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Sample records for 30-15 intermittent fitness

  1. Comparison Between 30-15 Intermittent Fitness Test and Multistage Field Test on Physiological Responses in Wheelchair Basketball Players

    PubMed Central

    Weissland, Thierry; Faupin, Arnaud; Borel, Benoit; Leprêtre, Pierre-Marie

    2015-01-01

    The intermittent nature of wheelchair court sports suggests using a similar protocol to assess repeated shuttles and recovery abilities. This study aimed to compare performances, physiological responses and perceived rating exertion obtained from the continuous multistage field test (MFT) and the 30-15 intermittent field test (30-15IFT). Eighteen trained wheelchair basketball players (WBP) (WBP: 32.0 ± 5.7 y, IWBF classification: 2.9 ± 1.1 points) performed both incremental field tests in randomized order. Time to exhaustion, maximal rolling velocity (MRV), VO2peak and the peak values of minute ventilation (VEpeak), respiratory frequency (RF) and heart rate (HRpeak) were measured throughout both tests; peak and net blood lactate (Δ[Lact−] = peak–rest values) and perceived rating exertion (RPE) values at the end of each exercise. No significant difference in VO2peak, VEpeak, and RF was found between both tests. 30-15IFT was shorter (12.4 ± 2.4 vs. 14.9 ± 5.1 min, P < 0.05) but induced higher values of MRV and Δ[Lact−] compared to MFT (14.2 ± 1.8 vs. 11.1 ± 1.9 km·h−1 and 8.3 ± 4.2 vs. 6.9 ± 3.3 mmol·L−1, P < 0.05). However, HRpeak and RPE values were higher during MFT than 30-15IFT(172.8 ± 14.0 vs. 166.8 ± 13.8 bpm and 15.3 ± 3.8 vs.13.8 ± 3.5, respectively, P < 0.05). The intermittent shuttles intercepted with rest period occurred during the 30-15IFT could explain a greater anaerobic solicitation. The higher HR and overall RPE values measured at the end of MFT could be explained by its longer duration and a continuous load stress compared to 30-15IFT. In conclusion, 30-15IFT has some advantages over MFT for assess in addition physical fitness and technical performance in WBP. PMID:26733875

  2. Comparison Between 30-15 Intermittent Fitness Test and Multistage Field Test on Physiological Responses in Wheelchair Basketball Players.

    PubMed

    Weissland, Thierry; Faupin, Arnaud; Borel, Benoit; Leprêtre, Pierre-Marie

    2015-01-01

    The intermittent nature of wheelchair court sports suggests using a similar protocol to assess repeated shuttles and recovery abilities. This study aimed to compare performances, physiological responses and perceived rating exertion obtained from the continuous multistage field test (MFT) and the 30-15 intermittent field test (30-15IFT). Eighteen trained wheelchair basketball players (WBP) (WBP: 32.0 ± 5.7 y, IWBF classification: 2.9 ± 1.1 points) performed both incremental field tests in randomized order. Time to exhaustion, maximal rolling velocity (MRV), VO2peak and the peak values of minute ventilation (V Epeak), respiratory frequency (RF) and heart rate (HRpeak) were measured throughout both tests; peak and net blood lactate (Δ[Lact(-)] = peak-rest values) and perceived rating exertion (RPE) values at the end of each exercise. No significant difference in VO2peak, VEpeak, and RF was found between both tests. 30-15IFT was shorter (12.4 ± 2.4 vs. 14.9 ± 5.1 min, P < 0.05) but induced higher values of MRV and Δ[Lact(-)] compared to MFT (14.2 ± 1.8 vs. 11.1 ± 1.9 km·h(-1) and 8.3 ± 4.2 vs. 6.9 ± 3.3 mmol·L(-1), P < 0.05). However, HRpeak and RPE values were higher during MFT than 30-15IFT(172.8 ± 14.0 vs. 166.8 ± 13.8 bpm and 15.3 ± 3.8 vs.13.8 ± 3.5, respectively, P < 0.05). The intermittent shuttles intercepted with rest period occurred during the 30-15IFT could explain a greater anaerobic solicitation. The higher HR and overall RPE values measured at the end of MFT could be explained by its longer duration and a continuous load stress compared to 30-15IFT. In conclusion, 30-15IFT has some advantages over MFT for assess in addition physical fitness and technical performance in WBP. PMID:26733875

  3. Comparison Between 30-15 Intermittent Fitness Test and Multistage Field Test on Physiological Responses in Wheelchair Basketball Players.

    PubMed

    Weissland, Thierry; Faupin, Arnaud; Borel, Benoit; Leprêtre, Pierre-Marie

    2015-01-01

    The intermittent nature of wheelchair court sports suggests using a similar protocol to assess repeated shuttles and recovery abilities. This study aimed to compare performances, physiological responses and perceived rating exertion obtained from the continuous multistage field test (MFT) and the 30-15 intermittent field test (30-15IFT). Eighteen trained wheelchair basketball players (WBP) (WBP: 32.0 ± 5.7 y, IWBF classification: 2.9 ± 1.1 points) performed both incremental field tests in randomized order. Time to exhaustion, maximal rolling velocity (MRV), VO2peak and the peak values of minute ventilation (V Epeak), respiratory frequency (RF) and heart rate (HRpeak) were measured throughout both tests; peak and net blood lactate (Δ[Lact(-)] = peak-rest values) and perceived rating exertion (RPE) values at the end of each exercise. No significant difference in VO2peak, VEpeak, and RF was found between both tests. 30-15IFT was shorter (12.4 ± 2.4 vs. 14.9 ± 5.1 min, P < 0.05) but induced higher values of MRV and Δ[Lact(-)] compared to MFT (14.2 ± 1.8 vs. 11.1 ± 1.9 km·h(-1) and 8.3 ± 4.2 vs. 6.9 ± 3.3 mmol·L(-1), P < 0.05). However, HRpeak and RPE values were higher during MFT than 30-15IFT(172.8 ± 14.0 vs. 166.8 ± 13.8 bpm and 15.3 ± 3.8 vs.13.8 ± 3.5, respectively, P < 0.05). The intermittent shuttles intercepted with rest period occurred during the 30-15IFT could explain a greater anaerobic solicitation. The higher HR and overall RPE values measured at the end of MFT could be explained by its longer duration and a continuous load stress compared to 30-15IFT. In conclusion, 30-15IFT has some advantages over MFT for assess in addition physical fitness and technical performance in WBP.

  4. The 30-15 Intermittent Fitness Test versus the Yo-Yo Intermittent Recovery Test Level 1: relationship and sensitivity to training.

    PubMed

    Buchheit, Martin; Rabbani, Alireza

    2014-05-01

    The aim of the current study was to examine the relationship between performance of the Yo-Yo Intermittent Recovery Test Level 1 (Yo-YoIR1) and the 30-15 Intermittent Fitness Test (30-15IFT) and to compare the sensitivity of both tests to training. Fourteen young soccer players performed both tests before and after an 8-wk training intervention, which included 6 sessions/wk: 2 resistance training sessions, 2 high-intensity interval training sessions after technical training (4 sets of 3:30 min of generic running and small-sided games [4v4] during the first and second 4-wk periods, respectively [90-95% maximal HR], interspersed with 3 min at 60-70% maximal HR), and 2 tactical-only training sessions. There was a large correlation between 30-15IFT and Yo-YoIR1 (r = .75, 90% confidence limits [CL] 0.57;0.86). While within-test percentage changes suggested a greater sensitivity to training for the Yo-YoIR1 (+35%, 90%CL 24;45) than for the 30-15IFT (+7%; 4;10), these changes were similarly rated as almost certain (with chances for greater/similar/lower values after training of 100/0/0 for both tests) and moderate, ie, standardized difference, ES = +1.2 90%CL (0.9;1.5) for Yo-YoIR1 and ES = +1.1 (0.7;1.5) for 30-15IFT. The difference in the change between the 2 tests was clearly trivial (0/100/0, ES = -0.1, 90%CL -0.1;-0.1). Both tests might evaluate slightly different physical capacities, but their sensitivity to training is almost certainly similar. These results also highlight the importance of using standardized differences instead of percentage changes in performance to assess the actual training effect of an intervention.

  5. Reliability, usefulness, and validity of the 30-15 Intermittent Ice Test in young elite ice hockey players.

    PubMed

    Buchheit, Martin; Lefebvre, Benjamin; Laursen, Paul B; Ahmaidi, Said

    2011-05-01

    The purpose of this study was to examine the reliability, usefulness, and validity of the 30-15 Intermittent Ice Test (30-15(IIT)) in 17 young elite ice hockey players. For the reliability and usefulness study, players performed the 30-15(IIT) 7 days apart. For the validity study, data derived from the first 30-15(IIT) were compared with those obtained from the 30-15 Intermittent Fitness Test (30-15(IFT), the running version of this test used as a reference marker for its ability to assess cardiovascular fitness in the field, that is, VO₂peak). Maximal speed, heart rate at exhaustion (HR(peak)) and postexercise blood-lactate levels ([La](b)) were collected for all tests, whereas submaximal HR was taken at stages 4 and 8 (HR(stage4) and HR(stage8)) during the 30-15(IIT). All intra-class correlation coefficients were >0.94. Coefficients of variation were 1.6% (90% CI, 1.3-2.3), 1.7% (1.3-2.8), 1.4% (1.0-2.2), and 0.7% (0.5-1.1) for maximal skating speed, HR(stage4), HR(stage8), and HR(peak), respectively. Correlations between maximal velocities and HR(peak) obtained for the 30-15(IIT) vs. 30-15(IFT) were very large (r = 0.72) and large (r = 0.61), respectively. Maximal skating speed was also largely correlated to estimated VO₂peak (r = 0.71). There was however no correlation for [La](b) values between both tests (r = 0.42). These results highlight the specificity of the on-ice 30-15(IIT) and show it to be a reliable and valid test for assessing cardiorespiratory fitness in young elite players. Coaches could interpret a change in performance of at least 2 stages, or a change in submaximal HR of more than 8% (≈8 b·min⁻¹) during the eighth stage to be a meaningful change in skating fitness.

  6. 46 CFR 58.30-15 - Pipe, tubing, valves, fittings, pumps, and motors.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-15 Pipe..., valves, flanges, and fittings shall be selected from those specifications that appear in 46 CFR 56.60-1, Table 56.60-1(a) or 46 CFR 56.60-2, Table 56.60-2(a); or they may be selected from the...

  7. 46 CFR 58.30-15 - Pipe, tubing, valves, fittings, pumps, and motors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-15 Pipe..., valves, flanges, and fittings shall be selected from those specifications that appear in 46 CFR 56.60-1, Table 56.60-1(a) or 46 CFR 56.60-2, Table 56.60-2(a); or they may be selected from the...

  8. 46 CFR 58.30-15 - Pipe, tubing, valves, fittings, pumps, and motors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-15 Pipe... hydraulic and pneumatic systems listed in § 58.30-1. (b) Materials used in the manufacture of tubing, pipes, valves, flanges, and fittings shall be selected from those specifications that appear in 46 CFR...

  9. 46 CFR 58.30-15 - Pipe, tubing, valves, fittings, pumps, and motors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-15 Pipe... hydraulic and pneumatic systems listed in § 58.30-1. (b) Materials used in the manufacture of tubing, pipes, valves, flanges, and fittings shall be selected from those specifications that appear in 46 CFR...

  10. 46 CFR 58.30-15 - Pipe, tubing, valves, fittings, pumps, and motors.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., valves, flanges, and fittings shall be selected from those specifications that appear in 46 CFR 56.60-1, Table 56.60-1(a) or 46 CFR 56.60-2, Table 56.60-2(a); or they may be selected from the material... reference; see 46 CFR 58.03-1) if not prohibited by the section of this subchapter dealing with...

  11. 46 CFR 78.30-15 - Watchmen.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Watchmen. 78.30-15 Section 78.30-15 Shipping COAST GUARD..., Patrolmen, and Watchmen § 78.30-15 Watchmen. (a) The provisions of this section shall apply to all vessels... applicable at all times when passengers are on board. (b) During the nighttime, a suitable number of...

  12. 15 CFR 30.15 - Introduction.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Introduction. 30.15 Section 30.15 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FOREIGN TRADE REGULATIONS Export Control and Licensing Requirements §...

  13. 46 CFR 78.30-15 - Watchmen.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Watchmen. 78.30-15 Section 78.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Lookouts, Pilothouse Watch... duties while on watch. (d) The uniform of the night watchman shall be conspicuously different from...

  14. 46 CFR 78.30-15 - Watchmen.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Watchmen. 78.30-15 Section 78.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Lookouts, Pilothouse Watch... duties while on watch. (d) The uniform of the night watchman shall be conspicuously different from...

  15. 46 CFR 78.30-15 - Watchmen.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Watchmen. 78.30-15 Section 78.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Lookouts, Pilothouse Watch... duties while on watch. (d) The uniform of the night watchman shall be conspicuously different from...

  16. 46 CFR 78.30-15 - Watchmen.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Watchmen. 78.30-15 Section 78.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Lookouts, Pilothouse Watch... duties while on watch. (d) The uniform of the night watchman shall be conspicuously different from...

  17. 46 CFR 111.30-15 - Nameplates.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Nameplates. 111.30-15 Section 111.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL... function. (b) Each nameplate for a circuit breaker must show the electrical load served and the setting...

  18. 46 CFR 111.30-15 - Nameplates.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Nameplates. 111.30-15 Section 111.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL... function. (b) Each nameplate for a circuit breaker must show the electrical load served and the setting...

  19. 46 CFR 111.30-15 - Nameplates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Nameplates. 111.30-15 Section 111.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL... function. (b) Each nameplate for a circuit breaker must show the electrical load served and the setting...

  20. 46 CFR 111.30-15 - Nameplates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Nameplates. 111.30-15 Section 111.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL... function. (b) Each nameplate for a circuit breaker must show the electrical load served and the setting...

  1. 46 CFR 111.30-15 - Nameplates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Nameplates. 111.30-15 Section 111.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL... function. (b) Each nameplate for a circuit breaker must show the electrical load served and the setting...

  2. Yo-Yo Intermittent Endurance Test-Level 1 to monitor changes in aerobic fitness in pre-pubertal boys.

    PubMed

    Fernandes, Luís; Krustrup, Peter; Silva, Gustavo; Rebelo, Antonio; Oliveira, José; Brito, João

    2016-01-01

    The present study aimed to examine the performance and heart rate responses during the Yo-Yo Intermittent Endurance Test-Level 1 (Yo-Yo IE1) in children under the age of 10. One hundred and seven male children (7-9 years) performed the Yo-Yo IE1 at the beginning (M1), middle (M2) and end (M3) of the school year. Data from individual heart rate curves of the Yo-Yo IE1 were analysed in order to detect the inflection point between an initial phase of fast rise in heart rate values and a second phase in which the rise of the heart rate values is much smaller. The distance covered in the Yo-Yo IE1 improved from M1 to M3 (884 ± 496 vs. 1032 ± 596 m; p < 0.05; d = 0.27), with intermediate values for M2 (962 ± 528 m). Peak heart rate (HRpeak) decreased from M1 to M2 and M3 (204 ± 9, 202 ± 9 and 200 ± 9 bpm, respectively; p < 0.05; d = 0.25-0.42). The 7th shuttle of the test (280 m), corresponding to 2.5 min, was identified as the inflection point between the two phases. Also, absolute heart rate at the 7th shuttle decreased progressively throughout the year (185 ± 9, 183 ± 10, and 179 ± 10 bpm; p < 0.05; d = 0.31-0.61). The present study provides evidence of the usefulness of a maximal as well as a submaximal version of Yo-Yo IE1 as a tool to monitor changes in aerobic fitness in pre-pubertal children.

  3. Negative binomial fits to multiplicity distributions from central collisions of {sup 16}O + Cu at 14.6A GeV/c and intermittency

    SciTech Connect

    Tannenbaum, M.J.

    1994-10-14

    An `intermittency` analysis of charged particle multiplicity data from the target multiplicy array (TMA) in central collisions of {sup 16}O+Cu at 14.6 A{times}GeV/c has been published by the AGS-E802 collaboration. The centrality cut was made using the Zero degree Calorimeter and requiring that the forward energy be less than one projectile nucleon (i.e. T{sub ZCAL} <13.6 GeV). In agreement with previous measurements, an apparent power-law growth of Normalized Factorial moments with decreasing pseudorapidity interval was observed in the range 1.0{ge}{delta}{eta}{ge}0.1. In the present work, multiplicity distributions in individual pseudorapidity bins are presented for the same data. These distributions are excellently fit by Negative Binomial Distributions (NBD) in all {delta}{eta} bins, allowing, for the first time, a systematic formulation of the subject of `intermittency` in terms of distributions, rather than moments. In agreement with all previous measurements of NBD fits to multiplicity distributions in hadron and lepton reactions, the k parameter of the NBD fit for central {sup 16}O+Cu collisions is found to exhibit an apparently linear increase with the {delta}{eta} interval, albeit with a much steeper slope than for the other reactions, and a non-zero intercept, k(0){ne}0. True intermittency, {xi}{yields}0, would occur if the intercept k(0){yields}0, which is not observed in any experiment. The correlation length for central {sup 16}O+Cu collisions, although smaller than expected, is quite finite and can be measured - which means that a length scale exists in these collisions and therefore there is no intermittency in the multiplicity fluctuations.

  4. Fitness

    MedlinePlus

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  5. 46 CFR 50.30-15 - Class II pressure vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Class II pressure vessels. 50.30-15 Section 50.30-15... Fabrication Inspection § 50.30-15 Class II pressure vessels. (a) Class II pressure vessels shall be subject to... pressure vessels shall be performed during the welding of the longitudinal joint. At this time the...

  6. 46 CFR 50.30-15 - Class II pressure vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Class II pressure vessels. 50.30-15 Section 50.30-15... Fabrication Inspection § 50.30-15 Class II pressure vessels. (a) Class II pressure vessels shall be subject to... pressure vessels shall be performed during the welding of the longitudinal joint. At this time the...

  7. 46 CFR 50.30-15 - Class II pressure vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Class II pressure vessels. 50.30-15 Section 50.30-15... Fabrication Inspection § 50.30-15 Class II pressure vessels. (a) Class II pressure vessels shall be subject to... pressure vessels shall be performed during the welding of the longitudinal joint. At this time the...

  8. 46 CFR 50.30-15 - Class II pressure vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Class II pressure vessels. 50.30-15 Section 50.30-15... Fabrication Inspection § 50.30-15 Class II pressure vessels. (a) Class II pressure vessels shall be subject to... pressure vessels shall be performed during the welding of the longitudinal joint. At this time the...

  9. 46 CFR 50.30-15 - Class II pressure vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Class II pressure vessels. 50.30-15 Section 50.30-15... Fabrication Inspection § 50.30-15 Class II pressure vessels. (a) Class II pressure vessels shall be subject to... pressure vessels shall be performed during the welding of the longitudinal joint. At this time the...

  10. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Expanded or rolled joints. 56.30-15 Section 56.30-15... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-15 Expanded or rolled joints. (a) Expanded or rolled joints may be used where experience or test has demonstrated that the joint is suitable for...

  11. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Expanded or rolled joints. 56.30-15 Section 56.30-15... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-15 Expanded or rolled joints. (a) Expanded or rolled joints may be used where experience or test has demonstrated that the joint is suitable for...

  12. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Expanded or rolled joints. 56.30-15 Section 56.30-15... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-15 Expanded or rolled joints. (a) Expanded or rolled joints may be used where experience or test has demonstrated that the joint is suitable for...

  13. 46 CFR 61.30-15 - Visual inspection.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Visual inspection. 61.30-15 Section 61.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC TESTS AND INSPECTIONS Tests and Inspections of Fired Thermal Fluid Heaters § 61.30-15 Visual inspection. Thermal...

  14. 46 CFR 61.30-15 - Visual inspection.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Visual inspection. 61.30-15 Section 61.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC TESTS AND INSPECTIONS Tests and Inspections of Fired Thermal Fluid Heaters § 61.30-15 Visual inspection. Thermal...

  15. 46 CFR 77.30-15 - Spare charges.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Spare charges. 77.30-15 Section 77.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS VESSEL CONTROL AND MISCELLANEOUS SYSTEMS AND EQUIPMENT Emergency Equipment § 77.30-15 Spare charges. (a) A complete recharge shall be carried for each gas mask and...

  16. 46 CFR 76.30-15 - Operation and installation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Operation and installation. 76.30-15 Section 76.30-15... EQUIPMENT Pneumatic Fire Detecting System, Details § 76.30-15 Operation and installation. (a) The system... the center of the circuit. (d) The fire detecting system shall be used for no other purpose...

  17. 46 CFR 76.30-15 - Operation and installation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Operation and installation. 76.30-15 Section 76.30-15... EQUIPMENT Pneumatic Fire Detecting System, Details § 76.30-15 Operation and installation. (a) The system... the center of the circuit. (d) The fire detecting system shall be used for no other purpose...

  18. 46 CFR 76.30-15 - Operation and installation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Operation and installation. 76.30-15 Section 76.30-15... EQUIPMENT Pneumatic Fire Detecting System, Details § 76.30-15 Operation and installation. (a) The system... the center of the circuit. (d) The fire detecting system shall be used for no other purpose...

  19. 46 CFR 61.30-15 - Visual inspection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Visual inspection. 61.30-15 Section 61.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC TESTS AND... safe and satisfactory condition. The visual examination includes, but is not limited to, the...

  20. 46 CFR 61.30-15 - Visual inspection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Visual inspection. 61.30-15 Section 61.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC TESTS AND... safe and satisfactory condition. The visual examination includes, but is not limited to, the...

  1. 46 CFR 61.30-15 - Visual inspection.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Visual inspection. 61.30-15 Section 61.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC TESTS AND... safe and satisfactory condition. The visual examination includes, but is not limited to, the...

  2. 46 CFR 98.30-15 - Leakage containment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Leakage containment. 98.30-15 Section 98.30-15 Shipping... Leakage containment. (a) No person may transfer a product to or from a vessel unless there is a container... draining or removing any leakage without mixing incompatible products or discharging into the...

  3. 46 CFR 98.30-15 - Leakage containment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Leakage containment. 98.30-15 Section 98.30-15 Shipping... Leakage containment. (a) No person may transfer a product to or from a vessel unless there is a container... draining or removing any leakage without mixing incompatible products or discharging into the water....

  4. 46 CFR 98.30-15 - Leakage containment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Leakage containment. 98.30-15 Section 98.30-15 Shipping... Leakage containment. (a) No person may transfer a product to or from a vessel unless there is a container... draining or removing any leakage without mixing incompatible products or discharging into the water....

  5. 46 CFR 98.30-15 - Leakage containment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Leakage containment. 98.30-15 Section 98.30-15 Shipping... Leakage containment. (a) No person may transfer a product to or from a vessel unless there is a container... draining or removing any leakage without mixing incompatible products or discharging into the water....

  6. 40 CFR 30.15 - Metric system of measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Metric system of measurement. 30.15... EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Pre-Award Requirements § 30.15 Metric system of...), declares that the metric system is the preferred measurement system for U.S. trade and commerce. The...

  7. 10 CFR 30.15 - Certain items containing byproduct material.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Register citations affecting § 30.15, see the List of CFR Sections Affected, which appears in the Finding... microcuries of krypton-85; (v) 5 microcuries of cesium-137; (vi) 30 microcuries of promethium-147;...

  8. 10 CFR 30.15 - Certain items containing byproduct material.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Register citations affecting § 30.15, see the List of CFR Sections Affected, which appears in the Finding... microcuries of krypton-85; (v) 5 microcuries of cesium-137; (vi) 30 microcuries of promethium-147;...

  9. 46 CFR 76.30-15 - Operation and installation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... EQUIPMENT Pneumatic Fire Detecting System, Details § 76.30-15 Operation and installation. (a) The system..., there shall also be an audible alarm in the engine room. (b) The tubing or detecting devices,...

  10. 40 CFR 30.15 - Metric system of measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Metric system of measurement. 30.15... measurement. The Metric Conversion Act, as amended by the Omnibus Trade and Competitiveness Act (15 U.S.C. 205), declares that the metric system is the preferred measurement system for U.S. trade and commerce. The...

  11. 40 CFR 30.15 - Metric system of measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Metric system of measurement. 30.15... measurement. The Metric Conversion Act, as amended by the Omnibus Trade and Competitiveness Act (15 U.S.C. 205), declares that the metric system is the preferred measurement system for U.S. trade and commerce. The...

  12. 40 CFR 30.15 - Metric system of measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Metric system of measurement. 30.15... measurement. The Metric Conversion Act, as amended by the Omnibus Trade and Competitiveness Act (15 U.S.C. 205), declares that the metric system is the preferred measurement system for U.S. trade and commerce. The...

  13. Predicting intermittent running performance: critical velocity versus endurance index.

    PubMed

    Buchheit, M; Laursen, P B; Millet, G P; Pactat, F; Ahmaidi, S

    2008-04-01

    The aim of the present study was to examine the ability of the critical velocity (CV) and the endurance index (EI) to assess endurance performance during intermittent exercise. Thirteen subjects performed two intermittent runs: 15-s runs intersected with 15 s of passive recovery (15/15) and 30-s runs with 30-s rest (30/30). Runs were performed until exhaustion at three intensities (100, 95 and 90 % of the speed reached at the end of the 30 - 15 intermittent fitness test, V (IFT)) to calculate i) CV from the slope of the linear relationship between the total covered distance and exhaustion time (ET) (iCV); ii) anaerobic distance capacity from the Y-intercept of the distance/duration relationship (iADC); and iii) EI from the relationship between the fraction of V (IFT) at which the runs were performed and the log-transformed ET (iEI). Anaerobic capacity was indirectly assessed by the final velocity achieved during the Maximal Anaerobic Running Test (VMART). ET was longer for 15/15 than for 30/30 runs at similar intensities. iCV (15/15) and iCV (30/30) were not influenced by changes in ET and were highly dependent on V (IFT). Neither iADC (15/15) nor iADC (30/30) were related to VMART. In contrast, iEI (15/15) was higher than iEI (30/30), and corresponded with the higher ET. In conclusion, only iEI estimated endurance capacity during repeated intermittent running.

  14. 41 CFR 60-30.15 - Authority and responsibilities of Administrative Law Judges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 1 2012-07-01 2009-07-01 true Authority and responsibilities of Administrative Law Judges. 60-30.15 Section 60-30.15 Public Contracts and Property Management... EQUAL OPPORTUNITY UNDER EXECUTIVE ORDER 11246 Hearings and Related Matters § 60-30.15 Authority...

  15. 41 CFR 60-30.15 - Authority and responsibilities of Administrative Law Judges.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 1 2014-07-01 2014-07-01 false Authority and responsibilities of Administrative Law Judges. 60-30.15 Section 60-30.15 Public Contracts and Property Management... EQUAL OPPORTUNITY UNDER EXECUTIVE ORDER 11246 Hearings and Related Matters § 60-30.15 Authority...

  16. 41 CFR 60-30.15 - Authority and responsibilities of Administrative Law Judges.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Authority and responsibilities of Administrative Law Judges. 60-30.15 Section 60-30.15 Public Contracts and Property Management... EQUAL OPPORTUNITY UNDER EXECUTIVE ORDER 11246 Hearings and Related Matters § 60-30.15 Authority...

  17. 41 CFR 60-30.15 - Authority and responsibilities of Administrative Law Judges.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 1 2013-07-01 2013-07-01 false Authority and responsibilities of Administrative Law Judges. 60-30.15 Section 60-30.15 Public Contracts and Property Management... EQUAL OPPORTUNITY UNDER EXECUTIVE ORDER 11246 Hearings and Related Matters § 60-30.15 Authority...

  18. 41 CFR 60-30.15 - Authority and responsibilities of Administrative Law Judges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 1 2011-07-01 2009-07-01 true Authority and responsibilities of Administrative Law Judges. 60-30.15 Section 60-30.15 Public Contracts and Property Management... EQUAL OPPORTUNITY UNDER EXECUTIVE ORDER 11246 Hearings and Related Matters § 60-30.15 Authority...

  19. 46 CFR 25.30-15 - Fixed fire-extinguishing systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Fixed fire-extinguishing systems. 25.30-15 Section 25.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS Fire Extinguishing Equipment § 25.30-15 Fixed fire-extinguishing systems. (a) When a fixed fire-extinguishing...

  20. 46 CFR 25.30-15 - Fixed fire-extinguishing systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Fixed fire-extinguishing systems. 25.30-15 Section 25.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS Fire Extinguishing Equipment § 25.30-15 Fixed fire-extinguishing systems. (a) When a fixed fire-extinguishing...

  1. 46 CFR 25.30-15 - Fixed fire-extinguishing systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Fixed fire-extinguishing systems. 25.30-15 Section 25.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS Fire Extinguishing Equipment § 25.30-15 Fixed fire-extinguishing systems. When a fixed fire-extinguishing system...

  2. 46 CFR 25.30-15 - Fixed fire-extinguishing systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Fixed fire-extinguishing systems. 25.30-15 Section 25.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS Fire Extinguishing Equipment § 25.30-15 Fixed fire-extinguishing systems. When a fixed fire-extinguishing system...

  3. 46 CFR 25.30-15 - Fixed fire-extinguishing systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Fixed fire-extinguishing systems. 25.30-15 Section 25.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS Fire Extinguishing Equipment § 25.30-15 Fixed fire-extinguishing systems. When a fixed fire-extinguishing system...

  4. Small-sided games versus interval training in amateur soccer players: effects on the aerobic capacity and the ability to perform intermittent exercises with changes of direction.

    PubMed

    Dellal, Alexandre; Varliette, Christophe; Owen, Adam; Chirico, Erica N; Pialoux, Vincent

    2012-10-01

    The purpose of this study was to compare the effects of small-sided games (SSGs) in soccer versus high-intensity intermittent training (HIT) on a continuous aerobic test (Vameval) and the performance in an intermittent test with changes of direction (CODs; 30-15 intermittent fitness test [30-15(IFT)]). Twenty-two amateur soccer players (mean age ± SD: 26.3 ± 4.7 years) were assigned to 3 different groups for 6 weeks: SSG group (n = 8), HIT group (n = 8), and control group (CG; n = 6). In addition to the usual technical and tactical sessions and competitive games, the SSG group performed 9 sessions of 2 versus 2 and 1 versus 1 SSGs, whereas the HIT group performed 9 sessions of intermittent runs in the form of 30 seconds of effort interspersed with 30 seconds of passive recovery (30s-30s), 15s-15s, and 10s-10s. The HIT and SSG groups showed performance improvements in the Vameval test (5.1 and 6.6%, respectively) and the 30-15(IFT) intermittent test with CODs (5.1 and 5.8%, respectively), whereas there was no change in the performance of the CG. Players from HIT and SSG groups showed similar increase in their performance in the 30-15(IFT) and the Vameval tests during the 6-week training period, especially with an increase significantly different to that in a traditional training as in the CG (p < 0.05). This investigation demonstrates that both SSG and HIT interventions are equally effective in developing the aerobic capacity and the ability to perform intermittent exercises with CODs in male amateur soccer players. Furthermore, these 2 methods of training applied during the 6 weeks induce similar effect on the recovery capacity and on the ability to repeat directional changes of 180°. Coaches will now be able to choose between these two methods according to the objective of the training and to optimize the training. PMID:22130398

  5. 49 CFR 30.15 - Restrictions on Federal public works projects.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Restrictions on Federal public works projects. 30.15 Section 30.15 Transportation Office of the Secretary of Transportation DENIAL OF PUBLIC WORKS CONTRACTS TO SUPPLIERS OF GOODS AND SERVICES OF COUNTRIES THAT DENY PROCUREMENT MARKET ACCESS TO...

  6. 49 CFR 30.15 - Restrictions on Federal public works projects.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Restrictions on Federal public works projects. 30.15 Section 30.15 Transportation Office of the Secretary of Transportation DENIAL OF PUBLIC WORKS CONTRACTS TO SUPPLIERS OF GOODS AND SERVICES OF COUNTRIES THAT DENY PROCUREMENT MARKET ACCESS TO...

  7. 46 CFR 195.30-15 - 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. 195.30-15 Section... VESSELS VESSEL CONTROL AND MISCELLANEOUS SYSTEMS AND EQUIPMENT Protection From Refrigerants § 195.30-15 Self-contained breathing apparatus. (a) Each vessel must have a self-contained breathing apparatus...

  8. 46 CFR 96.30-15 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Self-contained breathing apparatus. 96.30-15 Section 96... VESSELS VESSEL CONTROL AND MISCELLANEOUS SYSTEMS AND EQUIPMENT Protection From Refrigerants § 96.30-15 Self-contained breathing apparatus. (a) Each vessel must have a self-contained breathing apparatus...

  9. 46 CFR 96.30-15 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Self-contained breathing apparatus. 96.30-15 Section 96... VESSELS VESSEL CONTROL AND MISCELLANEOUS SYSTEMS AND EQUIPMENT Protection From Refrigerants § 96.30-15 Self-contained breathing apparatus. (a) Each vessel must have a self-contained breathing apparatus...

  10. 46 CFR 195.30-15 - Self-contained breathing apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Self-contained breathing apparatus. 195.30-15 Section... VESSELS VESSEL CONTROL AND MISCELLANEOUS SYSTEMS AND EQUIPMENT Protection From Refrigerants § 195.30-15 Self-contained breathing apparatus. (a) Each vessel must have a self-contained breathing apparatus...

  11. 46 CFR 54.30-15 - Requirement for analysis and computation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Section 54.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Mechanical Stress Relief § 54.30-15 Requirement for analysis and computation. (a) A stress... mechanical stress relief process. This analysis should include consideration of the local stresses in way...

  12. 46 CFR 35.30-15 - Combustible gas indicator-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Combustible gas indicator-TB/ALL. 35.30-15 Section 35.30... § 35.30-15 Combustible gas indicator—TB/ALL. (a) The provisions of this section shall apply only to... combustible gas indicator suitable for determining the presence of explosive concentrations of the...

  13. 46 CFR 35.30-15 - Combustible gas indicator-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Combustible gas indicator-TB/ALL. 35.30-15 Section 35.30... § 35.30-15 Combustible gas indicator—TB/ALL. (a) The provisions of this section shall apply only to... combustible gas indicator suitable for determining the presence of explosive concentrations of the...

  14. Elastic wave turbulence and intermittency.

    PubMed

    Chibbaro, Sergio; Josserand, Christophe

    2016-07-01

    We investigate the onset of intermittency for vibrating elastic plate turbulence in the framework of the weak wave turbulence theory using a numerical approach. The spectrum of the displacement field and the structure functions of the fluctuations are computed for different forcing amplitudes. At low forcing, the spectrum predicted by the theory is observed, while the fluctuations are consistent with Gaussian statistics. When the forcing is increased, the spectrum varies at large scales, corresponding to the oscillations of nonlinear structures made of ridges delimited by d cones. In this regime, the fluctuations exhibit small-scale intermittency that can be fitted via a multifractal model. The analysis of the nonlinear frequency shows that the intermittency is linked to the breakdown of the weak turbulence at large scales only. PMID:27575068

  15. Elastic wave turbulence and intermittency

    NASA Astrophysics Data System (ADS)

    Chibbaro, Sergio; Josserand, Christophe

    2016-07-01

    We investigate the onset of intermittency for vibrating elastic plate turbulence in the framework of the weak wave turbulence theory using a numerical approach. The spectrum of the displacement field and the structure functions of the fluctuations are computed for different forcing amplitudes. At low forcing, the spectrum predicted by the theory is observed, while the fluctuations are consistent with Gaussian statistics. When the forcing is increased, the spectrum varies at large scales, corresponding to the oscillations of nonlinear structures made of ridges delimited by d cones. In this regime, the fluctuations exhibit small-scale intermittency that can be fitted via a multifractal model. The analysis of the nonlinear frequency shows that the intermittency is linked to the breakdown of the weak turbulence at large scales only.

  16. 17 CFR 200.30-15 - Delegation of authority to Chief Operating Officer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... principles and standards of the National Performance Review and the strategic and quality management... Management General Organization § 200.30-15 Delegation of authority to Chief Operating Officer. Under Pub....

  17. 17 CFR 200.30-15 - Delegation of authority to Chief Operating Officer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... principles and standards of the National Performance Review and the strategic and quality management... Management General Organization § 200.30-15 Delegation of authority to Chief Operating Officer. Under Pub....

  18. 46 CFR 54.30-15 - Requirement for analysis and computation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... during test shall not exceed 90 percent of the yield strength of the material at test temperature. The..., as well as strength to carry the excess weight of the tank during the stress relief procedure. ... Section 54.30-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE...

  19. 46 CFR 54.30-15 - Requirement for analysis and computation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... PRESSURE VESSELS Mechanical Stress Relief § 54.30-15 Requirement for analysis and computation. (a) A stress... mechanical stress relief process. This analysis should include consideration of the local stresses in way of saddles or other supporting structure and additional bending stresses due to the weight of...

  20. 46 CFR 54.30-15 - Requirement for analysis and computation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PRESSURE VESSELS Mechanical Stress Relief § 54.30-15 Requirement for analysis and computation. (a) A stress... mechanical stress relief process. This analysis should include consideration of the local stresses in way of saddles or other supporting structure and additional bending stresses due to the weight of...

  1. 46 CFR 54.30-15 - Requirement for analysis and computation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... PRESSURE VESSELS Mechanical Stress Relief § 54.30-15 Requirement for analysis and computation. (a) A stress... mechanical stress relief process. This analysis should include consideration of the local stresses in way of saddles or other supporting structure and additional bending stresses due to the weight of...

  2. Intermittent Control Systems

    ERIC Educational Resources Information Center

    Montgomery, Thomas L.; And Others

    1975-01-01

    The technique of intermittent control systems for air quality control as developed and used by the Tennessee Valley Authority is investigated. Although controversial, all Tennessee Valley Authority sulfur dioxide elimination programs are scheduled to be operational this year. Existing or anticipated intermittent control systems are identified. (BT)

  3. Intermittent search strategies

    NASA Astrophysics Data System (ADS)

    Bénichou, Olivier; Voituriez, Raphael

    2015-10-01

    The following sections are included: * Introduction * Animals looking for food * Model of intermittent search * Minimizing the search time * Should animals really perform Lévy strategies? * How does a protein find its target sequence on DNA? * Active intermittent transport in cells * Optimizing the kinetic rate constant * Robustness of the results * Conclusion * Bibliography

  4. A narrow view of the broad iron line in MCG --6-30-15

    NASA Astrophysics Data System (ADS)

    Young, A. J.; Lee, J. C.; Reynolds, C. S.; Fabian, A. C.; Gibson, R.; Canizares, C. R.

    2004-12-01

    We present the deepest Chandra High Energy Transmission Grating Spectrometer observation of the Seyfert 1 galaxy MCG --6-30-15 to date. Concentrating on the hard X-ray band we note the continued presence of the relativistically broadened iron Kα fluorescence line, and discuss the various narrow emission and absorption features in this band. In particular, we find narrow, weak H- and He-like iron absorption lines, but no evidence of K-shell absorption lines from less highly ionized iron, supporting the relativistic disk line interpretation of the broad iron line. This work is supported by NASA contract NAS8-01129.

  5. Evaluating Light Source Color Rendition using the IES TM-30-15 Method

    SciTech Connect

    Houser, Kevin W.; Royer, Michael P.; David, Aurelien

    2015-11-30

    A system for evaluating the color rendition of light sources was recently published as IES TM-30-15 IES Method for Evaluating Light Source Color Rendition. The system includes a fidelity index (Rf) to quantify similarity to a reference illuminant, a relative-gamut index (Rg) to quantify saturation relative to a reference illuminant, and a color vector icon that visually presents information about color rendition. The calculation employs CAM02-UCS and uses a newly-developed set of reflectance functions, comprising 99 color evaluation samples (CES). The CES were down-selected from 105,000 real object samples and are uniformly distributed in color space (fairly representing different colors) and wavelength space (avoiding artificial increase of color rendition values by selective optimization).

  6. Intermittent facial swelling

    PubMed Central

    Pope, Charlie; Gopala Pillai, Suresh Kumar

    2014-01-01

    Intermittent facial swelling is an unusual presentation in the emergency department. The differential diagnosis may range from a variety of causes. Most common differential diagnosis is angio-oedema. However, more serious presentations such as superior venacaval obstruction must not be ignored. This case report presents a patient who was investigated in the hospital for 2 weeks (2 admissions) with intermittent facial swelling. He presented to the emergency department (3rd admission) and was diagnosed to have superior venacaval obstruction secondary to metastatic bronchogenic carcinoma. He underwent emergency endovascular stenting; however, he died within a few weeks. PMID:25326556

  7. A Reverberation-based Black Hole Mass for MCG-06-30-15

    NASA Astrophysics Data System (ADS)

    Bentz, Misty C.; Cackett, Edward M.; Crenshaw, D. Michael; Horne, Keith; Street, Rachel; Ou-Yang, Benjamin

    2016-10-01

    We present the results of a reverberation campaign targeting MGC-06-30-15. Spectrophotometric monitoring and broad-band photometric monitoring over the course of four months in spring 2012 allowed a determination of a time delay in the broad Hβ emission line of τ = 5.3 ± 1.8 days in the rest frame of the active galactic nucleus (AGN). Combined with the width of the variable portion of the emission line, we determine a black hole mass of M BH = (1.6 ± 0.4) × 106 M ⊙. Both the Hβ time delay and the black hole mass are in good agreement with expectations from the R BLR–L and M BH–σ ⋆ relationships for other reverberation-mapped AGNs. The Hβ time delay is also in good agreement with the relationship between Hβ and broad-band near-IR delays, in which the effective size of the broad-line region is ∼4–5 times smaller than the inner edge of the dust torus. Additionally, the reverberation-based mass is in good agreement with estimates from the scaling relationship of the break in the X-ray power spectral density, and with constraints based on stellar kinematics derived from integral field spectroscopy of the inner ∼0.5 kpc of the galaxy.

  8. [Acute intermittent porphyria].

    PubMed

    Catania, A; Caimi, G

    1983-11-10

    Acute intermittent porphyria (AIP) is a congenital disease which as its name suggests, runs intermittently. Biochemically it is characterised by over-production of hepatic ALA synthetase (ALA-s), inducible mitochondrial enzyme and an increase in prophyrinic precursors (PBG, ac S-ALA). Clinically it is characterised by an abdominal nervous symptomatology. The primary metabolic error has been identified as a deficiency in enzyme activity which partially blocks haem biosynthesis. During the appearance of clinical manifestations, certain factors are present which have the capacity of inducing hepatic ALA-s production in vitro. Apart from some preventive measures treatment is mainly of symptomatology and complications. More recently the use of ALA-s inhibitors has been introduced. PMID:6657112

  9. 31 CFR 30.15 - Q-15: What actions are necessary for a TARP recipient to comply with certification requirements...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... COMPENSATION AND CORPORATE GOVERNANCE § 30.15 Q-15: What actions are necessary for a TARP recipient to comply... S-K under the Federal securities laws (17 CFR 229.601(b)(99)(i)) to the TARP recipient's annual... to Treasury pursuant to the Interim Final Rule or as required pursuant to 31 CFR Part 30 may...

  10. Intermittent hypoxia and neurorehabilitation.

    PubMed

    Gonzalez-Rothi, Elisa J; Lee, Kun-Ze; Dale, Erica A; Reier, Paul J; Mitchell, Gordon S; Fuller, David D

    2015-12-15

    In recent years, it has become clear that brief, repeated presentations of hypoxia [i.e., acute intermittent hypoxia (AIH)] can boost the efficacy of more traditional therapeutic strategies in certain cases of neurologic dysfunction. This hypothesis derives from a series of studies in animal models and human subjects performed over the past 35 yr. In 1980, Millhorn et al. (Millhorn DE, Eldridge FL, Waldrop TG. Respir Physiol 41: 87-103, 1980) showed that electrical stimulation of carotid chemoafferent neurons produced a persistent, serotonin-dependent increase in phrenic motor output that outlasts the stimulus for more than 90 min (i.e., a "respiratory memory"). AIH elicits similar phrenic "long-term facilitation" (LTF) by a mechanism that requires cervical spinal serotonin receptor activation and de novo protein synthesis. From 2003 to present, a series of studies demonstrated that AIH can induce neuroplasticity in the injured spinal cord, causing functional recovery of breathing capacity after cervical spinal injury. Subsequently, it was demonstrated that repeated AIH (rAIH) can induce recovery of limb function, and the functional benefits of rAIH are greatest when paired with task-specific training. Since uncontrolled and/or prolonged intermittent hypoxia can elicit pathophysiology, a challenge of intermittent hypoxia research is to ensure that therapeutic protocols are well below the threshold for pathogenesis. This is possible since many low dose rAIH protocols have induced functional benefits without evidence of pathology. We propose that carefully controlled rAIH is a safe and noninvasive modality that can be paired with other neurorehabilitative strategies including traditional activity-based physical therapy or cell-based therapies such as intraspinal transplantation of neural progenitors. PMID:25997947

  11. Clean intermittent catheterization revisited.

    PubMed

    Lamin, Eliza; Newman, Diane K

    2016-06-01

    Catheterization is the insertion of a hollow flexible tube (called a catheter) to drain the urine from the bladder and is probably one of the oldest urologic procedures, dating back 3000 years. Since 1972, when urologist Dr Jack Lapides described a procedure for performing clean intermittent catheterization, this method of bladder management has become lifesaving for an individual who cannot empty their bladder independently. If the bladder is not emptied regularly, elevated storage pressures can develop which may put the upper tracts at risk of subsequent deterioration. Intermittent catheterization (IC) has become the first-line and preferred method of drainage in patients with neurogenic lower urinary tract dysfunction, as long as dexterity or available caregiver support and body habitus allow access. However, over the past 20 years, an evolution has occurred in the technology of catheters used for IC. But with these advances, so has controversy arisen. This article is a review of the current application of IC, the current technology in catheter material and systems, differences between reusable and one-time, or single-use catheters, the cost benefit of doing IC, and the infectious benefit.

