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Sample records for 2-min tidal breathing

  1. Patient-specific simulation of tidal breathing

    NASA Astrophysics Data System (ADS)

    Walters, M.; Wells, A. K.; Jones, I. P.; Hamill, I. S.; Veeckmans, B.; Vos, W.; Lefevre, C.; Fetitia, C.

    2016-03-01

    Patient-specific simulation of air flows in lungs is now straightforward using segmented airways trees from CT scans as the basis for Computational Fluid Dynamics (CFD) simulations. These models generally use static geometries, which do not account for the motion of the lungs and its influence on important clinical indicators, such as airway resistance. This paper is concerned with the simulation of tidal breathing, including the dynamic motion of the lungs, and the required analysis workflow. Geometries are based on CT scans obtained at the extremes of the breathing cycle, Total Lung Capacity (TLC) and Functional Residual Capacity (FRC). It describes how topologically consistent geometries are obtained at TLC and FRC, using a `skeleton' of the network of airway branches. From this a 3D computational mesh which morphs between TLC and FRC is generated. CFD results for a number of patient-specific cases, healthy and asthmatic, are presented. Finally their potential use in evaluation of the progress of the disease is discussed, focusing on an important clinical indicator, the airway resistance.

  2. In vitro estimations of in vivo jet nebulizer efficiency using actual and simulated tidal breathing patterns.

    PubMed

    Bosco, Andrew P; Rhem, Rod G; Dolovich, Myrna B

    2005-01-01

    In vivo aerosol delivery efficiency was estimated in vitro for two jet nebulizers using a breath monitor (Breathe!; Pari GmbH, Germany) and breath simulator (COMPAS; Pari GmbH) to reproduce subject tidal breathing patterns. The AeroEclipse (Trudell Medical International, Canada), a breath-actuated nebulizer, and the LC Star (Pari GmbH), a breath-enhanced nebulizer, were filled with levalbuterol HCl solution (Sepracor, USA) and operated with compressed O(2) at 8 lpm. Tidal breathing patterns of 20 adult subjects were digitally recorded with the Breathe! Breath Monitor. Subjects then breathed tidally from each nebulizer separately for 1 minute and to nebulizer dryness. Levalbuterol aerosol collected on filters placed between the nebulizer and mouth was chemically assayed to determine the inspired mass (IM), wasted mass (WM) and total emitted mass (TM). Measurements were repeated using the COMPAS Breath Simulator to simulate each subject's tidal breathing pattern. IM, WM, and TM measurements using actual versus simulated tidal breathing were highly comparable for each nebulizer, except the IM (p < 0.05) from LC Star measured at nebulizer dryness. Breath simulation was an inaccurate tool for estimating the time to nebulizer dryness as simulated measurements to nebulizer dryness took significantly longer than measurements preformed with actual tidal breathing (p < 0.001). While breath simulation provides an accurate in vitro tool for estimating in vivo aerosol delivery, it should not completely replace in vivo measurements until inherent limitations in simulator operation can be overcome to provide a more clinically realistic simulation. PMID:16379618

  3. Relationship between regional ventilation and aerosol deposition in tidal breathing

    SciTech Connect

    Trajan, M.; Logus, J.W.; Enns, E.G.; Man, S.F.

    1984-07-01

    The regional distribution of the deposition of 1.2 micron particles of 99mTc sulfur colloid inhaled by tidal breathing was compared with the distribution of ventilation as measured by a 133Xe washout technique. Twelve subjects were studied, 6 with normal pulmonary function tests, 5 with air-flow limitation, and 1 with unilateral phrenic nerve paralysis. Both xenon and aerosol were inhaled at tidal volume by the subjects while seated upright. A large field gamma camera acquired posterior scans. Thirteen experiments were also done on 7 dogs: 1 with extrathoracic obstruction of the airway to 1 lung, and 12 with bronchoconstriction from the instillation of methacholine chloride into the airways of a lower lobe. Two of these dogs were studied with a gamma camera system, and the others were studied with a Picker multi-probe system. Both in humans and in dogs, an increase in time constant, which indicated a decrease in ventilation, was associated with an increase in peripheral aerosol deposition when normalized for ventilation. It is suggested that the increased residence time is responsible for the increased deposition in regions that received lesser ventilation.

  4. Measuring tidal breathing parameters using a volumetric vest in neonates with and without lung disease.

    PubMed

    Olden, C; Symes, E; Seddon, P

    2010-11-01

    Lung function measurement is difficult in unsedated infants; tidal breathing parameters are a useful non-invasive surrogate, but even these measurements cause disturbance from applying a facemask. We investigated a novel volumetric vest system (FloRight), which measures volume changes of the respiratory system from changes in the magnetic fields induced by current-carrying coils around the entire chest and abdomen. Using a facemask and ultrasonic flowmeter as comparator, we assessed the validity and repeatability of tidal breathing parameters measured by FloRight in 10 healthy newborn infants during natural sleep. We also assessed the effect of a facemask on tidal volume and tidal expiratory flow parameters. To assess the ability of the FloRight system to detect disease, we compared the healthy infants with 11 infants suffering from bronchopulmonary dysplasia. Tidal parameters with the FloRight vest corresponded closely with facemask measurements. Mean difference, mask minus vest, for tidal volume was 0.096 ml (P < 0.05), with limits of agreement +4.5 to -4.3 ml. Coefficient of repeatability was similar for mask and vest measurements. Tidal volume measured by FloRight with mask in place (20.6 ml) was significantly higher than without mask (16.1 ml), but tidal expiratory flow parameters were not altered. FloRight measurements of tidal parameters were markedly different between the two groups of infants, with tidal volume per Kg significantly higher and tidal expiratory flow parameters significantly lower. Our findings suggest that the FloRight system is able to measure tidal breathing parameters accurately, in healthy newborn infants, without prior calibration on the infant. It appears to have at least sufficient sensitivity to detect severe respiratory disease. PMID:20872815

  5. Characterizing airway and alveolar nitric oxide exchange during tidal breathing using a three-compartment model.

    PubMed

    Condorelli, Peter; Shin, Hye-Won; George, Steven C

    2004-05-01

    Exhaled nitric oxide (NO) may be a useful marker of lung inflammation, but the concentration is highly dependent on exhalation flow rate due to a significant airway source. Current methods for partitioning pulmonary NO gas exchange into airway and alveolar regions utilize multiple exhalation flow rates or a single-breath maneuver with a preexpiratory breath hold, which is cumbersome for children and individuals with compromised lung function. Analysis of tidal breathing data has the potential to overcome these limitations, while still identifying region-specific parameters. In six healthy adults, we utilized a three-compartment model (two airway compartments and one alveolar compartment) to identify two potential flow-independent parameters that represent the average volumetric airway flux (pl/s) and the time-averaged alveolar concentration (parts/billion). Significant background noise and distortion of the signal from the sampling system were compensated for by using a Gaussian wavelet filter and a series of convolution integrals. Mean values for average volumetric airway flux and time-averaged alveolar concentration were 2,500 +/- 2,700 pl/s and 3.2 +/- 3.4 parts/billion, respectively, and were strongly correlated with analogous parameters determined from vital capacity breathing maneuvers. Analysis of multiple tidal breaths significantly reduced the standard error of the parameter estimates relative to the single-breath technique. Our initial assessment demonstrates the potential of utilizing tidal breathing for noninvasive characterization of pulmonary NO exchange dynamics. PMID:14729729

  6. Technical and practical issues for tidal breathing measurements of nasal nitric oxide in children.

    PubMed

    Beydon, Nicole; Chambellan, Arnaud; Alberti, Corinne; de Blic, Jacques; Clément, Annick; Escudier, Estelle; Le Bourgeois, Muriel

    2015-12-01

    To promote early screening of patients with suspected Primary Ciliary Dyskinesia (PCD), nasal nitric oxide (nNO) measurements during tidal breathing (TB) have been developed for children unable to ensure velum closure (VC) during breath hold or expiration against resistance. To investigate technical and practical issues related to TB-nNO methods in children referred for suspected or asserted PCD, we recorded, in a prospective multicenter study, TB-nNO (calculated as the mean of 5 peaks, 10 or 30 sec during tidal breathing) and VC-nNO when available. We studied 142 children (PCD diagnosis asserted in 47, excluded in 39). Nasal NO values were significantly different according to methods, VC-nNO being higher than TB-nNO (TB-nNO 5 peaks higher than mean of 10 or 30 sec). Specificity (90-94%) and sensitivity (86-97%) were similar between TB-nNO and VC-nNO methods. Age was more correlated with VC-nNO than with TB-nNO. TB-nNO could differ between the two nostrils by more than 10% (or 10 ppb when nNO absolute value lower 100 ppb) in 32-43% of the tested children, according to the different tidal breathing values, and was reproducible in the long term but influenced by ambient NO. Despite TB-nNO values being lower than VC-nNO, TB-nNO was found to be as discriminant for PCD, and probably more discriminant in children less than 8 years old, as the VC method. These results were obtained using the chemiluminescence technique which allows an easier assessment of relevant factors such as nasal permeability and ambient NO than the electrochemical technique. PMID:25731630

  7. 4DCT-based assessment of regional airflow distribution in healthy human lungs during tidal breathing

    NASA Astrophysics Data System (ADS)

    Choi, Jiwoong; Jahani, Nariman; Choi, Sanghun; Hoffman, Eric; Lin, Ching-Long

    2014-11-01

    Nonlinear dynamics of regional airflow distribution in healthy human lungs are studied with four-dimensional computed tomography (4DCT) quantitative imaging of four subjects. During the scanning session, subjects continuously breathed with tidal volumes controlled by the dual piston system. For each subject, 10 instantaneous volumetric image data sets (5 inspiratory and 5 expiratory phases) were reconstructed. A mass-preserving image registration was then applied to pairs of these image data to construct a breathing lung model. Regional distributions of local flow rate fractions are computed from time-varying local air volumes. The 4DCT registration-based method provides the link between local and global air volumes of the lung, allowing derivation of time-varying regional flow rates during the tidal breathing for computational fluid dynamics analysis. The local flow rate fraction remains greater in the lower lobes than in the upper lobes, being qualitatively consistent with those derived from three static CT (3SCT) images (Yin et al. JCP 2013). However, unlike 3SCT, the 4DCT data exhibit lung hysteresis between inspiration and expiration, providing more sensitive measures of regional ventilation and lung mechanics. NIH Grants U01-HL114494, R01-HL094315 and S10-RR022421.

  8. Assessment of regional ventilation and deformation using 4D-CT imaging for healthy human lungs during tidal breathing.

    PubMed

    Jahani, Nariman; Choi, Sanghun; Choi, Jiwoong; Iyer, Krishna; Hoffman, Eric A; Lin, Ching-Long

    2015-11-15

    This study aims to assess regional ventilation, nonlinearity, and hysteresis of human lungs during dynamic breathing via image registration of four-dimensional computed tomography (4D-CT) scans. Six healthy adult humans were studied by spiral multidetector-row CT during controlled tidal breathing as well as during total lung capacity and functional residual capacity breath holds. Static images were utilized to contrast static vs. dynamic (deep vs. tidal) breathing. A rolling-seal piston system was employed to maintain consistent tidal breathing during 4D-CT spiral image acquisition, providing required between-breath consistency for physiologically meaningful reconstructed respiratory motion. Registration-derived variables including local air volume and anisotropic deformation index (ADI, an indicator of preferential deformation in response to local force) were employed to assess regional ventilation and lung deformation. Lobar distributions of air volume change during tidal breathing were correlated with those of deep breathing (R(2) ≈ 0.84). Small discrepancies between tidal and deep breathing were shown to be likely due to different distributions of air volume change in the left and the right lungs. We also demonstrated an asymmetric characteristic of flow rate between inhalation and exhalation. With ADI, we were able to quantify nonlinearity and hysteresis of lung deformation that can only be captured in dynamic images. Nonlinearity quantified by ADI is greater during inhalation, and it is stronger in the lower lobes (P < 0.05). Lung hysteresis estimated by the difference of ADI between inhalation and exhalation is more significant in the right lungs than that in the left lungs. PMID:26316512

  9. Investigating in vivo airway wall mechanics during tidal breathing with optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Robertson, Claire; Lee, Sang-Won; Ahn, Yeh-Chan; Mahon, Sari; Chen, Zhongping; Brenner, Matthew; George, Steven C.

    2011-10-01

    Optical coherence tomography (OCT) is a nondestructive imaging technique offering high temporal and spatial resolution, which makes it a natural choice for assessing tissue mechanical properties. We have developed methods to mechanically analyze the compliance of the rabbit trachea in vivo using tissue deformations induced by tidal breathing, offering a unique tool to assess the behavior of the airways during their normal function. Four-hundred images were acquired during tidal breathing with a custom-built endoscopic OCT system. The surface of the tissue was extracted from a set of these images via image processing algorithms, filtered with a bandpass filter set at respiration frequency to remove cardiac and probe motion, and compared to ventilatory pressure to calculate wall compliance. These algorithms were tested on elastic phantoms to establish reliability and reproducibility. The mean tracheal wall compliance (in five animals) was 1.3+/-0.3×10-5 (mm Pa)-1. Unlike previous work evaluating airway mechanics, this new method is applicable in vivo, noncontact, and loads the trachea in a physiological manner. The technique may have applications in assessing airway mechanics in diseases such as asthma that are characterized by significant airway remodeling.

  10. Upper extremity muscle tone and response of tidal volume during manually assisted breathing for patients requiring prolonged mechanical ventilation

    PubMed Central

    Morino, Akira; Shida, Masahiro; Tanaka, Masashi; Sato, Kimihiro; Seko, Toshiaki; Ito, Shunsuke; Ogawa, Shunichi; Yokoi, Yuka; Takahashi, Naoaki

    2015-01-01

    [Purpose] The aim of the present study was to examine, in patients requiring prolonged mechanical ventilation, if the response of tidal volume during manually assisted breathing is dependent upon both upper extremity muscle tone and the pressure intensity of manually assisted breathing. [Subjects] We recruited 13 patients on prolonged mechanical ventilation, and assessed their upper extremity muscle tone using the modified Ashworth scale (MAS). The subjects were assigned to either the low MAS group (MAS≤2, n=7) or the high MAS group (MAS≥3, n=6). [Methods] The manually assisted breathing technique was applied at a pressure of 2 kgf and 4 kgf. A split-plot ANOVA was performed to compare the tidal volume of each pressure during manually assisted breathing between the low and the high MAS groups. [Results] Statistical analysis showed there were main effects of the upper extremity muscle tone and the pressure intensity of the manually assisted breathing technique. There was no interaction between these factors. [Conclusion] Our findings reveal that the tidal volume during the manually assisted breathing technique for patients with prolonged mechanical ventilation depends upon the patient’s upper extremity muscle tone and the pressure intensity. PMID:26357431

  11. Methods for Assessing Expiratory Flow Limitation during Tidal Breathing in COPD Patients

    PubMed Central

    Koulouris, Nickolaos G.; Kaltsakas, Georgios; Palamidas, Anastasios F.; Gennimata, Sofia-Antiopi

    2012-01-01

    Patients with severe COPD often exhale along the same flow-volume curve during quite breathing as during forced expiratory vital capacity manoeuvre, and this has been taken as indicating expiratory flow limitation at rest (EFLT). Therefore, EFLT, namely, attainment of maximal expiratory flow during tidal expiration, occurs when an increase in transpulmonary pressure causes no increase in expiratory flow. EFLT leads to small airway injury and promotes dynamic pulmonary hyperinflation with concurrent dyspnoea and exercise limitation. In fact, EFLT occurs commonly in COPD patients (mainly in GOLD III and IV stage) in whom the latter symptoms are common. The existing up-to-date physiological methods for assessing expiratory flow limitation (EFLT) are reviewed in the present work. Among the currently available techniques, the negative expiratory pressure (NEP) has been validated in a wide variety of settings and disorders. Consequently, it should be regarded as a simple, non invasive, most practical, and accurate new technique. PMID:23008769

  12. Tidal volume single-breath washin of SF6 and CH4 in transient microgravity.

    PubMed

    Dutrieue, Brigitte; Paiva, Manuel; Verbanck, Sylvia; Le Gouic, Marine; Darquenne, Chantal; Prisk, G Kim

    2003-01-01

    We performed tidal volume single-breath washins (SBW) by using tracers of different diffusivity and varied the time spent in microgravity (microG) before the start of the tests to look for time-dependent effects. SF(6) and CH(4) phase III slopes decreased by 35 and 26%, respectively, in microG compared with 1 G (P < 0.05), and the slope difference between gases disappeared. There was no effect of time in microG, suggesting that neither the hypergravity period preceding microG nor the time spent in microG affected gas mixing at volumes near functional residual capacity. In previous studies using SF(6) and He (Lauzon A-M, Prisk GK, Elliott AR, Verbanck S, Paiva M, and West JB. J Appl Physiol 82: 859-865, 1997), the vital capacity SBW showed an increase in slope difference between gases in transient microG, the opposite of the decrease in sustained microG. In contrast, tidal volume SBW showed a decrease in slope difference in both microG conditions. Because it is only the behavior of the more diffusive gas that differed between maneuvers and microG conditions, we speculate that, in the previous vital capacity SBW, the hypergravity period preceding the test in transient microG provoked conformational changes at low lung volumes near the acinar entrance. PMID:12391087

  13. Tidal volume single-breath washin of SF6 and CH4 in transient microgravity

    NASA Technical Reports Server (NTRS)

    Dutrieue, Brigitte; Paiva, Manuel; Verbanck, Sylvia; Le Gouic, Marine; Darquenne, Chantal; Prisk, G. Kim

    2003-01-01

    We performed tidal volume single-breath washins (SBW) by using tracers of different diffusivity and varied the time spent in microgravity (microG) before the start of the tests to look for time-dependent effects. SF(6) and CH(4) phase III slopes decreased by 35 and 26%, respectively, in microG compared with 1 G (P < 0.05), and the slope difference between gases disappeared. There was no effect of time in microG, suggesting that neither the hypergravity period preceding microG nor the time spent in microG affected gas mixing at volumes near functional residual capacity. In previous studies using SF(6) and He (Lauzon A-M, Prisk GK, Elliott AR, Verbanck S, Paiva M, and West JB. J Appl Physiol 82: 859-865, 1997), the vital capacity SBW showed an increase in slope difference between gases in transient microG, the opposite of the decrease in sustained microG. In contrast, tidal volume SBW showed a decrease in slope difference in both microG conditions. Because it is only the behavior of the more diffusive gas that differed between maneuvers and microG conditions, we speculate that, in the previous vital capacity SBW, the hypergravity period preceding the test in transient microG provoked conformational changes at low lung volumes near the acinar entrance.

  14. Breathing of a coral cay: Tracing tidally driven seawater recirculation in permeable coral reef sediments

    NASA Astrophysics Data System (ADS)

    Santos, Isaac R.; Erler, Dirk; Tait, Douglas; Eyre, Bradley D.

    2010-12-01

    Coral reefs are characterized by high gross productivity in spite of low nutrient concentrations. This apparent paradox may be partially reconciled if seawater recirculation in permeable sediments over large (meters) and long (hours to days) scales is an important source of recycled nitrogen and phosphorus to coral reefs. In this paper we use radon (222Rn, a natural tracer) to quantify tidally driven pore water (or groundwater) exchange between (1) an offshore coral cay island and its fringing reef lagoon and (2) a reef lagoon and the surrounding ocean. As seawater infiltrates Heron Island at high tide, it acquires a radon signal that can be detected when pore waters emerge from carbonate sands at low tide. A nonsteady state model indicated that vertical pore water upwelling rates (or saline submarine groundwater discharge) were >40 cm/d within the reef lagoon and >100 cm/d outside the lagoon at low tide. Within the lagoon, tidal pumping and temperature-driven convection were the main driving forces of pore water advection. At low tide, the reef lagoon level is about 1 m higher than the surrounding ocean. As a result, a steep hydraulic gradient develops at the reef edge, driving unidirectional filtration through the reef framework. Groundwaters were highly enriched in nitrate (average of 530 μmol, likely influenced by bird guano) relative to lagoon waters (1.9 μmol). Rough but conservative estimates indicated that groundwater-derived nitrate fluxes (7.9 mmol/m2/d) can replace the entire lagoon nitrate inventory every <19 days. We speculate that as offshore coral islands "breath" (inhale seawater at high tide and exhale groundwater at low tide), they release nutrients that lead to sustained productivity within coral reefs.

  15. A MATLAB toolbox for correcting within-individual effects of respiration rate and tidal volume on respiratory sinus arrhythmia during variable breathing.

    PubMed

    Schulz, Stefan M; Ayala, Erica; Dahme, Bernhard; Ritz, Thomas

    2009-11-01

    Respiratory sinus arrhythmia (RSA) is a common estimator of vagal outflow to the heart, dependent on parasympathetic activity. During variable breathing, both respiration rate and tidal volume contribute substantially to within-individual RSA variance. A respiratory control method allows for within-individual correction of the time-domain index of RSA. rsaToolbox is a set of MATLAB programs for scoring respiration-corrected RSA using measurements of cardiac interbeat intervals, respiratory-cycle times, and tidal volumes, recorded at different paced-breathing frequencies. The within-individual regression of RSA divided by tidal volume upon total respiratory cycle time is then used to estimate the baseline vagal tone for each breath of a given total respiratory-cycle time. During a subsequent analysis, the difference between the observed RSA (divided by the tidal volume at each breath) and the RSA divided by the tidal volume that was predicted by the baseline equation serves as an estimate of changes in vagal tone. rsaToolbox includes a graphical user interface for intuitive handling. Modular implementation of the algorithm also allows for flexible integration within other analytic strategies or for batch processing. PMID:19897819

  16. Extrathoracic and intrathoracic removal of O3 in tidal-breathing humans

    SciTech Connect

    Gerrity, T.R.; Weaver, R.A.; Berntsen, J.; House, D.E.; O'Neil, J.J.

    1988-07-01

    We measured the efficiency of O3 removal from inspired air by the extrathoracic and intrathoracic airways in 18 healthy, nonsmoking, young male volunteers. Removal efficiencies were measured as a function of O3 concentration (0.1, 0.2, and 0.4 ppm), mode of breathing (nose only, mouth only, and oronasal), and respiration frequency (12 and 24 breaths/min). Subjects were placed in a controlled environmental chamber into which O3 was introduced. A small polyethylene tube was then inserted into the nose of each subject, with the tip positioned in the posterior pharynx. Samples of air were collected from the posterior pharynx through the tube and into a rapidly responding O3 analyzer yielding inspiratory and expiratory O3 concentrations in the posterior pharynx. The O3 removal efficiency of the extrathoracic airways was computed with the use of the inspiratory concentration and the chamber concentration, and intrathoracic removal efficiency was computed with the use of the inspiratory and expiratory concentrations. The mean extrathoracic removal efficiency for all measurements was 39.6 +/- 0.7% (SE), and the mean intrathoracic removal efficiency was 91.0 +/- 0.5%. Significantly less O3 was removed both extrathoracically and intrathoracically when subjects breathed at 24 breaths/min compared with 12 breaths/min (P less than 0.001). O3 concentration had no effect on extrathoracic removal efficiency, but there was a significantly greater intrathoracic removal efficiency at 0.4 ppm than at 0.1 ppm (P less than 0.05). Mode of breathing significantly affected extrathoracic removal efficiency, with less O3 removed during nasal breathing than during either mouth breathing or oronasal breathing (P less than 0.01).

  17. Controlled breathing protocols probe human autonomic cardiovascular rhythms.

    PubMed

    Cooke, W H; Cox, J F; Diedrich, A M; Taylor, J A; Beightol, L A; Ames, J E; Hoag, J B; Seidel, H; Eckberg, D L

    1998-02-01

    The purpose of this study was to determine how breathing protocols requiring varying degrees of control affect cardiovascular dynamics. We measured inspiratory volume, end-tidal CO2, R-R interval, and arterial pressure spectral power in 10 volunteers who followed the following 5 breathing protocols: 1) uncontrolled breathing for 5 min; 2) stepwise frequency breathing (at 0.3, 0.25, 0.2, 0.15, 0.1, and 0.05 Hz for 2 min each); 3) stepwise frequency breathing as above, but with prescribed tidal volumes; 4) random-frequency breathing (approximately 0.5-0.05 Hz) for 6 min; and 5) fixed-frequency breathing (0.25 Hz) for 5 min. During stepwise breathing, R-R interval and arterial pressure spectral power increased as breathing frequency decreased. Control of inspired volume reduced R-R interval spectral power during 0.1 Hz breathing (P < 0.05). Stepwise and random-breathing protocols yielded comparable coherence and transfer functions between respiration and R-R intervals and systolic pressure and R-R intervals. Random- and fixed-frequency breathing reduced end-tidal CO2 modestly (P < 0.05). Our data suggest that stringent tidal volume control attenuates low-frequency R-R interval oscillations and that fixed- and random-rate breathing may decrease CO2 chemoreceptor stimulation. We conclude that autonomic rhythms measured during different breathing protocols have much in common but that a stepwise protocol without stringent control of inspired volume may allow for the most efficient assessment of short-term respiratory-mediated autonomic oscillations. PMID:9486278

  18. Controlled breathing protocols probe human autonomic cardiovascular rhythms

    NASA Technical Reports Server (NTRS)

    Cooke, W. H.; Cox, J. F.; Diedrich, A. M.; Taylor, J. A.; Beightol, L. A.; Ames, J. E. 4th; Hoag, J. B.; Seidel, H.; Eckberg, D. L.

    1998-01-01

    The purpose of this study was to determine how breathing protocols requiring varying degrees of control affect cardiovascular dynamics. We measured inspiratory volume, end-tidal CO2, R-R interval, and arterial pressure spectral power in 10 volunteers who followed the following 5 breathing protocols: 1) uncontrolled breathing for 5 min; 2) stepwise frequency breathing (at 0.3, 0.25, 0.2, 0.15, 0.1, and 0.05 Hz for 2 min each); 3) stepwise frequency breathing as above, but with prescribed tidal volumes; 4) random-frequency breathing (approximately 0.5-0.05 Hz) for 6 min; and 5) fixed-frequency breathing (0.25 Hz) for 5 min. During stepwise breathing, R-R interval and arterial pressure spectral power increased as breathing frequency decreased. Control of inspired volume reduced R-R interval spectral power during 0.1 Hz breathing (P < 0.05). Stepwise and random-breathing protocols yielded comparable coherence and transfer functions between respiration and R-R intervals and systolic pressure and R-R intervals. Random- and fixed-frequency breathing reduced end-tidal CO2 modestly (P < 0.05). Our data suggest that stringent tidal volume control attenuates low-frequency R-R interval oscillations and that fixed- and random-rate breathing may decrease CO2 chemoreceptor stimulation. We conclude that autonomic rhythms measured during different breathing protocols have much in common but that a stepwise protocol without stringent control of inspired volume may allow for the most efficient assessment of short-term respiratory-mediated autonomic oscillations.

  19. EXTRATHORACIC AND INTRATHORACIC REMOVAL OF O3 IN TIDAL-BREATHING HUMANS (JOURNAL VERSION)

    EPA Science Inventory

    The efficiency of ozone removal from inspired air by the extrathoracic and intrathoracic airways was measured in 18 healthy, nonsmoking, young male volunteers. Removal efficiencies were measured as a function of ozone concentration (0.1, 0.2, and 0.4 ppm), mode of breathing (nose...

  20. Similar ventilation distribution in normal subjects prone and supine during tidal breathing.

    PubMed

    Rodríguez-Nieto, M J; Peces-Barba, G; González Mangado, N; Paiva, M; Verbanck, S

    2002-02-01

    Multiple-breath washout (MBW) tests, with end-expiratory lung volume at functional residual capacity (FRC) and 90% O(2), 5% He, and 5% SF(6) as an inspired gas mixture, were performed in healthy volunteers in supine and prone postures. The semilog plot of MBW N(2) concentrations was evaluated in terms of its curvilinearity. The MBW N(2) normalized slope analysis yielded indexes of acinar and conductive ventilation heterogeneity (Verbanck S, Schuermans D, Van Muylem A, Paiva M, Noppen M, and Vincken W. J App Physiol 83: 1907-1916, 1997). Also, the difference between SF(6) and He normalized phase III slopes was computed in the first MBW expiration. Only MBW tests with similar FRC in the prone and supine postures (P > 0.1; n = 8) were considered. Prone and supine postures did not reveal any significant differences in curvilinearity, N(2) normalized slope-derived indexes of conductive or acinar ventilation heterogeneity, nor SF(6)-He normalized phase III slope difference in the first MBW expiration (P > 0.1 for all). The absence of significant changes in any of the MBW indexes suggests that ventilation heterogeneity is similar in the supine and prone postures of normal subjects breathing near FRC. PMID:11796673

  1. Real time noninvasive estimation of work of breathing using facemask leak-corrected tidal volume during noninvasive pressure support: validation study.

    PubMed

    Banner, Michael J; Tams, Carl G; Euliano, Neil R; Stephan, Paul J; Leavitt, Trevor J; Martin, A Daniel; Al-Rawas, Nawar; Gabrielli, Andrea

    2016-06-01

    We describe a real time, noninvasive method of estimating work of breathing (esophageal balloon not required) during noninvasive pressure support (PS) that uses an artificial neural network (ANN) combined with a leak correction (LC) algorithm, programmed to ignore asynchronous breaths, that corrects for differences in inhaled and exhaled tidal volume (VT) from facemask leaks (WOBANN,LC/min). Validation studies of WOBANN,LC/min were performed. Using a dedicated and popular noninvasive ventilation ventilator (V60, Philips), in vitro studies using PS (5 and 10 cm H2O) at various inspiratory flow rate demands were simulated with a lung model. WOBANN,LC/min was compared with the actual work of breathing, determined under conditions of no facemask leaks and estimated using an ANN (WOBANN/min). Using the same ventilator, an in vivo study of healthy adults (n = 8) receiving combinations of PS (3-10 cm H2O) and expiratory positive airway pressure was done. WOBANN,LC/min was compared with physiologic work of breathing/min (WOBPHYS/min), determined from changes in esophageal pressure and VT applied to a Campbell diagram. For the in vitro studies, WOBANN,LC/min and WOBANN/min ranged from 2.4 to 11.9 J/min and there was an excellent relationship between WOBANN,LC/breath and WOBANN/breath, r = 0.99, r(2) = 0.98 (p < 0.01). There were essentially no differences between WOBANN,LC/min and WOBANN/min. For the in vivo study, WOBANN,LC/min and WOBPHYS/min ranged from 3 to 12 J/min and there was an excellent relationship between WOBANN,LC/breath and WOBPHYS/breath, r = 0.93, r(2) = 0.86 (p < 0.01). An ANN combined with a facemask LC algorithm provides noninvasive and valid estimates of work of breathing during noninvasive PS. WOBANN,LC/min, automatically and continuously estimated, may be useful for assessing inspiratory muscle loads and guiding noninvasive PS settings as in a decision support system to appropriately unload inspiratory muscles. PMID:26070542

  2. Keep Kids' Mouths Healthy: Brush 2min2X

    MedlinePlus

    ... Kids’ Teeth Teeth Helpful Resources Links Keep Kids’ Mouths Healthy Roll over or click the time line below for healthy mouth information. Email Link Kids' Care Timeline Brush 2min2x - ...

  3. Tidal power

    SciTech Connect

    Hammons, T.J. )

    1993-03-01

    The paper reviews the physics of tidal power considering gravitational effects of moon and sun; semidiurnal, diurnal, and mixed tides; and major periodic components that affect the tidal range. Shelving, funneling, reflection, and resonance phenomena that have a significant effect on tidal range are also discussed. The paper then examines tidal energy resource for principal developments estimated from parametric modeling in Europe and worldwide. Basic parameters that govern the design of tidal power schemes in terms of mean tidal range and surface area of the enclosed basin are identified. While energy extracted is proportional to the tidal amplitude squared, requisite sluicing are is proportional to the square root of the tidal amplitude. Sites with large tidal amplitudes are therefore best suited for tidal power developments, whereas sites with low tidal amplitudes have sluicing that may be prohibitive. It is shown that 48% of the European tidal resource is in the United Kingdom, 42% in France and 8% in Ireland, other countries having negligible potential. Worldwide tidal resource is identified. Tidal barrage design and construction using caissons is examined, as are alternative operating modes (single-action generation, outflow generation, flood generation, two-way generation, twin basin generation, pumping, etc), development trends and possibilities, generation cost at the barrage boundary, sensitivity to discount rates, general economics, and markets. Environmental effects, and institutional constraints to the development of tidal barrage schemes are also discussed.

  4. Breath odor

    MedlinePlus

    ... tube) in place. The breath may have an ammonia-like odor (also described as urine-like or " ... kidney failure (can cause breath to smell like ammonia ) Diabetes (fruity or sweet chemical smell associated with ...

  5. Breathing Problems

    MedlinePlus

    ... re not getting enough air. Sometimes mild breathing problems are from a stuffy nose or hard exercise. ... emphysema or pneumonia cause breathing difficulties. So can problems with your trachea or bronchi, which are part ...

  6. Breathing difficulty

    MedlinePlus

    ... pulmonary disease (COPD), such as chronic bronchitis or emphysema Other lung disease Pneumonia Pulmonary hypertension Problems with ... of breath; Breathlessness; Difficulty breathing; Dyspnea Images Lungs Emphysema References Kraft M. Approach to the patient with ...

  7. Breath odor

    MedlinePlus

    ... is a potentially life-threatening condition. Breath that smells like feces can occur with prolonged vomiting , especially ... renal failure Bowel obstruction (can cause breath to smell like feces) Bronchiectasis Chronic kidney failure (can cause ...

  8. A breath sampling system assessing the influence of respiratory rate on exhaled breath composition.

    PubMed

    Lomonaco, T; Salvo, P; Ghimenti, S; Biagini, D; Bellagambi, F; Fuoco, R; Di Francesco, F

    2015-08-01

    This work presents a computerized system to monitor mouth pressure, tidal volume, exhaled airflow, respiration rate and end-tidal partial pressure of CO2 during breath collection. The system was used to investigate the effect of different respiratory rates on the volatile organic compounds (VOCs) concentrations in exhaled breath. For this purpose, VOCs with well-defined biochemical pathways and different chemical and physical properties were selected as biomarkers related to metabolism (acetone and isopropyl alcohol), cholesterol synthesis (isoprene) and intestinal microflora activity (ethanol). Mixed breath was collected from a nominally healthy volunteer in resting conditions by filling a Nalophan bag. The subject followed a regimented breathing pattern at different respiratory rates (10, 30 and 50 breaths per minute). Results highlight that ventilation pattern strongly influences the concentration of the selected compounds. The proposed system allows exhaled breath to be collected also in patients showing dyspnea such as in case of chronic heart failure, asthma and pulmonary diseases. PMID:26738056

  9. Syllable-Related Breathing in Infants in the Second Year of Life

    ERIC Educational Resources Information Center

    Parham, Douglas F.; Buder, Eugene H.; Oller, D. Kimbrough; Boliek, Carol A.

    2011-01-01

    Purpose: This study explored whether breathing behaviors of infants within the 2nd year of life differ between tidal breathing and breathing supporting single unarticulated syllables and canonical/articulated syllables. Method: Vocalizations and breathing kinematics of 9 infants between 53 and 90 weeks of age were recorded. A strict selection…

  10. Dirhythmic breathing.

    PubMed

    Flemister, G; Goldberg, N B; Sharp, J T

    1981-01-01

    Four patients with severe chronic obstructive lung disease and recent respiratory failure are described in whom two distinct simultaneous respiratory rhythms were identified, one at 8 to 13 breaths per minute and the other at 39 to 65 per minute. Magnetometer measurements of thoracoabdominal motion together with simultaneous electromyograms of multiple inspiratory muscles suggested that both rhythms were the result of coordinated action of several inspiratory muscles. We suggest that this phenomenon, which we have called dirhythmic breathing, results from the conflicting influence upon respiratory centers and motoneurons of two or more stimuli, some favoring rapid shallow breaths and others slow deep breaths. PMID:7449504

  11. Kidney motion during free breathing and breath hold for MR-guided radiotherapy

    NASA Astrophysics Data System (ADS)

    Stam, Mette K.; van Vulpen, Marco; Barendrecht, Maurits M.; Zonnenberg, Bernard A.; Intven, Martijn; Crijns, Sjoerd P. M.; Lagendijk, Jan J. W.; Raaymakers, Bas W.

    2013-04-01

    Current treatments for renal cell carcinoma have a high complication rate due to the invasiveness of the treatment. With the MRI-linac it may be possible to treat renal tumours non-invasively with high-precision radiotherapy. This is expected to reduce complications. To deliver a static dose distribution, radiation gating will be used. In this study the reproducibility and efficiency of free breathing gating and a breath hold treatment of the kidney was investigated. For 15 patients with a renal lesion the kidney motion during 2 min of free breathing and 10 consecutive expiration breath holds was studied with 2D cine MRI. The variability in kidney expiration position and treatment efficiency for gating windows of 1 to 20 mm was measured for both breathing patterns. Additionally the time trend in free breathing and the variation in expiration breath hold kidney position with baseline shift correction was determined. In 80% of the patients the variation in expiration position during free breathing is smaller than 2 mm. No clinically relevant time trends were detected. The variation in expiration breath hold is for all patients larger than the free breathing expiration variation. Gating on free breathing is, for gating windows of 1 to 5 mm more efficient than breath hold without baseline correction. When applying a baseline correction to the breath hold it increases the treatment efficiency. The kidney position is more reproducible in expiration free breathing than non-guided expiration breath hold. For small gating windows it is also more time efficient. Since free breathing also seems more comfortable for the patients it is the preferred breathing pattern for MRI-Linac treatments of the kidney.

  12. Breathing exercises: influence on breathing patterns and thoracoabdominal motion in healthy subjects

    PubMed Central

    Vieira, Danielle S. R.; Mendes, Liliane P. S.; Elmiro, Nathália S.; Velloso, Marcelo; Britto, Raquel R.; Parreira, Verônica F.

    2014-01-01

    BACKGROUND: The mechanisms underlying breathing exercises have not been fully elucidated. OBJECTIVES: To evaluate the impact of four on breathing exercises (diaphragmatic breathing, inspiratory sighs, sustained maximal inspiration and intercostal exercise) the on breathing pattern and thoracoabdominal motion in healthy subjects. METHOD: Fifteen subjects of both sexes, aged 23±1.5 years old and with normal pulmonary function tests, participated in the study. The subjects were evaluated using the optoelectronic plethysmography system in a supine position with a trunk inclination of 45° during quiet breathing and the breathing exercises. The order of the breathing exercises was randomized. Statistical analysis was performed by the Friedman test and an ANOVA for repeated measures with one factor (breathing exercises), followed by preplanned contrasts and Bonferroni correction. A p<0.005 value was considered significant. RESULTS: All breathing exercises significantly increased the tidal volume of the chest wall (Vcw) and reduced the respiratory rate (RR) in comparison to quiet breathing. The diaphragmatic breathing exercise was responsible for the lowest Vcw, the lowest contribution of the rib cage, and the highest contribution of the abdomen. The sustained maximal inspiration exercise promoted greater reduction in RR compared to the diaphragmatic and intercostal exercises. Inspiratory sighs and intercostal exercises were responsible for the highest values of minute ventilation. Thoracoabdominal asynchrony variables increased significantly during diaphragmatic breathing. CONCLUSIONS: The results showed that the breathing exercises investigated in this study produced modifications in the breathing pattern (e.g., increase in tidal volume and decrease in RR) as well as in thoracoabdominal motion (e.g., increase in abdominal contribution during diaphragmatic breathing), among others. PMID:25590447

  13. Breathing Problems

    MedlinePlus

    When you're short of breath, it's hard or uncomfortable for you to take in the oxygen your body needs. You may feel as if you're ... stuffy nose or hard exercise. But shortness of breath can also be a sign of a serious ...

  14. Positive emotion reduces dyspnea during slow paced breathing.

    PubMed

    Allen, Ben; Friedman, Bruce H

    2012-05-01

    Slow breathing is used to induce cardiovascular resonance, a state associated with health benefits, but it can also increase tidal volume and associated dyspnea (respiratory discomfort). Dyspnea may be decreased by induced positive affect. In this study, 71 subjects (36 men, M = 20 years) breathed at 6 breaths per min. In condition one, subjects paced their breathing by inhaling and exhaling as a vertical bar moved up and down. In condition two, breathing was paced by a timed slideshow of positive images; subjects inhaled during a black screen and exhaled as the image appeared. Cardiac, respiratory, and self-reported dyspnea and emotional indices were recorded. Tidal volume and the intensity and unpleasantness of dyspnea were reduced when paced breathing was combined with pleasant images. These results show that positive affect can reduce dyspnea during slow paced breathing, and may have applications for induced cardiovascular resonance. PMID:22292794

  15. Syllable-Related Breathing in Infants in the Second Year of Life

    PubMed Central

    Parham, Douglas F.; Buder, Eugene H.; Oller, D. Kimbrough; Boliek, Carol A.

    2010-01-01

    Purpose This study explored whether breathing behaviors of infants within the second year of life differ between tidal breathing and breathing supporting single unarticulated syllables and canonical/articulated syllables. Method Vocalizations and breathing kinematics of nine infants between 53 and 90 weeks of age were recorded. A strict selection protocol was used to identify analyzable breath cycles. Syllables were categorized based on consensus coding. Inspiratory and expiratory durations, excursions, and slopes were calculated for the three breath cycle types and normalized using mean tidal breath measures. Results Tidal breathing cycles were significantly different from syllable-related cycles on all breathing measures. There were no significant differences between unarticulated syllable cycles and canonical syllable cycles, even after controlling for utterance duration and sound pressure level. Conclusions Infants in the second year of life exhibit clear differences between tidal breathing and speech-related breathing, but categorically distinct breath support for syllable types with varying articulatory demands was not evident in the current findings. Speech development introduces increasingly complex utterances, so older infants may produce detectable articulation-related adaptations of breathing kinematics. For younger infants, breath support may vary systematically among utterance types, due more to phonatory variations than to articulatory demands. PMID:21173390

  16. Tidal Energy.

    ERIC Educational Resources Information Center

    Impact of Science on Society, 1987

    1987-01-01

    States that tidal power projects are feasible in a relatively limited number of locations around the world. Claims that together they could theoretically produce the energy equivalent to more than one million barrels of oil per year. (TW)

  17. Tidal Forms

    NASA Astrophysics Data System (ADS)

    Bolla Pittaluga, M.; Seminara, G.; Tambroni, N.

    2003-04-01

    We give an overview of some recent investigations on the mechanics of the processes whereby forms develop in tidal environments. The viewpoint taken here is mechanistic. Some of the questions which deserve an answer may be summarised as follows: i) do tidal channels tend to some altimetric long term equilibrium? ii) why are they typically convergent and weakly meandering? iii) how is such equilibrium affected by the hydrodynamics and morphodynamics of tidal inlets? iv) what is the hydrodynamic and morphodynamic role played by tidal flats adjacent to the channels? Some of the above questions have received a considerable attention in the last few years. Schuttelaars and de Swart (1996), Lanzoni and Seminara (2002) and, more recently, Bolla Pittaluga (2003) have investigated the first problem. In particular, the latter two contributions have shown that a straight tidal channel connected to a tidal sea at one end and closed at the other end tends to reach a long term equilibrium profile, which is slightly concave seaward and convex landward where a beach forms. The equilibrium profile is strongly sensitive to the harmonic content of the tidal forcing as well as to the value of sediment concentration established by the coastal hydrodynamics in the far field of the inlet region. Less important are the effect of channel convergence and the role of settling lag in the transport of suspended load. Insufficient attention has been devoted to the understanding of what mechanisms control channel convergence and meandering, though some similarities and differences between tidal and fluvial channels have emerged from some recent works. In particular, free bars form in tidal channels due to an instability mechanism essentially similar to that occurring under steady conditions though the oscillatory character of the flow field makes the bar pattern non migrating (Seminara and Tubino, 2001). Similarly, forced bars in curved tidal channels are driven by the development of

  18. Bad Breath

    MedlinePlus

    ... mouth and between your teeth produce the bad odor. Other problems in your mouth, such as gum ... and medicines are associated with a specific breath odor. Having good dental habits, like brushing and flossing ...

  19. Bad Breath

    MedlinePlus

    ... hygiene leads to bad breath because when food particles are left in your mouth, they can rot ... Flossing once a day helps get rid of particles wedged between your teeth. Also, visit your dentist ...

  20. Breath sounds

    MedlinePlus

    The lung sounds are best heard with a stethoscope. This is called auscultation. Normal lung sounds occur ... the bottom of the rib cage. Using a stethoscope, the doctor may hear normal breathing sounds, decreased ...

  1. How to breathe when you are short of breath

    MedlinePlus

    Pursed lip breathing; COPD - pursed lip breathing; Emphysema - pursed lip breathing; Chronic bronchitis - pursed lip breathing; Pulmonary fibrosis - pursed lip breathing; Interstitial lung disease - pursed lip breathing; Hypoxia - pursed lip breathing; ...

  2. Breathing difficulty - lying down

    MedlinePlus

    ... breath; Paroxysmal nocturnal dyspnea; PND; Difficulty breathing while lying down; Orthopnea ... Obesity (does not directly cause difficulty breathing while lying down but often worsens other conditions that lead ...

  3. Traveling with breathing problems

    MedlinePlus

    If you have breathing problems and you: Are short of breath most of the time Get short of breath when you walk 150 ... or less Have been in the hospital for breathing problems recently Use oxygen at home, even if ...

  4. Tidal Meanders

    NASA Astrophysics Data System (ADS)

    Marani, M.; Lanzoni, S.; Zandolin, D.; Seminara, S.; Rinaldo, A.

    Observational evidence is presented on the geometry of meandering tidal channels evolved within coastal wetlands characterized by different tidal, hydrodynamic, to- pographic, vegetational and ecological features. New insight is provided on the ge- ometrical properties of tidal meanders, with possible dynamic implications on their evolution. In particular, it is shown that large spatial gradients of leading flow rates induce important spatial variabilities of meander wavelengths and widths, while their ratio remains remarkably constant in the range of scales of observation. This holds regardless of changes in width and wavelength up to two orders of magnitude. This suggests a locally adapted evolution, involving the morphological adjustment to the chief landforming events driven by local hydrodynamics. The spectral analysis of lo- cal curvatures reveals that Kinoshita's model curve does not fit tidal meanders due to the presence of even harmonics, in particular the second mode. Geometric parameters are constructed that are suitable to detect possible geomorphic signatures of the tran- sitions from ebb- to flood-dominated hydrodynamics, here related to the skewness of the tidal meander. Trends in skewness, however, prove elusive to measure and fail to show detectable patterns. We also study comparatively the spatial patterns of evolu- tion of the ratios of channel width to depth, and the ratio of width to local radius of curvature. Interestingly, the latter ratio exhibits consistency despite sharp differences in channel incision. Since the degree of incision, epitomized by the width-to-depth ratio, responds to the relevant erosion and migrations mechanisms and is much sen- sitive to vegetation and sediment properties, it is noticeable that we observe a great variety of landscape carving modes and yet recurrent planar features like constant width/curvature and wavelength/width ratios.

  5. Tidal meanders

    NASA Astrophysics Data System (ADS)

    Marani, Marco; Lanzoni, Stefano; Zandolin, Diego; Seminara, Giovanni; Rinaldo, Andrea

    2002-11-01

    Observational evidence is presented on the geometry of meandering tidal channels evolved within coastal wetlands characterized by different tidal, hydrodynamic, topographic, vegetational and ecological features. New insight is provided on the geometrical properties of tidal meanders, with possible dynamic implications on their evolution. In particular, it is shown that large spatial gradients of leading flow rates induce important spatial variabilities of meander wavelengths and widths, while their ratio remains remarkably constant in the range of scales of observation. This holds regardless of changes in width and wavelength up to two orders of magnitude. This suggests a locally adapted evolution, involving the morphological adjustment to the chief landforming events driven by local hydrodynamics. The spectral analysis of local curvatures reveals that Kinoshita's model curve does not fit tidal meanders due to the presence of even harmonics, in particular the second mode. Geometric parameters are constructed that are suitable to detect possible geomorphic signatures of the transitions from ebb- to flood-dominated hydrodynamics, here related to the skewness of the tidal meander. Trends in skewness, however, prove elusive to measure and fail to show detectable patterns. We also study comparatively the spatial patterns of evolution of the ratios of channel width to depth, and the ratio of width to local radius of curvature. Interestingly, the latter ratio exhibits consistency despite sharp differences in channel incision. Since the degree of incision, epitomized by the width-to-depth ratio, responds to the relevant erosion and migrations mechanisms and is much sensitive to vegetation and sediment properties, it is noticeable that we observe a great variety of landscape carving modes and yet recurrent planar features like constant width/curvature and wavelength/width ratios.

  6. [Investigation of the structure breathing pattern in competitive exercises have athletes kettlebell Lifters].

    PubMed

    Tikhonov, V F; Agafonkina, T V

    2014-01-01

    The aim of the research is to determine the breathing pattern characteristics of kettlebell athletes. The main indicators were identified: breathing frequency (f), tidal volume (VT), minute ventilation (VE). We also searched for the dependence of these parameters using the weight of kettlebells and skill of the athletes.We used the spirograph SMP-21/01-"R-D" for qualitative and quantitative evaluation of the miain indicators of kettlebell athletes breathing patterns. Athletes who achieved Masters of Sports (MS) and candidate masters of sport (CMS), their changes in breathing during exercise occurs mainly on two parameters--the frequeincy of breathing and tidal yolume. We found out while the weight of the kettlebell increases the breathing frequen- cy increases and tidal volume decreases. Athletes who achieved International Masters of Sports (MSIC), they dominated the change of one parameter of breathing--on the tidalivolume, which increases from 0.7 +/- 0.11 to 1.2 +/- 0.11 (p < 001). In MSIC athletes tidal volume is approximately to level of 1.2 +/- 0.1, which invariably leads to an increase in breathing frequency. We discovered transition forms of breathing in competition exercises of Kettlebell sport. In our opinion high performance level of athletes is related to undergoing breathing regulation, trying constantly to keep same level of gas composition in functional residual capacity (FRC) at a time ofperforming competition exercises. This research highlights the importance of improving breathing patterns for Kettlebell athletes if they want to improve performance. PMID:25702464

  7. Changes in breathing pattern upon 100% oxygen in children at early school age.

    PubMed

    Jost, K; Lenherr, N; Singer, F; Schulzke, S M; Frey, U; Latzin, P; Yammine, S

    2016-07-01

    Nitrogen multiple-breath washout (N2MBW) is an increasingly used tidal breathing test in young children to assess ventilation inhomogeneity. However, the test requires 100% oxygen to perform. We aimed to examine the potential influence of pure oxygen on breathing pattern in school-aged children. We performed tidal breathing measurements under room air followed by N2MBW in 16 former preterm children and 24 healthy controls. We compared tidal volume (VT), coefficient of variation of VT (CVVT), respiratory rate (RR), and minute ventilation (VE) between tidal breathing and N2MBW, and between the start and end of tidal breathing. Mean (range) age was 6.8 (5.9, 9.0) years. VT, RR and VE showed no significant change upon oxygen-exposure, while CVVT significantly decreased by 5% (95% CI: 1.2, 9.0; p=0.012). However CVVT was also the only parameter which significantly decreased during tidal breathing. Overall, pure oxygen has no systematic effect on breathing pattern in young school-aged children. N2MBW can reliably be used as tracer gas in this age group. PMID:26970571

  8. Voluntary control of breathing does not alter vagal modulation of heart rate

    NASA Technical Reports Server (NTRS)

    Patwardhan, A. R.; Evans, J. M.; Bruce, E. N.; Eckberg, D. L.; Knapp, C. F.

    1995-01-01

    Variations in respiratory pattern influence the heart rate spectrum. It has been suggested, hence, that metronomic respiration should be used to correctly assess vagal modulation of heart rate by using spectral analysis. On the other hand, breathing to a metronome has been reported to increase heart rate spectral power in the high- or respiratory frequency region; this finding has led to the suggestion that metronomic respiration enhances vagal tone or alters vagal modulation of heart rate. To investigate whether metronomic breathing complicates the interpretation of heart rate spectra by altering vagal modulation, we recorded the electrocardiogram and respiration from eight volunteers during three breathing trials of 10 min each: 1) spontaneous breathing (mean rate of 14.4 breaths/min); 2) breathing to a metronome at the rate of 15, 18, and 21 breaths/min for 2, 6, and 2 min, respectively; and 3) breathing to a metronome at the rate of 18 breaths/min for 10 min. Data were also collected from eight volunteers who breathed spontaneously for 20 min and breathed metronomically at each subject's mean spontaneous breathing frequency for 20 min. Results from the three 10-min breathing trials showed that heart rate power in the respiratory frequency region was smaller during metronomic breathing than during spontaneous breathing. This decrease could be explained fully by the higher breathing frequencies used during trials 2 and 3 of metronomic breathing. When the subjects breathed metronomically at each subject's mean breathing frequency, the heart rate powers during metronomic breathing were similar to those during spontaneous breathing. Our results suggest that vagal modulation of heart rate is not altered and vagal tone is not enhanced during metronomic breathing.

  9. Shortness of Breath

    MedlinePlus

    ... Body & lifestyle changes > Shortness of breath Shortness of breath E-mail to a friend Please fill in ... oxygen your baby gets. Causes of shortness of breath during pregnancy Early pregnancy In the first few ...

  10. What Controls Your Breathing?

    MedlinePlus

    ... To a limited degree, you can change your breathing rate, such as by breathing faster or holding your ... oxygen levels in your blood and change your breathing rate as needed. Sensors in the airways detect lung ...

  11. Breath alcohol test

    MedlinePlus

    Alcohol test - breath ... There are various brands of breath alcohol tests. Each one uses a different method to test the level of alcohol in the breath. The machine may be electronic or manual. One ...

  12. Breath-Holding Spells

    MedlinePlus

    ... less than a minute before a child regains consciousness and resumes breathing normally. Breath-holding spells can ... spells cause kids to stop breathing and lose consciousness for up to a minute. In the most ...

  13. Rapid shallow breathing

    MedlinePlus

    Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Shallow, rapid breathing has many possible medical causes, including: Asthma Blood clot in an artery in the lung Choking Chronic obstructive ...

  14. Non-Contact Detection of Breathing Using a Microwave Sensor

    PubMed Central

    Dei, Devis; Grazzini, Gilberto; Luzi, Guido; Pieraccini, Massimiliano; Atzeni, Carlo; Boncinelli, Sergio; Camiciottoli, Gianna; Castellani, Walter; Marsili, Massimo; Dico, Juri Lo

    2009-01-01

    In this paper the use of a continuous-wave microwave sensor as a non-contact tool for quantitative measurement of respiratory tidal volume has been evaluated by experimentation in seventeen healthy volunteers. The sensor working principle is reported and several causes that can affect its response are analyzed. A suitable data processing has been devised able to reject the majority of breath measurements taken under non suitable conditions. Furthermore, a relationship between microwave sensor measurements and volume inspired and expired at quiet breathing (tidal volume) has been found. PMID:22574033

  15. Measurement of end-tidal PCO2 and PO2.

    PubMed

    Gardner, W

    1994-06-01

    This article describes the basic principles of the measurement of end-tidal carbon dioxide (CO2) and oxygen (O2) in humans. The description includes definitions of the major parameters of breathing (e.g., the composition of atmospheric air, arterial and venous blood; metabolism; lung capacity; volumetric measures of tidal volume, minute volume, and respiration frequency; pH regulation and cerebral acidity; barometric pressure and the partial pressures of CO2 and O2), the basic anatomical features of breathing, the means by which gases are exchanged between the lungs and blood, the techniques used in the measurement of respiratory variables, and the interpretation of these measurements. PMID:7918749

  16. A free-breathing lung motion model

    NASA Astrophysics Data System (ADS)

    Zhao, Tianyu

    Lung cancer has been the leading cause of cancer deaths for decades in the United States. Although radiotherapy is one of the most effective treatments, side effects from error in delivery of radiation due to organ motion during breathing remain a significant issue. To compensate the breathing motion during the treatment, a free breathing lung motion model, x= x0+αv+betaf, was developed and discussed, where x is the position of a piece of tissue located at reference position x0. α is a parameter which characterizes the motion due to local air filling (motion as a function of tidal volume) and beta is the parameter that accounts for the motion due to the imbalance of dynamical stress distributions during inspiration and exhalation which cause lung motion hysteresis (motion as a function of airflow). The parameters α and beta together provide a quantitative characterization of breathing motion that inherently includes the complex hysteresis interplay. The theoretical foundation of the model was built by investigating the stress distribution inside of a lung and the biomechanical properties of the lung tissues. Accuracy of the model was investigated by using 49 free-breathing patient data sets. Applications of the model in localizing lung cancer, monitoring radiation damage and suppressing artifacts in free-breathing PET images were also discussed. This work supported in part by NIHR01CA096679 and NIHR01CA116712.

  17. Breath holding spell

    MedlinePlus

    ... confronted Breath holding spells are more common in children with: Genetic conditions, such as Riley-Day syndrome or Rett syndrome Iron deficiency anemia A family history of breath holding spells (parents ...

  18. Minimizing Shortness of Breath

    MedlinePlus

    ... Top Doctors in the Nation Departments & Divisions Home Health Insights Stress & Relaxation Breathing and Relaxation Minimizing Shortness of Breath ... Management Assess Your Stress Coping Strategies Identifying ... & Programs Health Insights Doctors & Departments Research & Science Education & Training Make ...

  19. Breathing and Relaxation

    MedlinePlus

    ... Top Doctors in the Nation Departments & Divisions Home Health Insights Stress & Relaxation Breathing and Relaxation Breathing and Relaxation Make ... Management Assess Your Stress Coping Strategies Identifying ... & Programs Health Insights Doctors & Departments Research & Science Education & Training Make ...

  20. Fundamentals of breath malodour.

    PubMed

    Sanz, M; Roldán, S; Herrera, D

    2001-11-15

    Breath malodour is a condition that has health and social implications. The origin of breath malodour problems are related to both systemic and oral conditions. The advice of dental professionals for treatment of this condition occurs with regularity since 90% of breath odor problems emanate from the oral cavity. This paper provides a comprehensive review of the etiology of breath odor, its prevalence, diagnosis, and treatment strategies for the condition. PMID:12167916

  1. What Causes Bad Breath?

    MedlinePlus

    ... I Help a Friend Who Cuts? What Causes Bad Breath? KidsHealth > For Teens > What Causes Bad Breath? Print A A A Text Size en ... Qué es lo que provoca el mal aliento? Bad breath, or halitosis , can be a major problem, ...

  2. A Systematic Approach to Multiple Breath Nitrogen Washout Test Quality

    PubMed Central

    Klingel, Michelle; Pizarro, Maria Ester; Hall, Graham L.; Ramsey, Kathryn; Foong, Rachel; Saunders, Clare; Robinson, Paul D.; Webster, Hailey; Hardaker, Kate; Kane, Mica; Ratjen, Felix

    2016-01-01

    Background Accurate estimates of multiple breath washout (MBW) outcomes require correct operation of the device, appropriate distraction of the subject to ensure they breathe in a manner representative of their relaxed tidal breathing pattern, and appropriate interpretation of the acquired data. Based on available recommendations for an acceptable MBW test, we aimed to develop a protocol to systematically evaluate MBW measurements based on these criteria. Methods 50 MBW test occasions were systematically reviewed for technical elements and whether the breathing pattern was representative of relaxed tidal breathing by an experienced MBW operator. The impact of qualitative and quantitative criteria on inter-observer agreement was assessed across eight MBW operators (n = 20 test occasions, compared using a Kappa statistic). Results Using qualitative criteria, 46/168 trials were rejected: 16.6% were technically unacceptable and 10.7% were excluded due to inappropriate breathing pattern. Reviewer agreement was good using qualitative criteria and further improved with quantitative criteria from (κ = 0.53–0.83%) to (κ 0.73–0.97%), but at the cost of exclusion of further test occasions in this retrospective data analysis. Conclusions The application of the systematic review improved inter-observer agreement but did not affect reported MBW outcomes. PMID:27304432

  3. Breathing metabolic simulator

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    The development of a breathing metabolic simulator (BMS) is reported. This BMS simulates all of the breathing and metabolic parameters required for complete evaluation and test of life support and resuscitation equipment. It is also useful for calibrating and validating mechanical and gaseous pulmonary function test procedures. Breathing rate, breathing depth, breath velocity contour, oxygen uptake, and carbon dioxide release are all variable over wide ranges simulating conditions from sleep to hard work with respiratory exchange ratios covering the range from hypoventilation. In addition, all of these parameters are remotely controllable to facilitate use of the device in hostile or remote environments. The exhaled breath is also maintained at body temperature and a high humidity. The simulation is accurate to the extent of having a variable functional residual capacity independent of other parameters.

  4. Understanding the rhythm of breathing: so near yet so far

    PubMed Central

    Feldman, Jack L.; Del Negro, Christopher A.; Gray, Paul A.

    2013-01-01

    , responding rapidly (in less than one second) and with considerable precision, over an order of magnitude in metabolic demand for O2 (~0.25 to ~5 liters of O2/min). Breathing does indeed persist! Finally, breathing is genetically determined to work at birth, with a well-defined developmental program underlying a neuroanatomical organization with apparent segregation of function, i.e., rhythmogenesis is separate from motor pattern (burst shape and coordination) generation. Importantly, single human gene mutations can affect breathing, and several neurodegenerative disorders compromise breathing by direct effects on brainstem respiratory circuits (See below). PMID:23121137

  5. Breathing-metabolic simulator

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    Breathing-metabolic simulator was developed to be used for evaluation of life support equipment. Apparatus simulates human breathing rate and controls temperature and humidity of exhaled air as well as its chemical composition. All functions are designed to correspond to various degrees of human response.

  6. Simulated breath waveform control

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    Subsystem was developed which provides twelve waveform controls to breath drive mechanism. Twelve position, magnetically actuated rotary switch is connected to one end of crankshaft drive, such that it makes one complete revolution for each simulated breath. Connections with common wired point are included in modifications made to standard motor speed controller.

  7. Breath holding spell

    MedlinePlus

    ... children with: Genetic conditions, such as Riley-Day syndrome or Rett syndrome Iron deficiency anemia A family history of breath ... Editorial team. Related MedlinePlus Health Topics Breathing Problems Rett Syndrome Browse the Encyclopedia A.D.A.M., Inc. ...

