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Sample records for ciliary beat frequency

  1. Automatic analysis of ciliary beat frequency using optical flow

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    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. Swimming speed of larval snail does not correlate with size and ciliary beat frequency.

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    Chan, Kit Yu Karen; Jiang, Houshuo; Padilla, Dianna K

    2013-01-01

    Many marine invertebrates have planktonic larvae with cilia used for both propulsion and capturing of food particles. Hence, changes in ciliary activity have implications for larval nutrition and ability to navigate the water column, which in turn affect survival and dispersal. Using high-speed high-resolution microvideography, we examined the relationship between swimming speed, velar arrangements, and ciliary beat frequency of freely swimming veliger larvae of the gastropod Crepidula fornicata over the course of larval development. Average swimming speed was greatest 6 days post hatching, suggesting a reduction in swimming speed towards settlement. At a given age, veliger larvae have highly variable speeds (0.8-4 body lengths s(-1)) that are independent of shell size. Contrary to the hypothesis that an increase in ciliary beat frequency increases work done, and therefore speed, there was no significant correlation between swimming speed and ciliary beat frequency. Instead, there are significant correlations between swimming speed and visible area of the velar lobe, and distance between centroids of velum and larval shell. These observations suggest an alternative hypothesis that, instead of modifying ciliary beat frequency, larval C. fornicata modify swimming through adjustment of velum extension or orientation. The ability to adjust velum position could influence particle capture efficiency and fluid disturbance and help promote survival in the plankton.

  3. Swimming speed of larval snail does not correlate with size and ciliary beat frequency.

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    Kit Yu Karen Chan

    Full Text Available Many marine invertebrates have planktonic larvae with cilia used for both propulsion and capturing of food particles. Hence, changes in ciliary activity have implications for larval nutrition and ability to navigate the water column, which in turn affect survival and dispersal. Using high-speed high-resolution microvideography, we examined the relationship between swimming speed, velar arrangements, and ciliary beat frequency of freely swimming veliger larvae of the gastropod Crepidula fornicata over the course of larval development. Average swimming speed was greatest 6 days post hatching, suggesting a reduction in swimming speed towards settlement. At a given age, veliger larvae have highly variable speeds (0.8-4 body lengths s(-1 that are independent of shell size. Contrary to the hypothesis that an increase in ciliary beat frequency increases work done, and therefore speed, there was no significant correlation between swimming speed and ciliary beat frequency. Instead, there are significant correlations between swimming speed and visible area of the velar lobe, and distance between centroids of velum and larval shell. These observations suggest an alternative hypothesis that, instead of modifying ciliary beat frequency, larval C. fornicata modify swimming through adjustment of velum extension or orientation. The ability to adjust velum position could influence particle capture efficiency and fluid disturbance and help promote survival in the plankton.

  4. 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

  5. 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.

  6. Effects of histamine on ciliary beat frequency of ciliated cells from guinea pigs nasal mucosa.

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    An, Fengwei; Xing, Lijun; Zhang, Zhiqiang; Chen, Lei

    2015-10-01

    We aimed to investigate the effect of histamine on ciliary beat frequency (CBF) through combining high-speed digital microscopy and patch-clamp technology. Ciliated cells were obtained from septum and turbinate of 90-120-day-old healthy male guinea pigs. Tight seal was formed by applying negative pressure on the glass electrode after the drawing and pushing progress. Then, we enrolled high-speed digital microscopy to measure CBF before and after treatment with histamine of different concentrations ranging from 10(-6) to 10(-1) mol/L in Hank's solution and D-Hank's solution as well as after administrating adenosine triphosphate. One-way ANOVA, Student's t test or Kruskal-Wallis test was used for statistical comparisons. Glass electrode fix up ciliated cell is available at tip diameter of 2-5 μm and negative pressure of 10-20 cmH2O column. The baseline CBF in Hank's solution was higher than in D-Hank's solution. Treatment with 10(-6)-l0(-3) mol/L histamine of concentrations can stimulate a rise of CBF. Nevertheless, CBF in all groups decreased to baseline CBF within 20 min. Generally, 10(-2) mol/L histamine can stimulate a rise of CBF; meanwhile, the high concentration of histamine killed 50% ciliated cell. Histamine at 10(-1) mol/L killed all ciliated cells. Ciliary beating activity decreased in Ca(2+)-free solution. Moreover, adenosine triphosphate could increase CBF effectively after the stimulation effect of histamine. We construct an effective technology integrating patch-clamp technique with CBF measurements on ciliated cells. Extracellular histamine stimulation could increase CBF effectively.

  7. Effect of silymarin and harpagoside on inflammation reaction of BEAS-2B cells, on ciliary beat frequency (CBF) of trachea explants and on mucociliary clearance (MCC).

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    Boeckenholt, Corinna; Begrow, Frank; Verspohl, Eugen J

    2012-05-01

    Silymarin and harpagoside are derived from drugs which are used for their protective effects against hepatotoxicity and inflammatory processes. Both are now investigated with respect to the respiratory tract. They were able to reduce the release of the inflammatory cytokine RANTES (regulated on activation, normal T cells expressed and secreted) from BEAS-2B cells in a concentration-dependent manner when stimulated by a cytokine mix (10 ng/mL of TNF- α and IFN- γ). This effect was not due to a possible toxic effect (control experiments using LDH release as a marker). Silymarin but not harpagoside was able to increase ciliary beat frequency. Effects were comparable to positive controls (isoprenaline and salbutamol). Silymarin also increases mucociliary clearance. In conclusion, silymarin should be further investigated for its clinical use in distinct respiratory diseases.

  8. Quantitative analysis of ciliary beating in primary ciliary dyskinesia: a pilot study

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    Papon Jean-François

    2012-10-01

    Full Text Available Abstract Background Primary ciliary dyskinesia (PCD is a rare congenital respiratory disorder characterized by abnormal ciliary motility leading to chronic airway infections. Qualitative evaluation of ciliary beat pattern based on digital high-speed videomicroscopy analysis has been proposed in the diagnosis process of PCD. Although this evaluation is easy in typical cases, it becomes difficult when ciliary beating is partially maintained. We postulated that a quantitative analysis of beat pattern would improve PCD diagnosis. We compared quantitative parameters with the qualitative evaluation of ciliary beat pattern in patients in whom the diagnosis of PCD was confirmed or excluded. Methods Nasal nitric oxide measurement, nasal brushings and biopsies were performed prospectively in 34 patients with suspected PCD. In combination with qualitative analysis, 12 quantitative parameters of ciliary beat pattern were determined on high-speed videomicroscopy recordings of beating ciliated edges. The combination of ciliary ultrastructural abnormalities on transmission electron microscopy analysis with low nasal nitric oxide levels was the “gold standard” used to establish the diagnosis of PCD. Results This “gold standard” excluded PCD in 15 patients (non-PCD patients, confirmed PCD in 10 patients (PCD patients and was inconclusive in 9 patients. Among the 12 parameters, the distance traveled by the cilium tip weighted by the percentage of beating ciliated edges presented 96% sensitivity and 95% specificity. Qualitative evaluation and quantitative analysis were concordant in non-PCD patients. In 9/10 PCD patients, quantitative analysis was concordant with the “gold standard”, while the qualitative evaluation was discordant with the “gold standard” in 3/10 cases. Among the patients with an inconclusive “gold standard”, the use of quantitative parameters supported PCD diagnosis in 4/9 patients (confirmed by the identification of disease

  9. 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.

  10. 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.

  11. Finding the ciliary beating pattern with optimal efficiency

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    Osterman, Natan

    2011-01-01

    We introduce a measure for energetic efficiency of biological cilia acting individually or collectively and numerically determine the optimal beating patterns according to this criterion. Maximizing the efficiency of a single cilium leads to curly, often symmetric and somewhat counterintuitive patterns. But when looking at a densely ciliated surface, the optimal patterns become remarkably similar to what is observed in microorganisms like Paramecium. The optimal beating pattern then consists of a fast effective stroke and a slow sweeping recovery stroke. Metachronal coordination is essential for efficient pumping and the highest efficiency is achieved with antiplectic waves. Efficiency also increases with an increasing density of cilia up to the point where crowding becomes a problem. We finally relate the pumping efficiency of cilia to the swimming efficiency of a spherical microorganism and show that the experimentally estimated efficiency of Paramecium is surprisingly close to the theoretically possible op...

  12. Curvature regulation of the ciliary beat through axonemal twist

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    Sartori, Pablo; Geyer, Veikko F.; Howard, Jonathon; Jülicher, Frank

    2016-10-01

    Cilia and flagella are hairlike organelles that propel cells through fluid. The active motion of the axoneme, the motile structure inside cilia and flagella, is powered by molecular motors of the axonemal dynein family. These motors generate forces and torques that slide and bend the microtubule doublets within the axoneme. To create regular waveforms, the activities of the dyneins must be coordinated. It is thought that coordination is mediated by stresses due to radial, transverse, or sliding deformations, and which build up within the moving axoneme and feed back on dynein activity. However, which particular components of the stress regulate the motors to produce the observed waveforms of the many different types of flagella remains an open question. To address this question, we describe the axoneme as a three-dimensional bundle of filaments and characterize its mechanics. We show that regulation of the motors by radial and transverse stresses can lead to a coordinated flagellar motion only in the presence of twist. We show that twist, which could arise from torque produced by the dyneins, couples curvature to transverse and radial stresses. We calculate emergent beating patterns in twisted axonemes resulting from regulation by transverse stresses. The resulting waveforms are similar to those observed in flagella of Chlamydomonas and sperm. Due to the twist, the waveform has nonplanar components, which result in swimming trajectories such as twisted ribbons and helices, which agree with observations.

  13. 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.

  14. Levonorgestrel decreases cilia beat frequency of human fallopian tubes and rat oviducts without changing morphological structure.

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    Zhao, Weihong; Zhu, Qian; Yan, Mingxing; Li, Cheng; Yuan, Jiangjing; Qin, Guojuan; Zhang, Jian

    2015-02-01

    Levonorgestrel, a derivative of progesterone, effectively protects women against unwanted pregnancy as an emergency contraceptive. Previous studies have not been successful in determining the mechanism by which levonorgestrel acts. In the present study we analysed cilia beat action and cilia morphology following levonorgestrel exposure in vitro and in vivo using both light and electron microscopy. There was a significant decrease in the ciliary beat frequency (CBF) of human fallopian tubes between mucosal explants bathed in 5 μmol/L levonorgestrel and those bathed in medium alone (P levonorgestrel produced a similar reduction in CBF (~ 10%) compared with the saline control group (P levonorgestrel treatment in either system. Thus, levonorgestrel reduces CBF without damaging cilia morphology. Decreases in CBF may indicate a pathological role for levonorgestrel in the transportation of the ovum and zygote in the fallopian tube.

  15. 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.

  16. A distance meter using a terahertz intermode beat in an optical frequency comb.

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    Yokoyama, Shuko; Yokoyama, Toshiyuki; Hagihara, Yuki; Araki, Tsutomu; Yasui, Takeshi

    2009-09-28

    We propose a distance meter that utilizes an intermode beat of terahertz frequency in an optical frequency comb to perform high resolution and high dynamic range absolute distance measurements. The proposed system is based on a novel method, called multiheterodyne cross-correlation detection, in which intermode beat frequencies are scaled down to radio frequencies by optical mixing of two detuned optical frequency combs with a nonlinear optical crystal. Using this method, we obtained a 1.056 THz intermode beat and achieved a distance resolution of 0.820 microm from its phase measurement. Absolute distance measurement using 1.056 THz and 8.187 GHz intermode beats was also demonstrated in the range of 10 mm, resulting in a precision of 0.688 microm.

  17. Correlation technique and least square support vector machine combine for frequency domain based ECG beat classification.

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    Dutta, Saibal; Chatterjee, Amitava; Munshi, Sugata

    2010-12-01

    The present work proposes the development of an automated medical diagnostic tool that can classify ECG beats. This is considered an important problem as accurate, timely detection of cardiac arrhythmia can help to provide proper medical attention to cure/reduce the ailment. The proposed scheme utilizes a cross-correlation based approach where the cross-spectral density information in frequency domain is used to extract suitable features. A least square support vector machine (LS-SVM) classifier is developed utilizing the features so that the ECG beats are classified into three categories: normal beats, PVC beats and other beats. This three-class classification scheme is developed utilizing a small training dataset and tested with an enormous testing dataset to show the generalization capability of the scheme. The scheme, when employed for 40 files in the MIT/BIH arrhythmia database, could produce high classification accuracy in the range 95.51-96.12% and could outperform several competing algorithms.

  18. 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.

  19. Molecular modulation of airway epithelial ciliary response to sneezing.

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    Zhao, Ke-Qing; Cowan, Andrew T; Lee, Robert J; Goldstein, Natalia; Droguett, Karla; Chen, Bei; Zheng, Chunquan; Villalon, Manuel; Palmer, James N; Kreindler, James L; Cohen, Noam A

    2012-08-01

    Our purpose was to evaluate the effect of the mechanical force of a sneeze on sinonasal cilia function and determine the molecular mechanism responsible for eliciting the ciliary response to a sneeze. A novel model was developed to deliver a stimulation simulating a sneeze (55 mmHg for 50 ms) at 26°C to the apical surface of mouse and human nasal epithelial cells. Ciliary beating was visualized, and changes in ciliary beat frequency (CBF) were determined. To interrogate the molecular cascades driving sneeze-induced changes of CBF, pharmacologic manipulation of intra- and extracellular calcium, purinergic, PKA, and nitric oxide (NO) signaling were performed. CBF rapidly increases by ≥150% in response to a sneeze, which is dependent on the release of adenosine triphosphate (ATP), calcium influx, and PKA activation. Furthermore, apical release of ATP is independent of calcium influx, but calcium influx and subsequent increase in CBF are dependent on the ATP release. Lastly, we observed a blunted ciliary response in surgical specimens derived from patients with chronic rhinosinusitis compared to control patients. Apical ATP release with subsequent calcium mobilization and PKA activation are involved in sinonasal ciliary response to sneezing, which is blunted in patients with upper-airway disease.

  20. High-frequency binaural beats increase cognitive flexibility: evidence from dual-task crosstalk

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    Bernhard Hommel

    2016-08-01

    Full Text Available Increasing evidence suggests that cognitive-control processes can be configured to optimize either persistence of information processing (by amplifying competition between decision-making alternatives and top-down biasing of this competition or flexibility (by dampening competition and biasing. We investigated whether high-frequency binaural beats, an auditory illusion suspected to act as a cognitive enhancer, have an impact on cognitive-control configuration. We hypothesized that binaural beats in the gamma range bias the cognitive-control style towards flexibility, which in turn should increase the crosstalk between tasks in a dual-task paradigm. We replicated earlier findings that the reaction time in the first-performed task is sensitive to the compatibility between the responses in the first and the second task—an indication of crosstalk. As predicted, exposing participants to binaural beats in the gamma range increased this effect as compared to a control condition in which participants were exposed to a continuous tone of 340 Hz. These findings provide converging evidence that the cognitive-control style can be systematically biased by inducing particular internal states; that high-frequency binaural beats bias the control style towards more flexibility; and that different styles are implemented by changing the strength of local competition and top-down bias.

  1. 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.

  2. 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.

  3. Stability of beating frequency in cardiac myocytes by their community effect measured by agarose microchamber chip

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    Yasuda Kenji

    2005-05-01

    Full Text Available Abstract To understand the contribution of community effect on the stability of beating frequency in cardiac myocyte cell groups, the stepwise network formation of cells as the reconstructive approach using the on-chip agarose microchamber cell microcultivation system with photo-thermal etching method was applied. In the system, the shapes of agarose microstructures were changed step by step with photo-thermal etching of agarose-layer of the chip using a 1064-nm infrared focused laser beam to increase the interaction of cardiac myocyte cells during cultivation. First, individual rat cardiac myocyte in each microstructure were cultivated under isolated condition, and then connected them one by one through newly-created microchannels by photo-thermal etching to compare the contribution of community size for the magnitude of beating stability of the cell groups. Though the isolated individual cells have 50% fluctuation of beating frequency, their stability increased as the number of connected cells increased. And finally when the number reached to eight cells, they stabilized around the 10% fluctuation, which was the same magnitude of the tissue model cultivated on the dish. The result indicates the importance of the community size of cells to stabilize their performance for making cell-network model for using cells for monitoring their functions like the tissue model.

  4. Nasal nitric oxide and nitric oxide synthase expression in primary ciliary dyskinesia.

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    Pifferi, M; Bush, A; Maggi, F; Michelucci, A; Ricci, V; Conidi, M E; Cangiotti, A M; Bodini, A; Simi, P; Macchia, P; Boner, A L

    2011-03-01

    No study has evaluated the correlation between different expression of nitric oxide synthase (NOS) isoforms in nasal epithelial cells and nasal NO (nNO) level in primary ciliary dyskinesia (PCD). Gene expression of endothelial (NOS3) and inducible NOS (NOS2) and their correlation with nNO level, ciliary function and morphology were studied in patients with PCD or secondary ciliary dyskinesia (SCD). NOS3 gene polymorphisms were studied in blood leukocytes. A total of 212 subjects were studied (48 with PCD, 161 with SCD and three normal subjects). nNO level correlated with mean ciliary beat frequency (p = 0.044; r = 0.174). The lower the nNO level the higher was the percentage of immotile cilia (p<0.001; r = -0.375). A significant positive correlation between NOS2 gene expression and nNO levels was demonstrated in all children (p = 0.001; r = 0.428), and this correlation was confirmed in patients with PCD (p = 0.019; r = 0.484). NOS2 gene expression was lower in PCD than in SCD (p = 0.04). The NOS3 isoform correlated with missing central microtubules (p = 0.048; r = 0.447). nNO levels were higher in PCD subjects with the NOS3 thymidine 894 mutation, and this was associated with a higher ciliary beat frequency (p = 0.045). These results demonstrate a relationship between nNO level, NOS mRNA expression and ciliary beat frequency.

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

    Science.gov (United States)

    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. Study on mechanism of amplitude fluctuation of dual-frequency beat in microchip Nd:YAG laser

    Science.gov (United States)

    Chen, Hao; Tan, Yidong; Zhang, Shulian; Sun, Liqun

    2017-01-01

    In the laser heterodyne interferometry based on the microchip Nd:YAG dual-frequency laser, the amplitude of the beat note periodically fluctuates in time domain, which leads to the instability of the measurement. On the frequency spectrums of the two mono-frequency components of the laser and their beat note, several weak sideband signals are observed on both sides of the beat note. It is proved that the sideband frequencies are associated with the relaxation oscillation frequencies of the laser. The mechanism for the relaxation oscillations inducing the occurrence of the sideband signals is theoretically analyzed, and the quantitative relationship between the intensity ratio of the beat note to the sideband signal and the level of the amplitude fluctuation is simulated with the derived mathematical model. The results demonstrate that the periodical amplitude fluctuation of the beat note is actually induced by the relaxation oscillation. And the level of the amplitude fluctuation is lower than 10% when the intensity ratio is greater than 32 dB. These conclusions are beneficial to reduce the amplitude fluctuation of the microchip Nd:YAG dual-frequency laser and improve the stability of the heterodyne interferometry.

  7. 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.

  8. 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

    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......) of spontaneous swimming in Embiotoca lateralis were measured in a circular arena using video tracking and respirometry, respectively. The main variable influencing MO2 was pectoral fin beat frequency (r (2) = 0.71). No significant relationship was found between swimming speed and pectoral fin beat frequency...... consumption patterns are likely to be quite different in field situation compared to a small lab tank. In addition, our methods could be useful to measure metabolic costs of growth and development, or bioassays for possible toxicological effects on fish....

  9. 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.

  10. Measuring tail beat frequency and coast phase in school of fish for collective motion analysis

    Science.gov (United States)

    Terayama, Kei; Hioki, Hirohisa; Sakagami, Masa-aki

    2017-02-01

    We propose a measurement method of Tail Beat Frequency (TBF) and Coast Phase (CP) of fish swimming for isolated fish in a school of fish with visual tracking. For analysis of fish swimming behaviors, features that represent fish movements, e.g., TBF and CP, have been commonly used in the fields of biological and fisheries researches. We propose a measurement method for such features using particle filter and apply the method to a large school of fish in an aquarium. Experimental results show that the TBFs and the CPs are measured with our method accurately enough for further analysis of fish behaviors. The average errors of the TBFs was 0.126 (Hz) and the precision and recall of the classification for CP detection were 0.945 and 0.879 respectively.

  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. Auditory driving of the autonomic nervous system: Listening to theta-frequency binaural beats post-exercise increases parasympathetic activation and sympathetic withdrawal.

    Science.gov (United States)

    McConnell, Patrick A; Froeliger, Brett; Garland, Eric L; Ives, Jeffrey C; Sforzo, Gary A

    2014-01-01

    Binaural beats are an auditory illusion perceived when two or more pure tones of similar frequencies are presented dichotically through stereo headphones. Although this phenomenon is thought to facilitate state changes (e.g., relaxation), few empirical studies have reported on whether binaural beats produce changes in autonomic arousal. Therefore, the present study investigated the effects of binaural beating on autonomic dynamics [heart rate variability (HRV)] during post-exercise relaxation. Subjects (n = 21; 18-29 years old) participated in a double-blind, placebo-controlled study during which binaural beats and placebo were administered over two randomized and counterbalanced sessions (within-subjects repeated-measures design). At the onset of each visit, subjects exercised for 20-min; post-exercise, subjects listened to either binaural beats ('wide-band' theta-frequency binaural beats) or placebo (carrier tones) for 20-min while relaxing alone in a quiet, low-light environment. Dependent variables consisted of high-frequency (HF, reflecting parasympathetic activity), low-frequency (LF, reflecting sympathetic and parasympathetic activity), and LF/HF normalized powers, as well as self-reported relaxation. As compared to the placebo visit, the binaural-beat visit resulted in greater self-reported relaxation, increased parasympathetic activation and increased sympathetic withdrawal. By the end of the 20-min relaxation period there were no observable differences in HRV between binaural-beat and placebo visits, although binaural-beat associated HRV significantly predicted subsequent reported relaxation. Findings suggest that listening to binaural beats may exert an acute influence on both LF and HF components of HRV and may increase subjective feelings of relaxation.

  13. 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.

  14. Purinergically induced membrane fluidization in ciliary cells: characterization and control by calcium and membrane potential.

    Science.gov (United States)

    Alfahel, E; Korngreen, A; Parola, A H; Priel, Z

    1996-02-01

    To examine the role of membrane dynamics in transmembrane signal transduction, we studied changes in membrane fluidity in mucociliary tissues from frog palate and esophagus epithelia stimulated by extracellular ATP. Micromolar concentrations of ATP induced strong changes in fluorescence polarization, possibly indicating membrane fluidization. This effect was dosage dependent, reaching a maximum at 10-microM ATP. It was dependent on the presence of extracellular Ca2+ (or Mg2+), though it was insensitive to inhibitors of voltage-gated calcium channels. It was inhibited by thapsigargin and by ionomycin (at low extracellular Ca2+ concentration), both of which deplete Ca2+ stores. It was inhibited by the calcium-activated potassium channel inhibitors quinidine, charybdotoxin, and apamine and was reduced considerably by replacement of extracellular Na+ with K+. Hyperpolarization, or depolarization, of the mucociliary membrane induced membrane fluidization. The degree of membrane fluidization depended on the degree of hyperpolarization or depolarization of the ciliary membrane potential and was considerably lower than the effect induced by extracellular ATP. These results indicate that appreciable membrane fluidization induced by extracellular ATP depends both on an increase in intracellular Ca2+, mainly from its internal stores, and on hyperpolarization of the membrane. Calcium-dependent potassium channels couple the two effects. In light of recent results on the enhancement of ciliary beat frequency, it would appear that extracellular ATP-induced changes both in ciliary beat frequency and in membrane fluidity are triggered by similar signal transduction pathways.

  15. 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.

  16. Digitally synthesized beat frequency multiplexing for sub-millisecond fluorescence microscopy

    CERN Document Server

    Diebold, Eric D; Gossett, Daniel R; Jalali, Bahram

    2013-01-01

    Fluorescence imaging is the most widely used method for unveiling the molecular composition of biological specimens. However, the weak optical emission of fluorescent probes and the tradeoff between imaging speed and sensitivity is problematic for acquiring blur-free images of fast phenomena, such as sub-millisecond biochemical dynamics in live cells and tissues, and cells flowing at high speed. We report a solution that achieves real-time pixel readout rates one order of magnitude faster than a modern electron multiplier charge coupled device (EMCCD) - the gold standard in high-speed fluorescence imaging technology. Deemed fluorescence imaging using radiofrequency-multiplexed excitation (FIRE), this approach maps the image into the radiofrequency spectrum using the beating of digitally synthesized optical fields. We demonstrate diffraction-limited confocal fluorescence imaging of stationary cells at a frame rate of 4.4 kHz, as well as fluorescence microscopy in flow at a throughput of approximately 50,000 ce...

  17. 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.

  18. 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....

  19. Partition of aerobic and anaerobic swimming costs and their correlation to tail-beat frequency and burst activity in Sparus aurata

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2012-01-01

    until fatigue at 10°C. The anaerobic swimming cost was measured as the excess postexercise oxygen consumption (EPOC) following each swimming speed. To determine tail-beat frequency, amplitude and burst and coast behaviour, the peduncle position was determined at 25 s·' by video tracking. The data showed......, and resulted in a total anaerobic capacity of 170 mg O2 kg·'. Normalized tail-beat amplitude and frequency both predicted the swimming speed but only tail-beat frequency was able to predict the aerobic swimming cost. The change to burst and coast swimming was correlated to the first measurements of EPOC......Soc for experimental Biol Annual Meeting - Salzburg 2012 Bjørn Tirsgaard (University of Copenhagen, Denmark) and John Fleng Steffensen (University of Copenhagen, Denmark) Aerobic and anaerobic oxygen consumption was measured for 13 Sparus aurata swimming at incremental increasing swimming speeds...

  20. [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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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?...

  7. 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.

  8. Primary ciliary dyskinesia

    Directory of Open Access Journals (Sweden)

    Plavec Goran

    2004-01-01

    Full Text Available In patients with chronic respiratory diseases that last since the early childhood, primary ciliary dyskinesia (PCD needs to be considered. Four patients reviewed in this paper were with typical disease history and clinical picture, as well as clear ciliary axonema damage. Complete examination was performed in all the patients, including bronchoscopy with bronchography, and the examination of the biopsy samples of respiratory airways’ mucous membrane, obtained by transmission electron microscope (TEM. In two of the patients spermatozoa were also examined by TEM. Large anatomic deffects of airways were found in all the patients, but pulmonary function was normal (except in one case, representing one of PCD’s significant characteristics. First two cases fulfilled the criteria for Kartagener’s syndrome, which was initially sufficient for the diagnosis of PCD.

  9. Diagnosis of primary ciliary dyskinesia

    Directory of Open Access Journals (Sweden)

    Mary Anne Kowal Olm

    2015-06-01

    Full Text Available Primary ciliary dyskinesia (PCD is a genetic disorder of ciliary structure or function. It results in mucus accumulation and bacterial colonization of the respiratory tract which leads to chronic upper and lower airway infections, organ laterality defects, and fertility problems. We review the respiratory signs and symptoms of PCD, as well as the screening tests for and diagnostic investigation of the disease, together with details related to ciliary function, ciliary ultrastructure, and genetic studies. In addition, we describe the difficulties in diagnosing PCD by means of transmission electron microscopy, as well as describing patient follow-up procedures.

  10. Diagnosis of primary ciliary dyskinesia*

    Science.gov (United States)

    Olm, Mary Anne Kowal; Caldini, Elia Garcia; Mauad, Thais

    2015-01-01

    Primary ciliary dyskinesia (PCD) is a genetic disorder of ciliary structure or function. It results in mucus accumulation and bacterial colonization of the respiratory tract which leads to chronic upper and lower airway infections, organ laterality defects, and fertility problems. We review the respiratory signs and symptoms of PCD, as well as the screening tests for and diagnostic investigation of the disease, together with details related to ciliary function, ciliary ultrastructure, and genetic studies. In addition, we describe the difficulties in diagnosing PCD by means of transmission electron microscopy, as well as describing patient follow-up procedures. PMID:26176524

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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 %.

  16. CCDC151 Mutations Cause Primary Ciliary Dyskinesia by Disruption of the Outer Dynein Arm Docking Complex Formation

    NARCIS (Netherlands)

    Hjeij, R.; Onoufriadis, A.; Watson, C.M.; Slagle, C.E.; Klena, N.T.; Dougherty, G.W.; Kurkowiak, M.; Loges, N.T.; Diggle, C.P.; Morante, N.F.; Gabriel, G.C.; Lemke, K.L.; Li, Y.; Pennekamp, P.; Menchen, T.; Konert, F.; Marthin, J.K.; Mans, D.A.; Letteboer, S.J.F.; Werner, C.; Burgoyne, T.; Westermann, C.; Rutman, A.; Carr, I.M.; O'Callaghan, C.; Moya, E.; Chung, E.M.; Consortium, U.K.; Sheridan, E.; Nielsen, K.G.; Roepman, R.; Bartscherer, K.; Burdine, R.D.; Lo, C.W.; Omran, H.; Mitchison, H.M.

    2014-01-01

    A diverse family of cytoskeletal dynein motors powers various cellular transport systems, including axonemal dyneins generating the force for ciliary and flagellar beating essential to movement of extracellular fluids and of cells through fluid. Multisubunit outer dynein arm (ODA) motor complexes, p

  17. 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

    A diverse family of cytoskeletal dynein motors powers various cellular transport systems, including axonemal dyneins generating the force for ciliary and flagellar beating essential to movement of extracellular fluids and of cells through fluid. Multisubunit outer dynein arm (ODA) motor complexes...

  18. 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。

  19. Genetics Home Reference: primary ciliary dyskinesia

    Science.gov (United States)

    ... inversus totalis, they are often said to have Kartagener syndrome. Approximately 12 percent of people with primary ... Registry: Ciliary dyskinesia, primary, 17 Genetic Testing Registry: Kartagener syndrome Genetic Testing Registry: Primary ciliary dyskinesia Other ...

  20. 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.

  1. 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

  2. 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.......001) in patients with >1.5% ectopic beats compared with those with reverse remodeling (percent reduction in LVESV 31 ± 15%) than patients with ... biventricular pacing (reverse remodeling and higher risk of HF/death and VTA. This supports pre-implantation Holter monitoring of patients selected for CRT for optimal outcome. (MADIT-CRT: Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization...

  3. 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...

  4. 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.

  5. [The influence of an isotonic solution containing benzalkonium chloride and a hypertonic seawater solution on the function of ciliary epithelium from the nasal cavity in vitro].

    Science.gov (United States)

    Laberko, E L; Bogomil'sky, M R; Soldatsky, Yu L; Pogosova, I E

    2016-01-01

    The objective of the present study was to evaluate the influence of an isotonic saline solution containing benzalconium chloride and of a hypertonic seawater solution on the function of ciliary epithelium in the nasal cavity in vitro. To this effect, we investigated the cytological material obtained from 35 children presenting with adenoid tissue hypertrophy. The tissue samples were taken from the nasal cavity by the standard method. A cellular biopsy obtained from each patient was distributed between three tubes that contained isotonic saline solution supplemented by benzalconium chloride (0.1 mg/ml), a hypertonic seawater solution, and a standard physiological saline solution. It was shown that the number of the viable cells in both isotonic solutions was statistically comparable and significantly higher than in the hypertonic solution (p<0.05). The ciliary beat frequency of the cells embedded in the two isotonic solutions was not significantly different but considerably exceeded that in the hypertonic seawater solution (p<0.05). Thus, the present study has demonstrated the absence of the ciliotoxic influence of isotonic saline solution containing benzalconium chloride at a concentration of 0.1 mg/ml and the strong ciliotoxic effect of the hypertonic seawater solution. This finding gives reason to recommend isotonic solutions for the regular application whereas hypertonic solutions can be prescribed only during infectious and/or inflammatory ENT diseases.

