Afrikaans-speaking 4- to 9-year-olds from various socioeconomic backgrounds. The average percentile ranks for the composite language score as well ...

  19. the absence of presence. homiletical reflections on luther's notion of ...

    African Journals Online (AJOL)

    This paper addresses a complex but core issue of preaching, namely the experience of the elusiveness of God's presence (revelation) by taking cognisance of the notion of masking. Besides being a common cultural phenomenon, the art of masking could also be evaluated theologically and therefore homiletically. Luther's ...

  20. Optimal Software Strategies in the Presence of Network Externalities

    Science.gov (United States)

    Liu, Yipeng

    2009-01-01

    Network externalities or alternatively termed network effects are pervasive in computer software markets. While software vendors consider pricing strategies, they must also take into account the impact of network externalities on their sales. My main interest in this research is to describe a firm's strategies and behaviors in the presence of…

  1. Normal serum alkaline phosphatase in the presence of extensive ...

    African Journals Online (AJOL)

    Normal serum alkaline phosphatase in this patient in the presence of extensive skeletal metastases may be due to the combination of the following factors: relative hypogonadism, osteoporosis, low serum zinc and magnesium. This case report may provide a possible explanation for the observation that about 10% of men ...

  2. Cylindrically symmetric cosmological model in the presence of bulk ...

    Indian Academy of Sciences (India)

    Cylindrically symmetric non-static space–time is investigated in the presence of bulk stress given by Landau and Lifshitz. To get a solution, a supplementary condition between metric potentials is used. The viscosity coefficient of the bulk viscous fluid is assumed to be a power function of mass density whereas the coefficient ...

  3. Using Online Presence to Improve Online Collaborative Learning

    Directory of Open Access Journals (Sweden)

    Zoran Jeremic

    2012-02-01

    Full Text Available Social software tools have become an integral part of students’ personal lives and their primary communication medium. Likewise, these tools are increasingly entering the enterprise world (within the recent trend known as Enterprise 2.0 and becoming a part of everyday work routines. Aiming to keep the pace with the job requirements and also to position learning as an integral part of students’ life, the field of education is challenged to embrace social software. Personal Learning Environments (PLEs emerged as a concept that makes use of social software to facilitate collaboration, knowledge sharing, group formation around common interests, active participation and reflective thinking in online learning settings. Furthermore, social software allows for establishing and maintaining one’s presence in the online world. By being aware of a student's online presence, a PLE is better able to personalize the learning settings, e.g., through recommendation of content to use or people to collaborate with. Aiming to explore the potentials of online presence for the provision of recommendations in PLEs, in the scope of the OP4L project, we have develop a software solution that is based on a synergy of Semantic Web technologies, online presence and socially-oriented learning theories. In this paper we present the current results of this research work.

  4. Evaluation of β-carotene content and presence of some ...

    African Journals Online (AJOL)

    Evaluation of β-carotene content and presence of some phytochemicals in five indigenous fruits. IA Nwaogu, CS Alisi, CO Ibegbulem. Abstract. No Abstract. Plant Products Research Journal Vol. 10, 2006: 13-15. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  5. Movement patterns of coastal bottlenose dolphins in the presence of ...

    African Journals Online (AJOL)

    The presence and movement of Indo-Pacific bottlenose dolphins Tursiops aduncus were investigated using shore-based observations made during a humpback whale Megaptera novaeangliae migration survey at Cape Vidal, South Africa, undertaken between June and October 1988–1991. Occurrence was analysed as ...

  6. The presence of a primary male caregiver affects children's ...

    African Journals Online (AJOL)

    Afrikaans-speaking children with absent primary male caregivers are indeed distinguishable from those of children with present primary male caregivers. To date, studies on the effects of the presence/absence of a father figure on language development were mainly conducted in the United States of America, and their ...

  7. Quantum propagator in the presence of a perfectly reflecting wall

    International Nuclear Information System (INIS)

    Cacciari, Ilaria; Lantieri, Marco; Moretti, Paolo

    2007-01-01

    The transmission propagator for an arbitrary, finite range one-dimensional potential in the presence of a perfectly reflecting wall is calculated starting from the integral form of the Schroedinger equation. After a Laplace transform, the solution is obtained in a new and simple form by using matrix methods; we apply the results to an array of delta potentials

  8. Historical evidence for a pre-Columbian presence of Datura

    Indian Academy of Sciences (India)

    2007-12-04

    Dec 4, 2007 ... Further, the textual evidence traditionally cited in support of a pre-Columbian Old World presence of Datura species is suggested to be due to the misreading of classical Greek and Arabic sources. As a result, botanists generally accept the opinion that Datura species were transferred into the Old World in ...

  9. Computationally Secure Pattern Matching in the Presence of Malicious Adversaries

    DEFF Research Database (Denmark)

    Hazay, Carmit; Toft, Tomas

    2010-01-01

    simulation in the presence of malicious, polynomial-time adversaries (assuming that ElGamal encryption is semantically secure) and exhibits computation and communication costs of O(n + m) in a constant round complexity. In addition to the above, we propose a collection of protocols for variations...

  10. Relationships between CD4+ Counts and the Presence of Oral ...

    African Journals Online (AJOL)

    Relationships between CD4+ Counts and the Presence of Oral Lesions in Human Immunodeficiency Virus Positive Women in Nigeria. ... Annals of Medical and Health Sciences Research ... Keywords: CD4+ counts, Human immunodeficiency virus/Acquired immune deficiency syndrome positive women, Oral lesions ...

  11. Instructors' Perceptions of Instructor Presence in Online Learning Environments

    Science.gov (United States)

    Richardson, Jennifer C.; Besser, Erin; Koehler, Adrie; Lim, JiEun; Strait, Marquetta

    2016-01-01

    As online learning continues to grow significantly, various efforts have been explored and implemented in order to improve the instructional experiences of students. Specifically, research indicates that how an instructor establishes his or her presence in an online environment can have important implications for the students' overall learning…

  12. Presence of inbreeding during a selection experiment with Merino ...

    African Journals Online (AJOL)

    Presence of inbreeding during a selection experiment with Merino sheep. GJ Erasmus, AO de Lange, GJ Delport, JJ Olivier. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL.

  13. Spectrin interactions with globin chains in the presence of ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    We have shown the differential interactions of the erythroid skeletal protein spectrin with the globin subunits of adult haemoglobin ... high molecular weight complex; Kd, binding dissociation constant; Mg/ATP, ATP in presence of 10-fold molar excess of MgCl2; PMB, ... mercuribenzoic acid sodium salt (PMB), sodium azide,.