  12. Comment on "Intermittent plate tectonics?".

    PubMed

    Korenaga, Jun

    2008-06-01

    Silver and Behn (Reports, 4 January 2008, p. 85) proposed that intermittent plate tectonics may resolve a long-standing paradox in Earth's thermal evolution. However, their analysis misses one important term, which subsequently brings their main conclusion into question. In addition, the Phanerozoic eustasy record indicates that the claimed effect of intermittency is probably weak.

  13. Modeling Wind Erosion Intermittency

    NASA Astrophysics Data System (ADS)

    Dupont, S.

    2015-12-01

    To improve dust emission schemes in large scale transport models, we developed the first physically-based model simulating the full erosion process in a turbulent flow by resolving explicitly saltating particle trajectories and dust suspension, in presence of vegetation. The large-eddy simulation technic is used here to simulate the turbulent flow, allowing to solve explicitly the main wind gusts near the surface and so the intermittency of the erosion process. The model appeared able to reproduce the saltation intermittency as visualized through the presence of blowing sand structures near the surface, known as aeolian streamers observed on beaches during windy days. In presence of vegetation, the model further allowed us to investigate the sensitivity of sand erosion to the arrangement and morphology of plants (shrubs versus trees). More recently, we further used the model to reanalyze the dependence of the size distribution of the dust flux to the wind speed for idealized erosion events starting from an air free of dust. We found that the suspension of small dust (around 1 μm) can be a long nonstationary process (several hours depending on the wind intensity) due to the low deposition velocity of this particle size range. This leads to a continuous enrichment of the near-surface dust flux in small particles, enrichment that is enhanced with wind intensity, independently of the possible role of saltators. The model also showed that the size distribution and magnitude of dust fluxes at a few meters height differ from those of the emitted flux at the surface as particles start to be sorted through the deposition process within the saltation layer. This last result should be considered when evaluating or calibrating "physically based" dust emission schemes against measured near-surface turbulent diffusive dust fluxes.

  14. Soft X-Ray Emission Lines from a Relativistic Accretion Disk in MCG -6-30-15 and Mrk 766

    NASA Technical Reports Server (NTRS)

    Branduardi-Raymont, G.; Sako, M.; Kahn, S. M.; Brinkman, A. C.; Kaastra, J. S.; Page, M. J.

    2000-01-01

    XMM-Newton Reflection Grating Spectrometer (RGS) spectra of the Narrow Line Seyfert 1 galaxies MCG -6-30-15 and Mrk 766 are physically and spectroscopically inconsistent with standard models comprising a power-law continuum absorbed by either cold or ionized matter. We propose that the remarkably similar features detected in both objects in the 5 - 35 A band are H-like oxygen, nitrogen, and carbon emission lines, gravitation- ally redshifted and broadened by relativistic effects in the vicinity of a Kerr black hole. We discuss the implications of our interpretation, and demonstrate that the derived parameters can be physically self-consistent.

  15. Fringe Fitting

    NASA Astrophysics Data System (ADS)

    Cotton, W. D.

    Fringe Fitting Theory; Correlator Model Delay Errors; Fringe Fitting Techniques; Baseline; Baseline with Closure Constraints; Global; Solution Interval; Calibration Sources; Source Structure; Phase Referencing; Multi-band Data; Phase-Cals; Multi- vs. Single-band Delay; Sidebands; Filtering; Establishing a Common Reference Antenna; Smoothing and Interpolating Solutions; Bandwidth Synthesis; Weights; Polarization; Fringe Fitting Practice; Phase Slopes in Time and Frequency; Phase-Cals; Sidebands; Delay and Rate Fits; Signal-to-Noise Ratios; Delay and Rate Windows; Details of Global Fringe Fitting; Multi- and Single-band Delays; Phase-Cal Errors; Calibrator Sources; Solution Interval; Weights; Source Model; Suggested Procedure; Bandwidth Synthesis

  16. Influence of intermittency on the anisotropy of magnetic structure functions of solar wind turbulence

    NASA Astrophysics Data System (ADS)

    Pei, Zhongtian; He, Jiansen; Wang, Xin; Tu, Chuanyi; Marsch, Eckart; Wang, Linghua; Yan, Limei

    2016-02-01

    Intermittency appears to be connected with the spectral anisotropy of solar wind turbulence. We use the Local Intermittency Measure to identify and remove intermittency from the magnetic field data measured by the Ulysses spacecraft in fast solar wind. Structure functions are calculated based on the time sequences as obtained before and after removing intermittency and arranged by time scale (τ) and ΘRB (the angle between local mean magnetic field B0 and radial direction R). Thus, the scaling exponent (ξ(p, ΘRB)) of every structure function of order (p) is obtained for different angles. Before removing intermittency, ξ(p, ΘRB) shows a distinctive dependence on ΘRB: from monofractal scaling law at ΘRB ~0° to multifractal scaling law at ΘRB ~90°. In contrast after eliminating the intermittency, ξ(p, ΘRB) is found to be more monofractal for all ΘRB. The extended structure-function model is applied to ξ(p, ΘRB), revealing differences of its fitting parameters α (a proxy of the power spectral index) and P1 (fragmentation fraction) for the cases with and without intermittency. Parameter α shows an evident angular trend falling from 1.9 to 1.6 for the case with intermittency but has a relatively flat profile around 1.8 for the case without intermittency. Parameter P1 rises from around 0.5 to above 0.8 with increasing ΘRB for the intermittency case and is located between 0.5 and 0.8 for the case lacking intermittency. Therefore, we may infer that it is the anisotropy of intermittency that causes the scaling anisotropy of energy spectra and the unequal fragmentation of energy cascading.

  17. Challenging Oneself Intermittently to Improve Health

    PubMed Central

    Mattson, Mark P.

    2014-01-01

    Humans and their predecessors evolved in environments where they were challenged intermittently with: 1) food scarcity; 2) the need for aerobic fitness to catch/kill prey and avoid or repel attackers; and 3) exposure to biological toxins present in foodstuffs. Accordingly, cells and organ systems acquired and retained molecular signaling and metabolic pathways through which the environmental challenges enhanced the functionality and resilience of the cells and organisms. Within the past 60 years there has been a precipitous diminution of such challenges in modern societies because of the development of technologies that provide a continuous supply of energy-dense processed foods and that largely eliminate the need for physical exertion. As a consequence of the modern ‘couch potato’ lifestyle, signaling pathways that mediate beneficial effects of environmental challenges on health and disease resistance are disengaged, thereby rendering people vulnerable to obesity, diabetes, cardiovascular disease, cancers and neurodegenerative disorders. Reversal of the epidemic of diseases caused by unchallenging lifestyles will require a society-wide effort to re-introduce intermittent fasting, exercise and consumption of plants containing hormetic phytochemicals into daily and weekly routines. PMID:25552960

  18. Challenging oneself intermittently to improve health.

    PubMed

    Mattson, Mark P

    2014-12-01

    Humans and their predecessors evolved in environments where they were challenged intermittently with: 1) food scarcity; 2) the need for aerobic fitness to catch/kill prey and avoid or repel attackers; and 3) exposure to biological toxins present in foodstuffs. Accordingly, cells and organ systems acquired and retained molecular signaling and metabolic pathways through which the environmental challenges enhanced the functionality and resilience of the cells and organisms. Within the past 60 years there has been a precipitous diminution of such challenges in modern societies because of the development of technologies that provide a continuous supply of energy-dense processed foods and that largely eliminate the need for physical exertion. As a consequence of the modern 'couch potato' lifestyle, signaling pathways that mediate beneficial effects of environmental challenges on health and disease resistance are disengaged, thereby rendering people vulnerable to obesity, diabetes, cardiovascular disease, cancers and neurodegenerative disorders. Reversal of the epidemic of diseases caused by unchallenging lifestyles will require a society-wide effort to re-introduce intermittent fasting, exercise and consumption of plants containing hormetic phytochemicals into daily and weekly routines. PMID:25552960

  19. Scale Dependence of Spatiotemporal Intermittence of Rain

    NASA Technical Reports Server (NTRS)

    Kundu, Prasun K.; Siddani, Ravi K.

    2011-01-01

    It is a common experience that rainfall is intermittent in space and time. This is reflected by the fact that the statistics of area- and/or time-averaged rain rate is described by a mixed distribution with a nonzero probability of having a sharp value zero. In this paper we have explored the dependence of the probability of zero rain on the averaging space and time scales in large multiyear data sets based on radar and rain gauge observations. A stretched exponential fannula fits the observed scale dependence of the zero-rain probability. The proposed formula makes it apparent that the space-time support of the rain field is not quite a set of measure zero as is sometimes supposed. We also give an ex.planation of the observed behavior in tenus of a simple probabilistic model based on the premise that rainfall process has an intrinsic memory.

  20. ASCA observations of the warm absorber in MCG-6-30-15: The discovery of a change in column density

    NASA Technical Reports Server (NTRS)

    Fabian, Andrew C.; Kunieda, Hideyo; Inoue, Shigeru; Matsuoka, Masaru; Mihara, Tatehiro; Miyamoto, Sigenori; Otani, Chiko; Ricker, George; Tanaka, Yasuo; Yamauchi, Makoto

    1994-01-01

    We report the first X-ray observations of the Seyfert 1 galaxy MCG-6-30-15 obtained at medium spectral resolution. The partially-ionized, 'warm' absorber is resolved and shown to be due to O VII and O VIII. The main absorption edge agrees with that of O VII at the redshift of the galaxy to within 1%. The column density of the absorbing material is greater by a factor of 2 in the first of our two obsevations, which were 3 weeks apart, while the mean flux is slightly lower and the ionization parameter slightly higher. We also discuss the flourescent iron emssion line seen in the source, which is at 6.40 keV. The line is significantly broadened, with a Full Width at Half Maximum (FWHM) of about 0.4 keV.

  1. Intermittent Plate Tectonics

    NASA Astrophysics Data System (ADS)

    Silver, P. G.; Behn, M. D.

    2006-12-01

    Intermittent Plate Tectonics A basic premise of Earth Science is that plate tectonics has been continuously operating since it began early in Earth's history. Yet, plate-tectonic theory itself, specifically the collisional phase of the Wilson Cycle, constitutes a process that is capable of stopping all plate motion. The plausibility of a plate-tectonic hiatus is most easily illustrated by considering the expected future of the present-day plate-tectonic configuration. Since the opening of the Atlantic at ~200 ma, the area of the Atlantic basin has been growing at the expense of the Pacific. If this trend continues, relative plate motion models predict that in ~350 my, the Pacific Ocean basin will effectively close leading to widespread continent-continent collisions. Since a continent-continent collision represents the termination of subduction locally, the accumulated effect of all collisions is to stop subduction globally. In this scenario, ridges would then stop spreading and young oceanic lithosphere would cool, reaching a steady-state thickness of 100 km in about 80 my, based on the properties of oceanic lithosphere today. This would constitute the stoppage of plate tectonics. The presumption that plate tectonics never stops in the face of continental collisions is equivalent to requiring that subduction flux is approximately constant through time, such that subduction initiation roughly balances subduction termination. Such a balance then raises several questions about the subduction initiation process. When and how does subduction initiate? Is there a detectible relationship between subduction cessation and subduction initiation? We can gain some guidance into these questions by examining the plate motion history over the last 200 my. Subduction initiation has occurred over the last 80 my in three intra- oceanic subduction zones: Aleutians, Marianas-Izu-Bonin and Tonga-Kermadec in the Pacific basin. In these cases, however, subduction initiation would not

  2. Intermittency in dilute granular flows

    NASA Astrophysics Data System (ADS)

    Guo, Wenxuan; Zhang, Qiang; Wylie, Jonathan J.

    2016-07-01

    In this letter, we show that dilute granular systems can exhibit a type of intermittency that has no analogue in gas dynamics. We consider a simple system in which a very dilute set of granular particles falls under gravity through a nozzle. This setting is analogous to the classical problem of high-speed nozzle flow in the study of compressible gases. It is well known that very dilute granular systems exhibit behavior qualitatively similar to gases, and that gas flowing through a nozzle does not exhibit intermittency. Nevertheless, we show that the intermittency in dilute granular nozzle flows can occur and corresponds to complicated transitions between supersonic and subsonic regimes. We also provide detailed explanations of the mechanism underlying this phenomenon.

  3. Intermittent control of coexisting attractors.

    PubMed

    Liu, Yang; Wiercigroch, Marian; Ing, James; Pavlovskaia, Ekaterina

    2013-06-28

    This paper proposes a new control method applicable for a class of non-autonomous dynamical systems that naturally exhibit coexisting attractors. The central idea is based on knowledge of a system's basins of attraction, with control actions being applied intermittently in the time domain when the actual trajectory satisfies a proximity constraint with regards to the desired trajectory. This intermittent control uses an impulsive force to perturb one of the system attractors in order to switch the system response onto another attractor. This is carried out by bringing the perturbed state into the desired basin of attraction. The method has been applied to control both smooth and non-smooth systems, with the Duffing and impact oscillators used as examples. The strength of the intermittent control force is also considered, and a constrained intermittent control law is introduced to investigate the effect of limited control force on the efficiency of the controller. It is shown that increasing the duration of the control action and/or the number of control actuations allows one to successfully switch between the stable attractors using a lower control force. Numerical and experimental results are presented to demonstrate the effectiveness of the proposed method. PMID:23690639

  4. The evolution of intermittent breeding.

    PubMed

    Shaw, Allison K; Levin, Simon A

    2013-03-01

    A central issue in life history theory is how organisms trade off current and future reproduction. A variety of organisms exhibit intermittent breeding, meaning sexually mature adults will skip breeding opportunities between reproduction attempts. It's thought that intermittent breeding occurs when reproduction incurs an extra cost in terms of survival, energy, or recovery time. We have developed a matrix population model for intermittent breeding, and use adaptive dynamics to determine under what conditions individuals should breed at every opportunity, and under what conditions they should skip some breeding opportunities (and if so, how many). We also examine the effect of environmental stochasticity on breeding behavior. We find that the evolutionarily stable strategy (ESS) for breeding behavior depends on an individual's expected growth and mortality, and that the conditions for skipped breeding depend on the type of reproductive cost incurred (survival, energy, recovery time). In constant environments there is always a pure ESS, however environmental stochasticity and deterministic population fluctuations can both select for a mixed ESS. Finally, we compare our model results to patterns of intermittent breeding in species from a range of taxonomic groups.

  5. Vascular effects of intermittent hypoxia.

    PubMed

    Kanagy, Nancy L

    2009-01-01

    Obstructive sleep apnea is characterized by repeated upper airway obstruction during sleep and affects between 5% and 20% of the population. Epidemiological studies reveal that sleep apnea and associated intermittent hypoxemia increase the risk for hypertension and vascular disease but the mechanisms underlying these effects are incompletely understood. This review reports the results of rodent models of intermittent hypoxia (IH) and relates them to the observed hemodynamic and vascular consequences of sleep apnea. These animal studies have demonstrated that IH exposure in the absence of any other comorbidity causes hypertension, endothelial dysfunction, and augmented constrictor sensitivity, all due at least in part to increased vascular oxidative stress. Animal studies have used a variety of exposure paradigms to study intermittent hypoxia and these different exposure protocols can cause hypocapnia or hypercapnia-or maintain eucapnia-with accompanying alterations in plasma pH. It appears that these different profiles of arterial blood gases can lead to divergent results but the impact of these differences is still being investigated. Overall, the studies in rodents have clearly demonstrated that the vascular and hemodynamic impact of intermittent hypoxia provides a strong rationale for treating clinical sleep apnea to prevent the resulting cardiovascular morbidity and mortality.

  6. Aerobic Fitness for Young Athletes: Combining Game-based and High-intensity Interval Training.

    PubMed

    Harrison, C B; Kinugasa, T; Gill, N; Kilding, A E

    2015-11-01

    This study compared the effect of game-based training (GT) vs. a mix of game-based training and high-intensity interval training (MT) on physical performance characteristics. 26 young athletes (13.9±0.3 years) were assigned to either GT (n=13) or MT (n=13) for 6 weeks. Game-based training consisted of 2×8-11 min 3 vs. 3 'bucketball' SSGs separated by 3 min of passive rest twice per week, while MT consisted of one SSGs session and one high-intensity session of 15 s runs at 90-95% of the speed reached at the end of the 30-15 intermittent fitness test (VIFT) interspersed with 15 s passive recovery. Peak oxygen uptake (V˙ O2peak), VIFT, jump height, and speed were assessed pre- and post-training. Following training, V˙ O2peak (5.5±3.3%; ES=large) improved after MT, whereas VIFT improved after MT (6.6±3.2%; ES, large) and GT (4.2±5.5%, ES=small). 5-m sprint improved after GT (ES=small), while 20 m sprint and jump height were unchanged. In conclusion, while MT and GT were both effective at increasing performance parameters, greater effects were seen following MT. Therefore, MT should be considered as the preferred training method for improving aerobic power in young athletes.

  7. 5 CFR 340.403 - Intermittent employment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 340.403 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS OTHER THAN FULL-TIME CAREER EMPLOYMENT (PART-TIME, SEASONAL, ON-CALL, AND INTERMITTENT) Seasonal and intermittent... has an obligation to document the change in work schedule from intermittent to part-time or...

  8. 5 CFR 340.403 - Intermittent employment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 340.403 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS OTHER THAN FULL-TIME CAREER EMPLOYMENT (PART-TIME, SEASONAL, ON-CALL, AND INTERMITTENT) Seasonal and intermittent... has an obligation to document the change in work schedule from intermittent to part-time or...

  9. 5 CFR 340.403 - Intermittent employment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 340.403 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS OTHER THAN FULL-TIME CAREER EMPLOYMENT (PART-TIME, SEASONAL, ON-CALL, AND INTERMITTENT) Seasonal and intermittent... has an obligation to document the change in work schedule from intermittent to part-time or...

  10. 5 CFR 340.403 - Intermittent employment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 340.403 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS OTHER THAN FULL-TIME CAREER EMPLOYMENT (PART-TIME, SEASONAL, ON-CALL, AND INTERMITTENT) Seasonal and intermittent... has an obligation to document the change in work schedule from intermittent to part-time or...

  11. 5 CFR 340.403 - Intermittent employment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 340.403 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS OTHER THAN FULL-TIME CAREER EMPLOYMENT (PART-TIME, SEASONAL, ON-CALL, AND INTERMITTENT) Seasonal and intermittent... has an obligation to document the change in work schedule from intermittent to part-time or...

  12. The broadband spectral variability of MCG–6-30-15 observed by nuSTAR and XMM-Newton

    SciTech Connect

    Marinucci, A.; Matt, G.; Miniutti, G.; Guainazzi, M.; Parker, M. L.; Fabian, A. C.; Kara, E.; Brenneman, L.; Elvis, M.; Risaliti, G.; Arevalo, P.; Ballantyne, D. R.; Boggs, S. E.; Cappi, M.; Christensen, F. E.; Craig, W. W.; Hailey, C. J.; Harrison, F. A.; Reynolds, C. S.; Stern, D. K.; and others

    2014-05-20

    MCG–6-30-15, at a distance of 37 Mpc (z = 0.008), is the archetypical Seyfert 1 galaxy showing very broad Fe Kα emission. We present results from a joint NuSTAR and XMM-Newton observational campaign that, for the first time, allows a sensitive, time-resolved spectral analysis from 0.35 keV up to 80 keV. The strong variability of the source is best explained in terms of intrinsic X-ray flux variations and in the context of the light-bending model: the primary, variable emission is reprocessed by the accretion disk, which produces secondary, less variable, reflected emission. The broad Fe Kα profile is, as usual for this source, well explained by relativistic effects occurring in the innermost regions of the accretion disk around a rapidly rotating black hole. We also discuss the alternative model in which the broadening of the Fe Kα is due to the complex nature of the circumnuclear absorbing structure. Even if this model cannot be ruled out, it is disfavored on statistical grounds. We also detected an occultation event likely caused by broad-line region clouds crossing the line of sight.

  13. Intermittent search process and teleportation.

    PubMed

    Bénichou, O; Moreau, M; Suet, P-H; Voituriez, R

    2007-06-21

    The authors study an intermittent search process combining diffusion and "teleportation" phases in a d-dimensional spherical continuous system and in a regular lattice. The searcher alternates diffusive phases, during which targets can be discovered, and fast phases (teleportation) which randomly relocate the searcher, but do not allow for target detection. The authors show that this alternation can be favorable for minimizing the time of first discovery, and that this time can be optimized by a convenient choice of the mean waiting times of each motion phase. The optimal search strategy is explicitly derived in the continuous case and in the lattice case. Arguments are given to show that much more general intermittent motions do provide optimal search strategies in d dimensions. These results can be useful in the context of heterogeneous catalysis or in various biological examples of transport through membrane pores.

  14. Cognitive fitness.

    PubMed

    Gilkey, Roderick; Kilts, Clint

    2007-11-01

    Recent neuroscientific research shows that the health of your brain isn't, as experts once thought, just the product of childhood experiences and genetics; it reflects your adult choices and experiences as well. Professors Gilkey and Kilts of Emory University's medical and business schools explain how you can strengthen your brain's anatomy, neural networks, and cognitive abilities, and prevent functions such as memory from deteriorating as you age. The brain's alertness is the result of what the authors call cognitive fitness -a state of optimized ability to reason, remember, learn, plan, and adapt. Certain attitudes, lifestyle choices, and exercises enhance cognitive fitness. Mental workouts are the key. Brain-imaging studies indicate that acquiring expertise in areas as diverse as playing a cello, juggling, speaking a foreign language, and driving a taxicab expands your neural systems and makes them more communicative. In other words, you can alter the physical makeup of your brain by learning new skills. The more cognitively fit you are, the better equipped you are to make decisions, solve problems, and deal with stress and change. Cognitive fitness will help you be more open to new ideas and alternative perspectives. It will give you the capacity to change your behavior and realize your goals. You can delay senescence for years and even enjoy a second career. Drawing from the rapidly expanding body of neuroscience research as well as from well-established research in psychology and other mental health fields, the authors have identified four steps you can take to become cognitively fit: understand how experience makes the brain grow, work hard at play, search for patterns, and seek novelty and innovation. Together these steps capture some of the key opportunities for maintaining an engaged, creative brain. PMID:18159786

  15. On-off intermittency in earthquake occurrence

    SciTech Connect

    Bottiglieri, M.; Godano, C.

    2007-02-15

    The clustered occurrence of earthquakes is viewed as an intermittent phenomenon, interpreting the clusters of events as chaotic bursts combined to the Poissonian occurrence of background seismicity. In particular, we suggest that it can be interpreted as an example of on-off intermittency. This kind of intermittency is parameter driven and exhibits certain universal statistical properties. The study of a Californian catalogue allows to interpret earthquake occurrence as an on-off intermittent phenomenon. Our results suggest the existence of a branching mechanism in earthquake occurrence well explained by epidemic type models.

  16. Physiological effects of intermittent hypoxia.

    PubMed

    Powell, F L; Garcia, N

    2000-01-01

    Intermittent hypoxia (IH), or periodic exposure to hypoxia interrupted by return to normoxia or less hypoxic conditions, occurs in many circumstances. In high altitude mountaineering, IH is used to optimize acclimatization although laboratory studies have not generally revealed physiologically significant benefits. IH enhances athletic performance at sea level if blood oxygen capacity increases and the usual level of training is not decreased significantly. IH for high altitude workers who commute from low altitude homes is of considerable practical interest and the ideal commuting schedule for physical and mental performance is being studied. The effect of oxygen enrichment at altitude (i.e., intermittent normoxia on a background of chronic hypoxia) on human performance is under study also. Physiological mechanisms of IH, and specifically the differences between effects of IH and acute or chronic continuous hypoxia remains to be determined. Biomedical researchers are defining the molecular and cellular mechanisms for effects of hypoxia on the body in health and disease. A comparative approach may provide additional insight about the biological significance of these effects.

  17. Specificity of high-intensity intermittent action remains important to MMA athletes' physical conditioning: response to Paillard (2011).

    PubMed

    Del Vecchio, Fabrício Boscolo; Franchini, Emerson

    2013-02-01

    This response to Paillard (2011) focuses on the intermittent nature of mixed martial arts (MMA). It also emphasizes that the main goal of MMA athletes is to win by knockout or submission and that these actions normally are high-intensity actions or preceded by high-intensity actions. Additionally, there is evidence that high-intensity intermittent exercise protocols are able to improve aerobic fitness. It is important only to adjust physical training to the athletes' techniques and tactics. PMID:23829149

  18. COHO SALMON DEPENDENCE ON INTERMITTENT STREAMS

    EPA Science Inventory

    In February 2006, the US Supreme Court heard cases that may affect whether intermittent streams are jurisdictional waters under the Clean Water Act. In June 2006, however, the cases were remanded to the circuit court, leaving the status of intermittent streams uncertain once agai...

  19. Research Report: Intermittent hypobaric hypoxia and hyperbaric oxygen on GAP-43 in the rat carotid body.

    PubMed

    Peng, Zhengwu; Fan, Juan; Liu, Ling; Kuang, Fang; Xue, Fen; Wang, Bairen

    2015-01-01

    Adaptive changes in the carotid body (CB) including the expression of the growth-associated protein-43 (GAP-43) have been studied in response to low, but not high, oxygen exposure. Expression of GAP-43 in the CB of rats under different atmospheric pressures and oxygen partial pressure (PO2) conditions was investigated. Mature male Sprague-Dawley rats were exposed to intermittent hypobaric hypoxia (IHH, 0, 1, 2 and 3 weeks), intermittent hyperbaric oxygen (IHBO2, 0, 1, 5 and 10 days, sacrificed six hours or 24 hours after the last HBO2 exposure), and intermittent hyperbaric normoxia (IHN, same treatment pattern as IHBO2). GAP-43 was highly expressed (mainly in type I cells) in the CB of normal rats. IHH u-regulated GAP-43 expression in the CB with significant differences (immunohistochemical staining [IHC]: F(3,15)=40.64, P < 0.01; western blot [WB]: F(3,16) = 53.52, P < 0.01) across the subgroups. GAP-43 expression in the CB was inhibited by IHBO2 (controls vs. IHBO2 groups, IHC: F(6,30) = 15.85, P < 0.01; WB: F(6,29) = 15.95, P < 0.01). No detectable changes in GAP-43 expression were found for IHN. These findings indicated that different PO2 conditions, but not air pressures, played an important role in the plasticity of the CB, and that GAP-43 might be a viable factor for the plasticity of the CB. PMID:26742253

  20. Research Report: Intermittent hypobaric hypoxia and hyperbaric oxygen on GAP-43 in the rat carotid body.

    PubMed

    Peng, Zhengwu; Fan, Juan; Liu, Ling; Kuang, Fang; Xue, Fen; Wang, Bairen

    2015-01-01

    Adaptive changes in the carotid body (CB) including the expression of the growth-associated protein-43 (GAP-43) have been studied in response to low, but not high, oxygen exposure. Expression of GAP-43 in the CB of rats under different atmospheric pressures and oxygen partial pressure (PO2) conditions was investigated. Mature male Sprague-Dawley rats were exposed to intermittent hypobaric hypoxia (IHH, 0, 1, 2 and 3 weeks), intermittent hyperbaric oxygen (IHBO2, 0, 1, 5 and 10 days, sacrificed six hours or 24 hours after the last HBO2 exposure), and intermittent hyperbaric normoxia (IHN, same treatment pattern as IHBO2). GAP-43 was highly expressed (mainly in type I cells) in the CB of normal rats. IHH u-regulated GAP-43 expression in the CB with significant differences (immunohistochemical staining [IHC]: F(3,15)=40.64, P < 0.01; western blot [WB]: F(3,16) = 53.52, P < 0.01) across the subgroups. GAP-43 expression in the CB was inhibited by IHBO2 (controls vs. IHBO2 groups, IHC: F(6,30) = 15.85, P < 0.01; WB: F(6,29) = 15.95, P < 0.01). No detectable changes in GAP-43 expression were found for IHN. These findings indicated that different PO2 conditions, but not air pressures, played an important role in the plasticity of the CB, and that GAP-43 might be a viable factor for the plasticity of the CB.

  1. Intermittent chaos in the forced Brusselator

    NASA Astrophysics Data System (ADS)

    Chen, S.-G.; Hao, B.-L.; Wang, G.-R.

    1984-06-01

    It is shown numerically that in the model of trimolecular reaction under external periodic force (the forced Brusselator) there exists the intermittent route to chaos. The time development of intermittent chaos and the method to distinguish intermittency from transients are studied. The large region of period 3 in the parameter space, discovered previously in the forced Brusselator, as well as smaller regions of periods 4, 5, 6, . . . etc., correspond to tangent bifurcations in one-dimensional mappings. Intermittency appears just before the start of every tangent bifurcation. Therefore, the period-doubling and the intermittent routes to chaos are 'twin' phenomena and they should be observable in many other systems described by nonlinear differential equations.

  2. Anisotropic Intermittency of Magnetohydrodynamic Turbulence

    NASA Astrophysics Data System (ADS)

    Osman, K.; Kiyani, K. H.; Chapman, S. C.; Hnat, B.

    2014-12-01

    A higher-order multiscale analysis of spatial anisotropy in inertial range magnetohydrodynamic turbulence is presented using measurements from the STEREO spacecraft in fast ambient solar wind. We show for the first time that, when measuring parallel to the local magnetic field direction, the full statistical signature of the magnetic and Elsässer field fluctuations is that of a non-Gaussian globally scale invariant process. This is distinct from the classic multifractal scaling observed when the local magnetic field is perpendicular to the flow direction. These observations are interpreted as evidence for the weakness, or absence, of a parallel magnetofluid turbulence energy cascade. As such, these results present strong observational contraints on the statistical nature of intermittency in turbulent plasmas.

  3. Metabolic consequences of intermittent hypoxia.

    PubMed

    O'Donnell, Christopher P

    2007-01-01

    Insulin resistance is being recognized increasingly as the basis for the constellation of metabolic abnormalities that make up the metabolic syndrome, or Syndrome X. Insulin resistance is also the primary risk factor for the development of type 2 diabetes mellitus, which is currently reaching epidemic proportions by affecting more than 170 million people worldwide. A combination of environmental and genetic factors have led to a dramatic rise in visceral adiposity, the predominant factor causing insulin resistance and type 2 diabetes. Visceral adiposity is also the major risk factor for the development of Sleep Apnea (SA)--an association that has fueled interest in the co-morbidity of SA and the metabolic syndrome, but hampered attempts to ascribe an independent causative role for Sleep Apnea in the development of insulin resistance and type 2 diabetes. Numerous population and clinic-based epidemiologic studies have shown associations, often independent of obesity, between SA (or surrogates such as snoring) and measures of glucose dysregulation or type 2 diabetes. However, treatment of SA with continuous positive airway pressure (CPAP) has not been conclusive in demonstrating improvements in insulin resistance, perhaps due to the overwhelming effects of obesity. Here we show that in lean, otherwise healthy mice that exposure to intermittent hypoxia produced whole-body insulin resistance as determined by the hyperinsulinemic euglycemic clamp and reduced glucose utilization in oxidative muscle fibers, but did not cause a change in hepatic glucose output. Furthermore, the increase in insulin resistance was not affected by blockade of the autonomic nervous system. We conclude that intermittent hypoxia can cause acute insulin resistance in otherwise lean healthy animals, and the response occurs independent of activation of the autonomic nervous system. PMID:18269187

  4. High-intensity intermittent exercise and fat loss.

    PubMed

    Boutcher, Stephen H

    2011-01-01

    The effect of regular aerobic exercise on body fat is negligible; however, other forms of exercise may have a greater impact on body composition. For example, emerging research examining high-intensity intermittent exercise (HIIE) indicates that it may be more effective at reducing subcutaneous and abdominal body fat than other types of exercise. The mechanisms underlying the fat reduction induced by HIIE, however, are undetermined. Regular HIIE has been shown to significantly increase both aerobic and anaerobic fitness. HIIE also significantly lowers insulin resistance and results in a number of skeletal muscle adaptations that result in enhanced skeletal muscle fat oxidation and improved glucose tolerance. This review summarizes the results of HIIE studies on fat loss, fitness, insulin resistance, and skeletal muscle. Possible mechanisms underlying HIIE-induced fat loss and implications for the use of HIIE in the treatment and prevention of obesity are also discussed.

  5. Intermittent versus continuous operation of biosand filters.

    PubMed

    Young-Rojanschi, Candice; Madramootoo, Chandra

    2014-02-01

    The biosand filter is a household-scale point-of-use water filtration system based on slow sand filtration, but modified for intermittent operation. Studies on slow sand filters show that intermittent operation reduces filter effectiveness. However, continuous versus intermittent operation of biosand filters has never been compared. Eight 10-cm diameter columns were constructed to represent field biosand filters. Five were operated intermittently with a 24-h residence period, while the remaining three were operated continuously. Continuous operation of the filters resulted in significantly better reduction of Escherichia coli (3.71 log10 versus 1.67 log10), bacteriophage MS2 (2.25 log10 versus 0.85 log10), and turbidity (96% versus 87%). Dissolved oxygen levels at 5 and 10 cm of media depth in intermittent filters reached an average of 0 mg/L by 24 h of residence time on day 60 of the experiment. A simple numerical model was developed to describe E. coli removal during ripening from days 0-58 for continuously operated versus intermittent filters. This research confirms that although biosand filters were developed for intermittent operation, the filters perform significantly better when operated continuously. However, both operational modes resulted in a significant reduction of microbial indicators.

  6. Experiences of living with intermittent claudication.

    PubMed

    Egberg, Louise; Andreassen, Sissel; Mattiasson, Anne-Cathrine

    2012-03-01

    Intermittent claudication is a symptom caused by peripheral arterial disease (PAD) and is associated with pain, impaired mobility and loss of control. Walking ability is reduced due to the pain, and both physical and social functions are often negatively affected, which may lead to patients feeling they are a burden to others. An interview study using a qualitative descriptive design to describe experiences of living with intermittent claudication caused by PAD was carried out during Winter and Spring 2009/2010. Fifteen people suffering from intermittent claudication were interviewed, and the interviews were analyzed using qualitative thematic analysis. Intermittent claudication greatly affects daily living. Six themes were identified: "Experiencing discomfort in the legs," "Moving around in a new way," "Feeling inconvenient when forced to stop," "Missing previous life," "Incorporating intermittent claudication in daily life," and "To lead a strenuous life." The main theme was "Adjusting to a restricted life." The findings show that intermittent claudication has a major impact on daily life. Apart from the severity of symptoms, how the illness is experienced differs among patients, depending on how active the ill person is or wants to be. These findings suggest that increased knowledge about living with intermittent claudication is important to understand the effects on the ill person's life, as a complement to physical examinations when planning individual treatment. PMID:22321401

  7. Lactate kinetics after intermittent and continuous exercise training.

    PubMed

    Gharbi, Adnene; Chamari, Karim; Kallel, Amjad; Ahmaidi, Saîd; Tabka, Zouhair; Abdelkarim, Zbidi

    2008-01-01

    The purpose of this study was to assess, the effects of continuous and intermittent exercise training on lactate kinetic parameters and maximal aerobic speed (MAS) using field tests. Twenty-four male sport students were equally divided into continuous (CT) and intermittent (IT) physically trained groups. Another six participants acted as non-trained controls (CG). The trained participants practiced 6-days per week for 6 weeks. Before and after training, all participants completed an incremental exercise test to assess their MAS, and a 30- second supra-maximal exercise followed by 30 minutes of active recovery to determine the individual blood lactate recovery curve. It was found that exercise training has significantly increased MAS (p < 0.001), the lactate exchange and removal abilities as well as the lactate concentrations at the beginning of the recovery ([La]-(0)); for both CT and IT groups; this was accompanied by a significant reduction of the time to lactate-peak. Nevertheless, the improvement in MAS was significantly higher (p < 0.001) post-intermittent (15.1 % ± 2.4) than post-continuous (10.3 % ± 3.2) training. The lactate-exchange and removal abilities were also significantly higher for IT than for CT-group (P<0.05). Moreover, IT-group showed a significantly shorter half-time of the blood lactate (t-½-[La]) than CT-group (7.2 ± 0.5 min vs 7.7 ± 0.3 min, respectively) (p < 0.05). However, no significant differences were observed in peak blood lactate concentration ([La]peak), time to reach [La]peak (t-[La]peak), and [La]-(0) between the two physically-trained groups. We conclude that both continuous and intermittent training exercises were equally effective in improving t-[La]peak and [La]peak, although intermittent training was more beneficial in elevating MAS and in raising the lactate exchange (γ1) and removal (γ2) indexes. Key pointsCoaches and athletes need to be aware of the potentiality positive effects of exercise intensity.Improvements in

  8. Lactate Kinetics After Intermittent and Continuous Exercise Training

    PubMed Central

    Gharbi, Adnene; Chamari, Karim; Kallel, Amjad; Ahmaidi, Saîd; Tabka, Zouhair; Abdelkarim, Zbidi

    2008-01-01

    The purpose of this study was to assess, the effects of continuous and intermittent exercise training on lactate kinetic parameters and maximal aerobic speed (MAS) using field tests. Twenty-four male sport students were equally divided into continuous (CT) and intermittent (IT) physically trained groups. Another six participants acted as non-trained controls (CG). The trained participants practiced 6-days per week for 6 weeks. Before and after training, all participants completed an incremental exercise test to assess their MAS, and a 30- second supra-maximal exercise followed by 30 minutes of active recovery to determine the individual blood lactate recovery curve. It was found that exercise training has significantly increased MAS (p < 0.001), the lactate exchange and removal abilities as well as the lactate concentrations at the beginning of the recovery ([La]-(0)); for both CT and IT groups; this was accompanied by a significant reduction of the time to lactate-peak. Nevertheless, the improvement in MAS was significantly higher (p < 0.001) post-intermittent (15.1 % ± 2.4) than post-continuous (10.3 % ± 3.2) training. The lactate-exchange and removal abilities were also significantly higher for IT than for CT-group (P<0.05). Moreover, IT-group showed a significantly shorter half-time of the blood lactate (t-½-[La]) than CT-group (7.2 ± 0.5 min vs 7.7 ± 0.3 min, respectively) (p < 0.05). However, no significant differences were observed in peak blood lactate concentration ([La]peak), time to reach [La]peak (t-[La]peak), and [La]-(0) between the two physically-trained groups. We conclude that both continuous and intermittent training exercises were equally effective in improving t-[La]peak and [La]peak, although intermittent training was more beneficial in elevating MAS and in raising the lactate exchange (γ1) and removal (γ2) indexes. Key points Coaches and athletes need to be aware of the potentiality positive effects of exercise intensity. Improvements

  9. Intermittent sea-level acceleration

    NASA Astrophysics Data System (ADS)

    Olivieri, M.; Spada, G.

    2013-10-01

    Using instrumental observations from the Permanent Service for Mean Sea Level (PSMSL), we provide a new assessment of the global sea-level acceleration for the last ~ 2 centuries (1820-2010). Our results, obtained by a stack of tide gauge time series, confirm the existence of a global sea-level acceleration (GSLA) and, coherently with independent assessments so far, they point to a value close to 0.01 mm/yr2. However, differently from previous studies, we discuss how change points or abrupt inflections in individual sea-level time series have contributed to the GSLA. Our analysis, based on methods borrowed from econometrics, suggests the existence of two distinct driving mechanisms for the GSLA, both involving a minority of tide gauges globally. The first effectively implies a gradual increase in the rate of sea-level rise at individual tide gauges, while the second is manifest through a sequence of catastrophic variations of the sea-level trend. These occurred intermittently since the end of the 19th century and became more frequent during the last four decades.

  10. fits2hdf: FITS to HDFITS conversion

    NASA Astrophysics Data System (ADS)

    Price, D. C.; Barsdell, B. R.; Greenhill, L. J.

    2015-05-01

    fits2hdf ports FITS files to Hierarchical Data Format (HDF5) files in the HDFITS format. HDFITS allows faster reading of data, higher compression ratios, and higher throughput. HDFITS formatted data can be presented transparently as an in-memory FITS equivalent by changing the import lines in Python-based FITS utilities. fits2hdf includes a utility to port MeasurementSets (MS) to HDF5 files.

  11. Scalings of intermittent structures in magnetohydrodynamic turbulence

    NASA Astrophysics Data System (ADS)

    Zhdankin, Vladimir; Boldyrev, Stanislav; Uzdensky, Dmitri A.

    2016-05-01

    Turbulence is ubiquitous in plasmas, leading to rich dynamics characterized by irregularity, irreversibility, energy fluctuations across many scales, and energy transfer across many scales. Another fundamental and generic feature of turbulence, although sometimes overlooked, is the inhomogeneous dissipation of energy in space and in time. This is a consequence of intermittency, the scale-dependent inhomogeneity of dynamics caused by fluctuations in the turbulent cascade. Intermittency causes turbulent plasmas to self-organize into coherent dissipative structures, which may govern heating, diffusion, particle acceleration, and radiation emissions. In this paper, we present recent progress on understanding intermittency in incompressible magnetohydrodynamic turbulence with a strong guide field. We focus on the statistical analysis of intermittent dissipative structures, which occupy a small fraction of the volume but arguably account for the majority of energy dissipation. We show that, in our numerical simulations, intermittent structures in the current density, vorticity, and Elsässer vorticities all have nearly identical statistical properties. We propose phenomenological explanations for the scalings based on general considerations of Elsässer vorticity structures. Finally, we examine the broader implications of intermittency for astrophysical systems.

  12. Tobacco Dependence Among Intermittent Smokers

    PubMed Central

    Ferguson, Stuart G.; Dunbar, Michael S.; Scholl, Sarah M.

    2012-01-01

    Introduction: Intermittent smokers (ITS) are an increasingly prevalent segment of smokers, yet it is unknown whether or how dependence severity may vary across ITS. Methods: Participants were 217 ITS (70 never daily ITS [NITS], 138 converted ITS [CITS], and 9 unknown), who smoked 4–27 days per month, and 197 daily smokers (DS), recruited for a study on smoking patterns. Participants completed questionnaires on dependence (time to first cigarette after waking, Fagerström Test of Nicotine Dependence [FTND], Nicotine Dependence Syndrome Scale [NDSS], Wisconsin Inventory of Smoking Dependence Motives [WISDM], and Hooked on Nicotine Checklist [HONC]) and recorded each cigarette in real time over 3 weeks using Ecological Momentary Assessment. Logistic regression assessed differences in dependence between groups (DS vs. ITS; CITS vs. NITS), and least squares regression examined associations between dependence and smoking behavior (mean, maximum cigarettes per day; proportion of days smoked; longest period of abstinence) within ITS. Results: As expected, DS were significantly more dependent than ITS: FTND, NDSS, and WISDM discriminated between ITS and DS with greater than 90% accuracy. Similarly, among ITS, NITS demonstrated lower dependence than CITS. Within ITS, dependence measures also correlated with observed smoking rate and duration of abstinence. Conclusions: The study confirmed that DS are more dependent than ITS and that CITS are more dependent than NITS. Importantly, ITS exhibit features of dependence, and there is meaningful variation in dependence within ITS, suggesting that some aspects of dependence may appear with very infrequent smoking. Future work should examine implications for ITS’ potential progression to daily smoking and cessation outcome. PMID:22529224

  13. Hamiltonian inclusive fitness: a fitter fitness concept

    PubMed Central

    Costa, James T.

    2013-01-01

    In 1963–1964 W. D. Hamilton introduced the concept of inclusive fitness, the only significant elaboration of Darwinian fitness since the nineteenth century. I discuss the origin of the modern fitness concept, providing context for Hamilton's discovery of inclusive fitness in relation to the puzzle of altruism. While fitness conceptually originates with Darwin, the term itself stems from Spencer and crystallized quantitatively in the early twentieth century. Hamiltonian inclusive fitness, with Price's reformulation, provided the solution to Darwin's ‘special difficulty’—the evolution of caste polymorphism and sterility in social insects. Hamilton further explored the roles of inclusive fitness and reciprocation to tackle Darwin's other difficulty, the evolution of human altruism. The heuristically powerful inclusive fitness concept ramified over the past 50 years: the number and diversity of ‘offspring ideas’ that it has engendered render it a fitter fitness concept, one that Darwin would have appreciated. PMID:24132089

  14. Intermittent ephemeral river-breaching

    NASA Astrophysics Data System (ADS)

    Reniers, A. J.; MacMahan, J. H.; Gallagher, E. L.; Shanks, A.; Morgan, S.; Jarvis, M.; Thornton, E. B.; Brown, J.; Fujimura, A.