  6. Circular flow patterns induced by ciliary activity in reconstituted human bronchial epithelium

    Science.gov (United States)

    Viallat, Annie; Khelloufi, Kamel; Gras, Delphine; Chanez, Pascal; Aix Marseille Univ., CNRS, CINaM, Marseille, France Team; Aix Marseille Univ., CNRS, Inserm, LAI, Marseille, France Team

    2016-11-01

    Mucociliary clearance is the transport at the surface of airways of a complex fluid layer, the mucus, moved by the beats of microscopic cilia present on epithelial ciliated cells. We explored the coupling between the spatial organisation and the activity of cilia and the transport of surface fluids on reconstituted cultures of human bronchial epithelium at air-liquid interface, obtained by human biopsies. We reveal the existence of stable local circular surface flow patterns of mucus or Newtonian fluid at the epithelium surface. We find a power law over more than 3 orders of magnitude showing that the average ciliated cell density controls the size of these flow patterns, and, therefore the distance over which mucus can be transported. We show that these circular flow patterns result from the radial linear increase of the local propelling forces (due to ciliary beats) on each flow domain. This linear increase of local forces is induced by a fine self-regulation of both cilia density and orientation of ciliary beats. Local flow domains grow and merge during ciliogenesis to provide macroscopic mucus transport. This is possible only when the viscoelastic mucus continuously exerts a shear stress on beating cilia, revealing a mechanosensitive function of cilia. M. K. Khelloufi thanks the society MedBioMed for financial support. This work was supported by the ANR MUCOCIL project, Grant ANR-13-BSV5-0015 of the French Agence Nationale de la Recherche.

  7. Ciliary/Flagellar Protein Ubiquitination

    OpenAIRE

    Huan Long; Qiyu Wang; Kaiyao Huang

    2015-01-01

    Cilia/flagella are conserved eukaryotic organelles that play an important role in the control of cell motility and detection of environmental cues. However, the molecular mechanisms underlying ciliary/flagellar assembly, maintenance, disassembly, and signal transduction are not yet completely understood. Recent studies demonstrated that post-translational modifications (PTMs) such as phosphorylation, methylation, glutamylation, and ubiquitination are involved in these processes. In this mini ...

  8. 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

  9. 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...

  10. 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.

  11. 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.

  12. 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...... entered through a secure website and were reviewed centrally. Survival was analyzed using Kaplan-Meier analysis and Cox proportional hazards regression. MAIN OUTCOME MEASURES: Proportion of females, tumor-node-metastasis (TNM) stage, cell type, and melanoma-related mortality. RESULTS: Cumulative frequency...... type, known for 35% of tumors, and TNM stage (I in 22% and 21%, II in 49% and 52%, III in 30% and 28%, respectively) were comparable for children and young adults. Melanoma-related survival was 97% and 90% at 5 years and 92% and 80% at 10 years for children compared with young adults, respectively (P...

  13. Appropriate threshold levels of cardiac beat-to-beat variation in semi-automatic analysis of equine ECG recordings

    DEFF Research Database (Denmark)

    Madsen, Mette Flethøj; Kanters, Jørgen K.; Pedersen, Philip Juul

    2016-01-01

    Background: Although premature beats are a matter of concern in horses, the interpretation of equine ECG recordings is complicated by a lack of standardized analysis criteria and a limited knowledge of the normal beat-to-beat variation of equine cardiac rhythm. The purpose of this study was to de......Background: Although premature beats are a matter of concern in horses, the interpretation of equine ECG recordings is complicated by a lack of standardized analysis criteria and a limited knowledge of the normal beat-to-beat variation of equine cardiac rhythm. The purpose of this study...... was to determine the appropriate threshold levels of maximum acceptable deviation of RR intervals in equine ECG analysis, and to evaluate a novel two-step timing algorithm by quantifying the frequency of arrhythmias in a cohort of healthy adult endurance horses. Results: Beat-to-beat variation differed......, range 1–24). Conclusions: Beat-to-beat variation of equine cardiac rhythm varies according to HR, and threshold levels in equine ECG analysis should be adjusted accordingly. Standardization of the analysis criteria will enable comparisons of studies and follow-up examinations of patients. A small number...

  14. 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...

  15. 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 pressure...

  16. Off beat: pluralizing rhythm

    NARCIS (Netherlands)

    Hoogstad, J.H.; Stougaard Pedersen, B.

    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

  17. Linear systems analysis of the ciliary steering behavior associated with negative-phototaxis in Chlamydomonas reinhardtii.

    Science.gov (United States)

    Josef, Keith; Saranak, Jureepan; Foster, Kenneth W

    2006-12-01

    In response to light stimulation Chlamydomonas reinhardtii changes the beating frequency, beating pattern, and beating synchrony of the trans and cis cilia to steer the freely-swimming cell relative to light sources. To understand the cell steering behavior the impulse responses of the beating frequency and stroke velocity of each cilium have been obtained with high temporal resolution on cells held with a micropipette. Interestingly the response of each cilium is quite different. The trans cilium responds with less delay than the cis cilium for both beating frequency and stroke velocity. For light stimulation at 2 Hz, the critical cell-rotation frequency, both responses of the trans and cis cilia are about 180 degrees out of phase. The trans-cilium beating frequency response peaks at a stimulus frequency of 5-6 Hz, higher than the cis at 1-2 Hz. The stroke velocities of the trans and cis cilia have the same stimulus-frequency response (2 Hz), but the trans cilium has a shorter delay than the cis. The times to maximum response are much shorter than the time for a rotation of the cell. The use of two different approaches that enable the trans cilium to respond ahead of the cis for both the beating frequency and stroke velocity responses suggests the importance of both responses to phototaxis. Internal cell processing responsible for the time course of the responses is proposed.

  18. 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.

  19. 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.

  20. 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 .

  1. [Primary ciliary dyskinesia, immotile cilia syndrome, and Kartagener syndrome: diagnostic criteria].

    Science.gov (United States)

    Dombi, V H; Walt, H

    1996-03-16

    Primary ciliary dyskinesia is the generic term for a heterogeneous group of inherited diseases in which ciliary ultrastructure is defective and as a consequence ciliary motility is disturbed. An international consensus on the diagnostic criteria has not yet been reached. This paper reviews some recent findings which are useful in the diagnosis of the disease and attempts to establish the best diagnostic criteria. The marker symptoms are chronic bronchitis, otitis, and sinusitis since childhood. Additionally, one or more of the following criteria must be present: Kartagener syndrome, a dextrocardia situation, markedly reduced frequency in ciliary motility, or an essential ultrastructure deviation in more than 20% of the square cuts (e.g. reduced number of dynein arms). Biopsy of the ciliated mucosa is usually required for the above criteria and is studied by vital microscopy and transmission electron microscopy. Primary and secondary ciliary dyskinesia can be distinguished by these methods and the rare case of PCD without ultrastructure deficiency ruled out. In special cases a cell culture is recommended for the diagnosis. Practical aspects of the sampling methods and diagnostic pitfalls are reviewed.

  2. Primary ciliary dyskinesia diagnosed by electron microscopy in one case of Kartagener syndrome.

    Science.gov (United States)

    Rugină, Aniela Luminiţa; Dimitriu, Alexandru Grigore; Nistor, Nicolai; Mihăilă, Doina

    2014-01-01

    Primary ciliary dyskinesia (PCD) is associated with abnormalities in the structure of a function of motile cilia, causing impairment of muco-ciliary clearence, with bacterial overinfection of the upper and lower respiratory tract (chronic oto-sino-pulmonary disease), heterotaxia (situs abnormalities), with/without congenital heart disease, abnormal sperm motility with male infertility, higher frequency of ectopic pregnancy and female subfertility. The presence of recurrent respiratory tract infections in the pediatric age requires differentiation between primary immunodeficiency, diseases with abnormal mucus (e.g., cystic fibrosis) and abnormal ciliary diseases. This case was hospitalized for recurrent respiratory tract infections and total situs inversus at the age of five years, which has enabled the diagnosis of Kartagener syndrome. The PCD confirmation was performed by electron microscopy examination of nasal mucosa cells through which were confirmed dynein arms abnormalities. The diagnosis and early treatment of childhood PCD allows a positive development and a good prognosis, thus improving the quality of life.

  3. 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.

  4. 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.

  5. [Primary ciliary dyskinesia: clinical and genetic aspects].

    Science.gov (United States)

    D'Auria, E; Palazzo, S; Argirò, S; El, Oksha S; Riva, E

    2012-01-01

    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.

  6. 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.

  7. 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 ...

  8. 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.

  9. What can we learn about beat perception by comparing brain signals and stimulus envelopes?

    Science.gov (United States)

    Henry, Molly J.; Herrmann, Björn; Grahn, Jessica A.

    2017-01-01

    Entrainment of neural oscillations on multiple time scales is important for the perception of speech. Musical rhythms, and in particular the perception of a regular beat in musical rhythms, is also likely to rely on entrainment of neural oscillations. One recently proposed approach to studying beat perception in the context of neural entrainment and resonance (the “frequency-tagging” approach) has received an enthusiastic response from the scientific community. A specific version of the approach involves comparing frequency-domain representations of acoustic rhythm stimuli to the frequency-domain representations of neural responses to those rhythms (measured by electroencephalography, EEG). The relative amplitudes at specific EEG frequencies are compared to the relative amplitudes at the same stimulus frequencies, and enhancements at beat-related frequencies in the EEG signal are interpreted as reflecting an internal representation of the beat. Here, we show that frequency-domain representations of rhythms are sensitive to the acoustic features of the tones making up the rhythms (tone duration, onset/offset ramp duration); in fact, relative amplitudes at beat-related frequencies can be completely reversed by manipulating tone acoustics. Crucially, we show that changes to these acoustic tone features, and in turn changes to the frequency-domain representations of rhythms, do not affect beat perception. Instead, beat perception depends on the pattern of onsets (i.e., whether a rhythm has a simple or complex metrical structure). Moreover, we show that beat perception can differ for rhythms that have numerically identical frequency-domain representations. Thus, frequency-domain representations of rhythms are dissociable from beat perception. For this reason, we suggest caution in interpreting direct comparisons of rhythms and brain signals in the frequency domain. Instead, we suggest that combining EEG measurements of neural signals with creative behavioral

  10. The intraflagellar transport machinery in ciliary signaling

    DEFF Research Database (Denmark)

    Mourão, André; Christensen, Søren Tvorup; Lorentzen, Esben

    2016-01-01

    environmental cues necessary for organ development and maintenance of human health. Pathways reported to rely on the cilium organelle include Hedgehog, TGF-β, Wnt, PDGFRα, integrin and DNA damage repair signaling. An emerging theme in ciliary signaling is the requirement for active transport of signaling...

  11. An international registry for primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Werner, Claudius; Lablans, Martin; Ataian, Maximilian

    2016-01-01

    Primary ciliary dyskinesia (PCD) is a rare autosomal recessive disorder leading to chronic upper and lower airway disease. Fundamental data on epidemiology, clinical presentation, course and treatment strategies are lacking in PCD. We have established an international PCD registry to realise an u...

  12. 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.

  13. 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.

  14. Beat to beat variability in cardiovascular variables: noise or music?

    Science.gov (United States)

    Appel, M. L.; Berger, R. D.; Saul, J. P.; Smith, J. M.; Cohen, R. J.

    1989-01-01

    Cardiovascular variables such as heart rate, arterial blood pressure, stroke volume and the shape of electrocardiographic complexes all fluctuate on a beat to beat basis. These fluctuations have traditionally been ignored or, at best, treated as noise to be averaged out. The variability in cardiovascular signals reflects the homeodynamic interplay between perturbations to cardiovascular function and the dynamic response of the cardiovascular regulatory systems. Modern signal processing techniques provide a means of analyzing beat to beat fluctuations in cardiovascular signals, so as to permit a quantitative, noninvasive or minimally invasive method of assessing closed loop hemodynamic regulation and cardiac electrical stability. This method promises to provide a new approach to the clinical diagnosis and management of alterations in cardiovascular regulation and stability.

  15. Analysis of the forces acting on beating cilia

    Science.gov (United States)

    Sangani, Ashok S.; Vidyadharan, Jyothish; Foster, Kenneth W.

    2016-06-01

    Detailed analysis of the forces acting on a uniform-diameter beating cilium is carried out to determine the moment generated by the inter-doublet forces acting along the length of a cilium and the results are compared with the sliding-control theory according to which the moment is a function of the interdoublet sliding. In the central part of the cilium the inter-doublet forces are found to be proportional to the inter-doublet sliding. However, in spite of the uniformity of the diameter of the cilium, the proportionality constant, known as the dynamic stiffness, is not constant along its entire length. Significant variations are observed in the regions both near the tip of the cilium and proximal to the cell body. In the tip region the magnitude of the dynamic stiffness is found to decrease. This decrease is probably due to decrease in the number density of the molecular motors in that region and in the number of doublet microtubules. The behavior in the proximal region, on the other hand, does not appear to be well described by the sliding control theory. Our analysis therefore suggests that the dynamics of ciliary beating cannot be adequately described by a simple sliding-control theory with constant dynamic stiffness. Our analysis suggests that the cilium is differentiated into a basal region optimized for the creation of a wave and a central region optimized to support a traveling wave that provides the thrust for the cell.

  16. Cellular Mechanisms of Ciliary Length Control

    Directory of Open Access Journals (Sweden)

    Jacob Keeling

    2016-01-01

    Full Text Available Cilia and flagella are evolutionarily conserved, membrane-bound, microtubule-based organelles on the surface of most eukaryotic cells. They play important roles in coordinating a variety of signaling pathways during growth, development, cell mobility, and tissue homeostasis. Defects in ciliary structure or function are associated with multiple human disorders called ciliopathies. These diseases affect diverse tissues, including, but not limited to the eyes, kidneys, brain, and lungs. Many processes must be coordinated simultaneously in order to initiate ciliogenesis. These include cell cycle, vesicular trafficking, and axonemal extension. Centrioles play a central role in both cell cycle progression and ciliogenesis, making the transition between basal bodies and mitotic spindle organizers integral to both processes. The maturation of centrioles involves a functional shift from cell division toward cilium nucleation which takes place concurrently with its migration and fusion to the plasma membrane. Several proteinaceous structures of the distal appendages in mother centrioles are required for this docking process. Ciliary assembly and maintenance requires a precise balance between two indispensable processes; so called assembly and disassembly. The interplay between them determines the length of the resulting cilia. These processes require a highly conserved transport system to provide the necessary substances at the tips of the cilia and to recycle ciliary turnover products to the base using a based microtubule intraflagellar transport (IFT system. In this review; we discuss the stages of ciliogenesis as well as mechanisms controlling the lengths of assembled cilia.

  17. 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...

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

    Science.gov (United States)

    Gilpin, William; Prakash, Vivek N.; Prakash, Manu

    2016-11-01

    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 demonstrate that these vortices create a physical tradeoff between feeding and swimming in heterogenous environments, which manifests as distinct flow patterns or "eigenstrokes" representing each behavior-potentially implicating neuronal control of cilia. This quantitative interplay between larval form and hydrodynamic function generalizes to other invertebrates, and illustrates the potential effects of active boundary conditions in other biological and synthetic systems.

  19. Selective neuronal entrainment to the beat and meter embedded in a musical rhythm.

    Science.gov (United States)

    Nozaradan, Sylvie; Peretz, Isabelle; Mouraux, André

    2012-12-05

    Fundamental to the experience of music, beat and meter perception refers to the perception of periodicities while listening to music occurring within the frequency range of musical tempo. Here, we explored the spontaneous building of beat and meter hypothesized to emerge from the selective entrainment of neuronal populations at beat and meter frequencies. The electroencephalogram (EEG) was recorded while human participants listened to rhythms consisting of short sounds alternating with silences to induce a spontaneous perception of beat and meter. We found that the rhythmic stimuli elicited multiple steady state-evoked potentials (SS-EPs) observed in the EEG spectrum at frequencies corresponding to the rhythmic pattern envelope. Most importantly, the amplitude of the SS-EPs obtained at beat and meter frequencies were selectively enhanced even though the acoustic energy was not necessarily predominant at these frequencies. Furthermore, accelerating the tempo of the rhythmic stimuli so as to move away from the range of frequencies at which beats are usually perceived impaired the selective enhancement of SS-EPs at these frequencies. The observation that beat- and meter-related SS-EPs are selectively enhanced at frequencies compatible with beat and meter perception indicates that these responses do not merely reflect the physical structure of the sound envelope but, instead, reflect the spontaneous emergence of an internal representation of beat, possibly through a mechanism of selective neuronal entrainment within a resonance frequency range. Taken together, these results suggest that musical rhythms constitute a unique context to gain insight on general mechanisms of entrainment, from the neuronal level to individual level.

  20. Helkesimastix marina n. sp. (Cercozoa: Sainouroidea superfam. n.) a gliding zooflagellate of novel ultrastructure and unusual ciliary behaviour.

    Science.gov (United States)

    Cavalier-Smith, Thomas; Lewis, Rhodri; Chao, Ema E; Oates, Brian; Bass, David

    2009-08-01

    Unlike Helkesimastix faecicola and H. major, Helkesimastix marina is marine, ingests bacteria, is probably also a cannibal, and differs in cell cycle ciliary behaviour. Daughter kinetids have mirror symmetry; pre-division cilia beat asymmetrically. We sequenced its 18S rDNA and studied its ultrastructure to clarify its taxonomy. Helkesimastix (Helkesimastigidae fam. n.) differs unexpectedly radically from cercomonads, lacking their complex microtubular ciliary roots, grouping not with them but with Sainouridae within Pansomonadida. Longitudinal cortical microtubules emanate from a dense apical centrosomal plate, where a striated rhizoplast attaches the nucleus, and two very short subparallel centrioles attach by dense fibres. The marginally more posterior centriole, attached to the centrosomal plate by a dense forked fibre, bears the long 9+2 gliding posterior cilium and a microtubular root; the left-side, nucleus-attached, left centriole bears an immotile ciliary stump with abnormal axoneme of nine disorganized mainly singlet microtubules, unlike the sainourid anterior papilla. Both transitional regions have a proximal lattice, the posterior centriole with slender hub. Sainouroidea superfam. n. (Sainouridae; Helkesimastigidae) have homologous cytoskeletal geometry. Dorsal Golgi dictyosome and posterior microbody are attached to the nuclear envelope, which has slender micro-invaginations and probably a cortical lattice. Bacteria are digested posteriorly in association with numerous mitochondria with flat cristae.

  1. 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.

  2. The effect of binaural beats on verbal working memory and cortical connectivity

    Science.gov (United States)

    Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A.; Leonessa, Alexander

    2017-04-01

    Objective. Synchronization in activated regions of cortical networks affect the brain’s frequency response, which has been associated with a wide range of states and abilities, including memory. A non-invasive method for manipulating cortical synchronization is binaural beats. Binaural beats take advantage of the brain’s response to two pure tones, delivered independently to each ear, when those tones have a small frequency mismatch. The mismatch between the tones is interpreted as a beat frequency, which may act to synchronize cortical oscillations. Neural synchrony is particularly important for working memory processes, the system controlling online organization and retention of information for successful goal-directed behavior. Therefore, manipulation of synchrony via binaural beats provides a unique window into working memory and associated connectivity of cortical networks. Approach. In this study, we examined the effects of different acoustic stimulation conditions during an N-back working memory task, and we measured participant response accuracy and cortical network topology via EEG recordings. Six acoustic stimulation conditions were used: None, Pure Tone, Classical Music, 5 Hz binaural beats, 10 Hz binaural beats, and 15 Hz binaural beats. Main results. We determined that listening to 15 Hz binaural beats during an N-Back working memory task increased the individual participant’s accuracy, modulated the cortical frequency response, and changed the cortical network connection strengths during the task. Only the 15 Hz binaural beats produced significant change in relative accuracy compared to the None condition. Significance. Listening to 15 Hz binaural beats during the N-back task activated salient frequency bands and produced networks characterized by higher information transfer as compared to other auditory stimulation conditions.

  3. 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.

  4. 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

  5. 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.

  6. 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...

  7. 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.

  8. Recent advances in primary ciliary dyskinesia.

    Science.gov (United States)

    Takeuchi, Kazuhiko; Kitano, Masako; Ishinaga, Hajime; Kobayashi, Masayoshi; Ogawa, Satoru; Nakatani, Kaname; Masuda, Sawako; Nagao, Mizuho; Fujisawa, Takao

    2016-06-01

    Primary ciliary dyskinesia (PCD) is a genetic disease inherited in an autosomal recessive manner. The prevalence of PCD is estimated to be 1 in 20,000 live births. Congenital abnormality of the primary cilia results in situs inversus in 50% of patients. Decreased function of motile cilia causes chronic rhinosinusitis, otitis media with effusion, bronchiectasis and infertility. Cases with situs inversus are considered to show "Kartagener's syndrome", and diagnosis is not difficult. However, in cases without situs inversus, the diagnosis is much more troublesome. PCD without situs inversus is thus probably underdiagnosed. Prolonged chronic cough represents an important symptom that is seen in most patients. The diagnosis of PCD requires the presence of the characteristic clinical phenotypes and either: (1) specific ciliary ultrastructural defects identified by transmission electron microscopy in biopsy samples of respiratory epithelium; or (2) identification of mutation in one of the genes known to be associated with PCD. Nasal nitric oxide concentration is extremely low in PCD, and this could be useful for screening of the disease. At present, no fundamental therapies are available for PCD. Diagnosis in the early stages is important to prevent progression of bronchiectasis and deterioration of lung function by guidance for daily life, immunization, cessation of smoking and prompt therapy at the time of respiratory tract infection. Since PCD is inherited in an autosomal-recessive manner, genetic counseling is necessary after definite diagnosis.

  9. Demonstrations of Beats as Moving Interference Patterns.

    Science.gov (United States)

    Stein, T. S.; Dishman, L. G.

    1982-01-01

    Describes a ripple tank demonstration that displays interference patterns responsible for producing beats and provides photographs of computer simulations of various beat interference patterns. Includes programs for the computer simulation and equations of constructive interference paths in beat interference patterns. (Author/SK)

  10. Continuous wave terahertz spectroscopy system with stably tunable beat source using optical switch

    Science.gov (United States)

    Eom, Joo Beom; Kim, Chihoon; Ahn, Jaesung

    2017-01-01

    A tunable beat source has been made using an optical switch module. A stably-tunable beat source for continuous wave terahertz spectroscopy system was implemented by simply connecting 16 coaxial distributed feedback laser diodes to an optical switch. The terahertz frequency was rapidly changed without frequency drifts by changing the optical path. The continuous wave terahertz frequency was tuned from 0.05 to 0.8 THz in steps of 50 GHz or 0.4 nm. We measured continuous wave terahertz waveforms emitted from the photomixers using the switched optical beat source. We also calculated the terahertz frequency peaks by taking fast Fourier transforms of the measured terahertz waveforms. By equipping the implemented tunable beat source with an optical switch, a continuous wave terahertz spectroscopy system was constructed and used to demonstrate the feasibility of continuous wave terahertz spectroscopy for nondestructive tests using the spectra of two type of Si wafers with different resistivity.

  11. Effect of bunching of cilia and their interplay on muco-ciliary transport.

    Science.gov (United States)

    Roy, Yagnaseni; Sivathanu, Vivek; Das, Sarit K

    2013-11-01

    Cilia are hair-like organelles projecting from a eukaryotic cell, used either for locomotion or as sensors. Cilia commonly occur in patches. To take this into consideration, we represent cilia in multiple patches, instead of the conventional 'dense mat' representation. We focus on the combined action and interplay of these patches. The effects of varying the frequency, spacing and phase lag of the beating of one cilia bunch with respect to the beating of adjacent patches are studied. We model the Airway Surface Liquid (ASL) as a three-layer structure. The possibility of an optimum frequency of beating is noted and the change of mucous flow under different spacing and phase differences are observed.

  12. 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.

  13. 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.

  14. Ciliary extracellular vesicles: Txt msg orgnlls

    Science.gov (United States)

    Wang, Juan; Barr, Maureen M.

    2016-01-01

    Cilia are sensory organelles that protrude from cell surfaces to monitor the surrounding environment. In addition to its role as sensory receiver, the cilium also releases extracellular vesicles (EVs). The release of sub-micron sized EVs is a conserved form of intercellular communication used by all three kingdoms of life. These extracellular organelles play important roles in both short and long range signaling between donor and target cells and may coordinate systemic responses within an organism in normal and diseased states. EV shedding from ciliated cells and EV-cilia interactions are evolutionarily conserved phenomena, yet remarkably little is known about the relationship between the cilia and EVs and the fundamental biology of EVs. Studies in the model organisms Chlamydomonas and C. elegans have begun to shed light on ciliary EVs. Chlamydomonas EVs are shed from tips of flagella and are bioactive. C. elegans EVs are shed and released by ciliated sensory neurons in an intraflagellar transport (IFT)-dependent manner. C. elegans EVs play a role in modulating animal-to-animal communication, and this EV bioactivity is dependent on EV cargo content. Some ciliary pathologies, or ciliopathies, are associated with abnormal EV shedding or with abnormal cilia-EV interactions, suggest the cilium may be an important organelle as an EV donor or as an EV target. Until the past few decades, both cilia and EVs were ignored as vestigial or cellular junk. As research interest in these two organelles continues to gain momentum, we envision a new field of cell biology emerging. Here, we propose that the cilium is a dedicated organelle for EV biogenesis and EV reception. We will also discuss possible mechanisms by which EVs exert bioactivity and explain how what is learned in model organisms regarding EV biogenesis and function may provide insight to human ciliopathies. PMID:26983828

  15. 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.

  16. Identified Circadian Rhythm Genes of Ciliary Epithelium with Differential Display

    Institute of Scientific and Technical Information of China (English)

    Yanxia Li; Dongcheng Lu; Jian Ge; Yanna Li; Yehong Zhuo; Sears ML

    2001-01-01

    Purpose:To identify differential genes expressed in the rabbit ciliary epithelium duringthe circadian cycle of aqueous flow.Methods: Total RNA from ciliary epithelium of rabbits at 8AM (light on 1 hour) and8PM(light off 1 hour) were compared by differential display reverse transcription-polymerase chain reaetion(DD RT-PCR), using 6 % denaturing polyacrylamide electro-phoresis, choose differential display bands, cut and reamplify with the same primer, cloneand sequence. Search the database of Genbank, prolong them with 5' RACE and 3'RACE technique then clone, sequence and search database of Genbank.Results: 93 Significant differences gene expression were detected between light on andlight off in the rabbit ciliary epithelium.Conclusion: Differential display is a powerful tool to screen differentially expressedgenes in circadian rhythm of ciliary epithelium.

  17. PACRG, a protein linked to ciliary motility, mediates cellular signaling.

    OpenAIRE

    Loucks, Catrina M.; Bialas, Nathan J.; Dekkers, Martijn; Walker, Denise S.; Grundy, Laura J.; Li, Chunmei; Inglis, P. Nick; Kida, Katarzyna; Schafer, William R; Blacque, Oliver E; Jansen, Gert; Michel R Leroux

    2016-01-01

    Cilia are microtubule-based organelles that project from nearly all mammalian cell types. Motile cilia generate fluid flow, whereas nonmotile (primary) cilia are required for sensory physiology and modulate various signal transduction pathways. Here we investigate the nonmotile ciliary signaling roles of parkin coregulated gene (PACRG), a protein linked to ciliary motility. PACRG is associated with the protofilament ribbon, a structure believed to dictate the regular arrangement of motility-a...

  18. PACRG, a protein linked to ciliary motility, mediates cellular signaling

    OpenAIRE

    Loucks, Catrina M.; Bialas, Nathan J.; Dekkers, Martijn P. J.; Walker, Denise S.; Grundy, Laura J.; Li, Chunmei; Inglis, P. Nick; Kida, Katarzyna; Schafer, William R; Blacque, Oliver E; Jansen, Gert; Michel R Leroux

    2016-01-01

    Cilia are microtubule-based organelles that project from nearly all mammalian cell types. Motile cilia generate fluid flow, whereas nonmotile (primary) cilia are required for sensory physiology and modulate various signal transduction pathways. Here we investigate the nonmotile ciliary signaling roles of parkin coregulated gene (PACRG), a protein linked to ciliary motility. PACRG is associated with the protofilament ribbon, a structure believed to dictate the regular arrangement of motility-a...

  19. 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.

  20. 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

  1. 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.

  2. Measuring of beat up force on weaving machines

    Directory of Open Access Journals (Sweden)

    Bílek Martin

    2017-01-01

    Full Text Available The textile material (warp is stressed cyclically at a relative high frequency during the weaving process. Therefore, the special measuring device for analysis of beat up force in the textile material during the weaving process, has been devised in the Weaving Laboratory of the TUL. This paper includes a description of this measuring device. The experimental part includes measurements results for various materials (PES and VS and various warp thread densities of the produced fabric.

  3. 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.

  4. 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.

  5. 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

  6. Unattended musical beats enhance visual processing.

    Science.gov (United States)

    Escoffier, Nicolas; Sheng, Darren Yeo Jian; Schirmer, Annett

    2010-09-01

    The present study investigated whether and how a musical rhythm entrains a listener's visual attention. To this end, participants were presented with pictures of faces and houses and indicated whether picture orientation was upright or inverted. Participants performed this task in silence or with a musical rhythm playing in the background. In the latter condition, pictures could occur off-beat or on a rhythmically implied, silent beat. Pictures presented without the musical rhythm and off-beat were responded to more slowly than pictures presented on-beat. This effect was comparable for faces and houses. Together these results indicate that musical rhythm both synchronizes and facilitates concurrent stimulus processing.

  7. 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

  8. 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.

  9. Notes on the beating fantasy.

    Science.gov (United States)

    Sirois, François J

    2010-06-01

    This theoretical paper revisits the beating fantasy, which constitutes a crossroads of the psychic economy in that it condenses three primal phantasies, namely the primal scene, castration and seduction. Two forms of the phantasy have been distinguished: a 'fixed' form, apparently associated with the masochistic perversion, and a 'transitory' form, probably bound up with libidinal development. In Freud 's (1919) paper these two aspects are intertwined. The present contribution confines itself to the transitory form of the phantasy and its significance in the libidinal development of the girl, notably in the organization of passivity. With this in mind, particular attention is paid to the phantasy's third phase in this context, and an attempt made to show how this phase epitomizes the transformation of the instinctual pressure and might therefore be looked upon in this connection as the intermediate phase of the phantasy.

  10. PACRG, a protein linked to ciliary motility, mediates cellular signaling.

    Science.gov (United States)

    Loucks, Catrina M; Bialas, Nathan J; Dekkers, Martijn P J; Walker, Denise S; Grundy, Laura J; Li, Chunmei; Inglis, P Nick; Kida, Katarzyna; Schafer, William R; Blacque, Oliver E; Jansen, Gert; Leroux, Michel R

    2016-07-01

    Cilia are microtubule-based organelles that project from nearly all mammalian cell types. Motile cilia generate fluid flow, whereas nonmotile (primary) cilia are required for sensory physiology and modulate various signal transduction pathways. Here we investigate the nonmotile ciliary signaling roles of parkin coregulated gene (PACRG), a protein linked to ciliary motility. PACRG is associated with the protofilament ribbon, a structure believed to dictate the regular arrangement of motility-associated ciliary components. Roles for protofilament ribbon-associated proteins in nonmotile cilia and cellular signaling have not been investigated. We show that PACRG localizes to a small subset of nonmotile cilia in Caenorhabditis elegans, suggesting an evolutionary adaptation for mediating specific sensory/signaling functions. We find that it influences a learning behavior known as gustatory plasticity, in which it is functionally coupled to heterotrimeric G-protein signaling. We also demonstrate that PACRG promotes longevity in C. elegans by acting upstream of the lifespan-promoting FOXO transcription factor DAF-16 and likely upstream of insulin/IGF signaling. Our findings establish previously unrecognized sensory/signaling functions for PACRG and point to a role for this protein in promoting longevity. Furthermore, our work suggests additional ciliary motility-signaling connections, since EFHC1 (EF-hand containing 1), a potential PACRG interaction partner similarly associated with the protofilament ribbon and ciliary motility, also positively regulates lifespan.

  11. QUANTUM BEATS OF RECOIL-FREE γ-RADIATION

    OpenAIRE

    Perlow, G.; Monahan, J.; Potzel, W.

    1980-01-01

    The radiation from a Mössbauer source of 57Co in a copper matrix is frequency-modulated by vibrating the source with a quartz piezo-crystal driven by an oscillator. If the radiation passes through a resonant absorber (a "filter"), a time structure containing the oscillator frequency and its harmonics appears in the resulting counting rate. It may be seen by sorting the time of each count with respect to the cross-over time of a subharmonic of the oscillator. These quantum beats are caused by ...

  12. Synchronous Optical Pumping of Quantum Revival Beats for Atomic Magnetometery

    CERN Document Server

    Seltzer, S J; Romalis, M V

    2006-01-01

    We observe quantum beats with periodic revivals due to non-linear spacing of Zeeman levels in the ground state of potassium atoms and demonstrate their synchronous optical pumping by double modulation of the pumping light at the Larmor frequency and the revival frequency. We show that synchronous pumping increases the degree of spin polarization by a factor of 4. As a practical example, we explore the application of this double-modulation technique to atomic magnetometers operating in the geomagnetic field range and find that it can increase the sensitivity and reduce magnetic field orientation-dependent measurement errors endemic to alkali-metal magnetometers.

