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Sample records for ciliary beat frequency

  1. Automatic analysis of ciliary beat frequency using optical flow

    Science.gov (United States)

    Figl, Michael; Lechner, Manuel; Werther, Tobias; Horak, Fritz; Hummel, Johann; Birkfellner, Wolfgang

    2012-02-01

    Ciliary beat frequency (CBF) can be a useful parameter for diagnosis of several diseases, as e.g. primary ciliary dyskinesia. (PCD). CBF computation is usually done using manual evaluation of high speed video sequences, a tedious, observer dependent, and not very accurate procedure. We used the OpenCV's pyramidal implementation of the Lukas-Kanade algorithm for optical flow computation and applied this to certain objects to follow the movements. The objects were chosen by their contrast applying the corner detection by Shi and Tomasi. Discrimination between background/noise and cilia by a frequency histogram allowed to compute the CBF. Frequency analysis was done using the Fourier transform in matlab. The correct number of Fourier summands was found by the slope in an approximation curve. The method showed to be usable to distinguish between healthy and diseased samples. However there remain difficulties in automatically identifying the cilia, and also in finding enough high contrast cilia in the image. Furthermore the some of the higher contrast cilia are lost (and sometimes found) by the method, an easy way to distinguish the correct sub-path of a point's path have yet to be found in the case where the slope methods doesn't work.

  2. Analysis of ependymal ciliary beat pattern and beat frequency using high speed imaging: comparison with the photomultiplier and photodiode methods

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    O'Callaghan Chris

    2012-06-01

    Full Text Available Abstract Background The aim of this study was to compare beat frequency measurements of ependymal cilia made by digital high speed imaging to those obtained using the photomultiplier and modified photodiode techniques. Using high speed video analysis the relationship of the power and recover strokes was also determined. Methods Ciliated strips of ependyma attached to slices from the brain of Wistar rats were incubated at 30°C and observed using a ×50 water immersion lens. Ciliary beat frequency was measured using each of the three techniques: the high speed video, photodiode and photomultiplier. Readings were repeated after 30 minutes incubation at 37°C. Ependymal cilia were observed in slow motion and the precise movement of cilia during the recovery stroke relative to the path travelled during the power stroke was measured. Results The mean (95% confidence intervals beat frequencies determined by the high speed video, photomultiplier and photodiode at 30°C were 27.7 (26.6 to 28.8, 25.5 (24.4 to 26.6 and 20.8 (20.4 to 21.3 Hz, respectively. The mean (95% confidence intervals beat frequencies determined by the high speed video, photomultiplier and photodiode at 37°C were 36.4 (34 to 39.5, 38.4 (36.8 to 39.9 and 18.8 (16.9 to 20.5 Hz. The inter and intra observer reliability for measurement of ciliary beat frequency was 3.8% and 1%, respectively. Ependymal cilia were observed to move in a planar fashion during the power and recovery strokes with a maximum deviation to the right of the midline of 12.1(11.8 to 13.0° during the power stroke and 12.6(11.6 to 13.6° to the left of the midline during the recovery stroke. Conclusion The photodiode technique greatly underestimates ciliary beat frequency and should not be used to measure ependymal ciliary beat frequency at the temperatures studied. Ciliary beat frequency from the high speed video and photomultiplier techniques cannot be used interchangeably. Ependymal cilia had minimal deviation to

  3. Measurement of ciliary beat frequency using ultra-high resolution optical coherence tomography

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    Chen, Jason J.; Jing, Joseph C.; Su, Erica; Badger, Christopher; Coughlan, Carolyn A.; Chen, Zhongping; Wong, Brian J. F.

    2016-02-01

    Ciliated epithelial cells populate up to 80% of the surface area of the human airway and are responsible for mucociliary transport, which is the key protective mechanism that provides the first line of defense in the respiratory tract. Cilia beat in a rhythmic pattern and may be easily affected by allergens, pollutants, and pathogens, altering ciliary beat frequency (CBF) subsequently. Diseases including cystic fibrosis, chronic obstructive pulmonary disease, and primary ciliary dyskinesia may also decrease CBF. CBF is therefore a critical component of respiratory health. The current clinical method of measuring CBF is phase-contrast microscopy, which involves a tissue biopsy obtained via brushing of the nasal cavity. While this method is minimally invasive, the tissue sample must be oriented to display its profile view, making the visualization of a single layer of cilia challenging. In addition, the conventional method requires subjective analysis of CBF, e.g., manually counting by visual inspection. On the contrary, optical coherence tomography (OCT) has been used to study the retina in ophthalmology as well as vasculature in cardiology, and offers higher resolution than conventional computed tomography and magnetic resonance imaging. Based on this technology, our lab specifically developed an ultra-high resolution OCT system to image the microstructure of the ciliated epithelial cells. Doppler analysis was also performed to determine CBF. Lastly, we also developed a program that utilizes fast Fourier transform to determine CBF under phase-contrast microscopy, providing a more objective method compared to the current method.

  4. The Role of Ion Channels to Regulate Airway Ciliary Beat Frequency During Allergic Inflammation.

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    Joskova, M; Sutovska, M; Durdik, P; Koniar, D; Hargas, L; Banovcin, P; Hrianka, M; Khazaei, V; Pappova, L; Franova, S

    2016-01-01

    Overproduction of mucus is a hallmark of asthma. The aim of this study was to identify potentially effective therapies for removing excess mucus. The role of voltage-gated (Kir 6.1, KCa 1.1) and store-operated ion channels (SOC, CRAC) in respiratory cilia, relating to the tracheal ciliary beat frequency (CBF), was compared under the physiological and allergic airway conditions. Ex vivo experiments were designed to test the local effects of Kir 6.1, KCa 1.1 and CRAC ion channel modulators in a concentration-dependent manner on the CBF. Cilia, obtained with the brushing method, were monitored by a high-speed video camera and analyzed with ciliary analysis software. In natural conditions, a Kir 6.1 opener accelerated CBF, while CRAC blocker slowed it in a concentration-dependent manner. In allergic inflammation, the effect of Kir 6.1 opener was insignificant, with a tendency to decrease CBF. A cilio-inhibitory effect of a CRAC blocker, while gently reduced by allergic inflammation, remained significant. A KCa 1.1 opener turned out to significantly enhance the CBF under the allergic OVA-sensitized conditions. We conclude that optimally attuned concentration of KCa 1.1 openers or special types of bimodal SOC channel blockers, potentially given by inhalation, might benefit asthma. PMID:27369295

  5. Effects of perfluorooctane sulfonate on tracheal ciliary beating frequency in mice

    International Nuclear Information System (INIS)

    Perfluorooctane sulfonate (PFOS) is one of the emerging persistent organic pollutants, ubiquitously found in the global environment, even in human serum. PFOS has been reported to perturb Ca2+ homeostasis in Paramecium, cardiomyocytes and neurons. Since ciliary beat frequency (CBF) in the trachea is known to be increased by cytoplasmic Ca2+ elevation, the effects of PFOS on CBF were evaluated in a slice preparation using video-enhanced contrast microscopy. PFOS increased CBF by 11% (P 2+ concentration ([Ca2+]i) in mouse tracheal ciliary cells. In Ca2+-free solution, PFOS at 100 μM failed to increase CBF (0.96-fold of vehicle control). The addition of Gd3+ (1 μM), a store-operated Ca2+ channel blocker, did not prevent the increase in CBF (1.09-fold (P + concentration (50 mM), which causes depolarization of the plasma membrane potential and a transient increase in [Ca2+]i, increased CBF by 20% (P 2+ channels (VDCCs) in stimulation of CBF. Nifedipine (30 μM), a selective VDCC blocker, antagonized the effects of high K+ (0.92-fold of high K+ solution) and PFOS (0.96-fold of vehicle control) on CBF. In cells from peroxisome proliferator-activated receptor α (PPARα)-null mice, PFOS still increased CBF (1.12-fold (P 2+ through VDCC

  6. Immersed boundary-lattice Boltzmann method for simulation of muco-ciliary transport: effect of mucus depth at various amounts of cilia beat frequency

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    Shahmardan, M. M.; Sedaghat, M. H.; Norouzi, M.; Nazari, M.

    2015-12-01

    Numerical simulation based on immersed boundary-lattice Boltzmann method has been employed to study 2D muco-ciliary transport problem. The periciliary liquid (PCL) and mucus layers in this study are considered as the Newtonian and viscoelastic fluid respectively. An Oldroyd-B model is used as the constitutive equations of mucus layer. To simulate accurate effects of the cilia and PCL-mucus interface on the fluid, immersed boundary method is used. Numerical simulations have been performed to investigate the effects of mucus depth on the muco-ciliary clearance at various values of cilia beat frequencies. Our results show that, by increasing mucus depth, which results from air pollution and smoking, mean mucus velocity decreases. But it can be completely modified by increasing cilia beat frequency and the cilia beat frequency has great effect on the muco-ciliary clearance.

  7. Ciliary beating recovery in deficient human airway epithelial cells after lentivirus ex vivo gene therapy.

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    Brigitte Chhin

    2009-03-01

    Full Text Available Primary Ciliary Dyskinesia is a heterogeneous genetic disease that is characterized by cilia dysfunction of the epithelial cells lining the respiratory tracts, resulting in recurrent respiratory tract infections. Despite lifelong physiological therapy and antibiotics, the lungs of affected patients are progressively destroyed, leading to respiratory insufficiency. Recessive mutations in Dynein Axonemal Intermediate chain type 1 (DNAI1 gene have been described in 10% of cases of Primary Ciliary Dyskinesia. Our goal was to restore normal ciliary beating in DNAI1-deficient human airway epithelial cells. A lentiviral vector based on Simian Immunodeficiency Virus pseudotyped with Vesicular Stomatitis Virus Glycoprotein was used to transduce cultured human airway epithelial cells with a cDNA of DNAI1 driven by the Elongation Factor 1 promoter. Transcription and translation of the transduced gene were tested by RT-PCR and western blot, respectively. Human airway epithelial cells that were DNAI1-deficient due to compound heterozygous mutations, and consequently had immotile cilia and no outer dynein arm, were transduced by the lentivirus. Cilia beating was recorded and electron microscopy of the cilia was performed. Transcription and translation of the transduced DNAI1 gene were detected in human cells treated with the lentivirus. In addition, immotile cilia recovered a normal beat and outer dynein arms reappeared. We demonstrated that it is possible to obtain a normalization of ciliary beat frequency of deficient human airway epithelial cells by using a lentivirus to transduce cells with the therapeutic gene. This preliminary step constitutes a conceptual proof that is indispensable in the perspective of Primary Ciliary Dyskinesia's in vivo gene therapy. This is the first time that recovery of cilia beating is demonstrated in this disease.

  8. Ammonia excretion in mytilid mussels is facilitated by ciliary beating.

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    Thomsen, J; Himmerkus, N; Holland, N; Sartoris, F J; Bleich, M; Tresguerres, M

    2016-08-01

    The excretion of nitrogenous waste products in the form of ammonia (NH3) and ammonium (NH4 (+)) is a fundamental process in aquatic organisms. For mytilid bivalves, little is known about the mechanisms and sites of excretion. This study investigated the localization and the mechanisms of ammonia excretion in mytilid mussels. An Rh protein was found to be abundantly expressed in the apical cell membrane of the plicate organ, which was previously described as a solely respiratory organ. The Rh protein was also expressed in the gill, although at significantly lower concentrations, but was not detectable in mussel kidney. Furthermore, NH3/NH4 (+) was not enriched in the urine, suggesting that kidneys are not involved in active NH3/NH4 (+) excretion. Exposure to elevated seawater pH of 8.5 transiently reduced NH3/NH4 (+) excretion rates, but they returned to control values following 24 h acclimation. These mussels had increased abundance of V-type H(+)-ATPase in the apical membranes of plicate organ cells; however, NH3/NH4 (+) excretion rates were not affected by the V-type H(+)-ATPase specific inhibitor concanamycin A (100 nmol l(-1)). In contrast, inhibition of ciliary beating with dopamine and increased seawater viscosity significantly reduced NH3 excretion rates under control pH (8.0). These results suggest that NH3/NH4 (+) excretion in mytilid mussels takes place by passive NH3 diffusion across respiratory epithelia via the Rh protein, facilitated by the water current produced for filter feeding, which prevents accumulation of NH3 in the boundary layer. This mechanism would be energy efficient for sessile organisms, as they already generate water currents for filter feeding. PMID:27489216

  9. Geometric Clutch model version 3: the role of the inner and outer arm dyneins in the ciliary beat.

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    Lindemann, Charles B

    2002-08-01

    The Geometric Clutch model of ciliary and flagellar beating uses the transverse force (t-force) that develops between the outer doublets of the axoneme as the regulator for activating and deactivating the dynein motors and organizing the flagellar beat. The version of the model described here adds detail to the formulations used in the two previous versions as follows: (1) In place of two opposing sets of dyneins, the new model has four sets of dyneins, corresponding to two sets on each side of the axoneme acting in series. (2) The four sets of dyneins are each subdivided into two ranks representing inner and outer arm dyneins. (3) The force produced by each dynein is governed by a force-velocity relationship that is independently specified for the inner and outer arms. Consistent with the original model, the new version of the Geometric Clutch model can simulate both the effective and recovery stroke phases of the ciliary beat using a single uniform algorithm. In addition, the new version can operate with the outer arms disabled. Under this condition, the simulation exhibits a beat pattern similar to the original but the beat frequency is reduced to approximately one third. These results are contingent on using force-velocity relationships for the inner and outer arms similar to those described by Brokaw [1999: Cell Motil. Cytoskeleton 42:134-148], where the inner arms contribute most of the driving force at low shear velocities. This constitutes the first examination of the effects of the force-velocity characteristics of dynein on a cilia-like beat in a theoretical framework. PMID:12112138

  10. Intermode beat stabilized laser with frequency pulling.

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    Yokoyama, S; Araki, T; Suzuki, N

    1994-01-20

    A frequency-stabilized two-mode He-Ne laser has been developed. The intermode beat frequency of the experimental laser was approximately 600 MHz for a 25-cm cavity. The laser frequency in which the mode stands is pulled to the center of the gain curve (frequency pulling). The degree of pulling depends on where the longitudinal modes stand in the broadened gain curve. Beat frequency is thereby changed periodically of the order of hundreds of kilohertz with respect to cavity expansion. The frequency pulling was effectively used for frequency stabilization of the laser. The standing position of the longitudinal mode lights was locked in the gain curve by controlling the change of intermode beat frequency. A microwave mixer was applied to extract the frequency change of the intermode beat. Excellent frequency stability (10(10) for the laser oscillation and 10(6) for the beat frequency) was attained. The polarization orthogonality of the proposed laser was superior to that of Zeeman lasers.

  11. Control of ventricular ciliary beating by the Melanin Concentrating Hormone-expressing neurons of the lateral hypothalamus : a functional imaging survey.

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    Gregory eConductier

    2013-11-01

    Full Text Available The cyclic peptide Melanin-Concentrating Hormone (MCH is known to control a large number of brain functions in mammals such as food intake and metabolism, stress response, anxiety, sleep/wake cycle, memory and reward. Based on neuroanatomical and electrophysiological studies these functions were attributed to neuronal circuits expressing MCHR1, the single MCH receptor in rodents. In complement to our recently published work (Conductier et al. 2013 we provided here new data regarding the action of MCH on ependymocytes in the mouse brain. First, we establish that MCHR1 mRNA is expressed in the ependymal cells of the third ventricle epithelium. Second, we demonstated a tonic control of MCH-expressing neurons on ependymal cilia beat frequency using in vitro optogenics. Finally, we performed in vivo measurements of CSF flow using fluorescent micro-beads in wild-type and MCHR1 knockout mice. Collectively, our results demonstrated that MCH-expressing neurons modulate ciliary beating of ependymal cells at the third ventricle and could contribute to maintain cerebro-spinal fluid homeostasis.

  12. Gimme the beat: assessment of low frequency beat noise for drilling rig

    Energy Technology Data Exchange (ETDEWEB)

    Bilawchuk, Steven; Froment, Patrick [aci Acoustical Consultants Inc. (Canada)], email: stevenb@aciacoustical.com, email: patrickf@aciacoustical.com

    2011-07-01

    The concern of an Alberta resident over the noise level from a drilling rig led to a low frequency noise impact assessment being done by an acoustic consulting firm. This paper describes the investigation that was conducted to determine the low frequency noise source, evaluate its sound emission levels and spectra, and propose mitigation options. Noise measurements were made over several days, with a sound level meter and additionally, a weather monitoring station was also used. Analysis showed low frequency tonal noise at the residential location, resulting in an overall sound level exceeding the permissible sound level imposed by the Alberta noise regulating bodies. Moreover, a beat phenomenon was observed, and after detailed investigation of possible sources, it was established that shale shakers were responsible for the low frequency noise and the beat phenomenon, a fact verified by beat theory. Due to the temporary nature of the drilling rig's operation, no thorough mitigation options could be proposed but a simple stop gap solution for the shale shakers allowed the reduction of low frequency tonal noise.

  13. Robust estimation of the motile cilia beating frequency.

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    Meste, O; Brau, F; Guyon, A

    2015-10-01

    The estimation of the cilia beating frequency (CBF) is of great interest in understanding how the CBF modulates liquid fluxes and how it is controlled by the ciliated cell intra- and/or extracellular medium composition in physiological processes. Motion artifacts and camera defaults may hinder the computation of the frequency variations during long-lasting experiments. We have developed a new analysis approach consisting of a preliminary corrective step (removal of a grid pattern on the image sequence and shift compensation), followed by a harmonic model of the observed cilia using a maximum likelihood estimator framework. It is shown that a more accurate estimation of the frequency can be obtained by averaging the squared Fourier transform of individual pixels followed by a particular summation over the different frequencies, namely the compressed spectrum. Robustness of the proposed method over traditional approaches is shown by several examples and simulations. The method is then applied to images of samples containing ciliated ependymal cells located in the third cerebral ventricle of mouse brains, showing that even small variations in CBF in response to changes in the amount of oxygenation, pH or glucose were clearly visible in the computed frequencies. As a conclusion, this method reveals a fine metabolic tuning of the cilia beating in ependimocytes lining the third cerebral ventricle. Such regulations are likely to participate in homeostatic mechanisms regulating CSF movements and brain energy supply. PMID:26215519

  14. Functional optical coherence tomography for high-resolution mapping of cilia beat frequency in the mouse oviduct in vivo

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    Wang, Shang; Burton, Jason C.; Behringer, Richard R.; Larina, Irina V.

    2016-02-01

    Since mouse is a superior model for genetic analysis of human disorders, reproductive studies in mice have significant implications on further understanding of fertility and infertility in humans. Fertilized oocytes are transported through the reproductive tract by motile cilia lining the lumen of the oviduct as well as by oviduct contractions. While the role of cilia is well recognized, ciliary dynamics in the oviduct is not well understood, largely owing to the lack of live imaging approaches. Here, we report in vivo micro-scale mapping of cilia and cilia beat frequency (CBF) in the mouse oviduct using optical coherence tomography (OCT). This functional imaging method is based on spectral analysis of the OCT speckle variations produced by the beat of cilia in the oviduct, which does not require exogenous contrast agents. Animal procedures similar to the ones used for production of transgenic mice are utilized to expose the reproductive organs for imaging in anesthetized females. In this paper, we first present in vivo structural imaging of the mouse oviduct capturing the oocyte and the preimplantation embryo and then show the result of depth-resolved high-resolution CBF mapping in the ampulla of the live mouse. These data indicate that this structural and functional OCT imaging approach can be a useful tool for a variety of live investigations of mammalian reproduction and infertility.

  15. Culture of primary ciliary dyskinesia epithelial cells at air-liquid interface can alter ciliary phenotype but remains a robust and informative diagnostic aid.

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    Robert A Hirst

    Full Text Available BACKGROUND: The diagnosis of primary ciliary dyskinesia (PCD requires the analysis of ciliary function and ultrastructure. Diagnosis can be complicated by secondary effects on cilia such as damage during sampling, local inflammation or recent infection. To differentiate primary from secondary abnormalities, re-analysis of cilia following culture and re-differentiation of epithelial cells at an air-liquid interface (ALI aids the diagnosis of PCD. However changes in ciliary beat pattern of cilia following epithelial cell culture has previously been described, which has brought the robustness of this method into question. This is the first systematic study to evaluate ALI culture as an aid to diagnosis of PCD in the light of these concerns. METHODS: We retrospectively studied changes associated with ALI-culture in 158 subjects referred for diagnostic testing at two PCD centres. Ciliated nasal epithelium (PCD n = 54; non-PCD n  111 was analysed by high-speed digital video microscopy and transmission electron microscopy before and after culture. RESULTS: Ciliary function was abnormal before and after culture in all subjects with PCD; 21 PCD subjects had a combination of static and uncoordinated twitching cilia, which became completely static following culture, a further 9 demonstrated a decreased ciliary beat frequency after culture. In subjects without PCD, secondary ciliary dyskinesia was reduced. CONCLUSIONS: The change to ciliary phenotype in PCD samples following cell culture does not affect the diagnosis, and in certain cases can assist the ability to identify PCD cilia.

  16. Evidence for two extremes of ciliary motor response in a single swimming microorganism.

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    Jung, Ilyong; Powers, Thomas R; Valles, James M

    2014-01-01

    Because arrays of motile cilia drive fluids for a range of processes, the versatile mechano-chemical mechanism coordinating them has been under scrutiny. The protist Paramecium presents opportunities to compare how groups of cilia perform two distinct functions, swimming propulsion and nutrient uptake. We present how the body cilia responsible for propulsion and the oral-groove cilia responsible for nutrient uptake respond to changes in their mechanical environment accomplished by varying the fluid viscosity over a factor of 7. Analysis with a phenomenological model of trajectories of swimmers made neutrally buoyant with magnetic forces combined with high-speed imaging of ciliary beating reveal that the body cilia exert a nearly constant propulsive force primarily by reducing their beat frequency as viscosity increases. By contrast, the oral-groove cilia beat at a nearly constant frequency. The existence of two extremes of motor response in a unicellular organism prompts unique investigations of factors controlling ciliary beating. PMID:24411242

  17. Polarization-dependent loss characterization method based on optical frequency beat.

    Science.gov (United States)

    Ferreira da Silva, T; Nobre, C S; Temporão, G P

    2016-03-10

    Characterization of the polarization-dependent loss (PDL) of optical components is fundamental for the reliable operation of fiber-optic communication systems. Here we present a method for determining the PDL of optical devices based on optical frequency beating and spectral analysis. Depending on the beat note between components of two orthogonally polarized probe signals modulated at different frequencies, the PDL value and its axis can be determined from a single sweep of an optical spectrum analyzer. Our proposal represents an alternative high-speed option for PDL characterization. PMID:26974770

  18. Changing Frequency Separation of Kilohertz Quasi-Periodic Oscillations in the Sonic-Point Beat-Frequency Model

    CERN Document Server

    Lamb, F K; Lamb, Frederick K.

    2000-01-01

    Previous work on the sonic-point beat-frequency (SPBF) model of the kilohertz quasi-periodic oscillations (QPOs) observed in the X-ray flux from neutron stars in low-mass binary systems has shown that it naturally explains many properties of these QPOs. These include the existence of just two principal QPOs in a given source, the commensurability of the frequency separation \\Dnu\\ of the two kilohertz QPOs and the spin frequency \

  19. Beating frequency and amplitude modulation of the piano tone due to coupling of tones

    Science.gov (United States)

    Cartling, Bo

    2005-04-01

    The influence on a piano tone from weak coexcitation of damped adjacent tones due to coupling via the bridge is studied. The frequency and amplitude modulation of the sound resulting from coexcitation of one strong and one or two weak tones is analyzed. One weak tone causes frequency and amplitude modulation of the sound, and two weak tones produce beating frequency and amplitude modulation, where the beatings of the two modulations are of opposite phase. By digital recording of the sound of piano tones, the appearance of these phenomena is verified. The audibility of the observed frequency and amplitude modulation is discussed in terms of previously determined detection thresholds. The beating character of both frequency and amplitude modulations, however, distinguishes the phenomena from those previously studied and prompts further psychoacoustic investigations. It is shown that detuning of unison strings may significantly increase the frequency deviation of the frequency modulation in conjunction with affected amplitude modulation. The modulatory effects of coupling to adjacent tones therefore may possibly be utilized in the tuning process. A coupling of tones analogous to the situation in a piano may arise in other stringed musical instruments transferring string vibrations to a soundboard via a bridge. .

  20. Beyond the mucus escalator: Complex ciliary hydrodynamics in disease and function

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    Nawroth, Janna; Guo, Hanliang; John, Dabiri; Kanso, Eva; McFall-Ngai, Margaret

    2015-11-01

    Cilia are microscopic, hair-like structures lining external and internal body surfaces where they interact with fluids. The main function of motile cilia is often described as that of a ``mucus escalator'', i.e., a homogeneous ciliary carpet moving along layer of mucus along the surface to transport food, germ cells, debris, or pathogens. Accordingly, the performance of ciliary systems is usually measured in terms of a single metric, transport velocity, or its presumed proxy, ciliary beat frequency. We challenge this simple view through the observation that both healthy and diseased biological systems exhibit a variety of cilia morphologies, beat patterns, and arrangements, resulting in complex flow patterns and transport phenomena that cannot be reduced to a single parameter. Here we present two case studies. In one system, the ciliated surface creates two distinct flow regimes for first trapping and then sheltering potential symbiont bacteria for further biochemical screening. In the other system, chronic disease induces a misalignment of ciliary beat, leading to a pathological transition from uniform mucus transport to a pattern of stagnation and circulation. These studies suggest that (a), we need to develop a wider range of metrics for describing ciliary transport in biological and clinical contexts, and (b), engineered ciliated systems exploiting a variety of design parameters could provide novel ways of manipulating fluids at the microscale.

  1. Pulsed Frequency Shifted Feedback Laser for Accurate Long Distance Measurements: Beat Order Determination

    CERN Document Server

    Pique, Jean-Paul

    2012-01-01

    Long-distance measurements (10 m - 1000 m) with an accuracy of 10-7 is a challenge for many applications. We show that it is achievable with Frequency Shifted Feedback (FSF) laser interferometry technique, provided that the determination of the radio frequency beat order be made without ambiguity and on a time scale compatible with atmospheric applications. Using the pulsed-FSF laser that we developed for laser guide star application, we propose and test, up to 240 m, a simple method for measuring the beat order in real time. The moving-comb and Yatsenko models are also discussed. The first of these models fails to interpret our long-distance interferometry results. We show that the accuracy of long-distance measurements depends primarily on the stabilization of the acoustic frequency of the modulator.

  2. Enhanced speed in fluorescence imaging using beat frequency multiplexing

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    Mikami, Hideharu; Kobayashi, Hirofumi; Wang, Yisen; Hamad, Syed; Ozeki, Yasuyuki; Goda, Keisuke

    2016-03-01

    Fluorescence imaging using radiofrequency-tagged emission (FIRE) is an emerging technique that enables higher imaging speed (namely, temporal resolution) in fluorescence microscopy compared to conventional fluorescence imaging techniques such as confocal microscopy and wide-field microscopy. It works based on the principle that it uses multiple intensity-modulated fields in an interferometric setup as excitation fields and applies frequency-division multiplexing to fluorescence signals. Unfortunately, despite its high potential, FIRE has limited imaging speed due to two practical limitations: signal bandwidth and signal detection efficiency. The signal bandwidth is limited by that of an acousto-optic deflector (AOD) employed in the setup, which is typically 100-200 MHz for the spectral range of fluorescence excitation (400-600 nm). The signal detection efficiency is limited by poor spatial mode-matching between two interfering fields to produce a modulated excitation field. Here we present a method to overcome these limitations and thus to achieve higher imaging speed than the prior version of FIRE. Our method achieves an increase in signal bandwidth by a factor of two and nearly optimal mode matching, which enables the imaging speed limited by the lifetime of the target fluorophore rather than the imaging system itself. The higher bandwidth and better signal detection efficiency work synergistically because higher bandwidth requires higher signal levels to avoid the contribution of shot noise and amplifier noise to the fluorescence signal. Due to its unprecedentedly high-speed performance, our method has a wide variety of applications in cancer detection, drug discovery, and regenerative medicine.

  3. Strain fiber sensor based on beat frequency with chirped fiber Bragg grating

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    Wang, Xu; Zhang, Haojie; Wen, Quan; Chen, Longfei; Wang, Fang; Liu, Yufang; Yu, Kun

    2016-07-01

    We propose a strain fiber sensor that is interrogated via longitudinal mode beat frequency with a linear chirped fiber Bragg grating (CFBG). Unlike conventional sensors, in the proposed sensor, the CFBG is used to convert wavelength changes into resonant cavity length changes. Further, the beat frequency stability of the fiber laser is fully utilized to significantly improve measurement accuracy. Consequently, because cavity changes account for 5.1% of the total cavity length, the measurement accuracy can be as large as 7.06×10-7 ɛ-i.e., approximately five times greater than the accuracy obtained by stretching the resonant cavity fiber. The maximum experimental strain error range is ±14.5 μɛ.

  4. Ciliary kinematics of Chlamydomonas reinhardtii in Complex Fluids: Role of viscosity

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    Gopinath, Arvind; Qin, Boyang; Arratia, Paulo

    2014-11-01

    The motility behavior of microorganisms can be significantly affected by the rheology of their fluidic environment. Guided by our experiments on the swimming gait of Chlamydomonas reinhardtii in viscoelastic fluids, we focus on ciliary waveforms in Newtonian fluids and systematically study the effect of increasing viscosity. We find that the beat frequency as well as the wave speed are both strongly influenced by fluid viscosity. Interestingly, ciliary waveforms at low viscosity show a larger influence of the cell body than waveforms at higher viscosity. We use slender body theory and principal component analysis to elucidate the role of fluid viscosity in regulating the kinematics of the swimming process.

  5. Measurement of optical-beat frequency in a photoconductive terahertz-wave generator using microwave higher harmonics

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    Murasawa, Kengo; Sato, Koki; Hidaka, Takehiko

    2011-05-01

    A new method for measuring optical-beat frequencies in the terahertz (THz) region using microwave higher harmonics is presented. A microwave signal was applied to the antenna gap of a photoconductive (PC) device emitting a continuous electromagnetic wave at about 1 THz by the photomixing technique. The microwave higher harmonics with THz frequencies are generated in the PC device owing to the nonlinearity of the biased photoconductance, which is briefly described in this article. Thirteen nearly periodic peaks in the photocurrent were observed when the microwave was swept from 16 to 20 GHz at a power of -48 dBm. The nearly periodic peaks are generated by the homodyne detection of the optical beat with the microwave higher harmonics when the frequency of the harmonics coincides with the optical-beat frequency. Each peak frequency and its peak width were determined by fitting a Gaussian function, and the order of microwave harmonics was determined using a coarse (i.e., lower resolution) measurement of the optical-beat frequency. By applying the Kalman algorithm to the peak frequencies of the higher harmonics and their standard deviations, the optical-beat frequency near 1 THz was estimated to be 1029.81 GHz with the standard deviation of 0.82 GHz. The proposed method is applicable to a conventional THz-wave generator with a photomixer.

  6. Efficiency of dispersive wave generation from a dual-frequency beat signal

    CERN Document Server

    Webb, K E; Xu, Y Q; Genty, G; Murdoch, S G

    2016-01-01

    The emission of dispersive waves (DWs) by temporal solitons can be described as a cascaded four-wave mixing process triggered by a pair of monochromatic continuous waves (CWs). We report experimental and numerical results demonstrating that the efficiency of this process is strongly and non-trivially affected by the frequency detuning of the CW pump lasers. We explain our results by showing that individual cycles of the input dual-frequency beat signal can evolve as higher-order solitons whose temporal compression and soliton fission govern the DW efficiency. Analytical predictions based on the detuning dependence of the soliton order are shown to be in excellent agreement with experimental and numerical observations.

  7. Fast phase stabilization of a low frequency beat note for atom interferometry.

    Science.gov (United States)

    Oh, E; Horne, R A; Sackett, C A

    2016-06-01

    Atom interferometry experiments rely on the ability to obtain a stable signal that corresponds to an atomic phase. For interferometers that use laser beams to manipulate the atoms, noise in the lasers can lead to errors in the atomic measurement. In particular, it is often necessary to actively stabilize the optical phase between two frequency components of the beams. Typically this is achieved using a time-domain measurement of a beat note between the two frequencies. This becomes challenging when the frequency difference is small and the phase measurement must be made quickly. The method presented here instead uses a spatial interference detection to rapidly measure the optical phase for arbitrary frequency differences. A feedback system operating at a bandwidth of about 10 MHz could then correct the phase in about 3 μs. This time is short enough that the phase correction could be applied at the start of a laser pulse without appreciably degrading the fidelity of the atom interferometer operation. The phase stabilization system was demonstrated in a simple atom interferometer measurement of the (87)Rb recoil frequency. PMID:27370424

  8. Fast phase stabilization of a low frequency beat note for atom interferometry.

    Science.gov (United States)

    Oh, E; Horne, R A; Sackett, C A

    2016-06-01

    Atom interferometry experiments rely on the ability to obtain a stable signal that corresponds to an atomic phase. For interferometers that use laser beams to manipulate the atoms, noise in the lasers can lead to errors in the atomic measurement. In particular, it is often necessary to actively stabilize the optical phase between two frequency components of the beams. Typically this is achieved using a time-domain measurement of a beat note between the two frequencies. This becomes challenging when the frequency difference is small and the phase measurement must be made quickly. The method presented here instead uses a spatial interference detection to rapidly measure the optical phase for arbitrary frequency differences. A feedback system operating at a bandwidth of about 10 MHz could then correct the phase in about 3 μs. This time is short enough that the phase correction could be applied at the start of a laser pulse without appreciably degrading the fidelity of the atom interferometer operation. The phase stabilization system was demonstrated in a simple atom interferometer measurement of the (87)Rb recoil frequency.

  9. Pectoral fin beat frequency predicts oxygen consumption during spontaneous activity in a labriform swimming fish (Embiotoca lateralis)

    DEFF Research Database (Denmark)

    Tudorache, Christian; Jordan, Anders D.; Svendsen, Jon Christian;

    2009-01-01

    . Complementary to other methods within biotelemetry such as EMG it is suggested that such correlations of pectoral fin beat frequency may be used to measure the energy requirements of labriform swimming fish such as E. lateralis in the field, but need to be taken with great caution since movement and oxygen......The objective of this study was to identify kinematic variables correlated with oxygen consumption during spontaneous labriform swimming. Kinematic variables (swimming speed, change of speed, turning angle, turning rate, turning radius and pectoral fin beat frequency) and oxygen consumption (MO2...

  10. Odors pulsed at wing beat frequencies are tracked by primary olfactory networks and enhance odor detection

    Directory of Open Access Journals (Sweden)

    Shreejoy Tripathy

    2010-03-01

    Full Text Available Each down stroke of an insect’s wings accelerates axial airflow over the antennae. Modeling studies suggest that this can greatly enhance penetration of air and air-born odorants through the antennal sensilla thereby periodically increasing odorant-receptor interactions. Do these periodic changes result in entrainment of neural responses in the antenna and antennal lobe (AL? Does this entrainment affect olfactory acuity? To address these questions, we monitored antennal and AL responses in the moth Manduca sexta while odorants were pulsed at frequencies from 10-72 Hz, encompassing the natural wingbeat frequency. Power spectral density (PSD analysis was used to identify entrainment of neural activity. Statistical analysis of PSDs indicates that the antennal nerve tracked pulsed odor up to 30 Hz. Furthermore, at least 50% of AL local field potentials (LFPs and between 7-25% of unitary spiking responses also tracked pulsed odor up to 30 Hz in a frequency-locked manner. Application of bicuculline (200µM abolished pulse tracking in both LFP and unitary responses suggesting that GABAA receptor activation is necessary for pulse tracking within the AL. Finally, psychophysical measures of odor detection establish that detection thresholds are lowered when odor is pulsed at 20 Hz. These results suggest that AL networks can respond to the oscillatory dynamics of stimuli such as those imposed by the wing beat in a manner analogous to mammalian sniffing.

  11. Fungal Aflatoxins Reduce Respiratory Mucosal Ciliary Function.

    Science.gov (United States)

    Lee, Robert J; Workman, Alan D; Carey, Ryan M; Chen, Bei; Rosen, Phillip L; Doghramji, Laurel; Adappa, Nithin D; Palmer, James N; Kennedy, David W; Cohen, Noam A

    2016-01-01

    Aflatoxins are mycotoxins secreted by Aspergillus flavus, which can colonize the respiratory tract and cause fungal rhinosinusitis or bronchopulmonary aspergillosis. A. flavus is the second leading cause of invasive aspergillosis worldwide. Because many respiratory pathogens secrete toxins to impair mucociliary immunity, we examined the effects of acute exposure to aflatoxins on airway cell physiology. Using air-liquid interface cultures of primary human sinonasal and bronchial cells, we imaged ciliary beat frequency (CBF), intracellular calcium, and nitric oxide (NO). Exposure to aflatoxins (0.1 to 10 μM; 5 to 10 minutes) reduced baseline (~6-12%) and agonist-stimulated CBF. Conditioned media (CM) from A. fumigatus, A. niger, and A. flavus cultures also reduced CBF by ~10% after 60 min exposure, but effects were blocked by an anti-aflatoxin antibody only with A. flavus CM. CBF reduction required protein kinase C but was not associated with changes in calcium or NO. However, AFB2 reduced NO production by ~50% during stimulation of the ciliary-localized T2R38 receptor. Using a fluorescent reporter construct expressed in A549 cells, we directly observed activation of PKC activity by AFB2. Aflatoxins secreted by respiratory A. flavus may impair motile and chemosensory functions of airway cilia, contributing to pathogenesis of fungal airway diseases. PMID:27623953

  12. Fungal Aflatoxins Reduce Respiratory Mucosal Ciliary Function

    Science.gov (United States)

    Lee, Robert J.; Workman, Alan D.; Carey, Ryan M.; Chen, Bei; Rosen, Phillip L.; Doghramji, Laurel; Adappa, Nithin D.; Palmer, James N.; Kennedy, David W.; Cohen, Noam A.

    2016-01-01

    Aflatoxins are mycotoxins secreted by Aspergillus flavus, which can colonize the respiratory tract and cause fungal rhinosinusitis or bronchopulmonary aspergillosis. A. flavus is the second leading cause of invasive aspergillosis worldwide. Because many respiratory pathogens secrete toxins to impair mucociliary immunity, we examined the effects of acute exposure to aflatoxins on airway cell physiology. Using air-liquid interface cultures of primary human sinonasal and bronchial cells, we imaged ciliary beat frequency (CBF), intracellular calcium, and nitric oxide (NO). Exposure to aflatoxins (0.1 to 10 μM; 5 to 10 minutes) reduced baseline (~6–12%) and agonist-stimulated CBF. Conditioned media (CM) from A. fumigatus, A. niger, and A. flavus cultures also reduced CBF by ~10% after 60 min exposure, but effects were blocked by an anti-aflatoxin antibody only with A. flavus CM. CBF reduction required protein kinase C but was not associated with changes in calcium or NO. However, AFB2 reduced NO production by ~50% during stimulation of the ciliary-localized T2R38 receptor. Using a fluorescent reporter construct expressed in A549 cells, we directly observed activation of PKC activity by AFB2. Aflatoxins secreted by respiratory A. flavus may impair motile and chemosensory functions of airway cilia, contributing to pathogenesis of fungal airway diseases. PMID:27623953

  13. Fiber optic laser light scattering measurement of ciliary function of the fallopian tube

    Science.gov (United States)

    Halbert, Sheridan A.; Lim, Kap; Lee, Wylie I.

    1990-07-01

    A fiber-optic laser light-scattering system (FLS) for measuring ciliary function was evaluated by means of three sets of in vitro experiments. First, FLS performance was compared to that of a previously proven benchtop laser system (BLS). Using tissue excised from rabbit fallopian tubes, ciliary beat frequency (CBF) of each sample was measured with FLS and BLS. Paired CBF measurements showed excellent correlation between the two systems (r =0.93). Second, the FLS was used to evaluate the dependency of CBF on temperature (T) by using tissue sampies of rabbit oviductal fimbna. Regression analysis of CBF vs T showed a linear relationship over the range of 18-37°C for both individual samples (r =0.98) and pooled data from all experiments (r = 0.84). Fmally, the relalionship between CBF and ciliary ovum transport rate (TR) was tested by using T to modulate CBF of rabbit fimbria, in vitro. The relationship was linear over the range of CBF from 10 to 30 Hz (r2 = 0.83). At 37°C, CBF = 31+/-1 Hz, and TR = O.12+/-.02 mm/sec. equal to ovum transport rate in situ. The FLS is a valuable tool for characterizing ciliary activity and thus ovum transport function. Owing to the fact that ciliary dyskinesia resulting from disease of the fallopian tube is associated with infeitility, the FLS may be useful to acquire data important to the clinical evaluation of fallopian tube function and female infertility.

  14. Birefringence-induced frequency beating in high-finesse cavities by continuous-wave cavity ring-down spectroscopy

    Science.gov (United States)

    Dupré, Patrick

    2015-11-01

    By analyzing the decaying intensity, leaking out a high-finesse cavity previously "filled" by a cw laser source (using the cavity ring-down spectroscopy technique), we observed frequency beating between what we think are two orthogonal eigenpolarization states of the intracavity electromagnetic field. The time decay (ring down) is analyzed by varying the angle of the polarization analyzer located in front of the detector. A full modeling of the observed signal is proposed. It is based on the Jones matrix formalism required for modeling the cavity behavior following a rotated phase shifter. The full transfer function is first established in the frequency domain, and then Fourier transformed to recover the temporal response. The same optical cavity, i.e., constituted of the same set of mirrors, is used at two different wavelengths (˜800 and ˜880 nm). It demonstrates the differences in behavior between a high-finesse cavity (˜400 000 ) and a lower finesse cavity (˜50 000 ). Beating frequency, characteristics time, and beat amplitude are mainly discussed versus the analyzer angle. A cavity birefringence of ˜1.6 ×10-5 rad, resulting from the mirror birefringence is suggested. If the current analysis is in agreement with pulsed CRDS experiments (polarimetry) obtained in an isotropic moderate-finesse cavity, it differs from a recent work report on a high-finesse cavity associated with a source mode locking [Phys. Rev. A 85, 013837 (2012), 10.1103/PhysRevA.85.013837].

  15. Measurement of Terahertz Optical-Beat Frequency Using High-Order Harmonics of Microwave in a Photoconductive Device

    Directory of Open Access Journals (Sweden)

    Kengo Murasawa

    2011-01-01

    Full Text Available A method for measuring frequencies of the terahertz (THz radiation emitted by the antenna mounted on the photoconductive (PC device is presented. Two laser beams with slightly different frequencies irradiate the PC device, producing a beat current of 1 THz in the photocurrent. A microwave signal is applied to the antenna electrode. The frequency of the THz wave is measured using the homodyne detection of the optical beat with the high-order harmonics of the microwave. It is being investigated that the high-order harmonics are produced by the PC device owing to its nonlinearity. Periodic peaks generated by the homodyne detection were observed in the photocurrent, as the microwave was swept from 16 to 20 GHz with a power of −40 dBm. Using the peak frequencies, the THz-wave frequency was determined to be 1030.3±3.73 GHz. The measurement error is estimated to be less than 0.43 GHz. The proposed method realizes a compact frequency meter in the THz region.

  16. Superresolved optical imaging through higher-order spatial frequency harmonic generation without beating the diffraction limit of light

    CERN Document Server

    Li, Zhixiang; Zhang, Guoquan

    2016-01-01

    We proposed a method to achieve superresolved optical imaging without beating the diffraction limit of light. This is achieved by magnifying the ideal optical image of the object through higher-order spatial frequency generation while keeping the size of the effective point spread function of the optical imaging system unchanged. A proof-of-principle experiment was demonstrated in a modified $4f$-imaging system, where the spatial frequency of a two-line source was doubled or tripled on the confocal Fourier plane of the $4f$-imaging system through a light pulse storage and retrieval process based on the electromagnetically induced transparency effect in a Pr$^{3+}$:$\\rm Y_2SiO_5$ crystal, and an originally unresolvable image of the two line sources in the conventional $4f$-imaging system became resolvable with the spatial frequency doubling or tripling. Our results offer an original way towards improving optical imaging resolution without beating the diffraction limit of light, which is totally different from ...

  17. Mechanism of ciliary disassembly.

    Science.gov (United States)

    Liang, Yinwen; Meng, Dan; Zhu, Bing; Pan, Junmin

    2016-05-01

    As motile organelles and sensors, cilia play pivotal roles in cell physiology, development and organ homeostasis. Ciliary defects are associated with a class of cilia-related diseases or developmental disorders, termed ciliopathies. Even though the presence of cilia is required for diverse functions, cilia can be removed through ciliary shortening or resorption that necessitates disassembly of the cilium, which occurs normally during cell cycle progression, cell differentiation and in response to cellular stress. The functional significance of ciliary resorption is highlighted in controlling the G1-S transition during cell cycle progression. Internal or external cues that trigger ciliary resorption initiate signaling cascades that regulate several downstream events including depolymerization of axonemal microtubules, dynamic changes in actin and the ciliary membrane, regulation of intraflagellar transport and posttranslational modifications of ciliary proteins. To ensure ciliary resorption, both the active disassembly of the cilium and the simultaneous inhibition of ciliary assembly must be coordinately regulated. PMID:26869233

  18. Fish and robots swimming together in a water tunnel: robot color and tail-beat frequency influence fish behavior.

    Science.gov (United States)

    Polverino, Giovanni; Phamduy, Paul; Porfiri, Maurizio

    2013-01-01

    The possibility of integrating bioinspired robots in groups of live social animals may constitute a valuable tool to study the basis of social behavior and uncover the fundamental determinants of animal functions and dysfunctions. In this study, we investigate the interactions between individual golden shiners (Notemigonus crysoleucas) and robotic fish swimming together in a water tunnel at constant flow velocity. The robotic fish is designed to mimic its live counterpart in the aspect ratio, body shape, dimension, and locomotory pattern. Fish positional preference with respect to the robot is experimentally analyzed as the robot's color pattern and tail-beat frequency are varied. Behavioral observations are corroborated by particle image velocimetry studies aimed at investigating the flow structure behind the robotic fish. Experimental results show that the time spent by golden shiners in the vicinity of the bioinspired robotic fish is the highest when the robot mimics their natural color pattern and beats its tail at the same frequency. In these conditions, fish tend to swim at the same depth of the robotic fish, where the wake from the robotic fish is stronger and hydrodynamic return is most likely to be effective. PMID:24204882

  19. Fish and robots swimming together in a water tunnel: robot color and tail-beat frequency influence fish behavior.

    Directory of Open Access Journals (Sweden)

    Giovanni Polverino

    Full Text Available The possibility of integrating bioinspired robots in groups of live social animals may constitute a valuable tool to study the basis of social behavior and uncover the fundamental determinants of animal functions and dysfunctions. In this study, we investigate the interactions between individual golden shiners (Notemigonus crysoleucas and robotic fish swimming together in a water tunnel at constant flow velocity. The robotic fish is designed to mimic its live counterpart in the aspect ratio, body shape, dimension, and locomotory pattern. Fish positional preference with respect to the robot is experimentally analyzed as the robot's color pattern and tail-beat frequency are varied. Behavioral observations are corroborated by particle image velocimetry studies aimed at investigating the flow structure behind the robotic fish. Experimental results show that the time spent by golden shiners in the vicinity of the bioinspired robotic fish is the highest when the robot mimics their natural color pattern and beats its tail at the same frequency. In these conditions, fish tend to swim at the same depth of the robotic fish, where the wake from the robotic fish is stronger and hydrodynamic return is most likely to be effective.

  20. Stroma cell-derived factor-1α signaling enhances calcium transients and beating frequency in rat neonatal cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Ielham Hadad

    Full Text Available Stroma cell-derived factor-1α (SDF-1α is a cardioprotective chemokine, acting through its G-protein coupled receptor CXCR4. In experimental acute myocardial infarction, administration of SDF-1α induces an early improvement of systolic function which is difficult to explain solely by an anti-apoptotic and angiogenic effect. We wondered whether SDF-1α signaling might have direct effects on calcium transients and beating frequency.Primary rat neonatal cardiomyocytes were culture-expanded and characterized by immunofluorescence staining. Calcium sparks were studied by fluorescence microscopy after calcium loading with the Fluo-4 acetoxymethyl ester sensor. The cardiomyocyte enriched cellular suspension expressed troponin I and CXCR4 but was vimentin negative. Addition of SDF-1α in the medium increased cytoplasmic calcium release. The calcium response was completely abolished by using a neutralizing anti-CXCR4 antibody and partially suppressed and delayed by preincubation with an inositol triphosphate receptor (IP3R blocker, but not with a ryanodine receptor (RyR antagonist. Calcium fluxes induced by caffeine, a RyR agonist, were decreased by an IP3R blocker. Treatment with forskolin or SDF-1α increased cardiomyocyte beating frequency and their effects were additive. In vivo, treatment with SDF-1α increased left ventricular dP/dtmax.These results suggest that in rat neonatal cardiomyocytes, the SDF-1α/CXCR4 signaling increases calcium transients in an IP3-gated fashion leading to a positive chronotropic and inotropic effect.

  1. A Beat Frequency RF Modulator for Generation of Low Repetition Rate Electron Microbunches for the CEBAF Polarized Source

    Energy Technology Data Exchange (ETDEWEB)

    John Musson; Reza Kazimi; Benard Poelker; Joseph Grames; John Hansknecht

    2007-06-25

    Fiber-based drive lasers now produce all of the spin-polarized electron beams at CEBAF/Jefferson Lab. The flexibility of these drive lasers, combined with the existing three-beam CEBAF photoinjector Chopper, provides a means to implement a beat frequency technique to produce long time intervals between individual electron microbunches (tens of nanoseconds) by merely varying the nominal 499 MHz drive laser frequency by < 20%. This submission describes the RF Laser modulator that uses a divider and heterodyne scheme to maintain coherence with the accelerator Master Oscillator (MO), while providing delay resolution in increments of 2ns. Some possible uses for such a beam are discussed as well as intended future development.

  2. Wireless fiber laser sensor combining photonic generation beat frequency demodulation technology

    Science.gov (United States)

    Liu, Shengchun; Gu, Rong; Yu, Xiujuan; Yin, Zuowei; Chen, Xiangfei

    2011-12-01

    A simple wireless-fiber laser sensor is proposed base on directly photonic generation of microwave beat signal. In this scheme, a multi-longitudinal modes fiber laser is formed by two fiber Bragg gratings and a section of erbium-doped fiber. Two same 2G-GSM mobile antennas are used as wireless transmitter and receiver. By this method, the real-time monitoring of fiber laser sensors can be achieved through over ultra-long distance. This technique offers a simple, all-electrical and cheap way for fiber sensor information accessing wireless net. The experiment result shows the root mean square deviations of the sensor are about 4.7 μɛ and 6.7 μɛ at 2.38 GHz before and after wireless transmission, respectively.

  3. Energy savings in sea bass swimming in a school: measurements of tail beat frequency and oxygen consumption at different swimming speeds

    DEFF Research Database (Denmark)

    Herskin, J; Steffensen, JF

    1998-01-01

    Tail beat frequency of sea bass, Dicentrarchus labrax (L.) (23.5 ± 0·5 cm, LT), swimming at the front of a school was significantly higher than when swimming at the rear, for all water velocities tested from 14·8 to 32 cm s-1. The logarithm of oxygen consumption rate, and the tail beat frequency...... of solitary swimming sea bass (28·8 ± 0·4 cm, LT), were each correlated linearly with swimming speed, and also with one another. The tail beat frequency of individual fish was 9-14% lower when at the rear of a school than when at the front, corresponding to a 9-23% reduction in oxygen consumption rate....

  4. [Research of dual-photoelastic-modulator-based beat frequency modulation and Fourier-Bessel transform imaging spectrometer].

    Science.gov (United States)

    Wang, Zhi-Bin; Zhang, Rui; Wang, Yao-Li; Huang, Yan-Fei; Chen, You-Hua; Wang, Li-Fu; Yang, Qiang

    2014-02-01

    As the existing photoelastic-modulator(PEM) modulating frequency in the tens of kHz to hundreds of kHz between, leading to frequency of modulated interference signal is higher, so ordinary array detector cannot effectively caprure interference signal..A new beat frequency modulation method based on dual-photoelastic-modulator (Dual-PEM) and Fourier-Bessel transform is proposed as an key component of dual-photoelastic-modulator-based imaging spectrometer (Dual-PEM-IS) combined with charge coupled device (CCD). The dual-PEM are operated as an electro-optic circular retardance modulator, Operating the PEMs at slightly different resonant frequencies w1 and w2 respectively, generates a differential signal at a much lower heterodyne frequency that modulates the incident light. This method not only retains the advantages of the existing PEM, but also the frequency of modulated photocurrent decreased by 2-3 orders of magnitude (10-500 Hz) and can be detected by common array detector, and the incident light spectra can be obtained by Fourier-Bessel transform of low frequency component in the modulated signal. The method makes the PEM has the dual capability of imaging and spectral measurement. The basic principle is introduced, the basic equations is derived, and the feasibility is verified through the corresponding numerical simulation and experiment. This method has' potential applications in imaging spectrometer technology, and analysis of the effect of deviation of the optical path difference. This work provides the necessary theoretical basis for remote sensing of new Dual-PEM-IS and for engineering implementation of spectra inversion.

  5. Multi-input multi-output frequency-modulated continuous wave synthetic aperture radar system using beat-frequency division waveforms

    International Nuclear Information System (INIS)

    Attention has been paid to lightweight, cost-effective frequency-modulated continuous wave (FMCW) synthetic aperture radar (SAR) in recent years. Though FMCW SAR can operate at high altitude, it is still impracticable for wide swath or high Doppler bandwidth remote sensing because of the dramatic losses of range resolution and processing gain. Moreover, the system sampling rate is too high for real-time processing. All these restrictions caused by the bandwidth loss of the dechirp operation can be relieved by expanding the system sweep cycle. However, the broadening of the sweep cycle decreases the system pulse repetition frequency with azimuth ambiguity, which can be suppressed by exploiting the spatial diversity of multi-input multi-output (MIMO) systems. This paper reports a MIMO-FMCW SAR system using beat-frequency division waveforms. There is a small frequency interval and a large overlap (in frequency) between the orthogonal waveforms. As the frequency interval is much smaller than the signal bandwidth, the echoes that come from different transmitters can be separated by bandpass filtering with little intrapulse interference. Consequently, the applications of FMCW SAR systems can be extended for wider swath or higher Doppler bandwidth remote sensing. Theoretical analysis and simulation results illustrate the feasibility of this system. (paper)

  6. Multi-input multi-output frequency-modulated continuous wave synthetic aperture radar system using beat-frequency division waveforms

    Science.gov (United States)

    Wang, Jie; Chen, Long-yong; Liang, Xing-dong; Ding, Chi-biao; Hong, Wen; Zhou, Liang-jiang; Dong, Yong-wei; Li, Kun

    2013-07-01

    Attention has been paid to lightweight, cost-effective frequency-modulated continuous wave (FMCW) synthetic aperture radar (SAR) in recent years. Though FMCW SAR can operate at high altitude, it is still impracticable for wide swath or high Doppler bandwidth remote sensing because of the dramatic losses of range resolution and processing gain. Moreover, the system sampling rate is too high for real-time processing. All these restrictions caused by the bandwidth loss of the dechirp operation can be relieved by expanding the system sweep cycle. However, the broadening of the sweep cycle decreases the system pulse repetition frequency with azimuth ambiguity, which can be suppressed by exploiting the spatial diversity of multi-input multi-output (MIMO) systems. This paper reports a MIMO-FMCW SAR system using beat-frequency division waveforms. There is a small frequency interval and a large overlap (in frequency) between the orthogonal waveforms. As the frequency interval is much smaller than the signal bandwidth, the echoes that come from different transmitters can be separated by bandpass filtering with little intrapulse interference. Consequently, the applications of FMCW SAR systems can be extended for wider swath or higher Doppler bandwidth remote sensing. Theoretical analysis and simulation results illustrate the feasibility of this system.

  7. Pseudotumor of Ciliary Body

    Directory of Open Access Journals (Sweden)

    Mary Varghese

    2014-01-01

    Full Text Available Orbital pseudotumor is a benign disease involving the orbital structures. Pseudotumor of the ciliary body is rare. We present a case of a 27-year-old male who presented with gradual visual loss, pain, and redness in his left eye. On examination he was found to have a yellowish white mass at the periphery of anterior chamber in his left eye and ultrasound biomicroscopy (UBM revealed a ciliary body mass in the same eye. He was treated with systemic steroids, which was tapered over a period of 8 weeks. His symptoms improved and the ciliary body mass disappeared with no recurrence over the next 6 months. UBM is an important diagnostic tool for diagnosing ciliary body mass. Early diagnosis and prompt treatment with systemic steroids may help resolve pseudotumor of the ciliary body.

  8. LRRC6 mutation causes primary ciliary dyskinesia with dynein arm defects.

    Directory of Open Access Journals (Sweden)

    Amjad Horani

    Full Text Available Despite recent progress in defining the ciliome, the genetic basis for many cases of primary ciliary dyskinesia (PCD remains elusive. We evaluated five children from two unrelated, consanguineous Palestinian families who had PCD with typical clinical features, reduced nasal nitric oxide concentrations, and absent dynein arms. Linkage analyses revealed a single common homozygous region on chromosome 8 and one candidate was conserved in organisms with motile cilia. Sequencing revealed a single novel mutation in LRRC6 (Leucine-rich repeat containing protein 6 that fit the model of autosomal recessive genetic transmission, leading to a change of a highly conserved amino acid from aspartic acid to histidine (Asp146His. LRRC6 was localized to the cytoplasm and was up-regulated during ciliogenesis in human airway epithelial cells in a Foxj1-dependent fashion. Nasal epithelial cells isolated from affected individuals and shRNA-mediated silencing in human airway epithelial cells, showed reduced LRRC6 expression, absent dynein arms, and slowed cilia beat frequency. Dynein arm proteins were either absent or mislocalized to the cytoplasm in airway epithelial cells from a primary ciliary dyskinesia subject. These findings suggest that LRRC6 plays a role in dynein arm assembly or trafficking and when mutated leads to primary ciliary dyskinesia with laterality defects.

  9. [A case of primary ciliary dyskinesia who had been treated as asthma].

    Science.gov (United States)

    Hosoki, Koa; Fujisawa, Takao; Masuda, Sawako; Usui, Satoko; Ito, Hiroaki; Nagao, Mizuho; Terada, Akihiko; Iguchi, Kousei; Ogawa, Satoru; Nakatani, Kaname; Takeuchi, Kazuhiko

    2010-07-01

    We report a case of 18-old girl with primary ciliary dyskinesia (PCD) who had been diagnosed as asthma. Since birth, she had presented with unexplained productive cough, sputum, rhinorrhea, and stridor with situs solitus. Her familial history was negative for PCD. At 2 years of age, ciliary beat frequency and beat pattern were normal. She was diagnosed as rhinosinusitis, chronic secretory otitis media. At 3 years of age, she was diagnosed as asthma because of wheezing not associated with respiratory infection. Various asthma medications were then administered, including DSCG, inhaled corticosteroids, and salmeterol, but varying responses to the treatment were noted. Spirometry revealed persistent severe small airway obstruction. Beta2 agonist reversibility was recognized by impulse oscillation system, not with FEV1. At age of 18, chest CT disclosed bronchiectasis, and nasal nitric oxide concentration was very low, 98 ppb and a diagnostic approach for PCD was performed. Electron microscopic analysis of nasal cilia demonstrated defects of the outer and inner dynein arms, and the diagnosis of PCD was made. Mutations in DNAH1 and DNAI1 genes were found. The diagnosis of PCD is often difficult in the absence of situs inversus totalis. Recurrent wheeze with chronic rhinosinusitis, chronic otitis media, and brochiectasis may warrant detailed investigations for PCD, especially with nasal NO measurement. PMID:20703071

  10. Modeling pharmacological clock and memory patterns of interval timing in a striatal beat-frequency model with realistic, noisy neurons

    Directory of Open Access Journals (Sweden)

    Sorinel A. Oprisan

    2011-09-01

    Full Text Available In most species, the capability of perceiving and using the passage of time in the seconds-to-minutes range (interval timing is not only accurate but also scalar: errors in time estimation are linearly related to the estimated duration. The ubiquity of scalar timing extends over behavioral, lesion, and pharmacological manipulations. For example, in mammals, dopaminergic drugs induce an immediate, scalar change in the perceived time (clock pattern, whereas cholinergic drugs induce a gradual, scalar change in perceived time (memory pattern. How do these properties emerge from unreliable, noisy neurons firing in the milliseconds range? Neurobiological information relative to the brain circuits involved in interval timing provide support for an Striatal Beat Frequency (SBF model, in which time is coded by the coincidental activation of striatal spiny neurons by cortical neural oscillators. While biologically plausible, the impracticality of perfect oscillators, or their lack thereof, questions this mechanism in a brain with noisy neurons. We explored the computational mechanisms required for the clock and memory patterns in an SBF model with biophysically realistic and noisy Morris-Lecar neurons (SBF-ML. Under the assumption that dopaminergic drugs modulate the firing frequency of cortical oscillators, and that cholinergic drugs modulate the memory representation of the criterion time, we show that our SBF-ML model can reproduce the pharmacological clock and memory patterns observed in the literature. Numerical results also indicate that parameter variability (noise – which is ubiquitous in the form of small fluctuations in the intrinsic frequencies of neural oscillators within and between trails, and in the errors in recording/retrieving stored information related to criterion time – seems to be critical for the time-scale invariance of the clock and memory patterns.

  11. Features of amplitude and Doppler frequency variation of ELF/VLF waves generated by "beat-wave" HF heating at high latitudes

    Science.gov (United States)

    Tereshchenko, E. D.; Shumilov, O. I.; Kasatkina, E. A.; Gomonov, A. D.

    2014-07-01

    Observations of extremely low frequency (ELF, 3-3000 Hz) radio waves generated by a "beat-wave" (BW) high frequency (~ 4.04-4.9 MHz) ionospheric heating are presented. ELF waves were registered with the ELF receiver located at Lovozero (68°N, 35°E), 660 km east from the European Incoherent Scatter Tromso heating facility (69.6°N, 19.2°E). Frequency shifts between the generated beat-wave and received ELF waves were detected in all sessions. It is shown that the amplitudes of ELF waves depend on the auroral electrojet current strength. Our results showing a strong dependence of ELF signal intensities on the substorm development seem to support the conclusion that electrojet currents may affect the BW generation of ELF/VLF waves.

  12. DFB fiber laser static strain sensor based on beat frequency interrogation with a reference fiber laser locked to a FBG resonator.

    Science.gov (United States)

    Huang, Wenzhu; Feng, Shengwen; Zhang, Wentao; Li, Fang

    2016-05-30

    We report on a high-resolution static strain sensor developed with distributed feedback (DFB) fiber laser. A reference FBG resonator is used for temperature compensation. Locking another independent fiber laser to the resonator using the Pound-Drever-Hall technique results in a strain power spectral density better than Sε(f) = (4.6 × 10-21) ε2/Hz in the frequency range from 1 Hz to 1 kHz, corresponding to a minimum dynamic strain resolution of 67.8 pε/√Hz. This frequency stabilized fiber laser is proposed to interrogate the sensing DFB fiber laser by the beat frequency principle. As a reasonable DFB fiber laser setup is realized, a narrow beat frequency line-width of 3.23 kHz and a high beat frequency stability of 0.036 MHz in 15 minutes are obtained in the laboratory test, corresponding to a minimum static strain resolution of 270 pε. This is the first time that a sub-0.5 nε level for static strain measurement using DFB fiber laser is demonstrated. PMID:27410147

  13. Impact of reperfusion therapy and infarct localization on frequency of premature ventricular beats in acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Davor Horvat

    2015-08-01

    Full Text Available Aim To determine the impact of infarct localization and types of reperfusion therapy on the frequency of ventricular premature beats (VPBs in patients with acute myocardial infarction (AMI and reduced left ventricular ejection fraction (LVEF. Methods A total of 705 patients with acute ST elevation myocardial infarction (STEMI were divided according to the infarct localization (anteroseptal, anterolateral, inferior and posterior and reperfusion therapy (fibrinolysis or percutaneous coronary intervention with stenting into two groups: LVEF45% was a control group. The occurrence of VPBs10 per hour defined as a significant. Results In patients with fibrinolysis therapy and LVEF<45% significant number of VPBs were in anteroseptal (p=0.017, anterolateral (p<0.001 and posterior AMI (p<0.001, but in patients with percutaneous coronary intervention (PCI and LVEF<45% significant number of VPBs were only in anteroseptal AMI (p=0.001 localization. Conclusion In patients with reduced ejection fraction in AMI, treatment with PCI method has a better antiarrhythmic effect compared to fibrinolysis treatment.

  14. Geometry of ciliary dynamics

    Science.gov (United States)

    Peterson, Mark A.

    2009-07-01

    Cilia are motile biological appendages that are driven to bend by internal shear stresses between tubulin filaments. A continuum model of ciliary material is constructed that incorporates the essential ciliary constraints: (i) one-dimensional inextensibility of filaments, (ii) three-dimensional incompressibility, and (iii) shear strain only longitudinally along filaments. It is shown that twist of filaments about each other is not an independent degree of freedom under ciliary constraints. The constraint on twist appears in the equations of motion for cilia as a term not previously recognized. As another application of the same geometrical idea, a general approach to the polymorphism of bacterial flagella is proposed.

  15. Highly sensitive liquid-level sensor based on dual-wavelength double-ring fiber laser assisted by beat frequency interrogation.

    Science.gov (United States)

    Dai, Yi; Sun, Qizhen; Tan, Sisi; Wo, Jianghai; Zhang, Jiejun; Liu, Deming

    2012-12-01

    A highly sensitive liquid-level sensor based on dual-wavelength single-longitudinal-mode fiber laser is proposed and demonstrated. The laser is formed by exploiting two parallel arranged phase-shift fiber Bragg gratings (ps-FBGs), acting as ultra-narrow bandwidth filters, into a double-ring resonators. By beating the dual-wavelength lasing output, a stable microwave signal with frequency stability better than 5 MHz is obtained. The generated beat frequency varies with the change of dual-wavelength spacing. Based on this characteristic, with one ps-FBG serving as the sensing element and the other one acting as the reference element, a highly sensitive liquid level sensor is realized by monitoring the beat frequency shift of the laser. The sensor head is directly bonded to a float which can transfer buoyancy into axial strain on the fiber without introducing other elastic elements. The experimental results show that an ultra-high liquid-level sensitivity of 2.12 × 10(7) MHz/m within the measurement range of 1.5 mm is achieved. The sensor presents multiple merits including ultra-high sensitivity, thermal insensitive, good reliability and stability.

  16. Resonant Bloch-wave beatings.

    Science.gov (United States)

    Kartashov, Yaroslav V; Vysloukh, Victor A; Torner, Lluis

    2014-07-01

    We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch oscillations that accompanies resonant conversion of modes guided by the individual waveguides. The Bloch-wave beatings are found to be most pronounced when the length of the resonant mode conversion substantially exceeds the longitudinal period of the Bloch oscillations. The beating frequency decreases when the amplitude of waveguide bending decreases, while the beating amplitude is restricted by the amplitude of the Bloch oscillations that emerge from the second allowed band of the Floquet-Bloch lattice spectrum.

  17. Resonant Bloch-wave beatings

    CERN Document Server

    Kartashov, Yaroslav V; Torner, Lluis

    2014-01-01

    We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch oscillations that accompanies resonant conversion of modes guided by the individual waveguides. The Bloch-wave beatings are found to be most pronounced when the length of the resonant mode conversion substantially exceeds the longitudinal period of the Bloch oscillations. The beating frequency decreases when the amplitude of waveguide bending decreases, while the beating amplitude is restricted by the amplitude of the Bloch oscillations that emerge from the second allowed band of the Floquet-Bloch lattice spectrum.