  14. On the importance of presence within fandom spaces

    DEFF Research Database (Denmark)

    Jensen, Thessa

    2017-01-01

    Presence and copresence in Goffman’s sense are some of the main building blocks of fandom groups in online spaces. This article provides a definition of both especially developed to take the online environment of fandom into account. At the same time, a framework for analysis and design of fandom...

  15. [The presence of a companion in the primary care consultation].

    Science.gov (United States)

    Turabián, J L; Pérez Franco, B

    2015-01-01

    The presence of an adult accompanying the patient in the consulting room is a significant fact that deserves the attention of the physician. Some types of companions and their presence in the consultation have been described and may improve communication, patient management, and participatory decision making, achieving greater patient satisfaction. Consultations with companion are generally longer, and patients accompanied are often elderly, women, less educated, and with poorer physical and mental health. But it is not known exactly what is the significance of a consultation with a companion. It may be a semiological fact to keep in mind for the family diagnosis, or it may be the risks of their presence, the influence of medication, or the importance of the doctors themselves that are the cause of the presence of a companion. Different communication skills must be achieved during the interview with the companion in the consultation, rather than with the patient alone. Copyright © 2014. Publicado por Elsevier España, S.L.U.

  16. A Critical Hermeneutic Analysis of Presence in Nursing Practice

    Directory of Open Access Journals (Sweden)

    Alicia L. Bright

    2015-12-01

    Full Text Available Nursing presence, although it involves action at times, is a humanitarian quality of relating to a patient that is known to have powerful and positive implications for both nurse and patient. However, this phenomenon has not been well understood. Three theories, drawn from the work of Paul Ricoeur and Hans-Georg Gadamer, served as the boundaries for both data collection and analysis. The theories were narrative identity, play and solicitude. This study follows a critical hermeneutic approach to field research and data analysis. Literature regarding nursing presence is reviewed and discussed, and in-depth conversations with eleven participants are recorded. Examining the phenomenon of nursing presence through the hermeneutic lenses of narrative identity, play and solicitude has elucidated the role of ethical orientation, creativity and connection with the human experience through exploration of self and other. This more nuanced and complex understanding adds depth to the conversation and offers new possibilities to the effort to encourage and support presence in nursing practice.

  17. Deposition of silicon films in presence of nitrogen plasma— A ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. A design, development and validation work of plasma based 'activated reactive evaporation (ARE) system' is implemented for the deposition of the silicon films in presence of nitrogen plasma on substrate maintained at room temperature. This plasma based deposition system involves evaporation of pure silicon by.

  18. Wave scattering through classically chaotic cavities in the presence ...

    Indian Academy of Sciences (India)

    We present a maximum-entropy model for the transport of waves through a classically chaotic cavity in the presence of ... that limit, the distribution of the individual (angular) transmission and reflection coefficients becomes exponential – Rayleigh ... or light) can be affected as a result of absorption. In addition to its theoretical ...

  19. Near Surface Seismic Hazard Characterization in the Presence of High Velocity Contrasts

    Science.gov (United States)

    Gribler, G.; Mikesell, D.; Liberty, L. M.

    2017-12-01

    We present new multicomponent surface wave processing techniques that provide accurate characterization of near-surface conditions in the presence of large lateral or vertical shear wave velocity boundaries. A common problem with vertical component Rayleigh wave analysis in the presence of high contrast subsurface conditions is Rayleigh wave propagation mode misidentification due to an overlap of frequency-phase velocity domain dispersion, leading to an overestimate of shear wave velocities. By using the vertical and horizontal inline component signals, we isolate retrograde and prograde particle motions to separate fundamental and higher mode signals, leading to more accurate and confident dispersion curve picks and shear wave velocity estimates. Shallow, high impedance scenarios, such as the case with shallow bedrock, are poorly constrained when using surface wave dispersion information alone. By using a joint inversion of dispersion and horizontal-to-vertical (H/V) curves within active source frequency ranges (down to 3 Hz), we can accurately estimate the depth to high impedance boundaries, a significant improvement compared to the estimates based on dispersion information alone. We compare our approach to body wave results that show comparable estimates of bedrock topography. For lateral velocity contrasts, we observe horizontal polarization of Rayleigh waves identified by an increase in amplitude and broadening of the horizontal spectra with little variation in the vertical component spectra. The horizontal spectra offer a means to identify and map near surface faults where there is no topographic or clear body wave expression. With these new multicomponent active source seismic data processing and inversion techniques, we better constrain a variety of near surface conditions critical to the estimation of local site response and seismic hazards.

  20. Presence of hydrogen peroxide, a source of hydroxyl radicals, in acid electrolyzed water.

    Directory of Open Access Journals (Sweden)

    Takayuki Mokudai

    Full Text Available BACKGROUND: Acid electrolyzed water (AEW, which is produced through the electrolysis of dilute sodium chloride (NaCl or potassium chloride solution, is used as a disinfectant in various fields because of its potent antimicrobial activity. The hydroxyl radical, an oxygen radical species, is often suggested as a putative active ingredient for AEW antimicrobial activity. METHODOLOGY/PRINCIPAL FINDINGS: The aim of the present study is to detect hydroxyl radicals in AEW. The hydroxyl radicals in AEW prepared under different conditions were determined using an electron spin resonance (ESR technique. A signal from 5,5-dimethyl-1-pyrroline N-oxide (DMPO-OH, an adduct of DMPO and the hydroxyl radical, was detected in AEW prepared by double or triple electrolyses of 1% NaCl but not of 0.1% NaCl solution. Then the presence of hydrogen peroxide as a proposed source of hydroxyl radicals was examined using a combination of ESR and a Fenton reaction. The DMPO-OH signal was clearly detected, even in AEW prepared by single electrolysis of 0.1% NaCl solution, when ferrous sulfate was added to induce a Fenton reaction, indicating the presence of hydrogen peroxide in the AEW. Since sodium formate, a hydroxyl radical scavenger, did not affect the bactericidal activity of AEW, it is concluded that the radical is unlikely to contribute to the antimicrobial activity of AEW, although a small amount of the radical is produced from hydrogen peroxide. Dimethyl sulfoxide, the other hydroxyl radical scavenger used in the present study, canceled the bactericidal activity of AEW, accompanied by complete depletion of free available chlorine, suggesting that hypochlorous acid is probably a major contributor to the antimicrobial activity. CONCLUSIONS: It is strongly suggested that although hydrogen peroxide is present in AEW as a source of hydroxyl radicals, the antimicrobial activity of AEW does not depend on these radicals.