  13. 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

  14. Tracking EEG changes in response to alpha and beta binaural beats.

    Science.gov (United States)

    Vernon, D; Peryer, G; Louch, J; Shaw, M

    2014-07-01

    A binaural beat can be produced by presenting two tones of a differing frequency, one to each ear. Such auditory stimulation has been suggested to influence behaviour and cognition via the process of cortical entrainment. However, research so far has only shown the frequency following responses in the traditional EEG frequency ranges of delta, theta and gamma. Hence a primary aim of this research was to ascertain whether it would be possible to produce clear changes in the EEG in either the alpha or beta frequency ranges. Such changes, if possible, would have a number of important implications as well as potential applications. A secondary goal was to track any observable changes in the EEG throughout the entrainment epoch to gain some insight into the nature of the entrainment effects on any changes in an effort to identify more effective entrainment regimes. Twenty two healthy participants were recruited and randomly allocated to one of two groups, each of which was exposed to a distinct binaural beat frequency for ten 1-minute epochs. The first group listened to an alpha binaural beat of 10 Hz and the second to a beta binaural beat of 20 Hz. EEG was recorded from the left and right temporal regions during pre-exposure baselines, stimulus exposure epochs and post-exposure baselines. Analysis of changes in broad-band and narrow-band amplitudes, and frequency showed no effect of binaural beat frequency eliciting a frequency following effect in the EEG. Possible mediating factors are discussed and a number of recommendations are made regarding future studies, exploring entrainment effects from a binaural beat presentation.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Simulation of laser-driven plasma beat-wave propagation in collisional weakly relativistic plasmas

    Science.gov (United States)

    Kaur, Maninder; Nandan Gupta, Devki

    2016-11-01

    The process of interaction of lasers beating in a plasma has been explored by virtue of particle-in-cell (PIC) simulations in the presence of electron-ion collisions. A plasma beat wave is resonantly excited by ponderomotive force by two relatively long laser pulses of different frequencies. The amplitude of the plasma wave become maximum, when the difference in the frequencies is equal to the plasma frequency. We propose to demonstrate the energy transfer between the laser beat wave and the plasma wave in the presence of electron-ion collision in nearly relativistic regime with 2D-PIC simulations. The relativistic effect and electron-ion collision both affect the energy transfer between the interacting waves. The finding of simulation results shows that there is a considerable decay in the plasma wave and the field energy over time in the presence of electron-ion collisions.

  2. 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.

  3. 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.

  4. 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, ...

  5. High Blood Pressure: Keep the Beat Recipes

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: High Blood Pressure Keep the Beat Recipes Past Issues / Fall 2011 ... 65 million American adults—one in three—with high blood pressure, you have probably heard the advice, "watch your ...

  6. 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:

  7. The accommodative ciliary muscle function is preserved in older humans

    Science.gov (United States)

    Tabernero, Juan; Chirre, Emmanuel; Hervella, Lucia; Prieto, Pedro; Artal, Pablo

    2016-05-01

    Presbyopia, the loss of the eye’s accommodation capability, affects all humans aged above 45–50 years old. The two main reasons for this to happen are a hardening of the crystalline lens and a reduction of the ciliary muscle functionality with age. While there seems to be at least some partial accommodating functionality of the ciliary muscle at early presbyopic ages, it is not yet clear whether the muscle is still active at more advanced ages. Previous techniques used to visualize the accommodation mechanism of the ciliary muscle are complicated to apply in the older subjects, as they typically require fixation stability during long measurement times and/or to have an ultrasound probe directly in contact with the eye. Instead, we used our own developed method based on high-speed recording of lens wobbling to study the ciliary muscle activity in a small group of pseudophakic subjects (around 80 years old). There was a significant activity of the muscle, clearly able to contract under binocular stimulation of accommodation. This supports a purely lenticular-based theory of presbyopia and it might stimulate the search for new solutions to presbyopia by making use of the remaining contraction force still presented in the aging eye.

  8. Structural and functional lung disease in primary ciliary dyskinesia

    NARCIS (Netherlands)

    F. Santamaria (Francesca); S. Montella (Silvia); H.A.W.M. Tiddens (Harm); G. Guidi (Guido); V. Casotti (Valeria); M. Maglione (Marco); P.A. de Jong (Pim)

    2008-01-01

    textabstractBackground: High-resolution CT (HRCT) scan data on primary ciliary dyskinesia (PCD) related lung disease are scarce. Study objectives: We evaluated the lung disease in children and adults with PCD by a modified Brody composite HRCT scan score to assess the prevalence of the structural ab

  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. 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

  11. Frequency Structure of Heart Rate Variability

    OpenAIRE

    MUKHIN, V.

    2008-01-01

    Factor structure of heart rate periodogram has been detected with factor analysis. The results showed that there are at least four periodical phenomena of HRV. Two of them have not been discovered and physiologically explained yet. Their frequency ranges are 0.21 to 0.31 1/beat with the peak at 0.26 1/beat and 0.25 to 0.5 1/beat with the peak 0.35 1/beat. Despite of differences of the peak frequencies the frequency rages of the factors are overlapped. Therefore, power of spectral density with...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. [A rare case of primary ciliary dyskinesia with heterotaxy].

    Science.gov (United States)

    Quintela, Cátia; Meireles, Cláudia; Bettencourt, Maria João; Ribeirinho, Augusto; Bentes, Teresa

    2009-01-01

    Primary ciliary dyskinesia is an autosomal recessive disease with a clinical history of upper and lowers respiratory infections, rhinosinusitis and bronquitis associated with complete or partial situs inversus. The authors present a 78 -year -old male caucasian patient with rhinosinusitis, lower respiratory tract infection and dyspnea, chronic otitis with hearing deficit and infertility followed in Gastroenterology for dyspepsia and constipation. The radiological studies revealed agenesis of right frontal sinus; bronchial wall thickening; bronchiectasis; cecum and ascending colon located on the left and small bowel occupies right side of abdomen. He had no immunodeficiency, allergies, cystic fibrosis and others. We concluded primary ciliary dyskinesia with heterotaxy. For the rarity of this case we decided to present it.

  17. Connexins form functional hemichannels in porcine ciliary epithelium.

    Science.gov (United States)

    Shahidullah, Mohammad; Delamere, Nicholas A

    2014-01-01

    The expression of connexins in the ciliary epithelium is consistent with gap junctions between the pigmented (PE) and nonpigmented ciliary epithelium (NPE) that form when connexon hemichannels from adjacent cells pair to form a channel. Here we present evidence that suggests undocked connexons may form functional hemichannels that permit exchange of substances between NPE and the aqueous humor. Intact porcine eyes were perfused via the ciliary artery and propidium iodide (PI) (MW 668) was added to the aqueous humor compartment as a tracer. After calcium-free solution containing PI was introduced into the aqueous humor compartment for 30 min, fluorescence microscopy revealed PI in the NPE cell layer. PI entry into the NPE was inhibited by calcium and by the connexin antagonist 18α-glycyrrhetinic acid (18-AGA). Studies also were carried out with cultured porcine NPE. Under normal conditions, little PI entered the cultured cells but calcium-free medium stimulated PI accumulation and the entry was inhibited by 18-AGA. In cells loaded with calcein (MW 622), calcium-free solution stimulated calcein exit. 18-AGA partially suppressed calcein exit in calcium-free medium. Connexin 43 and connexin 50 proteins were detected by western blot analysis in both native and cultured NPE. In the intact eye, immunolocalization studies revealed connexin 50 at the basolateral, aqueous humor-facing, margin of the NPE. In contrast, connexin 43 was observed at the junction of the PE and NPE layer and on the basolateral membrane of PE. The results point to functional hemichannels at the NPE basolateral surface. It is feasible that hemichannels might contribute to the transfer of substances between the ciliary epithelium cytoplasm and aqueous humor.

  18. 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.

  19. Load Response of the Flagellar Beat

    Science.gov (United States)

    Klindt, Gary S.; Ruloff, Christian; Wagner, Christian; Friedrich, Benjamin M.

    2016-12-01

    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 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 energy efficiency of the flagellar beat and its ability to synchronize to oscillatory flows.

  20. 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.

  1. 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.

  2. The detuning of relativistic Langmuir waves in the beat-wave accelerator

    Science.gov (United States)

    McKinstrie, C. J.; Forslund, D. W.

    1987-03-01

    In the beat-wave accelerator, a large-amplitude Langmuir wave is produced by the beating of two laser beams whose frequencies differ by approximately the plasma frequency. The growth of this Langmuir wave saturates because of a nonlinear shift in its natural frequency. At present, there are three different formulas for the nonlinear frequency shift in the literature. By taking all relevant nonlinearities into account, the original result of Akhiezer and Polovin [Dokl. Akad. Nauk SSSR 102, 919 (1955)] is shown to be correct. The maximum amplitude of the Langmuir wave depends on the incident laser intensity and the frequency mismatch, which is the difference between the beat frequency of the incident waves and the plasma frequency. Two different studies have produced contradictory conclusions on the ``optimum'' frequency mismatch. The reasons for this contradiction are discussed and the result of Tang, Sprangle, and Sudan [Phys. Fluids 28, 1974 (1985)] is shown to be essentially correct. However, the requirements for effective beam loading make practical use of the optimum configuration impossible.

  3. 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.

  4. 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.

  5. 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.

  6. Acceleration of injected electrons by the plasma beat wave accelerator

    Science.gov (United States)

    Joshi, C.; Clayton, C. E.; Marsh, K. A.; Dyson, A.; Everett, M.; Lal, A.; Leemans, W. P.; Williams, R.; Katsouleas, T.; Mori, W. B.

    1992-07-01

    In this paper we describe the recent work at UCLA on the acceleration of externally injected electrons by a relativistic plasma wave. A two frequency laser was used to excite a plasma wave over a narrow range of static gas pressures close to resonance. Electrons with energies up to our detection limit of 9.1 MeV were observed when 2.1 MeV electrons were injected in the plasma wave. No accelerated electrons above the detection threshold were observed when the laser was operated on a single frequency or when no electrons were injected. Experimental results are compared with theoretical predictions, and future prospects for the plasma beat wave accelerator are discussed.

  7. 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.

  8. [THE STRUCTURE OF LYMPHATIC CAPILLARIES OF THE CILIARY BODY OF THE HUMAN EYE].

    Science.gov (United States)

    Borodin, Yu I; Bgatova, N P; Chernykh, V V; Trunov, A N; Pozhidayeva, A A; Konenkov, V I

    2015-01-01

    Using light microscopy, immunohistochemistry and electron microscopy, the structural organization of interstitial spaces and vessels of the ciliary body of the human eye (n = 5) were studied. The ciliary body was found to contain wide interstitial spaces--tissue clefts bound by collagen fibers and fibroblasts. Organ-specific lymphatic capillaries were also demonstrated in the ciliary body. According to the present findings and the lymphatic region concept, the first 2 elements of the lymphatic region of the eye were described: tissue clefts--prelymphatics and lymphatic capillaries of the ciliary body. The third element of the lymphatic region are the lymph nodes of the head and neck.

  9. THz radiation by beating Langmuir waves

    CERN Document Server

    Son, S; Park, J Y

    2013-01-01

    An intense terahertz (THz) radiation generated by the beating of two Langmuir waves, which are excited by the forward Raman scattering, is analyzed theoretically. The radiation energy per shot can be as high as 0.1 J, with the duration of 10 pico-second. Appropriate plasma density and the laser characteristics are examined.

  10. Newborn infants detect the beat in music

    NARCIS (Netherlands)

    Winkler, I.; Háden, G.P.; Ladinig, O.; Sziller, I.; Honing, H.

    2009-01-01

    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 o

  11. 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…

  12. Analysis of reproductive isolation between pearl millet (Pennisetum glaucum (L.) R.Br.) and P. ramosum, P. schweinfurthii, P. squamulatum, Cenchrus ciliaris

    OpenAIRE

    Marchais, Louis; TOSTAIN, Serge

    1997-01-01

    Crosses between pearl millet lines and #Pennisetum ramosum$, #P. schweinfurthii$, #P. squamulatum$ or #Cenchrus ciliaris$ were observed for the frequency and development of zygotes, the possibility of embryo rescue, and the fertility of F1 hybrids obtained. Eight per cent of the ovules from diploid millet x #P. ramosum$ crosses showed small embryos which could not be rescued. However, 59% of the ovules from tetraploid millet x #P. ramosum$ crosses showed well-developed embryos that were easy ...

  13. 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.

  14. 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.

  15. 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.

  16. 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 bradycardi...... and ventricular remodelling to proarrhythmic BVR with and without pharmacological I(Kr) block in order to identify the individual at risk....

  17. Finger-to-beat coordination skill of non-dancers, street dancers, and the world champion of a street-dance competition

    Directory of Open Access Journals (Sweden)

    Akito eMiura

    2016-04-01

    Full Text Available 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.

  18. 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.

  19. 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.

  20. Beat Gestures Modulate Auditory Integration in Speech Perception

    Science.gov (United States)

    Biau, Emmanuel; Soto-Faraco, Salvador

    2013-01-01

    Spontaneous beat gestures are an integral part of the paralinguistic context during face-to-face conversations. Here we investigated the time course of beat-speech integration in speech perception by measuring ERPs evoked by words pronounced with or without an accompanying beat gesture, while participants watched a spoken discourse. Words…

  1. Clinical and genetic aspects of primary ciliary dyskinesia/Kartagener syndrome.

    Science.gov (United States)

    Leigh, Margaret W; Pittman, Jessica E; Carson, Johnny L; Ferkol, Thomas W; Dell, Sharon D; Davis, Stephanie D; Knowles, Michael R; Zariwala, Maimoona A

    2009-07-01

    Primary ciliary dyskinesia is a genetically heterogeneous disorder of motile cilia. Most of the disease-causing mutations identified to date involve the heavy (dynein axonemal heavy chain 5) or intermediate(dynein axonemal intermediate chain 1) chain dynein genes in ciliary outer dynein arms, although a few mutations have been noted in other genes. Clinical molecular genetic testing for primary ciliary dyskinesia is available for the most common mutations. The respiratory manifestations of primary ciliary dyskinesia (chronic bronchitis leading to bronchiectasis, chronic rhino-sinusitis, and chronic otitis media)reflect impaired mucociliary clearance owing to defective axonemal structure. Ciliary ultrastructural analysis in most patients (>80%) reveals defective dynein arms, although defects in other axonemal components have also been observed. Approximately 50% of patients with primary ciliary dyskinesia have laterality defects (including situs inversus totalis and, less commonly, heterotaxy, and congenital heart disease),reflecting dysfunction of embryological nodal cilia. Male infertility is common and reflects defects in sperm tail axonemes. Most patients with primary ciliary dyskinesia have a history of neonatal respiratory distress, suggesting that motile cilia play a role in fluid clearance during the transition from a fetal to neonatal lung. Ciliopathies involving sensory cilia, including autosomal dominant or recessive polycystic kidney disease, Bardet-Biedl syndrome, and Alstrom syndrome, may have chronic respiratory symptoms and even bronchiectasis suggesting clinical overlap with primary ciliary dyskinesia.

  2. Beat-to-beat cycle length variability of spontaneously beating guinea pig sinoatrial cells: relative contributions of the membrane and calcium clocks.

    Directory of Open Access Journals (Sweden)

    Massimiliano Zaniboni

    Full Text Available The heartbeat arises rhythmically in the sino-atrial node (SAN and then spreads regularly throughout the heart. The molecular mechanism underlying SAN rhythm has been attributed by recent studies to the interplay between two clocks, one involving the hyperpolarization activated cation current If (the membrane clock, and the second attributable to activation of the electrogenic NaCa exchanger by spontaneous sarcoplasmic releases of calcium (the calcium clock. Both mechanisms contain, in principle, sources of beat-to-beat cycle length variability, which can determine the intrinsic variability of SAN firing and, in turn, contribute to the heart rate variability. In this work we have recorded long sequences of action potentials from patch clamped guinea pig SAN cells (SANCs perfused, in turn, with normal Tyrode solution, with the If inhibitor ivabradine (3 µM, then back to normal Tyrode, and again with the ryanodine channels inhibitor ryanodine (3 µM. We have found that, together with the expected increase in beating cycle length (+25%, the application of ivabradine brought about a significant and dramatic increase in beat-to-beat cycle length variability (+50%. Despite the similar effect on firing rate, ryanodine did not modify significantly beat-to-beat cycle length variability. Acetylcholine was also applied and led to a 131% increase of beating cycle length, with only a 70% increase in beat-to-beat cycle length variability. We conclude that the main source of inter-beat variability of SANCs firing rate is related to the mechanism of the calcium clock, whereas the membrane clock seems to act in stabilizing rate. Accordingly, when the membrane clock is silenced by application of ivabradine, stochastic variations of the calcium clock are free to make SANCs beating rhythm more variable.

  3. 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.

  4. 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).

  5. 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.

  6. Clinical spectrum of primary ciliary dyskinesia in childhood

    Science.gov (United States)

    Fretzayas, Andrew; Moustaki, Maria

    2016-01-01

    Although the triad of bronchiectasis, sinusitis and situs inversus was first described by Kartagener in 1933, the clinical spectrum of primary ciliary dyskinesia is still under investigation. Heterotaxy defects as well as upper and lower respiratory tract symptoms are the main manifestations in childhood. It is now recognized that situs inversus is encountered in only half of patients. The first lower respiratory symptoms may be present from infancy as neonatal respiratory distress. The most common lower airway manifestations are chronic wet cough, recurrent pneumonia and therapy resistant wheezing. Patients are at risk of developing bronchiectasis which may even be the presenting finding due to delayed diagnosis. Upper respiratory tract infections such as nasal congestion, nasal drainage and recurrent sinusitis as well as otologic manifestations such as otitis media or otorrhea with conductive hearing loss are also often encountered. It seems that the type of ciliary ultrastructure defects and the involved mutated genes are associated to some extent to the clinical profile. The disease, even in nowadays, is not recognized at an early age and the primary care clinician should have knowledge of its clinical spectrum in order to select appropriately the children who need further investigation for the diagnosis of this disorder. PMID:26862502

  7. Primary ciliary dyskinesia: considerations regarding six cases of Kartagener syndrome.

    Science.gov (United States)

    Ortega, Hugo Alejandro Vega; Vega, Nelson de Araujo; Santos, Bruno Quirino Dos; Maia, Guilherme Tavares da Silva

    2007-01-01

    Primary ciliary dyskinesia (PCD), previously known as immotile cilia syndrome, is an autosomal recessive hereditary disease that includes various patterns of ciliary ultrastructural defects. The most serious form is Kartagener syndrome (KS), which accounts for 50% of all cases of PCD. The incidence of PCD ranges from 1:20,000 to 1:60,000. Since PCD causes deficiency or even stasis of the transport of secretions throughout the respiratory tract, it favors the growth of viruses and bacteria. As a result, patients have lifelong chronic and recurrent infections, typically suffering from bronchitis, pneumonia, hemoptysis, sinusitis, and infertility. Bronchiectasis and other chronic conditions infections can be the end result of the irreversible bronchial alterations, leading to chronic cor pulmonale and its consequences. Only half of the patients affected by PDC present all of the symptoms, a condition designated complete KS, compared with incomplete KS, typically defined as cases in which situs inversus does not occur. The diagnosis is made clinically and confirmed through transmission electron microscopy. Since there is no specific therapy for PCD, it is recommended that, upon diagnosis, secondary infections be treated with potent antibiotics and prophylactic interventions be implemented. In this paper, we report six cases of PCD (five cases of complete KS and one case of KS) and review the related literature, focusing on the diagnostic, therapeutic and clinical aspects of this disease.

  8. 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.

  9. The Harvard Beat Assessment Test (H-BAT: A Battery for Assessing Beat Perception and Production and their Dissociation

    Directory of Open Access Journals (Sweden)

    Shinya eFujii

    2013-11-01

    Full Text Available 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.

  10. 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.

  11. Elastohydrodynamic synchronization of adjacent beating flagella

    Science.gov (United States)

    Goldstein, Raymond E.; Lauga, Eric; Pesci, Adriana I.; Proctor, Michael R. E.

    2016-11-01

    It is now well established that nearby beating pairs of eukaryotic flagella or cilia typically synchronize in phase. A substantial body of evidence supports the hypothesis that hydrodynamic coupling between the active filaments, combined with waveform compliance, provides a robust mechanism for synchrony. This elastohydrodynamic mechanism has been incorporated into bead-spring models in which the beating flagella are represented by microspheres tethered by radial springs as they are driven about orbits by internal forces. While these low-dimensional models reproduce the phenomenon of synchrony, their parameters are not readily relatable to those of the filaments they represent. More realistic models, which reflect the underlying elasticity of the axonemes and the active force generation, take the form of fourth-order nonlinear partial differential equations (PDEs). While computational studies have shown the occurrence of synchrony, the effects of hydrodynamic coupling between nearby filaments governed by such continuum models have been examined theoretically only in the regime of interflagellar distances d large compared to flagellar length L . Yet in many biological situations d /L ≪1 . Here we present an asymptotic analysis of the hydrodynamic coupling between two extended filaments in the regime d /L ≪1 and find that the form of the coupling is independent of the microscopic details of the internal forces that govern the motion of the individual filaments. The analysis is analogous to that yielding the localized induction approximation for vortex filament motion, extended to the case of mutual induction. In order to understand how the elastohydrodynamic coupling mechanism leads to synchrony of extended objects, we introduce a heuristic model of flagellar beating. The model takes the form of a single fourth-order nonlinear PDE whose form is derived from symmetry considerations, the physics of elasticity, and the overdamped nature of the dynamics. Analytical

  12. Beating the forger: authenticating ceramic antiquities

    Science.gov (United States)

    Stoneham, Doreen; Stoneham, Marshall

    2010-09-01

    Today's forger may have skills to match the artists and craftsmen of the past. But can they be exposed by scientific methods? Ceramic antiquities - including pottery, porcelains, and bronzes with a casting core - have long been valued, and demonstrable antiquity is crucial. Thermoluminescence provides key evidence as to when the object was fired. We describe the basic ideas, the methods themselves, and some of the potential limitations. Examples illustrate the remarkable ingenuity of forgers, who are making determined efforts to beat the physics-based tests of authenticity.

  13. A new heterodyne-beat circuit for the determination of static permittivity

    Science.gov (United States)

    Castex, Teodosia Arauz; de Vivar, Pedro Díaz; Paz, María B. Rebollo; Buep, Adrián H.

    1995-04-01

    A greatly improved heterodyne-beat oscillator was built using integrated circuits, to measure static permittivity of liquid samples. Frequency variation of the oscillator is of less than 0.7 Hz/h; that corresponds to a capacity variation of less than 0.005 pF/h. Permittivity can be measured with a precision of 0.003% and an accuracy better than 0.01%.

  14. 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.

  15. 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.

  16. Beat-to-beat heart rate detection in multi-lead abdominal fetal ECG recordings.

    Science.gov (United States)

    Peters, C H L; van Laar, J O E H; Vullings, R; Oei, S G; Wijn, P F F

    2012-04-01

    Reliable monitoring of fetal condition often requires more information than is provided by cardiotocography, the standard technique for fetal monitoring. Abdominal recording of the fetal electrocardiogram may offer valuable additional information, but unfortunately is troubled by poor signal-to-noise ratios during certain parts of pregnancy. To increase the usability of abdominal fetal ECG recordings, an algorithm was developed that enhances fetal QRS complexes in these recordings and thereby provides a promising method for detecting the beat-to-beat fetal heart rate in recordings with poor signal-to-noise ratios. The method was evaluated on generated recordings with controlled signal-to-noise ratios and on actual recordings that were performed in clinical practice and were annotated by two independent experts. The evaluation on the generated signals demonstrated excellent results (sensitivity of 0.98 for SNR≥1.5). Only for SNRheart rate detection exceeded 2 ms, which may still suffice for cardiotocography but is unacceptable for analysis of the beat-to-beat fetal heart rate variability. The sensitivity and positive predictive value of the method in actual recordings were reduced to approximately 90% for SNR≤2.4, but were excellent for higher signal-to-noise ratios.

  17. 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.

  18. Genotypic variation for salinity tolerance in Cenchrus ciliaris L

    Directory of Open Access Journals (Sweden)

    M. Iftikhar Hussain

    2016-07-01

    Full Text Available 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 – 148.9 g pot-1 in control; 96.4 – 133.8 g pot-1 at 10 dS m-1; 65.6 – 80.4 g pot-1 at 15 dS m-1, and 55.4- 65.6 g pot-1 at 20 dS m-1. The highest DW (148.9 g pot-1 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 land and arid regions to enhance farm productivity and reduce rural poverty.

  19. Semi-automatic, octave-spanning optical frequency counter.

    Science.gov (United States)

    Liu, Tze-An; Shu, Ren-Huei; Peng, Jin-Long

    2008-07-07

    This work presents and demonstrates a semi-automatic optical frequency counter with octave-spanning counting capability using two fiber laser combs operated at different repetition rates. Monochromators are utilized to provide an approximate frequency of the laser under measurement to determine the mode number difference between the two laser combs. The exact mode number of the beating comb line is obtained from the mode number difference and the measured beat frequencies. The entire measurement process, except the frequency stabilization of the laser combs and the optimization of the beat signal-to-noise ratio, is controlled by a computer running a semi-automatic optical frequency counter.

  20. 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...

  1. 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...

  2. 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.

  3. Enhancing Heart-Beat-Based Security for mHealth Applications.

    Science.gov (United States)

    Seepers, Robert M; Strydis, Christos; Sourdis, Ioannis; De Zeeuw, Chris I

    2017-01-01

    In heart-beat-based security, a security key is derived from the time difference between consecutive heart beats (the inter-pulse interval, IPI), which may, subsequently, be used to enable secure communication. While heart-beat-based security holds promise in mobile health (mHealth) applications, there currently exists no work that provides a detailed characterization of the delivered security in a real system. In this paper, we evaluate the strength of IPI-based security keys in the context of entity authentication. We investigate several aspects that should be considered in practice, including subjects with reduced heart-rate variability (HRV), different sensor-sampling frequencies, intersensor variability (i.e., how accurate each entity may measure heart beats) as well as average and worst-case-authentication time. Contrary to the current state of the art, our evaluation demonstrates that authentication using multiple, less-entropic keys may actually increase the key strength by reducing the effects of intersensor variability. Moreover, we find that the maximal key strength of a 60-bit key varies between 29.2 bits and only 5.7 bits, depending on the subject's HRV. To improve security, we introduce the inter-multi-pulse interval (ImPI), a novel method of extracting entropy from the heart by considering the time difference between nonconsecutive heart beats. Given the same authentication time, using the ImPI for key generation increases key strength by up to 3.4 × (+19.2 bits) for subjects with limited HRV, at the cost of an extended key-generation time of 4.8 × (+45 s).

  4. Regulation of ciliary neurotrophic factor receptor alpha in sciatic motor neurons following axotomy.

    Science.gov (United States)

    MacLennan, A J; Devlin, B K; Neitzel, K L; McLaurin, D L; Anderson, K J; Lee, N

    1999-01-01

    Spinal motor neurons are one of the few classes of neurons capable of regenerating axons following axotomy. Injury-induced expression of neurotrophic factors and corresponding receptors may play an important role in this rare ability. A wide variety of indirect data suggests that ciliary neurotrophic factor receptor alpha may critically contribute to the regeneration of injured spinal motor neurons. We used immunohistochemistry, in situ hybridization and retrograde tracing techniques to study the regulation of ciliary neurotrophic factor receptor alpha in axotomized sciatic motor neurons. Ciliary neurotrophic factor receptor alpha immunoreactivity, detected with two independent antisera, is increased in a subpopulation of caudal sciatic motor neuron soma one, two and six weeks after sciatic nerve transection and reattachment, while no changes are detected at one day and 15 weeks post-lesion. Ciliary neurotrophic factor receptor alpha messenger RNA levels are augmented in the same classes of neurons following an identical lesion, suggesting that increased synthesis contributes, at least in part, to the additional ciliary neurotrophic factor receptor alpha protein. Separating the proximal and distal nerve stumps with a plastic barrier does not noticeably affect the injury-induced change in ciliary neurotrophic factor receptor alpha regulation, thereby indicating that this injury response is not dependent on signals distal to the lesion traveling retrogradely through the nerve or signals generated by axonal growth through the distal nerve. The prolonged increases in ciliary neurotrophic factor receptor alpha protein and messenger RNA found in regenerating sciatic motor neurons contrast with the responses of non-regenerating central neurons, which are reported to display, at most, a short-lived increase in ciliary neurotrophic factor receptor alpha messenger RNA expression following injury. The present data are the first to demonstrate, in vivo, neuronal regulation of

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

    OpenAIRE

    Noone Peadar G

    2001-01-01

    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...

  6. Regulatory Factor X (RFX)-mediated transcriptional rewiring of ciliary genes in animals.

    Science.gov (United States)

    Piasecki, Brian P; Burghoorn, Jan; Swoboda, Peter

    2010-07-20

    Cilia were present in the last eukaryotic common ancestor (LECA) and were retained by most organisms spanning all extant eukaryotic lineages, including organisms in the Unikonta (Amoebozoa, fungi, choanoflagellates, and animals), Archaeplastida, Excavata, Chromalveolata, and Rhizaria. In certain animals, including humans, ciliary gene regulation is mediated by Regulatory Factor X (RFX) transcription factors (TFs). RFX TFs bind X-box promoter motifs and thereby positively regulate >50 ciliary genes. Though RFX-mediated ciliary gene regulation has been studied in several bilaterian animals, little is known about the evolutionary conservation of ciliary gene regulation. Here, we explore the evolutionary relationships between RFX TFs and cilia. By sampling the genome sequences of >120 eukaryotic organisms, we show that RFX TFs are exclusively found in unikont organisms (whether ciliated or not), but are completely absent from the genome sequences of all nonunikont organisms (again, whether ciliated or not). Sampling the promoter sequences of 12 highly conserved ciliary genes from 23 diverse unikont and nonunikont organisms further revealed that phylogenetic footprints of X-box promoter motif sequences are found exclusively in ciliary genes of certain animals. Thus, there is no correlation between cilia/ciliary genes and the presence or absence of RFX TFs and X-box promoter motifs in nonanimal unikont and in nonunikont organisms. These data suggest that RFX TFs originated early in the unikont lineage, distinctly after cilia evolved. The evolutionary model that best explains these observations indicates that the transcriptional rewiring of many ciliary genes by RFX TFs occurred early in the animal lineage.

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

    Science.gov (United States)

    Galati, Domenico F; Abuin, David S; Tauber, Gabriel A; Pham, Andrew T; Pearson, Chad G

    2015-12-23

    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.

  8. 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.

  9. Influence of endogenous ciliary neurotrophic factor on neural differentiation of adult rat hippocampal progenitors

    Institute of Scientific and Technical Information of China (English)

    Jun Ding; Zhili He; Juan Ruan; Ying Liu; Chengxin Gong; Shenggang Sun; Honghui Chen

    2013-01-01

    Ciliary neurotrophic factor is the only known neurotrophic factor that can promote differentiation of hippocampal neural progenitor cells to glial cells and neurons in adult rats. This process is similar to spontaneous differentiation. Therefore, ciliary neurotrophic factor may be involved in spontaneous differentiation of neural stem cells. To verify this hypothesis, the present study isolated neural progenitor cells from adult male rats and cultured them in vitro. Results showed that when neural progenitor cells were cultured in the absence of mitogen fibroblast growth factor-2 or epidermal growth factor, they underwent spontaneous differentiation into neurons and glial cells. Western blot and immunocytochemical staining showed that exogenous ciliary neurotrophic factor strongly induced adult hippocampal progenitor cells to differentiate into neurons and glial cells. Moreover, passage 4 adult hippocampal progenitor cells expressed high levels of endogenous ciliary neurotrophic factor, and a neutralizing antibody against ciliary neurotrophic factor prevented the spontaneous neuronal and glial differentiation of adult hippocampal progenitor cells. These results suggest that the spontaneous differentiation of adult hippocampal progenitor cells is mediated partially by endogenous ciliary neurotrophic factor.

  10. 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.

  11. 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.

  12. [Specific features of centriole formation and ciliogenesis in ciliary epithelium cells of respiratory tracts in patients with Kartagener syndrome].

    Science.gov (United States)

    Domaratskiĭ, K E; Uvakina, E V; Volkov, I K; Onishchenko, G E

    2005-01-01

    An electron microscopic study of the ciliary epithelium of respiratory tracts was carried out in children (members of the same family) with Kartagener syndrome, which is a variant of ciliary dyskinesia. It was shown that in the case of both mobile cilia and ciliary dyskinesia in man, centrioles are formed during formation of the ciliary basal bodies predominantly de novo, involving deuterosomes. A wide spectrum of pathological changes was described in literature, such as the absence of dynein arms in the axoneme and disorganization of axoneme structure. In addition to these changes in the ciliary system, we found integration of several ciliary axonemes by the same plasma membrane, running of microtubules from the plasma membrane as bundles, different orientation of basal legs, etc.