  8. Effect of a deep breath on gas mixing and diffusion in the lung.

    PubMed

    Prabhu, M B; Mink, J T; Graham, B L; Cotton, D J

    1990-03-01

    We examined the effect of a previous deep breath on both inert gas mixing and the single breath diffusing capacity (DLCOSB) during submaximal single breath maneuvers in normal subjects. Single breath washouts were performed either immediately after a deep breath or after breathing tidally for 10 min. Maneuvers consisted of inhaling test gas from functional residual capacity to 50% inspiratory capacity and, after either 0 or 6 s of breath holding, exhaling slowly back to residual volume. We measured the Fowler dead space, the Phase III slope of the alveolar plateau of the He washout (delta He/L), the amplitude of the cardiogenic oscillations (Oc), closing capacity, mixing efficiency (Emix) and DLCOSB using the three equation method. For maneuvers immediately after a deep breath we found that delta He/L was steeper and the Oc were larger for washouts with 6 s but not 0 s of breath holding, while Emix was significantly lower and DLCOSB significantly higher for both the 0 s and the 6 s breath holding maneuvers. We conclude that a deep breath increases DLCOSB but simultaneously also increases convective-dependent inhomogeneity in the lung. PMID:2356360

  9. Initial mechanical ventilator settings for pediatric patients: clinical judgement in selection of tidal volume.

    PubMed

    Kanter, R K; Blatt, S D; Zimmerman, J J

    1987-03-01

    Guidelines for selection of initial mechanical ventilator settings for pediatric patients were evaluated. Protocols specifying tidal volume or peak inspiratory pressure are difficult to apply for infants and children because of leaks at uncuffed endotracheal tubes, compression loss in ventilators, and inaccuracy of settings for intended tidal volume. To avoid these difficulties, the selection of tidal volume was based on subjective clinical observations: visible chest excursion and audible air entry at least simulating normal breathing. In 76 consecutive patients, use of the guidelines resulted in satisfactory PaCO2 for 97% and PaO2 for 89% of infants and children with a wide variety of respiratory disorders. Adequacy of gas exchange was not related to the patient's age, type of ventilator, tightness of fit of the endotracheal tube, or presence of spontaneous breathing. These results support a simple, versatile method of teaching selection of initial mechanical ventilator settings, relying on clinical judgment for regulation of tidal volume. PMID:3470010

  10. Dynamic diaphragmatic MRI during apnea struggle phase in breath-hold divers.

    PubMed

    Batinic, Tonci; Mihanovic, Frane; Breskovic, Toni; Zubin-Maslov, Petra; Lojpur, Mihajlo; Mijacika, Tanja; Dujic, Zeljko

    2016-02-01

    The purpose of the study was to provide insight in diaphragmatic involuntary breathing movements (IBM) during struggle phase of apnea at total lung capacity (TLC) and functional residual capacity (FRC) using magnetic resonance imaging along with measurements of hemodynamics and arterial oxygenation. The study was performed in eight elite breath-hold divers. There was a similar increase in diaphragmatic cranio-caudal excursions towards the end of TLC and FRC apnea. The greatest diaphragmatic excursion in both apneas and during tidal breathing was in the middle and posterior part of the diaphragm. Diaphragm thickness in elite BHD was within the reference range of normal values suggesting no diaphragmatic hypertrophy in this population. We found that the range of diaphragmatic excursions increases toward the end of apneas. Additionally, our data suggest that the diaphragm participates in IBM occurrence and that various segments of the diaphragm behave nonhomogenously both in tidal breathing and IBMs. PMID:26644078

  11. Breathing metabolic simulator.

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G., Jr.; Hendricks, C. M.; Morison, W. B.

    1971-01-01

    Description of a device for simulation of the human breathing and metabolic parameters required for the evaluation of respiratory diagnostic, monitoring, support and resuscitation equipment. The remotely controlled device allows wide variations in breathing rate and depth, breath velocity contour, oxygen uptake and carbon dioxide release to simulate conditions from sleep to hard work, with respiration exchange ratios ranging from hypoventilation to hyperventilation. It also reduces the cost of prolonged testing when simulation chambers with human subjects require three shifts of crews and standby physicians. Several block diagrams of the device and subsystems are given.

  12. Breathing patterns during eccentric exercise.

    PubMed

    Lechauve, J B; Perrault, H; Aguilaniu, B; Isner-Horobeti, M E; Martin, V; Coudeyre, E; Richard, R

    2014-10-01

    Eccentric (ECC) work is interesting for rehabilitation purposes because it is more efficient than concentric (CON). This study assessed respiratory patterns and electromyographic activity (EMG) during ECC and CON cycling, both at similar power outputs and VO2 in eight healthy male subjects. Measurements include ventilation (VE), tidal volume (Vt), breathing frequency (Fb), arterial blood gases, and vastus lateralis (VL) and biceps brachii (BB) EMG. At the same mechanical power, VO2 and VE were fivefold lower in ECC as was VL EMG while BB EMG, Vd/Vt, PaO2 and PaCO2, were not different between modalities. At the same VO2, there was no difference in VE but Vt was lower and Fb higher in ECC. VL EMG was not different between modalities while BB EMG was higher in ECC. The latter observation suggests that ECC cycling may result in arm bracing and restricted chest expansion. Since hyperpnea is a known trigger of exaggerated dynamic hyperinflation, the prescription of ECC cycling for patient rehabilitation requires further assessment. PMID:25083913

  13. Breathing pattern and exercise endurance time after exhausting cycling or breathing.

    PubMed

    Spengler, C M; Knöpfli-Lenzin, C; Birchler, K; Trapletti, A; Boutellier, U

    2000-03-01

    The aim of the present study was to investigate whether the changes in breathing pattern that frequently occur towards the end of exhaustive exercise (i.e., increased breathing frequency, fb, with or without decreased tidal volume) may be caused by the respiratory work itself rather than by leg muscle work. Eight healthy, trained subjects performed the following three sessions in random order: (A) two sequential cycling endurance tests at 78% peak O2 consumption (VO2peak) to exhaustion (A1, A2); (B) isolated, isocapnic hyperpnea (B1) at a minute ventilation (VE) and an exercise duration similar to that attained during a preliminary cycling endurance test at 78% VO2peak, followed by a cycling endurance test at 78% VO2peak (B2); (C) isolated, isocapnic hyperpnea (C1) at a VE at least 20% higher than that of the preliminary cycling test and the same exercise duration as the preliminary cycling test, followed by a cycling endurance test at 78% VO2peak (C2). Neither of the two isocapnic hyperventilation tasks (B1 or C1) affected either the breathing pattern or the endurance times of the subsequent cycling tests. Only cycling test A2 was significantly shorter [mean (SD) 26.5 (8.3) min] than tests A1 [41.0(9.0) min], B2 [41.9 (6.0) min], and C2 [42.0 (7.5) min]. In addition, compared to test A1, only the breathing pattern of test A2 was significantly different [i.e., VE: + 10.5 (7.6) 1 min(-1), and fb: + 12.1 (8.5) breaths min(-1)], in contrast to the breathing patterns of cycling tests B2 [VE: -2.5 (6.2) 1 min(-1), f(b): +0.2 (3.6) breaths min(-1)] and C2 [VE: -3.0 (7.0) 1 min(-1), fb: +0.6 (6.1) breaths min(-1)]. In summary, these results suggest that the changes in breathing pattern that occur towards the end of an exhaustive exercise test are a result of changes in the leg muscles rather than in the respiratory muscles themselves. PMID:10751097

  14. Breathing difficulties - first aid

    MedlinePlus

    ... a high altitude Blood clot in the lung Collapsed lung (pneumothorax) Heart attack Injury to the neck, chest wall, ... cavity with each breath. This can cause a collapsed lung . Bandage the wound with plastic wrap, a plastic ...

  15. Breathing - slowed or stopped

    MedlinePlus

    ... can occur with obstructive sleep apnea, for example. Prolonged apnea means a person has stopped breathing. If ... that requires immediate medical attention and first aid. Prolonged apnea with no heart activity in a person ...

  16. Shortness-of-Breath

    MedlinePlus

    ... can lead to shortness of breath include anxiety, panic attacks, anemia and even constipation. The experience of shortness ... are used to treat patients with anxiety or panic attacks. Other commonly used drugs include bronchodilators to widen ...

  17. Shortness of Breath

    MedlinePlus

    ... deep breath, which usually results in retention of carbon dioxide and not enough oxygen in blood (obesity hypoventilation ... for anemia), and oximetry or blood oxygen or carbon dioxide levels. Your doctor also may obtain a chest ...

  18. Tidal alignment of galaxies

    NASA Astrophysics Data System (ADS)

    Blazek, Jonathan; Vlah, Zvonimir; Seljak, Uroš

    2015-08-01

    We develop an analytic model for galaxy intrinsic alignments (IA) based on the theory of tidal alignment. We calculate all relevant nonlinear corrections at one-loop order, including effects from nonlinear density evolution, galaxy biasing, and source density weighting. Contributions from density weighting are found to be particularly important and lead to bias dependence of the IA amplitude, even on large scales. This effect may be responsible for much of the luminosity dependence in IA observations. The increase in IA amplitude for more highly biased galaxies reflects their locations in regions with large tidal fields. We also consider the impact of smoothing the tidal field on halo scales. We compare the performance of this consistent nonlinear model in describing the observed alignment of luminous red galaxies with the linear model as well as the frequently used "nonlinear alignment model," finding a significant improvement on small and intermediate scales. We also show that the cross-correlation between density and IA (the "GI" term) can be effectively separated into source alignment and source clustering, and we accurately model the observed alignment down to the one-halo regime using the tidal field from the fully nonlinear halo-matter cross correlation. Inside the one-halo regime, the average alignment of galaxies with density tracers no longer follows the tidal alignment prediction, likely reflecting nonlinear processes that must be considered when modeling IA on these scales. Finally, we discuss tidal alignment in the context of cosmic shear measurements.

  19. Archosaurian respiration and the pelvic girdle aspiration breathing of crocodyliforms.

    PubMed Central

    Claessens, Leon P. A. M.

    2004-01-01

    Birds and crocodylians, the only living archosaurs, are generally believed to employ pelvic girdle movements as a component of their respiratory mechanism. This in turn provides a phylogenetic basis for inferring that extinct archosaurs, including dinosaurs, also used pelvic girdle breathing. I examined lung ventilation through cineradiography (high-speed X-ray filming) and observed that alligators indeed rotate the pubis to increase tidal volume, but did not observe pelvic girdle movement contributing to lung ventilation in guinea fowl, emus or tinamous, despite extensive soft-tissue motion. Re-examination of fossil archosaurs reveals that pubic rotation evolved in basal crocodyliforms and that pelvic girdle breathing is not a general archosaurian mechanism. The appearance of pelvic aspiration in crocodyliforms is a striking example of the ability of amniotes to increase gas exchange or circumvent constraints on respiration through the evolution of novel accessory breathing mechanisms. PMID:15306317

  20. Breathing patterns after mid-cervical spinal contusion in rats

    PubMed Central

    Golder, FJ; Fuller, DD; Lovett-Barr, MR; Vinit, S; Resnick, DK; Mitchell, GS

    2011-01-01

    Respiratory failure is the leading cause of death after cervical spinal injury. We hypothesized that incomplete cervical spinal injuries would alter respiratory pattern and initiate plasticity in the neural control of breathing. Further, we hypothesized that the severity of cervical spinal contusion would correlate with changes in breathing pattern. Fourteen days after C4–C5 contusions, respiratory frequency and tidal volume were measured in unanesthetized Sprague Dawley rats in a whole body plethysmograph. Phrenic motor output was monitored in the same rats which were anesthetized, vagotomized, paralyzed and ventilated to eliminate and/or control sensory feedback that could alter breathing patterns. The extent of spinal injury was approximated histologically by measurements of the injury-induced cyst area in transverse sections; cysts ranged from 2 to 28% of spinal cross-sectional area, and had a unilateral bias. In unanesthetized rats, the severity of spinal injury correlated negatively with tidal volume (R2=0.85; p<0.001) and positively with breathing frequency (R2=0.65; p<0.05). Thus, the severity of C4–C5 spinal contusion dictates post-injury breathing pattern. In anesthetized rats, phrenic burst amplitude was decreased on the side of injury, and burst frequency correlated negatively with contusion size (R2=0.51; p<0.05). A strong correlation between unanesthetized breathing pattern and the pattern of phrenic bursts in anesthetized, vagotomized and ventilated rats suggests that changes in respiratory motor output after spinal injury reflect, at least in part, intrinsic neural mechanisms of CNS plasticity initiated by injury. PMID:21683697

  1. Limits to Tidal Power

    NASA Astrophysics Data System (ADS)

    Garrett, C.

    2008-12-01

    Ocean tides have been proposed as a source of renewable energy, though the maximum available power may be shown to be only a fraction of the present dissipation rate of 3.5 TW, which is small compared with global insolation (nearly 105 TW), wind dissipation (103 TW), and even human power usage of 15 TW. Nonetheless, tidal power could be a useful contributor in some locations. Traditional use of tidal power, involving the trapping of water behind a barrage at high tide, can produce an average power proportional to the area of the headpond and the square of the tidal range; the power density is approximately 6 W per square meter for a tidal range of 10 m. Capital costs and fears of environmental damage have put barrage schemes in disfavor, with interest turning to the exploitation of strong tidal currents, using turbines in a manner similar to wind turbines. There is a limit to the available power, however, as adding turbines reduces the flow, ultimately reducing the power. For sinusoidal forcing of flow in a channel connecting two large open basins, the maximum available power may be shown to be given approximately by 0.2ρ g a Q_max, where ρ is the water density, g gravity, a the amplitude of the tidal sea level difference along the channel, and Q_max is the maximum volume flux in the natural state. The same formula applies if the channel is the entrance to a semi-enclosed basin, with a now the amplitude of the external tide. A flow reduction of approximately 40% is typically associated with the maximum power extraction. The power would be reduced if only smaller environmental changes are acceptable, and reduced further by drag on supporting structures, dissipation in turbine wakes, and internal inefficiencies. It can be suggested that the best use of strong, cold, tidal currents is to provide cooling water for nuclear reactors.

  2. Tidal Disruption Events

    NASA Astrophysics Data System (ADS)

    Gezari, Suvi

    2013-12-01

    The majority of supermassive black holes in the Universe lie dormant and starved of fuel. These hidden beasts can be temporarily illuminated when an unlucky star passes close enough to be tidally disrupted and consumed by the black hole. Theorists first proposed in 1975 that tidal disruption events should be an inevitable consequence of supermassive black holes in galaxy nuclei and later argued that the resulting flare of radiation from the accretion of the stellar debris could be a unique signpost for the presence of a dormant black hole in the center of a normal galaxy. It was not until over two decades later that the first convincing tidal disruption event candidates emerged in the X-rays by the ROSAT All-Sky Survey. Since then, over a dozen total candidates have now emerged from searches across the electromagnetic spectrum, including the X-rays, the ultraviolet, and the optical. In the last couple of years, we have also witnessed a paradigm shift with the discovery of relativistic beamed emission associated with tidal disruption events. I review the census of observational candidates to date and discuss the exciting prospects for using large samples of tidal disruption events discovered with the next-generation of ground-based and space-based synoptic surveys to probe accretion disk and/or jet formation and black hole demographics.

  3. Cosmic tidal reconstruction

    NASA Astrophysics Data System (ADS)

    Zhu, Hong-Ming; Pen, Ue-Li; Yu, Yu; Er, Xinzhong; Chen, Xuelei

    2016-05-01

    The gravitational coupling of a long-wavelength tidal field with small-scale density fluctuations leads to anisotropic distortions of the locally measured small-scale matter correlation function. Since the local correlation function is known to be statistically isotropic in the absence of such tidal interactions, the tidal distortions can be used to reconstruct the long-wavelength tidal field and large-scale density field in analogy with the cosmic microwave background lensing reconstruction. In this paper we present the theoretical framework of cosmic tidal reconstruction and test the reconstruction in numerical simulations. We find that the density field on large scales can be reconstructed with good accuracy and the cross-correlation coefficient between the reconstructed density field and the original density field is greater than 0.9 on large scales (k ≲0.1 h /Mpc ), with the filter scale ˜1.25 Mpc /h . This is useful in the 21 cm intensity mapping survey, where the long-wavelength radial modes are lost due to a foreground subtraction process.

  4. The effect of inspiratory muscle fatigue on breathing pattern and ventilatory response to CO2.

    PubMed Central

    Mador, M J; Tobin, M J

    1992-01-01

    1. The effects of inducing inspiratory muscle fatigue on the subsequent breathing pattern were examined during resting unstimulated breathing and during CO2 rebreathing. In addition, we examined whether induction of inspiratory muscle fatigue alters CO2 responsiveness. 2. Global inspiratory muscle fatigue and diaphragmatic fatigue were achieved by having subjects breathe against an inspiratory resistive load while generating a predetermined fraction of either their maximal mouth pressure or maximal transdiaphragmatic pressure until they were unable to generate the target pressure. 3. Induction of inspiratory muscle fatigue had no effect on the subsequent breathing pattern during either unstimulated breathing or during CO2 rebreathing. 4. Following induction of inspiratory muscle fatigue, the slope of the ventilatory response to CO2 was significantly decreased from 18.8 +/- 3.3 during control to 13.8 +/- 2.1 l min-1 (% end-tidal CO2 concentration)-1 with fatigue (P < 0.02). PMID:1484352

  5. A miniature optical breathing sensor

    PubMed Central

    Mathew, Jinesh; Semenova, Yuliya; Farrell, Gerald

    2012-01-01

    We demonstrate a novel miniature optical breathing sensor based on an Agarose infiltrated photonic crystal fiber interferometer. The sensor detects the variation in relative humidity that occurs between inhaled and exhaled breath. The sensor interrogation system can determine the breathing pattern in real time and can also predict the breathing rate and the breathing status during respiration. The sensor is suitable for monitoring patients during a magnetic resonance imaging scan where use of sedatives and anesthetics necessitates breathing monitoring; electronic sensors are not suitable in such an environment and a visual observation of the patient's respiratory efforts is often difficult. PMID:23243581

  6. Breathing: Rhythmicity, Plasticity, Chemosensitivity

    PubMed Central

    Feldman, Jack L.; Mitchell, Gordon S.; Nattie, Eugene E.

    2010-01-01

    Breathing is a vital behavior that is particularly amenable to experimental investigation. We review recent progress on three problems of broad interest. (i) Where and how is respiratory rhythm generated? The preBötzinger Complex is a critical site, whereas pacemaker neurons may not be essential. The possibility that coupled oscillators are involved is considered. (ii) What are the mechanisms that underlie the plasticity necessary for adaptive changes in breathing? Serotonin-dependent long-term facilitation following intermittent hypoxia is an important example of such plasticity, and a model that can account for this adaptive behavior is discussed. (iii) Where and how are the regulated variables CO2 and pH sensed? These sensors are essential if breathing is to be appropriate for metabolism. Neurons with appropriate chemosensitivity are spread throughout the brainstem; their individual properties and collective role are just beginning to be understood. PMID:12598679

  7. Tidally Heated Terrestrial Exoplanets

    NASA Astrophysics Data System (ADS)

    Henning, Wade Garrett

    This work models the surface and internal temperatures for hypothetical terrestrial planets in situations involving extreme tidal heating. The feasibility of such planets is evaluated in terms of the orbital perturbations that may give rise to them, their required proximity to a hoststar, and the potential for the input tidal heating to cause significant partial melting of the mantle. Trapping terrestrial planets into 2:1 resonances with migrating Hot Jupiters is considered as a reasonable way for Earth-like worlds to both maintain high eccentricities and to move to short enough orbital periods (1-20 days) for extreme tidal heating to occur. Secular resonance and secular orbital perturbations may support moderate tidal heating at a low equilibrium eccentricity. At orbital periods below 10-30 days, with eccentricities from 0.01 to 0.1, tidal heat may greatly exceed radiogenic heat production. It is unlikely to exceed insolation, except when orbiting very low luminosity hosts, and thus will have limited surface temperature expression. Observations of such bodies many not be able to detect tidal surface enhancements given a few percent uncertainty in albedo, except on the nightside of spin synchronous airless objects. Otherwise detection may occur via spectral detection of hotspots or high volcanic gas concentrations including sulfur dioxide and hydrogen sulfide. The most extreme cases may be able to produce magma oceans, or magma slush mantles with up to 40-60% melt fractions. Tides may alter the habitable zones for smaller red dwarf stars, but are generally detrimental. Multiple viscoelastic models, including the Maxwell, Voigt-Kelvin, Standard Anelastic Solid, and Burgers rheologies are explored and applied to objects such as Io and the super-Earth planet GJ 876d. The complex valued Love number for the Burgers rheology is derived and found to be a useful improvement when modeling the low temperature behavior of tidal bodies, particularly during low eccentricity

  8. Reliability of respiratory tidal volume estimation by means of ambulatory inductive plethysmography.

    PubMed

    Grossman, Paul; Spoerle, Monika; Wilhelm, Frank H

    2006-01-01

    Ambulatory monitoring of ventilatory parameters in everyday life, field research and clinical situations may offer new insights into respiratory functioning in health and disease. Recent technological advances that employ ambulatory inductive plethysmography could make monitoring of respiration outside the clinic and laboratory feasible. Inductive plethysmography provides a method for nonintrusive assessment of both timing (e.g. respiration rate) and volumetric parameters (e.g. tidal volume and minute ventilation), by which tidal volume is initially calibrated to direct measures of volume. Estimates of tidal volume assessed by this technique have been validated in laboratory investigations, usually examining within-individual relations to direct measures over a large range of tidal volume variation. However, the reliability of individual differences in tidal volume or other breathing parameters has not been tested under naturalistic measurement conditions using inductive plethysmography. We examined the test-retest reliability of respiration rate, tidal volume and other volumetric parameters of breathing over a period of six weeks of repeated measurements during baseline conditions and breathing exercises with 16 healthy freely moving volunteers in a Yoga course. Reliability of measurement was evaluated by calculating the average week-to-week between-subject correlation coefficients for each physiological measure. Additionally because body-mass index has been previously positively correlated to tidal volume, we also assessed this relationship as an external criterion of validity of tidal volume estimation. Regarding the latter, similar correlations to those previous studies were found (r = 0.6). Furthermore, reliability estimates were high and consistent across respiratory measures (typically r's = 0.7-0.8). These results suggest the validity of ambulatory inductive plethysmographic measurement of respiration, at least under relatively sedentary conditions

  9. Ionospheric response to tidal waves measured by dynasonde techniques

    NASA Astrophysics Data System (ADS)

    Negrea, Cǎtǎlin; Zabotin, Nikolay; Bullett, Terence; Codrescu, Mihail; Fuller-Rowell, Tim

    2016-01-01

    Atmospheric tides are known to have a dramatic influence on thermospheric and ionospheric structure and variability. Considerable effort goes into understanding characteristics of tidal modes, their interactions with planetary and gravity waves and other tidal modes, as well as their influence on the background state of the thermosphere-ionosphere system. For the altitude interval between roughly 120 and 400 km, this effort is somewhat hindered by the lack of global observations. We propose a new method of determining tidal variability by making use of dynasonde measurements. The NeXtYZ inversion procedure produces altitude profiles of the ionospheric parameters with a vertical resolution typically better than 1 km. This, together with the typical 2 min cadence of the instrument, results in extensive data sets with wide temporal and altitude coverage. At any given altitude we have nonuniform sampling due to the natural ionospheric variability. A Lomb-Scargle implementation is used to obtain equivalent results at all altitudes and locations. We report height profiles of the first three tidal harmonics derived from dynasonde measurements. The data analyzed include the vertical electron density profiles, the ionospheric X (east-west) "tilt" measurement, and the derived zonal plasma density gradient. Both the tilt and the gradient are shown to be sensitive tracers of atmospheric waves. We use data from Wallops Island and San Juan, for two time intervals: 6 May- 6 June and 9 October- 8 November 2013, thus capturing seasonal, latitudinal, and altitude variations of tidal amplitude and phase. This proves the potential of using dynasonde-capable instruments as a data source for tidal studies in the thermosphere.

  10. Tidal Dissipation in Mercury

    NASA Technical Reports Server (NTRS)

    Bills, B. G.

    2002-01-01

    The spatial pattern and total inventory of tidal dissipation within Mercury depends sensitively on internal structure and on orbital eccentricity. Surface heat flow from this source may exceed 3 mW/sq m, and will vary with time as the orbital eccentricity fluctuates. Additional information is contained in the original extended abstract.

  11. Life and Breath

    ERIC Educational Resources Information Center

    Ellis, Helen D.

    1974-01-01

    This article describes a public education program combining the screening process and a follow-up program for teaching victims of emphysema and other respiratory diseases how to better their living condition through proper breathing, avoidance of air pollutants and cigarette smoking, and taking better care of themselves physically. (PD)

  12. Metabolic breath analyzer

    NASA Technical Reports Server (NTRS)

    Perry, C. L.

    1971-01-01

    Instrument measures metabolic breathing rate and dynamics of human beings in atmospheres ranging from normal air to 100 percent oxygen at ambient pressures from 14.7 to 3.0 psia. Measurements are made at rest or performing tasks up to maximum physical capacity under either zero or normal gravity.

  13. Firefighter's Breathing System

    NASA Technical Reports Server (NTRS)

    Mclaughlan, P. B.; Giorgini, E. A.; Sullivan, J. L.; Simmonds, M. R.; Beck, E. J.

    1976-01-01

    System, based on open-loop demand-type compressed air concept, is lighter and less bulky than former systems, yet still provides thirty minutes of air supply. Comfort, visibility, donning time, and breathing resistance have been improved. Apparatus is simple to recharge and maintain and is comparable in cost to previously available systems.

  14. INTERMITTENT POSITIVE PRESSURE BREATHING

    EPA Science Inventory

    Efficacy of long-term intermittent positive pressure breathing (IPPB) treatment when used as an adjunct to the overall care of ambulatory outpatients with chronic obstructive pulmonary disease. The evaluation compared the use of IPPB with use of a powered nebulizer.

  15. Breathing Like a Fish

    ERIC Educational Resources Information Center

    Katsioloudis, Petros J.

    2010-01-01

    Being able to dive and breathe underwater has been a challenge for thousands of years. In 1980, Fuji Systems of Tokyo developed a series of prototype gills for divers as a way of demonstrating just how good its membranes are. Even though gill technology has not yet reached the point where recipients can efficiently use implants to dive underwater,…

  16. Oronasal breathing during exercise.

    PubMed

    Saibene, F; Mognoni, P; Lafortuna, C L; Mostardi, R

    1978-12-15

    The shift from nasal to oronasal breathing (ONBS) has been observed on 73 subjects with two independent methods. A first group of 63 subjects exercising on a bicycle ergometer at increasing work load (98--196 W) has been observed. On 35 subjects the highest value of ventilation attained with nasal breathing was 40.2 +/- 9.41 . min-1 S.D. Ten subjects breathed through the mouth at all loads, while 5 never opened the mouth. On 13 subjects it was not possible to make reliable measurements. On a second group of 10 subjects utilizing a different techniques which did not need a face mask, the ventilation at which one changes the pattern of breathing was found to be 44.2 +/- 13.51 . min-1 S.D. On the same subjects nasal resistance did not show any correlation with ONBS. It is concluded that ONBS is not solely determined by nasal resistance, though an indirect effect due to hypoventilation and hence to changes in alveolar air composition cannot be ruled out. It is likely that ONBS is also influenced by psychological factors. PMID:569826

  17. Sigh-induced changes of breathing pattern in preterm infants

    PubMed Central

    Jost, Kerstin; Latzin, Philipp; Fouzas, Sotirios; Proietti, Elena; Delgado-Eckert, Edgar W; Frey, Urs; Schulzke, Sven M

    2015-01-01

    Sighs are thought to play an important role in control of breathing. It is unclear how sighs are triggered, and whether preterm birth and lung disease influence breathing pattern prior to and after a sigh in infants. To assess whether frequency, morphology, size, and short-term variability in tidal volume (VT) before, during, and after a sigh are influenced by gestational age at birth and lung disease (bronchopulmonary dysplasia, BPD) in former preterm infants and healthy term controls measured at equivalent postconceptional age (PCA). We performed tidal breathing measurements in 143 infants during quiet natural sleep at a mean (SD) PCA of 44.8 (1.3) weeks. A total of 233 sighs were analyzed using multilevel, multivariable regression. Sigh frequency in preterm infants increased with the degree of prematurity and severity of BPD, but was not different from that of term controls when normalized to respiratory rate. After a sigh, VT decreased remarkably in all infants (paired t-test: P < 0.001). There was no major effect of prematurity or BPD on various indices of sigh morphology and changes in VT prior to or after a sigh. Short-term variability in VT modestly increased with maturity at birth and infants with BPD showed an earlier return to baseline variability in VT following a sigh. In early infancy, sigh-induced changes in breathing pattern are moderately influenced by prematurity and BPD in preterm infants. The major determinants of sigh-related breathing pattern in these infants remain to be investigated, ideally using a longitudinal study design. PMID:26564066

  18. Breathing-Synchronized Delivery: A Potential Four-Dimensional Tomotherapy Treatment Technique

    SciTech Connect

    Zhang Tiezhi . E-mail: tiezhi.zhang@beaumont.edu; Lu Weiguo; Olivera, Gustavo H.; Keller, Harry; Jeraj, Robert; Manon, Rafael; Mehta, Minesh; Mackie, Thomas R.; Paliwal, Bhudatt

    2007-08-01

    Purpose: To introduce a four-dimensional (4D) tomotherapy treatment technique with improved motion control and patient tolerance. Methods and Materials: Computed tomographic images at 10 breathing phases were acquired for treatment planning. The full exhalation phase was chosen as the planning phase, and the CT images at this phase were used as treatment-planning images. Region of interest delineation was the same as in traditional treatment planning, except that no breathing motion margin was used in clinical target volume-planning target volume expansion. The correlation between delivery and breathing phases was set assuming a constant gantry speed and a fixed breathing period. Deformable image registration yielded the deformation fields at each phase relative to the planning phase. With the delivery/breathing phase correlation and voxel displacements at each breathing phase, a 4D tomotherapy plan was obtained by incorporating the motion into inverse treatment plan optimization. A combined laser/spirometer breathing tracking system has been developed to monitor patient breathing. This system is able to produce stable and reproducible breathing signals representing tidal volume. Results: We compared the 4D tomotherapy treatment planning method with conventional tomotherapy on a static target. The results showed that 4D tomotherapy can achieve dose distributions on a moving target similar to those obtained with conventional delivery on a stationary target. Regular breathing motion is fully compensated by motion-incorporated breathing-synchronized delivery planning. Four-dimensional tomotherapy also has close to 100% duty cycle and does not prolong treatment time. Conclusion: Breathing-synchronized delivery is a feasible 4D tomotherapy treatment technique with improved motion control and patient tolerance.

  19. Imposed Work of Breathing for Flow Meters with In-Line versus Flow-Through Technique during Simulated Neonatal Breathing

    PubMed Central

    2015-01-01

    Background The ability to determine airflow during nasal CPAP (NCPAP) treatment without adding dead space or resistance would be useful when investigating the physiologic effects of different NCPAP systems on breathing. The aim of this study was to investigate the effect on pressure stability of different flow measuring devices at the in-line and flow-through position, using simulated neonatal breathing. Methods Six different flow measure devices were evaluated by recording pressure changes and imposed work of breathing for breaths with 16 and 32 ml tidal volumes. The tests were performed initially with the devices in an in line position and with 5 and 10 L/min using flow through technique, without CPAP. The flow meters were then subsequently tested with an Infant Flow CPAP system at 3, 5 and 8 cm H2O pressure using flow through technique. The quality of the recorded signals was compared graphically. Results The resistance of the measuring devices generated pressure swings and imposed work of breathing. With bias flow, the resistance also generated CPAP pressure. Three of the devices had low resistance and generated no changes in pressure stability or CPAP pressure. The two devices intended for neonatal use had the highest measured resistance. Conclusion The importance of pressure stability and increased work of breathing during non-invasive respiratory support are insufficiently studied. Clinical trials using flow-through technique have not focused on pressure stability. Our results indicate that a flow-through technique might be a way forward in obtaining a sufficiently high signal quality without the added effects of rebreathing and increased work of breathing. The results should stimulate further research and the development of equipment for dynamic flow measurements in neonates. PMID:26192188

  20. Combined sensing platform for advanced diagnostics in exhaled mouse breath

    NASA Astrophysics Data System (ADS)

    Fortes, Paula R.; Wilk, Andreas; Seichter, Felicia; Cajlakovic, Merima; Koestler, Stefan; Ribitsch, Volker; Wachter, Ulrich; Vogt, Josef; Radermacher, Peter; Carter, Chance; Raimundo, Ivo M.; Mizaikoff, Boris

    2013-03-01

    Breath analysis is an attractive non-invasive strategy for early disease recognition or diagnosis, and for therapeutic progression monitoring, as quantitative compositional analysis of breath can be related to biomarker panels provided by a specific physiological condition invoked by e.g., pulmonary diseases, lung cancer, breast cancer, and others. As exhaled breath contains comprehensive information on e.g., the metabolic state, and since in particular volatile organic constituents (VOCs) in exhaled breath may be indicative of certain disease states, analytical techniques for advanced breath diagnostics should be capable of sufficient molecular discrimination and quantification of constituents at ppm-ppb - or even lower - concentration levels. While individual analytical techniques such as e.g., mid-infrared spectroscopy may provide access to a range of relevant molecules, some IR-inactive constituents require the combination of IR sensing schemes with orthogonal analytical tools for extended molecular coverage. Combining mid-infrared hollow waveguides (HWGs) with luminescence sensors (LS) appears particularly attractive, as these complementary analytical techniques allow to simultaneously analyze total CO2 (via luminescence), the 12CO2/13CO2 tracer-to-tracee (TTR) ratio (via IR), selected VOCs (via IR) and O2 (via luminescence) in exhaled breath, yet, establishing a single diagnostic platform as both sensors simultaneously interact with the same breath sample volume. In the present study, we take advantage of a particularly compact (shoebox-size) FTIR spectrometer combined with novel substrate-integrated hollow waveguide (iHWG) recently developed by our research team, and miniaturized fiberoptic luminescence sensors for establishing a multi-constituent breath analysis tool that is ideally compatible with mouse intensive care stations (MICU). Given the low tidal volume and flow of exhaled mouse breath, the TTR is usually determined after sample collection via gas

  1. Developments in tidal power

    NASA Astrophysics Data System (ADS)

    Charlier, R. H.

    Successful, planned, and potential tidal power plants and sites are discussed. Units are in operation in France and Russia, with the French plant using reversible blade turbines being used as a design guide for plants in Argentina and Australia. The U.S. is studying the feasibility of a plant in Passamaquaddy Bay, and Canada is pursuing construction of a plant in the Bay of Fundy. The Severn River in Great Britain is receiving a site study, and over a hundred plants have been built as local power systems in China. Bulb-type turbines, which enhance the volume emptying and filling the retaining basin, are considered as the highest performing power unit. Simpler one-way flow turbines have been suggested as more economical to install. Governmental, institutional, and investor impediments to tidal power plant are explored.

  2. Mapleson's Breathing Systems

    PubMed Central

    Kaul, Tej K; Mittal, Geeta

    2013-01-01

    Mapleson breathing systems are used for delivering oxygen and anaesthetic agents and to eliminate carbon dioxide during anaesthesia. They consist of different components: Fresh gas flow, reservoir bag, breathing tubes, expiratory valve, and patient connection. There are five basic types of Mapleson system: A, B, C, D and E depending upon the different arrangements of these components. Mapleson F was added later. For adults, Mapleson A is the circuit of choice for spontaneous respiration where as Mapleson D and its Bains modifications are best available circuits for controlled ventilation. For neonates and paediatric patients Mapleson E and F (Jackson Rees modification) are the best circuits. In this review article, we will discuss the structure of the circuits and functional analysis of various types of Mapleson systems and their advantages and disadvantages. PMID:24249884

  3. Emergency Response Breathing Apparatus

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Aerospace Design & Development, Inc.'s (ADD's) SCAMP was developed under an SBIR contract through Kennedy Space Center. SCAMP stands for Supercritical Air Mobility Pack. The technology came from the life support fuel cell support systems used for the Apollo and Space Shuttle programs. It uses supercritical cryogenic air and is able to function in microgravity environments. SCAMP's self-contained breathing apparatus(SCBA) systems are also ground-based and can provide twice as much air than traditional SCBA's due to its high-density capacity. The SCAMP system was designed for use in launch pad emergency rescues. ADD also developed a protective suit for use with SCAMP that is smaller and lighter system than the old ones. ADD's SCAMP allows for body cooling and breathing from the supercritical cryogenic air, requiring no extra systems. The improvement over the traditional SCBA allows for a reduction of injuries, such as heat stress, and makes it easier for rescuers to save lives.

  4. Relativistic tidal disruption events

    NASA Astrophysics Data System (ADS)

    Levan, A.

    2012-12-01

    In March 2011 Swift detected an extremely luminous and long-lived outburst from the nucleus of an otherwise quiescent, low luminosity (LMC-like) galaxy. Named Swift J1644+57, its combination of high-energy luminosity (1048 ergs s-1 at peak), rapid X-ray variability (factors of >100 on timescales of 100 seconds) and luminous, rising radio emission suggested that we were witnessing the birth of a moderately relativistic jet (Γ ˜ 2 - 5), created when a star is tidally disrupted by the supermassive black hole in the centre of the galaxy. A second event, Swift J2058+0516, detected two months later, with broadly similar properties lends further weight to this interpretation. Taken together this suggests that a fraction of tidal disruption events do indeed create relativistic outflows, demonstrates their detectability, and also implies that low mass galaxies can host massive black holes. Here, I briefly outline the observational properties of these relativistic tidal flares observed last year, and their evolution over the first year since their discovery.

  5. Overland Tidal Power Generation Using Modular Tidal Prism

    SciTech Connect

    Khangaonkar, Tarang; Yang, Zhaoqing; Geerlofs, Simon H.; Copping, Andrea

    2010-03-01

    Naturally occurring sites with sufficient kinetic energy suitable for tidal power generation with sustained currents > 1 to 2 m/s are relatively rare. Yet sites with greater than 3 to 4 m of tidal range are relatively common around the U.S. coastline. Tidal potential does exist along the shoreline but is mostly distributed, and requires an approach which allows trapping and collection to also be conducted in a distributed manner. In this paper we examine the feasibility of generating sustainable tidal power using multiple nearshore tidal energy collection units and present the Modular Tidal Prism (MTP) basin concept. The proposed approach utilizes available tidal potential by conversion into tidal kinetic energy through cyclic expansion and drainage from shallow modular manufactured overland tidal prisms. A preliminary design and configuration of the modular tidal prism basin including inlet channel configuration and basin dimensions was developed. The unique design was shown to sustain momentum in the penstocks during flooding as well as ebbing tidal cycles. The unstructured-grid finite volume coastal ocean model (FVCOM) was used to subject the proposed design to a number of sensitivity tests and to optimize the size, shape and configuration of MTP basin for peak power generation capacity. The results show that an artificial modular basin with a reasonable footprint (≈ 300 acres) has the potential to generate 10 to 20 kw average energy through the operation of a small turbine located near the basin outlet. The potential of generating a total of 500 kw to 1 MW of power through a 20 to 40 MTP basin tidal power farms distributed along the coastline of Puget Sound, Washington, is explored.

  6. Tidal Venuses: triggering a climate catastrophe via tidal heating.

    PubMed

    Barnes, Rory; Mullins, Kristina; Goldblatt, Colin; Meadows, Victoria S; Kasting, James F; Heller, René

    2013-03-01

    Traditionally, stellar radiation has been the only heat source considered capable of determining global climate on long timescales. Here, we show that terrestrial exoplanets orbiting low-mass stars may be tidally heated at high-enough levels to induce a runaway greenhouse for a long-enough duration for all the hydrogen to escape. Without hydrogen, the planet no longer has water and cannot support life. We call these planets "Tidal Venuses" and the phenomenon a "tidal greenhouse." Tidal effects also circularize the orbit, which decreases tidal heating. Hence, some planets may form with large eccentricity, with its accompanying large tidal heating, and lose their water, but eventually settle into nearly circular orbits (i.e., with negligible tidal heating) in the habitable zone (HZ). However, these planets are not habitable, as past tidal heating desiccated them, and hence should not be ranked highly for detailed follow-up observations aimed at detecting biosignatures. We simulated the evolution of hypothetical planetary systems in a quasi-continuous parameter distribution and found that we could constrain the history of the system by statistical arguments. Planets orbiting stars with masses<0.3 MSun may be in danger of desiccation via tidal heating. We have applied these concepts to Gl 667C c, a ∼4.5 MEarth planet orbiting a 0.3 MSun star at 0.12 AU. We found that it probably did not lose its water via tidal heating, as orbital stability is unlikely for the high eccentricities required for the tidal greenhouse. As the inner edge of the HZ is defined by the onset of a runaway or moist greenhouse powered by radiation, our results represent a fundamental revision to the HZ for noncircular orbits. In the appendices we review (a) the moist and runaway greenhouses, (b) hydrogen escape, (c) stellar mass-radius and mass-luminosity relations, (d) terrestrial planet mass-radius relations, and (e) linear tidal theories. PMID:23537135

  7. Dissipation of Tidal Energy

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The moon's gravity imparts tremendous energy to the Earth, raising tides throughout the global oceans. What happens to all this energy? This question has been pondered by scientists for over 200 years, and has consequences ranging from the history of the moon to the mixing of the oceans. Richard Ray at NASA's Goddard Space Flight Center, Greenbelt, Md. and Gary Egbert of the College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Ore. studied six years of altimeter data from the TOPEX/Poseidon satellite to address this question. According to their report in the June 15 issue of Nature, about 1 terawatt, or 25 to 30 percent of the total tidal energy dissipation, occurs in the deep ocean. The remainder occurs in shallow seas, such as on the Patagonian Shelf. 'By measuring sea level with the TOPEX/Poseidon satellite altimeter, our knowledge of the tides in the global ocean has been remarkably improved,' said Richard Ray, a geophysicist at Goddard. The accuracies are now so high that this data can be used to map empirically the tidal energy dissipation. (Red areas, above) The deep-water tidal dissipation occurs generally near rugged bottom topography (seamounts and mid-ocean ridges). 'The observed pattern of deep-ocean dissipation is consistent with topographic scattering of tidal energy into internal motions within the water column, resulting in localized turbulence and mixing', said Gary Egbert an associate professor at OSU. One important implication of this finding concerns the possible energy sources needed to maintain the ocean's large-scale 'conveyor-belt' circulation and to mix upper ocean heat into the abyssal depths. It is thought that 2 terawatts are required for this process. The winds supply about 1 terawatt, and there has been speculation that the tides, by pumping energy into vertical water motions, supply the remainder. However, all current general circulation models of the oceans ignore the tides. 'It is possible that properly

  8. Prehospital tidal volume influences hospital tidal volume: A cohort study

    PubMed Central

    Stoltze, Andrew J.; Wong, Terrence S.; Harland, Karisa K.; Ahmed, Azeemuddin; Fuller, Brian M.; Mohr, Nicholas M.

    2015-01-01

    Purpose To describe current practice of ventilation in a modern air medical system, and to measure the association of ventilation strategy with subsequent ventilator care and acute respiratory distress syndrome (ARDS). Materials and Methods Retrospective observational cohort study of intubated adult patients (n=235) transported by a university-affiliated air medical transport service to a 711-bed tertiary academic center between July 2011 and May 2013. Low tidal volume ventilation was defined as tidal volumes ≤ 8 mL/kg predicted body weight (PBW). Multivariable regression was used to measure the association between prehospital tidal volume, hospital ventilation strategy, and ARDS. Results Most patients (57%) were ventilated solely with bag-valve ventilation during transport. Mean tidal volume of mechanically ventilated patients was 8.6 mL/kg PBW (SD 0.2 mL/kg). Low tidal volume ventilation was used in 13% of patients. Patients receiving low tidal volume ventilation during air medical transport were more likely to receive low tidal volume ventilation in the emergency department (p < 0.001) and intensive care unit (p = 0.015). ARDS was not associated with pre-hospital tidal volume (p = 0.840). Conclusions Low tidal volume ventilation was rare during air medical transport. Air transport ventilation strategy influenced subsequent ventilation, but was not associated with ARDS. PMID:25813548

  9. Ventilatory inhomogeneity determined from multiple-breath washouts during sustained microgravity on Spacelab SLS-1.

    PubMed

    Prisk, G K; Guy, H J; Elliott, A R; Paiva, M; West, J B

    1995-02-01

    We used multiple-breath N2 washouts (MBNW) to study the inhomogeneity of ventilation in four normal humans (mean age 42.5 yr) before, during, and after 9 days of exposure to microgravity on Spacelab Life Sciences-1. Subjects performed 20-breath MBNW at tidal volumes of approximately 700 ml and 12-breath MBNW at tidal volumes of approximately 1,250 ml. Six indexes of ventilatory inhomogeneity were derived from data from 1) distribution of specific ventilation (SV) from mixed-expired and 2) end-tidal N2, 3) change of slope of N2 washout (semilog plot) with time, 4) change of slope of normalized phase III of successive breaths, 5) anatomic dead space, and 6) Bohr dead space. Significant ventilatory inhomogeneity was seen in the standing position at normal gravity (1 G). When we compared standing 1 G with microgravity, the distributions of SV became slightly narrower, but the difference was not significant. Also, there were no significant changes in the change of slope of the N2 washout, change of normalized phase III slopes, or the anatomic and Bohr dead spaces. By contrast, transition from the standing to supine position in 1 G resulted in significantly broader distributions of SV (P < 0.05) and significantly greater changes in the changes in slope of the N2 washouts (P < 0.001), indicating more ventilatory inhomogeneity in that posture. Thus these techniques can detect relatively small changes in ventilatory inhomogeneity. We conclude that the primary determinants of ventilatory inhomogeneity during tidal breathing in the upright posture are not gravitational in origin. PMID:7759429

  10. Ventilatory inhomogeneity determined from multiple-breath washouts during sustained microgravity on Spacelab SLS-1

    NASA Technical Reports Server (NTRS)

    Prisk, G. Kim; Guy, Harold J. B.; Elliott, Ann R.; Paiva, Manuel; West, John B.

    1995-01-01

    We used multiple-breath N2 washouts (MBNW) to study the homogeneity of ventilation in four normal humans (mean age 42.5 yr) before, during, and after 9 days of exposure to microgravity on Spacelab Life Sciences-1. Subjects performed 20-breath MBNW at tidal volumes of approximately 700 ml and 12-breath MBNW at tidal volumes of approximately 1,250 ml. Six indexes of ventilatory inhomogeneity were derived from data from (1) distribution of specific ventilation (SV) from mixed-expired and (2) end-tidal N2, (3) change of slope of N2 washout (semilog plot) with time, (4) change of slope of normalized phase III of successive breaths, (5) anatomic lead dead space, and (6) Bohr dead space. Significant ventilatory inhomogeneity was seen in the standing position at normal gravity (1 G). When we compared standing 1 G with microgravity, the distributions of SV became slightly narrower, but the difference was not significant. Also, there were no significant changes in the change of slope of the N2 washout, change of normalized phase III slopes, or the anatomic and Bohr dead spaces. By contrast, transition from the standing to supine position in 1 G resulted in significantly broader distributions of SV and significantly greater changes in the changes in slope of the N2 washouts, indicating more ventilatory inhomogeneity in that posture. Thus these techniques can detect relatively small changes in ventilatory inhomogeneity. We conclude that the primary determinants of ventilatory inhomogeneity during tidal breathing in the upright posture are not gravitational in origin.

  11. Breathing pattern and carbon dioxide retention in severe chronic obstructive pulmonary disease.

    PubMed Central

    Gorini, M.; Misuri, G.; Corrado, A.; Duranti, R.; Iandelli, I.; De Paola, E.; Scano, G.

    1996-01-01

    BACKGROUND: The factors leading to chronic hypercapnia and rapid shallow breathing in patients with severe chronic obstructive pulmonary disease (COPD) are not completely understood. In this study the interrelations between chronic carbon dioxide retention, breathing pattern, dyspnoea, and the pressure required for breathing relative to inspiratory muscle strength in stable COPD patients with severe airflow obstruction were studied. METHODS: Thirty patients with COPD in a clinically stable condition with forced expiratory volume in one second (FEV1) of < 1 litre were studied. In each patient the following parameters were assessed: (1) dyspnoea scale rating, (2) inspiratory muscle strength by measuring minimal pleural pressure (PPLmin), and (3) tidal volume (VT), flow, pleural pressure swing (PPLsw), total lung resistance (RL), dynamic lung elastance (ELdyn), and positive end expiratory alveolar pressure (PEEPi) during resting breathing. RESULTS: Arterial carbon dioxide tension (PaCO2) related directly to RL/PPLmin, and ELdyn/PPLmin, and inversely to VT and PPLmin. There was no relationship between PaCO2 and functional residual capacity (FRC), total lung capacity (TLC), or minute ventilation. PEEPi was similar in eucapnic and hypercapnic patients. Expressing PaCO2 as a combined function of VT and PPLmin (stepwise multiple regression analysis) explained 71% of the variance in PaCO2. Tidal volume was directly related to inspiratory time (TI), and TI was inversely related to the pressure required for breathing relative to inspiratory muscle strength (PPLsw, %PPLmin). There was an association between the severity of dyspnoea and both the increase in PPLsw (%PPLmin) and the shortening in TI. CONCLUSIONS: The results indicate that, in stable patients with COPD with severe airflow obstruction, hypercapnia is associated with shallow breathing and inspiratory muscle weakness, and rapid and shallow breathing appears to be linked to both a marked increase in the pressure

  12. Probing plasmonic breathing modes optically

    SciTech Connect

    Krug, Markus K. Reisecker, Michael; Hohenau, Andreas; Ditlbacher, Harald; Trügler, Andreas; Hohenester, Ulrich; Krenn, Joachim R.

    2014-10-27

    The confinement of surface plasmon modes in flat nanoparticles gives rise to plasmonic breathing modes. With a vanishing net dipole moment, breathing modes do not radiate, i.e., they are optically dark. Having thus escaped optical detection, breathing modes were only recently revealed in silver nanodisks with electron energy loss spectroscopy in an electron microscope. We show that for disk diameters >200 nm, retardation induced by oblique optical illumination relaxes the optically dark character. This makes breathing modes and thus the full plasmonic mode spectrum accessible to optical spectroscopy. The experimental spectroscopy data are in excellent agreement with numerical simulations.

  13. End-tidal CO2 in some aquatic mammals of large size.

    PubMed

    Mortola, Jacopo P; Seguin, Julie

    2009-01-01

    While resting on land or at the water surface, the breathing frequency (f) of aquatic mammals of medium and large size is lower than in terrestrial mammals of similar body weight (W), the difference widening with the increase in W. The allometric function for aquatic mammals is f proportional to W(-0.42) (f, breaths/min, W, kg) and that of terrestrial species is f proportional to W(-0.25). We asked whether or not resting breathing at such low f would entail high values of alveolar CO2. End-tidal alveolar CO2 pressure, taken as representative of alveolar CO2 pressure, PaCO2, was measured from the expired gas during resting breathing in captive specimens of aquatic species trained to rest in proximity of their keepers, either on land (walrus and sea lion) or at the water surface (dolphin, orca, beluga and hippopotamus). Their f during the recordings ranged from less than 1 (orca) to 6 (walrus) breaths/min. The average PaCO2 values ranged from 32 to 42 mm Hg, the peaks being a few mm Hg higher. These values were similar or slightly higher than literature data of many terrestrial species, with no relation to the animal f or W. The quasi-normality of PaCO2 in large aquatic species breathing at rest, despite their exceptionally low f and normal metabolism, can be explained mainly by two factors, their large tidal volume/W, about three times the average terrestrial value, and their peculiar breathing pattern with sustained high lung volume during the expiratory pause. This latter is key in avoiding a substantial rise in PaCO2 during the inter-breath pause. PMID:19026528

  14. Tidal Energy Research

    SciTech Connect

    Stelzenmuller, Nickolas; Aliseda, Alberto; Palodichuk, Michael; Polagye, Brian; Thomson, James; Chime, Arshiya; Malte, Philip

    2014-03-31

    This technical report contains results on the following topics: 1) Testing and analysis of sub-scale hydro-kinetic turbines in a flume, including the design and fabrication of the instrumented turbines. 2) Field measurements and analysis of the tidal energy resource and at a site in northern Puget Sound, that is being examined for turbine installation. 3) Conceptual design and performance analysis of hydro-kinetic turbines operating at high blockage ratio, for use for power generation and flow control in open channel flows.

  15. Tidal heating of Ariel

    NASA Technical Reports Server (NTRS)

    Tittemore, William C.

    1990-01-01

    During evolution through the 4:1 commensurability early in the history of the Uranian system, over 3.8 billion years ago, tidal heating may have raised the internal temperature of Ariel by up to about 20 K; the internal temperature of Ariel may already have been high in virtue of both accretional and radiogenic heating. The additional increase in Ariel's temperature could then have triggered the geological activity that led to a late resurfacing, by decreasing lithospheric thickness and exacerbating thermal stresses on it to the point where observed cracks and faults formed.

  16. Conservation of tidal marshes

    SciTech Connect

    Daiber, F.C.

    1986-01-01

    This book is the first attempt to examine collectively the various uses and the consequences of marsh conservation efforts. Author Franklin Daiber emphasizes tidal marsh conservation from a holistic perspective rather than from the perspective of a single purpose or special economic interest. He addresses a topic receiving increasing attention, namely the concept of open marsh management as a means of controlling mosquito production without harmful effects on other marsh organisms. Topics considered include: water management; dikes, impoundments, ponds and ditches; reclaimed land and impoundments; ditching and ponding for mosquito control; sewage disposal and waste treatment; dredge material for wetland restoration; insecticides; oil pollution; and petroleum hydrocarbon interactions.

  17. SU-E-J-178: A Normalization Method Can Remove Discrepancy in Ventilation Function Due to Different Breathing Patterns

    SciTech Connect

    Qu, H; Yu, N; Stephans, K; Xia, P

    2014-06-01

    Purpose: To develop a normalization method to remove discrepancy in ventilation function due to different breathing patterns. Methods: Twenty five early stage non-small cell lung cancer patients were included in this study. For each patient, a ten phase 4D-CT and the voluntarily maximum inhale and exhale CTs were acquired clinically and retrospectively used for this study. For each patient, two ventilation maps were calculated from voxel-to-voxel CT density variations from two phases of the quiet breathing and two phases of the extreme breathing. For the quiet breathing, 0% (inhale) and 50% (exhale) phases from 4D-CT were used. An in-house tool was developed to calculate and display the ventilation maps. To enable normalization, the whole lung of each patient was evenly divided into three parts in the longitude direction at a coronal image with a maximum lung cross section. The ratio of cumulated ventilation from the top one-third region to the middle one-third region of the lung was calculated for each breathing pattern. Pearson's correlation coefficient was calculated on the ratios of the two breathing patterns for the group. Results: For each patient, the ventilation map from the quiet breathing was different from that of the extreme breathing. When the cumulative ventilation was normalized to the middle one-third of the lung region for each patient, the normalized ventilation functions from the two breathing patterns were consistent. For this group of patients, the correlation coefficient of the normalized ventilations for the two breathing patterns was 0.76 (p < 0.01), indicating a strong correlation in the ventilation function measured from the two breathing patterns. Conclusion: For each patient, the ventilation map is dependent of the breathing pattern. Using a regional normalization method, the discrepancy in ventilation function induced by the different breathing patterns thus different tidal volumes can be removed.

  18. Tidal Pools--Miniature Oceans

    ERIC Educational Resources Information Center

    Plake, Linda Perry

    1977-01-01

    A comprehensive discussion of the biological activity in tidal pools is provided. The importance of environmental factors such as oxygen supply, temperature, salinity, and light is detailed. Plants and animals that might be found in a tidal pool are identified and described. (BT)

  19. Effects of breathing patterns and light exercise on linear and nonlinear heart rate variability.

    PubMed

    Weippert, Matthias; Behrens, Kristin; Rieger, Annika; Kumar, Mohit; Behrens, Martin

    2015-08-01

    Despite their use in cardiac risk stratification, the physiological meaning of nonlinear heart rate variability (HRV) measures is not well understood. The aim of this study was to elucidate effects of breathing frequency, tidal volume, and light exercise on nonlinear HRV and to determine associations with traditional HRV indices. R-R intervals, blood pressure, minute ventilation, breathing frequency, and respiratory gas concentrations were measured in 24 healthy male volunteers during 7 conditions: voluntary breathing at rest, and metronome guided breathing (0.1, 0.2 and 0.4 Hz) during rest, and cycling, respectively. The effect of physical load was significant for heart rate (HR; p < 0.001) and traditional HRV indices SDNN, RMSSD, lnLFP, and lnHFP (p < 0.01 for all). It approached significance for sample entropy (SampEn) and correlation dimension (D2) (p < 0.1 for both), while HRV detrended fluctuation analysis (DFA) measures DFAα1 and DFAα2 were not affected by load condition. Breathing did not affect HR but affected all traditional HRV measures. D2 was not affected by breathing; DFAα1 was moderately affected by breathing; and DFAα2, approximate entropy (ApEn), and SampEn were strongly affected by breathing. DFAα1 was strongly increased, whereas DFAα2, ApEn, and SampEn were decreased by slow breathing. No interaction effect of load and breathing pattern was evident. Correlations to traditional HRV indices were modest (r from -0.14 to -0.67, p < 0.05 to <0.01). In conclusion, while light exercise does not significantly affect short-time HRV nonlinear indices, respiratory activity has to be considered as a potential contributor at rest and during light dynamic exercise. PMID:26187271

  20. Study of airflow in the trachea of idealized model of human tracheobronchial airways during breathing cycle

    NASA Astrophysics Data System (ADS)

    Elcner, Jakub; Lizal, Frantisek; Jedelsky, Jan; Jicha, Miroslav

    2015-05-01

    The article deals with a numerical simulation and its verification by experiments in the trachea of idealized geometry of tracheobronchial airways by using unsteady RANS method. The breathing cycle was simulated by sinusoidal function with period of 4 seconds and tidal volume of 0.5 litres of air, which corresponds to breathing during resting condition. Results were compared with experiments measured by laser-Doppler velocimeter in eight points of four cross sections in the trachea. Model consists of the mouth cavity, larynx and tracheobronchial tree down to fourth generation of branching.

  1. DTP: a Tidal Power Revolution

    NASA Astrophysics Data System (ADS)

    Steijn, Robbert; Hulsbergen, Kees; van Banning, Gijs

    2013-04-01

    Tidal power can significantly contribute to the global mix of sustainable energy resources. It is climate-independent, fully predictable, and if designed properly it is environmentally friendly and socio-economically feasible. The two traditional methods of exploiting tidal power are Tidal Barrage and Tidal Stream. This study deals with an alternative Third Method, named Dynamic Tidal Power (DTP), which contrary to the other methods, utilises the oscillating character of tides, or more precisely: the acceleration inherent to unsteady flow. DTP uses a long dam (order of tens of km's), attached and perpendicular to a coast with shore-parallel tidal currents, to generate a local hydraulic head. This time-varying head is used to generate electricity in a more or less standard way with turbines and generators placed in (many) dam openings. For a first impression only: typical installed power for one DTP is more than 10 GW with electricity output > 2.1010 kWh/y and construction costs of ca. 1 EUR/W. The physical mechanism behind the creation of the head has been described by Hulsbergen e.a., (2012). Following a heuristic approach based on analytical work done by Kolkman (unpubl.), and output from numerical tidal models, Hulsbergen (2012) concluded that the maximum head (near the coast), is: hmax = 6,8*?*D*Vmax/(g*T), with Vmax the maximum alongshore flow velocity during the tidal cycle, T the tidal period and D the length of dam. Such simple relationship was also found by Mei (2012) who made a rigorous analysis of a process-based model. After a thorough reflection on DTP, this study will first check the above formula for hmax , by comparing its predictions with the output from various numerical tidal models. Any differences will be analysed in the study through an evaluation of the dominant physical processes and the schematisations inherent to both the analytical and the numerical models. The study will also address the effect of the openings in the dam, as well as the

  2. Clinical applications of breath testing

    PubMed Central

    Paschke, Kelly M; Mashir, Alquam

    2010-01-01

    Breath testing has the potential to benefit the medical field as a cost-effective, non-invasive diagnostic tool for diseases of the lung and beyond. With growing evidence of clinical worth, standardization of methods, and new sensor and detection technologies the stage is set for breath testing to gain considerable attention and wider application in upcoming years. PMID:21173863

  3. BREATHE to Understand©

    ERIC Educational Resources Information Center

    Swisa, Maxine

    2015-01-01

    BREATHE is an acronym for Breathe, Reflect, Empathize, Accept, Thank, Hearten, Engage. The addition of Understand allows for a holistic approach to living a healthy and balanced life both inside and outside the classroom. This paper took form as a result of my personal, spiritual journey, as well as my teaching practice. I noticed that the…

  4. Patient's breath controls comfort devices

    NASA Technical Reports Server (NTRS)

    Schrader, M.; Carpenter, B.; Nichols, C. D.

    1972-01-01

    Patient assist system for totally disabled persons was developed which permits a person, so paralyzed as to be unable to move, to activate by breathing, a call system to summon assistance, turn the page of a book, ajust his bed, or do any one of a number of other things. System consists of patient assist control and breath actuated switch.