  18. Computational modelling elucidates the mechanism of ciliary regulation in health and disease

    Directory of Open Access Journals (Sweden)

    Hundhausen Christian

    2011-09-01

    Full Text Available Abstract Background Ciliary dysfunction leads to a number of human pathologies, including primary ciliary dyskinesia, nephronophthisis, situs inversus pathology or infertility. The mechanism of cilia beating regulation is complex and despite extensive experimental characterization remains poorly understood. We develop a detailed systems model for calcium, membrane potential and cyclic nucleotide-dependent ciliary motility regulation. Results The model describes the intimate relationship between calcium and potassium ionic concentrations inside and outside of cilia with membrane voltage and, for the first time, describes a novel type of ciliary excitability which plays the major role in ciliary movement regulation. Our model describes a mechanism that allows ciliary excitation to be robust over a wide physiological range of extracellular ionic concentrations. The model predicts the existence of several dynamic modes of ciliary regulation, such as the generation of intraciliary Ca2+ spike with amplitude proportional to the degree of membrane depolarization, the ability to maintain stable oscillations, monostable multivibrator regimes, all of which are initiated by variability in ionic concentrations that translate into altered membrane voltage. Conclusions Computational investigation of the model offers several new insights into the underlying molecular mechanisms of ciliary pathologies. According to our analysis, the reported dynamic regulatory modes can be a physiological reaction to alterations in the extracellular environment. However, modification of the dynamic modes, as a result of genetic mutations or environmental conditions, can cause a life threatening pathology.

  19. Primary ciliary dyskinesiatwo cases reports

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Rezaee1

    2009-01-01

    Full Text Available (Received 22 December, 2009 ; Accepted 10 March, 2010AbstractPrimary ciliary dyskinesia and Kartagener's syndrome are rare genetic disorders. There is a ciliary dysfunction in these disorders that cause recurrent infections in respiratory and sinus tracts associated with dextrocardia, chronic vasomotor rhinitis and dextrocardia. The aim of this paper is to report two rare cases of Primary ciliary dyskinesia, including one case of primary ciliary dyskinesia and Kartagener's syndrome for additional knowledge. J Mazand Univ Med Sci 2009; 19(73: 85-89 (Persian.

  20. Beat Dreams?

    DEFF Research Database (Denmark)

    Sørensen, Bent

    2009-01-01

    Two of the founding members of the Beat Generation of the 1950s wrote dream books with almost identical titles: Jack Kerouac's Book of Dreams (1961) and William Burroughs' My Education: A Book of Dreams (1995). This paper queries the function of such dream books, both from a perspective of seeing...... dream writing as a confessional genre, and from the perspective of didacticism implicit in sharing one's dream life with one's readers. What role does memory, politics, fantasies and reality play in communicating with and via dreams?...

  1. Suppression of optical beat interference-noise in orthogonal frequency division multiple access-passive optical network link using self-homodyne balanced detection

    Science.gov (United States)

    Won, Yong-Yuk; Jung, Sang-Min; Han, Sang-Kook

    2014-08-01

    A new technique, which reduces optical beat interference (OBI) noise in orthogonal frequency division multiple access-passive optical network (OFDMA-PON) links, is proposed. A self-homodyne balanced detection, which uses a single laser for the optical line terminal (OLT) as well as for the optical network unit (ONU), reduces OBI noise and also improves the signal to noise ratio (SNR) of the discrete multi-tone (DMT) signal. The proposed scheme is verified by transmitting quadrature phase shift keying (QPSK)-modulated DMT signal over a 20-km single mode fiber. The optical signal to noise ratio (OSNR), that is required for BER of 10-5, is reduced by 2 dB in the balanced detection compared with a single channel due to the cancellation of OBI noise in conjunction with the local laser.

  2. Primary Ciliary Dyskinesia.

    Science.gov (United States)

    Knowles, Michael R; Zariwala, Maimoona; Leigh, Margaret

    2016-09-01

    Primary ciliary dyskinesia (PCD) is a recessive genetically heterogeneous disorder of motile cilia with chronic otosinopulmonary disease and organ laterality defects in ∼50% of cases. The prevalence of PCD is difficult to determine. Recent diagnostic advances through measurement of nasal nitric oxide and genetic testing has allowed rigorous diagnoses and determination of a robust clinical phenotype, which includes neonatal respiratory distress, daily nasal congestion, and wet cough starting early in life, along with organ laterality defects. There is early onset of lung disease in PCD with abnormal airflow mechanics and radiographic abnormalities detected in infancy and early childhood. PMID:27514592

  3. Primary ciliary dyskinesia.

    Science.gov (United States)

    Lobo, Jason; Zariwala, Maimoona A; Noone, Peadar G

    2015-04-01

    Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder of cilia structure, function, and biogenesis leading to chronic infections of the respiratory tract, fertility problems, and disorders of organ laterality. The diagnosis can be challenging, using traditional tools such as characteristic clinical features, ciliary function, and ultrastructural defects and newer screening tools such as nasal nitric oxide levels and genetic testing add to the diagnostic algorithm. There are 32 known PCD-causing genes, and in the future, comprehensive genetic testing may screen young infants before developing symptoms, thus improving survival. Therapies include surveillance of pulmonary function and microbiology, in addition to airway clearance, antibiotics, and early referral to bronchiectasis centers. As with cystic fibrosis (CF), standardized care at specialized centers using a multidisciplinary approach likely improves outcomes. In conjunction with the CF foundation, the PCD foundation, with experienced investigators and clinicians, is developing a network of PCD clinical centers to coordinate the effort in North America and Europe. As the network grows, clinical care and knowledge will improve. PMID:25826585

  4. Psychophysiological reactivity to auditory Binaural Beats stimulation in the alpha and theta EEG brain-wave frequency bands: A randomized, double–blind and placebo–controlled study in human healthy young adult subjects

    OpenAIRE

    Pfaff, Hans Uwe

    2014-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Psicología, Departamento de Psicología Biológica y de la Salud. Fecha de lectura: 25-06-2014 Binaural beats are an acoustical illusion of the perception of a “virtual” third tone, fluctuating (i.e. beating) in its volume evoked by two carrier–sinusoids of same amplitudes, but slightly different frequencies f1 and f2, presented by stereo-headphones. Although this illusion was discovered as early as 1839 ...

  5. In time with rhythms : beat perception and sensorimotor synchronisation

    NARCIS (Netherlands)

    Schlichting, Nadine

    2015-01-01

    Music and beat perception are strongly connected to movement, a phenomenon known as sensorimotor synchronisation. Neurophysiologically, simple metronome-like beat sounds entrain neural oscillations, so that the brain oscillates with the same frequency as the beat frequency. The usefulness of being e

  6. Losing the beat: deficits in temporal coordination

    Science.gov (United States)

    Palmer, Caroline; Lidji, Pascale; Peretz, Isabelle

    2014-01-01

    Tapping or clapping to an auditory beat, an easy task for most individuals, reveals precise temporal synchronization with auditory patterns such as music, even in the presence of temporal fluctuations. Most models of beat-tracking rely on the theoretical concept of pulse: a perceived regular beat generated by an internal oscillation that forms the foundation of entrainment abilities. Although tapping to the beat is a natural sensorimotor activity for most individuals, not everyone can track an auditory beat. Recently, the case of Mathieu was documented (Phillips-Silver et al. 2011 Neuropsychologia 49, 961–969. (doi:10.1016/j.neuropsychologia.2011.02.002)). Mathieu presented himself as having difficulty following a beat and exhibited synchronization failures. We examined beat-tracking in normal control participants, Mathieu, and a second beat-deaf individual, who tapped with an auditory metronome in which unpredictable perturbations were introduced to disrupt entrainment. Both beat-deaf cases exhibited failures in error correction in response to the perturbation task while exhibiting normal spontaneous motor tempi (in the absence of an auditory stimulus), supporting a deficit specific to perception–action coupling. A damped harmonic oscillator model was applied to the temporal adaptation responses; the model's parameters of relaxation time and endogenous frequency accounted for differences between the beat-deaf cases as well as the control group individuals. PMID:25385783

  7. Elastic interactions synchronize beating in cardiomyocytes.

    Science.gov (United States)

    Cohen, Ohad; Safran, Samuel A

    2016-07-13

    Motivated by recent experimental results, we study theoretically the synchronization of the beating phase and frequency of two nearby cardiomyocyte cells. Each cell is represented as an oscillating force dipole in an infinite, viscoelastic medium and the propagation of the elastic signal within the medium is predicted. We examine the steady-state beating of two nearby cells, and show that elastic interactions result in forces that synchronize the phase and frequency of beating in a manner that depends on their mutual orientation. The theory predicts both in-phase and anti-phase steady-state beating depending on the relative cell orientations, as well as how synchronized beating varies with substrate elasticity and the inter-cell distance. These results suggest how mechanics plays a role in cardiac efficiency, and may be relevant for the design of cardiomyocyte based micro devices and other biomedical applications. PMID:27352146

  8. CCDC65 mutation causes primary ciliary dyskinesia with normal ultrastructure and hyperkinetic cilia.

    Directory of Open Access Journals (Sweden)

    Amjad Horani

    Full Text Available BACKGROUND: Primary ciliary dyskinesia (PCD is a genetic disorder characterized by impaired ciliary function, leading to chronic sinopulmonary disease. The genetic causes of PCD are still evolving, while the diagnosis is often dependent on finding a ciliary ultrastructural abnormality and immotile cilia. Here we report a novel gene associated with PCD but without ciliary ultrastructural abnormalities evident by transmission electron microscopy, but with dyskinetic cilia beating. METHODS: Genetic linkage analysis was performed in a family with a PCD subject. Gene expression was studied in Chlamydomonas reinhardtii and human airway epithelial cells, using RNA assays and immunostaining. The phenotypic effects of candidate gene mutations were determined in primary culture human tracheobronchial epithelial cells transduced with gene targeted shRNA sequences. Video-microscopy was used to evaluate cilia motion. RESULTS: A single novel mutation in CCDC65, which created a termination codon at position 293, was identified in a subject with typical clinical features of PCD. CCDC65, an orthologue of the Chlamydomonas nexin-dynein regulatory complex protein DRC2, was localized to the cilia of normal nasal epithelial cells but was absent in those from the proband. CCDC65 expression was up-regulated during ciliogenesis in cultured airway epithelial cells, as was DRC2 in C. reinhardtii following deflagellation. Nasal epithelial cells from the affected individual and CCDC65-specific shRNA transduced normal airway epithelial cells had stiff and dyskinetic cilia beating patterns compared to control cells. Moreover, Gas8, a nexin-dynein regulatory complex component previously identified to associate with CCDC65, was absent in airway cells from the PCD subject and CCDC65-silenced cells. CONCLUSION: Mutation in CCDC65, a nexin-dynein regulatory complex member, resulted in a frameshift mutation and PCD. The affected individual had altered cilia beating patterns, and

  9. Visualizing acoustical beats with a smartphones

    CERN Document Server

    Giménez, Marcos H; Castro-Palacio, Juan C; Gómez-Tejedor, José A; Monsoriu, Juan A

    2016-01-01

    In this work, a new Physics laboratory experiment on Acoustics beats is presented. We have designed a simple experimental setup to study superposition of sound waves of slightly different frequencies (acoustic beat). The microphone of a smartphone is used to capture the sound waves emitted by two equidistant speakers from the mobile which are at the same time connected to two AC generators. The smartphone is used as a measuring instrument. By means of a simple and free AndroidTM application, the sound level (in dB) as a function of time is measured and exported to a .csv format file. Applying common graphing analysis and a fitting procedure, the frequency of the beat is obtained. The beat frequencies as obtained from the smartphone data are compared with the difference of the frequencies set at the AC generator. A very good agreement is obtained being the percentage discrepancies within 1 %.

  10. Beat-to-Beat Blood Pressure Monitor

    Science.gov (United States)

    Lee, Yong Jin

    2012-01-01

    This device provides non-invasive beat-to-beat blood pressure measurements and can be worn over the upper arm for prolonged durations. Phase and waveform analyses are performed on filtered proximal and distal photoplethysmographic (PPG) waveforms obtained from the brachial artery. The phase analysis is used primarily for the computation of the mean arterial pressure, while the waveform analysis is used primarily to obtain the pulse pressure. Real-time compliance estimate is used to refine both the mean arterial and pulse pressures to provide the beat-to-beat blood pressure measurement. This wearable physiological monitor can be used to continuously observe the beat-to-beat blood pressure (B3P). It can be used to monitor the effect of prolonged exposures to reduced gravitational environments and the effectiveness of various countermeasures. A number of researchers have used pulse wave velocity (PWV) of blood in the arteries to infer the beat-to-beat blood pressure. There has been documentation of relative success, but a device that is able to provide the required accuracy and repeatability has not yet been developed. It has been demonstrated that an accurate and repeatable blood pressure measurement can be obtained by measuring the phase change (e.g., phase velocity), amplitude change, and distortion of the PPG waveforms along the brachial artery. The approach is based on comparing the full PPG waveform between two points along the artery rather than measuring the time-of-flight. Minimizing the measurement separation and confining the measurement area to a single, well-defined artery allows the waveform to retain the general shape between the two measurement points. This allows signal processing of waveforms to determine the phase and amplitude changes. Photoplethysmography, which measures changes in arterial blood volume, is commonly used to obtain heart rate and blood oxygen saturation. The digitized PPG signals are used as inputs into the beat-to-beat blood

  11. Discussion on Improving the Light Beat-Frequency Methods Measuring the Speed of Light%光拍频法测光速实验的改进方法探讨

    Institute of Scientific and Technical Information of China (English)

    刘志军

    2014-01-01

    Measuring the speed of light with light beat-frequency method is one accomplished by measuring the speed of light beat-frequency and then indicating the speed of light indirectly. This article analyzes the principle and procedure of this method in detail. Adhere strictly to the principle of measuring the speed of light with light beat-frequency methods, it proposes some scientific and reasonable opinion based on studying the main problems and difficulties in the experiment.%光拍频法测光速是一种通过测量光拍的速度进而间接测量光速的方法。详细分析光拍频法测光速实验的实验原理和过程,在对实验方法中主要面临的问题和困难进行分析的基础上,忠实原有实验原理,提出了较为科学合理的实验改进意见和构想。

  12. Association between frequency of atrial and ventricular ectopic beats and biventricular pacing percentage and outcomes in patients with cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Ruwald, Martin H; Mittal, Suneet; Ruwald, Anne-Christine;

    2014-01-01

    -defibrillator device with data available on biventricular pacing percentage and pre-implantation 24-h Holter recordings were included. Using logistic regression, we estimated the influence of ectopic beats on the percentage of biventricular pacing. Reverse remodeling was measured as reductions in atrial and left...... ventricular end-systolic volumes (LVESV) at 1 year. Cox models were used to assess the influence of ectopic beats on the outcomes of heart failure (HF) or death, ventricular tachyarrhythmias (VTAs), and death. RESULTS: In the pre-implantation Holter recording, ectopic beats accounted for a mean 3.2 ± 5...... biventricular pacing (Holter monitoring of patients selected for CRT for optimal outcome. (MADIT-CRT: Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization...

  13. Beat-to-Beat Blood Pressure Monitor

    Science.gov (United States)

    Lee, Yong Jin

    2012-01-01

    This device provides non-invasive beat-to-beat blood pressure measurements and can be worn over the upper arm for prolonged durations. Phase and waveform analyses are performed on filtered proximal and distal photoplethysmographic (PPG) waveforms obtained from the brachial artery. The phase analysis is used primarily for the computation of the mean arterial pressure, while the waveform analysis is used primarily to obtain the pulse pressure. Real-time compliance estimate is used to refine both the mean arterial and pulse pressures to provide the beat-to-beat blood pressure measurement. This wearable physiological monitor can be used to continuously observe the beat-to-beat blood pressure (B3P). It can be used to monitor the effect of prolonged exposures to reduced gravitational environments and the effectiveness of various countermeasures. A number of researchers have used pulse wave velocity (PWV) of blood in the arteries to infer the beat-to-beat blood pressure. There has been documentation of relative success, but a device that is able to provide the required accuracy and repeatability has not yet been developed. It has been demonstrated that an accurate and repeatable blood pressure measurement can be obtained by measuring the phase change (e.g., phase velocity), amplitude change, and distortion of the PPG waveforms along the brachial artery. The approach is based on comparing the full PPG waveform between two points along the artery rather than measuring the time-of-flight. Minimizing the measurement separation and confining the measurement area to a single, well-defined artery allows the waveform to retain the general shape between the two measurement points. This allows signal processing of waveforms to determine the phase and amplitude changes.

  14. Plasma Beat-Wave Acceleration

    Science.gov (United States)

    Clayton, Christopher E.

    2002-04-01

    Among all the advanced accelerator concepts that use lasers as the power source, most of the effort to date has been with the idea of using a laser pulse to excite a accelerating mode in a plasma. Within this area, there are a variety of approaches for creating the accelerating mode, as indicated by the other talks in this session. What is common to these approaches is the physics of how a laser pulse pushes on plasma electrons to organize electron-density perturbations, the sources of the ultra-high (> GeV/M) accelerating gradients. It is the "ponderomotive force", proportional to the local gradient of the of the laser intensity, that pushes plasma electrons forward (on the leading edge of the pulse) and backwards (on the trailing edge) which leads to harmonic motion of the electrons. As the laser pulse moves through the plasma at group velocity Vg c, the oscillating electrons show up macroscopically as a plasma mode or wave with frequency w equal to the plasma frequency and k = w/Vg. For short laser pulses, this is the Laser Wakefield Accelerator (LWFA) concept. Closely related is the Plasma Beat-Wave Acceleration (PBWA) concept. Here, the laser pulse that perturbs the plasma is composed of two closely-spaced frequencies that "beat", i.e., periodically constructively and destructively interfere, forming an electromagnetic beat wave. One can visualize this as a train of short pulses. If this beating frequency is set to the plasma frequency, then each pulse in the train will reinforce the density perturbation caused by the previous pulse. The principal advantage of multiple pulses driving up the plasma wave as opposed to a single pulse is in efficiency, allowing for the production of relatively large diameter (more 1-D like) accelerating modes. In this talk I will discuss past, current and planned PBWA experiments which are taking place at UCLA, RAL in England, and LULI in France.

  15. Reversal of Dilated Cardiomyopathy After Successful Radio-Frequency Ablation of Frequent Atrial Premature Beats, a New Cause for Arrhythmia-Induced Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Paul Louis Vervueren, MD

    2012-12-01

    Full Text Available Incessant atrial premature beats as a potential cause for tachycardia-induced cardiomyopathy was suspected in a patient presenting with dilated non-ischemic cardiomyopathy and severely altered left ventricular ejection fraction. The elimination of a left atrial focus by percutaneous RF ablation led to normalization of the clinical status, of atrial and ventricular dimensions and left ventricular systolic function.

  16. Optical Beat-Wave Experiment on CTIX

    Science.gov (United States)

    Horton, Robert; Hwang, David; Liu, Fei; Zhu, Ben; Evans, Russell

    2009-11-01

    By launching intense electromagnetic waves at differing frequencies, a wave at the beat (difference) frequency can be created within a region of plasma. The beat wave is efficiently damped, and electron current generated, if the beat frequency is close to local plasma frequency, and if phase velocity is close to electron thermal velocity. Beat-wave acceleration of plasma electrons was previously demonstrated at low plasma density [1]. At the higher densities of the CTIX compact-toroid accelerator, plasma frequencies are such that CO2 lasers (f 30 THz) are a cost-effective driver. An experiment is being prepared to test beat-wave current drive using two TEA CO2 lasers on CTIX. The experiment will test models of wave mixing, quasilinear modification of the velocity distribution, and amplification of seed current by plasma kinetic effects. An application of the methods developed may be standoff current generation in a target plasma. Experimental issues to be addressed include: precisely-timed production of the compressed, target plasma; grating tuning of the CO2 lasers for frequency selection; high-peak-power, simultaneous operation of TEA lasers, design of optics; optical and plasma diagnostics. Initial results will be presented.[4pt] [1] Rogers, J. H. and Hwang, D. Q., Phys. Rev. Lett. v68 p3877 (1992).

  17. Nonlinear amplitude dynamics in flagellar beating

    CERN Document Server

    Oriola, David; Casademunt, Jaume

    2016-01-01

    The physical basis of flagellar and ciliary beating is a major problem in biology which is still far from completely understood. The fundamental cytoskeleton structure of cilia and flagella is the axoneme, a cylindrical array of microtubule doublets connected by passive crosslinkers and dynein motor proteins. The complex interplay of these elements leads to the generation of self-organized bending waves. Although many mathematical models have been proposed to understand this process, few attempts have been made to assess the role of dyneins on the nonlinear nature of the axoneme. Here, we investigate the nonlinear dynamics of flagella by considering an axonemal sliding control mechanism for dynein activity. This approach unveils the nonlinear selection of the oscillation amplitudes, which are typically either missed or prescribed in mathematical models. The explicit set of nonlinear equations are derived and solved numerically. Our analysis reveals the spatiotemporal dynamics of dynein populations and flagell...

  18. Selective particle capture by asynchronously beating cilia

    Science.gov (United States)

    Ding, Yang; Kanso, Eva

    2015-12-01

    Selective particle filtration is fundamental in many engineering and biological systems. For example, many aquatic microorganisms use filter feeding to capture food particles from the surrounding fluid, using motile cilia. One of the capture strategies is to use the same cilia to generate feeding currents and to intercept particles when the particles are on the downstream side of the cilia. Here, we develop a 3D computational model of ciliary bands interacting with flow suspended particles and calculate particle trajectories for a range of particle sizes. Consistent with experimental observations, we find optimal particle sizes that maximize capture rate. The optimal size depends nonlinearly on cilia spacing and cilia coordination, synchronous vs. asynchronous. These parameters affect the cilia-generated flow field, which in turn affects particle trajectories. The low capture rate of smaller particles is due to the particles' inability to cross the flow streamlines of neighboring cilia. Meanwhile, large particles have difficulty entering the sub-ciliary region once advected downstream, also resulting in low capture rates. The optimal range of particle sizes is enhanced when cilia beat asynchronously. These findings have potentially important implications on the design and use of biomimetic cilia in processes such as particle sorting in microfluidic devices.

  19. Mutations in ZMYND10, a gene essential for proper axonemal assembly of inner and outer dynein arms in humans and flies, cause primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Moore, Daniel J; Onoufriadis, Alexandros; Shoemark, Amelia;

    2013-01-01

    Primary ciliary dyskinesia (PCD) is a ciliopathy characterized by airway disease, infertility, and laterality defects, often caused by dual loss of the inner dynein arms (IDAs) and outer dynein arms (ODAs), which power cilia and flagella beating. Using whole-exome and candidate-gene Sanger resequ...

  20. Odor detection in Manduca sexta is optimized when odor stimuli are pulsed at a frequency matching the wing beat during flight.

    Directory of Open Access Journals (Sweden)

    Kevin C Daly

    Full Text Available Sensory systems sample the external world actively, within the context of self-motion induced disturbances. Mammals sample olfactory cues within the context of respiratory cycles and have adapted to process olfactory information within the time frame of a single sniff cycle. In plume tracking insects, it remains unknown whether olfactory processing is adapted to wing beating, which causes similar physical effects as sniffing. To explore this we first characterized the physical properties of our odor delivery system using hotwire anemometry and photo ionization detection, which confirmed that odor stimuli were temporally structured. Electroantennograms confirmed that pulse trains were tracked physiologically. Next, we quantified odor detection in moths in a series of psychophysical experiments to determine whether pulsing odor affected acuity. Moths were first conditioned to respond to a target odorant using Pavlovian olfactory conditioning. At 24 and 48 h after conditioning, moths were tested with a dilution series of the conditioned odor. On separate days odor was presented either continuously or as 20 Hz pulse trains to simulate wing beating effects. We varied pulse train duty cycle, olfactometer outflow velocity, pulsing method, and odor. Results of these studies, established that detection was enhanced when odors were pulsed. Higher velocity and briefer pulses also enhanced detection. Post hoc analysis indicated enhanced detection was the result of a significantly lower behavioral response to blank stimuli when presented as pulse trains. Since blank responses are a measure of false positive responses, this suggests that the olfactory system makes fewer errors (i.e. is more reliable when odors are experienced as pulse trains. We therefore postulate that the olfactory system of Manduca sexta may have evolved mechanisms to enhance odor detection during flight, where the effects of wing beating represent the norm. This system may even exploit

  1. Vortex arrays and ciliary tangles underlie the feeding-swimming tradeoff in starfish larvae

    CERN Document Server

    Gilpin, William; Prakash, Manu

    2016-01-01

    Many marine invertebrates have larval stages covered in linear arrays of beating cilia, which propel the animal while simultaneously entraining planktonic prey. These bands are strongly conserved across taxa spanning four major superphyla, and they are responsible for the unusual morphologies of many invertebrates. However, few studies have investigated their underlying hydrodynamics. Here, we study the ciliary bands of starfish larvae, and discover a beautiful pattern of slowly-evolving vortices that surrounds the swimming animals. Closer inspection of the bands reveals unusual ciliary "tangles" analogous to topological defects that break-up and re-form as the animal adjusts its swimming stroke. Quantitative experiments and modeling suggest that these vortices create a physical tradeoff between feeding and swimming, which manifests as distinct flow patterns or "eigenstrokes" representing each behavior---potentially implicating neuronal control of cilia. This quantitative interplay between larval form and hyd...

  2. Sperm-associated antigen 6 (SPAG6 deficiency and defects in ciliogenesis and cilia function: polarity, density, and beat.

    Directory of Open Access Journals (Sweden)

    Maria E Teves

    Full Text Available SPAG6, an axoneme central apparatus protein, is essential for function of ependymal cell cilia and sperm flagella. A significant number of Spag6-deficient mice die with hydrocephalus, and surviving males are sterile because of sperm motility defects. In further exploring the ciliary dysfunction in Spag6-null mice, we discovered that cilia beat frequency was significantly reduced in tracheal epithelial cells, and that the beat was not synchronized. There was also a significant reduction in cilia density in both brain ependymal and trachea epithelial cells, and cilia arrays were disorganized. The orientation of basal feet, which determines the direction of axoneme orientation, was apparently random in Spag6-deficient mice, and there were reduced numbers of basal feet, consistent with reduced cilia density. The polarized epithelial cell morphology and distribution of intracellular mucin, α-tubulin, and the planar cell polarity protein, Vangl2, were lost in Spag6-deficient tracheal epithelial cells. Polarized epithelial cell morphology and polarized distribution of α-tubulin in tracheal epithelial cells was observed in one-week old wild-type mice, but not in the Spag6-deficient mice of the same age. Thus, the cilia and polarity defects appear prior to 7 days post-partum. These findings suggest that SPAG6 not only regulates cilia/flagellar motility, but that in its absence, ciliogenesis, axoneme orientation, and tracheal epithelial cell polarity are altered.

  3. The impact of binaural beats on creativity

    Directory of Open Access Journals (Sweden)

    Susan A. Reedijk

    2013-11-01

    Full Text Available Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and whether possible effects may be mediated by the individual striatal dopamine level. Binaural beats were presented at alpha and gamma frequency. Participants completed a divergent and a convergent thinking task to assess two important functions of creativity, and filled out the Positive And Negative Affect Scale – mood State questionnaire (PANAS-S and affect grid to measure current mood. Dopamine levels in the striatum were estimated using spontaneous eye blink rates (EBRs. Results showed that binaural beats, regardless of the presented frequency, can affect divergent but not convergent thinking. Individuals with low EBRs mostly benefitted from alpha binaural beat stimulation, while individuals with high EBR were unaffected or even impaired by both alpha and gamma binaural beats. This suggests that binaural beats, and possibly other forms of cognitive entrainment, are not suited for a one-size-fits-all approach, and that individual cognitive-control systems need to be taken into account when studying cognitive enhancement methods.

  4. CCDC39 is required for assembly of inner dynein arms and the dynein regulatory complex and for normal ciliary motility in humans and dogs

    DEFF Research Database (Denmark)

    Merveille, Anne-Christine; Davis, Erica E; Becker-Heck, Anita;

    2011-01-01

    -assembly factors of axonemal dyneins, but these mutations account for only about 50% of cases of PCD. We exploited the unique properties of dog populations to positionally clone a new PCD gene, CCDC39. We found that loss-of-function mutations in the human ortholog underlie a substantial fraction of PCD cases...... with axonemal disorganization and abnormal ciliary beating. Functional analyses indicated that CCDC39 localizes to ciliary axonemes and is essential for assembly of inner dynein arms and the dynein regulatory complex....

  5. Research progress of airway ciliary function and related respiratory diseases%气道纤毛功能及相关呼吸系统疾病研究进展

    Institute of Scientific and Technical Information of China (English)

    冯宇; 李庆云; 刘嘉琳; 万欢英

    2010-01-01

    The normal mucociliary clearance system (MCC) requires not only mucus with optimum of viscoelastic and thickness, but also enough cilia with structural integrity and sufficient cilia beat frequency(CBF). Abnormality of ciliary structure and function, CBF or surface properties of mucus was found in several respiratory diseases, such as chronic obstructive pulmonary diseases, primary ciliary dyskinesia,cystic fibrosis,etc. Which implies the MCC should be new area for research on treatment of respiratory diseases. The review will focus on the research progress of airway ciliary function and related respiratory diseases.%正常的黏液纤毛清除功能要求黏液具有最佳的黏弹性和厚度,而足够数量、结构完整和一定摆动频率的纤毛则更重要.由于慢性阻塞性肺疾病,原发性纤毛运动障碍、囊性纤维化等多种疾病均存在纤毛结构和功能异常或纤毛周围的黏液流变学特征改变,因此气道黏液纤毛清除功能成为探索相关治疗的新领域之一.本文就影响纤毛结构及运动的因素及相关的呼吸系统疾病的研究进展作综述.

  6. Wearable Beat to Beat Blood Pressure Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A key component of NASA's human exploration programs is a system that monitors the health of the crew during space missions. The wearable beat-to-beat blood...

  7. Analysis of Axonemal Assembly During Ciliary Regeneration in Chlamydomonas.

    Science.gov (United States)

    Hunter, Emily L; Sale, Winfield S; Alford, Lea M

    2016-01-01

    Chlamydomonas reinhardtii is an outstanding model genetic organism for study of assembly of cilia. Here, methods are described for synchronization of ciliary regeneration in Chlamydomonas to analyze the sequence in which ciliary proteins assemble. In addition, the methods described allow analysis of the mechanisms involved in regulation of ciliary length, the proteins required for ciliary assembly, and the temporal expression of genes encoding ciliary proteins. Ultimately, these methods can contribute to discovery of conserved genes that when defective lead to abnormal ciliary assembly and human disease. PMID:27514926

  8. Non-typeable Haemophilus influenzae decreases cilia beating via protein kinase C epsilon

    Directory of Open Access Journals (Sweden)

    Bailey Kristina L

    2012-06-01

    Full Text Available Abstract Background Haemophilus influenzae infection of the nasal epithelium has long been associated with observations of decreased nasal ciliary beat frequency (CBF and injury to the ciliated epithelium. Previously, we have reported that several agents that slow CBF also have the effect of activating protein kinase C epsilon (PKCϵ activity in bronchial epithelial cells. The subsequent auto-downregulation of PKCϵ or the direct inhibition of PKCϵ leads to the specific detachment of the ciliated cells. METHODS: Primary cultures of ciliated bovine bronchial epithelial cells were exposed to filtered conditioned media supernatants from non-typeable H. influenzae (NTHi cultures. CBF and motile points were measured and PKCϵ activity assayed. Results NTHi supernatant exposure significantly and rapidly decreased CBF in a dose-dependent manner within 10 minutes of exposure. After 3 hours of exposure, the number of motile ciliated cells significantly decreased. Direct measurement of PKCϵ activity revealed a dose-dependent activation of PKCϵ in response to NTHi supernatant exposure. Both CBF and PKCϵ activity changes were only observed in fresh NTHi culture supernatant and not observed in exposures to heat-inactivated or frozen supernatants. Conclusions Our results suggest that CBF slowing observed in response to NTHi is consistent with the stimulated activation of PKCϵ. Ciliated cell detachment is associated with PKCϵ autodownregulation.

  9. Off beat: pluralizing rhythm

    NARCIS (Netherlands)

    J.H. Hoogstad; B. Stougaard Pedersen

    2013-01-01

    Off Beat: Pluralizing Rhythm draws attention to rhythm as a tool for analyzing various cultural objects. In fields as diverse as music, culture, nature, and economy, rhythm can be seen as a phenomenon that both connects and divides. It suggests a certain measure with which people, practices, and cul

  10. Investigation of beat-waves generation with high efficiency

    International Nuclear Information System (INIS)

    A method for generating high power beating radio-frequency wave with high conversion efficiency is proposed. Based on Cherenkov radiation, two longitudinal resonant modes are excited simultaneously and interacted with intense electron beam synchronously. An experiment was carried out and beat-waves with an average power of about 2.3 GW, frequencies of 9.29 GHz and 10.31 GHz, and efficiency of about 40% were obtained. Through controlling the electron energy, the amplitude proportions of the two resonant modes are altered, and different beat-wave patterns are formed

  11. Investigation of beat-waves generation with high efficiency

    Science.gov (United States)

    Song, W.; Shi, Y. C.; Deng, Y. Q.; Zhu, X. X.; Zhang, Z. Q.; Hu, X. G.

    2013-10-01

    A method for generating high power beating radio-frequency wave with high conversion efficiency is proposed. Based on Cherenkov radiation, two longitudinal resonant modes are excited simultaneously and interacted with intense electron beam synchronously. An experiment was carried out and beat-waves with an average power of about 2.3 GW, frequencies of 9.29 GHz and 10.31 GHz, and efficiency of about 40% were obtained. Through controlling the electron energy, the amplitude proportions of the two resonant modes are altered, and different beat-wave patterns are formed.

  12. Investigation of beat-waves generation with high efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Song, W.; Shi, Y. C.; Deng, Y. Q.; Zhu, X. X.; Zhang, Z. Q.; Hu, X. G. [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi' an, Shanxi 710024 (China)

    2013-10-21

    A method for generating high power beating radio-frequency wave with high conversion efficiency is proposed. Based on Cherenkov radiation, two longitudinal resonant modes are excited simultaneously and interacted with intense electron beam synchronously. An experiment was carried out and beat-waves with an average power of about 2.3 GW, frequencies of 9.29 GHz and 10.31 GHz, and efficiency of about 40% were obtained. Through controlling the electron energy, the amplitude proportions of the two resonant modes are altered, and different beat-wave patterns are formed.

  13. Research on Beat-less Control Strategy Based on Frequency Domain Analysis%基于频域分析的无拍频控制策略研究

    Institute of Scientific and Technical Information of China (English)

    董侃; 刁利军; 陈奕舟; 赵雷廷; 刘志刚

    2015-01-01

    动车组牵引传动系统由于单相脉冲整流器的引入,使直流环节存在2倍频脉动电压。该脉动电压会在电机侧产生拍频现象,引起电机转矩和电流脉动。本文分析产生拍频现象的原因,并通过对传动系统进行数学建模,得到电机转矩脉动和电机电流脉动与脉动电压的关系,采用一种基于频域分析的无拍频控制策略,通过加入一个补偿环节,根据脉动电压对电机转差频率进行修正,消除直流电压脉动引起的电机转矩和电流脉动,并通过仿真和实验对该方法进行了验证。%Because of the configuration of the single‐phase PWM converter in the traction drive system of EMU ,there exists a voltage ripple in the DC‐link ,which is twice the frequency of the grid .The DC ripple voltage will generate beat phenomenon at the motor ,and cause torque and current pulsation .In this paper ,the origin of the fluctuating DC volt‐age or beat phenomenon was analyzed ,and the relations among the motor torque ripple ,the motor current ripple and the DC voltage ripple were derived from the analytical model of the traction drive system .A beat‐less control scheme based on the frequency domain analysis was proposed .By adding a compensation link ,the slip frequency of the motor was modified in consistence with the ripple voltage ,to eliminate the torque and current ripple caused by DC voltage rip‐ple .The algorithm was verified by simulation and experiment .

  14. 基于摆频控制的鱼群自主游动数值模拟研究%Numerical simulating of self-propelled bionic fish swimming based on tail-beat frequency control method

    Institute of Scientific and Technical Information of China (English)

    王亮

    2013-01-01

    A novel numerical method used to simulate the self-propelled fish swimming is proposed.The self-propelled state is obtained by controlling the tail-beat frequency,so the novel method is called frequency control method (FCM).The governing equation of the FCM is derived from the approximate relation between the self-propelled swimming speed and the tail-beat frequency and the Newton's second law.The new method is validated by comparing the results obtained by the FCM with those achieved by the conventional speed control method (SCM,the swimming speed of SCM is determined by the Newton's second law).Both results are consistent with each other.In addition,the convergence rate of the FCM is also discussed and the optimal parameter is suggested.Finally,a fish school consisting of three self-propelled bionic fishes as a basic element,at Re=5000,have been numerically investigated.It is revealed that the energy consumption decreases 19% and the Froude efficiency increases 36% in average,respectively.%本文提出了一种通过控制仿生鱼摆频来达到自主推进状态的数值模拟新方法(简称摆频控制法),并利用自主游动速度与摆频之间的近似关系以及牛顿第二定律推导出了摆频的控制方程.通过与传统的速度控制法(仿生鱼的自主游动速度由牛顿第二定律确定)的比较,验证了该方法的可靠性,并对影响该方法收敛速度的敏感因子进行了讨论,给出了最优参数,并通过模拟三条仿生鱼组成的鱼群基本单位在Re=5000时的自主游动,证明了摆频控制方法在鱼群自主游动数值模拟中的有效性.结果表明,鱼群整体平均节能约19%,推进效率平均提高了约36%.

  15. Modeling of Nonlinear Beat Signals of TAE's

    Science.gov (United States)

    Zhang, Bo; Berk, Herbert; Breizman, Boris; Zheng, Linjin

    2012-03-01

    Experiments on Alcator C-Mod reveal Toroidal Alfven Eigenmodes (TAE) together with signals at various beat frequencies, including those at twice the mode frequency. The beat frequencies are sidebands driven by quadratic nonlinear terms in the MHD equations. These nonlinear sidebands have not yet been quantified by any existing codes. We extend the AEGIS code to capture nonlinear effects by treating the nonlinear terms as a driving source in the linear MHD solver. Our goal is to compute the spatial structure of the sidebands for realistic geometry and q-profile, which can be directly compared with experiment in order to interpret the phase contrast imaging diagnostic measurements and to enable the quantitative determination of the Alfven wave amplitude in the plasma core

  16. beat a dead horse

    Institute of Scientific and Technical Information of China (English)

    吕浙

    2005-01-01

    beat a dead horse的字面意思为“鞭打死马”。“鞭打死马”有什么作用?毫无疑问,一点意义也没有。因此,该习语的意思相当于中文的“徒劳,白费力气,白费口舌”。如:

  17. Primary ciliary dyskinesia: clinical and genetic aspects

    Directory of Open Access Journals (Sweden)

    E. D’Auria

    2012-06-01

    Full Text Available Primary ciliary dyskinesia (PCD is a rare, genetically heterogeneous disease, characterized by ciliary disfunction and impaired mucociliary clearance, resulting in a range of clinical manifestations such as chronic bronchitis, bronchiectasis, chronic rhino-sinusitis, chronic otitis media, situs viscerum inversus in almost 40-50% of cases and male infertility. The triad situs viscerum inversus, bronchiectasis and sinusitis is known as Kartagener syndrome. Up to now little is known about genetic, diagnostic and therapeutic aspects of primary motile ciliary diseases in children: for this reason, diagnosis is generally delayed and almost all treatments for PCD are not based on randomized studies but extrapolated from cystic fibrosis guidelines. The aim of this review is to propose to pediatricians a summary of current clinical and diagnostic evidence to obtain better knoledwge of this condition. The earlier diagnosis and the right treatment are both crucial to improve the prognosis of PCD.

  18. CCDC151 mutations cause primary ciliary dyskinesia by disruption of the outer dynein arm docking complex formation

    DEFF Research Database (Denmark)

    Hjeij, Rim; Onoufriadis, Alexandros; Watson, Christopher M;

    2014-01-01

    disorder of ciliary and flagellar dysmotility characterized by chronic upper and lower respiratory infections and defects in laterality. Here, by combined high-throughput mapping and sequencing, we identified CCDC151 loss-of-function mutations in five affected individuals from three independent families...... whose cilia showed a complete loss of ODAs and severely impaired ciliary beating. Consistent with the laterality defects observed in these individuals, we found Ccdc151 expressed in vertebrate left-right organizers. Homozygous zebrafish ccdc151(ts272a) and mouse Ccdc151(Snbl) mutants display a spectrum...... of situs defects associated with complex heart defects. We demonstrate that CCDC151 encodes an axonemal coiled coil protein, mutations in which abolish assembly of CCDC151 into respiratory cilia and cause a failure in axonemal assembly of the ODA component DNAH5 and the ODA-DC-associated components CCDC114...

  19. Mechanical communication in cardiac cell synchronized beating

    Science.gov (United States)

    Nitsan, Ido; Drori, Stavit; Lewis, Yair E.; Cohen, Shlomi; Tzlil, Shelly

    2016-05-01

    Cell-cell communication, which enables cells to coordinate their activity and is essential for growth, development and function, is usually ascribed a chemical or electrical origin. However, cells can exert forces and respond to environment elasticity and to mechanical deformations created by their neighbours. The extent to which this mechanosensing ability facilitates intercellular communication remains unclear. Here we demonstrate mechanical communication between cells directly for the first time, providing evidence for a long-range interaction that induces long-lasting alterations in interacting cells. We show that an isolated cardiac cell can be trained to beat at a given frequency by mechanically stimulating the underlying substrate. Deformations are induced using an oscillatory mechanical probe that mimics the deformations generated by a beating neighbouring cardiac cell. Unlike electrical field stimulation, the probe-induced beating rate is maintained by the cell for an hour after the stimulation stops, implying that long-term modifications occur within the cell. These long-term alterations provide a mechanism for cells that communicate mechanically to be less variable in their electromechanical delay. Mechanical coupling between cells therefore ensures that the final outcome of action potential pacing is synchronized beating. We further show that the contractile machinery is essential for mechanical communication.

  20. Conditional control of quantum beats in a cavity QED system

    CERN Document Server

    Norris, D G; Orozco, L A; 10.1088/1742-6596/274/1/012143

    2011-01-01

    We probe a ground-state superposition that produces a quantum beat in the intensity correlation of a two-mode cavity QED system. We mix drive with scattered light from an atomic beam traversing the cavity, and effectively measure the interference between the drive and the light from the atom. When a photon escapes the cavity, and upon detection, it triggers our feedback which modulates the drive at the same beat frequency but opposite phase for a given time window. This results in a partial interruption of the beat oscillation in the correlation function, that then returns to oscillate.

  1. A safe method of ciliary sulcus fixation of foldable intraocular lens using a ciliary sulcus guide.

    Science.gov (United States)

    Can, Ertuğrul; Gül, Adem; Birinci, Hakkı

    2016-08-01

    To describe a novel technique for implantation of intraocular lens in the absence of capsular support using a ciliary sulcus guide. Based on the anatomic knowledge of the ciliary sulcus and the sclera, a new instrument was developed to pierce the needle safely through the ciliary sulcus and sclera. While the foldable lens is stored inside the cartridge, the leading haptic is sutured with a cow-hitch knot. The needle is then inserted into the ciliary sulcus guide. The tip of the guide is inserted from the corneal incision and proceeded under the iris to touch and fit the ciliary sulcus. The needle is pushed from back side. The needle comes out at precise point at the sclera. Implantation of the lens was performed through a 2.8 mm clear cornea incision using the injector. The trailing haptic is tied after implantation, and then the same procedure is performed at the opposite side. We performed this technique to 15 aphakic eyes without sufficient capsular support. There was no bleeding or other intraoperative complication. All the points coming out the sclera were between 2 and 2.5 mm from the limbus. The ab interno technique for scleral fixation of IOL is quicker, easier and less traumatic then ab externo techniques. A new ciliary sulcus guide which is usable with both straight and curved needles eliminates the blind maneuvers of ab interno technique and makes this technique more safe and precise.

  2. Beat wave development work

    International Nuclear Information System (INIS)

    The first phase of experiments on beat wave acceleration have been completed at UCLA. Here we examined the suitability of a theta pinch as a plasma source. The beatwave was excited to amplitudes providing GeV/m-scale accelerating fields. However, trapped magnetic fields within the theta-pinch plasma hindered the injection of test particles. Optical diagnostics were developed to measure the accelerating gradient-length product which was found to be around 3 MeV. Future plans are also discussed. copyright 1989 American Institute of Physics

  3. Direct visualization of mechanical beats by means of an oscillating smartphone

    CERN Document Server

    Giménez, Marcos H; Monsoriu, Juan A

    2016-01-01

    The resonance phenomenon is widely known from Physics courses. Qualitatively speaking, it takes place in a driven oscillating system whenever the driven frequency approaches the natural frequency. It is when the amplitude of the oscillations become maximal. Very closely related to this phenomenon, there is another which is very surprising too. It takes place when the driven and natural frequencies of the system are slightly different and interfere constructively and destructively, forming the so called beats. The frequency of the beats is just the difference of the interfering waves frequencies. Beats are very noticeable in acoustic systems. We all have probably perceived them in the form of periodic ups and downs in the sound intensity volume. There are several works in this journal on visualizing the beats in acoustic systems. For instance, the microphone and the speaker of two mobile devices were used in previous work to analyze the acoustic beat produced by two signals of close frequencies. The formation ...

  4. Fourier analysis of wing beat signals: assessing the effects of genetic alterations of flight muscle structure in Diptera.

    OpenAIRE

    Hyatt, C J; Maughan, D W

    1994-01-01

    A method for determining and analyzing the wing beat frequency in Diptera is presented. This method uses an optical tachometer to measure Diptera wing movement during flight. The resulting signal from the optical measurement is analyzed using a Fast Fourier Transform (FFT) technique, and the dominant frequency peak in the Fourier spectrum is selected as the wing beat frequency. Also described is a method for determining quantitatively the degree of variability of the wing beat frequency about...

  5. Masses for Galactic Beat Cepheids

    Science.gov (United States)

    D'Cruz, Noella L.; Morgan, Siobahn M.; Böhm-Vitense, Erika

    2000-08-01

    Accurate mass determinations for Cepheids may be used to determine the degree of excess mixing in the interiors of their main-sequence progenitors: the larger the excess mixing, the larger the luminosity of the Cepheid of a given mass, or the smaller the mass of a Cepheid with given luminosity. Dynamical masses determined recently for a few Cepheid binaries indicate excess mixing somewhat stronger than that corresponding to the convective overshoot models by Schaller et al. Beat Cepheids can be used similarly to test main-sequence mixing in stellar interiors. The period ratios for beat Cepheids depend on luminosity, Teff, heavy element abundance, and mass. By comparing pulsational models and the observationally derived luminosity, Teff, metallicities, and period ratios it is possible to obtain masses for these stars, the so-called beat masses. With the old opacities masses much smaller than the evolutionary masses were obtained. With the new OPAL opacities a beat mass close to the dynamical mass was obtained for the binary beat Cepheid Y Carinae, showing that it is now possible to obtain reliable beat masses. In this paper, we determine beat masses for seven Galactic beat Cepheids for which photometric and spectroscopic data are available. We find an average mass around 4.2+/-0.3 Msolar for these stars, though the actual error limits for each star may be larger mainly because of uncertainties in E(B-V) and the heavy element abundances. (As derived spectroscopically, beat Cepheids are in general metal-poor, with -0.4relation between the derived beat masses and the luminosities again indicates excess mixing that is somewhat larger than that corresponding to the models by Schaller et al.

  6. Modulation of attosecond beating in resonant two-photon ionization

    CERN Document Server

    Galán, Álvaro J; Martín, Fernando

    2014-01-01

    We present a theoretical study of the photoelectron attosecond beating at the basis of RABBIT (Reconstruction of Attosecond Beating By Interference of Two-photon transitions) in the presence of autoionizing states. We show that, as a harmonic traverses a resonance, its sidebands exhibit a peaked phase shift as well as a modulation of the beating frequency itself. Furthermore, the beating between two resonant paths persists even when the pump and the probe pulses do not overlap, thus providing a sensitive non-holographic interferometric means to reconstruct coherent metastable wave packets. We characterize these phenomena quantitatively with a general finite-pulse analytical model that accounts for the effect of both intermediate and final resonances on two-photon processes, at a negligible computational cost. The model predictions are in excellent agreement with those of accurate ab initio calculations for the helium atom in the region of the N=2 doubly excited states.

  7. Photoreceptor Sensory Cilium: Traversing the Ciliary Gate

    Directory of Open Access Journals (Sweden)

    Hemant Khanna

    2015-10-01

    Full Text Available Cilia are antenna-like extensions of the plasma membrane found in nearly all cell types. In the retina of the eye, photoreceptors develop unique sensory cilia. Not much was known about the mechanisms underlying the formation and function of photoreceptor cilia, largely because of technical limitations and the specific structural and functional modifications that cannot be modeled in vitro. With recent advances in microscopy techniques and molecular and biochemical approaches, we are now beginning to understand the molecular basis of photoreceptor ciliary architecture, ciliary function and its involvement in human diseases. Here, I will discuss the studies that have revealed new knowledge of how photoreceptor cilia regulate their identity and function while coping with high metabolic and trafficking demands associated with processing light signal.

  8. Beat-Frequency/Microsphere Medical Ultrasonic Imaging

    Science.gov (United States)

    Yost, William T.; Cantrell, John H.; Pretlow, Robert A., III

    1995-01-01

    Medical ultrasonic imaging system designed to provide quantitative data on various flows of blood in chambers, blood vessels, muscles, and tissues of heart. Sensitive enough to yield readings on flows of blood in heart even when microspheres used as ultrasonic contrast agents injected far from heart and diluted by circulation of blood elsewhere in body.

  9. Intraocular electro-optic lens with ciliary muscle controlled accommodation.

    Science.gov (United States)

    Doornaert, Dries; Glorieux, Christ; De Gersem, Herbert; Puers, Robert; Spileers, Werner; Blanckaert, Johan

    2013-01-01

    In this paper a concept is proposed of an intraocular lens implant with electro-optic accommodation of a variable-focus hybrid liquid-crystal-based lens. The dioptric strength of the lens is electronically controlled by a signal that is derived from the change of inductance of a sensing coil due to a marker implanted in the nearby contracting or decontracting ciliary muscle. Analytical, numerical and experimental results are reported on the dependency of the frequency of a Colpitts oscillator circuit on the location of a nearby conductive marker. A concept is also reported on the use as an electro-optic lens of a device based on a liquid crystal in planar alignment, which is held between a flat and a curved window coated with optically transparent and electrically conductive layers. PMID:24110406

  10. Efficiency optimization and symmetry-breaking in a model of ciliary locomotion

    CERN Document Server

    Michelin, Sebastien

    2010-01-01

    A variety of swimming microorganisms, called ciliates, exploit the bending of a large number of small and densely-packed organelles, termed cilia, in order to propel themselves in a viscous fluid. We consider a spherical envelope model for such ciliary locomotion where the dynamics of the individual cilia are replaced by that of a continuous overlaying surface allowed to deform tangentially to itself. Employing a variational approach, we determine numerically the time-periodic deformation of such surface which leads to low-Reynolds locomotion with minimum rate of energy dissipation (maximum efficiency). Employing both Lagrangian and Eulerian points of views, we show that in the optimal swimming stroke, individual cilia display weak asymmetric beating, but that a significant symmetry-breaking occurs at the organism level, with the whole surface deforming in a wave-like fashion reminiscent of metachronal waves of biological cilia. This wave motion is analyzed using a formal modal decomposition, is found to occu...

  11. Ciliary metachronal wave propagation on the compliant surface of Paramecium cells.

    Science.gov (United States)

    Narematsu, Naoki; Quek, Raymond; Chiam, Keng-Hwee; Iwadate, Yoshiaki

    2015-12-01

    Ciliary movements in protozoa exhibit metachronal wave-like coordination, in which a constant phase difference is maintained between adjacent cilia. It is at present generally thought that metachronal waves require hydrodynamic coupling between adjacent cilia and the extracellular fluid. To test this hypothesis, we aspirated a Paramecium cell using a micropipette which completely sealed the surface of the cell such that no fluid could pass through the micropipette. Thus, the anterior and the posterior regions of the cell were hydrodynamically decoupled. Nevertheless, we still observed that metachronal waves continued to propagate from the anterior to the posterior ends of the cell, suggesting that in addition to hydrodynamic coupling, there are other mechanisms that can also transmit the metachronal waves. Such transmission was also observed in computational modeling where the fluid was fully decoupled between two partitions of a beating ciliary array. We also imposed cyclic stretching on the surface of live Paramecium cells and found that metachronal waves persisted in the presence of cyclic stretching. This demonstrated that, in addition to hydrodynamic coupling, a compliant substrate can also play a critical role in mediating the propagation of metachronal waves. PMID:26616106

  12. Gene expression studies in cells from primary ciliary dyskinesia patients identify 208 potential ciliary genes

    NARCIS (Netherlands)

    Geremek, Maciej; Bruinenberg, Marcel; Zietkiewicz, Ewa; Pogorzelski, Andrzej; Wijmenga, Cisca; Witt, Michal

    2011-01-01

    Cilia are small cellular projections that either act as sensors (primary cilia) or propel fluid over the epithelia of various organs (motile cilia). The organellum has gained much attention lately because of its involvement in a group of human diseases called ciliopathies. Primary ciliary dyskinesia

  13. The Pediatric Choroidal and Ciliary Body Melanoma Study

    DEFF Research Database (Denmark)

    Al-Jamal, Rana'a T; Cassoux, Nathalie; Desjardins, Laurence;

    2016-01-01

    PURPOSE: To collect comprehensive data on choroidal and ciliary body melanoma (CCBM) in children and to validate hypotheses regarding pediatric CCBM: children younger than 18 years, males, and those without ciliary body involvement (CBI) have more favorable survival prognosis than young adults 18...

  14. Modification of the algorithm for beat tracking of a musical melody

    OpenAIRE

    Khachai, M. Y.; Kobylkin, K. S.; Khachai, D. M.

    2013-01-01

    A new efficient modification of the known heuristic algorithm for real-time beat tracking is proposed. An improved formula for updating the relative frequencies of time intervals between adjacent onsets is used in the modification. The algorithm has shown good performance on the MIREX Beat Tracking test base. © 2013 Pleiades Publishing, Ltd.

  15. Artificial ciliary bundles with nano fiber tip links

    CERN Document Server

    Asadnia, Mohsen; Miao, Jianmin; Triantafyllou, Michael

    2015-01-01

    Mechanosensory ciliary bundles in fishes are the inspiration for carefully engineered artificial flow sensors. We report the development of a new class of ultrasensitive MEMS flow sensors that mimic the intricate morphology of the ciliary bundles, including the stereocilia, tip links, and the cupula, and thereby achieve threshold detection limits that match the biological example. An artificial ciliary bundle is achieved by fabricating closely-spaced arrays of polymer micro-pillars with gradiating heights. Tip links that form the fundamental sensing elements are realized through electrospinning aligned PVDF piezoelectric nano-fibers that link the distal tips of the polymer cilia. An optimized synthesis of hyaluronic acid-methacrylic anhydride hydrogel that results in properties close to the biological cupula, together with drop-casting method are used to form the artificial cupula that encapsulates the ciliary bundle. In testing, fluid drag force causes the ciliary bundle to slide, stretching the flexible nan...

  16. Beat Subterranean: Tactics of Assemblage and Worldmaking in Beat Generation Writing

    OpenAIRE

    Fazzino, Jimmy Michael

    2012-01-01

    My dissertation argues that the core beat trope of the subterranean can be developed as a productive means of literary analysis. I show that beat writers conceive of themselves and their work as existing within vast "underground" networks of radical and avant-garde art and literature, and by locating the beats within such assemblages, the subterranean offers, above all, a model for reconceptualizing beat geography. While the Beat Generation has been regarded as quintessentially American, beat...

  17. Prevention of adenosine A2A receptor activation diminishes beat-to-beat alternation in human atrial myocytes.

    Science.gov (United States)

    Molina, Cristina E; Llach, Anna; Herraiz-Martínez, Adela; Tarifa, Carmen; Barriga, Montserrat; Wiegerinck, Rob F; Fernandes, Jacqueline; Cabello, Nuria; Vallmitjana, Alex; Benitéz, Raúl; Montiel, José; Cinca, Juan; Hove-Madsen, Leif

    2016-01-01

    Atrial fibrillation (AF) has been associated with increased spontaneous calcium release from the sarcoplasmic reticulum and linked to increased adenosine A2A receptor (A2AR) expression and activation. Here we tested whether this may favor atrial arrhythmogenesis by promoting beat-to-beat alternation and irregularity. Patch-clamp and confocal calcium imaging was used to measure the beat-to-beat response of the calcium current and transient in human atrial myocytes. Responses were classified as uniform, alternating or irregular and stimulation of Gs-protein coupled receptors decreased the frequency where a uniform response could be maintained from 1.0 ± 0.1 to 0.6 ± 0.1 Hz; p < 0.01 for beta-adrenergic receptors and from 1.4 ± 0.1 to 0.5 ± 0.1 Hz; p < 0.05 for A2ARs. The latter was linked to increased spontaneous calcium release and after-depolarizations. Moreover, A2AR activation increased the fraction of non-uniformly responding cells in HL-1 myocyte cultures from 19 ± 3 to 51 ± 9 %; p < 0.02, and electrical mapping in perfused porcine atria revealed that adenosine induced electrical alternans at longer cycle lengths, doubled the fraction of electrodes showing alternation, and increased the amplitude of alternations. Importantly, protein kinase A inhibition increased the highest frequency where uniform responses could be maintained from 0.84 ± 0.12 to 1.86 ± 0.11 Hz; p < 0.001 and prevention of A2AR-activation with exogenous adenosine deaminase selectively increased the threshold from 0.8 ± 0.1 to 1.2 ± 0.1 Hz; p = 0.001 in myocytes from patients with AF. In conclusion, A2AR-activation promotes beat-to-beat irregularities in the calcium transient in human atrial myocytes, and prevention of A2AR activation may be a novel means to maintain uniform beat-to-beat responses at higher beating frequencies in patients with atrial fibrillation.

  18. Free-electron laser from wave-mechanical beats of 2 electron beams

    Science.gov (United States)

    Lichtenstein, R. M.

    1982-01-01

    It is possible, though technically difficult, to produce beams of free electrons that exhibit beats of a quantum mechanical nature. (1) the generation of electromagnetic radiation, e.g., light, based on the fact that the beats give rise to alternating charge and current densities; and a frequency shifter, based on the fact that a beam with beats constitutes a moving grating. When such a grating is exposed to external radiation of suitable frequency and direction, the reflected rediation will be shifted in frequency, since the grating is moving. A twofold increase of the frequency is readily attainable. It is shown that it is impossible to generate radiation, because the alternating electromagnetic fields that accompany the beats cannot reform themselves into freely propagating waves. The frequency shifter is useless as a practical device, because its reflectance is extremely low for realizable beams.

  19. Beating of wives: a cross-cultural perspective.

    Science.gov (United States)

    Campbell, J C

    1985-01-01

    This paper reports a more in-depth analysis of wife beating from a cross-cultural perspective. As background for the analysis, the methodological, operationalization, and measurement in previous cross-cultural research on wife beating is examined. Subsequently, a review of findings from these studies and the theoretical explanations from selected disciplines are presented as the basis of selection of variables expected to affect the presence and severity of wife abuse in a given culture. These variables are then examined with evidence from female perspective ethnographies on eleven different societies. This cross-cultural analysis of wife beating has illuminated more issues of methodology and variations of patterns than it has answered any questions about what may increase the frequency and severity of wife-beating in a given culture. It is possible that the beating of wives is a personal expression of hostility against women that may be expressed in addition to, or instead of, institutionalized aggression toward women in that culture. As such, wife beating can take many forms. It can be an indication of manhood, a means of personal control, a reflection of personal animosity, and an expression of sexual jealousy. These personal forms would be paralleled by societal expression such as gang rape, control of women by exclusion from the public sphere, general hostility between sexes, and the virtue of women becoming an issue of extended family and community honor. In conclusion, the importance of the variables is summarized and directions for future cross-cultural research on wife beating are suggested.

  20. Observation of single- and two-photon beating between independent Raman scattering

    CERN Document Server

    Chen, Li-Qing; Zhang, Guo-Wan; Ou, Z Y; Zhang, Weiping

    2010-01-01

    By using spontaneous Raman processes in the high gain regime, we produce two independent Raman Stokes fields from an atomic ensemble. Temporal beating is observed between the two directly generated Stokes fields in a single realization. The beat frequency is found to be a result of an AC Stark frequency shift effect. However, due to the spontaneous nature of the process, the phases of the two Stokes fields change from one realization to another so that the beat signal disappears after average over many realizations. On the other hand, the beat signal is recovered in a two-photon correlation measurement, showing a two-photon interference effect. The two-photon beat signal enables us to obtain dephasing information in the Raman process. The dephasing effect is found to depend on the temperature of the atomic medium.

  1. Ciliary abnormalities in senescent human fibroblasts impair proliferative capacity.

    Science.gov (United States)

    Breslin, Loretta; Prosser, Suzanna L; Cuffe, Sandra; Morrison, Ciaran G

    2014-01-01

    Somatic cells senesce in culture after a finite number of divisions indefinitely arresting their proliferation. DNA damage and senescence increase the cellular number of centrosomes, the 2 microtubule organizing centers that ensure bipolar mitotic spindles. Centrosomes also provide the basal body from which primary cilia extend to sense and transduce various extracellular signals, notably Hedgehog. Primary cilium formation is facilitated by cellular quiescence a temporary cell cycle exit, but the impact of senescence on cilia is unknown. We found that senescent human fibroblasts have increased frequency and length of primary cilia. Levels of the negative ciliary regulator CP110 were reduced in senescent cells, as were levels of key elements of the Hedgehog pathway. Hedgehog inhibition reduced proliferation in young cells with increased cilium length accompanying cell cycle arrest suggesting a regulatory function for Hedgehog in primary ciliation. Depletion of CP110 in young cell populations increased ciliation frequencies and reduced cell proliferation. These data suggest that primary cilia are potentially novel determinants of the reduced cellular proliferation that initiates senescence. PMID:25486364

  2. Ciliary abnormalities in senescent human fibroblasts impair proliferative capacity

    Science.gov (United States)

    Breslin, Loretta; Prosser, Suzanna L; Cuffe, Sandra; Morrison, Ciaran G

    2014-01-01

    Somatic cells senesce in culture after a finite number of divisions indefinitely arresting their proliferation. DNA damage and senescence increase the cellular number of centrosomes, the 2 microtubule organizing centers that ensure bipolar mitotic spindles. Centrosomes also provide the basal body from which primary cilia extend to sense and transduce various extracellular signals, notably Hedgehog. Primary cilium formation is facilitated by cellular quiescence a temporary cell cycle exit, but the impact of senescence on cilia is unknown. We found that senescent human fibroblasts have increased frequency and length of primary cilia. Levels of the negative ciliary regulator CP110 were reduced in senescent cells, as were levels of key elements of the Hedgehog pathway. Hedgehog inhibition reduced proliferation in young cells with increased cilium length accompanying cell cycle arrest suggesting a regulatory function for Hedgehog in primary ciliation. Depletion of CP110 in young cell populations increased ciliation frequencies and reduced cell proliferation. These data suggest that primary cilia are potentially novel determinants of the reduced cellular proliferation that initiates senescence. PMID:25486364

  3. Increased Short-Term Beat-To-Beat Variability of QT Interval in Patients with Acromegaly.

    Directory of Open Access Journals (Sweden)

    Andrea Orosz

    Full Text Available Cardiovascular diseases, including ventricular arrhythmias are responsible for increased mortality in patients with acromegaly. Acromegaly may cause repolarization abnormalities such as QT prolongation and impairment of repolarization reserve enhancing liability to arrhythmia. The aim of this study was to determine the short-term beat-to-beat QT variability in patients with acromegaly. Thirty acromegalic patients (23 women and 7 men, mean age±SD: 55.7±10.4 years were compared with age- and sex-matched volunteers (mean age 51.3±7.6 years. Cardiac repolarization parameters including frequency corrected QT interval, PQ and QRS intervals, duration of terminal part of T waves (Tpeak-Tend and short-term variability of QT interval were evaluated. All acromegalic patients and controls underwent transthoracic echocardiographic examination. Autonomic function was assessed by means of five standard cardiovascular reflex tests. Comparison of the two groups revealed no significant differences in the conventional ECG parameters of repolarization (QT: 401.1±30.6 ms vs 389.3±16.5 ms, corrected QT interval: 430.1±18.6 ms vs 425.6±17.3 ms, QT dispersion: 38.2±13.2 ms vs 36.6±10.2 ms; acromegaly vs control, respectively. However, short-term beat-to-beat QT variability was significantly increased in acromegalic patients (4.23±1.03 ms vs 3.02±0.80, P<0.0001. There were significant differences between the two groups in the echocardiographic dimensions (left ventricular end diastolic diameter: 52.6±5.4 mm vs 48.0±3.9 mm, left ventricular end systolic diameter: 32.3±5.2 mm vs 29.1±4.4 mm, interventricular septum: 11.1±2.2 mm vs 8.8±0.7 mm, posterior wall of left ventricle: 10.8±1.4 mm vs 8.9±0.7 mm, P<0.05, respectively. Short-term beat-to-beat QT variability was elevated in patients with acromegaly in spite of unchanged conventional parameters of ventricular repolarization. This enhanced temporal QT variability may be an early indicator of increased

  4. Doppler Beats or Interference Fringes?

    Science.gov (United States)

    Kelly, Paul S.

    1979-01-01

    Discusses the following: another version of Doppler beats; alternate proof of spin-1 sin-1/2 problems; some mechanisms related to Dirac's strings; Doppler redshift in oblique approach of source and observer; undergraduate experiment on noise thermometry; use of the time evolution operator; resolution of an entropy maximization controversy;…

  5. Increased Short-Term Beat-To-Beat Variability of QT Interval in Patients with Acromegaly.

    Science.gov (United States)

    Orosz, Andrea; Csajbók, Éva; Czékus, Csilla; Gavallér, Henriette; Magony, Sándor; Valkusz, Zsuzsanna; Várkonyi, Tamás T; Nemes, Attila; Baczkó, István; Forster, Tamás; Wittmann, Tibor; Papp, Julius Gy; Varró, András; Lengyel, Csaba

    2015-01-01

    Cardiovascular diseases, including ventricular arrhythmias are responsible for increased mortality in patients with acromegaly. Acromegaly may cause repolarization abnormalities such as QT prolongation and impairment of repolarization reserve enhancing liability to arrhythmia. The aim of this study was to determine the short-term beat-to-beat QT variability in patients with acromegaly. Thirty acromegalic patients (23 women and 7 men, mean age±SD: 55.7±10.4 years) were compared with age- and sex-matched volunteers (mean age 51.3±7.6 years). Cardiac repolarization parameters including frequency corrected QT interval, PQ and QRS intervals, duration of terminal part of T waves (Tpeak-Tend) and short-term variability of QT interval were evaluated. All acromegalic patients and controls underwent transthoracic echocardiographic examination. Autonomic function was assessed by means of five standard cardiovascular reflex tests. Comparison of the two groups revealed no significant differences in the conventional ECG parameters of repolarization (QT: 401.1±30.6 ms vs 389.3±16.5 ms, corrected QT interval: 430.1±18.6 ms vs 425.6±17.3 ms, QT dispersion: 38.2±13.2 ms vs 36.6±10.2 ms; acromegaly vs control, respectively). However, short-term beat-to-beat QT variability was significantly increased in acromegalic patients (4.23±1.03 ms vs 3.02±0.80, Pacromegaly in spite of unchanged conventional parameters of ventricular repolarization. This enhanced temporal QT variability may be an early indicator of increased liability to arrhythmia.