    2012-12-01

    In the summer of 2011 we performed a field experiment in Carmel River State Beach, CA, at a time when the intermittent natural breaching of the ephemeral Carmel River occurred due to an unusually rainy period prior to the experiment associated with El Nino. At this time the river would fill the lagoon over the period of a number of days after which a breach would occur. This allowed us to document a number of breaches with unique pre- and post-breach topographic surveys, accompanying ocean and lagoon water elevations as well as extremely high flow (4m/s) velocities in the river mouth during the breaching event. The topographic surveys were obtained with a GPS-equipped backpack mounted on a walking human and show the evolution of the river breaching with a gradually widening and deepening river channel that cuts through the pre-existing beach and berm. The beach face is qualified as a steep with an average beach slope of 1:10 with significant reflection of the incident waves (MacMahan et al., 2012). The wave directions are generally shore normal as the waves refract over the deep canyon that is located offshore of the beach. The tide is mixed semi-diurnal with a range on the order of one meter. Breaching typically occurred during the low-low tide. Grain size is highly variable along the beach with layers of alternating fine and coarse material that could clearly be observed as the river exit channel was cutting through the beach. Large rocky outcroppings buried under the beach sand are also present along certain stretches of the beach controlling the depth of the breaching channel. The changes in the water level measured within the lagoon and the ocean side allows for an estimate of the volume flux associated with the breach as function of morphology, tidal elevation and wave conditions as well as an assessment of the conditions and mechanisms of breach closure, which occurred on the time scale of O(0.5 days). Exploratory model simulations will be presented at the

  15. Modeling Integrated Water-User Decisions with Intermittent Supplies

    NASA Astrophysics Data System (ADS)

    Lund, J. R.; Rosenberg, D.

    2006-12-01

    We present an economic-engineering method to estimate urban water use demands with intermittent water supplies. A two-stage, probabilistic optimization formulation includes a wide variety of water supply enhancement and conservation actions that individual households can adopt to meet multiple water quality uses with uncertain water availability. We embed the optimization in Monte-Carlo simulations to show aggregate effects at a utility (citywide) scale for a population of user conditions and decisions. Parametric analysis provides derivations of supply curves to subsidize conservation, demand responses to alternative pricing, and customer willingness-to-pay to avoid shortages. Results show a good empirical fit for the average and distribution of billed residential water use in Amman, Jordan. Additional outputs give likely market penetration rates for household conservation actions, associated water savings, and subsidies required to entice further adoption. We discuss new insights to size, target, market, and finance conservation programs and interpret a demand curve with block pricing.

  16. Coherent Structures and Intermittency in Plasma Turbulence

    SciTech Connect

    Das, Amita; Kaw, Predhiman; Sen, Abhijit

    2008-10-15

    The paper discusses some fundamental issues related to the phenomenon of intermittency in plasma turbulence with particular reference to experimental observations in fusion devices. Intermittency is typically associated with the presence of coherent structures in turbulence. Since coherent structures can play an important role in governing the transport properties of a system they have received a great deal of attention in fusion research. We review some of the experimental measurements and numerical simulation studies on the presence and formation of coherent structures in plasmas and discuss their relevance to intermittency. Intermittency, as widely discussed in the context of neutral fluid turbulence, implies multiscaling behaviour in contrast to self-similar scaling patterns observed in self organized criticality (SOC) phenomenon. The experimental evidence from plasma turbulence measurements reveal a mixed picture--while some observations support the SOC model description others indicate the presence of multiscaling behaviour. We discuss these results in the light of our present understanding of plasma turbulence and in terms of certain unique aspects of intermittency as revealed by fluid models of plasmas.

  17. Intermittent versus Continuous Incremental Field Tests: Are Maximal Variables Interchangeable?

    PubMed

    Carminatti, Lorival J; Possamai, Carlos A P; de Moraes, Marcelo; da Silva, Juliano F; de Lucas, Ricardo D; Dittrich, Naiandra; Guglielmo, Luiz G A

    2013-01-01

    The aim of the present study was to compare physiological responses derived from an incremental progressive field test with a constant speed test i.e. intermittent versus continuous protocol. Two progressive maximum tests (Carminatti`s test (T-CAR) and the Vameval test (T-VAM)), characterized by increasing speed were used. T-CAR is an intermittent incremental test, performed as shuttle runs; while T-VAM is a continuous incremental test performed on an athletic track. Eighteen physically active, healthy young subjects (21.9 ± 2.0 years; 76.5 ± 8.6 kg, 1.78 ± 0.08 m, 11.2 ± 5.4% body fat), volunteered for this study. Subjects performed four different maximum test sessions conducted in the field: two incremental tests and two time to exhaustion tests (TTE) at peak test velocities (PV). No significant differences were found for PV (T-CAR = 15.6 ± 1.2; T-VAM = 15.5 ± 1.3 km·h(-1)) and maximal HR (T-CAR = 195 ± 11; T- VAM = 194 ± 14 bpm). During TTE, there were no significant differences for HR (TTET-CAR and TTET-VAM = 192 ± 12 bpm). However, there was a significant difference in TTE (p = 0.04) (TTET-CAR = 379 ± 84, TTET-VAM = 338 ± 58 s) with a low correlation (r = 0.41). The blood lactate concentration measured at the end of the TTE tests, showed no significant difference (TTET-CAR = 13.2 ± 2.4 vs. TTET-VAM = 12.9 ± 2.4 mmol·l(-1)). Based on the present findings, it is suggested that the maximal variables derived from T-CAR and T-VAM can be interchangeable in the design of training programs. Key pointsT-CAR is an intermittent shuttle run test that predicts the maximal aerobic speed with accuracy, hence, test results could be interchangeable with continuous straight-line tests.T-CAR provides valid field data for evaluating aerobic fitness.In comparison with T-VAM, T-CAR may be a more favourable way to prescribe intermittent training using a shuttle-running protocol.

  18. Intermittency and rough-pipe turbulence.

    PubMed

    Mehrafarin, Mohammad; Pourtolami, Nima

    2008-05-01

    Recently, by analyzing the measurement data of Nikuradze [NACA Tech. Memo No. 1292 (1950)], it has been proposed [N. Goldenfeld, Phys. Rev. Lett. 96, 044503 (2006)] that the friction factor, f , of rough-pipe flow obeys a scaling law in the turbulent regime. Here, we provide a phenomenological scaling argument to explain this law and demonstrate how intermittency modifies the scaling form, thereby relating f to the intermittency exponent, eta . By statistically analyzing the measurement data of f , we infer a satisfactory estimate for eta ( approximately 0.02) , the inclusion of which is shown to improve the data-collapse curve. This provides empirical evidence for intermittency other than the direct measurement of velocity fluctuations.

  19. Observation of intermittency in wave turbulence.

    PubMed

    Falcon, E; Fauve, S; Laroche, C

    2007-04-13

    We report the observation of intermittency in gravity-capillary wave turbulence on the surface of mercury. We measure the temporal fluctuations of surface wave amplitude at a given location. We show that the shape of the probability density function of the local slope increments of the surface waves strongly changes across the time scales. The related structure functions and the flatness are found to be power laws of the time scale on more than one decade. The exponents of these power laws increase nonlinearly with the order of the structure function. All these observations show the intermittent nature of the increments of the local slope in wave turbulence. We discuss the possible origin of this intermittency. PMID:17501356

  20. Complexity and Intermittent Turbulence in Space Plasmas

    NASA Technical Reports Server (NTRS)

    Chang, Tom; Tam, Sunny W. Y.; Wu, Cheng-Chin

    2004-01-01

    Sporadic and localized interactions of coherent structures arising from plasma resonances can be the origin of "complexity" of the coexistence of non- propagating spatiotemporal fluctuations and propagating modes in space plasmas. Numerical simulation results are presented to demonstrate the intermittent character of the non-propagating fluctuations. The technique of the dynamic renormalization-group is introduced and applied to the study of scale invariance of such type of multiscale fluctuations. We also demonstrate that the particle interactions with the intermittent turbulence can lead to the efficient energization of the plasma populations. An example related to the ion acceleration processes in the auroral zone is provided.

  1. Partnerships for the Fit.

    ERIC Educational Resources Information Center

    Golding, Lawrence A.

    1984-01-01

    The YMCA has helped train and employ fitness leaders while educating the public on physical fitness. Colleges and universities can help develop careers in fitness while maintaining their traditional role of developing teachers and coaches. (DF)

  2. Intermittent/transient faults in digital systems

    NASA Technical Reports Server (NTRS)

    Masson, G. M.; Glazer, R. E.

    1982-01-01

    Containment set techniques are applied to 8085 microprocessor controllers so as to transform a typical control system into a slightly modified version, shown to be crashproof: after the departure of the intermittent/transient fault, return to one proper control algorithm is assured, assuming no permanent faults occur.

  3. Temporal and spatial intermittencies within Newtonian turbulence

    NASA Astrophysics Data System (ADS)

    Kushwaha, Anubhav; Graham, Michael

    2015-11-01

    Direct numerical simulations of a pressure driven turbulent flow are performed in a large rectangular channel. Intermittent high- and low-drag regimes within turbulence that have earlier been found to exist temporally in minimal channels have been observed both spatially and temporally in full-size turbulent flows. These intermittent regimes, namely, ''active'' and ''hibernating'' turbulence, display very different structural and statistical features. We adopt a very simple sampling technique to identify these intermittent intervals, both temporally and spatially, and present differences between them in terms of simple quantities like mean-velocity, wall-shear stress and flow structures. By conditionally sampling of the low wall-shear stress events in particular, we show that the Maximum Drag Reduction (MDR) velocity profile, that occurs in viscoelastic flows, can also be approached in a Newtonian-fluid flow in the absence of any additives. This suggests that the properties of polymer drag reduction are inherent to all flows and their occurrence is just enhanced by the addition of polymers. We also show how the intermittencies within turbulence vary with Reynolds number. The work was supported by AFOSR grant FA9550-15-1-0062.

  4. Clean Intermittent Catheterization in the School Setting

    ERIC Educational Resources Information Center

    Katrancha, Elizabeth D.

    2008-01-01

    Spina bifida (SB) is a neural tube defect that causes many physical and mental disabilities. Bowel and bladder incontinence is the disability seen most often in these students that requires the school nurse's attention. Clean intermittent catheterization (CIC) provides the student with SB a vehicle to reach a satisfactory level of continence,…

  5. Aggression induced by intermittent positive reinforcement.

    PubMed

    Looney, T A; Cohen, P S

    1982-01-01

    Mammalian and non-mammalian species engage in aggressive behavior toward animate and inanimate targets when exposed to intermittent access to a positive reinforcer. This behavior, called extinction- or schedule-induced aggression, typically includes a biting or striking topography that inflicts damage on a target. This paper critically reviews research and theoretical issues concerning such aggression and suggests directions for future investigation.

  6. UNSTEADY DISPERSION IN RANDOM INTERMITTENT FLOW

    EPA Science Inventory

    The longitudinal dispersion coefficient of a conservative tracer was calculated from flow tests in a dead-end pipe loop system. Flow conditions for these tests ranged from laminar to transitional flow, and from steady to intermittent and random. Two static mixers linked in series...

  7. Odorant concentration differentiator for intermittent olfactory signals.

    PubMed

    Fujiwara, Terufumi; Kazawa, Tomoki; Sakurai, Takeshi; Fukushima, Ryota; Uchino, Keiro; Yamagata, Tomoko; Namiki, Shigehiro; Haupt, Stephan Shuichi; Kanzaki, Ryohei

    2014-12-10

    Animals need to discriminate differences in spatiotemporally distributed sensory signals in terms of quality as well as quantity for generating adaptive behavior. Olfactory signals characterized by odor identity and concentration are intermittently distributed in the environment. From these intervals of stimulation, animals process odorant concentration to localize partners or food sources. Although concentration-response characteristics in olfactory neurons have traditionally been investigated using single stimulus pulses, their behavior under intermittent stimulus regimens remains largely elusive. Using the silkmoth (Bombyx mori) pheromone processing system, a simple and behaviorally well-defined model for olfaction, we investigated the neuronal representation of odorant concentration upon intermittent stimulation in the naturally occurring range. To the first stimulus in a series, the responses of antennal lobe (AL) projection neurons (PNs) showed a concentration dependence as previously shown in many olfactory systems. However, PN response amplitudes dynamically changed upon exposure to intermittent stimuli of the same odorant concentration and settled to a constant, largely concentration-independent level. As a result, PN responses emphasized odorant concentration changes rather than encoding absolute concentration in pulse trains of stimuli. Olfactory receptor neurons did not contribute to this response transformation which was due to long-lasting inhibition affecting PNs in the AL. Simulations confirmed that inhibition also provides advantages when stimuli have naturalistic properties. The primary olfactory center thus functions as an odorant concentration differentiator to efficiently detect concentration changes, thereby improving odorant source orientation over a wide concentration range.

  8. Intermittent heat exposure and thirst in rats.

    PubMed

    Barney, Christopher C; Kuhrt, David M

    2016-04-01

    Adequate water intake, supporting both cardiovascular function and evaporative cooling, is a critical factor in mitigating the effects of heat waves, which are expected to increase with global warming. However, the regulation of water intake during periods of intermittent heat exposure is not well understood. In this study, the effects of access to water or no access during intermittent heat exposure were assessed using male Sprague-Dawley rats exposed to 37.5°C for 4 h/day. After 7 days of intermittent heat exposure, reductions in evaporative water loss were observed in all animals and reductions in water intake following heat exposure occurred as the days of heat exposure increased. Rats that were not allowed water during the 7 days of exposure had decreased rehydration levels, however, rats allowed access to water increased water intake during exposure and exhibited higher overall rehydration levels over the same time period. Peripheral administration of angiotensinII, mimicking activation of volemic thirst, or hypertonic saline solution, activating intracellular thirst, did not result in alteration of water intake in rats exposed to heat with access to water compared to control rats. In contrast, rats exposed to heat without access to water had reduced water intake after administration of hypertonic saline and increased water intake after administration of angiotensinIIcompared to control rats. These experiments demonstrate that thirst responses to intermittent heat exposure are altered by providing water during heat exposure and that intermittent heat exposure without access to water alters drinking responses to both intracellular and extracellular thirst challenges.

  9. A Pretty Good Fit

    ERIC Educational Resources Information Center

    Erickson, Tim

    2008-01-01

    We often look for a best-fit function to a set of data. This article describes how a "pretty good" fit might be better than a "best" fit when it comes to promoting conceptual understanding of functions. In a pretty good fit, students design the function themselves rather than choosing it from a menu; they use appropriate variable names; and they…

  10. Physical Fitness Assessment.

    ERIC Educational Resources Information Center

    Valdes, Alice

    This document presents baseline data on physical fitness that provides an outline for assessing the physical fitness of students. It consists of 4 tasks and a 13-item questionnaire on fitness-related behaviors. The fitness test evaluates cardiorespiratory endurance by a steady state jog; muscular strength and endurance with a two-minute bent-knee…

  11. 21 CFR 890.1600 - Intermittent pressure measurement system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intermittent pressure measurement system. 890.1600... Intermittent pressure measurement system. (a) Identification. An intermittent pressure measurement system is an evaluative device intended for medical purposes, such as to measure the actual pressure between the...

  12. 21 CFR 890.1600 - Intermittent pressure measurement system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Intermittent pressure measurement system. 890.1600 Section 890.1600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Intermittent pressure measurement system. (a) Identification. An intermittent pressure measurement system is...

  13. 21 CFR 890.1600 - Intermittent pressure measurement system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intermittent pressure measurement system. 890.1600 Section 890.1600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Intermittent pressure measurement system. (a) Identification. An intermittent pressure measurement system is...

  14. 21 CFR 890.1600 - Intermittent pressure measurement system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intermittent pressure measurement system. 890.1600 Section 890.1600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Intermittent pressure measurement system. (a) Identification. An intermittent pressure measurement system is...

  15. ImOSM: intermittent evolution and robustness of phylogenetic methods.

    PubMed

    Thi Nguyen, Minh Anh; Gesell, Tanja; von Haeseler, Arndt

    2012-02-01

    Among the criteria to evaluate the performance of a phylogenetic method, robustness to model violation is of particular practical importance as complete a priori knowledge of evolutionary processes is typically unavailable. For studies of robustness in phylogenetic inference, a utility to add well-defined model violations to the simulated data would be helpful. We therefore introduce ImOSM, a tool to imbed intermittent evolution as model violation into an alignment. Intermittent evolution refers to extra substitutions occurring randomly on branches of a tree, thus changing alignment site patterns. This means that the extra substitutions are placed on the tree after the typical process of sequence evolution is completed. We then study the robustness of widely used phylogenetic methods: maximum likelihood (ML), maximum parsimony (MP), and a distance-based method (BIONJ) to various scenarios of model violation. Violation of rates across sites (RaS) heterogeneity and simultaneous violation of RaS and the transition/transversion ratio on two nonadjacent external branches hinder all the methods recovery of the true topology for a four-taxon tree. For an eight-taxon balanced tree, the violations cause each of the three methods to infer a different topology. Both ML and MP fail, whereas BIONJ, which calculates the distances based on the ML estimated parameters, reconstructs the true tree. Finally, we report that a test of model homogeneity and goodness of fit tests have enough power to detect such model violations. The outcome of the tests can help to actually gain confidence in the inferred trees. Therefore, we recommend using these tests in practical phylogenetic analyses.

  16. FIT3D: Fitting optical spectra

    NASA Astrophysics Data System (ADS)

    Sánchez, S. F.; Pérez, E.; Sánchez-Blázquez, P.; González, J. J.; Rosales-Ortega, F. F.; Cano-Díaz, M.; López-Cobá, C.; Marino, R. A.; Gil de Paz, A.; Mollá, M.; López-Sánchez, A. R.; Ascasibar, Y.; Barrera-Ballesteros, J.

    2016-09-01

    FIT3D fits optical spectra to deblend the underlying stellar population and the ionized gas, and extract physical information from each component. FIT3D is focused on the analysis of Integral Field Spectroscopy data, but is not restricted to it, and is the basis of Pipe3D, a pipeline used in the analysis of datasets like CALIFA, MaNGA, and SAMI. It can run iteratively or in an automatic way to derive the parameters of a large set of spectra.

  17. Intermittent control: a computational theory of human control.

    PubMed

    Gawthrop, Peter; Loram, Ian; Lakie, Martin; Gollee, Henrik

    2011-02-01

    The paradigm of continuous control using internal models has advanced understanding of human motor control. However, this paradigm ignores some aspects of human control, including intermittent feedback, serial ballistic control, triggered responses and refractory periods. It is shown that event-driven intermittent control provides a framework to explain the behaviour of the human operator under a wider range of conditions than continuous control. Continuous control is included as a special case, but sampling, system matched hold, an intermittent predictor and an event trigger allow serial open-loop trajectories using intermittent feedback. The implementation here may be described as "continuous observation, intermittent action". Beyond explaining unimodal regulation distributions in common with continuous control, these features naturally explain refractoriness and bimodal stabilisation distributions observed in double stimulus tracking experiments and quiet standing, respectively. Moreover, given that human control systems contain significant time delays, a biological-cybernetic rationale favours intermittent over continuous control: intermittent predictive control is computationally less demanding than continuous predictive control. A standard continuous-time predictive control model of the human operator is used as the underlying design method for an event-driven intermittent controller. It is shown that when event thresholds are small and sampling is regular, the intermittent controller can masquerade as the underlying continuous-time controller and thus, under these conditions, the continuous-time and intermittent controller cannot be distinguished. This explains why the intermittent control hypothesis is consistent with the continuous control hypothesis for certain experimental conditions.

  18. Intermittent locomotion as an optimal control strategy

    PubMed Central

    Paoletti, P.; Mahadevan, L.

    2014-01-01

    Birds, fish and other animals routinely use unsteady effects to save energy by alternating between phases of active propulsion and passive coasting. Here, we construct a minimal model for such behaviour that can be couched as an optimal control problem via an analogy to travelling with a rechargeable battery. An analytical solution of the optimal control problem proves that intermittent locomotion has lower energy requirements relative to steady-state strategies. Additional realistic hypotheses, such as the assumption that metabolic cost at a given power should be minimal (the fixed gear hypothesis), a nonlinear dependence of the energy storage rate on propulsion and/or a preferred average speed, allow us to generalize the model and demonstrate the flexibility of intermittent locomotion with implications for biological and artificial systems. PMID:24711718

  19. Optimal Dynamics of Intermittent Water Supply

    NASA Astrophysics Data System (ADS)

    Lieb, Anna; Wilkening, Jon; Rycroft, Chris

    2014-11-01

    In many urban areas of the developing world, piped water is supplied only intermittently, as valves direct water to different parts of the water distribution system at different times. The flow is transient, and may transition between free-surface and pressurized, resulting in complex dynamical features with important consequences for water suppliers and users. These consequences include degradation of distribution system components, compromised water quality, and inequitable water availability. The goal of this work is to model the important dynamics and identify operating conditions that mitigate certain negative effects of intermittent water supply. Specifically, we will look at valve parameters occurring as boundary conditions in a network model of transient, transition flow through closed pipes. Optimization will be used to find boundary values to minimize pressure gradients and ensure equitable water availability.

  20. Quantifying intermittent transport in cell cytoplasm

    NASA Astrophysics Data System (ADS)

    Lagache, Thibault; Holcman, David

    2008-03-01

    Active cellular transport is a fundamental mechanism for protein and vesicle delivery, cell cycle, and molecular degradation. Viruses can hijack the transport system and use it to reach the nucleus. Most transport processes consist of intermittent dynamics, where the motion of a particle, such as a virus, alternates between pure Brownian and directed movement along microtubules. In this Rapid Communication, we estimate the mean time for a particle to attach to a microtubule network. This computation leads to a coarse grained equation of the intermittent motion in radial and cylindrical geometries. Finally, by using the degradation activity inside the cytoplasm, we obtain refined asymptotic estimations for the probability and the mean time a virus reaches a small nuclear pore.

  1. CONDITIONED ANALYSIS OF HIGH-LATITUDE SOLAR WIND INTERMITTENCY

    SciTech Connect

    D'Amicis, R.; Consolini, G.; Bavassano, B.; Bruno, R.

    2012-08-10

    The solar wind is a turbulent medium displaying intermittency. Its intermittent features have been widely documented and studied, showing how the intermittent character is different in fast and slow wind. In this paper, a statistical conditioned analysis of the solar wind intermittency for a period of high-latitude fast solar wind is presented. In particular, the intermittent features are investigated as a function of the Alfvenic degree of fluctuations at a given scale. The results show that the main contribution to solar wind intermittency is due to non-Alfvenic structures, while Alfvenic increments are found to be characterized by a smaller level of intermittency than the previous ones. Furthermore, the lifetime statistics of Alfvenic periods are discussed in terms of a multiscale texture of randomly oriented flux tubes.

  2. Intermittent chaotic chimeras for coupled rotators.

    PubMed

    Olmi, Simona; Martens, Erik A; Thutupalli, Shashi; Torcini, Alessandro

    2015-09-01

    Two symmetrically coupled populations of N oscillators with inertia m display chaotic solutions with broken symmetry similar to experimental observations with mechanical pendulums. In particular, we report evidence of intermittent chaotic chimeras, where one population is synchronized and the other jumps erratically between laminar and turbulent phases. These states have finite lifetimes diverging as a power law with N and m. Lyapunov analyses reveal chaotic properties in quantitative agreement with theoretical predictions for globally coupled dissipative systems.

  3. Climate, intermittent humidification, and humidifier fever.

    PubMed Central

    Anderson, K; Watt, A D; Sinclair, D; Lewis, C; McSharry, C P; Boyd, G

    1989-01-01

    Two summer outbreaks of humidifier fever (HF) are described in a microprocessor factory (factory A) and a printing factory (factory B). The air in each factory was humidified intermittently and controlled by present humidistats operating to maintain a relative humidity of 45% by an air handler incorporating a spray humidifier in factory A and two ceiling mounted spray humidifiers in factory B. Questionnaire data from each workforce suggested that although symptoms apparently occurred most commonly in both factories on return from holiday (41/57, 71.9%), many subjects (24/40, 60%) in factory A also had intermittent symptoms of ill defined periodicity for some time before the disorder was recognised. Similar intermittent symptoms with no discernible pattern occurred in factory B in a smaller number of subjects (4/17, 23.5%), all of whom were night or rotating shift workers. Both episodes of humidifier fever after return from summer holiday developed when nocturnal air temperatures were unseasonably low; not on the day of return to work but two days later (factory A) and one day later (factory B). Symptoms were most common in most workers who had circulating serum IgG antibody measured by ELISA to humidifier sludge in factory B (14/17, 82.9%) but were most common in IgG antibody negative subjects in factory A (27/40, 67.5%). A more classic form of humidifier fever redeveloped in factory B during winter when meteorological recordings suggested that humidification of intake air was more continuous. Humidifier fever in winter may have been the major influence on the formulation of the symptom pattern thought to be relevant for recognition of the disorder. A form of the illness, however, can occur during the summer which is camouflaged by intermittent humidification when the symptoms appear to be more closely associated with cool nocturnal air intake and unrelated to the pattern of attendance at work. PMID:2789971

  4. Fatigue during intermittent-sprint exercise.

    PubMed

    Bishop, David J

    2012-09-01

    1. There is a reversible decline in force production by muscles when they are contracting at or near their maximum capacity. The task-dependent nature of fatigue means that the mechanisms of fatigue may differ between different types of contractions. This paper examines how fatigue manifests during whole-body, intermittent-sprint exercise and discusses the potential muscular and neural mechanisms that underpin this fatigue. 2. Fatigue is defined as a reversible, exercise-induced reduction in maximal power output (e.g. during cycling exercise) or speed (e.g. during running exercise), even though the task can be continued. 3. The small changes in surface electromyogram (EMG), along with a lack of change in voluntary muscle activation (estimated from both percutaneous motor nerve stimulations and trans-cranial magnetic stimulation), indicate that there is little change in neural drive to the muscles following intermittent-sprint exercise. This, along with the observation that the decrease in EMG is much less than that which would be predicted from the decrease in power output, suggests that peripheral mechanisms are the predominant cause of fatigue during intermittent-sprint exercise. 4. At the muscle level, limitations in energy supply, including phosphocreatine hydrolysis and the degree of reliance on anaerobic glycolysis and oxidative metabolism, and the intramuscular accumulation of metabolic by-products, such as hydrogen ions, emerge as key factors responsible for fatigue.

  5. ACSM Fit Society Page

    MedlinePlus

    ... Exercise Current Sports Medicine Reports Exercise and Sport Sciences Reviews ACSM's Health & Fitness Journal Guidelines Books & Multimedia Sports Medicine Basics Fact Sheets Sports Medicine & Physical Activity Marketplace Health & Physical Activity Reference Database Fit ...

  6. Family Activities for Fitness

    ERIC Educational Resources Information Center

    Grosse, Susan J.

    2009-01-01

    This article discusses how families can increase family togetherness and improve physical fitness. The author provides easy ways to implement family friendly activities for improving and maintaining physical health. These activities include: walking, backyard games, and fitness challenges.

  7. Adaptive intermittent control: A computational model explaining motor intermittency observed in human behavior.

    PubMed

    Sakaguchi, Yutaka; Tanaka, Masato; Inoue, Yasuyuki

    2015-07-01

    It is a fundamental question how our brain performs a given motor task in a real-time fashion with the slow sensorimotor system. Computational theory proposed an influential idea of feed-forward control, but it has mainly treated the case that the movement is ballistic (such as reaching) because the motor commands should be calculated in advance of movement execution. As a possible mechanism for operating feed-forward control in continuous motor tasks (such as target tracking), we propose a control model called "adaptive intermittent control" or "segmented control," that brain adaptively divides the continuous time axis into discrete segments and executes feed-forward control in each segment. The idea of intermittent control has been proposed in the fields of control theory, biological modeling and nonlinear dynamical system. Compared with these previous models, the key of the proposed model is that the system speculatively determines the segmentation based on the future prediction and its uncertainty. The result of computer simulation showed that the proposed model realized faithful visuo-manual tracking with realistic sensorimotor delays and with less computational costs (i.e., with fewer number of segments). Furthermore, it replicated "motor intermittency", that is, intermittent discontinuities commonly observed in human movement trajectories. We discuss that the temporally segmented control is an inevitable strategy for brain which has to achieve a given task with small computational (or cognitive) cost, using a slow control system in an uncertain variable environment, and the motor intermittency is the side-effect of this strategy.

  8. Kids and Fitness.

    ERIC Educational Resources Information Center

    Corradini, Deedee

    1999-01-01

    Too many U.S. children are out of shape. Parents must help them learn to improve their fitness by exercising with them. The U.S. Conference of Mayors recently made physical fitness of the nation's children a primary emphasis. A sidebar presents information on how to contact local mayors to start up programs to help children improve their fitness.…

  9. Maternal Side-Effects of Continuous vs. Intermittent Method of EntonoxDuring Labor: A Randomized Clinical Trial.

    PubMed

    Agah, Jila; Baghani, Roya; Tabaraei, Yaser; Rad, Abolfazl

    2016-01-01

    Labor pain is one of the most tiresome types of pain. So human has been seeking to allay this pain until now. Administration of a suitable agent such as Entonox during labor is very beneficial for childbirth outcomes. Entonox can be administered in two ways: intermittently and continuously. The aim of this study is to demonstrate whether continuous method is as safe as intermittent method? This randomized clinical trial was performed in Mobini Hospital, Sabzevar, Iran. One hundred admitted women for vaginal delivery were included in this study. Fitted patients were randomly divided into two equal groups. After thorough training, the patients used Entonox during active phase of labor. Fifty parturients used it intermittently and 50 others used it continuously. Then, maternal adverse effects, satisfaction and labor progression were registered and compared in two groups. Statistical Analysis was performed by spss17 software, t-test and chi square test. The maternal side effects of Entonox had no significant difference in two groups (p>0.05). Mothers' satisfaction rate in continuous group was more than the intermittent group significantly (p<0.001). Meantime of active phase of labor had no significant difference between two groups (p=0.2). It seems that by more investigations, there will be conditions for mothers to choose the desired method of Entonox usage, intermittently or continuously. This approach leads to reduction of difficult labor and cesarean section and consequently helps improvement of maternal health level, both physically and psychologically. PMID:27642337

  10. Quasispecies on Fitness Landscapes.

    PubMed

    Schuster, Peter

    2016-01-01

    Selection-mutation dynamics is studied as adaptation and neutral drift on abstract fitness landscapes. Various models of fitness landscapes are introduced and analyzed with respect to the stationary mutant distributions adopted by populations upon them. The concept of quasispecies is introduced, and the error threshold phenomenon is analyzed. Complex fitness landscapes with large scatter of fitness values are shown to sustain error thresholds. The phenomenological theory of the quasispecies introduced in 1971 by Eigen is compared to approximation-free numerical computations. The concept of strong quasispecies understood as mutant distributions, which are especially stable against changes in mutations rates, is presented. The role of fitness neutral genotypes in quasispecies is discussed.

  11. Water infiltration and intermittent flow in rough-walled fractures

    SciTech Connect

    Su, G.

    1995-05-01

    Flow visualization experiments were conducted in transparent replicas of natural rough-walled fractures. The fracture was inclined to observe the interplay between capillary and gravity forces. Water was introduced into the fracture by a capillary siphon. Preferential flow paths were observed, where intermittent flow frequently occurred. The water infiltration experiments suggest that intermittent flow in fractures appears to be the rule rather than the exception. In order to investigate the mechanism causing intermittent flow in fractures, parallel plates with different apertures were assembled using lucite and glass. A medium-coarse-fine pore structure is believed to cause the intermittency in flow. Intermittent flow was successfully produced in the parallel plate experiments using the lucite plates. After several trials, intermittent flow was also produced in the glass plates.

  12. Hovering and intermittent flight in birds.

    PubMed

    Tobalske, Bret W

    2010-12-01

    Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound (~0.3 kg) and small birds with rounded wings do not use intermittent glides.

  13. Hovering and intermittent flight in birds.

    PubMed

    Tobalske, Bret W

    2010-12-01

    Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound (~0.3 kg) and small birds with rounded wings do not use intermittent glides. PMID:21098953

  14. Intermittent oral iron supplementation during pregnancy (Review)

    PubMed Central

    Peña-Rosas, Juan Pablo; De-Regil, Luz Maria; Dowswell, Therese; Viteri, Fernando E

    2014-01-01

    Background Anaemia is a frequent condition during pregnancy, particularly among women from developing countries who have insufficient iron intake to meet increased iron needs of both the mother and the fetus. Traditionally, gestational anaemia has been prevented with the provision of daily iron supplements throughout pregnancy, but adherence to this regimen due to side effects, interrupted supply of the supplements, and concerns about safety among women with an adequate iron intake, have limited the use of this intervention. Intermittent (i.e. one, two or three times a week on non-consecutive days) supplementation with iron alone or in combination with folic acid or other vitamins and minerals has recently been proposed as an alternative to daily supplementation. Objectives To assess the benefits and harms of intermittent supplementation with iron alone or in combination with folic acid or other vitamins and minerals to pregnant women on neonatal and pregnancy outcomes. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (23 March 2012). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) for ongoing studies and contacted relevant organisations for the identification of ongoing and unpublished studies (23 March 2012). Selection criteria Randomised or quasi-randomised trials. Data collection and analysis We assessed the methodological quality of trials using standard Cochrane criteria. Two review authors independently assessed trial eligibility, extracted data and conducted checks for accuracy. Main results This review includes 21 trials from 13 different countries, but only 18 trials (with 4072 women) reported on our outcomes of interest and contributed data to the review. All of these studies compared daily versus intermittent iron supplementation. Three studies provided iron alone, 12 iron+folic acid and three more iron plus multiple vitamins and minerals. Their methodological quality was mixed

  15. [Acute intermittent porphyria and inappropriate ADH syndrome].

    PubMed

    Tébar, M T; Aguilera, L

    2010-05-01

    A 44-year-old woman complained of abdominal pain of 4 days' duration accompanied by vomiting and painful urination. The admitting physician noted neurologic signs consistent with axonal polyneuropathy and hyponatremia. In the absence of other explanations for the syndrome, SIADH was diagnosed. Because of the nonspecific nature of the observations, the patient was assessed by various specialists and admitted to the anesthetic recovery unit due to worsening of neurologic signs and suspicion of acute intermittent porphyria. The diagnosis was confirmed by laboratory findings of elevated d-aminolevulinic acid and porphobilinogen levels and normal stool porphyrins. The patient improved with intravenous hematin infused over 4 days.

  16. Intermittency of principal stress directions within Arctic sea ice.

    PubMed

    Weiss, Jérôme

    2008-05-01

    The brittle deformation of Arctic sea ice is not only characterized by strong spatial heterogeneity as well as intermittency of stress and strain-rate amplitudes, but also by an intermittency of principal stress directions, with power law statistics of angular fluctuations, long-range correlations in time, and multifractal scaling. This intermittency is much more pronounced than that of wind directions, i.e., is not a direct inheritance of the turbulent forcing.

  17. Intermittency of principal stress directions within Arctic sea ice

    NASA Astrophysics Data System (ADS)

    Weiss, Jérôme

    2008-05-01

    The brittle deformation of Arctic sea ice is not only characterized by strong spatial heterogeneity as well as intermittency of stress and strain-rate amplitudes, but also by an intermittency of principal stress directions, with power law statistics of angular fluctuations, long-range correlations in time, and multifractal scaling. This intermittency is much more pronounced than that of wind directions, i.e., is not a direct inheritance of the turbulent forcing.

  18. High-intensity intermittent activities at school: controversies and facts.

    PubMed

    Ratel, S; Lazaar, N; Dore, E; Baquet, G; Williams, C A; Berthoin, S; Van Praagh, E; Bedu, M; Duche, P

    2004-09-01

    In comparison to continuous aerobic type activity, little is known about high-intensity intermittent physical activity in children. Repeated short-term high-intensity activities (> maximal aerobic speed and <10 s) are more characteristic of the spontaneous physical activity of children. Recent studies have shown during repetitive bouts of sprints separated by short recovery intervals, that prepubescent children compared with adults are more able to maintain their performance without substantial fatigue. Moreover, repetitive runs at high velocities (near and higher than the maximal aerobic speed) separated by short recovery periods may elicit a high oxygen consumption in children. Several studies using interval training programmes for 7 weeks, twice a week for 30 min in physical education lessons showed that children's aerobic performance (maximal O2 uptake, maximal aerobic speed) could be enhanced. Training based on these repeated short-term high-intensity exercises could also improve children's anaerobic performance (short-term muscle power, strength and speed). Current evidence suggests that recovery from high-intensity exercises is faster in children than in adults and that repeated runs at high velocities separated by short recovery intervals can improve both aerobic and anaerobic performance. Although continuous aerobic type activity is more scientifically established as a training mode, repeated short-term high-intensity exercises in physical education programmes should be considered to enhance aerobic, as well as, anaerobic fitness in children. PMID:15756166

  19. Diagnosing Intermittent and Persistent Faults using Static Bayesian Networks

    NASA Technical Reports Server (NTRS)

    Megshoel, Ole Jakob

    2010-01-01

    Both intermittent and persistent faults may occur in a wide range of systems. We present in this paper the introduction of intermittent fault handling techniques into ProDiagnose, an algorithm that previously only handled persistent faults. We discuss novel algorithmic techniques as well as how our static Bayesian networks help diagnose, in an integrated manner, a range of intermittent and persistent faults. Through experiments with data from the ADAPT electrical power system test bed, generated as part of the Second International Diagnostic Competition (DXC-10), we show that this novel variant of ProDiagnose diagnoses intermittent faults accurately and quickly, while maintaining strong performance on persistent faults.

  20. Study of intermittent field hardware failure data in digital electronics

    NASA Technical Reports Server (NTRS)

    Oneill, E. J.; Halverson, J. R.

    1980-01-01

    The collection and analysis of data concerning intermittent dailures in digital devices was performed using data from a computer design for shipboard usage. The failure data consisted of actual field failures classified by failure mechanisms and their likelihood of having been intermittent, potentially intermittent, or hard. Each class was studies with respect to computer operation in the ranges of 0 to 2,000 hours, 0 to 5, hours, and 0 to 10,000 hours. The study was done at the computer level as well as the microcircuit level. Results indicate that as age increases, the quasi-intermittent failure rate increases and the mean time to failure descreases.

  1. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5955 Intermittent... is a device attached to a mechanical ventilator that allows spontaneous breathing by a patient...

  2. Leak test fitting

    DOEpatents

    Pickett, P.T.

    A hollow fitting for use in gas spectrometry leak testing of conduit joints is divided into two generally symmetrical halves along the axis of the conduit. A clip may quickly and easily fasten and unfasten the halves around the conduit joint under test. Each end of the fitting is sealable with a yieldable material, such as a piece of foam rubber. An orifice is provided in a wall of the fitting for the insertion or detection of helium during testing. One half of the fitting also may be employed to test joints mounted against a surface.

  3. Leak test fitting

    DOEpatents

    Pickett, Patrick T.

    1981-01-01

    A hollow fitting for use in gas spectrometry leak testing of conduit joints is divided into two generally symmetrical halves along the axis of the conduit. A clip may quickly and easily fasten and unfasten the halves around the conduit joint under test. Each end of the fitting is sealable with a yieldable material, such as a piece of foam rubber. An orifice is provided in a wall of the fitting for the insertion or detection of helium during testing. One half of the fitting also may be employed to test joints mounted against a surface.

  4. Parameter estimation and optimal scheduling algorithm for a mathematical model of intermittent androgen suppression therapy for prostate cancer

    NASA Astrophysics Data System (ADS)

    Guo, Qian; Lu, Zhichang; Hirata, Yoshito; Aihara, Kazuyuki

    2013-12-01

    We propose an algorithm based on cross-entropy to determine parameters of a piecewise linear model, which describes intermittent androgen suppression therapy for prostate cancer. By comparing with clinical data, the parameter estimation for the switched system shows good fitting accuracy and efficiency. We further optimize switching time points for the piecewise linear model to obtain a feasible therapeutic schedule. The simulation results of therapeutic effect are superior to those of previous strategy.

  5. Adaptive intermittent control: A computational model explaining motor intermittency observed in human behavior.

    PubMed

    Sakaguchi, Yutaka; Tanaka, Masato; Inoue, Yasuyuki

    2015-07-01

    It is a fundamental question how our brain performs a given motor task in a real-time fashion with the slow sensorimotor system. Computational theory proposed an influential idea of feed-forward control, but it has mainly treated the case that the movement is ballistic (such as reaching) because the motor commands should be calculated in advance of movement execution. As a possible mechanism for operating feed-forward control in continuous motor tasks (such as target tracking), we propose a control model called "adaptive intermittent control" or "segmented control," that brain adaptively divides the continuous time axis into discrete segments and executes feed-forward control in each segment. The idea of intermittent control has been proposed in the fields of control theory, biological modeling and nonlinear dynamical system. Compared with these previous models, the key of the proposed model is that the system speculatively determines the segmentation based on the future prediction and its uncertainty. The result of computer simulation showed that the proposed model realized faithful visuo-manual tracking with realistic sensorimotor delays and with less computational costs (i.e., with fewer number of segments). Furthermore, it replicated "motor intermittency", that is, intermittent discontinuities commonly observed in human movement trajectories. We discuss that the temporally segmented control is an inevitable strategy for brain which has to achieve a given task with small computational (or cognitive) cost, using a slow control system in an uncertain variable environment, and the motor intermittency is the side-effect of this strategy. PMID:25897510

  6. Intermittent turbulence in flowing bacterial suspensions.

    PubMed

    Secchi, Eleonora; Rusconi, Roberto; Buzzaccaro, Stefano; Salek, M Mehdi; Smriga, Steven; Piazza, Roberto; Stocker, Roman

    2016-06-01

    Dense suspensions of motile bacteria, possibly including the human gut microbiome, exhibit collective dynamics akin to those observed in classic, high Reynolds number turbulence with important implications for chemical and biological transport, yet this analogy has remained primarily qualitative. Here, we present experiments in which a dense suspension of Bacillus subtilis bacteria was flowed through microchannels and the velocity statistics of the flowing suspension were quantified using a recently developed velocimetry technique coupled with vortex identification methods. Observations revealed a robust intermittency phenomenon, whereby the average velocity profile of the suspension fluctuated between a plug-like flow and a parabolic flow profile. This intermittency is a hallmark of the onset of classic turbulence and Lagrangian tracking revealed that it here originates from the presence of transient vortices in the active, collective motion of the bacteria locally reinforcing the externally imposed flow. These results link together two entirely different manifestations of turbulence and show the potential of the microfluidic approach to mimic the environment characteristic of certain niches of the human microbiome. PMID:27307513

  7. Intermittent turbulence in flowing bacterial suspensions.

    PubMed

    Secchi, Eleonora; Rusconi, Roberto; Buzzaccaro, Stefano; Salek, M Mehdi; Smriga, Steven; Piazza, Roberto; Stocker, Roman

    2016-06-01

    Dense suspensions of motile bacteria, possibly including the human gut microbiome, exhibit collective dynamics akin to those observed in classic, high Reynolds number turbulence with important implications for chemical and biological transport, yet this analogy has remained primarily qualitative. Here, we present experiments in which a dense suspension of Bacillus subtilis bacteria was flowed through microchannels and the velocity statistics of the flowing suspension were quantified using a recently developed velocimetry technique coupled with vortex identification methods. Observations revealed a robust intermittency phenomenon, whereby the average velocity profile of the suspension fluctuated between a plug-like flow and a parabolic flow profile. This intermittency is a hallmark of the onset of classic turbulence and Lagrangian tracking revealed that it here originates from the presence of transient vortices in the active, collective motion of the bacteria locally reinforcing the externally imposed flow. These results link together two entirely different manifestations of turbulence and show the potential of the microfluidic approach to mimic the environment characteristic of certain niches of the human microbiome.