  5. Design and Evaluation of an Intelligent Remote Tidal Volume Variability Monitoring System in E-Health Applications.

    PubMed

    Fekr, Atena Roshan; Radecka, Katarzyna; Zilic, Zeljko

    2015-09-01

    A reliable long-term monitoring and diagnosis of breath disorders at an early stage provides an improvement of medical act, life expectancy, and quality of life while decreasing the costs of treatment and medical services. Therefore, a real-time unobtrusive monitoring of respiration patterns, as well as breath parameters, is a critical need in medical applications. In this paper, we propose an intelligent system for patient home care, capable of measuring respiration rate and tidal volume variability via a wearable sensing technology. The proposed system is designed particularly for the goal of diagnosis and treatment in patients with pathological breathing, e.g., respiratory complications after surgery or sleep disorders. The complete system was comprised of wearable calibrated accelerometer sensor, Bluetooth low energy, and cloud database. The experiments are conducted with eight subjects and the overall error in respiration rate calculation is obtained 0.29%±0.33% considering SPR-BTA spirometer as the reference. We also introduce a method for tidal volume variability estimation while validated using Pearson correlation. Furthermore, since it is essential to detect the critical events resulted from sudden rise or fall in per breath tidal volume of the patients, we provide a technique to automatically find the accurate threshold values based on each individual breath characteristics. Therefore, the system is able to detect the major changes, precisely by more than 98%, and provide immediate feedback such as sound alarm for round-the-clock respiration monitoring. PMID:26087508

  6. Rapid shallow breathing index.

    PubMed

    Karthika, Manjush; Al Enezi, Farhan A; Pillai, Lalitha V; Arabi, Yaseen M

    2016-01-01

    Predicting successful liberation of patients from mechanical ventilation has been a focus of interest to clinicians practicing in intensive care. Various weaning indices have been investigated to identify an optimal weaning window. Among them, the rapid shallow breathing index (RSBI) has gained wide use due to its simple technique and avoidance of calculation of complex pulmonary mechanics. Since its first description, several modifications have been suggested, such as the serial measurements and the rate of change of RSBI, to further improve its predictive value. The objective of this paper is to review the utility of RSBI in predicting weaning success. In addition, the use of RSBI in specific patient populations and the reported modifications of RSBI technique that attempt to improve the utility of RSBI are also reviewed. PMID:27512505

  7. Breathing zone air sampler

    DOEpatents

    Tobin, John

    1989-01-01

    A sampling apparatus is provided which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

  8. Breathing rhythms and emotions.

    PubMed

    Homma, Ikuo; Masaoka, Yuri

    2008-09-01

    Respiration is primarily regulated for metabolic and homeostatic purposes in the brainstem. However, breathing can also change in response to changes in emotions, such as sadness, happiness, anxiety or fear. Final respiratory output is influenced by a complex interaction between the brainstem and higher centres, including the limbic system and cortical structures. Respiration is important in maintaining physiological homeostasis and co-exists with emotions. In this review, we focus on the relationship between respiration and emotions by discussing previous animal and human studies, including studies of olfactory function in relation to respiration and the piriform-amygdala in relation to respiration. In particular, we discuss oscillations of piriform-amygdala complex activity and respiratory rhythm. PMID:18487316

  9. Rapid shallow breathing index

    PubMed Central

    Karthika, Manjush; Al Enezi, Farhan A.; Pillai, Lalitha V.; Arabi, Yaseen M.

    2016-01-01

    Predicting successful liberation of patients from mechanical ventilation has been a focus of interest to clinicians practicing in intensive care. Various weaning indices have been investigated to identify an optimal weaning window. Among them, the rapid shallow breathing index (RSBI) has gained wide use due to its simple technique and avoidance of calculation of complex pulmonary mechanics. Since its first description, several modifications have been suggested, such as the serial measurements and the rate of change of RSBI, to further improve its predictive value. The objective of this paper is to review the utility of RSBI in predicting weaning success. In addition, the use of RSBI in specific patient populations and the reported modifications of RSBI technique that attempt to improve the utility of RSBI are also reviewed. PMID:27512505

  10. Tidal Venuses: Triggering a Climate Catastrophe via Tidal Heating

    PubMed Central

    Mullins, Kristina; Goldblatt, Colin; Meadows, Victoria S.; Kasting, James F.; Heller, René

    2013-01-01

    Abstract Traditionally, stellar radiation has been the only heat source considered capable of determining global climate on long timescales. Here, we show that terrestrial exoplanets orbiting low-mass stars may be tidally heated at high-enough levels to induce a runaway greenhouse for a long-enough duration for all the hydrogen to escape. Without hydrogen, the planet no longer has water and cannot support life. We call these planets “Tidal Venuses” and the phenomenon a “tidal greenhouse.” Tidal effects also circularize the orbit, which decreases tidal heating. Hence, some planets may form with large eccentricity, with its accompanying large tidal heating, and lose their water, but eventually settle into nearly circular orbits (i.e., with negligible tidal heating) in the habitable zone (HZ). However, these planets are not habitable, as past tidal heating desiccated them, and hence should not be ranked highly for detailed follow-up observations aimed at detecting biosignatures. We simulated the evolution of hypothetical planetary systems in a quasi-continuous parameter distribution and found that we could constrain the history of the system by statistical arguments. Planets orbiting stars with masses<0.3 MSun may be in danger of desiccation via tidal heating. We have applied these concepts to Gl 667C c, a ∼4.5 MEarth planet orbiting a 0.3 MSun star at 0.12 AU. We found that it probably did not lose its water via tidal heating, as orbital stability is unlikely for the high eccentricities required for the tidal greenhouse. As the inner edge of the HZ is defined by the onset of a runaway or moist greenhouse powered by radiation, our results represent a fundamental revision to the HZ for noncircular orbits. In the appendices we review (a) the moist and runaway greenhouses, (b) hydrogen escape, (c) stellar mass-radius and mass-luminosity relations, (d) terrestrial planet mass-radius relations, and (e) linear tidal theories. Key Words: Extrasolar terrestrial

  11. Galileo's tidal theory.

    PubMed

    Naylor, Ron

    2007-03-01

    The aim of Galileo's tidal theory was to show that the tides were produced entirely by the earth's motion and thereby to demonstrate the physical truth of Copernicanism. However, in the Dialogue Concerning the Two Chief World Systems Galileo did not explain some of the most significant aspects of the theory completely. As a consequence, the way the theory works has long been disputed. Though there exist a number of interpretations in the literature, the most widely accepted are based on ideas that are not explicitly articulated by Galileo in the Dialogue. This essay attempts to understand the way the theory functions in terms of Galilean physics. It is an interpretation of the theory based solely on Galileo's arguments--and one that reveals it to have had some unrecognized consequences. This interpretation indicates that Galileo's theory would not have worked in the manner he described in the Dialogue. PMID:17539198

  12. Tidal volume change and gas mixing in the lung.

    PubMed

    Damato, S; Cumming, G

    1989-01-01

    Changing the depth and the frequency of breathing affects the efficiency of ventilation. This has been studied in eight normal subjects using the technique of nitrogen washout whilst breathing a mixture of 79% argon and oxygen. The signals were converted to digital data at 50 Hz and all calculations were then done with the computer. The size of the dead space of the conducting airways (series dead space, VdS) and of the alveolar dead space (VdA) has been measured for carbon dioxide (CO2) and oxygen (O2). The nitrogen (N2) decay curve was computed allowing the calculation of first breath (AMEsb) and multi breath (AMEmb) alveolar mixing efficiency. The increase in VdS per 100 ml increase in tidal volume (Vt) was 3.7 ml for CO2 and 3.3 for O2. As VdS increased, VdA also increased by 11.1 ml for CO2 and 19.1 ml for O2, for each 100 ml increase in Vt. Whilst VdA and VdS increase with increasing Vt, the proportion of VdA + VdS in each breath diminishes with such an increase, the net result is that, for each 100 ml increase in Vt, alveolar ventilation increases by 86 ml for CO2 and 78 ml for O2. The increase of absolute values and the different behaviour of N2, AMEsb and AMEmb show a progressive decrease of the parallel component of the intra-pulmonary ventilation distribution with increasing Vt. It appears that the pattern of ventilation, as well as minute ventilation, plays a role in the effectiveness of ventilation. PMID:2635347

  13. Validation of Respiratory Inductance Plethysmography for Measuring Tidal Volume in Swine.

    PubMed

    Su, Zhenbo; Oto, Jun; Wang, Jingwen; Kimball, William R; Chenelle, Christopher T; Kacmarek, Robert M; King, David R; Jiang, Yandong; Duggan, Michael J

    2015-06-01

    Measuring tidal volume (VT) in nonintubated swine or swine with leaking breathing circuits is challenging. The aim of this study was to validate respiratory inductance plethysmography (RIP) for measuring VT in swine that are comparable in size to adult humans. To determine calibration curves, VT and RIP readings were obtained from anesthetized swine (n = 8; weight, 46-50 kg) during positive-pressure (mechanical) ventilation and spontaneous breathing. For positive-pressure ventilation, 6 pigs were mechanically ventilated by using the pressure-control mode. The 2 pigs in the spontaneously breathing cohort each received a single intravenous bolus dose of propofol to abolish spontaneous breathing; VT was measured during gradual return of their respiratory drive. A flow-volume sensor was placed between the proximal end of the endotracheal tube and breathing circuit for the recording of inspiratory and expiratory VT. RIP readings were recorded by using 2 bands, which simultaneously measured ribcage and abdominal excursions. The data revealed that VT was linearly correlated with the movements of both ribcage and abdomen as measured by using plethysmography over a large range of tidal volume (44 to 1065 mL). In addition, the intercept of the linear equation was small or even negative during spontaneous breathing but increased significantly (maximum, 145 mL, 59.2 ± 35.1 mL) during positive pressure ventilation. Our results indicate that VT in swine can be calculated by using a simple univariate linear regression equation with RIP readings obtained during either mechanical ventilation or spontaneous breathing. PMID:26141447

  14. Validation of Respiratory Inductance Plethysmography for Measuring Tidal Volume in Swine

    PubMed Central

    Su, Zhenbo; Oto, Jun; Wang, Jingwen; Kimball, William R; Chenelle, Christopher T; Kacmarek, Robert M; King, David R; Jiang, Yandong; Duggan, Michael J

    2015-01-01

    Measuring tidal volume (VT) in nonintubated swine or swine with leaking breathing circuits is challenging. The aim of this study was to validate respiratory inductance plethysmography (RIP) for measuring VT in swine that are comparable in size to adult humans. To determine calibration curves, VT and RIP readings were obtained from anesthetized swine (n = 8; weight, 46–50 kg) during positive-pressure (mechanical) ventilation and spontaneous breathing. For positive-pressure ventilation, 6 pigs were mechanically ventilated by using the pressure-control mode. The 2 pigs in the spontaneously breathing cohort each received a single intravenous bolus dose of propofol to abolish spontaneous breathing; VT was measured during gradual return of their respiratory drive. A flow–volume sensor was placed between the proximal end of the endotracheal tube and breathing circuit for the recording of inspiratory and expiratory VT. RIP readings were recorded by using 2 bands, which simultaneously measured ribcage and abdominal excursions. The data revealed that VT was linearly correlated with the movements of both ribcage and abdomen as measured by using plethysmography over a large range of tidal volume (44 to 1065 mL). In addition, the intercept of the linear equation was small or even negative during spontaneous breathing but increased significantly (maximum, 145 mL, 59.2 ± 35.1 mL) during positive pressure ventilation. Our results indicate that VT in swine can be calculated by using a simple univariate linear regression equation with RIP readings obtained during either mechanical ventilation or spontaneous breathing. PMID:26141447

  15. Recent progress in tidal modeling

    NASA Technical Reports Server (NTRS)

    Vial, F.; Forbes, J. M.

    1989-01-01

    Recent contributions to tidal theory during the last five years are reviewed. Specific areas where recent progress has occurred include: the action of mean wind and dissipation on tides, interactions of other waves with tides, the use of TGCM in tidal studies. Furthermore, attention is put on the nonlinear interaction between semidiurnal and diurnal tides. Finally, more realistic thermal excitation and background wind and temperature models have been developed in the past few years. This has led to new month-to-month numerical simulations of the semidiurnal tide. Some results using these models are presented and compared with ATMAP tidal climatologies.

  16. Anatomic and Pathologic Variability During Radiotherapy for a Hybrid Active Breath-Hold Gating Technique

    SciTech Connect

    Glide-Hurst, Carri K.; Gopan, Ellen; Hugo, Geoffrey D.

    2010-07-01

    Purpose: To evaluate intra- and interfraction variability of tumor and lung volume and position using a hybrid active breath-hold gating technique. Methods and Materials: A total of 159 repeat normal inspiration active breath-hold CTs were acquired weekly during radiotherapy for 9 lung cancer patients (12-21 scans per patient). A physician delineated the gross tumor volume (GTV), lungs, and spinal cord on the first breath-hold CT, and contours were propagated semiautomatically. Intra- and interfraction variability of tumor and lung position and volume were evaluated. Tumor centroid and border variability were quantified. Results: On average, intrafraction variability of lung and GTV centroid position was <2.0 mm. Interfraction population variability was 3.6-6.7 mm (systematic) and 3.1-3.9 mm (random) for the GTV centroid and 1.0-3.3 mm (systematic) and 1.5-2.6 mm (random) for the lungs. Tumor volume regressed 44.6% {+-} 23.2%. Gross tumor volume border variability was patient specific and demonstrated anisotropic shape change in some subjects. Interfraction GTV positional variability was associated with tumor volume regression and contralateral lung volume (p < 0.05). Inter-breath-hold reproducibility was unaffected by time point in the treatment course (p > 0.1). Increases in free-breathing tidal volume were associated with increases in breath-hold ipsilateral lung volume (p < 0.05). Conclusions: The breath-hold technique was reproducible within 2 mm during each fraction. Interfraction variability of GTV position and shape was substantial because of tumor volume and breath-hold lung volume change during therapy. These results support the feasibility of a hybrid breath-hold gating technique and suggest that online image guidance would be beneficial.

  17. Effects of the components of positive airway pressure on work of breathing during bronchospasm

    PubMed Central

    Miro, Adelaida M; Pinsky, Michael R; Rogers, Paul L

    2004-01-01

    Introduction Partial assist ventilation reduces work of breathing in patients with bronchospasm; however, it is not clear which components of the ventilatory cycle contribute to this process. Theoretically, expiratory positive airway pressure (EPAP), by reducing expiratory breaking, may be as important as inspiratory positive airway pressure (IPAP) in reducing work of breathing during acute bronchospasm. Method We compared the effects of 10 cmH2O of IPAP, EPAP, and continuous positive airwaypressure (CPAP) on inspiratory work of breathing and end-expiratory lung volume (EELV) in a canine model of methacholine-induced bronchospasm. Results Methacholine infusion increased airway resistance and work of breathing. During bronchospasm IPAP and CPAP reduced work of breathing primarily through reductions in transdiaphragmatic pressure per tidal volume (from 69.4 ± 10.8 cmH2O/l to 45.6 ± 5.9 cmH2O/l and to 36.9 ± 4.6 cmH2O/l, respectively; P < 0.05) and in diaphragmatic pressure–time product (from 306 ± 31 to 268 ± 25 and to 224 ± 23, respectively; P < 0.05). Pleural pressure indices of work of breathing were not reduced by IPAP and CPAP. EPAP significantly increased all pleural and transdiaphragmatic work of breathing indices. CPAP and EPAP similarly increased EELV above control by 93 ± 16 ml and 69 ± 12 ml, respectively. The increase in EELV by IPAP of 48 ± 8 ml (P < 0.01) was significantly less than that by CPAP and EPAP. Conclusion The reduction in work of breathing during bronchospasm is primarily induced by the IPAP component, and that for the same reduction in work of breathing by CPAP, EELV increases more. PMID:15025781

  18. Model analysis of tidal volume response to inspiratory elastic loads.

    PubMed

    Zin, W A; Rossi, A; Zocchi, L; Milic-Emili, J

    1984-07-01

    Based on experimental inspiratory driving pressure waveforms and active respiratory impedance data of anesthetized cats, we made model predictions of the factors that determine the immediate (first loaded breath) intrinsic (i.e., nonneural) tidal volume compensation to added inspiratory elastic loads. The time course of driving pressure (P) was given by P = atb, where a is the pressure at 1 s from onset of inspiration and represents the intensity of neuromuscular drive, t is time, and b is an index of the shape of the driving pressure wave. For a given active respiratory impedance, tidal volume compensation to added elastic loads decreases with increasing inspiratory duration and decreasing value of b but is independent of a. We have also assessed the validity of the "effective elastance" (Lynne-Davies et al., J. Appl. Physiol. 30: 512-516, 1971) as a predictor of tidal volume responses to elastic loads. In absence of vagal feedback, the effective elastance appears to be a reliable predictor, except for short inspiratory duration and a very high intrinsic resistance. PMID:6469787

  19. Automated 4D lung computed tomography reconstruction during free breathing for conformal radiation therapy

    NASA Astrophysics Data System (ADS)

    El Naqa, Issam M.; Low, Daniel A.; Christensen, Gary E.; Parikh, Parag J.; Song, Joo Hyun; Nystrom, Michelle M.; Lu, Wei; Deasy, Joseph O.; Hubenschmidt, James P.; Wahab, Sasha H.; Mutic, Sasa; Singh, Anurag K.; Bradley, Jeffrey D.

    2004-04-01

    We are developing 4D-CT to provide breathing motion information (trajectories) for radiation therapy treatment planning of lung cancer. Potential applications include optimization of intensity-modulated beams in the presence of breathing motion and intra-fraction target volume margin determination for conformal therapy. The images are acquired using a multi-slice CT scanner while the patient undergoes simultaneous quantitative spirometry. At each couch position, the CT scanner is operated in ciné mode and acquires up to 15 scans of 12 slices each. Each CT scan is associated with the measured tidal volume for retrospective reconstruction of 3D CT scans at arbitrary tidal volumes. The specific tasks of this project involves the development of automated registration of internal organ motion (trajectories) during breathing. A modified least-squares based optical flow algorithm tracks specific features of interest by modifying the eigenvalues of gradient matrix (gradient structural tensor). Good correlations between the measured motion and spirometry-based tidal volume are observed and evidence of internal hysteresis is also detected.

  20. Lung volumes, chest wall configuration, and pattern of breathing in microgravity.

    PubMed

    Paiva, M; Estenne, M; Engel, L A

    1989-10-01

    We studied the changes in functional residual capacity (FRC), thoracoabdominal volume (Vw), and chest wall configuration in five normal subjects seated in an aircraft flying parabolic trajectories resulting in 20-s periods of microgravity. We measured vital capacity (VC), inspiratory capacity, and tidal volume by integrating airflow at the mouth and changes in rib cage and abdominal volume (delta Vrc and delta Vab, respectively, where delta Vrc + delta Vab = delta Vw) using induction plethysmography. During microgravity (0 Gz) FRC decreased by 413 +/- 70 (SE) ml and VC by 0.37 liter. The decrease in Vw did not differ from that in FRC and was entirely the result of reduction of Vab, the Vrc showing no significant change. During tidal breathing the abdominal contribution (delta Vab/delta Vw) increased from 0.39 +/- 0.08 at 1 Gz to 0.57 +/- 0.08 at 0 Gz. During brief periods of hypergravity (approximately 1.8 Gz) all changes were opposite in sign and relatively smaller. Limited data during "roller coaster" flight patterns suggested that, in contrast to configurational changes, the temporal pattern of breathing was uninfluenced by changes in Gz. We conclude that at the onset of weightlessness there are substantial changes in lung volume and thoracoabdominal configuration. Abdominal contribution to tidal excursions increases but the temporal pattern of breathing is unchanged. PMID:2793756

  1. Fiber optic sensor for the assessment of breathing effort

    NASA Astrophysics Data System (ADS)

    Babchenko, Anatoly; Turinvenko, Sergei; Khanokh, Boris; Nitzan, Meir

    1995-01-01

    Several methods have been developed for the qualitative and quantitative measurement of breathing effort. The most useful kind of breathing pattern monitor includes devices for recording chest and abdomen dimension changes, such as impedance plethysmography and respiratory induction plethysmography. These devices can measure the tidal volume in relative terms, and even measure it in absolute terms after suitable calibration. In this study a novel method for measuring chest circumference based on an optical fiber is presented. The sensor is based on the measurement of light transmitted through a bent optical fiber, which is connected to an elastic band, wrapped around the chest, and whose radius of curvature changes due to the respiratory act. The amount of transmitted light is related to the radius of curvature of the fiber which depends on the chest circumference. The output of the respiratory sensor was checked qualitatively by changing the respiration rate and depth. The changes in breathing effort were clearly demonstrated in the sensor output recording. The respiratory effort was also correlated with the heart rate, measured by photoplethysmography. Statistically significant correlation was found between the lungs' volume and the heart rate, but the correlation coefficient was not high.

  2. Tidal radiation. [relativistic gravitational effects

    NASA Technical Reports Server (NTRS)

    Mashhoon, B.

    1977-01-01

    The general theory of tides is developed within the framework of Einstein's theory of gravitation. It is based on the concept of Fermi frame and the associated notion of tidal frame along an open curve in spacetime. Following the previous work of the author an approximate scheme for the evaluation of tidal gravitational radiation is presented which is valid for weak gravitational fields. The emission of gravitational radiation from a body in the field of a black hole is discussed, and for some cases of astrophysical interest estimates are given for the contributions of radiation due to center-of-mass motion, purely tidal deformation, and the interference between the center of mass and tidal motions.

  3. Palliative care - shortness of breath

    MedlinePlus

    ... to control shortness of breath: Call your doctor, palliative care team, or hospice nurse for advice Call 911 ... Bicanovsky L. Comfort care: symptom control in the dying. In: Walsh ... . 1st ed. Philadelphia, PA: Elsevier Saunders; 2008:chap 181.

  4. Visualizing Breath using Digital Holography

    NASA Astrophysics Data System (ADS)

    Hobson, P. R.; Reid, I. D.; Wilton, J. B.

    2013-02-01

    Artist Jayne Wilton and physicists Peter Hobson and Ivan Reid of Brunel University are collaborating at Brunel University on a project which aims to use a range of techniques to make visible the normally invisible dynamics of the breath and the verbal and non-verbal communication it facilitates. The breath is a source of a wide range of chemical, auditory and physical exchanges with the direct environment. Digital Holography is being investigated to enable a visually stimulating articulation of the physical trajectory of the breath as it leaves the mouth. Initial findings of this research are presented. Real time digital hologram replay allows the audience to move through holographs of breath-born particles.

  5. Liquid-Air Breathing Apparatus

    NASA Technical Reports Server (NTRS)

    Mills, Robert D.

    1990-01-01

    Compact unit supplies air longer than compressed-air unit. Emergency breathing apparatus stores air as cryogenic liquid instead of usual compressed gas. Intended for firefighting or rescue operations becoming necessary during planned potentially hazardous procedures.

  6. Tidal Love Numbers and Tidal Heating of a Rotating Body

    NASA Astrophysics Data System (ADS)

    Houben, Howard

    2010-10-01

    Many studies of tidal dissipation in solar system objects make use of Love numbers (non-dimensional measures of the height of the tidal bulge and the associated induced gravitational quadrupole moment) based on Kelvin's solution for the deformation of a homogeneous incompressible body. This solution ignores (assumes negligible) the inertial terms in the equations of motion. When the oscillatory tidal time dependence is included, analytic solutions can be obtained which, surprisingly, do not asymptote to Kelvin's solution in the long-period limit. When the Coriolis terms are also included, a system of three coupled second-order partial differential equations (for the three velocity components, or suitable substitutes) results. Free surface boundary conditions must be satisfied. When the object is not homogeneous, the Poisson equation for the gravitational potential must also be solved. There appear to be no analytic solutions for this system, but numerical solutions are straightforward, and the results can be tabulated in terms of non-dimensionalized values of the rigidity, viscosity, forcing frequency, and rotation frequency. This rotating system couples modes with different latitude structures. The resulting tidal torque is more complicated than usually assumed. In addition to the global net tidal torque that exchanges rotational and orbital angular momentum (and thus leads to the traditional tidal heating and orbital evolution), local differential torques act on the body. Depending on the body's long-term viscoelastic properties, considerable additional heating (which does not affect the orbital evolution and therefore does not figure in the calculation of the body's tidal dissipation factor) may occur, particularly in a layered, inhomogeneous object.

  7. Tidal volume measurements in infants: Opto-electronic plethysmography versus pneumotachograph.

    PubMed

    Reinaux, Cyda Maria Albuquerque; Aliverti, Andrea; da Silva, Lívia Gabriely Melo; da Silva, Rafael Justino; Gonçalves, Juliane Neves; Noronha, Jessica Brito; Filho, José Eulálio Cabral; de Andrade, Armèle Dornelas; de Amorim Britto, Murilo Carlos

    2016-08-01

    Tidal breathing measurements by Opto-Electronic Plethysmography (OEP) has been reported for infants limited to protocols with two chest wall compartments. Standard protocol for the analysis of adults, with three compartments of chest wall, has been unavailable for analysis of infants. We aimed to study the agreement of simultaneous measurements of tidal volume by OEP (VT,OEP ) and a heated pneumotachograph (PNT) (VT,PNT ) performed during sleeping in 20 infants (gestational age 35.1 ± 4.6 weeks) at 3-4 months postconceptual age with a three compartment protocol. From PNT and OEP measurements, tidal volume corrected (VT,PNT ) for ambient conditions were calculated with a total number of 200 breaths. The two methods were in good agreement with tidal volume mean difference of 0.02 ml and limit of agreement -4.11 to 4.08 ml (95%CI), no relationship was found between differences and means of OEP and PNT measurements. Pulmonary rib cage, abdominal rib cage and abdomen contributed by 12.4 ± 9.7%, 5.2 ± 5.1%, and 82.4 ± 11.4% to VT,OEP , respectively. The OEP experimental protocol based on 52 markers and a three-compartment model of the chest wall could be used in spontaneously sleeping infants. Pediatr Pulmonol. 2016;51:850-857. © 2016 Wiley Periodicals, Inc. PMID:26991671

  8. Diaphragm breathing movement measurement using ultrasound and radiographic imaging: a concurrent validity.

    PubMed

    Noh, Dong K; Lee, Jae J; You, Joshua H

    2014-01-01

    Recent ultrasound imaging evidence asserts that the diaphragm is an important multifunctional muscle to control breathing as well as stabilize the core and posture in humans. However, the validity and accuracy of ultrasound for the measurement of dynamic diaphragm movements during breathing and functional core activities have not been determined. The specific aim of this study was to validate the accuracy of ultrasound imaging measurements of diaphragm movements by concurrently comparing these measurements to the gold standard of radiographic imaging measurements. A total of 14 asymptomatic adults (9 males, 5 females; mean age =28.4 ± 3.0 years) were recruited to participate in the study. Ultrasound and radiographic images were used concurrently to determine diaphragm movement (inspiration, expiration, and excursion) during tidal breathing. Pearson correlation analysis showed strong correlations, ranging from r=0.78 to r=0.83, between ultrasound and radiographic imaging measurements of the diaphragm during inhalation, exhalation, and excursion. These findings suggest that ultrasound imaging measurement is useful to accurately evaluate diaphragm movements during tidal breathing. Clinically, ultrasound imaging measurements can be used to diagnose and treat diaphragm movement impairments in individuals with neuromuscular disorders including spinal cord injuries, stroke, and multiple sclerosis. PMID:24211983

  9. Reassessment of chemical control of breathing in undisturbed bullfrogs, Lithobates catesbeianus, using measurements of pulmonary ventilation.

    PubMed

    Santin, Joseph M; Hartzler, Lynn K

    2016-04-01

    Despite the importance of bullfrogs (Lithobates catesbeianus) as models in respiratory control, chemical control of breathing in conscious bullfrogs has never been assessed with methods that measure the tidal volume (VT). This has precluded the calculation of important respiratory variables like minute ventilation (V.E) and air convection requirement. To address this, we adapted airflow pneumotachography for use in bullfrogs and reassessed chemical control of breathing. We show that V.E measured with pneumotachography produces breathing pattern and metabolism values consistent with anurans. Second, we confirm that bullfrogs have small ventilatory responses to hypercarbia that include increases in tidal volume and a post-hypercarbic hyperpnea. We observed that the magnitude of the post-hypercarbic hyperpnea does not depend on ventilatory responses during hypercarbia. Finally, we showed that increases in breathing frequency and VT during hypoxia are differentially regulated with time. These findings comprise the first complete assessment of hypercarbic and hypoxic V.E responses in intact bullfrogs and emphasize the importance of measuring VT. PMID:26478178

  10. Tidal disruption event demographics

    NASA Astrophysics Data System (ADS)

    Kochanek, C. S.

    2016-09-01

    We survey the properties of stars destroyed in tidal disruption events (TDEs) as a function of black hole (BH) mass, stellar mass and evolutionary state, star formation history and redshift. For M_{BH} ≲ 10^7 M_{⊙}, the typical TDE is due to a M* ˜ 0.3 M⊙ M-dwarf, although the mass function is relatively flat for M_{ast } ≲ M_{⊙}. The contribution from older main-sequence stars and sub-giants is small but not negligible. From MBH ≃ 107.5-108.5 M⊙, the balance rapidly shifts to higher mass stars and a larger contribution from evolved stars, and is ultimately dominated by evolved stars at higher BH masses. The star formation history has little effect until the rates are dominated by evolved stars. TDE rates should decline very rapidly towards higher redshifts. The volumetric rate of TDEs is very high because the BH mass function diverges for low masses. However, any emission mechanism which is largely Eddington-limited for low BH masses suppresses this divergence in any observed sample and leads to TDE samples dominated by MBH ≃ 106.0-107.5 M⊙ BHs with roughly Eddington peak accretion rates. The typical fall-back time is relatively long, with 16 per cent having tfb < 10-1 yr (37 d), and 84 per cent having longer time-scales. Many residual rate discrepancies can be explained if surveys are biased against TDEs with these longer tfb, which seems very plausible if tfb has any relation to the transient rise time. For almost any BH mass function, systematic searches for fainter, faster time-scale TDEs in smaller galaxies, and longer time-scale TDEs in more massive galaxies are likely to be rewarded.

  11. Tidal Boundary Conditions in SEAWAT

    USGS Publications Warehouse

    Mulligan, Ann E.; Langevin, Christian; Post, Vincent E.A.

    2011-01-01

    SEAWAT, a U.S. Geological Survey groundwater flow and transport code, is increasingly used to model the effects of tidal motion on coastal aquifers. Different options are available to simulate tidal boundaries but no guidelines exist nor have comparisons been made to identify the most effective approach. We test seven methods to simulate a sloping beach and a tidal flat. The ocean is represented in one of the three ways: directly using a high hydraulic conductivity (high-K) zone and indirect simulation via specified head boundaries using either the General Head Boundary (GHB) or the new Periodic Boundary Condition (PBC) package. All beach models simulate similar water fluxes across the upland boundary and across the sediment-water interface although the ratio of intertidal to subtidal flow is different at low tide. Simulating a seepage face results in larger intertidal fluxes and influences near-shore heads and salinity. Major differences in flow occur in the tidal flat simulations. Because SEAWAT does not simulate unsaturated flow the water table only rises via flow through the saturated zone. This results in delayed propagation of the rising tidal signal inland. Inundation of the tidal flat is delayed as is flow into the aquifer across the flat. This is severe in the high-K and PBC models but mild in the GHB models. Results indicate that any of the tidal boundary options are fine if the ocean-aquifer interface is steep. However, as the slope of that interface decreases, the high-K and PBC approaches perform poorly and the GHB boundary is preferable.

  12. Prospective targeting and control of end-tidal CO2 and O2 concentrations

    PubMed Central

    Slessarev, Marat; Han, Jay; Mardimae, Alexandra; Prisman, Eitan; Preiss, David; Volgyesi, George; Ansel, Cliff; Duffin, James; Fisher, Joseph A

    2007-01-01

    Current methods of forcing end-tidal PCO2 (PETCO2) and PO2 (PETO2) rely on breath-by-breath adjustment of inspired gas concentrations using feedback loop algorithms. Such servo-control mechanisms are complex because they have to anticipate and compensate for the respiratory response to a given inspiratory gas concentration on a breath-by-breath basis. In this paper, we introduce a low gas flow method to prospectively target and control PETCO2 and PETO2 independent of each other and of minute ventilation in spontaneously breathing humans. We used the method to change PETCO2 from control (40 mmHg for PETCO2 and 100 mmHg for PETO2) to two target PETCO2 values (45 and 50 mmHg) at iso-oxia (100 mmHg), PETO2 to two target values (200 and 300 mmHg) at normocapnia (40 mmHg), and PETCO2 with PETO2 simultaneously to the same targets (45 with 200 mmHg and 50 with 300 mmHg). After each targeted value, PETCO2 and PETO2 were returned to control values. Each state was maintained for 30 s. The average difference between target and measured values for PETCO2 was ± 1 mmHg, and for PETO2 was ± 4 mmHg. PETCO2 varied by ± 1 mmHg and PETO2 by ± 5.6 mmHg (s.d.) over the 30 s stages. This degree of control was obtained despite considerable variability in minute ventilation between subjects (± 7.6 l min−1). We conclude that targeted end-tidal gas concentrations can be attained in spontaneously breathing subjects using this prospective, feed-forward, low gas flow system. PMID:17446225

  13. Standardization of exhaled breath condensate (EBC) collection using a feedback regulated breathing pattern

    EPA Science Inventory

    Collection of exhaled breath condensate (EBC) fluid by cooling of expired breath is a potentially valuable approach for the detection of biomarkers associated with disease or exposure to xenobiotics. EBC is generally collected using unregulated breathing patterns, perceived to el...

  14. The effect of breathing an ambient low‐density, hyperoxic gas on the perceived effort of breathing and maximal performance of exercise in well‐trained athletes

    PubMed Central

    Ansley, L; Petersen, D; Thomas, A; Gibson, A St Clair; Robson‐Ansley, P; Noakes, T D

    2007-01-01

    Background The role of the perception of breathing effort in the regulation of performance of maximal exercise remains unclear. Aims To determine whether the perceived effort of ventilation is altered through substituting a less dense gas for normal ambient air and whether this substitution affects performance of maximal incremental exercise in trained athletes. Methods Eight highly trained cyclists (mean SD) maximal oxygen consumption (VO2max) = 69.9 (7.9) (mlO2/kg/min) performed two randomised maximal tests in a hyperbaric chamber breathing ambient air composed of either 35% O2/65% N2 (nitrox) or 35% O2/65% He (heliox). A ramp protocol was used in which power output was incremented at 0.5 W/s. The trials were separated by at least 48 h. The perceived effort of breathing was obtained via Borg Category Ratio Scales at 3‐min intervals and at fatigue. Oxygen consumption (VO2) and minute ventilation (VE) were monitored continuously. Results Breathing heliox did not change the sensation of dyspnoea: there were no differences between trials for the Borg scales at any time point. Exercise performance was not different between the nitrox and heliox trials (peak power output = 451 (58) and 453 (56) W), nor was VO2max (4.96 (0.61) and 4.88 (0.65) l/min) or maximal VE (157 (24) and 163 (22) l/min). Between‐trial variability in peak power output was less than either VO2max or maximal VE. Conclusion Breathing a less dense gas does not improve maximal performance of exercise or reduce the perception of breathing effort in highly trained athletes, although an attenuated submaximal tidal volume and VE with a concomitant reduction in VO2 suggests an improved gas exchange and reduced O2 cost of ventilation when breathing heliox. PMID:17062658

  15. Short-term potentiation of breathing in humans.

    PubMed

    Fregosi, R F

    1991-09-01

    The purpose of this study was to determine if the increase in ventilation induced by hypoxic stimulation of the carotid bodies (CB) persists after cessation of the stimulus in humans. I reasoned that a short-term potentiation (STP) of breathing, sometimes called an "afterdischarge," could be unmasked by combining hypoxia with exercise, because ventilation increases synergistically under these conditions. Seven young healthy men performed mild bicycle exercise (30% peak power) while breathing O2 for 1.5 min ("control" state), and their CB were then stimulated by 1.5 min of hypoxic exercise (10% O2--balance N2). CB stimulation was then terminated by changing the inspirate back to O2 as exercise continued. Inspiratory and expiratory duration (TI and TE) and inspiratory flow and its time integral [tidal volume (VT)] were measured with a pneumotachometer. Inspired minute ventilation (VI) and mean inspiratory flow (VT/TI) declined exponentially after the cessation of CB stimulation, with first-order time constants of 28.6 +/- 6.7 and 24.6 +/- 1.6 (SD) s, respectively. The slow decay of VI was due primarily to potentiation of both TI and TE, although the effect on the latter predominated. Additional experiments in six subjects showed that brief intense CB stimulation with four to five breaths of N2 during mild exercise induced STP of similar magnitude to that observed in the hypoxic exercise experiments. Finally, the imposition of hyperoxia during air breathing exercise at a level of respiratory drive similar to that induced by the hypoxic exercise did not change VI significantly.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1757326

  16. Correlated Variability in the Breathing Pattern and End-Expiratory Lung Volumes in Conscious Humans

    PubMed Central

    Dellaca, Raffaele L.; Aliverti, Andrea; Lo Mauro, Antonella; Lutchen, Kenneth R.; Pedotti, Antonio; Suki, Bela

    2015-01-01

    In order to characterize the variability and correlation properties of spontaneous breathing in humans, the breathing pattern of 16 seated healthy subjects was studied during 40 min of quiet breathing using opto-electronic plethysmography, a contactless technology that measures total and compartmental chest wall volumes without interfering with the subjects breathing. From these signals, tidal volume (VT), respiratory time (TTOT) and the other breathing pattern parameters were computed breath-by-breath together with the end-expiratory total and compartmental (pulmonary rib cage and abdomen) chest wall volume changes. The correlation properties of these variables were quantified by detrended fluctuation analysis, computing the scaling exponentα. VT, TTOT and the other breathing pattern variables showed α values between 0.60 (for minute ventilation) to 0.71 (for respiratory rate), all significantly lower than the ones obtained for end-expiratory volumes, that ranged between 1.05 (for rib cage) and 1.13 (for abdomen) with no significant differences between compartments. The much stronger long-range correlations of the end expiratory volumes were interpreted by a neuromechanical network model consisting of five neuron groups in the brain respiratory center coupled with the mechanical properties of the respiratory system modeled as a simple Kelvin body. The model-based α for VT is 0.57, similar to the experimental data. While the α for TTOT was slightly lower than the experimental values, the model correctly predicted α for end-expiratory lung volumes (1.045). In conclusion, we propose that the correlations in the timing and amplitude of the physiological variables originate from the brain with the exception of end-expiratory lung volume, which shows the strongest correlations largely due to the contribution of the viscoelastic properties of the tissues. This cycle-by-cycle variability may have a significant impact on the functioning of adherent cells in the

  17. Progress in the Development of Volatile Exhaled Breath Signatures of Lung Cancer

    PubMed Central

    Wang, Xiao-Feng; Lim, Sung; Jett, James; Choi, Humberto; Zhang, Qi; Beukemann, Mary; Seeley, Meredith; Martino, Ray; Rhodes, Paul

    2015-01-01

    Rationale: Volatile organic compounds present in the exhaled breath have shown promise as biomarkers of lung cancer. Advances in colorimetric sensor array technology, breath collection methods, and clinical phenotyping may lead to the development of a more accurate breath biomarker. Objectives: Perform a discovery-level assessment of the accuracy of a colorimetric sensor array–based volatile breath biomarker. Methods: Subjects with biopsy-confirmed untreated lung cancer, and others at risk for developing lung cancer, performed tidal breathing into a breath collection instrument designed to expose a colorimetric sensor array to the alveolar portion of the breath. Random forest models were built from the sensor output of 70% of the study subjects and were tested against the remaining 30%. Models were developed to separate cancer and subgroups from control, and to characterize the cancer. Additional models were developed after matching the clinical phenotypes of cancer and control subjects. Measurements and Main Results: Ninety-seven subjects with lung cancer and 182 control subjects participated. The accuracies, reported as C-statistics, for models of cancer and subgroups versus control ranged from 0.794 to 0.861. The accuracy was improved by developing models for cancer and control groups selected through propensity matching for clinical variables. A model built using only subjects from the largest available clinical subgroup (49 subjects) had a C-statistic of 0.982. Models developed and tested to characterize cancer histology, and to compare early- with late-stage cancer, had C-statistics of 0.881–0.960. Conclusions: The colorimetric sensor array signature of exhaled breath volatile organic compounds was capable of distinguishing patients with lung cancer from clinically relevant control subjects in a discovery level trial. The incorporation of clinical phenotypes into the further development of this biomarker may optimize its accuracy. PMID:25965541

  18. Effect of gender on maximal breath-hold time.

    PubMed

    Cherouveim, Evgenia D; Botonis, Petros G; Koskolou, Maria D; Geladas, Nickos D

    2013-05-01

    This study examined the effect of gender on breath-hold time (BHT). Sixteen healthy subjects, eight males (M) and eight females (F), aged 18-30 years, without breath-hold (BH) experience, performed: (a) a pulmonary function test, (b) an incremental cycle ergometer test to exhaustion and (c) a BH protocol, which included eight repeated maximal efforts separated by 2-min intervals on two occasions: without (BHFOI) and with face immersion (BHFI) in cool water (14.8 ± 0.07 °C). Cardiovascular, ventilatory and hematological responses were studied before, during and after BH efforts. Maximal BHT was similar between genders (M: 103.90 ± 25.68 s; F: 104.97 ± 32.71 s, p > 0.05) and unaffected by face immersion (BHFOI: 105.13 ± 28.68 s; BHFI: 103.74 ± 31.19 s, p > 0.05). The aerobic capacity, lung volumes and hematological indexes were higher in males compared to females. BHT was predicted (r (2) = 0.98, p = 0.005) by aerobic capacity, total lung volume, hematocrit and hemoglobin concentration only in males. It was concluded that despite gender differences in physiological and anthropometrical traits, BH ability was not different between males and females, both not experienced in apneas. PMID:23187428

  19. TIDAL LIMITS TO PLANETARY HABITABILITY

    SciTech Connect

    Barnes, Rory; Jackson, Brian; Greenberg, Richard; Raymond, Sean N.

    2009-07-20

    The habitable zones (HZs) of main-sequence stars have traditionally been defined as the range of orbits that intercept the appropriate amount of stellar flux to permit surface water on a planet. Terrestrial exoplanets discovered to orbit M stars in these zones, which are close-in due to decreased stellar luminosity, may also undergo significant tidal heating. Tidal heating may span a wide range for terrestrial exoplanets and may significantly affect conditions near the surface. For example, if heating rates on an exoplanet are near or greater than that on Io (where tides drive volcanism that resurfaces the planet at least every 1 Myr) and produce similar surface conditions, then the development of life seems unlikely. On the other hand, if the tidal heating rate is less than the minimum to initiate plate tectonics, then CO{sub 2} may not be recycled through subduction, leading to a runaway greenhouse that sterilizes the planet. These two cases represent potential boundaries to habitability and are presented along with the range of the traditional HZ for main-sequence, low-mass stars. We propose a revised HZ that incorporates both stellar insolation and tidal heating. We apply these criteria to GJ 581 d and find that it is in the traditional HZ, but its tidal heating alone may be insufficient for plate tectonics.

  20. A Study of the Effects of Breath Management Instruction on the Breathing Mode, Knowledge of Breathing, and Performance Skills of College-Level Brass Players.

    ERIC Educational Resources Information Center

    Phillips, Kenneth H.; Sehmann, Karin Harfst

    1990-01-01

    Investigates the effectiveness of breathing instruction on the breath management, performance, and knowledge of breathing among college-level brass musicians. Finds that breathing instruction significantly improved the breath management and knowledge of the breathing for the experimental groups and the musical range of the trombone players in the…

  1. Meandering: fluvial versus tidal. (Invited)

    NASA Astrophysics Data System (ADS)

    Seminara, G.

    2009-12-01

    Tidal meanders (Marani et al, Water Resour Res, 2002) display similarities as well as important differences from fluvial meanders (Seminara, J Fluid Mech, 2006). Like fluvial meanders they have characteristic wavelengths scaling with channel width: this is why the convergent character of tidal channels leads to meander wavelengths decaying landward. Unlike fluvial meanders, the typical curvature spectra of tidal meanders contain even harmonics: hence, meander skewing does non display any distinct correlation with the flow direction and the known Kinoshita curve, which approximates the shape of fluvial meanders, is not appropriate to tidal meanders. Additional constraints are brought up by the spatial gradients of the basic bed profile connected to the finite length of tidal channels at equilibrium. In fact, it has been theoretically established (Schuttelaars and De Swart, Eur J Mech, B/Fluids, 1996, Seminara et al, J Fluid Mech submitted, 2009) and confirmed by controlled laboratory experiments (Tambroni et al., J Geoph Res, 2005) that tidal channels closed at one end and connected at the other end with a tidal sea, evolve towards an equilibrium configuration characterized by a ‘slow’ landward decay of the average flow depth. An equilibrium length of the channel is then determined by the formation of a shoreline. Channel curvature affects the lateral equilibrium topography and gives rise to a pattern of point bars and scour pools resembling that of fluvial channels. With some notable differences, though. In fact, Solari et al (J Fluid Mech, 2001) showed that long sequences of weakly sinuous identical meandering channels subject to a symmetrical tidal forcing develop a symmetrical bar-pool pattern with small symmetrical oscillations during the tidal cycle. However, in the laboratory investigations of Garotta et al. (Proceedings RCEM5,2007) the bar-pool pattern was somehow unexpected. In a first experiment, it was in phase with curvature only in the inner half of

  2. Tidal disruption of viscous bodies

    NASA Technical Reports Server (NTRS)

    Sridhar, S.; Tremaine, S.

    1992-01-01

    Tidal disruptions are investigated in viscous-fluid planetesimals whose radius is small relative to the distance of closest (parabolic-orbit) approach to a planet. The planetesimal surface is in these conditions always ellipsoidal, facilitating treatment by coupled ODEs which are solvable with high accuracy. While the disrupted planetesimals evolve into needlelike ellipsoids, their density does not decrease. The validity of viscous fluid treatment holds for solid (ice or rock) planetesimals in cases where tidal stresses are greater than material strength, but integrity is maintained by self-gravity.

  3. Beware Postpartum Shortness of Breath

    PubMed Central

    Akpinar, Guleser; Ipekci, Afsin; Gulen, Bedia; Ikizceli, Ibrahim

    2015-01-01

    Peripartum cardiomyopathy (PPCM) is one of the potentially life-threatening complications of pregnancy. We report a case of a 36-year-old female patient who presented with shortness of breath, swelling of feet after giving birth to triplets, and her tests revealed that left ventricle is dilated with its diameter on the borderline and she had EF 35% with advanced systolic dysfunction. Anterior wall and septum were severely hypokinetic. In the presence of these findings, the patient was evaluated as PPCM. PPCM must be considered in the differential diagnosis of a patient presenting with shortness of breath and swelling of feet, which are also common in pregnancy. PMID:26649031

  4. Beware Postpartum Shortness of Breath.

    PubMed

    Akpinar, Guleser; Ipekci, Afsin; Gulen, Bedia; Ikizceli, Ibrahim

    2015-01-01

    Peripartum cardiomyopathy (PPCM) is one of the potentially life-threatening complications of pregnancy. We report a case of a 36-year-old female patient who presented with shortness of breath, swelling of feet after giving birth to triplets, and her tests revealed that left ventricle is dilated with its diameter on the borderline and she had EF 35% with advanced systolic dysfunction. Anterior wall and septum were severely hypokinetic. In the presence of these findings, the patient was evaluated as PPCM. PPCM must be considered in the differential diagnosis of a patient presenting with shortness of breath and swelling of feet, which are also common in pregnancy. PMID:26649031

  5. Tidal frequency estimation for closed basins

    NASA Technical Reports Server (NTRS)

    Eades, J. B., Jr.

    1978-01-01

    A method was developed for determining the fundamental tidal frequencies for closed basins of water, by means of an eigenvalue analysis. The mathematical model employed, was the Laplace tidal equations.

  6. PECONIC ESTUARY PROGRAM TIDAL CREEK STUDY

    EPA Science Inventory

    EEA evaluated ten tidal creeks throughout the Peconic Estuary representing a wide range of watershed variables. Primary focus was directed towards the collection and analysis of the macrobenthic invertebrate communities of these ten tidal creeks. Analysis of the macrobenthic comm...

  7. Pulmonary oedema in breath-hold diving: an unusual presentation and computed tomography findings.

    PubMed

    Gempp, Emmanuel; Sbardella, Fabrice; Cardinale, Mickael; Louge, Pierre

    2013-09-01

    Haemoptysis and pulmonary oedema following deep breath-hold diving have been described in recent years. We describe the case of a 33-year-old healthy military diver who presented symptoms suggestive of pulmonary oedema after two breathhold dives, the first lasting 0.5-1 min and the second 1-2 min, to 6 metres' depth in the sea. The diagnosis was promptly confirmed with chest computed tomography showing bilateral interstitial infiltrates in the upper regions of the lungs. To our knowledge, this is the first report to document pulmonary oedema in this setting of shallow breath-hold diving with atypical radiological presentation. A definite mechanism for this specific distribution of lung injury remains unclear. PMID:24122192

  8. Follow your breath: respiratory interoceptive accuracy in experienced meditators.

    PubMed

    Daubenmier, Jennifer; Sze, Jocelyn; Kerr, Catherine E; Kemeny, Margaret E; Mehling, Wolf

    2013-08-01

    Attention to internal bodily sensations is a core feature of mindfulness meditation. Previous studies have not detected differences in interoceptive accuracy between meditators and nonmeditators on heartbeat detection and perception tasks. We compared differences in respiratory interoceptive accuracy between meditators and nonmeditators in the ability to detect and discriminate respiratory resistive loads and sustain accurate perception of respiratory tidal volume during nondistracted and distracted conditions. Groups did not differ in overall performance on the detection and discrimination tasks; however, meditators were more accurate in discriminating the resistive load with the lowest ceiling effect. Meditators were also more accurate during the nondistracted tracking task at a lag time of 1 s following the breath. Results provide initial support for the notion that meditators have greater respiratory interoceptive accuracy compared to nonmeditators. PMID:23692525

  9. FEV manoeuvre induced changes in breath VOC compositions: an unconventional view on lung function tests

    PubMed Central

    Sukul, Pritam; Schubert, Jochen K.; Oertel, Peter; Kamysek, Svend; Taunk, Khushman; Trefz, Phillip; Miekisch, Wolfram

    2016-01-01

    Breath volatile organic compound (VOC) analysis can open a non-invasive window onto pathological and metabolic processes in the body. Decades of clinical breath-gas analysis have revealed that changes in exhaled VOC concentrations are important rather than disease specific biomarkers. As physiological parameters, such as respiratory rate or cardiac output, have profound effects on exhaled VOCs, here we investigated VOC exhalation under respiratory manoeuvres. Breath VOCs were monitored by means of real-time mass-spectrometry during conventional FEV manoeuvres in 50 healthy humans. Simultaneously, we measured respiratory and hemodynamic parameters noninvasively. Tidal volume and minute ventilation increased by 292 and 171% during the manoeuvre. FEV manoeuvre induced substance specific changes in VOC concentrations. pET-CO2 and alveolar isoprene increased by 6 and 21% during maximum exhalation. Then they decreased by 18 and 37% at forced expiration mirroring cardiac output. Acetone concentrations rose by 4.5% despite increasing minute ventilation. Blood-borne furan and dimethyl-sulphide mimicked isoprene profile. Exogenous acetonitrile, sulphides, and most aliphatic and aromatic VOCs changed minimally. Reliable breath tests must avoid forced breathing. As isoprene exhalations mirrored FEV performances, endogenous VOCs might assure quality of lung function tests. Analysis of exhaled VOC concentrations can provide additional information on physiology of respiration and gas exchange. PMID:27311826

  10. Effects of therapeutic relationship, expectancy, and credibility in breathing therapies for anxiety.

    PubMed

    Kim, Sunyoung; Roth, Walton T; Wollburg, Eileen

    2015-01-01

    The authors investigated the effects of the quality of the therapeutic alliance, expectancy of improvement, and credibility of treatment on the outcome of two breathing therapies for anxiety and panic. Data were collected during a randomized clinical trial evaluating the efficacy of two theoretically opposing, end-tidal pCO2 feedback-assisted breathing therapies for patients experiencing anxiety attacks. In this study, five weekly individual breathing therapy sessions were administered for the patients who were experiencing anxiety attacks as symptoms of various anxiety disorders. The outcome of this trial indicated that regardless of the opposing breathing instructions (raise or lower pCO2) used in the two breathing therapies, patients in both treatment groups improved equally after treatment. Nonspecific factors rather than the different directions of pCO2 changes could have played a role in the improvement. Regression analyses showed that for both therapies patient-rated therapeutic alliance was predictive of improvement at the 1-month follow-up, and that patient-rated confidence that the therapy would produce improvement, an aspect of its credibility, accounted for almost half of the variance in improvement at the 6-month follow-up. Thus, two factors usually considered nonspecific were identified to be potent predictors of treatment outcome. PMID:26035087

  11. [Peculiarities of respiration mechanics in spontaneously breathing newborn infants. 1. Principles of the measurement technics].

    PubMed

    Wauer, R R; Schmalisch, G

    1983-01-01

    Disturbances of breathing mechanics may involve disturbances of ventilation as one cause of hypoxaemia. The qualitative and quantitative analysis of breathing mechanics has several diagnostical and therapeutical advantages, but their application in newborns, under conditions of spontaneous ventilation, is rendered more difficult by the missing co-operation of the newborns and by the missing of suitable measurement devices for a bedside measurement. The determination of parameters of breathing mechanics is based on the measurement of breathing flow rate (V), tidal volume (VT) and esophageal pressure (Pe). Bodyplethysmographs, face masks and nasal prongs can be used for the measurement of V and VT, however, face masks have the most methodological and technical advantages for the bedside application, moreover, they guarantee a very low injury of newborns. Until now the fluid-filled open catheter is used most frequently for the measurement of esophageal pressure, however, it will be replaced in future by the microtip pressure transducer (Tip-catheter), which offers fundamental advantages. In addition to these technical problems the complete clinical application of breathing mechanical investigations is rendered more difficult, because the standardization of the investigative conditions, the parameters and the proposals on evaluation techniques are absent until now. PMID:6670321

  12. FEV manoeuvre induced changes in breath VOC compositions: an unconventional view on lung function tests

    NASA Astrophysics Data System (ADS)

    Sukul, Pritam; Schubert, Jochen K.; Oertel, Peter; Kamysek, Svend; Taunk, Khushman; Trefz, Phillip; Miekisch, Wolfram

    2016-06-01

    Breath volatile organic compound (VOC) analysis can open a non-invasive window onto pathological and metabolic processes in the body. Decades of clinical breath-gas analysis have revealed that changes in exhaled VOC concentrations are important rather than disease specific biomarkers. As physiological parameters, such as respiratory rate or cardiac output, have profound effects on exhaled VOCs, here we investigated VOC exhalation under respiratory manoeuvres. Breath VOCs were monitored by means of real-time mass-spectrometry during conventional FEV manoeuvres in 50 healthy humans. Simultaneously, we measured respiratory and hemodynamic parameters noninvasively. Tidal volume and minute ventilation increased by 292 and 171% during the manoeuvre. FEV manoeuvre induced substance specific changes in VOC concentrations. pET-CO2 and alveolar isoprene increased by 6 and 21% during maximum exhalation. Then they decreased by 18 and 37% at forced expiration mirroring cardiac output. Acetone concentrations rose by 4.5% despite increasing minute ventilation. Blood-borne furan and dimethyl-sulphide mimicked isoprene profile. Exogenous acetonitrile, sulphides, and most aliphatic and aromatic VOCs changed minimally. Reliable breath tests must avoid forced breathing. As isoprene exhalations mirrored FEV performances, endogenous VOCs might assure quality of lung function tests. Analysis of exhaled VOC concentrations can provide additional information on physiology of respiration and gas exchange.

  13. FEV manoeuvre induced changes in breath VOC compositions: an unconventional view on lung function tests.

    PubMed

    Sukul, Pritam; Schubert, Jochen K; Oertel, Peter; Kamysek, Svend; Taunk, Khushman; Trefz, Phillip; Miekisch, Wolfram

    2016-01-01

    Breath volatile organic compound (VOC) analysis can open a non-invasive window onto pathological and metabolic processes in the body. Decades of clinical breath-gas analysis have revealed that changes in exhaled VOC concentrations are important rather than disease specific biomarkers. As physiological parameters, such as respiratory rate or cardiac output, have profound effects on exhaled VOCs, here we investigated VOC exhalation under respiratory manoeuvres. Breath VOCs were monitored by means of real-time mass-spectrometry during conventional FEV manoeuvres in 50 healthy humans. Simultaneously, we measured respiratory and hemodynamic parameters noninvasively. Tidal volume and minute ventilation increased by 292 and 171% during the manoeuvre. FEV manoeuvre induced substance specific changes in VOC concentrations. pET-CO2 and alveolar isoprene increased by 6 and 21% during maximum exhalation. Then they decreased by 18 and 37% at forced expiration mirroring cardiac output. Acetone concentrations rose by 4.5% despite increasing minute ventilation. Blood-borne furan and dimethyl-sulphide mimicked isoprene profile. Exogenous acetonitrile, sulphides, and most aliphatic and aromatic VOCs changed minimally. Reliable breath tests must avoid forced breathing. As isoprene exhalations mirrored FEV performances, endogenous VOCs might assure quality of lung function tests. Analysis of exhaled VOC concentrations can provide additional information on physiology of respiration and gas exchange. PMID:27311826

  14. Understanding Lung Problems: Make Each Breath Healthy

    MedlinePlus

    ... Each Breath Healthy Heath and Aging Understanding Lung Problems—Make Each Breath Healthy Chronic Obstructive Pulmonary Disease ( ... time your likelihood of having a serious lung problem increases, especially if you smoke. Lung problems that ...

  15. Submarines, Spacecraft, and Exhaled Breath

    EPA Science Inventory

    The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled b...

  16. Breathing Problems: An Individualized Program.

    ERIC Educational Resources Information Center

    Vodola, Thomas M.

    As one of the components of the Project ACTIVE (All Children Totally Involved Exercising) Teacher Training Model Kit, the manual is designed to enable the educator to organize, conduct, and evaluate individualized-personalized physical education programs for children (prekindergarten through high school) with breathing problems. An introductory…

  17. Particle Size Concentration Distribution and Influences on Exhaled Breath Particles in Mechanically Ventilated Patients

    PubMed Central

    Chen, Yi-Fang; Huang, Sheng-Hsiu; Wang, Yu-Ling; Chen, Chun-Wan

    2014-01-01

    Humans produce exhaled breath particles (EBPs) during various breath activities, such as normal breathing, coughing, talking, and sneezing. Airborne transmission risk exists when EBPs have attached pathogens. Until recently, few investigations had evaluated the size and concentration distributions of EBPs from mechanically ventilated patients with different ventilation mode settings. This study thus broke new ground by not only evaluating the size concentration distributions of EBPs in mechanically ventilated patients, but also investigating the relationship between EBP level and positive expiratory end airway pressure (PEEP), tidal volume, and pneumonia. This investigation recruited mechanically ventilated patients, with and without pneumonia, aged 20 years old and above, from the respiratory intensive care unit of a medical center. Concentration distributions of EBPs from mechanically ventilated patients were analyzed with an optical particle analyzer. This study finds that EBP concentrations from mechanically ventilated patients during normal breathing were in the range 0.47–2,554.04 particles/breath (0.001–4.644 particles/mL). EBP concentrations did not differ significantly between the volume control and pressure control modes of the ventilation settings in the mechanically ventilated patients. The patient EBPs were sized below 5 µm, and 80% of them ranged from 0.3 to 1.0 µm. The EBPs concentrations in patients with high PEEP (> 5 cmH2O) clearly exceeded those in patients with low PEEP (≤ 5 cmH2O). Additionally, a significant negative association existed between pneumonia duration and EBPs concentration. However, tidal volume was not related to EBPs concentration. PMID:24475230

  18. Breathing variability and brainstem serotonergic loss in a genetic model of multiple system atrophy.

    PubMed

    Flabeau, Olivier; Meissner, Wassilios G; Ozier, Annaig; Berger, Patrick; Tison, François; Fernagut, Pierre-Olivier

    2014-03-01

    Breathing disorders like sleep apnea, stridor, and dysrythmic breathing are frequent in patients with multiple system atrophy (MSA). These observations have been related to neurodegeneration in several pontomedullary respiratory nuclei and may explain the occurrence of sudden death. In this study, we sought to determine whether these functional and neuropathological characteristics could be replicated in a transgenic model of MSA. Mice expressing human wild-type α-synuclein under the control of the proteolipid promoter (PLP-αSYN) were compared with age-matched controls. Using whole-body, unrestrained plethysmography, the following breathing parameters were measured: inspiratory and expiratory times, tidal volume, expiratory volume, peak inspiratory and expiratory flows, and respiratory frequency. For each category, the mean, coefficient of variation, and irregularity score were analyzed. Brains were then processed for stereological cell counts of pontomedullary respiratory nuclei. A significant increase in the coefficient of variation and irregularity score was observed for inspiratory time, tidal volume, and expiratory volume in PLP-αSYN mice (P < 0.05). Glial cytoplasmic inclusions were found in the medullary raphe of PLP-αSYN mice, together with a loss of serotonergic immunoreactivity in the raphe obscurus (P < 0.001) and pallidus (P < 0.01). There was a negative correlation between α-synuclein burden and raphe pallidus cell counts (P < 0.05). There was no significant neuronal loss in the pre-Botzinger complex. The PLP-αSYN mouse model replicates the breathing variability and part of the neuronal depletion in pontomedullary respiratory nuclei observed in patients with MSA. Our findings support the use of this model for future candidate drugs in the breathing disorders observed in MSA. PMID:24442757

  19. 21 CFR 868.5620 - Breathing mouthpiece.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing mouthpiece. 868.5620 Section 868.5620...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5620 Breathing mouthpiece. (a) Identification. A breathing mouthpiece is a rigid device that is inserted into a patient's mouth and...