  6. Musicians' Perception of Beat in Monotonic Stimuli.

    Science.gov (United States)

    Duke, Robert A.

    1989-01-01

    Assesses musicians' perceptions of beat in monotonic stimuli and attempts to define empirically the range of perceived beat tempo in music. Subjects performed a metric pulse in response to periodic stimulus tones. Results indicate a relatively narrow range within which beats are perceived by trained musicians. (LS)

  7. Diagnosis by ultrastructural study of primary ciliary dyskinesia

    Directory of Open Access Journals (Sweden)

    Melgarejo-Moreno P

    2015-01-01

    Full Text Available Introduction and objective: Primary ciliary dyskinesia (PCD, also known as ciliary immotility (SIC syndrome is an inherited disorder that includes a group of diseases in which respiratory cilia are immobile, ciliary movement is dyskinetic and ineffective or no cilia . The aim of this study is to determine the ciliary ultrastructure in patients with suspected DCP. Method: In 8 patients with suspected DCP nasal mucosa biopsy is performed with endoscopy at the inferior turbinate in the middle third by the ENT service under local anesthesia. Results: Of the 8 cases studied in 2 cases no ciliary ultrastructural level defects were found. In two cases with abnormal ciliary ultrastructure is present Kartagener syndrome. In a case no cilia were observed in the nasal mucosa. Discussion: The DCP and SIC are synonymous terms from clinical and pathogenetic view: immobility and dyskinesia lead to an absence of mucociliary transport, stasis of respiratory secretions with their consequences: chronic infections of lower respiratory tract and from birth . The most common ultrastructural defect is the total or partial absence of dynein. Conclusions: The ultrastructural study allows the diagnosis of PCD because genetic diagnosis is complicated and therefore get an early diagnosis of this condition which serves to improve the morbidity and mortality of these patients.

  8. Simple non-invasive analysis of embryonic stem cell-derived cardiomyocytes beating in vitro

    Science.gov (United States)

    Radaszkiewicz, Katarzyna Anna; Sýkorová, Dominika; Karas, Pavel; Kudová, Jana; Kohút, Lukáš; Binó, Lucia; Večeřa, Josef; Víteček, Jan; Kubala, Lukáš; Pacherník, Jiří

    2016-02-01

    The analysis of digital video output enables the non-invasive screening of various active biological processes. For the monitoring and computing of the beating parameters of cardiomyocytes in vitro, CB Analyser (cardiomyocyte beating analyser) software was developed. This software is based on image analysis of the video recording of beating cardiomyocytes. CB Analyser was tested using cardiomyocytes derived from mouse embryonic stem cells at different stages of cardiomyogenesis. We observed that during differentiation (from day 18), the beat peak width decreased, which corresponded to the increased speed of an individual pulse. However, the beating frequency did not change. Further, the effects of epinephrine modulating mature cardiomyocyte functions were tested to validate the CB Analyser analysis. In conclusion, data show that CB Analyser is a useful tool for evaluating the functions of both developing and mature cardiomyocytes under various conditions in vitro.

  9. Feedback in a cavity QED system for control of quantum beats

    Directory of Open Access Journals (Sweden)

    Cimmarusti A.D.

    2013-08-01

    Full Text Available Conditional measurements on the undriven mode of a two-mode cavity QED system prepare a coherent superposition of ground states which generate quantum beats. The continuous system drive induces decoherence through the phase interruptions from Rayleigh scattering, which manifests as a decrease of the beat amplitude and an increase of the frequency of oscillation. We report recent experiments that implement a simple feedback mechanism to protect the quantum beat. We continuously drive the system until a photon is detected, heralding the presence of a coherent superposition. We then turn off the drive and let the superposition evolve in the dark, protecting it against decoherence. At a later time we reinstate the drive to measure the amplitude, phase, and frequency of the beats. The amplitude can increase by more than fifty percent, while the frequency is unchanged by the feedback.

  10. Abstract Possible: The Birmingham Beat

    OpenAIRE

    Bergman, Aeron; Salinas, Alejandra

    2013-01-01

    Gruppeutstilling. Samarbeidspartner: Alejandra Salinas. ABSTRACT YOUR SHIT IS Video loop and billboard. Eastside Projects, Birmingham UK Abstract Possible: The Birmingham Beat Curated by Maria Lind 6 October - 1 December 2012. Invited artists: José León Cerrillo, Zachary Formwalt, Goldin+Senneby, Wade Guyton, Yelena Popova, Alejandra Salinas and Aeron Bergman. Visningssted: Eastside Projects, Birmingham, UK. Se også: http://eastsideprojects.org/past/abstract-possible

  11. Beating phantasies: Mourned and unmourned.

    Science.gov (United States)

    Antinucci, Giuseppina

    2016-06-01

    This paper intends to explore the organizing function and fate of sado-masochistic phantasies in their fixed form, in the psychic life of patients who have suffered early traumas, due to environmental vicissitudes and maternal psychopathology. The theoretical starting point is provided by the Novicks' research into transitory and permanent beating phantasies in adult and child patients, their onset and their psychic function, based on an examination of Freud's paper 'A child is being beaten'. In this text Freud achieves an unprecedented syncretism, locating the phantasy at the intersection between the oedipal complex, which is a vertical structure organizing sexual and generational differences, and the fraternal dimension, which is horizontal and organizes the lateral relationship with that similar but different other who is the sibling. Reporting in some detail material from the analyses of two young women, whose clinical presentation and early traumas show some similarities, the author puts in the context of the analytic work the emerging of the sado-masochistic phantasies, emphasizing their use and function in the transference-countertransference interplay. The beating phantasies shore up a precarious sense of self, threatened with psychic depletion and death, in identification with the absent mother of early infancy. An overly close relationship with a sibling, experienced as a narcissistic double, compounds the clinical picture, to establish the triangle formed by the parent(s) and two children which features in the beating phantasy. Finally, the author explores the contribution of ameliorating factors, such as alternative identificatory figures, constitutional endowment and capacity for sublimation, to account for the different fate of the fixed beating phantasies. PMID:26602362

  12. Ciliary and non-ciliary expression and function of PACRG during vertebrate development

    Directory of Open Access Journals (Sweden)

    Thumberger Thomas

    2012-08-01

    Full Text Available Abstract Background Park2-co-regulated gene (PACRG is evolutionarily highly conserved from green algae to mammals. In Chlamydomonas and trypanosomes, the PACRG protein associates with flagella. Loss of PACRG results in shortened or absent flagella. In mouse the PACRG protein is required for spermatogenesis. The purpose of the present study was to analyze (1 the expression patterns of PACRG during vertebrate embryogenesis, and (2 whether the PACRG protein was required for left-right (LR axis specification through cilia-driven leftward flow in Xenopus laevis. Methods PACRG cDNAs were cloned and expression was analyzed during early embryonic development of Xenopus, mouse, rabbit and zebrafish. Antisense morpholino oligonucleotide (MO mediated gene knockdown was applied in Xenopus to investigate LR development at the level of tissue morphology, leftward flow and asymmetric marker gene expression, using timelapse videography, scanning electron microscopy (SEM and whole-mount in situ hybridization. Results were statistically evaluated using Wilcoxon paired and χ2 tests. Results PACRG mRNA expression was found in cells and tissues harboring cilia throughout the vertebrates. Highly localized expression was also detected in the brain. During early development, PACRG was specifically localized to epithelia where leftward flow arises, that is, the gastrocoel roof plate (GRP in Xenopus, the posterior notochord (PNC in mammals and Kupffer’s vesicle (KV in zebrafish. Besides its association with ciliary axonemes, subcellular localization of PACRG protein was found around the nucleus and in a spotty pattern in the cytoplasm. A green fluorescent protein (GFP fusion construct preferentially labeled cilia, rendering PACRG a versatile marker for live imaging. Loss-of-function in the frog resulted dose dependently in LR, neural tube closure and gastrulation defects, representing ciliary and non-ciliary functions of PACRG. Conclusions The PACRG protein is a novel

  13. Ciliary genes are down-regulated in bronchial tissue of primary ciliary dyskinesia patients.

    Directory of Open Access Journals (Sweden)

    Maciej Geremek

    Full Text Available Primary ciliary dyskinesia (PCD is a rare, genetically heterogeneous disease characterized by recurrent respiratory tract infections, sinusitis, bronchiectasis and male infertility. The pulmonary phenotype in PCD is caused by the impaired motility of cilia in the respiratory epithelium, due to ultrastructural defects of these organelles. We hypothesized that defects of multi-protein ciliary complexes should be reflected by gene expression changes in the respiratory epithelium. We have previously found that large group of genes functionally related to cilia share highly correlated expression pattern in PCD bronchial tissue. Here we performed an explorative analysis of differential gene expression in the bronchial tissue from six PCD patients and nine non-PCD controls, using Illumina HumanRef-12 Whole Genome BeadChips. We observed 1323 genes with at least 2-fold difference in the mean expression level between the two groups (t-test p-value <0.05. Annotation analysis showed that the genes down-regulated in PCD biopsies (602 were significantly enriched for terms related to cilia, whereas the up-regulated genes (721 were significantly enriched for terms related to cell cycle and mitosis. We assembled a list of human genes predicted to encode ciliary proteins, components of outer dynein arms, inner dynein arms, radial spokes, and intraflagellar transport proteins. A significant down-regulation of the expression of genes from all the four groups was observed in PCD, compared to non-PCD biopsies. Our data suggest that a coordinated down-regulation of the ciliome genes plays an important role in the molecular pathomechanism of PCD.

  14. Quantum-beat Auger spectroscopy

    CERN Document Server

    Zhang, Song Bin

    2015-01-01

    The concept of nonlinear quantum-beat pump-probe Auger spectroscopy is introduced by discussing a relatively simple four-level model system. We consider a coherent wave packet involving two low-lying states that was prepared by an appropriate pump pulse. This wave packet is subsequently probed by a weak, time-delayed probe pulse with nearly resonant coupling to a core-excited state of the atomic or molecular system. The resonant Auger spectra are then studied as a function of the duration of the probe pulse and the time delay. With a bandwidth of the probe pulse approaching the energy spread of the wave packet, the Auger yields and spectra show quantum beats as a function of pump-probe delay. An analytic theory for the quantum-beat Auger spectroscopy will be presented, which allows for the reconstruction of the wave packet by analyzing the delaydependent Auger spectra. The possibility of extending this method to a more complex manifold of electronic and vibrational energy levels is also discussed.

  15. CCDC103 mutations cause primary ciliary dyskinesia by disrupting assembly of ciliary dynein arms

    Science.gov (United States)

    Panizzi, Jennifer R.; Becker-Heck, Anita; Castleman, Victoria H.; Al-Mutairi, Dalal; Liu, Yan; Loges, Niki T.; Pathak, Narendra; Austin-Tse, Christina; Sheridan, Eamonn; Schmidts, Miriam; Olbrich, Heike; Werner, Claudius; Häffner, Karsten; Hellman, Nathan; Chodhari, Rahul; Gupta, Amar; Kramer-Zucker, Albrecht; Olale, Felix; Burdine, Rebecca D.; Schier, Alexander F.; O’Callaghan, Christopher; Chung, Eddie MK; Reinhardt, Richard; Mitchison, Hannah M.; King, Stephen M.; Omran, Heymut; Drummond, Iain A.

    2012-01-01

    Cilia are essential for fertilization, respiratory clearance, cerebrospinal fluid circulation, and to establish laterality1. Cilia motility defects cause Primary Ciliary Dyskinesia (PCD, MIM 242650), a disorder affecting 1:15-30,000 births. Cilia motility requires the assembly of multisubunit dynein arms that drive cilia bending2. Despite progress in understanding the genetic basis of PCD, mutations remain to be identified for several PCD linked loci3. Here we show that the zebrafish cilia paralysis mutant schmalhanstn222 (smh) mutant encodes the coiled-coil domain containing 103 protein (Ccdc103), a foxj1a regulated gene. Screening 146 unrelated PCD families identified patients in six families with reduced outer dynein arms, carrying mutations in CCDC103. Dynein arm assembly in smh mutant zebrafish was rescued by wild-type but not mutant human CCDC103. Chlamydomonas Ccdc103 functions as a tightly bound, axoneme-associated protein. The results identify Ccdc103 as a novel dynein arm attachment factor that when mutated causes Primary Ciliary Dyskinesia. PMID:22581229

  16. Respiratory sinus arrhythmia during anaesthesia: assessment of respiration related beat-to-beat heart rate variability analysis methods.

    Science.gov (United States)

    Loula, P; Jäntti, V; Yli-Hankala, A

    1997-11-01

    Beat-to-beat heart rate variability analysis is a powerful tool for the diagnosis of neuropathy. Respiration-related heart rate variability (respiratory sinus arrhythmia, RSA) reflects the function of parasympathetic nervous system during spontaneous ventilation while awake. RSA is also claimed to monitor the depth of anaesthesia. Power spectrum analysis or various averaging techniques of the heart rate variability are usually applied. The current literature, however, does not usually interpret the ground rules and limitations of the method used, and this may sometimes lead to erroneous conclusions on the data. The aim of our study was to compare and analyse critically the performance of different methods of evaluating RSA during anaesthesia and positive pressure ventilation. Power spectrum analysis, the root mean square of the successive RR-interval difference (RMSSD), and two respiration related methods, RSA index and average phase RSA, were included in the comparison. To test these methods, 11 patients were anaesthetised with isoflurane and their lungs were ventilated mechanically with a frequency of 6 cycles min-1. Each patient received a bolus dose of atropine (20 micrograms kg-1) during the trial. Electrocardiogram, electroencephalogram and tracheal pressure signal from respirator were recorded and analyses were performed off-line. We demonstrated that general indices, such as RMSSD, may be strongly affected by heart rate level and other non-respiration related variations in heart rate. We also showed that the effect of unwanted fluctuations on RSA can be reduced with respiration dependent beat-to-beat methods. Furthermore we confirmed that in addition to the amplitude, also the pattern of respiratory sinus arrhythmia is of interest: the pattern is reversed in phase compared to spontaneous breathing while awake, as we have shown earlier. To analyse RSA during anaesthesia, we recommend the use of an average phase RSA method based on beat-to-beat variability

  17. A high-density EEG investigation into steady state binaural beat stimulation.

    Directory of Open Access Journals (Sweden)

    Peter Goodin

    Full Text Available Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation altered vigilance or cortical frequencies and if personality traits were involved. Thirty-one participants were played binaural beat stimuli designed to elicit a response at either the Theta (7 Hz or Beta (16 Hz frequency bands while undertaking a zero-back vigilance task. EEG was recorded from a high-density electrode cap. No significant differences were found in vigilance or cortical frequency power during binaural beat stimulation compared to a white noise control period. Furthermore, no significant relationships were detected between the above and the Big Five personality traits. This suggests a short presentation of steady state binaural beats are not sufficient to alter vigilance or entrain cortical frequencies at the two bands examined and that certain personality traits were not more susceptible than others.

  18. Theory of beat wave excitation in an inhomogeneous plasma

    International Nuclear Information System (INIS)

    The theory of beat wave excitation in a slightly inhomogeneous plasma is presented. While the theory is general it applies directly to the experiments performed in Alaska by the ionospheric heating facilities HIPAS [High Power Auroral Simulation, Radio Sci. 25, 1269 (1990)] and HAARP [High Frequency Active Auroral Research Project, Geophys. Res. Lett. 25, 257 (1998)]. A ray tracing (WKB) formalism appropriate for computations is developed. The computational implementation of this formalism and extensive results will be presented in a follow up to this paper. Also the beat wave excitation of upper-hybrid waves is investigated analytically. The complicated trajectories of these waves in the plasma are described. When this beat wave reaches the plasma wave resonance it can, in the HIPAS-HAARP experiments, attain nonlinear amplitude. The electrostatic upper-hybrid waves are trapped around the density maximum of the ionosphere. This trapping is investigated in detail. Beat wave pumping of the trapped modes is possible using HAARP and HIPAS or with split beams from HAARP

  19. Bondage fantasies and beating fantasies.

    Science.gov (United States)

    Weiss, J

    1998-10-01

    Two male patients had masochistic sexual fantasies: one had bondage fantasies, the other beating fantasies. Each patient had been traumatized in childhood by his experiences with a martyr mother. Each had developed the belief that in an intimate sexual relationship with a woman he would hurt her. As a consequence, each tended to suppress his sexuality. Each used masochistic fantasies to reassure himself that he was not hurting his fantasied or real partner. The reassurance made it safe to experience his sexual feelings. The two patients' use of their masochistic fantasies is compared to the fetishist's use of his fetish, as described by Freud. PMID:9820894

  20. A ternary complex comprising transportin1, Rab8 and the ciliary targeting signal directs proteins to ciliary membranes

    Science.gov (United States)

    Madugula, Viswanadh

    2016-01-01

    ABSTRACT The sensory functions of cilia are dependent on the enrichment of cilium-resident proteins. Although it is known that ciliary targeting signals (CTSs) specifically target ciliary proteins to cilia, it is still unclear how CTSs facilitate the entry and retention of cilium-resident proteins at the molecular level. We found that non-ciliary membrane reporters can passively diffuse into cilia through the lateral transport pathway, and the translocation of membrane reporters through the ciliary diffusion barrier is facilitated by importin binding motifs and domains. Screening known CTSs of ciliary membrane residents uncovered that fibrocystin, photoreceptor retinol dehydrogenase, rhodopsin and retinitis pigmentosa 2 interact with transportin1 (TNPO1) through previously identified CTSs. We further discovered that a new ternary complex, comprising TNPO1, Rab8 and a CTS, can assemble or disassemble under the guanine nucleotide exchange activity of Rab8. Our study suggests a new mechanism in which the TNPO1–Rab8–CTS complex mediates selective entry into and retention of cargos within cilia. PMID:27633000

  1. Angioleiomyoma of the Ciliary Body:A Case Report

    Institute of Scientific and Technical Information of China (English)

    Jianhua Yan; Zhongyao Wu; Yongping Li; Guanguang Feng; Hao Zhang

    2004-01-01

    Purpose: To report a rare case of angioleiomyoma of the ciliary body Methods :The clinical manifestation, imaging findings, histopathologic characteristics were analyzed in a 32-year-old male patient with angioleiomyoma of the ciliary body. Results:The tumor was removed intact with local resection. Histopathologic examination revealed that the tumor was full of vessels and it was composed of spindle cells with abundant cytoplasm. Immunohistochemical studies showed positive for SMA and Desmin and negative for S100 and HMB-45. Conclusions: Angioleiomyoma of the ciliary body is a rare tumor that can be successfully treated with local surgical resection in this area. It needs to be differentiated from other tumors, especially malignant melanoma. Eye Science 2004;20:19-22.

  2. Progressive hemifacial atrophy with ciliary body atrophy and ocular hypotony

    Directory of Open Access Journals (Sweden)

    T Ashwini Kini

    2015-01-01

    Full Text Available Progressive hemifacial atrophy (PHA is a disease of unknown etiology affecting one-half of the face. Ocular involvement is uncommon. Atrophy of iris is rare, with only a few cases of partial atrophy being reported in the literature. We report a case of total atrophy of iris and ciliary body with associated ocular hypotony in a 16-year-old girl with PHA. We believe this is the first reported case of complete atrophy of iris and ciliary body in PHA. Ocular hypotony in PHA was thought to be due to intra-ocular inflammation. However in our case it appears to be secondary to severe atrophy of the ciliary body.

  3. Beat-type Langmuir wave emissions associated with a type III solar radio burst: Evidence of parametric decay

    Science.gov (United States)

    Hospodarsky, G. B.; Gurnett, D. A.

    1995-01-01

    Recent measurements from the plasma wave instrument on the Galileo spacecraft have shown that Langmuir waves observed in conjunction with a type III solar radio burst contain many beat-type waveforms, with beat frequencies ranging from about 150 to 650 Hz. Strong evidence exists that the beat pattern is produced by two closely spaced narrowband components. The most likely candidates for these two waves are a beam-generated Langmuir wave and an oppositely propagating Langmuir wave produced by parametric decay. In the parametric decay process, nonlinear interactions cause the beam-driven Langmuir wave to decay into a Langmuir wave and a low-frequency ion sound wave. Comparisons of the observed beat frequency are in good agreement with theoretical predictions for a three-wave parametric decay process. Weak low-frequency emissions are also sometimes observed at the predicted frequency of the ion sound wave.

  4. Conservation of ciliary proteins in plants with no cilia

    Directory of Open Access Journals (Sweden)

    Hodges Matthew E

    2011-12-01

    Full Text Available Abstract Background Eukaryotic cilia are complex, highly conserved microtubule-based organelles with a broad phylogenetic distribution. Cilia were present in the last eukaryotic common ancestor and many proteins involved in cilia function have been conserved through eukaryotic diversification. However, cilia have also been lost multiple times in different lineages, with at least two losses occurring within the land plants. Whereas all non-seed plants produce cilia for motility of male gametes, some gymnosperms and all angiosperms lack cilia. During these evolutionary losses, proteins with ancestral ciliary functions may be lost or co-opted into different functions. Results Here we identify a core set of proteins with an inferred ciliary function that are conserved in ciliated eukaryotic species. We interrogate this genomic dataset to identify proteins with a predicted ancestral ciliary role that have been maintained in non-ciliated land plants. In support of our prediction, we demonstrate that several of these proteins have a flagellar localisation in protozoan trypanosomes. The phylogenetic distribution of these genes within the land plants indicates evolutionary scenarios of either sub- or neo-functionalisation and expression data analysis shows that these genes are highly expressed in Arabidopsis thaliana pollen cells. Conclusions A large number of proteins possess a phylogenetic ciliary profile indicative of ciliary function. Remarkably, many genes with an ancestral ciliary role are maintained in non-ciliated land plants. These proteins have been co-opted to perform novel functions, most likely before the loss of cilia, some of which appear related to the formation of the male gametes.

  5. Intraflagellar Transport (IFT) Role in Ciliary Assembly, Resorption and Signalling

    DEFF Research Database (Denmark)

    Pedersen, Lotte B; Rosenbaum, Joel L

    2008-01-01

    Cilia and flagella have attracted tremendous attention in recent years as research demonstrated crucial roles for these organelles in coordinating a number of physiologically and developmentally important signaling pathways, including the platelet-derived growth factor receptor (PDGFR) alpha, Sonic...... is a complex, multistep process that is tightly coordinated with cell cycle progression and differentiation. The ciliary axoneme is extended from a modified centriole, the basal body, which migrates to and docks onto the apical plasma membrane early in ciliogenesis as cells enter growth arrest. The ciliary...

  6. Possible instabilities in the beat wave accelerator

    International Nuclear Information System (INIS)

    In this article the concept of the beat wave accelerator is studied with emphasis put on the plasma physics. An important effect is the relativistic nature of the electrons oscillating in the electric field of the beat wave. Various instabilities are presented which could limit the overall efficiency of the accelerating process. (author)

  7. The morphology, topography and cytoarchitectonics of the ciliary ganglion in the domestic turkey (Meleagris gallopavo domesticus).

    Science.gov (United States)

    Radzimirska, Małgorzata

    2003-11-01

    The ciliary ganglion of the domestic turkey (Meleagris gallopavo domesticus) is located between the posterior wall of the eyeball and the optic nerve. It is closely connected with the oculomotor nerve; in particular with its inferior branch. The ganglion has a cask-like shape and is adjacent to the inferior branch of the oculomotor nerve. From this ganglion postganglionic fibres emerge which are arranged in two fasciculi. These are termed the long ciliary nerves and the short ciliary nerves. A cross-section of the ciliary ganglion revealed two populations of cells: small ones - choroid cells and large ones - ciliary cells.

  8. Emergence of Synchronized Beating during the Regrowth of Eukaryotic Flagella

    Science.gov (United States)

    Goldstein, Raymond E.; Polin, Marco; Tuval, Idan

    2011-09-01

    A fundamental issue in the biology of eukaryotic flagella is the origin of synchronized beating observed in tissues and organisms containing multiple flagella. Recent studies of the biflagellate unicellular alga Chlamydomonas reinhardtii provided the first evidence that the interflagellar coupling responsible for synchronization is of hydrodynamic origin. To investigate this mechanism in detail, we study here synchronization in Chlamydomonas as its flagella slowly regrow after mechanically induced self-scission. The duration of synchronized intervals is found to be strongly dependent on flagellar length. Analysis within a stochastic model of coupled phase oscillators is used to extract the length dependence of the interflagellar coupling and the intrinsic beat frequencies of the two flagella. Physical and biological considerations that may explain these results are proposed.

  9. Prostaglandin induces the expression of matrix metalloproteinase-1 In ciliary melanocytes

    Institute of Scientific and Technical Information of China (English)

    WANG Ning-li; LU Qing-jun; LI Jun-hong; WANG Ling

    2008-01-01

    Background Latanoprost,a prostaglandin F2a analog,has been shown to be an effective intraocular pressure lowering agent which acts by inducing ciliary muscle cells to synthesise matrix metalloproteinases.However,the response of ciliary melanocytes to latanoprost has never been reported.This research has investigated the ability of latanoprost to induce matrix metalloproteinase-1 expression in human ciliary melanocytes,and thereby advance the understanding of the mechanism of PGF2a in decreasing Intraocular pressure.Methods In vitro human ciliary melanocytes were treated for 48 hours with five different concentrations of latanoprost (100,150,200,500,and 1000 nmol/L).Ciliary melanocytes treated with 0.01% ethanel(vehicle)were used as a control.The expression of matrix metalloproteinase-1 in ciliary melanocytes was determined by Western blotting and immunofluorescent staining.Results Western blotting showed that the expression of matrix metalloproteinase-1 in ciliary melanocytes was induced by latanoprost,and the level of expression was dependent on the concentration of latanoprost in the culture medium.Immunofluorescent staining showed that matrix metalloproteinase-1 was confined to the ciliary melanocyte cytoplasm.Conclusions Latanoprost induced the expression of matrix metalloproteinase-1 in human ciliary melanocytes in a dose-dependent manner.Ciliary melanocytes,as well as ciliary muscle cells,may also play an important role in uveoscleral outflow modulation.

  10. Multicavitary ciliary body melanoma presenting as a cyst

    Directory of Open Access Journals (Sweden)

    Jennifer Jang

    2013-01-01

    Full Text Available Cyst-like cavities in uveal melanoma occur rarely and can simulate a benign intraocular cystic lesion resulting in delayed diagnosis and inappropriate management. Herein, we describe a 66-year-old Caucasian female who presented with a "cystic" ciliary body mass in the right eye oculus dexter (OD. Slit lamp examination OD showed anterior bulging of the iris temporally from an underlying pigmented ciliary body mass and transillumination disclosed slight shadow from the tumor. Ultrasound biomicroscopy (UBM revealed multiple cyst-like cavities within a tumor, lined by "thick walls" of at least 200 μm and occupying 80% of the tumor volume. A clinical diagnosis of multi-cavitary ciliary body melanoma was suspected and partial lamellar sclero iridocyclectomy was performed. Histopathology confirmed the diagnosis of low-grade spindle melanoma of the ciliary body with multiple empty and fluid filled cyst-like cavities without epithelial lining. UBM is an important diagnostic tool in the differentiation of "thick walled" cavitary melanoma from "thin walled" benign pigment epithelial cyst.

  11. Development of a ciliary muscle-driven accommodating intraocular lens

    NARCIS (Netherlands)

    Hermans, Erik A.; Terwee, Thom T.; Koopmans, Steven A.; Dubbelman, Michiel; van der Heijde, Rob G. L.; Heethaar, Rob M.

    2008-01-01

    PURPOSE: To develop a ciliary muscle-driven accommodating intraocular lens (IOL) that has a large and predictable range of variable power as a step toward spectacle independence. SETTING: Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands. METHODS:

  12. Ciliary photoreceptors in the cerebral eyes of a protostome larva

    Directory of Open Access Journals (Sweden)

    Passamaneck Yale J

    2011-03-01

    Full Text Available Abstract Background Eyes in bilaterian metazoans have been described as being composed of either ciliary or rhabdomeric photoreceptors. Phylogenetic distribution, as well as distinct morphologies and characteristic deployment of different photopigments (ciliary vs. rhabdomeric opsins and transduction pathways argue for the co-existence of both of these two photoreceptor types in the last common bilaterian ancestor. Both receptor types exist throughout the Bilateria, but only vertebrates are thought to use ciliary photoreceptors for directional light detection in cerebral eyes, while all other invertebrate bilaterians studied utilize rhabdomeric photoreceptors for this purpose. In protostomes, ciliary photoreceptors that express c-opsin have been described only from a non-visual deep-brain photoreceptor. Their homology with vertebrate rods and cones of the human eye has been hypothesized to represent a unique functional transition from non-visual to visual roles in the vertebrate lineage. Results To test the hypothesis that protostome cerebral eyes employ exclusively rhabdomeric photoreceptors, we investigated the ultrastructure of the larval eyes in the brachiopod Terebratalia transversa. We show that these pigment-cup eyes consist of a lens cell and a shading pigment cell, both of which are putative photoreceptors, deploying a modified, enlarged cilium for light perception, and have axonal connections to the larval brain. Our investigation of the gene expression patterns of c-opsin, Pax6 and otx in these eyes confirms that the larval eye spots of brachiopods are cerebral eyes that deploy ciliary type photoreceptors for directional light detection. Interestingly, c-opsin is also expressed during early embryogenesis in all potential apical neural cells, becoming restricted to the anterior neuroectoderm, before expression is initiated in the photoreceptor cells of the eyes. Coincident with the expression of c-opsin in the presumptive neuroectoderm

  13. Beats and expansion of two-component Bose–Einstein condensates in the Thomas–Fermi limit

    International Nuclear Information System (INIS)

    A unique feature of multi-component Bose–Einstein condensates (BECs) is the possibility of beating frequencies in collective oscillations. We analytically determine this beating frequency for the two-component BEC in one-dimension. We also show that the Thomas–Fermi approximation, where the quantum pressure is neglected, describes well the expansion of the two-component condensate released from an harmonic trap. (paper)

  14. Electrical Brain Responses to Beat Irregularities in Two Cases of Beat Deafness.

    Science.gov (United States)

    Mathias, Brian; Lidji, Pascale; Honing, Henkjan; Palmer, Caroline; Peretz, Isabelle

    2016-01-01

    Beat deafness, a recently documented form of congenital amusia, provides a unique window into functional specialization of neural circuitry for the processing of musical stimuli: Beat-deaf individuals exhibit deficits that are specific to the detection of a regular beat in music and the ability to move along with a beat. Studies on the neural underpinnings of beat processing in the general population suggest that the auditory system is capable of pre-attentively generating a predictive model of upcoming sounds in a rhythmic pattern, subserved largely within auditory cortex and reflected in mismatch negativity (MMN) and P3 event-related potential (ERP) components. The current study examined these neural correlates of beat perception in two beat-deaf individuals, Mathieu and Marjorie, and a group of control participants under conditions in which auditory stimuli were either attended or ignored. Compared to control participants, Mathieu demonstrated reduced behavioral sensitivity to beat omissions in metrical patterns, and Marjorie showed a bias to identify irregular patterns as regular. ERP responses to beat omissions reveal an intact pre-attentive system for processing beat irregularities in cases of beat deafness, reflected in the MMN component, and provide partial support for abnormalities in later cognitive stages of beat processing, reflected in an unreliable P3b component exhibited by Mathieu-but not Marjorie-compared to control participants. P3 abnormalities observed in the current study resemble P3 abnormalities exhibited by individuals with pitch-based amusia, and are consistent with attention or auditory-motor coupling accounts of deficits in beat perception. PMID:26941591

  15. Electrical Brain Responses to Beat Irregularities in Two Cases of Beat Deafness.

    Science.gov (United States)

    Mathias, Brian; Lidji, Pascale; Honing, Henkjan; Palmer, Caroline; Peretz, Isabelle

    2016-01-01

    Beat deafness, a recently documented form of congenital amusia, provides a unique window into functional specialization of neural circuitry for the processing of musical stimuli: Beat-deaf individuals exhibit deficits that are specific to the detection of a regular beat in music and the ability to move along with a beat. Studies on the neural underpinnings of beat processing in the general population suggest that the auditory system is capable of pre-attentively generating a predictive model of upcoming sounds in a rhythmic pattern, subserved largely within auditory cortex and reflected in mismatch negativity (MMN) and P3 event-related potential (ERP) components. The current study examined these neural correlates of beat perception in two beat-deaf individuals, Mathieu and Marjorie, and a group of control participants under conditions in which auditory stimuli were either attended or ignored. Compared to control participants, Mathieu demonstrated reduced behavioral sensitivity to beat omissions in metrical patterns, and Marjorie showed a bias to identify irregular patterns as regular. ERP responses to beat omissions reveal an intact pre-attentive system for processing beat irregularities in cases of beat deafness, reflected in the MMN component, and provide partial support for abnormalities in later cognitive stages of beat processing, reflected in an unreliable P3b component exhibited by Mathieu-but not Marjorie-compared to control participants. P3 abnormalities observed in the current study resemble P3 abnormalities exhibited by individuals with pitch-based amusia, and are consistent with attention or auditory-motor coupling accounts of deficits in beat perception.

  16. Electrical brain responses to beat irregularities in two cases of beat deafness

    Directory of Open Access Journals (Sweden)

    Brian eMathias

    2016-02-01

    Full Text Available Beat deafness, a recently documented form of congenital amusia, provides a unique window into functional specialization of neural circuitry for the processing of musical stimuli: Beat-deaf individuals exhibit deficits that are specific to the detection of a regular beat in music and the ability to move along with a beat. Studies on the neural underpinnings of beat processing in the general population suggest that the auditory system is capable of pre-attentively generating a predictive model of upcoming sounds in a rhythmic pattern, subserved largely within auditory cortex and reflected in mismatch negativity (MMN and P3 event-related potential (ERP components. The current study examined these neural correlates of beat perception in two beat-deaf individuals, Mathieu and Marjorie, and a group of control participants under conditions in which auditory stimuli were either attended or ignored. Compared to control participants, Mathieu demonstrated reduced behavioral sensitivity to beat omissions in metrical patterns, and Marjorie showed a bias to identify irregular patterns as regular. ERP responses to beat omissions reveal an intact pre-attentive system for processing beat irregularities in cases of beat deafness, reflected in the MMN component, and provide partial support for abnormalities in later cognitive stages of beat processing, reflected in an unreliable P3b component exhibited by Mathieu – but not Marjorie – compared to control participants. P3 abnormalities observed in the current study resemble P3 abnormalities exhibited by individuals with pitch-based amusia, and are consistent with attention or auditory-motor coupling accounts of deficits in beat perception.

  17. Dynamic focusing in the zebrafish beating heart

    Science.gov (United States)

    Andrés-Delgado, L.; Peralta, M.; Mercader, N.; Ripoll, J.

    2016-03-01

    Of the large amount of the animal models available for cardiac research, the zebrafish is extremely valuable due to its transparency during early stages of development. In this work a dual illumination laser sheet microscope with simultaneous dual camera imaging is used to image the beating heart at 200 fps, dynamically and selectively focusing inside the beating heart through the use of a tunable lens. This dual color dynamic focusing enables imaging with cellular resolution at unprecedented high frame rates, allowing 3D imaging of the whole beating heart of embryonic zebrafish.

  18. On the beating of reinforcement pulp

    OpenAIRE

    Hiltunen, Eero

    2003-01-01

    The aim of this work was to gain a better understanding of the effect of reinforcement pulp beating on the strength of mechanical pulp-dominated paper. The main purpose of reinforcement pulp beating is to improve the runnability of paper. The first objective of this study was to maximize the runnability related strength properties by beating. It was assumed that the flaw-resisting ability of paper correlates with the runnability of the dry paper web. In-plane fracture properties were assumed ...

  19. Elastic Beating Pump Using Induced-Charge Electro-osmosis

    Science.gov (United States)

    Sugioka, Hideyuki

    2016-10-01

    Pumping a viscous liquid in a confined space is essential in microfluidic systems because the pressure-driven flow rate through small channels decreases with the third or fourth power of the channel size. Hence, inspired by a cilium's pumping ability in a confined space, we propose an elastic beating pump using a hydrodynamic force due to induced-charge electro-osmosis (ICEO) and numerically examine the pumping performance. By the multiphysics coupled simulation technique based on the boundary element method along with the thin double-layer approximation, we find that by selecting the optimum rigidity of the elastic beam, the ICEO elastic beating pump functions effectively at high frequencies with low applied voltages and shows a large average flow velocity with a remarkably large peak velocity that may be useful to flow a liquid with unexpectedly high viscosity. Furthermore, we propose a simple model that explains the characteristics of the time response behavior of the ICEO elastic beating pump tosome extent. By this analysis, we can considerably contribute to developments in studies on the artificial cilia having versatile functions.

  20. Beating Depression …Help Is Available

    Science.gov (United States)

    ... Navigation Bar Home Current Issue Past Issues Beating Depression …Help Is Available Past Issues / Summer 2007 Table ... treatments are available from your physician. Types of Depression Just like other illnesses, such as heart disease, ...

  1. High Blood Pressure: Keep the Beat Recipes

    Science.gov (United States)

    ... this page please turn Javascript on. Feature: High Blood Pressure Keep the Beat Recipes Past Issues / Fall 2011 ... National Heart, Lung, and Blood Institute To Improve Blood Pressure, Try the DASH Diet If you're one ...

  2. Heart Beat Classification Using Particle Swarm Optimization

    OpenAIRE

    Ali Khazaee

    2013-01-01

    This paper proposes a novel system to classify three types of electrocardiogram beats, namely normal beats and two manifestations of heart arrhythmia. This system includes three main modules: a feature extraction module, a classifier module, and an optimization module. In the feature extraction module, a proper set combining the shape features and timing features is proposed as the efficient characteristic of the patterns. In the classifier module, a multi-class support vector machine (SVM)-b...

  3. Walking to the beat of different drums: practical implications for the use of acoustic rhythms in gait rehabilitation.

    Science.gov (United States)

    Roerdink, Melvyn; Bank, Paulina J M; Peper, C Lieke E; Beek, Peter J

    2011-04-01

    Acoustic rhythms are frequently used in gait rehabilitation, with positive instantaneous and prolonged transfer effects on various gait characteristics. The gait modifying ability of acoustic rhythms depends on how well gait is tied to the beat, which can be assessed with measures of relative timing of auditory-motor coordination. We examined auditory-motor coordination in 20 healthy elderly individuals walking to metronome beats with pacing frequencies slower than, equal to, and faster than their preferred cadence. We found that more steps were required to adjust gait to the beat, the more the metronome rate deviated from the preferred cadence. Furthermore, participants anticipated the beat with their footfalls to various degrees, depending on the metronome rate; the faster the tempo, the smaller the phase advance or phase lead. Finally, the variability in the relative timing between footfalls and the beat was smaller for metronome rates closer to the preferred cadence, reflecting superior auditory-motor coordination. These observations have three practical implications. First, instantaneous effects of acoustic stimuli on gait characteristics may typically be underestimated given the considerable number of steps required to attune gait to the beat in combination with the usual short walkways. Second, a systematic phase lead of footfalls to the beat does not necessarily reflect a reduced ability to couple gait to the metronome. Third, the efficacy of acoustic rhythms to modify gait depends on metronome rate. Gait is coupled best to the beat for metronome rates near the preferred cadence.

  4. Up to date on primary ciliary dyskinesia in children.

    Science.gov (United States)

    Pifferi, Massimo; Di Cicco, Maria; Piras, Martina; Cangiotti, Angela M; Saggese, Giuseppe

    2013-10-01

    Primary ciliary dyskinesia (PCD) is a congenital, clinically and ultrastructurally heterogeneous disease due to abnormal structure and/or function of cilia, with impaired mucociliary transport leading to several respiratory disorders. PCD can be diagnosed by the combination of thorough clinical examination with functional and ultrastructural analysis of the cilia. This paper shows progresses in PCD diagnosis obtained by ciliogenesis in culture evaluation of ciliated respiratory cells and by genetic analysis of mutations in candidate genes. Moreover, since to date no specific treatments are available to correct the ciliary dysfunction, the paper shows the proper therapeutical approach by the use of respiratory physiotherapy and regular exercise to favour airways clearance, by antibiotics administration to control acute airway infections. Macrolides administration as antiinflammatory option is suggested. PMID:23973004

  5. Myristoylated CIL-7 regulates ciliary extracellular vesicle biogenesis.

    Science.gov (United States)

    Maguire, Julie E; Silva, Malan; Nguyen, Ken C Q; Hellen, Elizabeth; Kern, Andrew D; Hall, David H; Barr, Maureen M

    2015-08-01

    The cilium both releases and binds to extracellular vesicles (EVs). EVs may be used by cells as a form of intercellular communication and mediate a broad range of physiological and pathological processes. The mammalian polycystins (PCs) localize to cilia, as well as to urinary EVs released from renal epithelial cells. PC ciliary trafficking defects may be an underlying cause of autosomal dominant polycystic kidney disease (PKD), and ciliary-EV interactions have been proposed to play a central role in the biology of PKD. In Caenorhabditis elegans and mammals, PC1 and PC2 act in the same genetic pathway, act in a sensory capacity, localize to cilia, and are contained in secreted EVs, suggesting ancient conservation. However, the relationship between cilia and EVs and the mechanisms generating PC-containing EVs remain an enigma. In a forward genetic screen for regulators of C. elegans PKD-2 ciliary localization, we identified CIL-7, a myristoylated protein that regulates EV biogenesis. Loss of CIL-7 results in male mating behavioral defects, excessive accumulation of EVs in the lumen of the cephalic sensory organ, and failure to release PKD-2::GFP-containing EVs to the environment. Fatty acylation, such as myristoylation and palmitoylation, targets proteins to cilia and flagella. The CIL-7 myristoylation motif is essential for CIL-7 function and for targeting CIL-7 to EVs. C. elegans is a powerful model with which to study ciliary EV biogenesis in vivo and identify cis-targeting motifs such as myristoylation that are necessary for EV-cargo association and function. PMID:26041936

  6. Meiotic chromosome behaviour in Cenchrus ciliaris

    Directory of Open Access Journals (Sweden)

    N. C. Visser

    1998-12-01

    Full Text Available A basic chromosome number of x = 9 has been confirmed for Cenchrus ciliaris L. Polyploidy is common and levels vary from tetraploid to hexaploid. Aneuploidv is reported for a single specimen, where two chromosomes of a single genome were lost. Various meiotic irregularities were observed. The highest incidence of meiotic abnormalities was observed in the pentaploid specimens. This was attributed to their uneven polyploid level All specimens varied from segmental alloploid to alloploid.

  7. Effect of acute ethanol administration on zebrafish tail-beat motion.

    Science.gov (United States)

    Bartolini, Tiziana; Mwaffo, Violet; Butail, Sachit; Porfiri, Maurizio

    2015-11-01

    Zebrafish is becoming a species of choice in neurobiological and behavioral studies of alcohol-related disorders. In these efforts, the activity of adult zebrafish is typically quantified using indirect activity measures that are either scored manually or identified automatically from the fish trajectory. The analysis of such activity measures has produced important insight into the effect of acute ethanol exposure on individual and social behavior of this vertebrate species. Here, we leverage a recently developed tracking algorithm that reconstructs fish body shape to investigate the effect of acute ethanol administration on zebrafish tail-beat motion in terms of amplitude and frequency. Our results demonstrate a significant effect of ethanol on the tail-beat amplitude as well as the tail-beat frequency, both of which were found to robustly decrease for high ethanol concentrations. Such a direct measurement of zebrafish motor functions is in agreement with evidence based on indirect activity measures, offering a complementary perspective in behavioral screening.

  8. Fifth-order attosecond polarization beats using twin color-locked noisy lights in cascade three-level system with Doppler-free approach

    Institute of Scientific and Technical Information of China (English)

    Jianping Song; Xiangchen Zhang; Yanpeng Zhang; Keqing Lu; Yu Feng; Chenli Gan; Long Li; Yuanyuan Li; Xiaojun Yu; Hao Ge; Ruiqiong Ma; Chuangshe Li

    2005-01-01

    Fifth-order attosecond sum-frequency polarization beat (FASPB) is studied in a cascade three level system with the phase-conjugation fourth-order coherence function theory. An improved schematic diagram of geometry, which is different from that inducing fifth-order femtosecond different-frequency polarization beat(FFDPB), is used to obtain FASPB. By analyzing the cases that pump beams have either narrow or broad bandwidth, it is found that the temporal behavior of the sum-frequency polarization beat signal depends on the properties of the lasers and transverse relaxation rate of the atomic energy-level system. Finally,the cascaded four-wave mixing (FWM) processes and the difference between attosecond and femtosecond polarization beats have been discussed, it is found that cascaded or sequential lower processes can often obscure the direct fifth-order polarization beat processes.

  9. Photosynthesis of Digitaria ciliaris during repeated soil drought and rewatering

    Institute of Scientific and Technical Information of China (English)

    YaYong Luo; XueYong Zhao; JingHui Zhang; YuLin Li; XiaoAn Zuo; DianChao Sun

    2015-01-01

    The ability of psammophyte photosynthesis to withstand and recover from severe droughts is crucial for vegetation sta-bility in semi-arid sandy lands. The responses of gas exchange and chlorophyll fluorescence of an annual grass, Digitaria ciliaris, were measured through three soil drought and rewatering cycles. Results showed that the net photosynthesis rate (Pn) decreased by 92%, 95%, and 63%at end of the three drought periods, respectively, water use efficiency (WUE) de-creased by 67%, 54%, and 48%, while the constant intercellular CO2 concentration (Ci) increased by 1.08, 0.88, and 0.45 times. During those three cycles, the trapping probability with no dark adaptation (Fv′/Fm′) decreased by 55%, 51%, and 9%, the electron transport per cross section (ET0′/CS0′) decreased by 63%, 42%, and 18%, and the dissipation per cross section (DI0′/CS0′) increased by 97%, 96%, and 21%. These results indicated that D. ciliaris was subjected to photoinhi-bition and some non-stomatal limitation of photosynthesis under drought. However, after four days of rewatering, its photosynthetic characteristics were restored to control values. This capability to recover from drought may contribute to making the plant's use of water as efficient as possible. Furthermore, the photosynthesis decreased more slowly in the subsequent drought cycles than in the first cycle, allowing D. ciliaris to enhance its future drought tolerance after drought hardening. Thus, it acclimatizes itself to repeated soil drought.

  10. Recessive HYDIN mutations cause primary ciliary dyskinesia without randomization of left-right body asymmetry.

    Science.gov (United States)

    Olbrich, Heike; Schmidts, Miriam; Werner, Claudius; Onoufriadis, Alexandros; Loges, Niki T; Raidt, Johanna; Banki, Nora Fanni; Shoemark, Amelia; Burgoyne, Tom; Al Turki, Saeed; Hurles, Matthew E; Köhler, Gabriele; Schroeder, Josef; Nürnberg, Gudrun; Nürnberg, Peter; Chung, Eddie M K; Reinhardt, Richard; Marthin, June K; Nielsen, Kim G; Mitchison, Hannah M; Omran, Heymut

    2012-10-01

    Primary ciliary dyskinesia (PCD) is a genetically heterogeneous recessive disorder characterized by defective cilia and flagella motility. Chronic destructive-airway disease is caused by abnormal respiratory-tract mucociliary clearance. Abnormal propulsion of sperm flagella contributes to male infertility. Genetic defects in most individuals affected by PCD cause randomization of left-right body asymmetry; approximately half show situs inversus or situs ambiguous. Almost 70 years after the hy3 mouse possessing Hydin mutations was described as a recessive hydrocephalus model, we report HYDIN mutations in PCD-affected persons without hydrocephalus. By homozygosity mapping, we identified a PCD-associated locus, chromosomal region 16q21-q23, which contains HYDIN. However, a nearly identical 360 kb paralogous segment (HYDIN2) in chromosomal region 1q21.1 complicated mutational analysis. In three affected German siblings linked to HYDIN, we identified homozygous c.3985G>T mutations that affect an evolutionary conserved splice acceptor site and that subsequently cause aberrantly spliced transcripts predicting premature protein termination in respiratory cells. Parallel whole-exome sequencing identified a homozygous nonsense HYDIN mutation, c.922A>T (p.Lys307(∗)), in six individuals from three Faroe Island PCD-affected families that all carried an 8.8 Mb shared haplotype across HYDIN, indicating an ancestral founder mutation in this isolated population. We demonstrate by electron microscopy tomography that, consistent with the effects of loss-of-function mutations, HYDIN mutant respiratory cilia lack the C2b projection of the central pair (CP) apparatus; similar findings were reported in Hydin-deficient Chlamydomonas and mice. High-speed videomicroscopy demonstrated markedly reduced beating amplitudes of respiratory cilia and stiff sperm flagella. Like the hy3 mouse model, all nine PCD-affected persons had normal body composition because nodal cilia function is

  11. Beat note stabilization of a 10-60 GHz dual-polarization microlaser through optical down conversion.

    Science.gov (United States)

    Rolland, A; Brunel, M; Loas, G; Frein, L; Vallet, M; Alouini, M

    2011-02-28

    Down-conversion of a high-frequency beat note to an intermediate frequency is realized by a Mach-Zehnder intensity modulator. Optically-carried microwave signals in the 10-60 GHz range are synthesized by using a two-frequency solid-state microchip laser as a voltage-controlled oscillator inside a digital phase-locked loop. We report an in-loop relative frequency stability better than 2.5×10⁻¹¹. The principle is applicable to beat notes in the millimeter-wave range.

  12. Proarrhythmic electrical remodelling is associated with increased beat-to-beat variability of repolarisation

    DEFF Research Database (Denmark)

    Thomsen, Morten Bækgaard; Oros, Avram; Schoenmakers, Marieke;

    2007-01-01

    Acquired long-QT syndrome in combination with increased beat-to-beat variability of repolarisation duration (BVR) is associated with lethal torsades de pointes arrhythmias (TdP) in dogs with remodelled heart after atrioventricular block (AVB). We evaluated the relative contributions of bradycardia...

  13. Mutations in GAS8, a Gene Encoding a Nexin-Dynein Regulatory Complex Subunit, Cause Primary Ciliary Dyskinesia with Axonemal Disorganization.

    Science.gov (United States)

    Jeanson, Ludovic; Thomas, Lucie; Copin, Bruno; Coste, André; Sermet-Gaudelus, Isabelle; Dastot-Le Moal, Florence; Duquesnoy, Philippe; Montantin, Guy; Collot, Nathalie; Tissier, Sylvie; Papon, Jean-François; Clement, Annick; Louis, Bruno; Escudier, Estelle; Amselem, Serge; Legendre, Marie

    2016-08-01

    Primary ciliary dyskinesia (PCD) is an autosomal recessive disease characterized by chronic respiratory infections of the upper and lower airways, hypofertility, and, in approximately half of the cases, situs inversus. This complex phenotype results from defects in motile cilia and sperm flagella. Among the numerous genes involved in PCD, very few-including CCDC39 and CCDC40-carry mutations that lead to a disorganization of ciliary axonemes with microtubule misalignment. Focusing on this particular phenotype, we identified bi-allelic loss-of-function mutations in GAS8, a gene that encodes a subunit of the nexin-dynein regulatory complex (N-DRC) orthologous to DRC4 of the flagellated alga Chlamydomonas reinhardtii. Unlike the majority of PCD patients, individuals with GAS8 mutations have motile cilia, which, as documented by high-speed videomicroscopy, display a subtle beating pattern defect characterized by slightly reduced bending amplitude. Immunofluorescence studies performed on patients' respiratory cilia revealed that GAS8 is not required for the proper expression of CCDC39 and CCDC40. Rather, mutations in GAS8 affect the subcellular localization of another N-DRC subunit called DRC3. Overall, this study, which identifies GAS8 as a PCD gene, unveils the key importance of the corresponding protein in N-DRC integrity and in the proper alignment of axonemal microtubules in humans. PMID:27120127

  14. Measuring Neural Entrainment to Beat and Meter in Infants: Effects of Music Background

    Science.gov (United States)

    Cirelli, Laura K.; Spinelli, Christina; Nozaradan, Sylvie; Trainor, Laurel J.

    2016-01-01

    Caregivers often engage in musical interactions with their infants. For example, parents across cultures sing lullabies and playsongs to their infants from birth. Behavioral studies indicate that infants not only extract beat information, but also group these beats into metrical hierarchies by as early as 6 months of age. However, it is not known how this is accomplished in the infant brain. An EEG frequency-tagging approach has been used successfully with adults to measure neural entrainment to auditory rhythms. The current study is the first to use this technique with infants in order to investigate how infants' brains encode rhythms. Furthermore, we examine how infant and parent music background is associated with individual differences in rhythm encoding. In Experiment 1, EEG was recorded while 7-month-old infants listened to an ambiguous rhythmic pattern that could be perceived to be in two different meters. In Experiment 2, EEG was recorded while 15-month-old infants listened to a rhythmic pattern with an unambiguous meter. In both age groups, information about music background (parent music training, infant music classes, hours of music listening) was collected. Both age groups showed clear EEG responses frequency-locked to the rhythms, at frequencies corresponding to both beat and meter. For the younger infants (Experiment 1), the amplitudes at duple meter frequencies were selectively enhanced for infants enrolled in music classes compared to those who had not engaged in such classes. For the older infants (Experiment 2), amplitudes at beat and meter frequencies were larger for infants with musically-trained compared to musically-untrained parents. These results suggest that the frequency-tagging method is sensitive to individual differences in beat and meter processing in infancy and could be used to track developmental changes. PMID:27252619

  15. Wavelength of ocean waves and surf beat at duck from array measurements

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, A.A.; Menon, H.B.; Sarma, Y.V.B.; Jog, P.D.; Almeida, A.M.

    Wavelength of ocean waves and surf beat (infra gravity waves) has for the first time been computed as a function of frequency from different combinations of non-collinear 3-gauge arrays. Data at the 15-gauge polygonal array at 8 m depth at Duck...

  16. Short-term beat-to-beat variability of the QT interval is increased and correlates with parameters of left ventricular hypertrophy in patients with hypertrophic cardiomyopathy.

    Science.gov (United States)

    Orosz, Andrea; Baczkó, István; Nagy, Viktória; Gavallér, Henriette; Csanády, Miklós; Forster, Tamás; Papp, Julius Gy; Varró, András; Lengyel, Csaba; Sepp, Róbert

    2015-09-01

    Stratification models for the prediction of sudden cardiac death (SCD) are inappropriate in patients with hypertrophic cardiomyopathy (HCM). We investigated conventional electrocardiogram (ECG) repolarization parameters and the beat-to-beat short-term QT interval variability (QT-STV), a new parameter of proarrhythmic risk, in 37 patients with HCM (21 males, average age 48 ± 15 years). Resting ECGs were recorded for 5 min and the frequency corrected QT interval (QTc), QT dispersion (QTd), beat-to-beat short-term variability of QT interval (QT-STV), and the duration of terminal part of T waves (Tpeak-Tend) were calculated. While all repolarization parameters were significantly increased in patients with HCM compared with the controls (QTc, 488 ± 61 vs. 434 ± 23 ms, p < 0.0001; QT-STV, 4.5 ± 2 vs. 3.2 ± 1 ms, p = 0.0002; Tpeak-Tend duration, 107 ± 27 vs. 91 ± 10 ms, p = 0.0015; QTd, 47 ± 17 vs. 34 ± 9 ms, p = 0.0002), QT-STV had the highest relative increase (+41%). QT-STV also showed the best correlation with indices of left ventricular (LV) hypertrophy, i.e., maximal LV wall thickness normalized for body surface area (BSA; r = 0.461, p = 0.004) or LV mass (determined by cardiac magnetic resonance imaging) normalized for BSA (r = 0.455, p = 0.015). In summary, beat-to-beat QT-STV showed the most marked increase in patients with HCM and may represent a novel marker that merits further testing for increased SCD risk in HCM. PMID:26313025

  17. Study of beat phenomenon on a pile-supported pipeline system subjected to wave loading

    Institute of Scientific and Technical Information of China (English)

    Meng Xun; Huang Weiping; Li Huajun

    2007-01-01

    Classical beat phenomenon has been observed in most combined systems. The focus of this paper is to provide a better understanding of this phenomenon in an offshore pile-supported pipeline system. The beat phenomeon is caused by the coupling movement of the pipeline and its vertical pile support under certain conditions. It can induce excessive vibration and cause fatigue failure at pipe elbow. However, in some circumstances it does not exist. Numerical results in both frequency and time domains are presented to elucidate this phenomenon in a combined pipeline system. The conclusions of this paper could give constructive guidance to future design of simply supported pipeline systems.

  18. Beat that Word: How Listeners Integrate Beat Gesture and Focus in Multimodal Speech Discourse.

    Science.gov (United States)

    Dimitrova, Diana; Chu, Mingyuan; Wang, Lin; Özyürek, Asli; Hagoort, Peter

    2016-09-01

    Communication is facilitated when listeners allocate their attention to important information (focus) in the message, a process called "information structure." Linguistic cues like the preceding context and pitch accent help listeners to identify focused information. In multimodal communication, relevant information can be emphasized by nonverbal cues like beat gestures, which represent rhythmic nonmeaningful hand movements. Recent studies have found that linguistic and nonverbal attention cues are integrated independently in single sentences. However, it is possible that these two cues interact when information is embedded in context, because context allows listeners to predict what information is important. In an ERP study, we tested this hypothesis and asked listeners to view videos capturing a dialogue. In the critical sentence, focused and nonfocused words were accompanied by beat gestures, grooming hand movements, or no gestures. ERP results showed that focused words are processed more attentively than nonfocused words as reflected in an N1 and P300 component. Hand movements also captured attention and elicited a P300 component. Importantly, beat gesture and focus interacted in a late time window of 600-900 msec relative to target word onset, giving rise to a late positivity when nonfocused words were accompanied by beat gestures. Our results show that listeners integrate beat gesture with the focus of the message and that integration costs arise when beat gesture falls on nonfocused information. This suggests that beat gestures fulfill a unique focusing function in multimodal discourse processing and that they have to be integrated with the information structure of the message.

  19. Numerical modeling of surf beat generated by moving breakpoint

    Institute of Scientific and Technical Information of China (English)

    DONG GuoHai; MA XiaoZhou; TENG Bin

    2009-01-01

    As an important hydrodynamic phenomenon in the nearshore zone, the cross-shore surf beat is nu-merically studied in this paper with a fully nonlinear Boussinesq-type model, which resolves the pri-mary wave motion as well as the long waves. Compared with the classical Boussinesq equations, the equations adopted here allow for improved linear dispersion characteristics. Wave breaking and run-up in the swash zone are included in the numerical model. Mutual interactions between short waves and long waves are inherent in the model. The numerical study of long waves is based on bichromatic wave groups with a wide range of mean frequencies, group frequencies and modulation rates. The cross-shore variation in the amplitudes of short waves and long waves is investigated. The model results are compared with laboratory experiments from the literature and good agreement is found.

  20. Numerical modeling of surf beat generated by moving breakpoint

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    As an important hydrodynamic phenomenon in the nearshore zone, the cross-shore surf beat is numerically studied in this paper with a fully nonlinear Boussinesq-type model, which resolves the primary wave motion as well as the long waves. Compared with the classical Boussinesq equations, the equations adopted here allow for improved linear dispersion characteristics. Wave breaking and run-up in the swash zone are included in the numerical model. Mutual interactions between short waves and long waves are inherent in the model. The numerical study of long waves is based on bichromatic wave groups with a wide range of mean frequencies, group frequencies and modulation rates. The cross-shore variation in the amplitudes of short waves and long waves is investigated. The model results are compared with laboratory experiments from the literature and good agreement is found.

  1. Discinesia ciliar primária Primary ciliary dyskinesia

    Directory of Open Access Journals (Sweden)

    JOSÉ WELLINGTON ALVES DOS SANTOS

    2001-09-01

    Full Text Available Discinesia ciliar primária é uma doença autossômica recessiva caracterizada pela história de infecções repetidas do trato respiratório superior e inferior, otite média, bronquite e rinossinusite, associada a situs inversus na metade dos casos. O diagnóstico é estabelecido pela análise ciliar ultra-estrutural de espécimes respiratórios, após a exclusão inicial de outras doenças, como fibrose cística, deficiência de alfa-1-antitripsina, imunodeficiências (IgG, neutrófilos e complemento e síndrome de Young. O propósito deste artigo é revisar os achados clínicos, o diagnóstico e o manejo da discinesia ciliar primária, incluindo um fluxograma diagnóstico.Primary ciliary dyskinesia is an autosomal recessive disorder characterized by a history of recurrent upper and lower respiratory tract infections with chronic otitis media, bronchitis and rhinosinusitis, associated with situs inversus in 50% of cases. The diagnosis is established by ciliary ultrastructural analysis of respiratory specimens, after ruling out some disorders as cystic fibrosis, alpha-1 anti-trypsin deficiency, immune deficiencies (IgG, neutrophils and complement and Young's syndrome. The purpose of this paper is to review the clinical features, diagnosis and management of primary ciliary dyskinesia, including a diagnostic algorithm.

  2. Finger-to-Beat Coordination Skill of Non-dancers, Street Dancers, and the World Champion of a Street-Dance Competition

    Science.gov (United States)

    Miura, Akito; Fujii, Shinya; Okano, Masahiro; Kudo, Kazutoshi; Nakazawa, Kimitaka

    2016-01-01

    The coordination of body movements to a musical beat is a common feature of many dance styles. However, the auditory–motor coordination skills of dancers remain largely uninvestigated. The purpose of this study was to examine the auditory–motor coordination skills of non-dancers, street dancers, and the winner of a celebrated international street dance competition, while coordinating their rhythmic finger movements to a beat. The beat rate of a metronome increased from 1.0 to 3.7 Hz. The participants were asked to either flex or extend their index fingers on the beat in each condition. Under the extend-on-the-beat condition, both the dancers and non-dancers showed a spontaneous transition from the extend-on-the-beat to the flex-on-the-beat or to a phase wandering pattern. However, the critical frequency at which the transition occurred was significantly higher in the dancers (3.3 Hz) than in the non-dancers (2.6 Hz). Under the flex-on-the-beat condition, the dancers were able to maintain their coordination pattern more stably at high beat rates compared to the non-dancers. Furthermore, the world champion matched the timing of movement peak velocity to the beat across the different beat rates. This may give a sense of unity between the movement and the beat for the audience because the peak velocity of the rhythmic movement works as a temporal cue for the audiovisual synchrony perception. These results suggest that the skills of accomplished dancers lie in their small finger movements and that the sensorimotor learning of street dance is characterized by a stabilization of the coordination patterns, including the inhibition of an unintentional transition to other coordination patterns. PMID:27148148

  3. Finger-to-Beat Coordination Skill of Non-dancers, Street Dancers, and the World Champion of a Street-Dance Competition.

    Science.gov (United States)

    Miura, Akito; Fujii, Shinya; Okano, Masahiro; Kudo, Kazutoshi; Nakazawa, Kimitaka

    2016-01-01

    The coordination of body movements to a musical beat is a common feature of many dance styles. However, the auditory-motor coordination skills of dancers remain largely uninvestigated. The purpose of this study was to examine the auditory-motor coordination skills of non-dancers, street dancers, and the winner of a celebrated international street dance competition, while coordinating their rhythmic finger movements to a beat. The beat rate of a metronome increased from 1.0 to 3.7 Hz. The participants were asked to either flex or extend their index fingers on the beat in each condition. Under the extend-on-the-beat condition, both the dancers and non-dancers showed a spontaneous transition from the extend-on-the-beat to the flex-on-the-beat or to a phase wandering pattern. However, the critical frequency at which the transition occurred was significantly higher in the dancers (3.3 Hz) than in the non-dancers (2.6 Hz). Under the flex-on-the-beat condition, the dancers were able to maintain their coordination pattern more stably at high beat rates compared to the non-dancers. Furthermore, the world champion matched the timing of movement peak velocity to the beat across the different beat rates. This may give a sense of unity between the movement and the beat for the audience because the peak velocity of the rhythmic movement works as a temporal cue for the audiovisual synchrony perception. These results suggest that the skills of accomplished dancers lie in their small finger movements and that the sensorimotor learning of street dance is characterized by a stabilization of the coordination patterns, including the inhibition of an unintentional transition to other coordination patterns. PMID:27148148

  4. Riding the wave of ependymal cilia: genetic susceptibility to hydrocephalus in primary ciliary dyskinesia.

    Science.gov (United States)

    Lee, Lance

    2013-09-01

    Congenital hydrocephalus is a relatively common and debilitating birth defect with several known physiological causes. Dysfunction of motile cilia on the ependymal cells that line the ventricular surface of the brain can result in hydrocephalus by hindering the proper flow of cerebrospinal fluid. As a result, hydrocephalus can be associated with primary ciliary dyskinesia, a rare pediatric syndrome resulting from defects in ciliary and flagellar motility. Although the prevalence of hydrocephalus in primary ciliary dyskinesia patients is low, it is a common hallmark of the disease in mouse models, suggesting that distinct genetic mechanisms underlie the differences in the development and physiology of human and mouse brains. Mouse models of primary ciliary dyskinesia reveal strain-specific differences in the appearance and severity of hydrocephalus, indicating the presence of genetic modifiers segregating in inbred strains. These models may provide valuable insight into the genetic mechanisms that regulate susceptibility to hydrocephalus under the conditions of ependymal ciliary dysfunction. PMID:23686703

  5. Beating and insulting children as a risk for adult cancer, cardiac disease and asthma.

    Science.gov (United States)

    Hyland, Michael E; Alkhalaf, Ahmed M; Whalley, Ben

    2013-12-01

    The use of physical punishment for children is associated with poor psychological and behavioral outcomes, but the causal pathway is controversial, and the effects on later physical health unknown. We conducted a cross-sectional survey of asthma, cancer, and cardiac patients (150 in each category, 75 male) recruited from outpatient clinics and 250 healthy controls (125 male). All participants were 40-60 years old and citizens of Saudi Arabia, where the use of beating and insults is an acceptable parenting style. Demographic data and recalled frequency of beatings and insults as a child were assessed on an 8-point scale. Beating and insults were highly correlated (ρ = 0.846). Propensity score matching was used to control for demographic differences between the disease and healthy groups. After controlling for differences, more frequent beating (once or more per month) and insults were associated with a significantly increased risk for cancer (RR = 1.7), cardiac disease (RR = 1.3) and asthma (RR = 1.6), with evidence of increased risk for cancer and asthma with beating frequency of once every 6 months or more. Our results show that a threatening parenting style of beating and insults is associated with increased risk for somatic disease, possibly because this form of parenting induces stress. Our findings are consistent with previous research showing that child abuse and other early life stressors adversely affect adult somatic health, but provide evidence that the pathogenic effects occur also with chronic minor stress. A stress-inducing parenting style, even when normative, has long term adverse health consequences. PMID:23054177

  6. Beat Noise Limitation in Coherent Time-Spreading OCDMA Network

    Institute of Scientific and Technical Information of China (English)

    Ken-ichi; Kitayama; Koji; Mutsushima

    2003-01-01

    The BER performance of the coherent time-spreading OCDMA network is analyzed by considering the MAI and beat noises as well as the other additive noises. The influence and solution for the beat noise issue are discussed.

  7. Heat Beats Cold for Treating Jellyfish Stings

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_158584.html Heat Beats Cold for Treating Jellyfish Stings Evidence favors hot water or hot packs to ease pain ... 29, 2016 (HealthDay News) -- If you're unlucky enough to suffer a jellyfish sting, new research says that heat is better than cold for easing the pain. ...