  1. Presence in Video-Mediated Interactions: Case Studies at CSIRO

    Science.gov (United States)

    Alem, Leila

    Although telepresence and a sense of connectedness with others are frequently mentioned in media space studies, as far as we know, none of these studies report attempts at assessing this critical aspect of user experience. While some attempts have been made to measure presence in virtual reality or augmented reality, (a comprehensive review of existing measures is available in Baren and Ijsselsteijn [2004]), very little work has been reported in measuring presence in video-mediated collaboration systems. Traditional studies of video-mediated collaboration have mostly focused their evaluation on measures of task performance and user satisfaction. Videoconferencing systems can be seen as a type of media space; they rely on technologies of audio, video, and computing put together to create an environment extending the embodied mind. This chapter reports on a set of video-mediated collaboration studies conducted at CSIRO in which different aspects of presence are being investigated. The first study reports the sense of physical presence a specialist doctor experiences when engaged in a remote consultation of a patient using the virtual critical care unit (Alem et al., 2006). The Viccu system is an “always-on” system connecting two hospitals (Li et al., 2006). The presence measure focuses on the extent to which users of videoconferencing systems feel physically present in the remote location. The second study reports the sense of social presence users experience when playing a game of charades with remote partners using a video conference link (Kougianous et al., 2006). In this study the presence measure focuses on the extent to which users feel connected with their remote partners. The third study reports the sense of copresence users experience when building collaboratively a piece of Lego toy (Melo and Alem, 2007). The sense of copresence is the extent to which users feel present with their remote partner. In this final study the sense of copresence is

  2. Honey Bee Inhibitory Signaling Is Tuned to Threat Severity and Can Act as a Colony Alarm Signal.

    Directory of Open Access Journals (Sweden)

    Ken Tan

    2016-03-01

    Full Text Available Alarm communication is a key adaptation that helps social groups resist predation and rally defenses. In Asia, the world's largest hornet, Vespa mandarinia, and the smaller hornet, Vespa velutina, prey upon foragers and nests of the Asian honey bee, Apis cerana. We attacked foragers and colony nest entrances with these predators and provide the first evidence, in social insects, of an alarm signal that encodes graded danger and attack context. We show that, like Apis mellifera, A. cerana possesses a vibrational "stop signal," which can be triggered by predator attacks upon foragers and inhibits waggle dancing. Large hornet attacks were more dangerous and resulted in higher bee mortality. Per attack at the colony level, large hornets elicited more stop signals than small hornets. Unexpectedly, stop signals elicited by large hornets (SS large hornet had a significantly higher vibrational fundamental frequency than those elicited by small hornets (SS small hornet and were more effective at inhibiting waggle dancing. Stop signals resulting from attacks upon the nest entrance (SS nest were produced by foragers and guards and were significantly longer in pulse duration than stop signals elicited by attacks upon foragers (SS forager. Unlike SS forager, SS nest were targeted at dancing and non-dancing foragers and had the common effect, tuned to hornet threat level, of inhibiting bee departures from the safe interior of the nest. Meanwhile, nest defenders were triggered by the bee alarm pheromone and live hornet presence to heat-ball the hornet. In A. cerana, sophisticated recruitment communication that encodes food location, the waggle dance, is therefore matched with an inhibitory/alarm signal that encodes information about the context of danger and its threat level.

  3. Error signals driving locomotor adaptation

    DEFF Research Database (Denmark)

    Choi, Julia T; Jensen, Peter; Nielsen, Jens Bo

    2016-01-01

    anaesthesia (n = 5) instead of repetitive nerve stimulation. Foot anaesthesia reduced ankle adaptation to external force perturbations during walking. Our results suggest that cutaneous input plays a role in force perception, and may contribute to the 'error' signal involved in driving walking adaptation when...

  4. Syndecans, signaling, and cell adhesion

    DEFF Research Database (Denmark)

    Couchman, J R; Woods, A

    1996-01-01

    structures within the heparan sulfate chains, leaving the roles of chondroitin sulfate chains and extracellular portion of the core proteins to be elucidated. Evidence that syndecans are a class of receptor involved in cell adhesion is mounting, and their small cytoplasmic domains may link...... transmembrane signaling from matrix to cytoskeleton, as proposed for other classes of adhesion receptors....

  5. VLSI mixed signal processing system

    Science.gov (United States)

    Alvarez, A.; Premkumar, A. B.

    1993-01-01

    An economical and efficient VLSI implementation of a mixed signal processing system (MSP) is presented in this paper. The MSP concept is investigated and the functional blocks of the proposed MSP are described. The requirements of each of the blocks are discussed in detail. A sample application using active acoustic cancellation technique is described to demonstrate the power of the MSP approach.

  6. Mathematical Modelling Plant Signalling Networks

    KAUST Repository

    Muraro, D.

    2013-01-01

    During the last two decades, molecular genetic studies and the completion of the sequencing of the Arabidopsis thaliana genome have increased knowledge of hormonal regulation in plants. These signal transduction pathways act in concert through gene regulatory and signalling networks whose main components have begun to be elucidated. Our understanding of the resulting cellular processes is hindered by the complex, and sometimes counter-intuitive, dynamics of the networks, which may be interconnected through feedback controls and cross-regulation. Mathematical modelling provides a valuable tool to investigate such dynamics and to perform in silico experiments that may not be easily carried out in a laboratory. In this article, we firstly review general methods for modelling gene and signalling networks and their application in plants. We then describe specific models of hormonal perception and cross-talk in plants. This mathematical analysis of sub-cellular molecular mechanisms paves the way for more comprehensive modelling studies of hormonal transport and signalling in a multi-scale setting. © EDP Sciences, 2013.

  7. Noisy signaling: theory and experiment

    NARCIS (Netherlands)

    de Haan, T.; Offerman, T.; Sloof, R.

    2009-01-01

    We investigate a noisy signaling game, in which nature adds random noise to the message chosen. Theoretically, with an unfavorable prior the separating equilibrium vanishes for low noise. It reappears for intermediate and high noise, where messages increase with noise. A pooling equilibrium always

  8. Syndecans, signaling, and cell adhesion

    DEFF Research Database (Denmark)

    Couchman, J R; Woods, A

    1996-01-01

    with the microfilament cytoskeleton, thereby mediating signaling events. The molecular details are unknown, but the conservation of regions of syndecan cytoplasmic domains, and a strong tendency for homotypic association, support the idea that the ligand-induced clustering may be a discrete source of specific...