  20. Functional Analysis and Intervention for Breath Holding.

    ERIC Educational Resources Information Center

    Kern, Lee; And Others

    1995-01-01

    A functional analysis of breath-holding episodes in a 7-year-old girl with severe mental retardation and Cornelia-de-Lange syndrome indicated that breath holding served an operant function, primarily to gain access to attention. Use of extinction, scheduled attention, and a picture card communication system decreased breath holding. (Author/SW)

  1. Neural Mechanisms Underlying Breathing Complexity

    PubMed Central

    Hess, Agathe; Yu, Lianchun; Klein, Isabelle; De Mazancourt, Marine; Jebrak, Gilles; Mal, Hervé; Brugière, Olivier; Fournier, Michel; Courbage, Maurice; Dauriat, Gaelle; Schouman-Clayes, Elisabeth; Clerici, Christine; Mangin, Laurence

    2013-01-01

    Breathing is maintained and controlled by a network of automatic neurons in the brainstem that generate respiratory rhythm and receive regulatory inputs. Breathing complexity therefore arises from respiratory central pattern generators modulated by peripheral and supra-spinal inputs. Very little is known on the brainstem neural substrates underlying breathing complexity in humans. We used both experimental and theoretical approaches to decipher these mechanisms in healthy humans and patients with chronic obstructive pulmonary disease (COPD). COPD is the most frequent chronic lung disease in the general population mainly due to tobacco smoke. In patients, airflow obstruction associated with hyperinflation and respiratory muscles weakness are key factors contributing to load-capacity imbalance and hence increased respiratory drive. Unexpectedly, we found that the patients breathed with a higher level of complexity during inspiration and expiration than controls. Using functional magnetic resonance imaging (fMRI), we scanned the brain of the participants to analyze the activity of two small regions involved in respiratory rhythmogenesis, the rostral ventro-lateral (VL) medulla (pre-Bötzinger complex) and the caudal VL pons (parafacial group). fMRI revealed in controls higher activity of the VL medulla suggesting active inspiration, while in patients higher activity of the VL pons suggesting active expiration. COPD patients reactivate the parafacial to sustain ventilation. These findings may be involved in the onset of respiratory failure when the neural network becomes overwhelmed by respiratory overload We show that central neural activity correlates with airflow complexity in healthy subjects and COPD patients, at rest and during inspiratory loading. We finally used a theoretical approach of respiratory rhythmogenesis that reproduces the kernel activity of neurons involved in the automatic breathing. The model reveals how a chaotic activity in neurons can

  2. Capillary electrophoresis--a new tool for ionic analysis of exhaled breath condensate.

    PubMed

    Kubáň, Petr; Kobrin, Eeva-Gerda; Kaljurand, Mihkel

    2012-12-01

    Exhaled breath condensate has been analyzed for its ionic content by capillary electrophoresis with capacitively coupled contactless conductometric detection. A simple device for collection of small volumes (100-200 μL) of exhaled breath condensate in less than 2 min was developed. A method for simultaneous determination of inorganic cations, inorganic anions and organic anions from the samples using dual-opposite end injection principle with a short fused silica capillary (35 cm, 50 μm I.D.) was developed. A background electrolyte composed of 20mM 2-(N-morpholino)ethanesulfonic acid, 20 mM l-histidine, 30 μM cetyltrimethylammonium bromide and 2mM 18-crown-6 was used. The analysis time was less than 3 min with limits of detection reaching low μM levels for most of the anions and cations. It has been shown that changes of nitrite could be observed in acute inflammation of upper airways and in a person with diagnosed mild chronic obstructive pulmonary disease, while changes of other ions could also be observed. Lactate concentrations could also be monitored and about 4-fold increase of lactate concentration in exhaled breath condensate was determined following an exhaustive cycling exercise. The developed non-invasive sampling of exhaled breath condensate, followed by rapid capillary electrophoretic analysis, could be very useful in lung inflammatory disease screening as well as in monitoring fast metabolic processes such as lactate build-up and removal. PMID:22796027

  3. Spleen volume and blood flow response to repeated breath-hold apneas.

    PubMed

    Baković, Darija; Valic, Zoran; Eterović, Davor; Vukovic, Ivica; Obad, Ante; Marinović-Terzić, Ivana; Dujić, Zeljko

    2003-10-01

    The purpose of this study was 1) to answer whether the reduction in spleen size in breath-hold apnea is an active contraction or a passive collapse secondary to reduced splenic arterial blood flow and 2) to monitor the spleen response to repeated breath-hold apneas. Ten trained apnea divers and 10 intact and 7 splenectomized untrained persons repeated five maximal apneas (A1-A5) with face immersion in cold water, with 2 min interposed between successive attempts. Ultrasonic monitoring of the spleen and noninvasive cardiopulmonary measurements were performed before, between apneas, and at times 0, 10, 20, 40, and 60 min after the last apnea. Blood flows in splenic artery and splenic vein were not significantly affected by breath-hold apnea. The duration of apneas peaked after A3 (143, 127, and 74 s in apnea divers, intact, and splenectomized persons, respectively). A rapid decrease in spleen volume ( approximately 20% in both apnea divers and intact persons) was mainly completed throughout the first apnea. The spleen did not recover in size between apneas and only partly recovered 60 min after A5. The well-known physiological responses to apnea diving, i.e., bradycardia and increased blood pressure, were observed in A1 and remained unchanged throughout the following apneas. These results show rapid, probably active contraction of the spleen in response to breath-hold apnea in humans. Rapid spleen contraction and its slow recovery may contribute to prolongation of successive, briefly repeated apnea attempts. PMID:12819225

  4. Differences in spontaneous breathing pattern and mechanics in patients with severe COPD recovering from acute exacerbation.

    PubMed

    Vitacca, M; Porta, R; Bianchi, L; Clini, E; Ambrosino, N

    1999-02-01

    The aims of this study were to assess spontaneous breathing patterns in patients with chronic obstructive pulmonary disease (COPD) recovering from acute exacerbation and to assess the relationship between different breathing patterns and clinical and functional parameters of respiratory impairment. Thirty-four COPD patients underwent assessment of lung function tests, arterial blood gases, haemodynamics, breathing pattern (respiratory frequency (fR), tidal volume (VT), inspiratory and expiratory time (tI and tE), duty cycle (tI/ttot), VT/tI) and mechanics (oesophageal pressure (Poes), work of breathing (WOB), pressure-time product and index, and dynamic intrinsic positive end-expiratory pressure (PEEPi,dyn)). According to the presence (group 1) or absence (group 2) of Poes swings during the expiratory phase (premature inspiration), 20 (59%) patients were included in group 1 and 14 (41%) in group 2. Premature inspirations were observed 4.5+/-6.4 times x min(-1) (range 1-31), i.e. 20+/-21% (3.7-100%) of total fR calculated from VT tracings. In group 1 the coefficient of variation in VT, tE, tI/ttot, PEEPi,dyn, Poes and WOB of the eight consecutive breaths immediately preceding the premature inspiration was greater than that of eight consecutive breaths in group 2. There were no significant differences in the assessed parameters between the two groups in the overall population, whereas patients with chronic hypoxaemia in group 1 showed a more severe impairment in clinical conditions, mechanics and lung function than hypoxaemic patients in group 2. In spontaneously breathing patients with chronic obstructive pulmonary disease recovering from an acute exacerbation, detectable activity of inspiratory muscles during expiration was found in more than half of the cases. This phenomenon was not associated with any significant differences in anthropometric, demographic, physiological or clinical characteristics. PMID:10065683

  5. Horses Auto-Recruit Their Lungs by Inspiratory Breath Holding Following Recovery from General Anaesthesia

    PubMed Central

    Mosing, Martina; Waldmann, Andreas D.; MacFarlane, Paul; Iff, Samuel; Auer, Ulrike; Bohm, Stephan H.; Bettschart-Wolfensberger, Regula; Bardell, David

    2016-01-01

    This study evaluated the breathing pattern and distribution of ventilation in horses prior to and following recovery from general anaesthesia using electrical impedance tomography (EIT). Six horses were anaesthetised for 6 hours in dorsal recumbency. Arterial blood gas and EIT measurements were performed 24 hours before (baseline) and 1, 2, 3, 4, 5 and 6 hours after horses stood following anaesthesia. At each time point 4 representative spontaneous breaths were analysed. The percentage of the total breath length during which impedance remained greater than 50% of the maximum inspiratory impedance change (breath holding), the fraction of total tidal ventilation within each of four stacked regions of interest (ROI) (distribution of ventilation) and the filling time and inflation period of seven ROI evenly distributed over the dorso-ventral height of the lungs were calculated. Mixed effects multi-linear regression and linear regression were used and significance was set at p<0.05. All horses demonstrated inspiratory breath holding until 5 hours after standing. No change from baseline was seen for the distribution of ventilation during inspiration. Filling time and inflation period were more rapid and shorter in ventral and slower and longer in most dorsal ROI compared to baseline, respectively. In a mixed effects multi-linear regression, breath holding was significantly correlated with PaCO2 in both the univariate and multivariate regression. Following recovery from anaesthesia, horses showed inspiratory breath holding during which gas redistributed from ventral into dorsal regions of the lungs. This suggests auto-recruitment of lung tissue which would have been dependent and likely atelectic during anaesthesia. PMID:27331910

  6. Evaluation of Fractional Regional Ventilation Using 4D-CT and Effects of Breathing Maneuvers on Ventilation

    SciTech Connect

    Mistry, Nilesh N.; Diwanji, Tejan; Shi, Xiutao; Pokharel, Sabin; Feigenberg, Steven; Scharf, Steven M.; D'Souza, Warren D.

    2013-11-15

    Purpose: Current implementations of methods based on Hounsfield units to evaluate regional lung ventilation do not directly incorporate tissue-based mass changes that occur over the respiratory cycle. To overcome this, we developed a 4-dimensional computed tomography (4D-CT)-based technique to evaluate fractional regional ventilation (FRV) that uses an individualized ratio of tidal volume to end-expiratory lung volume for each voxel. We further evaluated the effect of different breathing maneuvers on regional ventilation. The results from this work will help elucidate the relationship between global and regional lung function. Methods and Materials: Eight patients underwent 3 sets of 4D-CT scans during 1 session using free-breathing, audiovisual guidance, and active breathing control. FRV was estimated using a density-based algorithm with mass correction. Internal validation between global and regional ventilation was performed by use of the imaging data collected during the use of active breathing control. The impact of breathing maneuvers on FRV was evaluated comparing the tidal volume from 3 breathing methods. Results: Internal validation through comparison between the global and regional changes in ventilation revealed a strong linear correlation (slope of 1.01, R{sup 2} of 0.97) between the measured global lung volume and the regional lung volume calculated by use of the “mass corrected” FRV. A linear relationship was established between the tidal volume measured with the automated breathing control system and FRV based on 4D-CT imaging. Consistently larger breathing volumes were observed when coached breathing techniques were used. Conclusions: The technique presented improves density-based evaluation of lung ventilation and establishes a link between global and regional lung ventilation volumes. Furthermore, the results obtained are comparable with those of other techniques of functional evaluation such as spirometry and hyperpolarized-gas magnetic

  7. Correlation of regional breath sound with regional ventilation in emphysema

    SciTech Connect

    Ploysongsang, Y.; Pare, J.A.; Macklem, P.T.

    1982-09-01

    We measured regional breath sound intensities (Ib) by a microphone amplifier system in 8 subjects with emphysema. We also measured regional white noise transmissions (Tn) from the same areas in all subjects. The recorded areas were 5, 10, 15, and 20 cm from the apex of the lung just lateral to the right anterior midclavicular line. Xenon ventilation indexes (xenon tidal raw counts, an index of total regional ventilation; xenon equilibration raw counts, an index of ventilating lung volume; xenon ventilation per unit volume (Vr), an index of ventilation per unit volume) were also recorded from the same areas. The Ib, Tn, Ib/Tn (an index of sound generation), and xenon ventilation indexes were all expressed as a fraction of the mean value of all four recorded areas. The Ib and Ib/Tn correlated best with the xenon tidal raw counts, correlated well with the xenon equilibration raw counts, and correlated poorly with Vr. We conclude that Ib and Ib/Tn can be used to quantify regional ventilation in subjects with emphysema.

  8. Breathing and affective picture processing across the adult lifespan.

    PubMed

    Gomez, Patrick; Filippou, Dimitra; Pais, Bruno; von Gunten, Armin; Danuser, Brigitta

    2016-09-01

    The present study investigated differences between healthy younger, middle-aged, and older adults in their respiratory responses to pictures of different valence and arousal. Expiratory time shortened and end-tidal PCO2 decreased with increasing arousal in all age groups; yet, compared to younger adults, older adults' overall change from baseline was smaller for expiratory time and larger for end-tidal PCO2. Contrary to their younger counterparts, older adults' inspiratory time did not shorten with increasing arousal. Inspiratory duty cycle did not covary with affective ratings for younger adults, increased with unpleasantness for middle-aged adults, and increased with arousal for older adults. Thoracic breathing increased with increasing unpleasantness only among older adults. Age had no effects on mean inspiratory flow and minute ventilation, which both augmented as arousal increased. We discuss how age effects on respiratory response magnitude and pattern may depend on age-associated biological changes or reflect age-related differences in emotional processing. PMID:27417701

  9. Drive mechanism for production of simulated human breath

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Lambert, J. W.; Morison, W. B.

    1972-01-01

    Simulated breath drive mechanism was developed as subsystem to breathing metabolic simulator. Mechanism reproduces complete range of human breath rate, breath depth, and breath waveform, as well as independently controlled functional residual capacity. Mechanism was found capable of simulating various individual human breathing characteristics without any changes of parts.

  10. Modeling the tidal and sub-tidal hydrodynamics in a shallow, micro-tidal estuary

    NASA Astrophysics Data System (ADS)

    Rayson, Matthew D.; Gross, Edward S.; Fringer, Oliver B.

    2015-05-01

    The three-dimensional hydrodynamics of Galveston Bay were simulated in two periods of several month duration. The physical setting of Galveston Bay is described by synthesis of long-term observations. Several processes in addition to tidal hydrodynamics and baroclinic circulation processes contribute substantially to the observed variability of currents, water level and salinity. The model was therefore forced with realistic water levels, river discharges, winds, coastal buoyancy currents (due to the Mississippi River plume) and surface heat fluxes. Quantitative metrics were used to evaluate model performance against observations and both spatial and temporal variability in tidal and sub-tidal hydrodynamics were generally well represented by the model. Three different unstructured meshes were tested, a triangular mesh that under-resolved the shipping channel, a triangular mesh that resolved it, and a mixed quadrilateral-triangular grid with approximately equivalent resolution. It is shown that salinity and sub-tidal velocity are better predicted when the important topographic features, such as the shipping channel, are resolved. It was necessary to increase the seabed drag roughness in the mixed quadrilateral-triangular grid simulation to attain similar performance to the equivalent triangular mesh.

  11. Influence of drive and timing mechanisms on breathing pattern and ventilation during mental task performance.

    PubMed

    Wientjes, C J; Grossman, P; Gaillard, A W

    1998-09-01

    Assessment of multiple respiratory measures may provide insight into how behavioral demands affect the breathing pattern. This is illustrated by data from a study among 44 subjects, in which tidal volume, respiration rate, minute ventilation and indices of central drive and timing mechanisms were assessed via inductive plethysmography, in addition to end-tidal PCO2. After a baseline, three conditions of a memory comparison task were presented. The first two conditions differed only with regard to the presence or absence of feedback of performance (NFB and FB). In the third 'all-or-nothing' (AON) condition, subjects only received a monetary bonus, if their performance exceeded that of the previous two conditions. Minute ventilation increased from baseline to all task conditions, and from NFB and FB to AON. Respiration rate increased in all task conditions, but there were no differences between task conditions. Tidal volume decreased during NFB, but was equal to baseline during FB and AON. Of the respiratory control indices, inspiratory flow rate covaried much more closely with minute ventilation than duty cycle. The task performance induced a minor degree of hyperventilation. The discussion focusses on how behavioral demands affect respiratory control processes to produce alterations in breathing pattern and ventilation. PMID:9792484

  12. Effect of ketamine on control of breathing in cats.

    PubMed

    Jaspar, N; Mazzarelli, M; Tessier, C; Milic-Emili, J

    1983-09-01

    We studied minute ventilation, breathing pattern, end-tidal CO2 partial pressure (PACO2), and tracheal occlusion pressure in cats anesthetized with ketamine (40 and 80 mg/kg) before and after CO2 inhalation. Before CO2 administration ventilation was reduced and PACO2 increased relative to unanesthetized cats at both ketamine doses. Breathing pattern was of the "apneustic" type, being characterized by 1) prolonged inspiratory duration and relatively short expiratory time and 2) markedly curvilinear (convex upward) inspiratory volume-time profile. The latter reflected a similar curvilinearity in the tracheal occlusion pressure waveform. During CO2 inhalation, the ventilatory response to CO2 was similar to that in unanesthetized cats in spite of a depressed tracheal occlusion pressure response. This discrepancy was due to the fact that in the presence of a convex upward inspiratory volume-time profile, the shortening of inspiratory duration with increasing CO2 results in a marked increase of mean inspiratory flow, and hence the ventilatory response to CO2 remains high. PMID:6415013

  13. Maine Tidal Power Initiative: Environmental Impact Protocols For Tidal Power

    SciTech Connect

    Peterson, Michael Leroy; Zydlewski, Gayle Barbin; Xue, Huijie; Johnson, Teresa R.

    2014-02-02

    The Maine Tidal Power Initiative (MTPI), an interdisciplinary group of engineers, biologists, oceanographers, and social scientists, has been conducting research to evaluate tidal energy resources and better understand the potential effects and impacts of marine hydro-kinetic (MHK) development on the environment and local community. Project efforts include: 1) resource assessment, 2) development of initial device design parameters using scale model tests, 3) baseline environmental studies and monitoring, and 4) human and community responses. This work included in-situ measurement of the environmental and social response to the pre-commercial Turbine Generator Unit (TGU®) developed by Ocean Renewable Power Company (ORPC) as well as considering the path forward for smaller community scale projects.

  14. Changes in partial pressures of respiratory gases during submerged voluntary breath hold across odontocetes: is body mass important?

    PubMed

    Noren, S R; Williams, T M; Ramirez, K; Boehm, J; Glenn, M; Cornell, L

    2012-02-01

    Odontocetes have an exceptional range in body mass spanning 10(3) kg across species. Because, size influences oxygen utilization and carbon dioxide production rates in mammals, this lineage likely displays an extraordinary variation in oxygen store management compared to other marine mammal groups. To examine this, we measured changes in the partial pressures of respiratory gases ([Formula: see text], [Formula: see text]), pH, and lactate in the blood during voluntary, quiescent, submerged breath holds in Pacific white-sided dolphins (Lagenorhynchus obliquidens), bottlenose dolphins (Tursiops truncatus), and a killer whale (Orcinus orca) representing a mass range of 96-3,850 kg. These measurements provided an empirical determination of the effect of body size on the variability in blood biochemistry during breath hold and experimentally determined aerobic dive limits (ADL) within one taxonomic group (odontocetes). For the species in this study, maximum voluntary breath-hold duration was positively correlated with body mass, ranging from 3.5 min in white-sided dolphins to 13.3 min for the killer whale. Variation in breath-hold duration was associated with differences in the rate of change for [Formula: see text] throughout breath hold; [Formula: see text] decreased twice as fast for the two smaller species (-0.6 mmHg O(2) min(-1)) compared to the largest species (-0.3 mmHg O(2) min(-1)). In contrast, the rate of increase in [Formula: see text] during breath hold was similar across species. These results demonstrate that large body size in odontocetes facilitates increased aerobic breath-hold capacity as mediated by decreased mass-specific metabolic rates (rates of change in [Formula: see text] served as a proxy for oxygen utilization). Indeed the experimentally determined 5 min ADL for bottlenose dolphins was surpassed by the 13.3 min maximum breath hold of the killer whale, which did not end in a rise in lactate. Rather, breath hold ended voluntarily as respiratory

  15. Simulating hydrodynamics on tidal mudflats

    NASA Astrophysics Data System (ADS)

    Cook, S.; Lippmann, T. C.

    2014-12-01

    Biogeochemical cycling in estuaries is governed by fluxes from both riverine sources and through estuarine sediment deposits. Although estimates from river sources are relatively common and easily sampled, estimates of nutrient fluxes through the fluid-sediment interface are less common and limited to deeper portions of the bays away from intertidal areas. Lack of quantifiable shear stress estimates over intertidal areas limits our overall understanding of nutrient budgets in estuaries. Unfortunately, observation of intertidal hydrodynamics and nutrient fluxes over tidal flats and near the water's edge is difficult owing to the temporally varying and spatially extensive region where the tides inundate, and thus numerical modeling is often employed. In this work, the Regional Ocean Modeling System (ROMS), a three dimensional numerical hydrodynamic model was used to investigate the shear stresses over intertidal mudflats in the Great Bay, a tidally-dominated New England estuary cut by several tidal channels and with over 50% of the estuary exposed at low tide. The ROMS wetting and drying scheme was used to simulate the rising and falling tide on the flats, a successful approach adapted in other regions of the world but not always inclusive of tidal channels. Bathymetric data obtained in 2009 and 2013 was used to define the model grid. Predicted tides are forced at Adam's Pt., a natural constriction in the estuary about 20 km upstream of the mouth and at the entrance to the Great Bay. Of particular interest are fluxes of material on-to and off-of the tidal flats which contribute to water quality conditions in the estuary, and are largely governed by shear stresses that drive nutrient fluxes at the fluid-sediment interface. Basin wide estimates of near-bottom shear stresses can be used to estimate first order nutrient fluxes over a tidal cycle and hence describe general biogeochemical dynamics of the estuary. Future work will include enhanced forcing of currents by

  16. Analysis of Exhaled Breath for Disease Detection

    NASA Astrophysics Data System (ADS)

    Amann, Anton; Miekisch, Wolfram; Schubert, Jochen; Buszewski, Bogusław; Ligor, Tomasz; Jezierski, Tadeusz; Pleil, Joachim; Risby, Terence

    2014-06-01

    Breath analysis is a young field of research with great clinical potential. As a result of this interest, researchers have developed new analytical techniques that permit real-time analysis of exhaled breath with breath-to-breath resolution in addition to the conventional central laboratory methods using gas chromatography-mass spectrometry. Breath tests are based on endogenously produced volatiles, metabolites of ingested precursors, metabolites produced by bacteria in the gut or the airways, or volatiles appearing after environmental exposure. The composition of exhaled breath may contain valuable information for patients presenting with asthma, renal and liver diseases, lung cancer, chronic obstructive pulmonary disease, inflammatory lung disease, or metabolic disorders. In addition, oxidative stress status may be monitored via volatile products of lipid peroxidation. Measurement of enzyme activity provides phenotypic information important in personalized medicine, whereas breath measurements provide insight into perturbations of the human exposome and can be interpreted as preclinical signals of adverse outcome pathways.

  17. Reconstruction of 4D-CT data sets acquired during free breathing for the analysis of respiratory motion

    NASA Astrophysics Data System (ADS)

    Ehrhardt, Jan; Werner, Rene; Frenzel, Thorsten; Säring, Dennis; Lu, Wei; Low, Daniel; Handels, Heinz

    2006-03-01

    Respiratory motion is a significant source of error in radiotherapy treatment planning. 4D-CT data sets can be useful to measure the impact of organ motion caused by breathing. But modern CT scanners can only scan a limited region of the body simultaneously and patients have to be scanned in segments consisting of multiple slices. For studying free breathing motion multislice CT scans can be collected simultaneously with digital spirometry over several breathing cycles. The 4D data set is assembled by sorting the free breathing multislice CT scans according to the couch position and the tidal volume. But artifacts can occur because there are no data segments for exactly the same tidal volume and all couch positions. We present an optical flow based method for the reconstruction of 4D-CT data sets from multislice CT scans, which are collected simultaneously with digital spirometry. The optical flow between the scans is estimated by a non-linear registration method. The calculated velocity field is used to reconstruct a 4D-CT data set by interpolating data at user-defined tidal volumes. By this technique, artifacts can be reduced significantly. The reconstructed 4D-CT data sets are used for studying inner organ motion during the respiratory cycle. The procedures described were applied to reconstruct 4D-CT data sets for four tumour patients who have been scanned during free breathing. The reconstructed 4D data sets were used to quantify organ displacements and to visualize the abdominothoracic organ motion.

  18. Tidal Debris Around Merger Remnants.

    NASA Astrophysics Data System (ADS)

    McQullan, Maria

    2015-01-01

    We present images of the interacting pair NGC 3310. These images were taken using the HDI camera on the 0.9m at Kitt Peak in Arizona. NGC 3310 is a starburst galaxy which recently underwent a collision with a much smaller mass galaxy. It has been postulated that this galaxy was then scattered in the orbit of NGC 3310 creating multiple tidal loops around the galaxy. In order to observe and study these loops, the data must be clear of noise within 1% error. We present our method of correcting to this precision level and an analysis of the tidal loop system. We will also discuss the implications of this stellar debris on the evolutionary history of this galaxy.

  19. Tidal acceleration of the moon

    NASA Technical Reports Server (NTRS)

    Williams, J. G.; Sinclair, W. S.; Yoder, C. F.

    1978-01-01

    The analysis of eight years of lunar laser ranging data yields a value for the tidally induced secular acceleration of the lunar orbital longitude of -23.8 + or - 4 arcsec/century per century. For semidiurnal tidal frequencies this corresponds to a terrestrial Q = 12 + or - 2. The error in n is dominated by noise in the data and its modeling. The error is expected to decrease significantly as future data become available and it may become possible to detect an 18.6-yr periodic modulation of the acceleration which would allow the separation of the effects of diurnal and semidiurnal tides. Comparison of the secular acceleration with values published from the analysis of classical astronomical observations does not show a significant difference which can be attributed to a changing gravitational constant.

  20. A Non-Invasive Method for Estimating Cardiopulmonary Variables Using Breath-by-Breath Injection of Two Tracer Gases

    PubMed Central

    Clifton, David A.; Hahn, Clive E. W.; Farmeryy, Andrew D.

    2013-01-01

    Conventional methods for estimating cardiopulmonary variables usually require complex gas analyzers and the active co-operation of the patient. Therefore, they are not compatible with the crowded environment of the intensive care unit (ICU) or operating theatre, where patient co-operation is typically impossible. However, it is these patients that would benefit the most from accurate estimation of cardiopulmonary variables, because of their critical condition. This paper describes the results of a collaborative development between an anesthesiologists and biomedical engineers to create a compact and non-invasive system for the measurement of cardiopulmonary variables such as lung volume, airway dead space volume, and pulmonary blood flow. In contrast with conventional methods, the compact apparatus and non-invasive nature of the proposed method allow it to be used in the ICU, as well as in general clinical settings. We propose the use of a non-invasive method, in which tracer gases are injected into the patient's inspired breath, and the concentration of the tracer gases is subsequently measured. A novel breath-by-breath tidal ventilation model is then used to estimate the value of a patient's cardiopulmonary variables. Experimental results from an artificial lung demonstrate minimal error in the estimation of known parameters using the proposed method. Results from analysis of a cohort of 20 healthy volunteers (within the Oxford University Hospitals NHS Trust) show that the values of estimated cardiopulmonary variables from these subjects lies within the expected ranges. Advantages of this method are that it is non-invasive, compact, portable, and can perform analysis in real time with less than 1 min of acquired respiratory data. PMID:27170849

  1. Self-contained breathing apparatus

    NASA Technical Reports Server (NTRS)

    Sullivan, J. L.; Giorgini, E. A.; Simmonds, M. R. (Inventor)

    1976-01-01

    A self-contained breathing apparatus with automatic redundant fluid pressure controls and a facemask mounted low pressure whistle alarm is described. The first stage of the system includes pair of pressure regulators connected in parallel with different outlet pressures, both of which reduce the pressure of the stored supply gas to pressures compatible with the second stage breathing demand regulator. A primary regulator in the first stage delivers a low output pressure to the demand regulator. In the event of a failure closed condition of the primary regulator an automatic transfer valve switches on the backup regulator. A warning that the supply pressure has been depleted is also provided by a supply pressure actuated transfer valve which transfers the output of the first stage pressure regulators from the primary to the backup regulator. The alarm is activated in either the failure closed condition or if the supply pressure is reduced to a dangerously low level.

  2. The athlete "out of breath".

    PubMed

    Couto, M; Moreira, A

    2016-03-01

    Athletes often complain about breathing problems. This is a crucial issue due to potential implications not only on their general health, but also on their competing performance. Asthma and exercise-induced bronchoconstriction are prevalent conditions in elite athletes, which leads doctors to rely most of the times on asthma medication to treat athletes feeling "out of breath". However, there are several other conditions that may mimic asthma and cause dyspnea in athletes. Effective treatment of dyspnea requires appropriate identification and treatment of all disorders. Proper knowledge and accurate diagnosis of such entities is mandatory, since asthma medication is not effective in those conditions. Herein we review the most common differential diagnosis of dyspnea in athletes, and describe the diagnostic strategies in order to increase awareness and to improve doctor's confidence on dealing with these patients. PMID:26934737

  3. Dynamical modeling of tidal streams

    SciTech Connect

    Bovy, Jo

    2014-11-01

    I present a new framework for modeling the dynamics of tidal streams. The framework consists of simple models for the initial action-angle distribution of tidal debris, which can be straightforwardly evolved forward in time. Taking advantage of the essentially one-dimensional nature of tidal streams, the transformation to position-velocity coordinates can be linearized and interpolated near a small number of points along the stream, thus allowing for efficient computations of a stream's properties in observable quantities. I illustrate how to calculate the stream's average location (its 'track') in different coordinate systems, how to quickly estimate the dispersion around its track, and how to draw mock stream data. As a generative model, this framework allows one to compute the full probability distribution function and marginalize over or condition it on certain phase-space dimensions as well as convolve it with observational uncertainties. This will be instrumental in proper data analysis of stream data. In addition to providing a computationally efficient practical tool for modeling the dynamics of tidal streams, the action-angle nature of the framework helps elucidate how the observed width of the stream relates to the velocity dispersion or mass of the progenitor, and how the progenitors of 'orphan' streams could be located. The practical usefulness of the proposed framework crucially depends on the ability to calculate action-angle variables for any orbit in any gravitational potential. A novel method for calculating actions, frequencies, and angles in any static potential using a single orbit integration is described in the Appendix.

  4. Spatial patterns of tidal heating

    NASA Astrophysics Data System (ADS)

    Beuthe, Mikael

    2013-03-01

    In a body periodically strained by tides, heating produced by viscous friction is far from homogeneous. The spatial distribution of tidal heating depends in a complicated way on the tidal potential and on the internal structure of the body. I show here that the distribution of the dissipated power within a spherically stratified body is a linear combination of three angular functions. These angular functions depend only on the tidal potential whereas the radial weights are specified by the internal structure of the body. The 3D problem of predicting spatial patterns of dissipation at all radii is thus reduced to the 1D problem of computing weight functions. I compute spatial patterns in various toy models without assuming a specific rheology: a viscoelastic thin shell stratified in conductive and convective layers, an incompressible homogeneous body and a two-layer model of uniform density with a liquid or rigid core. For a body in synchronous rotation undergoing eccentricity tides, dissipation in a mantle surrounding a liquid core is highest at the poles. Within a soft layer (or asthenosphere) in contact with a more rigid layer, the same tides generate maximum heating in the equatorial region with a significant degree-four structure if the soft layer is thin. The asthenosphere can be a layer of partial melting in the upper mantle or, very differently, an icy layer in contact with a silicate mantle or solid core. Tidal heating patterns are thus of three main types: mantle dissipation (with the icy shell above an ocean as a particular case), dissipation in a thin soft layer and dissipation in a thick soft layer. Finally, I show that the toy models predict well patterns of dissipation in Europa, Titan and Io. The formalism described in this paper applies to dissipation within solid layers of planets and satellites for which internal spherical symmetry and viscoelastic linear rheology are good approximations.

  5. Dynamical Modeling of Tidal Streams

    NASA Astrophysics Data System (ADS)

    Bovy, Jo

    2014-11-01

    I present a new framework for modeling the dynamics of tidal streams. The framework consists of simple models for the initial action-angle distribution of tidal debris, which can be straightforwardly evolved forward in time. Taking advantage of the essentially one-dimensional nature of tidal streams, the transformation to position-velocity coordinates can be linearized and interpolated near a small number of points along the stream, thus allowing for efficient computations of a stream's properties in observable quantities. I illustrate how to calculate the stream's average location (its "track") in different coordinate systems, how to quickly estimate the dispersion around its track, and how to draw mock stream data. As a generative model, this framework allows one to compute the full probability distribution function and marginalize over or condition it on certain phase-space dimensions as well as convolve it with observational uncertainties. This will be instrumental in proper data analysis of stream data. In addition to providing a computationally efficient practical tool for modeling the dynamics of tidal streams, the action-angle nature of the framework helps elucidate how the observed width of the stream relates to the velocity dispersion or mass of the progenitor, and how the progenitors of "orphan" streams could be located. The practical usefulness of the proposed framework crucially depends on the ability to calculate action-angle variables for any orbit in any gravitational potential. A novel method for calculating actions, frequencies, and angles in any static potential using a single orbit integration is described in the Appendix.

  6. Tidally-Induced Thermonuclear Supernovae

    SciTech Connect

    Rosswog, S.; Ramirez-Ruiz, E.; Hix, William Raphael

    2009-01-01

    We discuss the results of 3D simulations of tidal disruptions of white dwarfs by moderate-mass black holes as they may exist in the cores of globular clusters or dwarf galaxies. Our simulations follow self-consistently the hydrodynamic and nuclear evolution from the initial parabolic orbit over the disruption to the build-up of an accretion disk around the black hole. For strong enough encounters (pericentre distances smaller than about 1/3 of the tidal radius) the tidal compression is reversed by a shock and finally results in a thermonuclear explosion. These explosions are not restricted to progenitor masses close to the Chandrasekhar limit, we find exploding examples throughout the whole white dwarf mass range. There is, however, a restriction on the masses of the involved black holes: black holes more massive than 2x105M{circle_dot} swallow a typical 0.6M{circle_dot} white dwarf before their tidal forces can overwhelm the star's selfgravity. Therefore, this mechanism is characteristic for black holes of moderate masses. The material that remains bound to the black hole settles into an accretion disk and produces an Xray flare close to the Eddington limit of L{sub Edd} {approx} 10{sup 41}erg/s (Mbh/1000M{circle_dot}), typically lasting for a few months. The combination of a peculiar thermonuclear supernova together with an X-ray flare thus whistle-blows the existence of such moderate-mass black holes. The next generation of wide field space-based instruments should be able to detect such events.

  7. North American tidal power prospects

    NASA Astrophysics Data System (ADS)

    Wayne, W. W., Jr.

    1981-07-01

    Prospects for North American tidal power electrical generation are reviewed. Studies by the US Army Corps of Engineers of 90 possible generation schemes in Cobscook Bay, ME, indicated that maximum power generation rather than dependable capacity was the most economic method. Construction cost estimates for 15 MW bulb units in a single effect mode from basin to the sea are provided; five projects were considered ranging from 110-160 MW. Additional tidal power installations are examined for: Half-Moon Cove, ME (12 MW, 18 ft tide); Cook Inlet, AK, which is shown to pose severe environmental and engineering problems due to fish migration, earthquake hazards, and 300 ft deep silt deposits; and the Bay of Fundy, Canada. This last has a 17.8 MW plant under construction in a 29 ft maximum tide area. Other tidal projects of the Maritime Provinces are reviewed, and it is noted that previous economic evaluations based on an oil price of $16/barrel are in need of revision.

  8. Tidal Locking Of The Earth

    NASA Astrophysics Data System (ADS)

    Koohafkan, Michael

    2006-05-01

    The Moon's orbit and spin period are nearly synchronized, or tidally locked. Could the Moon's orbit and the Earth's spin eventually synchronize as well? The Moon's gravitational pull on the Earth produces tides in our oceans, and tidal friction gradually lengthens our days. Less obvious gravitational interactions between the Earth and Moon may also have effects on Earth's spin. The Earth is slightly distorted into an egg-like shape, and the torque exerted by the Moon on our equatorial bulge slowly changes the tilt of our spin axis. How do effects such as these change as the Moon drifts away from Earth? I will examine gravitational interactions between Earth and Moon to learn how they contribute to the deceleration of the Earth's rotation. My goal is to determine the amount of time it would take for the Earth's rotational speed to decelerate until the period of a single rotation matches the period of the Moon's orbit around Earth -- when the Earth is ``tidally locked'' with the Moon. I aim to derive a general mathematical expression for the rotational deceleration of the Earth due to Moon's gravitational influences.

  9. ARRAY OPTIMIZATION FOR TIDAL ENERGY EXTRACTION IN A TIDAL CHANNEL – A NUMERICAL MODELING ANALYSIS

    SciTech Connect

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea

    2014-04-18

    This paper presents an application of a hydrodynamic model to simulate tidal energy extraction in a tidal dominated estuary in the Pacific Northwest coast. A series of numerical experiments were carried out to simulate tidal energy extraction with different turbine array configurations, including location, spacing and array size. Preliminary model results suggest that array optimization for tidal energy extraction in a real-world site is a very complex process that requires consideration of multiple factors. Numerical models can be used effectively to assist turbine siting and array arrangement in a tidal turbine farm for tidal energy extraction.

  10. Breathing Mode in Complex Plasmas

    NASA Astrophysics Data System (ADS)

    Fujioka, K.; Henning, C.; Ludwig, P.; Bonitz, M.; Melzer, A.; Vitkalov, S.

    2007-11-01

    The breathing mode is a fundamental normal mode present in Coulomb systems, and may have utility in identifying particle charge and the Debye length of certain systems. The question remains whether this mode can be extended to strongly coupled Yukawa balls [1]. These systems are characterized by particles confined within a parabolic potential well and interacting through a shielded Coulomb potential [2,3]. The breathing modes for a variety of systems in 1, 2, and 3 dimensions are computed by solving the eigenvalue problem given by the dynamical (Hesse) matrix. These results are compared to theoretical investigations that assume a strict definition for a breathing mode within the system, and an analysis is made of the most fitting model to utilize in the study of particular systems of complex plasmas [1,4]. References [1] T.E. Sheridan, Phys. of Plasmas. 13, 022106 (2006)[2] C. Henning et al., Phys. Rev. E 74, 056403 (2006)[3] M. Bonitz et al., Phys. Rev. Lett. 96, 075001 (2006)[4] C. Henning et al., submitted for publication

  11. Breathing Dynamics in Heteropolymer DNA

    PubMed Central

    Ambjörnsson, Tobias; Banik, Suman K.; Krichevsky, Oleg; Metzler, Ralf

    2007-01-01

    While the statistical mechanical description of DNA has a long tradition, renewed interest in DNA melting from a physics perspective is nourished by measurements of the fluctuation dynamics of local denaturation bubbles by single molecule spectroscopy. The dynamical opening of DNA bubbles (DNA breathing) is supposedly crucial for biological functioning during, for instance, transcription initiation and DNA's interaction with selectively single-stranded DNA binding proteins. Motivated by this, we consider the bubble breathing dynamics in a heteropolymer DNA based on a (2+1)-variable master equation and complementary stochastic Gillespie simulations, providing the bubble size and the position of the bubble along the sequence as a function of time. We utilize new experimental data that independently obtain stacking and hydrogen bonding contributions to DNA stability. We calculate the spectrum of relaxation times and the experimentally measurable autocorrelation function of a fluorophore-quencher tagged basepair, and demonstrate good agreement with fluorescence correlation experiments. A significant dependence of opening probability and waiting time between bubble events on the local DNA sequence is revealed and quantified for a promoter sequence of the T7 phage. The strong dependence on sequence, temperature and salt concentration for the breathing dynamics of DNA found here points at a good potential for nanosensing applications by utilizing short fluorophore-quencher dressed DNA constructs. PMID:17237209

  12. Running and Breathing in Mammals

    NASA Astrophysics Data System (ADS)

    Bramble, Dennis M.; Carrier, David R.

    1983-01-01

    Mechanical constraints appear to require that locomotion and breathing be synchronized in running mammals. Phase locking of limb and respiratory frequency has now been recorded during treadmill running in jackrabbits and during locomotion on solid ground in dogs, horses, and humans. Quadrupedal species normally synchronize the locomotor and respiratory cycles at a constant ratio of 1:1 (strides per breath) in both the trot and gallop. Human runners differ from quadrupeds in that while running they employ several phase-locked patterns (4:1, 3:1, 2:1, 1:1, 5:2, and 3:2), although a 2:1 coupling ratio appears to be favored. Even though the evolution of bipedal gait has reduced the mechanical constraints on respiration in man, thereby permitting greater flexibility in breathing pattern, it has seemingly not eliminated the need for the synchronization of respiration and body motion during sustained running. Flying birds have independently achieved phase-locked locomotor and respiratory cycles. This hints that strict locomotor-respiratory coupling may be a vital factor in the sustained aerobic exercise of endothermic vertebrates, especially those in which the stresses of locomotion tend to deform the thoracic complex.

  13. Exhaled breath analysis and sleep.

    PubMed

    Carpagnano, Giovanna E

    2011-10-15

    It is currently estimated that the economic burden for obstructive sleep apnea syndrome (OSAS) cases not coming to medical attention is steadily increasing, thus making OSAS a major public health concern. For its increasing incidence among the common population, the interest of researchers and clinicians has been recently directed to the study of pathological mechanisms underlying sleep disorders. Current opinion is that airway inflammation and oxidative stress play a crucial role in the pathophysiology of OSAS. Recently there has been increasing interest in the investigation of lungs by non-invasive means measuring the exhaled breath volatile mediators, such as nitric oxide (NO), carbon monoxide (CO), ethane and pentane and finally the non-volatile substances in the liquid phase of exhalate, termed breath condensate. The non-invasiveness of these techniques for the study of airways affected by different respiratory disorders and among those, the OSAS, makes these ideally suited for the evaluation and serial monitoring of patients. Notwithstanding the increasing number of scientific contributions on the use of the exhaled markers in sleep disorders, at the moment, their use is not completely suitable for clinical application. An important contribution to the increase of our knowledge on exhaled markers and for their possible concrete application in clinical practice may come from future studies using proteomics, genomics and metabolomics. In this review, we focus on exhaled breath analysis giving an update on its general aspects, its application in OSAS, and finally its actual clinical applicability and areas for future direction. PMID:22003329

  14. Air-Breathing Rocket Engines

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This photograph depicts an air-breathing rocket engine prototype in the test bay at the General Applied Science Lab facility in Ronkonkoma, New York. Air-breathing engines, known as rocket based, combined-cycle engines, get their initial take-off power from specially designed rockets, called air-augmented rockets, that boost performance about 15 percent over conventional rockets. When the vehicle's velocity reaches twice the speed of sound, the rockets are turned off and the engine relies totally on oxygen in the atmosphere to burn hydrogen fuel, as opposed to a rocket that must carry its own oxygen, thus reducing weight and flight costs. Once the vehicle has accelerated to about 10 times the speed of sound, the engine converts to a conventional rocket-powered system to propel the craft into orbit or sustain it to suborbital flight speed. NASA's Advanced Space Transportation Program at Marshall Space Flight Center, along with several industry partners and collegiate forces, is developing this technology to make space transportation affordable for everyone from business travelers to tourists. The goal is to reduce launch costs from today's price tag of $10,000 per pound to only hundreds of dollars per pound. NASA's series of hypersonic flight demonstrators currently include three air-breathing vehicles: the X-43A, X-43B and X-43C.

  15. Dispersion in tidally averaged transport equation

    USGS Publications Warehouse

    Cheng, R.T.; Casulli, V.

    1992-01-01

    A general governing inter-tidal transport equation for conservative solutes has been derived without invoking the weakly nonlinear approximation. The governing inter-tidal transport equation is a convection-dispersion equation in which the convective velocity is a mean Lagrangian residual current, and the inter-tidal dispersion coefficient is defined by a dispersion patch. When the weakly nonlinear condition is violated, the physical significance of the Stokes' drift, as used in tidal dynamics, becomes questionable. For nonlinear problems, analytical solutions for the mean Lagrangian residual current and for the inter-tidal dispersion coefficient do not exist, they must be determined numerically. A rectangular tidal inlet with a constriction is used in the first example. The solutions of the residual currents and the computed properties of the inter-tidal dispersion coefficient are used to illuminate the mechanisms of the inter-tidal transport processes. Then, the present formulation is tested in a geometrically complex tidal estuary – San Francisco Bay, California. The computed inter-tidal dispersion coefficients are in the range between 5×104 and 5×106 cm2/sec., which are consistent with the values reported in the literature

  16. TIDAL FRICTION AND TIDAL LAGGING. APPLICABILITY LIMITATIONS OF A POPULAR FORMULA FOR THE TIDAL TORQUE

    SciTech Connect

    Efroimsky, Michael; Makarov, Valeri V. E-mail: vvm@usno.navy.mil

    2013-02-10

    Tidal torques play a key role in rotational dynamics of celestial bodies. They govern these bodies' tidal despinning and also participate in the subtle process of entrapment of these bodies into spin-orbit resonances. This makes tidal torques directly relevant to the studies of habitability of planets and their moons. Our work begins with an explanation of how friction and lagging should be built into the theory of bodily tides. Although much of this material can be found in various publications, a short but self-consistent summary on the topic has been lacking in the hitherto literature, and we are filling the gap. After these preparations, we address a popular concise formula for the tidal torque, which is often used in the literature, for planets or stars. We explain why the derivation of this expression, offered in the paper by Goldreich and in the books by Kaula (Equation (4.5.29)) and Murray and Dermott (Equation (4.159)), implicitly sets the time lag to be frequency independent. Accordingly, the ensuing expression for the torque can be applied only to bodies having a very special (and very hypothetical) rheology which makes the time lag frequency independent, i.e., the same for all Fourier modes in the spectrum of tide. This expression for the torque should not be used for bodies of other rheologies. Specifically, the expression cannot be combined with an extra assertion of the geometric lag being constant, because at finite eccentricities the said assumption is incompatible with the constant-time-lag condition.

  17. Breathing pattern--gas exchange relation and acute effect of almitrine in severe chronic airflow obstruction.

    PubMed

    Damato, S; Bellone, A; Castelli, T; Mendoza, M; Daniele, R

    1988-01-01

    Using a double-blind cross-over design, a single oral dose of 100 mg almitrine bismethylate and placebo were administered to 7 patients with chronic airflow limitation. In all patients, arterial blood gases at rest, ventilation and breathing pattern at rest and on exercise were measured before and 3 h after administration. Ventilation increased and PaCO2 decreased after almitrine; the mean PaO2 increase was statistically significant after active drug but the value increased more when tidal volume increased. It is concluded that in man the well-documented improvement in the V/Q relationship after almitrine is in part related to a pure ventilatory effect though the possibility of increasing ventilation by mainly increasing tidal volume. PMID:2907669

  18. State-dependent control of breathing by the retrotrapezoid nucleus

    PubMed Central

    Burke, Peter GR; Kanbar, Roy; Basting, Tyler M; Hodges, Walter M; Viar, Kenneth E; Stornetta, Ruth L; Guyenet, Patrice G

    2015-01-01

    Key points This study explores the state dependence of the hypercapnic ventilatory reflex (HCVR). We simulated an instantaneous increase or decrease of central chemoreceptor activity by activating or inhibiting the retrotrapezoid nucleus (RTN) by optogenetics in conscious rats. During quiet wake or non-REM sleep, hypercapnia increased both breathing frequency (fR) and tidal volume (VT) whereas, in REM sleep, hypercapnia increased VT exclusively. Optogenetic inhibition of RTN reduced VT in all sleep–wake states, but reduced fR only during quiet wake and non-REM sleep. RTN stimulation always increased VT but raised fR only in quiet wake and non-REM sleep. Phasic RTN stimulation produced active expiration and reduced early expiratory airflow (i.e. increased upper airway resistance) only during wake. We conclude that the HCVR is highly state-dependent. The HCVR is reduced during REM sleep because fR is no longer under chemoreceptor control and thus could explain why central sleep apnoea is less frequent in REM sleep. Abstract Breathing has different characteristics during quiet wake, non-REM or REM sleep, including variable dependence on . We investigated whether the retrotrapezoid nucleus (RTN), a proton-sensitive structure that mediates a large portion of the hypercapnic ventilatory reflex, regulates breathing differently during sleep vs. wake. Electroencephalogram, neck electromyogram, blood pressure, respiratory frequency (fR) and tidal volume (VT) were recorded in 28 conscious adult male Sprague–Dawley rats. Optogenetic stimulation of RTN with channelrhodopsin-2, or inhibition with archaerhodopsin, simulated an instantaneous increase or decrease of central chemoreceptor activity. Both opsins were delivered with PRSX8-promoter-containing lentiviral vectors. RTN and catecholaminergic neurons were transduced. During quiet wake or non-REM sleep, hypercapnia (3 or 6% ) increased both fR and VT whereas, in REM sleep, hypercapnia increased VT exclusively. RTN

  19. TIDAL NOVAE IN COMPACT BINARY WHITE DWARFS

    SciTech Connect

    Fuller, Jim; Lai Dong

    2012-09-01

    Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in the inner stellar envelope and the dissipation of these waves in the outer envelope. As the binary orbit decays, the WDs are synchronized from outside in (with the envelope synchronized first, followed by the core). We examine the deposition of tidal heat in the envelope of a carbon-oxygen WD and study how such tidal heating affects the structure and evolution of the WD. We show that significant tidal heating can occur in the star's degenerate hydrogen layer. This layer heats up faster than it cools, triggering runaway nuclear fusion. Such 'tidal novae' may occur in all WD binaries containing a CO WD, at orbital periods between 5 minutes and 20 minutes, and precede the final merger by 10{sup 5}-10{sup 6} years.

  20. Gravitoelectromagnetic analogy based on tidal tensors

    SciTech Connect

    Costa, L. Filipe O.; Herdeiro, Carlos A. R.

    2008-07-15

    We propose a new approach to a physical analogy between general relativity and electromagnetism, based on tidal tensors of both theories. Using this approach we write a covariant form for the gravitational analogues of the Maxwell equations, which makes transparent both the similarities and key differences between the two interactions. The following realizations of the analogy are given. The first one matches linearized gravitational tidal tensors to exact electromagnetic tidal tensors in Minkowski spacetime. The second one matches exact magnetic gravitational tidal tensors for ultrastationary metrics to exact magnetic tidal tensors of electromagnetism in curved spaces. In the third we show that our approach leads to a two-step exact derivation of Papapetrou's equation describing the force exerted on a spinning test particle. Analogous scalar invariants built from tidal tensors of both theories are also discussed.

  1. Tidal acceleration of black holes and superradiance

    NASA Astrophysics Data System (ADS)

    Cardoso, Vitor; Pani, Paolo

    2013-02-01

    Tidal effects have long ago locked the Moon in a synchronous rotation with the Earth and progressively increase the Earth-Moon distance. This ‘tidal acceleration’ hinges on dissipation. Binaries containing black holes may also be tidally accelerated, dissipation being caused by the event horizon—a flexible, viscous one-way membrane. In fact, this process is known for many years under a different guise: superradiance. Here, we provide compelling evidence for a strong connection between tidal acceleration and superradiant scattering around spinning black holes. In general relativity, tidal acceleration is obscured by the gravitational-wave emission. However, when coupling to light scalar degrees of freedom is allowed, an induced dipole moment produces a ‘polarization acceleration’, which might be orders of magnitude stronger than tidal quadrupolar effects. Consequences for optical and gravitational-wave observations are intriguing and it is not impossible that imprints of such a mechanism have already been observed.

  2. Repetitive transcranial magnetic stimulation over the supplementary motor area modifies breathing pattern in response to inspiratory loading in normal humans

    PubMed Central

    Nierat, Marie-Cécile; Hudson, Anna L.; Chaskalovic, Joël; Similowski, Thomas; Laviolette, Louis

    2015-01-01

    In awake humans, breathing depends on automatic brainstem pattern generators. It is also heavily influenced by cortical networks. For example, functional magnetic resonance imaging and electroencephalographic data show that the supplementary motor area becomes active when breathing is made difficult by inspiratory mechanical loads like resistances or threshold valves, which is associated with perceived respiratory discomfort. We hypothesized that manipulating the excitability of the supplementary motor area with repetitive transcranial magnetic stimulation would modify the breathing pattern response to an experimental inspiratory load and possibly respiratory discomfort. Seven subjects (three men, age 25 ± 4) were studied. Breathing pattern and respiratory discomfort during inspiratory loading were described before and after conditioning the supplementary motor area with repetitive stimulation, using an excitatory paradigm (5 Hz stimulation), an inhibitory paradigm, or sham stimulation. No significant change in breathing pattern during loading was observed after sham conditioning. Excitatory conditioning shortened inspiratory time (p = 0.001), decreased tidal volume (p = 0.016), and decreased ventilation (p = 0.003), as corroborated by an increased end-tidal expired carbon dioxide (p = 0.013). Inhibitory conditioning did not affect ventilation, but lengthened expiratory time (p = 0.031). Respiratory discomfort was mild under baseline conditions, and unchanged after conditioning of the supplementary motor area. This is the first study to show that repetitive transcranial magnetic stimulation conditioning of the cerebral cortex can alter breathing pattern. A 5 Hz conditioning protocol, known to enhance corticophrenic excitability, can reduce the amount of hyperventilation induced by inspiratory threshold loading. Further studies are needed to determine whether and under what circumstances rTMS can have an effect on dyspnoea. PMID:26483701

  3. Regulation of brain blood flow and oxygen delivery in elite breath-hold divers.

    PubMed

    Willie, Christopher K; Ainslie, Philip N; Drvis, Ivan; MacLeod, David B; Bain, Anthony R; Madden, Dennis; Maslov, Petra Zubin; Dujic, Zeljko

    2015-01-01

    The roles of involuntary breathing movements (IBMs) and cerebral oxygen delivery in the tolerance to extreme hypoxemia displayed by elite breath-hold divers are unknown. Cerebral blood flow (CBF), arterial blood gases (ABGs), and cardiorespiratory metrics were measured during maximum dry apneas in elite breath-hold divers (n=17). To isolate the effects of apnea and IBM from the concurrent changes on ABG, end-tidal forcing ('clamp') was then used to replicate an identical temporal pattern of decreasing arterial PO2 (PaO2) and increasing arterial PCO2 (PaCO2) while breathing. End-apnea PaO2 ranged from 23 to 37 mm Hg (30 ± 7 mm Hg). Elevation in mean arterial pressure was greater during apnea than during clamp reaching +54 ± 24% versus 34 ± 26%, respectively; however, CBF increased similarly between apnea and clamp (93.6 ± 28% and 83.4 ± 38%, respectively). This latter observation indicates that during the overall apnea period IBM per se do not augment CBF and that the brain remains sufficiently protected against hypertension. Termination of apnea was not determined by reduced cerebral oxygen delivery; despite 40% to 50% reductions in arterial oxygen content, oxygen delivery was maintained by commensurately increased CBF. PMID:25370857

  4. How to interpret hydrogen breath tests.

    PubMed

    Ghoshal, Uday C

    2011-07-01

    Hydrogen breath tests using various substrates like glucose, lactulose, lactose and fructose are being used more and more to diagnose small intestinal bacterial overgrowth (SIBO) and lactose or fructose malabsorption. Though quantitative culture of jejunal aspirate is considered as gold standard for the diagnosis of SIBO, hydrogen breath tests, in spite of their low sensitivity, are popular for their non-invasiveness. Glucose hydrogen breath test is more acceptable for the diagnosis of SIBO as conventionally accepted double-peak criterion on lactulose hydrogen breath test is very insensitive and recently described early-peak criterion is often false positive. Hydrogen breath test is useful to diagnose various types of sugar malabsorption. Technique and interpretation of different hydrogen breath tests are outlined in this review. PMID:21860825

  5. Graph-based retrospective 4D image construction from free-breathing MRI slice acquisitions

    NASA Astrophysics Data System (ADS)

    Tong, Yubing; Udupa, Jayaram K.; Ciesielski, Krzysztof C.; McDonough, Joseph M.; Mong, Andrew; Campbell, Robert M.

    2014-03-01

    4D or dynamic imaging of the thorax has many potential applications [1, 2]. CT and MRI offer sufficient speed to acquire motion information via 4D imaging. However they have different constraints and requirements. For both modalities both prospective and retrospective respiratory gating and tracking techniques have been developed [3, 4]. For pediatric imaging, x-ray radiation becomes a primary concern and MRI remains as the de facto choice. The pediatric subjects we deal with often suffer from extreme malformations of their chest wall, diaphragm, and/or spine, as such patient cooperation needed by some of the gating and tracking techniques are difficult to realize without causing patient discomfort. Moreover, we are interested in the mechanical function of their thorax in its natural form in tidal breathing. Therefore free-breathing MRI acquisition is the ideal modality of imaging for these patients. In our set up, for each coronal (or sagittal) slice position, slice images are acquired at a rate of about 200-300 ms/slice over several natural breathing cycles. This produces typically several thousands of slices which contain both the anatomic and dynamic information. However, it is not trivial to form a consistent and well defined 4D volume from these data. In this paper, we present a novel graph-based combinatorial optimization solution for constructing the best possible 4D scene from such data entirely in the digital domain. Our proposed method is purely image-based and does not need breath holding or any external surrogates or instruments to record respiratory motion or tidal volume. Both adult and children patients' data are used to illustrate the performance of the proposed method. Experimental results show that the reconstructed 4D scenes are smooth and consistent spatially and temporally, agreeing with known shape and motion of the lungs.

  6. Calculating lunar retreat rates using tidal rhythmites

    USGS Publications Warehouse

    Kvale, E.P.; Johnson, H.W.; Sonett, C.P.; Archer, A.W.; Zawistoski, A.N.N.

    1999-01-01

    Tidal rhythmites are small-scale sedimenta??r}- structures that can preserve a hierarchy of astronomically induced tidal periods. They can also preserve a record of periodic nontidal sedimentation. If properly interpreted and understood, tidal rhjthmites can be an important component of paleoastronomy and can be used to extract information on ancient lunar orbital dynamics including changes in Earth-Moon distance through geologic time. Herein we present techniques that can be used to calculate ancient Earth-Moon distances. Each of these techniques, when used on a modern high-tide data set, results in calculated estimates of lunar orbital periods and an EarthMoon distance that fall well within 1 percent of the actual values. Comparisons to results from modern tidal data indicate that ancient tidal rhythmite data as short as 4 months can provide suitable estimates of lunar orbital periods if these tidal records are complete. An understanding of basic tidal theory allows for the evaluation of completeness of the ancient tidal record as derived from an analysis of tidal rhythmites. Utilizing the techniques presented herein, it appears from the rock record that lunar orbital retreat slowed sometime during the midPaleozoic. Copyright ??1999, SEPM (Society for Sedimentary Geology).

  7. Sleep disordered breathing in pregnancy

    PubMed Central

    2015-01-01

    Key points Sleep disordered breathing (SDB) is common and the severity increases as pregnancy progresses. Frequent snoring, older age and high pre-pregnancy body mass index (>25 kg⋅m−2) could be reliable indicators for SDB in early pregnancy. SDB screening tools, including questionnaires, used in the nonpregnant population have poor predictive ability in pregnancy. Accumulating evidence suggests that SDB during pregnancy may be associated with increased risk of adverse pregnancy outcomes, including gestational diabetes and pre-eclampsia. However, the results should be interpreted cautiously because several studies failed to adjust for potential maternal confounders and have other study limitations. There are no pregnancy-specific practice guidelines for SDB treatment. Many clinicians and practices follow recommendations for the treatment in the general population. Women with pre-existing SDB might need to be reassessed, particularly after the sixth month of pregnancy, because symptoms can worsen with nasal congestion and weight gain. Educational aims To highlight the prevalence and severity of sleep disordered breathing (SDB) in the pregnant population. To inform readers about risk factors for SDB in pregnancy. To explore the impact of SDB on adverse maternal and fetal outcomes, and biological pathways for associated adverse maternal and fetal outcomes. To introduce current management options for SDB in pregnancy, including medical and behavioural approaches. Sleep disordered breathing (SDB) is very common during pregnancy, and is most likely explained by hormonal, physiological and physical changes. Maternal obesity, one of the major risk factors for SDB, together with physiological changes in pregnancy may predispose women to develop SDB. SDB has been associated with poor maternal and fetal outcomes. Thus, early identification, diagnosis and treatment of SDB are important in pregnancy. This article reviews the pregnancy-related changes affecting the

  8. Calculating rhythmicity of infant breathing using wavelets

    NASA Astrophysics Data System (ADS)

    Macey, Katherine E.; Page, Wyatt H.; Harper, Ronald M.; Macey, Paul M.; Ford, Rodney P. K.

    2000-12-01

    Breathing signals are one set of physiological data that may provide information regarding the mechanisms that cause SIDS. Isolated breathing pauses have been implicated in fatal events. Other features of interest include slow amplitude modulation of the breathing signal, a phenomenon whose origin is unclear, and periodic breathing. The latter describes a repetitive series of apnea, and may be considered an extreme manifestation of amplitude modulation with successive cessations of breathing. Rhythmicity is defined to assess the impact of amplitude modulation on breathing signals and describes the extent to which frequency components remain constant for the duration of the signal. The wavelet transform was used to identify sections of constant frequency components within signals. Rhythmicity can be evaluated for all the frequency components in a signal, for individual frequencies. The rhythmicity of eight breathing epochs from sleeping infants at high and low risk for SIDS was calculated. Initial results show breathing from infants at high risk for SIDS exhibits greater rhythmicity of modulating frequencies than breathing from low risk infants.

  9. Tidal disruption of solid bodies

    NASA Technical Reports Server (NTRS)

    Dobrovolskis, Anthony R.

    1990-01-01

    The problem of stress, strain, and breakup in solid satellites and stray bodies subject to tidal perturbations is presently addressed in view of three novel considerations. After presenting a new analytic solution for the stress tensor in a homogeneous and compressible elastic sphere, where the inclusion of compressibility alters stresses by several percent, realistic failure criteria are noted to demonstrate the general failure of such ductile bodies as iron meteoroids by plastic shear, while brittle ice bodies fail by either tensile or shear fracture. A reexamination of crack propagation after initial failure allows the diverse breakup criteria to be reconciled.

  10. The chemical neuroanatomy of breathing

    PubMed Central

    Alheid, George F.; McCrimmon, Donald R.

    2008-01-01

    The chemical neuroanatomy of breathing must ultimately encompass all the various neuronal elements physiologically identified in brainstem respiratory circuits and their apparent aggregation into “compartments” within the medulla and pons. These functionally defined respiratory compartments in the brainstem provide the major source of input to cranial motoneurons controlling the airways, and to spinal motoneurons activating inspiratory and expiratory pump muscles. This review provides an overview of the neuroanatomy of the major compartments comprising brainstem respiratory circuits, and a synopsis of the transmitters used by their constituent respiratory neurons. PMID:18706532

  11. 42 CFR 84.72 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.72...-Contained Breathing Apparatus § 84.72 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with breathing apparatus shall be designed and constructed to prevent: (a)...

  12. 42 CFR 84.85 - Breathing bags; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing bags; minimum requirements. 84.85 Section...-Contained Breathing Apparatus § 84.85 Breathing bags; minimum requirements. (a) Breathing bags shall have.... (b) Breathing bags shall be constructed of materials which are flexible and resistant to...

  13. Breathing

    MedlinePlus Videos and Cool Tools

    ... size of the thoracic cavity and decreases the pressure inside. As a result, air rushes in and ... volume of the thoracic cavity decreases, while the pressure within it increases. As a result, the lungs ...

  14. Breathing

    MedlinePlus Videos and Cool Tools

    ... respiratory system conduct air to the lungs, such as the trachea (windpipe) which branches into smaller structures ... the thoracic cavity and decreases the pressure inside. As a result, air rushes in and fills the ...