  8. Beat the Instructor: An Introductory Forecasting Game

    Science.gov (United States)

    Snider, Brent R.; Eliasson, Janice B.

    2013-01-01

    This teaching brief describes a 30-minute game where student groups compete in-class in an introductory time-series forecasting exercise. The students are challenged to "beat the instructor" who competes using forecasting techniques that will be subsequently taught. All forecasts are graphed prior to revealing the randomly generated…

  9. Quantum beats of the rigid rotor

    OpenAIRE

    Kowalski, K.; Rembieliński, J.

    2013-01-01

    The dynamics is investigated of a free particle on a sphere (rigid rotor or rotator) that is initially in a coherent state. The instability of coherent states with respect to the free evolution leads to nontrivial time-development of averages of observables representing the position of a particle on a sphere that can be interpreted as quantum beats.

  10. Model for the heart beat-to-beat time series during meditation

    Science.gov (United States)

    Capurro, A.; Diambra, L.; Malta, C. P.

    2003-09-01

    We present a model for the respiratory modulation of the heart beat-to-beat interval series. The model consists of a pacemaker, that simulates the membrane potential of the sinoatrial node, modulated by a periodic input signal plus correlated noise that simulates the respiratory input. The model was used to assess the waveshape of the respiratory signals needed to reproduce in the phase space the trajectory of experimental heart beat-to-beat interval data. The data sets were recorded during meditation practices of the Chi and Kundalini Yoga techniques. Our study indicates that in the first case the respiratory signal has the shape of a smoothed square wave, and in the second case it has the shape of a smoothed triangular wave.

  11. Cardiac beat-to-beat alternations driven by unusual spiral waves

    OpenAIRE

    Kim, Tae Yun; Woo, Sung-Jae; Hwang, Seong-min; Hong, Jin Hee; Lee, Kyoung J.

    2007-01-01

    Alternans, a beat-to-beat temporal alternation in the sequence of heartbeats, is a known precursor of the development of cardiac fibrillation, leading to sudden cardiac death. The equally important precursor of cardiac arrhythmias is the rotating spiral wave of electro-mechanical activity, or reentry, on the heart tissue. Here, we show that these two seemingly different phenomena can have a remarkable relationship. In well controlled in vitro tissue cultures, isotropic populations of rat vent...

  12. Left ventricular beat to beat performance in atrial fibrillation: dependence on contractility, preload, and afterload

    OpenAIRE

    Muntinga, H; Gosselink, A; Blanksma, P; De Kam, P J; van der Wall, E; Crijns, H.

    1999-01-01

    OBJECTIVE—To assess independent determinants of beat to beat variation in left ventricular performance during atrial fibrillation.
DESIGN—Prospective study.
SETTING—University hospital.
PATIENTS—Seven patients with chronic non-valvar atrial fibrillation.
INTERVENTIONS—Invasive and non-invasive haemodynamic variables were assessed using a non-imaging computerised nuclear probe, a balloon tipped flow directed catheter, and a non-invasive fingertip blood pressure measurement system linked to a p...

  13. QRS template matching for recognition of ventricular ectopic beats.

    Science.gov (United States)

    Krasteva, Vessela; Jekova, Irena

    2007-12-01

    We propose a quasi real-time method for discrimination of ventricular ectopic beats from both supraventricular and paced beats in the electrocardiogram (ECG). The heartbeat waveforms were evaluated within a fixed-length window around the fiducial points (100 ms before, 450 ms after). Our algorithm was designed to operate with minimal expert intervention and we define that the operator is required only to initially select up to three 'normal' heartbeats (the most frequently seen supraventricular or paced complexes). These were named original QRS templates and their copies were substituted continuously throughout the ECG analysis to capture slight variations in the heartbeat waveforms of the patient's sustained rhythm. The method is based on matching of the evaluated heartbeat with the QRS templates by a complex set of ECG descriptors, including maximal cross-correlation, area difference and frequency spectrum difference. Temporal features were added by analyzing the R-R intervals. The classification criteria were trained by statistical assessment of the ECG descriptors calculated for all heartbeats in MIT-BIH Supraventricular Arrhythmia Database. The performance of the classifiers was tested on the independent MIT-BIH Arrhythmia Database. The achieved unbiased accuracy is represented by sensitivity of 98.4% and specificity of 98.86%, both being competitive to other published studies. The provided computationally efficient techniques enable the fast post-recording analysis of lengthy Holter-monitor ECG recordings, as well as they can serve as a quasi real-time detection method embedded into surface ECG monitors. PMID:17805974

  14. Unraveling the nature of coherent beatings in chlorosomes

    Energy Technology Data Exchange (ETDEWEB)

    Dostál, Jakub [Department of Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund (Sweden); Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague (Czech Republic); Mančal, Tomáš; Pšenčík, Jakub [Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague (Czech Republic); Vácha, František [Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice (Czech Republic); Zigmantas, Donatas, E-mail: donatas.zigmantas@chemphys.lu.se [Department of Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund (Sweden)

    2014-03-21

    Coherent two-dimensional (2D) spectroscopy at 80 K was used to study chlorosomes isolated from green sulfur bacterium Chlorobaculum tepidum. Two distinct processes in the evolution of the 2D spectrum are observed. The first being exciton diffusion, seen in the change of the spectral shape occurring on a 100-fs timescale, and the second being vibrational coherences, realized through coherent beatings with frequencies of 91 and 145 cm{sup −1} that are dephased during the first 1.2 ps. The distribution of the oscillation amplitude in the 2D spectra is independent of the evolution of the 2D spectral shape. This implies that the diffusion energy transfer process does not transfer coherences within the chlorosome. Remarkably, the oscillatory pattern observed in the negative regions of the 2D spectrum (dominated by the excited state absorption) is a mirror image of the oscillations found in the positive part (originating from the stimulated emission and ground state bleach). This observation is surprising since it is expected that coherences in the electronic ground and excited states are generated with the same probability and the latter dephase faster in the presence of fast diffusion. Moreover, the relative amplitude of coherent beatings is rather high compared to non-oscillatory signal despite the reported low values of the Huang-Rhys factors. The origin of these effects is discussed in terms of the vibronic and Herzberg-Teller couplings.

  15. Finger beat-to-beat blood pressure responses to successive hand elevations.

    Science.gov (United States)

    Raamat, R; Jagomägi, K; Talts, J; Mäger, I

    2009-06-01

    We investigated finger beat-to-beat blood pressure responses to a series of successive hand elevations in 14 normal volunteers. By passive elevation of the hand by 40 cm and lowering it again after a minute, calibrated hydrostatic pressure changes were induced in the finger arteries of the subjects. Three successive procedures with a 2-min interval between them were performed. Transitions between positions were completed smoothly over a 10-s period. Non-invasive beat-to-beat mean arterial pressure (MAP) in the finger arteries was measured by applying the servo-oscillometric physiograph (University of Tartu, Estonia). A good agreement between the evoked MAP changes during all the three hand elevations (-31.2, -30.4 and -30.0 mmHg, respectively) and the calculated hydrostatic pressure change (-31.0 mmHg) was obtained. The height difference of approximately 40 cm and rate of 4-5 cm/s can be recommended for the hand elevation test, greater postural changes and higher rates may diminish agreement between the measured blood pressure response and the corresponding hydrostatic pressure change. The applied hydrostatic test may be helpful for assessing the accuracy of beat-to-beat finger blood pressure measurement. PMID:19027338

  16. Model for the respiratory modulation of the heart beat-to-beat time interval series

    Science.gov (United States)

    Capurro, Alberto; Diambra, Luis; Malta, C. P.

    2005-09-01

    In this study we present a model for the respiratory modulation of the heart beat-to-beat interval series. The model consists of a set of differential equations used to simulate the membrane potential of a single rabbit sinoatrial node cell, excited with a periodic input signal with added correlated noise. This signal, which simulates the input from the autonomous nervous system to the sinoatrial node, was included in the pacemaker equations as a modulation of the iNaK current pump and the potassium current iK. We focus at modeling the heart beat-to-beat time interval series from normal subjects during meditation of the Kundalini Yoga and Chi techniques. The analysis of the experimental data indicates that while the embedding of pre-meditation and control cases have a roughly circular shape, it acquires a polygonal shape during meditation, triangular for the Kundalini Yoga data and quadrangular in the case of Chi data. The model was used to assess the waveshape of the respiratory signals needed to reproduce the trajectory of the experimental data in the phase space. The embedding of the Chi data could be reproduced using a periodic signal obtained by smoothing a square wave. In the case of Kundalini Yoga data, the embedding was reproduced with a periodic signal obtained by smoothing a triangular wave having a rising branch of longer duration than the decreasing branch. Our study provides an estimation of the respiratory signal using only the heart beat-to-beat time interval series.

  17. Cdc42 deficiency causes ciliary abnormalities and cystic kidneys.

    Science.gov (United States)

    Choi, Soo Young; Chacon-Heszele, Maria F; Huang, Liwei; McKenna, Sarah; Wilson, F Perry; Zuo, Xiaofeng; Lipschutz, Joshua H

    2013-09-01

    Ciliogenesis and cystogenesis require the exocyst, a conserved eight-protein trafficking complex that traffics ciliary proteins. In culture, the small GTPase Cdc42 co-localizes with the exocyst at primary cilia and interacts with the exocyst component Sec10. The role of Cdc42 in vivo, however, is not well understood. Here, knockdown of cdc42 in zebrafish produced a phenotype similar to sec10 knockdown, including tail curvature, glomerular expansion, and mitogen-activated protein kinase (MAPK) activation, suggesting that cdc42 and sec10 cooperate in ciliogenesis. In addition, cdc42 knockdown led to hydrocephalus and loss of photoreceptor cilia. Furthermore, there was a synergistic genetic interaction between zebrafish cdc42 and sec10, suggesting that cdc42 and sec10 function in the same pathway. Mice lacking Cdc42 specifically in kidney tubular epithelial cells died of renal failure within weeks of birth. Histology revealed cystogenesis in distal tubules and collecting ducts, decreased ciliogenesis in cyst cells, increased tubular cell proliferation, increased apoptosis, increased fibrosis, and led to MAPK activation, all of which are features of polycystic kidney disease, especially nephronophthisis. Taken together, these results suggest that Cdc42 localizes the exocyst to primary cilia, whereupon the exocyst targets and docks vesicles carrying ciliary proteins. Abnormalities in this pathway result in deranged ciliogenesis and polycystic kidney disease.

  18. Cdc42 deficiency causes ciliary abnormalities and cystic kidneys.

    Science.gov (United States)

    Choi, Soo Young; Chacon-Heszele, Maria F; Huang, Liwei; McKenna, Sarah; Wilson, F Perry; Zuo, Xiaofeng; Lipschutz, Joshua H

    2013-09-01

    Ciliogenesis and cystogenesis require the exocyst, a conserved eight-protein trafficking complex that traffics ciliary proteins. In culture, the small GTPase Cdc42 co-localizes with the exocyst at primary cilia and interacts with the exocyst component Sec10. The role of Cdc42 in vivo, however, is not well understood. Here, knockdown of cdc42 in zebrafish produced a phenotype similar to sec10 knockdown, including tail curvature, glomerular expansion, and mitogen-activated protein kinase (MAPK) activation, suggesting that cdc42 and sec10 cooperate in ciliogenesis. In addition, cdc42 knockdown led to hydrocephalus and loss of photoreceptor cilia. Furthermore, there was a synergistic genetic interaction between zebrafish cdc42 and sec10, suggesting that cdc42 and sec10 function in the same pathway. Mice lacking Cdc42 specifically in kidney tubular epithelial cells died of renal failure within weeks of birth. Histology revealed cystogenesis in distal tubules and collecting ducts, decreased ciliogenesis in cyst cells, increased tubular cell proliferation, increased apoptosis, increased fibrosis, and led to MAPK activation, all of which are features of polycystic kidney disease, especially nephronophthisis. Taken together, these results suggest that Cdc42 localizes the exocyst to primary cilia, whereupon the exocyst targets and docks vesicles carrying ciliary proteins. Abnormalities in this pathway result in deranged ciliogenesis and polycystic kidney disease. PMID:23766535

  19. Algorithm for identifying and separating beats from arterial pulse records

    Directory of Open Access Journals (Sweden)

    Valentinuzzi Max E

    2005-08-01

    Full Text Available Abstract Background This project was designed as an epidemiological aid-selecting tool for a small country health center with the general objective of screening out possible coronary patients. Peripheral artery function can be non-invasively evaluated by impedance plethysmography. Changes in these vessels appear as good predictors of future coronary behavior. Impedance plethysmography detects volume variations after simple occlusive maneuvers that may show indicative modifications in arterial/venous responses. Averaging of a series of pulses is needed and this, in turn, requires proper determination of the beginning and end of each beat. Thus, the objective here is to describe an algorithm to identify and separate out beats from a plethysmographic record. A secondary objective was to compare the output given by human operators against the algorithm. Methods The identification algorithm detected the beat's onset and end on the basis of the maximum rising phase, the choice of possible ventricular systolic starting points considering cardiac frequency, and the adjustment of some tolerance values to optimize the behavior. Out of 800 patients in the study, 40 occlusive records (supradiastolic- subsystolic were randomly selected without any preliminary diagnosis. Radial impedance plethysmographic pulse and standard ECG were recorded digitizing and storing the data. Cardiac frequency was estimated with the Power Density Function and, thereafter, the signal was derived twice, followed by binarization of the first derivative and rectification of the second derivative. The product of the two latter results led to a weighing signal from which the cycles' onsets and ends were established. Weighed and frequency filters are needed along with the pre-establishment of their respective tolerances. Out of the 40 records, 30 seconds strands were randomly chosen to be analyzed by the algorithm and by two operators. Sensitivity and accuracy were calculated by means

  20. Laser-driven Beat-Wave Current Drive in Dense Plasmas with Demo on CTIX

    Science.gov (United States)

    Liu, Fei; Horton, Robert; Hwang, David; Zhu, Ben; Evans, Russell; Hong, Sean; Hsu, Scott

    2010-11-01

    The ability to remotely generate plasma current in dense plasmas hanging freely in vacuum in voluminous amount without obstruction to diagnostics will greatly enhance our ability to study the physics of high energy density plasmas in strong magnetic fields. Plasma current can be generated through nonlinear beat-wave process by launching two intense electromagnetic waves into unmagnetized plasma. Beat-wave acceleration of electrons has been demonstrated in a low-density plasma using microwaves [1]. The proposed PLX experimental facility presently under construction at Los Alamos offers the opportunity to test the method at a density level scalable to the study of HED plasmas. For PLX beat-wave experiments, CO2 lasers will be used as pump waves due to their high power and tunability. For a typical PLX density ne=10^17cm-3, two CO2 lasers can be separately tuned to 9P(28) and 10P(20) to match the 2.84THz plasma frequency. The beat-wave demo experiment will be conducted on CTIX. The laser arrangement is being converted to two independent single lasers. Frequency-tuning methods, optics focusing system and diagnostics system will be discussed. The laser measurements and results of synchronization of two lasers will be presented, and scaling to PLX experiments will be given. [1] Rogers, J. H. and Hwang, D. Q., PRL. v68 p3877 (1992).

  1. Expression of nitric oxide synthase and guanylate cyclase in the human ciliary body and trabecular meshwork

    Institute of Scientific and Technical Information of China (English)

    WU Ren-yi; MA Ning

    2012-01-01

    Background The role played by the nitric oxide (NO) signaling pathway in the aqueous humor dynamics is still unclear.This study was designed to investigate the expression and distribution of NO synthase (NOS) isoforms and guanylate cyclase (GC) in human ciliary body,trabecular meshwork and the Schlemm's canal.Methods Twelve eyes after corneal transplantation were used.Expression of three NOS isoforms (i.e.neuronal NOS (nNOS),inducible NOS (iNOS) and endothelial NOS (eNOS)) and GC were assessed in 10 eyes by immunohistochemical staining using monoclonal or polyclonal antibody of NOS and GC.Ciliary bodies were dissected free and the total proteins were extracted.Western blotting was performed to confirm the protein expression of 3 NOS isoforms and GC.Results Expression of 3 NOS isoforms and GC were observed in the ciliary epithelium,ciliary muscle,trabecular meshwork and the endothelium of the Schlemm's canal.Immunoreactivity of nNOS was detected mainly along the apical cytoplasmic junction of the non-pigmented epithelium (NPE) and pigmented epithelial (PE) cells.Protein expressions of 3 NOS isoforms and GC were confirmed in isolated human ciliary body by Western blotting.Conclusions The expression of NOS isoforms and GC in human ciliary body suggest the possible involvement of NO and cyclic guanosine monophosphate (cyclic GMP,cGMP) signaling pathway in the ciliary body,and may play a role in both processes of aqueous humor formation and drainage.

  2. Beat that Word: How Listeners Integrate Beat Gesture and Focus in Multimodal Speech Discourse.

    Science.gov (United States)

    Dimitrova, Diana; Chu, Mingyuan; Wang, Lin; Özyürek, Asli; Hagoort, Peter

    2016-09-01

    Communication is facilitated when listeners allocate their attention to important information (focus) in the message, a process called "information structure." Linguistic cues like the preceding context and pitch accent help listeners to identify focused information. In multimodal communication, relevant information can be emphasized by nonverbal cues like beat gestures, which represent rhythmic nonmeaningful hand movements. Recent studies have found that linguistic and nonverbal attention cues are integrated independently in single sentences. However, it is possible that these two cues interact when information is embedded in context, because context allows listeners to predict what information is important. In an ERP study, we tested this hypothesis and asked listeners to view videos capturing a dialogue. In the critical sentence, focused and nonfocused words were accompanied by beat gestures, grooming hand movements, or no gestures. ERP results showed that focused words are processed more attentively than nonfocused words as reflected in an N1 and P300 component. Hand movements also captured attention and elicited a P300 component. Importantly, beat gesture and focus interacted in a late time window of 600-900 msec relative to target word onset, giving rise to a late positivity when nonfocused words were accompanied by beat gestures. Our results show that listeners integrate beat gesture with the focus of the message and that integration costs arise when beat gesture falls on nonfocused information. This suggests that beat gestures fulfill a unique focusing function in multimodal discourse processing and that they have to be integrated with the information structure of the message. PMID:27027421

  3. Semiconductor optical amplifier-based heterodyning detection for resolving optical terahertz beat-tone signals from passively mode-locked semiconductor lasers

    International Nuclear Information System (INIS)

    An all-optical heterodyne approach based on a room-temperature controlled semiconductor optical amplifier (SOA) for measuring the frequency and linewidth of the terahertz beat-tone signal from a passively mode-locked laser is proposed. Under the injection of two external cavity lasers, the SOA acts as a local oscillator at their detuning frequency and also as an optical frequency mixer whose inputs are the self-modulated spectrum of the device under test and the two laser beams. Frequency and linewidth of the intermediate frequency signal (and therefore, the beat-tone signal) are resolved by using a photodiode and an electrical spectrum analyzer.

  4. Newborn infants detect the beat in music.

    Science.gov (United States)

    Winkler, István; Háden, Gábor P; Ladinig, Olivia; Sziller, István; Honing, Henkjan

    2009-02-17

    To shed light on how humans can learn to understand music, we need to discover what the perceptual capabilities with which infants are born. Beat induction, the detection of a regular pulse in an auditory signal, is considered a fundamental human trait that, arguably, played a decisive role in the origin of music. Theorists are divided on the issue whether this ability is innate or learned. We show that newborn infants develop expectation for the onset of rhythmic cycles (the downbeat), even when it is not marked by stress or other distinguishing spectral features. Omitting the downbeat elicits brain activity associated with violating sensory expectations. Thus, our results strongly support the view that beat perception is innate.

  5. Heart Beat Classification Using Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Ali Khazaee

    2013-05-01

    Full Text Available This paper proposes a novel system to classify three types of electrocardiogram beats, namely normal beats and two manifestations of heart arrhythmia. This system includes three main modules: a feature extraction module, a classifier module, and an optimization module. In the feature extraction module, a proper set combining the shape features and timing features is proposed as the efficient characteristic of the patterns. In the classifier module, a multi-class support vector machine (SVM-based classifier is proposed. For the optimization module, a particle swarm optimization algorithm is proposed to search for the best value of the SVM parameters and upstream by looking for the best subset of features that feed the classifier. Simulation results show that the proposed algorithm has very high recognition accuracy. This high efficiency is achieved with only little features, which have been selected using particle swarm optimizer.

  6. Robotic Catheters for Beating Heart Surgery

    OpenAIRE

    Kesner, Samuel Benjamin

    2011-01-01

    Compliant and flexible cardiac catheters provide direct access to the inside of the heart via the vascular system without requiring clinicians to stop the heart or open the chest. However, the fast motion of the intracardiac structures makes it difficult to modify and repair the cardiac tissue in a controlled and safe manner. In addition, rigid robotic tools for beating heart surgery require the chest to be opened and the heart exposed, making the procedures highly invasive. The novel robot...

  7. Beat-to-beat left ventricular performance in atrial fibrillation: radionuclide assessment with the computerized nuclear probe

    International Nuclear Information System (INIS)

    There is wide beat-to-beat variability in cycle length and left ventricular performance in patients with atrial fibrillation. In this study, left ventricular ejection fraction and relative left ventricular volumes were evaluated on a beat-to-beat basis with the computerized nuclear probe, an instrument with sufficiently high sensitivity to allow continuous evaluation of the radionuclide time-activity curve. Of 18 patients with atrial fibrillation, 5 had mitral stenosis, 6 had mitral regurgitation, and 7 had coronary artery disease. Fifty consecutive beats were analyzed in each patient. The mean left ventricular ejection fraction ranged from 17 to 51%. There was substantial beat-to-beat variation in cycle length and left ventricular ejection fraction in all patients, including those with marked left ventricular dysfunction. In 14 patients who also underwent multiple gated cardiac blood pool imaging, there was an excellent correlation between mean ejection fraction derived from the nuclear probe and gated ejection fraction obtained by gamma camera imaging (r . 0.90). Based on beat-to-beat analysis, left ventricular function was dependent on relative end-diastolic volume and multiple preceding cycle lengths, but not preceding end-systolic volumes. This study demonstrates that a single value for left ventricular ejection fraction does not adequately characterize left ventricular function in patients with atrial fibrillation. Furthermore, both the mean beat-to-beat and the gated ejection fraction may underestimate left ventricular performance at rest in such patients

  8. Genotypic Variation for Salinity Tolerance in Cenchrus ciliaris L.

    Science.gov (United States)

    Al-Dakheel, Abdullah J.; Hussain, M. Iftikhar

    2016-01-01

    Scarcity of irrigation water and increasing soil salinization has threatened the sustainability of forage production in arid and semi-arid region around the globe. Introduction of salt-tolerant perennial species is a promising alternative to overcome forage deficit to meet future livestock needs in salt-affected areas. This study presents the results of a salinity tolerance screening trial which was carried out in plastic pots buried in the open field for 160 buffelgrass (Cenchrus ciliaris L.) accessions for three consecutive years (2003–2005). The plastic pots were filled with sand, organic, and peat moss mix and were irrigated with four different quality water (EC 0, 10, 15, and 20 dS m−1). The results indicate that the average annual dry weights (DW) were in the range from 122.5 to 148.9 g/pot in control; 96.4–133.8 g/pot at 10 dS m−1; 65.6–80.4 g/pot at 15 dS m−1, and 55.4–65.6 g/pot at 20 dS m−1. The highest DW (148.9 g/pot) was found with accession 49 and the lowest with accession 23. Principle component analysis shows that PC-1 contributed 81.8% of the total variability, while PC-2 depicted 11.7% of the total variation among C. ciliaris accessions for DW. Hierarchical cluster analysis revealed that a number of accessions collected from diverse regions could be grouped into a single cluster. Accessions 3, 133, 159, 30, 23, 142, 141, 95, 49, 129, 124, and 127 were stable, salt tolerant, and produced good dry biomass yield. These accessions demonstrate sufficient salinity tolerance potential for promotion in marginal lands to enhance farm productivity and reduce rural poverty. PMID:27516762

  9. Genotypic Variation for Salinity Tolerance in Cenchrus ciliaris L.

    Science.gov (United States)

    Al-Dakheel, Abdullah J; Hussain, M Iftikhar

    2016-01-01

    Scarcity of irrigation water and increasing soil salinization has threatened the sustainability of forage production in arid and semi-arid region around the globe. Introduction of salt-tolerant perennial species is a promising alternative to overcome forage deficit to meet future livestock needs in salt-affected areas. This study presents the results of a salinity tolerance screening trial which was carried out in plastic pots buried in the open field for 160 buffelgrass (Cenchrus ciliaris L.) accessions for three consecutive years (2003-2005). The plastic pots were filled with sand, organic, and peat moss mix and were irrigated with four different quality water (EC 0, 10, 15, and 20 dS m(-1)). The results indicate that the average annual dry weights (DW) were in the range from 122.5 to 148.9 g/pot in control; 96.4-133.8 g/pot at 10 dS m(-1); 65.6-80.4 g/pot at 15 dS m(-1), and 55.4-65.6 g/pot at 20 dS m(-1). The highest DW (148.9 g/pot) was found with accession 49 and the lowest with accession 23. Principle component analysis shows that PC-1 contributed 81.8% of the total variability, while PC-2 depicted 11.7% of the total variation among C. ciliaris accessions for DW. Hierarchical cluster analysis revealed that a number of accessions collected from diverse regions could be grouped into a single cluster. Accessions 3, 133, 159, 30, 23, 142, 141, 95, 49, 129, 124, and 127 were stable, salt tolerant, and produced good dry biomass yield. These accessions demonstrate sufficient salinity tolerance potential for promotion in marginal lands to enhance farm productivity and reduce rural poverty. PMID:27516762

  10. Simultaneous sinus and lung infections in patients with primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Alanin, Mikkel Christian; Johansen, Helle Krogh; Aanaes, Kasper;

    2015-01-01

    Conclusion: The sinuses should be considered as a bacterial reservoir and a target for surgery and antibiotic treatment in patients with primary ciliary dyskinesia (PCD). The observed decrease in serum precipitating antibodies (precipitins) against Pseudomonas aeruginosa may indicate a beneficial...

  11. Measurement of ciliary flow generated on the surface of tracheal lumen

    Science.gov (United States)

    Kiyota, Koki; Ueno, Hironori; Ishikawa, Takuji; Numayama-Tsuruta, Keiko; Imai, Yohsuke; Omori, Toshihiro; Yamaguchi, Takami

    2012-11-01

    Although we consistently take air with virus and bacteria, these harmful substances are trapped on the surface of tracheal lumen and transported toward larynx from the trachea and bronchi by effective ciliary motion and swallowed it (clearance function). However, the 3-dimensional flow field generated by inhomogeneously distributed ciliary cells are largely unknown. In this study, we first succeeded to measure the ciliated cells' density by staining actin of the epithelial cells and tubulin of the cilia, respectively. Second, we analyzed the ciliary motion by labeling the tip of cilia with fluorescent particles, and tracking their movements to understand the mechanism of the flow generation. Last, in order to clarify the flow field induced by the ciliary motion, we measured the motion of tracer particles on the surface of tracheal epithelial cells by a confocal micro-PTV system. The results show that the mean velocity and the velocity disturbance decayed rapidly as the height from the epithelial cells were increased.

  12. Adenoma of nonpigmented epithelium in ciliary body:literature review and case report

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Adenomas of the nonpigmented ciliary epithelium (NPCE) are often clinically indistinguishable from amelanotic malignant melanomas of the ciliary body or metastatic carcinomas. This paper reports a case study of a distinctive variant of adenoma of the NPCE, which clinically appears as epiretinal membrane in the macular region. Histopathologic studies have revealed this is an adenoma of the NPCE. Identification of this clinic feature is important because it will miss the diagnosis of the adenoma of the NPCE. In this case study, B-scan ultrasonography as well as computerized tomography (CT) has been used to provide help in diagnosing the ciliary body tumor. Because of their anterior location in the ciliary body, partial lamellar sclerouvectomy is an effective method of treatment.

  13. Transition fibre protein FBF1 is required for the ciliary entry of assembled intraflagellar transport complexes

    OpenAIRE

    WEI, QING; Xu, Qingwen; Zhang, Yuxia; Li, Yujie; Zhang, Qing; Hu, Zeng; Harris, Peter C.; Torres, Vicente E.; Ling, Kun; Hu, Jinghua

    2013-01-01

    Sensory organelle cilia play critical roles in mammalian embryonic development and tissue homeostasis. Intraflagellar transport (IFT) machinery is required for the assembly and maintenance of cilia. Yet how this large complex passes through the size-dependent barrier at the ciliary base remains enigmatic. Here we report that FBF1, a highly conserved transition fibre protein, is required for the ciliary import of assembled IFT particles at the cilia base. We cloned dyf-19, the C. elegans homol...

  14. The Harvard Beat Assessment Test (H-BAT): a battery for assessing beat perception and production and their dissociation.

    Science.gov (United States)

    Fujii, Shinya; Schlaug, Gottfried

    2013-01-01

    Humans have the abilities to perceive, produce, and synchronize with a musical beat, yet there are widespread individual differences. To investigate these abilities and to determine if a dissociation between beat perception and production exists, we developed the Harvard Beat Assessment Test (H-BAT), a new battery that assesses beat perception and production abilities. H-BAT consists of four subtests: (1) music tapping test (MTT), (2) beat saliency test (BST), (3) beat interval test (BIT), and (4) beat finding and interval test (BFIT). MTT measures the degree of tapping synchronization with the beat of music, whereas BST, BIT, and BFIT measure perception and production thresholds via psychophysical adaptive stair-case methods. We administered the H-BAT on thirty individuals and investigated the performance distribution across these individuals in each subtest. There was a wide distribution in individual abilities to tap in synchrony with the beat of music during the MTT. The degree of synchronization consistency was negatively correlated with thresholds in the BST, BIT, and BFIT: a lower degree of synchronization was associated with higher perception and production thresholds. H-BAT can be a useful tool in determining an individual's ability to perceive and produce a beat within a single session.

  15. The Harvard Beat Assessment Test (H-BAT): a battery for assessing beat perception and production and their dissociation

    Science.gov (United States)

    Fujii, Shinya; Schlaug, Gottfried

    2013-01-01

    Humans have the abilities to perceive, produce, and synchronize with a musical beat, yet there are widespread individual differences. To investigate these abilities and to determine if a dissociation between beat perception and production exists, we developed the Harvard Beat Assessment Test (H-BAT), a new battery that assesses beat perception and production abilities. H-BAT consists of four subtests: (1) music tapping test (MTT), (2) beat saliency test (BST), (3) beat interval test (BIT), and (4) beat finding and interval test (BFIT). MTT measures the degree of tapping synchronization with the beat of music, whereas BST, BIT, and BFIT measure perception and production thresholds via psychophysical adaptive stair-case methods. We administered the H-BAT on thirty individuals and investigated the performance distribution across these individuals in each subtest. There was a wide distribution in individual abilities to tap in synchrony with the beat of music during the MTT. The degree of synchronization consistency was negatively correlated with thresholds in the BST, BIT, and BFIT: a lower degree of synchronization was associated with higher perception and production thresholds. H-BAT can be a useful tool in determining an individual's ability to perceive and produce a beat within a single session. PMID:24324421

  16. CO2 Laser Beat-Wave Experiment in an Unmagnetized Plasma

    Science.gov (United States)

    Liu, Fei; Hwang, David; Horton, Robert; Hong, Sean; Evans, Russell

    2012-10-01

    The ability to remotely generate plasma current in dense plasmas is a basic yet important investigation in experimental plasma physics and fusion energy research. It is even more advantageous if the wave penetration is independent of the electron acceleration process. Plasma current can be generated through beat-wave mixing process by launching two intense electromagnetic waves (φ>>φpe) into plasma. The beat wave formation process can be efficient if the difference frequency of the two pump waves is matched to a local resonant frequency of the medium, i.e. in this case the local plasma frequency. Beat wave can accelerate plasma electrons via quasi-linear Landau process, which has been demonstrated in a low-density plasma using microwaves.footnotetextRogers, J. H. and Hwang, D. Q., Phys. Rev. Lett. v68 p3877 (1992). The CO2 lasers provide the high tunability for the wave-particle interaction experiment at a variety of plasma densities with plasma frequency in THz range. Two sections of Lumonics TEA CO2 lasers have been modified to serve as the two pump wave sources with peak power over 100MW. The development of the tunable CO2 lasers, a high-density plasma target source and diagnostics system will be presented. The initial results of unbalanced beat-wave experiment using one high-power pulsed and one low-power CW CO2 lasers will be presented and discussed using the independent plasma source to control the φpe of the interaction region. This work is supported by U.S. DOE under Contract No. DE-FG02-10ER55083.

  17. Automated image analysis reveals the dynamic 3-dimensional organization of multi-ciliary arrays

    Directory of Open Access Journals (Sweden)

    Domenico F. Galati

    2016-01-01

    Full Text Available Multi-ciliated cells (MCCs use polarized fields of undulating cilia (ciliary array to produce fluid flow that is essential for many biological processes. Cilia are positioned by microtubule scaffolds called basal bodies (BBs that are arranged within a spatially complex 3-dimensional geometry (3D. Here, we develop a robust and automated computational image analysis routine to quantify 3D BB organization in the ciliate, Tetrahymena thermophila. Using this routine, we generate the first morphologically constrained 3D reconstructions of Tetrahymena cells and elucidate rules that govern the kinetics of MCC organization. We demonstrate the interplay between BB duplication and cell size expansion through the cell cycle. In mutant cells, we identify a potential BB surveillance mechanism that balances large gaps in BB spacing by increasing the frequency of closely spaced BBs in other regions of the cell. Finally, by taking advantage of a mutant predisposed to BB disorganization, we locate the spatial domains that are most prone to disorganization by environmental stimuli. Collectively, our analyses reveal the importance of quantitative image analysis to understand the principles that guide the 3D organization of MCCs.

  18. Roles of paroxetine and corticosterone on adult mammalian ciliary body cell proliferation

    Institute of Scientific and Technical Information of China (English)

    WANG Hua; LAU Benson WM; YAU Suk-yu; LI Suk-yee; LEUNG Nelson; WANG Ning-li; TANG Siu-wa; LEE Tatia MC; SO Kwok-fai

    2010-01-01

    Background The neurogenesis in retina of adult mammals is generally abolished, and this renders the retina lack of regenerative capacity.Despite this, there is a small population of nestin-positive cells in the ciliary epithelium which retains neurogenic potential.The present study aimed at investigating the effect of two drugs, corticosterone and paroxetine, on the cell proliferation of the ciliary body.Methods Adult Sprague-Dawley rats were given vehicle, corticosterone, paroxetine, or both corticosterone and paroxetine treatment for 14 days.Cell proliferation in the ciliary body was quantified using 5-bromo-2-deoxyuridine (BrdU) immunohistochemistry.Co-labelling of BrdU and stem cell marker was used to phenotype the BrdU immunoreactive cells.Results Corticosterone treatment suppressed while paroxetine treatment increased the cell proliferation of the ciliary body.Co-labelling with cell markers revealed that the BrdU positive cells also showed nestin expression but not glial fibrillary acidic protein (GFAP).Conclusions The results illustrate that proliferation of retinal progenitor cells situated in ciliary body are subjected to regulation by selective serotonin reuptake inhibitors (SSRI) and corticosteroid, which is similar to our previous findings in neurogenic regions in central nervous system (CNS).Paroxetine treatment could reverse the suppressive effect of corticosterone on ciliary body cell proliferation.This provides information for future investigation of retinal stem cell biology and potential treatment of retinal degenerative diseases.

  19. Attosecond Quantum-Beat Spectroscopy in Helium

    CERN Document Server

    Shivaram, Niranjan; Timmers, Henry; Sandhu, Arvinder

    2015-01-01

    The evolution of electron wavepackets determines the course of many physical and chemical phenomena and attosecond spectroscopy aims to measure and control such dynamics in real-time. Here, we investigate radial electron wavepacket motion in Helium by using an XUV attosecond pulse train to prepare a coherent superposition of excited states and a delayed femtosecond IR pulse to ionize them. Quantum beat signals observed in the high resolution photoelectron spectrogram allow us to follow the field-free evolution of the bound electron wavepacket and determine the time-dependent ionization dynamics of the low-lying 2p state.

  20. Beats on the Table: Beat Writing in the Chicago Review and Big Table

    Directory of Open Access Journals (Sweden)

    Jaap van der Bent

    2012-07-01

    Full Text Available Normal 0 21 false false false NL X-NONE X-NONE MicrosoftInternetExplorer4 Kleine literaire tijdschriften, zogenaamde little magazines, hebben een belangrijke rol gespeeld bij de doorbraak, in de loop van de jaren vijftig, van de Amerikaanse Beat Generation. Aangezien grotere uitgeverijen en de gevestigde tijdschriften lange tijd terugschrokken voor de zowel inhoudelijk als formeel van de norm afwijkende uitingen van de Beats, verscheen hun werk aanvankelijk vooral in kleinere tijdschriften als de twee waaraan in dit artikel aandacht wordt besteed: de Chicago Review en Big Table. Aan de hand van een beschrijving van de inhoud van deze twee tijdschriften wordt geprobeerd duidelijk te maken hoe het werk van de Beat Generation zich in deze tijdschriften gaandeweg een eigen plaats verwierf. Speciale aandacht wordt besteed aan de rol van de redacteuren Irving Rosenthal en Paul Carroll; door zijn uitgekiende strategie om voor het omstreden werk van Beat-auteur William S. Burroughs geleidelijk een steeds grotere plaats in te ruimen, bepaalde vooral Rosenthal het veranderende karakter van de Chicago Review. De veranderingen bij dat tijdschrift verliepen niet zonder slag of stoot en waren voor de eigenaar ervan, de University of Chicago, op een gegeven moment aanleiding om de Chicago Review aan censuur te onderwerpen. Ook deze censuur en de reactie erop, de oprichting van Big Table, worden in het artikel belicht.

  1. Force-inhibiting effect of Ser/Thr protein phosphatase 2A inhibitors on bovine ciliary muscle.

    OpenAIRE

    石田, 美織

    2015-01-01

    Ciliary muscle is a smooth muscle characterized by a rapid response to muscarinic receptor stimulation and sustained contraction. Although it is evident that these contractions are Ca(2+)-dependent, detailed molecular mechanisms are still unknown. In order to elucidate the role of Ser/Thr protein phosphatase 2A (PP2A) in ciliary muscle contraction, we examined the effects of okadaic acid and other PP2A inhibitors on contractions induced by carbachol (CCh) and ionomycin in bovine ciliary muscl...

  2. The chemical composition of Galactic beat Cepheids

    Science.gov (United States)

    Kovtyukh, V.; Lemasle, B.; Chekhonadskikh, F.; Bono, G.; Matsunaga, N.; Yushchenko, A.; Anderson, R. I.; Belik, S.; da Silva, R.; Inno, L.

    2016-08-01

    We determine the metallicity and detailed chemical abundances (α, iron-peak and neutron-capture elements) for the almost complete (18/24) sample of Galactic double mode Cepheids (also called beat Cepheids). Double mode Cepheids are Cepheids that pulsate in two modes simultaneously. We calibrate a new relation between their metallicity and their period ratio P1/P0. This linear relation allows to determine the metallicity of bimodal Cepheids with an accuracy of 0.03 dex in the range of [Fe/H] from +0.2 to -0.5 dex. By extrapolating the relation to Magellanic Clouds beat Cepheids, we provide their metallicity distribution function. Moreover, by using this relation, we also provide the first metallicity estimate for two double-mode F/1O Cepheids located in and beyond the Galactic bulge. Finally, we report the discovery of a super-Lithium rich double mode Cepheid V371 Per which has a Lithium abundance of logA(Li) = 3.54 ± 0.09 dex. Along with V1033 Cyg (which is an ordinary classical Cepheid), it is the second known Cepheid of such type in the Galaxy.

  3. Diagnosing primary ciliary dyskinesia: an international patient perspective

    Science.gov (United States)

    Dunn Galvin, Audrey; Rubbo, Bruna; Masefield, Sarah; Copeland, Fiona; Manion, Michele; Rindlisbacher, Bernhard; Redfern, Beatrice; Lucas, Jane S.

    2016-01-01

    Primary ciliary dyskinesia (PCD) is a rare genetic disorder characterised by progressive sino-pulmonary disease, with symptoms starting soon after birth. A European Respiratory Society (ERS) Task Force aims to address disparities in diagnostics across Europe by providing evidence-based clinical practice guidelines. We aimed to identify challenges faced by patients when referred for PCD diagnostic testing. A patient survey was developed by patient representatives and healthcare specialists to capture experience. Online versions of the survey were translated into nine languages and completed in 25 countries. Of the respondents (n=365), 74% were PCD-positive, 5% PCD-negative and 21% PCD-uncertain/inconclusive. We then interviewed 20 parents/patients. Transcripts were analysed thematically. 35% of respondents visited their doctor more than 40 times with PCD-related symptoms prior to diagnostic referral. Furthermore, the most prominent theme among interviewees was a lack of PCD awareness among medical practitioners and failure to take past history into account, leading to delayed diagnosis. Patients also highlighted the need for improved reporting of results and a solution to the “inconclusive” diagnostic status. These findings will be used to advise the ERS Task Force guidelines for diagnosing PCD, and should help stakeholders responsible for improving existing services and expanding provision for diagnosis of this rare disease. PMID:27492837

  4. Protective Effects of Ciliary Neurotrophic Factor on Denervated Skeletal Muscle

    Institute of Scientific and Technical Information of China (English)

    黄仕龙; 王发斌; 洪光祥; 万圣祥; 康皓

    2002-01-01

    Summary: To study the effects of ciliary neurotrophic factor (CNTF) on denervated skeletal muscle atrophy and to find a new approach to ameliorate atrophy of denervated muscle, a model was estab lished by cutting the right sciatic nerve in 36 Wistar mice, with the left side serving as control. Then they were divided into two groups randomly. CNTF (1 U/ml) 0. 1 ml was injected into the right tib-ial muscle every day in experimental group, and saline was used into another group for comparison.The muscle wet weight, muscle total protein, Ca2+, physiological response and morphology were an alyzed on the 7th, 14th and 28th day after operation. Our results showed that compared to control group, there was a significant increase in muscle wet weight, total protein, Ca2+ , muscle fiber cross section area in CNTF group (P< 0. 05). CNTF could ameliorate the decrease of tetanic tension (PO), post-tetanic twitch potentiation (PTP), and the prolonged muscle relaxation time (RT)caused by denervation (P<0. 05). The motor end-plate areas 7 days and 14 days after denervation was similar (P>0. 05), but significantly larger 28 days after the denervation (P<0.05). Our re-sults suggest that CNTF exerts myotrophic effects by attenuating the morphological and functional changes associated with denervation of rat muscles and has protective effects on denervated muscle and motor end plate.

  5. PICADAR: a diagnostic predictive tool for primary ciliary dyskinesia

    Science.gov (United States)

    Behan, Laura; Dimitrov, Borislav D.; Kuehni, Claudia E.; Hogg, Claire; Carroll, Mary; Evans, Hazel J.; Goutaki, Myrofora; Harris, Amanda; Packham, Samantha; Walker, Woolf T.

    2016-01-01

    Symptoms of primary ciliary dyskinesia (PCD) are nonspecific and guidance on whom to refer for testing is limited. Diagnostic tests for PCD are highly specialised, requiring expensive equipment and experienced PCD scientists. This study aims to develop a practical clinical diagnostic tool to identify patients requiring testing. Patients consecutively referred for testing were studied. Information readily obtained from patient history was correlated with diagnostic outcome. Using logistic regression, the predictive performance of the best model was tested by receiver operating characteristic curve analyses. The model was simplified into a practical tool (PICADAR) and externally validated in a second diagnostic centre. Of 641 referrals with a definitive diagnostic outcome, 75 (12%) were positive. PICADAR applies to patients with persistent wet cough and has seven predictive parameters: full-term gestation, neonatal chest symptoms, neonatal intensive care admittance, chronic rhinitis, ear symptoms, situs inversus and congenital cardiac defect. Sensitivity and specificity of the tool were 0.90 and 0.75 for a cut-off score of 5 points. Area under the curve for the internally and externally validated tool was 0.91 and 0.87, respectively. PICADAR represents a simple diagnostic clinical prediction rule with good accuracy and validity, ready for testing in respiratory centres referring to PCD centres. PMID:26917608

  6. Acupuncture Treatment for 98 Cases of Ventricular Premature Beat

    Institute of Scientific and Technical Information of China (English)

    Han Baojie; Wang Feng; Wang Xinzhong

    2008-01-01

    @@ Ventricular premature beat is a commonly encountered arrhythmia,which can occur in patients with and without cardiac diseases.In TCM.ventricular premature beat fall into the category of palpitation and obstruction of qi in the chest.The authors treated it with acupuncture and obtained satisfactory thera-peutic effects.A summary follows.

  7. Time-domain analysis of beat-to-beat variability of repolarization morphology in patients with ischemic cardiomyopathy.

    Science.gov (United States)

    Burattini, L; Zareba, W

    1999-01-01

    There is growing evidence that beat-to-beat changes in ventricular repolarization contribute to increased vulnerability to ventricular arrhythmias. Beat-to-beat repolarization variability is usually measured in the electrocardiogram (ECG) by tracking consecutive QT or RT intervals. However, these measurements strongly depend on the accurate identification of T-wave endpoints, and they do not reflect changes in repolarization morphology. In this article, we propose a new computerized time-domain method to measure beat-to-beat variability of repolarization morphology without the need to identify T-wave endpoints. The repolarization correlation index (RCI) is computed for each beat to determine the difference between the morphology of repolarization within a heart-rate dependent repolarization window compared to a template (median) repolarization morphology. The repolarization variability index (RVI) describes the mean value of repolarization correlation in a studied ECG recording. To validate our method, we analyzed repolarization variability in 128-beat segments from Holter ECG recordings of 42 ischemic cardiomyopathy (ICM) patients compared to 36 healthy subjects. The ICM patients had significantly higher values of RVI than healthy subjects (in lead X: 0.045 +/- 0.035 vs. 0.024 +/- 0.010, respectively; P 0.044). No significant correlation was found between the RVI values and the magnitude of heart rate, heart rate variability, QTc interval duration, or ejection fraction in studied ICM patients. In conclusion, our time-domain method, based on computation of repolarization correlation indices for consecutive beats, provides a new approach to quantify beat-to-beat variability of repolarization morphology without the need to identify T-wave endpoints. PMID:10688321

  8. Laser beat wave resonant terahertz generation in a magnetized plasma channel

    Energy Technology Data Exchange (ETDEWEB)

    Bhasin, Lalita; Tripathi, V. K. [Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India); Kumar, Pawan, E-mail: kumarpawan-30@yahoo.co.in [Department of Physics, Raj Kumar Goel Institute of Technology, Ghaziabad, Uttar Pradesh 201003 (India)

    2016-02-15

    Resonant excitation of terahertz (THz) radiation by nonlinear mixing of two lasers in a ripple-free self created plasma channel is investigated. The channel has a transverse static magnetic field and supports a THz X-mode with phase velocity close to the speed of light in vacuum when the frequency of the mode is close to plasma frequency on the channel axis and its value decreases with the intensity of lasers. The THz is resonantly driven by the laser beat wave ponderomotive force. The THz amplitude scales almost three half power of the intensity of lasers as the width of the THz eigen mode shrinks with laser intensity.

  9. An efficient method of addressing ectopic beats: new insight into data preprocessing of heart rate variability analysis

    Institute of Scientific and Technical Information of China (English)

    Feng WEN; Fang-tian HE

    2011-01-01

    Heart rate variability (HRV) analysis is affected by ectopic beats.An efficient method was proposed to deal with the ectopic beats.The method was based on trend correlation of the heart timing signal.Predictor of R-R interval (RRI) value at ectopic beat time was constructed by the weight calculation and the slope estimation of preceding normal RRI.The type of ectopic beat was detected and replaced by the predictor of RRI.The performance of the simulated signal after ectopic correction was tested by the standard value using power spectrum density (PSD) estimation,whereas the results of clinical data with ectopic beats were compared with the adjacent ectopic-free data.The result showed the frequency indexes after ectopy corrected had less error than other methods with the test of simulated signal and clinical data.It indicated our method could improve the PSD estimation in HRV analysis.The method had advantages of high accuracy and real time properties to recover the sinus node modulation.

  10. An efficient method of addressing ectopic beats: new insight into data preprocessing of heart rate variability analysis.

    Science.gov (United States)

    Wen, Feng; He, Fang-Tian

    2011-12-01

    Heart rate variability (HRV) analysis is affected by ectopic beats. An efficient method was proposed to deal with the ectopic beats. The method was based on trend correlation of the heart timing signal. Predictor of R-R interval (RRI) value at ectopic beat time was constructed by the weight calculation and the slope estimation of preceding normal RRI. The type of ectopic beat was detected and replaced by the predictor of RRI. The performance of the simulated signal after ectopic correction was tested by the standard value using power spectrum density (PSD) estimation, whereas the results of clinical data with ectopic beats were compared with the adjacent ectopic-free data. The result showed the frequency indexes after ectopy corrected had less error than other methods with the test of simulated signal and clinical data. It indicated our method could improve the PSD estimation in HRV analysis. The method had advantages of high accuracy and real time properties to recover the sinus node modulation.

  11. Beat Perception and Sociability: Evidence from Williams Syndrome

    Science.gov (United States)

    Lense, Miriam D.; Dykens, Elisabeth M.

    2016-01-01

    Beat perception in music has been proposed to be a human universal that may have its origins in adaptive processes involving temporal entrainment such as social communication and interaction. We examined beat perception skills in individuals with Williams syndrome (WS), a genetic, neurodevelopmental disorder. Musical interest and hypersociability are two prominent aspects of the WS phenotype although actual musical and social skills are variable. On a group level, beat and meter perception skills were poorer in WS than in age-matched peers though there was significant individual variability. Cognitive ability, sound processing style, and musical training predicted beat and meter perception performance in WS. Moreover, we found significant relationships between beat and meter perception and adaptive communication and socialization skills in WS. Results have implications for understanding the role of predictive timing in both music and social interactions in the general population, and suggest music as a promising avenue for addressing social communication difficulties in WS. PMID:27378982

  12. Beat Perception and Sociability: Evidence from Williams Syndrome.

    Science.gov (United States)

    Lense, Miriam D; Dykens, Elisabeth M

    2016-01-01

    Beat perception in music has been proposed to be a human universal that may have its origins in adaptive processes involving temporal entrainment such as social communication and interaction. We examined beat perception skills in individuals with Williams syndrome (WS), a genetic, neurodevelopmental disorder. Musical interest and hypersociability are two prominent aspects of the WS phenotype although actual musical and social skills are variable. On a group level, beat and meter perception skills were poorer in WS than in age-matched peers though there was significant individual variability. Cognitive ability, sound processing style, and musical training predicted beat and meter perception performance in WS. Moreover, we found significant relationships between beat and meter perception and adaptive communication and socialization skills in WS. Results have implications for understanding the role of predictive timing in both music and social interactions in the general population, and suggest music as a promising avenue for addressing social communication difficulties in WS. PMID:27378982

  13. Laser-frequency stabilization using forward scattering

    Science.gov (United States)

    Fellman, T.; Lindberg, Å.; Ståhlberg, B.

    1994-12-01

    Frequency stabilization of a single-mode dye laser is demonstrated using a simple magneto-optical forward scattering method. The dye laser was locked to the 2p4-3ss2, λ = 633 nm neon transition. Heterodyne beat-frequency measurements against a127I2-He-Ne meter standard laser showed a frequency stability of a few MHz.

  14. Computer Simulation of the Beating Human Heart

    Science.gov (United States)

    Peskin, Charles S.; McQueen, David M.

    2001-06-01

    The mechanical function of the human heart couples together the fluid mechanics of blood and the soft tissue mechanics of the muscular heart walls and flexible heart valve leaflets. We discuss a unified mathematical formulation of this problem in which the soft tissue looks like a specialized part of the fluid in which additional forces are applied. This leads to a computational scheme known as the Immersed Boundary (IB) method for solving the coupled equations of motion of the whole system. The IB method is used to construct a three-dimensional Virtual Heart, including representations of all four chambers of the heart and all four valves, in addition to the large arteries and veins that connect the heart to the rest of the circulation. The chambers, valves, and vessels are all modeled as collections of elastic (and where appropriate, actively contractile) fibers immersed in viscous incompressible fluid. Results are shown as a computer-generated video animation of the beating heart.

  15. Arf4 is required for Mammalian development but dispensable for ciliary assembly.

    Directory of Open Access Journals (Sweden)

    John A Follit

    2014-02-01

    Full Text Available The primary cilium is a sensory organelle, defects in which cause a wide range of human diseases including retinal degeneration, polycystic kidney disease and birth defects. The sensory functions of cilia require specific receptors to be targeted to the ciliary subdomain of the plasma membrane. Arf4 has been proposed to sort cargo destined for the cilium at the Golgi complex and deemed a key regulator of ciliary protein trafficking. In this work, we show that Arf4 binds to the ciliary targeting sequence (CTS of fibrocystin. Knockdown of Arf4 indicates that it is not absolutely required for trafficking of the fibrocystin CTS to cilia as steady-state CTS levels are unaffected. However, we did observe a delay in delivery of newly synthesized CTS from the Golgi complex to the cilium when Arf4 was reduced. Arf4 mutant mice are embryonic lethal and die at mid-gestation shortly after node formation. Nodal cilia appeared normal and functioned properly to break left-right symmetry in Arf4 mutant embryos. At this stage of development Arf4 expression is highest in the visceral endoderm but we did not detect cilia on these cells. In the visceral endoderm, the lack of Arf4 caused defects in cell structure and apical protein localization. This work suggests that while Arf4 is not required for ciliary assembly, it is important for the efficient transport of fibrocystin to cilia, and also plays critical roles in non-ciliary processes.

  16. Transition fibre protein FBF1 is required for the ciliary entry of assembled intraflagellar transport complexes.

    Science.gov (United States)

    Wei, Qing; Xu, Qingwen; Zhang, Yuxia; Li, Yujie; Zhang, Qing; Hu, Zeng; Harris, Peter C; Torres, Vicente E; Ling, Kun; Hu, Jinghua

    2013-01-01

    Sensory organelle cilia have critical roles in mammalian embryonic development and tissue homeostasis. Intraflagellar transport (IFT) machinery is required for the assembly and maintenance of cilia. Yet, how this large complex passes through the size-dependent barrier at the ciliary base remains enigmatic. Here we report that FBF1, a highly conserved transition fibre protein, is required for the ciliary import of assembled IFT particles at the ciliary base. We cloned dyf-19, the Caenorhabditis elegans homologue of human FBF1, in a whole-genome screen for ciliogenesis mutants. DYF-19 localizes specifically to transition fibres and interacts directly with the IFT-B component DYF-11/IFT54. Although not a structural component of transition fibres, DYF-19 is required for the transit of assembled IFT particles through the ciliary base. Furthermore, we found that human FBF1 shares conserved localization and function with its worm counterpart. We conclude that FBF1 is a key functional transition fibre component that actively facilitates the ciliary entry of assembled IFT machinery. PMID:24231678

  17. Evaluation of the beat-to-beat detection accuracy of PulseOn wearable optical heart rate monitor.

    Science.gov (United States)

    Parak, Jakub; Tarniceriu, Adrian; Renevey, Philippe; Bertschi, Mattia; Delgado-Gonzalo, Ricard; Korhonen, Ilkka

    2015-08-01

    Heart rate variability (HRV) provides significant information about the health status of an individual. Optical heart rate monitoring is a comfortable alternative to ECG based heart rate monitoring. However, most available optical heart rate monitoring devices do not supply beat-to-beat detection accuracy required by proper HRV analysis. We evaluate the beat-to-beat detection accuracy of a recent wrist-worn optical heart rate monitoring device, PulseOn (PO). Ten subjects (8 male and 2 female; 35.9±10.3 years old) participated in the study. HRV was recorded with PO and Firstbeat Bodyguard 2 (BG2) device, which was used as an ECG based reference. HRV was recorded during sleep. As compared to BG2, PO detected on average 99.57% of the heartbeats (0.43% of beats missed) and had 0.72% extra beat detection rate, with 5.94 ms mean absolute error (MAE) in beat-to-beat intervals (RRI) as compared to the ECG based RRI BG2. Mean RMSSD difference between PO and BG2 derived HRV was 3.1 ms. Therefore, PO provides an accurate method for long term HRV monitoring during sleep. PMID:26738173

  18. Mode beating and heterodyning of monolithically integrated semiconductor ring lasers

    Science.gov (United States)

    Liu, Chiyu

    Monolithically integrated semiconductor ring lasers (SRLs) are attractive optical sources for optoelectronic integrated circuits (OEICs) because they do not require any feedback elements, do not have parts exposed to external ambient, and can operate in a traveling-wave mode. They are promising candidates for wavelength filtering, unidirectional traveling-wave operation, and multiplexing/demultiplexing applications. Ring lasers can also be used as ultrashort pulse generators using various mode-locking schemes and as active gyro components. However, the SRL is a very complicated dynamic system, which requires more investigations to understand the performance regarding details of the design and fabrication. As a part of NASA-supported project "Monolithically Integrated Semiconductor Ring Laser Gyro for Space Applications", this dissertation research was focused on design and characterization of a novel monolithically integrated rotation sensor based on two large-size independent SRLs. Numerical modeling based on the beam propagation method (BPM) was used to design the fabrication parameters for the single-mode ridge-waveguide ring cavity and directional coupler waveguides. The mode internal coupling in single lateral-mode laser diodes with InGaAs/GaAs material system was investigated by optical experiments and numerical modeling. To gain the understanding of the SRL performance, optical and electrical characterization was performed on fabricated SRLs. Particular emphasis was placed on the study of optical and radio frequency (RF) beating spectra of longitudinal modes of ring lasers. RF measurements provide high accuracy in the diagnosis of laser oscillation parameters by purely electronic means, particularly in the measurement of the group index and its dependence on current and temperature. Theoretical analysis based on the effective index method provides good agreement between the experimental data and numerical calculations. Finally, optical heterodyning spectra

  19. 25-Gauge pars plana vitrectomy for ciliary block (malignant) glaucoma.

    Science.gov (United States)

    Meng, Li; Wei, Wenbin; Li, Yanlong; Hui, Xiaoying; Han, Xiaodong; Shi, Xiaobo

    2015-08-01

    To evaluate the efficacy of 25-ga pars plana vitrectomy (PPV) and 25-ga PPV combined with phacoemulsification surgery for managing ciliary block (malignant) glaucoma. The medical records of 11 eyes, in nine consecutive patients with malignant glaucoma were retrospectively reviewed to determine the efficacy of 25-ga PPV for alleviating this disease. All phakic eyes underwent phacoemulsification surgery during vitrectomy. Control of intraocular pressure (IOP), pre- and postoperative best-corrected visual acuity (BCVA), and development of intra- and postoperative complications were evaluated during follow-up. Malignant glaucoma was promptly resolved, and recurrence was not observed during a mean follow-up period of 12.7 ± 3.2 (range 6-18) months. The mean IOP decreased from 35.9 ± 2.9 mmHg, preoperatively, to 16.0 ± 1.4 mmHg, measured at last visit (P = 0.013). Although IOP control was achieved in all eyes after surgery, two eyes required long-term topical antiglaucoma medication. The mean logarithm of the minimum angle of resolution BCVA improved from +0.69 ± 0.11, preoperatively, to +0.29 ± 0.07, postoperatively (P = 0.027). No severe intraoperative complications were observed. Postoperative complications mostly occurred during the first week after surgery, including transient corneal edema and Descemet's membrane folds in three eyes, fibrotic exudation in 2, local iris posterior synechia in 1, and transient hypotony in 1, which were resolved spontaneously or with medication. The 25-ga PPV procedure seems to be safe and effective for treating malignant glaucoma. Combined vitrectomy with phacoemulsification surgery and a staged surgical approach may improve the success rate. PMID:25062710

  20. Quantitative optical coherence tomography imaging of intermediate flow defect phenotypes in ciliary physiology and pathophysiology

    Science.gov (United States)

    Huang, Brendan K.; Gamm, Ute A.; Jonas, Stephan; Khokha, Mustafa K.; Choma, Michael A.

    2015-03-01

    Cilia-driven fluid flow is a critical yet poorly understood aspect of pulmonary physiology. Here, we demonstrate that optical coherence tomography-based particle tracking velocimetry can be used to quantify subtle variability in cilia-driven flow performance in Xenopus, an important animal model of ciliary biology. Changes in flow performance were quantified in the setting of normal development, as well as in response to three types of perturbations: mechanical (increased fluid viscosity), pharmacological (disrupted serotonin signaling), and genetic (diminished ciliary motor protein expression). Of note, we demonstrate decreased flow secondary to gene knockdown of kif3a, a protein involved in ciliogenesis, as well as a dose-response decrease in flow secondary to knockdown of dnah9, an important ciliary motor protein.

  1. Long beating wavelength in the Schwarz-Hora effect

    CERN Document Server

    Morokov, Y N

    1997-01-01

    Thirty years ago, H.Schwarz has attempted to modulate an electron beam with optical frequency. When a 50-keV electron beam crossed a thin crystalline dielectric film illuminated with laser light, electrons produced the electron-diffraction pattern not only at a fluorescent target but also at a nonfluorescent target. In the latter case the pattern was of the same color as the laser light (the Schwarz-Hora effect). This effect was discussed extensively in the early 1970s. However, since 1972 no reports on the results of further attempts to repeat those experiments in other groups have appeared, while the failures of the initial such attempts have been explained by Schwarz. The analysis of the literature shows there are several unresolved up to now contradictions between the theory and the Schwarz experiments. In this work we consider the interpretation of the long-wavelength spatial beating of the Schwarz-Hora radiation. A more accurate expression for the spatial period has been obtained, taking into account th...

  2. Zebrafish Ciliopathy Screen Plus Human Mutational Analysis Identifies C21orf59 and CCDC65 Defects as Causing Primary Ciliary Dyskinesia

    Science.gov (United States)

    Austin-Tse, Christina; Halbritter, Jan; Zariwala, Maimoona A.; Gilberti, Renée M.; Gee, Heon Yung; Hellman, Nathan; Pathak, Narendra; Liu, Yan; Panizzi, Jennifer R.; Patel-King, Ramila S.; Tritschler, Douglas; Bower, Raqual; O’Toole, Eileen; Porath, Jonathan D.; Hurd, Toby W.; Chaki, Moumita; Diaz, Katrina A.; Kohl, Stefan; Lovric, Svjetlana; Hwang, Daw-Yang; Braun, Daniela A.; Schueler, Markus; Airik, Rannar; Otto, Edgar A.; Leigh, Margaret W.; Noone, Peadar G.; Carson, Johnny L.; Davis, Stephanie D.; Pittman, Jessica E.; Ferkol, Thomas W.; Atkinson, Jeffry J.; Olivier, Kenneth N.; Sagel, Scott D.; Dell, Sharon D.; Rosenfeld, Margaret; Milla, Carlos E.; Loges, Niki T.; Omran, Heymut; Porter, Mary E.; King, Stephen M.; Knowles, Michael R.; Drummond, Iain A.; Hildebrandt, Friedhelm

    2013-01-01

    Primary ciliary dyskinesia (PCD) is caused when defects of motile cilia lead to chronic airway infections, male infertility, and situs abnormalities. Multiple causative PCD mutations account for only 65% of cases, suggesting that many genes essential for cilia function remain to be discovered. By using zebrafish morpholino knockdown of PCD candidate genes as an in vivo screening platform, we identified c21orf59, ccdc65, and c15orf26 as critical for cilia motility. c21orf59 and c15orf26 knockdown in zebrafish and planaria blocked outer dynein arm assembly, and ccdc65 knockdown altered cilia beat pattern. Biochemical analysis in Chlamydomonas revealed that the C21orf59 ortholog FBB18 is a flagellar matrix protein that accumulates specifically when cilia motility is impaired. The Chlamydomonas ida6 mutant identifies CCDC65/FAP250 as an essential component of the nexin-dynein regulatory complex. Analysis of 295 individuals with PCD identified recessive truncating mutations of C21orf59 in four families and CCDC65 in two families. Similar to findings in zebrafish and planaria, mutations in C21orf59 caused loss of both outer and inner dynein arm components. Our results characterize two genes associated with PCD-causing mutations and elucidate two distinct mechanisms critical for motile cilia function: dynein arm assembly for C21orf59 and assembly of the nexin-dynein regulatory complex for CCDC65. PMID:24094744

  3. Beliefs about wife beating: an exploratory study with Lebanese students.

    Science.gov (United States)

    Obeid, Nadine; Chang, Doris F; Ginges, Jeremy

    2010-06-01

    In recent years, there has been a growing interest in understanding the sociocultural contexts and risk factors for domestic violence in the Arab world. This study provides an analysis of the religious, legal, and familial contexts of domestic violence in Lebanon and assesses contemporary attitudes toward women and wife beating in a sample of 206 Lebanese university students. Gender, patriarchal attitudes, religion, childhood experiences with family violence, and mother's employment status were investigated as predictors of attitudes toward wife beating. Consistent with feminist theories of wife abuse, gender and attitudes toward women's roles emerged as the strongest predictors of beliefs about wife beating. PMID:20445079

  4. "'Jackin’ for Beats'": DJing for Citation Critique

    Directory of Open Access Journals (Sweden)

    Todd Craig

    2013-10-01

    Full Text Available A challenge in teaching English composition is helping students envision plagiarism as “borrowing” – showing love to author(s and/or text(s that further their argument(s, versus “stealing” – biting someone’s style and words. Alastair Pennycook (1996 and Sarah Wakefield (2006 have contributed pieces to the elaborate plagiarism/citation puzzle, while Houston Baker situated the hip-hop DJ in seminal text Black Studies, Rap and the Academy (1993. Merging these moments introduces critical questions: Did Diddy invent “the remix” or become the illest beat-biter ever? How did DJ/Producers Pete Rock and Large Professor pay homage to previous musical genres to further hip-hop remix production without just taking 4-8 bar samples, copying sources and claiming unethical ownership? And how can this discussion provide students a window into citation conversations? This article will remix these “texts” to introduce the idea of DJ Rhetoric to discuss plagiarism. Through the lens of the hip-hop DJ in writing classrooms, one can foster an appreciation of the difference between “love and theft” in student citation. This article will couple examples from hip-hop music/culture while simultaneously remixing interviews from various hip-hop DJ/producers to help answer these difficult questions.

  5. Feathering collisions in beating reed simulation

    Science.gov (United States)

    Smyth, Tamara; Abel, Jonathan S.; Smith, Julius O.

    2003-10-01

    Pressure controlled valves are the primary sound production mechanisms for woodwind and brass musical instruments, as well as for many bioacoustic vocal systems such as the larynx and syrinx (the vocal organ in birds). During sound production, air flow sets a reed or membrane into motion creating a variable height in the valve channel and, potentially, periodically closing the channel completely. Depending on how this event is handled, an abrupt termination of air flow between open and closed states can cause undesirable discontinuities and inaccuracies in a discrete-time simulation-particularly at relatively low audio sampling rates. A solution was developed by re-examining the behavior of the differential equation governing volume flow through a pressure-controlled valve, paying particular attention to this rather troublesome transition. A closed-form solution for the time evolution of volume flow is given and used to derive an update for volume flow. The result is a smoother, more accurate, and nearly alias-free transition from open to closed. ``Feathered collisions'' of this nature can refine the sound quality produced by the numerical simulation of beating reeds, such as in clarinets, at typical audio sampling rates.