  9. Text Signals Influence Team Artifacts

    Science.gov (United States)

    Clariana, Roy B.; Rysavy, Monica D.; Taricani, Ellen

    2015-01-01

    This exploratory quasi-experimental investigation describes the influence of text signals on team visual map artifacts. In two course sections, four-member teams were given one of two print-based text passage versions on the course-related topic "Social influence in groups" downloaded from Wikipedia; this text had two paragraphs, each…

  10. Maternal health Indicators Signal Optimism

    African Journals Online (AJOL)

    user

    Maternal health Indicators Signal Optimism. Abraham Haileamlak, MD, Professor of Pediatrics and Child Health. Maternal health is a major health priority for international agencies and the Ethiopian. Government. Many low income countries including. Ethiopia, made substantial improvements in maternal health achieving ...

  11. Biophysical Aspects of Transmembrane Signaling

    CERN Document Server

    Damjanovich, Sandor

    2005-01-01

    Transmembrane signaling is one of the most significant cell biological events in the life and death of cells in general and lymphocytes in particular. Until recently biochemists and biophysicists were not accustomed to thinking of these processes from the side of a high number of complex biochemical events and an equally high number of physical changes at molecular and cellular levels at the same time. Both types of researchers were convinced that their findings are the most decisive, having higher importance than the findings of the other scientist population. Both casts were wrong. Life, even at cellular level, has a number of interacting physical and biochemical mechanisms, which finally build up the creation of an "excited" cell that will respond to particular signals from the outer or inner world. This book handles both aspects of the signalling events, and in some cases tries to unify our concepts and help understand the signals that govern the life and death of our cells. Not only the understanding, bu...

  12. Handbook of signal processing systems

    CERN Document Server

    Bhattacharyya, Shuvra S; Leupers, Rainer; Takala, Jarmo

    2010-01-01

    The Handbook is organized in four parts. The first part motivates representative applications that drive and apply state-of-the art methods for design and implementation of signal processing systems; the second part discusses architectures for implementing these applications; the third part focuses on compilers and simulation tools; and the fourth part describes models of computation and their associated design tools and methodologies.

  13. On statistical significance of signal

    International Nuclear Information System (INIS)

    Zhu Yongsheng

    2006-01-01

    A definition for the statistical significance of a signal in an experiment is proposed by establishing a correlation between the observed p-value and the normal distribution integral probability, which is suitable for both counting experiment and continuous test statistics. The explicit expressions to calculate the statistical significance for both cases are given. (author)

  14. Insulin Signalling: The Inside Story.

    Science.gov (United States)

    Posner, Barry I

    2017-02-01

    Insulin signalling begins with binding to its cell surface insulin receptor (IR), which is a tyrosine kinase. The insulin receptor kinase (IRK) is subsequently autophosphorylated and activated to tyrosine phosphorylate key cellular substrates that are essential for entraining the insulin response. Although IRK activation begins at the cell surface, it is maintained and augmented following internalization into the endosomal system (ENS). The peroxovanadium compounds (pVs) were discovered to activate the IRK in the absence of insulin and lead to a full insulin response. Thus, IRK activation is both necessary and sufficient for insulin signalling. Furthermore, this could be shown to occur with activation of only the endosomal IRK. The mechanism of pV action was shown to be the inhibition of IRK-associated phosphotyrosine phosphatases (PTPs). Our studies showed that the duration and intensity of insulin signalling are modulated within ENS by the recruitment of cellular substrates to ENS; intra-endosomal acidification, which promotes dissociation of insulin from the IRK; an endosomal acidic insulinase, which degrades intra-endosomal insulin; and IRK-associated PTPs, which dephosphorylate and, hence, deactivate the IRK. Therefore, the internalization of IRKs is central to insulin signalling and its regulation. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  15. VEGF Signaling in Neurological Disorders

    Directory of Open Access Journals (Sweden)

    Joon W. Shim

    2018-01-01

    Full Text Available Vascular endothelial growth factor (VEGF is a potent growth factor playing diverse roles in vasculogenesis and angiogenesis. In the brain, VEGF mediates angiogenesis, neural migration and neuroprotection. As a permeability factor, excessive VEGF disrupts intracellular barriers, increases leakage of the choroid plexus endothelia, evokes edema, and activates the inflammatory pathway. Recently, we discovered that a heparin binding epidermal growth factor like growth factor (HB-EGF—a class of EGF receptor (EGFR family ligands—contributes to the development of hydrocephalus with subarachnoid hemorrhage through activation of VEGF signaling. The objective of this review is to entail a recent update on causes of death due to neurological disorders involving cerebrovascular and age-related neurological conditions and to understand the mechanism by which angiogenesis-dependent pathological events can be treated with VEGF antagonisms. The Global Burden of Disease study indicates that cancer and cardiovascular disease including ischemic and hemorrhagic stroke are two leading causes of death worldwide. The literature suggests that VEGF signaling in ischemic brains highlights the importance of concentration, timing, and alternate route of modulating VEGF signaling pathway. Molecular targets distinguishing two distinct pathways of VEGF signaling may provide novel therapies for the treatment of neurological disorders and for maintaining lower mortality due to these conditions.

  16. Systems theory of Smad signalling.

    Science.gov (United States)

    Clarke, D C; Betterton, M D; Liu, X

    2006-11-01

    Transforming growth factor-beta (TGFbeta) signalling is an important regulator of cellular growth and differentiation. The principal intracellular mediators of TGFbeta signalling are the Smad proteins, which upon TGFbeta stimulation accumulate in the nucleus and regulate the transcription of target genes. To investigate the mechanisms of Smad nuclear accumulation, we developed a simple mathematical model of canonical Smad signalling. The model was built using both published data and our experimentally determined cellular Smad concentrations (isoforms 2, 3 and 4). We found in mink lung epithelial cells that Smad2 (8.5-12 x 10(4) molecules cell(-1)) was present in similar amounts to Smad4 (9.3-12 x 10(4) molecules cell(-1)), whereas both were in excess of Smad3 (1.1-2.0 x 10(4) molecules cell(-1)). Variation of the model parameters and statistical analysis showed that Smad nuclear accumulation is most sensitive to parameters affecting the rates of R-Smad phosphorylation and dephosphorylation and Smad complex formation/ dissociation in the nucleus. Deleting Smad4 from the model revealed that rate-limiting phospho-R-Smad dephosphorylation could be an important mechanism for Smad nuclear accumulation. Furthermore, we observed that binding factors constitutively localised to the nucleus do not efficiently mediate Smad nuclear accumulation, if dephosphorylation is rapid. We therefore conclude that an imbalance in the rates of R-Smad phosphorylation and dephosphorylation is likely an important mechanism of Smad nuclear accumulation during TGFbeta signalling.