  8. Game performance and intermittent hypoxic training

    PubMed Central

    Hinckson, E A; Hamlin, M J; Wood, M R; Hopkins, W G

    2007-01-01

    Live high‐train low altitude exposure simulated by hypoxic devices may improve athletic performance. In this study, intermittent normobaric hypoxia was achieved with the GO2altitude® hypoxicator to determine its effects on sea level performance in rugby players. Ten players were randomly assigned to two groups. Players in each group received 14 sessions of either hypoxic (10–15% O2) or normoxic (21% O2) exposure at rest over 14 consecutive days in a single blind fashion. Various performance measures were obtained consecutively in a single testing session pre‐ and post‐exposure. Effects of hypoxic exposure on maximum speed and sprint times were trivial (<1.0%) but unclear (90% likely range, ±5% to ±9%). In rugby simulation, hypoxic exposure produced impairments of peak power in two scrums (15%, ±8%; 9%, ±7%) and impairments of time in offensive sprints (7%, ±8%) and tackle sprints (11%, ±9%). Pending further research, rugby players would be unwise to use normobaric intermittent hypoxic exposure to prepare for games at sea level. PMID:17311807

  9. Muscle coordination changes during intermittent cycling sprints.

    PubMed

    Billaut, François; Basset, Fabien A; Falgairette, Guy

    2005-06-01

    Maximal muscle power is reported to decrease during explosive cyclical exercises owing to metabolic disturbances, muscle damage, and adjustments in the efferent neural command. The aim of the present study was to analyze the influence of inter-muscle coordination in fatigue occurrence during 10 intermittent 6-s cycling sprints, with 30-s recovery through electromyographic activity (EMG). Results showed a decrease in peak power output with sprint repetitions (sprint 1 versus sprint 10: -11%, P<0.01) without any significant modifications in the integrated EMG. The timing between the knee extensor and the flexor EMG activation onsets was reduced in sprint 10 (sprint 1 versus sprint 10: -90.2 ms, P<0.05), owing to an earlier antagonist activation with fatigue occurrence. In conclusion, the maximal power output, developed during intermittent cycling sprints of short duration, decreased possibly due to the inability of muscles to maintain maximal force. This reduction in maximal power output occurred in parallel to changes in the muscle coordination pattern after fatigue. PMID:15862899

  10. A family with acute intermittent porphyria.

    PubMed

    Billoo, Abdul Gaffar; Lone, Saira Waqar

    2008-05-01

    Porphyrias are inherited defects in heme metabolism that result in excessive secretion of porphyrins and porphyrin precursors. Porphyrias can be classified into acute, (neuropsychiatric), cutaneous and mixed forms. There are seven main types of porphyrias; acute intermittent porphyria and plumboporphyria are predominantly neuropsychiatric; congenital erythropoietic porphyria, porphyria cutanea tarda and erythropoietic protoporphyria have predominantly cutaneous manifestations and hereditary coproporphyria and variegate porphyria are classified as mixed as they both have neuropsychiatric and cutaneous features. They cause life-threatening attacks of neurovisceral symptoms that mimic many other acute medical and psychiatric conditions. Lack of clinical recognition often delays effective treatment, and inappropriate diagnostic tests may lead to misdiagnosis and inappropriate treatment. Although the specific enzyme and gene defect have been identified, diagnosis and treatment of these disorders present formidable challenges because their signs and symptoms mimic other common conditions. We present a case report of a 13 years old girl who suffers from acute intermittent porphyria and the family tree showing all members who suffer from it.

  11. Intermittent heat instabilities in an air plume

    NASA Astrophysics Data System (ADS)

    Le Mouël, Jean-Louis; Kossobokov, Vladimir G.; Perrier, Frederic; Morat, Pierre

    2016-08-01

    We report the results of heating experiments carried out in an abandoned limestone quarry close to Paris, in an isolated room of a volume of about 400 m3. A heat source made of a metallic resistor of power 100 W was installed on the floor of the room, at distance from the walls. High-quality temperature sensors, with a response time of 20 s, were fixed on a 2 m long bar. In a series of 24 h heating experiments the bar had been set up horizontally at different heights or vertically along the axis of the plume to record changes in temperature distribution with a sampling time varying from 20 to 120 s. When taken in averages over 24 h, the temperatures present the classical shape of steady-state plumes, as described by classical models. On the contrary, the temperature time series show a rich dynamic plume flow with intermittent trains of oscillations, spatially coherent, of large amplitude and a period around 400 s, separated by intervals of relative quiescence whose duration can reach several hours. To our knowledge, no specific theory is available to explain this behavior, which appears to be a chaotic interaction between a turbulent plume and a stratified environment. The observed behavior, with first-order factorization of a smooth spatial function with a global temporal intermittent function, could be a universal feature of some turbulent plumes in geophysical environments.

  12. Quantifying intermittency in the open drivebelt billiard

    NASA Astrophysics Data System (ADS)

    Dettmann, Carl P.; Georgiou, Orestis

    2012-06-01

    A "drivebelt" stadium billiard with boundary consisting of circular arcs of differing radius connected by their common tangents shares many properties with the conventional "straight" stadium, including hyperbolicity and mixing, as well as intermittency due to marginally unstable periodic orbits (MUPOs). Interestingly, the roles of the straight and curved sides are reversed. Here, we discuss intermittent properties of the chaotic trajectories from the point of view of escape through a hole in the billiard, giving the exact leading order coefficient limt →∞tP(t) of the survival probability P(t) which is algebraic for fixed hole size. However, in the natural scaling limit of small hole size inversely proportional to time, the decay remains exponential. The big distinction between the straight and drivebelt stadia is that in the drivebelt case, there are multiple families of MUPOs leading to qualitatively new effects. A further difference is that most marginal periodic orbits in this system are oblique to the boundary, thus permitting applications that utilise total internal reflection such as microlasers.

  13. Shearing of Materials with Intermittent Joints

    NASA Astrophysics Data System (ADS)

    Gerolymatou, Eleni; Triantafyllidis, Theodoros

    2016-07-01

    The strength of fractures is much lower as a rule than that of intact rock. As a result they play a controlling part in the mechanical behaviour in general and the failure in particular of rock mass. Though a large volume of experimental data is available on the shear resistance of joints, as well as on the propagation of single cracks, the same is not true for the mechanical behaviour of intermittent joints. The experimental data available in this case are limited and the strength of rock mass with intermittent joints is usually modelled using averaged values of cohesion or assuming the fractures to be continuous. In the present work, the results of simple shear tests on a series of gypsum specimens with pre-existing cracks are presented. Twelve different crack orientations and two normal stresses were tested. The hypothesis of averaged cohesion and the theory of fracture mechanics are used to reproduce the results. It is found that fracture mechanics provides a more suitable model for the experimental results, especially when crack interaction is taken into account.

  14. Regionalization of patterns of flow intermittence from gauging station records

    NASA Astrophysics Data System (ADS)

    Snelder, T. H.; Datry, T.; Lamouroux, N.; Larned, S. T.; Sauquet, E.; Pella, H.; Catalogne, C.

    2013-01-01

    Understanding large-scale patterns in flow intermittence is important for effective water resource management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times-series describing flow intermittence; the frequency of zero-flow periods (consecutive days of zero-flow) in each year of record (FREQ; yr-1), and the total number of zero-flow days in each year of record (DUR; days). These time series were used to calculate two indices for each station, the mean annual frequency of zero-flow periods (mFREQ; yr-1), and the mean duration of zero-flow periods (mDUR; days). Approximately 20% of stations had recorded at least one zero-flow period. Dissimilarities between pairs of gauges calculated from the annual times-series (FREQ and DUR) and geographic distances were weakly correlated, indicating that there was little spatial synchronization of zero-flow. A flow-regime classification for the gauging stations discriminated intermittent and perennial stations, and an intermittence classification grouped intermittent stations into three classes based on the values of mFREQ and mDUR. We used Random Forest (RF) models to relate the flow-regime and intermittence classifications to several environmental characteristics of the gauging station catchments. The RF model of the flow-regime classification had a cross-validated Cohen's kappa of 0.47, indicating fair performance and the intermittence classification had poor performance (cross-validated Cohen's kappa of 0.35). Both classification models identified significant environment-intermittence associations, in particular with regional-scale climate patterns and also catchment area, shape and slope. However, we suggest that the fair-to-poor performance of the classification models is because intermittence is also controlled by processes operating at scales smaller

  15. Regionalization of patterns of flow intermittence from gauging station records

    NASA Astrophysics Data System (ADS)

    Snelder, T. H.; Datry, T.; Lamouroux, N.; Larned, S. T.; Sauquet, E.; Pella, H.; Catalogne, C.

    2013-07-01

    Understanding large-scale patterns in flow intermittence is important for effective river management. The duration and frequency of zero-flow periods are associated with the ecological characteristics of rivers and have important implications for water resources management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times series describing flow intermittence; the frequency of zero-flow periods (consecutive days of zero flow) in each year of record (FREQ; yr-1), and the total number of zero-flow days in each year of record (DUR; days). These time series were used to calculate two indices for each station, the mean annual frequency of zero-flow periods (mFREQ; yr-1), and the mean duration of zero-flow periods (mDUR; days). Approximately 20% of stations had recorded at least one zero-flow period in their record. Dissimilarities between pairs of gauges calculated from the annual times series (FREQ and DUR) and geographic distances were weakly correlated, indicating that there was little spatial synchronization of zero flow. A flow-regime classification for the gauging stations discriminated intermittent and perennial stations, and an intermittence classification grouped intermittent stations into three classes based on the values of mFREQ and mDUR. We used random forest (RF) models to relate the flow-regime and intermittence classifications to several environmental characteristics of the gauging station catchments. The RF model of the flow-regime classification had a cross-validated Cohen's kappa of 0.47, indicating fair performance and the intermittence classification had poor performance (cross-validated Cohen's kappa of 0.35). Both classification models identified significant environment-intermittence associations, in particular with regional-scale climate patterns and also catchment area, shape

  16. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance.

    PubMed

    Baker, Lindsay B; Rollo, Ian; Stein, Kimberly W; Jeukendrup, Asker E

    2015-07-01

    Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1-2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30-60 g/h in the form of a 6%-7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a game

  17. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance.

    PubMed

    Baker, Lindsay B; Rollo, Ian; Stein, Kimberly W; Jeukendrup, Asker E

    2015-07-14

    Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1-2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30-60 g/h in the form of a 6%-7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a game

  18. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance

    PubMed Central

    Baker, Lindsay B.; Rollo, Ian; Stein, Kimberly W.; Jeukendrup, Asker E.

    2015-01-01

    Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1–2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a

  19. Physical Fitness and Counseling.

    ERIC Educational Resources Information Center

    Helmkamp, Jill M.

    Human beings are a delicate balance of mind, body, and spirit, so an imbalance in one domain affects all others. The purpose of this paper is to examine the effects that physical fitness may have on such human characteristics as personality and behavior. A review of the literature reveals that physical fitness is related to, and can affect,…

  20. Fitness in Disguise

    ERIC Educational Resources Information Center

    Williams, Neil F.; Germain, Jenna

    2008-01-01

    Physical fitness activities are often viewed as monotonous and tedious, so they fail to motivate students to become more physically active. This tedium could be relieved by using a "learning as play" strategy, widely used in other academic disciplines. This article describes how to incorporate fitness into a variety of games so that students do…

  1. Fitness and Americans.

    ERIC Educational Resources Information Center

    Nordholm, Catherine R.

    This document makes a number of observations about physical fitness in America. Among them are: (1) the symptoms of aging (fat accumulation, lowered basal metabolic rate, loss of muscular strength, reduction in motor fitness, reduction in work capacity, etc.) are not the result of disease but disuse; (2) society conditions the individual to…

  2. Fun & Fitness with Balloons

    ERIC Educational Resources Information Center

    Farrell, Anne; Faigenbaum, Avery; Radler, Tracy

    2010-01-01

    The urgency to improve fitness levels and decrease the rate of childhood obesity has been at the forefront of physical education philosophy and praxis. Few would dispute that school-age youth need to participate regularly in physical activities that enhance and maintain both skill- and health-related physical fitness. Regular physical activity…

  3. Fit for Life.

    ERIC Educational Resources Information Center

    Klahr, Gary Peter

    1992-01-01

    Although the 1980's fitness craze is wearing off and adults are again becoming "couch potatoes," this trend does not justify expansion of high school compulsory physical education requirements. To encourage commitment to lifetime physical fitness, the Phoenix (Arizona) Union High School District offers students private showers, relaxed uniform…

  4. Fitness: A Lifestyle Value.

    ERIC Educational Resources Information Center

    Hennyey, Donna J.

    1985-01-01

    Factors contributing to the evolution of fitness are discussed, and some of the challenges these hold for those in the fields of food and nutrition are identified. This includes a discussion of basic concepts of nutrition and exercise, misconceptions of nutrition and exercise, and fitness instructors as nutrition educators. (Author/CT)

  5. Equality of Fitness Centers

    ERIC Educational Resources Information Center

    Swoyer, Jesse O.

    2008-01-01

    The author, who has been a personal trainer for the past ten years, recently realized that all fitness centers are not equal. In February, he was able to participate in the grand opening of the Center for Independent Living of Central PA (CILCP), a fitness center that is designed to accommodate persons with disabilities living in the Central…

  6. Fit 2-B FATHERS.

    ERIC Educational Resources Information Center

    Maiorano, Joseph J.

    2001-01-01

    Fit 2-B FATHERS is a parenting-skills education program for incarcerated adult males. The goals of this program are for participants to have reduced recidivism rates and a reduced risk of their children acquiring criminal records. These goals are accomplished by helping participants become physically, practically, and socially fit for the demands…

  7. Dissipation Intermittency Increases Long-Distance Dispersal of Heavy Particles in the Canopy Sublayer

    NASA Astrophysics Data System (ADS)

    Duman, Tomer; Trakhtenbrot, Ana; Poggi, Davide; Cassiani, Massimo; Katul, Gabriel G.

    2016-04-01

    The dispersion of heavy particles such as seeds within canopies is evaluated using Lagrangian stochastic trajectory models, laboratory, and field experiments. Inclusion of turbulent kinetic energy dissipation rate intermittency is shown to increase long-distance dispersal (LDD) by contributing to the intermittent ejection of particles to regions of high mean velocity outside the canopy volume. Model evaluation against controlled flume experiments, featuring a dense rod canopy, detailed flow measurements, and imaged trajectories of spherical particles, demonstrates that superimposing a terminal velocity on the fluid velocity is insufficient to determine the particle dispersal kernel. Modifying the trajectory model by adding dissipation intermittency is found to be significant for dispersal predictions along with the addition of inertial and crossing trajectories' effects. Comparison with manual seed-release experiments in a forest using wind-dispersed seeds shows that the model captures most of the measured kernels when accepted uncertainties in plant area index and friction velocity are considered. Unlike the flume experiments, the model modifications for several wind-dispersed seeds have minor effects on short-distance dispersal. A large increase was predicted in LDD when including dissipation intermittency for the forest experiment. The main results suggest that fitting or calibrating models to the `main body' of measured kernels may not offer extrapolating foresight to LDD predictions. As inertial effects were found mostly negligible in the field conditions here, the extended trajectory model requires specifying only the seed's terminal velocity and a constant variance of the normalized dissipation rate. Therefore, the proposed modifications can be readily applied to classical trajectory models so as to improve LDD predictions.

  8. Human stick balancing: an intermittent control explanation.

    PubMed

    Gawthrop, Peter; Lee, Kwee-Yum; Halaki, Mark; O'Dwyer, Nicholas

    2013-12-01

    intermittent, and therefore, the continuous-time strategy cannot be correct. However, the model of intermittent control used in this paper is based on the virtual pivot continuous-time control scheme, handles time delays and moreover masquerades as the underlying continuous-time controller. In addition, the event-driven properties of intermittent control can explain experimentally observed variability.

  9. Intermittent versus Continuous Physiotherapy in Children with Cerebral Palsy

    ERIC Educational Resources Information Center

    Christiansen, Annette Sandahl; Lange, Christa

    2008-01-01

    The aim of this study was to compare the effect of the delivery of the same amount of intermittent versus continuous physiotherapy given to children with cerebral palsy (CP). This was organized either in an intermittent regime four times a week for 4 weeks alternating with a 6-week treatment pause, or a continuous once or twice a week regime, both…

  10. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... providing mechanical ventilation at a preset rate. (b) Classification. Class II (performance standards). ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intermittent mandatory ventilation attachment. 868... mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV)...

  11. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... providing mechanical ventilation at a preset rate. (b) Classification. Class II (performance standards). ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Intermittent mandatory ventilation attachment. 868... mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV)...

  12. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... providing mechanical ventilation at a preset rate. (b) Classification. Class II (performance standards). ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Intermittent mandatory ventilation attachment. 868... mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV)...

  13. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intermittent mandatory ventilation attachment. 868.5955 Section 868.5955 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV)...

  14. Bound by Children: Intermittent Cohabitation and Living Together Apart

    ERIC Educational Resources Information Center

    Cross-Barnet, Caitlin; Cherlin, Andrew; Burton, Linda

    2011-01-01

    In this article, we examine variations in low-income mothers' patterns of intermittent cohabitation and the voluntary and involuntary nature of these unions. Intermittent cohabitation involves couples living together and separating in repeating cycles. Using Three-City Study ethnographic data, we identified 45 low-income mothers involved in these…

  15. Limitations of inclusive fitness.

    PubMed

    Allen, Benjamin; Nowak, Martin A; Wilson, Edward O

    2013-12-10

    Until recently, inclusive fitness has been widely accepted as a general method to explain the evolution of social behavior. Affirming and expanding earlier criticism, we demonstrate that inclusive fitness is instead a limited concept, which exists only for a small subset of evolutionary processes. Inclusive fitness assumes that personal fitness is the sum of additive components caused by individual actions. This assumption does not hold for the majority of evolutionary processes or scenarios. To sidestep this limitation, inclusive fitness theorists have proposed a method using linear regression. On the basis of this method, it is claimed that inclusive fitness theory (i) predicts the direction of allele frequency changes, (ii) reveals the reasons for these changes, (iii) is as general as natural selection, and (iv) provides a universal design principle for evolution. In this paper we evaluate these claims, and show that all of them are unfounded. If the objective is to analyze whether mutations that modify social behavior are favored or opposed by natural selection, then no aspect of inclusive fitness theory is needed.

  16. Limitations of inclusive fitness

    PubMed Central

    Allen, Benjamin; Nowak, Martin A.; Wilson, Edward O.

    2013-01-01

    Until recently, inclusive fitness has been widely accepted as a general method to explain the evolution of social behavior. Affirming and expanding earlier criticism, we demonstrate that inclusive fitness is instead a limited concept, which exists only for a small subset of evolutionary processes. Inclusive fitness assumes that personal fitness is the sum of additive components caused by individual actions. This assumption does not hold for the majority of evolutionary processes or scenarios. To sidestep this limitation, inclusive fitness theorists have proposed a method using linear regression. On the basis of this method, it is claimed that inclusive fitness theory (i) predicts the direction of allele frequency changes, (ii) reveals the reasons for these changes, (iii) is as general as natural selection, and (iv) provides a universal design principle for evolution. In this paper we evaluate these claims, and show that all of them are unfounded. If the objective is to analyze whether mutations that modify social behavior are favored or opposed by natural selection, then no aspect of inclusive fitness theory is needed. PMID:24277847

  17. Family with intermittent maple syrup urine disease

    PubMed Central

    Valman, H. B.; Patrick, A. D.; Seakins, J. W. T.; Platt, J. W.; Gompertz, D.

    1973-01-01

    A family is described in which the 3 children presented with episodes of severe metabolic acidosis secondary to minor infections. 2 of them died, and 1 of these was severely retarded. The sole surviving child is 6 years old and is normal with respect to physical and mental development. Gas chromatography of the urine obtained during episodes of ketoacidosis showed the keto and hydroxy acids characteristic of maple syrup urine disease, and thin layer chromatography of the plasma and urine showed greatly increased concentrations of the branched chain amino acids. The urine and plasma of the surviving child was chromatographically normal between episodes. The leucocyte branched chain keto acid decarboxylase activity in this patient and her father was reduced. The range of features in this family with intermittent maple syrup urine disease illustrates the necessity for prompt and careful investigation of metabolic acidosis of unknown aetiology. PMID:4693464

  18. Modeling Power System Operation with Intermittent Resources

    SciTech Connect

    Marinovici, Maria C.; Kirkham, Harold; Glass, Kevin A.; Carlsen, Leif C.

    2013-02-27

    Electricity generating companies and power system operators face the need to minimize total fuel cost or maximize total profit over a given time period. These issues become optimization problems subject to a large number of constraints that must be satisfied simultaneously. The grid updates due to smart-grid technologies plus the penetration of intermittent re- sources in electrical grid introduce additional complexity to the optimization problem. The Renewable Integration Model (RIM) is a computer model of interconnected power system. It is intended to provide insight and advice on complex power systems management, as well as answers to integration of renewable energy questions. This paper describes RIM basic design concept, solution method, and the initial suite of modules that it supports.

  19. AN Fitting Reconditioning Tool

    NASA Technical Reports Server (NTRS)

    Lopez, Jason

    2011-01-01

    A tool was developed to repair or replace AN fittings on the shuttle external tank (ET). (The AN thread is a type of fitting used to connect flexible hoses and rigid metal tubing that carry fluid. It is a U.S. military-derived specification agreed upon by the Army and Navy, hence AN.) The tool is used on a drill and is guided by a pilot shaft that follows the inside bore. The cutting edge of the tool is a standard-size replaceable insert. In the typical Post Launch Maintenance/Repair process for the AN fittings, the six fittings are removed from the ET's GUCP (ground umbilical carrier plate) for reconditioning. The fittings are inspected for damage to the sealing surface per standard operations maintenance instructions. When damage is found on the sealing surface, the condition is documented. A new AN reconditioning tool is set up to cut and remove the surface damage. It is then inspected to verify the fitting still meets drawing requirements. The tool features a cone-shaped interior at 36.5 , and may be adjusted at a precise angle with go-no-go gauges to insure that the cutting edge could be adjusted as it wore down. One tool, one setting block, and one go-no-go gauge were fabricated. At the time of this reporting, the tool has reconditioned/returned to spec 36 AN fittings with 100-percent success of no leakage. This tool provides a quick solution to repair a leaky AN fitting. The tool could easily be modified with different-sized pilot shafts to different-sized fittings.

  20. Peritoneal infection in acute intermittent peritoneal dialysis.

    PubMed

    Sharma, Raj Kumar; Kumar, Jitendra; Gupta, Amit; Gulati, Sanjeev

    2003-11-01

    A prospective study was done to evaluate the incidence and microbiological trend of peritoneal infection in patients undergoing acute intermittent peritoneal dialysis (PD). Complete sterile procedure was ensured and at the completion of the procedure PD fluid was sent for bacteriological culture, sensitivity, and total and differential cell count. During the period September 2000 to February 2001 a total of 100 patients were evaluated. Male female ratio was 72:28. Mean age was 43.17 +/- 17.2 years. In 26 patients cyclers were used. Bacterial culture was positive in total of 30 cases (30%). Gram positive, Gram negative and mixed infection was found in 10%, 15%, and 5% respectively. Number of exchanges (31.61 +/- 7.7 vs. 31.3 +/- 6, p = 0.8) were similar and number of repositioning was significantly more in the infected group (23.3% vs. 11.4%, p < 0.01). Total cell count was significantly higher in infected group (274.3 +/- 502 vs. 31.25 +/- 79.34, p < 0.01). Among Gram +ve organisms Staphylococcus was found in 7, Enterococcus faecalis in 4 and Coryne bacterium sps. in 2 cases. Among Gram -ve organisms, E. coli was found in 4, Enterobacter in 3, Klebsiella 1, Pseudomonas 1, Acinetobacter arinatus 5, Acinetobacter baumani 3, and Citrobacter freundii 3. Mixed flora comprised of Enterococcus faecalis 3, Enterobacter 1, Staphlococcus 1, E. coli 3, Citrobacter 1, Acinobacter baumani 1. Although with the cyclers using collapsible bags, staphylococcus was not isolated, the total incidence of infection (11/26 cases) was not decreased with the use of cyclers. We conclude that in acute intermittent peritoneal dialysis the incidence of bacterial infection is 30% with preponderance of Gram -ve over Gram +ve organisms and organism of fecal origin being commoner than those of skin origin. Use of cycler-assisted over manual PD do not improve the incidence of infection. Repositioning of the stiff catheter significantly increases the incidence of infection.

  1. Influence of Dehydration on Intermittent Sprint Performance.

    PubMed

    Davis, Jon-Kyle; Laurent, C Matt; Allen, Kimberly E; Green, J Matt; Stolworthy, Nicola I; Welch, Taylor R; Nevett, Michael E

    2015-09-01

    This study examined the effects of dehydration on intermittent sprint performance and perceptual responses. Eight male collegiate baseball players completed intermittent sprints either dehydrated (DEHY) by 3% body mass or euhydrated (EU). Body mass was reduced through exercise in the heat with controlled fluid restriction occurring 1 day before the trial. Participants completed twenty-four 30-m sprints divided into 3 bouts of 8 sprints with 45 seconds of rest between each sprint and 3 minutes between each bout. Perceived recovery status (PRS) scale was recorded before the start of each trial. Heart rate (HR), ratings of perceived exertion (RPE) (0-10 OMNI scale), and perceived readiness (PR) scale were recorded after every sprint, and session RPE (SRPE) was recorded 20 minutes after completing the entire session. A 2 (condition) × 3 (bout of sprints) repeated-measures ANOVA revealed a significant main effect of condition on mean sprint time (p = 0.03), HR (p < 0.01), RPE (p = 0.01), and PR (p = 0.02). Post hoc tests showed significantly faster mean sprint times for EU vs. DEHY during the second (4.87 ± 0.29 vs. 5.03 ± 0.33 seconds; p = 0.01) and third bouts of sprints (4.91 ± 0.29 vs. 5.12 ± 0.44 seconds; p = 0.02). Heart rate was also significantly lower (p ≤ 0.05) for EU during the second and third bouts. Post hoc measures also showed significantly impaired (p ≤ 0.05) feelings of recovery (PRS) before exercise and increased (p ≤ 0.05) perceptual strain before each bout (PR) during the second and third bouts of repeated sprint work (i.e., RPE and PR) and after the total session (SRPE) in the DEHY condition. Dehydration impaired sprint performance, negatively altered perception of recovery status before exercise, and increased RPE and HR response.

  2. Intermittent drinking, oxytocin and human health.

    PubMed

    Pruimboom, L; Reheis, D

    2016-07-01

    Looking at a waterhole, it is surprising that so many animals share the same space without visible signs of anxiety or aggression. Although waterholes are the preferred feeding locations of large carnivores, waterholes are shared by all type of herbivores of all sizes and shapes, including elephants. Recent research shows that the homeostatic disturbances leading to the "thirst feeling" not only activate specific substances regulating water and mineral household, but also the "trust and love" hormone oxytocin, while decreasing the production of the typical stress hormone cortisol. People using drugs, seem to be in search for oxytocin, as evidenced in studies with individuals on drugs such as ecstasy and gamma-hydroxybyturate. Hot environment, drought and increased sweating also activate specific oxytocin-producing parts of the hypothalamus, just as breastfeeding does in mother and infant. Water homeostasis is the only allostatic system activating trust neuro-anatomy and we suggest that this is due to the fact that all animals depend on water, whereas food type is species specific. Our hypothesis; regulating drinking behaviour through intermittent bulk drinking could increase oxytocin signalling, recover human trust and increase health by down-regulation of stress axis activity and inflammatory activity of the immune system. Intermittent bulk drinking should be defined as water (including tea and coffee) drinking up to a feeling of satiety and regulated by a mild feeling of thirst. This would mean that people would not drink less quantity but less frequently and that's how all animals, but also human newborns behave. It is the latter group, which is probably the only group of humans with a normal fluid homeostasis. PMID:27241263

  3. Flared tube attachment fitting

    NASA Technical Reports Server (NTRS)

    Alkire, I. D.; King, J. P., Jr.

    1980-01-01

    Tubes can be flared first, then attached to valves and other flow line components, with new fitting that can be disassembled and reused. Installed fitting can be disassembled so parts can be inspected. It can be salvaged and reused without damaging flared tube; tube can be coated, tempered, or otherwise treated after it has been flared, rather than before, as was previously required. Fitting consists of threaded male portion with conical seating surface, hexagonal nut with hole larger than other diameter of flared end of tube, and split ferrule.

  4. Integrating the Levels of Person-Environment Fit: The Roles of Vocational Fit and Group Fit

    ERIC Educational Resources Information Center

    Vogel, Ryan M.; Feldman, Daniel C.

    2009-01-01

    Previous research on fit has largely focused on person-organization (P-O) fit and person-job (P-J) fit. However, little research has examined the interplay of person-vocation (P-V) fit and person-group (P-G) fit with P-O fit and P-J fit in the same study. This article advances the fit literature by examining these relationships with data collected…

  5. A clinical data validated mathematical model of prostate cancer growth under intermittent androgen suppression therapy

    NASA Astrophysics Data System (ADS)

    Portz, Travis; Kuang, Yang; Nagy, John D.

    2012-03-01

    Prostate cancer is commonly treated by a form of hormone therapy called androgen suppression. This form of treatment, while successful at reducing the cancer cell population, adversely affects quality of life and typically leads to a recurrence of the cancer in an androgen-independent form. Intermittent androgen suppression aims to alleviate some of these adverse affects by cycling the patient on and off treatment. Clinical studies have suggested that intermittent therapy is capable of maintaining androgen dependence over multiple treatment cycles while increasing quality of life during off-treatment periods. This paper presents a mathematical model of prostate cancer to study the dynamics of androgen suppression therapy and the production of prostate-specific antigen (PSA), a clinical marker for prostate cancer. Preliminary models were based on the assumption of an androgen-independent (AI) cell population with constant net growth rate. These models gave poor accuracy when fitting clinical data during simulation. The final model presented hypothesizes an AI population with increased sensitivity to low levels of androgen. It also hypothesizes that PSA production is heavily dependent on androgen. The high level of accuracy in fitting clinical data with this model appears to confirm these hypotheses, which are also consistent with biological evidence.

  6. Reach for Fitness.

    ERIC Educational Resources Information Center

    Simmons, Richard

    1986-01-01

    An excerpt is presented from a book offering fitness exercises for people with disabilities. The author reviews specific medical considerations of Down's Syndrome and examines nutritional concerns as well as precautions for a program of general exercise. (Author/CL)

  7. Exercise and Physical Fitness

    MedlinePlus

    ... Increase your chances of living longer Fitting regular exercise into your daily schedule may seem difficult at ... fine. The key is to find the right exercise for you. It should be fun and should ...

  8. The universal Higgs fit

    NASA Astrophysics Data System (ADS)

    Giardino, Pier Paolo; Kannike, Kristjan; Masina, Isabella; Raidal, Martti; Strumia, Alessandro

    2014-05-01

    We perform a state-of-the-art global fit to all Higgs data. We synthesise them into a `universal' form, which allows to easily test any desired model. We apply the proposed methodology to extract from data the Higgs branching ratios, production cross sections, couplings and to analyse composite Higgs models, models with extra Higgs doublets, supersymmetry, extra particles in the loops, anomalous top couplings, and invisible Higgs decays into Dark Matter. Best fit regions lie around the Standard Model predictions and are well approximated by our `universal' fit. Latest data exclude the dilaton as an alternative to the Higgs, and disfavour fits with negative Yukawa couplings. We derive for the first time the SM Higgs boson mass from the measured rates, rather than from the peak positions, obtaining M h = 124 .4 ± 1 .6 GeV.

  9. The Langley Fitness Center

    NASA Technical Reports Server (NTRS)

    1993-01-01

    NASA Langley recognizes the importance of healthy employees by committing itself to offering a complete fitness program. The scope of the program focuses on promoting overall health and wellness in an effort to reduce the risks of illness and disease and to increase productivity. This is accomplished through a comprehensive Health and Fitness Program offered to all NASA employees. Various aspects of the program are discussed.

  10. Fitting Galaxies on GPUs

    NASA Astrophysics Data System (ADS)

    Barsdell, B. R.; Barnes, D. G.; Fluke, C. J.

    2011-07-01

    Structural parameters are normally extracted from observed galaxies by fitting analytic light profiles to the observations. Obtaining accurate fits to high-resolution images is a computationally expensive task, requiring many model evaluations and convolutions with the imaging point spread function. While these algorithms contain high degrees of parallelism, current implementations do not exploit this property. With ever-growing volumes of observational data, an inability to make use of advances in computing power can act as a constraint on scientific outcomes. This is the motivation behind our work, which aims to implement the model-fitting procedure on a graphics processing unit (GPU). We begin by analysing the algorithms involved in model evaluation with respect to their suitability for modern many-core computing architectures like GPUs, finding them to be well-placed to take advantage of the high memory bandwidth offered by this hardware. Following our analysis, we briefly describe a preliminary implementation of the model fitting procedure using freely-available GPU libraries. Early results suggest a speed-up of around 10× over a CPU implementation. We discuss the opportunities such a speed-up could provide, including the ability to use more computationally expensive but better-performing fitting routines to increase the quality and robustness of fits.

  11. Inclusive fitness in agriculture

    PubMed Central

    Kiers, E. Toby; Denison, R. Ford

    2014-01-01

    Trade-offs between individual fitness and the collective performance of crop and below-ground symbiont communities are common in agriculture. Plant competitiveness for light and soil resources is key to individual fitness, but higher investments in stems and roots by a plant community to compete for those resources ultimately reduce crop yields. Similarly, rhizobia and mycorrhizal fungi may increase their individual fitness by diverting resources to their own reproduction, even if they could have benefited collectively by providing their shared crop host with more nitrogen and phosphorus, respectively. Past selection for inclusive fitness (benefits to others, weighted by their relatedness) is unlikely to have favoured community performance over individual fitness. The limited evidence for kin recognition in plants and microbes changes this conclusion only slightly. We therefore argue that there is still ample opportunity for human-imposed selection to improve cooperation among crop plants and their symbionts so that they use limited resources more efficiently. This evolutionarily informed approach will require a better understanding of how interactions among crops, and interactions with their symbionts, affected their inclusive fitness in the past and what that implies for current interactions. PMID:24686938

  12. Inclusive fitness in agriculture.

    PubMed

    Kiers, E Toby; Denison, R Ford

    2014-05-19

    Trade-offs between individual fitness and the collective performance of crop and below-ground symbiont communities are common in agriculture. Plant competitiveness for light and soil resources is key to individual fitness, but higher investments in stems and roots by a plant community to compete for those resources ultimately reduce crop yields. Similarly, rhizobia and mycorrhizal fungi may increase their individual fitness by diverting resources to their own reproduction, even if they could have benefited collectively by providing their shared crop host with more nitrogen and phosphorus, respectively. Past selection for inclusive fitness (benefits to others, weighted by their relatedness) is unlikely to have favoured community performance over individual fitness. The limited evidence for kin recognition in plants and microbes changes this conclusion only slightly. We therefore argue that there is still ample opportunity for human-imposed selection to improve cooperation among crop plants and their symbionts so that they use limited resources more efficiently. This evolutionarily informed approach will require a better understanding of how interactions among crops, and interactions with their symbionts, affected their inclusive fitness in the past and what that implies for current interactions.

  13. Inclusive fitness in agriculture.

    PubMed

    Kiers, E Toby; Denison, R Ford

    2014-05-19

    Trade-offs between individual fitness and the collective performance of crop and below-ground symbiont communities are common in agriculture. Plant competitiveness for light and soil resources is key to individual fitness, but higher investments in stems and roots by a plant community to compete for those resources ultimately reduce crop yields. Similarly, rhizobia and mycorrhizal fungi may increase their individual fitness by diverting resources to their own reproduction, even if they could have benefited collectively by providing their shared crop host with more nitrogen and phosphorus, respectively. Past selection for inclusive fitness (benefits to others, weighted by their relatedness) is unlikely to have favoured community performance over individual fitness. The limited evidence for kin recognition in plants and microbes changes this conclusion only slightly. We therefore argue that there is still ample opportunity for human-imposed selection to improve cooperation among crop plants and their symbionts so that they use limited resources more efficiently. This evolutionarily informed approach will require a better understanding of how interactions among crops, and interactions with their symbionts, affected their inclusive fitness in the past and what that implies for current interactions. PMID:24686938

  14. Mixing and diffusion in intermittent overturning turbulence

    NASA Astrophysics Data System (ADS)

    Redondo, Jose M.; Mahjoub, Otman B.; Gonzalez-Nieto, Pilar L.; Lawry, Andrew

    2014-05-01

    The improvements in experimental methods and high resolution image analysis are nowadays able to detect subtle changes in the structure of the turbulence over a wide range of temporal and spatial scales [1], we compare the scaling shown by different mixing fronts driven by buoyancy that form a Rayleigh-Taylor mixing front. We use PIV and density front tracking in several experimental configurations akin to geophysical overturning [2-7]. We parametrize the role of unstable stratification by means of the Atwood number and compare both the scaling and the multifractal and the maximum local fractal structure functions of the different markers used to visualize the front. Both reactive and passive scalar tracers are used to investigate the mixing structure and the intermittency of the flow. Different initial conditions are compared and the mixing efficiency of the overal turbulent process evaluated [6-7]. An interesting approach, relating the Multi-Fractal dimension spectra, the intermittency and the spectral exponent is to find relationships that may be used to parameterise the sub-grid turbulence in terms of generalized diffusivities [4 ] that take into account the topology and the self-similarity of the Mixing RT and RM flows. As an example, a relationship between the diffusivity, the exponent β, the intermittency μ, and D(i), may be found for the volume fraction or the concentration, at the same time other locally measured parameters such as the enstrophy or the gradient alignment as well as their multi-fractal structures may turn out to be physically relevant indicators of the local turbulence and the mixing. Several methods of deriving local eddy diffusivity and local entrainment should give more realistic estimates of the spatial/temporal non-homogeneities (and intermittencies in the Kolmogorov 62 sense obtained as spatial correlations of the turbulent dissipation, or from structure functions) and these values may be used to parameterise turbulence at a variety

  15. The Yo-Yo intermittent recovery test in basketball players.

    PubMed

    Castagna, Carlo; Impellizzeri, Franco M; Rampinini, Ermanno; D'Ottavio, Stefano; Manzi, Vincenzo

    2008-04-01

    The purpose of this study was to examine the physiological correlates of the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) in basketball players. Twenty-two male basketball players (means+/-S.D., body mass 72.4+/-11.4kg, height 181.7+/-6.9cm, age 16.8+/-2.0 years) were tested for maximal oxygen uptake (VO(2max)), ventilatory threshold (VT) and running economy (RE) on a motorized treadmill. Lower limb explosive strength and anaerobic-capacity was assessed using vertical jumps (CMJ), 15m shuttle running sprint (15mSR) and line drill (LD), respectively. The same test battery was replicated after an experimental basketball game in order to assess selective effect of fatigue on physical performance. Pre to post-game CMJ (40.3+/-5.7 versus 39.9+/-5.9cm) and 15mSR (5.80+/-0.25 versus 5.77+/-0.22s) performances were not significantly different (p>0.05). LD performance decreased significantly post-game (from 26.7+/-1.3 to 27.7+/-2.7s, p<0.001). Yo-Yo IR1 performances (m) were significantly related to VO(2max) (r=0.77, p=0.0001), speed at VO(2max) (r=0.71, p=0.0001) and %VO(2max) at VT (r=-0.60, p=0.04). Yo-Yo IR1 performance was significantly correlated to post-game LD decrements (r=-0.52, p=0.02). These findings show that Yo-Yo IR1 may be considered as a valid basketball-specific test for the assessment of aerobic fitness and game-related endurance.

  16. A study of intermittent flow in downward inclined pipes

    SciTech Connect

    Yang, J.; Sarica, C.; Chen, X.; Brill, J.P.

    1996-12-31

    The downward simultaneous flow of gas and liquid is often encountered in hilly terrain pipelines and steam injection wells. Most of the available methods for predicting the behavior of gas-liquid flow in pipes have been developed for horizontal and upward inclined pipes. In this study, co-current steady state slug flow in downward inclined pipes is investigated, experimentally and theoretically. A series of slug flow experiments are conducted with an air-kerosene system in a 2-in. diameter, 75-ft long pipe installed on an inclinable structure. Liquid holdup and pressure drop measurements are obtained for downward inclination angles from 0{degree} to {minus}90{degree} at different flow conditions. Correlations for slug flow characteristics are obtained based on the experimental data. A mechanistic model based on a unit cell approach has been proposed for the prediction of the detailed slug structure, and subsequently the pressure gradient. Fully developed slug flow could not be observed from {minus}50{degree} to {minus}90{degree}. A correlation was obtained for slug liquid holdup, and an analytical model and a correlation were developed for slug translational velocity. The lognormal distribution was found to best fit all the experimental slug length data. Equations for mean and design slug length were derived from the lognormal distribution function for inclination angles ranging from 0{degree} to {minus}30{degree}. A slug frequency correlation was also developed. The model can be used to predict intermittent flow behavior in downward inclined pipes. The correlations for slug liquid holdup, slug translational velocity, and slug length and frequency are closure relationships applicable to any model. Slug frequency information is also imperative for erosion and corrosion rate predictions.

  17. Rules, culture, and fitness.

    PubMed

    Baum, W M

    1995-01-01

    Behavior analysis risks intellectual isolation unless it integrates its explanations with evolutionary theory. Rule-governed behavior is an example of a topic that requires an evolutionary perspective for a full understanding. A rule may be defined as a verbal discriminative stimulus produced by the behavior of a speaker under the stimulus control of a long-term contingency between the behavior and fitness. As a discriminative stimulus, the rule strengthens listener behavior that is reinforced in the short run by socially mediated contingencies, but which also enters into the long-term contingency that enhances the listener's fitness. The long-term contingency constitutes the global context for the speaker's giving the rule. When a rule is said to be "internalized," the listener's behavior has switched from short- to long-term control. The fitness-enhancing consequences of long-term contingencies are health, resources, relationships, or reproduction. This view ties rules both to evolutionary theory and to culture. Stating a rule is a cultural practice. The practice strengthens, with short-term reinforcement, behavior that usually enhances fitness in the long run. The practice evolves because of its effect on fitness. The standard definition of a rule as a verbal statement that points to a contingency fails to distinguish between a rule and a bargain ("If you'll do X, then I'll do Y"), which signifies only a single short-term contingency that provides mutual reinforcement for speaker and listener. In contrast, the giving and following of a rule ("Dress warmly; it's cold outside") can be understood only by reference also to a contingency providing long-term enhancement of the listener's fitness or the fitness of the listener's genes. Such a perspective may change the way both behavior analysts and evolutionary biologists think about rule-governed behavior.

  18. Intermittent Renewable Management Pilot Phase 2

    SciTech Connect

    Kiliccote, Sila; Homan, Gregory; Anderson, Robert; Hernandez, John

    2015-04-01

    The Intermittent Renewable Management Pilot - Phase 2 (IRM2) was designed to study the feasibility of demand-side resources to participate into the California Independent System Operator (CAISO) wholesale market as proxy demand resources (PDR). The pilot study focused on understanding the issues related with direct participation of third-parties and customers including customer acceptance; market transformation challenges (wholesale market, technology); technical and operational feasibility; and value to the rate payers, DR resource owners and the utility on providing an enabling mechanism for DR resources into the wholesale markets. The customer had the option of committing to either three contiguous hour blocks for 24 days or six contiguous hours for 12 days a month with day-ahead notification that aligned with the CAISO integrated forward market. As a result of their being available, the customer was paid $10/ kilowatt (kW)-month for capacity in addition to CAISO energy settlements. The participants were limited to no more than a 2 megawatt (MW) capacity with a six-month commitment. Four participants successfully engaged in the pilot. In this report, we provide the description of the pilot, participant performance results, costs and value to participants as well as outline some of the issues encountered through the pilot. Results show that participants chose to participate with storage and the value of CAISO settlements were significantly lower than the capacity payments provided by the utility as incentive payments. In addition, this pilot revealed issues both on the participant side and system operations side. These issues are summarized in the report.The Intermittent Renewable Management Pilot - Phase 2 (IRM2) was designed to study the feasibility of demand-side resources to participate into the California Independent System Operator (CAISO) wholesale market as proxy demand resources (PDR). The pilot study focused on understanding the issues related with

  19. Ames Fitness Program

    NASA Technical Reports Server (NTRS)

    Pratt, Randy

    1993-01-01

    The Ames Fitness Program services 5,000 civil servants and contractors working at Ames Research Center. A 3,000 square foot fitness center, equipped with cardiovascular machines, weight training machines, and free weight equipment is on site. Thirty exercise classes are held each week at the Center. A weight loss program is offered, including individual exercise prescriptions, fitness testing, and organized monthly runs. The Fitness Center is staffed by one full-time program coordinator and 15 hours per week of part-time help. Membership is available to all employees at Ames at no charge, and there are no fees for participation in any of the program activities. Prior to using the Center, employees must obtain a physical examination and complete a membership package. Funding for the Ames Fitness Program was in jeopardy in December 1992; however, the employees circulated a petition in support of the program and collected more than 1500 signatures in only three days. Funding has been approved through October 1993.

  20. Coloring the FITS Universe

    NASA Astrophysics Data System (ADS)

    Levay, Z. G.

    2004-12-01

    A new, freely-available accessory for Adobe's widely-used Photoshop image editing software makes it much more convenient to produce presentable images directly from FITS data. It merges a fully-functional FITS reader with an intuitive user interface and includes fully interactive flexibility in scaling data. Techniques for producing attractive images from astronomy data using the FITS plugin will be presented, including the assembly of full-color images. These techniques have been successfully applied to producing colorful images for public outreach with data from the Hubble Space Telescope and other major observatories. Now it is much less cumbersome for students or anyone not experienced with specialized astronomical analysis software, but reasonably familiar with digital photography, to produce useful and attractive images.

  1. Ginga: Flexible FITS viewer

    NASA Astrophysics Data System (ADS)

    Jeschke, Eric

    2013-03-01

    Ginga is a viewer for astronomical data FITS (Flexible Image Transport System) files; the viewer centers around a FITS display widget which supports zooming and panning, color and intensity mapping, a choice of several automatic cut levels algorithms and canvases for plotting scalable geometric forms. In addition to this widget, the FITS viewer provides a flexible plugin framework for extending the viewer with many different features. A fairly complete set of "standard" plugins are provided for expected features of a modern viewer: panning and zooming windows, star catalog access, cuts, star pick/fwhm, thumbnails, and others. This viewer was written by software engineers at Subaru Telescope, National Astronomical Observatory of Japan, and is in use at that facility.