  6. Human induced pluripotent stem cell-derived beating cardiac tissues on paper.

    Science.gov (United States)

    Wang, Li; Xu, Cong; Zhu, Yujuan; Yu, Yue; Sun, Ning; Zhang, Xiaoqing; Feng, Ke; Qin, Jianhua

    2015-11-21

    There is a growing interest in using paper as a biomaterial scaffold for cell-based applications. In this study, we made the first attempt to fabricate a paper-based array for the culture, proliferation, and direct differentiation of human induced pluripotent stem cells (hiPSCs) into functional beating cardiac tissues and create "a beating heart on paper." This array was simply constructed by binding a cured multi-well polydimethylsiloxane (PDMS) mold with common, commercially available paper substrates. Three types of paper material (print paper, chromatography paper and nitrocellulose membrane) were tested for adhesion, proliferation and differentiation of human-derived iPSCs. We found that hiPSCs grew well on these paper substrates, presenting a three-dimensional (3D)-like morphology with a pluripotent property. The direct differentiation of human iPSCs into functional cardiac tissues on paper was also achieved using our modified differentiation approach. The cardiac tissue retained its functional activities on the coated print paper and chromatography paper with a beating frequency of 40-70 beats per min for up to three months. Interestingly, human iPSCs could be differentiated into retinal pigment epithelium on nitrocellulose membrane under the conditions of cardiac-specific induction, indicating the potential roles of material properties and mechanical cues that are involved in regulating stem cell differentiation. Taken together, these results suggest that different grades of paper could offer great opportunities as bioactive, low-cost, and 3D in vitro platforms for stem cell-based high-throughput drug testing at the tissue/organ level and for tissue engineering applications.

  7. Mercury Beating Heart: Modifications to the Classical Demonstration

    Science.gov (United States)

    Najdoski, Metodija; Mirceski, Valentin; Petrusevski, Vladimir M.; Demiri, Sani

    2007-01-01

    The mercury beating heart (MBH) is a commonly performed experiment, which is based on varying oxidizing agents and substituting other metals for iron. Various modified versions of the classical demonstration of the experiment are presented.

  8. "Keep the Beat": Healthy Blood Pressure Helps Prevent Heart Disease

    Science.gov (United States)

    ... Keep the Beat": Healthy Blood Pressure Helps Prevent Heart Disease Past Issues / Winter 2010 Table of Contents Your ... a condition that also increases the chance of heart disease and stroke. High blood pressure is especially common ...

  9. Botox Beats Implant for Urinary Incontinence in Women

    Science.gov (United States)

    ... html Botox Beats Implant for Urinary Incontinence in Women But both have side effects that may affect ... 2016 TUESDAY, Oct. 4, 2016 (HealthDay News) -- For women with bladder incontinence who haven't been helped ...

  10. Taming microwave plasma to beat thermodynamics in CO2 dissociation

    NARCIS (Netherlands)

    van Rooij, G.; van den Bekerom, D.; N. den Harder,; Minea, T.; G. Berden,; Bongers, W.; Engeln, R.; Graswinckel, M.; Zoethout, E.; M. C. M. van de Sanden,

    2015-01-01

    The strong non-equilibrium conditions provided by the plasma phase offer the opportunity to beat traditional thermal process energy efficiencies via preferential excitation of molecular vibrations. Simple molecular physics considerations are presented to explain potential dissociation pathways in a

  11. Towards T1-limited magnetic resonance imaging using Rabi beats

    CERN Document Server

    Fedder, H; Rempp, F; Wolf, T; Hemmer, P; Jelezko, F; Wrachtrup, J

    2010-01-01

    Two proof-of-principle experiments towards T1-limited magnetic resonance imaging with NV centers in diamond are demonstrated. First, a large number of Rabi oscillations is measured and it is demonstrated that the hyperfine interaction due to the NV's 14N can be extracted from the beating oscillations. Second, the Rabi beats under V-type microwave excitation of the three hyperfine manifolds is studied experimentally and described theoretically.

  12. Towards T 1-limited magnetic resonance imaging using Rabi beats

    Science.gov (United States)

    Fedder, H.; Dolde, F.; Rempp, F.; Wolf, T.; Hemmer, P.; Jelezko, F.; Wrachtrup, J.

    2011-03-01

    Two proof-of-principle experiments toward T 1-limited magnetic resonance imaging with NV centers in diamond are demonstrated. First, a large number of Rabi oscillations is measured and it is demonstrated that the hyperfine interaction due to the NV's 14N can be extracted from the beating oscillations. Second, the Rabi beats under V-type microwave excitation of the three hyperfine manifolds is studied experimentally and described theoretically.

  13. Cavity length dependence of mode beating in passively Q-switched Nd-solid state lasers

    Science.gov (United States)

    Zameroski, Nathan D.; Wanke, Michael; Bossert, David

    2013-03-01

    The temporal intensity profile of pulse(s) from passively Q-switched and passively Q-switched mode locked (QSML) solid-state lasers is known to be dependent on cavity length. In this work, the pulse width, modulation depth, and beat frequencies of a Nd:Cr:GSGG laser using a Cr+4:YAG passive Q-switch are investigated as function cavity length. Measured temporal widths are linearly correlated with cavity length but generally 3-5 ns larger than theoretical predictions. Some cavity lengths exhibit pulse profiles with no modulation while other lengths exhibit complete amplitude modulation. The observed beat frequencies at certain cavity lengths cannot be accounted for with passively QSML models in which the pulse train repetition rate is τRT-1, τRT= round-trip time. They can be explained, however, by including coupled cavity mode-locking effects. A theoretical model developed for a two section coupled cavity semiconductor laser is adapted to a solid-state laser to interpret measured beat frequencies. We also numerically evaluate the temporal criterion required to achieve temporally smooth Q-switched pulses, versus cavity length and pump rate. We show that in flash lamp pumped systems, the difference in buildup time between longitudinal modes is largely dependent on the pump rate. In applications where short pulse delay is important, the pumping rate may limit the ability to achieve temporally smooth pulses in passively Q-switched lasers. Simulations support trends in experimental data. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  14. Ionospheric very low frequency transmitter

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Spencer P. [New York University-Polytechnic School of Engineering, 5 Metrotech Center, Brooklyn, New York 11201 (United States)

    2015-02-15

    The theme of this paper is to establish a reliable ionospheric very low frequency (VLF) transmitter, which is also broad band. Two approaches are studied that generate VLF waves in the ionosphere. The first, classic approach employs a ground-based HF heater to directly modulate the high latitude ionospheric, or auroral electrojet. In the classic approach, the intensity-modulated HF heater induces an alternating current in the electrojet, which serves as a virtual antenna to transmit VLF waves. The spatial and temporal variations of the electrojet impact the reliability of the classic approach. The second, beat-wave approach also employs a ground-based HF heater; however, in this approach, the heater operates in a continuous wave mode at two HF frequencies separated by the desired VLF frequency. Theories for both approaches are formulated, calculations performed with numerical model simulations, and the calculations are compared to experimental results. Theory for the classic approach shows that an HF heater wave, intensity-modulated at VLF, modulates the electron temperature dependent electrical conductivity of the ionospheric electrojet, which, in turn, induces an ac electrojet current. Thus, the electrojet becomes a virtual VLF antenna. The numerical results show that the radiation intensity of the modulated electrojet decreases with an increase in VLF radiation frequency. Theory for the beat wave approach shows that the VLF radiation intensity depends upon the HF heater intensity rather than the electrojet strength, and yet this approach can also modulate the electrojet when present. HF heater experiments were conducted for both the intensity modulated and beat wave approaches. VLF radiations were generated and the experimental results confirm the numerical simulations. Theory and experimental results both show that in the absence of the electrojet, VLF radiation from the F-region is generated via the beat wave approach. Additionally, the beat wave approach

  15. A Case of Incomplete Central Retinal Artery Occlusion Associated with Short Posterior Ciliary Artery Occlusion

    Directory of Open Access Journals (Sweden)

    Shinji Makino

    2013-01-01

    Full Text Available To our knowledge, incomplete central retinal artery occlusion associated with short posterior ciliary artery occlusion is extremely rare. Herein, we describe a case of a 62-year-old man who was referred to our hospital with of transient blindness in his right eye. At initial examination, the patient’s best-corrected visual acuity was 18/20 in the right eye. Fundus examination showed multiple soft exudates around the optic disc and mild macular retinal edema in his right eye; however, a cherry red spot on the macula was not detected. Fluorescein angiography revealed delayed dye inflow into the nasal choroidal hemisphere that is supplied by the short posterior ciliary artery. The following day, the patient’s visual acuity improved to 20/20. Soft exudates around the optic disc increased during observation and gradually disappeared. His hemodynamic parameters revealed subclavian steal syndrome as examined by cervical ultrasonography and digital subtraction angiography. We speculate that his transient blindness was due to ophthalmic artery spasms. In this particular case, spasms of the ophthalmic artery and occlusion of the short posterior ciliary artery occurred simultaneously. As the short posterior ciliary artery branches from the ophthalmic artery, the anatomical location of the lesion might be near the branching of both arteries.

  16. Multicenter analysis of body mass index, lung function, and sputum microbiology in primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Maglione, Marco; Bush, Andrew; Nielsen, Kim G;

    2014-01-01

    BACKGROUND: No studies longitudinally, simultaneously assessed body mass index (BMI) and spirometry in primary ciliary dyskinesia (PCD). METHODS: We determined BMI and spirometry in 158 PCD children and adolescents from London, UK (n = 75), Naples, Italy (n = 23) and Copenhagen, Denmark (n = 60) ...

  17. Defining the proteome of human iris, ciliary body, retinal pigment epithelium, and choroid.

    Science.gov (United States)

    Zhang, Pingbo; Kirby, David; Dufresne, Craig; Chen, Yan; Turner, Randi; Ferri, Sara; Edward, Deepak P; Van Eyk, Jennifer E; Semba, Richard D

    2016-04-01

    The iris is a fine structure that controls the amount of light that enters the eye. The ciliary body controls the shape of the lens and produces aqueous humor. The retinal pigment epithelium and choroid (RPE/choroid) are essential in supporting the retina and absorbing light energy that enters the eye. Proteins were extracted from iris, ciliary body, and RPE/choroid tissues of eyes from five individuals and fractionated using SDS-PAGE. After in-gel digestion, peptides were analyzed using LC-MS/MS on an Orbitrap Elite mass spectrometer. In iris, ciliary body, and RPE/choroid, we identified 2959, 2867, and 2755 nonredundant proteins with peptide and protein false-positive rates of database of the human iris, ciliary body, and RPE/choroid may serve as a valuable resource for future investigations of the eye in health and disease. The MS proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifiers PXD001424 and PXD002194. PMID:26834087

  18. ZMYND10 is mutated in primary ciliary dyskinesia and interacts with LRRC6

    DEFF Research Database (Denmark)

    Zariwala, Maimoona A; Gee, Heon Yung; Kurkowiak, Małgorzata;

    2013-01-01

    Defects of motile cilia cause primary ciliary dyskinesia (PCD), characterized by recurrent respiratory infections and male infertility. Using whole-exome resequencing and high-throughput mutation analysis, we identified recessive biallelic mutations in ZMYND10 in 14 families and mutations in the...

  19. Choice of nasal nitric oxide technique as first-line test for primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Marthin, J K; Nielsen, K G

    2011-01-01

    Nasal nitric oxide (nNO) has a well-known potential as an indirect discriminative marker between patients with primary ciliary dyskinesia (PCD) and healthy subjects, but real-life experience and usefulness in young children is sparsely reported. Three nNO sampling methods were examined and compared...

  20. Sudden cardiac death in dogs with remodeled hearts is associated with larger beat-to-beat variability of repolarization

    DEFF Research Database (Denmark)

    Thomsen, Morten Bækgaard; Truin, Michiel; van Opstal, Jurren M;

    2005-01-01

    Increased proarrhythmia in dogs with chronic AV block (AVB) has been explained by ventricular remodeling causing a decrease in repolarization reserve. Beat-to-beat variability of repolarization (BVR) has been suggested to reflect repolarization reserve, in which high variability represents...... diminished reserve and larger propensity for repolarization-dependent ventricular arrhythmia. A subset of chronic AVB dogs (10%) suffers sudden cardiac death (SCD). With the assumption that repolarization defects constitute a potentially lethal proarrhythmic substrate, we hypothesized that BVR in SCD dogs....... In comparison, dogs with acute AVB had low variability (1.3 +/- 0.3 ms; n = 9; P Cardiac electrical remodeling after AVB is associated with an increase in beat-to-beat variability of repolarization. Chronic AVB dogs displaying further elevated variability of repolarization are prone...

  1. Local excision of ciliary body tumors:a long-term prospective cohort study in China

    Institute of Scientific and Technical Information of China (English)

    WEI Wen-bin; YANG Wen-li; HU Shi-min; LI Bin

    2008-01-01

    Background Ciliary body tumors are usually difficult to diagnose and treat in early stages.However,treatment of such tumors has trended toward ocular conservation instead of enucleation.Local excision of ciliary body tumors has become effective with the development of the modern vitrectomy,but long-term outcomes are still not clear.Therefore,we reported the outcome of locally excised ciliary body tumors after long-term follow-up.Methods Twenty-two patients (22 eyes),who had been diagnosed with ciliary body tumors in Beijing Tongren Hospital from January 1996 to June 2001,were enrolled in this prospective cohort study.Localized lamellar sclera-ciliary excisions were performed.In some cases,vitrectomies,scleral graft transplantations,and further excisions of the anterior choroid were performed.Diagnoses were confirmed by histopathologic examination.Patients were followed from five to eleven years after surgery.Their visual acuity,intraocular pressure and local recurrence were recorded with descriptive percentages.Results After surgery,all patients maintained normal eyeball appearances.Six patients maintained circular pupils.The final best corrected visual acuities (BCVA) varied from 0.02-1.00,including 18 patients (81.82%) who had BCVA equal to or better than that before surgery.Fifteen patients (68.18%) had BCVA better than 0.3.Only two patients had intraocular pressure (IOP) of less than 10 mmHg and the other patients maintained normal IOP.Nine cases (40.91%) were given confirmed diagnosis of malignant melanoma,four (18.18%) of melanocytoma,six (27.27%) of nonpigmented ciliary epithelial adenoma,two (9.09%) of neurofibroma,and one (4.55%) of neurinoma.Twenty patients (90.91%) had no recurrence during the follow-up period.In one case melanocytoma recurred seven years after surgery and enucleation was performed.One patient,whose operation removed a malignant melanoma with a diameter of 16 mm,died of hepatic metastasis five years after the operation.Conclusion For

  2. Observation of Atom-Wave Beats Using a Kerr Modulator for Atom Waves.

    Science.gov (United States)

    Décamps, B; Gillot, J; Vigué, J; Gauguet, A; Büchner, M

    2016-02-01

    A phase modulation puts the atom in a coherent superposition of quantum states with different kinetic energies. We have detected the interference of such modulated waves at the output of our atom interferometer, and we have observed beats at the difference of the modulation frequencies and its harmonics, in good agreement with theory. The phase modulations were produced by a Kerr phase modulator, i.e., by the propagation of the atom wave in a time-dependent electric field. An extension of this technique to electron interferometry should open the way to very high temporal resolution in electron microscopy. PMID:26894710

  3. Observation of Atom-Wave Beats Using a Kerr Modulator for Atom Waves.

    Science.gov (United States)

    Décamps, B; Gillot, J; Vigué, J; Gauguet, A; Büchner, M

    2016-02-01

    A phase modulation puts the atom in a coherent superposition of quantum states with different kinetic energies. We have detected the interference of such modulated waves at the output of our atom interferometer, and we have observed beats at the difference of the modulation frequencies and its harmonics, in good agreement with theory. The phase modulations were produced by a Kerr phase modulator, i.e., by the propagation of the atom wave in a time-dependent electric field. An extension of this technique to electron interferometry should open the way to very high temporal resolution in electron microscopy.

  4. Terahertz beat freuquency generation from two-mode lasing operation of coupled microdisk laser

    CERN Document Server

    Ryu, Jung-Wan; Kim, Chil-Min; Shinohara, Susumu; Kim, Sang Wook

    2012-01-01

    We propose a coupled microdisk laser as a compact and tunable laser source for the generation of a coherent continuous wave THz radiation by photomixing. Using the Schr\\"odinger-Bloch model including the nonlinear effect of active medium, we find single mode and two mode lasings depending on the pumping strength. We explain the transitions of lasing modes in terms of resonant modes which are the solutions of the Schr\\"odinger-Bloch model without active medium and nonlinear interaction. In particular, a two mode lasing is shown to generate THz oscillating frequency originating from the light beating of two nearly degenerated resonant modes with different symmetries.

  5. Beat-to-beat assessment of left ventricular ejection in atrial fibrillation

    International Nuclear Information System (INIS)

    Beat-to-beat left ventricular ejection was evaluated in a group of 20 patients with chronic atrial fibrillation using a computerized single probe detector. The reference group consisted of 10 patients with sinus rhythm. For each patient 30 successive cardiac cycles were analyzed and the relative variations of four parameters were assessed: R-R interval, diastolic and systolic time intervals, and ejection amplitude, corresponding to the left ventricular stroke volume. The mean variations were respectively 3.4%, 10.4%, 8.4%, and 11.8% in patients with sinus rhythm, and 21.9%, 37.9%, 10.6% and 30.5% in patients with artrial fibrillation. This demonstrates that changes in ejection are mainly related to the duration of the filling phase, with nearly constant systolic times. Correlations between R-R intervals and systolic ejection amplitudes were highly significant (P<0.001) in patients with atrial fibrillation in 85% of cases. This information complements the average ejection fraction obtained from multiple cycle superimposition. (orig.)

  6. Beat-to-beat analysis method for magnetocardiographic recordings during interventions

    International Nuclear Information System (INIS)

    Multichannel magnetocardiography (MCG) during exercise testing has been shown to detect myocardial ischaemia in patients with coronary artery disease. Previous studies on exercise MCG have focused on one or few time intervals during the recovery period and only a fragment of the data available has been utilized. We present a method for beat-to-beat analysis and parametrization of the MCG signal. The method can be used for studying and quantifying the changes induced in the MCG by interventions. We test the method with data recorded in bicycle exercise testing in healthy volunteers and patients with coronary artery disease. Information in all cardiac cycles recorded during the recovery period of exercise MCG testing is, for the first time, utilized in the signal analysis. Exercise-induced myocardial ischaemia was detected by heart rate adjustment of change in magnetic field map orientation. In addition to the ST segment, the T wave in the MCG was also found to provide information related to myocardial ischaemia. The method of analysis efficiently utilizes the spatial and temporal properties of multichannel MCG mapping, providing a new tool for detecting and quantifying fast phenomena during interventional MCG studies. The method can also be applied to an on-line analysis of MCG data. (author)

  7. Growth of the crabgrass species Digitaria ciliaris and Digitaria nuda Crescimento das espécies de capim-colchão Digitaria ciliaris e Digitaria nuda

    Directory of Open Access Journals (Sweden)

    R.C. Souza

    2012-06-01

    Full Text Available The aim of this research paper was to compare the growth of D. ciliaris and D. nuda crabgrass species under non-competitive conditions. To this end, two experiments were conducted, one from March - July 2010 and the other from February - June 2011. The experimental design of both trials was completely randomized making a factorial (2 seasons x 2 species crabgrass x 12 evaluation periods with four replications. Assessments began at 15 days after sowing (DAS, and repeated weekly until 92 DAS. The variables evaluated were total dry matter (roots+leaves+stems, leaf area, leaf number and tiller. The results were submitted to analysis of variance and the absolute growth rate, relative growth rate and leaf area ratio were calculated using the means, which were adjusted regression models. The crabgrass species were significantly different in leaf area, leaf number, tiller number and dry matter per plant. D. ciliaris for all variables was statistically higher than D. nuda. Regarding the speed at which the growth of the species occurred, the absolute growth rate and relative growth rate of D. ciliaris was also greater than D. nuda. In addition, D. ciliaris also had a lower leaf area ratio indicating greater efficiency in converting light energy into carbohydrates. It can be concluded that D. ciliaris has a higher growth rate in conditions where there is no limitation of nutrients and water availability in relation to D. nuda, mainly due to D. ciliaris have greater leaf area, number of leaves and dry matter accumulation per plant.O objetivo da presente pesquisa foi comparar o crescimento das espécies de capim colchão D. ciliaris e D. nuda, em condições não-competitivas. Para isso, foram conduzidos dois experimentos, um de março a julho de 2010 e outro de fevereiro a junho de 2011. O delineamento experimental de ambos os ensaios foi inteiramente casualizado, perfazendo um esquema fatorial (2 épocas x 2 espécies de capim colchão x 12 períodos de

  8. [Non-heart-beating donors are ineligible].

    Science.gov (United States)

    Heide, W

    2016-02-01

    The death of the donor is a mandatory prerequisite for organ transplantation (dead donor rule) worldwide. It is a medical, legal and ethical consensus to accept the concept of brain death, as first proposed in 1968 by the ad hoc committee of the Harvard Medical School, as a certain criterion of death. In isolated cases where the diagnosis of brain death was claimed to be wrong, it could be demonstrated that the diagnostic procedure for brain death had not been correctly performed. In March 2014 a joint statement by the German neuromedical societies emphasized that 1) the diagnosis of brain death is one of the safest diagnoses in medicine if performed according to accepted medical standards and criteria and 2) the concept of non-heart-beating donors (NHBD, i. e. organ donation after an arbitrarily defined duration of circulatory and cardiac arrest) practiced in some European countries must be absolutely rejected because it implicates a high risk of diagnostic error. According to the current literature it is unclear at what time cardiac and circulatory arrest is irreversible and leads to irreversible cessation of all functions of the entire brain including the brainstem, even though clinical signs of cessation of brain functions are always found after 10 min. Furthermore, is it often an arbitrary decision to exactly define the duration of cardiac arrest if continuous echocardiographic monitoring has not been carried out from the very beginning. Last but not least there are ethical concerns against the concept of NHBD because it might influence therapeutic efforts to resuscitate a patient with cardiac arrest. Therefore, the German Medical Council (BÄK) has repeatedly rejected the concept of NHBD for organ transplantation since 1995. PMID:26830897

  9. Intermode beating mode-locking technique for O-band mixed-cascaded Raman fiber lasers.

    Science.gov (United States)

    Luo, Zhengqian; Zhong, Min; Xiong, Fengfu; Wu, Duanduan; Huang, Yizhong; Li, Yingyue; Le, Lili; Xu, Bin; Xu, Huiying; Cai, Zhiping

    2015-02-15

    A novel intermode beating mode-locking (IBML) technique combined with a cascaded Raman process is proposed to mode-lock an O-band two-cascaded Raman fiber laser. Using a 980-m-long phosphosilicate fiber pumped by a 1064 nm laser, the second-order Raman oscillation at 1319 nm is generated by the mixed-cascaded Raman shifts of P2O5 and SiO2. By precisely matching the intermode beating frequencies of the 1064 nm pump laser and the second-order Raman cavity frequency, harmonic mode-locking at 1319 nm is initiated. The dynamic process of the IBML operation in the cascaded Raman laser is experimentally investigated. The 131st-order harmonic mode-locking with a repetition rate of 27.247 MHz is very stable with the radio-frequency (RF) signal-to-noise ratio of >56  dB and the RF supermode-suppression ratio of >43  dB. The mode-locked pulses with the square profile are confirmed as the noise-like pulses by an autocorrelator. The IBML technique, in combination with the cascaded Raman process, could offer an exciting new prospect for obtaining simple, compact, and arbitrary-wavelength mode-locked laser sources. PMID:25680135

  10. Observation of Quantum Beating from Two Coupled Parametric Six-Wave Mixing Signals in Rb

    Institute of Scientific and Technical Information of China (English)

    ZHU Chang-Jun; HE Jun-Fang; ZHAI Xue-Jun; XUE Bing

    2008-01-01

    Two processes of coupled difference-frequency axially phase-matched parametric six-wave mixing are carried out in Rb vapour by two-photon excitation using fs laser pulses, and parametric six-wave mixing signals in the infrared and near infrared regime are detected. The infrared parametric six-wave mixing signals are up-converted into the visible spectral range by sum-frequency mixing with the pump laser in a LiI03 crystal. Moreover, quantum beating at 608cm-1, corresponding to the 7s - 5d energy difference in Rb, is observed from the sum-frequency signal at 495 nm. As a result, we obtain modulated light signals in the visible, near infrared and infrared spectral ranges, and study the interference between 7s and 5d states of Rb.

  11. THz Wireless Transmission Systems Based on Photonic Generation of Highly Pure Beat-Notes

    DEFF Research Database (Denmark)

    Jia, Shi; Yu, Xianbin; Hu, Hao;

    2016-01-01

    noise, spectrum purity, tunability, and long-term stability. In the case of generating 400 GHz carrier, the measured timing jitter, linewidth, and long-term stability in the experiment are 51.5 fs, less than 2 Hz, and less than ±1 Hz with 3 hours, respectively. We also theoretically analyze the phase......-correlated optical frequency comb (OFC) is created for photomixing generation of the desired THz carrier frequencies with low phase noise. The OFC allows for the generation of flexibly tunable THz carrier frequencies. The performance of the generated THz carriers is experimentally characterized in terms of phase...... noise of photonically generated THz beat-notes when phase correlation of two optical comb tones is damaged due to their path-length difference. In addition, we demonstrate THz wireless transmission of various modulation formats, including OOK, QPSK, 16-QAM, and 32-QAM at beyond 10 Gb/s in such a system...

  12. High frequency ultrasound imaging in pupillary block glaucoma.

    OpenAIRE

    Aslanides, I M; Libre, P E; Silverman, R H; Reinstein, D Z; Lazzaro, D R; Rondeau, M J; Harmon, G K; Coleman, D J

    1995-01-01

    BACKGROUND--The diagnosis of pupillary block glaucoma requires sufficient clarity of the ocular media. This is particularly important for assessment of both the presence and patency of an iridotomy, and the determination of central anterior chamber depth. METHODS--High frequency ultrasonography was used in three patients with suspected pupillary block to determine iris configuration, posterior chamber volume, and ciliary body conformation. RESULTS--All patients demonstrated high frequency ult...

  13. Early repolarization as a predictor of premature ventricular beats.

    Science.gov (United States)

    Matoshvili, Z T; Petriashvili, Sh G; Archadze, A T; Azaladze, I G

    2015-02-01

    Early repolarization pattern (ERP) is a common ECG variant, characterized by J point elevation manifested either as terminal QRS slurring (the transition from the QRS segment to the ST segment) or notching (a positive deflection inscribed on terminal QRS complex) associated with concave upward ST-segment elevation and prominent T waves in at least two contiguous leads. Aim of this observational study was to compare number of premature ventricular beats in the different groups of patients with early repolarization. The result of this observational study shows that there are: 1,74 fold higher number of premature ventricular beats in 41-74 year subgroup VS 19-40 year subgroup; 1,31 fold higher number of premature ventricular beats in male subgroup VS female subgroup (But this difference is not statistically significant, because t=1,49, p=0,141); 2,85 fold higher number of premature ventricular beats in CAD+ERP subgroup VS ERP without CAD subgroup; 1,74 fold higher number of premature ventricular beats in HF+ERP subgroup VS ERP without HF subgroup; 1,81 fold higher number of premature ventricular beats in CAD+ERP subgroup VS CAD without ERP subgroup; 1,58 fold higher number of premature ventricular beats in HF+ERP subgroup VS HF without ERP subgroup; So, CAD+ERP is very arrhythmogenic condition, after this is HF+ERP, Then Age. This study shows that ERP independently increase number of PVB in different groups (CAD, HF). This is principally new and very important result. Also the number of patients is enough to make this conclusion.

  14. In vivo micro-scale tomography of ciliary behavior in the mammalian oviduct.

    Science.gov (United States)

    Wang, Shang; Burton, Jason C; Behringer, Richard R; Larina, Irina V

    2015-01-01

    Motile cilia in the mammalian oviduct play a key role in reproduction, such as transporting fertilized oocytes to the uterus for implantation. Due to their small size (~5-10 μm in length and ~300 nm in diameter), live visualization of cilia and their activity in the lumen of the oviduct through tissue layers represents a major challenge not yet overcome. Here, we report a functional low-coherence optical imaging technique that allows in vivo depth-resolved mapping of the cilia location and cilia beat frequency (CBF) in the intact mouse oviduct with micro-scale spatial resolution. We validate our approach with widely-used microscopic imaging methods, present the first in vivo mapping of the oviduct CBF in its native context, and demonstrate the ability of this approach to differentiate CBF in different locations of the oviduct at different post-conception stages. This technique opens a range of opportunities for live studies in reproductive medicine as well as other areas focused on cilia activity and related ciliopathies. PMID:26279472

  15. J point elevation as a predictor of premature ventricular beats.

    Science.gov (United States)

    Matoshvili, Z; Petriashvili, Sh; Archvadze, A; Azaladze, I

    2014-01-01

    Early repolarization pattern (ERP) is a common ECG variant, characterized by J point elevation manifested either as terminal QRS slurring (the transition from the QRS segment to the ST segment) or notching (a positive deflection inscribed on terminal QRS complex) associated with concave upward ST-segment elevation and prominent T waves in at least two contiguous leads. 36 patients were included in this observation. There are 36 patients (19-68 years old) with early repolarization ECG patterns. All this 36 patients were divided into two groups according to their level of J point elevation. First group consisted of 12 patients with J point elevation ≥0,15 mV; second group - of 24 patients with J point elevation premature ventricular beat during 24 h. Before and during this monitoring patients don't take any antyarrhythmic drugs. In the first group (J point elevation ≥0,15 mV) sum of premature ventricular beats were 27432, in the second group (J point elevation premature ventricular beats were 31 896. The results of this observational study shows that there is 1,72 fold higher number of premature ventricular beats in first group. So, J point elevation equal or more then 0,15 mV, is more arrhythmogenic and induces premature ventricular beats. This is principally new and very important result.

  16. The Masquerades of a Childhood Ciliary Body Medulloepithelioma: A Case of Chronic Uveitis, Cataract, and Secondary Glaucoma

    Directory of Open Access Journals (Sweden)

    Jocelyn Chua

    2012-01-01

    Full Text Available Ciliary body medulloepitheliomas in childhood often masquerade other intraocular conditions due to its insidious nature as well as its secondary effects on proximal intraocular tissues in the anterior chamber. We report a case where a ciliary body medulloepithelioma in a two-year-old boy presents with chronic uveitis, cataract, and an uncontrolled secondary glaucoma after an innocuous blunt ocular trauma. The diagnosis was only made after the occurrence of a ciliary body mass. We discuss the clinical features of ciliary body medulloepitheliomas, the implications of a delayed diagnosis and treatment as well as the concern of periorbital tumor seeding with the use of an aqueous shunt implant in this case.

  17. Effect of cAMP on short-circuit current in isolated human ciliary body

    Institute of Scientific and Technical Information of China (English)

    WU Ren-yi; MA Ning; HU Qian-qian

    2013-01-01

    Background Cyclic adenosine monophosphate (cAMP) could activate chloride channels in bovine ciliary body and trigger an increase in the ionic current (short-circuit current,Isc) across the ciliary processes in pigs.The purpose of this study was to investigate how cAMP modulates Isc in isolated human ciliary processes and the possible involvement of chloride transport across the tissue in cAMP-induced Isc change.Methods In an Ussing-type chamber system,the Isc changes induced by the cAMP analogue 8-bromo-cAMP and an adenylyl cyclase activator forskolin in isolated human ciliary processes were assessed.The involvement of Cl-component in the bath solution was investigated.The effect of Cl-channel (10 μmol/L niflumic acid and 1 mmol/L 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS)),K+ channel (10 mmol/L tetraethylammonium chloride (TEA)),or Na+ channel blockers (1 mmol/L amiloride) on 8-bromo-cAMP-induced Isc change was also studied.Results Dose-dependently,8-bromo-cAMP (10 nmol/L-30 μmol/L) or forskolin (10 nmol/L-3 μmol/L) increased Isc across the ciliary processes with an increase in negative potential difference on the non-pigmented epithelium (NPE) side of the tissue.Isc increase induced by 8-bromo-cAMP was more pronounced when the drug was applied on the NPE side than on the pigmented epithelium side.When the tissue was bathed in low Cl-solutions,the Isc increase was significantly inhibited.Finally,niflumic acid and DIDS,but not TEA or amiloride,significantly prevented the Isc increase induced by 8-bromo-cAMP.Conclusions cAMP stimulates stroma-to-aqueous anionic transport in isolated human ciliary processes.Chloride is likely to be among the ions,the transportation of which across the tissue is triggered by cAMP,suggesting the potential role of cAMP in the process of aqueous humor formation in human eyes.

  18. Bardet–Biedl syndrome proteins 1 and 3 regulate the ciliary trafficking of polycystic kidney disease 1 protein

    OpenAIRE

    Su, Xuefeng; Driscoll, Kaitlin; Yao, Gang; Raed, Anas; Wu, Maoqing; Beales, Philip L.; Zhou, Jing

    2014-01-01

    Bardet–Biedl syndrome (BBS) and autosomal dominant polycystic kidney disease (ADPKD) are two genetically distinct ciliopathies but share common phenotypes such as renal cysts. Seven BBS proteins form a complex called the BBSome which is localized at the basal body or ciliary axoneme and regulates the ciliary entry or flagellar exit of several signaling molecules. Here, we demonstrate that, unlike the seven-span somatostatin receptor 3 or the leptin receptor that interacts with all subunits of...

  19. Voltage-gated potassium channel Kvl.3 in rabbit ciliary epithelium regulates the membrane potential via coupling intracellular calcium

    Institute of Scientific and Technical Information of China (English)

    LI Yan-feng; ZHUO Ye-hong; BI Wei-na; BAI Yu-jing; LI Yan-na; WANG Zhi-jian

    2008-01-01

    Background The cell layer of the ciliary epithelium is responsible for aqueous humor secretion and maintenance.Ion channels play an important role in these processes.The main aim of this study was to determine whether the well-characterized members of the Kvl family (Kv1.3) contribute to the Kv currents in ciliary epithelium.Methods New Zealand White rabbits were maintained in a 12 hours light/dark cycle.Ciliary epithelium samples were isolated from the rabbits.We used Western blotting and immunocytochemistry to identify the expression and location of a voltage-gated potassium channel Kvl.3 in ciliary body epithelium.Membrane potential change after adding of Kv1.3 inhibitor margatoxin (MgTX) was observed with a fluorescence method.Results Western blotting and immunocytochemical studies showed that the Kv1.3 protein expressed in pigment ciliary epithelium and nonpigment ciliary epithelium,however it seemed to express more in the apical membrane of the nonpigmented epithelial cells.One nmol/L margatoxin,a specific inhibitor of Kv1.3 channels caused depolarization of the cultured nonpigmented epithelium (NPE) membrane potential.The cytosotic calcium increased after NPE cell depolarization,this increase of cytosolic calcium was partially blocked by 12.5 μmol/L dantrolene and 10 μmol/L nifedipine.These observations suggest that Kv1.3 channels modulate ciliary epithelium potential and effect calcium dependent mechanisms.Conclusion Kv1.3 channels contribute to K+ efflux at the membrane of rabbit ciliary epithelium.

  20. Beat & beyond : memoir, myth and visual arts in women of the beat generation = Más allá del "Beat": memoria, mito y arte visual en las mujeres de la generación beat

    OpenAIRE

    Encarnación Pinedo, Estíbaliz

    2016-01-01

    El objetivo de esta tesis doctoral es revaluar el trabajo de las mujeres de la Generación Beat dentro de un discurso artístico y literario post(Beat) o más allá de lo “Beat.” El capítulo dos, en el que se analizan once memorias, se centra en el dilema entre lo personal y lo literario y sirve para delinear el contexto socio-político y artístico en el que las autoras escribieron. A través del análisis de temas comunes a las distintas memorias (la escritura, los roles de género, y la conexión co...

  1. Robotic force stabilization for beating heart intracardiac surgery.

    Science.gov (United States)

    Yuen, Shelten G; Yip, Michael C; Vasilyev, Nikolay V; Perrin, Douglas P; del Nido, Pedro J; Howe, Robert D

    2009-01-01

    The manipulation of fast moving, delicate tissues in beating heart procedures presents a considerable challenge to surgeons. We present a new robotic force stabilization system that assists surgeons by maintaining a constant contact force with the beating heart. The system incorporates a novel, miniature uniaxial force sensor that is mounted to surgical instrumentation to measure contact forces during surgical manipulation. Using this sensor in conjunction with real-time tissue motion information derived from 3D ultrasound, we show that a force controller with feed-forward motion terms can provide safe and accurate force stabilization in an in vivo contact task against the beating mitral valve annulus. This confers a 50% reduction in force fluctuations when compared to a standard force controller and a 75% reduction in fluctuations when compared to manual attempts to maintain the same force. PMID:20425967

  2. Continuing studies of the plasma beat wave accelerator

    International Nuclear Information System (INIS)

    This is a proposal for the release of third year funds for the ''Plasma Beat Wave Accelerator'' program (PBWA) at UCLA under the direction of Professor C. Joshi. This report is also a summary of progress on this project since March 1990; i.e., the date of the last report to the DOE. Once again we note that although the program is for historical reasons called the Plasma Beat Wave Accelerator Program, our group is active in all areas of applications of lasers and plasmas in future high energy accelerators. These are as follows: heat gradient plasma structures; excited by plasma beat wave technique; laser wake field technique; and plasma wake field technique. Development of a photoinjector-driven, 20 MeV linac; and theoretical studies of the plasma lens and use of plasmas at the final focus

  3. Superresolution measurement of nanofiber diameter by modes beating

    Science.gov (United States)

    Fenton, E. F.; Solano, P.; Hoffman, J. E.; Orozco, L. A.; Rolston, S. L.; Fatemi, F. K.

    2016-05-01

    Nanofibers are becoming an important tool in quantum information technologies for coupling photonics systems to atomic systems. Nondestructive techniques for characterizing these nanofibers prior to integration into an apparatus are desirable. In this work, we probe the light propagating in a fused silica optical nanofiber (750-nm-diameter) by coupling it evanescently to a 6- μm-diameter microfiber that is scanned along the nanofiber length. This technique is capable of observing all possible beat lengths among different propagating modes. The beat lengths are strongly dependent on the nanofiber diameter and refractive index of the fiber. The steep dependence has enabled measurements of the fiber diameter with sub-Angstrom sensitivity. The diameter extracted from the beat length measurements agrees with a measurement made using scanning electron microscopy. Work supported by NSF.

  4. On readout of vibrational qubits using quantum beats

    International Nuclear Information System (INIS)

    Readout of the final states of qubits is a crucial step towards implementing quantum computation in experiment. Although not scalable to large numbers of qubits per molecule, computational studies show that molecular vibrations could provide a significant (factor 2–5 in the literature) increase in the number of qubits compared to two-level systems. In this theoretical work, we explore the process of readout from vibrational qubits in thiophosgene molecule, SCCl2, using quantum beat oscillations. The quantum beats are measured by first exciting the superposition of the qubit-encoding vibrational states to the electronically excited readout state with variable time-delay pulses. The resulting oscillation of population of the readout state is then detected as a function of time delay. In principle, fitting the quantum beat signal by an analytical expression should allow extracting the values of probability amplitudes and the relative phases of the vibrational qubit states. However, we found that if this procedure is implemented using the standard analytic expression for quantum beats, a non-negligible phase error is obtained. We discuss the origin and properties of this phase error, and propose a new analytical expression to correct the phase error. The corrected expression fits the quantum beat signal very accurately, which may permit reading out the final state of vibrational qubits in experiments by combining the analytic fitting expression with numerical modelling of the readout process. The new expression is also useful as a simple model for fitting any quantum beat experiments where more accurate phase information is desired

  5. Streptococcus pneumoniae-Induced Inhibition of Rat Ependymal Cilia Is Attenuated by Antipneumolysin Antibody

    OpenAIRE

    Hirst, Robert A; Mohammed, Bashir J.; Mitchell, Timothy J.; Andrew, Peter W.; O'Callaghan, Christopher

    2004-01-01

    Ciliated ependymal cells line the ventricular surfaces and aqueducts of the brain. In ex vivo experiments, pneumolysin caused rapid inhibition of the ependymal ciliary beat frequency and caused ependymal cell disruption. Wild-type pneumococci and pneumococci deficient in pneumolysin caused ciliary slowing, but penicillin lysis of wild-type, not pneumolysin-deficient, pneumococci increased the extent of ciliary inhibition. This effect was abolished by antipneumolysin antibody. Ependymal ciliar...

  6. Can We Learn to Beat the Best Stock

    CERN Document Server

    Borodin, A; Gogan, V; 10.1613/jair.1336

    2011-01-01

    A novel algorithm for actively trading stocks is presented. While traditional expert advice and "universal" algorithms (as well as standard technical trading heuristics) attempt to predict winners or trends, our approach relies on predictable statistical relations between all pairs of stocks in the market. Our empirical results on historical markets provide strong evidence that this type of technical trading can "beat the market" and moreover, can beat the best stock in the market. In doing so we utilize a new idea for smoothing critical parameters in the context of expert learning.

  7. The load-response of the flagellar beat

    CERN Document Server

    Klindt, Gary S; Wanger, Christian; Friedrich, Benjamin M

    2016-01-01

    Cilia and flagella exhibit regular bending waves that perform mechanical work on the surrounding fluid, to propel cellular swimmers and pump fluids inside organisms. Here, we quantify a force-velocity relationship of the beating flagellum, by exposing flagellated \\emph{Chlamydomonas} cells to controlled microfluidic flows. A simple theory of flagellar limit-cycle oscillations, calibrated by measurements in the absence of flow, reproduces this relationship quantitatively. We derive a link between the chemo-mechanical efficiency of the flagellar beat and its ability to synchronize to oscillatory flows.

  8. Ciliary and mucus-net filter feeding, with special reference to fluid mechanical characteristics

    DEFF Research Database (Denmark)

    Jørgensen, C.B.; Kiørboe, Thomas; Møhlenberg, F.;

    1984-01-01

    Filter characteristics were determined and compared in ciliary and mucus-net filter feeders. The ciliary feeders include the polychaete Sabella penicillus, the brachiopod Terebratulina retusa, the marine bivalves Monia squama, Cardium glaucum, and Petricola pholadiformis, and the freshwater...... bivalves Dreissena polymorpha, Unio pictorum and Anodonta cygnea. The mucus-net feeders are the polychaete Chaetopterus variopedatus, the gastropod Crepidula fornicata and the ascidians Styela clava, Ciona intestinalis, Ascidia virginea, A. obliqua and A. mentula. Efficiencies of particle retention as a...... function of particle size was determined by counting of particles in samples of inhalant and exhalant water. The lower threshold for efficient particle retention varied from .apprx. 6 .mu.m in T. retuso to .apprx. 1 .mu.m in D. polymorpha. Mucus nets efficiently retained particles down to 1-2 .mu.m. Filter...

  9. Longitudinal study of lung function in a cohort of primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Ellerman, A; Bisgaard, H

    1997-01-01

    Patients with primary ciliary dyskinesia (PCD) have pronounced stasis of their respiratory secretions and therefore recurrent lower airway infections, which raises concerns for the development of lung function. Twenty four patients with PCD have been studied prospectively with a standardized regime...... in our clinic for 2-16 yrs with clinic visits, including spirometry 2-4 times per year, daily physiotherapy and monthly sputum cultures with subsequent specific antibiotic treatment. Lung function was significantly lower in the 12 PCD patients entering the cohort as adults when compared to the PCD......, respectively, the lung function remained stable in most patients. It is concluded that primary ciliary dyskinesia is accompanied by a progressive deterioration in lung function if undertreated, but lung function can be maintained with appropriate antibiotic treatment and regular physiotherapy. This emphasizes...

  10. Dual-frequency Brillouin fiber laser for optical generation of tunable low-noise radio frequency/microwave frequency.

    Science.gov (United States)

    Geng, Jihong; Staines, Sean; Jiang, Shibin

    2008-01-01

    We demonstrate a new approach, i.e., a cw dual-frequency Brillouin fiber laser pumped by two independent single-frequency Er-doped fiber lasers, for the generation of tunable low-noise rf/microwave optical signals. Its inherent features of both linewidth narrowing effect in a Brillouin fiber cavity and common mode noise cancellation between two laser modes sharing a common cavity allow us to achieve high frequency stability without using a supercavity. Beat frequency of the dual-frequency Brillouin fiber laser can be tuned from tens of megahertz up to 100 GHz by thermally tuning the wavelengths of the two pump lasers with tuning sensitivity of approximately 1.4 GHz/ degrees C. Allan variance measurements show the beat signals have the hertz-level frequency stability.

  11. Adenoma of the Nonpigmented Ciliary Body and Iris Epithelium in Mexican Mestizo Patients

    Science.gov (United States)

    Serna-Ojeda, Juan Carlos; Ariza-Camacho, Enrique; Collado-Solórzano, Alberto; Flores-Sánchez, Blanca C.; Rodríguez-Reyes, Abelardo A.; Fulda-Graue, Emiliano

    2015-01-01

    The adenoma of the nonpigmented ciliary epithelium is a benign rare tumor, which may present with different clinical characteristics and requires resection along with histopathologic analysis and the identification of specific immunohistochemical markers for an accurate diagnosis. Here, we report a case series of 4 patients in a Mexican mestizo population with this diagnosis, their clinical features, the ultrasound imaging characteristics and the histopathological and immunohistochemical findings. PMID:27171918

  12. Identification of Ciliary and Ciliopathy Genes in Caenorhabditis Elegans through Comparative Genomics

    OpenAIRE

    Chen, Nansheng; Mah, Allan; Oliver E Blacque; Chu, Jeffrey; Phgora, Kiran; Bakhoum, Mathieu W.; Newbury, C. Rebecca Hunt; Khattra, Jaswinder; Chan, Susanna; Efimenko, Evgheni; Johnsen, Robert; Phirke, Prasad; Swoboda, Peter; Marra, Marco; Moerman, Donald

    2006-01-01

    Background The recent availability of genome sequences of multiple related Caenorhabditis species has made it possible to identify, using comparative genomics, similarly transcribed genes in Caenorhabditis elegans and its sister species. Taking this approach, we have identified numerous novel ciliary genes in C. elegans, some of which may be orthologs of unidentified human ciliopathy genes. Results By screening for genes possessing canonical X-box sequences in promoters of three Caenorhabditi...

  13. Rootletin organizes the ciliary rootlet to achieve neuron sensory function in Drosophila

    OpenAIRE

    Chen, Jieyan V.; Kao, Ling-Rong; Jana, Swadhin C.; Sivan-Loukianova, Elena; Mendonça, Susana; Cabrera, Oscar A.; Singh, Priyanka; Cabernard, Clemens; Eberl, Daniel F.; Bettencourt-Dias, Monica; Timothy L. Megraw

    2015-01-01

    Cilia are essential for cell signaling and sensory perception. In many cell types, a cytoskeletal structure called the ciliary rootlet links the cilium to the cell body. Previous studies indicated that rootlets support the long-term stability of some cilia. Here we report that Drosophila melanogaster Rootletin (Root), the sole orthologue of the mammalian paralogs Rootletin and C-Nap1, assembles into rootlets of diverse lengths among sensory neuron subtypes. Root mutant neurons lack rootlets a...

  14. Mouse models of polycystic kidney disease induced by defects of ciliary proteins

    Directory of Open Access Journals (Sweden)

    Je Yeong Ko

    2013-02-01

    Full Text Available Polycystic kidney disease (PKD is a common hereditarydisorder which is characterized by fluid-filled cysts in thekidney. Mutation in either PKD1, encoding polycystin-1 (PC1,or PKD2, encoding polycystin-2 (PC2, are causative genes ofPKD. Recent studies indicate that renal cilia, known asmechanosensors, detecting flow stimulation through renaltubules, have a critical function in maintaining homeostasis ofrenal epithelial cells. Because most proteins related to PKD arelocalized to renal cilia or have a function in ciliogenesis.PC1/PC2 heterodimer is localized to the cilia, playing a role incalcium channels. Also, disruptions of ciliary proteins, exceptfor PC1 and PC2, could be involved in the induction ofpolycystic kidney disease. Based on these findings, variousPKD mice models were produced to understand the roles ofprimary cilia defects in renal cyst formation. In this review, wewill describe the general role of cilia in renal epithelial cells,and the relationship between ciliary defects and PKD. We alsodiscuss mouse models of PKD related to ciliary defects basedon recent studies. [BMB Reports 2013; 46(2: 73-79

  15. Morphological, histochemical and immunohistochemical characterization of secretory production of the ciliary glands in the porcine eyelid

    Directory of Open Access Journals (Sweden)

    T Yasui

    2009-06-01

    Full Text Available In addition to performing general histology and cytology of the ciliary glands of the miniature pig, we studied the localization of glycoconjugates and b-defensins in these glands with the use of carbohydrate histochemical and immunohistochemical methods. The secretory cells of the glands were equipped with non-homogeneous secretory granules, a welldeveloped Golgi apparatus and rough endoplasmic reticulum. The secretory epithelium and luminal secretion of the glands contained large amounts of neutral and acidic glycoconjugates with various saccharide residues (a-L-Fuc, b-DGal, a-D-GalNAc and sialic acid. The sebaceous glands and tarsal glands also exhibited positive reactions to most of the histochemical methods. Additionally, the antimicrobial peptide group of b-defensins was demonstrated to be products of the ciliary glands, as well as the sebaceous glands and tarsal glands. The results obtained are discussed with regard to the specific function of the ciliary glandular secretions. These secretory products may be related to the moistening and general protection of the skin surface of the eyelid and ocular surface.

  16. Long-term clearance from small airways in subjects with ciliary dysfunction

    Directory of Open Access Journals (Sweden)

    Hjelte Lena

    2006-05-01

    Full Text Available Abstract The objective of this study was to investigate if long-term clearance from small airways is dependent on normal ciliary function. Six young adults with primary ciliary dyskinesia (PCD inhaled 111 Indium labelled Teflon particles of 4.2 μm geometric and 6.2 μm aerodynamic diameter with an extremely slow inhalation flow, 0.05 L/s. The inhalation method deposits particles mainly in the small conducting airways. Lung retention was measured immediately after inhalation and at four occasions up to 21 days after inhalation. Results were compared with data from ten healthy controls. For additional comparison three of the PCD subjects also inhaled the test particles with normal inhalation flow, 0.5 L/s, providing a more central deposition. The lung retention at 24 h in % of lung deposition (Ret24 was higher (p 24 with slow inhalation flow was 73.9 ± 1.9 % compared to 68.9 ± 7.5 % with normal inhalation flow in the three PCD subjects exposed twice. During day 7–21 the three PCD subjects exposed twice cleared 9 % with normal flow, probably representing predominantly alveolar clearance, compared to 19 % with slow inhalation flow, probably representing mainly small airway clearance. This study shows that despite ciliary dysfunction, clearance continues in the small airways beyond 24 h. There are apparently additional clearance mechanisms present in the small airways.

  17. Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair.

    Science.gov (United States)

    Zhang, Yanru; Zhang, Hui; Katiella, Kaka; Huang, Wenhua

    2014-07-15

    A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group > chemically extracted acellular nerve graft + ciliary neurotrophic factor group > chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anastomosis, but superior to chemically extracted acellular allogeneic nerve bridging alone. PMID:25221592

  18. Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair

    Institute of Scientific and Technical Information of China (English)

    Yanru Zhang; Hui Zhang; Kaka Katiella; Wenhua Huang

    2014-01-01

    A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune re-jection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regenera-tion. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group > chemically extracted acellular nerve graft + ciliary neurotrophic factor group > chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anasto-mosis, but superior to chemically extracted acellular allogeneic nerve bridging alone.

  19. Ciliary muscle contraction force and trapezius muscle activity during manual tracking of a moving visual target.

    Science.gov (United States)

    Domkin, Dmitry; Forsman, Mikael; Richter, Hans O

    2016-06-01

    Previous studies have shown an association of visual demands during near work and increased activity of the trapezius muscle. Those studies were conducted under stationary postural conditions with fixed gaze and artificial visual load. The present study investigated the relationship between ciliary muscle contraction force and trapezius muscle activity across individuals during performance of a natural dynamic motor task under free gaze conditions. Participants (N=11) tracked a moving visual target with a digital pen on a computer screen. Tracking performance, eye refraction and trapezius muscle activity were continuously measured. Ciliary muscle contraction force was computed from eye accommodative response. There was a significant Pearson correlation between ciliary muscle contraction force and trapezius muscle activity on the tracking side (0.78, pmuscle contraction during continuous eye-hand coordination, may increase trapezius muscle tension and thus contribute to the development of musculoskeletal complaints in the neck-shoulder area. Further experimental studies are required to clarify whether the relationship is valid within each individual or may represent a general personal trait, when individuals with higher eye accommodative response tend to have higher trapezius muscle activity. PMID:26746010

  20. HEATR2 plays a conserved role in assembly of the ciliary motile apparatus.

    Directory of Open Access Journals (Sweden)

    Christine P Diggle

    2014-09-01

    Full Text Available Cilia are highly conserved microtubule-based structures that perform a variety of sensory and motility functions during development and adult homeostasis. In humans, defects specifically affecting motile cilia lead to chronic airway infections, infertility and laterality defects in the genetically heterogeneous disorder Primary Ciliary Dyskinesia (PCD. Using the comparatively simple Drosophila system, in which mechanosensory neurons possess modified motile cilia, we employed a recently elucidated cilia transcriptional RFX-FOX code to identify novel PCD candidate genes. Here, we report characterization of CG31320/HEATR2, which plays a conserved critical role in forming the axonemal dynein arms required for ciliary motility in both flies and humans. Inner and outer arm dyneins are absent from axonemes of CG31320 mutant flies and from PCD individuals with a novel splice-acceptor HEATR2 mutation. Functional conservation of closely arranged RFX-FOX binding sites upstream of HEATR2 orthologues may drive higher cytoplasmic expression of HEATR2 during early motile ciliogenesis. Immunoprecipitation reveals HEATR2 interacts with DNAI2, but not HSP70 or HSP90, distinguishing it from the client/chaperone functions described for other cytoplasmic proteins required for dynein arm assembly such as DNAAF1-4. These data implicate CG31320/HEATR2 in a growing intracellular pre-assembly and transport network that is necessary to deliver functional dynein machinery to the ciliary compartment for integration into the motile axoneme.

  1. Primary ciliary dyskinesia: a report from ATS 2001, May 18–23, San Francisco

    Directory of Open Access Journals (Sweden)

    Noone Peadar G

    2001-06-01

    Full Text Available Abstract Primary ciliary dyskinesia (PCD is a genetic disorder of abnormal ciliary structure and function that leads to defective mucociliary clearance, resulting in oto-sino-pulmonary disease, and infertility. The disease is currently under intense investigation by a number of research groups worldwide. At the recent American Thoracic Society meeting in San Francisco in May 2001, two sessions focused on PCD; a symposium session on May 21 with several featured expert speakers was followed by a mini-symposium on Tuesday May 22, with one featured speaker and presentation of nine abstracts covering a range of research topics. Mattias Salathe (University of Miami, USA and Stephen Brody (Washington University, St Louis, USA chaired the symposium session. Presentations focused on the clinical spectrum of PCD, the genetics of PCD, a proteomics approach to detail the structure of cilia, the role of cilia in the embryology of situs laterality, and airway epithelial cell biology. The mini-symposium was chaired by Peadar Noone (University of North Carolina, USA and Malcolm King (University of Alberta, USA and included presentations on the use of PCD as a human disease model, accurate definition of the phenotype using clinical and cell biologic markers, and molecular studies. The latter reports ranged from isolation of a protein involved in ciliary structure and function to genetic studies using linkage analysis and the candidate gene approach. Clinicians and scientists alike displayed considerable interest at both sessions, and there were several lively question–answer sessions.

  2. High-power, mid-infrared, picosecond pulses generated by compression of a CO2 laser beat-wave in GaAs

    CERN Document Server

    Pigeon, J J; Joshi, C

    2015-01-01

    We report on the generation of a train of ~ 2 ps, 10 um laser pulses via multiple four-wave mixing and compression of an infrared laser beat-wave propagating in the negative group velocity dispersion region of bulk GaAs and a combination of GaAs and NaCl. The use of a 200 ps, 106 GHz beat-wave, produced by combining laser pulses amplified on the 10P(20) and 10P(16) transition of a CO2 laser, provides a novel method for generating high-power, picosecond, mid-IR laser pulses at a high repetition rate. By using 165 and 882 GHz beat-waves we show that cascaded phase-mismatched difference frequency generation plays a significant role in the four-wave mixing process in GaAs.

  3. Tuning the conductivity and inner structure of electrospun fibers to promote cardiomyocyte elongation and synchronous beating.

    Science.gov (United States)

    Liu, Yaowen; Lu, Jinfu; Xu, Guisen; Wei, Jiaojun; Zhang, Zhibin; Li, Xiaohong

    2016-12-01

    The key to addressing the challenges facing cardiac tissue engineering is the integration of physical, chemical, and electrical cues into scaffolds. Aligned and conductive scaffolds have been fabricated as synthetic microenvironments to improve the function of cardiomyocytes. However, up to now, the influence of conductive capability and inner structure of fibrous scaffolds have not been determined on the cardiomyocyte morphologies and beating patterns. In the current study, highly aligned fibers were fabricated with loaded up to 6% of carbon nanotubes (CNTs) to modulate the electrical conductivity, while blend and coaxial electrospinning were utilized to create a bulk distribution of CNTs in fiber matrices and a spatial embedment in fiber cores, respectively. Conductive networks were formed in the fibrous scaffolds after the inoculation of over 3% CNTs, and the increase in the conductivity could maintain the cell viabilities, induce the cell elongation, enhance the production of sarcomeric α-actinin and troponin I, and promote the synchronous beating of cardiomyocytes. Although the conductivity of blend fibers is slightly higher than that of coaxial fibers with the same CNT loadings, the lower exposures to CNTs resulted in higher cell viability, elongation, extracellular matrix secretion and beating rates for cardiomyocytes on coaxial fibers. Taken altogether, core-sheath fibers with loaded 5% of CNTs in the fiber cores facilitated the cardiomyocyte growth with a production of organized contractile proteins and a pulsation frequency close to that of the atrium. It is suggested that electrospun scaffolds that couple conductivity and fibrous structure considerations may provide optimal stimuli to foster cell morphology and functions for myocardial regeneration or establishment of in vitro cardiomyocyte culture platform for drug screening.

  4. A model of flagellar and ciliary functioning which uses the forces transverse to the axoneme as the regulator of dynein activation.

    Science.gov (United States)

    Lindemann, C B

    1994-01-01

    Ciliary and flagellar motion is driven by the dynein-tubulin interaction between adjacent doublets of the axoneme, and the resulting sliding displacements are converted into axonemal bends that are propagated. When the axoneme is bent in the normal beating plane, force develops across the axoneme in the plane of the bend. This transverse force (t-force) has maximal effect on the interdoublet spacing of outer doublets 2-4 on one side of the axoneme and doublets 7-9 on the opposite side. Episodes of sliding originates as the t-force brings these doublets into closer proximity (allowing dynein bridges to form) and are terminated when these doublets are separated from each other by the t-force. A second factor, the adhesive force of the dynein-tubulin attachments (bridges), also acts to pull neighboring doublets closer together. This force resists termination of a sliding episode once initiated, and acts locally to give the population of dynein bridges a type of excitability. In other words, as bridges form, the probability of nearby bridges attaching is increased by a positive feedback exerted through the interdoublet spacing. A conceptual working hypothesis explaining the behavior of cilia and flagella is proposed based on the above concepts. Additionally, the feasibility of this proposed mechanism is demonstrated using a computer simulation. The simulation uses a Monte Carlo-type algorithm for dynein attachment and adhesive force, together with a geometric evaluation of the t-force on the key microtubule pairs. This model successfully develops spontaneous oscillations from any starting configuration (including a straight position). It is compatible with the physical dimensions, mechanical properties and bridge forces measured in real cilia and flagella. In operation, it exhibits many of the observed actions of cilia and flagella, most notably wave propagation and the ability to produce both cilia-like and flagella-like waveforms. PMID:7820864

  5. Tunable optical frequency division using a phase-locked optical parametric oscillator.

    Science.gov (United States)

    Lee, D; Wong, N C

    1992-01-01

    We report the experimental demonstration of a novel optical parametric oscillator approach to tunable optical frequency division. The beat frequency of the signal and idler subharmonic outputs of a tunable cw KTP optical parametric oscillator was phase locked to a microwave reference frequency source, which thus permitted precise determination of the output frequencies at approximately half the input pump frequency.

  6. Investigation on laser accelerators. Plasma beat wave accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Akihiko; Miyamoto, Yasuaki; Hagiwara, Masayoshi; Suzuki, Mitsutoshi; Sudo, Osamu [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works

    1998-04-01

    Laser accelerator technology has characteristics of high energy, compact, short pulse and high luminescence{center_dot}low emittance. This means potential many applications in wide ranges of fields as well as high energy and nuclear physics. High power short laser pulses are injected to a plasma in the typical example of laser accelerators. Large electric fields are induced in the plasma. Electrons in the plasma are accelerated with the ponderomotive force of the electric field. The principles of interaction on beat wave, wakefield accelerators, inverse free electron laser and inverse Cherenkov radiation are briefly introduced. The overview of plasma beat wave accelerator study is briefly described on the programs at Chalk River Laboratories(Canada), UCLA(USA), Osaka Univ. (Japan) and Ecole Polytechnique (France). Issues of the plasma beat wave accelerator are discussed from the viewpoint of application. Existing laser technologies of CO{sub 2}, YAG and YFL are available for the present day accelerator technology. An acceleration length of beat wave interaction is limited due to its phase condition. Ideas on multi-staged acceleration using the phasing plasma fiber are introduced. (Y. Tanaka)

  7. Using Science and Much More to Beat the Flood

    Science.gov (United States)

    Seeley, Claire

    2014-01-01

    The Beat the Flood challenge involves designing and building a model flood-proof home, which is then tested in "flood" conditions. It is set on the fictitious Watu Island. The children form teams, with each team member being assigned a responsibility for the duration of the task--team leader, chief recorder, and resource manager. This…

  8. Beat-wave accelerator studies at the Rutherford Appleton Laboratory

    International Nuclear Information System (INIS)

    The study carried out in 1982-83 at the Rutherford Appleton Laboratory to examine how one might use the beat-wave principle to construct a useful high energy accelerator is reviewed, and comments are made on later developments. A number of problems are evident to which solutions cannot at present be foreseen. (author)

  9. Perceptions of Conducting: Accuracy in Detecting Modulated Beat.

    Science.gov (United States)

    Brittin, Ruth V.

    1992-01-01

    Presents findings of a study of viewers' ability to detect changes in conducting beat patterns. Reports that music education majors were significantly better able to detect tempo decreases than increases and better able than nonmajors to detect decreases. Indicates that nonmajors were better able than majors to identify tempo increases. (SG)

  10. Efficiency of brainwave entrainment by binaural beats in reducing anxiety

    Directory of Open Access Journals (Sweden)

    Ahmad Alipoor

    2014-04-01

    Full Text Available Background: Anxiety is a fundamental phenomenon that is a common symptom in all mental disorders. The aim of the present study was to assess the effect of brainwave entrainment on anxiety reduction using binaural beats. Methods: In this experimental double-blind study, 30 employees were selected from an engineering research firm through random sampling and replacement and divided into two groups: control group and experimental group. All participants completed the Spielberger’s State-Trait Anxiety Inventory (STAI. Then, the experimental group listened to binaural beats which was recorded on a non-vocal piece of music for 4 weeks, 3 sessions each week. Each session lasted about 20 minutes. At the same time, the control group listened to the background music without any entrainment sound. At the end, both groups completed the anxiety questionnaire and the anxiety scores of both groups obtained before and after intervention were analyzed by ANCOVA. Results: The findings showed that the brainwave entrainment using binaural beats led to the significant reduction of state anxiety (P<0.001 and trait anxiety (P<0.018. Conclusion: Brainwave entrainment using binaural beats is an effective factor in decreasing state and trait anxiety; so, it can be used to reduce anxiety in mental health centers.

  11. Reduced Order Dead-Beat Observers for a Bioreactor

    CERN Document Server

    Karafyllis, Iasson

    2010-01-01

    This paper studies the strong observability property and the reduced-order dead-beat observer design problem for a continuous bioreactor. New relationships between coexistence and strong observability, and checkable sufficient conditions for strong observability, are established for a chemostat with two competing microbial species. Furthermore, the dynamic output feedback stabilization problem is solved for the case of one species.

  12. Subdividing the beat: auditory and motor contributions to synchronization

    NARCIS (Netherlands)

    Loehr, J.D.; Palmer, C.

    2009-01-01

    THE CURRENT STUDY EXAMINED HOW AUDITORY AND kinematic information influenced pianists' ability to synchronize musical sequences with a metronome. Pianists performed melodies in which quarter-note beats were subdivided by intervening eighth notes that resulted from auditory information (heard tones),

  13. Factors associated with wife beating in Egypt: Analysis of two surveys (1995 and 2005)

    OpenAIRE

    Dhaher Enas; Labeeb Shokria; Mikolajczyk Rafael T; Akmatov Manas K; Khan Md Mobarak

    2008-01-01

    Abstract Background Wife beating is an important public health problem in many developing countries. We assessed the rates of wife beating and examined factors associated with wife beating in 1995 and 2005 in Egypt. Methods We used data from two Demographic and Health Surveys (DHS) conducted in Egypt in 1995 and 2005 using multistage household sampling. Data related to wife beating included information from 7122 women in 1995 and 5612 women in 2005. Logistic regression was used to analyze fac...

  14. Finding the beat: a neural perspective across humans and non-human primates

    OpenAIRE

    Merchant, Hugo; Grahn, Jessica; Trainor, Laurel; Rohrmeier, Martin; Fitch, W. Tecumseh

    2015-01-01

    Humans possess an ability to perceive and synchronize movements to the beat in music (‘beat perception and synchronization’), and recent neuroscientific data have offered new insights into this beat-finding capacity at multiple neural levels. Here, we review and compare behavioural and neural data on temporal and sequential processing during beat perception and entrainment tasks in macaques (including direct neural recording and local field potential (LFP)) and humans (including fMRI, EEG and...

  15. Fetal beat detection in abdominal ECG recordings: global and time adaptive approaches

    International Nuclear Information System (INIS)

    We present a method for location of fetal QRS in maternal abdominal ECG recordings. This method’s initial, global approach was proposed in the context of the 2013 PhysioNet/Computing in Cardiology Challenge where it was tested on the 447 four channel one-minute recordings. The first step is filtering to eliminate baseline wander and high frequency noise. Upon detection, maternal QRS is removed on each channel using a filter applied to the other three channels. Next we locate fetal QRS on each channel and select the channel with the best set of detections. The method was awarded the third-best score in the Challenge event 1 with 278.755 (beats/minute) and the fourth-best score on event 2 with 28.201 ms. The 5 min long recordings of the Abdominal and Direct Fetal ECG Database were used to further test the method. This database contains five recordings obtained from women in labor. Results in these longer recordings were not satisfactory. This appears to be particularly the case in recordings with a more clearly non-stationary nature. In a new approach to our method, some changes are introduced. Two features are updated over time: the filter used to eliminate maternal QRS and the channel used to detect fetal beats. These changes significantly improved the QRS detection performance on longer recordings, but the scores on the 1 minute Challenge recordings were degraded. (paper)

  16. Glucagon Increases Beating Rate but Not Contractility in Rat Right Atrium. Comparison with Isoproterenol.

    Directory of Open Access Journals (Sweden)

    Beatriz Merino

    Full Text Available This study evaluated the chronotropic and inotropic responses to glucagon in spontaneously beating isolated right atria of rat heart. For comparison, we also investigated the effects resulting from stimulating β-adrenoceptors with isoproterenol in this tissue. Isoproterenol increased both atrial frequency and contractility but glucagon only enhanced atrial rate. The transcript levels of glucagon receptors were about three times higher in sinoatrial node than in the atrial myocardium. Chronotropic responses to glucagon and isoproterenol were blunted by the funny current (If inhibitor ZD 7288. Inhibitors of protein kinase A, H-89 and KT-5720 reduced the chronotropic response to glucagon but not to isoproterenol. Inhibition of ryanodine receptors and calcium/calmodulin dependent protein kinase II (important regulators of sarcoplasmic reticulum Ca2+ release, with ruthenium red and KN-62 respectively, failed to alter chronotropic responses of either glucagon or isoproterenol. Non selective inhibition of phosphodiesterase (PDE with 3-isobutylmethylxantine or selective inhibition of PDE3 or PDE4 with cilostamide or rolipram respectively did not affect chronotropic effects of glucagon or isoproterenol. Our results indicate that glucagon increases beating rate but not contractility in rat right atria which could be a consequence of lower levels of glucagon receptors in atrial myocardium than in sinoatrial node. Chronotropic responses to glucagon or isoproterenol are mediated by If current but not by sarcoplasmic reticulum Ca2+ release, neither are regulated by PDE activity.