  15. News from the Breath Analysis Summit 2011.

    PubMed

    Corradi, Massimo; Mutti, Antonio

    2012-05-23

    This special section highlights some of the important work presented at the Breath Analysis Summit 2011, which was held in Parma (Italy) from 11 to 14 September 2011. The meeting, which was jointly organized by the International Association for Breath Research and the University of Parma, was attended by more than 250 delegates from 33 countries, and offered 34 invited lectures and 64 unsolicited scientific contributions. The summit was organized to provide a forum to scientists, engineers and clinicians to present their latest findings and to meet industry executives and entrepreneurs to discuss key trends, future directions and technologies available for breath analysis. A major focus was on nitric oxide, exhaled breath condensate, electronic nose, mass spectrometry and newer sensor technologies. Medical applications ranged from asthma and other respiratory diseases to gastrointestinal disease, occupational diseases, critical care and cancer. Most people identify breath tests with breathalysers used by police to estimate ethanol concentration in blood. However, breath testing has far more sophisticated applications. Breath analysis is rapidly evolving as a new frontier in medical testing for disease states in the lung and beyond. Every individual has a breath fingerprint-or 'breathprint'-that can provide useful information about his or her state of health. This breathprint comprises the many thousands of molecules that are expelled with each breath we exhale. Breath research in the past few years has uncovered the scientific and molecular basis for such clinical observations. Relying on mass spectrometry, we have been able to identify many such unique substances in exhaled breath, including gases, such as nitric oxide (NO) and carbon monoxide (CO), and a wide array of volatile organic compounds. Exhaled breath also carries aerosolized droplets that can be collected as an exhaled breath condensate that contains endogenously produced non-volatile compounds. Breath

  16. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing... the container. (d) Compressed breathing gas contained valves or a separate charging system or...

  17. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing... the container. (d) Compressed breathing gas contained valves or a separate charging system or...

  18. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing... the container. (d) Compressed breathing gas contained valves or a separate charging system or...

  19. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing... the container. (d) Compressed breathing gas contained valves or a separate charging system or...

  20. Kozai Cycles and Tidal Friction

    SciTech Connect

    L, K; P.P., E

    2009-07-17

    Several studies in the last three years indicate that close binaries, i.e. those with periods of {approx}< 3 d, are very commonly found to have a third body in attendance. We argue that this proves that the third body is necessary in order to make the inner period so short, and further argue that the only reasonable explanation is that the third body causes shrinkage of the inner period, from perhaps a week or more to the current short period, by means of the combination of Kozai cycles and tidal friction (KCTF). In addition, once KCTF has produced a rather close binary, magnetic braking also combined with tidal friction (MBTF) can decrease the inner orbit further, to the formation of a contact binary or even a merged single star. Some of the products of KCTF that have been suggested, either by others or by us, are W UMa binaries, Blue Stragglers, X-ray active BY Dra stars, and short-period Algols. We also argue that some components of wide binaries are actually merged remnants of former close inner pairs. This may include such objects as rapidly rotating dwarfs (AB Dor, BO Mic) and some (but not all) Be stars.

  1. Protective supplied breathing air garment

    DOEpatents

    Childers, Edward L.; von Hortenau, Erik F.

    1984-07-10

    A breathing air garment for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap.

  2. [Stahl, Leibniz, Hoffmann and breathing].

    PubMed

    Carvallo, Sarah

    2006-01-01

    At the beginning of the XVIII th century, Wilhelm Gottfried Leibniz and Friedrich Hoffmann criticize Georg Ernst Stahl's medical theory. They differenciate between unsound and true reasonings. Namely, they validate Stahl's definition of breath but extracting it from its animist basis and placing it in an epistemology obeying to the principle of sufficient reason and to the mechanical model. The stahlian discovery consists in understanding breath as a calorific ventilation against the ancient conception; the iatromechanists recognize its accuracy, but they try then to transpose it to a mechanical model of ventilation. Using it in a different epistemological context implies that they analyze the idea of discovery "true" in its contents, but "wrong" in its hypothesis. It impels to examine the epistemology of medical knowledge, as science and therapeutics, and in its links with the other scientific theories. Thus, if Leibniz as philosopher and Hoffmann as doctor consider Stahl's animism so important, it is because its discoveries question the fundamental principles of medicine. PMID:17153053

  3. Protective supplied breathing air garment

    DOEpatents

    Childers, E.L.; Hortenau, E.F. von.

    1984-07-10

    A breathing air garment is disclosed for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap. 17 figs.

  4. Work of Breathing into Snow in the Presence versus Absence of an Artificial Air Pocket Affects Hypoxia and Hypercapnia of a Victim Covered with Avalanche Snow: A Randomized Double Blind Crossover Study.

    PubMed

    Roubík, Karel; Sieger, Ladislav; Sykora, Karel

    2015-01-01

    Presence of an air pocket and its size play an important role in survival of victims buried in the avalanche snow. Even small air pockets facilitate breathing. We hypothesize that the size of the air pocket significantly affects the airflow resistance and work of breathing. The aims of the study are (1) to investigate the effect of the presence of an air pocket on gas exchange and work of breathing in subjects breathing into the simulated avalanche snow and (2) to test whether it is possible to breathe with no air pocket. The prospective interventional double-blinded study involved 12 male volunteers, from which 10 completed the whole protocol. Each volunteer underwent two phases of the experiment in a random order: phase "AP"--breathing into the snow with a one-liter air pocket, and phase "NP"--breathing into the snow with no air pocket. Physiological parameters, fractions of oxygen and carbon dioxide in the airways and work of breathing expressed as pressure-time product were recorded continuously. The main finding of the study is that it is possible to breath in the avalanche snow even with no air pocket (0 L volume), but breathing under this condition is associated with significantly increased work of breathing. The significant differences were initially observed for end-tidal values of the respiratory gases (EtO2 and EtCO2) and peripheral oxygen saturation (SpO2) between AP and NP phases, whereas significant differences in inspiratory fractions occurred much later (for FIO2) or never (for FICO2). The limiting factor in no air pocket conditions is excessive increase in work of breathing that induces increase in metabolism accompanied by higher oxygen consumption and carbon dioxide production. The presence of even a small air pocket reduces significantly the work of breathing. PMID:26666523

  5. Work of Breathing into Snow in the Presence versus Absence of an Artificial Air Pocket Affects Hypoxia and Hypercapnia of a Victim Covered with Avalanche Snow: A Randomized Double Blind Crossover Study

    PubMed Central

    2015-01-01

    Presence of an air pocket and its size play an important role in survival of victims buried in the avalanche snow. Even small air pockets facilitate breathing. We hypothesize that the size of the air pocket significantly affects the airflow resistance and work of breathing. The aims of the study are (1) to investigate the effect of the presence of an air pocket on gas exchange and work of breathing in subjects breathing into the simulated avalanche snow and (2) to test whether it is possible to breathe with no air pocket. The prospective interventional double-blinded study involved 12 male volunteers, from which 10 completed the whole protocol. Each volunteer underwent two phases of the experiment in a random order: phase “AP”—breathing into the snow with a one-liter air pocket, and phase “NP”—breathing into the snow with no air pocket. Physiological parameters, fractions of oxygen and carbon dioxide in the airways and work of breathing expressed as pressure-time product were recorded continuously. The main finding of the study is that it is possible to breath in the avalanche snow even with no air pocket (0 L volume), but breathing under this condition is associated with significantly increased work of breathing. The significant differences were initially observed for end-tidal values of the respiratory gases (EtO2 and EtCO2) and peripheral oxygen saturation (SpO2) between AP and NP phases, whereas significant differences in inspiratory fractions occurred much later (for FIO2) or never (for FICO2). The limiting factor in no air pocket conditions is excessive increase in work of breathing that induces increase in metabolism accompanied by higher oxygen consumption and carbon dioxide production. The presence of even a small air pocket reduces significantly the work of breathing. PMID:26666523

  6. Submarines, spacecraft and exhaled breath.

    PubMed

    Pleil, Joachim D; Hansel, Armin

    2012-03-01

    Foreword The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled breath. What may have escaped our notice is a complementary field of research that explores the creation and maintenance of artificial atmospheres practised by the submarine air monitoring and air purification (SAMAP) community. SAMAP is comprised of manufacturers, researchers and medical professionals dealing with the engineering and instrumentation to support human life in submarines and spacecraft (including shuttlecraft and manned rockets, high-altitude aircraft, and the International Space Station (ISS)). Here, the immediate concerns are short-term survival and long-term health in fairly confined environments where one cannot simply 'open the window' for fresh air. As such, one of the main concerns is air monitoring and the main sources of contamination are CO(2) and other constituents of human exhaled breath. Since the inaugural meeting in 1994 in Adelaide, Australia, SAMAP meetings have been held every two or three years alternating between the North American and European continents. The meetings are organized by Dr Wally Mazurek (a member of IABR) of the Defense Systems Technology Organization (DSTO) of Australia, and individual meetings are co-hosted by the navies of the countries in which they are held. An overriding focus at SAMAP is life support (oxygen availability and carbon dioxide removal). Certainly, other air constituents are also important; for example, the closed environment of a submarine or the ISS can build up contaminants from consumer products, cooking, refrigeration, accidental fires, propulsion and atmosphere maintenance. However, the most immediate concern is sustaining human metabolism: removing exhaled CO(2) and replacing metabolized O(2). Another

  7. TIDALLY HEATED TERRESTRIAL EXOPLANETS: VISCOELASTIC RESPONSE MODELS

    SciTech Connect

    Henning, Wade G.; O'Connell, Richard J.; Sasselov, Dimitar D.

    2009-12-20

    Tidal friction in exoplanet systems, driven by orbits that allow for durable nonzero eccentricities at short heliocentric periods, can generate internal heating far in excess of the conditions observed in our own solar system. Secular perturbations or a notional 2:1 resonance between a hot Earth and hot Jupiter can be used as a baseline to consider the thermal evolution of convecting bodies subject to strong viscoelastic tidal heating. We compare results first from simple models using a fixed Quality factor and Love number, and then for three different viscoelastic rheologies: the Maxwell body, the Standard Anelastic Solid (SAS), and the Burgers body. The SAS and Burgers models are shown to alter the potential for extreme tidal heating by introducing the possibility of new equilibria and multiple response peaks. We find that tidal heating tends to exceed radionuclide heating at periods below 10-30 days, and exceed insolation only below 1-2 days. Extreme cases produce enough tidal heat to initiate global-scale partial melting, and an analysis of tidal limiting mechanisms such as advective cooling for earthlike planets is discussed. To explore long-term behaviors, we map equilibria points between convective heat loss and tidal heat input as functions of eccentricity. For the periods and magnitudes discussed, we show that tidal heating, if significant, is generally detrimental to the width of habitable zones.

  8. Simple theory for designing tidal power schemes

    NASA Astrophysics Data System (ADS)

    Prandle, D.

    Basic parameters governing the design of tidal power schemes are identified and converted to dimensionless form by reference to (i) the mean tidal range and (ii) the surface area of the enclosed basin. Optimum values for these dimensionless parameters are derived and comparison made with actual engineering designs. A theoretical framework is thus established which can be used (i) to make a rudimentary design at any specific location or (ii) to compare and evaluate designs for various locations. Both one-way (flood or ebb) and two-way (flood and ebb) schemes are examined and, theoretically, the two-way scheme is shown to be more efficient. However, in practice, two-way schemes suffer disadvantages arising from (i) two-way flow through both turbines and sluices and (ii) lower average turbine heads. An important dimensional aspect of tidal power schemes is that, while energy extracted is proportional to the tidal amplitude squared, the requisite sluicing area is proportional to the square root of the tidal amplitude. In consequence, sites with large tidal amplitudes are best suited to tidal power development whereas for sites with low tidal amplitudes sluicing costs may be prohibitive.

  9. Tidal characteristics of Maputo Bay, Mozambique

    NASA Astrophysics Data System (ADS)

    Canhanga, Sinibaldo; Dias, João Miguel

    2005-12-01

    The tidal characteristics of Maputo Bay (a bay located in South part of Mozambique) were assessed in this work through the implementation of a numerical model (SIMSYS2D) and exploration of its numerical results, and by the analysis of observed time series of free surface elevations in Maputo Harbor. The calibration of the numerical model was carried out based on time series of tidal currents and free surface elevation, which were collected at Maputo Harbor, Baixo Ribeiro and Portuguese Island. By means of the model results, important harmonic constants of the tidal heights and currents, as well as the form factor, were computed. These results have revealed that there is a phase delay and an increase in amplitude of the major constituents as the tide propagates to the inshore zone. Based on these results, the tidal ellipses in whole Maputo Bay were also computed, which showed the pattern of the tidal currents. The hydrodynamics of the Maputo Bay under extreme tidal conditions were also analyzed (during the largest spring tide and smallest neap tide). The phase difference between tidal heights and currents revealed that there are no maximum fluxes of energy in most of Maputo Bay and that the mean tidal current (residual) may be different from zero in this system.

  10. Tidal deformations of a spinning compact object

    NASA Astrophysics Data System (ADS)

    Pani, Paolo; Gualtieri, Leonardo; Maselli, Andrea; Ferrari, Valeria

    2015-07-01

    The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the tidal Love numbers in general relativity, which are due to the difficulty in separating the tidal field from the linear response of the object in the solution, even in the static case. By extending the standard procedure to identify the linear response in the static case, we prove analytically that the Love numbers of a Kerr black hole remain zero to second order in the spin. As a by-product, we provide the explicit form for a slowly-rotating, tidally-deformed Kerr black hole to quadratic order in the spin, and discuss its geodesic and geometrical properties.

  11. The tidal spectrum underneath Antarctic Ice Shelves

    NASA Astrophysics Data System (ADS)

    Pedley, M.; Paren, J. G.; Potter, J. R.

    1986-11-01

    A year-long tidal record has been obtained from beneath the George VI Ice Shelf, Antarctica. An unusual feature of the record is a significant response in tidal species 3 to 7. These harmonics are practically absent from records further north on the west coast of the Antarctic Peninsula but are present in all tidal height records from George VI Sound. A strong ter-diurnal signal also exists in the tidal currents under the ice shelf. Nonlinearity also occurs in the tidal motion of the Ronne and Ekström ice shelves but has not been reported from the Ross Ice Shelf. The tidal dynamics of several Antarctic ice shelves have therefore been modified by a region of strong nonlinear response to tidal forcing. If nonlinear tides in the semidiurnal band are present on the Ross Ice Shelf, they could account for difficulties in modeling the area's weak semidiurnal tides. An anelastic component in the deformation of the ice at the grounding line is tentatively proposed as the mechanism responsible. The positioning of recording pressure sensors in pairs on the seafloor and at the ice shelf base will allow this hypothesis to be tested and also provide a value for the power dissipated by tidally induced flexure at the grounding line.

  12. Sediment transport through a tidal creek

    NASA Astrophysics Data System (ADS)

    Green, Malcolm O.; Hancock, Nicole J.

    2012-08-01

    A 3-month field experiment was conducted at Henderson Creek, New Zealand. The data show how tidal creeks that are an extension of the freshwater drainage network (as opposed to tidal creeks that are part of an estuarine distributary network with no direct connection to the land) variously import, export and deposit fine sediment sourced from both landward and seaward of the creek, depending on the wind and freshwater runoff, and modulated by the tide. During freshwater spates, saltwater was largely displaced from the tidal creek at low tide, and sediment sourced from the land was deposited inside the tidal creek and exported to the wider estuary beyond the base of the creek. In one spate, during which 80 mm of rain fell in less than one day, 580 t of sediment was sourced from landward of the tidal creek, and a maximum of 33% of this was exported to the wider estuary. Between rainstorms when it was calm, sediment was returned from the wider estuary by tidal currents (but not necessarily the same sediment that was exported during spates), and sediment was also eroded from the middle reaches of the tidal creek and transported to the upper reaches, where it was deposited. The up-estuary deposition is explainable in Lagrangian terms as a type of settling lag, which results in an asymmetrical response of suspended-sediment concentration to current speed in the tidal creek. The return of sediment to the tidal creek between spates was greatly enhanced by wind waves that resuspended sediments from the intertidal flats of the wider estuary, with that sediment being transported by tidal currents into the tidal creek where it was deposited, largely in the middle reaches. There is a broad consensus that waves drive a net loss of sediment from intertidal flats to offshore, which reverses a net accumulation of sediment on intertidal flats during calm weather. In contrast, waves on the intertidal flats outside the mouth of Henderson Creek initiate net landward transport of

  13. Apolo Ohno: Breathing Easier | NIH MedlinePlus the Magazine

    MedlinePlus

    ... of this page please turn Javascript on. Feature: Breathing Easier Apolo Ohno: Breathing Easier Past Issues / Fall 2013 Table of Contents ... training, I started experiencing decreased exercise endurance, trouble breathing, and coughing. These symptoms affected my ability to ...

  14. Tidal triggering effect on earthquakes occurrence

    NASA Astrophysics Data System (ADS)

    Contadakis, M. E.; Arabelos, D.; Spatalas, S. D.

    2016-01-01

    In this review we present the investigation for the tidal triggering evidence on the earthquakes at various seismic areas of Greece. The result of our analysis using the HiCum method, indicate that the monthly variation of the frequencies of earthquake occurrence is in accordance with the period of the tidal lunar monthly (Mm) variations. The same happens with the corresponding diurnal and semi-diurnal variations of the frequencies of earthquake occurrence with the diurnal (K1), (O1) and semi-diurnal solar (S2) and semidiurnal lunar (M2) tidal variations. The confidence level of the Tidal-Earthquake frequency period compliance is very sensitive to the seismicity of the area and we call it Tidal - Earthquake frequency compliance parameter. We suggest that this parameter may be used in earthquake risk evaluation.

  15. Relativistic theory of tidal Love numbers

    SciTech Connect

    Binnington, Taylor; Poisson, Eric

    2009-10-15

    In Newtonian gravitational theory, a tidal Love number relates the mass multipole moment created by tidal forces on a spherical body to the applied tidal field. The Love number is dimensionless, and it encodes information about the body's internal structure. We present a relativistic theory of Love numbers, which applies to compact bodies with strong internal gravities; the theory extends and completes a recent work by Flanagan and Hinderer, which revealed that the tidal Love number of a neutron star can be measured by Earth-based gravitational-wave detectors. We consider a spherical body deformed by an external tidal field, and provide precise and meaningful definitions for electric-type and magnetic-type Love numbers; and these are computed for polytropic equations of state. The theory applies to black holes as well, and we find that the relativistic Love numbers of a nonrotating black hole are all zero.

  16. How Does a Hopping Kangaroo Breathe?

    ERIC Educational Resources Information Center

    Giuliodori, Mauricio J.; Lujan, Heidi L.; Janbaih, Hussein; DiCarlo, Stephen E.

    2010-01-01

    We developed a model to demonstrate how a hopping kangaroo breathes. Interestingly, a kangaroo uses less energy to breathe while hopping than while standing still. This occurs, in part, because rather than using muscle power to move air into and out of the lungs, air is pulled into (inspiration) and pushed out of (expiration) the lungs as the…

  17. Tracheomalacia and breath holding: a case report.

    PubMed

    Griffiths, H; Doull, I; Williams, R G; Marnane, C

    2000-10-01

    A child with a long standing history of cyanotic breath holding attacks presented with acute respiratory distress. Subsequent investigation established that her clinical condition was caused by tracheomalacia. We hypothesise that tracheomalacia might be an under recognised contributor to cyanotic breath holding attacks, the pathogenesis of which is poorly understood. PMID:10999873

  18. NASA firefighters breathing system program report

    NASA Technical Reports Server (NTRS)

    Wood, W. B.

    1977-01-01

    Because of the rising incidence of respiratory injury to firefighters, local governments expressed the need for improved breathing apparatus. A review of the NASA firefighters breathing system program, including concept definition, design, development, regulatory agency approval, in-house testing, and program conclusion is presented.

  19. EXHALED BREATH ANALYSIS FOR HUMAN EXPOSURE RESEARCH

    EPA Science Inventory

    Exhaled breath collection and analysis has historically been used in environmental research studies to characterize exposures to volatile organic compounds. The use of this approach is based on the fact that many compounds present in blood are reflected in the breath, and that...

  20. Impact Loading and Locomotor-Respiratory Coordination Significantly Influence Breathing Dynamics in Running Humans

    PubMed Central

    Daley, Monica A.; Bramble, Dennis M.; Carrier, David R.

    2013-01-01

    Locomotor-respiratory coupling (LRC), phase-locking between breathing and stepping rhythms, occurs in many vertebrates. When quadrupedal mammals gallop, 1∶1 stride per breath coupling is necessitated by pronounced mechanical interactions between locomotion and ventilation. Humans show more flexibility in breathing patterns during locomotion, using LRC ratios of 2∶1, 2.5∶1, 3∶1, or 4∶1 and sometimes no coupling. Previous studies provide conflicting evidence on the mechanical significance of LRC in running humans. Some studies suggest LRC improves breathing efficiency, but others suggest LRC is mechanically insignificant because ‘step-driven flows’ (ventilatory flows attributable to step-induced forces) contribute a negligible fraction of tidal volume. Yet, although step-driven flows are brief, they cause large fluctuations in ventilatory flow. Here we test the hypothesis that running humans use LRC to minimize antagonistic effects of step-driven flows on breathing. We measured locomotor-ventilatory dynamics in 14 subjects running at a self-selected speed (2.6±0.1 ms−1) and compared breathing dynamics in their naturally ‘preferred’ and ‘avoided’ entrainment patterns. Step-driven flows occurred at 1-2X step frequency with peak magnitudes of 0.97±0.45 Ls−1 (mean ±S.D). Step-driven flows varied depending on ventilatory state (high versus low lung volume), suggesting state-dependent changes in compliance and damping of thoraco-abdominal tissues. Subjects naturally preferred LRC patterns that minimized antagonistic interactions and aligned ventilatory transitions with assistive phases of the step. Ventilatory transitions initiated in ‘preferred’ phases within the step cycle occurred 2x faster than those in ‘avoided’ phases. We hypothesize that humans coordinate breathing and locomotion to minimize antagonistic loading of respiratory muscles, reduce work of breathing and minimize rate of fatigue. Future work could address the potential

  1. Impact loading and locomotor-respiratory coordination significantly influence breathing dynamics in running humans.

    PubMed

    Daley, Monica A; Bramble, Dennis M; Carrier, David R

    2013-01-01

    Locomotor-respiratory coupling (LRC), phase-locking between breathing and stepping rhythms, occurs in many vertebrates. When quadrupedal mammals gallop, 1∶1 stride per breath coupling is necessitated by pronounced mechanical interactions between locomotion and ventilation. Humans show more flexibility in breathing patterns during locomotion, using LRC ratios of 2∶1, 2.5∶1, 3∶1, or 4∶1 and sometimes no coupling. Previous studies provide conflicting evidence on the mechanical significance of LRC in running humans. Some studies suggest LRC improves breathing efficiency, but others suggest LRC is mechanically insignificant because 'step-driven flows' (ventilatory flows attributable to step-induced forces) contribute a negligible fraction of tidal volume. Yet, although step-driven flows are brief, they cause large fluctuations in ventilatory flow. Here we test the hypothesis that running humans use LRC to minimize antagonistic effects of step-driven flows on breathing. We measured locomotor-ventilatory dynamics in 14 subjects running at a self-selected speed (2.6±0.1 ms(-1)) and compared breathing dynamics in their naturally 'preferred' and 'avoided' entrainment patterns. Step-driven flows occurred at 1-2X step frequency with peak magnitudes of 0.97±0.45 Ls(-1) (mean ±S.D). Step-driven flows varied depending on ventilatory state (high versus low lung volume), suggesting state-dependent changes in compliance and damping of thoraco-abdominal tissues. Subjects naturally preferred LRC patterns that minimized antagonistic interactions and aligned ventilatory transitions with assistive phases of the step. Ventilatory transitions initiated in 'preferred' phases within the step cycle occurred 2x faster than those in 'avoided' phases. We hypothesize that humans coordinate breathing and locomotion to minimize antagonistic loading of respiratory muscles, reduce work of breathing and minimize rate of fatigue. Future work could address the potential consequences of

  2. Diaphragmatic amplitude and accessory inspiratory muscle activity in nasal and mouth-breathing adults: a cross-sectional study.

    PubMed

    Trevisan, Maria Elaine; Boufleur, Jalusa; Soares, Juliana Corrêa; Haygert, Carlos Jesus Pereira; Ries, Lilian Gerdi Kittel; Corrêa, Eliane Castilhos Rodrigues

    2015-06-01

    The purpose of this study was to evaluate the electromyographic activity of the accessory inspiratory muscles and the diaphragmatic amplitude (DA) in nasal and mouth-breathing adults. The study evaluated 38 mouth-breathing (MB group) and 38 nasal-breathing (NB group) adults, from 18 to 30years old and both sexes. Surface electromyography (sEMG) was used to evaluate the amplitude and symmetry (POC%) of the sternocleidomastoid (SCM) and upper trapezius (UT) muscles at rest, during nasal slow inspiration at Lung Total Capacity (LTC) and, during rapid and abrupt inspiration: Sniff, Peak Nasal Inspiratory Flow (PNIF) and Maximum Inspiratory Pressure (MIP). M-mode ultrasonography assessed the right diaphragm muscle amplitude in three different nasal inspirations: at tidal volume (TV), Sniff and inspiration at LTC. The SCM activity was significantly lower in the MB group during Sniff, PNIF (p<0.01, Mann-Whitney test) and MIP (p<0.01, t-test). The groups did not differ during rest and inspiration at LTC, regarding sEMG amplitude and POC%. DA was significantly lower in the MB group at TV (p<0.01, Mann-Whitney) and TLC (p=0.03, t-test). Mouth breathing reflected on lower recruitment of the accessory inspiratory muscles during fast inspiration and lower diaphragmatic amplitude, compared to nasal breathing. PMID:25900327

  3. Slow breathing influences cardiac autonomic responses to postural maneuver: Slow breathing and HRV.

    PubMed

    Vidigal, Giovanna Ana de Paula; Tavares, Bruna S; Garner, David M; Porto, Andrey A; Carlos de Abreu, Luiz; Ferreira, Celso; Valenti, Vitor E

    2016-05-01

    Chronic slow breathing has been reported to improve Heart Rate Variability (HRV) in patients with cardiovascular disorders. However, it is not clear regarding its acute effects on HRV responses on autonomic analysis. We evaluated the acute effects of slow breathing on cardiac autonomic responses to postural change manoeuvre (PCM). The study was conducted on 21 healthy male students aged between 18 and 35 years old. In the control protocol, the volunteer remained at rest seated for 15 min under spontaneous breathing and quickly stood up within 3 s and remained standing for 15 min. In the slow breathing protocol, the volunteer remained at rest seated for 10 min under spontaneous breath, then performed slow breathing for 5 min and rapidly stood up within 3 s and remained standing for 15 min. Slow breathing intensified cardiac autonomic responses to postural maneuver. PMID:27157952

  4. Computer simulation of breathing systems for divers

    SciTech Connect

    Sexton, P.G.; Nuckols, M.L.

    1983-02-01

    A powerful new tool for the analysis and design of underwater breathing gas systems is being developed. A versatile computer simulator is described which makes possible the modular ''construction'' of any conceivable breathing gas system from computer memory-resident components. The analysis of a typical breathing gas system is demonstrated using this simulation technique, and the effects of system modifications on performance of the breathing system are shown. This modeling technique will ultimately serve as the foundation for a proposed breathing system simulator under development by the Navy. The marriage of this computer modeling technique with an interactive graphics system will provide the designer with an efficient, cost-effective tool for the development of new and improved diving systems.

  5. Breath Testing for Small Intestinal Bacterial Overgrowth: Should We Bother?

    PubMed

    Pimentel, Mark

    2016-03-01

    The hydrogen breath test is based on following breath hydrogen levels after the administration of a carbohydrate (most commonly lactulose) to a patient with suspected small intestinal bacterial overgrowth. The test is based on the interaction between the administered carbohydrate and the intestinal bacteria. The resulting fermentation produces hydrogen. A positive breath test is based on a breath hydrogen rise prior to the expected arrival time in the highly microbial cecum. Despite renewed enthusiasm for breath testing in recent years due to associations with conditions such as irritable bowel syndrome, breath testing poses many challenges. In this argument against breath testing, several pitfalls that complicate breath testing will be described. PMID:26902227

  6. Modified ventilatory response characteristics to exercise in breath-hold divers.

    PubMed

    Roecker, Kai; Metzger, Jule; Scholz, Tobias; Tetzlaff, Kay; Sorichter, Stephan; Walterspacher, Stephan

    2014-09-01

    Specific adjustments to repeated extreme apnea are not fully known and understood. While a blunted ventilatory chemosensitivity to CO2 is described for elite breath-hold divers (BHDs) at rest, it is unclear whether specific adaptations affect their response to dynamic exercise. Eight elite BHDs with a previously validated decrease in CO2 chemosensitivity, 8 scuba divers (SCDs), and 8 matched control subjects were included in a study where markers of ventilatory response, Fowler's dead space, partial pressure of carbon dioxide (pCO2), and blood lactate concentrations during cycle exercise were measured. Maximal power output did not differ between the groups, but lactate threshold (θL) appeared at a significantly lowered respiratory compensation point (RCP) and at a higher VO2 for the BHDs. End-tidal (petCO2) and estimated arterial pCO2 (paCO2) were significantly higher in BHDs at θL, the RCP, and maximum exhaustion. BHDs showed a significantly (P < .01) slower breathing pattern in relation to a given tidal volume at a specific work rate. In summary, BHDs presented signs of a metabolic shift from aerobic to anaerobic energy supply, decreased chemosensitivity during exercise, and a distinct ventilatory-response pattern during cycle exercise that differs from SCDs and controls. PMID:24231513

  7. Tidal Streams Near and Far

    NASA Astrophysics Data System (ADS)

    Fardal, Mark A.

    2014-06-01

    The Pandas survey of stars in M31's disk and halo is crisscrossed by numerous tidal features from both M31 and the Milky Way. Here I focus on two narrow stellar streams visible in the survey. They have comparable angular extent in the survey (10-13 degrees long versus only 0.3 degree wide), but one is a local Milky Way stream at about 30 kpc and one is in M31, roughly 25 times more distant. I estimate the stellar mass and metallicity in the streams and the distance gradient along them. The kinematics of the M31 stream is sparsely sampled by red giant stars and globular clusters. Bayesian modeling of the stream data yields accurate constraints on the orbital parameters of the streams.

  8. Breathing synchronization in interconnected networks

    PubMed Central

    Louzada, V. H. P.; Araújo, N. A. M.; Andrade, J. S.; Herrmann, H. J.

    2013-01-01

    Global synchronization in a complex network of oscillators emerges from the interplay between its topology and the dynamics of the pairwise interactions among its numerous components. When oscillators are spatially separated, however, a time delay appears in the interaction which might obstruct synchronization. Here we study the synchronization properties of interconnected networks of oscillators with a time delay between networks and analyze the dynamics as a function of the couplings and communication lag. We discover a new breathing synchronization regime, where two groups appear in each network synchronized at different frequencies. Each group has a counterpart in the opposite network, one group is in phase and the other in anti-phase with their counterpart. For strong couplings, instead, networks are internally synchronized but a phase shift between them might occur. The implications of our findings on several socio-technical and biological systems are discussed. PMID:24256765

  9. The indoor air we breathe.

    PubMed

    Oliver, L C; Shackleton, B W

    1998-01-01

    Increasingly recognized as a potential public health problem since the outbreak of Legionnaire's disease in Philadelphia in 1976, polluted indoor air has been associated with health problems that include asthma, sick building syndrome, multiple chemical sensitivity, and hypersensitivity pneumonitis. Symptoms are often nonspecific and include headache, eye and throat irritation, chest tightness and shortness of breath, and fatigue. Air-borne contaminants include commonly used chemicals, vehicular exhaust, microbial organisms, fibrous glass particles, and dust. Identified causes include defective building design and construction, aging of buildings and their ventilation systems, poor climate control, inattention to building maintenance. A major contributory factor is the explosion in the use of chemicals in building construction and furnishing materials over the past four decades. Organizational issues and psychological variables often contribute to the problem and hinder its resolution. This article describes the health problems related to poor indoor air quality and offers solutions. PMID:9769764

  10. Aerosol deposition characteristics in distal acinar airways under cyclic breathing conditions

    PubMed Central

    Ma, Baoshun

    2011-01-01

    Although the major mechanisms of aerosol deposition in the lung are known, detailed quantitative data in anatomically realistic models are still lacking, especially in the acinar airways. In this study, an algorithm was developed to build multigenerational three-dimensional models of alveolated airways with arbitrary bifurcation angles and spherical alveolar shape. Using computational fluid dynamics, the deposition of 1- and 3-μm aerosol particles was predicted in models of human alveolar sac and terminal acinar bifurcation under rhythmic wall motion for two breathing conditions (functional residual capacity = 3 liter, tidal volume = 0.5 and 0.9 liter, breathing period = 4 s). Particles entering the model during one inspiration period were tracked for multiple breathing cycles until all particles deposited or escaped from the model. Flow recirculation inside alveoli occurred only during transition between inspiration and expiration and accounted for no more than 1% of the whole cycle. Weak flow irreversibility and convective transport were observed in both models. The average deposition efficiency was similar for both breathing conditions and for both models. Under normal gravity, total deposition was ∼33 and 75%, of which ∼67 and 96% occurred during the first cycle, for 1- and 3-μm particles, respectively. Under zero gravity, total deposition was ∼2–5% for both particle sizes. These results support previous findings that gravitational sedimentation is the dominant deposition mechanism for micrometer-sized aerosols in acinar airways. The results also showed that moving walls and multiple breathing cycles are needed for accurate estimation of aerosol deposition in acinar airways. PMID:21330617

  11. Volitional pursed lips breathing in patients with stable chronic obstructive pulmonary disease improves exercise capacity.

    PubMed

    Bhatt, Surya P; Luqman-Arafath, T K; Gupta, Arun K; Mohan, Anant; Stoltzfus, Jill C; Dey, Tanujit; Nanda, Sudip; Guleria, Randeep

    2013-02-01

    Pursed lips breathing (PLB) is used by a proportion of patients with chronic obstructive pulmonary disease (COPD) to alleviate dyspnea. It is also commonly used in pulmonary rehabilitation. Data to support its use in patients who do not spontaneously adopt PLB are limited. We performed this study to assess the acute effects of PLB on exercise capacity in nonspontaneously PLB patients with stable COPD. We performed a randomized crossover study comparing 6-min walk test (6MWT) at baseline without PLB with 6WMT using volitional PLB. Spirometry, maximal inspiratory and expiratory mouth pressures, and diaphragmatic excursion during tidal and vital capacity breathing using B-mode ultrasonography were measured at baseline and after 10 min of PLB. A Visual Analog Scale (VAS) assessed subjective breathlessness at rest, after 6MWT and after 6MWT with PLB. p ≤ 0.01 was considered significant. Mean ± SD age of patients was 53.1 ± 7.4 years. Forced expiratory volume in 1 second was 1.1 ± 0.4 L/min (38.4 ± 13.2% predicted). Compared with spontaneous breathing, all but one patient with PLB showed a significant increment in 6MW distance (+34.9 ± 26.4 m; p = 0.002). There was a significant reduction in respiratory rate post 6MWT with PLB compared with spontaneous breathing (-4.4 ± 2.8 per minute; p = 0.003). There was no difference in VAS scores. There was a significant correlation between improvement in 6MWT distance and increase in diaphragmatic excursion during forced breathing. The improvement was greater in patients who had poorer baseline exercise performance. PLB has an acute benefit on exercise capacity. Sustained PLB or short bursts of PLB may improve exercise capacity in stable COPD. PMID:23149383

  12. Adenosine A1 Receptors in Mouse Pontine Reticular Formation Depress Breathing, Increase Anesthesia Recovery Time, and Decrease Acetylcholine Release

    PubMed Central

    Gettys, George C.; Liu, Fang; Kimlin, Ed; Baghdoyan, Helen A.; Lydic, Ralph

    2012-01-01

    Background Clinical and preclinical data demonstrate the analgesic actions of adenosine. Central administration of adenosine agonists, however, suppresses arousal and breathing by poorly understood mechanisms. This study tested the two-tailed hypothesis that adenosine A1 receptors in the pontine reticular formation (PRF) of C57BL/6J mice modulate breathing, behavioral arousal, and PRF acetylcholine release. Methods Three sets of experiments used 51 mice. First, breathing was measured by plethysmography after PRF microinjection of the adenosine A1 receptor agonist N6-sulfophenyl adenosine (SPA) or saline. Second, mice were anesthetized with isoflurane and time to recovery of righting response (RoRR) was quantified after PRF microinjection of SPA or saline. Third, acetylcholine release in the PRF was measured before and during microdialysis delivery of SPA, the adenosine A1 receptor antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), or SPA and DPCPX. Results First, SPA significantly decreased respiratory rate (−18%), tidal volume (−12%) and minute ventilation (−16%). Second, SPA concentration accounted for 76% of the variance in RoRR. Third, SPA concentration accounted for a significant amount of the variance in acetylcholine release (52%), RoRR (98%), and breathing rate (86%). DPCPX alone caused a concentration-dependent increase in acetylcholine, decrease in RoRR, and decrease in breathing rate. Coadministration of SPA and DPCPX blocked the SPA-induced decrease in acetylcholine and increase in RoRR. Conclusions Endogenous adenosine acting at adenosine A1 receptors in the PRF modulates breathing, behavioral arousal, and acetylcholine release. The results support the interpretation that an adenosinergic-cholinergic interaction within the PRF comprises one neurochemical mechanism underlying the wakefulness stimulus for breathing. PMID:23263018

  13. Atmospheric noise of a breaking tidal bore.

    PubMed

    Chanson, Hubert

    2016-01-01

    A tidal bore is a surge of waters propagating upstream in an estuary as the tidal flow turns to rising and the flood tide propagates into a funnel-shaped system. Large tidal bores have a marked breaking roller. The sounds generated by breaking tidal bores were herein investigated in the field (Qiantang River) and in laboratory. The sound pressure record showed two dominant periods, with some similarity with an earlier study [Chanson (2009). J. Acoust. Soc. Am. 125(6), 3561-3568]. The two distinct phases were the incoming tidal bore when the sound amplitude increased with the approaching bore, and the passage of the tidal bore in front of the microphone when loud and powerful noises were heard. The dominant frequency ranged from 57 to 131 Hz in the Qiantang River bore. A comparison between laboratory and prototype tidal bores illustrated both common features and differences. The low pitch sound of the breaking bore had a dominant frequency close to the collective oscillations of bubble clouds, which could be modeled with a bubble cloud model using a transverse dimension of the bore roller. The findings suggest that this model might be over simplistic in the case of a powerful breaking bore, like that of the Qiantang River. PMID:26827000

  14. Tidal river dynamics: Implications for deltas

    NASA Astrophysics Data System (ADS)

    Hoitink, A. J. F.; Jay, D. A.

    2016-03-01

    Tidal rivers are a vital and little studied nexus between physical oceanography and hydrology. It is only in the last few decades that substantial research efforts have been focused on the interactions of river discharge with tidal waves and storm surges into regions beyond the limit of salinity intrusion, a realm that can extend inland hundreds of kilometers. One key phenomenon resulting from this interaction is the emergence of large fortnightly tides, which are forced long waves with amplitudes that may increase beyond the point where astronomical tides have become extinct. These can be larger than the linear tide itself at more landward locations, and they greatly influence tidal river water levels and wetland inundation. Exploration of the spectral redistribution and attenuation of tidal energy in rivers has led to new appreciation of a wide range of consequences for fluvial and coastal sedimentology, delta evolution, wetland conservation, and salinity intrusion under the influence of sea level rise and delta subsidence. Modern research aims at unifying traditional harmonic tidal analysis, nonparametric regression techniques, and the existing understanding of tidal hydrodynamics to better predict and model tidal river dynamics both in single-thread channels and in branching channel networks. In this context, this review summarizes results from field observations and modeling studies set in tidal river environments as diverse as the Amazon in Brazil, the Columbia, Fraser and Saint Lawrence in North America, the Yangtze and Pearl in China, and the Berau and Mahakam in Indonesia. A description of state-of-the-art methods for a comprehensive analysis of water levels, wave propagation, discharges, and inundation extent in tidal rivers is provided. Implications for lowland river deltas are also discussed in terms of sedimentary deposits, channel bifurcation, avulsion, and salinity intrusion, addressing contemporary research challenges.

  15. Active breathing control (ABC): Determination and reduction of breathing-induced organ motion in the chest

    SciTech Connect

    Gagel, Bernd . E-mail: BGagel@UKAachen.de; Demirel, Cengiz M.P.; Kientopf, Aline; Pinkawa, Michael; Piroth, Marc; Stanzel, Sven; Breuer, Christian; Asadpour, Branka; Jansen, Thomas; Holy, Richard; Wildberger, Joachim E.; Eble, Michael J.

    2007-03-01

    Purpose: Extensive radiotherapy volumes for tumors of the chest are partly caused by interfractional organ motion. We evaluated the feasibility of respiratory observation tools using the active breathing control (ABC) system and the effect on breathing cycle regularity and reproducibility. Methods and Materials: Thirty-six patients with unresectable tumors of the chest were selected for evaluation of the ABC system. Computed tomography scans were performed at various respiratory phases starting at the same couch position without patient movement. Threshold levels were set at minimum and maximum volume during normal breathing cycles and at a volume defined as shallow breathing, reflecting the subjective maximal tolerable reduction of breath volume. To evaluate the extent of organ movement, 13 landmarks were considering using commercial software for image coregistration. In 4 patients, second examinations were performed during therapy. Results: Investigating the differences in a normal breathing cycle versus shallow breathing, a statistically significant reduction of respiratory motion in the upper, middle, and lower regions of the chest could be detected, representing potential movement reduction achieved through reduced breath volume. Evaluating interfraction reproducibility, the mean displacement ranged between 0.24 mm (chest wall/tracheal bifurcation) to 3.5 mm (diaphragm) for expiration and shallow breathing and 0.24 mm (chest wall) to 5.25 mm (diaphragm) for normal inspiration. Conclusions: By modifying regularity of the respiratory cycle through reduction of breath volume, a significant and reproducible reduction of chest and diaphragm motion is possible, enabling reduction of treatment planning margins.

  16. Breath analysis: translation into clinical practice.

    PubMed

    Brodrick, Emma; Davies, Antony; Neill, Paul; Hanna, Louise; Williams, E Mark

    2015-06-01

    Breath analysis in respiratory disease is a non-invasive technique which has the potential to complement or replace current screening and diagnostic techniques without inconvenience or harm to the patient. Recent advances in ion mobility spectrometry (IMS) have allowed exhaled breath to be analysed rapidly, reliably and robustly thereby facilitating larger studies of exhaled breath profiles in clinical environments. Preliminary studies have demonstrated that volatile organic compound (VOC) breath profiles of people with respiratory disease can be distinguished from healthy control groups but there is a need to validate, standardise and ensure comparability between laboratories before real-time breath analysis becomes a clinical reality. It is also important that breath sampling procedures and methodologies are developed in conjunction with clinicians and the practicalities of working within the clinical setting are considered to allow the full diagnostic potential of these techniques to be realised. A protocol is presented, which has been developed over three years and successfully deployed for quickly and accurately collecting breath samples from 323 respiratory patients recruited from 10 different secondary health care clinics. PMID:25971863

  17. An Ultrasonic Contactless Sensor for Breathing Monitoring

    PubMed Central

    Arlotto, Philippe; Grimaldi, Michel; Naeck, Roomila; Ginoux, Jean-Marc

    2014-01-01

    The monitoring of human breathing activity during a long period has multiple fundamental applications in medicine. In breathing sleep disorders such as apnea, the diagnosis is based on events during which the person stops breathing for several periods during sleep. In polysomnography, the standard for sleep disordered breathing analysis, chest movement and airflow are used to monitor the respiratory activity. However, this method has serious drawbacks. Indeed, as the subject should sleep overnight in a laboratory and because of sensors being in direct contact with him, artifacts modifying sleep quality are often observed. This work investigates an analysis of the viability of an ultrasonic device to quantify the breathing activity, without contact and without any perception by the subject. Based on a low power ultrasonic active source and transducer, the device measures the frequency shift produced by the velocity difference between the exhaled air flow and the ambient environment, i.e., the Doppler effect. After acquisition and digitization, a specific signal processing is applied to separate the effects of breath from those due to subject movements from the Doppler signal. The distance between the source and the sensor, about 50 cm, and the use of ultrasound frequency well above audible frequencies, 40 kHz, allow monitoring the breathing activity without any perception by the subject, and therefore without any modification of the sleep quality which is very important for sleep disorders diagnostic applications. This work is patented (patent pending 2013-7-31 number FR.13/57569). PMID:25140632

  18. Delayed feedback applied to breathing in humans

    NASA Astrophysics Data System (ADS)

    Janson, N. B.; Pototsky, A.; Parkes, C.

    2013-10-01

    We studied the response of healthy volunteers to the delayed feedback generated from the breathing signals. Namely, in the freely-breathing volunteers the breathing signal was recorded, delayed by τ seconds and fed back to the same volunteer in real time in the form of a visual and auditory stimulus of low intensity, i.e. the stimulus was crucially non-intrusive. In each case volunteers were instructed to breathe in the way which was most comfortable for them, and no explanation about the kind of applied stimulus was provided to them. Each volunteer experienced 10 different delay times ranging between 10% and 100% of the average breathing period without external stimulus. It was observed that in a significant proportion of subjects (11 out of 24) breathing was slowed down in the presence of delayed feedback with moderate delay. Also, in 6 objects out of 24 the delayed feedback was able to induce transition from nearly periodic to irregular breathing. These observations are consistent with the phenomena observed in numerical simulation of the models of periodic and chaotic self-oscillations with delays, and also in experiments with simpler self-oscillating systems.

  19. An ultrasonic contactless sensor for breathing monitoring.

    PubMed

    Arlotto, Philippe; Grimaldi, Michel; Naeck, Roomila; Ginoux, Jean-Marc

    2014-01-01

    The monitoring of human breathing activity during a long period has multiple fundamental applications in medicine. In breathing sleep disorders such as apnea, the diagnosis is based on events during which the person stops breathing for several periods during sleep. In polysomnography, the standard for sleep disordered breathing analysis, chest movement and airflow are used to monitor the respiratory activity. However, this method has serious drawbacks. Indeed, as the subject should sleep overnight in a laboratory and because of sensors being in direct contact with him, artifacts modifying sleep quality are often observed. This work investigates an analysis of the viability of an ultrasonic device to quantify the breathing activity, without contact and without any perception by the subject. Based on a low power ultrasonic active source and transducer, the device measures the frequency shift produced by the velocity difference between the exhaled air flow and the ambient environment, i.e., the Doppler effect. After acquisition and digitization, a specific signal processing is applied to separate the effects of breath from those due to subject movements from the Doppler signal. The distance between the source and the sensor, about 50 cm, and the use of ultrasound frequency well above audible frequencies, 40 kHz, allow monitoring the breathing activity without any perception by the subject, and therefore without any modification of the sleep quality which is very important for sleep disorders diagnostic applications. This work is patented (patent pending 2013-7-31 number FR.13/57569). PMID:25140632

  20. Optimization of a retrospective technique for respiratory-gated high speed micro-CT of free-breathing rodents

    NASA Astrophysics Data System (ADS)

    Ford, Nancy L.; Wheatley, Andrew R.; Holdsworth, David W.; Drangova, Maria

    2007-09-01

    The objective of this study was to develop a technique for dynamic respiratory imaging using retrospectively gated high-speed micro-CT imaging of free-breathing mice. Free-breathing C57Bl6 mice were scanned using a dynamic micro-CT scanner, comprising a flat-panel detector mounted on a slip-ring gantry. Projection images were acquired over ten complete gantry rotations in 50 s, while monitoring the respiratory motion in synchrony with projection-image acquisition. Projection images belonging to a selected respiratory phase were retrospectively identified and used for 3D reconstruction. The effect of using fewer gantry rotations—which influences both image quality and the ability to quantify respiratory function—was evaluated. Images reconstructed using unique projections from six or more gantry rotations produced acceptable images for quantitative analysis of lung volume, CT density, functional residual capacity and tidal volume. The functional residual capacity (0.15 ± 0.03 mL) and tidal volumes (0.08 ± 0.03 mL) measured in this study agree with previously reported measurements made using prospectively gated micro-CT and at higher resolution (150 µm versus 90 µm voxel spacing). Retrospectively gated micro-CT imaging of free-breathing mice enables quantitative dynamic measurement of morphological and functional parameters in the mouse models of respiratory disease, with scan times as short as 30 s, based on the acquisition of projection images over six gantry rotations.

  1. Evolution of satellite resonances by tidal dissipation.

    NASA Technical Reports Server (NTRS)

    Greenberg, R.

    1973-01-01

    Analysis of a realistic model shows how satellites' gravitational interaction can halt their differential tidal evolution when resonant commensurabilities of their orbital periods are reached. The success of this study lends support to the hypothesis that orbit-orbit resonances among satellites in the solar system, including the Titan-Hyperion case, did evolve as a result of tidal energy dissipation. Consideration of the time scale for this evolution process, possible now that the capture mechanism has been revealed, can offer more sophisticated constraints on the tidal dissipation function, Q, and on past orbital conditions.

  2. Tidal influence on subtropical estuarine methane emissions

    NASA Astrophysics Data System (ADS)

    Sturm, Katrin; Grinham, Alistair; Werner, Ursula; Yuan, Zhiguo

    2014-05-01

    The relatively unstudied subtropical estuaries, particularly in the Southern Hemisphere, represent an important gap in our understanding of global greenhouse gas (GHG) emissions. These systems are likely to form an important component of GHG budgets as they occupy a relatively large surface area, over 38 000 km2 in Australia. Here, we present studies conducted in the Brisbane River estuary, a representative system within the subtropical region of Queensland, Australia. This is a highly modified system typical of 80% of Australia's estuaries. Generally, these systems have undergone channel deepening and straightening for safer shipping access and these modifications have resulted in large increases in tidal reach. The Brisbane River estuary's natural tidal reach was 16 km and this is now 85 km and tidal currents influence double the surface area (9 km2 to 18 km2) in this system. Field studies were undertaken to improve understanding of the driving factors behind methane water-air fluxes. Water-air fluxes in estuaries are usually calculated with the gas exchange coefficient (k) for currents and wind as well as the concentration difference across the water-air interface. Tidal studies in the lower and middle reaches of the estuary were performed to monitor the influence of the tidal stage (a proxy for kcurrent) on methane fluxes. Results for both investigated reaches showed significantly higher methane fluxes during the transition time of tides, the time of greatest tidal currents, than during slack tide periods. At these tidal transition times with highest methane chamber fluxes, lowest methane surface water concentrations were monitored. Modelled fluxes using only wind speed (kwind) were at least one order of magnitude lower than observed from floating chambers, demonstrating that current speed was likely the driving factor of water-air fluxes. An additional study was then conducted sampling the lower, middle and upper reaches during a tidal transition period

  3. Melting of Io by tidal dissipation

    NASA Technical Reports Server (NTRS)

    Peale, S. J.; Cassen, P.; Reynolds, R. T.

    1979-01-01

    The resonant structure of Io leads to forced eccentricities that are considerably larger than the free values. Although still modest by all standards, these forced eccentricities coupled with the enormous tides induced by Jupiter lead to magnitudes of tidal dissipation that are large enough to completely dominate the thermal history of Io. In the present paper, the forced eccentricities are calculated and then substituted into an expression for the total tidal dissipation. The results point to the possibility that the dissipation of tidal energy in Io may have melted a major fraction of Io's mass.

  4. Applications of breath gas analysis in medicine

    NASA Astrophysics Data System (ADS)

    Amann, Anton; Poupart, Guy; Telser, Stefan; Ledochowski, Maximilian; Schmid, Alex; Mechtcheriakov, Sergei

    2004-12-01

    Volatile organic compounds (VOCs) in exhaled breath gas provide valuable information about the subjects' physiological and pathophysiological condition. Proton-transfer-reaction mass spectrometry (PTR-MS) allows rapid and online measurements of these substances. We present results of three studies illustrating the potential of breath gas analysis by PTR-MS in various contexts: long-time online monitoring of VOCs in sleeping subjects suggests that VOC profiles are related to sleep stages. Analysis of VOC concentrations in the breath of carbohydrate malabsorbers emphasizes the role played by bacteria in the gut. Finally, we demonstrate the large intra- and intersubject concentration variability of VOCs by considering one particular mass.

  5. Variability in Diaphragm Motion During Normal Breathing, Assessed With B-Mode Ultrasound

    PubMed Central

    Harper, Caitlin J; Shahgholi, Leili; Cieslak, Kathryn; Hellyer, Nathan J.; Strommen, Jeffrey A.; Boon, Andrea J.

    2014-01-01

    STUDY DESIGN Clinical measurement, cross-sectional. OBJECTIVES To establish a set of normal values for diaphragm thickening with tidal breathing in healthy subjects. BACKGROUND Normal values for diaphragm contractility, as imaged sonographically, have not been described, despite the known role of the diaphragm in contributing to spinal stability. If the normal range of diaphragm contractility can be defined in a reliable manner, ultrasound has the potential to be used clinically and in research as a biofeedback tool to enhance diaphragm activation/contractility. METHODS B-mode ultrasound was performed on 150 healthy subjects to visualize and measure hemi-diaphragm thickness on each side at resting inspiration and expiration. Primary outcome measures were hemi-diaphragm thickness and thickening ratio, stratified for age, gender, and body mass index. Interrater and intrarater reliability were also measured. RESULTS Normal thickness of the diaphragm at rest ranged from 0.12 to 1.18 cm, with slightly greater thickness in men but no effect of age. Average ± SD change in thickness from resting expiration to resting inspiration was 20.0% ± 15.5% on the right and 23.5% ± 24.4% on the left; however, almost one third of healthy subjects had no to minimal diaphragm thickening with tidal breathing. CONCLUSION There is wide variability in the degree of diaphragm contractility during quiet breathing. B-mode ultrasound appears to be a reliable means of determining the contractility of the diaphragm, an important muscle in spinal stability. Further studies are needed to validate this imaging modality as a clinical tool in the neuromuscular re-education of the diaphragm to improve spinal stability in both healthy subjects and in patients with low back pain. PMID:24175600

  6. Characterization of free breathing patterns with 5D lung motion model

    SciTech Connect

    Zhao Tianyu; Lu Wei; Yang Deshan; Mutic, Sasa; Noel, Camille E.; Parikh, Parag J.; Bradley, Jeffrey D.; Low, Daniel A.

    2009-11-15

    Purpose: To determine the quiet respiration breathing motion model parameters for lung cancer and nonlung cancer patients. Methods: 49 free breathing patient 4DCT image datasets (25 scans, cine mode) were collected with simultaneous quantitative spirometry. A cross-correlation registration technique was employed to track the lung tissue motion between scans. The registration results were applied to a lung motion model: X-vector=X-vector{sub 0}+{alpha}-vector{beta}-vector f, where X-vector is the position of a piece of tissue located at reference position X-vector{sub 0} during a reference breathing phase (zero tidal volume v, zero airflow f). {alpha}-vector is a parameter that characterizes the motion due to air filling (motion as a function of tidal volume v) and {beta}-vector is the parameter that accounts for the motion due to the imbalance of dynamical stress distributions during inspiration and exhalation that causes lung motion hysteresis (motion as a function of airflow f). The parameters {alpha}-vector and {beta}-vector together provide a quantitative characterization of breathing motion that inherently includes the complex hysteresis interplay. The {alpha}-vector and {beta}-vector distributions were examined for each patient to determine overall general patterns and interpatient pattern variations. Results: For 44 patients, the greatest values of |{alpha}-vector| were observed in the inferior and posterior lungs. For the rest of the patients, |{alpha}-vector| reached its maximum in the anterior lung in three patients and the lateral lung in two patients. The hysteresis motion {beta}-vector had greater variability, but for the majority of patients, |{beta}-vector| was largest in the lateral lungs. Conclusions: This is the first report of the three-dimensional breathing motion model parameters for a large cohort of patients. The model has the potential for noninvasively predicting lung motion. The majority of patients exhibited similar |{alpha}-vector| maps

  7. Mapping of tide and tidal flow fields along a tidal channel with vessel-based observations

    NASA Astrophysics Data System (ADS)

    Li, Chunyan; Blanton, Jack; Chen, Changsheng

    2004-04-01

    We present the results of a study focused on the tidal regime of a shallow channel with a large intertidal area. Data from a vessel-towed acoustic Doppler current profiler (ADCP) were used to infer tidal constituents for both tidal elevation and tidal current along an upstream portion of the Okatee River, South Carolina. The tidal elevation is estimated from the depth recorded by the moving ADCP. This tidal elevation is then used to correct the vertical coordinates of each depth bin below the ADCP for the velocity profiles. The ability to resolve both tidal elevation and velocity allows us to determine that the tide is a standing wave. A statistical analysis demonstrates that the along-channel velocity has a stronger tidal signal (larger R2 values) than the across-channel velocity. When only the M2 and mean components are included in the harmonic analysis, about 75% of the covered area along the ship track has a "good fit," where at least 70% of the variability can be explained by the tidal and mean components. By adding the M4 component to the harmonic analysis, an additional 2% of the covered area has "good fit" for the elevation, depth-averaged velocity, and mid-depth velocity, but 12% for the near-surface velocity. The observed spatial distribution of the residual flow is in reasonable agreement with that predicted by an unstructured grid, finite-volume coastal ocean model (FVCOM).

  8. Effect on lung volumes of oxygen concentration when breathing is restricted.

    PubMed

    Baker, A B; McGinn, A; Joyce, C

    1993-03-01

    We have examined the effect of the fractional concentration of nitrogen (FIN2) on the decrease in lung volumes which occurs during restricted breathing with oxygen-nitrogen mixtures. Conscious human subjects breathed one of five gas mixtures of oxygen and nitrogen for 15 min on each of five occasions. For the final 5 min of each 15-min period, functional residual capacity (FRC) was reduced by one tidal volume, by external pressurization. After return to normal breathing, the subjects showed a statistically significant decrease in FRC and residual volume (RV), which became larger as FIO2 increased from 30% to 100%. This reduction in lung volumes was resistant to early reexpansion. The maximum decrease in both FRC and RV was found with 100% oxygen, and was 10% of the control lung volumes. The use of a mixture of 75% nitrogen and 25% oxygen prevented this decrease in lung volumes. Nitrogen 50% reduced the decrease in FRC, but did not affect the decrease in RV. The difference in effect on lung volumes between FIO2 25% and 30% was statistically significant, indicating a watershed area for FIN2 between 70% and 75%. PMID:8471366

  9. Influence of breathing pattern and lung inflation on impulse oscillometry measurements in horses.

    PubMed

    Van Erck, E; Votion, D; Kirschvink, N; Genicot, B; Lindsey, J; Art, T; Lekeux, P

    2004-11-01

    The objective of this paper was to determine if changes in ventilation patterns could influence the outcome of respiratory function measurements performed with our impulse oscillometry system (IOS) in horses. In a first study, IOS tests were performed in vitro on six isolated equine lungs. Lung inflation levels were controlled by modifying depressurisation inside an artificial thorax and different ventilation patterns were imposed. In a second in vivo study, transient variations in breathing pattern were evaluated both with the IOS and a current reference technique (CRT) in five healthy mature horses after an intravenous (i.v.) injection of lobeline hydrochloride. In both studies, respiratory rate (RR, range: 7-42 breaths/min.) and tidal volume (V(T), range: 0.4-25 L) had minor or no influence on IOS parameters. The influence of lung inflation, most marked for resistance at 5 Hz (R(5 Hz)), was limited for the considered physiological range. In vivo, statistical models indicated that maximal changes in pleural pressure (Max Delta Ppl) and peak flows were the main determinants of the variability of the resistance (R(rs)) and the reactance (X(rs)) of the respiratory system. The fourfold increase in baseline Max Delta Ppl and peak flows obtained during hyperpnoea caused a significant increase in R(rs) at 5 and 10 Hz and a decrease in X(rs) at all frequencies. We conclude that IOS parameters are not influenced by tachypnoea, but will reflect alterations in respiratory mechanics caused by hyperpnoeic breathing. PMID:15501143

  10. Contributions of tidal lung inflation to human R-R interval and arterial pressure fluctuations

    NASA Technical Reports Server (NTRS)

    Koh, J.; Brown, T. E.; Beightol, L. A.; Eckberg, D. L.

    1998-01-01

    We studied the effects of mechanical lung inflation on respiratory frequency R-R interval and arterial pressure fluctuations in nine healthy young adults undergoing elective orthopedic surgery. We conducted this research to define the contribution of pulmonary and thoracic stretch receptor input to respiratory sinus arrhythmia. We compared fast Fourier transform spectral power during three modes of ventilation: (1) spontaneous, frequency-controlled (0.25 Hz) breathing, (2) intermittent positive pressure ventilation (0.25 Hz, with a tidal volume of 8 ml/kg) and (3) high frequency jet ventilation (5.0 Hz, 2.5 kg/cm2), after sedation and vecuronium paralysis. Mean R-R intervals, arterial pressures and arterial blood gas levels were comparable during all three breathing conditions. Respiratory frequency systolic pressure spectral power was comparable during spontaneous breathing and conventional mechanical ventilation, but was significantly reduced during high frequency jet ventilation (P < 0.05). Respiratory frequency R-R interval spectral power (used as an index of respiratory sinus arrhythmia) declined dramatically with sedation and muscle paralysis (P < 0.05), but was greater during conventional mechanical, than high frequency jet ventilation (P < 0.05). These results suggest that although phasic inputs from pulmonary and thoracic stretch receptors make a statistically significant contribution to respiratory sinus arrhythmia, that contribution is small.

  11. Compartmental chest wall volume changes during volitional hyperpnoea with constant tidal volume in healthy individuals.

    PubMed

    Illi, Sabine K; Hostettler, Stefanie; Aliverti, Andrea; Spengler, Christina M

    2013-01-15

    Prolonged high-intensity ventilation is associated with the development of rapid shallow breathing with decreased end-inspiratory volumes of all chest wall compartments. During respiratory muscle endurance training using normocapnic hyperpnoea, tidal volume (V(T)) is normally kept constant. The aim of this study was to investigate possible changes in muscle recruitment during constant-V(T) hyperpnoea, to assess potential mechanisms related to rapid shallow breathing. Ten healthy subjects performed 1h of normocapnic hyperpnoea at 70% of maximal voluntary ventilation. Chest wall volume changes were assessed by optoelectronic plethysmography. End-inspiratory (1.08 ± 0.18 versus 0.96 ± 0.27 l, p=0.017) and end-expiratory volumes (-0.13 ± 0.15 versus -0.31 ± 0.19 l, p=0.007) of the pulmonary ribcage decreased significantly and lung function and respiratory muscle strength were reduced (all p<0.05). Since with forced, constant V(T) only the inspiratory rib cage muscles were unable to sustain end-inspiratory volume of their compartment, inspiratory rib cage muscles are the most likely candidate responsible for the development of rapid shallow breathing. PMID:22959999

  12. A tidal plume front and internal solitons

    NASA Astrophysics Data System (ADS)

    Johnson, Donald R.; Weidemann, Alan D.