  2. Intermittent hypoxic training: fact and fancy.

    PubMed

    Levine, Benjamin D

    2002-01-01

    Intermittent hypoxic training (IHT) refers to the discontinuous use of normobaric or hypobaric hypoxia, in an attempt to reproduce some of the key features of altitude acclimatization, with the ultimate goal to improve sea-level athletic performance. In general, IHT can be divided into two different strategies: (1) providing hypoxia at rest with the primary goal being to stimulate altitude acclimatization or (2) providing hypoxia during exercise, with the primary goal being to enhance the training stimulus. Each approach has many different possible application strategies, with the essential variable among them being the "dose" of hypoxia necessary to achieve the desired effect. One approach, called living high-training low, has been shown to improve sea-level endurance performance. This strategy combines altitude acclimatization (2500 m) with low altitude training to ensure high-quality training. The opposite strategy, living low-training high, has also been proposed by some investigators. The primacy of the altitude acclimatization effect in IHT is demonstrated by the following facts: (1) living high-training low clearly improves performance in athletes of all abilities, (2) the mechanism of this improvement is primarily an increase in erythropoietin, leading to increased red cell mass, V(O2max), and running performance, and (3) rather than intensifying the training stimulus, training at altitude or under hypoxia leads to the opposite effect - reduced speeds, reduced power output, reduced oxygen flux - and therefore is not likely to provide any advantage for a well-trained athlete.

  3. Optimal Intermittent Reorientation in Insect Navigation

    NASA Astrophysics Data System (ADS)

    Peleg, Orit; Mahadevan, Lakshminarayanan; Applied Math Lab Team

    2015-03-01

    The process of navigation is often accompanied by several cognitive demanding activities, such as motor control, locomotion planning, and multi-sensory acquisition and integration. Organisms with limited cognitive resources must therefore multitask and develop optimal schemes to dynamically allocate resources to the different tasks. An extreme example of task alternations during navigation is the hallmark of ball rolling dung beetles. The beetles need to roll their dung-ball along a straight path away from the dung pile where intense competition occurs. Before initiating a roll, dung beetles climb on top of the ball and rotate about their vertical axis. This action serves as an orientation mechanism that allows them to set an initial bearing, and to regain this bearing if they experience an unintentional disturbance along the way. We developed a model inspired by the beetle's navigational scheme, where an agent performs a random walk intermittent by reorientation events, in which its heading direction is corrected. We show that the resultant paths are a characteristic of correlated diffusion in short time scale, and biased diffusion in the long time scale. We identify optimal alternation schemes and characterize their robustness upon introducing noisy sensory acquisition and rough environmental conditions.

  4. Acute Intermittent Porphyria in Argentina: An Update

    PubMed Central

    Cerbino, Gabriela Nora; Gerez, Esther Noemí; Varela, Laura Sabina; Melito, Viviana Alicia; Parera, Victoria Estela; Rossetti, María Victoria

    2015-01-01

    Porphyrias are a group of metabolic diseases that arise from deficiencies in the heme biosynthetic pathway. A partial deficiency in hydroxymethylbilane synthase (HMBS) produces a hepatic disorder named Acute Intermittent Porphyria (AIP); the acute porphyria is more frequent in Argentina. In this paper we review the results obtained for 101 Argentinean AIP families and 6 AIP families from foreign neighbour countries studied at molecular level at Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP). Thirty-five different mutations were found, of which 14 were described for the first time in our population. The most prevalent type of mutations was the missense mutations (43%) followed by splice defects (26%) and small deletions (20%). An odd case of a double heterozygous presentation of AIP in a foreign family from Paraguay is discussed. Moreover, it can be noted that 38 new families were found carrying the most frequent mutation in Argentina (p.G111R), increasing to 55.66% the prevalence of this genetic change in our population and adding further support to our previous hypothesis of a founder effect for this mutation in Argentina. Identification of patients with an overt AIP is important because treatment depends on an accurate diagnosis, but more critical is the identification of asymptomatic relatives to avoid acute attacks which may progress to death. PMID:26075277

  5. Acute intermittent porphyria in Argentina: an update.

    PubMed

    Cerbino, Gabriela Nora; Gerez, Esther Noemí; Varela, Laura Sabina; Melito, Viviana Alicia; Parera, Victoria Estela; Batlle, Alcira; Rossetti, María Victoria

    2015-01-01

    Porphyrias are a group of metabolic diseases that arise from deficiencies in the heme biosynthetic pathway. A partial deficiency in hydroxymethylbilane synthase (HMBS) produces a hepatic disorder named Acute Intermittent Porphyria (AIP); the acute porphyria is more frequent in Argentina. In this paper we review the results obtained for 101 Argentinean AIP families and 6 AIP families from foreign neighbour countries studied at molecular level at Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP). Thirty-five different mutations were found, of which 14 were described for the first time in our population. The most prevalent type of mutations was the missense mutations (43%) followed by splice defects (26%) and small deletions (20%). An odd case of a double heterozygous presentation of AIP in a foreign family from Paraguay is discussed. Moreover, it can be noted that 38 new families were found carrying the most frequent mutation in Argentina (p.G111R), increasing to 55.66% the prevalence of this genetic change in our population and adding further support to our previous hypothesis of a founder effect for this mutation in Argentina. Identification of patients with an overt AIP is important because treatment depends on an accurate diagnosis, but more critical is the identification of asymptomatic relatives to avoid acute attacks which may progress to death.

  6. Automated administration of intermittent intravenous doses.

    PubMed

    Lutomski, D M; Schwartz-Fulton, J; Rivera, J O

    1985-11-01

    The cost difference of administering cimetidine 300 mg via intravenous piggyback (IVPB) every six hours by a conventional separate container system versus using an automated intermittent i.v. administration system was evaluated. The study was conducted in two phases. Phase 1 documented the amount of drug waste with the two systems, and phase 2 examined the practical use of the IVAC Multi Dose System. Nurses who administered the medication using the multiple-dose system completed a questionnaire on its operation. A materials cost analysis was performed to compare the two methods. The two systems were found to have approximately equivalent amounts of drug waste over the 30-day evaluation period of phase 1. The mean percentage of doses wasted was 12.2% with the conventional single-dose minibag method and 12.7% with the automated multiple-dose method. The multiple-dose system had a lower cost per dose of cimetidine ($2.25 versus $3.47). These savings appear to outweigh the cost of the additional equipment necessary for the automated system. The majority of nurses preferred the multiple-dose system. Potential problems encountered in accurately delivering doses with the multiple-dose automated system were identified, and possible solutions are suggested. The use of an automated multiple-dose i.v. administration system can potentially decrease the materials cost portion of drug administration. The total impact on hospital costs needs to be evaluated, and other comparisons with alternative administration systems need to be performed.

  7. Defense styles in Intermittent Explosive Disorder.

    PubMed

    Puhalla, Alexander A; McCloskey, Michael S; Brickman, Lauren J; Fauber, Robert; Coccaro, Emil F

    2016-04-30

    The overreliance on immature and/or neurotic defense mechanisms, as opposed to more mature defensive functioning has been linked to several psychiatric disorders. However, to date, the role of defense styles among individuals with Intermittent Explosive Disorder (IED) has not been examined. Given that individuals with IED display difficulties controlling their anger and aggression, one might expect these individuals to exhibit more immature and less mature defense styles. The current study compared participants with IED to a personality disorder (PD) comparison group, as well as to healthy volunteers (HV) on the Defense Style Questionnaire, a self-report measure that assesses the extent to which individuals endorse using mature, immature, and neurotic defense styles. Subjects with IED had significantly higher scores than both comparison groups on immature defense styles and exhibited lower scores on mature defense mechanisms. Hierarchical regression of significant defense style subscales showed that higher levels of acting out and lower levels of sublimation uniquely discriminated participants with IED from the PD and HV comparison groups. PMID:27086223

  8. Cutaneous sporotrichosis. Intermittent treatment (pulses) with itraconazole.

    PubMed

    Bonifaz, Alexandro; Fierro, Leonel; Saúl, Amado; Ponce, Rosa María

    2008-01-01

    Sporotrichosis is a subcutaneous and exceptionally deep mycosis caused by a dimorphic fungus, Sporothrix schenckii. Itraconazole is a triazole derivative leading to good results in the treatment of sporotrichosis. Patients with cutaneous sporotrichosis proven with mycological tests (direct examination and culture) were enrolled. All patients underwent laboratory tests (at baseline and on a monthly basis) and received oral itraconazole 400 mg/day for one week with a 3-week break (pulses); thereafter the drug was administered as pulses until clinical and mycological cure was achieved. Five patients with sporotrichosis were enrolled, 4 with cutaneous lymphangitic form and one with fixed cutaneous form. Clinical and mycological cure was achieved in 4/5 cases (80%), with a mean number of pulses of 3.5. No patient had side effects and no laboratory test abnormalities occurred. Intermittent or pulsed itraconazole was effective in treating cutaneous sporotrichosis. It may be considered as a new treatment choice that entails an important reduction in total medication use.

  9. Defense styles in Intermittent Explosive Disorder.

    PubMed

    Puhalla, Alexander A; McCloskey, Michael S; Brickman, Lauren J; Fauber, Robert; Coccaro, Emil F

    2016-04-30

    The overreliance on immature and/or neurotic defense mechanisms, as opposed to more mature defensive functioning has been linked to several psychiatric disorders. However, to date, the role of defense styles among individuals with Intermittent Explosive Disorder (IED) has not been examined. Given that individuals with IED display difficulties controlling their anger and aggression, one might expect these individuals to exhibit more immature and less mature defense styles. The current study compared participants with IED to a personality disorder (PD) comparison group, as well as to healthy volunteers (HV) on the Defense Style Questionnaire, a self-report measure that assesses the extent to which individuals endorse using mature, immature, and neurotic defense styles. Subjects with IED had significantly higher scores than both comparison groups on immature defense styles and exhibited lower scores on mature defense mechanisms. Hierarchical regression of significant defense style subscales showed that higher levels of acting out and lower levels of sublimation uniquely discriminated participants with IED from the PD and HV comparison groups.

  10. Sex differences associated with intermittent swim stress.

    PubMed

    Warner, Timothy A; Libman, Matthew K; Wooten, Katherine L; Drugan, Robert C

    2013-11-01

    Various animal models of depression have been used to seek a greater understanding of stress-related disorders. However, there is still a great need for novel research in this area, as many individuals suffering from depression are resistant to current treatment methods. Women have a higher rate of depression, highlighting the need to investigate mechanisms of sex differences. Therefore, we employed a new animal model to assess symptoms of depression, known as intermittent swim stress (ISS). In this model, the animal experiences 100 trials of cold water swim stress. ISS has already been shown to cause signs of behavioral depression in males, but has yet to be assessed in females. Following ISS exposure, we looked at sex differences in the Morris water maze and forced swim test. The results indicated a spatial learning effect only in the hidden platform task between male and female controls, and stressed and control males. A consistent spatial memory effect was only seen for males exposed to ISS. In the forced swim test, both sexes exposed to ISS exhibited greater immobility, and the same males and females also showed attenuated climbing and swimming, respectively. The sex differences could be due to different neural substrates for males and females. The goal of this study was to provide the first behavioral examination of sex differences following ISS exposure, so the stage of estrous cycle was not assessed for the females. This is a necessary future direction for subsequent experiments. The current article highlights the importance of sex differences in response to stress.

  11. Linking the Fits, Fitting the Links: Connecting Different Types of PO Fit to Attitudinal Outcomes

    ERIC Educational Resources Information Center

    Leung, Aegean; Chaturvedi, Sankalp

    2011-01-01

    In this paper we explore the linkages among various types of person-organization (PO) fit and their effects on employee attitudinal outcomes. We propose and test a conceptual model which links various types of fits--objective fit, perceived fit and subjective fit--in a hierarchical order of cognitive information processing and relate them to…

  12. Factors relevant to utility integration of intermittent renewable technologies

    SciTech Connect

    Wan, Yih-huei; Parsons, B.K.

    1993-08-01

    This study assesses factors that utilities must address when they integrate intermittent renewable technologies into their power-supply systems; it also reviews the literature in this area and has a bibliography containing more than 350 listings. Three topics are covered: (1) interface (hardware and design-related interconnection), (2) operability/stability, and (3) planning. This study finds that several commonly held perceptions regarding integration of intermittent renewable energy technologies are not valid. Among findings of the study are the following: (1) hardware and system design advances have eliminated most concerns about interface; (2) cost penalties have not occurred at low to moderate penetration levels (and high levels are feasible); and (3) intermittent renewable energy technologies can have capacity values. Obstacles still interfering with intermittent renewable technologies are also identified.

  13. [Disease picture of neural intermittent claudication in lumbar spinal stenosis].

    PubMed

    Krüger, J; Tönnies, H; Senff, H

    1985-05-01

    The article reports on 56 patients on whom operation was performed for neurogenic intermittent claudication up to the end of 1983. The diagnostic, operative, and post-operative results are described in detail.

  14. Large-scale intermittency in two-dimensional driven turbulence

    NASA Astrophysics Data System (ADS)

    Jun, Yonggun; Wu, X. L.

    2005-09-01

    It is generally believed that two-dimensional turbulence is immune to intermittency possibly due to the absence of vortex stretching. However, in turbulence created in a freely suspended soap film by electromagnetic forcing, it is found that intermittency is not insignificant. We draw this conclusion based on the measured velocity structure function Sp(l)(≡⟨∣δvl∣p⟩)∝lζp on scales l greater than the energy injection scale linj . The scaling exponent ζp vs p deviates from the expected linear relation and shows intermittent behavior comparable to that observed in fully developed three-dimensional turbulence in wind tunnels. Our measurements demonstrate that intermittency can be accounted for by the nonuniform distribution of saddle points in the flow.

  15. Characterization of intermittency in renewal processes: Application to earthquakes

    SciTech Connect

    Akimoto, Takuma; Hasumi, Tomohiro; Aizawa, Yoji

    2010-03-15

    We construct a one-dimensional piecewise linear intermittent map from the interevent time distribution for a given renewal process. Then, we characterize intermittency by the asymptotic behavior near the indifferent fixed point in the piecewise linear intermittent map. Thus, we provide a framework to understand a unified characterization of intermittency and also present the Lyapunov exponent for renewal processes. This method is applied to the occurrence of earthquakes using the Japan Meteorological Agency and the National Earthquake Information Center catalog. By analyzing the return map of interevent times, we find that interevent times are not independent and identically distributed random variables but that the conditional probability distribution functions in the tail obey the Weibull distribution.

  16. Experimental and numerical study of the intermittency exponent mu

    NASA Technical Reports Server (NTRS)

    Praskovsky, Alexander

    1994-01-01

    After publication of the Kolmogorov refined similarity hypotheses, the small-scale intermittency of the energy dissipation field became a central problem in fully developed turbulence (FDT). This phenomenon has been studied in many different ways, e.g. by searching for corrections to scaling exponents in the inertial range velocity structure functions. A direct measure of this intermittency is, however, available by studying the local rate of energy dissipation, and it may be quantitatively characterized by the intermittency exponent mu. As far as we know, nobody has posed an obvious question: Is the intermittency exponent mu a unique constant, i.e., are the values mu(sub kappa), mu(sub epsilon), mu(sub r), mu(sub b), and mu(sub e) the same at high Reynolds numbers, or do they create a set of different (and perhaps independent) exponents? This paper addresses the above question using the high Reynolds number experiments.

  17. HARSHNESS: CHARACTERIZATION OF INTERMITTENT STREAM HABITAT OVER SPACE AND TIME

    EPA Science Inventory

    Frequently disturbed environments, such as intermittent streams, are ecologically useful for studying how disturbance characteristics (e.g., frequency, magnitude) affect community structure and succession. A harshness index summarizing spatial and temporal characteristics of pra...

  18. Intermittent/transient fault phenomena in digital systems

    NASA Technical Reports Server (NTRS)

    Masson, G. M.

    1977-01-01

    An overview of the intermittent/transient (IT) fault study is presented. An interval survivability evaluation of digital systems for IT faults is discussed along with a method for detecting and diagnosing IT faults in digital systems.

  19. Critical velocity during continuous and intermittent exercises in children.

    PubMed

    Berthoin, Serge; Baquet, Georges; Dupont, Gregory; Van Praagh, Emmanuel

    2006-09-01

    The purpose of this study was to apply the "critical velocity" concept to short intermittent high-intensity running exercises in prepubescent girls and boys and to compare the running performances obtained either by intermittent or continuous exercise runs. Eleven 8 to 11-year-old children underwent a maximal graded field test to determine peak oxygen uptake (peakVO2) and maximal aerobic velocity (MAV). During the six following sessions, they randomly performed three continuous runs (90, 100, and 110% of MAV) and three intermittent runs (120, 130, and 140% of MAV) until exhaustion. Intermittent exercises consisted of repeated 15 s runs each one separated by a 15 s passive recovery interval. For continuous as well as intermittent exercises, distance versus time to exhaustion (TTE) relationships were calculated to determine continuous (CVc) and intermittent (CVi) critical velocities. Values for peakVO2 and MAV were 45.8 +/- 5.3 ml x kg(-1) x min(-1) and 10.5 +/- 1.0 km h(-1), respectively. For the whole population, a significant relationship was found between the distance to exhaustion (DTE) and TTE for continuous (r2= 0.99, P < 0.05) and intermittent exercises (r2 = 0.99, P < 0.05). Significant relationships were found between peakVO2 and both CVc (r2= 0.60, P < 0.01) and CVi (r2= 0.47, P < 0.05). In conclusion, as for continuous exercises, a linear relationship was found between DTE and TTE for short high-intensity intermittent exercises. CVc was significantly related to peakVO2, while a significant lower relationship was found between peakVO2 and CVi.

  20. The minimum transition hypothesis for intermittent hierarchical motor control.

    PubMed

    Karniel, Amir

    2013-01-01

    In intermittent control, instead of continuously calculating the control signal, the controller occasionally changes this signal at certain sparse points in time. The control law may include feedback, adaptation, optimization, or any other control strategies. When, where, and how does the brain employ intermittency as it controls movement? These are open questions in motor neuroscience. Evidence for intermittency in human motor control has been repeatedly observed in the neural control of movement literature. Moreover, some researchers have provided theoretical models to address intermittency. Even so, the vast majority of current models, and I would dare to say the dogma in most of the current motor neuroscience literature involves continuous control. In this paper, I focus on an area in which intermittent control has not yet been thoroughly considered, the structure of muscle synergies. A synergy in the muscle space is a group of muscles activated together by a single neural command. Under the assumption that the motor control is intermittent, I present the minimum transition hypothesis (MTH) and its predictions with regards to the structure of muscle synergies. The MTH asserts that the purpose of synergies is to minimize the effort of the higher level in the hierarchy by minimizing the number of transitions in an intermittent control signal. The implications of the MTH are not only for the structure of the muscle synergies but also to the intermittent and hierarchical nature of the motor system, with various predictions as to the process of skill learning, and important implications to the design of brain machine interfaces and human robot interaction.

  1. Intermittent Turbulence in the Very Stable Ekman Layer

    SciTech Connect

    Barnard, James C.

    2001-01-05

    INTERMITTENT TURBULENCE IN THE VERY STABLE EKMAN LAYER This study describes a Direct Numerical Simulation (DNS) of a very stable Ekman layer in which a constant downward heat flux is applied at the lower boundary, thus cooling the fluid above. Numerical experiments were performed in which the strength of the imposed heat flux was varied. For downward heat fluxes above a certain critical value the turbulence becomes intermittent and, as the heat flux increases beyond this value, the flow tends to relaminarize because of the very strong ambient stratification. We adopt Mahrt?s (1999) definition of the very stable boundary layer as a boundary layer in which intermittent, rather than continuous turbulence, is observed. Numerical experiments were used to test various hypothesis of where in ?stability parameter space? the very stable boundary layer is found. These experiments support the findings of Howell and Sun (1999) that the boundary layer will exhibit intermittency and therefore be categorized as ?very stable?, when the stability parameter, z/L, exceeds unity. Another marker for the very stable boundary layer, Derbyshire?s (1990) maximum heat flux criterion, was also examined. Using a case study drawn from the simulations where turbulence intermittency was observed, the mechanism that causes the intermittence was investigated. It was found that patchy turbulence originates from a vigorous inflectional, Ekman-like instability -- a roll cell -- that lifts colder air over warmer air. The resulting convective instability causes an intense burst of turbulence. This turbulence is short-lived because the lifting motion of the roll cell, as well as the roll cell itself, is partially destroyed after the patchy turbulence is generated. Examples of intermittent turbulence obtained from the simulations appear to be consistent with observations of intermittency even though the Reynolds number of the DNS is relatively low (400).

  2. Curve Fit Challenge

    ERIC Educational Resources Information Center

    Harper, Suzanne R.; Driskell, Shannon

    2005-01-01

    Graphic tips for using the Geometer's Sketchpad (GSP) are described. The methods to import an image into GSP, define a coordinate system, plot points and curve fit the function using a graphical calculator are demonstrated where the graphic features of GSP allow teachers to expand the use of the technology application beyond the classroom.

  3. Talking Sport and Fitness

    ERIC Educational Resources Information Center

    Dixon-Watmough, Rebecca; Keogh, Brenda; Naylor, Stuart

    2012-01-01

    For some time the Association for Science Education (ASE) has been aware that it would be useful to have some resources available to get children talking and thinking about issues related to health, sport and fitness. Some of the questions about pulse, breathing rate and so on are pretty obvious to everyone, and there is a risk of these being…

  4. Finding What Fits

    ERIC Educational Resources Information Center

    Casey, Stephanie A.

    2016-01-01

    Statistical association between two variables is one of the fundamental statistical ideas in school curricula. Reasoning about statistical association has been deemed one of the most important cognitive activities that humans perform. Students are typically introduced to statistical association through the study of the line of best fit because it…

  5. Manual for physical fitness

    NASA Technical Reports Server (NTRS)

    Coleman, A. E.

    1981-01-01

    Training manual used for preflight conditioning of NASA astronauts is written for audience with diverse backgrounds and interests. It suggests programs for various levels of fitness, including sample starter programs, safe progression schedules, and stretching exercises. Related information on equipment needs, environmental coonsiderations, and precautions can help readers design safe and effective running programs.

  6. Fit for Life.

    ERIC Educational Resources Information Center

    Vail, Kathleen

    1999-01-01

    Children who hate gym grow into adults who associate physical activity with ridicule and humiliation. Physical education is reinventing itself, stressing enjoyable activities that continue into adulthood: aerobic dance, weight training, fitness walking, mountain biking, hiking, inline skating, karate, rock-climbing, and canoeing. Cooperative,…

  7. Kids Weigh to Fitness.

    ERIC Educational Resources Information Center

    Maione, Mary Jane

    A description is given of a program that provides preventive measures to check obesity in children and young people. The 24-week program is divided into two parts--a nutrition component and an exercise component. At the start and end of the program, tests are given to assess the participants' height, weight, body composition, fitness level, and…

  8. Water Fit to Drink.

    ERIC Educational Resources Information Center

    Donovan, Edward P.

    The major objective of this module is to help students understand how water from a source such as a lake is treated to make it fit to drink. The module, consisting of five major activities and a test, is patterned after Individualized Science Instructional System (ISIS) modules. The first activity (Planning) consists of a brief introduction and a…

  9. Manitoba Schools Fitness 1989.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education, Winnipeg.

    This manual outlines physical fitness tests that may be used in the schools. The tests are based on criterion standards which indicate the levels of achievement at which health risk factors may be reduced. Test theory, protocols, and criterion charts are presented for: (1) muscle strength and endurance, (2) body composition, (3) flexibility, and…

  10. Teaching Aerobic Fitness Concepts.

    ERIC Educational Resources Information Center

    Sander, Allan N.; Ratliffe, Tom

    2002-01-01

    Discusses how to teach aerobic fitness concepts to elementary students. Some of the K-2 activities include location, size, and purpose of the heart and lungs; the exercise pulse; respiration rate; and activities to measure aerobic endurance. Some of the 3-6 activities include: definition of aerobic endurance; heart disease risk factors;…

  11. Evaluation of the Intermittent Exotropia Questionnaire Using Rasch Analysis

    PubMed Central

    Leske, David A.; Holmes, Jonathan M.; Melia, B. Michele

    2015-01-01

    IMPORTANCE The Intermittent Exotropia Questionnaire (IXTQ) is a patient, proxy, and parental report of quality of life specific to children with intermittent exotropia. We refine the IXTQ using Rasch analysis to improve reliability and validity. OBSERVATION Rasch analysis was performed on responses of 575 patients with intermittent exotropia enrolled from May 15, 2008, through July 24, 2013, and their parents from each of the 4 IXTQ health-related quality-of-life questionnaires (child 5 through 7 years of age and child 8 through 17 years of age, proxy, and parent questionnaires). Questionnaire performance and structure were confirmed in a separate cohort of 379 patients with intermittent exotropia. One item was removed from the 12-item child and proxy questionnaires, and response options in the 8- to 17-year-old child IXTQ and proxy IXTQ were combined into 3 response options for both questionnaires. Targeting was relatively poor for the child and proxy questionnaires. For the parent questionnaire, 3 subscales (psychosocial, function, and surgery) were evident. One item was removed from the psychosocial subscale. Resulting subscales had appropriate targeting. CONCLUSIONS AND RELEVANCE The Rasch-revised IXTQ may be a useful instrument for determining how intermittent exotropia affects health-related quality of life of children with intermittent exotropia and their parents, particularly for cohort studies. PMID:25634146

  12. Suppression of methanogenesis in hydrogen fermentation by intermittent feeding.

    PubMed

    Yun, Jeonghee; Kim, Tae Gwan; Cho, Kyung-Suk

    2015-01-01

    This study investigated whether intermittent feeding by using a concentrated carbon source is an appropriate method for selective enrichment of hydrogenesis by means of methanogen suppression. In a conventional reactor fed continuously for 10 d, methanogens increased from 2.8 × 10(7) to 1.1 × 10(9) gene copy number (GCN)/mg-cell dry weight, and methane concentration in the resulting biogas was 5.8%. However, when a carbon source was intermittently supplied for 10 d to the reactor, the number of methanogens was reduced 98.9% from 2.77 × 10(7) to 1.2 × 10(3) GCN/mg-cell dry weight, and methane was not detected during this period of intermittent feeding. Intermittent feeding shifted the dominants in the reactor from Clostridiaceae (70.5%) and Lactobacillaceae (11.0%) to Acetobacteraceae (62.0%) and Clostridiaceae (38.0%). In the reactor operated in continuous feeding mode after intermittent feeding, methane concentration was below 0.3% and the portion of methanogens in the bacterial community was maintained below 0.2%. These results suggest that the intermittent feeding of a carbon source during hydrogen production processes is a suitable method to suppress the activity of methanogens. PMID:26325509

  13. Quantifying the Intermittency of Fractal Processes with Biological Applications

    NASA Astrophysics Data System (ADS)

    Bickel, David

    2001-03-01

    A number of biological phenomena tend to have intermittent departures from their typical dynamics. The extent to which a fractal is intermittent can be qualified and quantified by differential intermittency (DI) or finite-difference intermittency (FI), the degree to which the generalized Hurst exponents differ. The generalized codimensions of a singular measure are a special case of the FI of the corresponding devil's staircase. Intermittency has uses in data-model and data-data comparisons, e.g., an FI of the heart rate distinguishes healthy subjects from those with heart failure. An FI of the S&P 500 index implies that the stock market is also more intermittent than most previously proposed models. In addition, an FI of human activity quantifies restfulness at night. Viral DNA composition, on the other hand, has an FI of zero, reflecting its unifractal nature. DNA evolution has been modeled as a point process with a positive FI, consistent with mammalian sequence data, under the assumption of a common ancestor. Selected References: D. R. Bickel, Phys. Lett. A 262 (1999) 251; D. R. Bickel, Physica A 265 (1999) 634; D. R. Bickel, Fractals 8 (2000) 1; D. R. Bickel and B. J. West, J. Mol. Evol. 47 (1998) 551; abstracts on http://sonser4.uth.tmc.edu/research/db.htm.

  14. Modeling of Flow Transition Using an Intermittency Transport Equation

    NASA Technical Reports Server (NTRS)

    Suzen, Y. B.; Huang, P. G.

    1999-01-01

    A new transport equation for intermittency factor is proposed to model transitional flows. The intermittent behavior of the transitional flows is incorporated into the computations by modifying the eddy viscosity, mu(sub t), obtainable from a turbulence model, with the intermittency factor, gamma: mu(sub t, sup *) = gamma.mu(sub t). In this paper, Menter's SST model (Menter, 1994) is employed to compute mu(sub t) and other turbulent quantities. The proposed intermittency transport equation can be considered as a blending of two models - Steelant and Dick (1996) and Cho and Chung (1992). The former was proposed for near-wall flows and was designed to reproduce the streamwise variation of the intermittency factor in the transition zone following Dhawan and Narasimha correlation (Dhawan and Narasimha, 1958) and the latter was proposed for free shear flows and was used to provide a realistic cross-stream variation of the intermittency profile. The new model was used to predict the T3 series experiments assembled by Savill (1993a, 1993b) including flows with different freestream turbulence intensities and two pressure-gradient cases. For all test cases good agreements between the computed results and the experimental data are observed.

  15. Bladder emptying by intermittent electrical stimulation of the pudendal nerve

    NASA Astrophysics Data System (ADS)

    Boggs, Joseph W.; Wenzel, Brian J.; Gustafson, Kenneth J.; Grill, Warren M.

    2006-03-01

    Persons with a suprasacral spinal cord injury cannot empty their bladder voluntarily. Bladder emptying can be restored by intermittent electrical stimulation of the sacral nerve roots (SR) to cause bladder contraction. However, this therapy requires sensory nerve transection to prevent dyssynergic contraction of the external urethral sphincter (EUS). Stimulation of the compound pudendal nerve trunk (PN) activates spinal micturition circuitry, leading to a reflex bladder contraction without a reflex EUS contraction. The present study determined if PN stimulation could produce bladder emptying without nerve transection in cats anesthetized with α-chloralose. With all nerves intact, intermittent PN stimulation emptied the bladder (64 ± 14% of initial volume, n = 37 across six cats) more effectively than either distention-evoked micturition (40 ± 19%, p < 0.001, n = 27 across six cats) or bilateral intermittent SR stimulation (25 ± 23%, p < 0.005, n = 4 across two cats). After bilateral transection of the nerves innervating the urethral sphincter, intermittent SR stimulation voided 79 ± 17% (n = 12 across three cats), comparable to clinical results obtained with SR stimulation. Voiding via intermittent PN stimulation did not increase after neurotomy (p > 0.10), indicating that PN stimulation was not limited by bladder-sphincter dyssynergia. Intermittent PN stimulation holds promise for restoring bladder emptying following spinal injury without requiring nerve transection.

  16. Extensive fitness and human cooperation.

    PubMed

    van Hateren, J H

    2015-12-01

    Evolution depends on the fitness of organisms, the expected rate of reproducing. Directly getting offspring is the most basic form of fitness, but fitness can also be increased indirectly by helping genetically related individuals (such as kin) to increase their fitness. The combined effect is known as inclusive fitness. Here it is argued that a further elaboration of fitness has evolved, particularly in humans. It is called extensive fitness and it incorporates producing organisms that are merely similar in phenotype. The evolvability of this mechanism is illustrated by computations on a simple model combining heredity and behaviour. Phenotypes are driven into the direction of high fitness through a mechanism that involves an internal estimate of fitness, implicitly made within the organism itself. This mechanism has recently been conjectured to be responsible for producing agency and goals. In the model, inclusive and extensive fitness are both implemented by letting fitness increase nonlinearly with the size of subpopulations of similar heredity (for the indirect part of inclusive fitness) and of similar phenotype (for the phenotypic part of extensive fitness). Populations implementing extensive fitness outcompete populations implementing mere inclusive fitness. This occurs because groups with similar phenotype tend to be larger than groups with similar heredity, and fitness increases more when groups are larger. Extensive fitness has two components, a direct component where individuals compete in inducing others to become like them and an indirect component where individuals cooperate and help others who are already similar to them.

  17. Intermittency and Topology of Shock Induced Mixing

    NASA Astrophysics Data System (ADS)

    Tellez, Jackson; Redondo, Jose M.; Ben Mahjoub, Otman; Malik, Nadeem; Vila, Teresa

    2016-04-01

    The advance of a Rayleigh-Taylor front is described in Linden & Redondo (1991),[1-3] and may be shown to follow a quadratic law in time where the width of the growing region of instability depends on the local mixing efficiency of the different density fluids that accelerate against each other g is the acceleration and A is the Atwood number defined as the diference of densities divided by their sum. This results show the independence of the large amplitude structures on the initial conditions the width of the mixing region depends also on the intermittency of the turbulence. Then dimensional analysis may also depend on the relevant reduced acceleration driven time and the molecular reactive time akin to Damkholer number and the fractal structure of the contact zone [2,4]. Detailed experiments and simulations on RT and RM shock induced fronts analized with respect to structure functions are able to determine which mechanisms are most effective in local mixing which increase the effective fractal dimension, as well as the effect of higher order geometrical parameters, such as the structure functions, in non-homogeneous fluids (Mahjoub et al 1998)[5]. The structure of a Mixing blob shows a relatively sharp head with most of the mixing taking place at the sides due to what seems to be shear instability very similar to the Kelvin-Helmholtz instabilities, but with sideways accelerations. The formation of the blobs and spikes with their secondary instabilities produces a turbulent cascade, evident just after about 1 non-dimensional time unit, from a virtual time origin that takes into account the linear growth phase, as can be seen by the growth of the fractal dimension for different volume fractions. Two-dimensional cuts of the 3D flow also show that vortex flows have closed or spiral streamlines around their core. Examples of such flows can be also seen in the laboratory, for example at the interface of atwo-layer stratified fluid in a tank in which case streamlines

  18. Intermittency and Topology of Shock Induced Mixing

    NASA Astrophysics Data System (ADS)

    Tellez, Jackson; Redondo, Jose M.; Ben Mahjoub, Otman; Malik, Nadeem; Vila, Teresa

    2016-04-01

    The advance of a Rayleigh-Taylor front is described in Linden & Redondo (1991),[1-3] and may be shown to follow a quadratic law in time where the width of the growing region of instability depends on the local mixing efficiency of the different density fluids that accelerate against each other g is the acceleration and A is the Atwood number defined as the diference of densities divided by their sum. This results show the independence of the large amplitude structures on the initial conditions the width of the mixing region depends also on the intermittency of the turbulence. Then dimensional analysis may also depend on the relevant reduced acceleration driven time and the molecular reactive time akin to Damkholer number and the fractal structure of the contact zone [2,4]. Detailed experiments and simulations on RT and RM shock induced fronts analized with respect to structure functions are able to determine which mechanisms are most effective in local mixing which increase the effective fractal dimension, as well as the effect of higher order geometrical parameters, such as the structure functions, in non-homogeneous fluids (Mahjoub et al 1998)[5]. The structure of a Mixing blob shows a relatively sharp head with most of the mixing taking place at the sides due to what seems to be shear instability very similar to the Kelvin-Helmholtz instabilities, but with sideways accelerations. The formation of the blobs and spikes with their secondary instabilities produces a turbulent cascade, evident just after about 1 non-dimensional time unit, from a virtual time origin that takes into account the linear growth phase, as can be seen by the growth of the fractal dimension for different volume fractions. Two-dimensional cuts of the 3D flow also show that vortex flows have closed or spiral streamlines around their core. Examples of such flows can be also seen in the laboratory, for example at the interface of atwo-layer stratified fluid in a tank in which case streamlines

  19. Return to fitness.

    PubMed

    Dinubile, Nicholas A

    2008-12-01

    The cornerstone of personal health is prevention. The concept of exercise as medicine is a lesson I have preached throughout my career, both with my patients in my private practice as well as through my years working with athletes at all levels including the Philadelphia 76ers basketball team and the Pennsylvania Ballet. It is also a message I relayed as a Special Advisor to the President's Council on Physical Fitness and Sports (PCPFS) during the first Bush administration, working closely with my old friend-and fitness advocate and visionary himself-Governor Arnold Schwarzenegger, who served as Chairman to the PCPFS. Arnold's impact on our nation's health was an extremely positive one that was felt in communities from coast-to-coast. Exercise, activity, and prevention were key components of his prescription for change and improved health for our country. He has also always personally inspired me to see my role as a physician and "healer" in a much broader context.

  20. Health/Fitness Instructor's Handbook.

    ERIC Educational Resources Information Center

    Howley, Edward T.; Franks, B. Don

    This book identifies the components of physical fitness that are related to positive health as distinct from the simple performance of specific motor tasks. The positive health concept is expanded to further clarify the relationship of physical fitness to total fitness. The disciplinary knowledge base that is essential for fitness professionals is…

  1. Agriculture increases individual fitness.

    PubMed

    Kovaka, Karen; Santana, Carlos; Patel, Raj; Akçay, Erol; Weisberg, Michael

    2016-01-01

    We question the need to explain the onset of agriculture by appealing to the second type of multilevel selection (MLS2). Unlike eusocial insect colonies, human societies do not exhibit key features of evolutionary individuals. If we avoid the mistake of equating Darwinian fitness with health and quality of life, the adoption of agriculture is almost certainly explicable in terms of individual-level selection and individual rationality. PMID:27561384

  2. Metabolic Flux and Fitness

    PubMed Central

    Dykhuizen, Daniel E.; Dean, Antony M.; Hartl, Daniel L.

    1987-01-01

    Studies of Escherichia coli under competition for lactose in chemostat cultures have been used to determine the selective effects of variation in the level of the β-galactoside permease and the β-galactosidase enzyme. The results determine the adaptive topography of these gene products relative to growth in limiting lactose and enable predictions concerning the selective effects of genetic variants found in natural populations. In the terms of metabolic control theory, the β-galactosidase enzyme at wild-type-induced levels has a small control coefficient with respect to fitness (C = 0.018), and hence genetic variants resulting in minor changes in enzyme activity have disproportionately small effects on fitness. However, the apparent control coefficient of the β-galactoside permease at wild-type-induced levels is large (C = 0.551), and hence even minor changes in activity affect fitness. Therefore, we predict that genetic polymorphisms in the lacZ gene are subject to less effective selection in natural populations than are those in the lacY gene. The β-galactoside permease is also less efficient than might be expected, and possible forces resulting in selection for an intermediate optimum level of permease activity are considered. The selective forces that maintain the lactose operon in a regulated state in natural populations are also discussed. PMID:3104135

  3. Fitness and employee productivity.

    PubMed

    Howard, J; Mikalachki, A

    1979-09-01

    What should management consider when deciding whether to sponsor a company fitness program? This article gives pragmatic answers to the business community as well as outlining critical avenues for future research for both academics and corporations. Understanding the nature of the commitment is a prerequisite for success. Whether the program should be short term and serve as a catalyst for future individual efforts, or a long-term commitment, is a question which must be considered. Decisions of this type are partially dependent on what criteria are used to evaluate success. As measurements of employee productivity are very subjective or non-existent, absenteeism and turnover are potential yardsticks. Details of employee programs must also address the issue of participation as well as the frequency, intensity and duration. Future research must separate the effect of the fitness improvement from the benfits derived from just being in a program. The measurement of productivity and the long-term effect of fitness programs, especially short-term programs, are also areas for future work.

  4. Fitting the phenomenological MSSM

    SciTech Connect

    AbdusSalam, Shehu S.; Allanach, Benjamin C.; Quevedo, Fernando; Feroz, Farhan; Hobson, Mike

    2010-05-01

    We perform a global Bayesian fit of the phenomenological minimal supersymmetric standard model (pMSSM) to current indirect collider and dark matter data. The pMSSM contains the most relevant 25 weak-scale MSSM parameters, which are simultaneously fit using 'nested sampling' Monte Carlo techniques in more than 15 years of CPU time. We calculate the Bayesian evidence for the pMSSM and constrain its parameters and observables in the context of two widely different, but reasonable, priors to determine which inferences are robust. We make inferences about sparticle masses, the sign of the {mu} parameter, the amount of fine-tuning, dark matter properties, and the prospects for direct dark matter detection without assuming a restrictive high-scale supersymmetry breaking model. We find the inferred lightest CP-even Higgs boson mass as an example of an approximately prior-independent observable. This analysis constitutes the first statistically convergent pMSSM global fit to all current data.

  5. Precompetition taper and nutritional strategies: special reference to training during Ramadan intermittent fast.

    PubMed

    Mujika, Iñigo; Chaouachi, Anis; Chamari, Karim

    2010-06-01

    A marked reduction in the training load in the lead-up to major competitions allows athletes to reduce the fatigue induced by intense training and improve competition performance. This tapered training phase is based on the reduction in training volume while maintaining pretaper training intensity and frequency. In parallel to training load reductions, nutritional strategies characterised by lowered energy intakes need to be implemented to match lowered energy expenditure. The Ramadan intermittent fast imposes constrained nutritional practices on Muslim athletes, inducing a shift to a greater reliance on fat oxidation to meet energy needs and a possible increase in protein breakdown. The training load is often reduced during Ramadan to match the absence of energy and fluid intake during daylight, which implies a risk of losing training induced adaptations. Should coaches and athletes decide to reduce the training load during Ramadan, the key role of training intensity in retaining training induced adaptations should be kept in mind. However, experienced elite Muslim athletes are able to maintain their usual training load during this month of intermittent fasting without decrements in measures of fitness and with only minor adverse effects.

  6. Intermittent watt-level ultrasonication facilitates vancomycin release from therapeutic acrylic bone cement.

    PubMed

    Cai, Xun-Zi; Chen, Xian-Zhen; Yan, Shi-Gui; Ruan, Zou-Rong; Yan, Rui-Jian; Ji, Kang; Xu, Jia

    2009-07-01

    Ultrasound holds promise for enhancing the vancomycin release from cement though the length of time when local drug level exceeded the minimum inhibitory concentration (T(>MIC)) was not prolonged by the previous protocol of milliwatt-level ultrasonication. Here vancomycin-loaded cements were subjected to continuous watt-level ultrasonication (CUG), intermittent watt-level ultrasonication (IUG) or no ultrasonication (NUG) for 14 d during immersion in 40-ml phosphate buffered saline (PBS) for 28 d. The T(>MIC) for IUG was more than three times that for NUG. In contrast, T(>MIC) for CUG was slightly shortened. The subtherapeutic release of vancomycin between 15 d and 28 d for IUG was one-ninth that for NUG. The fitting equations indicated a significant enhancement on the burst release and the slow release for IUG; however, the continuous ultrasonication hampered the slow release. SEM images exhibited denser craters and pores with larger diameters and less residual drug in specimens from IUG relative to those from both CUG and NUG. Intermittent watt-level ultrasonication improved the ultrasound-enhanced vancomycin release from cement in view of the prolonged T(>MIC) and the inhibited subtherapeutic release compared with continuous ultrasonication. The mechanisms may be associated with the distinctive effects of detaching forces and pushing forces by acoustic microstreams. PMID:19090490

  7. Aerodynamics of intermittent bounds in flying birds

    NASA Astrophysics Data System (ADS)

    Tobalske, Bret W.; Hearn, Jason W. D.; Warrick, Douglas R.

    sagittal plane during upstroke of flapping flight, we hypothesize that body lift is produced during flapping phases. Future efforts to model the mechanics of intermittent flight should take into account that flap-bounding birds may support up to 20% of their weight even with their wings fully flexed.

  8. Aerodynamics of intermittent bounds in flying birds

    NASA Astrophysics Data System (ADS)

    Tobalske, Bret W.; Hearn, Jason W. D.; Warrick, Douglas R.

    2009-05-01

    sagittal plane during upstroke of flapping flight, we hypothesize that body lift is produced during flapping phases. Future efforts to model the mechanics of intermittent flight should take into account that flap-bounding birds may support up to 20% of their weight even with their wings fully flexed.

  9. Study of intermittency in e sup + e sup minus annihilations at 29 GeV

    SciTech Connect

    Abachi, S.; Derrick, M.; Kooijman, P.; Musgrave, B.; Price, L.; Repond, J.; Sugano, K. ); Blockus, D.; Brabson, B.; Brom, J.M.; Jung, C.; Ogren, H.; Rust, D.R. ); Cork, B. ); Akerlof, C.; Chapman, J.; Errede, D.; Ken, M.T.; Meyer, D.I.; Neal, H.; Nitz, D.; Thun, R.; Tschirhart, R. (Michigan Univ., Ann Arbor, MI (US

    1990-06-15

    Charged particle multiplicity distributions from e{sup +}e{sup {minus}} annihilations at 29 GeV have been analyzed in selected rapidity and azimuthal angle intervals. The data were taken with the High Resolution Spectrometer at PEP. The factorial moments of the multiplicity distributions increase as the rapidity interval is decreased, the so-called intermittency phenomenon. These direct measurements of the moments agree with values derived from negative binomial fits to our multiplicity distributions in various central rapidity windows. The factorial moments are also given for the distribution in azimuthal angle around the beam direction and for the two-dimensional distribution in rapidity and azimuthal angle around the jet directions.

  10. Intermittency on simultaneous observations of riometer at several Antarctic locations

    NASA Astrophysics Data System (ADS)

    Ovalle, E. M.; Foppiano, A. J.; Stepanova, M. V.; Weatherwax, A. T.