  17. Ambulatory instrument for monitoring indirect beat-to-beat blood pressure in superficial temporal artery using volume-compensation method.

    Science.gov (United States)

    Tanaka, S; Yamakoshi, K

    1996-11-01

    A portable instrument, based on a volume-compensation technique, is designed for ambulatory monitoring of indirect beat-to-beat blood pressure (BP) in the superficial temporal artery. The instrument consists of a small disc-type cuff and a portable unit carried by the subject. Several components are integrated in the cuff for applying counter-pressure to the artery, i.e. a reflectance-type photo-plethysmographic sensor for arterial volume detection, a pressure sensor for cuff pressure Pc measurement and a nozzle flapper-type- electro-pneumatic convertor for controlling Pc. The portable unit includes volume servo control circuitry and a microprocessor-based signal-processing and recording unit. This automatically performs all the necessary measurement procedures and stores into a memory IC element the processed systolic, mean and diastolic blood pressure data, together with pulse intervals on a beat-to-beat basis from the servo-controlled Pc (indirectly measured BP waveform). With this instrument, momentary changes in BP during ambulatory situations such as bicycle ergometer exercise and daily activities including motorway driving are successfully recorded. From the results of simultaneous measurement of the subject's posture changes, the effect of posture change on blood pressure, e.g. baroreceptor-cardiac reflex, is also clearly demonstrated.

  18. Use of seismocardiogram for the beat-to-beat assessment of the Pulse Transit Time: A pilot study.

    Science.gov (United States)

    Di Rienzo, Marco; Vaini, Emanuele; Lombardi, Prospero

    2015-08-01

    We propose a new methodology for the estimation of Pulse Transit Time, PTT, based on the use of the seismocardiogram for the identification of the aortic valve opening, AO. This method has been implemented to obtain a first description of the AO-derived PTT beat-to-beat variability at rest and during the recovery after a cycloergometer exercise at 25W and 100W, its relation with systolic blood pressure, S(BP), and its difference with respect to variability of the Pulse Arrival Time, PAT (i.e. the BP transit time estimated by considering the ECG R peak instead of AO as proximal site). Our preliminary data indicate that 1) the fast components of the PTT variability are only marginally influenced by respiration; 2) only the slower components of the PTT variability are correlated with systolic BP; 3) major differences exist in the dynamics of PTT and PAT, being PAT variability significantly larger and importantly influenced by the beat-to-beat changes occurring in the Pre Ejection Period. PMID:26737949

  19. A review of beat-to-beat vectorcardiographic (VCG) parameters for analyzing repolarization variability in ECG signals.

    Science.gov (United States)

    Hasan, Muhammad A; Abbott, Derek

    2016-02-01

    Elevated ventricular repolarization lability is believed to be linked to the risk of ventricular tachycardia/ventricular fibrillation. However, ventricular repolarization is a complex electrical phenomenon, and abnormalities in ventricular repolarization are not completely understood. To evaluate repolarization lability, vectorcardiography (VCG) is an alternative approach where the electrocardiographic (ECG) signal can be considered as possessing both magnitude and direction. Recent research has shown that VCG is advantageous over ECG signal analysis for identification of repolarization abnormality. One of the key reasons is that the VCG approach does not rely on exact identification of the T-wave offset, which improves the reproducibility of the VCG technique. However, beat-to-beat variability in VCG is an emerging area for the investigation of repolarization abnormality though not yet fully realized. Therefore, the purpose of this review is to explore the techniques, findings, and efficacy of beat-to-beat VCG parameters for analyzing repolarization lability, which may have potential utility for further study. PMID:25992510

  20. Beat-to-beat systolic time-interval measurement from heart sounds and ECG

    International Nuclear Information System (INIS)

    Systolic time intervals are highly correlated to fundamental cardiac functions. Several studies have shown that these measurements have significant diagnostic and prognostic value in heart failure condition and are adequate for long-term patient follow-up and disease management. In this paper, we investigate the feasibility of using heart sound (HS) to accurately measure the opening and closing moments of the aortic heart valve. These moments are crucial to define the main systolic timings of the heart cycle, i.e. pre-ejection period (PEP) and left ventricular ejection time (LVET). We introduce an algorithm for automatic extraction of PEP and LVET using HS and electrocardiogram. PEP is estimated with a Bayesian approach using the signal's instantaneous amplitude and patient-specific time intervals between atrio-ventricular valve closure and aortic valve opening. As for LVET, since the aortic valve closure corresponds to the start of the S2 HS component, we base LVET estimation on the detection of the S2 onset. A comparative assessment of the main systolic time intervals is performed using synchronous signal acquisitions of the current gold standard in cardiac time-interval measurement, i.e. echocardiography, and HS. The algorithms were evaluated on a healthy population, as well as on a group of subjects with different cardiovascular diseases (CVD). In the healthy group, from a set of 942 heartbeats, the proposed algorithm achieved 7.66 ± 5.92 ms absolute PEP estimation error. For LVET, the absolute estimation error was 11.39 ± 8.98 ms. For the CVD population, 404 beats were used, leading to 11.86 ± 8.30 and 17.51 ± 17.21 ms absolute PEP and LVET errors, respectively. The results achieved in this study suggest that HS can be used to accurately estimate LVET and PEP. (paper)

  1. Full stabilization of a microresonator-based optical frequency comb.

    Science.gov (United States)

    Del'Haye, P; Arcizet, O; Schliesser, A; Holzwarth, R; Kippenberg, T J

    2008-08-01

    We demonstrate control and stabilization of an optical frequency comb generated by four-wave mixing in a monolithic microresonator with a mode spacing in the microwave regime (86 GHz). The comb parameters (mode spacing and offset frequency) are controlled via the power and the frequency of the pump laser, which constitutes one of the comb modes. Furthermore, generation of a microwave beat note at the comb's mode spacing frequency is demonstrated, enabling direct stabilization to a microwave frequency standard.

  2. Development of the ciliary body: morphological changes in the distal portion of the optic cup in the human.

    Science.gov (United States)

    Peces-Peña, M D; de la Cuadra-Blanco, C; Vicente, A; Mérida-Velasco, J R

    2013-01-01

    This study seeks to determine the main events that occur in the development of the ciliary body (CB) in the 5-14th week of development. The CB develops from the distal portion of the optic cup (OC) and the neighboring mesenchyme. During the 5th week of development, 4 zones were observed in the distal portion of the OC: in zone 1, the epithelia of the outer and inner layers of the OC came into contact. This contact coincided with the appearance of mainly apical granule pigments. This zone corresponded to the anlage of the epithelial layers of the CB. In zone 2, the cells surrounded the marginal sinus and contained scarce pigment granules and nuclei in the basal position. This zone corresponded to the anlage of the iris. Zone 3 was triangular in shape and its vertex ran towards the marginal sinus and corresponded to common cell progenitors. Zone 4 corresponded to the retinal pigment epithelium anlage and the neural retina anlage. We determined the onset of the stroma and the ciliary muscle anlage at the end of the 7th week. In the 13-14th week, we observed the anlage of the orbicularis ciliaris (pars plana of the CB) and corona ciliaris (pars plicata of the CB), in addition to the anlage of the ciliary muscle. Our study, therefore, establishes a precise timetable of the development of the CB.

  3. MHD dissipative flow and heat transfer of Casson fluids due to metachronal wave propulsion of beating cilia with thermal and velocity slip effects under an oblique magnetic field

    Science.gov (United States)

    Akbar, Noreen Sher; Tripathi, D.; Bég, O. Anwar; Khan, Z. H.

    2016-11-01

    A theoretical investigation of magnetohydrodynamic (MHD) flow and heat transfer of electrically-conducting viscoplastic fluids through a channel is conducted. The robust Casson model is implemented to simulate viscoplastic behavior of fluids. The external magnetic field is oblique to the fluid flow direction. Viscous dissipation effects are included. The flow is controlled by the metachronal wave propagation generated by cilia beating on the inner walls of the channel. The mathematical formulation is based on deformation in longitudinal and transverse velocity components induced by the ciliary beating phenomenon with cilia assumed to follow elliptic trajectories. The model also features velocity and thermal slip boundary conditions. Closed-form solutions to the non-dimensional boundary value problem are obtained under physiological limitations of low Reynolds number and large wavelength. The influence of key hydrodynamic and thermo-physical parameters i.e. Hartmann (magnetic) number, Casson (viscoplastic) fluid parameter, thermal slip parameter and velocity slip parameter on flow characteristics are investigated. A comparative study is also made with Newtonian fluids (corresponding to massive values of plastic viscosity). Stream lines are plotted to visualize trapping phenomenon. The computations reveal that velocity increases with increasing the magnitude of Hartmann number near the channel walls whereas in the core flow region (center of the channel) significant deceleration is observed. Temperature is elevated with greater Casson parameter, Hartmann number, velocity slip, eccentricity parameter, thermal slip and also Brinkmann (dissipation) number. Furthermore greater Casson parameter is found to elevate the quantity and size of the trapped bolus. In the pumping region, the pressure rise is reduced with greater Hartmann number, velocity slip, and wave number whereas it is enhanced with greater cilia length.

  4. An efficient method for ectopic beats cancellation based on radial basis function.

    Science.gov (United States)

    Mateo, Jorge; Torres, Ana; Rieta, José J

    2011-01-01

    The analysis of the surface Electrocardiogram (ECG) is the most extended noninvasive technique in cardiological diagnosis. In order to properly use the ECG, we need to cancel out ectopic beats. These beats may occur in both normal subjects and patients with heart disease, and their presence represents an important source of error which must be handled before any other analysis. This paper presents a method for electrocardiogram ectopic beat cancellation based on Radial Basis Function Neural Network (RBFNN). A train-able neural network ensemble approach to develop customized electrocardiogram beat classifier in an effort to further improve the performance of ECG processing and to offer individualized health care is presented. Six types of beats including: Normal Beats (NB); Premature Ventricular Contractions (PVC); Left Bundle Branch Blocks (LBBB); Right Bundle Branch Blocks (RBBB); Paced Beats (PB) and Ectopic Beats (EB) are obtained from the MIT-BIH arrhythmia database. Four morphological features are extracted from each beat after the preprocessing of the selected records. Average Results for the RBFNN based method provided an ectopic beat reduction (EBR) of (mean ± std) EBR = 7, 23 ± 2.18 in contrast to traditional compared methods that, for the best case, yielded EBR = 4.05 ± 2.13. The results prove that RBFNN based methods are able to obtain a very accurate reduction of ectopic beats together with low distortion of the QRST complex.

  5. First Beta-Beating Measurement in the LHC

    CERN Document Server

    Aiba, M; Franchi, A; Giovannozzi, M; Kain, V; Morita, A; Tomás, R; Vanbavinckhove, G; Wenninger, J

    2009-01-01

    This note reports on the first LHC beta-beating and coupling measurements. Thanks to an excellent functioning of the BPM system and the related software, injection oscillations were recorded for the first 90 turns at all BPMs of Beam 2. Three different algorithms are used to measure the optics parameters from the BPM data. All algorithms show consistent measurements but feature different accuracy. The Singular Value Decomposition (SVD) approach shows a high resolution despite the limited number of turns. The vertical beta-beating is observed to be about a factor of two larger than in the horizontal plane. This asymetry is partly due to sextupoles misalignments but also suggests the possible existance of focusing errors at defocussing locations. Rather large coupling is observed since no skew quadrupole was excited at the time of the data acquisition. We also report a list of suspected malfunctioning BPMs identified through various analyses.

  6. Statistics of quantum beats in the time dependence of the neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Prokopets, G.A.; Prokopets, A.G. [National University of Kyiv-Mohyla Academy, Physics and Mathematics Department, Kyiv (Ukraine)

    2011-12-15

    The numerical calculations of the delay time distributions for the neutron scattering have been carried out. The scattering of the short wave packet of neutrons with the broad energy interval 500-800 keV by {sup 58}Ni nuclei has been studied. The decay curves and average times of the compound scattering were found as for the forward scattering as for the specific spin-parity states. The time oscillations of the decay curves were identified as quantum beats that were caused by the interference of the excited resonance set. The statistical analysis of the frequency spectra of the decay curves oscillations has been carried out. The behavior of the examined statistical observables turns out to be close to the Poisson law. (orig.)

  7. Statistics of quantum beats in the time dependence of the neutron scattering

    International Nuclear Information System (INIS)

    The numerical calculations of the delay time distributions for the neutron scattering have been carried out. The scattering of the short wave packet of neutrons with the broad energy interval 500-800 keV by 58Ni nuclei has been studied. The decay curves and average times of the compound scattering were found as for the forward scattering as for the specific spin-parity states. The time oscillations of the decay curves were identified as quantum beats that were caused by the interference of the excited resonance set. The statistical analysis of the frequency spectra of the decay curves oscillations has been carried out. The behavior of the examined statistical observables turns out to be close to the Poisson law. (orig.)

  8. High-gain X-ray free electron laser by beat-wave terahertz undulator

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chao; Hei, DongWei [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi' an City 710024 (China); Institute of Energy, Tsinghua University, Beijing 100084 (China); Pellegrin, Claudio; Tantawi, Sami [SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94309 (United States)

    2013-12-15

    The THz undulator has a higher gain to realize a much brighter X-ray at saturation, compared with the optical undulator under the same undulator strength and beam quality. In order to fill the high-power THz gap and realize the THz undulator, two superimposed laser pulses at normal incidence to the electron-beam moving direction form an equivalent high-field THz undulator by the frequency difference to realize the high-gain X-ray Free electron laser. The pulse front tilt of lateral fed lasers is used to realize the electron-laser synchronic interaction. By PIC simulation, a higher gain and a larger X-ray radiation power by the beat wave THz undulator could be realized, compared with the optical undulator for the same electron beam parameters.

  9. A waveguide polarization toolset design based on mode beating

    OpenAIRE

    Hutchings, D.C.; Holmes, B.M.

    2011-01-01

    A toolset of waveguide elements is examined, which can be combined to produce polarization functional devices in a single contiguous waveguide. In particular, waveguide implementations of an optical isolator and a polarization modulator are discussed. The waveguide elements, i.e., quasi-phase-matched nonreciprocal polarization mode converter, reciprocal polarization mode converter (R-PMC), and a differential phase shifter, are all based on mode beating. A universal 3-dB R-PMC specification is...

  10. Robotic Motion Compensation for Beating Heart Intracardiac Surgery

    OpenAIRE

    Howe, Robert D.; Yuen, Shelten G.; Kettler, Daniel T.; Notovny, Paul M.; Plowes, Richard D.

    2009-01-01

    3D ultrasound imaging has enabled minimally invasive, beating heart intracardiac procedures. However, rapid heart motion poses a serious challenge to the surgeon that is compounded by significant time delays and noise in 3D ultrasound. This paper investigates the concept of using a one-degree-of-freedom motion compensation system to synchronize with tissue motions that may be approximated by 1D motion models. We characterize the motion of the mitral valve annulus and show that it is well appr...

  11. Observation of chaotic beats in a driven memristive Chua's circuit

    OpenAIRE

    Ahamed, A. Ishaq; Srinivasan, K.; Murali, K.; Lakshmanan, M.

    2010-01-01

    In this paper, a time varying resistive circuit realising the action of an active three segment piecewise linear flux controlled memristor is proposed. Using this as the nonlinearity, a driven Chua's circuit is implemented. The phenomenon of chaotic beats in this circuit is observed for a suitable choice of parameters. The memristor acts as a chaotically time varying resistor (CTVR), switching between a less conductive OFF state and a more conductive ON state. This chaotic switching is govern...

  12. Moving to the beat and singing are linked in humans

    Directory of Open Access Journals (Sweden)

    Simone eDalla Bella

    2015-12-01

    Full Text Available The abilities to sing and to move to the beat of a rhythmic auditory stimulus emerge early during development, and both engage perceptual, motor, and sensorimotor processes. These similarities between singing and synchronization to a beat may be rooted in biology. Patel (2008 has suggested that motor synchronization to auditory rhythms may have emerged during evolution as a byproduct of selection for vocal learning (vocal learning and synchronization hypothesis. This view predicts a strong link between vocal performance and synchronization skills in humans. Here we tested this prediction by asking occasional singers to tap along with auditory pulse trains and to imitate familiar melodies. Both vocal imitation and synchronization skills were measured in terms of accuracy and precision or consistency. Accurate and precise singers tapped more in the vicinity of the pacing stimuli (i.e., they were more accurate than inaccurate and imprecise singers. Moreover, accurate singers were more consistent when tapping to the beat. These differences cannot be ascribed to basic motor skills or to motivational factors. Individual differences in terms of singing proficiency and synchronization skills may reflect the variability of a shared sensorimotor translation mechanism.

  13. Effects of spontaneous otoacoustic emissions on frequency discrimination

    DEFF Research Database (Denmark)

    Hansen, Rói; Santurette, Sébastien; Verhulst, Sarah

    2013-01-01

    When an external tone is presented in proximity to the frequency of a spontaneous otoacoustic emission (SOAE), the SOAE typically synchronizes to the external tone, a phenomenon known as "entrainment". As the tone moves further away from the SOAE frequency, beating patterns between the SOAE and t...

  14. Convergent evolution of RFX transcription factors and ciliary genes predated the origin of metazoans

    Directory of Open Access Journals (Sweden)

    Chen Nansheng

    2010-05-01

    Full Text Available Abstract Background Intraflagellar transport (IFT genes, which are critical for the development and function of cilia and flagella in metazoans, are tightly regulated by the Regulatory Factor X (RFX transcription factors (TFs. However, how and when their evolutionary relationship was established remains unknown. Results We have identified evidence suggesting that RFX TFs and IFT genes evolved independently and their evolution converged before the first appearance of metazoans. Both ciliary genes and RFX TFs exist in all metazoans as well as some unicellular eukaryotes. However, while RFX TFs and IFT genes are found simultaneously in all sequenced metazoan genomes, RFX TFs do not co-exist with IFT genes in most pre-metazoans and thus do not regulate them in these organisms. For example, neither the budding yeast nor the fission yeast possesses cilia although both have well-defined RFX TFs. Conversely, most unicellular eukaryotes, including the green alga Chlamydomonas reinhardtii, have typical cilia and well conserved IFT genes but lack RFX TFs. Outside of metazoans, RFX TFs and IFT genes co-exist only in choanoflagellates including M. brevicollis, and only one fungus Allomyces macrogynus of the 51 sequenced fungus genomes. M. brevicollis has two putative RFX genes and a full complement of ciliary genes. Conclusions The evolution of RFX TFs and IFT genes were independent in pre-metazoans. We propose that their convergence in evolution, or the acquired transcriptional regulation of IFT genes by RFX TFs, played a pivotal role in the establishment of metazoan.

  15. Chemical constituents of Cenchrus ciliaris L. from the Cholistan desert, Pakistan

    Directory of Open Access Journals (Sweden)

    Ashraf Muhammad Aqeel

    2013-01-01

    Full Text Available The Cholistan Desert is an extension of the Great Indian Desert, covering an area of 26,330 km2. The desert can be divided into two main geomorphic regions: the northern region, known as Lesser Cholistan, constituting the desert margin and consisting of a series of saline alluvial flats alternating with low sand ridges/dunes; and the southern region, known as Greater Cholistan, a wind-resorted sandy desert comprised of a number of old Hakra River terraces with various forms of sand ridges and inter-ridge valleys. Cholistan Desert presents a complex pattern of alluvial and aeolian depositions. In the present study we evaluated the nutritive value of different accessions of the perennial range grass Cenchrus ciliaris collected from the Cholistan Desert, Pakistan. Standard method, Benedict’s quantitative reagent for carbohydrates, crude protein and nitrogen by the Kjeldahl method, mineral analysis by flame photometer and estimation of crude fiber by using acid base treatment, were utilized. The results suggest that Cenchrus ciliaris has medicinal and nutritional importance, and that it could be a good source of important nutrients for humans, helping to alleviate poverty in poor local communities.

  16. C2 Domains as Protein-Protein Interaction Modules in the Ciliary Transition Zone

    Directory of Open Access Journals (Sweden)

    Kim Remans

    2014-07-01

    Full Text Available RPGR-interacting protein 1 (RPGRIP1 is mutated in the eye disease Leber congenital amaurosis (LCA and its structural homolog, RPGRIP1-like (RPGRIP1L, is mutated in many different ciliopathies. Both are multidomain proteins that are predicted to interact with retinitis pigmentosa G-protein regulator (RPGR. RPGR is mutated in X-linked retinitis pigmentosa and is located in photoreceptors and primary cilia. We solved the crystal structure of the complex between the RPGR-interacting domain (RID of RPGRIP1 and RPGR and demonstrate that RPGRIP1L binds to RPGR similarly. RPGRIP1 binding to RPGR affects the interaction with PDEδ, the cargo shuttling factor for prenylated ciliary proteins. RPGRIP1-RID is a C2 domain with a canonical β sandwich structure that does not bind Ca2+ and/or phospholipids and thus constitutes a unique type of protein-protein interaction module. Judging from the large number of C2 domains in most of the ciliary transition zone proteins identified thus far, the structure presented here seems to constitute a cilia-specific module that is present in multiprotein transition zone complexes.

  17. Posterior Ciliary Artery Occlusion Caused by Hyaluronic Acid Injections Into the Forehead

    Science.gov (United States)

    Hu, Xiu Zhuo; Hu, Jun Yan; Wu, Peng Sen; Yu, Sheng Bo; Kikkawa, Don O.; Lu, Wei

    2016-01-01

    Abstract Although cosmetic facial soft tissue fillers are generally safe and effective, improper injections can lead to devastating and irreversible consequences. We represent the first known case of posterior ciliary artery occlusion caused by hyaluronic acid. A 41-year-old female presented with right visual loss 7 hours after receiving cosmetic hyaluronic acid injections into her forehead. Examination revealed no light perception in the right eye and multiple dark ischemic area of injection over the forehead and nose. The right fundus revealed a pink retina with optic nerve edema. Fluorescein angiogram showed several filling defects in the choroidal circulation and late hyperfluorescence in the choroid. A right posterior ciliary artery occlusion and embolic occlusion of facial artery braches was diagnosed. With hyaluronidase injection, hyperbaric oxygen therapy, oral aspirin, oral acetazolamide and dexamethasone venotransfuse treatment, the patient's forehead and nasal skin improved and vision recovered to hand movements. With proper technique, vascular occlusion is rare following facial filler injection. Vision consequences can be severe if filler emboli enter the ocular circulation. Physicians should be aware of this potential side effect, recognize its presentation, and be knowledgeable of effective management. PMID:26986163

  18. Posterior Ciliary Artery Occlusion Caused by Hyaluronic Acid Injections Into the Forehead: A Case Report.

    Science.gov (United States)

    Hu, Xiu Zhuo; Hu, Jun Yan; Wu, Peng Sen; Yu, Sheng Bo; Kikkawa, Don O; Lu, Wei

    2016-03-01

    Although cosmetic facial soft tissue fillers are generally safe and effective, improper injections can lead to devastating and irreversible consequences. We represent the first known case of posterior ciliary artery occlusion caused by hyaluronic acid. A 41-year-old female presented with right visual loss 7 hours after receiving cosmetic hyaluronic acid injections into her forehead. Examination revealed no light perception in the right eye and multiple dark ischemic area of injection over the forehead and nose. The right fundus revealed a pink retina with optic nerve edema. Fluorescein angiogram showed several filling defects in the choroidal circulation and late hyperfluorescence in the choroid. A right posterior ciliary artery occlusion and embolic occlusion of facial artery braches was diagnosed. With hyaluronidase injection, hyperbaric oxygen therapy, oral aspirin, oral acetazolamide and dexamethasone venotransfuse treatment, the patient's forehead and nasal skin improved and vision recovered to hand movements. With proper technique, vascular occlusion is rare following facial filler injection. Vision consequences can be severe if filler emboli enter the ocular circulation. Physicians should be aware of this potential side effect, recognize its presentation, and be knowledgeable of effective management. PMID:26986163

  19. Fetal calf serum-mediated inhibition of neurite growth from ciliary ganglion neurons in vitro.

    Science.gov (United States)

    Davis, G E; Skaper, S D; Manthorpe, M; Moonen, G; Varon, S

    1984-01-01

    Embryonic chick ciliary ganglion (CG) neurons cultured in fetal calf serum-containing medium have been previously reported to extend neurites on polyornithine (PORN) substrata precoated with a neurite-promoting factor (PNPF) from rat schwannoma-conditioned medium. On PORN substrata alone, however, no neuritic growth occurred. This was interpreted as evidence that PORN was an incompetent substratum for ciliary neuritic growth. In this study, we now find that an untreated PORN substratum allows neuritic growth in serum-free defined medium. When PNPF was added to PORN, a more rapid and extensive neuritic response occurred. After 5 hr of culture, a 60% neuritic response occurred on PNPF/PORN, whereas no neurons initiated neurites until 10-12 hr on PORN. The inhibitory effect of fetal calf serum noted above on PORN could be obtained in part by pretreating the substratum with serum for 1 hr. Maximal inhibitory effects in the PORN pretreatment were achieved after 30 min and were not further improved by treatments up to 4 hr. Bovine serum albumin was also found to inhibit neurite growth on PORN to about 60% of the inhibition obtained by an equivalent amount of serum protein. Fetal calf serum was shown to cause a 15% reduction in the percentage of neurons bearing neurites after its addition to 18-hr serum-free PORN cultures and to cause statistically significant reductions in neurite lengths measured 2 hr later.

  20. Genotypic variation in response to salinity in a new sexual germplasm of Cenchrus ciliaris L.

    Science.gov (United States)

    Quiroga, Mariana; Tommasino, Exequiel; Griffa, Sabrina; Ribotta, Andrea; Colomba, Eliana López; Carloni, Edgardo; Grunberg, Karina

    2016-05-01

    As part of a breeding program for new salt-tolerant sexual genotypes of Cenchrus ciliaris L., here we evaluated the salt-stress response of two new sexual hybrids, obtained by controlled crosses, at seedling and germination stages. A seedling hydroponic experiment with 300 mM NaCl was performed and physiological variables and growth components were evaluated. While salt-treated sexual material did not show a decrease in productivity with respect to control plants, a differential response in some physiological characteristics was observed. Sexual hybrid 1-9-1 did not suffer oxidative damage and its proline content did not differ from that of control treatment. By contrast, sexual hybrid 1-7-11 suffered oxidative damage and accumulated proline, maintaining its growth under saline stress. At the germination stage, sexual hybrid 1-9-1 presented the highest Germination Rate Index at the maximum NaCl concentration assayed, suggesting an ecological advantage in this genotype. These new sexual resources are promising maternal parental with differential response to salt and could be incorporated in a breeding program of C. ciliaris in the search of new genotypes tolerant to salinity. PMID:26906150

  1. Is the Blazhko effect the beating of a near-resonant double-mode pulsation?

    CERN Document Server

    Bryant, Paul H

    2014-01-01

    In this paper it is shown that the Blazhko Effect may result from a near-resonant type of double-mode pulsation, where two periodic oscillations with slightly different frequencies gradually slip in phase by one pulsation cycle every Blazhko cycle, producing a beat frequency type of modulation. One of the oscillations is strongly non-sinusoidal while the other is not. This paper extends previous work on this hypothesis by developing a simple model that can accurately reproduce several important features found in Kepler data for RR Lyr, including the pulsation waveform, the upper and lower Blazhko envelope functions and the motion, disappearance and reappearance of the bump feature. This model is consistent with the fact that the triplet peaks in the spectra for most RR Lyrae stars have a larger peak on the higher frequency side. The current model is related to the hybrid mode model described in a previous paper. The motion and disappearance of the bump feature are shown to be an illusion, just an artifact of ...

  2. Dynamic curvature regulation accounts for the symmetric and asymmetric beats of Chlamydomonas flagella

    CERN Document Server

    Sartori, Pablo; Scholich, Andre; Jülicher, Frank; Howard, Jonathon

    2015-01-01

    Axonemal dyneins are the molecular motors responsible for the beating of cilia and flagella. These motors generate sliding forces between adjacent microtubule doublets within the axoneme, the motile cytoskeletal structure inside the flagellum. To create regular, oscillatory beating patterns, the activities of the axonemal dyneins must be coordinated both spatially and temporally. It is thought that coordination is mediated by stresses or strains that build up within the moving axoneme, but it is not known which components of stress or strain are involved, nor how they feed back on the dyneins. To answer this question, we used isolated, reactivate axonemes of the unicellular alga Chlamydomonas as a model system. We derived a theory for beat regulation in a two-dimensional model of the axoneme. We then tested the theory by measuring the beat waveforms of wild type axonemes, which have asymmetric beats, and mutant axonemes, in which the beat is nearly symmetric, using high-precision spatial and temporal imaging....

  3. Presence of collagen IV in the ciliary zonules of the human eye : An immunohistochemical study by LM and TEM

    NARCIS (Netherlands)

    Los, LI; van der Worp, RJ; van Luyn, MJA; Hooymans, JMM

    2004-01-01

    The ciliary zonules of the eye are composed of fibrillar and non-fibrillar components. Fibrils provide tensile strength and elasticity, whereas non-fibrillar components serve as a coating surrounding the fibrils. This coating behaves as a barrier to macromolecules. The present light and transmission

  4. Individual differences in beat perception affect gait responses to low- and high-groove music.

    Science.gov (United States)

    Leow, Li-Ann; Parrott, Taylor; Grahn, Jessica A

    2014-01-01

    Slowed gait in patients with Parkinson's disease (PD) can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the "beat," which might be difficult for patients with PD who tend to show weak beat perception. One solution may be to use high-groove music, which has high beat salience that may facilitate synchronization, and affective properties, which may improve motivation to move. As a first step to understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low-groove music, high-groove music, and metronome cues. High-groove music was predicted to elicit better synchronization than low-groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1) preferred tempo: beat rate matched to preferred step rate and (2) faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high-groove music, and worst with low-groove music. In addition, high-groove music elicited longer and faster steps than low-groove music, both at preferred tempo and at faster tempo. Low-groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation. PMID:25374521

  5. Matrix Organisation : The design of cross-beat teamwork in newsrooms

    OpenAIRE

    Grubenmann, Stephanie

    2016-01-01

    Confronted by increased internal and external complexity, traditional forms of newswork have reached their limits. Journalistic start-ups, such as Quartz and NZZ.at, form emerging editorial teams around "obsessions" or "phenomena" to gain cross-beat perspectives of complex issues such as climate change, the financial crisis or the refugee crisis. Legacy media experimenting with cross-beat newswork see themselves confronted by challenges arising predominantly from beat structures. Consequently...

  6. Individual differences in beat perception affect gait responses to low- and high-groove music.

    Directory of Open Access Journals (Sweden)

    Li-Ann eLeow

    2014-10-01

    Full Text Available Slowed gait in Parkinson’s disease (PD patients can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the beat, which might be difficult for PD patients who tend to show weak beat perception. One solution may be to use high groove music, which has high beat salience that may facilitate synchronization, and affective properties which may improve motivation to move. As a first step in understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low groove music, high groove music, and metronome cues. High groove music was predicted to elicit better synchronization than low groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1 preferred tempo: beat rate matched to preferred step rate and (2 faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high groove music, and worst with low groove music. In addition, high groove music elicited longer and faster steps than low groove music, both at preferred tempo and at faster tempo. Low groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation.

  7. Can compressed sensing beat the Nyquist sampling rate?

    CERN Document Server

    Yaroslavsky, L

    2015-01-01

    Data saving capability of "Compressed sensing (sampling)" in signal discretization is disputed and found to be far below the theoretical upper bound defined by the signal sparsity. On a simple and intuitive example, it is demonstrated that, in a realistic scenario for signals that are believed to be sparse, one can achieve a substantially larger saving than compressing sensing can. It is also shown that frequent assertions in the literature that "Compressed sensing" can beat the Nyquist sampling approach are misleading substitution of terms and are rooted in misinterpretation of the sampling theory.

  8. Different Rebellions--The and the Angry Beat Generation Man

    Institute of Scientific and Technical Information of China (English)

    欧国芳

    2012-01-01

    The Beat Generation (BG) and the Angry Man (AYM) both emerged after the Second World War. Thus, the misunderstanding of the two has existed for a long time. Large quantities of people called the BG the American Angry Young Man. Undoubtedly, the two resembled each other to some extent. However, the BG and the AYM can't be treated alike, for their differences far outweighed their similarities. This paper aims to analyze their differences in many aspects like the national environment and their memberships, which consequently led to other differences such as the differences in essences, features, influence and finale.

  9. Enhanced timing abilities in percussionists generalize to rhythms without a musical beat

    Science.gov (United States)

    Cameron, Daniel J.; Grahn, Jessica A.

    2014-01-01

    The ability to entrain movements to music is arguably universal, but it is unclear how specialized training may influence this. Previous research suggests that percussionists have superior temporal precision in perception and production tasks. Such superiority may be limited to temporal sequences that resemble real music or, alternatively, may generalize to musically implausible sequences. To test this, percussionists and nonpercussionists completed two tasks that used rhythmic sequences varying in musical plausibility. In the beat tapping task, participants tapped with the beat of a rhythmic sequence over 3 stages: finding the beat (as an initial sequence played), continuation of the beat (as a second sequence was introduced and played simultaneously), and switching to a second beat (the initial sequence finished, leaving only the second). The meters of the two sequences were either congruent or incongruent, as were their tempi (minimum inter-onset intervals). In the rhythm reproduction task, participants reproduced rhythms of four types, ranging from high to low musical plausibility: Metric simple rhythms induced a strong sense of the beat, metric complex rhythms induced a weaker sense of the beat, nonmetric rhythms had no beat, and jittered nonmetric rhythms also had no beat as well as low temporal predictability. For both tasks, percussionists performed more accurately than nonpercussionists. In addition, both groups were better with musically plausible than implausible conditions. Overall, the percussionists' superior abilities to entrain to, and reproduce, rhythms generalized to musically implausible sequences. PMID:25540617

  10. Distinguishing between overdrive excited and suppressed ventricular beats in guinea pig ventricular myocardium

    Directory of Open Access Journals (Sweden)

    Amara eGreer-Short

    2015-02-01

    Full Text Available Rapid ventricular pacing rates induces two types of beats following pacing cessation: recovery cycle length (RCL prolongation (overdrive suppression and RCL shortening (overdrive excitation. The goals of this study were to compare common experimental protocols for studying triggered activity in whole-heart preparations and differentiate between recovery beats using a new methodology. Post-pacing recovery beat cycle length (RCL and QRS were normalized to pre-paced R-R and QRS intervals and analyzed using a K-means clustering algorithm. Control hearts only produced suppressed beats: RCL ratio increased with rapid pacing (25±4.0%, n=10 without changing QRS duration. Rapid pacing during hypercalcemia + hypothermia (5.5 mM and 34°C produced significantly earlier excited beats (53±14%, n=5 with wider QRS durations (58±6.3%, n=5 than suppressed beats. Digoxin + hypothermia (0.75 M produced the most excited beats with significantly earlier RCL (44±3.2%, n=6 and wider QRS (60±3.1%, n=6 ratios relative to suppressed beats. Increasing pacing further shortened RCL (30±7.8%, n=6. In a prospective study, TTX (100 nM increased RCL ratio (15±6.0%, n=10 without changing the QRS duration of excited beats. The algorithm was compared to a cross-correlation analysis with 93% sensitivity and 94% specificity. This ECG based algorithm distinguishes between triggered and automatic activity.

  11. Enhanced Timing Abilities in Percussionists Generalize to Rhythms Without a Musical Beat

    Directory of Open Access Journals (Sweden)

    Daniel J Cameron

    2014-12-01

    Full Text Available The ability to entrain movements to music is arguably universal, but it is unclear how specialized training may influence this. Previous research suggests that percussionists have superior temporal precision in perception and production tasks. Such superiority may be limited to temporal sequences that resemble real music or, alternatively, may generalize to musically implausible sequences. To test this, percussionists and nonpercussionists completed two tasks that used rhythmic sequences varying in musical plausibility. In the beat tapping task, participants tapped with the beat of a rhythmic sequence over 3 stages: finding the beat (as an initial sequence played, continuation of the beat (as a second sequence was introduced and played simultaneously, and switching to a second beat (the initial sequence finished, leaving only the second. The metres of the two sequences were either congruent or incongruent, as were their tempi (minimum inter-onset intervals. In the rhythm reproduction task, participants reproduced rhythms of four types, ranging from high to low musical plausibility: Metric simple rhythms induced a strong sense of the beat, metric complex rhythms induced a weaker sense of the beat, nonmetric rhythms had no beat, and jittered nonmetric rhythms also had no beat as well as low temporal predictability. For both tasks, percussionists performed more accurately than nonpercussionists. In addition, both groups were better with musically plausible than implausible conditions. Overall, the percussionists’ superior abilities to entrain to, and reproduce, rhythms generalized to musically implausible sequences.

  12. Simultaneous beat-by-beat investigation of the effects of the Valsalva maneuver on left and right ventricular filling and the possible mechanism.

    Directory of Open Access Journals (Sweden)

    Zhen Wang

    Full Text Available Although the influence of the Valsalva maneuver on the heart and circulatory system has been investigated, the mechanism of intrathoracic pressure influencing cardiovascular function is unclear. To test our hypothesis that the interaction between the anatomy-determined partially-intrathoracic system and the fully-intrathoracic system might explain those issues and help to disclose the mechanism, we used the Hitachi dual pulse wave Doppler echocardiographic apparatus to investigate simultaneously the beat-by-beat influence of 40-mmHg Valsalva maneuver on left and right cardiac ventricular filling in 30 male adult volunteers. The mitral and tricuspid blood inflow velocity spectra during the Valsalva maneuver were recorded simultaneously. The peak velocity (PV, velocity-time integral (VTI and inflow volume (IV of each cycle were measured or calculated. The PV, VTI and IV of the left heart remained unchanged at the first beat after the Valsalva maneuver onset (compared with those at rest, p>0.1 and then decreased gradually to the lowest at the 11±1.2th beat (range, 9th to 12th beat. Simultaneously, the PV, VTI and IV of the right heart decreased significantly (p<0.05 at the first cycle, decreased rapidly to the lowest at the 6±0.8th beat (range, 4th to 7th beat and then increased gradually to the 9±1.3th beat (range, 8th to 10th beat. These results suggest that the left heart and right heart have different physiological responses to the Valsalva maneuver. These could be explained by our hypothesis, the interaction between the partially-intrathoracic system and the fully-intrathoracic system, which might help to disclose the mechanism of how intrathoracic pressure influences the heart and circulatory system.

  13. Efficient heart beat detection using embedded system electronics

    Science.gov (United States)

    Ramasamy, Mouli; Oh, Sechang; Varadan, Vijay K.

    2014-04-01

    The present day bio-technical field concentrates on developing various types of innovative ambulatory and wearable devices to monitor several bio-physical, physio-pathological, bio-electrical and bio-potential factors to assess a human body's health condition without intruding quotidian activities. One of the most important aspects of this evolving technology is monitoring heart beat rate and electrocardiogram (ECG) from which many other subsidiary results can be derived. Conventionally, the devices and systems consumes a lot of power since the acquired signals are always processed on the receiver end. Because of this back end processing, the unprocessed raw data is transmitted resulting in usage of more power, memory and processing time. This paper proposes an innovative technique where the acquired signals are processed by a microcontroller in the front end of the module and just the processed signal is then transmitted wirelessly to the display unit. Therefore, power consumption is considerably reduced and clearer data analysis is performed within the module. This also avoids the need for the user to be educated about usage of the device and signal/system analysis, since only the number of heart beats will displayed at the user end. Additionally, the proposed concept also eradicates the other disadvantages like obtrusiveness, high power consumption and size. To demonstrate the above said factors, a commercial controller board was used to extend the monitoring method by using the saved ECG data from a computer.

  14. In vivo electroporation mediated gene delivery to the beating heart.

    Directory of Open Access Journals (Sweden)

    Erick L Ayuni

    Full Text Available Gene therapy may represent a promising alternative strategy for cardiac muscle regeneration. In vivo electroporation, a physical method of gene transfer, has recently evolved as an efficient method for gene transfer. In the current study, we investigated the efficiency and safety of a protocol involving in vivo electroporation for gene transfer to the beating heart. Adult male rats were anesthetised and the heart exposed through a left thoracotomy. Naked plasmid DNA was injected retrograde into the transiently occluded coronary sinus before the electric pulses were applied. Animals were sacrificed at specific time points and gene expression was detected. Results were compared to the group of animals where no electric pulses were applied. No post-procedure arrhythmia was observed. Left ventricular function was temporarily altered only in the group were high pulses were applied; CK-MB (Creatine kinase and TNT (Troponin T were also altered only in this group. Histology showed no signs of toxicity. Gene expression was highest at day one. Our results provide evidence that in vivo electroporation with an optimized protocol is a safe and effective tool for nonviral gene delivery to the beating heart. This method may be promising for clinical settings especially for perioperative gene delivery.

  15. Stimulated Brillouin side-scattering of the beat wave excited by two counter-propagating X-mode lasers in magnetized plasma

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Kanika; Sajal, Vivek, E-mail: vsajal@rediffmail.com; Kumar, Ravindra; Sharma, Navneet K. [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida 201307, Uttar Pradesh (India); Baliyan, Sweta [Department of Physics, Maitreyi College, University of Delhi, New Delhi 110021 (India)

    2015-06-15

    The stimulated Brillouin scattering (SBS) of nonresonant beat mode in the presence of static magnetic field is investigated in a plasma. Two counter-propagating lasers of frequencies (ω{sub 1} and ω{sub 2}) and wave vectors (k{sub 1} and k{sub 2}) drive a nonresonant space charge beat mode at the phase matching condition of frequency ω{sub 0}≈ω{sub 1}∼ω{sub 2} and wave number k{sup →}{sub 0}≈k{sup →}{sub 1}+k{sup →}{sub 2}. The driver wave parametrically excites a pair of ion acoustic wave (ω,k{sup →}) and a sideband electromagnetic wave (ω{sub 3},k{sup →}{sub 3}). The beat wave couples with the sideband electromagnetic wave to exert a nonlinear ponderomotive force at the frequency of ion acoustic wave. Density perturbations due to ion acoustic wave and ponderomotive force couple with the oscillatory motion of plasma electron due to velocity of beat wave to give rise to a nonlinear current (by feedback mechanism) responsible for the growth of sideband wave at resonance. The growth rate of SBS was reduced (from ∼10{sup 12}s{sup −1} to 10{sup 10}s{sup −1}) by applying a transverse static magnetic field ∼90 T. The present study can be useful for the excitation of fast plasma waves (for the purpose of electron acceleration) by two counter-propagating laser beams.

  16. Continued administration of ciliary neurotrophic factor protects mice from inflammatory pathology in experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Kuhlmann, Tanja; Remington, Leah; Cognet, Isabelle;

    2006-01-01

    Multiple sclerosis is an inflammatory disease of the central nervous system that leads to loss of myelin and oligodendrocytes and damage to axons. We show that daily administration (days 8 to 24) of murine ciliary neurotrophic factor (CNTF), a neurotrophic factor that has been described...... as a survival and differentiation factor for neurons and oligodendrocytes, significantly ameliorates the clinical course of a mouse model of multiple sclerosis. In the acute phase of experimental autoimmune encephalomyelitis induced by myelin oligodendrocyte glycoprotein peptide 35-55, treatment with CNTF did...... it was withdrawn. After cessation of CNTF treatment, inflammation and symptoms returned to control levels. However, slight but significantly higher numbers of oligodendrocytes, NG2-positive cells, axons, and neurons were observed in mice that had been treated with high concentrations of CNTF. Our results show...

  17. Disruption of Bardet-Biedl syndrome ciliary proteins perturbs planar cell polarity in vertebrates.

    Science.gov (United States)

    Ross, Alison J; May-Simera, Helen; Eichers, Erica R; Kai, Masatake; Hill, Josephine; Jagger, Daniel J; Leitch, Carmen C; Chapple, J Paul; Munro, Peter M; Fisher, Shannon; Tan, Perciliz L; Phillips, Helen M; Leroux, Michel R; Henderson, Deborah J; Murdoch, Jennifer N; Copp, Andrew J; Eliot, Marie-Madeleine; Lupski, James R; Kemp, David T; Dollfus, Hélène; Tada, Masazumi; Katsanis, Nicholas; Forge, Andrew; Beales, Philip L

    2005-10-01

    The evolutionarily conserved planar cell polarity (PCP) pathway (or noncanonical Wnt pathway) drives several important cellular processes, including epithelial cell polarization, cell migration and mitotic spindle orientation. In vertebrates, PCP genes have a vital role in polarized convergent extension movements during gastrulation and neurulation. Here we show that mice with mutations in genes involved in Bardet-Biedl syndrome (BBS), a disorder associated with ciliary dysfunction, share phenotypes with PCP mutants including open eyelids, neural tube defects and disrupted cochlear stereociliary bundles. Furthermore, we identify genetic interactions between BBS genes and a PCP gene in both mouse (Ltap, also called Vangl2) and zebrafish (vangl2). In zebrafish, the augmented phenotype results from enhanced defective convergent extension movements. We also show that Vangl2 localizes to the basal body and axoneme of ciliated cells, a pattern reminiscent of that of the BBS proteins. These data suggest that cilia are intrinsically involved in PCP processes.

  18. The presence of synaptic and chromosome disjunction mutants in Cenchrus ciliaris (Poaceae: Paniceae

    Directory of Open Access Journals (Sweden)

    N. C. Visser

    1999-12-01

    Full Text Available Synaptic mutants are present in  Cenchrus ciliaris L This species, due to the presence of linear bivalents and occasion­al trivalents and quadrivalents, is an intermediate desynaptic species. In addition, geographical distribution and environmental factors, such as high temperatures and low humidity, could also have had an influence on the desynapsis observed.The disjunction of chromosomes during anaphase I was mostly abnormal in this desynaptic species. Precocious disjunction of chromosomes into chromatids occurred during anaphase I Due to the high incidence of this chromosome abnormality, a mutant gene,  'pc'  responsible for the disjunction of chromosomes, must be present. The absence of cytokinesis in one specimen indicates a recessive mutant gene,  'va' to be active in this species.

  19. The behaviour of both Listeria monocytogenes and rat ciliated ependymal cells is altered during their co-culture

    OpenAIRE

    Fadaee-Shohada, Mina J.; Hirst, Robert A; Andrew Rutman; Roberts, Ian S.; Chris O'Callaghan; Andrew, Peter W.

    2010-01-01

    BACKGROUND: Ciliated ependymal cells line the cerebral ventricles and aqueducts separating the infected CSF from the brain parenchyma in meningitis. PRINCIPAL FINDINGS: Investigation of the interaction of Listeria monocytogenes with cultured rat brain ependymal cells showed that certain strains reduced the beat frequency of the cilia but all the strains studied significantly reduced the ciliary beat amplitude (the linear distance travelled by the tip of each cilium per beat cycle). CONCLUSION...

  20. Effects of ouabain and furosemide on transepithelial electrical parameters of the isolated shark ciliary epithelium.

    Science.gov (United States)

    Wiederholt, M; Zadunaisky, J A

    1987-08-01

    Sections of the ciliary epithelium of adult sharks (Squalus acanthias) were mounted in Ussing-type chambers (area 0.2 cm2) for measurements of transepithelial potential difference (PD), short circuit current (SCC) and calculation of transepithelial resistance (R). In 15 preparations PD was aqueous side negative (-0.51 +/- 0.12 mV; SCC 18.3 +/- 2.5 microA cm-2; R 30.7 +/- 3.1 Ohm cm2). However, in 15 other preparations incubated in identical Ringer's solution PD was aqueous side positive (0.53 +/- 0.09 mV; SCC -19.6 +/- 2.3 microA cm-2; R 27.9 +/- 2.8 Ohm cm2). 10(-5) M ouabain or 10(-4) M furosemide were applied either to the aqueous or blood side of the isolated ciliary epithelium at transepithelial negative or positive PD. When the transepithelial PD was positive on the aqueous side ouabain decreased PD and SCC within 15 to 45 min. When the spontaneous PD was negative both PD and SCC decreased when ouabain was applied to the blood side. When the drug was given to the aqueous side a biphasic response (first stimulation, then inhibition) of PD and SCC was observed. Furosemide when given to the blood side (with aqueous side PD positive) or to the aqueous side (with aqueous side PD negative) decreased PD and SCC. However, a transient stimulation of both electrical parameters was observed when furosemide was applied to either the blood side (with aqueous side PD negative) or to the aqueous side (with aqueous side PD positive). The polarity and magnitude of PD and SCC probably depend on the relative activity of sodium and chloride pumps across the cell membranes of the non-pigmented and/or pigmented cell layer. However, additional transport mechanisms cannot be excluded. PMID:3038770

  1. DNAH6 and Its Interactions with PCD Genes in Heterotaxy and Primary Ciliary Dyskinesia

    Science.gov (United States)

    Onuoha, Ezenwa Obi; Damerla, Rama Rao; Francis, Richard; Furutani, Yoshiyuki; Tariq, Muhammad; King, Stephen M.; Hendricks, Gregory; Cui, Cheng; Saydmohammed, Manush; Lee, Dong Min; Zahid, Maliha; Sami, Iman; Leatherbury, Linda; Pazour, Gregory J.; Ware, Stephanie M.; Nakanishi, Toshio; Goldmuntz, Elizabeth; Tsang, Michael; Lo, Cecilia W.

    2016-01-01

    Heterotaxy, a birth defect involving left-right patterning defects, and primary ciliary dyskinesia (PCD), a sinopulmonary disease with dyskinetic/immotile cilia in the airway are seemingly disparate diseases. However, they have an overlapping genetic etiology involving mutations in cilia genes, a reflection of the common requirement for motile cilia in left-right patterning and airway clearance. While PCD is a monogenic recessive disorder, heterotaxy has a more complex, largely non-monogenic etiology. In this study, we show mutations in the novel dynein gene DNAH6 can cause heterotaxy and ciliary dysfunction similar to PCD. We provide the first evidence that trans-heterozygous interactions between DNAH6 and other PCD genes potentially can cause heterotaxy. DNAH6 was initially identified as a candidate heterotaxy/PCD gene by filtering exome-sequencing data from 25 heterotaxy patients stratified by whether they have airway motile cilia defects. dnah6 morpholino knockdown in zebrafish disrupted motile cilia in Kupffer’s vesicle required for left-right patterning and caused heterotaxy with abnormal cardiac/gut looping. Similarly DNAH6 shRNA knockdown disrupted motile cilia in human and mouse respiratory epithelia. Notably a heterotaxy patient harboring heterozygous DNAH6 mutation was identified to also carry a rare heterozygous PCD-causing DNAI1 mutation, suggesting a DNAH6/DNAI1 trans-heterozygous interaction. Furthermore, sequencing of 149 additional heterotaxy patients showed 5 of 6 patients with heterozygous DNAH6 mutations also had heterozygous mutations in DNAH5 or other PCD genes. We functionally assayed for DNAH6/DNAH5 and DNAH6/DNAI1 trans-heterozygous interactions using subthreshold double-morpholino knockdown in zebrafish and showed this caused heterotaxy. Similarly, subthreshold siRNA knockdown of Dnah6 in heterozygous Dnah5 or Dnai1 mutant mouse respiratory epithelia disrupted motile cilia function. Together, these findings support an oligogenic disease

  2. DNAH6 and Its Interactions with PCD Genes in Heterotaxy and Primary Ciliary Dyskinesia.

    Directory of Open Access Journals (Sweden)

    You Li

    2016-02-01

    Full Text Available Heterotaxy, a birth defect involving left-right patterning defects, and primary ciliary dyskinesia (PCD, a sinopulmonary disease with dyskinetic/immotile cilia in the airway are seemingly disparate diseases. However, they have an overlapping genetic etiology involving mutations in cilia genes, a reflection of the common requirement for motile cilia in left-right patterning and airway clearance. While PCD is a monogenic recessive disorder, heterotaxy has a more complex, largely non-monogenic etiology. In this study, we show mutations in the novel dynein gene DNAH6 can cause heterotaxy and ciliary dysfunction similar to PCD. We provide the first evidence that trans-heterozygous interactions between DNAH6 and other PCD genes potentially can cause heterotaxy. DNAH6 was initially identified as a candidate heterotaxy/PCD gene by filtering exome-sequencing data from 25 heterotaxy patients stratified by whether they have airway motile cilia defects. dnah6 morpholino knockdown in zebrafish disrupted motile cilia in Kupffer's vesicle required for left-right patterning and caused heterotaxy with abnormal cardiac/gut looping. Similarly DNAH6 shRNA knockdown disrupted motile cilia in human and mouse respiratory epithelia. Notably a heterotaxy patient harboring heterozygous DNAH6 mutation was identified to also carry a rare heterozygous PCD-causing DNAI1 mutation, suggesting a DNAH6/DNAI1 trans-heterozygous interaction. Furthermore, sequencing of 149 additional heterotaxy patients showed 5 of 6 patients with heterozygous DNAH6 mutations also had heterozygous mutations in DNAH5 or other PCD genes. We functionally assayed for DNAH6/DNAH5 and DNAH6/DNAI1 trans-heterozygous interactions using subthreshold double-morpholino knockdown in zebrafish and showed this caused heterotaxy. Similarly, subthreshold siRNA knockdown of Dnah6 in heterozygous Dnah5 or Dnai1 mutant mouse respiratory epithelia disrupted motile cilia function. Together, these findings support an

  3. Interacting cortical and basal ganglia networks underlying finding and tapping to the musical beat.

    Science.gov (United States)

    Kung, Shu-Jen; Chen, Joyce L; Zatorre, Robert J; Penhune, Virginia B

    2013-03-01

    Humans are able to find and tap to the beat of musical rhythms varying in complexity from children's songs to modern jazz. Musical beat has no one-to-one relationship with auditory features-it is an abstract perceptual representation that emerges from the interaction between sensory cues and higher-level cognitive organization. Previous investigations have examined the neural basis of beat processing but have not tested the core phenomenon of finding and tapping to the musical beat. To test this, we used fMRI and had musicians find and tap to the beat of rhythms that varied from metrically simple to metrically complex-thus from a strong to a weak beat. Unlike most previous studies, we measured beat tapping performance during scanning and controlled for possible effects of scanner noise on beat perception. Results showed that beat finding and tapping recruited largely overlapping brain regions, including the superior temporal gyrus (STG), premotor cortex, and ventrolateral PFC (VLPFC). Beat tapping activity in STG and VLPFC was correlated with both perception and performance, suggesting that they are important for retrieving, selecting, and maintaining the musical beat. In contrast BG activity was similar in all conditions and was not correlated with either perception or production, suggesting that it may be involved in detecting auditory temporal regularity or in associating auditory stimuli with a motor response. Importantly, functional connectivity analyses showed that these systems interact, indicating that more basic sensorimotor mechanisms instantiated in the BG work in tandem with higher-order cognitive mechanisms in PFC.

  4. The role of the basal ganglia in beat perception: neuroimaging and neuropsychological investigations.

    Science.gov (United States)

    Grahn, Jessica A

    2009-07-01

    Perception of musical rhythms is culturally universal. Despite this special status, relatively little is known about the neurobiology of rhythm perception, particularly with respect to beat processing. Findings are presented here from a series of studies that have specifically examined the neural basis of beat perception, using functional magnetic resonance imaging (fMRI) and studying patients with Parkinson's disease. fMRI data indicate that novel beat-based sequences robustly activate the basal ganglia when compared to irregular, nonbeat sequences. Furthermore, although most healthy participants find it much easier to discriminate changes in beat-based sequences compared to irregular sequences, Parkinson's disease patients fail to show the same degree of benefit. Taken together, these data suggest that the basal ganglia are performing a crucial function in beat processing. The results of an additional fMRI study indicate that the role of the basal ganglia is strongly linked to internal generation of the beat. Basal ganglia activity is greater when participants listen to rhythms in which internal generation of the beat is required, as opposed to rhythms with strongly externally cued beats. Functional connectivity between part of the basal ganglia (the putamen) and cortical motor areas (premotor and supplementary motor areas) is also higher during perception of beat rhythms compared to nonbeat rhythms. Increased connectivity between cortical motor and auditory areas is found in those with musical training. The findings from these converging methods strongly implicate the basal ganglia in processing a regular beat, particularly when internal generation of the beat is required. PMID:19673753

  5. Use of beat-to-beat cardiovascular variability data to determine the validity of sham therapy as the placebo control in osteopathic manipulative medicine research.

    Science.gov (United States)

    Henley, Charles E; Wilson, Thad E

    2014-11-01

    Osteopathic manipulative medicine researchers often use sham therapy as the placebo control during clinical trials. Optimally, the sham therapy should be a hands-on procedure that is perceptually indistinguishable from osteopathic manipulative treatment, does not create an effect on its own, and is not a treatment intervention. However, the sham therapy itself may often influence the outcome. The use of cardiovascular variability (eg, beat-to-beat heart rate variability) as a surrogate for the autonomic nervous system is one objective method by which to identify such an effect. By monitoring cardiovascular variability, investigators can assess autonomic nervous system activity as a response to the sham therapy and quickly determine whether or not the selected sham therapy is a true placebo control. The authors provide evidence for assessment of beat-to-beat heart rate variability as one method for assuring objectivity of sham therapy as a placebo control in osteopathic manipulative medicine research.

  6. Dual-etalon cavity ring-down frequency-comb spectroscopy with broad band light source

    Science.gov (United States)

    Chandler, David W; Strecker, Kevin E

    2014-04-01

    In an embodiment, a dual-etalon cavity-ring-down frequency-comb spectrometer system is described. A broad band light source is split into two beams. One beam travels through a first etalon and a sample under test, while the other beam travels through a second etalon, and the two beams are recombined onto a single detector. If the free spectral ranges ("FSR") of the two etalons are not identical, the interference pattern at the detector will consist of a series of beat frequencies. By monitoring these beat frequencies, optical frequencies where light is absorbed may be determined.

  7. The steady-state response of the cerebral cortex to the beat of music reflects both the comprehension of music and attention

    Directory of Open Access Journals (Sweden)

    Benjamin eMeltzer

    2015-08-01

    Full Text Available The brain's analyses of speech and music share a range of neural resources and mechanisms. Music displays a temporal structure of complexity similar to that of speech, unfolds over comparable timescales, and elicits cognitive demands in tasks involving comprehension and attention. During speech processing, synchronized neural activity of the cerebral cortex in the delta and theta frequency bands tracks the envelope of a speech signal, and this neural activity is modulated by high-level cortical functions such as speech comprehension and attention. It remains unclear, however, whether the cortex also responds to the natural rhythmic structure of music and how the response, if present, is influenced by higher cognitive processes. Here we employ electroencephalography (EEG to show that the cortex responds to the beat of music and that this steady-state response reflects musical comprehension and attention. We show that the cortical response to the beat is weaker when subjects listen to a familiar tune than when they listen to an unfamiliar, nonsensical musical piece. Furthermore, we show that in a task of intermodal attention there is a larger neural response at the beat frequency when subjects attend to a musical stimulus than when they ignore the auditory signal and instead focus on a visual one. Our findings may be applied in clinical assessments of auditory processing and music cognition as well as in the construction of auditory brain-machine interfaces.

  8. Keeping the Beat: A Large Sample Study of Bouncing and Clapping to Music

    Science.gov (United States)

    Tranchant, Pauline; Vuvan, Dominique T.; Peretz, Isabelle

    2016-01-01

    The vast majority of humans move in time with a musical beat. This behaviour has been mostly studied through finger-tapping synchronization. Here, we evaluate naturalistic synchronization responses to music–bouncing and clapping–in 100 university students. Their ability to match the period of their bounces and claps to those of a metronome and musical clips varying in beat saliency was assessed. In general, clapping was better synchronized with the beat than bouncing, suggesting that the choice of a specific movement type is an important factor to consider in the study of sensorimotor synchronization processes. Performance improved as a function of beat saliency, indicating that beat abstraction plays a significant role in synchronization. Fourteen percent of the population exhibited marked difficulties with matching the beat. Yet, at a group level, poor synchronizers showed similar sensitivity to movement type and beat saliency as normal synchronizers. These results suggest the presence of quantitative rather than qualitative variations when losing the beat. PMID:27471854

  9. Beat processing is pre-attentive for metrically simple rhythms with clear accents: an ERP study.

    Directory of Open Access Journals (Sweden)

    Fleur L Bouwer

    Full Text Available The perception of a regular beat is fundamental to music processing. Here we examine whether the detection of a regular beat is pre-attentive for metrically simple, acoustically varying stimuli using the mismatch negativity (MMN, an ERP response elicited by violations of acoustic regularity irrespective of whether subjects are attending to the stimuli. Both musicians and non-musicians were presented with a varying rhythm with a clear accent structure in which occasionally a sound was omitted. We compared the MMN response to the omission of identical sounds in different metrical positions. Most importantly, we found that omissions in strong metrical positions, on the beat, elicited higher amplitude MMN responses than omissions in weak metrical positions, not on the beat. This suggests that the detection of a beat is pre-attentive when highly beat inducing stimuli are used. No effects of musical expertise were found. Our results suggest that for metrically simple rhythms with clear accents beat processing does not require attention or musical expertise. In addition, we discuss how the use of acoustically varying stimuli may influence ERP results when studying beat processing.

  10. Beat processing is pre-attentive for metrically simple rhythms with clear accents: an ERP study.

    Science.gov (United States)

    Bouwer, Fleur L; Van Zuijen, Titia L; Honing, Henkjan

    2014-01-01

    The perception of a regular beat is fundamental to music processing. Here we examine whether the detection of a regular beat is pre-attentive for metrically simple, acoustically varying stimuli using the mismatch negativity (MMN), an ERP response elicited by violations of acoustic regularity irrespective of whether subjects are attending to the stimuli. Both musicians and non-musicians were presented with a varying rhythm with a clear accent structure in which occasionally a sound was omitted. We compared the MMN response to the omission of identical sounds in different metrical positions. Most importantly, we found that omissions in strong metrical positions, on the beat, elicited higher amplitude MMN responses than omissions in weak metrical positions, not on the beat. This suggests that the detection of a beat is pre-attentive when highly beat inducing stimuli are used. No effects of musical expertise were found. Our results suggest that for metrically simple rhythms with clear accents beat processing does not require attention or musical expertise. In addition, we discuss how the use of acoustically varying stimuli may influence ERP results when studying beat processing.

  11. Beat processing is pre-attentive for metrically simple rhythms with clear accents: an ERP study.

    Science.gov (United States)

    Bouwer, Fleur L; Van Zuijen, Titia L; Honing, Henkjan

    2014-01-01

    The perception of a regular beat is fundamental to music processing. Here we examine whether the detection of a regular beat is pre-attentive for metrically simple, acoustically varying stimuli using the mismatch negativity (MMN), an ERP response elicited by violations of acoustic regularity irrespective of whether subjects are attending to the stimuli. Both musicians and non-musicians were presented with a varying rhythm with a clear accent structure in which occasionally a sound was omitted. We compared the MMN response to the omission of identical sounds in different metrical positions. Most importantly, we found that omissions in strong metrical positions, on the beat, elicited higher amplitude MMN responses than omissions in weak metrical positions, not on the beat. This suggests that the detection of a beat is pre-attentive when highly beat inducing stimuli are used. No effects of musical expertise were found. Our results suggest that for metrically simple rhythms with clear accents beat processing does not require attention or musical expertise. In addition, we discuss how the use of acoustically varying stimuli may influence ERP results when studying beat processing. PMID:24870123

  12. Beat processing is pre-attentive for metrically simple rhythms with clear accents: An ERP study

    NARCIS (Netherlands)

    F.L. Bouwer; T.L. van Zuijen; H. Honing

    2014-01-01

    The perception of a regular beat is fundamental to music processing. Here we examine whether the detection of a regular beat is pre-attentive for metrically simple, acoustically varying stimuli using the mismatch negativity (MMN), an ERP response elicited by violations of acoustic regularity irrespe

  13. Peak misdetection in heart-beat-based security : Characterization and tolerance

    NARCIS (Netherlands)

    Seepers, Robert M; Strydis, Christos; Peris-Lopez, Pedro; Sourdis, Ioannis; De Zeeuw, Chris I

    2014-01-01

    The Inter-Pulse-Interval (IPI) of heart beats has previously been suggested for security in mobile health (mHealth) applications. In IPI-based security, secure communication is facilitated through a security key derived from the time difference between heart beats. However, there currently exists no

  14. Keeping the Beat: A Large Sample Study of Bouncing and Clapping to Music.

    Science.gov (United States)

    Tranchant, Pauline; Vuvan, Dominique T; Peretz, Isabelle

    2016-01-01

    The vast majority of humans move in time with a musical beat. This behaviour has been mostly studied through finger-tapping synchronization. Here, we evaluate naturalistic synchronization responses to music-bouncing and clapping-in 100 university students. Their ability to match the period of their bounces and claps to those of a metronome and musical clips varying in beat saliency was assessed. In general, clapping was better synchronized with the beat than bouncing, suggesting that the choice of a specific movement type is an important factor to consider in the study of sensorimotor synchronization processes. Performance improved as a function of beat saliency, indicating that beat abstraction plays a significant role in synchronization. Fourteen percent of the population exhibited marked difficulties with matching the beat. Yet, at a group level, poor synchronizers showed similar sensitivity to movement type and beat saliency as normal synchronizers. These results suggest the presence of quantitative rather than qualitative variations when losing the beat. PMID:27471854

  15. Differences between the neurogenic and proliferative abilities of Müller glia with stem cell characteristics and the ciliary epithelium from the adult human eye

    OpenAIRE

    Bhatia, Bhairavi; Jayaram, Hari; Singhal, Shweta; Jones, Megan F; Limb, G. Astrid

    2011-01-01

    Much controversy has arisen on the nature and sources of stem cells in the adult human retina. Whilst ciliary epithelium has been thought to constitute a source of neural stem cells, a population of Müller glia in the neural retina has also been shown to exhibit neurogenic characteristics. This study aimed to compare the neurogenic and proliferative abilities between these two major cell populations. It also examined whether differences exist between the pigmented and non-pigmented ciliary ep...

  16. Synchronization using environmental coupling in mercury beating heart oscillators

    Science.gov (United States)

    Singla, Tanu; Montoya, Fernando; Rivera, M.; Tajima, Shunsuke; Nakabayashi, Seiichiro; Parmananda, P.

    2016-06-01

    We report synchronization of Mercury Beating Heart (MBH) oscillators using the environmental coupling mechanism. This mechanism involves interaction of the oscillators with a common medium/environment such that the oscillators do not interact among themselves. In the present work, we chose a modified MBH system as the common environment. In the absence of coupling, this modified system does not exhibit self sustained oscillations. It was observed that, as a result of the coupling of the MBH oscillators with this common environment, the electrical and the mechanical activities of both the oscillators synchronized simultaneously. Experimental results indicate the emergence of both lag and the complete synchronization in the MBH oscillators. Simulations of the phase oscillators were carried out in order to better understand the experimental observations.