    1998-07-01

    A tidal plume front (internal tidal bore) propagating from the Apalachicola Bay outflow into the northern Gulf of Mexico is examined in a brief set of observations. Temperature and salinity time series showed a radially spreading "pool" of estuarine water with a character similar to a previously observed "turbulent rotor", and with a following packet of internal solitons. Features associated with these observations may be pertinent to interpretation of remotely sensed plumes and to predictive modeling.

  13. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air... employed in lieu of the breathing tubes required. (c)(1) A flexible, nonkinking type breathing tube...

  14. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air... employed in lieu of the breathing tubes required. (c)(1) A flexible, nonkinking type breathing tube...

  15. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air... employed in lieu of the breathing tubes required. (c)(1) A flexible, nonkinking type breathing tube...

  16. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air... employed in lieu of the breathing tubes required. (c)(1) A flexible, nonkinking type breathing tube...

  17. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  18. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  19. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  20. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  1. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  2. Portable breathing apparatus for coal mines

    NASA Technical Reports Server (NTRS)

    Vandolah, R. W.

    1972-01-01

    The state of the art in portable oxygen breathing equipment is reported. Considered are self-containing as well as chemically generating oxygen sources and their effectiveness and limitations in mine rescue operations.

  3. Does a Smaller Waist Mean Smelly Breath?

    MedlinePlus

    ... overnight on the surface of the tongue when saliva production is diminished." ; Tips to combat halitosis: ; 1. Drink ... after meals can help keep bad breath away. Saliva production increases during chewing and this can help neutralize ...

  4. Shortness of Breath in Infants and Children

    MedlinePlus

    ... object? Yes Any small object can block an airway and cause shortness of breath or CHOKING. Take ... remove the object). If necessary, carefully clear the airway with a sweeping motion of your finger. If ...

  5. Breathing Problems - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Breathing Problems URL of this page: https://medlineplus.gov/languages/breathingproblems.html Other topics A-Z A B ...

  6. Breathing exercises for adults with asthma.

    PubMed

    2015-11-01

    Asthma is a common long-term condition that remains poorly controlled in many people despite the availability of pharmacological interventions, evidence-based treatment guidelines and care pathways.(1) There is considerable public interest in the use of non-pharmacological approaches for the treatment of asthma.(2) A survey of people with asthma reported that many have used complementary and alternative medicine, often without the knowledge of their clinical team.(3) Such interventions include breathing techniques, herbal products, homeopathy and acupuncture. The role of breathing exercises within the management of asthma has been controversial, partly because early claims of effectiveness were exaggerated.(4) UK national guidance and international guidelines on the management of asthma have included the option of breathing exercise programmes as an adjuvant to pharmacological treatment.(5,6) Here we discuss the types of breathing exercises used and review the evidence for their effectiveness. PMID:26563876

  7. The retrotrapezoid nucleus and breathing.

    PubMed

    Guyenet, Patrice G; Stornetta, Ruth L; Abbott, Stephen B G; Depuy, Seth D; Kanbar, Roy

    2012-01-01

    The retrotrapezoid nucleus (RTN) is located in the rostral medulla oblongata close to the ventral surface and consists of a bilateral cluster of glutamatergic neurons that are non-aminergic and express homeodomain transcription factor Phox2b throughout life. These neurons respond vigorously to increases in local pCO(2) via cell-autonomous and paracrine (glial) mechanisms and receive additional chemosensory information from the carotid bodies. RTN neurons exclusively innervate the regions of the brainstem that contain the respiratory pattern generator (RPG). Lesion or inhibition of RTN neurons largely attenuates the respiratory chemoreflex of adult rats whereas their activation increases respiratory rate, inspiratory amplitude and active expiration. Phox2b mutations that cause congenital central hypoventilation syndrome in humans prevent the development of RTN neurons in mice. Selective deletion of the RTN Phox2b-VGLUT2 neurons by genetic means in mice eliminates the respiratory chemoreflex in neonates.In short, RTN Phox2b-VGLUT2 neurons are a major nodal point of the CNS network that regulates pCO(2) via breathing and these cells are probable central chemoreceptors. PMID:23080151

  8. Half Moon Cove Tidal Project. Feasibility report

    SciTech Connect

    Not Available

    1980-11-01

    The proposed Half Moon Cove Tidal Power Project would be located in a small cove in the northern part of Cobscook Bay in the vicinity of Eastport, Maine. The project would be the first tidal electric power generating plant in the United States of America. The basin impounded by the barrier when full will approximate 1.2 square miles. The average tidal range at Eastport is 18.2 feet. The maximum spring tidal range will be 26.2 feet and the neap tidal range 12.8 feet. The project will be of the single pool-type single effect in which generation takes place on the ebb tide only. Utilizing an average mean tidal range of 18.2 feet the mode of operation enables generation for approximately ten and one-half (10-1/2) hours per day or slightly in excess of five (5) hours per tide. The installed capacity will be 12 MW utilizing 2 to 6 MW units. An axial flow, or Bulb type of turbine was selected for this study.

  9. Ocean tidal effects on Earth rotation

    NASA Astrophysics Data System (ADS)

    Gross, Richard S.

    2009-12-01

    Tidal forces due to the tide-raising potential deform the solid and fluid regions of the Earth, causing the Earth's inertia tensor to change, and hence causing the Earth's rate of rotation and length-of-day to change. Because both the tide-raising potential and the solid Earth's elastic response to the tidal forces caused by this potential are well-known, accurate models for the effects of the elastic solid body tides on the Earth's rotation are available. However, models for the effect of the ocean tides on the Earth's rotation are more problematic because of the need to model the dynamic response of the oceans to the tidal forces. Hydrodynamic ocean tide models that have recently become available are evaluated here for their ability to account for long-period ocean tidal signals in length-of-day observations. Of the models tested here, the older altimetric data-constrained model of Kantha et al. (1998) is shown to still do the best job of accounting for ocean tidal effects in length-of-day, particularly at the fortnightly tidal frequency. The model currently recommended by the IERS is shown to do the worst job.

  10. TIDAL INTERACTIONS IN MERGING WHITE DWARF BINARIES

    SciTech Connect

    Piro, Anthony L.

    2011-10-20

    The recently discovered system J0651 is the tightest known detached white dwarf (WD) binary. Since it has not yet initiated Roche-lobe overflow, it provides a relatively clean environment for testing our understanding of tidal interactions. I investigate the tidal heating of each WD, parameterized in terms of its tidal Q parameter. Assuming that the heating can be radiated efficiently, the current luminosities are consistent with Q {sub 1} {approx} 7 x 10{sup 10} and Q {sub 2} {approx} 2 x 10{sup 7}, for the He and C/O WDs, respectively. Conversely, if the observed luminosities are merely from the cooling of the WDs, these estimated values of Q represent the upper limits. A large Q {sub 1} for the He WD means its spin velocity will be slower than that expected if it was tidally locked, which, since the binary is eclipsing, may be measurable via the Rossiter-McLaughlin effect. After one year, gravitational wave emission shifts the time of eclipses by 5.5 s, but tidal interactions cause the orbit to shrink more rapidly, changing the time by up to an additional 0.3 s after a year. Future eclipse timing measurements may therefore infer the degree of tidal locking.

  11. Haemoptysis after breath-hold diving.

    PubMed

    Boussuges, A; Pinet, C; Thomas, P; Bergmann, E; Sainty, J M; Vervloet, D

    1999-03-01

    Pulmonary oedema has been described in swimmers and self-contained underwater breathing apparatus (Scuba) divers. This study reports three cases of haemoptysis secondary to alveolar haemorrhage in breath-hold divers. Contributory factors, such as haemodynamic modifications secondary to immersion, cold exposure, exercise and exposure to an increase in ambient pressure, could explain this type of accident. Furthermore, these divers had taken aspirin, which may have aggravated the bleeding. PMID:10232449

  12. Breathing hospital air can make you sick.

    PubMed

    Brownson, K

    1999-12-01

    Indoor air quality has deteriorated so much since the 1970s oil shortage and subsequent energy-efficient construction of buildings that people are becoming seriously ill by just breathing the indoor air. This is a problem with all industrial buildings and hospital staff are at particular risk. There are various things that hospital managers from different departments can do to make the air safe for staff and patients to breathe. PMID:10787631

  13. Hydrogen breath tests in gastrointestinal diseases.

    PubMed

    Rana, Satya Vati; Malik, Aastha

    2014-10-01

    Hydrogen breath tests are widely used to explore pathophysiology of functional gastrointestinal (GI) disorders. Small intestinal bacterial overgrowth (SIBO) and carbohydrate malabsorption are disorders detected by these tests that have been proposed to be of great importance for symptoms of GI diseases. Glucose hydrogen breath test is more acceptable for diagnosis of SIBO whereas lactose and fructose hydrogen breath tests are used for detection of lactose and fructose maldigestion respectively. Lactulose hydrogen breath test is also used widely to measure the orocecal transit time for GI motility. These methods are noninvasive and inexpensive. Many patients with functional gut disorders are unaware of the relationship between diet and GI symptoms they present. In particular, patients with chronic symptoms may regard their condition as normal and may not be aware that their symptoms can be effectively managed following a proper diagnosis. Patients with symptoms of abdominal pain, bloating, flatulence and altered bowel movements (diarrhea and constipation), or with a medical diagnosis of irritable bowel syndrome or celiac disease, may have undiagnosed carbohydrate malabsorption or SIBO. Hydrogen breath tests are specific and sensitive diagnostic tests that can be used to either confirm or eliminate the possibility of carbohydrate malabsorption or SIBO in such patients. Breath tests, though valuable tools, are underutilized in evaluating dyspepsia and functional bloating and diarrhea as well as suspected malabsorption. However, because of their simplicity, reproducibility and safety of procedure they are now being substituted to more uncomfortable and expensive techniques that were traditionally used in gastroenterology. PMID:25298621

  14. Breath tests and airway gas exchange.

    PubMed

    Anderson, Joseph C; Hlastala, Michael P

    2007-01-01

    Measuring soluble gas in the exhaled breath is a non-invasive technique used to estimate levels of respiratory, solvent, and metabolic gases. The interpretation of these measurements is based on the assumption that the measured gases exchange in the alveoli. While the respiratory gases have a low blood-solubility and exchange in the alveoli, high blood-soluble gases exchange in the airways. The effect of airway gas exchange on the interpretation of these exhaled breath measurements can be significant. We describe airway gas exchange in relation to exhaled measurements of soluble gases that exchange in the alveoli. The mechanisms of airway gas exchange are reviewed and criteria for determining if a gas exchanges in the airways are provided. The effects of diffusion, perfusion, temperature and breathing maneuver on airway gas exchange and on measurement of exhaled soluble gas are discussed. A method for estimating the impact of airway gas exchange on exhaled breath measurements is presented. We recommend that investigators should carefully control the inspired air conditions and type of exhalation maneuver used in a breath test. Additionally, care should be taken when interpreting breath tests from subjects with pulmonary disease. PMID:16413216

  15. Optoacoustic 13C-breath test analyzer

    NASA Astrophysics Data System (ADS)

    Harde, Hermann; Helmrich, Günther; Wolff, Marcus

    2010-02-01

    The composition and concentration of exhaled volatile gases reflects the physical ability of a patient. Therefore, a breath analysis allows to recognize an infectious disease in an organ or even to identify a tumor. One of the most prominent breath tests is the 13C-urea-breath test, applied to ascertain the presence of the bacterium helicobacter pylori in the stomach wall as an indication of a gastric ulcer. In this contribution we present a new optical analyzer that employs a compact and simple set-up based on photoacoustic spectroscopy. It consists of two identical photoacoustic cells containing two breath samples, one taken before and one after capturing an isotope-marked substrate, where the most common isotope 12C is replaced to a large extent by 13C. The analyzer measures simultaneously the relative CO2 isotopologue concentrations in both samples by exciting the molecules on specially selected absorption lines with a semiconductor laser operating at a wavelength of 2.744 μm. For a reliable diagnosis changes of the 13CO2 concentration of 1% in the exhaled breath have to be detected at a concentration level of this isotope in the breath of about 500 ppm.

  16. Monitoring breath markers under controlled conditions.

    PubMed

    Righettoni, Marco; Ragnoni, Alessandro; Güntner, Andreas T; Loccioni, Claudio; Pratsinis, Sotiris E; Risby, Terence H

    2015-12-01

    Breath analysis has the potential to detect and monitor diseases as well as to reduce the corresponding medical costs while improving the quality of a patient's life. Herein, a portable prototype, consisting of a commercial breath sampler modified to work as a platform for solid-state gas sensors was developed. The sensor is placed close to the mouth (<10 cm) and minimizes the mouth-to-sensor path to avoid contamination and dilution of the target breath marker. Additionally with an appropriate cooling concept, even high sensor operating temperatures (e.g. 350 °C) could be used. Controlled sampling is crucial for accurate repeatable analysis of the human breath and these concerns have been addressed by this novel prototype. The device helps a subject control their exhaled flow rate which increases reproducibility of intra-subject breath samples. The operation of this flame-made selective chemo-resistive gas sensor is demonstrated by the detection of breath acetone. PMID:26469378

  17. Breath-based biomarkers for tuberculosis

    NASA Astrophysics Data System (ADS)

    Kolk, Arend H. J.; van Berkel, Joep J. B. N.; Claassens, Mareli M.; Walters, Elisabeth; Kuijper, Sjoukje; Dallinga, Jan W.; van Schooten, Fredrik-Jan

    2012-06-01

    We investigated the potential of breath analysis by gas chromatography - mass spectrometry (GC-MS) to discriminate between samples collected prospectively from patients with suspected tuberculosis (TB). Samples were obtained in a TB endemic setting in South Africa where 28% of the culture proven TB patients had a Ziehl-Neelsen (ZN) negative sputum smear. A training set of breath samples from 50 sputum culture proven TB patients and 50 culture negative non-TB patients was analyzed by GC-MS. A classification model with 7 compounds resulted in a training set with a sensitivity of 72%, specificity of 86% and accuracy of 79% compared with culture. The classification model was validated with an independent set of breath samples from 21 TB and 50 non-TB patients. A sensitivity of 62%, specificity of 84% and accuracy of 77% was found. We conclude that the 7 volatile organic compounds (VOCs) that discriminate breath samples from TB and non-TB patients in our study population are probably host-response related VOCs and are not derived from the VOCs secreted by M. tuberculosis. It is concluded that at present GC-MS breath analysis is able to differentiate between TB and non-TB breath samples even among patients with a negative ZN sputum smear but a positive culture for M. tuberculosis. Further research is required to improve the sensitivity and specificity before this method can be used in routine laboratories.

  18. Hydrodynamics and sediment suspension in shallow tidal channels intersecting a tidal flat

    NASA Astrophysics Data System (ADS)

    Pieterse, Aline; Puleo, Jack A.; McKenna, Thomas E.

    2016-05-01

    A field study was conducted on a tidal flat intersected by small tidal channels (depth <0.1 m, width <2 m) within a tidal marsh. Data were collected in the channels, and on the adjacent tidal flat that encompasses approximately 1600 m2 in planform area. Hydrodynamic processes and sediment suspension between the channels and adjacent flat were compared. Shear stress and turbulent kinetic energy were computed from high frequency velocity measurements. Maximum water depth at the field site varied from 0.11 m during the lowest neap high tide to 0.58 m during a storm event. In the channel intersecting the tidal flat, the shear stress, turbulence and along-channel velocity were ebb dominant; e.g. 0.33 m/s peak velocity for ebb compared to 0.19 m/s peak velocity for flood. Distinct pulses in velocity occurred when the water level was near the tidal flat level. The velocity pulse during flood tide occurred at a higher water level than during ebb tide. No corresponding velocity pulse on the tidal flat was observed. Sediment concentrations peaked at the beginning and end of each tidal cycle, and often had a secondary peak close to high tide, assumed to be related to sediment advection. The influence of wind waves on bed shear stress and sediment suspension was negligible. Water levels were elevated during a storm event such that the tidal flat remained inundated for 4 tidal cycles. The water did not drain from the tidal flat into the channels during the storm, and no velocity pulses occurred. Along-channel velocities, turbulent kinetic energy, and shear stresses were therefore smaller in the channels during storm conditions than during non-storm conditions.

  19. Upper limb kinematic differences between breathing and non-breathing conditions in front crawl sprint swimming.

    PubMed

    McCabe, Carla B; Sanders, Ross H; Psycharakis, Stelios G

    2015-11-26

    The purpose of this study was to determine whether the breathing action in front crawl (FC) sprint swimming affects the ipsilateral upper limb kinematics relative to a non-breathing stroke cycle (SC). Ten male competitive swimmers performed two 25m FC sprints: one breathing to their preferred side (Br) and one not breathing (NBr). Both swim trials were performed through a 6.75m(3) calibrated space and recorded by six gen-locked JVC KY32 CCD cameras. A paired t-test was used to assess statistical differences between the trials, with a confidence level of p<0.05 accepted as significant. Swimmers were slower (3%) when breathing. Within the entry phase, swimmers had a slower COM horizontal velocity (3.3%), less shoulder flexion (8%), abduction (33%) and roll (4%) when breathing. The pull phase was longer in duration (14%) swimmers had a shallower hand path (11%), less shoulder abduction (11%), a slower hand vertical acceleration (30%) and slower centre of mass (COM) horizontal velocity (3%) when breathing. In the push phase, swimmers had a smaller elbow range of motion (ROM) (38%), faster backwards hand speed (25%) and faster hand vertical acceleration (33%) when breathing. Swimmers rolled their shoulders more (12%) in the recovery phase when breathing. This study confirms that swim performance is compromised by the inclusion of taking a breath in sprint FC swimming. It was proposed that swimmers aim to orient their ipsilateral shoulder into a stronger position by stretching and rolling the shoulders more in the entry phase whilst preparing to take a breath. Swimmers should focus on lengthening the push phase by extending the elbow more and not accelerating the hand too quickly upwards when preparing to inhale. PMID:26456423

  20. Plant distributions along salinity and tidal gradients in Oregon tidal marshes

    EPA Science Inventory

    Accurately modeling climate change effects on tidal marshes in the Pacific Northwest requires understanding how plant assemblages and species are presently distributed along gradients of salinity and tidal inundation. We outline on-going field efforts by the EPA and USGS to dete...

  1. Adsorption of desflurane by the silica gel filters in breathing circuits: an in vitro study

    PubMed Central

    Song, Seok Young; Lim, Bo Reum

    2015-01-01

    Background During general anesthesia, a heated breathing circuit (HBC) is used to replace the heat and moisture exchange function of the upper airway. One HBC uses an air dryer filter that employs silica gel (SG) as a desiccant. SG is capable of adsorbing many organic compounds. Therefore, we undertook an in vitro study of the adsorption of desflurane by SG filters. Methods An HBC was connected to an anesthesia machine, and a test lung was connected to the circuit. The test lung was mechanically ventilated with 2 or 4 L/min of fresh gas flow, with and without the air dryer filter. Desflurane was administered at a 6 vol% on the vaporizer dial setting. The experiment was repeated 15 times in each group. The end-tidal concentrations were measured during the experiments. The air dryer filter weights were measured before and after the experiments, and the times required to achieve the specific end-tidal desflurane concentrations were determined. Results Significant differences in the end-tidal concentrations of desflurane were observed between the control and filter groups (P < 0.001). The filter weights increased significantly after the experiments (P < 0.001). The times required to achieve the same end-tidal desflurane concentrations were different with the application of the air dryer filter (P < 0.001). Conclusions The adsorption of desflurane with the use of an air dryer filter was verified in this in vitro study. Careful attention is needed when using air dryer gel filters during general anesthesia. PMID:26045931

  2. Chemical sensors for breath gas analysis: the latest developments at the Breath Analysis Summit 2013.

    PubMed

    Tisch, Ulrike; Haick, Hossam

    2014-06-01

    Profiling the body chemistry by means of volatile organic compounds (VOCs) in the breath opens exciting new avenues in medical diagnostics. Gas sensors could provide ideal platforms for realizing portable, hand-held breath testing devices in the near future. This review summarizes the latest developments and applications in the field of chemical sensors for diagnostic breath testing that were presented at the Breath Analysis Summit 2013 in Wallerfangen, Germany. Considerable progress has been made towards clinically applicable breath testing devices, especially by utilizing chemo-sensitive nanomaterials. Examples of several specialized breath testing applications are presented that are either based on stand-alone nanomaterial-based sensors being highly sensitive and specific to individual breath compounds over others, or on combinations of several highly specific sensors, or on experimental nanomaterial-based sensors arrays. Other interesting approaches include the adaption of a commercially available MOx-based sensor array to indirect breath testing applications, using a sample pre-concentration method, and the development of compact integrated GC-sensor systems. The recent trend towards device integration has led to the development of fully integrated prototypes of point-of-care devices. We describe and compare the performance of several prototypes that are based on different sensing technologies and evaluate their potential as low-cost and readily available next-generation medical devices. PMID:24682160

  3. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Compressed breathing gas and liquefied breathing gas containers; minimum requirements. 84.81 Section 84.81 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE...

  4. The fast exercise drive to breathe.

    PubMed

    Duffin, James

    2014-02-01

    This paper presents a personal view of research into the exercise drive to breathe that can be observed to act immediately to increase breathing at the start of rhythmic exercise. It is based on a talk given at the Experimental Biology 2013 meeting in a session entitled 'Recent advances in understanding mechanisms regulating breathing during exercise'. This drive to breathe has its origin in a combination of central command, whereby voluntary motor commands to the exercising muscles produce a concurrent respiratory drive, and afferent feedback, whereby afferent information from the exercising muscles affects breathing. The drive at the start and end of rhythmic exercise is proportional to limb movement frequency, and its magnitude decays as exercise continues so that the immediate decrease of ventilation at the end of exercise is about 60% of the immediate increase at the start. With such evidence for the effect of this fast drive to breathe at the start and end of rhythmic exercise, its existence during exercise is hypothesised. Experiments to test this hypothesis have, however, provided debatable evidence. A fast drive to breathe during both ramp and sine wave changes in treadmill exercise speed and grade appears to be present in some individuals, but is not as evident in the general population. Recent sine-wave cycling experiments show that when cadence is varied sinusoidally the ventilation response lags by about 10 s, whereas when pedal loading is varied ventilation lags by about 30 s. It therefore appears that limb movement frequency is effective in influencing ventilation during exercise as well as at the start and end of exercise. PMID:23940383

  5. Ventilatory efficiency and breathing pattern in world-class cyclists: A three-year observational study.

    PubMed

    Salazar-Martínez, Eduardo; Terrados, Nicolás; Burtscher, Martin; Santalla, Alfredo; Naranjo Orellana, José

    2016-07-15

    The purpose of this three-year observational study was to analyze the ventilatory efficiency and breathing pattern in world-class professional cyclists. Twelve athletes (22.61±3.8years; 177.38±5.5cm; 68.96±5.5kg and VO2max 75.51±3.3mLkg(-1)min(-1)) were analyzed retrospectively. For each subject, respiratory and performance variables were recorded during incremental spiroergometry: oxygen uptake (VO2), carbon dioxide output (VCO2), pulmonary ventilation (VE), tidal volume (Vt), breathing frequency (fR), driving (Vt/Ti), timing (Ti/Ttot), peak power output (PPO) and maximum oxygen uptake (VO2max). Ventilatory efficiency (VE/VCO2 slope) was calculated from the beginning of exercise testing to the second ventilatory threshold (VT2). The VE/VCO2 slope was unaffected during the study period (24.63±3.07; 23.61±2:79; 24:89±2:61) with a low effect size (ES=0.04). The PPO improved significantly in the third year (365±33.74; 386.36±32.33; 415.00±24.15) (p<0.05). The breathing pattern variables, Vt/Ti and Ti/Ttot, did not change significantly over the three year period (ES=0.00; ES=0.03 respectively). These findings suggest that changes in cycling performance in world-class professional cyclists do not modify breathing variables related to the control of ventilatory efficiency. PMID:27083403

  6. Metabolic and Ventilatory Changes During and After High-Frequency Yoga Breathing

    PubMed Central

    Telles, Shirley; Singh, Nilkamal; Balkrishna, Acharya

    2015-01-01

    Background Practicing high-frequency yoga breathing (HFYB) induced a hypermetabolic state in a single subject during the practice but the effect has not been studied in multiple practitioners. Material/Methods Healthy male volunteers (n=47, group mean age ±S.D., 23.2±4.1 years) were recruited as an experimental group and another twenty volunteers were recruited as a control group. The experimental group practiced either HFYB (Breath rate 1.0 Hz) or breath awareness (BAW) on two separate days. The sequence was reversed for alternate participants. The control group was assessed under similar conditions while sitting at ease. The breath rate (RR), tidal volume (VT), ventilation (VE), VO2, VCO2, arterial PCO2 and energy expenditure (EE Kcal/day) were assessed for 35 minutes using an open circuit oxygen consumption analyzer. The assessment period was divided into before, during and after conditions. Repeated measures analyses of variance (ANOVA) were used to compare data recorded during and after the two practices with data recorded before. Before-After comparisons in the control group were with paired t-tests. Results The most relevant significant changes were increases in VE, VO2, VCO2 and EE during HFYB, while the same variables decreased during the control period. However after HFYB there was no change in VO2 or EE, although VE decreased as it did after the control period. Conclusions HFYB induces a hypermetabolic state for the duration of the practice which returns to baseline after HFYB suggesting a possible application for HFYB in hypometabolic states. PMID:26270968

  7. Metabolic and Ventilatory Changes During and After High-Frequency Yoga Breathing.

    PubMed

    Telles, Shirley; Singh, Nilkamal; Balkrishna, Acharya

    2015-01-01

    BACKGROUND Practicing high-frequency yoga breathing (HFYB) induced a hypermetabolic state in a single subject during the practice but the effect has not been studied in multiple practitioners. MATERIAL AND METHODS Healthy male volunteers (n=47, group mean age ± S.D., 23.2 ± 4.1 years) were recruited as an experimental group and another twenty volunteers were recruited as a control group. The experimental group practiced either HFYB (Breath rate 1.0 Hz) or breath awareness (BAW) on two separate days. The sequence was reversed for alternate participants. The control group was assessed under similar conditions while sitting at ease. The breath rate (RR), tidal volume (VT), ventilation (VE), VO2, VCO2, arterial PCO2 and energy expenditure (EE Kcal/day) were assessed for 35 minutes using an open circuit oxygen consumption analyzer. The assessment period was divided into before, during and after conditions. Repeated measures analyses of variance (ANOVA) were used to compare data recorded during and after the two practices with data recorded before. Before-After comparisons in the control group were with paired t-tests. RESULTS The most relevant significant changes were increases in VE, VO2, VCO2 and EE during HFYB, while the same variables decreased during the control period. However after HFYB there was no change in VO2 or EE, although VE decreased as it did after the control period. CONCLUSIONS HFYB induces a hypermetabolic state for the duration of the practice which returns to baseline after HFYB suggesting a possible application for HFYB in hypometabolic states. PMID:26270968

  8. Tidal Distortion of Titan: Implications for Surface Features and Tidal Measurements

    NASA Astrophysics Data System (ADS)

    Sohl, F.; Hussmann, H.; Coustenis, A.; Knapmeyer, M.; Lange, C.; Solomonidou, A.; Stephan, K.; Wagner, F. W.

    2012-04-01

    Titan is unique due to its similarity to the Earth and terrestrial planets in spite of the satellite's ice-rich bulk composition. Gravitational field data acquired by the Cassini spacecraft suggest that Titan's interior is composed of a mixture of rock and ice and is only partly differentiated. Titan is tidally locked with respect to Saturn and thereby subject to periodic tidal forcing of its interior and surface. Based on interior structure models and assumptions on rheological properties of planetary materials (i.e. ice, rock, water-ammonia ocean), we compute the elastic body tide Love numbers h2, k2, and l2 in order to describe Titan's tidal response. Key parameters, e.g., tidally-induced changes of local gravity, tilt relative to the direction of gravity, and areal strain are then given by linear combinations of h2, k2, and l2. We find peak-to-peak amplitudes of tidally-induced surface displacement and tilt variation on the order of up to a few tens of metres and a few arc seconds, respectively. Based on the obtained variations of tidal parameters, we will address possible implications for morphotectonic surface features and compositional heterogeneity on Titan. In addition, we will address possible measurements of global tidal distortion by using a network of several small landed stations. Each of those would have to carry an instrument suite to monitor tidally-induced changes of local gravity, tilt relative to the direction of gravity, and areal strain at the surface of Titan. Furthermore, tidal stresses are expected to induce significant seismic activity comparable to tidally-induced quakes on the Moon, and possibly along with seismicity induced by localized cryovolcanic activity.

  9. Ridges and tidal stress on Io

    USGS Publications Warehouse

    Bart, G.D.; Turtle, E.P.; Jaeger, W.L.; Keszthelyi, L.P.; Greenberg, R.

    2004-01-01

    Sets of ridges of uncertain origin are seen in twenty-nine high-resolution Galileo images, which sample seven locales on Io. These ridges are on the order of a few kilometers in length with a spacing of about a kilometer. Within each locale, the ridges have a consistent orientation, but the orientations vary from place to place. We investigate whether these ridges could be a result of tidal flexing of Io by comparing their orientations with the peak tidal stress orientations at the same locations. We find that ridges grouped near the equator are aligned either north-south or east-west, as are the predicted principal stress orientations there. It is not clear why particular groups run north-south and others east-west. The one set of ridges observed far from the equator (52?? S) has an oblique azimuth, as do the tidal stresses at those latitudes. Therefore, all observed ridges have similar orientations to the tidal stress in their region. This correlation is consistent with the hypothesis that tidal flexing of Io plays an important role in ridge formation. ?? 2004 Elsevier Inc. All rights reserved.

  10. The Debris Streams from Tidal Disruption Events

    NASA Astrophysics Data System (ADS)

    Coughlin, Eric

    2016-01-01

    When a star comes within a critical distance of a supermassive black hole, the tidal force exerted by the hole overcomes the stellar self-gravity. The star is subsequently torn apart, creating a stream of tidally-shredded debris that initially recedes from the hole, eventually returns to pericenter, forms an accretion disk and generates a highly luminous event that can sometimes be accompanied by the production of relativistic jets. This entire process is known as a tidal disruption event (TDE), and dozens of these events have already been observed. I will discuss my most recent work that has analyzed the tidal disruption process, and in particular I will focus on the results of numerical and analytical investigations that show that the streams of debris produced during TDEs can be gravitationally unstable. Specifically, I will describe how compressive motions augment the importance of self-gravity not long after the star is disrupted, resulting in the fragmentation of the debris stream into small-scale clumps. These findings will be discussed in the context of the observational signatures of tidal disruption events, and I will also relate these results to my past investigations concerning accretion disk formation and jet launching during TDEs.

  11. Ecological sounds affect breath duration more than artificial sounds.

    PubMed

    Murgia, Mauro; Santoro, Ilaria; Tamburini, Giorgia; Prpic, Valter; Sors, Fabrizio; Galmonte, Alessandra; Agostini, Tiziano

    2016-01-01

    Previous research has demonstrated that auditory rhythms affect both movement and physiological functions. We hypothesized that the ecological sounds of human breathing can affect breathing more than artificial sounds of breathing, varying in tones for inspiration and expiration. To address this question, we monitored the breath duration of participants exposed to three conditions: (a) ecological sounds of breathing, (b) artificial sounds of breathing having equal temporal features as the ecological sounds, (c) no sounds (control). We found that participants' breath duration variability was reduced in the ecological sound condition, more than in the artificial sound condition. We suggest that ecological sounds captured the timing of breathing better than artificial sounds, guiding as a consequence participants' breathing. We interpreted our results according to the Theory of Event Coding, providing further support to its validity, and suggesting its possible extension in the domain of physiological functions which are both consciously and unconsciously controlled. PMID:25637249

  12. Modeling studies of the far-field effects of tidal flat reclamation on tidal dynamics in the East China Seas

    NASA Astrophysics Data System (ADS)

    Song, Dehai; Wang, Xiao Hua; Zhu, Xueming; Bao, Xianwen

    2013-11-01

    In recent decades, the reclamation of tidal flat carried out by the authorities around the Bohai Sea, Yellow Sea, and East China Sea (BYECS) has reached new heights as a consequence of significant economic expansion in the coastal areas. We are concerned that the tidal flat reclamation may have not only local but also far-field effects on tidal dynamics in the entire BYECS. Numerical study shows different tidal patterns due to tidal energy redistribution when tidal flats around the BYECS are removed, in which the tidal range and phase are changed, and the amphidromic points are displaced. Tidal flats provide storage and dissipation for tidal energy; the former is much more significant than the latter. Loss of these functions caused by tidal flat reclamation will induce a redistribution of the extra tidal energy. Furthermore, we show that far-field effects on tidal dynamics would be observed on the west coast of Korea following significant reclamation on the Chinese Jiangsu coast. In turn, reclamation on the west coast of Korea may generate the far-field effects on the Chinese coast. Reclamation in the BYECS can result in rise of tidal amplitude and onshore sediment transport. The former may enhance the coastal hazards such as storm surge, and the latter may result in severe siltation. Therefore, careful consideration must always be given to any proposed artificial changes to tidal flat, given the effects of these on both the local environment and further afield.

  13. Pulse Ejection Presentation System Synchronized with Breathing

    NASA Astrophysics Data System (ADS)

    Kadowaki, Ami; Sato, Junta; Ohtsu, Kaori; Bannai, Yuichi; Okada, Kenichi

    Trials on transmission of olfactory information together with audio/visual information are currently being conducted in the field of multimedia. However, continuous emission of scents in high concentration creates problems of human adaptation and remnant odors in air. To overcome such problems we developed an olfactory display in conjunction with Canon Inc. This display has high emission control in the ink-jet so that it can provide stable pulse emission of scents. Humans catch a scent when they breathe in and inhale smell molecules in air. Therefore, it is important that the timing of scent presentation is synchronized with human breathing. We also developed a breath sensor which detects human inspiration. In this study, we combined the olfactory display with the breath sensor to make a pulse ejection presentation system synchronized the breath. The experimental evaluation showed that the system had more than 90 percent of detection rate. Another evaluation was held at KEIO TECHNO-MALL 2007. From questionnaire results of the participants, we found that the system made the user feel continuous sense of smell avoiding adaptation. It is expected that our system enables olfactory information to be synchronized with audio/visual information in arbitrary duration at any time.

  14. Sudarshan kriya yoga: Breathing for health

    PubMed Central

    Zope, Sameer A.; Zope, Rakesh A

    2013-01-01

    Breathing techniques are regularly recommended for relaxation, stress management, control of psychophysiological states, and to improve organ function. Yogic breathing, defined as a manipulation of breath movement, has been shown to positively affect immune function, autonomic nervous system imbalances, and psychological or stress-related disorders. The aim of this study was to assess and provide a comprehensive review of the physiological mechanisms, the mind–body connection, and the benefits of Sudarshan Kriya Yoga (SKY) in a wide range of clinical conditions. Various online databases searched were Medline, Psychinfo, EMBASE, and Google Scholar. All the results were carefully screened and articles on SKY were selected. The references from these articles were checked to find any other potentially relevant articles. SKY, a unique yogic breathing practice, involves several types of cyclical breathing patterns, ranging from slow and calming to rapid and stimulating. There is mounting evidence to suggest that SKY can be a beneficial, low-risk, low-cost adjunct to the treatment of stress, anxiety, post-traumatic stress disorder, depression, stress-related medical illnesses, substance abuse, and rehabilitation of criminal offenders. PMID:23440614

  15. Sudarshan kriya yoga: Breathing for health.

    PubMed

    Zope, Sameer A; Zope, Rakesh A

    2013-01-01

    Breathing techniques are regularly recommended for relaxation, stress management, control of psychophysiological states, and to improve organ function. Yogic breathing, defined as a manipulation of breath movement, has been shown to positively affect immune function, autonomic nervous system imbalances, and psychological or stress-related disorders. The aim of this study was to assess and provide a comprehensive review of the physiological mechanisms, the mind-body connection, and the benefits of Sudarshan Kriya Yoga (SKY) in a wide range of clinical conditions. Various online databases searched were Medline, Psychinfo, EMBASE, and Google Scholar. All the results were carefully screened and articles on SKY were selected. The references from these articles were checked to find any other potentially relevant articles. SKY, a unique yogic breathing practice, involves several types of cyclical breathing patterns, ranging from slow and calming to rapid and stimulating. There is mounting evidence to suggest that SKY can be a beneficial, low-risk, low-cost adjunct to the treatment of stress, anxiety, post-traumatic stress disorder, depression, stress-related medical illnesses, substance abuse, and rehabilitation of criminal offenders. PMID:23440614

  16. Tidal response of Europa's subsurface ocean

    NASA Astrophysics Data System (ADS)

    Karatekin, Özgür; Comblen, Richard; Toubeau, Jonathan; Deleersnijder, Eric; van Hoolst, Tim; Dehant, Veronique

    2010-05-01

    Observations of Cassini and Galileo spacecrafts suggest the presence of subsurface global water oceans under the icy shells of several satellites of Jupiter and Saturn. Previous studies have shown that in the presence of subsurface oceans, time-variable tides cause large periodic surface displacements and that tidal dissipation in the icy shell becomes a major energy source that can affect long-term orbital evolution. However, in most studies so far, the dynamics of these satellite oceans have been neglected. In the present study, we investigate the tidal response of the subsurface ocean of Europa to a time-varying potential. Two-dimensional nonlinear shallow water equations are solved on a sphere by means of a finite element code. The resulting ocean tidal flow velocities and surface displacements will be presented.

  17. Oceanic tidal signals in magnetic satellite data

    NASA Astrophysics Data System (ADS)

    Wardinski, I.; Lesur, V.

    2015-12-01

    In this study we discuss the observation of oceanic tidal signals in magnetic satellite data. We analyse 10 years of CHAMP satellite data. The detection algorithm is applied on residual signal that remains after the derivation of GRIMM 42 (Lesur et al., 2015). The signals found represent the major tidal constituents, such as the M2 tide. However, other tidal constituents appear to be swallowed by unmodelled external and induced magnetic signal, particularly in equatorial and circumpolar regions. A part of the study also focuses on the temporal variability of the signal detection and its dependence on geomagnetic activity. Possible refinements to the detection algorithm and its applicability to SWARM data are also presented and discussed.

  18. Tidal analysis of Met rocket wind data

    NASA Technical Reports Server (NTRS)

    Bedinger, J. F.; Constantinides, E.

    1976-01-01

    A method of analyzing Met Rocket wind data is described. Modern tidal theory and specialized analytical techniques were used to resolve specific tidal modes and prevailing components in observed wind data. A representation of the wind which is continuous in both space and time was formulated. Such a representation allows direct comparison with theory, allows the derivation of other quantities such as temperature and pressure which in turn may be compared with observed values, and allows the formation of a wind model which extends over a broader range of space and time. Significant diurnal tidal modes with wavelengths of 10 and 7 km were present in the data and were resolved by the analytical technique.

  19. Gravitational circulation in a tidal strait

    USGS Publications Warehouse

    Smith, P.E.; Cheng, R.T.; Burau, J.R.; Simpson, M.R.

    1991-01-01

    Eight months of continuous measurements of tidal current profiles with an acoustic Doppler current profiler (ADCP) were made in Carquinez Strait, California, during 1988 for the purpose of estimating long-term variations in vertical profiles of Eulerian residual currents. Salinity stratification near the ADCP deployment site also was analyzed. The strength of density-driven gravitational circulation and the amount of salinity stratification in the strait varied significantly over the spring-neap tidal cycle. Density currents and stratification were greater during neap tides when vertical mixing from the tide is at a minimum. Landward residual currents along the bottom were observed only during neap tides. Simulations made with a three-dimensional model to supplement the field measurements show a significant, tidally induced lateral variation in residual currents across the strait. The Stokes drift of 1-2 cm/s in the strait is small relative to the speed of gravitational currents.

  20. Is slow slip in Cascadia tidally modulated?

    NASA Astrophysics Data System (ADS)

    Hawthorne, J. C.; Rubin, A. M.

    2009-12-01

    Several studies have shown that the seismic tremor in episodic tremor and slip is tidally modulated, suggesting a strong sensitivity to the rather small tidal stresses. We address whether the slip is also tidally modulated by examining data from six borehole strainmeters in northwest Washington and southern Vancouver Island. We use the processed data provided by Plate Boundary Observatory (PBO), which is resampled to 5-minute intervals. However, we recompute empirical corrections for tides, a long-term linear trend, and barometric pressure in the 50 days surrounding each slow slip event. We then fit sinusoids at the tidal periods to the processed data as proxies for the tidally modulated component of slip, along with a linear trend as a proxy for the net strain in the slow slip. The data are too noisy to allow detection any tidal modulation using only a single event and station. We therefore simultaneously fit data from multiple stations and from three slow slip events since 2007. This assumes that the phase of the tides at the slipping regions detected by all stations is the same and that the phase of the fault response to the tidal stress is constant. Combining the stations and events both reduces the noise at the tidal periods and creates a longer time series, which allows us to separate energy at the different tidal frequencies. We find significant tidal signals at the 12.4 and 25.8-hour periods which differ from zero at the 1.5 to 2-sigma level. Errors are estimated by bootstrapping the slow slip strain and by considering the tidal signal at times before the slow slip event. The 12.4 and 25.8-hour sinusoids have amplitudes of 23 (10-40 at 2-sigma) and 15 (0-30 at 2-sigma) percent of the maximum amplitude that does not allow the slow slip strain signal to change sign, where the mean strain rate is estimated from the linear trends fit to the slow slip data. In terms of slip rate, the sinusoids at each period could then modulate the slip rate 23 and 15 percent

  1. Tidal deceleration of the moon's mean motion

    NASA Technical Reports Server (NTRS)

    Cheng, M. K.; Eanes, R. J.; Tapley, B. D.

    1992-01-01

    The secular change in the mean motion of the moon, n, caused by the tidal dissipation in the ocean and solid earth is due primarily to the effect of the diurnal and semidiurnal tides. The long-period ocean tides produce an increase in n, but the effects are only 1 percent of the diurnal and semidiurnal ocean tides. In this investigation, expressions for these effects are obtained by developing the tidal potential in the ecliptic reference system. The computation of the amplitude of equilibrium tide and the phase corrections is also discussed. The averaged tidal deceleration of the moon's mean motion, n, from the most recent satellite ocean tide solutions is -25.25 +/- 0.4 arcseconds/sq century. The value for n inferred from the satellite-determined ocean-tide solution is in good agreement with the value obtained from the analysis of 20 years of lunar laser-ranging observations.

  2. Technologies for Clinical Diagnosis Using Expired Human Breath Analysis

    PubMed Central

    Mathew, Thalakkotur Lazar; Pownraj, Prabhahari; Abdulla, Sukhananazerin; Pullithadathil, Biji

    2015-01-01

    This review elucidates the technologies in the field of exhaled breath analysis. Exhaled breath gas analysis offers an inexpensive, noninvasive and rapid method for detecting a large number of compounds under various conditions for health and disease states. There are various techniques to analyze some exhaled breath gases, including spectrometry, gas chromatography and spectroscopy. This review places emphasis on some of the critical biomarkers present in exhaled human breath, and its related effects. Additionally, various medical monitoring techniques used for breath analysis have been discussed. It also includes the current scenario of breath analysis with nanotechnology-oriented techniques. PMID:26854142

  3. From Globular Clusters to Tidal Dwarfs: Structure Formation in Tidal Tails

    NASA Astrophysics Data System (ADS)

    Knierman, K.; Hunsberger, S.; Gallagher, S.; Charlton, J.; Whitmore, B.; Hibbard, J.; Kundu, A.; Zaritsky, D.

    1999-12-01

    Galaxy interactions trigger star formation in tidal debris. How does this star formation depend on the local and global physical conditions? Using WFPC2/HST images, we investigate the range of structure within tidal tails of four classic ``Toomre Sequence'' mergers: NGC 4038/9 (``Antennae''), NGC 7252 (``Atoms for Peace''), NGC 3921, and NGC 3256. These tails contain a variety of stellar associations with sizes from globular clusters up to dwarf Irregulars. We explore whether there is a continuum between the two extremes. Our eight fields sample seven tidal tails at a variety of stages in the evolutionary sequence. Some of these tails are rich in HI while others are HI poor. Large tidal dwarfs are embedded in three of the tails. Using V and I WFPC2 images, we measure luminosities and colors of substructures within the tidal tails. The properties of globular cluster candidates in the tails will be contrasted with those of the hundreds of young clusters in the central regions of these mergers. We address whether globular clusters form and survive in the tidal tails and whether tidal dwarfs are composed of only young stars. By comparing the properties of structures in the tails of the four mergers with different ages, we examine systematic evolution of structure along the evolutionary sequence and as a function of HI content. We acknowledge support from NASA through STScI, and from NSF for an REU supplement for Karen Knierman.

  4. Tidal instability in a rotating heated core

    NASA Astrophysics Data System (ADS)

    Cebron, D.; Maubert, P.; Le Bars, M.

    2011-12-01

    The tidal (or elliptical) instability comes from a triadic parametric resonance between two inertial waves of a rotating fluid and an imposed elliptic deformation. Previous studies of this instability have been conducted with an isothermal fluid. Nevertheless, in all natural systems, temperature differences are also present, which lead to stratification or to convection. The previous studies need then to be reinvestigated in order to quantify the impact of a temperature field on the elliptical instability. Conversely, from a thermal point of view, many studies have been performed regarding the convective flow of an incompressible homogeneous fluid in a rotating spherical shell. However, since most astrophysical bodies are tidally deformed, these studies have to be reinvestigated to account for the potential presence of an elliptical instability. Note that this is different from the direct resonance of a forced gravito-inertial wave considered by Kumazawa et al. (1994). The guideline of our study is given by the following questions: (i) how is the growth rate of the tidal instability modified by an imposed temperature difference in an ellipsoidal geometry? (ii) Does the tidal instability grow over an established convective flow? (iii) Is the heat flux modified by the instability, and what are the scaling laws involved? In this work, we tackle these questions using a systematic numerical study of the thermo-elliptical rotating flow in a fixed triaxial ellipsoidal shell. In particular, we validate general physical processes of direct relevance for planetary dynamics. We demonstrate also that the tidal instability can grow on a convective flow, and may disrupt the famous Busse columns in planetary cores. Finally, we show that the heat flux at planetary scales may be controlled by the forced convection due to this tidal instability, which in any case plays a fundamental role in the organization of fluid motions. Kumazawa, M., Yoshida, S., Ito, T., Yoshioka, H., 1994

  5. Unravelling tidal dissipation in gaseous giant planets

    NASA Astrophysics Data System (ADS)

    Guenel, M.; Mathis, S.; Remus, F.

    2014-06-01

    Context. Tidal dissipation in planetary interiors is one of the key physical mechanisms that drive the evolution of star-planet and planet-moon systems. New constraints on this dissipation are now obtained both in the solar and exo-planetary systems. Aims: Tidal dissipation in planets is intrinsically related to their internal structure. Indeed, the dissipation behaves very differently when we compare its properties in solid and fluid planetary layers. Since planetary interiors consist of both types of regions, it is necessary to be able to assess and compare the respective intensity of the reservoir of dissipation in each type of layers. Therefore, in the case of giant planets, the respective contribution of the potential central dense rocky/icy core and of the deep convective fluid envelope must be computed as a function of the mass and the radius of the core. This will allow us to obtain their respective strengths. Methods: Using a method that evaluates the reservoir of dissipation associated to each region, which is a frequency-average of complex tidal Love numbers, we compared the respective contributions of the central core and of the fluid envelope. Results: For Jupiter- and Saturn-like planets, we show that the viscoelastic dissipation in the core could dominate the turbulent friction acting on tidal inertial waves in the envelope. However, the fluid dissipation would not be negligible. This demonstrates that it is necessary to build complete models of tidal dissipation in planetary interiors from their deep interior to their surface without any arbitrary assumptions. Conclusions: We demonstrate how important it is to carefully evaluate the respective strength of each type of dissipation mechanism in planetary interiors and to go beyond the usually adopted ad-hoc models. We confirm the significance of tidal dissipation in the potential dense core of gaseous giant planets.

  6. The Tidal Perturbations of the Galilean Satellites

    NASA Astrophysics Data System (ADS)

    Jacobson, Robert A.; Folkner, William M.

    2014-11-01

    To support the Juno mission currently enroute to Jupiter and preproject studies for the Europa Clipper mission, we developed new ephemerides for the Jovian satellites (the Galileans and four inners). The ephemerides are based on orbits that were determined by fitting a data set that included Earth-based astrometry from 1891 through 2013, Galilean satellite mutual events from 1973 through 2009, Galilean satellite eclipse timings from 1878 to 2013, and data acquired by the Pioneer, Voyager, Ulysses, Cassini, Galileo, and New Horizons spacecraft. As a part of the data fit we also redetermined the Jovian system gravity parameters and the spacecraft trajectories to be consistent with the satellite orbits. The dynamical model for the satellite orbits did not include tidal perturbations. Lainey et al. (2009 Nature 459, 957) determined tidal parameters for Jupiter and Io from a fit of the Galilean satellite orbits to Earth-based astrometry from 1891 to 2007 and mutual events from 1973 to 2003; he estimated only the satellite states and the tidal parameters. Subsequent to our ephemeris development, we activated the tide model and repeated our orbit analysis adding the determination of the tidal parameters. We found that if we omitted the spacecraft data and estimated only satellite states and tidal parameters, we obtained results similar to Lainey. However, when we included the spacecraft data in the fit, the tidal acceleration on Io was smaller but still caused a positive secular acceleration. The remaining task is to discriminate between the effects of the tide raised on Jupiter by Io and that raised on Io by Jupiter.

  7. Effect of dietary turmeric on breath hydrogen.

    PubMed

    Shimouchi, Akito; Nose, Kazutoshi; Takaoka, Motoko; Hayashi, Hiroko; Kondo, Takaharu

    2009-08-01

    Turmeric is widely used in Indian cuisine. The main constituents of turmeric are curcumin and its analogues, which are well-known antioxidant compounds. In the present study, we hypothesized that turmeric in curry might increase bowel motility and activate hydrogen-producing bacterial flora in the colon, thereby increasing the concentration of breath hydrogen. Eight healthy subjects fasted for 12 h and ingested curry and rice with or without turmeric (turmeric knockout curry). Breath-hydrogen concentrations were analyzed every 15 min for 6 h by gas chromatography with a semiconductor detector. Curry with turmeric significantly increased the area under the curve of breath hydrogen and shortened small-bowel transit time, compared with curry not containing turmeric. These results suggested that dietary turmeric activated bowel motility and carbohydrate colonic fermentation. PMID:19034660

  8. Sleep and Breathing at High Altitude.

    PubMed

    Wickramasinghe, Himanshu; Anholm, James D.

    1999-01-01

    Sleep at high altitude is characterized by poor subjective quality, increased awakenings, frequent brief arousals, marked nocturnal hypoxemia, and periodic breathing. A change in sleep architecture with an increase in light sleep and decreasing slow-wave and REM sleep have been demonstrated. Periodic breathing with central apnea is almost universally seen amongst sojourners to high altitude, although it is far less common in long-standing high altitude dwellers. Hypobaric hypoxia in concert with periodic breathing appears to be the principal cause of sleep disruption at altitude. Increased sleep fragmentation accounts for the poor sleep quality and may account for some of the worsened daytime performance at high altitude. Hypoxic sleep disruption contributes to the symptoms of acute mountain sickness. Hypoxemia at high altitude is most severe during sleep. Acetazolamide improves sleep, AMS symptoms, and hypoxemia at high altitude. Low doses of a short acting benzodiazepine (temazepam) may also be useful in improving sleep in high altitude. PMID:11898114

  9. Exhaled Breath Analysis in Heart Failure.

    PubMed

    Marcondes-Braga, Fabiana G; Batista, Guilherme Lopes; Bacal, Fernando; Gutz, Ivano

    2016-08-01

    Heart failure (HF) is a clinical condition that presents high morbidity and mortality and is one of the main reasons for hospital admissions all over the world. Although biochemical processes that occur in the body during heart failure are known, this syndrome is still associated to poor prognosis. Exhaled breath analysis has emerged as a promising noninvasive tool in different clinical conditions and, recently, it has been also tested in patients with HF. This review presents the main breath HF biomarkers, which reflect metabolic changes that occur in this complex syndrome. It also discusses the diagnostic and prognostic value of exhaled breath compounds for HF and makes a short description of the main technologies involved in this analysis. Some perspectives on the area are presented as well. PMID:27287200

  10. Modeling of deep breath vasoconstriction reflex.

    PubMed

    Chalacheva, Patjanaporn; Khoo, Michael C K

    2015-08-01

    Deep breaths akin to sighs have been reported to cause peripheral vasoconstriction. Our previous simulation studies have shown that this phenomenon cannot be reproduced in existing circulatory control models without inclusion of a respiratory-vascular coupling mechanism. To better understand this "sigh-vasoconstriction reflex", we investigated the effect of spontaneous and passively induced sighs as well as spontaneous breathing on peripheral vasoconstriction during wakefulness and non-rapid eye movement sleep in human subjects. We found that both spontaneous and induced sighs caused vasoconstriction during wakefulness and sleep. The coupling between respiration and vasoconstriction is also present even in an absence of deep breaths. The coupling mechanism is largely linear with increased nonlinearity during induced sighs. Since peripheral vascular resistance modulation is known to be sympathetically mediated, investigation of this coupling could potentially allow us to assess sympathetic function through non-invasive measurements and simple interventions. PMID:26738099

  11. Tidally Heated ExoMoons (THEM)

    NASA Astrophysics Data System (ADS)

    Dobos, V.

    2014-04-01

    More than a thousand exoplanets have been identified to date (Schneider 2014); however, moons orbiting exoplanets have not been discovered, yet. Nevertheless, it is probable that exomoons will be detected in the near future if they are not much more rare in exoplanetary systems than they are in the Solar System (Heller & Barnes 2013, Peters & Turner 2013, Kaltenegger 2010). For this reason it is important to begin to develop basic theoretical models of exomoons in advance of the first detections. Habitability is a particularly important aspect, since life might well develop on a non-planetary body if it has suitable characteristics and environmentals. Tidal forces produced by the planet which the moon orbits can induce friction inside the satellite that will have a warming effect (Peale et al. 1979). In the Solar System there are several examples for moons that have significant heating due to tidal forces. On exomoons that are too far from their central star to have habitable surface temperatures due to radiative heating, it is possible that warmth area of the surface produced by tidal heating could allow the emergence of life (Scharf 2006). This investigation focuses on tidal heating, studying the surface temperature of hypothetical exomoons for different orbital and interior parameters of the body. The aim of our research is to describe the conditions that allow the existence of water reservoirs in the liquid phase state on or near the surface. We modified and extended the public code of Heller & Barnes (2013) for the purposes of this investigation. References Heller, R., Barnes, R. 2013 Exomoon Habitability Constrained by Illumination and Tidal Heating, Astrobiology 13, 18 Kaltenegger, L. 2010 Characterizing habitable exomoons, The Astrophysical Journal Letters 712, 125 Peale, S. J., Cassen, P., Reynolds, R. T. 1979 Melting of Io by Tidal Dissipation, Science 203, 892 Peters, M. A., Turner, E. L. 2013 On the direct imaging of tidally heated exomoons, The

  12. SN 2012hn: a tidal detonation event?

    NASA Astrophysics Data System (ADS)

    Maccarone, Thomas

    2013-09-01

    We propose for a 30 kilosecond observation of SN 2102hn, a Ca-rich gap transient. These enigmatic objects, with properties intermediate between those of classical novae and Type Ia supernovae, can be well-explained by tidal detonations of low mass white dwarfs by intermediate mass black holes. In such a case, fall-back accretion of the tidal debris would power an X-ray source for which we propose to search. Because supermassive black holes will swallow white dwarfs whole, a successful outcome to this proposal would both explain the Ca-rich gap transients *and* establish the existence of intermediate mass black holes.

  13. Energy analysis of wave and tidal power

    NASA Astrophysics Data System (ADS)

    Harrison, R.; Smith, K. G.; Varley, J. S.

    1980-06-01

    Energy requirements for building wave- and tidal-power systems are estimated and the relationship between energy requirements and extraction efficiency is examined for wavepower systems. It is found that a point of maximum net output is reached, beyond which further increases in extraction efficiency result in decreased net energy. In this manner, the energy analysis identifies a limit on the energy which could, in principle, be extracted by a wave-energy system. Finally, it is noted that although similar limits could be identified for other types of energy sources, the tidal power analysis is confined to a brief comparison of energy inputs and outputs.

  14. Tidal disruption of stars by SMBHs

    NASA Astrophysics Data System (ADS)

    Komossa, S.

    2016-06-01

    The tidal disruption and subsequent accretion of stars by supermassive black holes produces spectacular flares in the X-ray sky. First found with ROSAT, ongoing and upcoming sky surveys will find these events in the 1000s. In X-rays, tidal disruption events (TDEs) provide us with powerful new probes of accretion physics under extreme conditions, of the formation of disk winds, of relativistic effects near the SMBH, and of the presence of supermassive binary black holes. This talk reviews the status of observations, and discusses future prospects. XMM-Newton will continue to play an important role in identifying new events and carry out spectroscopic follow-ups.

  15. Decompression sickness following breath-hold diving.

    PubMed

    Schipke, J D; Gams, E; Kallweit, Oliver

    2006-01-01

    Despite convincing evidence of a relationship between breath-hold diving and decompression sickness (DCS), the causal connection is only slowly being accepted. Only the more recent textbooks have acknowledged the risks of repetitive breath-hold diving. We compare four groups of breath-hold divers: (1) Japanese and Korean amas and other divers from the Pacific area, (2) instructors at naval training facilities, (3) spear fishers, and (4) free-dive athletes. While the number of amas is likely decreasing, and Scandinavian Navy training facilities recorded only a few accidents, the number of spear fishers suffering accidents is on the rise, in particular during championships or using scooters. Finally, national and international associations (e.g., International Association of Free Drives [IAFD] or Association Internationale pour Le Developpment De L'Apnee [AIDA]) promote free-diving championships including deep diving categories such as constant weight, variable weight, and no limit. A number of free-diving athletes, training for or participating in competitions, are increasingly accident prone as the world record is presently set at a depth of 171 m. This review presents data found after searching Medline and ISI Web of Science and using appropriate Internet search engines (e.g., Google). We report some 90 cases in which DCS occurred after repetitive breath-hold dives. Even today, the risk of suffering from DCS after repetitive breath-hold diving is often not acknowledged. We strongly suggest that breath-hold divers and their advisors and physicians be made aware of the possibility of DCS and of the appropriate therapeutic measures to be taken when DCS is suspected. Because the risk of suffering from DCS increases depending on depth, bottom time, rate of ascent, and duration of surface intervals, some approaches to assess the risks are presented. Regrettably, none of these approaches is widely accepted. We propose therefore the development of easily manageable

  16. Electrospray ionization of volatiles in breath

    NASA Astrophysics Data System (ADS)

    Martínez-Lozano, P.; de La Mora, J. Fernández

    2007-08-01

    Recent work by Zenobi and colleagues [H. Chen, A. Wortmann, W. Zhang, R. Zenobi, Angew. Chem. Int. Ed. 46 (2007) 580] reports that human breath charged by contact with an electrospray (ES) cloud yields many mass peaks of species such as urea, glucose, and other ions, some with molecular weights above 1000 Da. All these species are presumed to be involatile, and to originate from breath aerosols by so-called extractive electrospray ionization EESI [H. Chen, A. Venter, R.G. Cooks, Chem. Commun. (2006) 2042]. However, prior work by Fenn and colleagues [C.M. Whitehouse, F. Levin, C.K. Meng, J.B. Fenn, Proceedings of the 34th ASMS Conference on Mass Spectrometry and Allied Topics, Denver, 1986 p. 507; S. Fuerstenau, P. Kiselev, J.B. Fenn, Proceedings of the 47th ASMS Conference on Mass Spectrometry, 1999, Dallas, TX, 1999] and by Hill and colleagues [C. Wu, W.F. Siems, H.H. Hill Jr., Anal. Chem. 72 (2000) 396] have reported the ability of electrospray drops to ionize a variety of low vapor pressure substances directly from the gas phase, without an apparent need for the vapor to be brought into the charging ES in aerosol form. The Ph.D. Thesis of Martínez-Lozano [P. Martínez-Lozano Sinués, Ph.D. Thesis, Department of Thermal and Fluid Engineering, University Carlos III of Madrid; April 5, 2006 (in Spanish); http://hdl.handle.net/10016/655] had also previously argued that the numerous human breath species observed via a similar ES ionization approach were in fact ionized directly from the vapor. Here, we observe that passage of the breath stream through a submicron filter does not eliminate the majority of the breath vapors seen in the absence of the filter. We conclude that direct vapor charging is the leading mechanism in breath ionization by electrospray drops, though aerosol ionization may also play a role.

  17. Contribution to the theory of tidal oscillations of an elastic earth. External tidal potential

    NASA Technical Reports Server (NTRS)

    Musen, P.

    1974-01-01

    The differential equations of the tidal oscillations of the earth were established under the assumption that the interior of the earth is laterally inhomogeneous. The theory was developed using vectorial and dyadic symbolism to shorten the exposition and to reduce the differential equations to a symmetric form convenient for programming and for numerical integration. The formation of tidal buldges on the surfaces of discontinuity and the changes in the internal density produce small periodic variations in the exterior geopotential which are reflected in the motion of artificial satellites. The analoques of Love elastic parameters in the expansion of exterior tidal potential reflect the asymmetric and inhomogeneous structure of the interior of the earth.

  18. A breathing mode for warped compactifications

    NASA Astrophysics Data System (ADS)

    Underwood, Bret

    2011-10-01

    In general warped compactifications, non-trivial backgrounds for the warp factor and the dilaton break D-dimensional diffeomorphism invariance, so that dilaton fluctuations can be gauged away completely and eaten by the metric. More specifically, the warped volume modulus and the dilaton are not independent, but combine into a single gauge-invariant degree of freedom in the lower dimensional effective theory, the warped breathing mode. This occurs for all strengths of the warping, even the weakly warped limit. This warped breathing mode appears as a natural zero mode deformation of backgrounds sourced by p-branes and affects the identification of the independent degrees of freedom of flux compactifications.

  19. Environmental testing of escape breathing apparatus

    SciTech Connect

    Stengel, J W

    1982-05-03

    A new generation of 60-minute self-contained breathing apparatus was being introduced into the underground coal mining industry for use as respiratory protection during fires and mine disasters. Little field experience existed from which to predict the survivability of this new life-support equipment. A series of environmental tests was proposed consisting of exposure to heat, cold, shock, and vibration. Treated and untreated apparatus were evaluated and compared by use on human subjects and a mechanical breathing simulator. Results are reported. After field data have been collected, information may be able to be correlated with environmental testing and used as a predictor of survivability.

  20. Breathing air trailer acceptance test procedure

    SciTech Connect

    Kostelnik, A.J.