  13. 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.

  14. 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.

  15. The impact of beat-to-beat variability in optimising the acute hemodynamic response in cardiac resynchronisation therapy

    Directory of Open Access Journals (Sweden)

    Steven Niederer

    2015-12-01

    Conclusion: The beat-to-beat variation in AHR is significant in the context of CRT cut off values. A LOS optimisation offers a novel index to identify the optimal pacing site that accounts for both the mean and variation of the baseline measurement and pacing protocol.

  16. 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

  17. 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.

  18. ELF/VLF wave generation from the beating of two HF ionospheric heating sources

    Science.gov (United States)

    Cohen, M. B.; Moore, R. C.; Golkowski, M.; Lehtinen, N. G.

    2012-12-01

    It is well established that Extremely Low Frequency (ELF, 0.3-3 kHz) and Very Low Frequency (VLF, 3-30 kHz) radio waves can be generated via modulated High Frequency (HF, 3-10 MHz) heating of the lower ionosphere (60-100 km). The ionospheric absorption of HF power modifies the conductivity of the lower ionosphere, which in the presence of natural currents such as the auroral electrojet, creates an `antenna in the sky.' We utilize a theoretical model of the HF to ELF/VLF conversion and the ELF/VLF propagation, and calculate the amplitudes of the generated ELF/VLF waves when two HF heating waves, separated by the ELF/VLF frequency, are transmitted from two adjacent locations. The resulting ELF/VLF radiation pattern exhibits a strong directional dependence (as much as 15 dB) that depends on the physical spacing of the two HF sources. This beat wave source can produce signals 10-20 dB stronger than those generated using amplitude modulation, particularly for frequencies greater than 5-10 kHz. We evaluate recent suggestions that beating two HF waves generates ELF/VLF waves in the F-region (>150 km), and conclude that those experimental results may have misinterpreted, and can be explained strictly by the much more well established D region mechanism.

  19. 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...

  20. 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.

  1. "'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.

  2. 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 body, and RPE/choroid. Four "missing proteins" were identified in ciliary body based on ≥2 proteotypic peptides. The mass spectrometric proteome 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.

  3. 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.

  4. Simple hybrid wire-wireless fiber laser sensor by direct photonic generation of beat signal.

    Science.gov (United States)

    Liu, Shengchun; Gao, Liang; Yin, Zuowei; Shi, Yuechun; Zhang, Liang; Chen, Xiangfei; Cheng, Jianchun

    2011-04-20

    Based on direct photonic generation of a beat signal, a simple hybrid wire-wireless fiber laser sensor is proposed. In the sensor, an improved multilongitudinal modes fiber laser cavity is set up by only a fiber Bragg grating, a section of erbium-doped fiber, and a broadband reflector. A photodetector is used to detect the electrical beat signal. Next, the beat signal including the sensor information can access the wireless network through the wireless transmission. At last, a frequency spectrum analyzer is used to demodulate the sensing information. With this method, the long-distance real-time monitor of the fiber sensor can be realized. The proposed technique offers a simple and cheap way for sensing information of the fiber sensor to access the wireless sensor network. An experiment was implemented to measure the strain and the corresponding root mean square deviation is about -5.7 με at 916 MHz and -3.8 με at 1713 MHz after wireless transmission.

  5. 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.

  6. Best Way to Beat Back Zika a Matter of Debate

    Science.gov (United States)

    ... fullstory_162423.html Best Way to Beat Back Zika a Matter of Debate Analysis found conflicting evidence ... methods for controlling the mosquitoes that can transmit Zika and other diseases. The researchers, from the University ...

  7. 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 ...

  8. After Stroke, 'Blue' Light May Help Beat the Blues

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163731.html After Stroke, 'Blue' Light May Help Beat the Blues Akin ... a danger for people recovering from a debilitating stroke. But new research suggests that tweaking a rehabilitation ...

  9. 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

  10. 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.

  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. KIF13B establishes a CAV1-enriched microdomain at the ciliary transition zone to promote Sonic hedgehog signalling

    DEFF Research Database (Denmark)

    Schou, Kenneth Bødtker; Mogensen, Johanne Bay; Morthorst, Stine Kjær

    2017-01-01

    Ciliary membrane composition is controlled by transition zone (TZ) proteins such as RPGRIP1, RPGRIPL and NPHP4, which are vital for balanced coordination of diverse signalling systems like the Sonic hedgehog (Shh) pathway. Activation of this pathway involves Shh-induced ciliary accumulation...

  14. Brachytherapy, A viable option of globe salvage in treatment of large ciliary body melanocytoma

    Directory of Open Access Journals (Sweden)

    Mahesh P Shanmugam

    2014-01-01

    Full Text Available We report a case of large histopathologically proven melanocytoma of the ciliary body in a 15-year-old male, presented with rapid extraocular growth following incisional biopsy with scleral patch graft. We chose brachytherapy with Ruthenium 106 plaque over enucleation as the later was refused by the parents. The initial apical height of the tumor was 14.2 mm on ultrasonography. Two weeks after brachytherapy, the mass regressed to a size of 8.1 mm and 1 year later to 6.7 mm. This is the first case report showing the response of brachytherapy to ciliary body melanocytoma, which results in ocular and visual acuity salvation with considerable decreased in size of the tumor. The authors conclude that brachytherapy is an option in the management of non-resectable melanocytoma of the ciliary body.

  15. Identification of lymphatics in the ciliary body of the human eye: a novel "uveolymphatic" outflow pathway.

    Science.gov (United States)

    Yücel, Yeni H; Johnston, Miles G; Ly, Tina; Patel, Manoj; Drake, Brian; Gümüş, Ersin; Fraenkl, Stephan A; Moore, Sara; Tobbia, Dalia; Armstrong, Dianna; Horvath, Eva; Gupta, Neeru

    2009-11-01

    Impaired aqueous humor flow from the eye may lead to elevated intraocular pressure and glaucoma. Drainage of aqueous fluid from the eye occurs through established routes that include conventional outflow via the trabecular meshwork, and an unconventional or uveoscleral outflow pathway involving the ciliary body. Based on the assumption that the eye lacks a lymphatic circulation, the possible role of lymphatics in the less well defined uveoscleral pathway has been largely ignored. Advances in lymphatic research have identified specific lymphatic markers such as podoplanin, a transmembrane mucin-type glycoprotein, and lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1). Lymphatic channels were identified in the human ciliary body using immunofluorescence with D2-40 antibody for podoplanin, and LYVE-1 antibody. In keeping with the criteria for lymphatic vessels in conjunctiva used as positive control, D2-40 and LYVE-1-positive lymphatic channels in the ciliary body had a distinct lumen, were negative for blood vessel endothelial cell marker CD34, and were surrounded by either discontinuous or no collagen IV-positive basement membrane. Cryo-immunogold electron microscopy confirmed the presence D2-40-immunoreactivity in lymphatic endothelium in the human ciliary body. Fluorescent nanospheres injected into the anterior chamber of the sheep eye were detected in LYVE-1-positive channels of the ciliary body 15, 30, and 45 min following injection. Four hours following intracameral injection, Iodine-125 radio-labeled human serum albumin injected into the sheep eye (n = 5) was drained preferentially into cervical, retropharyngeal, submandibular and preauricular lymph nodes in the head and neck region compared to reference popliteal lymph nodes (P human ciliary body, and that fluid and solutes flow at least partially through this system. The discovery of a uveolymphatic pathway in the eye is novel and highly relevant to studies of glaucoma and other eye diseases.

  16. 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

  17. Positive airway pressure improves nocturnal beat-to-beat blood pressure surges in obesity hypoventilation syndrome with obstructive sleep apnea.

    Science.gov (United States)

    Carter, Jason R; Fonkoue, Ida T; Grimaldi, Daniela; Emami, Leila; Gozal, David; Sullivan, Colin E; Mokhlesi, Babak

    2016-04-01

    Positive airway pressure (PAP) treatment has been shown to have a modest effect on ambulatory blood pressure (BP) in patients with obstructive sleep apnea (OSA). However, there is a paucity of data on the effect of PAP therapy on rapid, yet significant, BP swings during sleep, particularly in obesity hypoventilation syndrome (OHS). The present study hypothesizes that PAP therapy will improve nocturnal BP on the first treatment night (titration PAP) in OHS patients with underlying OSA, and that these improvements will become more significant with 6 wk of PAP therapy. Seventeen adults (7 men, 10 women; age 50.4 ± 10.7 years, BMI 49.3 ± 2.4 kg/m(2)) with OHS and clinically diagnosed OSA participated in three overnight laboratory visits that included polysomnography and beat-to-beat BP monitoring via finger plethysmography. Six weeks of PAP therapy, but not titration PAP, lowered mean nocturnal BP. In contrast, when nocturnal beat-to-beat BPs were aggregated into bins consisting of at least three consecutive cardiac cycles with a >10 mmHg BP surge (i.e., Δ10-20, Δ20-30, Δ30-40, and Δ>40 mmHg), titration, and 6-wk PAP reduced the number of BP surges per hour (time × bin, P < 0.05). PAP adherence over the 6-wk period was significantly correlated to reductions in nocturnal systolic (r = 0.713, P = 0.001) and diastolic (r = 0.497, P = 0.043) BP surges. Despite these PAP-induced improvements in nocturnal beat-to-beat BP surges, 6 wk of PAP therapy did not alter daytime BP. In conclusion, PAP treatment reduces nocturnal beat-to-beat BP surges in OHS patients with underlying OSA, and this improvement in nocturnal BP regulation was greater in patients with higher PAP adherence.

  18. Coexisting Raman- and Rayleigh-Enhanced Four-Wave Mixing in Femtosecond Polarization Beats

    Institute of Scientific and Technical Information of China (English)

    NIE Zhi-Qiang; ZHAO Yan; ZHANG Yan-Peng; GAN Chen-Li; ZHENG Huai-Sin; LI Chang-Biao; LU Ke-Qing

    2009-01-01

    Based on the polarization interference of Raman- and Rayleigh-enhanced four-wave mixing processes,heterodyne detection of the Raman,Rayleigh and coexisting Raman and Rayleigh femtosecond difference-frequency polarization beats is investigated in the cw and the three Markovian stochastic models,respectively.These two processes exhibit asymmetric and symmetric spectra,respectively,and the thermal effect in them can be suppressed by a field-correlation method.Such studies of coexisting Raman- and Rayleigh-enhanced four-wave mixing processes can have important applications in coherence quantum control,and quantum information processing.

  19. Coherent Phase Control of Ultrafast Polarization Beats in Reverse V-Type Three-Level System

    Institute of Scientific and Technical Information of China (English)

    LI Ling; NIE Zhi-Qiang; JIANG Tong; ZHANG Yan-Peng; LI Pei-Zhe; GAN Chen-Li; SONG Jian-Ping; LI Yuan-Yuan

    2007-01-01

    We investigate the third-order nonlinear absorption and dispersion of femto- and atto-second polarization beats between the one-photon degenerate four-wave mixing process and the two-photon nondegenerate four-wave mixing process in the pure homogeneously-broadened reverse V-three-level using twin noisy Gelds. The third-order nonlinear response can be controlled and modified by the colour-locked correlation of twin noisy fields. Most importantly, the coherent phase control in optical heterodyne detection for studying the phase dispersion of the third-order susceptibility is demonstrated. The radiation-matter detuning oscillation is also considered in the frequency domain.

  20. 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.

  1. 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.

  2. Adaptive control with self-tuning for non-invasive beat-by-beat blood pressure measurement.

    Science.gov (United States)

    Nogawa, Masamichi; Ogawa, Mitsuhiro; Yamakoshi, Takehiro; Tanaka, Shinobu; Yamakoshi, Ken-ichi

    2011-01-01

    Up to now, we have successfully carried out the non-invasive beat-by-beat measurement of blood pressure (BP) in the root of finger, superficial temporal and radial artery based on the volume-compensation technique with reasonable accuracy. The present study concerns with improvement of control method for this beat-by-beat BP measurement. The measurement system mainly consists of a partial pressurization cuff with a pair of LED and photo-diode for the detection of arterial blood volume, and a digital self-tuning control method. Using healthy subjects, the performance and accuracy of this system were evaluated through comparison experiments with the system using a conventional empirically tuned PID controller. The significant differences of BP measured in finger artery were not showed in systolic (SBP), p=0.52, and diastolic BP (DBP), p=0.35. With the advantage of the adaptive control with self-tuning method, which can tune the control parameters without disturbing the control system, the application area of the non-invasive beat-by-beat measurement method will be broadened.

  3. LEFT-VENTRICULAR BEAT-TO-BEAT PERFORMANCE IN ATRIAL-FIBRILLATION - CONTRIBUTION OF FRANK-STARLING MECHANISM AFTER SHORT RATHER THAN LONG RR INTERVALS

    NARCIS (Netherlands)

    GOSSELINK, ATM; BLANKSMA, PK; CRIJNS, HJGM; VANGELDER, IC; DEKAM, PJ; HILLEGE, HL; NIEMEIJER, MG; LIE, KI; MEIJLER, FL

    1995-01-01

    Objectives. This study sought to evaluate control mechanisms of the varying left ventricular performance in atrial fibrillation. Background. Atrial fibrillation is characterized by a randomly irregular ventricular response, resulting in continuous variation in left ventricular beat-to-beat mechanica

  4. Coding for stable transmission of W-band radio-over-fiber system using direct-beating of two independent lasers.

    Science.gov (United States)

    Yang, L G; Sung, J Y; Chow, C W; Yeh, C H; Cheng, K T; Shi, J W; Pan, C L

    2014-10-20

    We demonstrate experimentally Manchester (MC) coding based W-band (75 - 110 GHz) radio-over-fiber (ROF) system to reduce the low-frequency-components (LFCs) signal distortion generated by two independent low-cost lasers using spectral shaping. Hence, a low-cost and higher performance W-band ROF system is achieved. In this system, direct-beating of two independent low-cost CW lasers without frequency tracking circuit (FTC) is used to generate the millimeter-wave. Approaches, such as delayed self-heterodyne interferometer and heterodyne beating are performed to characterize the optical-beating-interference sub-terahertz signal (OBIS). Furthermore, W-band ROF systems using MC coding and NRZ-OOK are compared and discussed.

  5. 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.

  6. The ''phase velocity'' of nonlinear plasma waves in the laser beat-wave accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Spence, W.L.

    1985-04-01

    A calculational scheme for beat-wave accelerators is introduced that includes all orders in velocity and in plasma density, and additionally accounts for the influence of plasma nonlinearities on the wave's phase velocity. The main assumption is that the laser frequencies are very large compared to the plasma frequency - under which it is possible to sum up all orders of forward Raman scattering. It is found that the nonlinear plasma wave does not have simply a single phase velocity, but that the beat-wave which drives it is usefully described by a non-local ''effective phase velocity'' function. A time-space domain approach is followed. (LEW)

  7. 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.

  8. 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.

  9. GABA maintains the proliferation of progenitors in the developing chick ciliary marginal zone and non-pigmented ciliary epithelium.

    Directory of Open Access Journals (Sweden)

    Henrik Ring

    Full Text Available GABA is more than the main inhibitory neurotransmitter found in the adult CNS. Several studies have shown that GABA regulates the proliferation of progenitor and stem cells. This work examined the effects of the GABA(A receptor system on the proliferation of retinal progenitors and non-pigmented ciliary epithelial (NPE cells. qRT-PCR and whole-cell patch-clamp electrophysiology were used to characterize the GABA(A receptor system. To quantify the effects on proliferation by GABA(A receptor agonists and antagonists, incorporation of thymidine analogues was used. The results showed that the NPE cells express functional extrasynaptic GABA(A receptors with tonic properties and that low concentration of GABA is required for a baseline level of proliferation. Antagonists of the GABA(A receptors decreased the proliferation of dissociated E12 NPE cells. Bicuculline also had effects on progenitor cell proliferation in intact E8 and E12 developing retina. The NPE cells had low levels of the Cl-transporter KCC2 compared to the mature retina, suggesting a depolarising role for the GABA(A receptors. Treatment with KCl, which is known to depolarise membranes, prevented some of the decreased proliferation caused by inhibition of the GABA(A receptors. This supported the depolarising role for the GABA(A receptors. Inhibition of L-type voltage-gated Ca(2+ channels (VGCCs reduced the proliferation in the same way as inhibition of the GABA(A receptors. Inhibition of the channels increased the expression of the cyclin-dependent kinase inhibitor p27(KIP1, along with the reduced proliferation. These results are consistent with that when the membrane potential indirectly regulates cell proliferation with hyperpolarisation of the membrane potential resulting in decreased cell division. The increased expression of p27(KIP1 after inhibition of either the GABA(A receptors or the L-type VGCCs suggests a link between the GABA(A receptors, membrane potential, and

  10. Mutations in LCA5, encoding the ciliary protein lebercilin, cause Leber congenital amaurosis.

    NARCIS (Netherlands)

    Hollander, A.I. den; Koenekoop, R.K.; Mohamed, M.D.; Arts, H.H.; Boldt, K.; Towns, K.V.; Sedmak, T.; Beer, M. de; Nagel-Wolfrum, K.; McKibbin, M.; Dharmaraj, S.; Lopez, I.; Ivings, L.; Williams, G.A.; Springell, K.; Woods, C.G.; Jafri, H.; Rashid, Y.; Strom, T.M.; Zwaag, B. van der; Gosens, I.; Kersten, F.F.J.; Wijk, E. van; Veltman, J.A.; Zonneveld, M.N.; Beersum, S.E.C. van; Maumenee, I.H.; Wolfrum, U.; Cheetham, M.E.; Ueffing, M.; Cremers, F.P.M.; Inglehearn, C.F.; Roepman, R.

    2007-01-01

    Leber congenital amaurosis (LCA) causes blindness or severe visual impairment at or within a few months of birth. Here we show, using homozygosity mapping, that the LCA5 gene on chromosome 6q14, which encodes the previously unknown ciliary protein lebercilin, is associated with this disease. We dete

  11. Gene Expression and Functional Annotation of the Human Ciliary Body Epithelia

    NARCIS (Netherlands)

    S.F. Janssen (Sarah); T.G.M.F. Gorgels (Theo); K. Bossers (Koen); J.B. ten Brink (Jacoline); A.H.W. Essing (Anke); M.H. Nagtegaal (Marleen); P.J. van der Spek (Peter); N.M. Jansonius (Nomdo); A.A.B. Bergen (Arthur)

    2012-01-01

    textabstractPurpose: 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 molecu

  12. Gene Expression and Functional Annotation of the Human Ciliary Body Epithelia

    NARCIS (Netherlands)

    Janssen, Sarah F.; Gorgels, Theo G. M. F.; Bossers, Koen; ten Brink, Jacoline B.; Essing, Anke H. W.; Nagtegaal, Martijn; van der Spek, Peter J.; Jansonius, Nomdo M.; Bergen, Arthur A. B.

    2012-01-01

    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 signatur

  13. Study and retina allotransplantation of porcine ciliary epithelium (CE)-derived cells

    NARCIS (Netherlands)

    Cogliati, Tiziana Paola

    2012-01-01

    This thesis reports the isolation, characterization and allotransplantation in porcine retina of ciliary epithelium (CE)-derived cells, also known as retinal stem cells (RSCs). The self-renewal capacity and differentiation potential of these cells in vitro and in vivo makes them candidate donors in

  14. Heteromerization of ciliary G protein-coupled receptors in the mouse brain.

    Directory of Open Access Journals (Sweden)

    Jill A Green

    Full Text Available Nearly every cell type in the mammalian body projects from its cell surface a primary cilium that provides important sensory and signaling functions. Defects in the formation or function of primary cilia have been implicated in the pathogenesis of many human developmental disorders and diseases, collectively termed ciliopathies. Most neurons in the brain possess cilia that are enriched for signaling proteins such as G protein-coupled receptors and adenylyl cyclase type 3, suggesting neuronal cilia sense neuromodulators in the brain and contribute to non-synaptic signaling. Indeed, disruption of neuronal cilia or loss of neuronal ciliary signaling proteins is associated with obesity and learning and memory deficits. As the functions of primary cilia are defined by the signaling proteins that localize to the ciliary compartment, identifying the complement of signaling proteins in cilia can provide important insights into their physiological roles. Here we report for the first time that different GPCRs can colocalize within the same cilium. Specifically, we found the ciliary GPCRs, melanin-concentrating hormone receptor 1 (Mchr1 and somatostatin receptor 3 (Sstr3 colocalizing within cilia in multiple mouse brain regions. In addition, we have evidence suggesting Mchr1 and Sstr3 form heteromers. As GPCR heteromerization can affect ligand binding properties as well as downstream signaling, our findings add an additional layer of complexity to neuronal ciliary signaling.

  15. A longitudinal study of lung bacterial pathogens in patients with primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    C. Alanin, M.; G. Nielsen, K.; von Buchwald, C.

    2015-01-01

    In patients with primary ciliary dyskinesia (PCD), impaired mucociliary clearance leads to an accumulation of secretions in the airways and susceptibility to repeated bacterial infections. The primary aim of this study was to investigate the bacterial flora in non-chronic and chronic infections i...

  16. [Kartagener sindrome (primary ciliary dyskinesia). Report of a case and literature review].

    Science.gov (United States)

    Pino Rivero, V; Pardo Romero, G; Iglesias González, R J; Rodríguez Carmona, M; del Castillo Beneyto, F

    2007-01-01

    Kartagener syndrome (a clinical variant of primary ciliary dyskinesia) is a recessive autossomical disease characterized by the triad of chronic sinusitis, bronchiectasis and situs inversus with dextrocardia. We report one case described in a 8 years old boy who besides presented a seromucous otitis and bronchitis of repetition. Finally we performed a short bibliographic review at respect of this uncommon pathology.

  17. 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 ...

  18. 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 compar...

  19. 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 surv...

  20. 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) ...

  1. 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

  2. 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.

  3. Regulation of anterior chamber drainage by bicarbonate-sensitive soluble adenylyl cyclase in the ciliary body.

    Science.gov (United States)

    Lee, Yong S; Tresguerres, Martin; Hess, Kenneth; Marmorstein, Lihua Y; Levin, Lonny R; Buck, Jochen; Marmorstein, Alan D

    2011-12-02

    Glaucoma is a leading cause of blindness affecting as many as 2.2 million Americans. All current glaucoma treatment strategies aim to reduce intraocular pressure (IOP). IOP results from the resistance to drainage of aqueous humor (AH) produced by the ciliary body in a process requiring bicarbonate. Once secreted into the anterior chamber, AH drains from the eye via two pathways: uveoscleral and pressure-dependent or conventional outflow (C(t)). Modulation of "inflow" and "outflow" pathways is thought to occur via distinct, local mechanisms. Mice deficient in the bicarbonate channel bestrophin-2 (Best2), however, exhibit a lower IOP despite an increase in AH production. Best2 is expressed uniquely in nonpigmented ciliary epithelial (NPE) cells providing evidence for a bicarbonate-dependent communicative pathway linking inflow and outflow. Here, we show that bicarbonate-sensitive soluble adenylyl cyclase (sAC) is highly expressed in the ciliary body in NPE cells, but appears to be absent from drainage tissues. Pharmacologic inhibition of sAC in mice causes a significant increase in IOP due to a decrease in C(t) with no effect on inflow. In mice deficient in sAC IOP is elevated, and C(t) is decreased relative to wild-type mice. Pharmacologic inhibition of sAC did not alter IOP or C(t) in sAC-deficient mice. Based on these data we propose that the ciliary body can regulate C(t) and that sAC serves as a critical sensor of bicarbonate in the ciliary body regulating the secretion of substances into the AH that govern outflow facility independent of pressure.

  4. Regulation of Anterior Chamber Drainage by Bicarbonate-sensitive Soluble Adenylyl Cyclase in the Ciliary Body*

    Science.gov (United States)

    Lee, Yong S.; Tresguerres, Martin; Hess, Kenneth; Marmorstein, Lihua Y.; Levin, Lonny R.; Buck, Jochen; Marmorstein, Alan D.

    2011-01-01

    Glaucoma is a leading cause of blindness affecting as many as 2.2 million Americans. All current glaucoma treatment strategies aim to reduce intraocular pressure (IOP). IOP results from the resistance to drainage of aqueous humor (AH) produced by the ciliary body in a process requiring bicarbonate. Once secreted into the anterior chamber, AH drains from the eye via two pathways: uveoscleral and pressure-dependent or conventional outflow (Ct). Modulation of “inflow” and “outflow” pathways is thought to occur via distinct, local mechanisms. Mice deficient in the bicarbonate channel bestrophin-2 (Best2), however, exhibit a lower IOP despite an increase in AH production. Best2 is expressed uniquely in nonpigmented ciliary epithelial (NPE) cells providing evidence for a bicarbonate-dependent communicative pathway linking inflow and outflow. Here, we show that bicarbonate-sensitive soluble adenylyl cyclase (sAC) is highly expressed in the ciliary body in NPE cells, but appears to be absent from drainage tissues. Pharmacologic inhibition of sAC in mice causes a significant increase in IOP due to a decrease in Ct with no effect on inflow. In mice deficient in sAC IOP is elevated, and Ct is decreased relative to wild-type mice. Pharmacologic inhibition of sAC did not alter IOP or Ct in sAC-deficient mice. Based on these data we propose that the ciliary body can regulate Ct and that sAC serves as a critical sensor of bicarbonate in the ciliary body regulating the secretion of substances into the AH that govern outflow facility independent of pressure. PMID:21994938

  5. Mechanisms of Beat-to-Beat Regulation of Cardiac Pacemaker Cell Function by Ca2+ Cycling Dynamics

    Science.gov (United States)

    Yaniv, Yael; Stern, Michael D.; Lakatta, Edward G.; Maltsev, Victor A.

    2013-01-01

    Whether intracellular Ca2+ cycling dynamics regulate cardiac pacemaker cell function on a beat-to-beat basis remains unknown. Here we show that under physiological conditions, application of low concentrations of caffeine (2–4 mM) to isolated single rabbit sinoatrial node cells acutely reduces their spontaneous action potential cycle length (CL) and increases Ca2+ transient amplitude for several cycles. Numerical simulations, using a modified Maltsev-Lakatta coupled-clock model, faithfully reproduced these effects, and also the effects of CL prolongation and dysrhythmic spontaneous beating (produced by cytosolic Ca2+ buffering) and an acute CL reduction (produced by flash-induced Ca2+ release from a caged Ca2+ buffer), which we had reported previously. Three contemporary numerical models (including the original Maltsev-Lakatta model) failed to reproduce the experimental results. In our proposed new model, Ca2+ releases acutely change the CL via activation of the Na+/Ca2+ exchanger current. Time-dependent CL reductions after flash-induced Ca2+ releases (the memory effect) are linked to changes in Ca2+ available for pumping into sarcoplasmic reticulum which, in turn, changes the sarcoplasmic reticulum Ca2+ load, diastolic Ca2+ releases, and Na+/Ca2+ exchanger current. These results support the idea that Ca2+ regulates CL in cardiac pacemaker cells on a beat-to-beat basis, and suggest a more realistic numerical mechanism of this regulation. PMID:24094396

  6. Mechanisms of beat-to-beat regulation of cardiac pacemaker cell function by Ca²⁺ cycling dynamics.

    Science.gov (United States)

    Yaniv, Yael; Stern, Michael D; Lakatta, Edward G; Maltsev, Victor A

    2013-10-01

    Whether intracellular Ca(2+) cycling dynamics regulate cardiac pacemaker cell function on a beat-to-beat basis remains unknown. Here we show that under physiological conditions, application of low concentrations of caffeine (2-4 mM) to isolated single rabbit sinoatrial node cells acutely reduces their spontaneous action potential cycle length (CL) and increases Ca(2+) transient amplitude for several cycles. Numerical simulations, using a modified Maltsev-Lakatta coupled-clock model, faithfully reproduced these effects, and also the effects of CL prolongation and dysrhythmic spontaneous beating (produced by cytosolic Ca(2+) buffering) and an acute CL reduction (produced by flash-induced Ca(2+) release from a caged Ca(2+) buffer), which we had reported previously. Three contemporary numerical models (including the original Maltsev-Lakatta model) failed to reproduce the experimental results. In our proposed new model, Ca(2+) releases acutely change the CL via activation of the Na(+)/Ca(2+) exchanger current. Time-dependent CL reductions after flash-induced Ca(2+) releases (the memory effect) are linked to changes in Ca(2+) available for pumping into sarcoplasmic reticulum which, in turn, changes the sarcoplasmic reticulum Ca(2+) load, diastolic Ca(2+) releases, and Na(+)/Ca(2+) exchanger current. These results support the idea that Ca(2+) regulates CL in cardiac pacemaker cells on a beat-to-beat basis, and suggest a more realistic numerical mechanism of this regulation.

  7. Feasibility Study of a Laser Beat-Wave Seeded THz FEL at the Neptune Laboratory

    CERN Document Server

    Reiche, Sven; Pellegrini, Claudio; Rosenzweig, James E; Shvets, Gennady; Tochitsky, Sergei Ya

    2005-01-01

    Free-Electron Laser in the THz range can be used to generate high output power radiation or to modulate the electron beam longitudinally on the radiation wavelength scale. Microbunching on the scale of 1-5 THz is of particular importance for potential phase-locking of a modulated electron beam to a laser-driven plasma accelerating structure. However the lack of a seeding source for the FEL at this spectral range limits operation to a SASE FEL only, which denies a subpicosecond synchronization of the current modulation or radiation with an external laser source. One possibility to overcome this problem is to seed the FEL with two external laser beams, which difference (beat-wave) frequency is matched to the resonant FEL frequency in the THz range. In this presentation we study feasibility of an experiment on laser beat-wave injection in the THz FEL considered at the UCLA Neptune Laboratory, where both a high brightness photoinjector and a two-wavelength, TW-class CO2 laser system exist. By incorporating the en...

  8. 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.

  9. 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.

  10. 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.

  11. Robust autoresonant excitation in the plasma beat-waveaccelerator: A theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Lindberg, R.R.; Charman, A.E.; Wurtele, J.S.

    2004-11-03

    A modified version of the Plasma Beat-Wave Accelerator scheme is introduced and analyzed, which is based on autoresonant phase-locking of the nonlinear Langmuir wave to the slowly chirped beat frequency of the driving lasers via adiabatic passage through resonance. This new scheme is designed to overcome some of the well-known limitations of previous approaches, namely relativistic detuning and nonlinear modulation or other non-uniformity or non-stationarity in the driven Langmuir wave amplitude, and sensitivity to frequency mismatch due to measurement uncertainties and density fluctuations and inhomogeneities. As in previous schemes, modulational instabilities of the ionic background ultimately limit the useful interaction time, but nevertheless peak electric fields at or approaching the wave-breaking limit seem readily attainable. Compared to traditional approaches, the autoresonant scheme achieves larger accelerating electric fields for given laser intensity, or comparable fields for less laser power; the plasma wave excitation is much more robust to variations or uncertainties in plasma density; it is largely insensitive to the precise choice of chirp rate, provided only that chirping is sufficiently slow; and the quality and uniformity of the resulting plasma wave and its suitability for accelerator applications may be superior. In underdense plasmas, the total frequency shift required is only of the order of a few percent of the laser carrier frequency, and for possible experimental proofs-of-principle, the scheme might be implemented with relatively little additional modification to existing systems based on either solid-state amplifiers and Chirped Pulse Amplification techniques, or, with somewhat greater technological effort, using a CO{sub 2} or other gas laser system.

  12. 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)

  13. 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…

  14. 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.

  15. 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.

  16. 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.

  17. 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.

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

    Science.gov (United States)

    Pigeon, J J; Tochitsky, S Ya; Joshi, C

    2015-12-15

    We report on the generation of a train of ∼2  ps, 10 μm 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 crystals. 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.

  19. High-power, mid-infrared, picosecond pulses generated by compression of a CO_2 laser beat-wave in GaAs

    Science.gov (United States)

    Pigeon, J. J.; Tochitsky, S. Ya.; Joshi, C.

    2015-12-01

    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.

  20. 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.

  1. Primary ciliary dyskinesia: Kartagener syndrome in a family with a novel DNAH5 gene mutation and variable phenotypes

    OpenAIRE

    2015-01-01

    Background: Primary ciliary dyskinesia is a genetically heterogeneous autosomal recessive disorder with variable clinical manifestations, including chronic rhinosinusitis, otitis media, bronchitis, pneumonia, bronchiectasis, situs inversus totalis, reduced fertility in female patients and male infertility. The condition occurs as a result of abnormal ciliary structure and function. It is presented in early life with an estimated incidence of approximately 1/16,000–20,000. About 50% of the aff...