  17. A Serpentine Way to Signaling

    Indian Academy of Sciences (India)

    IAS Admin

    coding genome. This article will take you through the years of discovery, experimentation and characterization of the structure and molecular mechanisms of GPCR signaling and how this discovery impacts a vast area of research in health and medicine. History: John Langley, Paul Ehrlich and the birth of the receptor theory.

  18. Family Presence During Resuscitation: A Double-Edged Sword.

    Science.gov (United States)

    Hassankhani, Hadi; Zamanzadeh, Vahid; Rahmani, Azad; Haririan, Hamidreza; Porter, Joanne E

    2017-03-01

    To illuminate the meaning of the lived experiences of resuscitation team members with the presence of the patient's family during resuscitation in the cultural context of Iran. An interpretative phenomenology was used to discover the lived experiences of the nurses and physicians of Tabriz hospitals, Iran, with family presence during resuscitation (FPDR). A total of 12 nurses and 9 physicians were interviewed over a 6-month period. The interviews were audio recorded and semistructured, and were transcribed verbatim. Van Manen's technique was used for data analysis. Two major themes and 10 subthemes emerged, including destructive presence (cessation of resuscitation, interference in resuscitation, disruption to the resuscitation team's focus, argument with the resuscitation team, and adverse mental image in the family) and supportive presence (trust in the resuscitation team, collaboration with the resuscitation team, alleviating the family's concern and settling their nerves, increasing the family's satisfaction, and reducing conflict with resuscitation team members). Participants stated that FPDR may work as a double-edged sword for the family and resuscitation team, hurting or preserving quality. It is thus recommended that guidelines be created to protect patients' and families' rights, while considering the positive aspects of the phenomenon for hospitals. A liaison support person would act to decrease family anxiety levels and would be able to de-escalate any potentially aggressive or confrontational events during resuscitation. Well-trained and expert cardiopulmonary resuscitation team members do not have any stress in the presence of family during resuscitation. Resuscitation events tend to be prolonged when family members are allowed to be present. © 2017 Sigma Theta Tau International.

  19. Leaching of spent fuel in the presence of environmental material

    International Nuclear Information System (INIS)

    Le Lous, Karine

    1997-01-01

    The aim of this work is the study of the alteration kinetics of spent fuels and the making of a status of the radioactivity released by spent fuels in conditions of direct disposal in deep underground. A system has been fitted inside a shielded cell to study the leaching by synthetic groundwater of fuel powder irradiated at 60 GWJ.tU -1 in the presence of environmental material (clay or granite) at 40 bars and 90 deg. C. This system allows to reach and keep reductive conditions characteristic of the redox conditions of a deep geological repository. The preparation of calibrated spent fuel powders and the recovery of the activity fixed by the environmental materials has required the implementation of specific procedures. Similar experiments have been performed in parallel with Simfuel in a controlled area. A first series of experiments has been carried out in 4 environments for each fuel. Important sorption phenomena take place in the environmental materials and the actinide concentrations stabilize rapidly at low values: 10 -8 mol/l for U, 10 -12 mol/l for Pu and 10 -13 -10 -14 mol/l for Cm. The activity released by 90 Sr at the end of each experiment is about two times higher in the presence of clay than in the presence of granite. The average alteration rates are of about 0.2 mg.m -2 /day in the presence of granite and 0.4 to 0.6 mg.m -2 /day in the presence of clay. They are comparable to those reported in the literature for reducing conditions. Such tests are necessary to determine the leaching rate of spent fuels in reducing conditions and in the absence of environmental materials in order to show the possible effects of these materials. (J.S.)

  20. Emotion regulation during threat: Parsing the time course and consequences of safety signal processing

    Science.gov (United States)

    HEFNER, KATHRYN R.; VERONA, EDELYN; CURTIN, JOHN. J.

    2017-01-01

    Improved understanding of fear inhibition processes can inform the etiology and treatment of anxiety disorders. Safety signals can reduce fear to threat, but precise mechanisms remain unclear. Safety signals may acquire attentional salience and affective properties (e.g., relief) independent of the threat; alternatively, safety signals may only hold affective value in the presence of simultaneous threat. To clarify such mechanisms, an experimental paradigm assessed independent processing of threat and safety cues. Participants viewed a series of red and green words from two semantic categories. Shocks were administered following red words (cue+). No shocks followed green words (cue−). Words from one category were defined as safety signals (SS); no shocks were administered on cue+ trials. Words from the other (control) category did not provide information regarding shock administration. Threat (cue+ vs. cue−) and safety (SS+ vs. SS−) were fully crossed. Startle response and ERPs were recorded. Startle response was increased during cue+ versus cue−. Safety signals reduced startle response during cue+, but had no effect on startle response during cue−. ERP analyses (PD130 and P3) suggested that participants parsed threat and safety signal information in parallel. Motivated attention was not associated with safety signals in the absence of threat. Overall, these results confirm that fear can be reduced by safety signals. Furthermore, safety signals do not appear to hold inherent hedonic salience independent of their effect during threat. Instead, safety signals appear to enable participants to engage in effective top-down emotion regulatory processes. PMID:27088643

  1. Analysis of activin/TGFB-signaling modulators within the normal and dysfunctional adult human testis reveals evidence of altered signaling capacity in a subset of seminomas

    DEFF Research Database (Denmark)

    Dias, Vinali L; Rajpert-De Meyts, Ewa; McLachlan, Robert

    2009-01-01

    cancer patients and from normal men subjected to gonadotropin suppression with androgen-based contraceptives. Our findings identify distinct differences between normal and gonadotropin-deprived human testis in the expression and cellular localization of activin/TGFB-signaling modulators. The presence...

  2. Fertility signaling - the proximate mechanism of worker policing in a clonal ant

    DEFF Research Database (Denmark)

    Hartmann, Anne; D'Ettorre, Patrizia; Jones, Graeme R.

    2005-01-01

    In eusocial insects, the ability to regulate reproduction relies on cues that signal the presence of fertile individuals. We investigated the variation of cuticular hydrocarbons (CHCs) with reproductive status in Platythyrea punctata, an ant, in which all workers are capable of producing daughters...... to old reproductives, but not when it was similar to that of nonreproductives. CHCs appear to signal the fertility of individuals and induce policing behavior towards surplus reproductive workers....

  3. Robust power detector for wideband signals among many single tone signals

    Energy Technology Data Exchange (ETDEWEB)

    Musgrove, Cameron H.; Thompson, Douglas

    2018-03-06

    Various technologies for isolating a signal of interest from signals received contemporaneously by an antenna are described herein. A time period for which a signal of interest is present in a second signal can be identified based upon ratios of values of the second signal to the mean value of the second signal. When the ratio of the value of the second signal at a particular time to the mean of the second signal exceeds a threshold value, the signal of interest is considered to be present in the second signal.