    1994-09-14

    This Acceptance Test Procedure (ATP) will document compliance with the requirements of WHC-S-0251 Rev. 0 and ECNs 613530 and 606113. The equipment being tested is a Breathing Air Supply Trailer purchased as a Design and Fabrication procurement activity for use in the core sampling program. The ATP was written by the Seller and will be performed by the Seller with representatives of the Westinghouse Hanford Company witnessing the test at the Seller`s location. This test procedure is to verify that the American Bristol Industries, Inc., Model 5014-0001 low pressure Mobile Breathing Air Trailer, meets or exceeds the requirements of the Westinghouse Hanford specification.

  1. Tidal capture of stars by a massive black hole

    NASA Technical Reports Server (NTRS)

    Novikov, I. D.; Pethick, C. J.; Polnarev, A. G.

    1992-01-01

    The processes leading to tidal capture of stars by a massive black hole and the consequences of these processes in a dense stellar cluster are discussed in detail. When the amplitude of a tide and the subsequent oscillations are sufficiently large, the energy deposited in a star after periastron passage and formation of a bound orbit cannot be estimated directly using the linear theory of oscillations of a spherical star, but rather numerical estimates must be used. The evolution of a star after tidal capture is discussed. The maximum ratio R of the cross-section for tidal capture to that for tidal disruption is about 3 for real systems. For the case of a stellar system with an empty capture loss cone, even in the case when the impact parameter for tidal capture only slightly exceeds the impact parameter for direct tidal disruption, tidal capture would be much more important than tidal disruption.

  2. Don't Cross the (Tidal) Streams

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-09-01

    In a tidal disruption event (TDE), an unfortunate star passes too close to a dormant supermassive black hole (BH) and gets torn apart by tidal forces, feeding the BH for a short time. Oddly, were not finding nearly as many TDEs typically detected due to their distinctive observational signatures as theory says we should. A recent study suggests that we might be missing many of these events, due to the way the streams of shredded stars fall onto the BHs.Signatures of ShreddingWhen a BH tears a star apart, the stars material is stretched out into whats known as a tidal stream. That stream continues on a trajectory around the BH, with roughly half the material eventually falling back on the BH, whipping around it in a series of orbits. Where those orbits intersect each other, the material smashes together and circularizes, forming a disk that then accretes onto the BH.What does a TDE look like? We dont observe anything until after the tidal streams collide and the material begins to accrete onto the BH. At that point we observe a sudden peak in luminosity, which then gradually decreases (scaling roughly as time-5/3) as the tail end of whats left of the star accretes and the BHs food source eventually runs out.So why have we only been observing about a tenth as many TDEs as theory predicts we should see? By studying the structure of tidal streams in TDEs, James Guillochon (Harvard-Smithsonian Center for Astrophysics) and Enrico Ramirez-Ruiz (UC Santa Cruz) have found a potential reason and the culprit is general relativity.Dark YearsThe authors run a series of simulations of TDEs around black holes of varying masses and spins to see what form the resulting tidal streams take over time. They find that precession of the tidal stream due to the BHs gravitational effects changes how the stream interacts with itself, and therefore what we observe. Some cases behave like what we expect for whats currently considered a typical TDE but some dont.Example from simulations of a

  3. Carotid body denervation improves autonomic and cardiac function and attenuates disordered breathing in congestive heart failure

    PubMed Central

    Marcus, Noah J; Rio, Rodrigo; Schultz, Evan P; Xia, Xiao-Hong; Schultz, Harold D

    2014-01-01

    In congestive heart failure (CHF), carotid body (CB) chemoreceptor activity is enhanced and is associated with oscillatory (Cheyne–Stokes) breathing patterns, increased sympathetic nerve activity (SNA) and increased arrhythmia incidence. We hypothesized that denervation of the CB (CBD) chemoreceptors would reduce SNA, reduce apnoea and arrhythmia incidence and improve ventricular function in pacing-induced CHF rabbits. Resting breathing, renal SNA (RSNA) and arrhythmia incidence were measured in three groups of animals: (1) sham CHF/sham–CBD (sham–sham); (2) CHF/sham–CBD (CHF–sham); and (3) CHF/CBD (CHF–CBD). Chemoreflex sensitivity was measured as the RSNA and minute ventilatory () responses to hypoxia and hypercapnia. Respiratory pattern was measured by plethysmography and quantified by an apnoea–hypopnoea index, respiratory rate variability index and the coefficient of variation of tidal volume. Sympatho-respiratory coupling (SRC) was assessed using power spectral analysis and the magnitude of the peak coherence function between tidal volume and RSNA frequency spectra. Arrhythmia incidence and low frequency/high frequency ratio of heart rate variability were assessed using ECG and blood pressure waveforms, respectively. RSNA and responses to hypoxia were augmented in CHF–sham and abolished in CHF–CBD animals. Resting RSNA was greater in CHF–sham compared to sham–sham animals (43 ± 5% max vs. 23 ± 2% max, P < 0.05), and this increase was not found in CHF–CBD animals (25 ± 1% max, P < 0.05 vs. CHF–sham). Low frequency/high frequency heart rate variability ratio was similarly increased in CHF and reduced by CBD (P < 0.05). Respiratory rate variability index, coefficient of variation of tidal volume and apnoea–hypopnoea index were increased in CHF–sham animals and reduced in CHF–CBD animals (P < 0.05). SRC (peak coherence) was increased in CHF–sham animals (sham–sham 0.49 ± 0.05; CHF–sham 0.79

  4. Coughing Wheezing Shortness of Breath Tightness in Chest

    MedlinePlus

    ... Issues Coughing Wheezing Shortness of Breath Tightness in Chest Past Issues / Fall 2006 Table of Contents For ... short of breath or feel tightness in your chest, you might have asthma. If you do, you ...

  5. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply... for noxious or offensive odor before each diving operation....

  6. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply... for noxious or offensive odor before each diving operation....

  7. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply... for noxious or offensive odor before each diving operation....

  8. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply... for noxious or offensive odor before each diving operation....

  9. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply... for noxious or offensive odor before each diving operation....

  10. 42 CFR 84.115 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with...

  11. 42 CFR 84.115 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with...

  12. 42 CFR 84.115 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with...

  13. 42 CFR 84.115 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with...

  14. Coughing Wheezing Shortness of Breath Tightness in Chest

    MedlinePlus

    ... Current Issue Past Issues Coughing Wheezing Shortness of Breath Tightness in Chest Past Issues / Fall 2006 Table ... you cough a lot, wheeze, are short of breath or feel tightness in your chest, you might ...

  15. Meeting Reports for 2013: Recent Advances in Breath Biomarker Research

    EPA Science Inventory

    This article reports the efforts of the breath research community affiliated with the International Association of Breath Research (IABR) in disseminating research results in high profile technical meetings in the United States (US). Specifically, we describe presentations at a ...

  16. ALVEOLAR BREATH SAMPLING AND ANALYSIS IN HUMAN EXPOSURE ASSESSMENT STUDIES

    EPA Science Inventory

    Alveolar breath sampling and analysis can be extremely useful in exposure assessment studies involving volatile organic compounds (VOCs). Over recent years scientists from the EPA's National Exposure Research Laboratory have developed and refined an alveolar breath collection ...

  17. How Tidal Forces Cause Ocean Tides in the Equilibrium Theory

    ERIC Educational Resources Information Center

    Ng, Chiu-king

    2015-01-01

    We analyse why it is erroneous to think that a tidal bulge is formed by pulling the water surface directly up by a local vertical tidal force. In fact, ocean tides are caused by the global effect of the horizontal components of the tidal forces.

  18. Tidal stress triggering of earthquakes in Southern California

    NASA Astrophysics Data System (ADS)

    Bucholc, Magda; Steacy, Sandy

    2016-05-01

    We analyse the influence of the solid Earth tides and ocean loading on the occurrence time of Southern California earthquakes. For each earthquake, we calculate tidal Coulomb failure stress and stress rate on a fault plane that is assumed to be controlled by the orientation of the adjacent fault. To reduce bias when selecting data for testing the tide-earthquake relationship, we create four earthquake catalogues containing events within 1, 1.5, 2.5 and 5 km of nearest faults. We investigate the difference in seismicity rates at times of positive and negative tidal stresses/stress rates given three different cases. We consider seismicity rates during times of positive versus negative stress and stress rate, as well as 2 and 3 hr surrounding the local tidal stress extremes. We find that tidal influence on earthquake occurrence is found to be statistically non-random only in close proximity to tidal extremes meaning that magnitude of tidal stress plays an important role in tidal triggering. A non-random tidal signal is observed for the reverse events. Along with a significant increase in earthquake rates around tidal Coulomb stress maxima, the strength of tidal correlation is found to be closely related to the amplitude of the peak tidal Coulomb stress (τp). The most effective tidal triggering is found for τp ≥ 1 kPa, which is much smaller than thresholds suggested for static and dynamic triggering of aftershocks.

  19. Tidal Marshes: The Boundary between Land and Ocean.

    ERIC Educational Resources Information Center

    Gosselink, James

    An overview of the ecology of the tidal marshes along the gulf coast of the United States is presented. The following topics are included: (1) the human impact on tidal marshes; (2) the geologic origins of tidal marshes; (3) a description of the physical characteristics and ecosystem of the marshlands; (4) a description of the marshland food chain…

  20. Large tidal currents near Bear Island and related tidal energy losses from the North Atlantic

    NASA Astrophysics Data System (ADS)

    Huthnance, John M.

    1981-01-01

    Independent series of current meter measurements between northern Norway and Bear Island (19°E, 74 1/2° N) by MAFF Fisheries Laboratory, Lowestoft in 1972 and the Norwegian River and Harbour Laboratory in 1978 both show a ten-fold increase in diurnal tidal currents near Bear Island. The increase appears to be due partly to excitation of a topographic mode of natural frequency less than the tidal constituent K1. Part of the increase is also due simply to the shallower water near Bear Island and is shared by the semi-diurnal tidal currents. Tidal energy fluxes out of the Norwegian Sea total about 5 × 10 10 W between Norway and Bear Island and 6 × 10 10 W between Bear Island and Greenland, in contrast with the observational estimate 7 × 10 10 W entering the Norwegian Sea between Scotland and Iceland.

  1. Tidal constraints on the interior of Venus

    NASA Astrophysics Data System (ADS)

    Dumoulin, C.; Tobie, G.; Verhoeven, O.; Rosenblatt, P.; Rambaux, N.

    2015-10-01

    As a prospective study for a future exploration of Venus, we propose to systematically investigate the signature of the internal structure in the gravity field and the rotation state of Venus, through the determination of the moment of inertia and the tidal Love number.

  2. Observations of tidal disruptions by black holes

    NASA Astrophysics Data System (ADS)

    Gezari, Suvi

    2013-04-01

    It was first proposed by theorists in the late 1970's that an inevitable consequence of a massive black hole lurking in the center of a galaxy is that stars will pass close enough to the black hole to be ripped apart by its extreme tidal forces and consumed. The resulting flare of radiation from the accretion of the stellar debris would then be a unique signpost for the presence of a dormant black hole in the center of a normal galaxy. It was not until over two decades later that the first convincing tidal disruption event candidates emerged in the X-rays by the ROSAT All-Sky Survey. Since then over a dozen total candidates have now been discovered from searches across the electromagnetic spectrum, including the X-rays, the ultraviolet, and the optical. In the last couple years, we have also witnessed a paradigm shift with the discovery of the onset of relativistic, jetted emission in a tidal disruption event. I will review the census of observational candidates to date, and discuss the exciting prospects for using large samples of tidal disruption events discovered with the next-generation of ground-based and space-based synoptic surveys to probe accretion physics, jet formation, and black hole demographics.

  3. Constraining Deep Earth Structure Using Tidal Tomography

    NASA Astrophysics Data System (ADS)

    Lau, H. C.; Tromp, J.; Ishii, M.; Mitrovica, J. X.; Yang, H.; Davis, J. L.; Latychev, K.

    2013-12-01

    The solid Earth responses to luni-solar tidal forcings, as measured by space-geodetic and/or seismic techniques, have the potential to provide important and novel constraints on the long-wavelength density and elastic structure of the deep mantle as well as anelastic behavior at tidal frequencies. Here we describe a normal-mode theory for computing the semi-diurnal and long-period body tide response of a 3-D, rotating and anelastic Earth. The new theory provides a framework for incorporating body tide observations to infer deep Earth structure using tomographic methods, and, in this regard, it extends our earlier numerical formulation of this problem (Latychev et al., EPSL, 2008). To begin, we use normal-mode theory to treat the response of spherically symmetric, elastic Earth models, and demonstrate that the theory accurately reproduces the tidal Love numbers widely used in body-tide calculations. Next, we compute the body tide response of 3-D Earth models and benchmark these results against a finite-element formulation of this response. We also present results of an analysis which explores the sensitivity of the predictions to different models of mantle Q. Finally, we present preliminary inferences of deep mantle elastic and density structure based, in part, on the semi-diurnal tidal (radial displacement) response estimated from a network of GPS stations. We discuss the implications of these results for the structure and buoyancy of deep mantle LLSVPs.

  4. Life on the Tidal Mudflats: Elkhorn Slough.

    ERIC Educational Resources Information Center

    Andresen, Ruth

    Life in an estuarine environment is studied in this set of audio-visual materials prepared for grades 6-12. A 71-frame colored filmstrip, cassette tape narration, and teacher's guide focus upon Elkhorn Slough, a tidal mudflat in the Monterey Bay area, California. Topics examined range from river drainage and the effects of pollution on living…

  5. Spectrophotometric Evolutionary Models for Tidal Dwarfs (Poster)

    NASA Astrophysics Data System (ADS)

    Weilbacher, P. M.; Fritze-v. Alvensleben, U.

    We describe our procedure to model Tidal Dwarf Galaxies in the context of our evolutionary synthesis code. Our analysis shows strong contributions of gaseous emission lines to optical colors and of continuum emission to NIR colors during the burst phase. This underlines the importance of including both types of emission when modeling any type of star-bursting galaxies.

  6. Reinterpreting The Sagittarius Dwarf Tidal Debris

    NASA Astrophysics Data System (ADS)

    Newby, Matthew T.; Newberg, Heidi Jo; Thompson, Jeffery M.; Weiss, Jake

    2015-01-01

    Tidal debris from the Sagittarius dwarf galaxy (Sgr) has been used as a primary constraint in several determinations of the Milky Way Galaxy's total mass and dark matter distribution. However, the apparent "bifurcation" of both the leading and trailing tidal tails has never been satisfactorily explained. Using the powerful MilkyWay@home volunteer computing platform, we were surprised that the apparently fainter of the bifurcated tidal tails required an extremely wide stream to fit the observed stellar densities. Here, through additional analysis, we show that both the primary and secondary tidal tails of Sgr, as well as the Virgo overdensity, are all wider than previously thought, and dominate star counts in the Galactic halo. Additionally, we present evidence of a stellar "envelope" about the primary Sgr stream, which may be direct evidence for a subhalo-rich (or "lumpy") dark matter distribution. This research was supported by the NSF through grant AST 10-09670, and crowd funding from the MilkyWay@home volunteers.

  7. Tidal Energy Dissipation from Topex/Poseidon

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Egbert, G. D.; Smith, David E. (Technical Monitor)

    2000-01-01

    In a recent paper ({\\it Nature, 405,} 775, 2000) we concluded that 25 to 30\\% of the ocean's tidal energy dissipation, or about 1 terawatt, occurs in the deep ocean, with the remaining 2.6 TW in shallow seas. The physical mechanism for deep-ocean dissipation is apparently scattering of the surface tide into internal modes; Munk and Wunsch have suggested that this mechanism may provide half the power needed for mixing the deep-ocean. This paper builds further evidence for $1\\pm 0.2$ TW of deep-ocean dissipation. The evidence is extracted from tidal elevations deduced from seven years of Topex/Poseidon satellite altimeter data. The dissipation rate Is formed as a balance between the rate of working by tidal forces and the energy flux divergence. While dynamical assumptions are required to compute fluxes, area integrals of the energy balance are, owing to the tight satellite constraints, remarkably insensitive to these assumptions. A large suite of tidal solutions based on a wide range of dynamical assumptions, on perturbations to bathymetric models, and on simulated elevation data are used to assess this sensitivity. These and Monte Carlo error fields from a generalized inverse model are used to establish error uncertainties.

  8. 2008 NWFSC Tidal Freshwater Genetics Results

    SciTech Connect

    David Teel

    2009-05-01

    Genetic Analysis of Juvenile Chinook Salmon for inclusion in 'Ecology of Juvenile Salmon in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2008. Annual Report to Bonneville Power Administration, Contract DE-AC05-76RL01830.'

  9. Estuaries and Tidal Marshes. Habitat Pac.

    ERIC Educational Resources Information Center

    Fish and Wildlife Service (Dept. of Interior), Washington, DC.

    This educational packet consists of an overview, three lesson plans, student data sheets, and a poster. The overview examines estuaries and tidal or salt marshes by discussing the plants and animals in these habitats, marsh productivity, benefits and management of the habitats, historical aspects, and development and pollution. A glossary and list…

  10. The Tidal Radius of the Arches Cluster

    NASA Astrophysics Data System (ADS)

    Hosek, Matthew; Lu, Jessica R.; Anderson, Jay; Ghez, Andrea; Morris, Mark; Clarkson, William

    2015-08-01

    At a projected distance of just ˜26 pc from the center of the Milky Way, the Arches cluster allows us to examine the structure of a young massive cluster in the strong tidal environment of the Galactic center (GC). We use the HST WFC3IR camera to conduct an astrometric and photometric study of the outer region of the Arches cluster (R > 6.25”) in order to measure its radial profile. Using proper motions we separate cluster members from field stars down to F153M = 20 mag (˜2.5 M_sun) over a 120” x 120” field of view, covering an area 144 times larger than previous proper motion studies. This is a significant improvement over photometrically-determined cluster membership, which is complicated by the high degree of differential reddening across the field. Using cluster membership probabilities, a derived extinction map, and extensive completeness simulations, we construct the radial profile of the Arches cluster to a radius of ˜80” (˜3.1 pc assuming a distance of 8 kpc). Evidence of mass segregation out to this radius is observed, and no significant tidal tail structure is apparent. We find that the projected radial extent of the Arches cluster is significantly larger than its expected tidal radius. This result suggests either that the cluster is not as close to the GC as previously thought or that it is inflated beyond its nominal tidal radius.

  11. TIDAL EVOLUTION OF CLOSE-IN PLANETS

    SciTech Connect

    Matsumura, Soko; Rasio, Frederic A.; Peale, Stanton J.

    2010-12-20

    Recent discoveries of several transiting planets with clearly non-zero eccentricities and some large obliquities started changing the simple picture of close-in planets having circular and well-aligned orbits. The two major scenarios that form such close-in planets are planet migration in a disk and planet-planet interactions combined with tidal dissipation. The former scenario can naturally produce a circular and low-obliquity orbit, while the latter implicitly assumes an initially highly eccentric and possibly high-obliquity orbit, which are then circularized and aligned via tidal dissipation. Most of these close-in planets experience orbital decay all the way to the Roche limit as previous studies showed. We investigate the tidal evolution of transiting planets on eccentric orbits, and find that there are two characteristic evolution paths for them, depending on the relative efficiency of tidal dissipation inside the star and the planet. Our study shows that each of these paths may correspond to migration and scattering scenarios. We further point out that the current observations may be consistent with the scattering scenario, where the circularization of an initially eccentric orbit occurs before the orbital decay primarily due to tidal dissipation in the planet, while the alignment of the stellar spin and orbit normal occurs on a similar timescale to the orbital decay largely due to dissipation in the star. We also find that even when the stellar spin-orbit misalignment is observed to be small at present, some systems could have had a highly misaligned orbit in the past, if their evolution is dominated by tidal dissipation in the star. Finally, we also re-examine the recent claim by Levrard et al. that all orbital and spin parameters, including eccentricity and stellar obliquity, evolve on a similar timescale to orbital decay. This counterintuitive result turns out to have been caused by a typo in their numerical code. Solving the correct set of tidal

  12. Relativistic tidal properties of neutron stars

    SciTech Connect

    Damour, Thibault; Nagar, Alessandro

    2009-10-15

    We study the various linear responses of neutron stars to external relativistic tidal fields. We focus on three different tidal responses, associated to three different tidal coefficients: (i) a gravito-electric-type coefficient G{mu}{sub l}=[length]{sup 2l+1} measuring the lth-order mass multipolar moment GM{sub a{sub 1}}{sub ...a{sub I}} induced in a star by an external lth-order gravito-electric tidal field G{sub a{sub 1}}{sub ...a{sub I}}; (ii) a gravito-magnetic-type coefficient G{sigma}{sub l}=[length]{sup 2l+1} measuring the lth spin multipole moment GS{sub a{sub 1}}{sub ...a{sub I}} induced in a star by an external lth-order gravito-magnetic tidal field H{sub a{sub 1}}{sub ...a{sub I}}; and (iii) a dimensionless 'shape' Love number h{sub l} measuring the distortion of the shape of the surface of a star by an external lth-order gravito-electric tidal field. All the dimensionless tidal coefficients G{mu}{sub l}/R{sup 2l+1}, G{sigma}{sub l}/R{sup 2l+1}, and h{sub l} (where R is the radius of the star) are found to have a strong sensitivity to the value of the star's 'compactness'c{identical_to}GM/(c{sub 0}{sup 2}R) (where we indicate by c{sub 0} the speed of light). In particular, G{mu}{sub l}/R{sup 2l+1}{approx}k{sub l} is found to strongly decrease, as c increases, down to a zero value as c is formally extended to the 'black hole (BH) limit'c{sup BH}=1/2. The shape Love number h{sub l} is also found to significantly decrease as c increases, though it does not vanish in the formal limit c{yields}c{sup BH}, but is rather found to agree with the recently determined shape Love numbers of black holes. The formal vanishing of {mu}{sub l} and {sigma}{sub l} as c{yields}c{sup BH} is a consequence of the no-hair properties of black holes. This vanishing suggests, but in no way proves, that the effective action describing the gravitational interactions of black holes may not need to be augmented by nonminimal worldline couplings.

  13. From tidal dwarf galaxies to satellite galaxies

    NASA Astrophysics Data System (ADS)

    Bournaud, F.; Duc, P.-A.

    2006-09-01

    The current popular cosmological models have granted the population of dwarf satellite galaxies a key role: their number, location, and masses constrain both the distribution of dark matter and the physical evolution of their hosts. In the past years, there has been increasing observational evidence that objects with masses of dwarf galaxies can form in the tidal tails of colliding galaxies, as well as speculations that they could become satellite-like galaxies orbiting around their progenitors and thus be cosmologically important. Yet, whether the so-called "Tidal Dwarf Galaxy" (TDG) candidates are really long-lived objects and not transient features only present in young interacting systems is still largely an open question to which numerical simulations may give precise answers. We present here a set of 96 N-body simulations of colliding galaxies with various mass ratios and encounter geometries, including gas dynamics and star formation. We study the formation and long-term evolution of their TDG candidates. Among the 593 substructures initially identified in tidal tails, about 75% fall back onto their progenitor or are disrupted in a few 108 years. The remaining 25% become long-lived bound objects that typically survive more than 2 Gyr with masses above 108 M⊙. These long-lived, satellite-like objects, are found to form in massive gaseous accumulations originally located in the outermost regions of the tidal tails. Studying the statistical properties of the simulated TDGs, we infer several basic properties that dwarf galaxies should meet to have a possible tidal origin and apply these criteria to the Local Group dwarfs. We further found that the presence of TDGs would foster the anisotropy observed in the distribution of classical satellite galaxies around their host. Identifying the conditions fulfilled by interacting systems that were able to form long-lived tidal dwarfs - a spiral merging with a galaxy between 1/4 and 8 times its mass, on a prograde orbit

  14. Possibility of oscillatory tidal heating of Enceladus

    NASA Astrophysics Data System (ADS)

    Shoji, D.; Hussmann, H.; Sohl, F.; Kurita, K.

    2012-12-01

    Enceladus radiates ~16 GW of heat from its surface [1]. One efficient heat source of Enceladus is tidal heating which is maintained by the orbital resonance with Dione. However, assuming that the current eccentricity of Enceladus is in equilibrium with the resonance, tidal heating can generate only 1.1 GW of heat [2]. In the case of a non-equilibrium state, tidal heating rate and eccentricity evolve by interacting with each other. For homogeneous model of Enceladus, corresponding coupling calculations have been conducted by Meyer and Wisdom [3]. In their calculations, generated heat and eccentricity reach equilibrium state soon. In this work, we have performed coupling calculation among tidal heating rate, eccentricity and the interior structure of Enceladus. We constructed spherical shell Maxwell model for simplicity. Conventionally, dissipation factor (Q-value) of Saturn is estimated to more than 18,000 [2]. However, the latest observation implies a Q-value of Saturn that is one of order of magnitude less than conventional values [4]. We performed the calculation with different values of the Saturnian dissipation factor. In addition to the tidal heat, we took 7 GW of shear heat into consideration as an additional heat source[5]. In our calculation, if water-ice mixture (~10^9 Pa s in viscosity) exists between convective ice and silicate core instead of liquid ocean, eccentricity and heating rate oscillate with an 50-million-years cycle when the Q-value of Saturn is assumed around 3800. Minimum value of eccentricity is 0.005, which is comparable to the current value (0.0047). Generated tidal heat oscillates between 3 GW and 10 GW. Combined with shear heat, 17 GW of heat is generated at maximum. Although conditions for oscillatory heating are hard to fulfill and more consideration is needed, current large heat radiation of Enceladus may be remnant of episodically large tidal heating. Enceladus has divergent surface conditions, which might be related to episodic

  15. Effect of breathing of a helium-oxygen mixture on adaptation to effort in humans during high-altitude hypoxia.

    PubMed

    Debiński, W; Kłossowski, M; Gembicka, D

    1986-01-01

    The study was carried out on 17 healthy males aged 20-27 years subjected for 15 minutes to submaximal effort on a cycle ergometer (Elema-Schonander) under conditions of breathing ambient atmospheric air or a helium-oxygen mixture (20% O2 + 80% He) and under hypobaric pressure simulating an altitude of 3500 m above sea level. During the experiment the heart rate was recorded with ECG, and determinations were performed of the minute volume, respiratory rate, tidal volume and systolic arterial blood pressure. In the serum of venous blood obtained before and 3 minutes after the exercise the concentrations were measured of lactate (LA), pyruvate (PA) and glucose. High-altitude hypoxia caused unifavourable changes in the adaptation to effort manifesting themselves as an increase of the values of the determined physiological and biochemical indices. On the other hand, favourable changes were observed of the reaction to exercise while the subjects were breathing the helium-oxygen mixture during high-altitude hypoxia. The minute volume increased owing to increased tidal volume, and the exercise-induced rise of lactate (LA), pyruvate (PA) and the LA/PA ratio was lower. This may suggest reduced energy cost of respiration and reduced anaerobic metabolism under these conditions. PMID:3788607

  16. The Air We Breathe. Activity Packet.

    ERIC Educational Resources Information Center

    Connecticut State Dept. of Environmental Protection, Hartford.

    This packet of materials is intended to provide teachers with an interdisciplinary approach to integrating air quality education into the existing curriculum of Connecticut schools. The unit is designed to complement the student booklet "The Air We Breathe," which is included. A major portion of the document is comprised of teaching activities.…

  17. Online sample conditioning for portable breath analyzers.

    PubMed

    Prabhakar, Amlendu; Iglesias, Rodrigo A; Shan, Xiaonan; Xian, Xiaojun; Zhang, Lihua; Tsow, Francis; Forzani, Erica S; Tao, Nongjian

    2012-08-21

    Various innovative chemical sensors have been developed in recent years to sense dangerous substances in air and trace biomarkers in breath. However, in order to solve real world problems, the sensors must be equipped with efficient sample conditioning that can, e.g., control the humidity, which is discussed much less in the literature. To meet the demand, a miniaturized mouthpiece was developed for personal breath analyzers. A key function of the mouthpiece is to condition the humidity in real breath samples without changing the analyte concentrations and introducing substantial backpressure, which is achieved with optimized packing of desiccant particles. Numerical simulations were carried out to determine the performance of the mouthpiece in terms of various controllable parameters, such as the size, density, and geometry of the packing. Mouthpieces with different configurations were built and tested, and the experimental data validated the simulation findings. A mouthpiece with optimized performance reducing relative humidity from 95% (27,000 ppmV) to 29% (8000 ppmV) whereas retaining 92% nitric oxide (50 ppbV to 46 ppbV) was built and integrated into a hand-held exhaled nitric oxide sensor, and the performance of exhaled nitric oxide measurement was in good agreement with the gold standard chemiluminescence technique. Acetone, carbon dioxide, oxygen, and ammonia samples were also measured after passing through the desiccant mouthpiece using commercial sensors to examine wide applicability of this breath conditioning approach. PMID:22812638

  18. [Death by erotic asphyxiation (breath control play)].

    PubMed

    Madea, Burkhard; Hagemeier, Lars

    2013-01-01

    Most cases of sexual asphyxia are due to autoerotic activity. Asphyxia due to oronasal occlusion is mostly seen in very old or very young victims. Oronasal occlusion is also used in sadomasochistic sexual practices like "breath control play" or "erotic asphyxiation". If life saving time limitations of oronasal occlusion are not observed, conviction for homicide caused by negligence is possible. PMID:23596893

  19. Nocturnal periodic breathing in primary pulmonary hypertension.

    PubMed

    Schulz, R; Baseler, G; Ghofrani, H A; Grimminger, F; Olschewski, H; Seeger, W

    2002-04-01

    Cheyne-Stokes respiration is frequently observed in congestive heart failure. Among other factors, prolongation of circulation time, hypocapnia and hypoxia are thought to underlie this sleep-related breathing disorder. Primary pulmonary hypertension (PPH) is also characterized by reduced cardiac output and blood gas alterations. Therefore, the aim of the present study was to determine whether a nocturnal periodic breathing (PB) occurs in PPH. A total of 20 consecutive patients with PPH who had been admitted for pharmacological investigation of pulmonary vasoreactivity were investigated by lung function testing, right heart catheterization and full-night attended polysomnography. PB was detected in six patients (30%) (mean +/- SEM: apnoea/hypopnoea index 37 +/- 5 h(-1); arterial oxygen saturation was <90% during 56 +/- 6.5% of total sleep time). The patients with PB had more severe haemodynamic impairment than those without. They also had a more marked reduction in the pulmonary diffusion capacity and greater arterial hypoxia. PB was markedly improved or even eradicated by nasal oxygen during the night. Periodic breathing occurs in patients with advanced primary pulmonary hypertension and can be reversed by nocturnal nasal oxygen. The clinical and prognostic significance of periodic breathing in primary pulmonary hypertension needs to be determined by further studies. PMID:11998995

  20. Crew equipment applications - Firefighter's Breathing System.

    NASA Technical Reports Server (NTRS)

    Smith, W. L.

    1973-01-01

    The Firefighter's Breathing System (FBS) represents a significant step in applying NASA's crew equipment technologists and technologies to civilian sector problems. This paper describes the problem, the utilization of user-design committees as a forum for development of design goals, the design of the FBS, and the field test program to be conducted.

  1. The NASA firefighter's breathing system program

    NASA Technical Reports Server (NTRS)

    Mclaughlan, P. B.; Carson, M. A.

    1974-01-01

    The research is reported in the development of a firefighter's breathing system (FBS) to satisfy the operational requirements of fire departments while remaining within their cost constraints. System definition for the FBS is discussed, and the program status is reported. It is concluded that the most difficult problem in the FBS Program is the achievement of widespread fire department acceptance of the system.

  2. Breathing Your Way to a Better Chorus.

    ERIC Educational Resources Information Center

    Boardman, Susan D.

    1996-01-01

    Describes a series of breathing exercises designed to produce a more focused and cohesive choral group. Maintains that these exercises will improve singing, develop body awareness, and result in a more vital and responsive class. Exercises are illustrated by accompanying photographs. (MJP)

  3. The Physics of Breath-Hold Diving.

    ERIC Educational Resources Information Center

    Aguilella, Vicente; Aguilella-Arzo, Marcelo

    1996-01-01

    Analyzes physical features of breath-hold diving. Considers the diver's descent and the initial surface dive and presents examples that show the diver's buoyancy equilibrium varying with depth, the driving force supplied by finning, and the effect of friction between the water and the diver. (Author/JRH)

  4. Air breathing direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source.

  5. Quantification of periodic breathing in premature infants

    PubMed Central

    Mohr, Mary A.; Fairchild, Karen D.; Patel, Manisha; Sinkin, Robert A.; Clark, Matthew T.; Moorman, J. Randall; Lake, Douglas E.; Kattwinkel, John; Delos, John B.

    2015-01-01

    Background Periodic breathing (PB), regular cycles of short apneic pauses and breaths, is common in newborn infants. To characterize normal and potentially pathologic PB, we used our automated apnea detection system and developed a novel method for quantifying PB. We identified a preterm infant who died of SIDS and who, on review of her breathing pattern while in the NICU, had exaggerated PB. Methods We analyzed the chest impedance signal for short apneic pauses and developed a wavelet transform method to identify repetitive 10–40 second cycles of apnea/breathing. Clinical validation was performed to distinguish PB from apnea clusters and determine the wavelet coefficient cutoff having optimum diagnostic utility. We applied this method to analyze the chest impedance signals throughout the entire NICU stays of all 70 infants born at 32 weeks’ gestation admitted over a two-and-a-half year period. This group includes an infant who died of SIDS and her twin. Results For infants of 32 weeks’ gestation, the fraction of time spent in PB peaks 7–14 days after birth at 6.5%. During that time the infant that died of SIDS spent 40% of each day in PB and her twin spent 15% of each day in PB. Conclusions This wavelet transform method allows quantification of normal and potentially pathologic PB in NICU patients. PMID:26012526

  6. Online sample conditioning for portable breath analyzers

    PubMed Central

    Prabhakar, Amlendu; Iglesias, Rodrigo A.; Xian, Xiaojun; Zhang, Lihua; Tsow, Francis; Forzani, Erica S.; Tao, Nongjian

    2013-01-01

    Various innovative chemical sensors have been developed in recent years to sense dangerous substances in air and trace biomarkers in breath. However, in order to solve real world problems, the sensors must be equipped with efficient sample conditioning that can, e.g., control the humidity, which is much less discussed in literatures. To meet the demand, a miniaturized mouthpiece was developed for personal breath analyzers. A key function of the mouthpiece is to condition the humidity in real breath samples without changing the analyte concentrations and introducing substantial backpressure, which is achieved with optimized packing of desiccant particles. Numerical simulations were carried out to determine the performance of the mouthpiece in terms of various controllable parameters, such as the size, density and geometry of the packing. Mouthpieces with different configurations were built and tested, and the experimental data validated the simulation findings. A mouthpiece with optimized performance reducing relative humidity from 95% (27,000 ppmV) to 29% (8000 ppmV) whereas retaining 92% nitric oxide (50ppbV to 46ppbV) was built and integrated into a handheld exhaled nitric oxide sensor, and the performance of exhaled nitric oxide measurement was in good agreement with the gold standard chemiluminescence technique. Acetone, carbon dioxide, nitric oxide, oxygen and ammonia samples were also measured after passing through the desiccant mouthpiece using commercial sensors to examine wide applicability of this breath conditioning approach. PMID:22812638

  7. Single Breath-Hold Physiotherapy Technique

    PubMed Central

    Mevada, Surekha T.; Al-Mahruqi, Najma; El-Beshlawi, Ismail; El-Shinawy, Mohamed; Zachariah, Mathew; Al-Rawas, Abdul H.; Daar, Shahina; Wali, Yasser

    2016-01-01

    Magnetic resonance imaging using T2* (MRI T2*) is a highly sensitive and non-invasive technique for the detection of tissue iron load. Although the single breath-hold multi-echo T2* technique has been available at the Sultan Qaboos University Hospital (SQUH), Muscat, Oman, since 2006, it could not be performed on younger patients due to their inability to hold their breath after expiration. This study was carried out between May 2007 and May 2015 and assessed 50 SQUH thalassaemic patients aged 7–17 years old. Seven of these patients underwent baseline and one-year follow-up MRI T2* scans before receiving physiotherapy training. Subsequently, all patients were trained by a physiotherapist to hold their breath for approximately 15–20 seconds at the end of expiration before undergoing baseline and one-year follow-up MRI T2* scans. Failure rates for the pre- and post-training groups were 6.0% and 42.8%, respectively. These results indicate that the training of thalassaemic patients in breath-hold techniques is beneficial and increases rates of compliance for MRI T2* scans. PMID:26909218

  8. Continuous Exhaled Breath Analysis on the Icu

    NASA Astrophysics Data System (ADS)

    Bos, Lieuwe D. J.; Sterk, Peter J.; Schultz, Marcus J.

    2011-09-01

    During admittance to the ICU, critically ill patients frequently develop secondary infections and/or multiple organ failure. Continuous monitoring of biological markers is very much needed. This study describes a new method to continuously monitor biomarkers in exhaled breath with an electronic nose.

  9. Fast and Accurate Exhaled Breath Ammonia Measurement

    PubMed Central

    Solga, Steven F.; Mudalel, Matthew L.; Spacek, Lisa A.; Risby, Terence H.

    2014-01-01

    This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that uses a quantum cascade based laser. The monitor is coupled to a sampler that measures mouth pressure and carbon dioxide. The system is temperature controlled and specifically designed to address the reactivity of this compound. The sampler provides immediate feedback to the subject and the technician on the quality of the breath effort. Together with the quick response time of the monitor, this system is capable of accurately measuring exhaled breath ammonia representative of deep lung systemic levels. Because the system is easy to use and produces real time results, it has enabled experiments to identify factors that influence measurements. For example, mouth rinse and oral pH reproducibly and significantly affect results and therefore must be controlled. Temperature and mode of breathing are other examples. As our understanding of these factors evolves, error is reduced, and clinical studies become more meaningful. This system is very reliable and individual measurements are inexpensive. The sampler is relatively inexpensive and quite portable, but the monitor is neither. This limits options for some clinical studies and provides rational for future innovations. PMID:24962141

  10. METHODS FOR SAMPLING AND ANALYSIS OF BREATH

    EPA Science Inventory

    The research program surveyed and evaluated the methods and procedures used to identify and quantitate chemical constituents in human breath. Methods have been evaluated to determine their ease and rapidity, as well as cost, accuracy, and precision. During the evaluation, a secon...

  11. Phox2b-expressing neurons of the parafacial region regulate breathing rate, inspiration, and expiration in conscious rats.

    PubMed

    Abbott, Stephen B G; Stornetta, Ruth L; Coates, Melissa B; Guyenet, Patrice G

    2011-11-01

    The retrotrapezoid nucleus contains Phox2b-expressing glutamatergic neurons (RTN-Phox2b neurons) that regulate breathing in a CO₂-dependent manner. Here we use channelrhodopsin-based optogenetics to explore how these neurons control breathing in conscious and anesthetized adult rats. Respiratory entrainment (pacing) of breathing frequency (fR) was produced over 57% (anesthetized) and 28% (conscious) of the natural frequency range by burst activation of RTN-Phox2b neurons (3-8 × 0.5-20 ms pulses at 20 Hz). In conscious rats, pacing under normocapnic conditions increased tidal volume (V(T)) and each inspiration was preceded by active expiration, denoting abdominal muscle contraction. During long-term pacing V(T) returned to prestimulation levels, suggesting that central chemoreceptors such as RTN-Phox2b neurons regulate V(T) partly independently of their effect on fR. Randomly applied light trains reset the respiratory rhythm and shortened the expiratory phase when the stimulus coincided with late-inspiration or early-expiration. Importantly, continuous (20 Hz) photostimulation of the RTN-Phox2b neurons and a saturating CO₂ concentration produced similar effects on breathing that were much larger than those elicited by phasic RTN stimulation. In sum, consistent with their anatomical projections, RTN-Phox2b neurons regulate lung ventilation by controlling breathing frequency, inspiration, and active expiration. Adult RTN-Phox2b neurons can entrain the respiratory rhythm if their discharge is artificially synchronized, but continuous activation of these neurons is much more effective at increasing lung ventilation. These results suggest that RTN-Phox2b neurons are no longer rhythmogenic in adulthood and that their average discharge rate may be far more important than their discharge pattern in driving lung ventilation. PMID:22072691

  12. The analysis of components that lead to increased work of breathing in chronic obstructive pulmonary disease patients

    PubMed Central

    Chen, Sibei; Li, Ying; Zheng, Zeguang; Luo, Qun

    2016-01-01

    Background This study is to explore the components and related mechanism responsible for the increase of work of breathing (WB) in chronic obstructive pulmonary disease (COPD) patients. Methods Eight COPD patients and eight healthy volunteers were recruited in the study. The rebreathing method was used to increase end-tidal CO2 partial pressure (PetCO2) and stimulate the increase in ventilation (VE). The increase in VE, WB, and changes in the compositions of WB were observed and analyzed. The WB and its components were calculated using the Campbell diagram. Results The inspiratory work (Wi) of breathing, a major component of total work of breathing (Wtot), in the COPD group was significantly higher than the control group during quiet breathing (P<0.05). As the minute VE increased, Wtot and Wi increased in a linear manner, and the slope of increase was significantly higher in the COPD group as compared to the normal group (P<0.05). The analyses of changes in overcoming airway resistance (Wrs) and lung/chest-wall elastance (Wel) indicated that the slope of increase (response to VE increase) of Wrs was not significantly different between the two groups (P>0.05) although the Wrs in the COPD group was always higher than the normal group (P<0.05). However, as the VE increased, the slope of the increase in Wel was significantly higher in the COPD group than the normal group. Work done to overcome the intrinsic PEEP (WPEEPi), a component of the Wel, was not observed in the control group. However, WPEEPi increased gradually as VE increased and accounted for 56% of Wel at the end of rebreathing trial in COPD group. Conclusions Airway resistance was the main cause for increased WB during quiet breathing. As the VE increased, an increase of WPEEPi became an important part of increased WB in COPD patients, so it is important to reduce dynamic hyperinflation in COPD patients. PMID:27621878

  13. Tidally Induced Bars of Galaxies in Clusters

    NASA Astrophysics Data System (ADS)

    Łokas, Ewa L.; Ebrová, Ivana; del Pino, Andrés; Sybilska, Agnieszka; Athanassoula, E.; Semczuk, Marcin; Gajda, Grzegorz; Fouquet, Sylvain

    2016-08-01

    Using N-body simulations, we study the formation and evolution of tidally induced bars in disky galaxies in clusters. Our progenitor is a massive, late-type galaxy similar to the Milky Way, composed of an exponential disk and a Navarro-Frenk-White dark matter halo. We place the galaxy on four different orbits in a Virgo-like cluster and evolve it for 10 Gyr. As a reference case, we also evolve the same model in isolation. Tidally induced bars form on all orbits soon after the first pericenter passage and survive until the end of the evolution. They appear earlier, are stronger and longer, and have lower pattern speeds for tighter orbits. Only for the tightest orbit are the properties of the bar controlled by the orientation of the tidal torque from the cluster at pericenter. The mechanism behind the formation of the bars is the angular momentum transfer from the galaxy stellar component to its halo. All of the bars undergo extended periods of buckling instability that occur earlier and lead to more pronounced boxy/peanut shapes when the tidal forces are stronger. Using all simulation outputs of galaxies at different evolutionary stages, we construct a toy model of the galaxy population in the cluster and measure the average bar strength and bar fraction as a function of clustercentric radius. Both are found to be mildly decreasing functions of radius. We conclude that tidal forces can trigger bar formation in cluster cores, but not in the outskirts, and thus can cause larger concentrations of barred galaxies toward the cluster center.

  14. Ice rheology and tidal heating of Enceladus

    NASA Astrophysics Data System (ADS)

    Shoji, D.; Hussmann, H.; Kurita, K.; Sohl, F.

    2013-09-01

    For the saturnian satellite Enceladus, the possible existence of a global ocean is a major issue. For the stability of an internal ocean, tidal heating is suggested as an effective heat source. However, assuming Maxwell rheology ice, it has been shown that a global scale ocean on Enceladus cannot be maintained (Roberts, J.F., Nimmo, F. [2008]. Icarus 194, 675-689). Here, we analyze tidal heating and the stability of a global ocean from the aspect of anelastic behavior. The Maxwell model is the most typical and widely used viscoelastic model. However, in the tidal frequency domain, energy is also dissipated by the anelastic response involving time-dependent or transient creep mechanisms, which is different from the viscoelastic response caused by steady-state creep. The Maxwell model cannot adequately address anelasticity, which has a large effect in the high viscosity range. Burgers and Andrade models are suggested as suitable models for the creep behavior of ice in the frequency domain. We calculate tidal heating in the ice layer and compare it with the radiated heat assuming both convection and conduction of the ice layer. Though anelastic behavior increases the heating rate, it is insufficient to maintain a global subsurface ocean if the ice layer is convecting, even though a wide parameter range is taken into account. One possibility to maintain a global ocean is that Enceladus’ ice shell is conductive and its tidal response is similar to that of the Burgers body with comparatively small transient shear modulus and viscosity. If the surface ice with large viscosity is dissipative by anelastic response, the heat produced in the ice layer would supersede the cooling rate and a subsurface ocean could be maintained without freezing.

  15. Tidal Tales of Minor Mergers: Star Formation in Minor Merger Tidal Tails

    NASA Astrophysics Data System (ADS)

    Knierman, Karen; Scowen, P.; Groppi, C.; Veach, T.; Knezek, P. M.; Mullan, B.; Konstanopoulos, I. S.; Charlton, J. C.; Jansen, R.; Wehner, E.

    2014-07-01

    While major mergers and their tidal debris are well studied, they are less common than minor mergers and likely played a role in forming most large galaxies, including the Milky Way. Tidal debris regions have large amounts of neutral gas but a lower gas density and may have higher turbulence.Star formation tracers such as young star cluster populations and Halpha, CO, and CII emission were studied to determine the different factors that may influence star formation in tidal debris. These tracers were compared to the reservoirs of gas available for star formation to estimate the star formation efficiency (SFE). The SFR of tidal debris can reach up to 50% of the total star formation in the system. The SFE of tidal tails in minor mergers can range over orders of magnitude on both local and global scales. From the tidal debris environments in this study, this variance appears to stem from the formation conditions of the debris. A large survey with TMT as well as the continuing programs of ALMA and the EVLA can provide a larger sample of environments to study the threshold for star formation and can inform star formation models, particularly at low densities.

  16. 21 CFR 868.5330 - Breathing gas mixer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing gas mixer. 868.5330 Section 868.5330...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5330 Breathing gas mixer. (a) Identification. A breathing gas mixer is a device intended for use in conjunction with a respiratory...

  17. 21 CFR 868.2375 - Breathing frequency monitor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Breathing frequency monitor. 868.2375 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2375 Breathing frequency monitor. (a) Identification. A breathing (ventilatory) frequency monitor is a device intended to measure or monitor a...

  18. 46 CFR 169.736 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.736 Self-contained breathing apparatus. Each locker or space containing self-contained breathing apparatus must be marked “SELF-CONTAINED... 46 Shipping 7 2010-10-01 2010-10-01 false Self-contained breathing apparatus. 169.736 Section...

  19. 46 CFR 169.736 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.736 Self-contained breathing apparatus. Each locker or space containing self-contained breathing apparatus must be marked “SELF-CONTAINED... 46 Shipping 7 2012-10-01 2012-10-01 false Self-contained breathing apparatus. 169.736 Section...

  20. 46 CFR 169.736 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.736 Self-contained breathing apparatus. Each locker or space containing self-contained breathing apparatus must be marked “SELF-CONTAINED... 46 Shipping 7 2013-10-01 2013-10-01 false Self-contained breathing apparatus. 169.736 Section...

  1. 46 CFR 169.736 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.736 Self-contained breathing apparatus. Each locker or space containing self-contained breathing apparatus must be marked “SELF-CONTAINED... 46 Shipping 7 2014-10-01 2014-10-01 false Self-contained breathing apparatus. 169.736 Section...

  2. Human respiratory deposition of particles during oronasal breathing

    NASA Astrophysics Data System (ADS)

    Swift, David L.; Proctor, Donald F.

    Deposition of particles in the tracheobronchial and pulmonary airways is computed as a function of particle size, correcting for deposition in the parallel nasal and oral airways with oronasal breathing. Thoracic deposition is lower at all sizes for oronasal breathing than for mouth breathing via tube, and is negligible for aerodynamic equivalent diameters of 10 μm or larger.

  3. 42 CFR 84.88 - Breathing bag test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing bag test. 84.88 Section 84.88 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.88 Breathing bag test. (a)...

  4. Hands-Off Approaches to Teaching Breath Support.

    ERIC Educational Resources Information Center

    Stufft, William David

    1998-01-01

    Addresses the importance of using a hands-off approach in today's world when teaching music students breath support techniques since any kind of touching might be seen as improper. Provides three different approaches in which students learn intercostal breathing methods. Considers the role of good posture in breath control. (CMK)

  5. 21 CFR 868.5240 - Anesthesia breathing circuit.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Anesthesia breathing circuit. 868.5240 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5240 Anesthesia breathing circuit. (a) Identification. An anesthesia breathing circuit is a device that is intended to administer medical gases to...

  6. 21 CFR 868.5240 - Anesthesia breathing circuit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anesthesia breathing circuit. 868.5240 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5240 Anesthesia breathing circuit. (a) Identification. An anesthesia breathing circuit is a device that is intended to administer medical gases to...

  7. 21 CFR 868.5240 - Anesthesia breathing circuit.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Anesthesia breathing circuit. 868.5240 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5240 Anesthesia breathing circuit. (a) Identification. An anesthesia breathing circuit is a device that is intended to administer medical gases to...

  8. 21 CFR 868.5240 - Anesthesia breathing circuit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia breathing circuit. 868.5240 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5240 Anesthesia breathing circuit. (a) Identification. An anesthesia breathing circuit is a device that is intended to administer medical gases to...

  9. 21 CFR 868.5240 - Anesthesia breathing circuit.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Anesthesia breathing circuit. 868.5240 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5240 Anesthesia breathing circuit. (a) Identification. An anesthesia breathing circuit is a device that is intended to administer medical gases to...

  10. 46 CFR 197.340 - Breathing gas supply.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Breathing gas supply. 197.340 Section 197.340 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.340 Breathing gas supply. (a) A primary breathing gas supply for...

  11. 46 CFR 108.635 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.635 Self-contained breathing apparatus. Each locker or space containing self-contained breathing apparatus must be marked: “SELF CONTAINED... 46 Shipping 4 2010-10-01 2010-10-01 false Self-contained breathing apparatus. 108.635 Section...

  12. 46 CFR 169.736 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Self-contained breathing apparatus. 169.736 Section 169... VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.736 Self-contained breathing apparatus. Each locker or space containing self-contained breathing apparatus must be marked...

  13. 46 CFR 108.703 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.703 Self-contained breathing apparatus. (a) Each unit must be equipped with a self-contained breathing apparatus described in § 108.497(a) to use as... 46 Shipping 4 2010-10-01 2010-10-01 false Self-contained breathing apparatus. 108.703 Section...

  14. 46 CFR 108.635 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.635 Self-contained breathing apparatus. Each locker or space containing self-contained breathing apparatus must be marked: “SELF CONTAINED... 46 Shipping 4 2011-10-01 2011-10-01 false Self-contained breathing apparatus. 108.635 Section...

  15. 46 CFR 108.703 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.703 Self-contained breathing apparatus. (a) Each unit must be equipped with a self-contained breathing apparatus described in § 108.497(a) to use as... 46 Shipping 4 2011-10-01 2011-10-01 false Self-contained breathing apparatus. 108.703 Section...

  16. Oral Breathing Challenge in Participants with Vocal Attrition

    ERIC Educational Resources Information Center

    Sivasankar, Mahalakshmi; Fisher, Kimberly V.

    2003-01-01

    Vocal folds undergo osmotic challenge by mouth breathing during singing, exercising, and loud speaking. Just 15 min of obligatory oral breathing, to dry the vocal folds, increases phonation threshold pressure (P[subscript th]) and expiratory vocal effort in healthy speakers (M. Sivasankar & K. Fisher, 2002). We questioned whether oral breathing is…

  17. 42 CFR 84.132 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.132 Section 84.132 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL... Respirators § 84.132 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction...

  18. 42 CFR 84.195 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.195 Section 84.195 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL... Cartridge Respirators § 84.195 Breathing tubes; minimum requirements. Flexible breathing tubes used...

  19. 42 CFR 84.172 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.172... Air-Purifying Particulate Respirators § 84.172 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators shall be designed and constructed to prevent:...

  20. Breath measurements as volatile organic compound biomarkers.

    PubMed Central

    Wallace, L; Buckley, T; Pellizzari, E; Gordon, S

    1996-01-01

    A brief review of the uses of breath analysis in studies of environmental exposure to volatile organic compounds (VOCs) is provided. The U.S. Environmental Protection Agency's large-scale Total Exposure Assessment Methodology Studies have measured concentrations of 32 target VOCs in the exhaled breath of about 800 residents of various U.S. cities. Since the previous 12-hr integrated personal air exposures to the same chemicals were also measured, the relation between exposure and body burden is illuminated. Another major use of the breath measurements has been to detect unmeasured pathways of exposure; the major impact of active smoking on exposure to benzene and styrene was detected in this way. Following the earlier field studies, a series of chamber studies have provided estimates of several important physiological parameters. Among these are the fraction, f, of the inhaled chemical that is exhaled under steady-state conditions and the residence times. tau i in several body compartments, which may be associated with the blood (or liver), organs, muscle, and fat. Most of the targeted VOCs appear to have similar residence times of a few minutes, 30 min, several hours, and several days in the respective tissue groups. Knowledge of these parameters can be helpful in estimating body burden from exposure or vice versa and in planning environmental studies, particularly in setting times to monitor breath in studies of the variation with time of body burden. Improvements in breath methods have made it possible to study short-term peak exposure situations such as filling a gas tank or taking a shower in contaminated water. PMID:8933027

  1. Precise mimicking of exercise hyperpnea to investigate the oxygen cost of breathing.

    PubMed

    Dominelli, P B; Render, J N; Molgat-Seon, Y; Foster, G E; Sheel, A W

    2014-09-15

    The oxygen cost of exercise hyperpnea (V˙(O2 RM)) has been quantified using a variety of techniques with inconsistent findings. Between-study variation relates to poor control of breathing patterns and lung mechanics. We developed a methodology allowing precise matching of exercising WOB in order to estimate V˙(O2 RM). Thirteen healthy young subjects (7 male) completed an incremental cycle exercise test, familiarization and experimental days where exercise hyperpnea was mimicked. On experimental days, feedback of exercise flow, volume and the respiratory pressures were provided while end-tidal CO2 was kept at exercise levels during each 5-min trial. Minute ventilation levels between 50 and 100% maximum were mimicked 3-5 times. The r(2) between exercise and mimic trails was 0.99 for frequency, tidal volume and minute ventilation; 0.86 for esophageal pressure swings and 0.93 for WOB. The coefficient of variation for (V˙(O2) averaged 4.3, 4.4 and 5.7% for 50, 75 and 100% ventilation trials. When WOB and other respiratory parameters are tightly controlled, the V˙(O2 RM) can be consistently estimated. PMID:24981705

  2. Circadian rhythm of breath hydrogen in young women.

    PubMed

    Kagaya, M; Iwata, M; Toda, Y; Nakae, Y; Kondo, T

    1998-08-01

    Breath hydrogen levels, which reflect colonic fermentation of undigested starches, are usually low in the fasted state. Fasting levels of breath hydrogen are important for estimation of oro-cecal transit time and diagnosis of lactase deficiency. In young women, however, fasting levels of breath hydrogen are high. To clarify the reason for this, we studied the circadian pattern of breath hydrogen and the effect of alpha-D-galactosidase on fasting breath hydrogen in one study, and the effect of sleep deprivation on fasting breath hydrogen in another study, in 13 women students aged 21-23 years. In the first study, two breath samples were collected, one in the evening and the other the next morning. On another occasion, alpha-D-galactosidase was given before dinner and breath samples were collected the next morning. In the second study, the circadian rhythm of breath hydrogen was assessed for 3 days and the subjects were deprived of sleep on the second night. Breath samples were collected every 30 min, except during the second night when samples were collected at 1-h intervals. Fasting breath hydrogen was 24 +/- 3.9 ppm (mean +/- SE), which did not differ from the value for the previous night. Alpha-D-galactosidase significantly decreased fasting breath hydrogen levels, to 17 +/- 2.4 ppm (P < 0.05). There was a clear circadian pattern of breath hydrogen, high in the morning and decreasing to the nadir by 16:00. After dinner, the level increased again and stayed high during the night. Sleep deprivation did not affect fasting levels of breath hydrogen. High fasting breath hydrogen levels in young women followed a circadian pattern and this may have been due, in part, to an high intake of dietary fiber on the previous day. PMID:9719227

  3. Comparison of cerebral vascular reactivity measures obtained using breath-holding and CO2 inhalation.

    PubMed

    Tancredi, Felipe B; Hoge, Richard D

    2013-07-01

    Stimulation of cerebral vasculature using hypercapnia has been widely used to study cerebral vascular reactivity (CVR), which can be expressed as the quantitative change in cerebral blood flow (CBF) per mm Hg change in end-tidal partial pressure of CO2 (PETCO2). We investigate whether different respiratory manipulations, with arterial spin labeling used to measure CBF, lead to consistent measures of CVR. The approaches included: (1) an automated system delivering variable concentrations of inspired CO2 for prospective targeting of PETCO2, (2) administration of a fixed concentration of CO2 leading to subject-dependent changes in PETCO2, (3) a breath-hold (BH) paradigm with physiologic modeling of CO2 accumulation, and (4) a maneuver combining breath-hold and hyperventilation. When CVR was expressed as the percent change in CBF per mm Hg change in PETCO2, methods 1 to 3 gave consistent results. The CVR values using method 4 were significantly lower. When CVR was expressed in terms of the absolute change in CBF (mL/100 g per minute per mm Hg), greater discrepancies became apparent: methods 2 and 3 gave lower absolute CVR values compared with method 1, and the value obtained with method 4 was dramatically lower. Our findings indicate that care must be taken to ensure that CVR is measured over the linear range of the CBF-CO2 dose-response curve, avoiding hypocapnic conditions. PMID:23571282

  4. Effect of ozone on breathing in dogs: vagal and nonvagal mechanisms

    SciTech Connect

    Sasaki, K.; Nadel, J.A.; Hahn, H.L.

    1987-01-01

    We exposed two awake dogs with a chronic tracheostomy and the cervical vagus nerves exteriorized in skin loops to 1.0 ppm of ozone (O/sub 3/) for 2 h at intervals of 4 wk. We measured ventilatory variables before and after O/sub 3/ exposure during rest and exercise before and after vagal block. We compared the effects of vagal blockade, exercise, and O/sub 3/ on the primary determinants of breathing pattern (VT/TI, VT/TE, TI, and TE) in each of three conditions: base line (steady state), during hypercapnia, and after inhalation of 1% histamine. Under base-line conditions, O/sub 3/ increased respiratory rate and decreased tidal volume (VT) by shortening time of expiration (TE) and time of inspiration (TI) without affecting VT/TI, an indicator of the neural drive to breathing. During progressive hypercapnia, O/sub 3/ shortened TE and TI by effects both on tonic (nonvolume-related) and on phasic (volume-related) vagal inputs, and only the latter were prevented completely by cooling of the vagus nerves. Histamine-induced tachypnea was increased by O/sub 3/ and was totally blocked by cooling the vagus nerves. It was concluded that O/sub 3/ shortens the timing of respiration without increasing ventilatory drive, shortens TI and TE through vagal and nonvagal pathways, increases tonic nonvagal and phasic vagal inputs, and stimulates more than one vagal fiber type.

  5. Aerosol Deposition in the Human Respiratory Tract Breathing Air and 80:20 Heliox

    PubMed Central

    DARQUENNE, CHANTAL; PRISK, G. KIM

    2005-01-01

    Aerosol mixing resulting from turbulent flows is thought to be an important mechanism of deposition in the upper respiratory tract (URT). Since turbulence levels are a function of gas density, the use of a low density carrier gas would be expected to reduce deposition in the URT. We measured aerosol deposition in the respiratory tract of 8 healthy subjects using both air and heliox, a low density gas mixture containing 80% helium and 20% oxygen, as the carrier gas. The subjects breathed 0.5, 1, and 2 μm-diameter monodisperse polystyrene latex particles from a reservoir at a constant flow rate (~450 mL/sec) and tidal volume (~900 mL). Aerosol concentration and flow rate were measured at the mouth using a photometer and a pneumotachograph, respectively. Deposition was 17.0%, 20.3%, and 38.9% in air and 16.8%, 18.5%, and 36.9% in heliox for 0.5, 1, and 2 μm-diameter particles, respectively. There was a small but statistically significant decrease in deposition when using heliox compared to air for 1 and 2 μm-diameter particles (p < 0.05). While it could not be directly measured from these data, it is likely that when breathing heliox instead of air, deposition is reduced in the URT and increased in the small airways and alveoli. PMID:15625820

  6. Effects of dietary inorganic nitrate on static and dynamic breath-holding in humans.

    PubMed

    Schiffer, Tomas A; Larsen, Filip J; Lundberg, Jon O; Weitzberg, Eddie; Lindholm, Peter

    2013-01-15

    Inorganic nitrate has been shown to reduce oxygen cost during exercise. Since the nitrate-nitrite-NO pathway is facilitated during hypoxia, we investigated the effects of dietary nitrate on oxygen consumption and cardiovascular responses during apnea. These variables were measured in two randomized, double-blind, placebo-controlled, crossover protocols at rest and ergometer exercise in competitive breath-hold divers. Subjects held their breath for predetermined times along with maximum effort apneas after two separate 3-day periods with supplementation of potassium nitrate/placebo. In contrast to our hypothesis, nitrate supplementation led to lower arterial oxygen saturation (SaO(2), 77 ± 3%) compared to placebo (80 ± 2%) during static apnea, along with lower end-tidal fraction of oxygen (FETO(2)) after 4 min of apnea (nitrate 6.9 ± 0.4% vs. placebo 7.6 ± 0.4%). Maximum apnea duration was shorter after nitrate (329 ± 13 s) compared to placebo (344 ± 13 s). During cycle ergometry nitrate had no effect on SaO(2), FETO(2) or maximum apnea duration. The negative effects of inorganic nitrate during static apnea may be explained by an attenuated diving response. PMID:23099220

  7. Modeling of Panchromatic Tidal Disruption Flares

    NASA Astrophysics Data System (ADS)

    Ramirez-Ruiz, Enrico

    The disruption of stars by SMBHs has been linked to more than a dozen flares in the cores of galaxies out to redshift z ~ 0.4. At the time of this writing, PS1-10jh is the only claimed tidal disruption event that captures the rise, peak, and decay of the flare. By capturing all three phases, and with the addition of spectroscopic information, this event provides significantly more information on the underlying mechanisms than the small number of poorly sampled flares: * The spectrum of PS1-10jh is well-modeled by a single blackbody whose temperature evolves weakly in time, and whose size is tens of times larger than the tidal radius, hinting at the presence of a reprocessing region.* The light curve is consistent with the bolometric luminosity closely following the rate of mass fallback, which suggests that the returning material must circularize by the first epoch of observation. * The fact that HeII emission lines are observed, but hydrogen lines are not, is consistent with the fact that material at the distance of the photosphere would be fully ionized, as suggested by broad-line regions found about steadily-accreting active galactic nuclei. Our group has been leading the effort to determine the behavior and appearance of tidal disruption events by both focusing on the hydrodynamics of the disruptions themselves, and on the hydrodynamics of the formation of the disk arising from the fallback of the bound debris. By assuming that circularization is effective and invoking the presence of a simple reprocessing mechanism, we were able to find a convincing match between our model and the data. In this proposal, we aim to understand why the simple assumptions that we made to explain the behavior of PS1-10jh work so well, and whether these conditions are generally applicable to a large fraction of tidal disruption events. While our simulations provided unprecedented detail on the fallback of the debris and the resulting structure, it is still incomplete in that it does

  8. Shear Stress, Turbulence Production and Dissipation in Small Tidal Channels Intersecting a Tidal Flat

    NASA Astrophysics Data System (ADS)

    Pieterse, A.; Puleo, J. A.; McKenna, T. E.