  2. Functional and Molecular Characterization of Rod-like Cells from Retinal Stem Cells Derived from the Adult Ciliary Epithelium

    OpenAIRE

    Gian Carlo Demontis; Claudia Aruta; Antonella Comitato; Anna De Marzo; Valeria Marigo

    2012-01-01

    In vitro generation of photoreceptors from stem cells is of great interest for the development of regenerative medicine approaches for patients affected by retinal degeneration and for high throughput drug screens for these diseases. In this study, we show unprecedented high percentages of rod-fated cells from retinal stem cells of the adult ciliary epithelium. Molecular characterization of rod-like cells demonstrates that they lose ciliary epithelial characteristics but acquire photoreceptor...

  3. 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.

  4. KIF13B establishes a CAV1-enriched microdomain at the ciliary transition zone to promote Sonic hedgehog signalling

    Science.gov (United States)

    Schou, Kenneth B.; Mogensen, Johanne B.; Morthorst, Stine K.; Nielsen, Brian S.; Aleliunaite, Aiste; Serra-Marques, Andrea; Fürstenberg, Nicoline; Saunier, Sophie; Bizet, Albane A.; Veland, Iben R.; Akhmanova, Anna; Christensen, Søren T.; Pedersen, Lotte B.

    2017-01-01

    Ciliary membrane composition is controlled by transition zone (TZ) proteins such as RPGRIP1, RPGRIPL and NPHP4, which are vital for balanced coordination of diverse signalling systems like the Sonic hedgehog (Shh) pathway. Activation of this pathway involves Shh-induced ciliary accumulation of Smoothened (SMO), which is disrupted by disease-causing mutations in TZ components. Here we identify kinesin-3 motor protein KIF13B as a novel member of the RPGRIP1N-C2 domain-containing protein family and show that KIF13B regulates TZ membrane composition and ciliary SMO accumulation. KIF13B is upregulated during ciliogenesis and is recruited to the ciliary base by NPHP4, which binds to two distinct sites in the KIF13B tail region, including an RPGRIP1N-C2 domain. KIF13B and NPHP4 are both essential for establishment of a CAV1 membrane microdomain at the TZ, which in turn is required for Shh-induced ciliary SMO accumulation. Thus KIF13B is a novel regulator of ciliary TZ configuration, membrane composition and Shh signalling. PMID:28134340

  5. Role of gap junction channel in the development of beat-to-beat action potential repolarization variability and arrhythmias.

    Science.gov (United States)

    Magyar, Janos; Banyasz, Tamas; Szentandrassy, Norbert; Kistamas, Kornel; Nanasi, Peter P; Satin, Jonathan

    2015-01-01

    The short-term beat-to-beat variability of cardiac action potential duration (SBVR) occurs as a random alteration of the ventricular repolarization duration. SBVR has been suggested to be more predictive of the development of lethal arrhythmias than the action potential prolongation or QT prolongation of ECG alone. The mechanism underlying SBVR is not completely understood but it is known that SBVR depends on stochastic ion channel gating, intracellular calcium handling and intercellular coupling. Coupling of single cardiomyocytes significantly decreases the beat-to-beat changes in action potential duration (APD) due to the electrotonic current flow between neighboring cells. The magnitude of this electrotonic current depends on the intercellular gap junction resistance. Reduced gap junction resistance causes greater electrotonic current flow between cells, and reduces SBVR. Myocardial ischaemia (MI) is known to affect gap junction channel protein expression and function. MI increases gap junction resistance that leads to slow conduction, APD and refractory period dispersion, and an increase in SBVR. Ultimately, development of reentry arrhythmias and fibrillation are associated post-MI. Antiarrhythmic drugs have proarrhythmic side effects requiring alternative approaches. A novel idea is to target gap junction channels. Specifically, the use of gap junction channel enhancers and inhibitors may help to reveal the precise role of gap junctions in the development of arrhythmias. Since cell-to-cell coupling is represented in SBVR, this parameter can be used to monitor the degree of coupling of myocardium.

  6. 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.

  7. The Beats as Cultural Others/Exotics in Recent Memoirs by Exile Poets

    DEFF Research Database (Denmark)

    Sørensen, Bent

    with figures associated with the Beat Generation. This paper examines the representation of Beat writers such as Ginsberg and Jack Kerouac in Codrescu and Simic's texts, and argues that the exile poets overlay the well-known figures of the Beat writers with yet another dimension of otherness and exoticism...

  8. Genetic factors contributing to human primary ciliary dyskinesia and male infertility.

    Science.gov (United States)

    Ji, Zhi-Yong; Sha, Yan-Wei; Ding, Lu; Li, Ping

    2016-06-07

    Primary ciliary dyskinesia (PCD) is an autosomal-recessive disorder resulting from the loss of normal ciliary function. Symptoms include neonatal respiratory distress, chronic sinusitis, bronchiectasis, situs inversus, and infertility. However, only 15 PCD-associated genes have been identified to cause male infertility to date. Owing to the genetic heterogeneity of PCD, comprehensive molecular genetic testing is not considered the standard of care. Here, we provide an update of the progress on the identification of genetic factors related to PCD associated with male infertility, summarizing the underlying molecular mechanisms, and discuss the clinical implications of these findings. Further research in this field will impact the diagnostic strategy for male infertility, enabling clinicians to provide patients with informed genetic counseling, and help to adopt the best course of treatment for developing directly targeted personalized medicine.

  9. Cri du chat syndrome and primary ciliary dyskinesia: a common genetic cause on chromosome 5p.

    Science.gov (United States)

    Shapiro, Adam J; Weck, Karen E; Chao, Kay C; Rosenfeld, Margaret; Nygren, Anders O H; Knowles, Michael R; Leigh, Margaret W; Zariwala, Maimoona A

    2014-10-01

    Cri du chat syndrome (CdCS) and primary ciliary dyskinesia (PCD) are rare diseases that present with frequent respiratory symptoms. PCD can be caused by hemizygous DNAH5 mutation in combination with a 5p segmental deletion attributable to CdCS on the opposite chromosome. Chronic oto-sino-pulmonary symptoms or organ laterality defects in CdCS should prompt an evaluation for PCD.

  10. Impact of the Smoothened inhibitor, IPI-926, on smoothened ciliary localization and Hedgehog pathway activity.

    Directory of Open Access Journals (Sweden)

    Marisa O Peluso

    Full Text Available A requisite step for canonical Hedgehog (Hh pathway activation by Sonic Hedgehog (Shh ligand is accumulation of Smoothened (Smo to the primary cilium (PC. Activation of the Hh pathway has been implicated in a broad range of cancers, and several Smo antagonists are being assessed clinically, one of which is approved for the treatment of advanced basal cell carcinoma. Recent reports demonstrate that various Smo antagonists differentially impact Smo localization to the PC while still exerting inhibitory activity. In contrast to other synthetic small molecule Smo antagonists, the natural product cyclopamine binds to and promotes ciliary accumulation of Smo and "primes" cells for Hh pathway hyper-responsiveness after compound withdrawal. We compared the properties of IPI-926, a semi-synthetic cyclopamine analog, to cyclopamine with regard to potency, ciliary Smo accumulation, and Hh pathway activity after compound withdrawal. Like cyclopamine, IPI-926 promoted accumulation of Smo to the PC. However, in contrast to cyclopamine, IPI-926 treatment did not prime cells for hyper-responsiveness to Shh stimulation after compound withdrawal, but instead demonstrated continuous inhibition of signaling. By comparing the levels of drug-induced ciliary Smo accumulation with the degree of Hh pathway activity after compound withdrawal, we propose that a critical threshold of ciliary Smo is necessary for "priming" activity to occur. This "priming" appears achievable with cyclopamine, but not IPI-926, and is cell-line dependent. Additionally, IPI-926 activity was evaluated in a murine tumor xenograft model and a pharmacokinetic/pharmacodynamic relationship was examined to assess for in vivo evidence of Hh pathway hyper-responsiveness. Plasma concentrations of IPI-926 correlated with the degree and duration of Hh pathway suppression, and pathway activity did not exceed baseline levels out to 96 hours post dose. The overall findings suggest that IPI-926 possesses

  11. The Development of the Ciliary Epithelium in the Embryonic Chicken Eye

    Science.gov (United States)

    1989-08-04

    experiment was to test the role of I extraocular tissues in eye growth. The periocular mesoderm ! I I was stripped away from a small area on one surface...Eichhorn and Barany , 1985). The cells in the pigmented and nonpigmented layers of the ciliary epithelium begin to differentiate from the adjacent...Statistics: The data from the individual chicken embryos in each experimental group were compared to each other and then pooled. Student’s T- test

  12. Flow Field Analysis of Micromixer Powered by Ciliary Motion of Vorticella

    Science.gov (United States)

    Hayasaka, Yo; Nagai, Moeto; Matsumoto, Nobuyoshi; Kawashima, Takahiro; Shibata, Takayuki

    We demonstrate the observation of a flow field generated by ciliary motion of Vorticella in a microfluidic chamber. We applied the property that Vorticella vibrates its cilia and create a flow field to a micromixer. The stability and mixing performance of Vorticella were measured by PIV (Particle Image Velocimetry). One cell of Vorticella mixed the half area of the microchamber. We revealed that the flow field of a single cell in a chamber was more stable than that of multiple cells.

  13. A novel ICK mutation causes ciliary disruption and lethal endocrine-cerebro-osteodysplasia syndrome

    OpenAIRE

    Kayserili Karabey, Hülya; Oud, M.M.; Bonnard, C.; Mans, D.A.; Altunoğlu, U.; Tohari, S.; Ng, A.Y.J.; Eskin, A.; Lee, H.; Rupar, C.A.; Wagenaar, N.P.; Wu, K.M.; Lahiry, P.; Pazour, G.J.; Nelson, S.F.; Hegele, R.A.; Roepman, R; Venkatesh, B.; Siu, V.M.; Reversade, B.; Arts, H.H.

    2016-01-01

    Background: Endocrine-cerebro-osteodysplasia (ECO) syndrome [MIM:612651] caused by a recessive mutation (p.R272Q) in Intestinal cell kinase (ICK) shows significant clinical overlap with ciliary disorders. Similarities are strongest between ECO syndrome, the Majewski and Mohr-Majewski short-rib thoracic dysplasia (SRTD) with polydactyly syndromes, and hydrolethalus syndrome. In this study, we present a novel homozygous ICK mutation in a fetus with ECO syndrome and compare the effect of this mu...

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Nervous system and ciliary structures of Micrognathozoa (Gnathifera): evolutionary insight from an early branch in Spiralia

    Science.gov (United States)

    Worsaae, Katrine

    2016-01-01

    Recent studies show that Gnathifera, comprising Rotifera, Gnathostomulida and Micrognathozoa, constitute the sister group to the remaining Spiralia (containing, e.g. flatworms, segmented worms and molluscs). Therefore, a better understanding of Gnathifera is central for unravelling the evolution of the highly diverse Spiralia. Here, we describe the previously unstudied nervous system and ciliary structures of Micrognathozoa, using immunohistochemistry and confocal laser scanning microscopy. The nervous system is simple with a large brain, paired sub-esophageal ganglia, two trunk commissures, two pairs of ventral longitudinal nerves and peripheral nerves. The paired ventro-lateral nerve cords are confirmed to be a symplesiomorphy of Gnathifera (possibly even Spiralia), whereas the paired ventro-median nerves are not previously reported in Gnathifera. A pharyngeal ganglion is described for Micrognathozoa: a complex structure with two apical tufts of ciliary receptors, now shown to be shared by all Gnathifera. The ventral pattern of external ciliophores is re-described, and protonephridia with multi-ciliated collecting tubules similar to those of Rotifera are confirmed. A range of new details from a simple nervous system and complex set of ciliary structures in a microscopic metazoan are hereby unravelled. The many resemblances with Rotifera corroborate their close relationship, and shed more light on the evolution of Gnathifera. PMID:27853545

  1. 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.

  2. 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.

  3. 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.

  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. 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.

  6. 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.

  7. Beating the Spin-Down Limit on Gravitational Wave Emission from the Crab Pulsar

    Science.gov (United States)

    Abbott, B.; Abbott, R.; Adhikari, R.; Ajith, P.; Allen, B.; Allen, G.; Amin, R.; Anderson, S. B.; Anderson, W. G.; Arain, M. A.; Araya, M.; Armandula, H.; Armor, P.; Aso, Y.; Aston, S.; Aufmuth, P.; Aulbert, C.; Babak, S.; Ballmer, S.; Bantilan, H.; Barish, B. C.; Barker, C.; Barker, D.; Barr, B.; Barriga, P.; Barton, M. A.; Bastarrika, M.; Bayer, K.; Betzwieser, J.; Beyersdorf, P. T.; Bilenko, I. A.; Billingsley, G.; Biswas, R.; Black, E.; Blackburn, K.; Blackburn, L.; Blair, D.; Bland, B.; Bodiya, T. P.; Bogue, L.; Bork, R.; Boschi, V.; Bose, S.; Brady, P. R.; Braginsky, V. B.; Brau, J. E.; Brinkmann, M.; Brooks, A.; Brown, D. A.; Brunet, G.; Bullington, A.; Buonanno, A.; Burmeister, O.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Camp, J. B.; Cannizzo, J.; Cannon, K.; Cao, J.; Cardenas, L.; Casebolt, T.; Castaldi, G.; Cepeda, C.; Chalkley, E.; Charlton, P.; Chatterji, S.; Chelkowski, S.; Chen, Y.; Christensen, N.; Clark, D.; Clark, J.; Cokelaer, T.; Conte, R.; Cook, D.; Corbitt, T.; Coyne, D.; Creighton, J. D. E.; Cumming, A.; Cunningham, L.; Cutler, R. M.; Dalrymple, J.; Danzmann, K.; Davies, G.; DeBra, D.; Degallaix, J.; Degree, M.; Dergachev, V.; Desai, S.; DeSalvo, R.; Dhurandhar, S.; Díaz, M.; Dickson, J.; Dietz, A.; Donovan, F.; Dooley, K. L.; Doomes, E. E.; Drever, R. W. P.; Duke, I.; Dumas, J.-C.; Dupuis, R. J.; Dwyer, J. G.; Echols, C.; Effler, A.; Ehrens, P.; Espinoza, E.; Etzel, T.; Evans, T.; Fairhurst, S.; Fan, Y.; Fazi, D.; Fehrmann, H.; Fejer, M. M.; Finn, L. S.; Flasch, K.; Fotopoulos, N.; Freise, A.; Frey, R.; Fricke, T.; Fritschel, P.; Frolov, V. V.; Fyffe, M.; Garofoli, J.; Gholami, I.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Goda, K.; Goetz, E.; Goggin, L.; González, G.; Gossler, S.; Gouaty, R.; Grant, A.; Gras, S.; Gray, C.; Gray, M.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Grimaldi, F.; Grosso, R.; Grote, H.; Grunewald, S.; Guenther, M.; Gustafson, E. K.; Gustafson, R.; Hage, B.; Hallam, J. M.; Hammer, D.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G.; Harstad, E.; Hayama, K.; Hayler, T.; Heefner, J.; Heng, I. S.; Hennessy, M.; Heptonstall, A.; Hewitson, M.; Hild, S.; Hirose, E.; Hoak, D.; Hosken, D.; Hough, J.; Huttner, S. H.; Ingram, D.; Ito, M.; Ivanov, A.; Johnson, B.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kamat, S.; Kanner, J.; Kasprzyk, D.; Katsavounidis, E.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Kells, W.; Keppel, D. G.; Khalili, F. Ya.; Khan, R.; Khazanov, E.; Kim, C.; King, P.; Kissel, J. S.; Klimenko, S.; Kokeyama, K.; Kondrashov, V.; Kopparapu, R. K.; Kozak, D.; Kozhevatov, I.; Krishnan, B.; Kwee, P.; Lam, P. K.; Landry, M.; Lang, M. M.; Lantz, B.; Lazzarini, A.; Lei, M.; Leindecker, N.; Leonhardt, V.; Leonor, I.; Libbrecht, K.; Lin, H.; Lindquist, P.; Lockerbie, N. A.; Lodhia, D.; Lormand, M.; Lu, P.; Lubinski, M.; Lucianetti, A.; Lück, H.; Machenschalk, B.; MacInnis, M.; Mageswaran, M.; Mailand, K.; Mandic, V.; Márka, S.; Márka, Z.; Markosyan, A.; Markowitz, J.; Maros, E.; Martin, I.; Martin, R. M.; Marx, J. N.; Mason, K.; Matichard, F.; Matone, L.; Matzner, R.; Mavalvala, N.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McHugh, M.; McIntyre, G.; McIvor, G.; McKechan, D.; McKenzie, K.; Meier, T.; Melissinos, A.; Mendell, G.; Mercer, R. A.; Meshkov, S.; Messenger, C. J.; Meyers, D.; Miller, J.; Minelli, J.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Miyakawa, O.; Moe, B.; Mohanty, S.; Moreno, G.; Mossavi, K.; MowLowry, C.; Mueller, G.; Mukherjee, S.; Mukhopadhyay, H.; Müller-Ebhardt, H.; Munch, J.; Murray, P.; Myers, E.; Myers, J.; Nash, T.; Nelson, J.; Newton, G.; Nishizawa, A.; Numata, K.; O'Dell, J.; Ogin, G.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Pan, Y.; Pankow, C.; Papa, M. A.; Parameshwaraiah, V.; Patel, P.; Pedraza, M.; Penn, S.; Perreca, A.; Petrie, T.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Plissi, M. V.; Postiglione, F.; Principe, M.; Prix, R.; Quetschke, V.; Raab, F.; Rabeling, D. S.; Radkins, H.; Rainer, N.; Rakhmanov, M.; Ramsunder, M.; Rehbein, H.; Reid, S.; Reitze, D. H.; Riesen, R.; Riles, K.; Rivera, B.; Robertson, N. A.; Robinson, C.; Robinson, E. L.; Roddy, S.; Rodriguez, A.; Rogan, A. M.; Rollins, J.; Romano, J. D.; Romie, J.; Route, R.; Rowan, S.; Rüdiger, A.; Ruet, L.; Russell, P.; Ryan, K.; Sakata, S.; Samidi, M.; Sancho de la Jordana, L.; Sandberg, V.; Sannibale, V.; Saraf, S.; Sarin, P.; Sathyaprakash, B. S.; Sato, S.; Saulson, P. R.; Savage, R.; Savov, P.; Schediwy, S. W.; Schilling, R.; Schnabel, R.; Schofield, R.; Schutz, B. F.; Schwinberg, P.; Scott, S. M.; Searle, A. C.; Sears, B.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Shawhan, P.; Shoemaker, D. H.; Sibley, A.; Siemens, X.; Sigg, D.; Sinha, S.; Sintes, A. M.

    2008-08-01

    We present direct upper limits on gravitational wave emission from the Crab pulsar using data from the first 9 months of the fifth science run of the Laser Interferometer Gravitational-wave Observatory (LIGO). These limits are based on two searches. In the first we assume that the gravitational wave emission follows the observed radio timing, giving an upper limit on gravitational wave emission that beats indirect limits inferred from the spin-down and braking index of the pulsar and the energetics of the nebula. In the second we allow for a small mismatch between the gravitational and radio signal frequencies and interpret our results in the context of two possible gravitational wave emission mechanisms.

  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. Theoretical and experimental investigation of direct detection optical OFDM transmission using beat interference cancellation receiver.

    Science.gov (United States)

    Nezamalhosseini, S Alireza; Chen, Lawrence R; Zhuge, Qunbi; Malekiha, Mahdi; Marvasti, Farokh; Plant, David V

    2013-07-01

    We theoretically and experimentally evaluate a beat interference cancellation receiver (BICR) for direct detection optical orthogonal frequency-division multiplexing (DD-OFDM) systems that improves the spectral efficiency (SE) by reducing the guard band between the optical carrier and the optical OFDM signal while mitigating the impact of signal-signal mixing interference (SSMI). Experimental results show that the bit-error-rate (BER) is improved by about three orders of magnitude compared to the conventional receiver after 320 km single-mode fiber (SMF) transmission for 10 Gb/s data with a 4-QAM modulation using reduced guard band single-sideband OFDM (RSSB-OFDM) signal with 1.67 bits/s/Hz SE.

  10. 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...... are larger than in matched control chronic AVB dogs. From a population of 200 chronic AVB dogs, initially two groups were chosen retrospectively: 8 dogs that died suddenly (SCD) and 8 control dogs. Control dogs had a longer lifespan after AVB (10 to 18 weeks) than SCD dogs (5 to 10 weeks). All dogs had...

  11. Calcium release near l-type calcium channels promotes beat-to-beat variability in ventricular myocytes from the chronic AV block dog

    NARCIS (Netherlands)

    Antoons, G.; Johnson, Daniel M; Dries, Eef; Santiago, Demetrio J; Ozdemir, Semir; Lenaerts, Ilse; Beekman, Jet D M; Houtman, Marien J C; Sipido, Karin R; Vos, Marc A

    2015-01-01

    Beat-to-beat variability of ventricular repolarization (BVR) has been proposed as a strong predictor of Torsades de Pointes (TdP). BVR is also observed at the myocyte level, and a number of studies have shown the importance of calcium handling in influencing this parameter. The chronic AV block (CAV

  12. Left ventricular beat-to-beat performance in atrial fibrillation: Contribution of Frank-Starling mechanism after short rather than long intervals

    NARCIS (Netherlands)

    Gosselink, A.T.M.; Blanksma, P.K.; Crijns, H.J.G.M.; Gelder, I.C. van; Kam, P.J. de; Hillege, H.L.; Niemeijer, M.G.; Lie, K.I.; Meijler, F.L.

    1995-01-01

    This study sought to evaluate control mechanisms of the varying left ventricular performance in atrial fibrillation. Atrial fibrillation is characterized by a randomly irregular ventricular response, resulting in continuous variation in left ventricular beat-to-beat mechanical behavior and hemodynam

  13. Non-contact precision profile measurement to rough-surface objects with optical frequency combs

    Science.gov (United States)

    Onoe, Taro; Takahashi, Satoru; Takamasu, Kiyoshi; Matsumoto, Hirokazu

    2016-12-01

    In this research, we developed a new method for the high precision and contactless profile measurement of rough-surfaced objects using optical frequency combs. The uncertainty of the frequency beats of an optical frequency comb is very small (relative uncertainty is 10-10 in our laboratory). In addition, the wavelengths corresponding to these frequency beats are long enough to measure rough-surfaced objects. We can conduct high-precision measurement because several GHz frequency beats can be used if the capability of the detector permits. Moreover, two optical frequency combs with Rb-stabilized repetition frequencies are used for the measurement instead of an RF frequency oscillator; thus, we can avoid the cyclic error caused by the RF frequency oscillator. We measured the profile of a wood cylinder with a rough surface (diameter is approximately 113.2 mm) and compared the result with that of coordinate measuring machine (CMM).

  14. 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.

  15. 基于NX8.5的打纬摇轴载荷及模态分析%Analysis of Beating-up Rocker Shaft Load and Modal Based on NX8.5

    Institute of Scientific and Technical Information of China (English)

    杨剑宇

    2014-01-01

    本文利用 UGNX8.5软件对剑杆织机共轭凸轮打纬机构中的打纬摇轴进行了载荷及模态分析,并通过数据分析,得到了打纬摇轴各阶的固有频率和振型,以及最大应力和最大应变值,从而提出了打纬摇轴设计的改进措施,为提高织造过程中的打纬质量和合理设计打纬摇轴提供了理论依据。%By using software NX8.5, this paper analyzes the load and modal of the beating-up rocker shaft in the beating-up mechanism of conjugate cam of rapier loom. Based on the data analysis, the natural frequency and vibration mode in beating-up process, and the maximum stress and maximum strain values have been ob-tained. Therefore, measures of improving the beating-up rocker shaft design have been put forward, which provides theoretical basis for the improvement of beating-up quality in weaving process and the proper design of beating-up rocker shaft.

  16. SRS-A leukotrienes decrease the activity of human respiratory cilia

    DEFF Research Database (Denmark)

    Bisgaard, H; Pedersen, M

    1987-01-01

    We have studied the effects of the slow reacting substance of anaphylaxis (SRS-A) constituents leukotrienes (LT) C4 and D4 on the ciliary activity of human respiratory cells. The ciliary beat frequency on human nasal cells harvested by cell scraping from the inferior turbinate was measured...... in a blind design by a microphoto-oscillographic technique. A total of 740 ciliated cells from seventy-four cell scrapings were studied. Mean baseline of ciliary beat frequency was 10.2 Hz. The ciliary beat frequency exhibited a pronounced variability in the spontaneous changes between the cell scrapings......, yet less so within cell samples from the cell scrapings. We, therefore, evaluated the effect of the test solutions relative to the spontaneous decrease found during simultaneous perfusion with control solution of samples from the same cell scrapings. LTC4, 3-300 nmol/l, caused a highly significantly...

  17. 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.

  18. VAMP7 modulates ciliary biogenesis in kidney cells.

    Directory of Open Access Journals (Sweden)

    Christina M Szalinski

    Full Text Available Epithelial cells elaborate specialized domains that have distinct protein and lipid compositions, including the apical and basolateral surfaces and primary cilia. Maintaining the identity of these domains is required for proper cell function, and requires the efficient and selective SNARE-mediated fusion of vesicles containing newly synthesized and recycling proteins with the proper target membrane. Multiple pathways exist to deliver newly synthesized proteins to the apical surface of kidney cells, and the post-Golgi SNAREs, or VAMPs, involved in these distinct pathways have not been identified. VAMP7 has been implicated in apical protein delivery in other cell types, and we hypothesized that this SNARE would have differential effects on the trafficking of apical proteins known to take distinct routes to the apical surface in kidney cells. VAMP7 expressed in polarized Madin Darby canine kidney cells colocalized primarily with LAMP2-positive compartments, and siRNA-mediated knockdown modulated lysosome size, consistent with the known function of VAMP7 in lysosomal delivery. Surprisingly, VAMP7 knockdown had no effect on apical delivery of numerous cargoes tested, but did decrease the length and frequency of primary cilia. Additionally, VAMP7 knockdown disrupted cystogenesis in cells grown in a three-dimensional basement membrane matrix. The effects of VAMP7 depletion on ciliogenesis and cystogenesis are not directly linked to the disruption of lysosomal function, as cilia lengths and cyst morphology were unaffected in an MDCK lysosomal storage disorder model. Together, our data suggest that VAMP7 plays an essential role in ciliogenesis and lumen formation. To our knowledge, this is the first study implicating an R-SNARE in ciliogenesis and cystogenesis.

  19. Optic nerve fast axonal transport abnormalities in primates. Occurrence after short posterior ciliary artery occlusion.

    Science.gov (United States)

    Radius, R L

    1980-11-01

    Fast axonal transport abnormalities in primate (Aotus trivirgatus) optic nerve were studied in ten eyes at various intervals after occlusion of the lateral short posterior ciliary circulation. Evidence of focal axonal ischemia, as indicated by swelling of mitochondria and dissolution of cytoplasmic detail, was noted as early as one hour after occlusion. Accumulation of mitochondria, microvesicles, and dense bodies, indicating focal interruption of axonal transport mechanisms, was noted in eyes examined at 2, 4, and 6 hours. This accumulation of organelles was limited to the region of the lamina cribrosa. Nerve head abnormalities were not seen in two eyes studied at two weeks.

  20. RF communication with implantable wireless device: effects of beating heart on performance of miniature antenna.

    Science.gov (United States)

    Murphy, Olive H; Borghi, Alessandro; Bahmanyar, Mohammad Reza; McLeod, Christopher N; Navaratnarajah, Manoraj; Yacoub, Magdi; Toumazou, Christofer

    2014-06-01

    The frequency response of an implantable antenna is key to the performance of a wireless implantable sensor. If the antenna detunes significantly, there are substantial power losses resulting in loss of accuracy. One reason for detuning is because of a change in the surrounding environment of an antenna. The pulsating anatomy of the human heart constitutes such a changing environment, so detuning is expected but this has not been quantified dynamically before. Four miniature implantable antennas are presented (two different geometries) along with which are placed within the heart of living swine the dynamic reflection coefficients. These antennas are designed to operate in the short range devices frequency band (863-870 MHz) and are compatible with a deeply implanted cardiovascular pressure sensor. The measurements recorded over 27 seconds capture the effects of the beating heart on the frequency tuning of the implantable antennas. When looked at in the time domain, these effects are clearly physiological and a combination of numerical study and posthumous autopsy proves this to be the case, while retrospective simulation confirms this hypothesis. The impact of pulsating anatomy on antenna design and the need for wideband implantable antennas is highlighted.

  1. 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....

  2. 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.

  3. On the quantum beats in mesoscopic loop structures

    Energy Technology Data Exchange (ETDEWEB)

    Tralle, I.; Pasko, W

    2003-11-17

    A simple theory of quantum interference phenomenon, quantum beats which are due to Larmor precession of spins in mesoscopic structure, is presented. The similarities between this effect and Josephson, scalar Aharonov-Bohm and Aharonov-Casher effects, as well as their differences are considered. Possible application of the effect to the construction of the device, complementary to SQUID's is discussed. Such device could be useful for measuring the slightest magnetic field deviations from the spatial uniformity in extremely small scale.

  4. How to beat the sphere-packing bound with feedback

    OpenAIRE

    Sahai, Anant

    2006-01-01

    The sphere-packing bound $E_{sp}(R)$ bounds the reliability function for fixed-length block-codes. For symmetric channels, it remains a valid bound even when strictly causal noiseless feedback is allowed from the decoder to the encoder. To beat the bound, the problem must be changed. While it has long been known that variable-length block codes can do better when trading-off error probability with expected block-length, this correspondence shows that the {\\em fixed-delay} setting also present...

  5. Modulation of attosecond beating by resonant two-photon transition

    CERN Document Server

    Galán, Álvaro Jiménez; Martín, Fernando

    2015-01-01

    We present an analytical model that characterizes two-photon transitions in the presence of autoionising states. We applied this model to interpret resonant RABITT spectra, and show that, as a harmonic traverses a resonance, the phase of the sideband beating significantly varies with photon energy. This phase variation is generally very different from the $\\pi$ jump observed in previous works, in which the direct path contribution was negligible. We illustrate the possible phase profiles arising in resonant two-photon transitions with an intuitive geometrical representation.

  6. 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.

  7. Narrow-linewidth chirped frequency comb from a frequency-shifted feedback Ti:sapphire laser seeded by a phase-modulated single-frequency fiber laser.

    Science.gov (United States)

    Brandl, Matthias F; Mücke, Oliver D

    2010-12-15

    Frequency-shifted feedback (FSF) lasers have emerged as powerful tools for precision distance metrology. At the output of a Michelson interferometer, the detected rf spectra of the FSF laser light contain a length-dependent heterodyne beat signal whose linewidth ultimately limits the achievable accuracy of length measurements. Here, we demonstrate a narrow-linewidth chirped frequency comb from an FSF Ti:sapphire ring laser seeded by a phase-modulated, ultra-low-phase-noise, single-frequency fiber laser. We experimentally investigate the influence of the seed laser linewidth on the resulting width and shape of the length-dependent rf beat signal. An ultranarrow heterodyne beat linewidth of <20 Hz is observed.

  8. 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...

  9. 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.

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    Dhaher Enas

    2008-09-01

    Full Text Available 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 factors independently associated with wife beating. Special weights were used to obtain nationally representative estimates. Results In 1995 17.5% of married women in Egypt experienced wife beating in the last 12 months, in 2005 – 18.9% or 16.0%, using different measures. The association between socio-demographic differentials and wife beating was weaker in the newer survey. The 12-month prevalence of wife beating was lower only when both partners were educated, but the differences across education levels were less pronounced in 2005. Based on the information available in the 2005 survey, more educated women experienced less severe forms of wife beating than less educated women. Conclusion Different measures used in both surveys make a direct comparison difficult. The observed patterns indicate that the changes in prevalence may be masked by two opposite processes occurring in the society: a decrease in (severe forms of wife beating and an increase in reporting of wife beating. Improving the access to education for women and raising education levels in the whole society may help reducing wife beating.

  12. 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.

  13. 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.