    2016-03-01

    It is well known that auroral radio wave absorption, as measured by riometers, consists of periods of relative quiescence which are interrupted by short bursts of activity. Such patterns in activity are observed in systems ranging from the stock market to turbulence, i.e. they exhibit intermittency. In the case of the auroral absorption it has also been found that intermittency strongly depends on the magnetic local time, being largest in the night-time sector. This can be interpreted as indicating that the precipitating particles responsible of the absorption exhibit intermittency, especially near the substorm eye, where the level of turbulence increases. Here, we analyse simultaneous observations of riometer absorption at seven Antarctic locations, to determine whether they exhibit intermittency. We determine the Probability Distribution Functions of the fluctuations of riometer absorption for absorption events larger than 0.1 dB, as well as those for the time-intervals between absorption events. Observations are for locations within the austral auroral absorption zone and on the polar cap. It is found that the parameters of a power law used to describe the calculated PDFs are consistent with the formation of coherent structures being more frequent within the auroral zone, as a manifestation of intermittency.

  11. Intermittent ambiguous stimuli: Implicit memory causes periodic perceptual alternations

    PubMed Central

    Brascamp, J. W.; Pearson, J.; Blake, R.; van den Berg, A. V.

    2009-01-01

    When viewing a stimulus that has multiple plausible real-world interpretations, perception alternates between these interpretations every few seconds. Alternations can be halted by intermittently removing the stimulus from view. The same interpretation dominates over many successive presentations, and perception stabilizes. Here we study perception during long sessions of such intermittent presentation. We demonstrate that, rather than causing truly stable perception, intermittent presentation gives rise to a perceptual alternation cycle with its own characteristics and dependencies, different from those during continuous presentation. Alternations during intermittent viewing typically occur once every few minutes—much less frequently than the seconds-scale alternations during continuous viewing. Strikingly, alternations during intermittent viewing occur at fairly regular intervals, making for a surprisingly periodic alternation cycle. The duration of this cycle becomes longer as the blank duration between presentations is increased, reaching dozens of minutes in some cases. We interpret our findings in terms of a mathematical model that describes a neural network with competition between alternative interpretations. Network sensitivities depend on prior dominance, thus providing a memory for past perception. Slow changes in sensitivity produce both perceptual stabilization and the regular but infrequent alternations, meaning that the same memory traces are responsible for both. This model provides a good description of psychophysical findings, and offers several indications regarding their neural basis. PMID:19757942

  12. Intermittent hypoxia induces functional recovery following cervical spinal injury

    PubMed Central

    Vinit, Stéphane; Lovett-Barr, Mary Rachael; Mitchell, Gordon S.

    2009-01-01

    Respiratory-related complications are the leading cause of death in spinal cord injury (SCI) patients. Few effective SCI treatments are available after therapeutic interventions are performed in the period shortly after injury (e.g. spine stabilization and prevention of further spinal damage). In this review we explore the capacity to harness endogenous spinal plasticity induced by intermittent hypoxia to optimize function of surviving (spared) neural pathways associated with breathing. Two primary questions are addressed: 1) does intermittent hypoxia induce plasticity in spinal synaptic pathways to respiratory motor neurons following experimental SCI? and 2) can this plasticity improve respiratory function? In normal rats, intermittent hypoxia induces serotonin-dependent plasticity in spinal pathways to respiratory motor neurons. Early experiments suggest that intermittent hypoxia also enhances respiratory motor output in experimental models of cervical SCI, (cervical hemisection) and that the capacity to induce functional recovery is greater with longer durations post-injury. Available evidence suggests that intermittent hypoxia-induced spinal plasticity has considerable therapeutic potential to treat respiratory insufficiency following chronic cervical spinal injury. PMID:19651247

  13. A Parameterization of Intermittent Turbulence in the Stable Boundary Layer

    SciTech Connect

    Lundquist, J K; Nitao, E N; Loosmore, G A

    2003-08-01

    This model explores the interaction between a cooling vegetated surface and the lower atmosphere. Neglecting any possibility of intermittence generated from the top of the stable boundary layer, the frequency of intermittency can be defined as a function of the three input quantities--pressure gradient force, cloud cover fraction, and boundary layer height. It is not clear if the amplitude of the intermittency and the time to reach a quasi-steady state can also be described as a function of the inputs. In addition, time-dependent inputs have an effect on the overall intermittency. Fluctuations in the pressure gradient force have the most influence in decreasing the periods while varying cloud cover fraction decreases the amplitude of the intermittence. It is unclear whether the transition time is affected by the fluctuating inputs. To gauge the sufficiency of this model, the results must be compared to experimental studies and models that include the forcing at the top of the stable boundary layer.

  14. Scaling the Thrust Production and Energetics of Inviscid Intermittent Swimming

    NASA Astrophysics Data System (ADS)

    Akoz, Emre; Moored, Keith

    2015-11-01

    Many fish have adopted an intermittent swimming gait sometimes referred as a burst-and-coast behavior. By using this gait, fish have been estimated at reducing their energetic cost of swimming by about 50%. Lighthill proposed that the skin friction drag of an undulating body can be around 400% greater than a rigidly-held coasting body, which may explain the energetic savings of intermittent swimming. Recent studies have confirmed the increase in skin friction drag over an undulating body, however, the increase is on the order of 20-70%. This more modest gain in skin friction drag is not sufficient to lead to the observed energy savings. Motivated by these observations, we investigate the inviscid mechanisms behind intermittent swimming for parameters typical of biology. We see that there is an energy savings at a fixed swimming speed for intermittent swimming as compared to continuous swimming. Then we consider three questions: What is the nature of the inviscid mechanism that leads to the observed energy savings, how do the forces and energetics of intermittent swimming scale with the swimming parameters, and what are the limitations to the benefit? Supported by the Office of Naval Research under Program Director Dr. Bob Brizzola, MURI grant number N00014-14-1-0533.

  15. Invasion fitness, inclusive fitness, and reproductive numbers in heterogeneous populations.

    PubMed

    Lehmann, Laurent; Mullon, Charles; Akçay, Erol; Van Cleve, Jeremy

    2016-08-01

    How should fitness be measured to determine which phenotype or "strategy" is uninvadable when evolution occurs in a group-structured population subject to local demographic and environmental heterogeneity? Several fitness measures, such as basic reproductive number, lifetime dispersal success of a local lineage, or inclusive fitness have been proposed to address this question, but the relationships between them and their generality remains unclear. Here, we ascertain uninvadability (all mutant strategies always go extinct) in terms of the asymptotic per capita number of mutant copies produced by a mutant lineage arising as a single copy in a resident population ("invasion fitness"). We show that from invasion fitness uninvadability is equivalently characterized by at least three conceptually distinct fitness measures: (i) lineage fitness, giving the average individual fitness of a randomly sampled mutant lineage member; (ii) inclusive fitness, giving a reproductive value weighted average of the direct fitness costs and relatedness weighted indirect fitness benefits accruing to a randomly sampled mutant lineage member; and (iii) basic reproductive number (and variations thereof) giving lifetime success of a lineage in a single group, and which is an invasion fitness proxy. Our analysis connects approaches that have been deemed different, generalizes the exact version of inclusive fitness to class-structured populations, and provides a biological interpretation of natural selection on a mutant allele under arbitrary strength of selection.

  16. Scenedesmus dimorphus biofilm: Photoefficiency and biomass production under intermittent lighting.

    PubMed

    Toninelli, Andrea Efrem; Wang, Junfeng; Liu, Mingshen; Wu, Hong; Liu, Tianzhong

    2016-01-01

    This study investigated the effect of intermittent lighting on the growth performances of a Scenedesmus dimorphus biofilm. Flashing light effect (FLE) is common in traditional suspended cultures of microalgae; yet, publications about this phenomenon, in the context of biofilm cultivation, are scarce. In this work we demonstrate that, thanks to intermittent illumination, it is possible for attached cultivations to fulfill FLE, improve photoefficiency and productivity as well as providing protection from photoinhibition using much lower flashing light frequencies than those usually required with suspended cultures. Medium frequency intermittent lighting (0.1 Hz) guaranteed excellent light integration resulting in 9.13 g m(-2) d(-1) biomass productivity, which was 8.9% higher than with continuous lighting. Results showed that a light fraction value of 0.5 always improved photoefficiency values as related to continuous light with a 118.8% maximum increase. PMID:27561323

  17. Scenedesmus dimorphus biofilm: Photoefficiency and biomass production under intermittent lighting

    PubMed Central

    Toninelli, Andrea Efrem; Wang, Junfeng; Liu, Mingshen; Wu, Hong; Liu, Tianzhong

    2016-01-01

    This study investigated the effect of intermittent lighting on the growth performances of a Scenedesmus dimorphus biofilm. Flashing light effect (FLE) is common in traditional suspended cultures of microalgae; yet, publications about this phenomenon, in the context of biofilm cultivation, are scarce. In this work we demonstrate that, thanks to intermittent illumination, it is possible for attached cultivations to fulfill FLE, improve photoefficiency and productivity as well as providing protection from photoinhibition using much lower flashing light frequencies than those usually required with suspended cultures. Medium frequency intermittent lighting (0.1 Hz) guaranteed excellent light integration resulting in 9.13 g m−2 d−1 biomass productivity, which was 8.9% higher than with continuous lighting. Results showed that a light fraction value of 0.5 always improved photoefficiency values as related to continuous light with a 118.8% maximum increase. PMID:27561323

  18. Acute intermittent porphyria with SIADH and fluctuating dysautonomia.

    PubMed

    Nabin, A; Thapa, L J; Paudel, R; Rana, P V S

    2012-01-01

    Three cases of acute intermittent porphyria are reported. While in first case severe pain in abdomen with intermittent exacerbation was the only presentation, the second patient presented as accelerated hypertension and acute abdominal crises in whom the clinical course was characterized by development of deep coma due to inappropriate secretion of antidiuretic hormone before she made complete recovery. The third patient, initially manifested as acute encephalitic syndrome. After initial improvement, she developed features of acute intermittent porphyria i.e. acute abdomen, neuropsychiatric symptoms, and rapidly progressing acute motor neuropathy leading to respiratory and bulbar paralysis. In addition, she developed severe and fluctuating dysautonomia leading to cardiac arrest and fatal termination. The importance of early diagnosis, recognition of autonomic disturbances, prompt treatment and counseling for avoidance of precipitating factors is stressed.

  19. Photonic integrated circuits unveil crisis-induced intermittency.

    PubMed

    Karsaklian Dal Bosco, Andreas; Akizawa, Yasuhiro; Kanno, Kazutaka; Uchida, Atsushi; Harayama, Takahisa; Yoshimura, Kazuyuki

    2016-09-19

    We experimentally investigate an intermittent route to chaos in a photonic integrated circuit consisting of a semiconductor laser with time-delayed optical feedback from a short external cavity. The transition from a period-doubling dynamics to a fully-developed chaos reveals a stage intermittently exhibiting these two dynamics. We unveil the bifurcation mechanism underlying this route to chaos by using the Lang-Kobayashi model and demonstrate that the process is based on a phenomenon of attractor expansion initiated by a particular distribution of the local Lyapunov exponents. We emphasize on the crucial importance of the distribution of the steady-state solutions introduced by the time-delayed feedback on the existence of this intermittent dynamics. PMID:27661954

  20. Complexity Induced Anisotropic Bimodal Intermittent Turbulence in Space Plasmas

    NASA Technical Reports Server (NTRS)

    Chang, Tom; Tam, Sunny W. Y.; Wu, Cheng-Chin

    2004-01-01

    The "physics of complexity" in space plasmas is the central theme of this exposition. It is demonstrated that the sporadic and localized interactions of magnetic coherent structures arising from the plasma resonances can be the source for the coexistence of nonpropagating spatiotemporal fluctuations and propagating modes. Non-Gaussian probability distribution functions of the intermittent fluctuations from direct numerical simulations are obtained and discussed. Power spectra and local intermittency measures using the wavelet analyses are presented to display the spottiness of the small-scale turbulent fluctuations and the non-uniformity of coarse-grained dissipation that can lead to magnetic topological reconfigurations. The technique of the dynamic renormalization group is applied to the study of the scaling properties of such type of multiscale fluctuations. Charged particle interactions with both the propagating and nonpropagating portions of the intermittent turbulence are also described.

  1. Obstructive sleep apnea and cancer: effects of intermittent hypoxia?

    PubMed

    Kukwa, Wojciech; Migacz, Ewa; Druc, Karolina; Grzesiuk, Elzbieta; Czarnecka, Anna M

    2015-01-01

    Obstructive sleep apnea (OSA) is a common disorder characterized by pauses in regular breathing. Apneic episodes lead to recurrent hypoxemia-reoxygenation cycles with concomitant cellular intermittent hypoxia. Studies suggest that intermittent hypoxia in OSA may influence tumorigenesis. This review presents recent articles on the potential role of OSA in cancer development. Relevant research has focused on: molecular pathways mediating the influence of intermittent hypoxia on tumor physiology, animal and epidemiological human studies linking OSA and cancer. Current data relating OSA to risk of neoplastic disease remain scarce, but recent studies reveal the potential for a strong relation. More work is, therefore, needed on the impact of OSA on many cancer-related aspects. Results may offer enlightenment for improved cancer diagnosis and treatment. PMID:26562000

  2. Temporal intermittency of energy dissipation in magnetohydrodynamic turbulence.

    PubMed

    Zhdankin, Vladimir; Uzdensky, Dmitri A; Boldyrev, Stanislav

    2015-02-13

    Energy dissipation in magnetohydrodynamic (MHD) turbulence is known to be highly intermittent in space, being concentrated in sheetlike coherent structures. Much less is known about intermittency in time, another fundamental aspect of turbulence which has great importance for observations of solar flares and other space or astrophysical phenomena. In this Letter, we investigate the temporal intermittency of energy dissipation in numerical simulations of MHD turbulence. We consider four-dimensional spatiotemporal structures, "flare events," responsible for a large fraction of the energy dissipation. We find that although the flare events are often highly complex, they exhibit robust power-law distributions and scaling relations. We find that the probability distribution of dissipated energy has a power-law index close to α≈1.75, similar to observations of solar flares, indicating that intense dissipative events dominate the heating of the system. We also discuss the temporal asymmetry of flare events as a signature of the turbulent cascade.

  3. Intermittency in Hall-magnetohydrodynamics with a strong guide field

    SciTech Connect

    Rodriguez Imazio, P.; Martin, L. N.; Dmitruk, P.; Mininni, P. D.

    2013-05-15

    We present a detailed study of intermittency in the velocity and magnetic field fluctuations of compressible Hall-magnetohydrodynamic turbulence with an external guide field. To solve the equations numerically, a reduced model valid when a strong guide field is present is used. Different values for the ion skin depth are considered in the simulations. The resulting data are analyzed computing field increments in several directions perpendicular to the guide field, and building structure functions and probability density functions. In the magnetohydrodynamic limit, we recover the usual results with the magnetic field being more intermittent than the velocity field. In the presence of the Hall effect, field fluctuations at scales smaller than the ion skin depth show a substantial decrease in the level of intermittency, with close to monofractal scaling.

  4. Bound by Children: Intermittent Cohabitation and Living Together Apart.

    PubMed

    Cross-Barnet, Caitlin; Cherlin, Andrew; Burton, Linda

    2011-12-01

    In this article, we examine variations in low-income mothers' patterns of intermittent cohabitation and the voluntary and involuntary nature of these unions. Intermittent cohabitation involves couples living together and separating in repeating cycles. Using Three-City Study ethnographic data, we identified 45 low-income mothers involved in these arrangements, 18 of whom resided with their children's fathers occasionally while saying that they were not in a cohabiting relationship. We term such relationships living together apart (LTA). Data analysis revealed that distinct patterns of voluntary and involuntary separations and reunifications characterized intermittent cohabitation and LTA and that these relationships were shaped by the bonds that shared parenting created and the economic needs of both parents. We argue that these dimensions may explain some disparate accounts of cohabitation status in low-income populations. They also demonstrate previously unexplored diversity in cohabiting relationships and suggest further questioning contemporary definitions of families.

  5. Intermittent hypoxia and respiratory plasticity in humans and other animals: does exposure to intermittent hypoxia promote or mitigate sleep apnoea?

    PubMed Central

    Mateika, Jason H.; Narwani, Gunjan

    2009-01-01

    This review focuses on two phenomena that are initiated during and after exposure to intermittent hypoxia. The two phenomena are referred to as long-term facilitation and progressive augmentation of respiratory motor output. Both phenomena are forms of respiratory plasticity. Long-term facilitation is characterized by a sustained elevation in respiratory activity after exposure to intermittent hypoxia. Progressive augmentation is characterized by a gradual increase in respiratory activity from the initial to the final hypoxic exposure. There is much speculation that long-term facilitation may have a significant role in individuals with sleep apnoea because this disorder is characterized by periods of upper airway collapse accompanied by intermittent hypoxia, one stimulus known to induce long-term facilitation. It has been suggested that activation of long-term facilitation may serve to mitigate apnoea by facilitating ventilation and, more importantly, upper airway muscle activity. We examine the less discussed but equally plausible situation that exposure to intermittent hypoxia might ultimately lead to the promotion of apnoea. There are at least two scenarios in which apnoea might be promoted following exposure to intermittent hypoxia. In both scenarios, long-term facilitation of upper airway muscle activity is initiated but ultimately rendered ineffective because of other physiological conditions. Thus, one of the primary goals of this review is to discuss, with support from basic and clinical studies, whether various forms of respiratory motor neuronal plasticity have a beneficial and/or a detrimental impact on breathing stability in individuals with sleep apnoea. PMID:19060117

  6. Bioenergetic and metabolic response to continuous v intermittent nasoenteric feeding.

    PubMed

    Heymsfield, S B; Casper, K; Grossman, G D

    1987-06-01

    Resting thermal energy losses and metabolic balances of N, K, P, Ca, Na, and Mg were compared during continuous and intermittent nasoenteric formula infusion in four healthy men. Each feeding protocol lasted 1 week in a 4-week double crossover experiment. The initial feeding schedule was established randomly. Continuous nasoenteric formula infusion produced no increase in thermal energy losses above the fasting level; energy expenditure fell with sleep to the same extent as with intermittent feeding. Thermal losses were similar during intermittent feeding with the exception of the thermic effect of food that produced an additional average energy loss of 115.7 kcal/d. The total resting and sleeping 24-hour energy expenditure was significantly lower (P less than .01) during continuous formula infusion (means +/- SD for n = 8 balance periods, 1344 +/- 119 kcal) compared to intermittent feeding (1457 +/- 179 kcal). No significant differences in nutrient absorption or balances of N, Na, Ca, and Mg were detected between the two feeding protocols. In contrast, continuous infusion of formula was accompanied by negative balances of K and the cytosolic portion of P; weight balance was slightly negative. Weight, K, and cytosolic P balances were all positive during intermittent feeding (P = NS, less than 0.01, and P less than .05 compared to respective continuous infusion periods). Hence, 1 week of continuous nasogastric formula infusion is associated with similar nutrient absorption, a significant reduction in thermal energy losses, and equivalent protein (N) balance relative to intermittent feeding. Differences in weight balance between the two feeding protocols can be ascribed largely to fluid and mineral shifts. These results suggest that energy requirements are lower during continuous formula infusion by about 100 kcal/d compared to regular meal ingestion. PMID:3108622

  7. Challenges to Cabin Humidity Removal Presented by Intermittent Condensing Conditions

    NASA Technical Reports Server (NTRS)

    vonJouanne, Roger G.; Williams, David E.

    2007-01-01

    On-orbit temperature and humidity control (THC) is more easily accomplished when the THC hardware is either consistently dry (i.e., no humidity control is occurring), or consistently wet. The system is especially challenged when intermittent wet/dry conditions occur. The first six years of on-orbit ISS operations have revealed specific concerns within the THC system, specifically in the condensing heat exchanger and the downstream air/water separator. Failed or degraded hardware has been returned to ground and investigated. This paper presents the investigation findings, and the recommended hardware and procedural revisions to prevent and recover from the effects of intermittent condensing conditions.

  8. Dealing with uncertainty in modeling intermittent water supply

    NASA Astrophysics Data System (ADS)

    Lieb, A. M.; Rycroft, C.; Wilkening, J.

    2015-12-01

    Intermittency in urban water supply affects hundreds of millions of people in cities around the world, impacting water quality and infrastructure. Building on previous work to dynamically model the transient flows in water distribution networks undergoing frequent filling and emptying, we now consider the hydraulic implications of uncertain input data. Water distribution networks undergoing intermittent supply are often poorly mapped, and household metering frequently ranges from patchy to nonexistent. In the face of uncertain pipe material, pipe slope, network connectivity, and outflow, we investigate how uncertainty affects dynamical modeling results. We furthermore identify which parameters exert the greatest influence on uncertainty, helping to prioritize data collection.

  9. [Evidence-based renal replacement therapy--intermittent versus CRRT].

    PubMed

    Jörres, Achim

    2013-03-01

    Continuous and intermittent renal replacement procedures are equally adequate therapies for acute kidney injury. The choice of modality should be made individually and on the basis of the specific clinical situation which may include switching between modalities during the course of treatment. In patients with haemodynamic instability or at risk of disequilibrium and cerebral edema CRRT or prolonged intermittent treatment may offer advantages whilst IHD should be preferred for the acute treatment of life-threatening electrolyte abnormalities or metabolic acidosis. Overall, the different modalities should be viewed as complementary.

  10. Solar flare intermittency and the earth's temperature anomalies.

    PubMed

    Scafetta, Nicola; West, Bruce J

    2003-06-20

    We argue that Earth's short-term temperature anomalies and the solar flare intermittency are linked. The analysis is based upon the study of the scaling of both the spreading and the entropy of the diffusion generated by the fluctuations of the temperature time series. The joint use of these two methods evidences the presence of a Lévy component in the temporal persistence of the temperature data sets that corresponds to the one that would be induced by the solar flare intermittency. The mean monthly temperature data sets cover the period from 1856 to 2002. PMID:12857233

  11. Teaching children and young people intermittent self-catheterization.

    PubMed

    Bray, Lucy; Sanders, Caroline

    2007-06-01

    The need to catheterize through the urethra can begin at any age and stage of development in a child's life and may involve different strategies for teaching. Intermittent self-catheterization, as a self-management technique, can be of benefit both physically and psychologically to children and young people. Educational strategies are available to aid health care providers in teaching children and young people self-intermittent catheterization. Use of innovative techniques and resources may assist the practitioner in teaching self-catheterization successfully to this challenging population.

  12. SE-FIT

    NASA Technical Reports Server (NTRS)

    Chen, Yongkang; Weislogel, Mark; Schaeffer, Ben; Semerjian, Ben; Yang, Lihong; Zimmerli, Gregory

    2012-01-01

    The mathematical theory of capillary surfaces has developed steadily over the centuries, but it was not until the last few decades that new technologies have put a more urgent demand on a substantially more qualitative and quantitative understanding of phenomena relating to capillarity in general. So far, the new theory development successfully predicts the behavior of capillary surfaces for special cases. However, an efficient quantitative mathematical prediction of capillary phenomena related to the shape and stability of geometrically complex equilibrium capillary surfaces remains a significant challenge. As one of many numerical tools, the open-source Surface Evolver (SE) algorithm has played an important role over the last two decades. The current effort was undertaken to provide a front-end to enhance the accessibility of SE for the purposes of design and analysis. Like SE, the new code is open-source and will remain under development for the foreseeable future. The ultimate goal of the current Surface Evolver Fluid Interface Tool (SEFIT) development is to build a fully integrated front-end with a set of graphical user interface (GUI) elements. Such a front-end enables the access to functionalities that are developed along with the GUIs to deal with pre-processing, convergence computation operation, and post-processing. In other words, SE-FIT is not just a GUI front-end, but an integrated environment that can perform sophisticated computational tasks, e.g. importing industry standard file formats and employing parameter sweep functions, which are both lacking in SE, and require minimal interaction by the user. These functions are created using a mixture of Visual Basic and the SE script language. These form the foundation for a high-performance front-end that substantially simplifies use without sacrificing the proven capabilities of SE. The real power of SE-FIT lies in its automated pre-processing, pre-defined geometries, convergence computation operation

  13. Florida's Fit to Achieve Program.

    ERIC Educational Resources Information Center

    Sander, Allan N.; And Others

    1993-01-01

    Describes Florida's "Fit to Achieve," a cardiovascular fitness education program for elementary students. Children are taught responsibility for their own cardiovascular fitness through proper exercise, personal exercise habits, and regular aerobic exercise. The program stresses collaborative effort between physical educators and classroom…

  14. Fit Indices Versus Test Statistics

    ERIC Educational Resources Information Center

    Yuan, Ke-Hai

    2005-01-01

    Model evaluation is one of the most important aspects of structural equation modeling (SEM). Many model fit indices have been developed. It is not an exaggeration to say that nearly every publication using the SEM methodology has reported at least one fit index. Most fit indices are defined through test statistics. Studies and interpretation of…

  15. Intermittent Screening and Treatment versus Intermittent Preventive Treatment of Malaria in Pregnancy: Provider Knowledge and Acceptability

    PubMed Central

    Smith Paintain, Lucy; Antwi, Gifty D.; Jones, Caroline; Amoako, Esther; Adjei, Rose O.; Afrah, Nana A.; Greenwood, Brian; Chandramohan, Daniel; Tagbor, Harry; Webster, Jayne

    2011-01-01

    Malaria in pregnancy (MiP) is associated with increased risks of maternal and foetal complications. The WHO recommends a package of interventions including intermittent preventive treatment (IPT) with sulphadoxine-pyrimethamine (SP), insecticide-treated nets and effective case management. However, with increasing SP resistance, the effectiveness of SP-IPT has been questioned. Intermittent screening and treatment (IST) has recently been shown in Ghana to be as efficacious as SP-IPT. This study investigates two important requirements for effective delivery of IST and SP-IPT: antenatal care (ANC) provider knowledge, and acceptance of the different strategies. Structured interviews with 134 ANC providers at 67 public health facilities in Ashanti Region, Ghana collected information on knowledge of the risks and preventative and curative interventions against MiP. Composite indicators of knowledge of SP-IPT, and case management of MiP were developed. Log binomial regression of predictors of provider knowledge was explored. Qualitative data were collected through in-depth interviews with fourteen ANC providers with some knowledge of IST to gain an indication of the factors influencing acceptance of the IST approach. 88.1% of providers knew all elements of the SP-IPT policy, compared to 20.1% and 41.8% who knew the treatment policy for malaria in the first or second/third trimesters, respectively. Workshop attendance was a univariate predictor of each knowledge indicator. Qualitative findings suggest preference for prevention over cure, and increased workload may be barriers to IST implementation. However, a change in strategy in the face of SP resistance is likely to be supported; health of pregnant women is a strong motivation for ANC provider practice. If IST was to be introduced as part of routine ANC activities, attention would need to be given to improving the knowledge and practices of ANC staff in relation to appropriate treatment of MiP. Health worker support for

  16. Effects of Intermittent Fasting, Caloric Restriction, and Ramadan Intermittent Fasting on Cognitive Performance at Rest and During Exercise in Adults.

    PubMed

    Cherif, Anissa; Roelands, Bart; Meeusen, Romain; Chamari, Karim

    2016-01-01

    The aim of this review was to highlight the potent effects of intermittent fasting on the cognitive performance of athletes at rest and during exercise. Exercise interacts with dietary factors and has a positive effect on brain functioning. Furthermore, physical activity and exercise can favorably influence brain plasticity. Mounting evidence indicates that exercise, in combination with diet, affects the management of energy metabolism and synaptic plasticity by affecting molecular mechanisms through brain-derived neurotrophic factor, an essential neurotrophin that acts at the interface of metabolism and plasticity. The literature has also shown that certain aspects of physical performance and mental health, such as coping and decision-making strategies, can be negatively affected by daylight fasting. However, there are several types of intermittent fasting. These include caloric restriction, which is distinct from fasting and allows subjects to drink water ad libitum while consuming a very low-calorie food intake. Another type is Ramadan intermittent fasting, which is a religious practice of Islam, where healthy adult Muslims do not eat or drink during daylight hours for 1 month. Other religious practices in Islam (Sunna) also encourage Muslims to practice intermittent fasting outside the month of Ramadan. Several cross-sectional and longitudinal studies have shown that intermittent fasting has crucial effects on physical and intellectual performance by affecting various aspects of bodily physiology and biochemistry that could be important for athletic success. Moreover, recent findings revealed that immunological variables are also involved in cognitive functioning and that intermittent fasting might impact the relationship between cytokine expression in the brain and cognitive deficits, including memory deficits. PMID:26438184

  17. Effects of Intermittent Fasting, Caloric Restriction, and Ramadan Intermittent Fasting on Cognitive Performance at Rest and During Exercise in Adults.

    PubMed

    Cherif, Anissa; Roelands, Bart; Meeusen, Romain; Chamari, Karim

    2016-01-01

    The aim of this review was to highlight the potent effects of intermittent fasting on the cognitive performance of athletes at rest and during exercise. Exercise interacts with dietary factors and has a positive effect on brain functioning. Furthermore, physical activity and exercise can favorably influence brain plasticity. Mounting evidence indicates that exercise, in combination with diet, affects the management of energy metabolism and synaptic plasticity by affecting molecular mechanisms through brain-derived neurotrophic factor, an essential neurotrophin that acts at the interface of metabolism and plasticity. The literature has also shown that certain aspects of physical performance and mental health, such as coping and decision-making strategies, can be negatively affected by daylight fasting. However, there are several types of intermittent fasting. These include caloric restriction, which is distinct from fasting and allows subjects to drink water ad libitum while consuming a very low-calorie food intake. Another type is Ramadan intermittent fasting, which is a religious practice of Islam, where healthy adult Muslims do not eat or drink during daylight hours for 1 month. Other religious practices in Islam (Sunna) also encourage Muslims to practice intermittent fasting outside the month of Ramadan. Several cross-sectional and longitudinal studies have shown that intermittent fasting has crucial effects on physical and intellectual performance by affecting various aspects of bodily physiology and biochemistry that could be important for athletic success. Moreover, recent findings revealed that immunological variables are also involved in cognitive functioning and that intermittent fasting might impact the relationship between cytokine expression in the brain and cognitive deficits, including memory deficits.

  18. How to measure inclusive fitness.

    PubMed

    Creel, S

    1990-09-22

    Although inclusive fitness (Hamilton 1964) is regarded as the basic currency of natural selection, difficulty in applying inclusive fitness theory to field studies persists, a quarter-century after its introduction (Grafen 1982, 1984; Brown 1987). For instance, strict application of the original (and currently accepted) definition of inclusive fitness predicts that no one should ever attempt to breed among obligately cooperative breeders. Much of this confusion may have arisen because Hamilton's (1964) original verbal definition of inclusive fitness was not in complete accord with his justifying model. By re-examining Hamilton's original model, a modified verbal definition of inclusive fitness can be justified.

  19. STATISTICS OF TURBULENT FIELD VARIATIONS, NON-GAUSSIANITY AND INTERMITTENCY

    SciTech Connect

    Ragot, B. R

    2009-05-10

    Statistics of magnetic field and velocity variations are important to the study of turbulence. Their departure from Gaussianity on the short separation scales has long been recognized and ascribed to intermittency. Non-Gaussian log-normal statistics of field-line separations are now predicted, however, from simple nonfluctuating turbulence Fourier spectra that do not model any intermittency, and one may wonder how this result may impact our interpretation of the statistics of field variations. It is shown in this paper how the intermittency of the turbulence can be taken into account to estimate the distributions of field-line separations and of field variations from the simple Fourier-spectra calculations. The first accurate theory/modeling predictions for the observed in situ distributions of turbulent field variations are thereby made, free of parameter adjustment. Magnetic field data from Helios 2 and Wind are used for the validation. Because the field variations are measured between points of constant separation and not between real field lines, intermittency remains the main cause for the observed non-Gaussianity of the statistics of field variations on the short scales, even if spatial limitations and/or short-scale phase correlations could also contribute to the deviations from Gaussianity.

  20. Challenges, developments and perspectives in intermittent river ecology

    EPA Science Inventory

    Although more than half the world's river networks comprise channels that periodically cease to flow and dry [intermittent rivers (IRs)], river ecology was largely developed from and for perennial systems. Ecological knowledge of IRs is rapidly increasing, so there is a need to s...

  1. Abnormal intermittency of heart rate in patients with neurocardiogenic syncope

    NASA Astrophysics Data System (ADS)

    Yum, Myung-Kul; Kim, Kyung-Sik; Kim, June-Soo

    2002-03-01

    Introduction: We aim to test our hypothesis that, during daily activity, though not as prominent as during HUT test, the patients may show different degree of intermittency in heart rates compared to healthy persons. METHOD AND RESULTS: Thirty patients with neurocardiogenic syncope who showed a positive HUT test and thirty healthy controls without history of syncope were included. Their twenty-four hour ambulatory electrocardiograms were digitized and RR interval (RRI) data of six-hour interval were analyzed. To quantify the intermittency (C1) behavior, The intermittency analysis was performed using Mexican hat wavelet. For the syncope group, the values of C1 were significantly higher at 6AM-6PM and lower at 6AM-midnight, respectively. However, the values were not different at midnight-6AM. The significant night-day circadian change shown in the control group was lost in C1. CONCLUSION: When compared to healthy control, the patients with neurocardiogenic syncope shows increased intermittency of heart rates in daytime during daily activity, and abnormal circadian rhythms of the index. These new findings may be useful for investigating the pathophysiology of neurocardiogenic syncope and early identification of the patients.

  2. Muscle Fatigue during Intermittent Exercise in Individuals with Mental Retardation

    ERIC Educational Resources Information Center

    Zafeiridis, Andreas; Giagazoglou, Paraskevi; Dipla, Konstantina; Salonikidis, Konstantinos; Karra, Chrisanthi; Kellis, Eleftherios

    2010-01-01

    This study examined fatigue profile during intermittent exercise in 10 men with mild to moderate mental retardation (MR) and 10 men without mental retardation (C). They performed 4 x 30 s maximal knee extensions and flexions with 1-min rest on an isokinetic dynamometer. Peak torque of flexors (PTFL) and extensors (PTEX), total work (TW), and…

  3. The Effects of Resource Intermittency on Electricity System Emissions

    NASA Astrophysics Data System (ADS)

    Sechrist, B.; Jacobson, M. Z.

    2015-12-01

    Since society subsidizes the production of renewable electricity in order to decrease emissions from the electric power system, it is important to quantify the environmental benefits of renewables. We use the intermittency characteristics of renewable resources to assess the impact of renewable generation on the emissions of carbon dioxide and other air pollutants. Previous studies have investigated the impact of wind or solar generation on emissions; rather than focusing on a particular technology, we separate the intermittent resource into its components - specifically variability, predictability, and timing - and isolate the effect of each component. For the Texas electricity grid, we use the observed outputs of generating units to econometrically estimate the effect of each intermittency characteristic on CO2, SO2, and NOx emissions. We then use the econometric results to evaluate and compare the expected emissions implications of adding different resources to the system. While the econometric estimates are derived from the wind currently online in Texas, the decomposition of the intermittency makes the results technology agnostic and allows for a comparison between prospective resources of different types. Preliminary results will be presented.

  4. 21 CFR 890.1600 - Intermittent pressure measurement system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Intermittent pressure measurement system. 890.1600 Section 890.1600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices §...

  5. Acute intermittent porphyria: Diagnostic dilemma and treatment options

    PubMed Central

    Kaur, Mohan Deep; Hazarika, Nita; Saraswat, Namita; Sood, Rajesh

    2015-01-01

    Acute intermittent porphyria (AIP) presents with diverse group of symptoms making its early diagnosis difficult. Delaying diagnosis and treatment of AIP can be fatal or can cause long term or permanent neurological damage. We present here a case report of AIP where the diagnosis was missed. The diversity of symptoms and details concerning the treatment options for AIP are discussed. PMID:26330726

  6. Mathematical analysis of intermittent gas injection model in oil production

    NASA Astrophysics Data System (ADS)

    Tasmi, Silvya, D. R.; Pudjo, S.; Leksono, M.; Edy, S.

    2016-02-01

    Intermittent gas injection is a method to help oil production process. Gas is injected through choke in surface and then gas into tubing. Gas forms three areas in tubing: gas column area, film area and slug area. Gas column is used to propel slug area until surface. A mathematical model of intermittent gas injection is developed in gas column area, film area and slug area. Model is expanding based on mass and momentum conservation. Using assume film thickness constant in tubing, model has been developed by Tasmi et. al. [14]. Model consists of 10 ordinary differential equations. In this paper, assumption of pressure in gas column is uniform. Model consist of 9 ordinary differential equations. Connection of several variables can be obtained from this model. Therefore, dynamics of all variables that affect to intermittent gas lift process can be seen from four equations. To study the behavior of variables can be analyzed numerically and mathematically. In this paper, simple mathematically analysis approach is used to study behavior of the variables. Variables that affect to intermittent gas injection are pressure in upstream valve and in gas column. Pressure in upstream valve will decrease when gas mass in valve greater than gas mass in choke. Dynamic of the pressure in the gas column will decrease and increase depending on pressure in upstream valve.

  7. Predicting and generalizing the refuge function of intermittent and ephemeral streams

    EPA Science Inventory

    Intermittent and ephemeral streams can provide important functions within stream networks. For fish, intermittent and ephemeral streams can contribute energy and materials to downstream perennial waters, serve as seasonal habitats, and/or provide refuge functions. Understanding t...

  8. Impacts of Urbanization and Intermittent Flow on Macroinvertebrates in Headwater Stream

    EPA Science Inventory

    Recent Supreme Court cases have brought increased attention to the contribution of intermittent waters to the health of downstream ecosystems. However, there is still limited knowledge on what factors are shaping these frequently disturbed intermittent stream communities. The obj...

  9. LINKING DERMAL MODELING AND LOADING DATA TO PREDICT LONG-TERM DOSES FROM INTERMITTENT DERMAL CONTACT

    EPA Science Inventory

    In this paper we assess dermal exposure and dose resulting from intermittent contact with residue-contaminated surfaces. These estimates require an understanding of (1) the quantitative relationship between exposure and absorbed dose; (2) the impact of intermittent exposure on ...

  10. Intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats.

    PubMed

    Chen, Xiaofei; Zhao, Tong; Huang, Xin; Wu, Liying; Wu, Kuiwu; Fan, Ming; Zhu, Lingling

    2016-05-01

    Increasing studies have shown protective effects of intermittent hypoxia on brain injury and heart ischemia. However, the effect of intermittent hypoxia on blood glucose metabolism, especially in diabetic conditions, is rarely observed. The aim of this study was to investigate whether intermittent hypoxia influences blood glucose metabolism in type 1 diabetic rats. Streptozotocin-induced diabetic adult rats and age-matched control rats were treated with intermittent hypoxia (at an altitude of 3 km, 4 h per day for 3 weeks) or normoxia as control. Fasting blood glucose, body weight, plasma fructosamine, plasma insulin, homeostasis model assessment of insulin resistance (HOMA-IR), pancreas β-cell mass, and hepatic and soleus glycogen were measured. Compared with diabetic rats before treatment, the level of fasting blood glucose in diabetic rats after normoxic treatment was increased (19.88 ± 5.69 mmol/L vs. 14.79 ± 5.84 mmol/L, p < 0.05), while it was not different in diabetic rats after hypoxic treatment (13.14 ± 5.77 mmol/L vs. 14.79 ± 5.84 mmol/L, p > 0.05). Meanwhile, fasting blood glucose in diabetic rats after hypoxic treatment was also lower than that in diabetic rats after normoxic treatment (13.14 ± 5.77 mmol/L vs. 19.88 ± 5.69 mmol/L, p<0.05). Plasma fructosamine in diabetic rats receiving intermittent hypoxia was significantly lower than that in diabetic rats receiving normoxia (1.28 ± 0.11 vs. 1.39 ± 0.11, p < 0.05), while there were no significant changes in body weight, plasma insulin and β-cell mass. HOMA-IR in diabetic rats after hypoxic treatment was also lower compared with diabetic rats after normoxic treatment (3.48 ± 0.48 vs. 3.86 ± 0.42, p < 0.05). Moreover, intermittent hypoxia showed effect on the increase of soleus glycogen but not hepatic glycogen. We conclude that intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats and its regulation on muscular

  11. Characterizing spatial and temporal patterns of intermittent rivers

    NASA Astrophysics Data System (ADS)

    de Vries, Stefan B.; Hoeve, Jasper; Sauquet, Eric; Leigh, Catherine; Bonada, Núria; Fike, Kimberly; Dahm, Clifford; Booij, Martijn J.; Datry, Thibault

    2015-04-01

    Intermittent rivers (IRs) support high biodiversity due to their dynamic alternations between terrestrial and aquatic phases. They represent a large proportion of the river network. However the current knowledge on these ecosystems is limited. The international research project "Intermittent River Biodiversity Analysis and Synthesis" (IRBAS, www.irbas.fr) aims to collect and analyze data on IR biodiversity from France, Spain, North America and Australia. These activities ultimately should help in identifying relationships between flow regime components and ecological responses. The IRBAS project will provide guidelines for policy-makers and resource managers for effective water and habitat management, restoration and preservation. This work examines one of the aspects in the IRBAS project: studying the large-scale spatial distribution of IRs as well as the year-to-year variability of zero-flow events. IRs were described by two variables: the frequency of periods without flow (FREQ) per time period (months or years) and the total number of zero-flow days (DUR) in a specified time window (month or year). Daily discharge data from more than 1700 gauging stations with no significant human influence on flow were collected from France, Spain, Australia and conterminous United States. A minimum length of 30 years of data starting from 1970 was required with less than 5% of missing data. Climate data for France and Australia were also collected. A classification of perennial versus intermittent rivers was defined, with 455 stations out of the 1684 considered "intermittent", i.e. the gauging station records had, on average, at least 5 zero-flow days per year. The analysis of the subset of IRs showed that: - Greater than 50% of the IRs in the database is located in Australia, where only 35% of the stations are considered perennial. In Spain the proportion of IRs reaches 25%. The proportion of intermittent rivers in France (7%) is certainly underestimated as a consequence of

  12. Sensitization of Parker fittings

    SciTech Connect

    Wilber, W.W.

    1985-09-01

    At your request, ferrules from 316 SS Parker-Hannifen compression fittings at the FFTF have been examined and evaluated to determine the metallurgical condition as related to carbide precipitation in grain boundaries (known as sensitization) and the implications this may have with regard to corrosion resistance. To accomplish this, two ferrules from new stock, two ferrules from old stock and two ferrules that had seen service were examined metallurgically. The samples were prepared for optical metallography. They were viewed in both the etched and unetched condition and analyzed on the scanning electron microscope (SEM) for elemental content. It was confirmed that the ferrules from new stock had a 5 mil thick nitrided layer on the ferrule ID at the lead end and that the 316 SS ferrule material was in the sensitized condition, indicating low resistance to aqueous corrosion. The material from old stock had no nitride layer but was in the sensitized condition indicating low resistance to aqueous corrosion. The ferrules that had seen service had not been nitrided and were not sensitized indicating high resistance to aqueous corrosion.

  13. Fitness in fluctuating environments

    NASA Astrophysics Data System (ADS)

    Tanase Nicola, Sorin; Nemenman, Ilya

    2011-03-01

    Often environments change faster than the time needed to evolve optimal phenotypes through cycles of mutation and selection. We focus on this case, but assume that environmental oscillations are slower than an individual's lifetime. This is relevant, for example, for bacterial populations confronted with daily environmental changes. We analyze a resource-limited competition between a mutant phenotype and the ancestor. Environmental dynamics is represented by periodically varying, off-phase parameters of the corresponding Lotka-Volterra model. For the very slow dynamics (but still faster than the fixation time scale) the strength and the sign of selection are functions of the birth/death rates averaged over all of the environmental states and independent of the period of the fluctuations. For faster fluctuations, selection depends on the particular sequence of the successive environmental states. In particular, a time reversal of the environmental dynamics can change the sign of the selection. We conclude that the fittest phenotype in a changing environment can be very different from both the optimal phenotype in the average environment, and the phenotype with the largest average fitness.

  14. Thermal degradation of groundnut oil during continuous and intermittent frying.

    PubMed

    Das, Amit K; Babylatha, R; Pavithra, A S; Khatoon, Sakina

    2013-12-01

    The quality of refined groundnut oil, as affected by frying Poori, was assessed with respect to two types of frying operations viz., continuous frying and intermittent frying. Continuous frying was carried out consistently for 8 h, whereas intermittent frying was performed for 2 h everyday for 4 days for a total of 8 frying hours. The purpose of the study was to compare the level of deterioration that occurred during the two operations. Among the parameters studied, peroxide value (11.3 ± 0.26 meqO2/kg), anisidine value (172.4 ± 2.71), diene value (1.57 ± 0.095), oxidized fatty acid (2.6 ± 0.17%) and viscosity (103.8 ± 2.5 mPa s(-1)), were found to be higher after 8 h due to intermittent frying. The corresponding values 4.9 ± 0.15, 133.3 ± 0.49, 0.811 ± 0.04, 0.38 ± 0.023 and 81.8 ± 2.02 were observed in continuous frying. Parameters such as iodine value, unsaturated fatty acids, saponification value and smoke point decreased significantly (P < 0.5) due to intermittent frying. Results showed that intermittent frying caused more quality degradation to GNO than continuous frying.