  4. BPSK Demodulation Using Digital Signal Processing

    Science.gov (United States)

    Garcia, Thomas R.

    1996-01-01

    A digital communications signal is a sinusoidal waveform that is modified by a binary (digital) information signal. The sinusoidal waveform is called the carrier. The carrier may be modified in amplitude, frequency, phase, or a combination of these. In this project a binary phase shift keyed (BPSK) signal is the communication signal. In a BPSK signal the phase of the carrier is set to one of two states, 180 degrees apart, by a binary (i.e., 1 or 0) information signal. A digital signal is a sampled version of a "real world" time continuous signal. The digital signal is generated by sampling the continuous signal at discrete points in time. The rate at which the signal is sampled is called the sampling rate (f(s)). The device that performs this operation is called an analog-to-digital (A/D) converter or a digitizer. The digital signal is composed of the sequence of individual values of the sampled BPSK signal. Digital signal processing (DSP) is the modification of the digital signal by mathematical operations. A device that performs this processing is called a digital signal processor. After processing, the digital signal may then be converted back to an analog signal using a digital-to-analog (D/A) converter. The goal of this project is to develop a system that will recover the digital information from a BPSK signal using DSP techniques. The project is broken down into the following steps: (1) Development of the algorithms required to demodulate the BPSK signal; (2) Simulation of the system; and (3) Implementation a BPSK receiver using digital signal processing hardware.

  5. Signaling Molecules and Pulp Regeneration.

    Science.gov (United States)

    Schmalz, Gottfried; Widbiller, Matthias; Galler, Kerstin M

    2017-09-01

    Signaling molecules play an essential role in tissue engineering because they regulate regenerative processes. Evidence exists from animal studies that single molecules such as members of the transforming growth factor beta superfamily and factors that induce the growth of blood vessels (vascular endothelial growth factor), nerves (brain-derived neurotrophic factor), or fibroblasts (fibroblast growth factor) may induce reparative dentin formation. Mainly the formation of atubular dentin (osteodentin) has been described after the application of single molecules or combinations of recombinant growth factors on healthy exposed pulps or in pulp regeneration. Generally, such preparations have not received regulatory approval on the market so far. Only the use of granulocyte colony-stimulating factors together with cell transplantation is presently tested clinically. Besides approaches with only 1 or few combined molecules, the exploitation of tissue-derived growth factors depicts a third promising way in dental pulp tissue engineering. Preparations such as platelet-rich plasma or platelet-rich fibrin provide a multitude of endogenous signaling molecules, and special regulatory approval for the market does not seem necessary. Furthermore, dentin is a perfect reservoir of signaling molecules that can be mobilized by treatment with demineralizing agents such as EDTA. This conditions the dentin surface and allows for contact differentiation of pulp stem cells into odontoblastlike cells, protects dentin from resorption, and enhances cell growth as well as attachment to dentin. By ultrasonic activation, signaling molecules can be further released from EDTA pretreated dentin into saline, thus avoiding cytotoxic EDTA in the final preparation. The use of dentin-derived growth factors offers a number of advantages because they are locally available and presumably are most fit to induce signaling processes in dental pulp. However, better characterization and standardization of the

  6. Sono-electroanalysis of copper: enhanced detection and determination in the presence of surfactants.

    Science.gov (United States)

    Hardcastle, Joanna Lorraine; Hignett, Geraldine; Melville, James L; Compton, Richard G

    2002-04-01

    Surfactant adsorption has been shown to have a passivating effect on the electrode surface during anodic stripping voltammetric measurements. In the present work the feasibility of sono-anodic stripping analysis for the determination of copper in aqueous media contaminated with surfactant has been studied at an unmodified bare glassy carbon electrode. We illustrate the deleterious effect of three common surfactants, sodium dodecyl sulfate (SDS), dodecyl pyridinium chloride (DPC) and Triton-X 100 (TX-100) on conventional electroanalysis. The analogous sono-electroanalytical response was investigated for each surfactant at ultrasound intensities above and below the cavitation threshold. The enhancement in the stripping signal observed is attributed to the increased mass transport due to acoustic streaming and above the cavitation threshold the intensity of cavitational events is significantly increased leading to shearing of adsorbed surfactant molecules from the surface. As a result accurate analyses for SDS concentrations up to 100 ppm are possible, with analytical signals visible in solutions of SDS and TX-100 of 1000 ppm. Analysis is reported in high concentration of surfactant with use of sono-solvent double extraction. The power of this technique is clearly illustrated by the ability to obtain accurate measurements of copper concentration from starting solutions containing 1000 ppm SDS or TX-100. This was also exemplified by analysis of the low concentration 0.3 microM Cu(II) solution giving a percentage recovery of 94% in the presence of 1000 ppm SDS or TX-100.

  7. Sphingolipid Metabolism of a Sea Anemone Is Altered by the Presence of Dinoflagellate Symbionts.

    Science.gov (United States)

    Kitchen, Sheila A; Poole, Angela Z; Weis, Virginia M

    2017-12-01

    In host-microbe interactions, signaling lipids function in interpartner communication during both the establishment and maintenance of associations. Previous evidence suggests that sphingolipids play a role in the mutualistic cnidarian-Symbiodinium symbiosis. Exogenously applied sphingolipids have been shown to alter this partnership, though endogenous host regulation of sphingolipids by the sphingosine rheostat under different symbiotic conditions has not been characterized. The rheostat regulates levels of pro-survival sphingosine-1-phosphate (S1P) and pro-apoptotic sphingosine (Sph) through catalytic activities of sphingosine kinase (SPHK) and S1P phosphatase (SGPP). The role of the rheostat in recognition and establishment of cnidarian-Symbiodinium symbiosis was investigated in the sea anemone Aiptasia pallida by measuring gene expression, protein levels, and sphingolipid metabolites in symbiotic, aposymbiotic, and newly recolonized anemones. Comparison of two host populations showed that symbiotic animals from one population had lower SGPP gene expression and Sph lipid concentrations compared to aposymbiotic animals, while the other population had higher S1P concentrations than their aposymbiotic counterparts. In both populations, the host rheostat trended toward host cell survival in the presence of symbionts. Furthermore, upregulation of both rheostat enzymes on the first day of host recolonization by symbionts suggests a role for the rheostat in host-symbiont recognition during symbiosis onset. Collectively, these data suggest a regulatory role of sphingolipid signaling in cnidarian-Symbiodinium symbiosis and symbiont uptake.