  14. Arbitrary optical frequency synthesis traced to an optical frequency comb

    Science.gov (United States)

    Cai, Zihang; Zhang, Weipeng; Yang, Honglei; Li, Yan; Wei, Haoyun

    2016-11-01

    An arbitrary optical frequency synthesizer with a broad tuning range and high frequency accuracy is presented. The system includes an external cavity diode laser (ECDL) as the output laser, an Erbium-doped optical frequency comb being a frequency reference, and a control module. The optical frequency from the synthesizer can be continuously tuned by the large-scale trans-tooth switch and the fine intra-tooth adjustment. Robust feedback control by regulating the current and PZT voltage enables the ECDL to phase-lock to the Erbium-doped optical frequency comb, therefore to keep stable frequency output. In the meanwhile, the absolute frequency of the synthesizer is determined by the repetition rate, the offset frequency and the beat frequency. All the phase lock loops in the system are traced back to a Rubidium clock. A powerful and friendly software is developed to make the operation convenient by integrating the functions of frequency setting, tuning, tracing, locking and measuring into a LabVIEW interface. The output frequency tuning span and the uncertainty of the system are evaluated as >6 THz and <3 kHz, respectively. The arbitrary optical frequency synthesizer will be a versatile tool in diverse applications, such as synthetic wavelength based absolute distance measurement and frequency-stabilized Cavity Ring-Down Spectroscopy.

  15. Anatomical and histological data on the ciliary ganglion in the Egyptian spiny mouse (Acomys cahirinus Desmarest).

    Science.gov (United States)

    Nowak, Elzbieta; Kuder, Tadeusz; Szczurkowski, Aleksander; Kuchinka, Jacek

    2004-08-01

    The morphology and topography of the ciliary ganglion in the Egyptian spiny mouse were studied with use of histochemical and histological techniques. The ciliary ganglion of the Egyptian spiny mouse consisted of between 3 and 4 agglomerations of nerve cells. The largest was situated at the point where the ventral branch of the oculomotor nerve divides into two branches. The next two smaller aggregations were located on the superior and lateral surfaces of the optic nerve where it crossed the oculomotor nerve. From the main agglomerations of neurocytes arose between 3 and 4 intensively stained postganglionic cholinergic fibres. These followed the optic nerve to the eyeball. On the cross-sections of these bundles small agglomerations of neurocytes were observed. These decreased in size to only 2 or 3 cells towards the sclera. The ganglionic neurocytes in the largest ganglion varied from 15 to 30 microm in diameter. They were distributed uniformly over the whole surface of the sections. All the ganglia had connective capsules.

  16. 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.

  17. 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.

  18. Contact transcleral ciliary body photodynamic therapy with verteporfin in pigmented rabbits: effect of repeated treatments.

    Science.gov (United States)

    Charisis, Spyridon K; Naoumidi, Irene I; Ginis, Harilaos S; Detorakis, Efstathios T; Tsilimbaris, Miltiadis K

    2010-01-01

    We studied the effect on the intraocular pressure (IOP) and the ciliary body (CB) morphology after four consecutive contact transcleral photodynamic treatments of the ciliary body (CB-PDT) with verteporfin in pigmented rabbits. Twenty-two pigmented rabbits underwent CB-PDT (study group), performed once (six rabbits) or repeated for up to four times (16 rabbits). Six additional rabbits received only laser treatment without photosensitizer administration (control group). CB-PDT was performed in one eye in rabbits of the study group, with the fellow eye serving as internal control. Verteporfin dosage was 1 mg kg(-1) as bolus injection and laser settings were 40 mW (600 microm core optical fiber) for 1.5 min per spot, for 10 spots. In repeated CB-PDT, treatments were performed in 4-day intervals. Daily IOP measurements were recorded. Histological studies were performed at selected time points. An IOP reduction, more sustained following repeated treatments, was detected in all treated eyes but not in fellow eyes or in the control group. On the average, the IOP was restored to pretreatment levels 4 days after the last treatment. No serious adverse events were observed and the CB architecture was intact at the end of the experiment. Repeated CB-PDT is safe and results in a short-term reduction of IOP. Induced CB alterations are reversible.

  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. Diagnosis of primary ciliary dyskinesia: potential options for resource-limited countries

    Directory of Open Access Journals (Sweden)

    Nisreen Rumman

    2017-01-01

    Full Text Available Primary ciliary dyskinesia is a genetic disease of ciliary function leading to chronic upper and lower respiratory tract symptoms. The diagnosis is frequently overlooked because the symptoms are nonspecific and the knowledge about the disease in the primary care setting is poor. Additionally, none of the available tests is accurate enough to be used in isolation. These tests are expensive, and need sophisticated equipment and expertise to analyse and interpret results; diagnosis is therefore only available at highly specialised centres. The diagnosis is particularly challenging in countries with limited resources due to the lack of such costly equipment and expertise. In this review, we discuss the importance of early and accurate diagnosis especially for countries where the disease is clinically prevalent but diagnostic tests are lacking. We review the diagnostic tests available in specialised centres (nasal nitric oxide, high-speed video microscopy, transmission electron microscopy, immunofluorescence and genetics. We then consider modifications that might be considered in less well-resourced countries whilst maintaining acceptable accuracy.

  1. 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.

  2. 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.

  3. A sensorimotor theory of temporal tracking and beat induction.

    Science.gov (United States)

    Todd, N P McAngus; Lee, C S; O'Boyle, D J

    2002-02-01

    In this paper, we develop a theory of the neurobiological basis of temporal tracking and beat induction as a form of sensory-guided action. We propose three principal components for the neurological architecture of temporal tracking: (1) the central auditory system, which represents the temporal information in the input signal in the form of a modulation power spectrum; (2) the musculoskeletal system, which carries out the action and (3) a controller, in the form of a parieto-cerebellar-frontal loop, which carries out the synchronisation between input and output by means of an internal model of the musculoskeletal dynamics. The theory is implemented in the form of a computational algorithm which takes sound samples as input and synchronises a simple linear mass-spring-damper system to simulate audio-motor synchronisation. The model may be applied to both the tracking of isochronous click sequences and beat induction in rhythmic music or speech, and also accounts for the approximate Weberian property of timing.

  4. 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.

  5. Changes in intracellular calcium concentration influence beat-to-beat variability of action potential duration in canine ventricular myocytes.

    Science.gov (United States)

    Kistamas, K; Szentandrassy, N; Hegyi, B; Vaczi, K; Ruzsnavszky, F; Horvath, B; Banyasz, T; Nanasi, P P; Magyar, J

    2015-02-01

    The aim of the present work was to study the influence of changes in intracellular calcium concentration ([Ca(2+)]i) on beat-to-beat variability (short term variability, SV) of action potential duration (APD) in isolated canine ventricular cardiomyocytes. Series of action potentials were recorded from enzymatically isolated canine ventricular cells using conventional microelectrode technique. Drug effects on SV were evaluated as relative SV changes determined by plotting the drug-induced changes in SV against corresponding changes in APD and comparing these data to the exponential SV-APD function obtained with inward and outward current injections. Exposure of myocytes to the Ca(2+) chelator BAPTA-AM (5 μM) decreased, while Ca(2+) ionophore A23187 (1 μM) increased the magnitude of relative SV. Both effects were primarily due to the concomitant changes in APD. Relative SV was reduced by BAPTA-AM under various experimental conditions including pretreatment with veratridine, BAY K8644, dofetilide or E-4031. Contribution of transient changes of [Ca(2+)]i due to Ca(2+) released from the sarcoplasmic reticulum (SR) was studied using 10 μM ryanodine and 1 μM cyclopiazonic acid: relative SV was reduced by both agents. Inhibition of the Na(+)-Ca(2+) exchanger by 1 μM SEA0400 increased relative SV. It is concluded that elevation of [Ca(2+)]i increases relative SV significantly. More importantly, Ca(2+) released from the SR is an important component of this effect.

  6. Metachronal waves in the flagellar beating of Volvox and their hydrodynamic origin.

    Science.gov (United States)

    Brumley, Douglas R; Polin, Marco; Pedley, Timothy J; Goldstein, Raymond E

    2015-07-06

    Groups of eukaryotic cilia and flagella are capable of coordinating their beating over large scales, routinely exhibiting collective dynamics in the form of metachronal waves. The origin of this behavior--possibly influenced by both mechanical interactions and direct biological regulation--is poorly understood, in large part due to a lack of quantitative experimental studies. Here we characterize in detail flagellar coordination on the surface of the multicellular alga Volvox carteri, an emerging model organism for flagellar dynamics. Our studies reveal for the first time that the average metachronal coordination observed is punctuated by periodic phase defects during which synchrony is partial and limited to specific groups of cells. A minimal model of hydrodynamically coupled oscillators can reproduce semi-quantitatively the characteristics of the average metachronal dynamics, and the emergence of defects. We systematically study the model's behaviour by assessing the effect of changing intrinsic rotor characteristics, including oscillator stiffness and the nature of their internal driving force, as well as their geometric properties and spatial arrangement. Our results suggest that metachronal coordination follows from deformations in the oscillators' limit cycles induced by hydrodynamic stresses, and that defects result from sufficiently steep local biases in the oscillators' intrinsic frequencies. Additionally, we find that random variations in the intrinsic rotor frequencies increase the robustness of the average properties of the emergent metachronal waves.

  7. 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.

  8. 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

  9. Efficiency of beating cloth in sampling for soybean insect pests in different row spacing and cultivars

    Directory of Open Access Journals (Sweden)

    Glauber Renato Stürmer

    2014-06-01

    Full Text Available An experiment was conducted to compare the collecting capacity of three types of beating cloth in sampling for soybeans caterpillars and stink bugs in different row spacing and cultivars. The experiment was conducted in a completely randomized design with six replications in a 2x3x3 factorial, using two cultivars (BMX Potencia RR and Fundacep 53 RR, three row spacing (0.4, 0.5 and 0.6 m and three types of beating cloth (beating cloth, wide beating cloth and vertical beat sheet. To determinate the collecting capacity of caterpillars, samples were taken at V9, V11 and R1 stages and for stink bugs, the samplings were performed at R5.3 and R5.5 stages. Results showed no interaction between the factors, indicating independence among them. Caterpillars had no preference between cultivars, however, stink bugs had a higher population density on Fundacep 53 RR. In the three evaluation dates, the density of larvae was higher when soybean was sown with reduced spacing. For stink bugs, higher infestation was observed on soybean sown with 0.4 m row spacing in the first assessment (R5.3, difference not observed in the evaluation at R5.5. The wide beating cloth and vertical beating cloth showed greater collecting capacity for caterpillars and bugs over beating cloth.

  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.

    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.

  12. 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

  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. Impact of thymol in thyme extracts on their antispasmodic action and ciliary clearance.

    Science.gov (United States)

    Begrow, Frank; Engelbertz, Jonas; Feistel, Björn; Lehnfeld, Romanus; Bauer, Katrin; Verspohl, Eugen J

    2010-03-01

    Thyme is a herb with broncholytic und secretomotoric effects. Its activity on beta (2) receptors as a possible mechanism of action was demonstrated. Major components are thymol and carvacrol which are claimed to be responsible for its effects and, therefore, used for standardization in the German pharmacopoeia (0.03 % phenols calculated as thymol). Our aim was to investigate the impact of thymol by using thyme extracts with either normal or extremely low thymol concentrations ( 0.038 %). The antispasmodic effect on smooth muscles of the trachea and the ileum and the effect on ciliary activity (respiratory clearance) were investigated. In addition, pure thymol and carvacrol were investigated separately and in spiking experiments. Thymol and carvacrol had a concentration-dependent antispasmodic effect in the rat trachea either being stimulated by acetylcholine, K (+) or Ba (++). The same result was observed with respect to the increase of mucociliary transport in mice. Extracts with very low thymol contents are effective in all models used except acetylcholine-induced rat ileum contraction. When thyme extracts with normal thymol contents or with very low thymol contents were compared, the extract with normal thymol contents was more effective, both as a relaxant (rat ileum) and as an antispasmodic compound (rat trachea contraction induced by either acetylcholine, Ba (++) or K (+)) and in ciliary transport experiments. Thyme extracts with very low thymol contents (practically free of volatile oil) were equally effective with respect to endothelin effects. When an extract with very low thymol contents is spiked with increasing concentrations of thymol, a concentration-dependent increase concerning the antispasmodic effect (Ba (++)-induced trachea contraction) is observed. In conclusion, the data show that in various models of antispasmodic effect (ileum and trachea) and by measuring ciliary activity, thymol (and carvacrol) is (are) active, although other not identified

  15. 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.

  16. Beating Rayleigh's Curse by Imaging Using Phase Information

    Science.gov (United States)

    Tham, Weng-Kian; Ferretti, Hugo; Steinberg, Aephraim M.

    2017-02-01

    Every imaging system has a resolution limit, typically defined by Rayleigh's criterion. Given a fixed number of photons, the amount of information one can gain from an image about the separation between two sources falls to zero as the separation drops below this limit, an effect dubbed "Rayleigh's curse." Recently, in a quantum-information-inspired proposal, Tsang and co-workers found that there is, in principle, infinitely more information present in the full electromagnetic field in the image plane than in the intensity alone, and suggested methods for extracting this information and beating the Rayleigh limit. In this Letter, we experimentally demonstrate a simple scheme that captures most of this information, and show that it has a greatly improved ability to estimate the distance between a pair of closely separated sources, achieving near-quantum-limited performance and immunity to Rayleigh's curse.

  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. Global Beta-beating Compensation of the ALS W16 Wiggler.

    Science.gov (United States)

    Robin, David; Nishimura, Hiroshi; Safranek, James

    1997-05-01

    The W16 wiggler is the first wiggler and highest field insertion device to be installed in the ALS storage ring. When the gaps of the W16 wiggler are closed, the vertical tune increases by 0.07 and the vertical beta function is distorted by 35 %. There are 48 quadrupoles in the ring whose fields can be adjusted individually to restore the tunes and partially compensate the beta beating. In order to adjust the quadrupole field strengths to accurately compensate the focussing, it is necessary to have a method to precisely determine the beta-beating. In this paper we compare measurements of the induced beta-beating using two methods: measuring the tune dependence on quadrupole field strength and fitting a lattice model with measured response matricies. The fitted model also allows us to predict quadrupole field strengths that will best compensate the beta beating. These quadrupole field strengths are then applied and the resultant beta-beating is measured.

  19. Remote beating of parallel or orthogonally polarized dual-wavelength optical carriers for 5G millimeter-wave radio-over-fiber link.

    Science.gov (United States)

    Wang, Huai-Yung; Chi, Yu-Chieh; Lin, Gong-Ru

    2016-08-08

    A novel millimeter-wave radio over fiber (MMW-RoF) link at carrier frequency of 35-GHz is proposed with the use of remotely beating MMW generation from reference master and injected slave colorless laser diode (LD) carriers at orthogonally polarized dual-wavelength injection-locking. The slave colorless LD supports lasing one of the dual-wavelength master modes with orthogonal polarizations, which facilitates the single-mode direct modulation of the quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM) data. Such an injected single-carrier encoding and coupled dual-carrier transmission with orthogonal polarization effectively suppresses the cross-heterodyne mode-beating intensity noise, the nonlinear modulation (NLM) and four-wave mixing (FWM) sidemodes during injection locking and fiber transmission. In 25-km single-mode fiber (SMF) based wireline system, the dual-carrier under single-mode encoding provides baseband 24-Gbit/s 64-QAM OFDM transmission with an error vector magnitude (EVM) of 8.8%, a bit error rate (BER) of 3.7 × 10-3, a power penalty of wireless transmission, the beat MMW carrier at 35 GHz can deliver the passband 16-QAM OFDM at 4 Gbit/s to show corresponding EVM and BER of 15.5% and 1.4 × 10-3, respectively, after 25-km SMF and 1.6-m free-space transmission.

  20. 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.

  1. Long-term periodicity in LSI+61303 as beat frequency between orbital and precessional rate

    CERN Document Server

    Massi, M

    2013-01-01

    Context: In the binary system LSI+61303 the peak flux density of the radio outburst, which is related to the orbital period of 26.4960 +/- 0.0028d, exibits a modulation of 1667 +/- 8 d. The radio emission at high spatial resolution appears structured in a precessing jet with a precessional period of 27-28 d. Aims: How close is the precessional period of the radio jet to the orbital period? Any periodicity in the radio emission should be revealed by timing analysis. The aim of this work is to establish the accurate value of the precessional period. Methods: We analyzed 6.7 years of the Green Bank Interferometer database at 2.2 GHz and 8.3 GHz with the Lomb-Scargle and phase dispersion minimization (PDM) methods and performed simulations. Results: The periodograms show two periodicities, P1 = 26.49 +/- 0.07 d (\

  2. A new beat interference cancellation receiver with 3×3 optical coupler for the SSB-OOFDM signal with reduced guard band

    Science.gov (United States)

    Zhang, Ying; Ma, Jianxin

    2016-05-01

    In this paper, we present a new method to implement beat interference cancellation receiver (BICR) for single-sideband optical orthogonal frequency division multiplexing (SSB-OOFDM) signal, which improves the spectral efficiency (SE) by reducing the guard band (GB) between the optical carrier and the OOFDM signal while mitigating the impact of signal-signal beat interference (SSBI). This BICR structure is relatively simple using only an optical interleaver (IL), a 3×3 optical coupler (OC) and three photodiodes (PDs). A system simulation for the 40 Gbit/s 16-QAM SSB-OOFDM signal with the reduced GB is carried out to prove the feasibility of this new scheme. The simulation results show that our proposed BICR has a better performance to suppress SSBI and a higher SE than the conventional direct-detection receiver (CDDR) according to the EVMs and the constellations.

  3. IgG4-related intraocular inflammation masquerading as ciliary body melanoma in a young girl

    Directory of Open Access Journals (Sweden)

    Dipankar Das

    2016-01-01

    Full Text Available Immunoglobulin G4 (IgG4-related diseases affects various tissues and organs of the human body. Orbital, adnexal, and scleral inflammations were already reported in the medical literature. To the best of our knowledge, we report the first case of intraocular IgG4-associated inflammatory mass in the ciliary body mimicking as a melanoma in a 23-year-old female from Northeast India. Characteristic histopathology, immunohistochemistry in the tissue, protein chemistry, and raised serum IgG4 were supportive for the diagnosis. As this newly diagnosed disease has multi-organ affection and little is known about its pathogenesis particularly in eye and adnexa, the present case will open many challenges in clinico-pathological diagnosis and research in the future.

  4. Aerobic fitness in children and young adults with primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Madsen, Astrid Hellerup; Green, Kent; Buchvald, Frederik

    2013-01-01

    patients. CONCLUSION: One-third of PCD patients exhibited substantially lower aerobic fitness than healthy subjects. Aerobic fitness correlated with FEV1, DLCO/VA and self-reported complaints of limitations in vigorous physical activity. These findings are most likely explained by PCD pulmonary disease...... and its impact on pulmonary function and physical ability. Considering fitness as an important outcome and including regular strenuous physical activity in PCD treatment would probably altogether increase pulmonary clearance, lung function, aerobic fitness, and quality of life, and prevent lifestyle......BACKGROUND: Although aerobic fitness is regarded as an overall prognostic measure of morbidity and mortality, its evaluation in the chronic progressive sinopulmonary disease primary ciliary dyskinesia (PCD) has been infrequently and inconsistently reported. Here we assessed peak oxygen uptake (VO2...

  5. 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.

  6. 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

  7. 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

  8. Cell context-specific expression of primary cilia in the human testis and ciliary coordination of Hedgehog signalling in mouse Leydig cells

    DEFF Research Database (Denmark)

    Berg Nygaard, Marie; Almstrup, Kristian; Lindbæk, Louise;

    2015-01-01

    Primary cilia are sensory organelles that coordinate numerous cellular signalling pathways during development and adulthood. Defects in ciliary assembly or function lead to a series of developmental disorders and diseases commonly referred to as ciliopathies. Still, little is known about...

  9. 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.

  10. 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.

  11. 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.

  12. Comparative usefulness of beat-to-beat QT dispersion and QT interval fluctuations for identifying patients with organic heart disease at risk for ventricular arrhythmias.

    Science.gov (United States)

    Galeano, Erdulfo J; Yoshida, Akihiro; Ohnishi, Yoshio; Okajima, Katsunori; Ishida, Akihiko; Kitamura, Hidetsuna; Kubo, Shinya; Yokoyama, Mitsuhiro

    2003-02-01

    The comparative usefulness of 10 min of beat-to-beat 12-lead QT dispersion (QTd) and QT interval variability index (QTVI) analysis for identifying patients with organic heart disease (OHD) at risk for ventricular arrhythmias was assessed in 86 subjects: 54 had OHD without a history of ventricular arrhythmias, 15 had OHD with documented ventricular tachycardia, and there were 17 controls. The following parameters were analyzed among the groups: (1) the average QTd (mean QTd), (2) the difference between the maximum and minimum QTd observed over the recording time (QTd variation), (3) the maximum difference of QTd between consecutive beats (QTd maximum), (4) the QTd standard deviation (QTd variability), and (5) QTVI, calculated in lead I or II according to an established formula: log 10 [(QTv/QTm2) / (HRv/HRm2)]. All the analyzed parameters were significantly increased in the patients with and without ventricular tachycardia when compared with the controls. QTd variation, QTd maximum and QTd variability were the only variables that remained significantly increased in the group of patients with documented ventricular tachycardia, compared with those without arrhythmia. Thus, beat-to-beat fluctuations of both the QT interval and QTd may be markers of temporal electrical instability in patients with OHD.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. Multiwavelength fiber lasers based on spatial mode beating for high resolution linear and angular displacement sensing

    Science.gov (United States)

    Chen, Nan-Kuang; Chang, Yung-Hsiang; Cheng, Wood-Hi; Guo, Tuan; Guan, Bai-Ou

    2014-05-01

    We demonstrate multiwavelength fiber lasers by incorporating the micro Michelson interferometer with spatial mode beating phenomenon, which comes from the interferences among cladding modes, into ring cavity for high resolution linear and angular displacement sensing.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. Neural responses to sounds presented on and off the beat of ecologically valid music

    Directory of Open Access Journals (Sweden)

    Adam eTierney

    2013-05-01

    Full Text Available The tracking of rhythmic structure is a vital component of speech and music perception. It is known that sequences of identical sounds can give rise to the percept of alternating strong and weak sounds, and that this percept is linked to enhanced cortical and oscillatory responses. The neural correlates of the perception of rhythm elicited by ecologically valid, complex stimuli, however, remain unexplored. Here we report the effects of a stimulus’ alignment with the beat on the brain’s processing of sound. Human subjects listened to short popular music pieces while simultaneously hearing a target sound. Cortical and brainstem electrophysiological onset responses to the sound were enhanced when it was presented on the beat of the music, as opposed to shifted away from it. Moreover, the size of the effect of alignment with the beat on the cortical response correlated strongly with the ability to tap to a beat, suggesting that the ability to synchronize to the beat of simple isochronous stimuli and the ability to track the beat of complex, ecologically valid stimuli may rely on overlapping neural resources. These results suggest that the perception of musical rhythm may have robust effects on processing throughout the auditory system.

  12. 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.

  13. 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.

  14. 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.

  15. Brain Ciliary Neurotrophic Factor (CNTF and hypothalamic control of energy homeostasis

    Directory of Open Access Journals (Sweden)

    Vacher Claire-Marie

    2011-09-01

    Full Text Available Cytokines play an important role in energy-balance regulation. Notably leptin, an adipocyte-secreted cytokine, regulates the activity of hypothalamic neurons that are involved in the modulation of appetite. Leptin decreases appetite and stimulates weight loss in rodents. Unfortunately, numerous forms of obesity in humans seem to be resistant to leptin action. The ciliary neurotrophic factor (CNTF is a neurocytokine that belongs to the same family as leptin and that was originally characterized as a neurotrophic factor that promotes the survival of a broad spectrum of neuronal cell types and that enhances neurogenesis in adult rodents. It presents the advantage of stimulating weight loss in humans, despite the leptin resistance. Moreover, the weight loss persists several weeks after the cessation of treatment. Hence, CNTF has been considered as a promising therapeutic tool for the treatment of obesity and has prompted intense research aimed at identifying the cellular and molecular mechanisms underlying its potent anorexigenic properties. It has been found that CNTF shares signaling pathways with leptin and is expressed in the arcuate nucleus (ARC, a key hypothalamic region controlling food intake. Endogenous CNTF may also participate in the control of energy balance. Indeed, its expression in the ARC is inversely correlated to body weight in rats fed a high-sucrose diet. Thus hypothalamic CNTF may act, in some individuals, as a protective factor against weight gain during hypercaloric diet and could account for individual differences in the susceptibility to obesity.

  16. Using myc genes to search for stem cells in the ciliary margin of the Xenopus retina.

    Science.gov (United States)

    Xue, Xiao Yan; Harris, William A

    2012-04-01

    The ciliary marginal zone (CMZ) of fish and frog retinas contains cells that proliferate throughout postembryonic development as the retina grows with increasing body size, indicating the presence of stem cells in this region. However, neither the location nor the molecular identity of retinal stem cells has been identified. Here, we show in Xenopus that c-myc and n-myc are sequentially expressed both during development and in the post-embryonic retina. The c-myc+/n-myc- cells near the extreme periphery of the CMZ cycle more slowly and preferentially retain DNA label compared to their more central cmyc+/n-myc+ neighbors which cycle rapidly and preferentially dilute DNA label. During retinal development c-myc is functionally required earlier than n-myc, and n-myc expression depends on earlier c-myc expression. The expression of c-myc but not n-myc in the CMZ depends on growth factor signaling. Our results suggest that c-myc+/n-myc- cells in the far peripheral CMZ are candidates for a niche-dependent population of retinal stem cells that give rise to more centrally located and rapidly dividing n-myc+ progenitors of more limited proliferative potential. Analysis of homologues of these genes in the zebrafish CMZ suggests that the transition from c-myc to n-myc expression might be conserved in other lower vertebrates whose retinas growth throughout life.

  17. Physiological Flow of Jeffrey Six Constant Fluid Model due to Ciliary Motion

    Science.gov (United States)

    Shaheen, A.; Hussain, S.; Nadeem, S.

    2016-12-01

    The main purpose of this article is to present a mathematical model of ciliary motion in an annulus. In this analysis, the peristaltic motion of non-Newtonian Jeffrey six constant fluid is observed in an annulus with ciliated tips in the presence of heat and mass transfer. The effects of viscous dissipation are also considered. The flow equations of non-Newtonian fluid for the two-dimensional tube in cylindrical coordinates are simplified using the low Reynolds number and long wave-length approximations. The main equations for Jeffrey six constant fluid are considered in cylindrical coordinates system. The resulting nonlinear problem is solved using the regular perturbation technique in terms of a variant of small dimensionless parameter α. The results of the solutions for velocity, temperature and concentration field are presented graphically. Bk is Brinkman number, ST is soret number, and SH is the Schmidth number. Outcome for the longitudinal velocity, pressure rise, pressure gradient and stream lines are represented through graphs. in the history, the viscous-dissipation effect is usually represented by the Brinkman number.

  18. The ciliary margin zone of the mammalian retina generates retinal ganglion cells

    Science.gov (United States)

    Marcucci, Florencia; Murcia-Belmonte, Veronica; Coca, Yaiza; Ferreiro-Galve, Susana; Wang, Qing; Kuwajima, Takaaki; Khalid, Sania; Ross, M. Elizabeth; Herrera, Eloisa; Mason, Carol

    2016-01-01

    Summary The retina of lower vertebrates grows continuously by integrating new neurons generated from progenitors in the ciliary margin zone (CMZ). Whether the mammalian CMZ provides the neural retina with retinal cells is controversial. Live-imaging of embryonic retina expressing eGFP in the CMZ shows that cells migrate laterally from the CMZ to the neural retina where differentiated retinal ganglion cells (RGCs) reside. As Cyclin D2, a cell-cycle regulator, is enriched in ventral CMZ, we analyzed Cyclin D2−/− mice to test whether the CMZ is a source of retinal cells. Neurogenesis is diminished in Cyclin D2 mutants, leading to a reduction of RGCs in the ventral retina. In line with these findings, in the albino retina, the decreased production of ipsilateral RGCs is correlated with fewer Cyclin D2+ cells. Together, these results implicate the mammalian CMZ as a neurogenic site that produces RGCs and whose proper generation depends on Cyclin D2 activity. PMID:28009286

  19. The international primary ciliary dyskinesia cohort (iPCD Cohort): methods and first results

    Science.gov (United States)

    Goutaki, Myrofora; Maurer, Elisabeth; Halbeisen, Florian S.; Amirav, Israel; Barbato, Angelo; Behan, Laura; Boon, Mieke; Casaulta, Carmen; Clement, Annick; Crowley, Suzanne; Haarman, Eric; Hogg, Claire; Karadag, Bulent; Koerner-Rettberg, Cordula; Leigh, Margaret W.; Loebinger, Michael R.; Mazurek, Henryk; Morgan, Lucy; Nielsen, Kim G.; Omran, Heymut; Schwerk, Nicolaus; Scigliano, Sergio; Werner, Claudius; Yiallouros, Panayiotis; Zivkovic, Zorica; Lucas, Jane S.

    2017-01-01

    Data on primary ciliary dyskinesia (PCD) epidemiology is scarce and published studies are characterised by low numbers. In the framework of the European Union project BESTCILIA we aimed to combine all available datasets in a retrospective international PCD cohort (iPCD Cohort). We identified eligible datasets by performing a systematic review of published studies containing clinical information on PCD, and by contacting members of past and current European Respiratory Society Task Forces on PCD. We compared the contents of the datasets, clarified definitions and pooled them in a standardised format. As of April 2016 the iPCD Cohort includes data on 3013 patients from 18 countries. It includes data on diagnostic evaluations, symptoms, lung function, growth and treatments. Longitudinal data are currently available for 542 patients. The extent of clinical details per patient varies between centres. More than 50% of patients have a definite PCD diagnosis based on recent guidelines. Children aged 10–19 years are the largest age group, followed by younger children (≤9 years) and young adults (20–29 years). This is the largest observational PCD dataset available to date. It will allow us to answer pertinent questions on clinical phenotype, disease severity, prognosis and effect of treatments, and to investigate genotype–phenotype correlations. PMID:28052956

  20. “Would you like to meet the secret Beat?” – Tram Combs and a Beat poetry less celebrated

    DEFF Research Database (Denmark)

    Sørensen, Bent

    My friend Gorm H. Rasmussen, a Danish poet, novelist and travel writer, is a great fan of the Beat writers and many other American authors. One afternoon in November 2009 he was staking out Paul Auster in what is purportedly this author’s favorite café in Brooklyn. Frustrated that the writer had...

  1. The Crazy Dumbsaint of the Mind or Poet-Prophets of the Beat and Beatific: William Blake’s Resurrection in the American Beat Generation

    Science.gov (United States)

    2007-11-02

    and prose of this small group of avant-garde writers, self-proclaimed as the Beat Generation, continues a tradition of prophecy and visionary poetry...in which Blake’s Romantic depictions of the French and American Revolutions are replaced with a much more ominous political moment defined by the threat of nuclear Armageddon.

  2. To beat or not to beat a tick: comparison of DNA extraction methods for ticks (Ixodes scapularis

    Directory of Open Access Journals (Sweden)

    Alyssa D. Ammazzalorso

    2015-08-01

    Full Text Available Background. Blacklegged ticks (Ixodes scapularis are important disease vectors in the United States, known to transmit a variety of pathogens to humans, including bacteria, protozoa, and viruses. Their importance as a disease vector necessitates reliable and comparable methods for extracting microbial DNA from ticks. Furthermore, to explore the population genetics or genomics of this tick, appropriate DNA extraction techniques are needed for both the vector and its microbes. Although a few studies have investigated different methods of DNA isolation from ticks, they are limited in the number and types of DNA extraction and lack species-specific quantification of DNA yield.Methods. Here we determined the most efficient and consistent method of DNA extraction from two different developmental stages of I. scapularis—nymph and adult—that are the most important for disease transmission. We used various methods of physical disruption of the hard, chitinous exoskeleton, as well as commercial and non-commercial DNA isolation kits. To gauge the effectiveness of these methods, we quantified the DNA yield and confirmed the DNA quality via PCR of both tick and microbial genetic material.Results. DNA extraction using the Thermo GeneJET Genomic DNA Purification Kit resulted in the highest DNA yields and the most consistent PCR amplification when combined with either cutting or bead beating with select matrices across life stages. DNA isolation methods using ammonium hydroxide as well as the MoBio PowerSoil kit also produced strong and successful PCR amplification, but only for females.Discussion. We contrasted a variety of readily available methods of DNA extraction from single individual blacklegged ticks and presented the results through a quantitative and qualitative assessment.

  3. Exploring how musical rhythm entrains brain activity with electroencephalogram frequency-tagging.

    Science.gov (United States)

    Nozaradan, Sylvie

    2014-12-19

    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.