  15. The influence of continuous and intermittent traffic noise on sleep

    NASA Astrophysics Data System (ADS)

    Eberhardt, J. L.; Stråle, L.-O.; Berlin, M. H.

    1987-08-01

    The effects of road traffic noise on sleep were studied in the laboratory using nine young male adults (aged 20-26). The subjects were exposed to noise with different temporal characteristics: (i) continuous traffic noise of 36 dB(A) or 45 dB(A), (ii) intermittent noise of 50 truck passages with L pmax = 45 dB(A) ( L eq = 29 dB(A)) or L pmax = 55 dB(A) ( L eq = 36 dB(A)), and (iii) a combination of continuous (45 dB(A)) and intermittent ( L pmax = 55 dB(A)) traffic noise. For one noise condition (intermittent 55 dB(A)) the effect of the use of ear plugs was also studied. The intermittent noise of L pmax = 45 dB(A) caused transitions towards lighter sleep, whereas 55 dB(A) was needed to induce awakening effects. It could be shown that the probability for arousal reactions depends on the emergence of the noise peaks from the background, rather than the absolute noise peak level. Continuous traffic noise of 45 dB(A) caused REM sleep deficits, while intermittent traffic noise of L pmax = 45 dB(A) caused stage III+IV deficits. The night with ear plugs was virtually undisturbed. After nights with REM sleep deficits the subjective sleep quality was rated lower and mood was influenced adversely. For the types of exposure used in the present investigation L eq alone is not an adequate descriptor of the noise dose, relating to the sleep disturbances observed. From the present experiment, together with other existing data, it might be concluded that the WHO recommendation of L eq = 35 dB(A) is adequate, but should be supplemented with a maximum noise level, as expressed for example in L pmax or LI, that should not be exceeded.

  16. Ring intermittency near the boundary of the synchronous time scales of chaotic oscillators.

    PubMed

    Zhuravlev, Maxim O; Koronovskii, Alexey A; Moskalenko, Olga I; Ovchinnikov, Alexey A; Hramov, Alexander E

    2011-02-01

    In this Brief Report we study both experimentally and numerically the intermittent behavior taking place near the boundary of the synchronous time scales of chaotic oscillators being in the regime of time scale synchronization. We have shown that the observed type of the intermittent behavior should be classified as the ring intermittency.

  17. TransFit: Finite element analysis data fitting software

    NASA Technical Reports Server (NTRS)

    Freeman, Mark

    1993-01-01

    The Advanced X-Ray Astrophysics Facility (AXAF) mission support team has made extensive use of geometric ray tracing to analyze the performance of AXAF developmental and flight optics. One important aspect of this performance modeling is the incorporation of finite element analysis (FEA) data into the surface deformations of the optical elements. TransFit is software designed for the fitting of FEA data of Wolter I optical surface distortions with a continuous surface description which can then be used by SAO's analytic ray tracing software, currently OSAC (Optical Surface Analysis Code). The improved capabilities of Transfit over previous methods include bicubic spline fitting of FEA data to accommodate higher spatial frequency distortions, fitted data visualization for assessing the quality of fit, the ability to accommodate input data from three FEA codes plus other standard formats, and options for alignment of the model coordinate system with the ray trace coordinate system. TransFit uses the AnswerGarden graphical user interface (GUI) to edit input parameters and then access routines written in PV-WAVE, C, and FORTRAN to allow the user to interactively create, evaluate, and modify the fit. The topics covered include an introduction to TransFit: requirements, designs philosophy, and implementation; design specifics: modules, parameters, fitting algorithms, and data displays; a procedural example; verification of performance; future work; and appendices on online help and ray trace results of the verification section.

  18. Beyond power laws: a new approach for analyzing single molecule photoluminescence intermittency.

    PubMed

    Riley, E A; Hess, C M; Whitham, P J; Reid, P J

    2012-05-14

    The photoluminescence intermittency (PI) exhibited by single emitters has been studied for over a decade. To date, the vast majority of PI analyses involve parsing the data into emissive and non-emissive events, constructing histograms of event durations, and fitting these histograms to either exponential or power law probability distributions functions (PDFs). Here, a new method for analyzing PI data is presented where the data are used directly to construct a cumulative distribution function (CDF), and maximum-likelihood estimation techniques are used to determine the best fit of a model PDF to the CDF. Statistical tests are then employed to quantitatively evaluate the hypothesis that the CDF (data) is represented by the model PDF. The analysis method is outlined and applied to PI exhibited by single CdSe∕CdS core-shell nanocrystals and the organic chromophore violamine R isolated in single crystals of potassium-acid phthalate. Contrary to previous studies, the analysis presented here demonstrates that the PI exhibited by these systems is not described by a power law. The analysis developed here is also used to quantify heterogeneity within PI data obtained from a collection of CdSe/CdS nanocrytals, and for the determination of statistically significant changes in PI accompanying perturbation of the emitter. In summary, the analysis methodology presented here provides a more statistically robust approach for analyzing PI data.

  19. Fitness Landscapes of Functional RNAs.

    PubMed

    Kun, Ádám; Szathmáry, Eörs

    2015-08-21

    The notion of fitness landscapes, a map between genotype and fitness, was proposed more than 80 years ago. For most of this time data was only available for a few alleles, and thus we had only a restricted view of the whole fitness landscape. Recently, advances in genetics and molecular biology allow a more detailed view of them. Here we review experimental and theoretical studies of fitness landscapes of functional RNAs, especially aptamers and ribozymes. We find that RNA structures can be divided into critical structures, connecting structures, neutral structures and forbidden structures. Such characterisation, coupled with theoretical sequence-to-structure predictions, allows us to construct the whole fitness landscape. Fitness landscapes then can be used to study evolution, and in our case the development of the RNA world.

  20. Fitness Landscapes of Functional RNAs

    PubMed Central

    Kun, Ádám; Szathmáry, Eörs

    2015-01-01

    The notion of fitness landscapes, a map between genotype and fitness, was proposed more than 80 years ago. For most of this time data was only available for a few alleles, and thus we had only a restricted view of the whole fitness landscape. Recently, advances in genetics and molecular biology allow a more detailed view of them. Here we review experimental and theoretical studies of fitness landscapes of functional RNAs, especially aptamers and ribozymes. We find that RNA structures can be divided into critical structures, connecting structures, neutral structures and forbidden structures. Such characterisation, coupled with theoretical sequence-to-structure predictions, allows us to construct the whole fitness landscape. Fitness landscapes then can be used to study evolution, and in our case the development of the RNA world. PMID:26308059

  1. VPFIT: Voigt profile fitting program

    NASA Astrophysics Data System (ADS)

    Carswell, R. F.; Webb, J. K.

    2014-08-01

    The VPFIT program fits multiple Voigt profiles (convolved with the instrument profiles) to spectroscopic data that is in FITS or an ASCII file. It requires CFITSIO (ascl:1010.001) and PGPLOT (ascl:1103.002); the tarball includes RDGEN (ascl:1408.017), which can be used with VPFIT to set up the fits, fit the profiles, and examine the result in interactive mode for setting up initial guesses; vpguess (ascl:1408.016) can also be used to set up an initial file.

  2. The meaning of "physical fitness".

    PubMed

    Hopkins, W G; Walker, N P

    1988-11-01

    The understanding of the term "physical fitness" was determined for a randomly selected sample (n = 94) of a population using a self-administered mailed questionnaire. Subjects were asked to state and give a reason for their perceived level of physical fitness, to state their perceived performance level in a number of physical fitness tests (muscular strength, daily physical work capacity, fatness, level of regular physical exercise, exercise speed, and body flexibility), and to rate how well these tests measure physical fitness. The reason most frequently stated for perceived level of physical fitness was the level of habitual physical activity (43%); significantly less frequently (P less than 0.01-0.0001) cited were reasons related to health (23%), physical performance (12%), and obesity (3%). The variation in perceived level of physical fitness was best explained by the variation in imagined regular exercise and fatness (r2 = 0.66, P less than 0.0001) with no significant additional contribution from imagined performance in remaining fitness tests. The measurement of regular exercise was most favored as a test of physical fitness. These results, taken together with evidence of the physical and psychological health benefits of regular exercise, imply that the most appropriate measure of physical fitness for the average person is an assessment of the habitual physical activity level.

  3. Got Fitness? Addressing Student Fitness Needs within Secondary Physical Education

    ERIC Educational Resources Information Center

    Banks, Aaron; Reimann, Bonnie

    2007-01-01

    Feeling trapped within your daily teaching routine? Are the same curricular activities getting you down, or worse yet ... your students? Perhaps you and your students are craving an injection of new and fun fitness activities designed for the secondary level. The development of health-related fitness has long been associated with primary…

  4. Use of Intermittent Recompression and Nitrox Breathing Mixtures during Lunar Extravehicular Activities

    NASA Technical Reports Server (NTRS)

    Gernhardt, M.L.; Abercromby, A.F.

    2009-01-01

    INTRODUCTION: NASA's plans for lunar surface exploration include pressurized suitport rovers that are quickly ingressed and egressed with minimal consumables losses. This capability enables crewmembers to perform multiple short extravehicular activities (EVAs) at different locations in a single day versus a single 8-hr EVA. Modeling work and empirical human and animal data indicate that intermittent recompressions between EVA suit pressure and cabin pressure reduce decompression stress. Savings in crew time and gas losses may also be achieved if the N2 purge is shortened to 2 minutes, achieving 80% O2 (vs. 8 minutes, 95% O2). METHODS: A validated Tissue Bubble Dynamics Model was used to predict decompression stress using 80% and 95% O2 breathing mixtures during 3 x 2-hr EVAs (4.3 PSIA) with 1hr recompressions back to 8.0 PSIA (32% O2) versus a single 8-hr EVA. 15 minutes was spent at 6.0 PSIA before depressurizations to 4.3 PSIA; initial EVA tasks could be performed during this time. Model validation was based on significant prediction (p<0.001) and goodness of fit with 84 cases of DCS in 668 altitude exposures (McFadden s rho-squared=0.214). RESULTS: A 2.2% predicted increase in DCS risk due to the shortened purge is more than compensated for by a predicted 2.5% reduction in DCS risk due to intermittent recompression. 15 minutes at 80% O2, 6.0 PSIA prior to a 4.3 PSIA EVA prevents supersaturation in the brain and spinal cord (5-10 minute half-time compartments) and reduces tissue tensions in 40 min compartments, where most of the body s inert gas is located, to approximately the same levels (4.39 vs 4.00 PSIA) as achieved during a 40 min 95% O2 prebreathe at 10.2 PSIA. CONCLUSIONS: Intermittent recompressions between lunar EVAs may enable reductions in suit purge and prebreathe requirements, decompression stress, and/or suit operating pressures.

  5. Fitness testing of tennis players: How valuable is it?

    PubMed Central

    Fernandez-Fernandez, Jaime; Ulbricht, Alexander; Ferrauti, Alexander

    2014-01-01

    In tennis, sport-specific technical skills are predominant factors, although a complex profile of physical performance factors is also required. The fitness test batteries assist in examining tennis players’ capabilities for performance at different levels in the laboratory as well as in the field, in the junior or elite level. While laboratory tests can be, and are, used to evaluate basic performance characteristics of athletes in most individual sports, in a more specific approach, field-based methods are better suited to the demands of complex intermittent sports like tennis. A regular test battery performed at different periods of the year allows to obtain an individual's performance profile, as well as the ability to prescribe individual training interventions. Thus, the aim of the present review was to describe and evaluate the different physical tests recommended and used by practitioners, sports scientists and institutions (national tennis federations). PMID:24668375

  6. NLINEAR - NONLINEAR CURVE FITTING PROGRAM

    NASA Technical Reports Server (NTRS)

    Everhart, J. L.

    1994-01-01

    A common method for fitting data is a least-squares fit. In the least-squares method, a user-specified fitting function is utilized in such a way as to minimize the sum of the squares of distances between the data points and the fitting curve. The Nonlinear Curve Fitting Program, NLINEAR, is an interactive curve fitting routine based on a description of the quadratic expansion of the chi-squared statistic. NLINEAR utilizes a nonlinear optimization algorithm that calculates the best statistically weighted values of the parameters of the fitting function and the chi-square that is to be minimized. The inputs to the program are the mathematical form of the fitting function and the initial values of the parameters to be estimated. This approach provides the user with statistical information such as goodness of fit and estimated values of parameters that produce the highest degree of correlation between the experimental data and the mathematical model. In the mathematical formulation of the algorithm, the Taylor expansion of chi-square is first introduced, and justification for retaining only the first term are presented. From the expansion, a set of n simultaneous linear equations are derived, which are solved by matrix algebra. To achieve convergence, the algorithm requires meaningful initial estimates for the parameters of the fitting function. NLINEAR is written in Fortran 77 for execution on a CDC Cyber 750 under NOS 2.3. It has a central memory requirement of 5K 60 bit words. Optionally, graphical output of the fitting function can be plotted. Tektronix PLOT-10 routines are required for graphics. NLINEAR was developed in 1987.

  7. [Intermittent hypoxic training--the state of science].

    PubMed

    Schöffel, N; Senff, T; Gerber, A; de Roux, A; Bauer, T T; Groneberg, D A

    2008-05-01

    Intermittent hypoxic training (IHT) plays an important role concerning methods of training. Considering the enormous logistic and pecuniary investments for altitude training, there is a high demand for more efficient concepts. The intermittent hypoxic training is a new, alternative form of altitude training. The idea of IHT is to economise the currently most reliable and evaluated method which is known as "live high - train low" (LHTL). Thus, IHT combines a normal training at sea level with short training sessions in a chamber that creates a hypoxic but normobaric environment. Its aim is to initiate a similar level of erythropoesis as that usually achieved through long stays in high altitude with a minimised effort. This study analyses the results of selected studies that deal with IHT, evaluating the performance improvements in general and possible haematological variances/changes specifically.

  8. Intermittency, dissipation, and scaling in two-dimensional magnetohydrodynamic turbulence

    SciTech Connect

    Merrifield, J. A.; Chapman, S. C.; Dendy, R. O.

    2007-01-15

    Direct numerical simulations (DNS) provide a means to test phenomenological models for the scaling properties of intermittent MHD turbulence. The well-known model of She and Leveque, when generalized to MHD, is in good agreement with the DNS in three dimensions, however, it does not coincide with DNS in two dimensions (2D). This is resolved here using the results of recent DNS of driven MHD turbulence in 2D which directly determine the scaling of the rate of dissipation. Specifically, a simple modification to generalized refined similarity is proposed that captures the results of the 2D MHD simulations. This leads to a new generalization of She and Leveque in MHD that is coincident with the DNS results in 2D. A key feature of this model is that the most intensely dissipating structures, which are responsible for the intermittency, are thread-like in 2D, independent of whether the underlying phenomenology of the cascade is Kolmogorov or Iroshnikov Kraichnan.

  9. Synchronization of intermittent behavior in ensembles of multistable dynamical systems.

    PubMed

    Sevilla-Escoboza, R; Buldú, J M; Pisarchik, A N; Boccaletti, S; Gutiérrez, R

    2015-03-01

    We propose a methodology to analyze synchronization in an ensemble of diffusively coupled multistable systems. First, we study how two bidirectionally coupled multistable oscillators synchronize and demonstrate the high complexity of the basins of attraction of coexisting synchronous states. Then, we propose the use of the master stability function (MSF) for multistable systems to describe synchronizability, even during intermittent behavior, of a network of multistable oscillators, regardless of both the number of coupled oscillators and the interaction structure. In particular, we show that a network of multistable elements is synchronizable for a given range of topology spectra and coupling strengths, irrespective of specific attractor dynamics to which different oscillators are locked, and even in the presence of intermittency. Finally, we experimentally demonstrate the feasibility and robustness of the MSF approach with a network of multistable electronic circuits.

  10. [Intermittent thrombolytic treatment. Results during severe, chronic arterial diseases].

    PubMed

    Fiessinger, J N; Aiach, M; Lagneau, P; Cormier, J M; Housset, E

    1975-04-20

    38 patients with severe chronic arteritis of the lower limbs were treated with streptokinase intermittently. All had been refused for surgical operation. One patient died, 4 others had early interruption of treatment. Eleven of the 38 patients had efficient thrombolysis confirmed by arteriography. The facts confirm the possibility of thrombolysis during chronic arterial disease. The fact that the aggravation was recent was favourable factor in prognosis. The eleven patients improved, had severe aggravation of symptomes for less than 2 months. Thus thrombolytic treatment has a place of choice in the treatment of severe arterial disease where surgery is impossible, or dangerous, owing to the uncertain state of the vascular bed below the lesion. Efficacious, it permits reconstructive surgery in cases where it had been at first refused. The use of intermittent treatment, apart from advantages of confort and cost, seems to increase the efficacy of treatment.

  11. Intermittency in fractal Fourier hydrodynamics: Lessons from the Burgers equation.

    PubMed

    Buzzicotti, Michele; Biferale, Luca; Frisch, Uriel; Ray, Samriddhi Sankar

    2016-03-01

    We present theoretical and numerical results for the one-dimensional stochastically forced Burgers equation decimated on a fractal Fourier set of dimension D. We investigate the robustness of the energy transfer mechanism and of the small-scale statistical fluctuations by changing D. We find that a very small percentage of mode-reduction (D ≲ 1) is enough to destroy most of the characteristics of the original nondecimated equation. In particular, we observe a suppression of intermittent fluctuations for D < 1 and a quasisingular transition from the fully intermittent (D=1) to the nonintermittent case for D ≲ 1. Our results indicate that the existence of strong localized structures (shocks) in the one-dimensional Burgers equation is the result of highly entangled correlations amongst all Fourier modes. PMID:27078449

  12. Optimization of the rapping process of an intermittent electrostatic precipitator

    NASA Astrophysics Data System (ADS)

    Miloua, F.; Tilmatine, A.; Gouri, R.; Kadous, N.; Dascalescu, L.

    2008-01-01

    Intermittent operation mode is specific to electrostatic precipitators (ESP) used in workshops where the polluting product is produced in a discontinuous way. The rapping system is necessary in order to ensure a continuous and effective operation of a dry electrostatic precipitator, but causes at the same time, a problem of re-entrainment of dust and thus the degradation of filtration efficiency. The objective of this paper is to propose a procedure based on the methodology of experimental designs (Tagushi's Methodology) aiming at optimizing the rapping process; it consists to determine optimal values of rapping, i.e. the moment, the position and the force of rapping. Several “one-factor-at-a-time" experimental designs followed by a Full Factorial design, made it possible to model the process and to analyze interactions between the factors. The experiments were carried out on a laboratory experimental device which simulates an industrial precipitator with intermittent operation.

  13. Horizontal running mattress suture modified with intermittent simple loops.

    PubMed

    Chacon, Anna H; Shiman, Michael I; Strozier, Narissa; Zaiac, Martin N

    2013-01-01

    Using the combination of a horizontal running mattress suture with intermittent loops achieves both good eversion with the horizontal running mattress plus the ease of removal of the simple loops. This combination technique also avoids the characteristic railroad track marks that result from prolonged non-absorbable suture retention. The unique feature of our technique is the incorporation of one simple running suture after every two runs of the horizontal running mattress suture. To demonstrate its utility, we used the suturing technique on several patients and analyzed the cosmetic outcome with post-operative photographs in comparison to other suturing techniques. In summary, the combination of running horizontal mattress suture with simple intermittent loops demonstrates functional and cosmetic benefits that can be readily taught, comprehended, and employed, leading to desirable aesthetic results and wound edge eversion.

  14. Tissue-specific splicing mutation in acute intermittent porphyria

    SciTech Connect

    Grandchamp, B.; Picat, C. ); Mignotte, V.; Romeo, P.H.; Goossens, M. ); Wilson, J.H.P.; Sandkuyl, L. ); Te Velde, K. ); Nordmann, Y. )

    1989-01-01

    An inherited deficiency of porphobilinogen deaminase in humans is responsible for the autosomal dominant disease acute intermittent porphyria. Different classes of mutations have been described at the protein level suggesting that this is a heterogeneous disease. It was previously demonstrated that porphobilinogen deaminase is encoded by two distinct mRNA species expressed in a tissue-specific manner. Analysis of the genomic sequences indicated that these two mRNAs are transcribed from two promoters and only differ in their first exon. The first mutation identified in the human porphobilinogen deaminase gene is a single-base substitution (G {yields} A) in the canonical 5{prime} splice donor site of intron 1. This mutation leads to a particular subtype of acute intermittent porphyria characterized by the restriction of the enzymatic defect to nonerythropoietic tissues. Hybridization analysis using olignonucleotide probes after in vitro amplification of genomic DNA offers another possibility of detecting asymptomatic carriers of the mutation in affected families.

  15. Modeling and Optimization for Management of Intermittent Water Supply

    NASA Astrophysics Data System (ADS)

    Lieb, A. M.; Wilkening, J.; Rycroft, C.

    2014-12-01

    In many urban areas, piped water is supplied only intermittently, as valves direct water to different parts of the water distribution system at different times. The flow is transient, and may transition between free-surface and pressurized, resulting in complex dynamical features with important consequences for water suppliers and users. These consequences include degradation of distribution system components, compromised water quality, and inequitable water availability. The goal of this work is to model the important dynamics and identify operating conditions that mitigate certain negative effects of intermittent water supply. Specifically, we will look at controlling valve parameters occurring as boundary conditions in a network model of transient, transition flow through closed pipes. Gradient-based optimization will be used to find boundary values to minimize pressure gradients and ensure equitable water availability at system endpoints.

  16. [Intermittent thrombolytic treatment. Results during severe, chronic arterial diseases].

    PubMed

    Fiessinger, J N; Aiach, M; Lagneau, P; Cormier, J M; Housset, E

    1975-04-20

    38 patients with severe chronic arteritis of the lower limbs were treated with streptokinase intermittently. All had been refused for surgical operation. One patient died, 4 others had early interruption of treatment. Eleven of the 38 patients had efficient thrombolysis confirmed by arteriography. The facts confirm the possibility of thrombolysis during chronic arterial disease. The fact that the aggravation was recent was favourable factor in prognosis. The eleven patients improved, had severe aggravation of symptomes for less than 2 months. Thus thrombolytic treatment has a place of choice in the treatment of severe arterial disease where surgery is impossible, or dangerous, owing to the uncertain state of the vascular bed below the lesion. Efficacious, it permits reconstructive surgery in cases where it had been at first refused. The use of intermittent treatment, apart from advantages of confort and cost, seems to increase the efficacy of treatment. PMID:176733

  17. Intermittency in fractal Fourier hydrodynamics: Lessons from the Burgers equation

    NASA Astrophysics Data System (ADS)

    Buzzicotti, Michele; Biferale, Luca; Frisch, Uriel; Ray, Samriddhi Sankar

    2016-03-01

    We present theoretical and numerical results for the one-dimensional stochastically forced Burgers equation decimated on a fractal Fourier set of dimension D . We investigate the robustness of the energy transfer mechanism and of the small-scale statistical fluctuations by changing D . We find that a very small percentage of mode-reduction (D ≲1 ) is enough to destroy most of the characteristics of the original nondecimated equation. In particular, we observe a suppression of intermittent fluctuations for D <1 and a quasisingular transition from the fully intermittent (D =1 ) to the nonintermittent case for D ≲1 . Our results indicate that the existence of strong localized structures (shocks) in the one-dimensional Burgers equation is the result of highly entangled correlations amongst all Fourier modes.

  18. Vorticity scaling and intermittency in drift-interchange plasma turbulence

    SciTech Connect

    Dura, P. D.; Hnat, B.; Robinson, J.; Dendy, R. O.

    2012-09-15

    The effects of spatially varying magnetic field strength on the scaling properties of plasma turbulence, modelled by an extended form of Hasegawa-Wakatani model, are investigated. We study changes in the intermittency of the velocity, density, and vorticity fields, as functions of the magnetic field inhomogeneity C=-{partial_derivative} ln B/{partial_derivative}x. While the velocity fluctuations are always self-similar and their scaling is unaffected by the value of C, the intermittency levels in density and vorticity change with parameter C, reflecting morphological changes in the coherent structures due to the interchange mechanism. Given the centrality of vorticity in conditioning plasma transport, this result is of interest in scaling the results of transport measurements and simulations in tokamak edge plasmas, where drift-interchange turbulence in the presence of a magnetic field gradient is likely to occur.

  19. Spinal Plasticity following Intermittent Hypoxia: Implications for Spinal Injury

    PubMed Central

    Dale-Nagle, Erica A.; Hoffman, Michael S.; MacFarlane, Peter M.; Satriotomo, Irawan; Lovett-Barr, Mary Rachael; Vinit, Stéphane; Mitchell, Gordon S.

    2011-01-01

    Plasticity is a fundamental property of the neural system controlling breathing. One frequently studied model of respiratory plasticity is long-term facilitation of phrenic motor output (pLTF) following acute intermittent hypoxia (AIH). pLTF arises from spinal plasticity, increasing respiratory motor output through a mechanism that requires new synthesis of brain derived neurotrophic factor (BDNF), activation of its high affinity receptor, tropomyosin-related kinase B (TrkB) and extracellular-related kinase (ERK) mitogen-activated protein (MAP) kinase signaling in or near phrenic motor neurons. Since intermittent hypoxia induces spinal plasticity, we are exploring the potential to harness repetitive AIH as a means of inducing functional recovery in conditions causing respiratory insufficiency, such as cervical spinal injury. Since repetitive AIH induces phenotypic plasticity in respiratory and motor neurons, it may restore respiratory motor function in patients with incomplete spinal injury. PMID:20536940

  20. Development of intermittent redox flow battery for PV system

    SciTech Connect

    Tsuda, Izumi; Kurokawa, Kosuke; Nozaki, Ken

    1994-12-31

    Redox flow battery has been developed as a storage device for photovoltaic systems. The pump loss is the greatest problem for redox flow battery under the low current condition. An intermittent flow redox battery has been developed for the reduction of the pump loss. The experimental results of this battery show that the efficiency under the intermittent pump operation increases higher than the continuous pump operation. Moreover, inert gas bubble technology has been introduced to improve the performance under the high current condition. It is clear from the experiments that this technology increases the efficiencies. The simulation results of these technologies are coincident with experimental results. It is shown by the simulation that they can improve the Faradic and energy efficiencies of a number of stacks in series.

  1. Liver transplantation as a cure for acute intermittent porphyria.

    PubMed

    Soonawalla, Zahir F; Orug, Taner; Badminton, Michael N; Elder, George H; Rhodes, Jonathan M; Bramhall, Simon R; Elias, Elwyn

    2004-02-28

    Acute intermittent porphyria occasionally causes frequent and crippling acute neurovisceral attacks associated with increased hepatic production of porphyrin precursors, resulting in long-term damage, poor quality of life, and shortened life expectancy. There has been no cure for this condition, but replacement of deficient hepatic enzymes might restore excretion of porphyrin precursors to normal and prevent acute attacks. We aimed to treat severe acute intermittent porphyria in a 19-year-old woman by liver transplantation. After the transplant, concentrations of haem precursors in the patient's urine returned to normal, and 1.5 years later her quality of life was good. Our report suggests some hope of cure for selected patients with severe forms of this disease. PMID:15001330

  2. Detailed characteristics of intermittent current pulses due to positive corona

    SciTech Connect

    Liu, Yang Cui, Xiang; Lu, Tiebing; Wang, Zhenguo; Li, Xuebao; Xiang, Yu; Wang, Xiaobo

    2014-08-15

    In order to get detailed characteristics of intermittent current pulses due to positive corona such as the repetition rate of burst-pulse trains, the peak value ratio of the primary pulse to the secondary pulse, the number of pulses per burst, and the interval of the secondary pulses, a systematic study was carried out in a coaxial conductor-cylinder electrode system with the conductor electrode being set with a discharge point. Empirical formulae for the number of pulses per burst and the interval of the secondary pulses are first presented. A theoretical model based on the motion of the space-charge clouds is proposed. Analysis with the model gives explanations to the experimental results and reveals some new insights into the physical mechanism of positive intermittent corona.

  3. Intermittent exercise alters endurance in an eight-legged ectotherm.

    PubMed

    Weinstein, R B; Full, R J

    1992-05-01

    Most animals move intermittently, yet many proposed performance limitations of terrestrial locomotion are based on steady-state measurements and assumptions. We examined the effect of work-rest transitions by exercising the ghost crab, Ocypode quadrata (28.1 +/- 8.1 g), intermittently on a treadmill at 0.30 m/s, a supramaximal speed [i.e., greater than the speed that elicits the maximal rate of oxygen consumption (VO2)]. Duration of the exercise and pause periods, ratio of exercise to pause, and speed during the exercise period were varied to determine the effect on performance. Crabs fatigued after 7.5 min of continuous running, a distance capacity (i.e., total distance traveled before fatigue) of 135 m. When the task was done intermittently with 2-min exercise and 2-min pause periods, the crabs fatigued after 87 min (a total distance of 787 m), representing an 5.8-fold increase in distance capacity compared with continuous exercise at the same absolute speed (0.30 m/s) and a 2.2-fold increase in distance capacity compared with continuous exercise at the same average speed (0.15 m/s). Pause periods less than 30 s did not result in greater distance capacity compared with continuous exercise at the same average speed. Longer (3-5 min) and shorter exercise periods (less than or equal to 30 s) decreased distance capacity. Leg muscle lactate increased 10-fold to 15 mumol/g leg during intermittent exercise. However, significant amounts of lactate were cleared from the leg during the brief pause periods.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Ensuring patient adherence to clean intermittent self-catheterization

    PubMed Central

    Seth, Jai H; Haslam, Collette; Panicker, Jalesh N

    2014-01-01

    Patient performance of clean intermittent self-catheterization is a crucial component of the management of incomplete bladder emptying, which can arise from a variety of conditions. This allows patients to have more control over their bladder emptying, and avoids the inconveniences that come with an indwelling urethral catheter. There are, however, barriers that patients face when performing this task which may ultimately limit adherence. In this article, these barriers are discussed in more detail with potential solutions to counter them. PMID:24611001

  5. Single Stage Surgical Outcomes for Large Angle Intermittent Exotropia

    PubMed Central

    Yang, Min; Chen, Jingchang; Shen, Tao; Kang, Ying; Deng, Daming; Lin, Xiaoming; Wu, Heping; Chen, Qiwen; Ye, Xuelian; Li, Jianqun; Yan, Jianhua

    2016-01-01

    Although there were many prior studies about exotropia, few focused on large-angle intermittent exotropia. The goal of this study was to evaluate single-stage surgical outcomes for large-angle intermittent exotropia and analyze risk factors that may affect the success of surgery. Records from intermittent exotropia patients with exodeviations >60 prism diopters(PD) who were surgically treated at the Zhongshan Ophthalmic Center, of Sun Yat-Sen University were reviewed. Included within this review were data on, pre- and post-operative ocular motility, primary alignment, binocular vision and complications. Patients with exodeviations ≤70PD received two-muscle surgery, while those with exodeviations >70PD were subjected to a three-muscle procedure. A total of 40 records were reviewed. The mean exodeviation was 73±9PD at distance and 75±26PD at near. There were 25 patients received two-muscle surgery and 15 the three-muscle procedure. Orthophoria (deviation within 8PD) was obtained in 77.5% of these patients and the ratios of surgical under-correction and over-correction were 15% and 7.5% respectively. However, when combining ocular alignment with binocular vision as the success criteria, success rates decreased to 30%. No statistically significant differences in success rates were obtained between the two- and three-muscle surgery groups. Seven subjects experienced an abduction deficit during the initial postoperative stages, but eventually showed a full recovery. One patient required a second surgery for overcorrection. No statistically significant risk factors for poor outcome were revealed. Our data showed that single-stage two- and three-muscle surgeries for large-angle intermittent exotropia are effective in achieving a favorable outcome. PMID:26919493

  6. Apparatus producing constant cable tension for intermittent demand

    DOEpatents

    Lauritzen, T.

    1984-05-23

    This invention relates to apparatus for producing constant tension in cable or the like when it is unreeled and reeled from a drum or spool under conditions of intermittent demand. The invention is particularly applicable to the handling of superconductive cable, but the invention is also applicable to the unreeling and reeling of other strands, such as electrical cable, wire, cord, other cables, fish line, wrapping paper and numerous other materials.

  7. Intermittent fasting during Ramadan: does it affect sleep?

    PubMed

    Bahammam, Ahmed S; Almushailhi, Khalid; Pandi-Perumal, Seithikurippu R; Sharif, Munir M

    2014-02-01

    Islamic intermittent fasting is distinct from regular voluntary or experimental fasting. We hypothesised that if a regimen of a fixed sleep-wake schedule and a fixed caloric intake is followed during intermittent fasting, the effects of fasting on sleep architecture and daytime sleepiness will be minimal. Therefore, we designed this study to objectively assess the effects of Islamic intermittent fasting on sleep architecture and daytime sleepiness. Eight healthy volunteers reported to the Sleep Disorders Centre on five occasions for polysomnography and multiple sleep latency tests: (1) during adaptation; (2) 3 weeks before Ramadan, after having performed Islamic fasting for 1 week (baseline fasting); (3) 1 week before Ramadan (non-fasting baseline); (4) 2 weeks into Ramadan (Ramadan); and (5) 2 weeks after Ramadan (non-fasting; Recovery). Daytime sleepiness was assessed using the Epworth Sleepiness Scale and the multiple sleep latency test. The participants had a mean age of 26.6 ± 4.9 years, a body mass index of 23.7 ± 3.5 kg m(-2) and an Epworth Sleepiness Scale score of 7.3 ± 2.7. There was no change in weight or the Epworth Sleepiness Scale in the four study periods. The rapid eye movement sleep percentage was significantly lower during fasting. There was no difference in sleep latency, non-rapid eye movement sleep percentage, arousal index and sleep efficiency. The multiple sleep latency test analysis revealed no difference in the sleep latency between the 'non-fasting baseline', 'baseline fasting', 'Ramadan' and 'Recovery' time points. Under conditions of a fixed sleep-wake schedule and a fixed caloric intake, Islamic intermittent fasting results in decreased rapid eye movement sleep with no impact on other sleep stages, the arousal index or daytime sleepiness.

  8. Intermittent patient suction system, self-contained control

    DOEpatents

    Lewis, Jay L.

    1992-01-01

    An intermittent patient suction system, a self-contained control device therefor and methods of making the same are provided, the self-contained control device having a housing that contains two restrictor units therein for respectively controlling the "on" time and "off" time that the control device applies a vacuum and does not apply a vacuum through the output of the control device to the patient.

  9. GRIDS: Grid-Scale Rampable Intermittent Dispatchable Storage

    SciTech Connect

    2010-09-01

    GRIDS Project: The 12 projects that comprise ARPA-E’s GRIDS Project, short for “Grid-Scale Rampable Intermittent Dispatchable Storage,” are developing storage technologies that can store renewable energy for use at any location on the grid at an investment cost less than $100 per kilowatt hour. Flexible, large-scale storage would create a stronger and more robust electric grid by enabling renewables to contribute to reliable power generation.

  10. Holdup of the liquid slug in two phase intermittent flow

    SciTech Connect

    Barnea, D.; Brauner, N.

    1985-01-01

    A physical model for the prediction of gas holdup in liquid slugs in horizontal and vertical two phase pipe slug flow is presented. This model can also be used to yield the transitio between elongated bubbles and slug flow within the intermittent flow pattern. In addition a previously published model for predicting the stable slug length in vertical upward slug flow is extended here for the case of horizontal slug flow.

  11. [Intermittent hemodialysis, irreplaceable in specific cases of severe poisoning].

    PubMed

    Ventresca, M; Teta, D; Burnier, M; Kissling, S

    2015-02-25

    The medical practitioner is in general well aware of the indications for hemodialysis in severe, acute or chronic renal insufficiency. Apart from the traditional indications for renal replacement therapy, there are some cases such as metfomin and ethylene glycol poisoning, lithium intoxication severe hypercalcemia and tumor lysis syndrome, in which intermittent hemodialysis is the most effective treatment, or sometimes the only effective one. Although these situations remain infrequent, it is crucial to recognize them as quickly as possible. PMID:25898458

  12. Intermittent fasting during Ramadan: does it affect sleep?

    PubMed

    Bahammam, Ahmed S; Almushailhi, Khalid; Pandi-Perumal, Seithikurippu R; Sharif, Munir M

    2014-02-01

    Islamic intermittent fasting is distinct from regular voluntary or experimental fasting. We hypothesised that if a regimen of a fixed sleep-wake schedule and a fixed caloric intake is followed during intermittent fasting, the effects of fasting on sleep architecture and daytime sleepiness will be minimal. Therefore, we designed this study to objectively assess the effects of Islamic intermittent fasting on sleep architecture and daytime sleepiness. Eight healthy volunteers reported to the Sleep Disorders Centre on five occasions for polysomnography and multiple sleep latency tests: (1) during adaptation; (2) 3 weeks before Ramadan, after having performed Islamic fasting for 1 week (baseline fasting); (3) 1 week before Ramadan (non-fasting baseline); (4) 2 weeks into Ramadan (Ramadan); and (5) 2 weeks after Ramadan (non-fasting; Recovery). Daytime sleepiness was assessed using the Epworth Sleepiness Scale and the multiple sleep latency test. The participants had a mean age of 26.6 ± 4.9 years, a body mass index of 23.7 ± 3.5 kg m(-2) and an Epworth Sleepiness Scale score of 7.3 ± 2.7. There was no change in weight or the Epworth Sleepiness Scale in the four study periods. The rapid eye movement sleep percentage was significantly lower during fasting. There was no difference in sleep latency, non-rapid eye movement sleep percentage, arousal index and sleep efficiency. The multiple sleep latency test analysis revealed no difference in the sleep latency between the 'non-fasting baseline', 'baseline fasting', 'Ramadan' and 'Recovery' time points. Under conditions of a fixed sleep-wake schedule and a fixed caloric intake, Islamic intermittent fasting results in decreased rapid eye movement sleep with no impact on other sleep stages, the arousal index or daytime sleepiness. PMID:23937329

  13. Intermittent punishment of Sdelta responding in matching to sample.

    PubMed

    ZIMMERMAN, J; FERSTER, C B

    1963-07-01

    Incorrect matching responses of two pigeons on matching to sample were either continuously (CRF) or intermittently (FR) followed by a time out (TO). The matching accuracy was examined as a function of both TO duration and TO frequency (ratio size). With intermediate TO durations (10 sec, 1 min), accuracy increased as the frequency of TO increased. With an extremely short (1 sec) and an extremely long (10 min) TO duration, accuracy was poor over the entire range of frequencies.

  14. My Career: Group Fitness Instructor

    ERIC Educational Resources Information Center

    Green, Kathleen

    2013-01-01

    This article presents an interview with Tammy Kenney, who teaches a yoga-Pilates class in several different gyms. In this interview, Kenney talks about her career as a group fitness instructor and gives her best advice for someone who wants to teach group fitness.

  15. Motivating Students in Fitness Activities

    ERIC Educational Resources Information Center

    Wilkinson, Carol; Hunter, Mike

    2008-01-01

    Physical educators have a responsibility to motivate students to develop personal fitness. This is a critical concept as physical education is the only part of the curriculum capable of meeting the health needs of students regarding physical activity. Current physical educators must promote fitness in ways that motivate students to engage in…

  16. Exercise Prescription for Physical Fitness.

    ERIC Educational Resources Information Center

    Pollock, Michael L.; And Others

    1995-01-01

    Examines current guidelines for physical fitness, noting issues that may influence the updating of the American College of Sports Medicine exercise statement. Differences between exercise prescription for fitness and physical activity for health are discussed, noting the importance of designing individualized programs with appropriate levels of…

  17. On the Trail to Fitness.

    ERIC Educational Resources Information Center

    American School and University, 1979

    1979-01-01

    The University of Hartford planned fitness trail will allow students to develop their bodies by providing a jogging route to improve cardiovascular fitness and exercise stations designed to provide warm-up exercises and improve strength, flexibility, balance, and endurance. (Author/MLF)

  18. Fitness and Health. Beginnings Workshop.

    ERIC Educational Resources Information Center

    Child Care Information Exchange, 2000

    2000-01-01

    Presents five articles on children's fitness and health: "Relaxation: Every Child's Right to Simply Be" (Patrice Thomas and Wendy Shepherd); "Infant Massage" (Carolyn Oleson); "Fitness and the Young Child" (James M. Poole); "Partners in Health: Helping Families Advocate for Their Children's Health Care" (Karen Sokal-Gutierrez); and "Preventing…

  19. Prolapsing Gastric Polyp Causing Intermittent Gastric Outlet Obstruction.

    PubMed

    Kosai, Nik Ritza; Gendeh, Hardip Singh; Norfaezan, Abdul Rashid; Razman, Jamin; Sutton, Paul Anthony; Das, Srijit

    2015-06-01

    Gastric polyps are often an incidental finding on upper gastrointestinal endoscopy, with an incidence up to 5%. The majority of gastric polyps are asymptomatic, occurring secondary to inflammation. Prior reviews discussed Helicobacter pylori (H pylori)-associated singular gastric polyposis; however, we present a rare and unusual case of recurrent multiple benign gastric polyposis post H pylori eradication resulting in intermittent gastric outlet obstruction. A 70-year-old independent male, Chinese in ethnicity, with a background of diabetes mellitus, hypertension, and a simple renal cyst presented with a combination of melena, anemia, and intermittent vomiting of partially digested food after meals. Initial gastroscopy was positive for H pylori; thus he was treated with H pylori eradication and proton pump inhibitors. Serial gastroscopy demonstrated multiple sessile gastric antral polyps, the largest measuring 4 cm. Histopathologic examination confirmed a benign hyperplastic lesion. Computed tomography identified a pyloric mass with absent surrounding infiltration or metastasis. A distal gastrectomy was performed, whereby multiple small pyloric polyps were found, the largest prolapsing into the pyloric opening, thus explaining the intermittent nature of gastric outlet obstruction. Such polyps often develop from gastric ulcers and, if left untreated, may undergo neoplasia to form malignant cells. A distal gastrectomy was an effective choice of treatment, taking into account the polyp size, quantity, and potential for malignancy as opposed to an endoscopic approach, which may not guarantee a complete removal of safer margins and depth. Therefore, surgical excision is favorable for multiple large gastric polyps with risk of malignancy.

  20. Intermittency and velocity fluctuations in hopper flows prone to clogging.

    PubMed

    Thomas, C C; Durian, D J

    2016-08-01

    We study experimentally the dynamics of granular media in a discharging hopper. In such flows, there often appears to be a critical outlet size D_{c} such that the flow never clogs for D>D_{c}. We report on the time-averaged velocity distributions, as well as temporal intermittency in the ensemble-averaged velocity of grains in a viewing window, for both DD_{c}, near and far from the outlet. We characterize the velocity distributions by the standard deviation and the skewness of the distribution of vertical velocities. We propose a measure for intermittency based on the two-sample Kolmogorov-Smirnov D_{KS} statistic for the velocity distributions as a function of time. We find that there is no discontinuity or kink in these various measures as a function of hole size. This result supports the proposition that there is no well-defined D_{c} and that clogging is always possible. Furthermore, the intermittency time scale of the flow is set by the speed of the grains at the hopper exit. This latter finding is consistent with a model of clogging as the independent sampling for stable configurations at the exit with a rate set by the exiting grain speed [C. C. Thomas and D. J. Durian, Phys. Rev. Lett. 114, 178001 (2015)PRLTAO0031-900710.1103/PhysRevLett.114.178001].

  1. Intermittency and velocity fluctuations in hopper flows prone to clogging

    NASA Astrophysics Data System (ADS)

    Thomas, C. C.; Durian, D. J.

    2016-08-01

    We study experimentally the dynamics of granular media in a discharging hopper. In such flows, there often appears to be a critical outlet size Dc such that the flow never clogs for D >Dc . We report on the time-averaged velocity distributions, as well as temporal intermittency in the ensemble-averaged velocity of grains in a viewing window, for both D Dc , near and far from the outlet. We characterize the velocity distributions by the standard deviation and the skewness of the distribution of vertical velocities. We propose a measure for intermittency based on the two-sample Kolmogorov-Smirnov DKS statistic for the velocity distributions as a function of time. We find that there is no discontinuity or kink in these various measures as a function of hole size. This result supports the proposition that there is no well-defined Dc and that clogging is always possible. Furthermore, the intermittency time scale of the flow is set by the speed of the grains at the hopper exit. This latter finding is consistent with a model of clogging as the independent sampling for stable configurations at the exit with a rate set by the exiting grain speed [C. C. Thomas and D. J. Durian, Phys. Rev. Lett. 114, 178001 (2015), 10.1103/PhysRevLett.114.178001].

  2. Intermittency of solar system plasma turbulence near Venus and Earth

    NASA Astrophysics Data System (ADS)

    Teodorescu, Eliza; Echim, Marius; Chang, Tom

    2016-04-01

    We analyze magnetic field data from Venus Express (VEX) and CLUSTER to investigate the turbulent properties of the solar wind and the Earth's and Venus' magnetosheaths. A systematic study of the PDFs (Probability Distribution Functions) of the measured magnetic fluctuations and their fourth order moments (kurtosis) reveals numerous intermittent time series. The presence of intermittency is marked by non-Gaussian PDFs with heavy wings and a scale dependent kurtosis. Higher order analyses on the scale dependence of several moment orders of the PDFs, the structure functions, along with the scaling of the kurtosis allow for a selection of scales that pertain to different scaling regimes, governed by different physics. On such sub-ranges of scales we investigate the fractal structure of fluctuations through the Rank Ordered Multifractal Analysis - ROMA (Chang and Wu, 2008). ROMA is applied to a selection of intermittent magnetic field time series in the solar wind and planetary magnetosheaths and helps to quantify the turbulence properties through the estimation of a spectrum of local Hurst exponents. Research supported by the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 313038/STORM, and a grant of the Romanian Ministry of National Education, CNCS - UEFISCDI, project number PN-II-ID-PCE-2012-4-0418.