  8. Transmit Waveform Optimization for Spatial-Frequency Diversity MIMO Radar in the Presence of Clutter

    Directory of Open Access Journals (Sweden)

    Yonghao Tang

    2014-01-01

    Full Text Available Benefitting from the independent target echoes of diversity channels, diversity MIMO radar can efficiently improve system performance, such as target detection and parameter estimation. Due to the fact that the RCS (radar cross section of complex target may vary with the different transmitted carrier frequencies and array geometries, many recent researches study at the background of diversity MIMO radar equipped with widely separated array antennas or working at multiple carrier frequencies, respectively. In this paper, a new MIMO radar system combining the spatial and frequency diversities is investigated in the presence of signal-dependent clutter, which is called spatial-frequency diversity MIMO radar. With the prior information of target and clutter, a new method for joint optimization of transmitted waveforms and receiving filters is proposed to enhance the target detection ability of spatial-frequency diversity MIMO radar. Inspired by the MIMO communication system, the water-filling algorithm is introduced into the transmitted energy allocation problem for each carrier frequency channel. Simulation results show that the proposed system has a better performance in output signal-to-clutter-noise ratio (SCNR compared to conventional diversity MIMO radar system.

  9. Pattern formation of Dictystelium discoideum in the presence of laminar flow and cAMP pulses

    Science.gov (United States)

    Gholami, Azam; Steinbock, Oliver; Zykov, Vladimir; Bodenschatz, Eberhard

    2014-03-01

    Dictyostelium discoideum (D.d) amobae undergo starvation-induced multicellular development in which single cells aggregate chemotactically towards cAMP signals emitted periodically from an aggregation center. We are investigating spatiotemporal pattern formation of D.d. cells under the presence of a laminar flow. Starved cells are loaded into a straight millifluidic device with an external flow and cell response to the signaling molecule cAMP is monitored indirectly using dark-field microscopy. The observed contraction waves develop simultaneously over the entire channel, are propagating only in flow direction, and have curved wave fronts resembling the parabolic flow profile. The wave dynamics analysis shows that the wave velocity is locked to the flow velocity and yields a wave period of T0 6 min, which matches the typical oscillation period of extracellular cAMP in spatial homogeneous, well-stirred systems. We apply a small cAMP perturbation at the inlet region of the channel and observe the spatiotemporal response of the cells as the pulse is propagating down the channel. The results show that D.d. cells are in the oscillatory regime and the system can be forced within resonance tongue. We compared our results with analytical and numerical analysis of Goldbeter model.

  10. Optimal Gaussian squeezed states for atom interferometry in the presence of phase diffusion

    International Nuclear Information System (INIS)

    Tikhonenkov, Igor; Moore, Michael G.; Vardi, Amichay

    2010-01-01

    We optimize the signal-to-noise ratio of a Mach-Zehnder atom interferometer with Gaussian squeezed input states in the presence interactions. For weak interactions, our results coincide with those of Huang and Moore [Y. P. Huang and M. G. Moore, Phys. Rev. Lett. 100, 250406 (2008)], with an optimal initial number variance σ o ∝N 1/3 and an optimal signal-to-noise ratio s o ∝N 2/3 for the total atom number N. As the interaction strength u increases past unity, phase diffusion becomes dominant, leading to a transition in the optimal squeezing from initial number squeezing to initial phase squeezing with σ o ∝√(uN) and s o ∝√(N/u) shot-noise scaling. The initial phase squeezing translates into hold-time number squeezing, which is less sensitive to interactions than coherent states and improves s o by a factor of √(u).

  11. Deletion of Melanin Concentrating Hormone Receptor-1 disrupts overeating in the presence of food cues.

    Science.gov (United States)

    Sherwood, Andrew; Holland, Peter C; Adamantidis, Antoine; Johnson, Alexander W

    2015-12-01

    Exposure to environmental cues associated with food can evoke eating behavior in the absence of hunger. This capacity for reward cues to promote feeding behaviors under sated conditions can be examined in the laboratory using cue-potentiated feeding (CPF). The orexigenic neuropeptide Melanin Concentrating Hormone (MCH) is expressed throughout brain circuitry critical for CPF. We examined whether deletion of the MCH receptor, MCH-1R, would in KO mice disrupt overeating in the presence of a Pavlovian CS+ associated with sucrose delivery. While both wild-type controls and KO mice showed comparable food magazine approach responses during the CPF test, MCH-1R deletion significantly impaired the ability of the CS+ to evoke overeating of sucrose under satiety. Through the use of a refined analysis of meal intake, it was revealed that this disruption to overeating behavior in KO mice reflected a reduction in the capacity for the CS+ to initiate and maintain bursts of licking behavior. These findings suggest that overeating during CPF requires intact MCH-1R signaling and may be due to an influence of the CS+ on the palatability of food and on regulatory mechanisms of peripheral control. Thus, disruptions to MCH-1R signaling may be a useful pharmacological tool to inhibit this form of overeating behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. 33 CFR 62.47 - Sound signals.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sound signals. 62.47 Section 62... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.47 Sound signals. (a) Often sound signals are located on or adjacent to aids to navigation. When visual signals are obscured...

  13. Predicting Secretory Proteins with SignalP

    DEFF Research Database (Denmark)

    Nielsen, Henrik

    2017-01-01

    SignalP is the currently most widely used program for prediction of signal peptides from amino acid sequences. Proteins with signal peptides are targeted to the secretory pathway, but are not necessarily secreted. After a brief introduction to the biology of signal peptides and the history...

  14. Optimizing pTILT perfusion imaging in the presence of off-resonance frequency.

    Science.gov (United States)

    Ouyang, Cheng; Sutton, Bradley P

    2013-07-01

    To optimize the perfusion measurements and to recover loss of tagging efficiency from the blood flow measurements in the presence of static field inhomogeneity with the pseudo-continuous arterial spin labeling technique of pTILT, which is sensitive to off-resonance effects due to the employment of concatenated radiofrequency (RF) pulses for labeling. Numerical Bloch simulations were performed to explore the labeling responses of concatenated RF pulses (45°, ±45°) in pTILT as a function of off-resonance frequency. A correction method was proposed by curve-fitting the measured blood flow signal to the signal model obtained from the simulations. The performance of the proposed correction method was examined for three healthy subjects on a 3 Tesla magnet after good shimming as well as under a "worst-case" scenario with deliberate mis-shimming. In cases after good shimming, in which the off-resonance frequency was less than 50 Hz, the perfusion measurements by the optimized pTILT sequence were improved by 12.7% compared with the original pTILT. With a "worst-case" mis-shimming and frequency offset by 80 Hz, the blood flow signal was increased by 68.9% and 64.8% for optimized global and localized pTILT, respectively. Addressing the impact of off-resonance frequency on concatenated RF pulses, tagging efficiency can be effectively recovered in pTILT perfusion measurements. This strategy may be extended to other applications of concatenated RF pulses where sensitivity to magnetic field inhomogeneity prevents accurate quantification. Copyright © 2013 Wiley Periodicals, Inc.