  4. Cross-cultural influences on rhythm processing: reproduction, discrimination, and beat tapping.

    Science.gov (United States)

    Cameron, Daniel J; Bentley, Jocelyn; Grahn, Jessica A

    2015-01-01

    The structures of musical rhythm differ between cultures, despite the fact that the ability to entrain movement to musical rhythm occurs in virtually all individuals across cultures. To measure the influence of culture on rhythm processing, we tested East African and North American adults on perception, production, and beat tapping for rhythms derived from East African and Western music. To assess rhythm perception, participants identified whether pairs of rhythms were the 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 by the culture of the participant and 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 for unfamiliar rhythms. Moreover, there were differences between the two participant groups, and between the two types of rhythms, in the metrical level selected for beat tapping. 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.

  5. 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.

  6. Experimental Study on the Prevention of Anterior Segment Ischemia by Preservation of Anterior Ciliary Vessels

    Institute of Scientific and Technical Information of China (English)

    Yanna Li; Guanghuan Mai; Zhijian Wang; Xinping Yu; Huanyun Yu; Yan Guo; Xiaoming Lin; Daming Deng; Ying Kang

    2003-01-01

    Purpose: To observe the effect of preserving anterior ciliary vessels (ACVs) on anteriorsegments of rabbit eyes undergoing tenotomy of extraocular muscles.Methods: Thirty-two adult New Zealand white rabbits were divided into four groups.Same procedures were done in both eyes in each group except that left eyes underwentpreservation of ACVs. In the first group medial and lateral recti, in the second group,superior and inferior recti, in the third group, medial, lateral and superior or inferior rectiand in the fourth group, all four recti, underwent tenotomy. Slit-lamp examination,intraocular pressure (IOP) measurement, total protein and lactic acid quantification inaqueous humor were done in all eyes pre- and post-operatively. By four weeks afteroperation, the eyes were enucleated for histological examination and electron microscopy.All data were analyzed using SPSS version 10.Results: In the left eyes of both group 1 and group 2, no inflammatory response wasobserved. In the left eyes of group 3 and 4, we observed mild inflammatory response withslit-lamp examination, which disappeared in one wk. However, we did not findsignificant changes in IOP, total protein and lactic acid of aqueous humor, histology andelectron microscopic examination in these groups. In the right eyes in group 2, 3 and 4,we observed moderate to severe inflammatory changes, a few even developed anteriorsegment ischemia, appeared as decreased IOP, increased total protein and lactic acid inaqueous humor, along with pathological and electron-microscopic changes.Conclusion: Simultaneous tenotomy of three or four recti or two vertical recti on one eyemay decrease anterior segment blood flow even lead to ischemia. ACVs preservation mayprotect the blood circulation in anterior segment. Our study suggests that ACVspreservation in strabismus surgeries especially those involving multi-recti tenotomies mayprevent potential anterior segment ischemia.

  7. 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.

  8. Nasal nitric oxide screening for primary ciliary dyskinesia: systematic review and meta-analysis.

    Science.gov (United States)

    Collins, Samuel A; Gove, Kerry; Walker, Woolf; Lucas, Jane S A

    2014-12-01

    Nasal nitric oxide (nNO) concentrations are low in patients with primary ciliary dyskinesia (PCD) providing a noninvasive screening test. We conducted a systematic review of the literature to examine the utility of nNO in screening for PCD, in particular 1) different respiratory manoeuvres during sampling (velum closure, tidal breathing, etc.), 2) accuracy in screening young/uncooperative children, 3) stationary versus portable analysers, and 4) nNO in "atypical" PCD. 96 papers were assessed according to modified PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria and 22 were included in this review. Meta-analysis of 11 studies comparing nNO during a velum closure breath hold gave a mean±SD nNO of 19.4±18.6 nL·min(-1) in PCD (n = 478) and 265.0±118.9 nL·min(-1) in healthy controls (n = 338). Weighted mean difference for PCD versus healthy controls was 231.1 nL·min(-1) (95% CI 193.3-268.9; n = 338) and 114.1 nL·min(-1) (95% CI 101.5-126.8; n = 415) for PCD versus cystic fibrosis. Five studies of nNO measurement during tidal breathing demonstrated that this is an acceptable manoeuvre in young children where velum closure is not possible, but the discriminatory value was reduced. Four small studies of portable NO analysers suggest these are reliable tools for screening for PCD. However, nNO must be interpreted alongside clinical suspicion. Future studies should focus on standardising sampling techniques and reporting.

  9. '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.

  10. 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.

  11. Reduced ciliary polycystin-2 in induced pluripotent stem cells from polycystic kidney disease patients with PKD1 mutations.

    Science.gov (United States)

    Freedman, Benjamin S; Lam, Albert Q; Sundsbak, Jamie L; Iatrino, Rossella; Su, Xuefeng; Koon, Sarah J; Wu, Maoqing; Daheron, Laurence; Harris, Peter C; Zhou, Jing; Bonventre, Joseph V

    2013-10-01

    Heterozygous mutations in PKD1 or PKD2, which encode polycystin-1 (PC1) and polycystin-2 (PC2), respectively, cause autosomal dominant PKD (ADPKD), whereas mutations in PKHD1, which encodes fibrocystin/polyductin (FPC), cause autosomal recessive PKD (ARPKD). However, the relationship between these proteins and the pathogenesis of PKD remains unclear. To model PKD in human cells, we established induced pluripotent stem (iPS) cell lines from fibroblasts of three ADPKD and two ARPKD patients. Genetic sequencing revealed unique heterozygous mutations in PKD1 of the parental ADPKD fibroblasts but no pathogenic mutations in PKD2. Undifferentiated PKD iPS cells, control iPS cells, and embryonic stem cells elaborated primary cilia and expressed PC1, PC2, and FPC at similar levels, and PKD and control iPS cells exhibited comparable rates of proliferation, apoptosis, and ciliogenesis. However, ADPKD iPS cells as well as somatic epithelial cells and hepatoblasts/biliary precursors differentiated from these cells expressed lower levels of PC2 at the cilium. Additional sequencing confirmed the retention of PKD1 heterozygous mutations in iPS cell lines from two patients but identified possible loss of heterozygosity in iPS cell lines from one patient. Furthermore, ectopic expression of wild-type PC1 in ADPKD iPS-derived hepatoblasts rescued ciliary PC2 protein expression levels, and overexpression of PC1 but not a carboxy-terminal truncation mutant increased ciliary PC2 expression levels in mouse kidney cells. Taken together, these results suggest that PC1 regulates ciliary PC2 protein expression levels and support the use of PKD iPS cells for investigating disease pathophysiology.

  12. Sinus surgery can improve quality of life, lung infections, and lung function in patients with primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Alanin, Mikkel Christian; Aanaes, Kasper; Høiby, Niels;

    2016-01-01

    BACKGROUND: Chronic rhinosinusitis (CRS) and bacterial sinusitis are ubiquitous in patients with primary ciliary dyskinesia (PCD). From the sinuses, Pseudomonas aeruginosa can infect the lungs. METHODS: We studied the effect of endoscopic sinus surgery (ESS) on symptoms of CRS and lower airway...... patients (62%). Four patients with preoperative P. aeruginosa lung colonization (25%) had no regrowth during follow-up; 2 of these had P. aeruginosa sinusitis. Sinonasal symptoms were improved 12 months after ESS and we observed a trend toward better lung function after ESS. CONCLUSION: We demonstrated...

  13. Rrespuesta fisiológica del pasto buffel (cenchrus ciliaris l.) a diferentes alturas de defoliación

    OpenAIRE

    Sergio Beltrán López; Jorge Pérez Pérez; Alfonso Hernández Garay; Edmundo García Moya; José G. Herrera Haro

    2002-01-01

    El conocimiento de la capacidad de las especies forrajeras para recuperarse después de una defoliación, es esencial para un mejor manejo. El objetivo de este estudio fue evaluar la respuesta del pasto buffel (Cenchrus ciliaris L.) a cuatro alturas de defoliación: 5, 10 y 20 cm y un testigo (sin corte) en invernadero. Se utilizó un diseño completamente al azar con cinco repeticiones. Las variables evaluadas fueron: rendimiento acumulado de materia seca (MS), densidad de tallos, crecimiento fol...

  14. 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.

  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. Clinical Observation of Chinese Herbal Fumigation plus Mulberry Stick Beating for Heel Pain

    Institute of Scientific and Technical Information of China (English)

    Shen Qing-he; Shen Zhi-fang; Yan Yu-qin; Zhu Gao-feng

    2014-01-01

    Objective:To observe the clinical efficacy of Chinese herbal fumigation plus beating with mulberry stick in treating heel pain. Methods: Sixty patients with heel pain were randomized into a treatment group and a control group, 30 in each group. The treatment group was intervened by Chinese herbal fumigation plus beating with mulberry stick, and the control group was by orally taking Diclofenac Sodium Sustained Release Tablets plus external use of She Xiang Zhen Tong Gao (Moschus Analgesic Plaster). After one treatment course, the visual analogue scale (VAS) was used to observe the change of pain, and the clinical efficacies were also evaluated. Results: After intervention, the improvement of VAS score in the treatment group was more significant than that in the control group (P Conclusion:Chinese herbal fumigation plus beating with mulberry stick can produce a higher clinical efficacy than orally taking Diclofenac Sodium Sustained Release Tablets in treating heel pain.

  18. Morphological and mechanical effects of extended beating on EFB pulp web

    Science.gov (United States)

    Zukeri, Mohd Ridzuan Hafiz Mohd; Ghazali, Arniza; Lazin, Mohd Azli Khairil Mat

    2012-09-01

    The pulp extracted from the alkaline peroxide pulping (APP) of EFB was beaten from 500 revolutions to 10000 revolutions using PFI mill to investigate the morphological changes undergone by the pulp and the resultant effect on paper sheet properties. As a result of beating, pulp elements were observed as intensely fibrillated, reducing the amounts of fibre bundles and thus, reducing interruption in the inter-fiber bonding. To a defined extent, beating was also seen as unwinding the structure of vessel element to a single strand of loose spiral body. These fibrillated vessel elements of APP pulp from EFB, plus the fines element germinating from further segmentation of the vessels, were the factors contributing to the overall strength improvement of the produced EFB pulp network. The applied increment in beating revolution had apparently widened the known broad spectrum quality of APP pulp from EFB. This demonstrates EFB potential for application in specialty paper production.

  19. 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.

  20. 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.

  1. 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.

  2. Enhanced acceleration of injected electrons in a laser-beat-wave-induced plasma channel.

    Science.gov (United States)

    Tochitsky, S Ya; Narang, R; Filip, C V; Musumeci, P; Clayton, C E; Yoder, R B; Marsh, K A; Rosenzweig, J B; Pellegrini, C; Joshi, C

    2004-03-05

    Enhanced energy gain of externally injected electrons by a approximately 3 cm long, high-gradient relativistic plasma wave (RPW) is demonstrated. Using a CO2 laser beat wave of duration longer than the ion motion time across the laser spot size, a laser self-guiding process is initiated in a plasma channel. Guiding compensates for ionization-induced defocusing (IID) creating a longer plasma, which extends the interaction length between electrons and the RPW. In contrast to a maximum energy gain of 10 MeV when IID is dominant, the electrons gain up to 38 MeV energy in a laser-beat-wave-induced plasma channel.

  3. Spin Quantum Beats in InP Quantum Dots in a Magnetic Field

    Science.gov (United States)

    2001-06-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP013252 TITLE: Spin Quantum Beats in InP Quantum Dots in a Magnetic Field...Technology" SRPN.05 St Petersburg, Russia, June 18-22, 2001 (0 2001 loffe Institute Spin quantum beats in InP quantum dots in a magnetic field L A... quantum dots . A detailed description of the structure is given in [ ]. The luminescence was excited by 3 ps pulses of a Ti:sapphire laser, 40 meV above

  4. Terahertz generation by beating two Langmuir waves in a warm and collisional plasma

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiao-Bo; Qiao, Xin; Cheng, Li-Hong; Tang, Rong-An; Zhang, Ai-Xia; Xue, Ju-Kui, E-mail: xuejk@nwnu.edu.cn [Key Laboratory of Atomic & Molecular Physics and Functional Materials of Gansu Province, College of Physics and Electronics Engineering, Northwest Normal University, Lanzhou 730070 (China)

    2015-09-15

    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.

  5. K channel kinetics during the spontaneous heart beat in embryonic chick ventricle cells.

    OpenAIRE

    Mazzanti, M.; DeFelice, L J

    1988-01-01

    By averaging the current that passes through cell-attached patches on beating heart cells, while measuring action potentials with a whole-cell electrode, we were able to study K channels during beating. In 7-d chick ventricle in 1.3 mM K physiological solutions at room temperature, delayed-rectifier channels have three linear conductance states: 60, 30, and 15 pS. The 60 and 15 pS conductances can exist alone, but all three states may appear in the same patch as interconverting conductance le...

  6. Prototype Automated Equipment to Perform Poising and Beat Rate Operations on the M577 MTSQ Fuze.

    Science.gov (United States)

    1978-09-30

    r 80 4 22 008 . ~ . j.- Il - -Acoes! ,, jr BULOVA SYTEMS A NSTRUMENTS CORPORATION uomae,± TABLE OF CONTENTS !Distr Flbtioo/ Paragraph Title [ 1, hiIt ...Wheel location is also established. The axial location of the weld location is chosen so as to cause the Timer to run approximately 1 to 1 1/2 beats per...Timer is running under the driving torque of its own mainspring. Standard M577 instrumentation for the detection and readout of the beat rate and the

  7. 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.

  8. 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...

  9. [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)

  10. Nephrocystin-5, a ciliary IQ domain protein, is mutated in Senior-Loken syndrome and interacts with RPGR and calmodulin.

    Science.gov (United States)

    Otto, Edgar A; Loeys, Bart; Khanna, Hemant; Hellemans, Jan; Sudbrak, Ralf; Fan, Shuling; Muerb, Ulla; O'Toole, John F; Helou, Juliana; Attanasio, Massimo; Utsch, Boris; Sayer, John A; Lillo, Concepcion; Jimeno, David; Coucke, Paul; De Paepe, Anne; Reinhardt, Richard; Klages, Sven; Tsuda, Motoyuki; Kawakami, Isao; Kusakabe, Takehiro; Omran, Heymut; Imm, Anita; Tippens, Melissa; Raymond, Pamela A; Hill, Jo; Beales, Phil; He, Shirley; Kispert, Andreas; Margolis, Benjamin; Williams, David S; Swaroop, Anand; Hildebrandt, Friedhelm

    2005-03-01

    Nephronophthisis (NPHP) is the most frequent genetic cause of chronic renal failure in children. Identification of four genes mutated in NPHP subtypes 1-4 (refs. 4-9) has linked the pathogenesis of NPHP to ciliary functions. Ten percent of affected individuals have retinitis pigmentosa, constituting the renal-retinal Senior-Loken syndrome (SLSN). Here we identify, by positional cloning, mutations in an evolutionarily conserved gene, IQCB1 (also called NPHP5), as the most frequent cause of SLSN. IQCB1 encodes an IQ-domain protein, nephrocystin-5. All individuals with IQCB1 mutations have retinitis pigmentosa. Hence, we examined the interaction of nephrocystin-5 with RPGR (retinitis pigmentosa GTPase regulator), which is expressed in photoreceptor cilia and associated with 10-20% of retinitis pigmentosa. We show that nephrocystin-5, RPGR and calmodulin can be coimmunoprecipitated from retinal extracts, and that these proteins localize to connecting cilia of photoreceptors and to primary cilia of renal epithelial cells. Our studies emphasize the central role of ciliary dysfunction in the pathogenesis of SLSN.

  11. Functional and Molecular Characterization of Rod-like Cells from Retinal Stem Cells Derived from the Adult Ciliary Epithelium

    Science.gov (United States)

    Demontis, Gian Carlo; Aruta, Claudia; Comitato, Antonella; De Marzo, Anna; Marigo, Valeria

    2012-01-01

    In vitro generation of photoreceptors from stem cells is of great interest for the development of regenerative medicine approaches for patients affected by retinal degeneration and for high throughput drug screens for these diseases. In this study, we show unprecedented high percentages of rod-fated cells from retinal stem cells of the adult ciliary epithelium. Molecular characterization of rod-like cells demonstrates that they lose ciliary epithelial characteristics but acquire photoreceptor features. Rod maturation was evaluated at two levels: gene expression and electrophysiological functionality. Here we present a strong correlation between phototransduction protein expression and functionality of the cells in vitro. We demonstrate that in vitro generated rod-like cells express cGMP-gated channels that are gated by endogenous cGMP. We also identified voltage-gated channels necessary for rod maturation and viability. This level of analysis for the first time provides evidence that adult retinal stem cells can generate highly homogeneous rod-fated cells. PMID:22432014

  12. Functional and molecular characterization of rod-like cells from retinal stem cells derived from the adult ciliary epithelium.

    Directory of Open Access Journals (Sweden)

    Gian Carlo Demontis

    Full Text Available In vitro generation of photoreceptors from stem cells is of great interest for the development of regenerative medicine approaches for patients affected by retinal degeneration and for high throughput drug screens for these diseases. In this study, we show unprecedented high percentages of rod-fated cells from retinal stem cells of the adult ciliary epithelium. Molecular characterization of rod-like cells demonstrates that they lose ciliary epithelial characteristics but acquire photoreceptor features. Rod maturation was evaluated at two levels: gene expression and electrophysiological functionality. Here we present a strong correlation between phototransduction protein expression and functionality of the cells in vitro. We demonstrate that in vitro generated rod-like cells express cGMP-gated channels that are gated by endogenous cGMP. We also identified voltage-gated channels necessary for rod maturation and viability. This level of analysis for the first time provides evidence that adult retinal stem cells can generate highly homogeneous rod-fated cells.

  13. Axonemal dynein intermediate-chain gene (DNAI1) mutations result in situs inversus and primary ciliary dyskinesia (Kartagener syndrome).

    Science.gov (United States)

    Guichard, C; Harricane, M C; Lafitte, J J; Godard, P; Zaegel, M; Tack, V; Lalau, G; Bouvagnet, P

    2001-04-01

    Kartagener syndrome (KS) is a trilogy of symptoms (nasal polyps, bronchiectasis, and situs inversus totalis) that is associated with ultrastructural anomalies of cilia of epithelial cells covering the upper and lower respiratory tracts and spermatozoa flagellae. The axonemal dynein intermediate-chain gene 1 (DNAI1), which has been demonstrated to be responsible for a case of primary ciliary dyskinesia (PCD) without situs inversus, was screened for mutation in a series of 34 patients with KS. We identified compound heterozygous DNAI1 gene defects in three independent patients and in two of their siblings who presented with PCD and situs solitus (i.e., normal position of inner organs). Strikingly, these five patients share one mutant allele (splice defect), which is identical to one of the mutant DNAI1 alleles found in the patient with PCD, reported elsewhere. Finally, this study demonstrates a link between ciliary function and situs determination, since compound mutation heterozygosity in DNAI1 results in PCD with situs solitus or situs inversus (KS).

  14. Disentangling beat perception from sequential learning and examining the influence of attention and musical abilities on ERP responses to rhythm

    NARCIS (Netherlands)

    Bouwer, F.L.; Werner, C.M.; Knetemann, M.; Honing, H.

    2016-01-01

    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

  15. 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

  16. Comparative effect of mechanical beating and nanofibrillation of cellulose on paper properties made from bagasse and softwood pulps.

    Science.gov (United States)

    Afra, Elyas; Yousefi, Hossein; Hadilam, Mohamad Mahdi; Nishino, Takashi

    2013-09-12

    Cellulose fibers were fibrillated using mechanical beating (shearing refiner) and ultra-fine friction grinder, respectively. The fibrillated fibers were then used to make paper. Mechanical beating process created a partial skin fibrillation, while grinding turned fiber from micro to nanoscale through nanofibrillation mechanism. The partially fibrillated and nano fibrillated fibers had significant effects on paper density, tear strength, tensile strength and water drainage time. The effect of nanofibrillation on paper properties was quantitatively higher than that of mechanical beating. Paper sheets from nanofibrillated cellulose have a higher density, higher tensile strength and lower tear strength compared to those subjected to mechanical beating. Mechanical beating and nanofibrillation were both found to be promising fiber structural modifications. Long water drainage time was an important drawback of both fibrillation methods.

  17. Active Faraday optical frequency standard.

    Science.gov (United States)

    Zhuang, Wei; Chen, Jingbiao

    2014-11-01

    We propose the mechanism of an active Faraday optical clock, and experimentally demonstrate an active Faraday optical frequency standard based on 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 standard 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 281(23) Hz, which is 1.9×10(4) times smaller than the natural linewidth of the cesium 852-nm transition line. The maximum emitted light power reaches 75 μW. The active Faraday optical frequency standard reported here has 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 new generation of optical atomic clocks.

  18. Emergence of flagellar beating from the collective behavior of individual ATP-powered dyneins

    NARCIS (Netherlands)

    Namdeo, S.; Onck, P. R.

    2016-01-01

    Flagella are hair-like projections from the surface of eukaryotic cells, and they play an important role in many cellular functions, such as cell-motility. The beating of flagella is enabled by their internal architecture, the axoneme, and is powered by a dense distribution of motor proteins, dynein

  19. Beating Time/Making Time: The Impact of Work Scheduling on Men's Family Roles.

    Science.gov (United States)

    Hood, Jane; Golden, Susan

    1979-01-01

    Case studies examine men's family situations. Attempts to beat time by working from noon to midnight result in unintended negative consequences for one family. For another, creation of a split-shift family when a wife returns to work brings a father closer to his children and wife. (Author)

  20. BEAT: A Web-Based Boolean Expression Fault-Based Test Case Generation Tool

    Science.gov (United States)

    Chen, T. Y.; Grant, D. D.; Lau, M. F.; Ng, S. P.; Vasa, V. R.

    2006-01-01

    BEAT is a Web-based system that generates fault-based test cases from Boolean expressions. It is based on the integration of our several fault-based test case selection strategies. The generated test cases are considered to be fault-based, because they are aiming at the detection of particular faults. For example, when the Boolean expression is in…

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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…

  7. 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

  8. 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…

  9. 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

  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. 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…

  12. 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.

  13. 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).

  14. 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.

  15. A continuum model for flow induced by metachronal coordination between beating cilia

    NARCIS (Netherlands)

    Hussong, J.; Breugem, W.-P.; Westerweel, J.

    2011-01-01

    In this numerical study we investigate the flow induced by metachronal coordination between beating cilia arranged in a densely packed layer by means of a continuum model. The continuum approach allows us to treat the problem as two-dimensional as well as stationary, in a reference frame moving with

  16. Vertical beat response and vortex-induce force identification of 1-D bluff body Vortex-Induced Vibration%一维钝体竖向涡激振动拍振响应及涡激力识别

    Institute of Scientific and Technical Information of China (English)

    鲜荣; 廖海黎; 朱超

    2011-01-01

    涡激振动是在低风速下很容易出现的一种风致振动现象,一维钝体涡激振动具有自激、自限特性.拍振则是涡激振动一种典型形式,为钝体固有频率和涡脱频率共同作用结果.拍振理论研究目前为止仍未有满意结果;主要通过数值计算方法和风洞试验进行研究,数值计算难度很大难以实现;风洞试验研究较直观,但不能解释其作用机制.基于Scanlan非线性模型,采用KBM法(渐近法)推导一维钝体竖向涡激振动拍振响应一次近似解,探讨通过拍振时程响应曲线识别气动参数、涡激力方法.最后,以一大跨度桥梁主梁节段模型风洞试验为例,识别气动参数及其非线性涡激力.%Vortex-Induced Vibration (VIV) is one kind of wind-induced vibration phenomenon which is easily occured on relatively low wind speed. VIV of 1-d bluff body has a few characteristics such as self-excitation,self-limitation. Beat is one representative oscillation type of VIV as a result of influence of natural frequency and vortex frequency. Beat is the representative phenomenon of coupling between flow and bluff body. Presently, there is still lack of satisfaction theory to describe beat. So the main available methods to research beat ate numerical study and wind tunnel test. However, numerical study can hardly be successful because of tremendous calculation work. Then, wind tunnel test can get VIV straightly although it can not interpret the VIV mechanism. The vertical beat response of 1-d bluff body can be expressed by Scanlan's nonlinear empirical model Furthermore,the way is discussed to identify aerodynamic parameters and vortex-induced force on beat state. Lastly,the aerodynamic parameters and nonlinear vortex-shedding force are identified by taking a long-span bridge girder section model wind tunnel test as an example.

  17. Neural Networks for Beat Perception in Musical Rhythm.

    Science.gov (United States)

    Large, Edward W; Herrera, Jorge A; Velasco, Marc J

    2015-01-01

    Entrainment of cortical rhythms to acoustic rhythms has been hypothesized to be the neural correlate of pulse and meter perception in music. Dynamic attending theory first proposed synchronization of endogenous perceptual rhythms nearly 40 years ago, but only recently has the pivotal role of neural synchrony been demonstrated. Significant progress has since been made in understanding the role of neural oscillations and the neural structures that support synchronized responses to musical rhythm. Synchronized neural activity has been observed in auditory and motor networks, and has been linked with attentional allocation and movement coordination. Here we describe a neurodynamic model that shows how self-organization of oscillations in interacting sensory and motor networks could be responsible for the formation of the pulse percept in complex rhythms. In a pulse synchronization study, we test the model's key prediction that pulse can be perceived at a frequency for which no spectral energy is present in the amplitude envelope of the acoustic rhythm. The result shows that participants perceive the pulse at the theoretically predicted frequency. This model is one of the few consistent with neurophysiological evidence on the role of neural oscillation, and it explains a phenomenon that other computational models fail to explain. Because it is based on a canonical model, the predictions hold for an entire family of dynamical systems, not only a specific one. Thus, this model provides a theoretical link between oscillatory neurodynamics and the induction of pulse and meter in musical rhythm.

  18. Beating the market with small portfolios: Evidence from Brazil

    Directory of Open Access Journals (Sweden)

    André A.P. Santos

    2015-01-01

    Full Text Available Optimal portfolios with a restriction on the number of assets, also referred to as cardinality-constrained portfolios, have been receiving attention in the literature due to its popularity among market practitioners and retail investors. In most cases, however, the interest is in proposing efficient optimization methods to solve the problem, with little or no attention to the characteristics of the resulting portfolio such as risk-adjusted performance and turnover. We address this question by implementing a tractable reformulation of the cardinality-constrained version of the minimum variance portfolio. We analyze the out-of-sample performance of cardinality-constrained portfolios according to alternative criteria and check the robustness of the results for portfolios with alternative number of assets and under alternative re-balancing frequencies. Our empirical application for the Brazilian equities market shows that cardinality-constrained minimum variance portfolios with very few assets, e.g. 3 stocks, can deliver statistically lower portfolio risk and higher Sharpe ratios in comparison to the market index. Similar results are obtained for constrained portfolios with 5 and 10 assets and under daily, weekly, and monthly re-balancing frequencies. Our evidence indicates that it is possible to obtain better risk-adjusted performance with fewer securities in the portfolio by using an improved allocation scheme.

  19. Neural Networks for Beat Perception in Musical Rhythm

    Science.gov (United States)

    Large, Edward W.; Herrera, Jorge A.; Velasco, Marc J.

    2015-01-01

    Entrainment of cortical rhythms to acoustic rhythms has been hypothesized to be the neural correlate of pulse and meter perception in music. Dynamic attending theory first proposed synchronization of endogenous perceptual rhythms nearly 40 years ago, but only recently has the pivotal role of neural synchrony been demonstrated. Significant progress has since been made in understanding the role of neural oscillations and the neural structures that support synchronized responses to musical rhythm. Synchronized neural activity has been observed in auditory and motor networks, and has been linked with attentional allocation and movement coordination. Here we describe a neurodynamic model that shows how self-organization of oscillations in interacting sensory and motor networks could be responsible for the formation of the pulse percept in complex rhythms. In a pulse synchronization study, we test the model's key prediction that pulse can be perceived at a frequency for which no spectral energy is present in the amplitude envelope of the acoustic rhythm. The result shows that participants perceive the pulse at the theoretically predicted frequency. This model is one of the few consistent with neurophysiological evidence on the role of neural oscillation, and it explains a phenomenon that other computational models fail to explain. Because it is based on a canonical model, the predictions hold for an entire family of dynamical systems, not only a specific one. Thus, this model provides a theoretical link between oscillatory neurodynamics and the induction of pulse and meter in musical rhythm. PMID:26635549

  20. 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.

  1. 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.

  2. 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

    Primary ciliary dyskinesia (PCD) is an inherited disorder characterized by recurrent infections of the upper and lower respiratory tract, reduced fertility in males and situs inversus in about 50% of affected individuals (Kartagener syndrome). It is caused by motility defects in the respiratory...

  3. Hand-held tidal breathing nasal nitric oxide measurement--a promising targeted case-finding tool for the diagnosis of primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Marthin, June Kehlet; Nielsen, Kim Gjerum

    2013-01-01

    BACKGROUND: Nasal nitric oxide (nNO) measurement is an established first line test in the work-up for primary ciliary dyskinesia (PCD). Tidal breathing nNO (TB-nNO) measurements require minimal cooperation and are potentially useful even in young children. Hand-held NO devices are becoming increa...

  4. Work Hardening Behavior of 1020 Steel During Cold-Beating Simulation

    Science.gov (United States)

    CUI, Fengkui; LING, Yuanfei; XUE, Jinxue; LIU, Jia; LIU, Yuhui; LI, Yan

    2017-03-01

    The present research of cold-beating formation mainly focused on roller design and manufacture, kinematics, constitutive relation, metal flow law, thermo-mechanical coupling, surface micro-topography and microstructure evolution. However, the research on surface quality and performance of workpieces in the process of cold-beating is rare. Cold-beating simulation experiment of 1020 steel is conducted at room temperature and strain rates ranging from 2000 to 4000 s-1 base on the law of plastic forming. According to the experimental data, the model of strain hardening of 1020 steel is established, Scanning Electron Microscopy(SEM) is conducted, the mechanism of the work hardening of 1020 steel is clarified by analyzing microstructure variation of 1020 steel. It is found that the strain rate hardening effect of 1020 steel is stronger than the softening effect induced by increasing temperatures, the process of simulation cold-beating cause the grain shape of 1020 steel significant change and microstructure elongate significantly to form a fibrous tissue parallel to the direction of deformation, the higher strain rate, the more obvious grain refinement and the more hardening effect. Additionally, the change law of the work hardening rate is investigated, the relationship between dislocation density and strain, the relationship between work hardening rate and dislocation density is obtained. Results show that the change trend of the work hardening rate of 1020 steel is divided into two stages, the work hardening rate decreases dramatically in the first stage and slowly decreases in the second stage, finally tending toward zero. Dislocation density increases with increasing strain and strain rate, work hardening rate decreases with increasing dislocation density. The research results provide the basis for solving the problem of improving the surface quality and performance of workpieces under cold-beating formation of 1020 steel.

  5. Lack of beat isochrony disrupts motor performance in a child drummer prodigy

    Directory of Open Access Journals (Sweden)

    Farrugia Nicolas

    2011-12-01

    Full Text Available Several studies have focused on coupling between perception and action (e.g., via finger tapping, and more generally on entrainment, in average musicians and non-musicians. Yet, little is known about the effects of entrainment on timing and movement kinematics in individuals exhibiting outstanding rhythmical abilities. In this study we examined the effect of beat isochrony on the performance of IF, a 7-year-old child drummer prodigy. IF displayed very early (at 3-4 years of age outstanding musical abilities, and exceptional sensorimotor synchronization. To assess whether temporal regularity of the underlying beat (i.e., isochrony during music playing affects IF’s performance we tested IF and a “control” group (i.e., children from music schools with 1-to1.5 years of percussion training in a motion capture study. Participants imitated a short 6-note isochronous metrical pattern (Strong-weak-weak-Strong-weak-weak on a percussion pad under four conditions. In the first condition the pattern was imitated repeatedly along with a metronome. In the second condition, the pattern was repeated but with a break in between repetitions, together with a metronome. In the third condition, similar breaks were introduced, but disrupting beat isochrony (i.e., with an irregular, though predictable, metronome. Finally, in the fourth condition break durations were random. IF exhibited higher temporal accuracy than controls with an isochronous metronome. However, his performance was much less accurate with disrupted beat isochrony. This was accompanied by overall differences between IF and controls in movement kinematics in terms of movement amplitude, and anticipation times. Enhanced performance in the presence of an isochronous beat, as opposed to lack of isochrony, suggests that motor entrainment may act as a marker of musical expertise early during development.