    2014-12-01

    A 16-day field experiment was conducted in March and April 2013 in a tidal wetland in Kent County, Delaware. The study area was a tidal flat fed by a second-order channel that flows into the Brockonbridge Gut, a small tributary of Delaware Bay. The goal of the field study was to investigate spatio-temporal variability in the hydrodynamics of the tidal flat and the small channels that intersect it, over the period of one spring-neap tidal cycle. The experiment combined remotely-sensed imagery with high-frequency in-situ measurements. A tower with imagers (RGB, NIR, TIR) was deployed to quantify the spatial variations of inundation of the channels, flat and marsh. In-situ sensors that measure flow velocity, sediment concentration and water depth were deployed at six locations on the tidal flat and in the channels. At three locations, a Nortek Vectrino II - profiling velocimeter was deployed that measures a 30 mm velocity profile at 1 mm vertical increments at 100 Hz. These velocity profiles are used to compute turbulent kinetic energy, turbulence dissipation and stress profiles close to the bed. Results show that peak velocities in the channels occur at the beginning and end of ebbing tide, when the water level is below the tidal flat level. At these instances, peaks in turbulence and bed stress also occur. The flow velocity and turbulence peaks are smaller when the water level does not fall below the tidal flat level. On the tidal flat, the flow velocities and turbulence are generally small compared to the intersecting tidal channel. Maximum flow velocities in the channels are around 0.4 m/s, while on the flat maximum velocities are under 0.1 m/s. A comparison is made between turbulence production and dissipation in both the channel and on the tidal flat to determine if advection and diffusion are important in this environment. In addition, the hydrodynamics at several locations in the channel are compared to investigate changes throughout the study area.

  9. Tidal changes in a heavily modified coastal wetland

    NASA Astrophysics Data System (ADS)

    Ferrarin, Christian; Tomasin, Alberto; Bajo, Marco; Petrizzo, Antonio; Umgiesser, Georg

    2015-06-01

    Changes in tidal regime in the heavily modified Venice Lagoon, Italy, are investigated using long-term observations and numerical modelling. The amplitudes of the major tidal constituents exhibit a significant increase over the last century. Analysis of tide gauge data in the adjacent Adriatic Sea reveals that these changes could be only partially attributed to the rise of the mean sea level. Numerical experiments confirm that natural and anthropogenic morphological changes are responsible for the alteration of tidal regime inside the lagoon. Temporal and spatial changes in tidal asymmetry highlight the complex impacts of human interventions on tidal changes and long-term morphodynamics. Our results suggest that over time the lagoon became more and more an ebb-dominant system. Moreover, in Venice the tidal modulations are significantly impacting the frequency with which high water level thresholds are exceeded. Occurrence of flooding events is therefore influenced by sea level rise and secondarily by the increase in amplitude of principal tidal waves.

  10. Neostigmine but not sugammadex impairs upper airway dilator muscle activity and breathing

    PubMed Central

    Eikermann, M.; Zaremba, S.; Malhotra, A.; Jordan, A. S.; Rosow, C.; Chamberlin, N. L.

    2008-01-01

    Background Cholinesterase inhibitor-based reversal agents, given in the absence of neuromuscular block, evoke a partial upper airway obstruction by decreasing skeletal upper airway muscle function. Sugammadex reverses neuromuscular block by encapsulating rocuronium. However, its effects on upper airway integrity and breathing are unknown. Methods Fifty-one adult male rats were anaesthetized with isoflurane, tracheostomized, and a femoral artery and vein were cannulated. First, we compared the efficacy of sugammadex 15 mg kg−1 and neostigmine 0.06 mg kg−1 to reverse respiratory effects of rocuronium-induced partial paralysis [train-of-four ratio (T4/T1)=0.5]. Subsequently, we compared the safety of sugammadex and neostigmine given after recovery of the T4/T1 to 1, by measuring phasic genioglossus activity and breathing. Results During partial paralysis (T4/T1=0.5), time to recovery of minute volume to baseline values was 10.9 (2), 75.8 (18), and 153 (54) s with sugammadex, neostigmine, and placebo, respectively (sugammadex was significantly faster than neostigmine and placebo, P<0.05). Recovery of T4/T1 was also faster for sugammadex than neostigmine and placebo. Neostigmine administration after complete recovery of T4/T1 decreased upper airway dilator muscle activity to 64 (30)% of baseline and decreased tidal volume (P<0.05 for both variables), whereas sugammadex had no effect on either variable. Conclusions In contrast to neostigmine, which significantly impairs upper airway dilator muscle activity when given after recovery from neuromuscular block, a reversal dose of sugammadex given under the same conditions does not affect genioglossus muscle activity and normal breathing. Human studies will be required to evaluate the clinical relevance of our findings. PMID:18559352

  11. Controlling Asthma by Training of Capnometry-Assisted Hypoventilation (CATCH) vs Slow Breathing

    PubMed Central

    Ritz, Thomas; Rosenfield, David; Steele, Ashton M.; Millard, Mark W.

    2014-01-01

    BACKGROUND: Hyperventilation has been associated with adverse effects on lung function, symptoms, and well-being in asthma. We examined whether raising end-tidal CO2 levels (ie, Pco2) compared with slow breathing is associated with improvements in asthma control, including peak flow variability. METHODS: One hundred twenty patients with asthma were randomly assigned to capnometry-assisted respiratory training (CART) for raising Pco2 or slow breathing and awareness training (SLOW) for slowing respiratory rate. Patients received five weekly sessions and completed bid homework exercises over 4 weeks. Blinded assessments at baseline, posttreatment, 1- and 6-month follow-up of asthma control, Pco2, and diurnal peak flow variability were primary outcome measures. Additionally, we measured pulmonary function (spirometry, forced oscillation, exhaled nitric oxide, and methacholine challenge), symptoms, quality of life, and bronchodilator use. Because the control group received active treatment, we expected improvements in asthma control in both groups but more pronounced benefits from CART. RESULTS: Improvements were seen in 17 of 21 clinical indexes (81.0%) in both interventions, including the primary outcome variables asthma control (d = 0.81), peak flow variability (d = 0.54), quality of life, bronchodilator use, lung function, and airway hyperreactivity. Most improvements were sustained across the 6-month follow-up. Compared with slow breathing, CART showed greater increases in Pco2 (d = 1.45 vs 0.64 for CART vs SLOW, respectively) and greater reductions in respiratory impedance during treatment, less distress during methacholine challenge, and greater reduction in asthma symptoms at follow-up (P < .05). CONCLUSIONS: Brief interventions aimed at raising Pco2 or slowing respiratory rate provide significant, sustained, and clinically meaningful improvements in asthma control. Raising Pco2 was associated with greater benefits in aspects of lung function and long

  12. A new double-tracer gas single-breath washout to assess early cystic fibrosis lung disease.

    PubMed

    Singer, Florian; Stern, Georgette; Thamrin, Cindy; Abbas, Chiara; Casaulta, Carmen; Frey, Urs; Latzin, Philipp

    2013-02-01

    In cystic fibrosis (CF), tests for ventilation inhomogeneity are sensitive but not established for clinical routine. We assessed feasibility of a new double-tracer gas single-breath washout (SBW) in school-aged children with CF and control subjects, and compared SBW between groups and with multiple-breath nitrogen washout (MBNW). Three SBW and MBNW were performed in 118 children (66 with CF) using a side-stream ultrasonic flowmeter setup. The double-tracer gas containing 5% sulfur hexafluoride and 26.3% helium was applied during one tidal breath. Outcomes were SBW phase III slope (SIII(DTG)), MBNW-derived lung clearance index (LCI), and indices of acinar (S(acin)) and conductive (S(cond)) ventilation inhomogeneity. SBW took significantly less time to perform than MBNW. SBW and MBNW were feasible in 109 (92.4%) and 98 (83.0%) children, respectively. SIII(DTG) differed between children with CF and controls, mean±sd was -456.7±492.8 and -88.4±129.1 mg·mol·L(-1), respectively. Abnormal SIII(DTG) was present in 36 (59%) children with CF. SIII(DTG) was associated with LCI (r= -0.58) and S(acin) (r= -0.58), but not with S(cond). In CF, steeply sloping SIII(DTG) potentially reflects ventilation inhomogeneity near the acinus entrance. This tidal SBW is a promising test to assess ventilation inhomogeneity in an easy and fast way. PMID:22599360

  13. Employing an Incentive Spirometer to Calibrate Tidal Volumes Estimated from a Smartphone Camera.

    PubMed

    Reyes, Bersain A; Reljin, Natasa; Kong, Youngsun; Nam, Yunyoung; Ha, Sangho; Chon, Ki H

    2016-01-01

    A smartphone-based tidal volume (VT) estimator was recently introduced by our research group, where an Android application provides a chest movement signal whose peak-to-peak amplitude is highly correlated with reference VT measured by a spirometer. We found a Normalized Root Mean Squared Error (NRMSE) of 14.998% ± 5.171% (mean ± SD) when the smartphone measures were calibrated using spirometer data. However, the availability of a spirometer device for calibration is not realistic outside clinical or research environments. In order to be used by the general population on a daily basis, a simple calibration procedure not relying on specialized devices is required. In this study, we propose taking advantage of the linear correlation between smartphone measurements and VT to obtain a calibration model using information computed while the subject breathes through a commercially-available incentive spirometer (IS). Experiments were performed on twelve (N = 12) healthy subjects. In addition to corroborating findings from our previous study using a spirometer for calibration, we found that the calibration procedure using an IS resulted in a fixed bias of -0.051 L and a RMSE of 0.189 ± 0.074 L corresponding to 18.559% ± 6.579% when normalized. Although it has a small underestimation and slightly increased error, the proposed calibration procedure using an IS has the advantages of being simple, fast, and affordable. This study supports the feasibility of developing a portable smartphone-based breathing status monitor that provides information about breathing depth, in addition to the more commonly estimated respiratory rate, on a daily basis. PMID:26999152

  14. Employing an Incentive Spirometer to Calibrate Tidal Volumes Estimated from a Smartphone Camera

    PubMed Central

    Reyes, Bersain A.; Reljin, Natasa; Kong, Youngsun; Nam, Yunyoung; Ha, Sangho; Chon, Ki H.

    2016-01-01

    A smartphone-based tidal volume (VT) estimator was recently introduced by our research group, where an Android application provides a chest movement signal whose peak-to-peak amplitude is highly correlated with reference VT measured by a spirometer. We found a Normalized Root Mean Squared Error (NRMSE) of 14.998% ± 5.171% (mean ± SD) when the smartphone measures were calibrated using spirometer data. However, the availability of a spirometer device for calibration is not realistic outside clinical or research environments. In order to be used by the general population on a daily basis, a simple calibration procedure not relying on specialized devices is required. In this study, we propose taking advantage of the linear correlation between smartphone measurements and VT to obtain a calibration model using information computed while the subject breathes through a commercially-available incentive spirometer (IS). Experiments were performed on twelve (N = 12) healthy subjects. In addition to corroborating findings from our previous study using a spirometer for calibration, we found that the calibration procedure using an IS resulted in a fixed bias of −0.051 L and a RMSE of 0.189 ± 0.074 L corresponding to 18.559% ± 6.579% when normalized. Although it has a small underestimation and slightly increased error, the proposed calibration procedure using an IS has the advantages of being simple, fast, and affordable. This study supports the feasibility of developing a portable smartphone-based breathing status monitor that provides information about breathing depth, in addition to the more commonly estimated respiratory rate, on a daily basis. PMID:26999152

  15. Metabolite Content Profiling of Bottlenose Dolphin Exhaled Breath

    PubMed Central

    2014-01-01

    Changing ocean health and the potential impact on marine mammal health are gaining global attention. Direct health assessments of wild marine mammals, however, is inherently difficult. Breath analysis metabolomics is a very attractive assessment tool due to its noninvasive nature, but it is analytically challenging. It has never been attempted in cetaceans for comprehensive metabolite profiling. We have developed a method to reproducibly sample breath from small cetaceans, specifically Atlantic bottlenose dolphins (Tursiops truncatus). We describe the analysis workflow to profile exhaled breath metabolites and provide here a first library of volatile and nonvolatile compounds in cetacean exhaled breath. The described analytical methodology enabled us to document baseline compounds in exhaled breath of healthy animals and to study changes in metabolic content of dolphin breath with regard to a variety of factors. The method of breath analysis may provide a very valuable tool in future wildlife conservation efforts as well as deepen our understanding of marine mammals biology and physiology. PMID:25254551

  16. Metabolite content profiling of bottlenose dolphin exhaled breath.

    PubMed

    Aksenov, Alexander A; Yeates, Laura; Pasamontes, Alberto; Siebe, Craig; Zrodnikov, Yuriy; Simmons, Jason; McCartney, Mitchell M; Deplanque, Jean-Pierre; Wells, Randall S; Davis, Cristina E

    2014-11-01

    Changing ocean health and the potential impact on marine mammal health are gaining global attention. Direct health assessments of wild marine mammals, however, is inherently difficult. Breath analysis metabolomics is a very attractive assessment tool due to its noninvasive nature, but it is analytically challenging. It has never been attempted in cetaceans for comprehensive metabolite profiling. We have developed a method to reproducibly sample breath from small cetaceans, specifically Atlantic bottlenose dolphins (Tursiops truncatus). We describe the analysis workflow to profile exhaled breath metabolites and provide here a first library of volatile and nonvolatile compounds in cetacean exhaled breath. The described analytical methodology enabled us to document baseline compounds in exhaled breath of healthy animals and to study changes in metabolic content of dolphin breath with regard to a variety of factors. The method of breath analysis may provide a very valuable tool in future wildlife conservation efforts as well as deepen our understanding of marine mammals biology and physiology. PMID:25254551

  17. Breath Analysis Using Laser Spectroscopic Techniques: Breath Biomarkers, Spectral Fingerprints, and Detection Limits

    PubMed Central

    Wang, Chuji; Sahay, Peeyush

    2009-01-01

    Breath analysis, a promising new field of medicine and medical instrumentation, potentially offers noninvasive, real-time, and point-of-care (POC) disease diagnostics and metabolic status monitoring. Numerous breath biomarkers have been detected and quantified so far by using the GC-MS technique. Recent advances in laser spectroscopic techniques and laser sources have driven breath analysis to new heights, moving from laboratory research to commercial reality. Laser spectroscopic detection techniques not only have high-sensitivity and high-selectivity, as equivalently offered by the MS-based techniques, but also have the advantageous features of near real-time response, low instrument costs, and POC function. Of the approximately 35 established breath biomarkers, such as acetone, ammonia, carbon dioxide, ethane, methane, and nitric oxide, 14 species in exhaled human breath have been analyzed by high-sensitivity laser spectroscopic techniques, namely, tunable diode laser absorption spectroscopy (TDLAS), cavity ringdown spectroscopy (CRDS), integrated cavity output spectroscopy (ICOS), cavity enhanced absorption spectroscopy (CEAS), cavity leak-out spectroscopy (CALOS), photoacoustic spectroscopy (PAS), quartz-enhanced photoacoustic spectroscopy (QEPAS), and optical frequency comb cavity-enhanced absorption spectroscopy (OFC-CEAS). Spectral fingerprints of the measured biomarkers span from the UV to the mid-IR spectral regions and the detection limits achieved by the laser techniques range from parts per million to parts per billion levels. Sensors using the laser spectroscopic techniques for a few breath biomarkers, e.g., carbon dioxide, nitric oxide, etc. are commercially available. This review presents an update on the latest developments in laser-based breath analysis. PMID:22408503

  18. Breath isoprene: Muscle dystrophy patients support the concept of a pool of isoprene in the periphery of the human body

    PubMed Central

    King, J.; Mochalski, P.; Unterkofler, K.; Teschl, G.; Klieber, M.; Stein, M.; Amann, A.; Baumann, M.

    2016-01-01

    Breath isoprene accounts for most of the hydrocarbon removal via exhalation and is thought to serve as a non-invasive indicator for assaying several metabolic effects in the human body. The primary objective of this paper is to introduce a novel working hypothesis with respect to the endogenous source of this compound in humans: the idea that muscle tissue acts as an extrahepatic production site of substantial amounts of isoprene. This new perspective has its roots in quantitative modeling studies of breath isoprene dynamics under exercise conditions and is further investigated here by presenting pilot data from a small cohort of late stage Duchenne muscle dystrophy patients (median age 21, 4 male, 1 female). For these prototypic test subjects isoprene concentrations in end-tidal breath and peripheral venous blood range between 0.09–0.47 and 0.11–0.72 nmol/l, respectively, amounting to a reduction by a factor of 8 and more as compared to established nominal levels in normal healthy adults. While it remains unclear whether isoprene can be ascribed a direct physiological mechanism of action, some indications are given as to why isoprene production might have evolved in muscle. PMID:22683640

  19. Tidal instability in exoplanetary systems evolution

    NASA Astrophysics Data System (ADS)

    Cébron, D.; Moutou, C.; Le Bars, M.; Le Gal, P.; Farès, R.

    2011-02-01

    A new element is proposed to play a role in the evolution of extrasolar planetary systems: the tidal (or elliptical) instability. It comes from a parametric resonance and takes place in any rotating fluid whose streamlines are (even slightly) elliptically deformed. Based on theoretical, experimental and numerical works, we estimate the growth rate of the instability for hot-jupiter systems, when the rotation period of the star is known. We present the physical process, its application to stars, and preliminary results obtained on a few dozen systems, summarized in the form of a stability diagram. Most of the systems are trapped in the so-called "forbidden zone", where the instability cannot grow. In some systems, the tidal instability is able to grow, at short timescales compared to the system evolution. Implications are discussed in the framework of misaligned transiting systems, as the rotational axis of the star would be unstable in systems where this elliptical instability grows.

  20. Reservoir response to tidal and barometric effects

    SciTech Connect

    Hanson, J.M.

    1980-05-29

    Solid earth tidal strain and surface loading due to fluctuations in barometric pressure have the effect, although extremely minute, of dilating or contracting the effective pore volume in a porous reservoir. If a well intersects the formation, the change in pore pressure can be measured with sensitive quartz pressure gauges. Mathematical models of the relevant fluid dynamics of the well-reservoir system have been generated and tested against conventional well pumping results or core data at the Salton Sea Geothermal Field (SSGF), California and at the Raft River, Geothermal Field (RRGF), Idaho. Porosity-total compressibility product evaluation based on tidal strain response compares favorably with results based on conventional pumping techniques. Analysis of reservoir response to barometric loading using Auto Regressive Integrated Moving Average (ARIMA) stochastic modeling appears also to have potential use for the evaluation of reservoir parameters.

  1. Experiments on topographies lacking tidal conversion

    NASA Astrophysics Data System (ADS)

    Maas, Leo; Paci, Alexandre; Yuan, Bing

    2015-11-01

    In a stratified sea, internal tides are supposedly generated when the tide passes over irregular topography. It has been shown that for any given frequency in the internal wave band there are an infinite number of exceptions to this rule of thumb. This ``stealth-like'' property of the topography is due to a subtle annihilation of the internal waves generated during the surface tide's passage over the irregular bottom. We here demonstrate this in a lab-experiment. However, for any such topography, subsequently changing the surface tide's frequency does lead to tidal conversion. The upshot of this is that a tidal wave passing over an irregular bottom is for a substantial part trapped to this irregularity, and only partly converted into freely propagating internal tides. Financially supported by the European Community's 7th Framework Programme HYDRALAB IV.

  2. Web access to tidal models for TIMED

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Forbes, J.; Miyahara, S.; Hagan, M.

    As part of the interdisciplinary investigation "Tides, Planetary Waves, and Eddy Forcing of the Mean MLT Circulation", we provide web-based access to global monthly mean tidal fields from two models: the Kyushu University General Circulation Model, and the NCAR/HAO Global Scale Wave Model. Interactive solutions (Hough functions) to Laplace's Tidal Equation and various animations are also available. Herein, we briefly describe the models and illustrate the various tabular and plot options available. This web site also illustrates web data sharing protocols relevant to wider applications: (1) Balance of public access vs. rights of the investigators - Data sharing agreements, appropriate uses and attribution of the data; (2) Levels of accessibility - Agreement, simple form, application and request for password; (3) Methods of data distribution - Data tables, data files, archived data files, plots; (4) Database management - data dictionary, data recovery, resource lock, security.

  3. Capturing American black ducks in tidal waters

    USGS Publications Warehouse

    Harrison, M.K., Sr.; Haramis, G.M.; Jorde, D.G.; Stotts, D.B.

    2000-01-01

    We modified conventional, funnel-entrance dabbling duck bait traps to increase captures for banding of American Black Ducks (Anas rubripes) in tidal saltmarsh habitats of Smith Island, Maryland, one of the few remaining strongholds for breeding Black Ducks in the Chesapeake Bay. Traps and trapping techniques were adapted to tidal creeks and refined to improve capture rate, reduce mortality, and minimize interference by gulls. Best results were achieved by synchronizing trapping with predawn, low-tide foraging patterns of Black Ducks. Trap entrances were critical to retaining ducks, and use of loafing platforms reduced overall mortality to 3% of captures per year. We captured 3071 Black Ducks during the 14-year period, 1984-199

  4. Tidal Forces as Drivers of Collisional Evolution

    NASA Technical Reports Server (NTRS)

    Asphaug, E.; Agnor, C.; Williams, Q.

    2005-01-01

    Planetary collisions are usually understood as shock-related phenomena, analogous to impact cratering. But at large scales, where the impact timescale is comparable to the gravitational timescale, collisions can be dominated by gravitational torques and disruptive tides. Shock physics fares poorly, in many respects, in explaining asteroid and meteorite genesis. Melts, melt residues, welded agglomerates and hydrous and gasrich phases among meteorites lead to an array of diverse puzzles whose solution might be explained, in part, by the thermomechanics of tidal unloading. Comet Shoemaker-Levy 9 disrupted in a process that is common in the present and ancestral solar system, so here we consider specific effects tidal disruption had on the evolution of asteroids, comets and meteorites the unaccreted residues of planet formation.

  5. Tidal Disruption of Primordial Planetary Bodies

    NASA Astrophysics Data System (ADS)

    Asphaug, E.; Agnor, C.; Williams, Q.; Petit, J.; Rivkin, A.

    2003-12-01

    Introduction: We evaluate the tidal disruption of planetary embryos from dynamical, geophysical and meteoritical perspectives. It is widely believed that the present population of asteroids (and thus most meteorites) derive from material that survived intense (99.9%) mass depletion in the protoplanetary disk between Earth and Jupiter. According to this scenario, about one in a thousand bodies survived scattering, close encounters and mergers to become the ancestors of the present main belt and the precursors of meteorites. Close tidal encounters were inevitable, because a deep Roche encounter near a growing planet is about as likely as accretion onto the same planet. Process and Implications: This "long march" took its toll on the survivors, which begat the present asteroids and meteorites. Specifically, for very weak bodies (rubble piles, or those with deep regolith) and for gravity-dominated bodies with viscosity less than (ν lim ˜ √ {G}ρ 3/2 R2~1011 poise for 100 km radius), an encounter with periapsis <~0.5 Rroche results in catastrophic removal of half the original mass [1]. Even partially molten silicate bodies have sufficiently low viscosity to undergo disruptive tidal deformation. Abundant mantle water at this early phase lowers viscosity and enhances disruption energetics. Our dynamical calculations show that a few percent of the surviving primordial asteroids underwent catastrophic tidal disruption during encounters with the transitory main-belt embryos [c.f. 2], if a majority were either partially molten or rubble piles during the first ~3 Ma. Melting and differentiation of asteroid parent bodies took place during this time [3], so planetary mantles may have been tidally stripped in a process that may have been as common as giant collisions. Tidal disruption produces a symmetric chain of fragments. In models of tidal disruption [1], differentiated bodies pull apart into one or more central cores almost devoid of mantle rock, flanked by core

  6. Tidal power from the Severn. Volume 1

    SciTech Connect

    Not Available

    1986-01-01

    This interim study on the generation of electricity from tidal power in the Severn Estuary has been carried out by the Severn Tidal Power Group (STPG0) under a joint funding arrangement with the Department of Energy. Two schemes have been examined, one being an extension to the work carried out by the Severn Barrage Committee in 1981, under the chairmanship of Sir Herman Bondi, and relates to the barrage alignment between Lavernock Point on the Welsh shore and Brean Down on the English shore (known as the Cardiff Weston line). The other scheme would be much smaller with a barrage in the vicinity of English Stones, some eight kilometres downstream from the existing Severn Bridge (English Stones scheme). The results of the investigation are presented. The main purpose of this report is to present the results of the commercial viability studies and discuss their implications. It also summarises the findings of the technical, environmental, infrastructure, economic and financing studies.

  7. Intermittency in a tidal river turbulent flow

    NASA Astrophysics Data System (ADS)

    Schmitt, Francois G.; Le Kien, Trung; Thiébaut, Maxime; Sentchev, Alexei

    2016-04-01

    We consider here fixed point measurements of the turbulent velocity recorded in the Sea Schelde river at Temse, 10 km south-west of Antwerp (Belgium). An Acoustic Doppler Velocimeter (ADV) was recording 3 components of the flow velocity at 32 Hz, 1 m below the surface, during 2 tidal cycles (25h)s. At this position, the river flow is still strongly influenced by the tide. The measurements cover different tidal current regimes: strong ebb and flood flow with velocity of 1.5m/s, and also a flow reversal. The Taylor based Reynolds number is estimated to be 530. The intermittency during the flow reversal period is studied using cumulants approach, and during stationary flows in both directions, the intermittency is studied using traditional scaling approaches. The scale invariant moment functions obtained are compared to laboratory experiments.

  8. Ocean, Wave and Tidal Energy Systems; (USA)

    SciTech Connect

    Raridon, M.H.; Hicks, S.C.

    1991-01-01

    Ocean, Wave, and Tidal Energy Systems (OES) announces on a biomonthly basis the current worldwide information available on all aspects of ocean thermal energy conversion systems based on exploitation of the temperature difference between the surface water and ocean depth. All aspects of salinity gradient power systems based on extracting energy from mixing fresh water with seawater are included, along with information on wave and tidal power. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database (EDB) during the past two months. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency's Energy Technology Data Exchange or government-to-government agreements.

  9. Positive pressure breathing during rest and exercise.

    PubMed

    den Hartog, E A; Heus, R

    2003-03-01

    The requirements to maintain a positive pressure with respiratory protection during heavy exercise and the effects on ventilation and feelings of discomfort were investigated. Eight male subjects participated, using the respirator system during rest and exercise at about 80% of their individual maximum power. A blower was used at maximum and medium capacity and at two pressure levels (3 and 15 mbar). Additionally, the mouth pressure was used as a feedback for the blower. The blower decreased the fraction of the breathing cycle with negative pressures from 50% (SD 4%) to 15% (SD 10%) during exercise. Negative pressures occurred at all settings of the blower during exercise. Thus, the currently available commercial blower systems do not supply a sufficient airflow to maintain a positive pressure during heavy exercise. Positive pressure breathing did not affect the ventilation and the circulation. But the oxygen consumption was higher with the blower and respirator than without. PMID:12628576

  10. Lateral pharyngeal fat pad pressure during breathing.

    PubMed

    Winter, W C; Gampper, T; Gay, S B; Suratt, P M

    1996-12-01

    The purpose of this study was to test whether pressure in tissue lateral to the upper airway, the lateral pharyngeal fat pad, differs from atmospheric and pharyngeal pressure and whether it changes with breathing. We studied five male pigs by inserting a transducer-tipped catheter into their fat pad space using computed tomography (CT) scan guidance. We measured airflow with a pneumotachograph attached to a face mask and pharyngeal pressure with a balloon catheter. Fat pad pressure correlated positively with airflow and with pharyngeal pressure, decreasing during inspiration and increasing during expiration. Pressure in the fat pad differed from atmospheric pressure, generally exceeding it, and from pharyngeal pressure. We conclude that lateral pharyngeal fat pad pressure differs from atmospheric and pharyngeal pressure and that it changes with breathing. PMID:9085504

  11. Protective supplied-breathing-air garment

    DOEpatents

    Childers, E.L.; von Hortenau, E.F.

    1982-05-28

    A breathing-air garment for isolating a wearer from hostile environments containing toxins or irritants is disclosed. The garment includes a suit and a separate head-protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air-delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air-delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit sealed with an adhesive sealing flap.

  12. Universe out of a breathing bubble

    SciTech Connect

    Guendelman, Eduardo I.; Sakai, Nobuyuki

    2008-06-15

    We consider the model of a false-vacuum bubble with a thin wall where the surface energy density is composed of two different components, 'domain-wall' type and 'dust' type, with opposite signs. We find stably oscillating solutions, which we call 'breathing bubbles'. By decay to a lower mass state, such a breathing bubble could become either (i) a child universe or ii) a bubble that 'eats up' the original universe, depending on the sign of the surface energy of the domain-wall component. We also discuss the effect of the finite-thickness corrections to the thin-wall approximation and possible origins of the energy contents of our model.

  13. Retrotrapezoid nucleus, respiratory chemosensitivity and breathing automaticity

    PubMed Central

    Guyenet, Patrice G.; Bayliss, Douglas A.; Stornetta, Ruth L.; Fortuna, Michal G.; Abbott, Stephen B.; Depuy, Seth D.

    2009-01-01

    SUMMARY Breathing automaticity and CO2 regulation are inseparable neural processes. The retrotrapezoid nucleus (RTN), a group of glutamatergic neurons that express the transcription factor Phox2b, may be a crucial nodal point through which breathing automaticity is regulated to maintain CO2 constant. This review updates the analysis presented in prior publications. Additional evidence that RTN neurons have central respiratory chemoreceptor properties is presented but this is only one of many factors that determine their activity. The RTN is also regulated by powerful inputs from the carotid bodies and, at least in the adult, by many other synaptic inputs. We also analyze how RTN neurons may control the activity of the downstream central respiratory pattern generator. Specifically, we review the evidence which suggests that RTN neurons a) innervate the entire ventral respiratory column, and b) control both inspiration and expiration. Finally, we argue that the RTN neurons are the adult form of the parafacial respiratory group in neonate rats. PMID:19712903

  14. Microstructured optical fiber interferometric breathing sensor

    NASA Astrophysics Data System (ADS)

    Favero, Fernando C.; Villatoro, Joel; Pruneri, Valerio

    2012-03-01

    In this paper a simple photonic crystal fiber (PCF) interferometric breathing sensor is introduced. The interferometer consists of a section of PCF fusion spliced at the distal end of a standard telecommunications optical fiber. Two collapsed regions in the PCF caused by the splicing process allow the excitation and recombination of a core and a cladding PCF mode. As a result, the reflection spectrum of the device exhibits a sinusoidal interference pattern that instantly shifts when water molecules, present in exhaled air, are adsorbed on or desorbed from the PCF surface. The device can be used to monitor a person's breathing whatever the respiration rate. The device here proposed could be particularly important in applications where electronic sensors fail or are not recommended. It may also be useful in the evaluation of a person's health and even in the diagnosis and study of the progression of serious illnesses such as sleep apnea syndrome.

  15. Universe out of a breathing bubble

    NASA Astrophysics Data System (ADS)

    Guendelman, Eduardo I.; Sakai, Nobuyuki

    2008-06-01

    We consider the model of a false-vacuum bubble with a thin wall where the surface energy density is composed of two different components, “domain-wall” type and “dust” type, with opposite signs. We find stably oscillating solutions, which we call “breathing bubbles.” By decay to a lower mass state, such a breathing bubble could become either (i) a child universe or ii) a bubble that “eats up” the original universe, depending on the sign of the surface energy of the domain-wall component. We also discuss the effect of the finite-thickness corrections to the thin-wall approximation and possible origins of the energy contents of our model.

  16. Tidal Heating in Multilayered Terrestrial Exoplanets

    NASA Technical Reports Server (NTRS)

    Henning, Wade G.; Hurford, Terry

    2014-01-01

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R(sub E) is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  17. Effect of tidal fields on star clusters

    NASA Technical Reports Server (NTRS)

    Chernoff, David; Weinberg, Martin

    1991-01-01

    We follow the dynamical evolution of a star cluster in a galactic tidal field using a restricted N-body code. We find large asymmetric distortions in the outer profile of the cluster in the first 10 or so crossing times as material is lost. Prograde stars escape preferentially and establish a potentially observable retrograde rotation in the halo. We present the rate of particle loss and compare with the prescription proposed by Lee and Ostriker (1987).

  18. Adventures of a tidally induced bar

    NASA Astrophysics Data System (ADS)

    Łokas, E. L.; Athanassoula, E.; Debattista, V. P.; Valluri, M.; Pino, A. del; Semczuk, M.; Gajda, G.; Kowalczyk, K.

    2014-12-01

    Using N-body simulations, we study the properties of a bar induced in a discy dwarf galaxy as a result of tidal interaction with the Milky Way. The bar forms at the first pericentre passage and survives until the end of the evolution at 10 Gyr. Fourier decomposition of the bar reveals that only even modes are significant and preserve a hierarchy so that the bar mode is always the strongest. They show a characteristic profile with a maximum, similar to simulated bars forming in isolated galaxies and observed bars in real galaxies. We adopt the maximum of the bar mode as a measure of the bar strength and we estimate the bar length by comparing the density profiles along the bar and perpendicular to it. The bar strength and the bar length decrease with time, mainly at pericentres, as a result of tidal torques acting at those times and not to secular evolution. The pattern speed of the bar varies significantly on a time-scale of 1 Gyr and is controlled by the orientation of the tidal torque from the Milky Way. The bar is never tidally locked, but we discover a hint of a 5/2 orbital resonance between the third and fourth pericentre passage. The speed of the bar decreases in the long run so that the bar changes from initially rather fast to slow in the later stages. The boxy/peanut shape is present for some time and its occurrence is preceded by a short period of buckling instability.

  19. Tidal and Dynamical Evolution of Binary Asteroids

    NASA Astrophysics Data System (ADS)

    Jacobson, Seth A.; Scheeres, D. J.

    2009-05-01

    We derive a realistic model for the evolution of a tidally perturbed binary, using classical theory, to examine the system just after a spin-up fission event. The spin rate of an asteroid can be increased by the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect -- thermal re-radiation from an asymmetric body, which induces torques that can rotationally accelerate the body. If the asteroid is modeled as a "rubble pile", a collection of gravitationally bound gravel with no tensile strength, increasing the spin rate will lead to a fission process that would resemble that of a viscous fluidic body [Holsapple 2007]. However, high-resolution imagery of an asteroid's constituents indicates that there is a significant distribution of size scales. A specific example is the asteroid Itokawa, which appears to be two such rubble piles in contact with each other [Fujiwara 2006]. The shape of these bodies will be irregular (modeled as tri-axial ellipsoids with a gravitational potential expanded up to second order). Their motions will raise tides on the opposing body. These tides will dissipate energy, potentially providing enough energy loss for the system to settle into a stable orbit. Fissioned binary systems are always initially unstable [Scheeres 2009, 2008]. We expect tidal dissipation rates to vary widely during the initial evolution of the system, due to this instability. The model applies instantaneous tidal torques to determine energy loss. Our preliminary results indicate that tidal energy dissipation could relax the system to a state of relative equilibrium on order 100,000 years, creating systems similar to those observed. Holsapple, K. A., Icarus, 187, 2007. Fujiwara, A., Science, 312, 2006. Scheeres, D., CMDA, 2009 (Accepted Jan 10, 2009). Scheeres, D., AAS, DDA meeting #39, #9.01, 2008.

  20. Abandoned Channel Fill Sequences in Tidal Estuaries

    NASA Astrophysics Data System (ADS)

    Gray, A. B.; Pasternack, G. B.; Goni, M. A.; Watson, E. B.

    2014-12-01

    This study proposes a modification of the current model for abandoned channel fill stratigraphy produced in unidirectional flow river reaches to incorporate seasonal tidal deposition. Evidence supporting this concept came from a study of two consecutive channel abandonment sequences in Ropers Slough of the lower Eel River Estuary in northern California. Aerial photographs showed that Ropers Slough was abandoned around 1943, reoccupied after the 1964 flood, and abandoned again in 1974 with fill continuing to the present. Planform geomorphic characteristics derived from these images were used in conjunction with sub-cm resolution stratigraphic analyses to describe the depositional environment processes and their resultant sedimentary deposits. Results showed that both abandonment sequences recorded quasi-annual scale fluvial/tidal deposition couplets. In both cases tidal deposits contained very little sand, and were higher in organic and inorganic carbon content than the sandier fluvial through-flow deposits. However, the two abandonment fills differed significantly in terms of the temporal progression of channel narrowing and fluvial sediment deposition characteristics. The first abandonment sequence led to a more rapid narrowing of Ropers Slough and produced deposits with a positive relationship between grain size/deposit thickness and discharge. The second abandonment resulted in a much slower narrowing of Ropers Slough and generally thinner fluvial deposits with no clear relationship between grain size/deposit thickness and discharge. The δ13C values and organic nitrogen to organic carbon ratios of deposits from the first phase overlapped with Eel River suspended sediment characteristics found for low flows (1-5 times mean discharge), while those of the second phase were consistent suspended sediment from higher flows (7-10 times mean discharge). The abandoned channel fill sequences appeared to differ due to the topographic steering of bed sediment transport and

  1. Tidal Response of Titan's Lakes and Seas

    NASA Astrophysics Data System (ADS)

    Karatekin, O.; Demain, C.; Deleersnijder, E.

    2011-12-01

    The Cassini spacecraft has revealed a vast set of lakes/seas filled or partially filled with liquid hydrocarbons and empty lake basins in the high latitudes of Titan. The seas and lakes of Titan provide an opportunity to explore an exciting aqueous environment whose characteristics are very different from what we know on Earth. The lakes appear in various shapes and sizes and are filled with liquid hydrocarbons, primarily methane and ethane. Recently, the Cassini spacecraft provided observations suggesting for the first time temporal variations in lake surfaces. The variation in the shorelines can be explained by different hypothesis including evaporation and tides. During Titan's 16 day orbital period around Saturn, the time-dependent tidal response of the lakes may affect the shorelines. Although the estimated tidal amplitudes by theoretical consideration yield smaller than the observed depth changes on Ontario Lacus, tides can have more significant effects of other lakes/seas with tidal amplitudes up to several meters. In the present study, besides Ontario Lacus we also consider Ligeia Mare, one of three large methane seas discovered by Cassini in the northern hemisphere of Titan and the target for the discovery mission of Titan Mare Explorer (TiME). The tidal response of Titan's lakes an seas are investigated by means of two- dimensional nonlinear shallow water equations The governing partial differential equations on the sphere are solved using SLIM (Second-generation Louvain- la- Neuve Ice-Ocean Model - http://www.climate.be/SLIM). SLIM is a hydrodynamical model based on finite element method. As all general circulation models, it uses primitive variables as prognostic quantities. Partial differential equations are discretized on curved surfaces using triangular meshes. The mesh is generated from recursive subdivisions of the faces of an icosahedron using GMSH software.. The code has a wetting-drying algorithm. The simulations can take into account several

  2. DIRECTLY IMAGING TIDALLY POWERED MIGRATING JUPITERS

    SciTech Connect

    Dong Subo; Katz, Boaz; Socrates, Aristotle

    2013-01-10

    Upcoming direct-imaging experiments may detect a new class of long-period, highly luminous, tidally powered extrasolar gas giants. Even though they are hosted by {approx} Gyr-'old' main-sequence stars, they can be as 'hot' as young Jupiters at {approx}100 Myr, the prime targets of direct-imaging surveys. They are on years-long orbits and presently migrating to 'feed' the 'hot Jupiters'. They are expected from 'high-e' migration mechanisms, in which Jupiters are excited to highly eccentric orbits and then shrink semimajor axis by a factor of {approx}10-100 due to tidal dissipation at close periastron passages. The dissipated orbital energy is converted to heat, and if it is deposited deep enough into the atmosphere, the planet likely radiates steadily at luminosity L {approx} 100-1000 L{sub Jup}(2 Multiplication-Sign 10{sup -7}-2 Multiplication-Sign 10{sup -6} L{sub Sun }) during a typical {approx} Gyr migration timescale. Their large orbital separations and expected high planet-to-star flux ratios in IR make them potentially accessible to high-contrast imaging instruments on 10 m class telescopes. {approx}10 such planets are expected to exist around FGK dwarfs within {approx}50 pc. Long-period radial velocity planets are viable candidates, and the highly eccentric planet HD 20782b at maximum angular separation {approx}0.''08 is a promising candidate. Directly imaging these tidally powered Jupiters would enable a direct test of high-e migration mechanisms. Once detected, the luminosity would provide a direct measurement of the migration rate, and together with mass (and possibly radius) estimate, they would serve as a laboratory to study planetary spectral formation and tidal physics.

  3. Surface velocity fields from tidal interactions

    NASA Astrophysics Data System (ADS)

    Koenigsberger, Gloria; Moreno, Edmundo; Harrington, David

    2009-09-01

    Binary stars in eccentric orbits are the clearest example of stars whose equatorial rotation velocity is not synchronized with orbital motion. Under these conditions, the surface velocity field is perturbed from its purely rotational nature, thus modifying the shape of the observationally-detectable photospheric absorption lines on a variety of timescales. Absorption lines are used to derive basic stellar parameters and gain a better physical understanding of the star. Although their variability is often interpreted in terms of non-radial pulsation theory, it is important to understand the nature of the surface velocity fields that are induced by the tidal interactions alone, especially under conditions of rapid rotation and large orbital eccentricity, where the perturbations become highly non-linear. We use a time-marching numerical calculation from first principles to model the surface velocity field due to the tidal interaction (Moreno & Koenigsberger 1999; Toledano et al. 2007). This velocity field is then projected along the line-of-sight to the observer to predict the orbital phase-dependent line-profile variability (Moreno et al. 2005). We compare our model results with very high quality observational data of the B-type binary system α Vir (Spica, HD 116658, P = 4d, e = 0.1), whose variability has in the past been modeled in the context of non-radial pulsations (Smith 1985). Our model reproduces the general features of the observations (Harrington et al. 2009). It is interesting to note that because tidal flows are associated with viscous shear energy dissipation, the question arises as to whether the atmospheric structure of an asynchronously rotating binary star may be reliably modeled using techniques that disregard the dynamical effects on the stellar surface of the tidal interactions.

  4. Tidal radius estimates for three open clusters

    NASA Astrophysics Data System (ADS)

    Danilov, V. M.; Loktin, A. V.

    2015-10-01

    A new method is developed for estimating tidal radii and masses of open star clusters (OCL) based on the sky-plane coordinates and proper motions and/or radial velocities of cluster member stars. To this end, we perform the correlation and spectral analysis of oscillations of absolute values of stellar velocity components relative to the cluster mass center along three coordinate planes and along each coordinate axis in five OCL models. Mutual correlation functions for fluctuations of absolute values of velocity field components are computed. The spatial Fourier transform of the mutual correlation functions in the case of zero time offset is used to compute wavenumber spectra of oscillations of absolute values of stellar velocity components. The oscillation spectra of these quantities contain series of local maxima at equidistant wavenumber k values. The ratio of the tidal radius of the cluster to the wavenumber difference Δ k of adjacent local maxima in the oscillation spectra of absolute values of velocity field components is found to be the same for all five OCL models. This ratio is used to estimate the tidal radii and masses of the Pleiades, Praesepe, and M67 based on the proper motions and sky-plane coordinates of the member stars of these clusters. The radial dependences of the absolute values of the tangential and radial projections of cluster star velocities computed using the proper motions relative to the cluster center are determined, along with the corresponding autocorrelation functions and wavenumber spectra of oscillations of absolute values of velocity field components. The Pleiades virial mass is estimated assuming that the cluster is either isolated or non-isolated. Also derived are the estimates of the Pleiades dynamical mass assuming that it is non-stationary and non-isolated. The inferred Pleiades tidal radii corresponding to these masses are reported.

  5. Tidal heating in multilayered terrestrial exoplanets

    SciTech Connect

    Henning, Wade G.; Hurford, Terry

    2014-07-01

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R{sub E} is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  6. Tidal evolution of stars hosting massive planets

    NASA Astrophysics Data System (ADS)

    Ferraz-Mello, Sylvio; Pereira, Elielson S.; Moda, Lucas F. R.

    2015-08-01

    The tidal interaction between one close-in companion (exoplanet or brown-dwarf) and its host star transfers angular momentum from the orbit of the companion to the rotation of the star. In this communication, we present one model for the exchange of angular momentum between the orbit of the companion and the rotation of the star, due to the tidal interaction, and discuss the limits in which the transfer is significant. If the star is active, its rotation period is initially increasing due to the star's wind braking, but at some point the braking is overcome by the tidal transfer of angular momentum from the planet orbit and the rotation period starts decreasing, up to an inward spiraling of the planet orbit and its eventual fall in the star, when a rapid decrease in the star rotation period is seen. In non-active stars, the rotation period is driven towards the neighborhood of the orbital period. For a complete study of several cases see Ferraz-Mello et al. astro-ph/1503.04369. One consequence of these results is that the presence of a significant tidal torque does not allow us to use the gyrochronology rules to estimate the age of a star hosting a large close-in companion. Simulations using hypothetical values show that a companion with mass over 1 Jupiter mass in an orbit within 0.04 AU from a solar-type star (i.e. with period less than 3 days) produces in the rotation of the star an evolution different from that predicted for single stars.

  7. A monitoring of breathing using a hetero-core optical fiber sensor

    NASA Astrophysics Data System (ADS)

    Akita, S.; Seki, A.; Watanabe, K.

    2011-04-01

    A monitoring human breath has been seen as an important source of factor for vital status for emergency medical service. The monitoring of breathing has been tested and evaluated in a possible breath condition of a person to be monitored. A hetero-core optical fiber humidity sensor was developed for in order to monitor relative humidity in a medial mask. Elements for determent breath condition were extracted from the light intensity changing at some human breath condition, which were Breath depth, Breath cycle, Breath time and Check breathing. It is found that the elements had differences relative to normal breathing.

  8. Breathing air trailer acceptance test report

    SciTech Connect

    Kostelnik, A.J.

    1996-02-12

    This Acceptance Test Report documents compliance with the requirements of specification WHC-S-0251, Rev.0 and ECNs 613530 and 606113. The equipment was tested according to WHC-SD-WM-ATP-104. The equipment tested is a Breathing Air Supply Trailer purchased as a design and fabrication procurement activity. The ATP was written by the Seller and was performed by the Seller with representatives of the Westinghouse Hanford Company witnessing portions of the test at the Seller`s location.

  9. Breath Analysis in Pulmonary Arterial Hypertension

    PubMed Central

    Cikach, Frank S.; Tonelli, Adriano R.; Barnes, Jarrod; Paschke, Kelly; Newman, Jennie; Grove, David; Dababneh, Luma; Wang, Sihe

    2014-01-01

    Background: Pulmonary arterial hypertension (PAH) is a progressive and devastating condition characterized by vascular cell proliferation and is associated with several metabolic derangements. We hypothesized that metabolic derangements in PAH can be detected by measuring metabolic by-products in exhaled breath. Methods: We collected breath and blood samples from patients with PAH at the time of right-sided heart catheterization (n = 31) and from healthy control subjects (n = 34). Breath was analyzed by selected ion flow tube-mass spectrometry in predetermined training and validation cohorts. Results: Patients with PAH were 51.5 ± 14 years old, and 27 were women (85%). Control subjects were 38 ± 13 years old, and 22 were women (65%). Discriminant analysis in the training set identified three ion peaks (H3O+29+, NO+56+, and O2+98+) and the variable age that correctly classified 88.9% of the individuals. In an independent validation cohort, 82.8% of the individuals were classified correctly. The concentrations of the volatile organic compounds 2-propanol, acetaldehyde, ammonia, ethanol, pentane, 1-decene, 1-octene, and 2-nonene were different in patients with PAH compared with control subjects. Exhaled ammonia was higher in patients with PAH (median [interquartile range]: 94.7 parts per billion (ppb) [70-129 ppb] vs 60.9 ppb [46-77 ppb], P < .001) and was associated with right atrial pressure (ρ = 0.57, P < .001), mean pulmonary artery pressure (ρ = 0.43, P = .015), cardiac index by thermodilution (ρ = −0.39, P = .03), pulmonary vascular resistance (ρ = 0.40, P = .04), mixed venous oxygen (ρ = −0.59, P < .001), and right ventricular dilation (ρ = 0.42, P = .03). Conclusions: Breathprint is different between patients with PAH and healthy control subjects. Several specific compounds, including ammonia, were elevated in the breath of patients with PAH. Exhaled ammonia levels correlated with severity of disease. PMID:24091389

  10. Houses need to breathe--right?

    SciTech Connect

    Sherman, Max H.

    2004-10-01

    Houses need to breathe, but we can no longer leave the important functions associated with ventilation to be met accidentally. A designed ventilation system must be considered as much a part of a home as its heating system. Windows are a key part of that system because they allow a quick increase in ventilation for unusual events, but neither they nor a leaky building shell can be counted on to provide minimum levels.

  11. Air breathing direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming; Gottesfeld, Shimshon

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source. Water loss from the cell is minimized by making the conductive cathode assembly hydrophobic and the conductive anode assembly hydrophilic.

  12. Breath tests and irritable bowel syndrome.

    PubMed

    Rana, Satya Vati; Malik, Aastha

    2014-06-28

    Breath tests are non-invasive tests and can detect H₂ and CH₄ gases which are produced by bacterial fermentation of unabsorbed intestinal carbohydrate and are excreted in the breath. These tests are used in the diagnosis of carbohydrate malabsorption, small intestinal bacterial overgrowth, and for measuring the orocecal transit time. Malabsorption of carbohydrates is a key trigger of irritable bowel syndrome (IBS)-type symptoms such as diarrhea and/or constipation, bloating, excess flatulence, headaches and lack of energy. Abdominal bloating is a common nonspecific symptom which can negatively impact quality of life. It may reflect dietary imbalance, such as excess fiber intake, or may be a manifestation of IBS. However, bloating may also represent small intestinal bacterial overgrowth. Patients with persistent symptoms of abdominal bloating and distension despite dietary interventions should be referred for H₂ breath testing to determine the presence or absence of bacterial overgrowth. If bacterial overgrowth is identified, patients are typically treated with antibiotics. Evaluation of IBS generally includes testing of other disorders that cause similar symptoms. Carbohydrate malabsorption (lactose, fructose, sorbitol) can cause abdominal fullness, bloating, nausea, abdominal pain, flatulence, and diarrhea, which are similar to the symptoms of IBS. However, it is unclear if these digestive disorders contribute to or cause the symptoms of IBS. Research studies show that a proper diagnosis and effective dietary intervention significantly reduces the severity and frequency of gastrointestinal symptoms in IBS. Thus, diagnosis of malabsorption of these carbohydrates in IBS using a breath test is very important to guide the clinician in the proper treatment of IBS patients. PMID:24976698

  13. Breath tests and irritable bowel syndrome

    PubMed Central

    Rana, Satya Vati; Malik, Aastha

    2014-01-01

    Breath tests are non-invasive tests and can detect H2 and CH4 gases which are produced by bacterial fermentation of unabsorbed intestinal carbohydrate and are excreted in the breath. These tests are used in the diagnosis of carbohydrate malabsorption, small intestinal bacterial overgrowth, and for measuring the orocecal transit time. Malabsorption of carbohydrates is a key trigger of irritable bowel syndrome (IBS)-type symptoms such as diarrhea and/or constipation, bloating, excess flatulence, headaches and lack of energy. Abdominal bloating is a common nonspecific symptom which can negatively impact quality of life. It may reflect dietary imbalance, such as excess fiber intake, or may be a manifestation of IBS. However, bloating may also represent small intestinal bacterial overgrowth. Patients with persistent symptoms of abdominal bloating and distension despite dietary interventions should be referred for H2 breath testing to determine the presence or absence of bacterial overgrowth. If bacterial overgrowth is identified, patients are typically treated with antibiotics. Evaluation of IBS generally includes testing of other disorders that cause similar symptoms. Carbohydrate malabsorption (lactose, fructose, sorbitol) can cause abdominal fullness, bloating, nausea, abdominal pain, flatulence, and diarrhea, which are similar to the symptoms of IBS. However, it is unclear if these digestive disorders contribute to or cause the symptoms of IBS. Research studies show that a proper diagnosis and effective dietary intervention significantly reduces the severity and frequency of gastrointestinal symptoms in IBS. Thus, diagnosis of malabsorption of these carbohydrates in IBS using a breath test is very important to guide the clinician in the proper treatment of IBS patients. PMID:24976698

  14. Dust Reprocessing of Stellar Tidal Disruption Flares

    NASA Astrophysics Data System (ADS)

    van Velzen, Sjoert; Gorjian, Varoujan; Krolik, Julian; Mendez, Alexander

    2015-10-01

    A stellar tidal disruption flare (TDF) occurs when a star gets too close to a supermassive black hole and is shredded into streams that are accreted. Traditionally, TDFs are observed at optical to soft X-ray wavelengths. We have recently made a discovery that opens a new (and unexpected) wavelength regime for the study of these flares: transient emission at 3.4 micron in WISE multi-epoch imaging. This dust reprocessing signal was not previously predicted, but will likely be of great importance to further our (limited) understanding the TDF emission mechanism. Since the radius of the IR-emitting shell is determined by the dust sublimation temperature, the break in the IR light curve can be used to measure the bolometric luminosity of the tidal flare. With the low-cadence WISE observations as a proof-of-concept, the time is ripe to use warm Spitzer observations to make a major breakthrough: we wish to obtain the first well-sampled light curve of dust reverberation by a stellar tidal flare. If successful, these observations will have lasting impact; near-future synoptic surveys (ZTF, LSST) will find thousands of TDFs per year, which can be followed-up by IR missions (JWST, WFIRST) to obtain a census of dust within the sphere of influence of quiescent supermassive black holes.

  15. The Cellular Building Blocks of Breathing

    PubMed Central

    Ramirez, J.M.; Doi, A.; Garcia, A.J.; Elsen, F.P.; Koch, H.; Wei, A.D.

    2013-01-01

    Respiratory brainstem neurons fulfill critical roles in controlling breathing: they generate the activity patterns for breathing and contribute to various sensory responses including changes in O2 and CO2. These complex sensorimotor tasks depend on the dynamic interplay between numerous cellular building blocks that consist of voltage-, calcium-, and ATP-dependent ionic conductances, various ionotropic and metabotropic synaptic mechanisms, as well as neuromodulators acting on G-protein coupled receptors and second messenger systems. As described in this review, the sensorimotor responses of the respiratory network emerge through the state-dependent integration of all these building blocks. There is no known respiratory function that involves only a small number of intrinsic, synaptic, or modulatory properties. Because of the complex integration of numerous intrinsic, synaptic, and modulatory mechanisms, the respiratory network is capable of continuously adapting to changes in the external and internal environment, which makes breathing one of the most integrated behaviors. Not surprisingly, inspiration is critical not only in the control of ventilation, but also in the context of “inspiring behaviors” such as arousal of the mind and even creativity. Far-reaching implications apply also to the underlying network mechanisms, as lessons learned from the respiratory network apply to network functions in general. PMID:23720262

  16. Breathing is different in the quantum world

    NASA Astrophysics Data System (ADS)

    Bonitz, Michael; Bauch, Sebastian; Balzer, Karsten; Henning, Christian; Hochstuhl, David

    2009-11-01

    Interacting classicle particles in a harmonic trap are known to possess a radial collective oscillation -- the breathing mode (BM). In case of Coulomb interaction its frequency is universal -- it is independent of the particle number and system dimensionality [1]. Here we study strongly correlated quantum systems. We report a qualitatively different breathing behavior: a quantum system has two BMs one of which is universal whereas the frequency of the other varies with system dimensionality, the particle spin and the strength of the pair interaction. The results are based on exact solutions of the time-dependent Schr"odinger equation for two particles and on time-dependent many-body results for larger particle numbers. Finally, we discuss experimental ways to excite and measure the breathing frequencies which should give direct access to key properties of trapped particles, including their many-body effects [2]. [4pt] [1] C. Henning et al., Phys. Rev. Lett. 101, 045002 (2008) [0pt] [2] S. Bauch, K. Balzer, C. Henning, and M. Bonitz, submitted to Phys. Rev. Lett., arXiv:0903.1993

  17. Integrated engineering modeling for air breathing rockets

    NASA Astrophysics Data System (ADS)

    Chitilappilly, Lazar T.; Subramanyam, J. D. A.

    An innovative aerodynamic-propulsion-flight integrated modeling is carried out for airbreathing rockets, the propulsion of which has primary dependence on flight conditions. The integrated modeling is highly beneficial for design and analysis of accelerating air breathing rockets characterized by continuously varying flight conditions. The details of the modeling is described; the force accounting, trajectory analysis, solving the flow in the sub-systems (air intake, primary rocket, secondary combustion chamber and secondary nozzle), matching the subsystem flow fields and determining the mode of operation. Operational features are listed of the computer software developed, air breathing integrated design and analysis engineering software. It gives all the propulsion and flight parameters from take-off of the rocket to end of flight and has been instrumental in the design of the research air breathing rocket ABR-200(I). The hundreds of flight performance analyses required for design is possible by the engineering approach adopted for solving the propulsor flow field. The software results are compared with ejector mode and connected pipe mode static tests. The overall validation of the software is achieved by flight tests; the performance predictions have matched exactly with that measured during thee first and second flights of the ABR-200(I).

  18. The immune response to resistive breathing.

    PubMed

    Vassilakopoulos, T; Roussos, C; Zakynthinos, S

    2004-12-01

    Resistive breathing is an "immune challenge" for the body, initiating an inflammatory response consisting of an elevation of plasma cytokines, and the recruitment and activation of lymphocyte subpopulations. These cytokines do not originate from monocytes, but are, instead, produced within the diaphragm, secondary to the increased muscle activation. Oxidative stress is a major stimulus for the cytokine induction, secondary to resistive breathing. The production of cytokines within the diaphragm may be mediating the diaphragm muscle fibre injury that occurs with strenuous contractions, or contributing towards the expected repair process. These cytokines may also compromise diaphragmatic contractility or contribute towards the development of muscle cachexia. They may also have systemic effects, mobilising glucose from the liver and free fatty acid from the adipose tissue to the strenuously working respiratory muscles. At the same time, they stimulate the hypothalamic-pituitary-adrenal axis, leading to production of adrenocorticotropin and beta-endorphins. The adrenocorticotropin response may represent an attempt of the organism to reduce the injury occurring in the respiratory muscles via the production of glucocorticoids and the induction of the acute phase-response proteins. The beta-endorphin response would decrease the activation of the respiratory muscles and change the pattern of breathing, which becomes more rapid and shallow, possibly in an attempt to reduce and/or prevent further injury to the respiratory muscles. PMID:15572550

  19. Optimal air-breathing launch vehicle design

    NASA Technical Reports Server (NTRS)

    Hattis, P. D.

    1981-01-01

    A generalized two-point boundary problem methodology, similar to techniques used in deterministic optimal control studies, is applied to the design and flight analysis of a two-stage air-breathing launch vehicle. Simultaneous consideration is given to configuration and trajectory by treating geometry, dynamic discontinuities, and time-dependent flight variables all as controls to be optimized with respect to a single mathematical performance measure. While minimizing fuel consumption, inequality constraints are applied to dynamic pressure and specific force. The optimal system fuel consumption and staging Mach number are found to vary little with changes in the inequality constraints due to substantial geometry and trajectory adjustments. Staging, from an air-breathing first stage to a rocket-powered second stage, consistently occurs near Mach 3.5. The dynamic pressure bound has its most pronounced effects on vehicle geometry, particularly the air-breathing propulsion inlet area, and on the first-stage altitude profile. The specific force has its greatest influence on the second-stage thrust history.

  20. Genetics and early disturbances of breathing control.

    PubMed

    Gaultier, Claude; Amiel, Jeanne; Dauger, Stéphane; Trang, Ha; Lyonnet, Stanislas; Gallego, Jorge; Simonneau, Michel

    2004-05-01

    Early disturbances in breathing control, including apneas of prematurity and apparently life-threatening events, account for some cases of sudden infant death syndrome and for a rare disorder called congenital central hypoventilation syndrome (CCHS). Data suggesting a genetic basis for CCHS have been obtained. Recently, we found heterozygous de novo mutations of the PHOX2B gene in 18 of 29 individuals with CCHS. Most mutations consisted of five to nine alanine expansions within a 20-residue polyalanine tract, probably resulting from nonhomologous recombination. Other mutations, generally inherited from one of the parents, in the coding regions of genes involved in the endothelin and RET signaling pathways and in the brain-derived-neurotrophic factor (BDNF) gene have been found in a few CCHS patients. Interestingly, all these genes are involved in the development of neural crest cells. Targeted disruption of these genes in mice has provided information on the pathophysiological mechanisms underlying CCHS. Despite the identification of these genes involved in breathing control, none of the genetically engineered mice developed to date replicate the full human CCHS respiratory phenotype. Recent insights into the genetic basis for CCHS may shed light on the genetics of other early disturbances in breathing control, such as apnea of prematurity and sudden infant death syndrome. PMID:14739359