  15. MR neurography in ulnar neuropathy as surrogate parameter for the presence of disseminated neuropathy.

    Directory of Open Access Journals (Sweden)

    Philipp Bäumer

    Full Text Available PURPOSE: Patients with ulnar neuropathy of unclear etiology occasionally present with lesion extension from elbow to upper arm level on MRI. This study investigated whether MRI thereby distinguishes multifocal neuropathy from focal-compressive neuropathy at the elbow. METHODS: This prospective study was approved by the institutional ethics committee and written informed consent was obtained from all participants. 122 patients with ulnar mononeuropathy of undetermined localization and etiology by clinical and electrophysiological examination were assessed by MRI at upper arm and elbow level using T2-weighted fat-saturated sequences at 3T. Twenty-one patients were identified with proximal ulnar nerve lesions and evaluated for findings suggestive of disseminated neuropathy (i subclinical lesions in other nerves, (ii unfavorable outcome after previous decompressive elbow surgery, and (iii subsequent diagnosis of inflammatory or other disseminated neuropathy. Two groups served as controls for quantitative analysis of nerve-to-muscle signal intensity ratios: 20 subjects with typical focal ulnar neuropathy at the elbow and 20 healthy subjects. RESULTS: In the group of 21 patients with proximal ulnar nerve lesion extension, T2-w ulnar nerve signal was significantly (p<0.001 higher at upper arm level than in both control groups. A cut-off value of 1.92 for maximum nerve-to-muscle signal intensity ratio was found to be sensitive (86% and specific (100% to discriminate this group. Ten patients (48% exhibited additional T2-w lesions in the median and/or radial nerve. Another ten (48% had previously undergone elbow surgery without satisfying outcome. Clinical follow-up was available in 15 (71% and revealed definitive diagnoses of multifocal neuropathy of various etiologies in four patients. In another eight, diagnoses could not yet be considered definitive but were consistent with multifocal neuropathy. CONCLUSION: Proximal ulnar nerve T2 lesions at upper

  16. Evaluation of Sonochemiluminescence in a Phantom in the Presence of Protoporphyrin IX Conjugated to Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ahmad Shanei

    2012-03-01

    Full Text Available Introduction When a liquid is irradiated with high-intensity and low-frequency ultrasound, acoustic cavitation occurs and there are some methods to determine and quantify this phenomenon. The existing methods for performing these experiments include sonochemiluminescence (SCL and chemical dosimetric methods. The particles in a liquid decrease the ultrasonic intensity threshold needed for cavitation onset. In this study, a new nanoconjugate made up of Protoporphyrin IX (PpIX and gold nanoparticles (GNP, i.e., Au-PpIX was used to provide nucleation sites for cavitation. The nonradiative relaxation time of PpIX in the presence of GNPs is longer than the similar time for PpIX without GNPs. This effect can be used in medical diagnostic and therapeutic applications. Materials and Methods The acoustic cavitation activity was investigated studying integrated SCL signal in the wavelength range of 400-500 nm in polyacrylamide gel phantom containing luminol using a cooled CCD spectrometer at different intensities of 1 MHz ultrasound. In order to confirm these results, a chemical dosimetric method was utilized, too. Results SCL signal level in gel phantom containing Au-PpIX was higher than the other phantoms. These results have been confirmed by the chemical dosimetric data. Conclusion This finding can be related to the existence of PpIX as a sensitizer and GNPs as cavitation nuclei. In other words, nanoparticles have acted as the sites for cavitation and have increased the cavitation rate. Another theory is that activation of PpIX has produced more free radicals and has enhanced the SCL signal level.

  17. Empirical mode decomposition for analyzing acoustical signals

    Science.gov (United States)

    Huang, Norden E. (Inventor)

    2005-01-01

    The present invention discloses a computer implemented signal analysis method through the Hilbert-Huang Transformation (HHT) for analyzing acoustical signals, which are assumed to be nonlinear and nonstationary. The Empirical Decomposition Method (EMD) and the Hilbert Spectral Analysis (HSA) are used to obtain the HHT. Essentially, the acoustical signal will be decomposed into the Intrinsic Mode Function Components (IMFs). Once the invention decomposes the acoustic signal into its constituting components, all operations such as analyzing, identifying, and removing unwanted signals can be performed on these components. Upon transforming the IMFs into Hilbert spectrum, the acoustical signal may be compared with other acoustical signals.

  18. Experiment and practice on signal processing

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-11-15

    The contents of this book contains basic practice of CEM Tool, discrete time signal and experiment and practice of system, experiment and practice of discrete time signal sampling, practice of frequency analysis, experiment of digital filter design, application of digital signal processing, project related voice, basic principle of signal processing, the technique of basic image signal processing, biology astronomy and Robot soccer with apply of image signal processing technique, control video signal and project related image. It also has an introduction of CEM Linker I. O in the end.

  19. Alternatives to Pyrotechnic Distress Signals; Additional Signal Evaluation

    Science.gov (United States)

    2017-06-01

    stars ” include 3 LEDs pre-soldered to a small aluminum based circuit board/heat sink. For each color, RDC installed 2 stars , yielding six, series...connected LEDS. The Red-Orange color, with a lower maximum current rating required 4 LED stars to achieve the desired luminosity. Figure 5. Signal...Behavioral Sciences: New York, MCGraw- Hill . Young R., Dye D., Brunsman-Johnson C., Locklear C., Amerson T., Lewandowski M., Reubelt V., Rothblum A

  20. SignalPlant: an open signal processing software platform

    Czech Academy of Sciences Publication Activity Database

    Plešinger, Filip; Jurčo, Juraj; Halámek, Josef; Jurák, Pavel

    2016-01-01

    Roč. 37, č. 7 (2016), N38-N48 ISSN 0967-3334 R&D Projects: GA ČR GAP103/11/0933; GA MŠk(CZ) LO1212; GA ČR GAP102/12/2034 Institutional support: RVO:68081731 Keywords : data visualization * software * signal processing * ECG * EEG Subject RIV: FS - Medical Facilities ; Equipment Impact factor: 2.058, year: 2016