  6. Ultraefficient Cooling of Resonators: Beating Sideband Cooling with Quantum Control

    Science.gov (United States)

    Wang, Xiaoting; Vinjanampathy, Sai; Strauch, Frederick; Jacobs, Kurt

    2012-02-01

    There is presently a great deal of interest in cooling high-frequency micro- and nano-mechanical oscillators to their ground states. The present state of the art in cooling mechanical resonators is a version of sideband cooling, which was originally developed in the context of cooling trapped ions. Here we present a method based on quantum control that uses the same configuration as sideband cooling--coupling the resonator to be cooled to a second microwave (or optical) auxiliary resonator--but will cool significantly colder. This is achieved by applying optimal control and varying the strength of the coupling between the two resonators over a time on the order of the period of the mechanical resonator. As part of our analysis, we also obtain a method for fast, high-fidelity quantum information transfer between resonators.

  7. Power Spectrum Analysis of Heart Rate Fluctuation: A Quantitative Probe of Beat-To-Beat Cardiovascular Control

    Science.gov (United States)

    Akselrod, Solange; Gordon, David; Ubel, F. Andrew; Shannon, Daniel C.; Barger, A. Clifford; Cohen, Richard J.

    1981-07-01

    Power spectrum analysis of heart rate fluctuations provides a quantitative noninvasive means of assessing the functioning of the short-term cardiovascular control systems. We show that sympathetic and parasympathetic nervous activity make frequency-specific contributions to the heart rate power spectrum, and that renin-angiotensin system activity strongly modulates the amplitude of the spectral peak located at 0.04 hertz. Our data therefore provide evidence that the reninangiotensin system plays a significant role in short-term cardiovascular control on the time scale of seconds to minutes.

  8. 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.

  9. 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

  10. What do we need to hear a beat? The influence of attention, musical abilities, and accents on the perception of metrical rhythm

    NARCIS (Netherlands)

    Bouwer, F.L.

    2016-01-01

    In this dissertation, I examine beat perception, the process that allows us to make music together. I explore the effects of attention, musical abilities, and accents on beat perception. Additionally, I address several methodological issues that arise when probing beat perception with event-related

  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. Fast, precise, and widely tunable frequency control of an optical parametric oscillator referenced to a frequency comb

    Science.gov (United States)

    Prehn, Alexander; Glöckner, Rosa; Rempe, Gerhard; Zeppenfeld, Martin

    2017-03-01

    Optical frequency combs (OFCs) provide a convenient reference for the frequency stabilization of continuous-wave lasers. We demonstrate a frequency control method relying on tracking over a wide range and stabilizing the beat note between the laser and the OFC. The approach combines fast frequency ramps on a millisecond timescale in the entire mode-hop free tuning range of the laser and precise stabilization to single frequencies. We apply it to a commercially available optical parametric oscillator (OPO) and demonstrate tuning over more than 60 GHz with a ramping speed up to 3 GHz/ms. Frequency ramps spanning 15 GHz are performed in less than 10 ms, with the OPO instantly relocked to the OFC after the ramp at any desired frequency. The developed control hardware and software are able to stabilize the OPO to sub-MHz precision and to perform sequences of fast frequency ramps automatically.

  13. 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.

  14. Beat-to-Beat Variation in Periodicity of Local Calcium Releases Contributes to Intrinsic Variations of Spontaneous Cycle Length in Isolated Single Sinoatrial Node Cells.

    Directory of Open Access Journals (Sweden)

    Oliver Monfredi

    Full Text Available Spontaneous, submembrane local Ca(2+ releases (LCRs generated by the sarcoplasmic reticulum in sinoatrial nodal cells, the cells of the primary cardiac pacemaker, activate inward Na(+/Ca(2+-exchange current to accelerate the diastolic depolarization rate, and therefore to impact on cycle length. Since LCRs are generated by Ca(2+ release channel (i.e. ryanodine receptor openings, they exhibit a degree of stochastic behavior, manifested as notable cycle-to-cycle variations in the time of their occurrence.The present study tested whether variation in LCR periodicity contributes to intrinsic (beat-to-beat cycle length variability in single sinoatrial nodal cells.We imaged single rabbit sinoatrial nodal cells using a 2D-camera to capture LCRs over the entire cell, and, in selected cells, simultaneously measured action potentials by perforated patch clamp.LCRs begin to occur on the descending part of the action potential-induced whole-cell Ca(2+ transient, at about the time of the maximum diastolic potential. Shortly after the maximum diastolic potential (mean 54±7.7 ms, n = 14, the ensemble of waxing LCR activity converts the decay of the global Ca(2+ transient into a rise, resulting in a late, whole-cell diastolic Ca(2+ elevation, accompanied by a notable acceleration in diastolic depolarization rate. On average, cells (n = 9 generate 13.2±3.7 LCRs per cycle (mean±SEM, varying in size (7.1±4.2 µm and duration (44.2±27.1 ms, with both size and duration being greater for later-occurring LCRs. While the timing of each LCR occurrence also varies, the LCR period (i.e. the time from the preceding Ca(2+ transient peak to an LCR's subsequent occurrence averaged for all LCRs in a given cycle closely predicts the time of occurrence of the next action potential, i.e. the cycle length.Intrinsic cycle length variability in single sinoatrial nodal cells is linked to beat-to-beat variations in the average period of individual LCRs each cycle.

  15. Single Agent Antihypertensive Therapy and Orthostatic Blood Pressure Behaviour in Older Adults Using Beat-to-Beat Measurements: The Irish Longitudinal Study on Ageing.

    Directory of Open Access Journals (Sweden)

    Mark Canney

    Full Text Available Impaired blood pressure (BP stabilisation after standing, defined using beat-to-beat measurements, has been shown to predict important health outcomes. We aimed to define the relationship between individual classes of antihypertensive agent and BP stabilisation among hypertensive older adults.Cross-sectional analysis from The Irish Longitudinal Study on Ageing, a cohort study of Irish adults aged 50 years and over. Beat-to-beat BP was recorded in participants undergoing an active stand test. We defined grade 1 hypertension according to European Society of Cardiology criteria (systolic BP [SBP] 140-159 mmHg ± diastolic BP [DBP] 90-99 mmHg. Outcomes were: (i initial orthostatic hypotension (IOH (SBP drop ≥40 mmHg ± DBP drop ≥20 mmHg within 15 seconds [s] of standing accompanied by symptoms; (ii sustained OH (SBP drop ≥20 mmHg ± DBP drop ≥10 mmHg from 60 to 110 s inclusive; (iii impaired BP stabilisation (SBP drop ≥20 mmHg ± DBP drop ≥10 mmHg at any 10 s interval during the test. Outcomes were assessed using multivariable-adjusted logistic regression.A total of 536 hypertensive participants were receiving monotherapy with a renin-angiotensin-aldosterone-system inhibitor (n = 317, 59.1%, beta-blocker (n = 89, 16.6%, calcium channel blocker (n = 89, 16.6% or diuretic (n = 41, 7.6%. A further 783 untreated participants met criteria for grade 1 hypertension. Beta-blockers were associated with increased odds of initial OH (OR 2.05, 95% CI 1.31-3.21 and sustained OH (OR 3.36, 95% CI 1.87-6.03 versus untreated grade 1 hypertension. Multivariable adjustment did not attenuate the results. Impaired BP stabilisation was evident at 20 s (OR 2.59, 95% CI 1.58-4.25 and persisted at 110 s (OR 2.90, 95% CI 1.64-5.11. No association was found between the other agents and any study outcome.Beta-blocker monotherapy was associated with a >2-fold increased odds of initial OH and a >3-fold increased odds of sustained OH and impaired BP stabilisation

  16. Novel pressure sensor by diode-pumped birefringent Nd:YAG dual-frequency laser

    Science.gov (United States)

    Huang, Chunning; Li, Yan; Zhang, Shulian; Guo, Hui

    2002-09-01

    The prototype of a novel sensor based on laser frequency splitting technology is presented in this paper and the results of a series of experiments are reported. A scheme of the novel pressure sensor by diode-pumped birefringent Nd:YAG dual-frequency laser is brought forward. As a result of the stress birefringence the laser's longitudinal mode is split to two with frequency difference. Both the theoretical analysis and the experiments indicate that there is a direct ratio relation between the frequency difference and the pressure imposed on the Nd:YAG crystal. Therefore when the external pressure is sensed by the Nd:YAG dual-frequency laser and the beat frequency is measured by the frequency counter, the pressure value can be obtained from the magnitude of the beat frequency. The laser can operate under single mode or complex modes with little error to the experiment results. Some research work under different pumping ways is finished and it indicates that the beat frequency has little relation with pumping ways. The experiment has a good linearity (R greater than 0.999) with satisfied precision, sensitivity (5.27 MHz/kPa) and stability, which provides a good academic and experimental foundation for further research.

  17. Neural networks for beat perception in musical rhythm

    Directory of Open Access Journals (Sweden)

    Edward W Large

    2015-11-01

    Full Text Available Entrainment of cortical rhythms to acoustic rhythms has been hypothesized to be the neural correlate of pulse and meter perception in music. Dynamic attending theory first proposed synchronization of endogenous perceptual rhythms nearly forty years ago, but only recently has the pivotal role of neural synchrony been demonstrated. Significant progress has since been made in understanding the role of neural oscillations and the neural structures that support synchronized responses to musical rhythm. Synchronized neural activity has been observed in auditory and motor networks, and has been linked with attentional allocation and movement coordination. Here we describe a neurodynamic model that shows how self-organization of oscillations in interacting sensory and motor networks could be responsible for the formation of the pulse percept in complex rhythms. We test the model's prediction that pulse can be perceived at a frequency for which no spectral energy is present in the amplitude envelope of the acoustic rhythm. The result provides a theoretical link between oscillatory neurodynamics and the induction of pulse and meter in musical rhythm.

  18. 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

    The current diagnostic work-up and monitoring of pulmonary infections may be perceived as invasive, is time consuming and expensive. In this explorative study, we investigated whether or not a non-invasive exhaled breath analysis using an electronic nose would discriminate between cystic fibrosis...... (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......, this method significantly discriminates CF patients suffering from a chronic pulmonary P. aeruginosa (PA) infection from CF patients without a chronic pulmonary infection. Further studies are needed for verification and to investigate the role of electronic nose technology in the very early diagnostic workup...

  19. Effect of myocardial protection during beating heart surgery with right sub-axiliary approach

    Institute of Scientific and Technical Information of China (English)

    MA Jie; LI Xin-hua; YAN Zi-xing; LIU Ai-jun; ZHANG Wen-kai; YANG Li-na

    2009-01-01

    Background Cardiac troponin-I (cTnl) is one of the three regulatory subunits of the cardiac troponin which has the high sensibility and specificity of responding to myocardial injury. Studies have demonstrated that cTnl is released into the blood stream within hours following acute myocardial reperfusion injury. The clinical utility of cTnl for the assessment of myocardial damage is that it is more specific than creatine kinase MB (CKMB). This study investigated cTnl as a sensitive marker of myocardial reperfusion injury and its clinical value on beating heart surgery with right sub-axiliary incision. Methods From December 2002 threugh December 2004,100 patients with atrial septal defect (ASD), ventricular septal defect (VSD), atrial septal defect and ventricular septal defect (ASD+VSD), and tetralogy of Fallot were randomly divided into two groups: the treatment group (n=50) was operated on with a beating heart under extracorporeal circulation (ECC), and the control group (n=50) on an conventional arresting heart under ECC. The two groups both used a right sub-axillary incision. Blood samples from a central venous catheter (CVC) were collected before, at the end of aortic clamping, immediately after discontinue cardiopulmonary bypass (CPB), 3, 6, 24, and 48 hours after operation. The Abbott Axsym system with hol-automation fluorescent immunity analyzer was used for the quantitative determination of cTnl. cTnl was detected to investigate the effect of myocardial ischemia reperfusion injury and the clinical value of beating heart surgery with right sub-axillary incision. Results There were no significant differences between the two groups before operation. At the end of aortic clamping and thereafter, cTnl significantly increased in both groups, and reached the peak point at 6 hours after operation. At all the tested points, cTnl was significantly higher in the control group than the beating heart group (P <0.05), especially at 6 hours post operation (P <0.01). The

  20. The development of the larval nervous system, musculature and ciliary bands of Pomatoceros lamarckii (Annelida: heterochrony in polychaetes

    Directory of Open Access Journals (Sweden)

    Shimeld Sebastian M

    2006-10-01

    Full Text Available Abstract Background To understand the evolution of animals it is essential to have taxon sampling across a representative spread of the animal kingdom. With the recent rearrangement of most of the Bilateria into three major clades (Ecdysozoa, Lophotrochozoa and Deuterostomia it has become clear that the Lophotrochozoa are relatively poorly represented in our knowledge of animal development, compared to the Ecdysozoa and Deuterostomia. We aim to contribute towards redressing this balance with data on the development of the muscular, nervous and ciliary systems of the annelid Pomatoceros lamarckii (Serpulidae. We compare our data with other lophotrochozoans. Results P. lamarckii develops locomotory and feeding structures that enable it to become a swimming, planktotrophic larva within 24 hours. Formation of the trochophore includes development of a prototroch, metatroch and neurotroch, development of apical and posterior nervous elements at similar times, and development of musculature around the ciliary bands and digestive tract prior to development of any body wall muscles. The adult nervous and muscular systems are essentially preformed in the late larva. Interestingly, the muscular systems of the larvae and juvenile worms do not include the circular muscles of the body wall, which are considered to be plesiomorphic for annelids, although the possibility that circular muscles develop after these stages cannot be ruled out at this point. Conclusion A comparison between polychaetes shows variability in the timing (heterochrony of development of body wall muscles and elements of the nervous system. These heterochronies are one route for evolution of different life history strategies, such as adaptations to feeding requirements.

  1. The ciliary inner dynein arm, I1 dynein, is assembled in the cytoplasm and transported by IFT before axonemal docking.

    Science.gov (United States)

    Viswanadha, Rasagnya; Hunter, Emily L; Yamamoto, Ryosuke; Wirschell, Maureen; Alford, Lea M; Dutcher, Susan K; Sale, Winfield S

    2014-10-01

    To determine mechanisms of assembly of ciliary dyneins, we focused on the Chlamydomonas inner dynein arm, I1 dynein, also known as dynein f. I1 dynein assembles in the cytoplasm as a 20S complex similar to the 20S I1 dynein complex isolated from the axoneme. The intermediate chain subunit, IC140 (IDA7), and heavy chains (IDA1, IDA2) are required for 20S I1 dynein preassembly in the cytoplasm. Unlike I1 dynein derived from the axoneme, the cytoplasmic 20S I1 complex will not rebind I1-deficient axonemes in vitro. To test the hypothesis that I1 dynein is transported to the distal tip of the cilia for assembly in the axoneme, we performed cytoplasmic complementation in dikaryons formed between wild-type and I1 dynein mutant cells. Rescue of I1 dynein assembly in mutant cilia occurred first at the distal tip and then proceeded toward the proximal axoneme. Notably, in contrast to other combinations, I1 dynein assembly was significantly delayed in dikaryons formed between ida7 and ida3. Furthermore, rescue of I1 dynein assembly required new protein synthesis in the ida7 × ida3 dikaryons. On the basis of the additional observations, we postulate that IDA3 is required for 20S I1 dynein transport. Cytoplasmic complementation in dikaryons using the conditional kinesin-2 mutant, fla10-1 revealed that transport of I1 dynein is dependent on kinesin-2 activity. Thus, I1 dynein complex assembly depends upon IFT for transport to the ciliary distal tip prior to docking in the axoneme.

  2. Cross-talk between ciliary epithelium and trabecular meshwork cells in-vitro: a new insight into glaucoma.

    Directory of Open Access Journals (Sweden)

    Natalie Lerner

    Full Text Available PURPOSE: It is assumed that the non-pigmented ciliary epithelium plays a role in regulating intraocular pressure via its neuroendocrine activities. To test this hypothesis, we investigated the effect on a human trabecular meshwork (TM cell line (NTM of co-culture with a human non-pigmented ciliary epithelium cell line (ODM-2. METHODS: The cellular cross-talk between ODM-2 and NTM cells was studied in a co-culture system in which the two cell types were co-cultured for 5 to 60 min or 2, 4 and 8h and then removed from the co-culture and analyzed. Analyses of the ERK and p38 mitogen-activated protein kinase (MAPK pathways and of the activity of TM phosphatases and matrix metalloproteins (MMPs were performed. Acid and alkaline phosphatase activity was determined by the DiFMUP (6, 8-difluoro-4-methylumbelliferyl phosphate assay. MMP levels were determined by gelatin zymography. RESULTS: Exposure of NTM cells to ODM-2 cells led to the activation of the MAPK signal transduction pathways in NTM cells within 5 min of co-culture. Phosphorylation of ERK1/ERK2 and p38 peaked at 10 and 15 min and then decreased over time. Interaction between ODM-2 and NTM cells promoted the expression of MMP-9 in the NTM cells after 4h of co-culture. CONCLUSIONS: Our findings provide support for the hypothesis that crosstalk does indeed take place between ODM-2 and NTM cells. Future studies should be designed to determine the relationship between the MMP system, MAPK kinases and phosphatases. Manipulation of these signaling molecules and the related NTM signal transduction pathways may provide targets for developing improved treatments for glaucoma.

  3. 纤毛疾病和与之相关的基因%Ciliary Disease and the Related Genes

    Institute of Scientific and Technical Information of China (English)

    柳林; 纪伟

    2012-01-01

    Recently, Cilia has been added to a well-known causes of human diseases. Unlike other cellular organdies, cilia ate tiny hair-like organelles that attached to the cell surface, and are located on almost all polarized cell types of the human body. Cilia play a crucial role in regulating vertebrate development and tissue homeostasis. The various cellular functions of cilia explain why cilia-related disorders can affect many organ systems. Defects in ciliary genes cause lots of ciliary diseases, such as: Nephronophthisis, Joubert Syndrome, Meckel-Gruber Syndrome and Bardet Biedl Syndrome.%近年来,研究发现纤毛在生成或者形态的缺陷均能导致新生儿遗传性疾病.与其他细胞器不同的是,纤毛这一小的毛发状细胞器能在几乎所有的极性细胞表面上生成,而且功能非常多样化.纤毛在调节脊椎动物的发育和内环境的平衡起着相当重要的作用,而与纤毛相关基因的缺失则与一系列疾病相关,包括:Nephronophthisis、Joubert综合症、Meckel-Gruber综合症和Bardet Biedl综合症等.结合最近的研究,本文主要对四类主纤毛相关疾病的基因进行归类总结.

  4. Perceiving temporal regularity in music: the role of auditory event-related potentials (ERPs) in probing beat perception.

    Science.gov (United States)

    Honing, Henkjan; Bouwer, Fleur L; Háden, Gábor P

    2014-01-01

    The aim of this chapter is to give an overview of how the perception of a regular beat in music can be studied in humans adults, human newborns, and nonhuman primates using event-related brain potentials (ERPs). Next to a review of the recent literature on the perception of temporal regularity in music, we will discuss in how far ERPs, and especially the component called mismatch negativity (MMN), can be instrumental in probing beat perception. We conclude with a discussion on the pitfalls and prospects of using ERPs to probe the perception of a regular beat, in which we present possible constraints on stimulus design and discuss future perspectives.

  5. 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.

  6. Brainwave Acousto-Optic Adjuster Based on Binaural Auditory Beat%基于双声拍的脑电波声光调节装置

    Institute of Scientific and Technical Information of China (English)

    张晓磊; 姚俊强; 沈斌; 应家顺; 彭雪峰

    2013-01-01

    A brainwave acousto-optic adjuster based on binaural auditory beat was designed by the use of the ATmega8.When two tones of slightly different frequency are presented separately to the left and right ears,the listener perceives a single tone that varies in amplitude at a frequency equal to the frequency difference between the two tones,which was known as "Binaural Auditory Beats (BAT)".The BAT within the brainwave frequency range can affect brain activity and states of consciousness,so we can adjust the brainwave by the BAT.Make use of this law,we product two auditory signals with different frequency by ATmega8,after low pass filter,presented separately to the left and right ear,formed BAT,then set two LEDs flash with the same frequency as the BAT before the left and right eyes.The combined action of light and BAT with the same frequency could adjust the brainwave arbitrarily.%利用ATmega8单片机制作了一种基于双声拍的脑电波光电调节装置.两列频率差别较小的声波分别输入人的左右耳中,会产生一种振幅周期性变化的新的声波,新声波的频率为原来两列声波的频率差,这种现象称为“双声拍”.双声拍的频率位于人脑电波范围时会影响大脑的活跃程度和意识状态,通过调节双声拍的频率即可调节脑电波.基于这一原理,本文利用ATmega8单片机产生两列声波,低通滤波后将不同频率的声波通过左右耳输入大脑,形成“双声拍”;再将双眼前放置两个闪烁频率与双声拍频相同的LED,在声光的共同作用下,可以达到任意调节脑电波频率的目的.

  7. Validation of New and Existing Decision Rules for the Estimation of Beat-to-Beat Pulse Transit Time

    Directory of Open Access Journals (Sweden)

    Xiaolin Zhou

    2015-01-01

    Full Text Available Pulse transit time (PTT is a pivotal marker of vascular stiffness. Because the actual PTT duration in vivo is unknown and the complicated variation in waveform may occur, the robust determination of characteristic point is still a very difficult task in the PTT estimation. Our objective is to devise a method for real-time estimation of PTT duration in pulse wave. It has an ability to reduce the interference caused by both high- and low-frequency noise. The reproducibility and performance of these methods are assessed on both artificial and clinical pulse data. Artificial data are generated to investigate the reproducibility with various signal-to-noise ratios. For all artificial data, the mean biases obtained from all methods are less than 1 ms; collectively, this newly proposed method has minimum standard deviation (SD, <1 ms. A set of data from 33 participants together with the synchronously recorded continuous blood pressure data are used to investigate the correlation coefficient (CC. The statistical analysis shows that our method has maximum values of mean CC (0.5231, sum of CCs (17.26, and median CC (0.5695 and has the minimum SD of CCs (0.1943. Overall, the test results in this study indicate that the newly developed method has advantages over traditional decision rules for the PTT measurement.

  8. Quantum beats in the polarization response of a dielectric to intense few-cycle laser pulses

    CERN Document Server

    Korbman, Michael; Yakovlev, Vladislav S

    2012-01-01

    We have investigated the polarization response of a dielectric to intense few-cycle laser pulses with a focus on interband tunnelling. Once charge carriers are created in an initially empty conduction band, they make a significant contribution to the polarization response. In particular, the coherent superposition of conduction- and valence-band states results in quantum beats. We investigate how the quantum-beat part of the polarization response is affected by excitation dynamics and the attosecond-scale motion of charge carriers in an intense laser field. We find that, with the onset of tunnelling and Bloch oscillations, the nonlinear polarization response becomes sensitive to the carrier-envelope phase of a laser pulse.

  9. Drive and the Action Calculation of GetLLM, in Beta-Beat.src

    CERN Document Server

    Sherman, Alexander Charles

    2013-01-01

    The Beta-Beat.src program is used to analyze data collected by Beam Position Monitors (BPMs) in accelerators at CERN. The Beams department at CERN uses it to study the behaviour of a beam as it traverses an accelerator, and in particular the LHC. Two pieces of code in Beta-Beat.src are “drive”, a C/C++ program, and “GetLLM”, a python program. This report described the modification of the drive code to be compatible with windows and take advantage of elements of C++, as well as a change in the calculation of the action in GetLLM to reduce its relative uncertainty. The dynamic aperture is recalculated with the new action and sees a reduction in its uncertainty.

  10. Without it no music: beat induction as a fundamental musical trait.

    Science.gov (United States)

    Honing, Henkjan

    2012-04-01

    Beat induction (BI) is the cognitive skill that allows us to hear a regular pulse in music to which we can then synchronize. Perceiving this regularity in music allows us to dance and make music together. As such, it can be considered a fundamental musical trait that, arguably, played a decisive role in the origins of music. Furthermore, BI might be considered a spontaneously developing, domain-specific, and species-specific skill. Although both learning and perception/action coupling were shown to be relevant in its development, at least one study showed that the auditory system of a newborn is able to detect the periodicities induced by a varying rhythm. A related study with adults suggested that hierarchical representations for rhythms (meter induction) are formed automatically in the human auditory system. We will reconsider these empirical findings in the light of the question whether beat and meter induction are fundamental cognitive mechanisms.

  11. Generation of the quadripartite Greenberger-Horne-Zeilinger entangled state in quantum beat lasers

    Science.gov (United States)

    Wang, Fei

    2013-12-01

    In this letter, a scheme is presented to obtain quadripartite Greenberger-Horne-Zeilinger (GHZ) entanglement via quantum beats in a four-level diamond configuration atomic system. When the top and the ground states are initially prepared in a coherent superposition, the four quantized fields coupling with four dipole-allowed transitions can be correlated with each other by using a strong microwave field to drive the dipole-forbidden transition. It is the combined effect of atomic coherence-controlled correlated-spontaneous emission and double quantum beats that results in the quadripartite GHZ-type entanglement. Our numerical results show that the quadripartite entanglement, which can be controlled effectively by varying the amplitude and phase of the microwave field, occurs in a very wide parameter range. In addition, using input-output theory, we find that the output quadripartite entanglement is robust against thermal fluctuations, which may be useful for long-distance quantum communications.

  12. High Frequency Color Doppler Image of Choroidal Detachment

    Institute of Scientific and Technical Information of China (English)

    Jinghong Wu; Lijuan Zou; Zhongyao Wu; Lixun Cheng

    2000-01-01

    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.

  13. Rhesus monkeys (Macaca mulatta detect rhythmic groups in music, but not the beat.

    Directory of Open Access Journals (Sweden)

    Henkjan Honing

    Full Text Available It was recently shown that rhythmic entrainment, long considered a human-specific mechanism, can be demonstrated in a selected group of bird species, and, somewhat surprisingly, not in more closely related species such as nonhuman primates. This observation supports the vocal learning hypothesis that suggests rhythmic entrainment to be a by-product of the vocal learning mechanisms that are shared by several bird and mammal species, including humans, but that are only weakly developed, or missing entirely, in nonhuman primates. To test this hypothesis we measured auditory event-related potentials (ERPs in two rhesus monkeys (Macaca mulatta, probing a well-documented component in humans, the mismatch negativity (MMN to study rhythmic expectation. We demonstrate for the first time in rhesus monkeys that, in response to infrequent deviants in pitch that were presented in a continuous sound stream using an oddball paradigm, a comparable ERP component can be detected with negative deflections in early latencies (Experiment 1. Subsequently we tested whether rhesus monkeys can detect gaps (omissions at random positions in the sound stream; Experiment 2 and, using more complex stimuli, also the beat (omissions at the first position of a musical unit, i.e. the 'downbeat'; Experiment 3. In contrast to what has been shown in human adults and newborns (using identical stimuli and experimental paradigm, the results suggest that rhesus monkeys are not able to detect the beat in music. These findings are in support of the hypothesis that beat induction (the cognitive mechanism that supports the perception of a regular pulse from a varying rhythm is species-specific and absent in nonhuman primates. In addition, the findings support the auditory timing dissociation hypothesis, with rhesus monkeys being sensitive to rhythmic grouping (detecting the start of a rhythmic group, but not to the induced beat (detecting a regularity from a varying rhythm.

  14. Persistent Down-Beating Torsional Positional Nystagmus: Posterior Semicircular Canal Light Cupula?

    Science.gov (United States)

    Ichimura, Akihide; Otsuka, Koji

    2016-01-01

    A 16-year-old boy with rotatory positional vertigo and nausea, particularly when lying down, visited our clinic. Initially, we observed vertical/torsional (downward/leftward) nystagmus in the supine position, and it did not diminish. In the sitting position, nystagmus was not provoked. Neurological examinations were normal. We speculated that persistent torsional down-beating nystagmus was caused by the light cupula of the posterior semicircular canal. This case provides novel insights into the light cupula pathophysiology.

  15. Persistent Down-Beating Torsional Positional Nystagmus: Posterior Semicircular Canal Light Cupula?

    Directory of Open Access Journals (Sweden)

    Akihide Ichimura

    2016-01-01

    Full Text Available A 16-year-old boy with rotatory positional vertigo and nausea, particularly when lying down, visited our clinic. Initially, we observed vertical/torsional (downward/leftward nystagmus in the supine position, and it did not diminish. In the sitting position, nystagmus was not provoked. Neurological examinations were normal. We speculated that persistent torsional down-beating nystagmus was caused by the light cupula of the posterior semicircular canal. This case provides novel insights into the light cupula pathophysiology.

  16. Persistent Down-Beating Torsional Positional Nystagmus: Posterior Semicircular Canal Light Cupula?

    OpenAIRE

    Akihide Ichimura; Koji Otsuka

    2016-01-01

    A 16-year-old boy with rotatory positional vertigo and nausea, particularly when lying down, visited our clinic. Initially, we observed vertical/torsional (downward/leftward) nystagmus in the supine position, and it did not diminish. In the sitting position, nystagmus was not provoked. Neurological examinations were normal. We speculated that persistent torsional down-beating nystagmus was caused by the light cupula of the posterior semicircular canal. This case provides novel insights into t...

  17. Phase-controlled entanglement in a quantum-beat laser: application to quantum lithography

    Science.gov (United States)

    Sete, Eyob A.; Dorfman, Konstantin E.; Dowling, Jonathan P.

    2011-11-01

    We study entanglement generation and control in a quantum-beat laser coupled to a two-mode squeezed vacuum reservoir. We show that the generated entanglement is robust against cavity losses and environmental decoherence and can be controlled by tuning the phases of the microwave and the squeezed input fields. Moreover, we discuss two-photon correlations, absorption and implementations in quantum optical lithography.

  18. Semisupervised ECG Ventricular Beat Classification With Novelty Detection Based on Switching Kalman Filters.

    Science.gov (United States)

    Oster, Julien; Behar, Joachim; Sayadi, Omid; Nemati, Shamim; Johnson, Alistair E W; Clifford, Gari D

    2015-09-01

    Automatic processing and accurate diagnosis of pathological electrocardiogram (ECG) signals remains a challenge. As long-term ECG recordings continue to increase in prevalence, driven partly by the ease of remote monitoring technology usage, the need to automate ECG analysis continues to grow. In previous studies, a model-based ECG filtering approach to ECG data from healthy subjects has been applied to facilitate accurate online filtering and analysis of physiological signals. We propose an extension of this approach, which models not only normal and ventricular heartbeats, but also morphologies not previously encountered. A switching Kalman filter approach is introduced to enable the automatic selection of the most likely mode (beat type), while simultaneously filtering the signal using appropriate prior knowledge. Novelty detection is also made possible by incorporating a third mode for the detection of unknown (not previously observed) morphologies, and denoted as X-factor. This new approach is compared to state-of-the-art techniques for the ventricular heartbeat classification in the MIT-BIH arrhythmia and Incart databases. F1 scores of 98.3% and 99.5% were found on each database, respectively, which are superior to other published algorithms' results reported on the same databases. Only 3% of all the beats were discarded as X-factor, and the majority of these beats contained high levels of noise. The proposed technique demonstrates accurate beat classification in the presence of previously unseen (and unlearned) morphologies and noise, and provides an automated method for morphological analysis of arbitrary (unknown) ECG leads.

  19. Study protocol, rationale and recruitment in a European multi-centre randomized controlled trial to determine the efficacy and safety of azithromycin maintenance therapy for 6 months in primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Kobbernagel, Helene E; Buchvald, Frederik F; Haarman, Eric G

    2016-01-01

    BACKGROUND: Clinical management of primary ciliary dyskinesia (PCD) respiratory disease is currently based on improving mucociliary clearance and controlling respiratory infections, through the administration of antibiotics. Treatment practices in PCD are largely extrapolated from more common chr...

  20. A Miniature Mobile Robot for Navigation and Positioning on the Beating Heart

    Science.gov (United States)

    Patronik, Nicholas A.; Ota, Takeyoshi; Zenati, Marco A.; Riviere, Cameron N.

    2010-01-01

    Robotic assistance enhances conventional endoscopy; yet, limitations have hindered its mainstream adoption for cardiac surgery. HeartLander is a miniature mobile robot that addresses several of these limitations by providing precise and stable access over the surface of the beating heart in a less-invasive manner. The robot adheres to the heart and navigates to any desired target in a semiautonomous fashion. The initial therapies considered for HeartLander generally require precise navigation to multiple surface targets for treatment. To balance speed and precision, we decompose any general target acquisition into navigation to the target region followed by fine positioning to each target. In closed-chest, beating-heart animal studies, we demonstrated navigation to targets located around the circumference of the heart, as well as acquisition of target patterns on the anterior and posterior surfaces with an average error of 1.7 mm. The average drift encountered during station-keeping was 0.7 mm. These preclinical results demonstrate the feasibility of precise semiautonomous delivery of therapy to the surface of the beating heart using HeartLander. PMID:20179783