  17. The quantum beat principles and applications of atomic clocks

    CERN Document Server

    Major, F

    2007-01-01

    This work attempts to convey a broad understanding of the physical principles underlying the workings of these quantum-based atomic clocks, with introductory chapters placing them in context with the early development of mechanical clocks and the introduction of electronic time-keeping as embodied in the quartz-controlled clocks. While the book makes no pretense at being a history of atomic clocks, it nevertheless takes a historical perspective in its treatment of the subject. Intended for nonspecialists with some knowledge of physics or engineering, The Quantum Beat covers a wide range of salient topics relevant to atomic clocks, treated in a broad intuitive manner with a minimum of mathematical formalism. Detailed descriptions are given of the design principles of the rubidium, cesium, hydrogen maser, and mercury ion standards; the revolutionary changes that the advent of the laser has made possible, such as laser cooling, optical pumping, the formation of "optical molasses," and the cesium "fountain" stand...

  18. Oxidized Cellulose with Different Carboxyl Content: Structure and Properties before and after Beating

    Science.gov (United States)

    Vendula, Hejlová; Miloslav, Milichovský

    Our recent studies concentrated in investigating influence of beating oxidized cellulose, with different carboxyl content, on changing their basic properties (degree of polymerization, WRV - water resistant value and X-ray diffraction). Cellulose samples of oxidized cellulose were beated by toroidal beating machine. Cellulose consists of both amorphous and crystalline regions. Cellulose consists of linear chains of poly[ß-1,4-D- anhydroglucopyranose] (C6nH10n + 2O5n + 1 (n = degree of polymerization of glucose)), which crystallize through hydrogen bonding between the chains and has cellobiose as repeat unit. Oxidized cellulose is preparing by oxidation of cellulose in the C6 position of the glucopyranose units to carboxylic group (-COOH) and polyanhydroglukuronic acid (PAGA) is arised. An other option is oxidation with sodium hypochlorite with catalytic amounts of sodium bromide and 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) under various conditions. Beating and refining or mechanical treatment of fibers in water is an important step in using pulps for papermaking. It is an energy intensive process. The purpose of the treatment is to modify fiber properties to obtain the most desirable paper machine runnability and product properties. End of beating pulps was characterized by position, when all beated pulps under mixture passed through of riddle (about sizes mesh of 50). During beating of samples about different ratio of oxidation it was found, that samples with higher contents of COOH groups in starting pulp are characterized by a significantly lower specific beating energy consumption needed to achieving the same sizes of particles. X-ray analyse shows that for non-beated oxidized cellulose was perceptible high share amorphous contents compared with beated oxidized cellulose.

  19. Clinical value of measurement of pulmonary radioaerosol mucociliary clearance in the work up of primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Munkholm, Mathias; Nielsen, Kim Gjerum; Mortensen, Jann

    2015-01-01

    BACKGROUND: We aimed to evaluate and define the general clinical applicability and impact of pulmonary radioaerosol mucociliary clearance (PRMC) on the work up of patients suspected of having primary ciliary dyskinesia (PCD). In addition, we wanted to evaluate the accuracy of the reference values...... primarily to results from nasal ciliary function testing, to electron microscopic (EM) examination of the ultrastructure of the cilia, and to the final clinical diagnosis. RESULTS: Of the 239 patients, 27 ended up with a final clinical diagnosis of definitive PCD. No patients with a PRMC test...... that was normal or otherwise not consistent with PCD ended up with PCD as final clinical diagnosis (though a minority of patients in this group ended up unresolved in regard to PCD). Forty percent of patients with an abnormal PRMC test ended up with PCD as final clinical diagnosis. Furthermore, the PRMC test had...

  20. RPGR-containing protein complexes in syndromic and non-syndromic retinal degeneration due to ciliary dysfunction

    Indian Academy of Sciences (India)

    Carlos A. Murga-Zamalloa; Anand Swaroop; Hemant Khanna

    2009-12-01

    Dysfunction of primary cilia due to mutations in cilia-centrosomal proteins is associated with pleiotropic disorders. The primary (or sensory) cilium of photoreceptors mediates polarized trafficking of proteins for efficient phototransduction. Retinitis pigmentosa GTPase regulator (RPGR) is a cilia-centrosomal protein mutated in >70% of X-linked RP cases and 10%–20% of simplex RP males. Accumulating evidence indicates that RPGR may facilitate the orchestration of multiple ciliary protein complexes. Disruption of these complexes due to mutations in component proteins is an underlying cause of associated photoreceptor degeneration. Here, we highlight the recent developments in understanding the mechanism of cilia-dependent photoreceptor degeneration due to mutations in RPGR and RPGR-interacting proteins in severe genetic diseases, including retinitis pigmentosa, Leber congenital amaurosis (LCA), Joubert syndrome, and Senior–Loken syndrome, and explore the physiological relevance of photoreceptor ciliary protein complexes.

  1. Surgical treatment of iris and ciliary body melanoma: follow-up of a 25-year series of patients

    DEFF Research Database (Denmark)

    Klauber, Stefan; Jensen, Peter K; Prause, Jan U;

    2010-01-01

    Purpose: To evaluate outcome of surgical resection of iris and irido-ciliary melanomas. Method: Retrospective analysis of all cases treated in Denmark 1975-1999 with clinical follow-up in 2002 and death certificate analysis in 2008. A quality of life questionnaire was completed at follow-up. Resu......Purpose: To evaluate outcome of surgical resection of iris and irido-ciliary melanomas. Method: Retrospective analysis of all cases treated in Denmark 1975-1999 with clinical follow-up in 2002 and death certificate analysis in 2008. A quality of life questionnaire was completed at follow...... had died of melanoma-related causes. Only one patient had a local recurrence, which was successfully treated by cryotherapy. The quality of life-related questions demonstrated that most patients (40) suffered from photophobia, and eight patients had changed their driving habits, not driving at night...

  2. COMPARATIVE PRIMARY PHYTO-PROFILE AND MICROCIDAL ACTIVITY OF CENCHRUS CILIARIS (ANJAN GRASS AND WITHANIA SOMNIFERA (WINTER CHERRY

    Directory of Open Access Journals (Sweden)

    Singariya P.

    2012-04-01

    Full Text Available Crude extracts of different parts (root, stem, leaf and seed of Cenchrus ciliaris (CAZRI-358 and (root, stem, leaf and flower of Withania somnifera (RUBL-20668 and were successively extracted with polar to non polar solvents (water, chloroform and benzene using soxhlet assembly. The extracts were then screened for their antimicrobial activity in-vitro against one gram positive bacteria (Bacillus subtilis, two gram negative bacteria (Pseudomonas aeruginosa and Enterobactor aerogens and one fungus (Aspergillus flavus by disc diffusion assay. Serial dilution method was used to determine minimum inhibitory concentration (MIC and minimum bactericidal/fungicidal concentration (MBC/MFC. Chloroform extract of leaves of both the plants showed highest activity, by W. somnifera (IZ-20.83±0.21 mm, AI- 1.389 and (IZ-20.67±0.24 mm, AI- 1.148 by C. ciliaris against B. subtilis and P. aeruginosa respectively.

  3. Banding and Step-Stair Artifacts on the Cardiac-CT Caused By Pseudo-Ectopic Beats

    OpenAIRE

    Singh, Amolak; Sethi, Yash; Watkins, Sonya; Youtsey, Angela; Thomas, Angie

    2009-01-01

    Step-stair and banding artifacts may result from irregular ventricular rhythm caused by atrial fibrillation or premature ectopic ventricular contractions. In the case reported here, severe banding and misalignment artifacts occurred due to electrocardiographic noise mimicking ectopic beats. Severe EKG noise or pseudo-ectopic beats may cause rare but serious artifacts during cardiac-CT acquisition. Vendor-provided software for correcting ectopic beats can be used to remove pseudo-ectopic beats...

  4. Ciliary neurotrophic factor promotes motor reinnervation of the musculocutaneous nerve in an experimental model of end-to-side neurorrhaphy

    OpenAIRE

    Čelakovský Pavel; Stejskal Lubomír; Raška Otakar; Klusáková Ilona; Dubový Petr; Haninec Pavel

    2011-01-01

    Abstract Background It is difficult to repair nerve if proximal stump is unavailable or autogenous nerve grafts are insufficient for reconstructing extensive nerve damage. Therefore, alternative methods have been developed, including lateral anastomosis based on axons' ability to send out collateral sprouts into denervated nerve. The different capacity of a sensory or motor axon to send a sprout is controversial and may be controlled by cytokines and/or neurotrophic factors like ciliary neuro...

  5. Beat wave excitation of electron plasma wave by relativistic cross focusing of cosh-Gaussian laser beams in plasma

    Science.gov (United States)

    Singh, Arvinder; Gupta, Naveen

    2015-06-01

    A scheme for beat wave excitation of electron plasma wave (EPW) is proposed by relativistic cross-focusing of two coaxial Cosh-Gaussian (ChG) laser beams in an under dense plasma. The plasma wave is generated on account of beating of two coaxial laser beams of frequencies ω1 and ω2 . The mechanism for laser produced nonlinearity is assumed to be relativistic nonlinearity in electron mass. Following moment theory approach in Wentzel Kramers Brillouin (W.K.B) approximation, the coupled differential equations governing the evolution of spot size of laser beams with distance of propagation have been derived. The relativistic nonlinearity depends not only on the intensity of first laser beam but also on the intensity of second laser beam. Therefore, propagation dynamics of one laser beam affect that of second beam and hence cross-focusing of the two laser beams takes place. Due to non uniform intensity distribution of pump laser beams, the background electron concentration gets modified. The amplitude of EPW, which depends on the background electron concentration, thus gets nonlinearly coupled with the laser beams. The effects of relativistic electron mass nonlinearity and the cross-focusing of pump beams on excitation of EPW have been incorporated. Numerical simulations have been carried out to investigate the effect of laser as well as plasma parameters on cross-focusing of laser beams and further its effect on power of excited EPW.

  6. Rer1p maintains ciliary length and signaling by regulating γ-secretase activity and Foxj1a levels.

    Science.gov (United States)

    Jurisch-Yaksi, Nathalie; Rose, Applonia J; Lu, Huiqi; Raemaekers, Tim; Munck, Sebastian; Baatsen, Pieter; Baert, Veerle; Vermeire, Wendy; Scales, Suzie J; Verleyen, Daphne; Vandepoel, Roel; Tylzanowski, Przemko; Yaksi, Emre; de Ravel, Thomy; Yost, H Joseph; Froyen, Guy; Arrington, Cammon B; Annaert, Wim

    2013-03-18

    Cilia project from the surface of most vertebrate cells and are important for several physiological and developmental processes. Ciliary defects are linked to a variety of human diseases, named ciliopathies, underscoring the importance of understanding signaling pathways involved in cilia formation and maintenance. In this paper, we identified Rer1p as the first endoplasmic reticulum/cis-Golgi-localized membrane protein involved in ciliogenesis. Rer1p, a protein quality control receptor, was highly expressed in zebrafish ciliated organs and regulated ciliary structure and function. Both in zebrafish and mammalian cells, loss of Rer1p resulted in the shortening of cilium and impairment of its motile or sensory function, which was reflected by hearing, vision, and left-right asymmetry defects as well as decreased Hedgehog signaling. We further demonstrate that Rer1p depletion reduced ciliary length and function by increasing γ-secretase complex assembly and activity and, consequently, enhancing Notch signaling as well as reducing Foxj1a expression.

  7. Sonic Hedgehog dependent phosphorylation by CK1α and GRK2 is required for ciliary accumulation and activation of smoothened.

    Directory of Open Access Journals (Sweden)

    Yongbin Chen

    2011-06-01

    Full Text Available Hedgehog (Hh signaling regulates embryonic development and adult tissue homeostasis through the GPCR-like protein Smoothened (Smo, but how vertebrate Smo is activated remains poorly understood. In Drosophila, Hh dependent phosphorylation activates Smo. Whether this is also the case in vertebrates is unclear, owing to the marked sequence divergence between vertebrate and Drosophila Smo (dSmo and the involvement of primary cilia in vertebrate Hh signaling. Here we demonstrate that mammalian Smo (mSmo is activated through multi-site phosphorylation of its carboxyl-terminal tail by CK1α and GRK2. Phosphorylation of mSmo induces its active conformation and simultaneously promotes its ciliary accumulation. We demonstrate that graded Hh signals induce increasing levels of mSmo phosphorylation that fine-tune its ciliary localization, conformation, and activity. We show that mSmo phosphorylation is induced by its agonists and oncogenic mutations but is blocked by its antagonist cyclopamine, and efficient mSmo phosphorylation depends on the kinesin-II ciliary motor. Furthermore, we provide evidence that Hh signaling recruits CK1α to initiate mSmo phosphorylation, and phosphorylation further increases the binding of CK1α and GRK2 to mSmo, forming a positive feedback loop that amplifies and/or sustains mSmo phosphorylation. Hence, despite divergence in their primary sequences and their subcellular trafficking, mSmo and dSmo employ analogous mechanisms for their activation.

  8. OFD1, as a Ciliary Protein, Exhibits Neuroprotective Function in Photoreceptor Degeneration Models.

    Directory of Open Access Journals (Sweden)

    Juan Wang

    Full Text Available Ofd1 is a newly identified causative gene for Retinitis pigmentosa (RP, a photoreceptor degenerative disease. This study aimed to examine Ofd1 localization in retina and further to investigate its function in photoreceptor degeneration models. Ofd1 localization in rat retina was examined using immunofluorescence. N-methyl-N-nitrosourea (MNU-induced rats and Royal College of Surgeons (RCS rats were used as photoreceptor degeneration models. The expression pattern of Ofd1, other ciliary associated genes and Wnt signaling pathway genes were examined in rat models. Furthermore, pEGFP-Ofd1-CDS and pSUPER-Ofd1-shRNA were constructed to overexpress and knockdown the expression level in 661W and R28 cells. MNU was also used to induce cell death. Cilia formation was observed using immunocytochemistry (ICC. Reactive oxygen species (ROS were detected using the 2', 7'-Dichlorofluorescin diacetate (DCFH-DA assay. Apoptosis genes expression was examined using qRT-PCR, Western blotting and fluorescence-activated cell sorting (FACS. Ofd1 localized to outer segments of rat retina photoreceptors. Ofd1 and other ciliary proteins expression levels increased from the 1st and 4th postnatal weeks and decreased until the 6th week in the RCS rats, while their expression consistently decreased from the 1st and 7th day in the MNU rats. Moreover, Wnt signaling pathway proteins expression was significantly up-regulated in both rat models. Knockdown of Ofd1 expression resulted in a smaller population, shorter length of cell cilia, and lower cell viability. Ofd1 overexpression partially attenuated MNU toxic effects by reducing ROS levels and mitigating apoptosis. To the best of our knowledge, this is the first study demonstrating Ofd1 localization and its function in rat retina and in retinal degeneration rat models. Ofd1 plays a role in controlling photoreceptor cilium length and number. Importantly, it demonstrates a neuroprotective function by protecting the photoreceptor

  9. Psychophysical tuning curves for very low centre frequencies

    DEFF Research Database (Denmark)

    Orellana, Carlos Andrés Jurado; Moore, Brian C.J.; Pedersen, Christian Sejer

    2010-01-01

    low frequencies, psychophysical tuning curves (PTCs) were obtained for centre frequencies of 31.5, 40, and 50 Hz. An equal-loudness-level contour was also obtained using closely spaced frequencies. This was used as a rough estimate of the shape of the individual middle-ear transfer function......Prediction and assessment of problems produced by low-frequency noise requires information about frequency selectivity in the low-frequency range. However, there are few data on frequency selectivity for centre frequencies below 100 Hz. To estimate the characteristics of auditory tuning for very...... in the frequency range below 100 Hz. Preliminary results on 1 subject are described. The PTCs showed distinct irregularities around the signal frequency, which may reflect the influence of beats. However, the overall shapes of the PTCs were broad, indicating that frequency selectivity at low frequencies...

  10. Viscosity and not biological mechanisms often controls the effects of temperature on ciliary activity and swimming velocity of small aquatic organisms

    DEFF Research Database (Denmark)

    Larsen, Poul Scheel; Riisgård, H. U.

    2009-01-01

    A number of studies have shown that temperature-dependent viscosity of the ambient water controls or strongly affects bio-mechanical activity such as beat frequency of water-pumping cilia in mussels and ascidians, swimming velocity of sperm cells, ciliates and small (micro- and meso-scale) aquatic...... is used to assess to what extent the response is purely physical/mechanical or biological. We argue that a power-law dependence of bio-mechanical activity (a) on kinematic viscosity (ν), i.e. a ~ ν^−m, should be applied to available data. Based on a general close matching of the response data to power...... organisms using cilia or small appendages for propulsion. Here we summarize results from the literature and from own studies on bio-mechanical activities in response to changing temperature or manipulated viscosity at constant temperature, both having the same change in kinematic viscosity. The survey...

  11. Real-Time Analysis of Beats in Music for Entertainment Robots

    Directory of Open Access Journals (Sweden)

    Yue-Der Lin

    2012-12-01

    Full Text Available The dancing actions for entertainment robots are usually designed in advance and saved in a database according to the beats and rhythm of the given music. This research is devoted to developing a real-time algorithm that can detect the primary information of the music needed for the actions of entertainment robots. The computation of the proposed algorithm is very efficient and can satisfy the requirement of real-time processing by a digital signal controller. The digitized music signal is first normalized to make the algorithm robust for miscellaneous music volume. Next, the primary features of the beat for the music are extracted. Based on the extracted features, the algorithm will then identify the occurrence of beats in the music through the use of an optimized classifier. From the accumulated information of the timing for the beats, the algorithm can provide the predicted timing information of the next beat through regression analysis. The type and tempo of the given music can also be derived thereafter. The entertainment robot can thus move or dance according to the information derived by the algorithm. A graphical user interface (GUI program in LabVIEW is also utilized to observe and verify the analysis results. In this study, the ratio for correct beat detection is greater than 90%. The prediction ratio for the correct timing of beats is over 80%, and it is 100% correct for both music type and music tempo.

  12. Readout for intersatellite laser interferometry: Measuring low frequency phase fluctuations of high-frequency signals with microradian precision

    DEFF Research Database (Denmark)

    Gerberding, Oliver; Diekmann, Christian; Kullmann, Joachim;

    2015-01-01

    Precision phase readout of optical beat note signals is one of the core techniques required for inter-satellite laser interferometry. Future space based gravitational wave detectors like eLISA require such a readout over a wide range of MHz frequencies, due to orbit induced Doppler shifts...

  13. Recent invasion of buffel grass (Cenchrus ciliaris of a natural protected area from the southern Sonoran Desert Invasión reciente de zacate buffel (Cenchrus ciliaris en un área natural protegida del desierto sonorense

    Directory of Open Access Journals (Sweden)

    Erick De la Barrera

    2008-12-01

    Full Text Available The Centro Ecológico de Sonora is a natural protected area where the natural vegetation remained undisturbed at least until 1997. Since then, Cenchrus ciliaris has become a prominent element of the vegetation because of disturbance. Climate, soil properties, population structure and biological activity for C. ciliaris were studied to gain understanding of the ecological mechanisms that favored the invasion by this exotic grass. Mean air temperature and annual rainfall were 24.8°C and 302 mm. The soil was a loamy-sand that was poor in most nutrients, but particularly rich in phosphorus. Pennisetum ciliare was the most abundant species at the Centro Ecológico, representing over one third of total plant ground cover. Basal area for individual plants ranged from less than 1 cm² to almost 1 m². Living leaves per plant increased with precipitation, peaking at 199 leaves in March 2005, and no living leaves were found after 103 days without rain. The environmental conditions prevalent at Centro Ecológico are very favorable for C. ciliaris, whose establishment was apparently triggered by a major disturbance caused by the development of housing projects.El Centro Ecológico de Sonora es un área natural protegida donde la vegetación autóctona permaneció sin disturbios por lo menos hasta 1997. Desde entonces, Cenchrus ciliaris se ha convertido en un elemento prominente de la vegetación. Se estudiaron el clima, las propiedades del suelo, la estructura de la población y la actividad biológica de C. ciliaris, como una aproximación al entendimiento de los mecanismos ecológicos que favorecieron la invasión por este pasto exótico. La temperatura media del aire y la precipitación anual fueron de 24.8 °C y 302 mm. El suelo fue una arena limosa pobre en minerales, pero particularmente rica en fósforo. Cenchrus ciliaris fue la especie herbácea más abundante en el Centro Ecológico, representando más de un tercio de la cobertura vegetal. El

  14. Apparatus for using a time interval counter to measure frequency stability

    Science.gov (United States)

    Greenhall, Charles A. (Inventor)

    1989-01-01

    An apparatus for measuring the relative stability of two signals is disclosed comprising a means for mixing the two signals down to a beat note sine wave and for producing a beat note square wave whose upcrossings are the same as the sine wave. A source of reference frequency is supplied to a clock divider and interval counter to synchronize them and to generate a picket fence for providing a time reference grid of period shorter than the beat period. An interval counter is employed to make a preliminary measurement between successive upcrossings of the beat note square wave for providing an approximate time interval therebetween as a reference. The beat note square wave and the picket fence are then provided to the interval counter to provide an output consisting of the time difference between the upcrossing of each beat note square wave cycle and the next picket fence pulse such that the counter is ready for each upcrossing and dead time is avoided. A computer containing an algorithm for calculating the exact times of the beat note upcrossings then computes the upcrossing times.

  15. Interpretation of Normal and Pathological ECG Beats using Multiresolution Wavelet Analysis

    Directory of Open Access Journals (Sweden)

    Shubhada S.Ardhapurkar

    2012-12-01

    Full Text Available The Discrete wavelet transform has great capability to analyse the temporal and spectral properties of non stationary signal like ECG. In this paper, we have developed and evaluated a robust algorithm using multiresolution analysis based on the discrete wavelet transform (DWT for twelve-lead electrocardiogram (ECG temporal feature extraction. In the first step, ECG was denoised considerably by employing kernel density estimation on subband coefficients then QRS complexes were detected. Further, by selecting appropriate coefficients and applying wave segmentation strategy P and T wave peaks were detected. Finally, the determination of P and T wave onsets and ends was performed. The novelty of this approach lies in detection of different morphologies in ECG wave with few decision rules. We have evaluated the algorithm on normal and abnormal beats from various manually annotated databases from physiobank having different sampling frequencies. The QRS detector obtained a sensitivity of 99.5% and a positive predictivity of 98.9% over the first lead of the MIT-BIH Arrhythmia Database.

  16. Beating the standard quantum limit for force sensing with a coupled two-mode optomechanical system

    CERN Document Server

    Xu, Xunnong

    2013-01-01

    Optomechanics allows the transduction of weak forces to optical fields, with many efforts approaching the standard quantum limit. We consider force-sensing using a mirror-in-the-middle setup and use two coupled cavity modes originated from normal mode splitting for separating pump and probe fields. We find that this two-mode model can be reduced to an effective single-mode model, if we drive the pump mode strongly and detect the signal from the weak probe mode. The optimal force detection sensitivity at zero frequency (DC) is calculated and we show that one can beat the standard quantum limit by driving the cavity close to instability. The best sensitivity achievable is limited by mechanical thermal noise and by optical losses. We also find that the bandwidth where optimal sensitivity is maintained is proportional to the cavity damping in the resolved sideband regime. Finally, the squeezing spectrum of the output signal is calculated, and it shows almost perfect squeezing at DC is possible by using a high qua...

  17. The evolutionary neuroscience of musical beat perception: the Action Simulation for Auditory Prediction (ASAP hypothesis.

    Directory of Open Access Journals (Sweden)

    Aniruddh D. Patel

    2014-05-01

    Full Text Available Every human culture has some form of music with a beat: a perceived periodic pulse that structures the perception of musical rhythm and which serves as a framework for synchronized movement to music. What are the neural mechanisms of musical beat perception, and how did they evolve? One view, which dates back to Darwin and implicitly informs some current models of beat perception, is that the relevant neural mechanisms are relatively general and are widespread among animal species. On the basis of recent neural and cross-species data on musical beat processing, this paper argues for a different view. Here we argue that beat perception is a complex brain function involving temporally-precise communication between auditory regions and motor planning regions of the cortex (even in the absence of overt movement. More specifically, we propose that simulation of periodic movement in motor planning regions provides a neural signal that helps the auditory system predict the timing of upcoming beats. This action simulation for auditory prediction (ASAP hypothesis leads to testable predictions. We further suggest that ASAP relies on dorsal auditory pathway connections between auditory regions and motor planning regions via the parietal cortex, and suggest that these connections may be stronger in humans than in nonhuman primates due to the evolution of vocal learning in our lineage. This suggestion motivates cross-species research to determine which species are capable of human-like beat perception, i.e., beat perception that involves accurate temporal prediction of beat times across a fairly broad range of tempi.

  18. Disentangling beat perception from sequential learning and examining the influence of attention and musical abilities on ERP responses to rhythm.

    Science.gov (United States)

    Bouwer, Fleur L; Werner, Carola M; Knetemann, Myrthe; Honing, Henkjan

    2016-05-01

    Beat perception is the ability to perceive temporal regularity in musical rhythm. When a beat is perceived, predictions about upcoming events can be generated. These predictions can influence processing of subsequent rhythmic events. However, statistical learning of the order of sounds in a sequence can also affect processing of rhythmic events and must be differentiated from beat perception. In the current study, using EEG, we examined the effects of attention and musical abilities on beat perception. To ensure we measured beat perception and not absolute perception of temporal intervals, we used alternating loud and soft tones to create a rhythm with two hierarchical metrical levels. To control for sequential learning of the order of the different sounds, we used temporally regular (isochronous) and jittered rhythmic sequences. The order of sounds was identical in both conditions, but only the regular condition allowed for the perception of a beat. Unexpected intensity decrements were introduced on the beat and offbeat. In the regular condition, both beat perception and sequential learning were expected to enhance detection of these deviants on the beat. In the jittered condition, only sequential learning was expected to affect processing of the deviants. ERP responses to deviants were larger on the beat than offbeat in both conditions. Importantly, this difference was larger in the regular condition than in the jittered condition, suggesting that beat perception influenced responses to rhythmic events in addition to sequential learning. The influence of beat perception was present both with and without attention directed at the rhythm. Moreover, beat perception as measured with ERPs correlated with musical abilities, but only when attention was directed at the stimuli. Our study shows that beat perception is possible when attention is not directed at a rhythm. In addition, our results suggest that attention may mediate the influence of musical abilities on beat

  19. Quantum beats in the field ionization of Rydberg atoms in the presence of magnetic fields

    Science.gov (United States)

    Gregoric, Vincent C.; Hastings, Hannah; Carroll, Thomas J.; Noel, Michael W.

    2016-05-01

    By exciting a coherent superposition and varying its phase evolution, quantum beats in the selective field ionization of Rydberg atoms have been observed. Here, we present a study exploring the effect of electric and magnetic fields on quantum beats. Beginning with a single excited state, a coherent superposition is created by a short electric field pulse in the presence of a static magnetic field. The resulting quantum beats are then observed in the field ionization spectrum. Additionally, millimeter-wave spectroscopy is used to probe the state populations in this superposition. This work is supported by the National Science Foundation under Grants No. 1205895 and No. 1205897.

  20. MNS1 is essential for spermiogenesis and motile ciliary functions in mice.

    Directory of Open Access Journals (Sweden)

    Jian Zhou

    Full Text Available During spermiogenesis, haploid round spermatids undergo dramatic cell differentiation and morphogenesis to give rise to mature spermatozoa for fertilization, including nuclear elongation, chromatin remodeling, acrosome formation, and development of flagella. The molecular mechanisms underlining these fundamental processes remain poorly understood. Here, we report that MNS1, a coiled-coil protein of unknown function, is essential for spermiogenesis. We find that MNS1 is expressed in the germ cells in the testes and localizes to sperm flagella in a detergent-resistant manner, indicating that it is an integral component of flagella. MNS1-deficient males are sterile, as they exhibit a sharp reduction in sperm production and the remnant sperm are immotile with abnormal short tails. In MNS1-deficient sperm flagella, the characteristic arrangement of "9+2" microtubules and outer dense fibers are completely disrupted. In addition, MNS1-deficient mice display situs inversus and hydrocephalus. MNS1-deficient tracheal motile cilia lack some outer dynein arms in the axoneme. Moreover, MNS1 monomers interact with each other and are able to form polymers in cultured somatic cells. These results demonstrate that MNS1 is essential for spermiogenesis, the assembly of sperm flagella, and motile ciliary functions.

  1. Expression of ciliary neurotrophic factor after induction of ocular hypertension in the retina of rats

    Institute of Scientific and Technical Information of China (English)

    WU Qiang; ZHANG Min; SONG Bei-wen; LU Bin; HU Ping

    2007-01-01

    Background Glaucoma is mainly characterized by the loss of retinal ganglion cells. Ciliary neurotrophic factor (CNTF) is believed to stimulate the regeneration of axons of retinal ganglion cells. The objective of our study was to detect the expression of CNTF in the retina of a rat glaucoma model with increased intraocular pressure (lOP).Methods The rat glaucoma model was set up by electrocoagulating at least three episcleral and limbal veins. The location and the expression level of CNTF were detected at 1, 3, 7, 14, and 28 days post-surgery by immunohistochemistry, semiquantitative reverse-transcription polymerase chain reaction (RT-PCR), and Western blot analysis.Results The rat glaucoma model with chronic, moderately elevated lOP was successfully produced. A minimum expression of CNTF was found in the ganglion cell layer of the retinas of the control group, and temporally increased expression and intensity of CNTF were found in the experimental retinas.Conclusion The expression of endogenous CNTF in the rat retina was found altered after the induction of ocular hypertension.

  2. Peripheral sensory processing in mammalian gravity receptors - Observations of ciliary tuft configurations

    Science.gov (United States)

    Ross, Muriel D.; Donovan, Kathleen; Rogers, Charles

    1987-01-01

    Scanning electron microscopy was used to study dynamic polarizations of clustered cells of the anterior part of rat saccular macula and to shed light on the possible roles of two types of hair cells integrated into the same neural circuitry: those with short stereocilia and long kinocilium (ss/lk), and those with long stereocilia and still longer kinocilium (ls/lk). It was found that the ss/lk-type cells could be further subdivided into two types, whereas the ls/lk cells consisted of four major kinds. It was also found that the kinocilium was most often fixed in a recovery stroke position (curved basally, and the upper portion projected back over the tuft) and that the kinocilia were not aligned in parallel in any given part of a macula, even though each cilium pointed in the proper direction relative to the striola line. The possibility of a relationship between the ciliary tuft morphology and the function of the hair cell of which it is a part is discussed.

  3. Rootletin organizes the ciliary rootlet to achieve neuron sensory function in Drosophila.

    Science.gov (United States)

    Chen, Jieyan V; Kao, Ling-Rong; Jana, Swadhin C; Sivan-Loukianova, Elena; Mendonça, Susana; Cabrera, Oscar A; Singh, Priyanka; Cabernard, Clemens; Eberl, Daniel F; Bettencourt-Dias, Monica; Megraw, Timothy L

    2015-10-26

    Cilia are essential for cell signaling and sensory perception. In many cell types, a cytoskeletal structure called the ciliary rootlet links the cilium to the cell body. Previous studies indicated that rootlets support the long-term stability of some cilia. Here we report that Drosophila melanogaster Rootletin (Root), the sole orthologue of the mammalian paralogs Rootletin and C-Nap1, assembles into rootlets of diverse lengths among sensory neuron subtypes. Root mutant neurons lack rootlets and have dramatically impaired sensory function, resulting in behavior defects associated with mechanosensation and chemosensation. Root is required for cohesion of basal bodies, but the cilium structure appears normal in Root mutant neurons. We show, however, that normal rootlet assembly requires centrioles. The N terminus of Root contains a conserved domain and is essential for Root function in vivo. Ectopically expressed Root resides at the base of mother centrioles in spermatocytes and localizes asymmetrically to mother centrosomes in neuroblasts, both requiring Bld10, a basal body protein with varied functions. PMID:26483560

  4. Circulating levels of ciliary neurotrophic factor in normal pregnancy and preeclampsia

    Directory of Open Access Journals (Sweden)

    Akahori,Yoichiro

    2010-04-01

    Full Text Available

    Ciliary neurotrophic factor (CNTF has been shown to decrease food intake in mouse models of obesity and to improve insulin sensitivity. It is well known that tight regulation of glucose metabolism is essential for successful gestational outcomes (e.g. fetal growth, and that abnormal insulin resistance is associated with preeclampsia (PE. To investigate the possibility that CNTF might be involved in the regulation of insulin resistance during pregnancy, circulating levels of CNTF were assessed in non-pregnant, normal pregnant, postpartum, and pregnant women with PE. Sera from healthy non-pregnant women (n10, pregnant women (n30:1st trimester;n10, 2nd trimester n10;3rd trimester;n10, postpartum women (n10, and patients with PE (n11 were studied with Western blotting. Circulating CNTF was detected by Western blotting, and the levels of CNTF in pregnant women were decreased as compared with those in non-pregnant women, and tended to decrease as pregnancy progressed. A significant decrease was found in PE as compared with normal pregnancy. Circulating CNTF might be associated with physiological and abnormal insulin resistance during pregnancy.

  5. Preservation and Observation of Amterior Ciliary Vessels in Rectus Muscles during Strabismus Surgery

    Institute of Scientific and Technical Information of China (English)

    GuanghuanMai; JianhuaYan

    1995-01-01

    Purpose:To observe the form and number of the anterior ciliary vessels(ACV)in rectus muscles.To train technician in preservation an d obsevation of ACV,so preservation can be done in caes with a rish of anterior segment ischemia(ASI).Methods:Curved foreign knife,iris hook,plastic rubber band and standard operat-ing loupes(3x)or microscope were used in the surgery on 34cases of comitant strabismus and 18cases of paralytic strabismus.Results:The ACVs per muscle in medial,lateral,superior,inferior rectus were3.08,3.26,3.50and3.50respectively in 89muscles of 52surgical strabismus cas-es.All ACVs in 16rectus muscles and 90out of 220ACVs in 73rectus muscles were too small ortoo short to be dissected.The sucess rate of ACV preservation was91.5%(119/130).105out of 130vessels were saved using loupe magnifica-tion and 14pit pf130vessels were saved under operating microscope.Conclusions:The number of ACVinrectus muscles are more than 2in our obser-vation cases.The ACVpreservation has the clinical value of allowing us toper-form muscle sugery on three or more rectus muscles simultaneously and get fonal surgical results more earlier after acv in each muscle are dissected and preserved otherwinse staged surgery are needed.The each strabismus surgeon must knov this technique.

  6. THE ANALYSIS OF HEART FREQUENCY OF HORSES UNDER LOAD

    Directory of Open Access Journals (Sweden)

    Eva Mlyneková

    2013-02-01

    Full Text Available In our work we analysed the heart frequency of 11 warmblood horses on the load regulator of motion. The test lasted 3 weeks with gradual increase of load. The load was applied only in a step with gradual increase of time of load in up-sloping direction. The mean values of heart frequency of tested horses were within 61 beats/min. At the evaluation of maximum value of heart frequency we detected its twofold increase in comparison with mean values. The maximum rate of heart frequency under load was at the level of 147 beats/min. Detected values were not statistically significant which confirms that the load on tested horses was not causing any physiological changes.

  7. Fast beating null strip during the reflection of pulsed Gaussian beams incident at the Rayleigh angle.

    Science.gov (United States)

    Declercq, Nico F

    2006-12-22

    It is well known that harmonic bounded Gaussian beams undergo a transformation into two bounded beams upon reflection on a solid immersed in a liquid. The effect is known as the Schoch effect and can be found at the Rayleigh angle for thick plates and at the different Lamb angles for thin plates. Here, a study is made on the effect of pulsed Gaussian beams reflected on solids. It is found experimentally that the Rayleigh wave phenomenon still generates two reflected bounded beams, whereas Lamb wave phenomena do not generate this effect. This fact may be explained intuitively by realizing that the Rayleigh phenomenon is a coincidental phenomenon that is generated in situ, whereas the Lamb wave phenomenon is a non-coincidental phenomenon that is generated only after incident sound is influenced by both sides of a thin plate. Another explanation is the fact that Rayleigh waves are not dispersive, whereas stimulation and propagation of Lamb waves is frequency dependent. A pulse contains many frequencies and therefore only a fraction of the incident pulse is transformed into a Lamb wave. In this paper, numerical simulations are performed that show that actually the Schoch effect does occur neither for Rayleigh waves, nor for Lamb waves. As a matter of fact, a pulse, incident at the Rayleigh angle, generates two reflected lobes with a null zone of a different kind. The null zone is beating several times during the passage of each pulse. This results in a 'null zone' having a lower mean intensity than any of the two lobes, still less outspoken than for the case of harmonic incident bounded beams. This effect does only occur for Rayleigh wave generation and is much less outspoken for Lamb wave generation. PMID:16815510

  8. Coordinated Beating of Algal Flagella is Mediated by Basal Coupling

    Science.gov (United States)

    Wan, Kirsty; Goldstein, Raymond

    Cilia or flagella often exhibit synchronized behavior. This includes phase-locking, as seen in Chlamydomonas, and metachronal wave formation in the respiratory cilia of higher organisms. Since the observations by Gray and Rothschild of phase synchrony of nearby swimming spermatozoa, it has been a working hypothesis that synchrony arises from hydrodynamic interactions between beating filaments. Recent work on the dynamics of physically separated pairs of flagella isolated from the multicellular alga Volvox has shown that hydrodynamic coupling alone is sufficient for synchrony. However, the situation is more complex when considering multiple flagella on a single cell. We suggest that a mechanism, internal to the cell, provides an additional flagellar coupling. For instance, flagella of Chlamydomonas mutants deficient in filamentary connections between basal bodies are found to display markedly different synchronization from the wildtype. Diverse flagellar coordination strategies found in quadri-, octo- and hexadecaflagellates reveal further evidence that intracellular couplings between flagellar basal bodies compete with hydrodynamic interactions to determine the precise form of flagellar synchronization in unicellular algae.

  9. Non-heart-beating organ donation in Italy.

    Science.gov (United States)

    Geraci, P M; Sepe, V

    2011-06-01

    In 2007 the non-heart-beating organ donation (NHBD) "Programma Alba" (Sunrise Programme) started in Pavia, Italy. The initial plan was to cut down waiting list for kidney transplantation, while its final aim is to shorten organ transplantation waiting lists. When compared to European countries and the USA, the Italian NHBD program has taken longer to get established. Initially Italian physicians were not entirely aware of the NHBD organ viability for transplantation, furthermore ethical issues and the need to regulate medical requirements to Italian law slowed down the NHBD program. In particular, Italian legislation provides for death ascertainment after irreversible cardiac arrest, 20-minute flat electrocardiogram. This no-touch period is longer when compared to worldwide legislation, and organ viability has been a main concern for Italian transplant doctors over the years. However, recent data let up to 40-minute warm ischemia time to preserve organ viability; this has encouraged Pavia's group to establish the NHBD "Programma Alba". It was designed according to Italian legislation from death diagnosis to graft placement, from this perspective must the significant role of the Transplant coordinator be recognized. Since 2007 seven kidneys have been gathered from seven NHBD. Of these, six NHBD kidneys have been transplanted. Currently, four patients are out of dialysis. This report is a detailed description of NHBD "Programma Alba" and its preliminary results. PMID:21617625

  10. Taming microwave plasma to beat thermodynamics in CO2 dissociation.

    Science.gov (United States)

    van Rooij, G J; van den Bekerom, D C M; den Harder, N; Minea, T; Berden, G; Bongers, W A; Engeln, R; Graswinckel, M F; Zoethout, E; van de Sanden, M C M

    2015-01-01

    The strong non-equilibrium conditions provided by the plasma phase offer the opportunity to beat traditional thermal process energy efficiencies via preferential excitation of molecular vibrations. Simple molecular physics considerations are presented to explain potential dissociation pathways in plasma and their effect on energy efficiency. A common microwave reactor approach is evaluated experimentally with Rayleigh scattering and Fourier transform infrared spectroscopy to assess gas temperatures (exceeding 10(4) K) and conversion degrees (up to 30%), respectively. The results are interpreted on a basis of estimates of the plasma dynamics obtained with electron energy distribution functions calculated with a Boltzmann solver. It indicates that the intrinsic electron energies are higher than is favorable for preferential vibrational excitation due to dissociative excitation, which causes thermodynamic equilibrium chemistry to dominate. The highest observed energy efficiencies of 45% indicate that non-equilibrium dynamics had been at play. A novel approach involving additives of low ionization potential to tailor the electron energies to the vibrational excitation regime is proposed.

  11. Microwave radiation and heart-beat rate of rabbits.

    Science.gov (United States)

    Chou, C K; Han, L F; Guy, A W

    1980-06-01

    Each of three adult New Zealand rabbits, 2 male and 1 female albinos, was exposed dorsally or ventrally, to 2450-MHz plane waves for 20 min under each of several field conditions: 1) to continuous waves (CW) at 5 mW/cm2; 2) to pulsed waves (PW) of 1-microsecond width that recurred 700 pps at an average of 5 mW/cm2 and at a peak of 7.1 W/cm2; 3) to PW of 10-microseconds width at a peak of 13.7 W/cm2 that were synchronized with and triggered by the R wave of the electrocardiogram (EKG) at various delay times (0, 100, and 200 ms; and 4) to CW at 80 mW/cm2. Carbon-loaded Teflon electrodes were used to record the EKG from forelimbs of an animal before, during, and after irradiation whilst it was maintained in a constant exposure geometry in a wooden squeeze box. Field induced changes in the heart-beat rate were observed at 80 mW/cm2 but not a lower average power densities, although a peak positive chronotropic effect might have been occasioned by PM introduced at 100 and 200 ms after the R wave peak. No cumulative effect was observed over a period of four months. Thermographic analysis revealed relatively little absorption of microwave energy by the myocardium irrespective of anatomical aspect of exposure.

  12. Exploring how musical rhythm entrains brain activity with electroencephalogram frequency-tagging

    Science.gov (United States)

    Nozaradan, Sylvie

    2014-01-01

    The ability to perceive a regular beat in music and synchronize to this beat is a widespread human skill. Fundamental to musical behaviour, beat and meter refer to the perception of periodicities while listening to musical rhythms and often involve spontaneous entrainment to move on these periodicities. Here, we present a novel experimental approach inspired by the frequency-tagging approach to understand the perception and production of rhythmic inputs. This approach is illustrated here by recording the human electroencephalogram responses at beat and meter frequencies elicited in various contexts: mental imagery of meter, spontaneous induction of a beat from rhythmic patterns, multisensory integration and sensorimotor synchronization. Collectively, our observations support the view that entrainment and resonance phenomena subtend the processing of musical rhythms in the human brain. More generally, they highlight the potential of this approach to help us understand the link between the phenomenology of musical beat and meter and the bias towards periodicities arising under certain circumstances in the nervous system. Entrainment to music provides a highly valuable framework to explore general entrainment mechanisms as embodied in the human brain. PMID:25385771

  13. Observation of Quantum Beat in Rb by Parametric Four-Wave Mixing

    Institute of Scientific and Technical Information of China (English)

    ZHU Chang-Jun; HE Jun-Fang; XUE Bing; ZHAI Xue-Jun

    2007-01-01

    @@ Two coupled parametric four-wave-mixing processes in Rb atoms are studied using perturbation theory, which reveals clear evidence of the appearance of quantum beat at 608cm-1, corresponding to the energy difference of the 7s - 5d states of Rb atoms, in the parametric four-wave-mixing signals. A pump-probe technique is utilized to observe the quantum beat. Time-varying characteristics of the quantum beat are investigated using time-dependent Fourier transform. The results show that the time-varying characteristics of the quantum beat not only offers a sensitive detecting method for observing the decay of atomic wave packets, but also provides a potential tool for monitoring the dissociation of molecules.

  14. Beat synchronization predicts neural speech encoding and reading readiness in preschoolers.

    Science.gov (United States)

    Woodruff Carr, Kali; White-Schwoch, Travis; Tierney, Adam T; Strait, Dana L; Kraus, Nina

    2014-10-01

    Temporal cues are important for discerning word boundaries and syllable segments in speech; their perception facilitates language acquisition and development. Beat synchronization and neural encoding of speech reflect precision in processing temporal cues and have been linked to reading skills. In poor readers, diminished neural precision may contribute to rhythmic and phonological deficits. Here we establish links between beat synchronization and speech processing in children who have not yet begun to read: preschoolers who can entrain to an external beat have more faithful neural encoding of temporal modulations in speech and score higher on tests of early language skills. In summary, we propose precise neural encoding of temporal modulations as a key mechanism underlying reading acquisition. Because beat synchronization abilities emerge at an early age, these findings may inform strategies for early detection of and intervention for language-based learning disabilities. PMID:25246562

  15. The ability to tap to a beat relates to cognitive, linguistic, and perceptual skills.

    Science.gov (United States)

    Tierney, Adam T; Kraus, Nina

    2013-03-01

    Reading-impaired children have difficulty tapping to a beat. Here we tested whether this relationship between reading ability and synchronized tapping holds in typically-developing adolescents. We also hypothesized that tapping relates to two other abilities. First, since auditory-motor synchronization requires monitoring of the relationship between motor output and auditory input, we predicted that subjects better able to tap to the beat would perform better on attention tests. Second, since auditory-motor synchronization requires fine temporal precision within the auditory system for the extraction of a sound's onset time, we predicted that subjects better able to tap to the beat would be less affected by backward masking, a measure of temporal precision within the auditory system. As predicted, tapping performance related to reading, attention, and backward masking. These results motivate future research investigating whether beat synchronization training can improve not only reading ability, but potentially executive function and auditory processing as well.

  16. Coherence analysis of optical frequency-modulated continuous-wave interference.

    Science.gov (United States)

    Zheng, Jesse

    2006-06-01

    I analyze the coherence of optical frequency-modulated continuous-wave (FMCW) interference. With a simple model modified from the classical coherence theory, I successfully derive the relationships among the frequency bandwidth, coherence length, and coherence time of the practical optical source, and the contrast of the beat signal in optical FMCW interference. PMID:16724123

  17. Look at the Beat, Feel the Meter:Top-down Effects of Meter Induction on Auditory and Visual Modalities

    Directory of Open Access Journals (Sweden)

    Alexandre eCelma-Miralles

    2016-03-01

    Full Text Available Recent research has demonstrated top-down effects on meter induction in the auditory modality. However, little is known about these effects in the visual domain, especially without the involvement of motor acts such as tapping. In the present study, we aim to assess whether the projection of meter on auditory beats is also present in the visual domain. We asked sixteen musicians to internally project binary (i.e. a strong-weak pattern and ternary (i.e. a strong-weak-weak pattern meter onto separate, but analogue, visual and auditory isochronous stimuli. Participants were presented with sequences of tones or blinking circular shapes (i.e. flashes at 2.4 Hz while their electrophysiological responses were recorded. A frequency analysis of the elicited steady-state evoked potentials allowed us to compare the frequencies of the beat (2.4 Hz, its first harmonic (4.8 Hz, the binary subharmonic (1.2 Hz, and ternary subharmonic (0.8 Hz within and across modalities. Taking the amplitude spectra into account, we observed an enhancement of the amplitude at 0.8 Hz in the ternary condition for both modalities, suggesting meter induction across modalities. There was an interaction between modality and voltage at 2.4 and 4.8 Hz. Looking at the power spectra, we also observed significant differences from zero in the auditory, but not in the visual, binary condition at 1.2 Hz. These findings suggest that meter processing is modulated by top-down mechanisms that interact with our perception of rhythmic events and that such modulation can also be found in the visual domain. The reported cross-modal effects of meter may shed light on the origins of our timing mechanisms, partially developed in primates and allowing humans to synchronize across modalities accurately.

  18. The Effect of Dopaminergic Medication on Beat-Based Auditory Timing in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Daniel J Cameron

    2016-02-01

    Full Text Available Parkinson’s disease (PD adversely affects timing abilities. Beat-based timing is a mechanism that times events relative to a regular interval, such as the ‘beat’ in musical rhythm, and is impaired in PD. It is unknown if dopaminergic medication influences beat-based timing in PD. Here we tested beat-based timing over two sessions in participants with PD (OFF then ON dopaminergic medication, and unmedicated control participants. People with PD and control participants completed two tasks. The first was a discrimination task in which participants compared two rhythms and determined whether they were the same or different. Rhythms either had a beat structure (metric simple rhythms, or did not (metric complex rhythms, as in previous studies. Discrimination accuracy was analyzed to test for the effects of beat structure, as well as differences between participants with PD and controls, and effects of medication (PD group only. The second task was the Beat Alignment Test (BAT, in which participants listened to music with regular tones superimposed, and responded as to whether the tones were ‘on’ or ‘off’ the beat of the music. Accuracy was analyzed to test for differences between participants with PD and controls, and for an effect of medication in patients.Both patients and controls discriminated metric simple rhythms better than metric complex rhythms. Controls also improved at the discrimination task in the second vs. first session, whereas people with PD did not. For participants with PD, the difference in performance between metric simple and metric complex rhythms was greater (sensitivity to changes in simple rhythms increased and sensitivity to changes in complex rhythms decreased when ON vs. OFF medication. Performance also worsened with disease severity. For the Beat Alignment Test, no group differences or effects of medication were found. Overall, these findings suggest that timing is impaired in PD, and that dopaminergic

  19. The Effect of Dopaminergic Medication on Beat-Based Auditory Timing in Parkinson's Disease.

    Science.gov (United States)

    Cameron, Daniel J; Pickett, Kristen A; Earhart, Gammon M; Grahn, Jessica A

    2016-01-01

    Parkinson's disease (PD) adversely affects timing abilities. Beat-based timing is a mechanism that times events relative to a regular interval, such as the "beat" in musical rhythm, and is impaired in PD. It is unknown if dopaminergic medication influences beat-based timing in PD. Here, we tested beat-based timing over two sessions in participants with PD (OFF then ON dopaminergic medication) and in unmedicated control participants. People with PD and control participants completed two tasks. The first was a discrimination task in which participants compared two rhythms and determined whether they were the same or different. Rhythms either had a beat structure (metric simple rhythms) or did not (metric complex rhythms), as in previous studies. Discrimination accuracy was analyzed to test for the effects of beat structure, as well as differences between participants with PD and controls, and effects of medication (PD group only). The second task was the Beat Alignment Test (BAT), in which participants listened to music with regular tones superimposed, and responded as to whether the tones were "ON" or "OFF" the beat of the music. Accuracy was analyzed to test for differences between participants with PD and controls, and for an effect of medication in patients. Both patients and controls discriminated metric simple rhythms better than metric complex rhythms. Controls also improved at the discrimination task in the second vs. first session, whereas people with PD did not. For participants with PD, the difference in performance between metric simple and metric complex rhythms was greater (sensitivity to changes in simple rhythms increased and sensitivity to changes in complex rhythms decreased) when ON vs. OFF medication. Performance also worsened with disease severity. For the BAT, no group differences or effects of medication were found. Overall, these findings suggest that timing is impaired in PD, and that dopaminergic medication influences beat-based and non-beat

  20. Stochastic Alternating Dynamics for Synchronous EAD-Like Beating Rhythms in Cultured Cardiac Myocytes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ning; ZHANG Hui-Min; LIU Zhi-Qiang; DING Xue-Li; YANG Ming-Hao; GU Hua-Guang; REN Wei

    2009-01-01

    Dissolved cardiac myocytes can couple together and generate synchronous beatings in culture. We observed a synchronized early after-depolarization(EAD)-like rhythm in cultured cardiac myocytes and reproduced the experimental observation in a network mathematical model whose dynamics are close to a Hopf bifurcation. The mechanism for this EAD-like rhythm is attributed to noised-induced stochastic alternatings between the focus and the limit cycle. These results provide novel understandings for pathological heart rhythms like the early immature beatings.

  1. Individual Differences in Beat Perception Affect Gait Responses to Low- and High-Groove Music

    OpenAIRE

    Leow, Li-Ann; Parrott, Taylor; Grahn, Jessica A.

    2014-01-01

    Slowed gait in patients with Parkinson’s disease (PD) can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the “beat,” which might be difficult for patients with PD who tend to show weak beat pe...

  2. Finding the beat: a neural perspective across humans and non-human primates.

    Science.gov (United States)

    Merchant, Hugo; Grahn, Jessica; Trainor, Laurel; Rohrmeier, Martin; Fitch, W Tecumseh

    2015-03-19

    Humans possess an ability to perceive and synchronize movements to the beat in music ('beat perception and synchronization'), and recent neuroscientific data have offered new insights into this beat-finding capacity at multiple neural levels. Here, we review and compare behavioural and neural data on temporal and sequential processing during beat perception and entrainment tasks in macaques (including direct neural recording and local field potential (LFP)) and humans (including fMRI, EEG and MEG). These abilities rest upon a distributed set of circuits that include the motor cortico-basal-ganglia-thalamo-cortical (mCBGT) circuit, where the supplementary motor cortex (SMA) and the putamen are critical cortical and subcortical nodes, respectively. In addition, a cortical loop between motor and auditory areas, connected through delta and beta oscillatory activity, is deeply involved in these behaviours, with motor regions providing the predictive timing needed for the perception of, and entrainment to, musical rhythms. The neural discharge rate and the LFP oscillatory activity in the gamma- and beta-bands in the putamen and SMA of monkeys are tuned to the duration of intervals produced during a beat synchronization-continuation task (SCT). Hence, the tempo during beat synchronization is represented by different interval-tuned cells that are activated depending on the produced interval. In addition, cells in these areas are tuned to the serial-order elements of the SCT. Thus, the underpinnings of beat synchronization are intrinsically linked to the dynamics of cell populations tuned for duration and serial order throughout the mCBGT. We suggest that a cross-species comparison of behaviours and the neural circuits supporting them sets the stage for a new generation of neurally grounded computational models for beat perception and synchronization. PMID:25646516

  3. Individual differences in beat perception affect gait responses to low- and high-groove music.

    OpenAIRE

    Li-Ann eLeow; Taylor eParrott; Grahn, Jessica A.

    2014-01-01

    Slowed gait in Parkinson’s disease (PD) patients can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the beat, which might be difficult for PD patients who tend to show weak beat perception. On...

  4. Quasi-phase-matching of high-order-harmonic generation using multimode polarization beating

    OpenAIRE

    Liu, Lewis Z.; O'Keeffe, Kevin; Hooker, Simon M.

    2013-01-01

    The generalization of quasi-phase-matching using polarization beating and of multimode quasi-phase-matching (MMQPM) for the generation of high-order harmonics is explored, and a method for achieving polarization beating is proposed. If two (and in principle more) modes of a waveguide are excited, modulation of the intensity, phase, and/or polarization of the guided radiation will be achieved. By appropriately matching the period of this modulation to the coherence length, quasi-phase-matching...

  5. ECG Morphological Variability in Beat Space for Risk Stratification After Acute Coronary Syndrome

    OpenAIRE

    Liu, Yun; Syed, Zeeshan; Scirica, Benjamin M.; Morrow, David A; Guttag, John V.; Stultz, Collin M.

    2014-01-01

    Background: Identification of patients who are at high risk of adverse cardiovascular events after an acute coronary syndrome (ACS) remains a major challenge in clinical cardiology. We hypothesized that quantifying variability in electrocardiogram (ECG) morphology may improve risk stratification post‐ACS. Methods and Results: We developed a new metric to quantify beat‐to‐beat morphologic changes in the ECG: morphologic variability in beat space (MVB), and compared our metric to published ECG ...

  6. Spin-Dependent Beats Created by Irradiation of Microwave Field Through a Quantum Dot

    Science.gov (United States)

    Tagani, M. Bagheri; Soleimani, H. Rahimpour

    We study spin-dependent transport through a quantum dot with Zeeman split levels coupled to ferromagnetic leads and under influence of microwave irradiation. Current polarization, spin current, spin accumulation and tunneling magnetoresistance are analyzed using nonequilibrium Green's function formalism and rate equations. Spin-dependent beats in spin resolved currents are observed. The effects of magnetic field, temperature and Coulomb interaction on these beats are studied.

  7. Detection and removal of ventricular ectopic beats in atrial fibrillation recordings via principal component analysis.

    Science.gov (United States)

    Martínez, Arturo; Alcaraz, Raúl; Rieta, José J

    2011-01-01

    Ectopic beats are early heart beats with remarkable large amplitude that provoke serious disturbances in the analysis of electrocardiograms (ECG). These beats are very common in atrial fibrillation (AF) and are the source of important residua when the QRST is intended to be removed. Given that QRST cancellation is a binding step in the appropriate analysis of atrial activity (AA) in AF, a method for ventricular ectopic beats cancellation is proposed as a previous step to the application of any QRST removal technique. First, the method discriminates between normal and ectopic beats with an accuracy higher than 99% through QRS morphological characterization. Next, the most similar ectopic beats to the one under cancellation are clustered and serve to get their eigenvector matrix by principal component analysis. Finally, the highest variance eigenvector is used as cancellation template. The reduction ectopic rate (RER) has been defined to evaluate the method's performance by using templates generated with 5, 10, 20, 40 or 80 ectopics. Optimal results were reached with the 5 most similar complexes, yielding a RER higher than 5.5. In addition, a decreasing RER trend was noticed as the number of considered ectopics for cancellation increased. As conclusion, given that ectopics presented a remarkable variability in their morphology, the proposed cancellation approach is a robust ectopic remover and can notably facilitate the later application of any QRST cancellation technique to extract the AA in the best conditions. PMID:22255385

  8. Gene expression and functional annotation of the human ciliary body epithelia.

    Directory of Open Access Journals (Sweden)

    Sarah F Janssen

    Full Text Available PURPOSE: The ciliary body (CB of the human eye consists of the non-pigmented (NPE and pigmented (PE neuro-epithelia. We investigated the gene expression of NPE and PE, to shed light on the molecular mechanisms underlying the most important functions of the CB. We also developed molecular signatures for the NPE and PE and studied possible new clues for glaucoma. METHODS: We isolated NPE and PE cells from seven healthy human donor eyes using laser dissection microscopy. Next, we performed RNA isolation, amplification, labeling and hybridization against 44×k Agilent microarrays. For microarray conformations, we used a literature study, RT-PCRs, and immunohistochemical stainings. We analyzed the gene expression data with R and with the knowledge database Ingenuity. RESULTS: The gene expression profiles and functional annotations of the NPE and PE were highly similar. We found that the most important functionalities of the NPE and PE were related to developmental processes, neural nature of the tissue, endocrine and metabolic signaling, and immunological functions. In total 1576 genes differed statistically significantly between NPE and PE. From these genes, at least 3 were cell-specific for the NPE and 143 for the PE. Finally, we observed high expression in the (NPE of 35 genes previously implicated in molecular mechanisms related to glaucoma. CONCLUSION: Our gene expression analysis suggested that the NPE and PE of the CB were quite similar. Nonetheless, cell-type specific differences were found. The molecular machineries of the human NPE and PE are involved in a range of neuro-endocrinological, developmental and immunological functions, and perhaps glaucoma.

  9. Frequent ventricular premature beats increase blood pressure variability in rats

    Institute of Scientific and Technical Information of China (English)

    Chao-yu MIAO; Li-ping XU; Jian-guo LIU; He-hui XIE; Wen-jun YUAN; Ding-feng SU

    2004-01-01

    AIM: The present study was designed to test a hypothesis that nonfatal ventricular arrhythmia such as ventricular premature beats (VPB) is a contributing factor in the elevation of blood pressure variability (BPV). METHODS:Blood pressure (BP) and electrocardiogram were continuously recorded. The relation between VPB and BPV was observed under conscious state in chronic myocardial infarction (MI) rats one month after ligation of the left.coronary artery, and further verified under anesthetized state in rat model of ventricular arrhythmia produced by acute intravenous infusion of aconitine. RESULTS: MI rats exhibited a big difference in the count and pattern of VPB, and were divided into no VPB, occasional VPB, and frequent VPB groups. Among the three groups, there were no differences in BP, heart period (HP), and MI size. However, BPV was markedly higher in frequent not occasional VPB rats, and HP variability (HPV) was larger in both frequent and occasional VPB rats, when compared with no VPB rats. In the whole population of MI rats, BPV was positively correlated with VPB and HPV, not with BP, HP and MI size. Infusion of aconitine had no effect on BP, HP, BPV, and HPV during the period without VPB.Frequent VPB after several minutes of aconitine infusion induced significant increase in BPV and HPV with no change in BP and HP. BPV was also positively correlated with VPB and HPV, not with BP and HP. Hemodynamics in aconitine-evoked ventricular tachycardia was characterized as lower BP, higher BPV, and higher HPV.CONCLUSION: High BPV can be caused by frequent not occasional VPB in rats.

  10. 铷原子中参量六波混频和量子拍的研究%Parametric Six-Wave Mixing and Quantum Beatings in Rb

    Institute of Scientific and Technical Information of China (English)

    朱长军; 薛兵; 翟学军; 贺俊芳

    2009-01-01

    在铷原子中实现了轴向相位匹配的参量六波混频,并探测到位于红外光谱区的六波混频信号.六波混频信号与泵浦激光进行和频,产生了位于可见光范围内的可调谐的和频信号,并从和频信号中观察到频率为608 cm-1的量子拍.结果表明,六波混频信号中的量子拍能够用于研究原子和分子的相干特性.%Axially phase-matched parametric six-wave mixing was achieved in Rb and the parametric six-wave mixing signals in the infrared range were detected. Tunable signals in the visible range were produced by sum-frequency mixing of the pump laser and the parametric six-wave mixing signals in the infrared range. And, quantum beating at a frequency of 608 cm-1 was observed from the sum-frequency signal, indicating that the coherent properties of atoms and molecules can be studied by means of quantum beating recovered from parametric six-wave mixing signals.

  11. Mutations in DNAJB13, Encoding an HSP40 Family Member, Cause Primary Ciliary Dyskinesia and Male Infertility.

    Science.gov (United States)

    El Khouri, Elma; Thomas, Lucie; Jeanson, Ludovic; Bequignon, Emilie; Vallette, Benoit; Duquesnoy, Philippe; Montantin, Guy; Copin, Bruno; Dastot-Le Moal, Florence; Blanchon, Sylvain; Papon, Jean François; Lorès, Patrick; Yuan, Li; Collot, Nathalie; Tissier, Sylvie; Faucon, Catherine; Gacon, Gérard; Patrat, Catherine; Wolf, Jean Philippe; Dulioust, Emmanuel; Crestani, Bruno; Escudier, Estelle; Coste, André; Legendre, Marie; Touré, Aminata; Amselem, Serge

    2016-08-01

    Primary ciliary dyskinesia (PCD) is an autosomal-recessive disease due to functional or ultra-structural defects of motile cilia. Affected individuals display recurrent respiratory-tract infections; most males are infertile as a result of sperm flagellar dysfunction. The great majority of the PCD-associated genes identified so far encode either components of dynein arms (DAs), which are multiprotein-ATPase complexes essential for ciliary motility, or proteins involved in DA assembly. To identify the molecular basis of a PCD phenotype characterized by central complex (CC) defects but normal DA structure, a phenotype found in ∼15% of cases, we performed whole-exome sequencing in a male individual with PCD and unexplained CC defects. This analysis, combined with whole-genome SNP genotyping, identified a homozygous mutation in DNAJB13 (c.833T>G), a gene encoding a HSP40 co-chaperone whose ortholog in the flagellated alga Chlamydomonas localizes to the radial spokes. In vitro studies showed that this missense substitution (p.Met278Arg), which involves a highly conserved residue of several HSP40 family members, leads to protein instability and triggers proteasomal degradation, a result confirmed by the absence of endogenous DNAJB13 in cilia and sperm from this individual. Subsequent DNAJB13 analyses identified another homozygous mutation in a second family; the study of DNAJB13 transcripts obtained from airway cells showed that this mutation (c.68+1G>C) results in a splicing defect consistent with a loss-of-function mutation. Overall, this study, which establishes mutations in DNAJB13 as a cause of PCD, unveils the key role played by DNAJB13 in the proper formation and function of ciliary and flagellar axonemes in humans. PMID:27486783

  12. The ciliary proteins Meckelin and Jouberin are required for retinoic acid-dependent neural differentiation of mouse embryonic stem cells.

    Science.gov (United States)

    Romani, Sveva; Illi, Barbara; De Mori, Roberta; Savino, Mauro; Gleeson, Joseph G; Valente, Enza Maria

    2014-01-01

    The dysfunction of the primary cilium, a complex, evolutionarily conserved, organelle playing an important role in sensing and transducing cell signals, is the unifying pathogenetic mechanism of a growing number of diseases collectively termed "ciliopathies", typically characterized by multiorgan involvement. Developmental defects of the central nervous system (CNS) characterize a subset of ciliopathies showing clinical and genetic overlap, such as Joubert syndrome (JS) and Meckel syndrome (MS). Although several knock-out mice lacking a variety of ciliary proteins have shown the importance of primary cilia in the development of the brain and CNS-derived structures, developmental in vitro studies, extremely useful to unravel the role of primary cilia along the course of neural differentiation, are still missing. Mouse embryonic stem cells (mESCs) have been recently proven to mimic brain development, giving the unique opportunity to dissect the CNS differentiation process along its sequential steps. In the present study we show that mESCs express the ciliary proteins Meckelin and Jouberin in a developmentally-regulated manner, and that these proteins co-localize with acetylated tubulin labeled cilia located at the outer embryonic layer. Further, mESCs differentiating along the neuronal lineage activate the cilia-dependent sonic hedgehog signaling machinery, which is impaired in Meckelin knock-out cells but results unaffected in Jouberin-deficient mESCs. However, both lose the ability to acquire a neuronal phenotype. Altogether, these results demonstrate a pivotal role of Meckelin and Jouberin during embryonic neural specification and indicate mESCs as a suitable tool to investigate the developmental impact of ciliary proteins dysfunction.

  13. Evaluation of the safety of high-frequency chest wall oscillation (HFCWO) therapy in blunt thoracic trauma patients

    OpenAIRE

    Becker Brian; Ney Arthur L; Palmer Cassandra A; Anderson Casandra A; Schaffel Steven D; Quickel Robert R

    2008-01-01

    Abstract Background Airway clearance is frequently needed by patients suffering from blunt chest wall trauma. High Frequency Chest Wall Oscillation (HFCWO) has been shown to be effective in helping to clear secretions from the lungs of patients with cystic fibrosis, bronchiectasis, asthma, primary ciliary dyskinesia, emphysema, COPD, and many others. Chest wall trauma patients are at increased risk for development of pulmonary complications related to airway clearance. These patients frequent...

  14. Psychophysical tuning curves for frequences below 100 Hz

    DEFF Research Database (Denmark)

    Orellana, Carlos Andrés Jurado; Pedersen, Christian Sejer; Moore, Brian C.J.

    2011-01-01

    Psychophysical tuning curves (PTCs) were measured for sinusoidal signals with frequency /f_s / = 31.5, 40, 50, 63, and 80 Hz, using sinusoidal and narrowband-noise maskers. For the former, conditions were included where a pair of beating tones were added to reduce the use of cues related to beats...... the frequency at the tips for /f_s / between 31.5 and 50 Hz; however, the tips did not fall below 40 to 50 Hz. The bandwidths of the PTCs increased with decreasing /f_s / below 80 Hz. However, bandwidths remained roughly constant if the METF was included as part of auditory filtering for frequencies below 40 Hz........ Estimates of each subject's middle-ear transfer function (METF) were obtained from equal-loudness contours measured from 20 to 160 Hz. With decreasing /f_s /, the PTCs progressively broadened and became markedly asymmetrical, with shallow upper skirts and steep lower skirts. For the sinusoidal maskers...

  15. A case report of primary ciliary dyskinesia, laterality defects and developmental delay caused by the co-existence of a single gene and chromosome disorder.

    LENUS (Irish Health Repository)

    Casey, Jillian P

    2015-01-01

    Primary ciliary dyskinesia (PCD) is a rare autosomal recessive disorder characterised by abnormal ciliary motion and impaired mucociliary clearance, leading to recurrent respiratory infections, sinusitis, otitis media and male infertility. Some patients also have laterality defects. We recently reported the identification of three disease-causing PCD genes in the Irish Traveller population; RSPH4A, DYX1C1 and CCNO. We have since assessed an additional Irish Traveller family with a complex phenotype involving PCD who did not have any of the previously identified PCD mutations.

  16. Extracting fetal heart beats from maternal abdominal recordings: selection of the optimal principal components

    International Nuclear Information System (INIS)

    This study presents a systematic comparison of different approaches to the automated selection of the principal components (PC) which optimise the detection of maternal and fetal heart beats from non-invasive maternal abdominal recordings. A public database of 75 4-channel non-invasive maternal abdominal recordings was used for training the algorithm. Four methods were developed and assessed to determine the optimal PC: (1) power spectral distribution, (2) root mean square, (3) sample entropy, and (4) QRS template. The sensitivity of the performance of the algorithm to large-amplitude noise removal (by wavelet de-noising) and maternal beat cancellation methods were also assessed. The accuracy of maternal and fetal beat detection was assessed against reference annotations and quantified using the detection accuracy score F1 [2*PPV*Se / (PPV + Se)], sensitivity (Se), and positive predictive value (PPV). The best performing implementation was assessed on a test dataset of 100 recordings and the agreement between the computed and the reference fetal heart rate (fHR) and fetal RR (fRR) time series quantified. The best performance for detecting maternal beats (F1 99.3%, Se 99.0%, PPV 99.7%) was obtained when using the QRS template method to select the optimal maternal PC and applying wavelet de-noising. The best performance for detecting fetal beats (F1 89.8%, Se 89.3%, PPV 90.5%) was obtained when the optimal fetal PC was selected using the sample entropy method and utilising a fixed-length time window for the cancellation of the maternal beats. The performance on the test dataset was 142.7 beats2/min2 for fHR and 19.9 ms for fRR, ranking respectively 14 and 17 (out of 29) when compared to the other algorithms presented at the Physionet Challenge 2013. (paper)

  17. Multispectral Kerr frequency comb initiated by Faraday ripples

    CERN Document Server

    Huang, Shu-Wei

    2016-01-01

    In a uniform microresonator, the generation of a broadband Kerr frequency comb is triggered by Turing patterns. Here, we study a distinctly different route to initiate the Kerr frequency comb by Faraday ripples. Momentum conservation is ensured by azimuthal modulation of the cavity dispersion. With a good agreement with the theoretical analysis, we demonstrate a multispectral Kerr frequency comb covering telecommunication O, C, L, and 2 {\\mu}m bands. Comb coherence and absence of a subcomb offset are confirmed by cw heterodyne beat note and amplitude noise spectra measurements. The device can be used for achieving broadband optical frequency synthesizer and high-capacity coherent telecommunication.

  18. Soliton radiation beat analysis of optical pulses generated from two continuous-wave lasers

    International Nuclear Information System (INIS)

    We propose a fibre-based approach for generation of optical frequency combs (OFCs) with the aim of calibration of astronomical spectrographs in the low and medium-resolution range. This approach includes two steps: in the first step, an appropriate state of optical pulses is generated and subsequently moulded in the second step delivering the desired OFC. More precisely, the first step is realised by injection of two continuous-wave (CW) lasers into a conventional single-mode fibre, whereas the second step generates a broad OFC by using the optical solitons generated in step one as initial condition. We investigate the conversion of a bichromatic input wave produced by two initial CW lasers into a train of optical solitons, which happens in the fibre used as step one. Especially, we are interested in the soliton content of the pulses created in this fibre. For that, we study different initial conditions (a single cosine-hump, an Akhmediev breather, and a deeply modulated bichromatic wave) by means of soliton radiation beat analysis and compare the results to draw conclusion about the soliton content of the state generated in the first step. In case of a deeply modulated bichromatic wave, we observed the formation of a collective soliton crystal for low input powers and the appearance of separated solitons for high input powers. An intermediate state showing the features of both, the soliton crystal and the separated solitons, turned out to be most suitable for the generation of OFC for the purpose of calibration of astronomical spectrographs

  19. Energy harvesting from the tail beating of a carangiform swimmer using ionic polymer-metal composites.

    Science.gov (United States)

    Cha, Youngsu; Verotti, Matteo; Walcott, Horace; Peterson, Sean D; Porfiri, Maurizio

    2013-09-01

    In this paper, we study energy harvesting from the beating of a biomimetic fish tail using ionic polymer-metal composites. The design of the biomimetic tail is based on carangiform swimmers and is specifically inspired by the morphology of the heterocercal tail of thresher sharks. The tail is constituted of a soft silicone matrix molded in the form of the heterocercal tail and reinforced by a steel beam of rectangular cross section. We propose a modeling framework for the underwater vibration of the biomimetic tail, wherein the tail is assimilated to a cantilever beam with rectangular cross section and heterogeneous physical properties. We focus on base excitation in the form of a superimposed rotation about a fixed axis and we consider the regime of moderately large-amplitude vibrations. In this context, the effect of the encompassing fluid is described through a hydrodynamic function, which accounts for inertial, viscous and convective phenomena. The model is validated through experiments in which the base excitation is systematically varied and the motion of selected points on the biomimetic tail tracked in time. The feasibility of harvesting energy from an ionic polymer-metal composite attached to the vibrating structure is experimentally and theoretically assessed. The response of the transducer is described using a black-box model, where the voltage output is controlled by the rate of change of the mean curvature. Experiments are performed to elucidate the impact of the shunting resistance, the frequency of the base excitation and the placement of the ionic polymer-metal composite on energy harvesting from the considered biomimetic tail. PMID:23793023

  20. Soliton radiation beat analysis of optical pulses generated from two continuous-wave lasers

    Energy Technology Data Exchange (ETDEWEB)

    Zajnulina, M.; Giannone, D.; Haynes, R.; Roth, M. M. [innoFSPEC-VKS, Leibniz Institute for Astrophysics, An der Sternwarte 16, 14482 Potsdam (Germany); Böhm, M. [innoFSPEC-InFaSe, University of Potsdam, Am Mühlenberg 3, 14476 Golm (Germany); Blow, K. [Aston Institute of Photonic Technologies, Aston Triangle, Birmingham B4 7ET (United Kingdom); Rieznik, A. A. [Instituto Tecnologico de Buenos Aires and CONICET, Buenos Aires (Argentina)

    2015-10-15

    We propose a fibre-based approach for generation of optical frequency combs (OFCs) with the aim of calibration of astronomical spectrographs in the low and medium-resolution range. This approach includes two steps: in the first step, an appropriate state of optical pulses is generated and subsequently moulded in the second step delivering the desired OFC. More precisely, the first step is realised by injection of two continuous-wave (CW) lasers into a conventional single-mode fibre, whereas the second step generates a broad OFC by using the optical solitons generated in step one as initial condition. We investigate the conversion of a bichromatic input wave produced by two initial CW lasers into a train of optical solitons, which happens in the fibre used as step one. Especially, we are interested in the soliton content of the pulses created in this fibre. For that, we study different initial conditions (a single cosine-hump, an Akhmediev breather, and a deeply modulated bichromatic wave) by means of soliton radiation beat analysis and compare the results to draw conclusion about the soliton content of the state generated in the first step. In case of a deeply modulated bichromatic wave, we observed the formation of a collective soliton crystal for low input powers and the appearance of separated solitons for high input powers. An intermediate state showing the features of both, the soliton crystal and the separated solitons, turned out to be most suitable for the generation of OFC for the purpose of calibration of astronomical spectrographs.

  1. 基于高斯低通滤波的音乐节拍提取%Music Beat Extraction Based on Low-Pass Gaussian Filter

    Institute of Scientific and Technical Information of China (English)

    胡建建; 曾培峰; 唐莉萍; 臧珠萍

    2011-01-01

    A music beat extraction method based on low-pass Gaussian filter is proposed. And musical energy extraction is applied to calculate the energy envelop. Also denoise is archived by data addition in spatial domain. The quantity of data is reduced also in addition. Then, a low-pass Gaussian filter is formed to depress high frequency components and increase the prominence of low-frequency tempo information.Finally, the beat of music signal is located by peak detection calculation. The experimental results demonstrate that the proposed algorithm is capable of extracting music beat with high accuracy and it is practicable to real-time applications.%提出一种基于高斯低通滤波的节拍提取算法,对音乐信号进行能量分析,确定信号的能量包络.在获得能量包络基础上,采用叠加分析的方法,实现在减少有待分析数据量的同时,消除信号的噪声.然后,应用高斯窗函数构造一个低通滤波器,对压缩后的信号数据进行低通滤波处理,滤除音乐信号中不能决定节拍信息的高频部分.最后,通过峰值检测的方法确定音乐信号的节拍.实验结果表明,本文所采用的方法提取结果准确,且实用性强.

  2. [Endoscopically controlled optimization of trans-scleral suture fixation of posterior chamber lenses in the ciliary sulcus].

    Science.gov (United States)

    Althaus, C; Sundmacher, R

    1993-08-01

    Two technical difficulties have to be overcome in transscleral suture fixation of posterior chamber intraocular lenses (PCL) in the ciliary sulcus: first, exact needle penetration through the sulcus, and second, exact positioning of the PCL haptics in the sulcus. Incongruence of the two may lead to long-term complications by compression or even strangulation of ciliary processes. Intraocular endoscopy was used intraoperatively to visualize the site of needle penetration and the final location of the haptics in patients. It turned out that with our previously described standard techniques the precision was far less than anticipated. Thus, new technical ways had to be sought to improve the precision of positioning. In secondary implantation without perforating keratoplasty we achieved the best results when the needle was passed ab externo before opening the eye and before anterior vitrectomy, taking advantage of a precisely prepared sclerocorneal zone. Passing the needle ab externo in an already hypotonic eyeball gives much less precise results. In combination with perforating keratoplasty with an open-sky approach, needle penetration ab interno is reliable. Correct positioning of the PCL haptics is at least as difficult as correct needle penetration, a fact which up to now has mostly been ignored. In 33 consecutively operated eyes the technique of implantation and PCL design was varied under endoscopical control.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Strain-dependent brain defects in mouse models of primary ciliary dyskinesia with mutations in Pcdp1 and Spef2.

    Science.gov (United States)

    Finn, R; Evans, C C; Lee, L

    2014-09-26

    Hydrocephalus is caused by the accumulation of cerebrospinal fluid (CSF) in the cerebral ventricular system which results in an enlargement of the cranium due to increased intraventricular pressure. The increase in pressure within the brain typically results in sloughing of ciliated ependymal cells, loss of cortical gray matter, and increased gliosis. Congenital hydrocephalus is associated with several syndromes including primary ciliary dyskinesia (PCD), a rare, genetically heterogeneous, pediatric syndrome that results from defects in motile cilia and flagella. We have examined the morphological and physiological defects in the brains of two mouse models of PCD, nm1054 and bgh, which have mutations in Pcdp1 (also known as Cfap221) and Spef2, respectively. Histopathological and immunohistochemical analyses of mice with these mutations on the C57BL/6J and 129S6/SvEvTac genetic backgrounds demonstrate strain-dependent morphological brain damage. Alterations in astrocytosis, microglial activation, myelination, and the neuronal population were identified and are generally more severe on the C57BL/6J background. Analysis of ependymal ciliary clearance ex vivo and CSF flow in vivo demonstrate a physiological defect in nm1054 and bgh mice on both genetic backgrounds, indicating that abnormal cilia-driven flow is not the sole determinant of the severity of hydrocephalus in these models. These results suggest that genetic modifiers play an important role in susceptibility to severe PCD-associated hydrocephalus. PMID:25073043

  4. Caenorhabditis elegans ciliary protein NPHP-8, the homologue of human RPGRIP1L, is required for ciliogenesis and chemosensation.

    Science.gov (United States)

    Liu, Lin; Zhang, Mingshu; Xia, Zhiping; Xu, Pingyong; Chen, Liangyi; Xu, Tao

    2011-07-01

    Nephronophthisis (NPHP) is the most frequent genetic cause of end-stage renal failure in children and young adults. NPHP8/RPGRIP1L is a novel ciliary gene that, when mutated, in addition to causing NPHP, also causes Joubert syndrome (JBTS) and Meckel syndrome (MKS). The exact function of NPHP8 and how defects in NPHP8 lead to human diseases are poorly understood. Here, we studied the Caenorhabditis elegans homolog nphp-8 (C09G5.8) and explored the possible function of NPHP-8 in ciliated sensory neurons. We determined the gene structure of nphp-8 through rapid amplification of cDNA ends (RACE) analysis and discovered an X-box motif that had been previously overlooked. Moreover, NPHP-8 co-localized with NPHP-4 at the transition zone at the base of cilia. Mutation of nphp-8 led to abnormal dye filling (Dyf) and shorter cilia lengths in a subset of ciliary neurons. In addition, chemotaxis to several volatile attractants was significantly impaired in nphp-8 mutants. Our data suggest that NPHP-8/RPGRIP1L plays an important role in cilia formation and cilia-mediated chemosensation in a cell type-specific manner. PMID:21689635

  5. Active Faraday optical frequency standards

    CERN Document Server

    Zhuang, Wei

    2014-01-01

    We propose the mechanism of active Faraday optical clock, and experimentally demonstrate active Faraday optical frequency standards based on 852 nm narrow bandwidth Faraday atomic filter by the method of velocity-selective optical pumping of cesium vapor. The center frequency of the active Faraday optical frequency standards is determined by the cesium 6 $^{2}S_{1/2}$ $F$ = 4 to 6 $^{2}P_{3/2}$ $F'$ = 4 and 5 crossover transition line. The optical heterodyne beat between two similar independent setups shows that the frequency linewidth reaches 996(26) Hz, which is 5.3 $\\times$ 10$^{3}$ times smaller than the natural linewidth of the cesium 852 nm transition line. The maximum emitted light power reaches 75 $\\upmu$W. The active Faraday optical frequency standards reported here have advantages of narrow linewidth and reduced cavity pulling, which can readily be extended to other atomic transition lines of alkali and alkaline-earth metal atoms trapped in optical lattices at magic wavelengths, making it useful for...

  6. 4D ultrasound and 3D MRI registration of beating heart

    International Nuclear Information System (INIS)

    To realize intra-cardiac surgery without cardio-pulmonary bypass, a medical imaging technique with both high image quality and data acquisition rate that is fast enough to follow heart beat movements is required. In this research, we proposed a method that utilized the image quality of MRI and the speed of ultrasound. We developed a 4D image reconstruction method using image registration of 3D MRI and 4D ultrasound images. The registration method consists of rigid registration between 3D MRI and 3D ultrasound with the same heart beat phase, and non-rigid registration between 3D ultrasound images from different heart beat phases. Non-rigid registration was performed with B-spline based registration using variable spring model. In phantom experiment using balloon phantom, registration accuracy was less than 2 mm for total heart volume variation range of 10%. We applied our registration method on 3D MRI and 4D ultrasound images of a volunteer's beating heart data and confirmed through visual observation that heart beat pattern was well reproduced. (orig.)

  7. Independent Control of the Static and Dynamic Components of the Chlamydomonas Flagellar Beat.

    Science.gov (United States)

    Geyer, Veikko F; Sartori, Pablo; Friedrich, Benjamin M; Jülicher, Frank; Howard, Jonathon

    2016-04-25

    When the green alga Chlamydomonas reinhardtii swims, it uses the breaststroke beat of its two flagella to pull itself forward [1]. The flagellar waveform can be decomposed into a static component, corresponding to an asymmetric time-averaged shape, and a dynamic component, corresponding to the time-varying wave [2]. Extreme lightening conditions photoshock the cell, converting the breaststroke beat into a symmetric sperm-like beat, which causes a reversal of the direction of swimming [3]. Waveform conversion is achieved by a reduction in magnitude of the static component, whereas the dynamic component remains unchanged [2]. The coupling between static and dynamic components, however, is poorly understood, and it is not known whether the static component requires the dynamic component or whether it can exist independently. We used isolated and reactivated axonemes [4] to investigate the relation between the two beat components. We discovered that, when reactivated in the presence of low ATP concentrations, axonemes displayed the static beat component in absence of the dynamic component. Furthermore, we found that the amplitudes of the two components depend on ATP in qualitatively different ways. These results show that the decomposition into static and dynamic components is not just a mathematical concept but that the two components can independently control different aspects of cell motility: the static component controls swimming direction, whereas the dynamic component provides propulsion. PMID:27040779

  8. 'Confessing out the soul to conform to the rhythm of thought': a reading of Allen Ginsberg’s Beat poetry

    Directory of Open Access Journals (Sweden)

    H. Kruger

    2007-07-01

    Full Text Available Much critical writing about the Beat Movement has focused on the strong interrelationship between the literary and social discourses within and around the movement. However, the study of Beat literature also necessitates an awareness of its position within the literary discourse of the twentieth century. Beat writing may be seen as standing in the unstable, shifting territory between two equally unstable, shifting literary movements: modernism and postmodernism. Beat poetry pits itself against high modernism and the New Critical tradition, draws upon some aspects of early avant-garde modernism, and simultaneously remoulds these aspects into what may be regarded as the beginnings of postmodernism in the USA. This article presents a reading of Allen Ginsberg’s Beat poetry against this literary-historical background. A brief general overview of some of the key characteristics of Beat poetry is given, followed by a discussion of a number of Beat poems, organised around some salient features of Ginsberg’s Beat poetry that may be linked to Beat poetry’s position in the transition from modernism to postmodernism.

  9. Action of Administered Ciliary Neurotrophic Factor on the Mouse Dorsal Vagal Complex

    Science.gov (United States)

    Senzacqua, Martina; Severi, Ilenia; Perugini, Jessica; Acciarini, Samantha; Cinti, Saverio; Giordano, Antonio

    2016-01-01

    Ciliary neurotrophic factor (CNTF) induces weight loss in obese rodents and humans through activation of the hypothalamic Jak-STAT (Janus kinase-signal transducer and activator of transcription) signaling pathway. Here, we tested the hypothesis that CNTF also affects the brainstem centers involved in feeding and energy balance regulation. To this end, wild-type and leptin-deficient (ob/ob and db/db) obese mice were acutely treated with intraperitoneal recombinant CNTF. Coronal brainstem sections were processed for immunohistochemical detection of STAT3, STAT1, STAT5 phosphorylation and c-Fos. In wild-type mice, CNTF treatment for 45 min induced STAT3, STAT1, and STAT5 phosphorylation in neurons as well as glial cells of the area postrema; here, the majority of CNTF-responsive cells activated multiple STAT isoforms, and a significant proportion of CNTF-responsive glial cells bore the immaturity and plasticity markers nestin and vimentin. After 120 min CNTF treatment, c-Fos expression was intense in glial cells and weak in neurons of the area postrema, it was intense in several neurons of the rostral and caudal solitary tract nucleus (NTS), and weak in some cholinergic neurons of the dorsal motor nucleus of the vagus. In the ob/ob and db/db mice, Jak-STAT activation and c-Fos expression were similar to those induced in wild-type mouse brainstem. Treatment with CNTF (120 min, to induce c-Fos expression) and leptin (25 min, to induce STAT3 phosphorylation) demonstrated the co-localization of the two transcription factors in a small neuron population in the caudal NTS portion. Finally, weak immunohistochemical CNTF staining, detected in funiculus separans, and meningeal glial cells, matched the modest amount of CNTF found by RT-qPCR in micropunched area postrema tissue, which in contrast exhibited a very high amount of CNTF receptor. Collectively, the present findings show that the area postrema and the NTS exhibit high, distinctive responsiveness to circulating

  10. Action of Administered Ciliary Neurotrophic Factor on the Mouse Dorsal Vagal Complex.

    Science.gov (United States)

    Senzacqua, Martina; Severi, Ilenia; Perugini, Jessica; Acciarini, Samantha; Cinti, Saverio; Giordano, Antonio

    2016-01-01

    Ciliary neurotrophic factor (CNTF) induces weight loss in obese rodents and humans through activation of the hypothalamic Jak-STAT (Janus kinase-signal transducer and activator of transcription) signaling pathway. Here, we tested the hypothesis that CNTF also affects the brainstem centers involved in feeding and energy balance regulation. To this end, wild-type and leptin-deficient (ob/ob and db/db) obese mice were acutely treated with intraperitoneal recombinant CNTF. Coronal brainstem sections were processed for immunohistochemical detection of STAT3, STAT1, STAT5 phosphorylation and c-Fos. In wild-type mice, CNTF treatment for 45 min induced STAT3, STAT1, and STAT5 phosphorylation in neurons as well as glial cells of the area postrema; here, the majority of CNTF-responsive cells activated multiple STAT isoforms, and a significant proportion of CNTF-responsive glial cells bore the immaturity and plasticity markers nestin and vimentin. After 120 min CNTF treatment, c-Fos expression was intense in glial cells and weak in neurons of the area postrema, it was intense in several neurons of the rostral and caudal solitary tract nucleus (NTS), and weak in some cholinergic neurons of the dorsal motor nucleus of the vagus. In the ob/ob and db/db mice, Jak-STAT activation and c-Fos expression were similar to those induced in wild-type mouse brainstem. Treatment with CNTF (120 min, to induce c-Fos expression) and leptin (25 min, to induce STAT3 phosphorylation) demonstrated the co-localization of the two transcription factors in a small neuron population in the caudal NTS portion. Finally, weak immunohistochemical CNTF staining, detected in funiculus separans, and meningeal glial cells, matched the modest amount of CNTF found by RT-qPCR in micropunched area postrema tissue, which in contrast exhibited a very high amount of CNTF receptor. Collectively, the present findings show that the area postrema and the NTS exhibit high, distinctive responsiveness to circulating

  11. Effect of primary iris and ciliary body cyst on anterior chamber angle in patients with shallow anterior chamber

    Institute of Scientific and Technical Information of China (English)

    Bing-hong WANG; Yu-feng YAO

    2012-01-01

    Objective:To evaluate the prevalence of primary iris and/or ciliary body cysts in eyes with shallow anterior chamber and their effect on the narrowing of the anterior chamber angle.Methods:Among the general physical check-up population,subjects with shallow anterior chambers,as judged by van Herick technique,were recruited for further investigation.Ultrasound biomicroscope (UBM) was used to detect and measure the cysts located in the iris and/or ciliary body,the anterior chamber depth (ACD),the angle opening distance at 500 μm (AOD500),and the trabecular-iris angle (TIA).A-scan ultrasonography was used to measure the ocular biometry,including lens thickness,axial length,lens/axial length factor (LAF),and relative lens position (RLP).The effect of the cyst on narrowing the corresponding anterior chamber angle and the entire angle was evaluated by the UBM images,ocular biometry,and gonioscopic grading.The eye with unilateral cyst was compared with the eye without the cyst for further analysis.Results:Among the 727 subjects with shallow anterior chamber,primary iris and ciliary body cysts were detected in 250 (34.4%) patients; among them 96 (38.4%) patients showed unilateral single cyst,21 (8.4%) patients had unilateral double cysts,and 42 (16.8%) patients manifested unilateral multiple and multi-quadrants cysts.Plateau iris configuration was found in 140 of 361 (38.8%) eyes with cysts.The mean size of total cysts was (0.6547±0.2319) mm.In evaluation of the effect of the cyst size and location on narrowing the corresponding angle to their position,the proportion of the cysts causing corresponding angle narrowing or closure among the cysts larger than 0.8 mm (113/121,93.4%) was found to be significantly higher than that of the cysts smaller than 0.8 mm (373/801,46.6%),and a significant higher proportion was also found in the cysts located at iridociliary sulcus (354/437,81.0%) than in that at the pars plicata (131/484,27.1%).In evaluating the effect

  12. PWM Switching Frequency Effects on Eddy Current Sensors for Magnetically Suspended Flywheel Systems

    Science.gov (United States)

    Jansen, Ralph; Lebron, Ramon; Dever, Timothy P.; Birchenough, Arthur G.

    2003-01-01

    A flywheel magnetic bearing (MB) pulse width modulated power amplifier (PWM) configuration is selected to minimize noise generated by the PWMs in the flywheel position sensor system. Two types of noise are addressed: beat frequency noise caused by variations in PWM switching frequencies, and demodulation noise caused by demodulation of high order harmonics of the switching voltage into the MB control band. Beat frequency noise is eliminated by synchronizing the PWM switch frequencies, and demodulation noise is minimized by selection of a switching frequency which does not have harmonics at the carrier frequency of the sensor. The recommended MB PWM system has five synchronized PWMs switching at a non-integer harmonic of the sensor carrier.

  13. Beta beat correction and improvement in Indus-2 storage ring performance

    International Nuclear Information System (INIS)

    The periodicity restoration or the beta beat correction is an important step to enhance the operational performance of any storage ring in terms of the better injection efficiency and improved beam lifetime etc. A method of linear beam optics from closed orbit has been used for the beta beat correction in Indus-2 store ring, where 26 power supplies driving the 72 quadrupoles are used as a degree of freedoms. In this method, the measured response matrix is fitted to the theoretical orbit response matrix and deviations of the quadrupole strengths are determined. Correction of these deviation in strengths are applied in the operating machine through the power supplies driving the quadrupoles. We will discuss the method used for the beta beat correction in Indus-2 storage ring and will present the effects of the correction on the injection efficiency and beam lifetime. (author)

  14. Wavelet Entropy as a Measure of Ventricular Beat Suppression from the Electrocardiogram in Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Philip Langley

    2015-09-01

    Full Text Available A novel method of quantifying the effectiveness of the suppression of ventricular activity from electrocardiograms (ECGs in atrial fibrillation is proposed. The temporal distribution of the energy of wavelet coefficients is quantified by wavelet entropy at each ventricular beat. More effective ventricular activity suppression yields increased entropies at scales dominated by the ventricular and atrial components of the ECG. Two studies are undertaken to demonstrate the efficacy of the method: first, using synthesised ECGs with controlled levels of residual ventricular activity, and second, using patient recordings with ventricular activity suppressed by an average beat template subtraction algorithm. In both cases wavelet entropy is shown to be a good measure of the effectiveness of ventricular beat suppression.

  15. Substrate stiffness-modulated registry phase correlations in cardiomyocytes map structural order to coherent beating

    Science.gov (United States)

    Dasbiswas, K.; Majkut, S.; Discher, D. E.; Safran, Samuel A.

    2015-01-01

    Recent experiments show that both striation, an indication of the structural registry in muscle fibres, as well as the contractile strains produced by beating cardiac muscle cells can be optimized by substrate stiffness. Here we show theoretically how the substrate rigidity dependence of the registry data can be mapped onto that of the strain measurements. We express the elasticity-mediated structural registry as a phase-order parameter using a statistical physics approach that takes the noise and disorder inherent in biological systems into account. By assuming that structurally registered myofibrils also tend to beat in phase, we explain the observed dependence of both striation and strain measurements of cardiomyocytes on substrate stiffness in a unified manner. The agreement of our ideas with experiment suggests that the correlated beating of heart cells may be limited by the structural order of the myofibrils, which in turn is regulated by their elastic environment.

  16. Intra-beat Scaling Properties of Cardiac Arrhythmias and Sudden Cardiac Death

    Science.gov (United States)

    Rodríguez, Eduardo; Lerma, Claudia; Echeverría, Juan C.; Alvarez-Ramirez, Jose

    2008-02-01

    We applied detrended fluctuation analysis (DFA) to characterize the intra-beat scaling dynamics of electrocardiographic (ECG) recordings from the PhysioNet Sudden Cardiac Death Holter Database. The main finding of this contribution is that, in such recordings involving different types of arrhythmias; the ECG waveform, besides showing a less-random intra-beat dynamics, becomes more regular during bigeminy, ventricular tachycardia (VT) or even atrial fibrillation (AFIB) and ventricular fibrillation (VF) despite the appearance of erratic traces. Thus, notwithstanding that these cardiac rhythm abnormalities are generally considered as irregular and some of them generated by random impulses or wavefronts, the intra-beat scaling properties suggest that regularity dominates the underlying mechanisms of arrhythmias. Among other explanations, this may result from shorted or restricted -less complex- pathways of conduction of the electrical activity within the ventricles.

  17. Probing an Excited-State Atomic Transition Using Hyperfine Quantum Beat Spectroscopy

    CERN Document Server

    Wade, Christopher G; Keaveney, James; Adams, Charles S; Weatherill, Kevin J

    2014-01-01

    We describe a method to observe the dynamics of an excited-state transition in a room temperature atomic vapor using hyperfine quantum beats. Our experiment using cesium atoms consists of a pulsed excitation of the D2 transition, and continuous-wave driving of an excited-state transition from the 6P$_{3/2}$ state to the 7S$_{1/2}$ state. We observe quantum beats in the fluorescence from the 6P$_{3/2}$ state which are modified by the driving of the excited-state transition. The Fourier spectrum of the beat signal yields evidence of Autler-Townes splitting of the 6P$_{3/2}$, F = 5 hyperfine level and Rabi oscillations on the excited-state transition. A detailed model provides qualitative agreement with the data, giving insight to the physical processes involved.

  18. RULE BASED CLASSIFICATION OF ISCHEMIC ECG BEATS USING ANT-MINER

    Directory of Open Access Journals (Sweden)

    S. Murugan,

    2010-08-01

    Full Text Available Myocardial ischemia is the most common cardiac disease and is characterized by a high risk of sudden cardiac death. The accurate ischemic episode detection, where a sequence of cardiac beats is assessed, is based on the correct detection of ischemic beats. In this paper, a data mining approach, association rule based classification using Ant-Miner algorithm is proposed for automatic detection of ischemic ECG beats. The proposed work has two steps: initially the noise is removed and the features are extracted from the ECG signals. With these features, the Ant-Miner is applied to extract the rules. European Society of Cardiology ST-T database of ECGbeats is used to analyze the performance of our proposed method with the existing. The greater accuracy of the proposed method shows its high performance than the existing.

  19. On the Interaction of Two Beating Electrostatic Waves with Plasma Electrons

    Science.gov (United States)

    Malá, Z.

    2002-01-01

    This paper is devoted to the study of the interaction of particles with two beating plasma waves. We follow the instructional article by Ott and Dum. According to them, the sum of wave actions during the interaction is constant, supposing the effect of trapped particles on the beat can be neglected. In the present paper, this problem is solved more generally, just for the case of trapped and also untrapped particles in the wave. Our study shows that the sum of wave actions is constant also in the case when the influence of the trapped particles on the amplitudes of two waves was considered. On the contrary this conclusion is not valid if it is supposed that two original waves are amplitude modulated e.g. by the influence of the interaction of the beat with particles.

  20. Effects of biological pre-treatment of pine chips on the beating performance of Kraft pulp

    Institute of Scientific and Technical Information of China (English)

    Sami IMAMOGLU; Celil ATIK

    2007-01-01

    The Calabrien pine (Pinus brutia ) wood chips prior to kraft pulping were biologically pre-treated with selected whiterot fungi ( Ceriporiopsis subvermispora ), which was recorded to be preferentially attacking the lignin component of the wood. The effects of this treatment on beating performance and physical strength of resultant papers were studied in detail. Bio-treated samples showed comparable and, in most cases, higher physico-mechanical properties than those obtained from untreated controls. Under the same beating conditions the bio-treated kraft pulp was noted to have the lower SR° indicating a lower degree of external fibrillation. The paper made from bio-treated kraft pulp has a higher density, tensile property, air permeability and swellability. Furthermore, remarkable energy savings up to 33 % were observed when beating bio-treated kraft pulp. This study contributes to a better understanding of the mechanisms taking place during bio-treatment and the modification processes of cell wall components.

  1. Pulse compression by parametric beating with a prepared Raman coherence

    International Nuclear Information System (INIS)

    We present a general analysis for the interaction of a probe-laser radiation with a coherently prepared molecular Raman medium. We describe a general formalism that includes dispersive effects, such as group velocity and group-velocity dispersion (GVD). When dispersion is negligible, the analysis is especially simple and insightful. We show that molecular oscillations result in a modulated instantaneous susceptibility of the medium. The effect of the time-varying susceptibility on a probe-laser pulse is twofold: the output frequency becomes modulated because of the time-varying phase velocity, and the pulse shape becomes deformed because of the time-varying group velocity. We identify two mechanisms for pulse compression: (1) Frequency chirping with subsequent pulse compression by normal linear GVD (possibly in the same medium) and (2) Compression due to the time-varying group velocity. We analyze various aspects of pulse compression in the coherent Raman medium and derive conservation relations for this process. When we consider a probe-laser pulse that is much shorter than the molecular oscillation period, we observe frequency chirping, compression, or stretching of this pulse, depending on its relative timing with respect to the molecular oscillations. Based on our analysis, we propose a method for selective compression or frequency conversion of single ultrashort pulses

  2. A method for using a time interval counter to measure frequency stability

    Science.gov (United States)

    Greenhall, C. A.

    1987-01-01

    It is shown how a commercial time interval counter can be used to measure the relative stability of two signals that are offset in frequency and mixed down to a beat note of about 1 Hz. To avoid the dead-time problem, the counter is set up to read the time interval between each beat note upcrossing and the next pulse of a 10 Hz reference pulse train. The actual upcrossing times are recovered by a simple algorithm whose outputs can be used for computing residuals and Allan variance. A noise floor-test yielded a delta f/f Allan deviation of 1.3 times 10 to the minus 9th power/tau relative to the beat frequency.

  3. A conserved role for Notch in priming the cellular response to Shh through ciliary localisation of the key Shh transducer, Smoothened

    DEFF Research Database (Denmark)

    Stasiulewicz, Magdalena; Gray, Shona; Mastromina, Ioanna;

    2015-01-01

    , we show Notch activity promotes longer primary cilia both in vitro and in vivo. Strikingly, these Notch-regulated effects are Shh-independent. These data identify Notch signalling as a novel modulator of Shh signalling which acts mechanistically via regulation of ciliary localisation of key...

  4. Activating and relaxing music entrains the speed of beat synchronized walking.

    Directory of Open Access Journals (Sweden)

    Marc Leman

    Full Text Available Inspired by a theory of embodied music cognition, we investigate whether music can entrain the speed of beat synchronized walking. If human walking is in synchrony with the beat and all musical stimuli have the same duration and the same tempo, then differences in walking speed can only be the result of music-induced differences in stride length, thus reflecting the vigor or physical strength of the movement. Participants walked in an open field in synchrony with the beat of 52 different musical stimuli all having a tempo of 130 beats per minute and a meter of 4 beats. The walking speed was measured as the walked distance during a time interval of 30 seconds. The results reveal that some music is 'activating' in the sense that it increases the speed, and some music is 'relaxing' in the sense that it decreases the speed, compared to the spontaneous walked speed in response to metronome stimuli. Participants are consistent in their observation of qualitative differences between the relaxing and activating musical stimuli. Using regression analysis, it was possible to set up a predictive model using only four sonic features that explain 60% of the variance. The sonic features capture variation in loudness and pitch patterns at periods of three, four and six beats, suggesting that expressive patterns in music are responsible for the effect. The mechanism may be attributed to an attentional shift, a subliminal audio-motor entrainment mechanism, or an arousal effect, but further study is needed to figure this out. Overall, the study supports the hypothesis that recurrent patterns of fluctuation affecting the binary meter strength of the music may entrain the vigor of the movement. The study opens up new perspectives for understanding the relationship between entrainment and expressiveness, with the possibility to develop applications that can be used in domains such as sports and physical rehabilitation.

  5. Activating and relaxing music entrains the speed of beat synchronized walking.

    Science.gov (United States)

    Leman, Marc; Moelants, Dirk; Varewyck, Matthias; Styns, Frederik; van Noorden, Leon; Martens, Jean-Pierre

    2013-01-01

    Inspired by a theory of embodied music cognition, we investigate whether music can entrain the speed of beat synchronized walking. If human walking is in synchrony with the beat and all musical stimuli have the same duration and the same tempo, then differences in walking speed can only be the result of music-induced differences in stride length, thus reflecting the vigor or physical strength of the movement. Participants walked in an open field in synchrony with the beat of 52 different musical stimuli all having a tempo of 130 beats per minute and a meter of 4 beats. The walking speed was measured as the walked distance during a time interval of 30 seconds. The results reveal that some music is 'activating' in the sense that it increases the speed, and some music is 'relaxing' in the sense that it decreases the speed, compared to the spontaneous walked speed in response to metronome stimuli. Participants are consistent in their observation of qualitative differences between the relaxing and activating musical stimuli. Using regression analysis, it was possible to set up a predictive model using only four sonic features that explain 60% of the variance. The sonic features capture variation in loudness and pitch patterns at periods of three, four and six beats, suggesting that expressive patterns in music are responsible for the effect. The mechanism may be attributed to an attentional shift, a subliminal audio-motor entrainment mechanism, or an arousal effect, but further study is needed to figure this out. Overall, the study supports the hypothesis that recurrent patterns of fluctuation affecting the binary meter strength of the music may entrain the vigor of the movement. The study opens up new perspectives for understanding the relationship between entrainment and expressiveness, with the possibility to develop applications that can be used in domains such as sports and physical rehabilitation.

  6. Cross-Cultural Influences on Rhythm Processing: Reproduction, Discrimination, and Beat Tapping

    Directory of Open Access Journals (Sweden)

    Daniel J Cameron

    2015-04-01

    Full Text Available The structures of musical rhythm differ between cultures, despite the fact that the ability to synchronize one’s movements to musical rhythms appears to be universal. To measure the influence of culture on rhythm processing, we tested East African and North American adults on the perception, production, and beat tapping of rhythms derived from East African and Western music. To assess rhythm perception, participants identified whether pairs of rhythms were same or different. To assess rhythm production, participants reproduced rhythms after hearing them. To assess beat tapping, participants tapped the beat along with repeated rhythms. We expected that performance in all three tasks would be influenced both by the culture of the participant and by the culture of the rhythm. Specifically, we predicted that a participant’s ability to discriminate, reproduce, and accurately tap the beat would be better for rhythms from their own culture than for rhythms from another culture. In the rhythm discrimination task, there were no differences in discriminating culturally familiar and unfamiliar rhythms. In the rhythm reproduction task, both groups reproduced East African rhythms more accurately than Western rhythms, but East African participants also showed an effect of cultural familiarity, leading to a significant interaction. In the beat tapping task, participants in both groups tapped the beat more accurately for culturally familiar than unfamiliar rhythms. The results demonstrate that culture does influence the processing of musical rhythm. In terms of the function of musical rhythm, our results are consistent with theories that musical rhythm enables synchronization. Musical rhythm may foster musical cultural identity by enabling within-group synchronization to music, perhaps supporting social cohesion.

  7. ZBF-DMTD SYNTHETICAL METHOD FOR SHORT-TERM FREQUENCY STABILITY MEASUREMENT

    Institute of Scientific and Technical Information of China (English)

    包志华; 曹培培

    1995-01-01

    This paper presents a zero beat frequency double mixer time difference (ZBF-DMTD) synthetical method for measuring short-term.frequency stability Allen variance σy2(τ) of frequency sourse. The new method has a high measurement preclsion and is easy to realize and spread in engineering. The paper dlscribes the structure and design of the ZBFDMTD automatic measurement system,and gives the contrast measurement results.

  8. Terahertz generation by beating two Langmuir waves in a warm and collisional plasma

    International Nuclear Information System (INIS)

    Terahertz (THz) radiation generated by beating of two Langmuir waves in a warm and collisional plasma is discussed theoretically. The critical angle between the two Langmuir waves and the critical wave-length (wave vector) of Langmuir waves for generating THz radiation are obtained analytically. Furthermore, the maximum radiation energy is obtained. We find that the critical angle, the critical wave-length, and the generated radiation energy strongly depend on plasma temperature and wave-length of the Langmuir waves. That is, the THz radiation generated by beating of two Langmuir waves in a warm and collisional plasma can be controlled by adjusting the plasma temperature and the Langmuir wave-length

  9. Estimation of beat-to-beat changes in stroke volume from arterial pressure: A comparison of two pressure wave analysis techniques during head- up tilt testing in young, healthy men

    NARCIS (Netherlands)

    Jellema, W.T.; Imholz, B.P.M.; Oosting, H.; Wesseling, K.H.; Lieshout, J.J. van

    1999-01-01

    Objective: The aim of this study was to compare beat-to-beat changes in stroke volume (SV) estimated by two different pressure wave analysis techniques during orthostatic stress testing: pulse contour analysis and Modelflow, ie, simulation of a three-element model of aortic input impedance. Methods:

  10. Precision Controlling of Frequency Difference for Elastic-Stress Birefringence He-Ne Dual-Frequency Lasers

    Institute of Scientific and Technical Information of China (English)

    ZHOU Lu-Fei; ZHANG Shu-Lian; GUO Hong; REN Zhou

    2007-01-01

    Birefringence-Zeeman dual frequency lasers are capable of producing frequency difference from several kilohertz to hundreds of megahertz, but the precision of giving and stabilizing of the beat frequency still needs improvement to the range of ±200 kHz. We design a new elastic force-exerting device comprised of the bottom part, two arms and two pieces of force-exerting sheets. The frequency difference smoothly tuning is realized with this device in a large range of 2 MHz to 20 MHz. Power-balance frequency stabilization system is used to investigate characters of the temperature, frequency difference and laser power. The precision of the frequency difference has reach up to JrlOO kHz after system temperature balance. Analyses of the laser frequency difference and power character are carried out.

  11. Discinesia ciliar primária: quando o pediatra deve suspeitar e como diagnosticar? Primary ciliary dyskinesia: when the pediatrician must suspect and how to do the diagnosis?

    Directory of Open Access Journals (Sweden)

    Mary Anne K. Olm

    2007-12-01

    from secondary ciliary defects and to describe the clinical features, screening and diagnostic laboratorial tests, and the clinical management of this disorder. DATA SOURCES: A bibliographical search was obtained from Medline, Lilacs and SciELO databases, from 1980 to 2007. DATA SYNTHESIS: PCD is an autossomic recessive disorder with abnormal structure and/or function of the cilia, leading to reduced mucociliary clearance. The clinical manifestations include upper and lower respiratory tracts, with recurrent ear, sinus and lung infections that may progress to bronchiectasis. Situs inversus and male infertility are other clinical features of this disorder. PCD should be suspected by pediatricians in the following clinical situations: full term neonates with respiratory distress without apparent causes, presence of dextrocardia, infants with chronic cough and/or recurrent upper airways infections in the absence of immunodeficiency and cystic fibrosis, children with atypical asthma and bronchiectasis without a definitive cause. The diagnostic screening tests are the saccharine and nasal nitric oxide tests. Functional and ultrastructural evaluations demand an electronic microscopic analysis and the observation of the frequency and the pattern of the ciliary movement. CONCLUSIONS: Although the prevalence of PCD is low, the difficulties in establishing the diagnosis due to the complex investigations demanded and the unfamiliarity of the disease by physicians lead to underdiagnosis. Early diagnosis and treatment of PCD are essential to reduce the morbidity and to avoid complications.

  12. Accuracy and repeatability of direct ciliary sulcus diameter measurements by full-scale 50-megahertz ultrasound biomicroscopy

    Institute of Scientific and Technical Information of China (English)

    LI De-jiao; WANG Ning-li; CHEN Shu; LI Shu-ning; MU Da-peng; WANG Tao

    2009-01-01

    Background Phakic intraocular lens (pIOL) implantation has been a popular means for the treatment of high ametropia. Measurements of ciliary sulcus diameter is important for pIOL size determining. But till now, no perfect system can directly measure it. The present study was to evaluate the accuracy, repeatability and reproducibility of direct sulcus diameter measurements obtained by a full-scale 50-megahertz (MHz) ultrasound biomicroscopy (UBM).Methods A fresh cadaver human eye with a scale marker inserted through the posterior chamber plane from 3 o'clock to 9 o'clock meridian and 30 randomly selected eyes from 30 normal subjects were scanned by full-scale 50-MHz UBM in horizontal meridional scan plane. The distance between the scales and the whole length of the marker inside the cadaver eye were measured by the same observer using the "built-in" measurement tools and the indicating error of instrument was calculated. Reproducibility of the measurement was evaluated in 30 eyes by 2 operators using Blander and Altman plot test. Repeatability was evaluated from 10 successive eyes randomly selected from the 30 eyes by one operator.Results On a scale of 1 mm, the greatest indicating error was 40 μm; the mean largest indicating error of 1 mm scale from the 10 images was (26±14) μm; on a scale of 11 mm, the greatest indicating error was 70 μo; the error rate was 0.64%. The mean length of the needle inside the eye of the 10 images was 11.05 mm, with the mean indicating error of 47 μm, the average error rate was 0.43%. For ciliary sulcus diameter measurements in vivo, the coefficient of variation was 0.38%; the coefficients of repeatability for intra-observer and inter-observer measurements were 1.99% and 2.55%, respectively. The limits of agreement for intra-observer and inter-observer measurement were-0.41 mm to 0.48 mm and -0.59 mm to 0.58 ram, respectively.Conclusion The full-scale 50-MHz UBM can be a high accuracy and good repeatability means for direct

  13. Forage supply in thinned Caatinga enriched with buffel grass (Cenchrus ciliaris L. grazed by goats and sheep=Oferta de forragem em Caatinga raleada e enriquecida com capim buffel (Cenchrus ciliaris L. pastejada por ovinos e caprinos

    Directory of Open Access Journals (Sweden)

    Diogo da Costa Soares

    2012-04-01

    Full Text Available Forage supply from herbs was assessed in a thinned Caatinga enriched with buffel grass (Cenchrus ciliaris L. exposed to goat and sheep grazing. The 2.4 ha experimental area, located at the Experimental Station of the Federal University of Campina Grande, in Santa Terezinha, Paraíba State, Brazil, was divided into four 0.6 ha paddocks, which were further subdivided into two 0.3 ha experimental plots. Twelve F1 (Boer x SRD goats and 12 Santa Inês sheep were divided in four groups of six animals of the same species. The herbaceous vegetation was separated into buffel grass (Cenchrus ciliaris L., dicotyledons and other grass species. Treatments were randomized to plots according to a completely random design with two treatments, four replications, with measures repeated in time (July/1, Aug/1, Sept/1 and Oct/1. Buffel grass dry mater (DM availability was higher in the sheep grazed than in the goat-grazed area. Buffel grass DM supply did not change from July to September, while dicotyledons DM supply decreased. Grazing affected availability, accumulation rate and supply of the forage produced (DM basis by dicotyledonous herbs. Buffel grass forage availability was not affected during the experimental period.Objetivou-se avaliar a oferta de forragem do estrato herbáceo de uma Caatinga raleada e enriquecida com capim buffel (Cenchrus ciliaris L., submetida ao pastejo de caprinos e ovinos. O experimento foi realizado na Universidade Federal de Campina Grande, Estado da Paraíba. A área experimental foi de 2,4 ha, dividida em quatro piquetes de 0,6 ha, nos quais foram alocadas parcelas experimentais de 0,3 ha. Utilizaram-se 12 caprinos F1 (Bôer x SRD e 12 ovinos Santa Inês, que foram distribuídos em quatro grupos de seis animais. A vegetação herbácea foi separada em capim buffel (Cenchrus ciliaris L., dicotiledôneas e outras gramínea. Utilizou-se um delineamento inteiramente casualizado, com observações repetidas no tempo (1/jul., 1/ago., 1

  14. Mnemonic Effect of Iconic Gesture and Beat Gesture in Adults and Children: Is Meaning in Gesture Important for Memory Recall?

    Science.gov (United States)

    So, Wing Chee; Chen-Hui, Colin Sim; Wei-Shan, Julie Low

    2012-01-01

    Abundant research has shown that encoding meaningful gesture, such as an iconic gesture, enhances memory. This paper asked whether gesture needs to carry meaning to improve memory recall by comparing the mnemonic effect of meaningful (i.e., iconic gestures) and nonmeaningful gestures (i.e., beat gestures). Beat gestures involve simple motoric…

  15. Megalin–deficiency causes high myopia, retinal pigment epithelium-macromelanosomes and abnormal development of the ciliary body in mice

    DEFF Research Database (Denmark)

    Storm, Tina; Heegaard, Steffen; Christensen, Erik I;

    2014-01-01

    In man, mutations of the megalin-encoding gene causes the rare Donnai-Barrow/Facio-Oculo-Acoustico-Renal Syndrome, which is partially characterized by high-grade myopia. Previous studies of renal megalin function have established that megalin is crucial for conservation of renal filtered nutrients...... that megalin localizes to vesicular structures in the RPE and NPCBE cells. Histological investigations of ocular mouse tissue also identified a severe myopia phenotype as well as enlarged RPE melanosomes and abnormal ciliary body development in the megalin-deficient mice. In conclusion, the complex ocular...... phenotype observed in the megalin-deficient mice suggests that megalin-mediated developmental abnormalities may contribute to the high myopia phenotype observed in the Donnai-Barrow Syndrome patients and, thus, that megalin harbors important roles in ocular development and physiology. Finally, our data show...

  16. Exhaled breath analysis using electronic nose in cystic fibrosis and primary ciliary dyskinesia patients with chronic pulmonary infections

    DEFF Research Database (Denmark)

    Joensen, Odin; Paff, Tamara; Haarman, Eric G;

    2014-01-01

    of CF patients having a chronic P. aeruginosa infection differed significantly from to non-chronically infected CF patients p = 0.044. We confirmed the previously established discriminative power of exhaled breath analysis in separation between healthy subjects and patients with CF or PCD. Furthermore...... (CF) and primary ciliary dyskinesia (PCD) with or without various well characterized chronic pulmonary infections. We recruited 64 patients with CF and 21 with PCD based on known chronic infection status. 21 healthy volunteers served as controls. An electronic nose was employed to analyze exhaled...... breath samples. Principal component reduction and discriminant analysis were used to construct internally cross-validated receiver operator characteristic (ROC) curves. Breath profiles of CF and PCD patients differed significantly from healthy controls p = 0.001 and p = 0.005, respectively. Profiles...

  17. High Frequency Color Doppler Image of Choroidal Detachment

    Institute of Scientific and Technical Information of China (English)

    JinghongWu; LijuanZou; 等

    2002-01-01

    Purpose:To study the Color Doppler Image (CDI) characteristics of choroidal detachment and the applied value of CDI.Methods:Seventy-two cases (74 eyes) of choroidal detachment were studied retrospectively.Results:The typical ultragraph of chroridal detachment displayed one or several smooth hemispherical or lobuler circular thick bands, with convex side toward vitreous cavity.Most of the choroidal detachments were located before the equator, a few of them were beyond the equator.CDI displayed blood flow singnal in the band.Pulse Doppler showed the frequency spectrum features of retinal detachment band were similar to those of central retinal vessels, whereas the frequency spectum features of choroidal detachment bend resembled those of ciliary artery in some cases of retinal detachment (RD) accompanied by choroidal detachment.Conclusion:CDI could make a correct and precise diagnosis of choroidal detachment.Eye Science 2000;16:61-64.

  18. Nonlinear modification of the laser noise power spectrum induced by a frequency-shifted optical feedback

    CERN Document Server

    Lacot, Eric; Girardeau, Vadim; Hugon, Olivier; Jacquin, Olivier

    2016-01-01

    In this article, we study the non-linear coupling between the stationary (i.e. the beating modulation signal) and transient (i.e. the laser quantum noise) dynamics of a laser subjected to frequency shifted optical feedback. We show how the noise power spectrum and more specifically the relaxation oscillation frequency of the laser are modified under different optical feedback condition. Specifically we study the influence of (i) the amount of light returning to the laser cavity and (ii) the initial detuning between the frequency shift and intrinsic relaxation frequency. The present work shows how the relaxation frequency is related to the strength of the beating signal and the shape of the noise power spectrum gives an image of the Transfer Modulation Function (i.e. of the amplification gain) of the nonlinear-laser dynamics.The theoretical predictions, confirmed by numerical resolutions, are in good agreements with the experimental data.

  19. Frequency noise characterisation of narrow linewidth diode lasers

    Science.gov (United States)

    Turner, L. D.; Weber, K. P.; Hawthorn, C. J.; Scholten, R. E.

    2002-01-01

    We examine several approaches to laser frequency noise measurement in the frequency and time domains. Commonly employed methods such as optical frequency discrimination and the Allan variance are found to be complex, expensive, time-consuming, or incomplete. We describe a practical method of demodulating a laser beat note to measure a frequency noise spectrum, using a phase-locked loop frequency discriminator based on a single low-cost integrated circuit. This method measures the frequency noise spectrum of a laser directly and in detail and is insensitive to intensity fluctuations. The advantages of this scheme are demonstrated through measurement of the frequency noise spectrum for two external cavity diode lasers (ECDL), clearly distinguishing several common noise sources. These are isolated and removed, reducing the individual laser rms linewidth from 2 MHz to 450 kHz. The spectrum is used to calculate the Allan variance, which shows almost none of the important information.

  20. Attitudes toward Wife Beating: A Cross-Country Study in Asia

    Science.gov (United States)

    Rani, Manju; Bonu, Sekhar

    2009-01-01

    Using demographic and health surveys conducted between 1998 and 2001 from seven countries (Armenia, Bangladesh, Cambodia, India, Kazakhstan, Nepal, and Turkey), the study found that acceptance of wife beating ranged from 29% in Nepal, to 57% in India (women only), and from 26% in Kazakhstan, to 56% in Turkey (men only). Increasing wealth predicted…

  1. Lung Transplantation from Nonheparinized Category III Non-Heart-Beating Donors. A Single-Centre Report

    NARCIS (Netherlands)

    Erasmus, Michiel E.; Verschuuren, Erik A. M.; Nijkamp, Danielle M.; Vermeyden, J. Wytse; van der Bij, Wim

    2010-01-01

    Background. Despite the increasing use of extended lung donors, the shortage of lung donors remains. Usage of non-heart-beating (NHB) lung donors contributes to fight this shortage. We describe our experience in 21 consecutive adult lung transplantations using nonheparinized category III NHB donors

  2. Why Some Schools with Latino Children Beat the Odds...and Others Don't

    Science.gov (United States)

    Waits, Mary Jo; Campbell, Heather E.; Gau, Rebecca; Jacobs, Ellen; Rex, Tom; Hess, Robert K.

    2006-01-01

    Throughout Arizona and the Southwest, the odds are against high achievement in schools with a mostly Latino, mostly poor student enrollment. Some schools, however, "beat the odds" and achieve consistently high results or show steady gains. Why do these schools succeed where others fail? Using the methodology of business guru Jim Collins…

  3. Should Individual Investors Use Technical Trading Rules to Attempt to Beat the Market?

    Directory of Open Access Journals (Sweden)

    Thomas S. Coe

    2010-01-01

    Full Text Available Problem statement: Despite widespread academic acceptance of the Efficient Markets Hypothesis, some stock traders still use technical trading rules in an attempt to beat the market. Approach: This study looked at four trading rules, namely, the arithmetic moving average, the relative strength index, a stochastic oscillator and its moving average. These trading rules compare the relationship of current prices to past price patterns to generate a signal when to buy and sell stocks. The trading rules were tested over the years 2000-2009, a period of time that exhibited bull and bear markets, to determine if traders could actively trade a stock and beat a passive investment strategy. Results: We tested the four trading rules against the 576 stocks that comprise the S&P 100, the NASDAQ 100 and the S&P Midcap 400. The results proved discouraging to that strategy, in that no one trading rule consistently beat the market. Conclusion/Recommendations: Since technical trading rules cannot be used to consistently beat a long-term buy and hold strategy, we recommend that investors first use fundamental analysis to select stocks and then apply a technical trading rule to enhance potential trading gains.

  4. Beat Keeping in a Sea Lion As Coupled Oscillation: Implications for Comparative Understanding of Human Rhythm.

    Science.gov (United States)

    Rouse, Andrew A; Cook, Peter F; Large, Edward W; Reichmuth, Colleen

    2016-01-01

    Human capacity for entraining movement to external rhythms-i.e., beat keeping-is ubiquitous, but its evolutionary history and neural underpinnings remain a mystery. Recent findings of entrainment to simple and complex rhythms in non-human animals pave the way for a novel comparative approach to assess the origins and mechanisms of rhythmic behavior. The most reliable non-human beat keeper to date is a California sea lion, Ronan, who was trained to match head movements to isochronous repeating stimuli and showed spontaneous generalization of this ability to novel tempos and to the complex rhythms of music. Does Ronan's performance rely on the same neural mechanisms as human rhythmic behavior? In the current study, we presented Ronan with simple rhythmic stimuli at novel tempos. On some trials, we introduced "perturbations," altering either tempo or phase in the middle of a presentation. Ronan quickly adjusted her behavior following all perturbations, recovering her consistent phase and tempo relationships to the stimulus within a few beats. Ronan's performance was consistent with predictions of mathematical models describing coupled oscillation: a model relying solely on phase coupling strongly matched her behavior, and the model was further improved with the addition of period coupling. These findings are the clearest evidence yet for parity in human and non-human beat keeping and support the view that the human ability to perceive and move in time to rhythm may be rooted in broadly conserved neural mechanisms.

  5. The Patterns of Music: Young Children Learning Mathematics through Beat, Rhythm, and Melody

    Science.gov (United States)

    Geist, Kamile; Geist, Eugene A.; Kuznik, Kathleen

    2012-01-01

    Research on music and music therapy suggests that math and music are related in the brain from very early in life. Musical elements such as steady beat, rhythm, melody, and tempo possess inherent mathematical principles such as spatial properties, sequencing, counting, patterning, and one-to-one correspondence. With new understanding about the…

  6. Effects of Movement, Tempo, and Gender on Steady Beat Performance of Kindergarten Children

    Science.gov (United States)

    Rose, Paige

    2016-01-01

    The purposes of this research were to discover the effects of manual (hand) and pedal (foot) movements, tempo, and gender on steady beat accuracy. Participants (N = 119) consisted of male (n = 63) and female (n = 56) kindergarten students randomly divided into two groups, counterbalanced with regard to school, homeroom, and gender. Participants…

  7. Behind Beats and Rhymes: Working Class from a Hampton Roads Hip Hop Homeplace

    Science.gov (United States)

    Durham, Aisha S.

    2009-01-01

    The film documentary titled "Hip Hop: beyond beats and rhymes" captures ongoing conversations among scholars, cultural critics, and hip hop insiders about the state of African Americans by interrogating distinct expressive forms associated with hip hop culture. Durham draws from two scenes to describe her memories as the researched underclass and…

  8. Analysis of spiritual pressure of the Beat Generation in On the Road

    Institute of Scientific and Technical Information of China (English)

    刘英波

    2015-01-01

    This paper aims to make an analysis of the double spiritual pressure of the Beat Generation in On the Road. Through the analysis, it shows the readers an actual American society after the World War II, and spiritual pressures that American young people meet.

  9. Beat Keeping in a Sea Lion as Coupled Oscillation: Implications for Comparative Understanding of Human Rhythm

    Directory of Open Access Journals (Sweden)

    Andrew A Rouse

    2016-06-01

    Full Text Available Human capacity for entraining movement to external rhythms—i.e., beat keeping—is ubiquitous, but its evolutionary history and neural underpinnings remain a mystery. Recent findings of entrainment to simple and complex rhythms in non-human animals pave the way for a novel comparative approach to assess the origins and mechanisms of rhythmic behavior. The most reliable non-human beat keeper to date is a California sea lion, Ronan, who was trained to match head movements to isochronous repeating stimuli and showed spontaneous generalization of this ability to novel tempos and to the complex rhythms of music. Does Ronan’s performance rely on the same neural mechanisms as human rhythmic behavior? In the current study, we presented Ronan with simple rhythmic stimuli at novel tempos. On some trials, we introduced perturbations, altering either tempo or phase in the middle of a presentation. Ronan quickly adjusted her behavior following all perturbations, recovering her consistent phase and tempo relationships to the stimulus within a few beats. Ronan’s performance was consistent with predictions of mathematical models describing coupled oscillation: a model relying solely on phase coupling strongly matched her behavior, and the model was further improved with the addition of period coupling. These findings are the clearest evidence yet for parity in human and non-human beat keeping and support the view that the human ability to perceive and move in time to rhythm may be rooted in broadly conserved neural mechanisms.

  10. Siim Nestor soovitab : Stereo ÖÖ. Mutant Disco. Beats from the Vault. Turbodisko / Siim Nestor

    Index Scriptorium Estoniae

    Nestor, Siim, 1974-

    2006-01-01

    Oma debüütalbumit "Migration" tutvustav ameerika diskor Alex Attias üritustel "Stereo ÖÖ" 19. mail Tallinnas Von Krahlis. Üritustest "Mutant Disco" 19. mail Tallinnas klubis Privé ja Tartus 20. mail klubis Illusion, "Beats from the Vault" 19. mail Tallinnas klubis Võit ja "Turbodisko" 20. mail Tallinnas klubis KuKu

  11. Social media as beat : tweets as a news source during the 2010 British and Dutch elections

    NARCIS (Netherlands)

    Broersma, Marcel; Graham, Todd

    2011-01-01

    While the newspaper industry is in crisis and less time and resources are available for news gathering, social media turn out to be a convenient and cheap beat for (political) journalism. During the 2010 elections, 24 percent of British and 48 percent of Dutch candidates shared their thoughts, visio

  12. Amplitude differences least squares method applied to temporal cardiac beat alignment

    Science.gov (United States)

    Correa, R. O.; Laciar, E.; Valentinuzzi, M. E.

    2007-11-01

    High resolution averaged ECG is an important diagnostic technique in post-infarcted and/or chagasic patients with high risk of ventricular tachycardia (VT). It calls for precise determination of the synchronism point (fiducial point) in each beat to be averaged. Cross-correlation (CC) between each detected beat and a reference beat is, by and large, the standard alignment procedure. However, the fiducial point determination is not precise in records contaminated with high levels of noise. Herein, we propose an alignment procedure based on the least squares calculation of the amplitude differences (LSAD) between the ECG samples and a reference or template beat. Both techniques, CC and LSAD, were tested in high resolution ECG's corrupted with white noise and 50 Hz line interference of varying amplitudes (RMS range: 0-100μV). Results point out that LSDA produced a lower alignment error in all contaminated records while in those blurred by power line interference better results were found only within the 0-40 μV range. It is concluded that the proposed method represents a valid alignment alternative.

  13. Movement in Steady Beat: Learning on the Move, Ages 3-7. Second Edition.

    Science.gov (United States)

    Weikart, Phyllis S.

    The ability to feel and maintain steady, rhythmic beat is important for children to develop in early childhood and will assist them in mastering concepts in language and literacy, mathematics, and other content areas as well as increase body coordination and related physical abilities. Designed as an activity supplement to High Scope movement and…

  14. The Ability to Tap to a Beat Relates to Cognitive, Linguistic, and Perceptual Skills

    Science.gov (United States)

    Tierney, Adam T.; Kraus, Nina

    2013-01-01

    Reading-impaired children have difficulty tapping to a beat. Here we tested whether this relationship between reading ability and synchronized tapping holds in typically-developing adolescents. We also hypothesized that tapping relates to two other abilities. First, since auditory-motor synchronization requires monitoring of the relationship…

  15. Social Media as Beat : Tweets as a news source during the 2010 British and Dutch elections

    NARCIS (Netherlands)

    Broersma, M.J.; Graham, T.S.

    2012-01-01

    While the newspaper industry is in crisis and less time and resources are available for newsgathering, social media turn out to be a convenient and cheap beat for (political) journalism. This article investigates the use of Twitter as a source for newspaper coverage of the 2010 British and Dutch ele

  16. Influence of microwaves on the beating rate of isolated rat hearts.

    Science.gov (United States)

    Yee, K C; Chou, C K; Guy, A W

    1988-01-01

    Previous reports have shown that microwave exposure can decrease the beating rate of isolated rat hearts. These experiments were conducted at room temperature and with the hearts exposed to air. We observed arrhythmia frequently at room temperature, and the variation of heart beat was so large that it makes the results difficult to reproduce. Therefore, we employed a double-circulating system to provide perfusion through the coronary artery and around the outside of the heart to maintain the rat hearts at 37.7 degrees C. No arrhythmias were observed in our experiments, and the hearts were beating for at least 1 h. The effects of 16-Hz modulated 2,450-MHz pulsed microwaves (10 microseconds, 100 pps) on the beating rate of 50 isolated rat hearts were studied. Results showed no statistically significant changes of heart rate in exposed groups at SARs of 2 and 10 W/kg compared with the control group. The effect seen at 200 W/kg was shown to be similar to that resulting from heating the heart.

  17. Tagasiviitavad tõendid: teine pilk pilditeadusele / Beat Wyss ; intervjueerinud Ivar-Kristjan Hein

    Index Scriptorium Estoniae

    Wyss, Beat, 1947-

    2011-01-01

    Intervjuus Karlsruhe kunsti- ja disainiülikooli kunstiajaloo ja meediateooria professori Beat Wyssiga on teemaks Zürichis tema juhitav uurimisprojekt, mille keskmes on Venezia biennaal Ida-Euroopa riikide positsioonilt, tema EKA Kunstiteaduse Instituudi doktorantidele peetud seminar "Tagasiviitavad tõendid. Teine pilk pilditeadusele", tema kaasaegse kunsti universaalsed põhimõtted

  18. Beat Keeping in a Sea Lion As Coupled Oscillation: Implications for Comparative Understanding of Human Rhythm.

    Science.gov (United States)

    Rouse, Andrew A; Cook, Peter F; Large, Edward W; Reichmuth, Colleen

    2016-01-01

    Human capacity for entraining movement to external rhythms-i.e., beat keeping-is ubiquitous, but its evolutionary history and neural underpinnings remain a mystery. Recent findings of entrainment to simple and complex rhythms in non-human animals pave the way for a novel comparative approach to assess the origins and mechanisms of rhythmic behavior. The most reliable non-human beat keeper to date is a California sea lion, Ronan, who was trained to match head movements to isochronous repeating stimuli and showed spontaneous generalization of this ability to novel tempos and to the complex rhythms of music. Does Ronan's performance rely on the same neural mechanisms as human rhythmic behavior? In the current study, we presented Ronan with simple rhythmic stimuli at novel tempos. On some trials, we introduced "perturbations," altering either tempo or phase in the middle of a presentation. Ronan quickly adjusted her behavior following all perturbations, recovering her consistent phase and tempo relationships to the stimulus within a few beats. Ronan's performance was consistent with predictions of mathematical models describing coupled oscillation: a model relying solely on phase coupling strongly matched her behavior, and the model was further improved with the addition of period coupling. These findings are the clearest evidence yet for parity in human and non-human beat keeping and support the view that the human ability to perceive and move in time to rhythm may be rooted in broadly conserved neural mechanisms. PMID:27375418

  19. Quantum beats in forward scattering: subnanosecond studies with a mode-locked dye laser.

    Science.gov (United States)

    Harde, H; Burggraf, H; Mlynek, J; Lange, W

    1981-06-01

    Time-resolved polarization spectroscopy of transient coherent superpositions of atomic substates is extended to the picosecond time scale by using a synchronously pumped mode-locked dye laser. As a first demonstration, hyperfine beats in the sodium D(1) and D(2), lines were resolved. The ground-state splitting could be determined with an accuracy of better than 10(-3).

  20. Quantum beats in forward scattering - Subnanosecond studies with a mode-locked dye laser

    Science.gov (United States)

    Harde, H.; Burggraf, H.; Mlynek, J.; Lange, W.

    1981-06-01

    Time-resolved polarization spectroscopy of transient coherent superpositions of atomic substates is extended to the picosecond time scale by using a synchronously pumped mode-locked dye laser. As a first demonstration, hyperfine beats in the sodium D1 and D2 lines were resolved. The ground-state splitting could be determined with an accuracy of better than 0.001.