  3. Sensitivity of intermittent streams to climate variations in the USA

    USGS Publications Warehouse

    Eng, Kenny; Wolock, David M.; Dettinger, Mike

    2015-01-01

    There is a great deal of interest in the literature on streamflow changes caused by climate change because of the potential negative effects on aquatic biota and water supplies. Most previous studies have primarily focused on perennial streams, and there have been only a few studies examining the effect of climate variability on intermittent streams. Our objectives in this study were to (1) identify regions of similar zero-flow behavior, and (2) evaluate the sensitivity of intermittent streams to historical variability in climate in the United States. This study was carried out at 265 intermittent streams by evaluating: (1) correlations among time series of flow metrics (number of zero-flow events, the average of the central 50% and largest 10% of flows) with climate (magnitudes, durations and intensity), and (2) decadal changes in the seasonality and long-term trends of these flow metrics. Results identified five distinct seasonality patterns in the zero-flow events. In addition, strong associations between the low-flow metrics and historical changes in climate were found. The decadal analysis suggested no significant seasonal shifts or decade-to-decade trends in the low-flow metrics. The lack of trends or changes in seasonality is likely due to unchanged long-term patterns in precipitation over the time period examined.

  4. Intermittency of rheological regimes in uniform liquid-granular flows.

    PubMed

    Armanini, Aronne; Larcher, Michele; Fraccarollo, Luigi

    2009-05-01

    We present a detailed analysis of a free surface-saturated liquid-granular mixture flowing over a static loose bed of grains, where the coexistence of layers dominated by collisional and frictional interactions among particles was observed. Kinetic theory was applied to the flow described above and it proved suitable for describing a realistic behavior of the collisional layers, although it failed to interpret the regions of the flow domain dominated by the frictional contacts. The paper provides a conceptual scheme with which to overcome this problem by focusing on the mechanisms governing the transition from the frictional to the collisional regime. In particular we observed that in highly concentrated flows the transition layer exhibits a typical intermittency of the dominating rheological regime, switching alternately from the frictional to the collisional one. By filtering the velocity signal, we introduced an intermittency function that made it possible to extend the validity of the equations derived from dense gas analogy, typical of the collisional regimes, also in the intermittent phase of the flow. Owing to the small values of the Stokes number, in the application of the kinetic theory we accounted for the possible variation of the elastic restitution coefficient along the flow depth. PMID:19518448

  5. Intermittency and velocity fluctuations in hopper flows prone to clogging.

    PubMed

    Thomas, C C; Durian, D J

    2016-08-01

    We study experimentally the dynamics of granular media in a discharging hopper. In such flows, there often appears to be a critical outlet size D_{c} such that the flow never clogs for D>D_{c}. We report on the time-averaged velocity distributions, as well as temporal intermittency in the ensemble-averaged velocity of grains in a viewing window, for both DD_{c}, near and far from the outlet. We characterize the velocity distributions by the standard deviation and the skewness of the distribution of vertical velocities. We propose a measure for intermittency based on the two-sample Kolmogorov-Smirnov D_{KS} statistic for the velocity distributions as a function of time. We find that there is no discontinuity or kink in these various measures as a function of hole size. This result supports the proposition that there is no well-defined D_{c} and that clogging is always possible. Furthermore, the intermittency time scale of the flow is set by the speed of the grains at the hopper exit. This latter finding is consistent with a model of clogging as the independent sampling for stable configurations at the exit with a rate set by the exiting grain speed [C. C. Thomas and D. J. Durian, Phys. Rev. Lett. 114, 178001 (2015)PRLTAO0031-900710.1103/PhysRevLett.114.178001]. PMID:27627374

  6. Magnetic intermittency of solar wind turbulence in the dissipation range

    NASA Astrophysics Data System (ADS)

    Pei, Zhongtian; He, Jiansen; Tu, Chuanyi; Marsch, Eckart; Wang, Linghua

    2016-04-01

    The feature, nature, and fate of intermittency in the dissipation range are an interesting topic in the solar wind turbulence. We calculate the distribution of flatness for the magnetic field fluctuations as a functionof angle and scale. The flatness distribution shows a "butterfly" pattern, with two wings located at angles parallel/anti-parallel to local mean magnetic field direction and main body located at angles perpendicular to local B0. This "butterfly" pattern illustrates that the flatness profile in (anti-) parallel direction approaches to the maximum value at larger scale and drops faster than that in perpendicular direction. The contours for probability distribution functions at different scales illustrate a "vase" pattern, more clear in parallel direction, which confirms the scale-variation of flatness and indicates the intermittency generation and dissipation. The angular distribution of structure function in the dissipation range shows an anisotropic pattern. The quasi-mono-fractal scaling of structure function in the dissipation range is also illustrated and investigated with the mathematical model for inhomogeneous cascading (extended p-model). Different from the inertial range, the extended p-model for the dissipation range results in approximate uniform fragmentation measure. However, more complete mathematicaland physical model involving both non-uniform cascading and dissipation is needed. The nature of intermittency may be strong structures or large amplitude fluctuations, which may be tested with magnetic helicity. In one case study, we find the heating effect in terms of entropy for large amplitude fluctuations seems to be more obvious than strong structures.

  7. Role of nitric oxide in cardiovascular adaptation to intermittent hypoxia.

    PubMed

    Manukhina, Eugenia B; Downey, H Fred; Mallet, Robert T

    2006-04-01

    Hypoxia is one of the most frequently encountered stresses in health and disease. The duration, frequency, and severity of hypoxic episodes are critical factors determining whether hypoxia is beneficial or harmful. Adaptation to intermittent hypoxia has been demonstrated to confer cardiovascular protection against more severe and sustained hypoxia, and, moreover, to protect against other stresses, including ischemia. Thus, the direct and cross protective effects of adaptation to intermittent hypoxia have been used for treatment and prevention of a variety of diseases and to increase efficiency of exercise training. Evidence is mounting that nitric oxide (NO) plays a central role in these adaptive mechanisms. NO-dependent protective mechanisms activated by intermittent hypoxia include stimulation of NO synthesis as well as restriction of NO overproduction. In addition, alternative, nonenzymic sources of NO and negative feedback of NO synthesis are important factors in optimizing NO concentrations. The adaptive enhancement of NO synthesis and/or availability activates or increases expression of other protective factors, including heat shock proteins, antioxidants and prostaglandins, making the protection more robust and sustained. Understanding the role of NO in mechanisms of adaptation to hypoxia will support development of therapies to prevent and treat hypoxic or ischemic damage to organs and cells and to increase adaptive capabilities of the organism. PMID:16565431

  8. Distribution of Chironomidae in a semiarid intermittent river of Brazil.

    PubMed

    Farias, R L; Carvalho, L K; Medeiros, E S F

    2012-12-01

    The effects of the intermittency of water flow on habitat structure and substrate composition have been reported to create a patch dynamics for the aquatic fauna, mostly for that associated with the substrate. This study aims to describe the spatial distribution of Chironomidae in an intermittent river of semiarid Brazil and to associate assemblage composition with environmental variables. Benthic invertebrates were sampled during the wet and dry seasons using a D-shaped net (40 cm wide and 250 μm mesh), and the Chironomidae were identified to genus level. The most abundant genera were Tanytarsus, Polypedilum, and Saetheria with important contributions of the genera Procladius, Aedokritus, and Dicrotendipes. Richness and density were not significantly different between the study sites, and multiple regression showed that the variation in richness and density explained by the environmental variables was significant only for substrate composition. The composition of genera showed significant spatial segregation across the study sites. Canonical Correspondence Analysis showed significant correspondence between Chironomidae composition and the environmental variables, with submerged vegetation, elevation, and leaf litter being important predictors of the Chironomidae fauna. This study showed that Chironomidae presented important spatial variation along the river and that this variation was substantially explained by environmental variables associated with the habitat structure and river hierarchy. We suggest that the observed spatial segregation in the fauna results in the high diversity of this group of organisms in intermittent streams.

  9. Intermittent outgassing through a non-Newtonian fluid.

    PubMed

    Divoux, Thibaut; Bertin, Eric; Vidal, Valérie; Géminard, Jean-Christophe

    2009-05-01

    We report an experimental study of the intermittent dynamics of a gas flowing through a column of a non-Newtonian fluid. In a given range of the imposed constant flow rate, the system spontaneously alternates between two regimes: bubbles emitted at the bottom either rise independently one from the other or merge to create a winding flue which then connects the bottom air entrance to the free surface. The observations are reminiscent of the spontaneous changes in the degassing regime observed on volcanoes and suggest that, in the nature, such a phenomenon is likely to be governed by the non-Newtonian properties of the magma. We focus on the statistical distribution of the lifespans of the bubbling and flue regimes in the intermittent steady state. The bubbling regime exhibits a characteristic time whereas, interestingly, the flue lifespan displays a decaying power-law distribution. The associated exponent, which is significantly smaller than the value 1.5 often reported experimentally and predicted in some standard intermittency scenarios, depends on the fluid properties and can be interpreted as the ratio of two characteristic times of the system.

  10. FITS Liberator: Image processing software

    NASA Astrophysics Data System (ADS)

    Lindberg Christensen, Lars; Nielsen, Lars Holm; Nielsen, Kaspar K.; Johansen, Teis; Hurt, Robert; de Martin, David

    2012-06-01

    The ESA/ESO/NASA FITS Liberator makes it possible to process and edit astronomical science data in the FITS format to produce stunning images of the universe. Formerly a plugin for Adobe Photoshop, the current version of FITS Liberator is a stand-alone application and no longer requires Photoshop. This image processing software makes it possible to create color images using raw observations from a range of telescopes; the FITS Liberator continues to support the FITS and PDS formats, preferred by astronomers and planetary scientists respectively, which enables data to be processed from a wide range of telescopes and planetary probes, including ESO's Very Large Telescope, the NASA/ESA Hubble Space Telescope, NASA's Spitzer Space Telescope, ESA's XMM-Newton Telescope and Cassini-Huygens or Mars Reconnaissance Orbiter.

  11. Fit-testing for firefighters.

    PubMed

    Brickman, C P

    1999-01-01

    When fit-testing firefighters who may be required to wear an SCBA unit in the positive pressure mode for IDLH or structural firefighting applications, use these guidelines. 1. The firefighter shall be allowed to pick the most acceptable respirator from a sufficient number of respirator models and sizes so the respirator is acceptable to, and correctly fits, the firefighter. 2. Before a firefighter may be required to use the SCBA, he/she must be fit-tested with the same make, model, style, and size of respirator that will be used. If different makes, models, styles, and sizes of facepieces are used, the firefighter must be fit-tested for each. 3. Based on current interpretations and guidance, OSHA requires firefighters to be quantitatively or qualitatively fit-tested while in the negative pressure mode. 4. Quantitative fit-testing of these respirators shall be accomplished by modifying the facepiece to allow sampling inside the facepiece and breathing zone of the user, midway between the nose and mouth. This requirement shall be accomplished by installing a permanent sampling probe onto a surrogate facepiece or by using a sampling adapter designed to temporarily provide a means of sampling air from inside the facepiece. 5. Qualitative fit-testing can be accomplished by converting the user's actual facepiece into a negative pressure respirator with appropriate filters or by using an identical negative pressure air-purifying respirator facepiece with the same sealing surfaces as a surrogate for the SCBA facepiece. 6. If after passing the fit-test the firefighter subsequently determines the fit of the respirator is unacceptable, he/she shall be given a reasonable opportunity to select a different respirator facepiece and be retested. 7. The new standard requires initial and at least annual fit-testing using quantitative or qualitative fit-testing protocols. 8. Additional fit-testing may be required whenever physical changes to the employee occur that may affect

  12. Characterization of wind power resource and its intermittency

    NASA Astrophysics Data System (ADS)

    Gunturu, U. B.; Schlosser, C. A.

    2011-12-01

    Wind resource in the continental and offshore United States has been calculated and characterized using metrics that describe - apart from abundance - its availability, persistence and intermittency. The Modern Era Retrospective-Analysis for Research and Applications (MERRA) boundary layer flux data has been used to construct wind power density profiles at 50, 80, 100 and 120 m turbine hub heights. The wind power density estimates at 50 m are qualitatively similar to those in the US wind atlas developed by the National Renewable Energy Laboratory (NREL), but quantitatively a class less in some regions, but are within the limits of uncertainty. We also show that for long tailed distributions like those of the wind power density, the mean is an overestimation and median is a more robust metric for summary representation of wind power resource.Generally speaking, the largest and most available wind power density resources are found in off-shore regions of the Atlantic and Pacific coastline, and the largest on-shore resource potential lies in the central United States. However, the intermittency and widespread synchronicity of on-shore wind power density are substantial, and highlights areas where considerable back-up generation technologies will be required. Generation-duration curves are also presented for the independent systems operator (ISO) zones of the U.S. to highlight the regions with the largest capacity factor (MISO, ERCOT, and SWPP) as well as the periods and extent to which all ISOs contain no wind power and the potential benefits of aggregation on wind power intermittency in each region. The impact of raising the wind turbine hub height on metrics of abundance, persistence, variability and intermittency is analyzed. There is a general increase in availability and abundance of wind resource but there is also an increase in intermittency with respect to a 'usable wind power' crossing level in low resource regions. A similar perspective of wind resource for

  13. Intermittent turbulence in solar wind from the south polar hole

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, A. A.; Feynman, J.; Goldstein, B. E.; Smith, E. J.; Balogh, A.

    1995-01-01

    The magnetic fields measured by the Ulysses spacecraft are used to study solar wind turbulence in the fast solar wind from the south polar hole. The spacecraft was at about 46 deg south latitude and 3.9 AU. For a magnetic field with a Gaussian distribution the power spectrum (second-order structure function) is sufficient to completely characterize the turbulence. However, the actual distribution is non-Gaussian so that the effects of intermittency must be taken into account. The observed spectral exponents include effects of intermittency and cannot be directly compared with the standard second-order spectral theories such as the Kolmogorov and Kraichnan theories. To permit a better comparison of the observations with the theoretical models, we study the structure characteristics of the data. We find the exponents of the second-order structure functions (power spectra) and the higher-order normalized structure functions for the components of the magnetic fields. We show that these sets of exponents can be approximately described by two basic numbers: the spectral exponent and the intermittency exponent. The intermittency exponent characterizes correlation properties of the energy cascade from large to small scales. Before comparing the observations to the theoretically expected values, a reduction must be made to the observed spectral exponent. The amount of the reduction depends on both the intermittency exponent and the model of the energy cascade assumed in the turbulence theory. We reduce the measured spectral indices according to a simple model for Alfven turbulence that is described here. We then compare our reduced spectral indices with second-order spectral theory. The reduced spectral indices for the period range of 1 min to about a half hour are remarkably constant and in good agreement with the value of 3/2. Thus our treatment is self-consistent. Our tentative conclusion is that the high-frequency turbulence appears to agree with the model of random

  14. Continuous morphine produces more tolerance than intermittent or acute treatment.

    PubMed

    Dighe, Shveta V; Madia, Priyanka A; Sirohi, Sunil; Yoburn, Byron C

    2009-05-01

    Dosing protocol and analgesic efficacy have been proposed to be important determinants of the magnitude of opioid tolerance. The present study examined the effect of acute, intermittent and continuous treatment with the low analgesic efficacy agonist morphine on analgesic tolerance. Mice were implanted s.c. with a 25 mg morphine pellet for 1-7 days. Other mice were implanted s.c. with two 25 mg, or one 75 mg morphine pellet for 7 days. The release of morphine from subcutaneous implanted pellets was quantitated using a spectrophotometric assay. In other studies, mice were injected with morphine once (18.5-185 mg/kg/day; approximately 10-100 times ED(50) for morphine analgesia) or once/day for 7 days. Controls were implanted with a placebo pellet or injected with saline. Analysis of drug release from a 25 mg pellet indicated that release was greatest during the first 24 h, declined and then remained relatively constant. The amount of morphine released over 7 days by a 75 mg pellet (23.9 mg) was more than that of a single 25 mg pellet (15.4 mg) but less than two 25 mg pellets (30.8 mg). Following treatment, morphine cumulative dose-response studies were conducted (tail flick). Continuous treatment with morphine using pellet implantation produced a dose-dependent shift in the morphine ED(50) by 3.3, 5.8 and 8.5 fold for one 25 mg pellet, one 75 mg pellet and two 25 mg pellets, respectively. Acute and intermittent morphine administration produced substantially less analgesic tolerance than continuous release of morphine by implant pellets. The maximum shift in the ED(50) was 1.6 for acute treatment and 2.7 for 7 day intermittent treatment; despite a larger total daily dose. The present results indicate that continuous treatment with morphine results in greater analgesic tolerance than acute or intermittent morphine treatment even at comparable daily doses. These results are consistent with the suggestion that intermittent dosing has reduced risk of producing opioid

  15. Human control of an inverted pendulum: is continuous control necessary? Is intermittent control effective? Is intermittent control physiological?

    PubMed

    Loram, Ian D; Gollee, Henrik; Lakie, Martin; Gawthrop, Peter J

    2011-01-15

    Human motor control is often explained in terms of engineering 'servo' theory. Recently, continuous, optimal control using internal models has emerged as a leading paradigm for voluntary movement. However, these engineering paradigms are designed for high band-width, inflexible, consistent systems whereas human control is low bandwidth and flexible using noisy sensors and actuators. By contrast, engineering intermittent control was designed for bandwidth-limited applications. Our general interest is whether intermittent rather than continuous control is generic to human motor control. Currently, it would be assumed that continuous control is the superior and physiologically natural choice for controlling unstable loads, for example as required for maintaining human balance. Using visuo-manual tracking of an unstable load, we show that control using gentle, intermittent taps is entirely natural and effective. The gentle tapping method resulted in slightly superior position control and velocity minimisation, a reduced feedback time delay, greater robustness to changing actuator gain and equal or greater linearity with respect to the external disturbance. Control was possible with a median contact rate of 0.8±0.3 s(-1). However, when optimising position or velocity regulation, a modal contact rate of 2 s(-1) was observed. This modal rate was consistent with insignificant disturbance-joystick coherence beyond 1-2 Hz in both tapping and continuous contact methods. For this load, these results demonstrate a motor control process of serial ballistic trajectories limited to an optimum rate of 2 s(-1). Consistent with theoretical reasoning, our results suggest that intermittent open loop action is a natural consequence of human physiology.

  16. Fitting Polynomial Equations to Curves and Surfaces

    NASA Technical Reports Server (NTRS)

    Arbuckle, P. D.; Sliwa, S. M.; Tiffany, S. H.

    1986-01-01

    FIT is computer program for interactively determining least-squares polynomial equations that fit user-supplied data. Finds leastsquares fits for functions of two independent variables. Interactive graphical and editing capabilities in FIT enables user to control polynomial equations to be fitted to data arising from most practical applications. FIT written in FORTRAN and COMPASS.

  17. The Yo-Yo intermittent recovery test : a useful tool for evaluation of physical performance in intermittent sports.

    PubMed

    Bangsbo, Jens; Iaia, F Marcello; Krustrup, Peter

    2008-01-01

    The two Yo-Yo intermittent recovery (IR) tests evaluate an individual's ability to repeatedly perform intense exercise. The Yo-Yo IR level 1 (Yo-Yo IR1) test focuses on the capacity to carry out intermittent exercise leading to a maximal activation of the aerobic system, whereas Yo-Yo IR level 2 (Yo-Yo IR2) determines an individual's ability to recover from repeated exercise with a high contribution from the anaerobic system. Evaluations of elite athletes in various sports involving intermittent exercise showed that the higher the level of competition the better an athlete performs in the Yo-Yo IR tests. Performance in the Yo-Yo IR tests for young athletes increases with rising age. The Yo-Yo IR tests have shown to be a more sensitive measure of changes in performance than maximum oxygen uptake. The Yo-Yo IR tests provide a simple and valid way to obtain important information of an individual's capacity to perform repeated intense exercise and to examine changes in performance.

  18. AKLSQF - LEAST SQUARES CURVE FITTING

    NASA Technical Reports Server (NTRS)

    Kantak, A. V.

    1994-01-01

    The Least Squares Curve Fitting program, AKLSQF, computes the polynomial which will least square fit uniformly spaced data easily and efficiently. The program allows the user to specify the tolerable least squares error in the fitting or allows the user to specify the polynomial degree. In both cases AKLSQF returns the polynomial and the actual least squares fit error incurred in the operation. The data may be supplied to the routine either by direct keyboard entry or via a file. AKLSQF produces the least squares polynomial in two steps. First, the data points are least squares fitted using the orthogonal factorial polynomials. The result is then reduced to a regular polynomial using Sterling numbers of the first kind. If an error tolerance is specified, the program starts with a polynomial of degree 1 and computes the least squares fit error. The degree of the polynomial used for fitting is then increased successively until the error criterion specified by the user is met. At every step the polynomial as well as the least squares fitting error is printed to the screen. In general, the program can produce a curve fitting up to a 100 degree polynomial. All computations in the program are carried out under Double Precision format for real numbers and under long integer format for integers to provide the maximum accuracy possible. AKLSQF was written for an IBM PC X/AT or compatible using Microsoft's Quick Basic compiler. It has been implemented under DOS 3.2.1 using 23K of RAM. AKLSQF was developed in 1989.

  19. Total force fitness: the military family fitness model.

    PubMed

    Bowles, Stephen V; Pollock, Liz Davenport; Moore, Monique; Wadsworth, Shelley MacDermid; Cato, Colanda; Dekle, Judith Ward; Meyer, Sonia Wei; Shriver, Amber; Mueller, Bill; Stephens, Mark; Seidler, Dustin A; Sheldon, Joseph; Picano, James; Finch, Wanda; Morales, Ricardo; Blochberger, Sean; Kleiman, Matthew E; Thompson, Daniel; Bates, Mark J

    2015-03-01

    The military lifestyle can create formidable challenges for military families. This article describes the Military Family Fitness Model (MFFM), a comprehensive model aimed at enhancing family fitness and resilience across the life span. This model is intended for use by Service members, their families, leaders, and health care providers but also has broader applications for all families. The MFFM has three core components: (1) family demands, (2) resources (including individual resources, family resources, and external resources), and (3) family outcomes (including related metrics). The MFFM proposes that resources from the individual, family, and external areas promote fitness, bolster resilience, and foster well-being for the family. The MFFM highlights each resource level for the purpose of improving family fitness and resilience over time. The MFFM both builds on existing family strengths and encourages the development of new family strengths through resource-acquiring behaviors. The purpose of this article is to (1) expand the military's Total Force Fitness (TFF) intent as it relates to families and (2) offer a family fitness model. This article will summarize relevant evidence, provide supportive theory, describe the model, and proffer metrics that support the dimensions of this model.

  20. Total force fitness: the military family fitness model.

    PubMed

    Bowles, Stephen V; Pollock, Liz Davenport; Moore, Monique; Wadsworth, Shelley MacDermid; Cato, Colanda; Dekle, Judith Ward; Meyer, Sonia Wei; Shriver, Amber; Mueller, Bill; Stephens, Mark; Seidler, Dustin A; Sheldon, Joseph; Picano, James; Finch, Wanda; Morales, Ricardo; Blochberger, Sean; Kleiman, Matthew E; Thompson, Daniel; Bates, Mark J

    2015-03-01

    The military lifestyle can create formidable challenges for military families. This article describes the Military Family Fitness Model (MFFM), a comprehensive model aimed at enhancing family fitness and resilience across the life span. This model is intended for use by Service members, their families, leaders, and health care providers but also has broader applications for all families. The MFFM has three core components: (1) family demands, (2) resources (including individual resources, family resources, and external resources), and (3) family outcomes (including related metrics). The MFFM proposes that resources from the individual, family, and external areas promote fitness, bolster resilience, and foster well-being for the family. The MFFM highlights each resource level for the purpose of improving family fitness and resilience over time. The MFFM both builds on existing family strengths and encourages the development of new family strengths through resource-acquiring behaviors. The purpose of this article is to (1) expand the military's Total Force Fitness (TFF) intent as it relates to families and (2) offer a family fitness model. This article will summarize relevant evidence, provide supportive theory, describe the model, and proffer metrics that support the dimensions of this model. PMID:25735013

  1. ALFA: Automated Line Fitting Algorithm

    NASA Astrophysics Data System (ADS)

    Wesson, R.

    2015-12-01

    ALFA fits emission line spectra of arbitrary wavelength coverage and resolution, fully automatically. It uses a catalog of lines which may be present to construct synthetic spectra, the parameters of which are then optimized by means of a genetic algorithm. Uncertainties are estimated using the noise structure of the residuals. An emission line spectrum containing several hundred lines can be fitted in a few seconds using a single processor of a typical contemporary desktop or laptop PC. Data cubes in FITS format can be analysed using multiple processors, and an analysis of tens of thousands of deep spectra obtained with instruments such as MUSE will take a few hours.

  2. Potential Fifty Percent Reduction in Saturation Diving Decompression Time Using a Combination of Intermittent Recompression and Exercise

    NASA Technical Reports Server (NTRS)

    Gernhardt, Michael I.; Abercromby, Andrew; Conklin, Johnny

    2007-01-01

    Conventional saturation decompression protocols use linear decompression rates that become progressively slower at shallower depths, consistent with free gas phase control vs. dissolved gas elimination kinetics. If decompression is limited by control of free gas phase, linear decompression is an inefficient strategy. The NASA prebreathe reduction program demonstrated that exercise during O2 prebreathe resulted in a 50% reduction (2 h vs. 4 h) in the saturation decompression time from 14.7 to 4.3 psi and a significant reduction in decompression sickness (DCS: 0 vs. 23.7%). Combining exercise with intermittent recompression, which controls gas phase growth and eliminates supersaturation before exercising, may enable more efficient saturation decompression schedules. A tissue bubble dynamics model (TBDM) was used in conjunction with a NASA exercise prebreathe model (NEPM) that relates tissue inert gas exchange rate constants to exercise (ml O2/kg-min), to develop a schedule for decompression from helium saturation at 400 fsw. The models provide significant prediction (p < 0.001) and goodness of fit with 430 cases of DCS in 6437 laboratory dives for TBDM (p = 0.77) and with 22 cases of DCS in 159 altitude exposures for NEPM (p = 0.70). The models have also been used operationally in over 25,000 dives (TBDM) and 40 spacewalks (NEPM). The standard U.S. Navy (USN) linear saturation decompression schedule from saturation at 400 fsw required 114.5 h with a maximum Bubble Growth Index (BGI(sub max)) of 17.5. Decompression using intermittent recompression combined with two 10 min exercise periods (75% VO2 (sub peak)) per day required 54.25 h (BGI(sub max): 14.7). Combined intermittent recompression and exercise resulted in a theoretical 53% (2.5 day) reduction in decompression time and theoretically lower DCS risk compared to the standard USN decompression schedule. These results warrant future decompression trials to evaluate the efficacy of this approach.

  3. Kinematic Fitting of Detached Vertices

    SciTech Connect

    Mattione, Paul

    2007-05-01

    The eg3 experiment at the Jefferson Lab CLAS detector aims to determine the existence of the $\\Xi_{5}$ pentaquarks and investigate the excited $\\Xi$ states. Specifically, the exotic $\\Xi_{5}^{--}$ pentaquark will be sought by first reconstructing the $\\Xi^{-}$ particle through its weak decays, $\\Xi^{-}\\to\\pi^{-}\\Lambda$ and $\\Lambda\\to\\pi^{-}$. A kinematic fitting routine was developed to reconstruct the detached vertices of these decays, where confidence level cuts on the fits are used to remove background events. Prior to fitting these decays, the exclusive reaction $\\gamma D\\rightarrow pp\\pi^{-}$ was studied in order to correct the track measurements and covariance matrices of the charged particles. The $\\Lambda\\rightarrow p\\pi^{-}$ and $\\Xi^{-}\\to\\pi^{-}\\Lambda$ decays were then investigated to demonstrate that the kinematic fitting routine reconstructs the decaying particles and their detached vertices correctly.

  4. Periodic Pattern of Genetic and Fitness Diversity during Evolution of an Artificial Cell-Like System.

    PubMed

    Ichihashi, Norikazu; Aita, Takuyo; Motooka, Daisuke; Nakamura, Shota; Yomo, Tetsuya

    2015-12-01

    Genetic and phenotypic diversity are the basis of evolution. Despite their importance, however, little is known about how they change over the course of evolution. In this study, we analyzed the dynamics of the adaptive evolution of a simple evolvable artificial cell-like system using single-molecule real-time sequencing technology that reads an entire single artificial genome. We found that the genomic RNA population increases in fitness intermittently, correlating with a periodic pattern of genetic and fitness diversity produced by repeated diversification and domination. In the diversification phase, a genomic RNA population spreads within a genetic space by accumulating mutations until mutants with higher fitness are generated, resulting in an increase in fitness diversity. In the domination phase, the mutants with higher fitness dominate, decreasing both the fitness and genetic diversity. This study reveals the dynamic nature of genetic and fitness diversity during adaptive evolution and demonstrates the utility of a simplified artificial cell-like system to study evolution at an unprecedented resolution.

  5. Deming's General Least Square Fitting

    1992-02-18

    DEM4-26 is a generalized least square fitting program based on Deming''s method. Functions built into the program for fitting include linear, quadratic, cubic, power, Howard''s, exponential, and Gaussian; others can easily be added. The program has the following capabilities: (1) entry, editing, and saving of data; (2) fitting of any of the built-in functions or of a user-supplied function; (3) plotting the data and fitted function on the display screen, with error limits if requested,more » and with the option of copying the plot to the printer; (4) interpolation of x or y values from the fitted curve with error estimates based on error limits selected by the user; and (5) plotting the residuals between the y data values and the fitted curve, with the option of copying the plot to the printer. If the plot is to be copied to a printer, GRAPHICS should be called from the operating system disk before the BASIC interpreter is loaded.« less

  6. The measurement theory of fitness.

    PubMed

    Wagner, Günter P

    2010-05-01

    In this article, an approach to measure fitness is proposed that considers fitness as a measure of competitive ability among phenotypes or genotypes. This approach is based on pairwise competition tests and is related to measures of "utility" in mathematical economics. Extending the results from utility theory it is possible to recover the classical Wrightian fitness measure without reference to models of population growth. A condition, quasi-BTL, similar to the Bradley-Terry-Luce condition of classical utility theory is shown to be necessary for the existence of frequency and context-independent fitness measures. Testing for violations of this quasi-BTL condition can be used to the detect genotype-by-genotype interactions and frequency-dependent fitness. A method for the detection of genotype by environment interactions is proposed that avoids potential scaling artifacts. Furthermore the measurement theoretical approach allows one to derive Wright's selection equation. This shows that classical selection equations are entirely general and exact. It is concluded that measurement theory is able to give definite answers to a number theoretical and practical questions. For instance, this theory identifies the correct scale for measuring gene interaction with respect to fitness and shows that different scales may lead to wrong conclusions. PMID:20002165

  7. Deming's General Least Square Fitting

    SciTech Connect

    Rinard, Phillip

    1992-02-18

    DEM4-26 is a generalized least square fitting program based on Deming''s method. Functions built into the program for fitting include linear, quadratic, cubic, power, Howard''s, exponential, and Gaussian; others can easily be added. The program has the following capabilities: (1) entry, editing, and saving of data; (2) fitting of any of the built-in functions or of a user-supplied function; (3) plotting the data and fitted function on the display screen, with error limits if requested, and with the option of copying the plot to the printer; (4) interpolation of x or y values from the fitted curve with error estimates based on error limits selected by the user; and (5) plotting the residuals between the y data values and the fitted curve, with the option of copying the plot to the printer. If the plot is to be copied to a printer, GRAPHICS should be called from the operating system disk before the BASIC interpreter is loaded.

  8. Fitness of the US workforce.

    PubMed

    Pronk, Nicolaas P

    2015-03-18

    Fitness matters for the prevention of premature death, chronic diseases, productivity loss, excess medical care costs, loss of income or family earnings, and other social and economic concerns. The workforce may be viewed as a corporate strategic asset, yet its fitness level appears to be relatively low and declining. Over the past half-century, obesity rates have doubled, physical activity levels are below par, and cardiorespiratory fitness often does not meet minimum acceptable job standards. During this time, daily occupational energy expenditure has decreased by more than 100 calories. Employers should consider best practices and design workplace wellness programs accordingly. Particular attention should be paid to human-centered cultures. Research should address ongoing surveillance needs regarding fitness of the US workforce and close gaps in the evidence base for fitness and business-relevant outcomes. Policy priorities should consider the impact of both state and federal regulations, adherence to current regulations that protect and promote worker health, and the introduction of incentives that allow employers to optimize the fitness of their workforce through supportive legislation and organizational policies.

  9. Carbon-Carbon Turbocharger Housing Unit for Intermittent Combustion Engines

    NASA Technical Reports Server (NTRS)

    Northam, G. Burton (Inventor); Ransone, Philip O. (Inventor); Rivers, H. Kevin (Inventor)

    1998-01-01

    An improved, lightweight, turbine housing unit for an intermittent combustion reciprocating internal combustion engine turbocharger is prepared from a lay-up or molding of carbon-carbon composite materials in a single-piece or two-piece process. When compared to conventional steel or cast iron, the use of carbon-carbon composite materials in a turbine housing unit reduces the overall weight of the engine and reduces the heat energy loss used in the turbocharging process. This reduction in heat energy loss and weight reduction provides for more efficient engine operation.

  10. Retrofitting activated sludge systems to intermittent aeration for nitrogen removal.

    PubMed

    Hanhan, O; Artan, N; Orhon, D

    2002-01-01

    The paper provides the basis and the conceptual approach of applying process kinetics and modelling to the design of alternating activated sludge systems for retrofitting existing activated sludge plants to intermittent aeration for nitrogen removal. It shows the significant role of the two specific parameters, namely, the aerated fraction and the cycle time ratio on process performance through model simulations and proposes a way to incorporate them into a design procedure using process stoichiometry and mass balance. It illustrates the effect of these parameters, together with the sludge age, in establishing the balance between the denitrification potential and the available nitrogen created in the anoxic/aerobic sequences of system operation.

  11. Grid superfluid turbulence and intermittency at very low temperature

    NASA Astrophysics Data System (ADS)

    Krstulovic, Giorgio

    2016-06-01

    Low-temperature grid-generated turbulence is investigated by using numerical simulations of the Gross-Pitaevskii equation. The statistics of regularized velocity increments are studied. Increments of the incompressible velocity are found to be skewed for turbulent states. Results are later confronted with the (quasi) homogeneous and isotropic Taylor-Green flow, revealing the universality of the statistics. For this flow, the statistics are found to be intermittent and a Kolmogorov constant close to the one of classical fluid is found for the second-order structure function.

  12. Intermittent hepatic porphyria in pregnancy with good perinatal outcome.

    PubMed

    Vidosavljević, Domagoj; Sijanović, Siniša; Rubin, Mirjana; Košuta Petrović, Maja; Abičić Žuljević, Kristina; Simić, Ivana

    2012-02-01

    Porphyrias are rare metabolic diseases caused by enzymatic defects of the haeme biosynthesis. Association of pregnancy and acute porphyria is rare, but mortality rate among pregnant women from acute attack has been reported up to 42%. This paper presents a patient with pregnancy complicated by intermittent hepatic porphyria with good perinatal outcome. The pattern of the attack in pregnancy varies individually and it makes porphyric pregnancies a challenge. Previously diagnosed porphyria patients should be closely monitored during pregnancy and diagnosis of acute porphyria must be also considered in all pregnant women with unexplained abdominal pain.

  13. Theory of fluorescence intermittency in quantum dots and other fluorophores

    NASA Astrophysics Data System (ADS)

    Volkan-Kacso, Sandor

    2011-12-01

    The purpose of the dissertation is to provide a theoretical explanation to the phenomenon of fluorescence intermittency. This is achieved by proposing a model of Multiple Recombination Centers (MRC), which is shown to successfully reproduce the main features of the phenomenon. Virtually all known types of optically active nanoscale objects to date show extremely long correlations in the fluctuations of fluorescence intensity. Experimentally collected intensity trajectories from such single fluorophores show fluctuations on the timescales longer than seconds. This phenomenon is generically referred to as fluorescence intermittency or blinking. In colloidal quantum dots blinking often assumes the shape of a random telegraph-like intermittency, a stochastic series of "ON" and "OFF" time intervals. Amazingly, the distribution of these ON and OFF times follow a universal power law dependence. Spectral characterization of trajectories effectively renders blinking an optical 1/f type noise. By a suitable Bayesian estimation method we point out that the conventional method of analysis using intensity histograms is problematic for such trajectories: The qualitative properties of the distributions strongly depend on the threshold value chosen for the separation the ON and OFF states. We propose phenomenological MRC model for the quantum dot and its environment by modeling the multiple channels of non-radiative relaxation as a collection of a few interacting two-level systems. We show how this model of multiple recombination centers reproduces key experimental features of blinking, including the strong threshold dependence. After a survey of existing models of blinking, we show that the MRC model is the only self-consistent model that can explain the long-range correlations found between blinking times. Beyond quantum dots, a carefully performed spectral analysis of intensity fluctuations observed in other fluorophores such as self-assembled quantum dots, nanorods, nanowires

  14. Evaluation of the intermittent GTA cold wire feed weld system

    SciTech Connect

    Dereskiewicz, J.P.

    1991-08-01

    An intermittent gas tungsten arc cold wire feed process was statistically evaluated to determine the feasibility of applying this process to meet the 0.030-inch weld penetration and peak temperature requirements when unfavorable joint tolerances exist on a subassembly weld. The wire feed system was determined to only slightly benefit the welding process over normal pulsed gas tungsten arc welding using traditional wire feeding capabilities. However, the complexity of this process and extensive welding operator training and qualification does not outweigh the benefits of incorporating this synchronized pulse wire feed system in production. 2 refs., 43 figs., 11 tabs.

  15. Retrofitting activated sludge systems to intermittent aeration for nitrogen removal.

    PubMed

    Hanhan, O; Artan, N; Orhon, D

    2002-01-01

    The paper provides the basis and the conceptual approach of applying process kinetics and modelling to the design of alternating activated sludge systems for retrofitting existing activated sludge plants to intermittent aeration for nitrogen removal. It shows the significant role of the two specific parameters, namely, the aerated fraction and the cycle time ratio on process performance through model simulations and proposes a way to incorporate them into a design procedure using process stoichiometry and mass balance. It illustrates the effect of these parameters, together with the sludge age, in establishing the balance between the denitrification potential and the available nitrogen created in the anoxic/aerobic sequences of system operation. PMID:12420968

  16. Google matrix and Ulam networks of intermittency maps.

    PubMed

    Ermann, L; Shepelyansky, D L

    2010-03-01

    We study the properties of the Google matrix of an Ulam network generated by intermittency maps. This network is created by the Ulam method which gives a matrix approximant for the Perron-Frobenius operator of dynamical map. The spectral properties of eigenvalues and eigenvectors of this matrix are analyzed. We show that the PageRank of the system is characterized by a power law decay with the exponent beta dependent on map parameters and the Google damping factor alpha . Under certain conditions the PageRank is completely delocalized so that the Google search in such a situation becomes inefficient.

  17. Echolocation of insects using intermittent frequency-modulated sounds.

    PubMed

    Matsuo, Ikuo; Takanashi, Takuma

    2015-09-01

    Using echolocation influenced by Doppler shift, bats can capture flying insects in real three-dimensional space. On the basis of this principle, a model that estimates object locations using frequency modulated (FM) sound was proposed. However, no investigation was conducted to verify whether the model can localize flying insects from their echoes. This study applied the model to estimate the range and direction of flying insects by extracting temporal changes from the time-frequency pattern and interaural range difference, respectively. The results obtained confirm that a living insect's position can be estimated using this model with echoes measured while emitting intermittent FM sounds. PMID:26428826

  18. Flow Intermittency, Dispersion, and Correlated Continuous Time Random Walks in Porous Media

    SciTech Connect

    de Anna, Pietro; Le Borgne, Tanguy; Dentz, Marco; Tartakovsky, Alexandre M.; Bolster, Diogo; Davy, Philippe

    2013-05-01

    We study the intermittency of fluid velocities in porous media and its relation to anomalous dispersion. Lagrangian velocities measured at equidistant points along streamlines are shown to form a spatial Markov process. As a consequence of this remarkable property, the dispersion of fluid particles can be described by a continuous time random walk with correlated temporal increments. This new dynamical picture of intermittency provides a direct link between the microscale flow, its intermittent properties, and non-Fickian dispersion.

  19. Intermittency in 200 GeV/nucleon S+S collisions

    SciTech Connect

    Jacobs, P.; Bloomer, M.A.

    1992-03-01

    We have studied one and two-dimensional intermittency in S+S collisions at 200 GeV/nucleon in a high statistics electronic measurement at the CERN SPS using pad-readout streamer tubes. We observe no intermittency signal beyond that produced by folding the Fritiof event generator with a detailed model of our detector. Even though the observed signal contains significant distortions due to experimental effects, we show that we are sensitive to intermittency in the collision.

  20. Measured, modeled, and causal conceptions of fitness

    PubMed Central

    Abrams, Marshall

    2012-01-01

    This paper proposes partial answers to the following questions: in what senses can fitness differences plausibly be considered causes of evolution?What relationships are there between fitness concepts used in empirical research, modeling, and abstract theoretical proposals? How does the relevance of different fitness concepts depend on research questions and methodological constraints? The paper develops a novel taxonomy of fitness concepts, beginning with type fitness (a property of a genotype or phenotype), token fitness (a property of a particular individual), and purely mathematical fitness. Type fitness includes statistical type fitness, which can be measured from population data, and parametric type fitness, which is an underlying property estimated by statistical type fitnesses. Token fitness includes measurable token fitness, which can be measured on an individual, and tendential token fitness, which is assumed to be an underlying property of the individual in its environmental circumstances. Some of the paper's conclusions can be outlined as follows: claims that fitness differences do not cause evolution are reasonable when fitness is treated as statistical type fitness, measurable token fitness, or purely mathematical fitness. Some of the ways in which statistical methods are used in population genetics suggest that what natural selection involves are differences in parametric type fitnesses. Further, it's reasonable to think that differences in parametric type fitness can cause evolution. Tendential token fitnesses, however, are not themselves sufficient for natural selection. Though parametric type fitnesses are typically not directly measurable, they can be modeled with purely mathematical fitnesses and estimated by statistical type fitnesses, which in turn are defined in terms of measurable token fitnesses. The paper clarifies the ways in which fitnesses depend on pragmatic choices made by researchers. PMID:23112804

  1. Intermittent dust mass loss from activated asteroid P/2013 P5 (PANSTARRS)

    SciTech Connect

    Moreno, F.; Pozuelos, F.

    2014-02-01

    We present observations and models of the dust environment of activated asteroid P/2013 P5 (PANSTARRS). The object displayed a complex morphology during the observations, with the presence of multiple tails. We combined our own observations, all made with instrumentation attached to the 10.4 m Gran Telescopio Canarias on La Palma, with previously published Hubble Space Telescope images to build a model aimed at fitting all the observations. Altogether, the data cover a full three month period of observations which can be explained by intermittent dust loss. The most plausible scenario is that of an asteroid rotating with the spinning axis oriented perpendicular to the orbit plane and losing mass from the equatorial region, consistent with rotational break-up. Assuming that the ejection velocity of the particles (v ∼ 0.02-0.05 m s{sup –1}) corresponds to the escape velocity, the object diameter is constrained to ∼30-130 m for bulk densities 3000-1000 kg m{sup –3}.

  2. Can Mathematical Models Predict the Outcomes of Prostate Cancer Patients Undergoing Intermittent Androgen Deprivation Therapy?

    NASA Astrophysics Data System (ADS)

    Everett, R. A.; Packer, A. M.; Kuang, Y.

    2014-04-01

    Androgen deprivation therapy is a common treatment for advanced or metastatic prostate cancer. Like the normal prostate, most tumors depend on androgens for proliferation and survival but often develop treatment resistance. Hormonal treatment causes many undesirable side effects which significantly decrease the quality of life for patients. Intermittently applying androgen deprivation in cycles reduces the total duration with these negative effects and may reduce selective pressure for resistance. We extend an existing model which used measurements of patient testosterone levels to accurately fit measured serum prostate specific antigen (PSA) levels. We test the model's predictive accuracy, using only a subset of the data to find parameter values. The results are compared with those of an existing piecewise linear model which does not use testosterone as an input. Since actual treatment protocol is to re-apply therapy when PSA levels recover beyond some threshold value, we develop a second method for predicting the PSA levels. Based on a small set of data from seven patients, our results showed that the piecewise linear model produced slightly more accurate results while the two predictive methods are comparable. This suggests that a simpler model may be more beneficial for a predictive use compared to a more biologically insightful model, although further research is needed in this field prior to implementing mathematical models as a predictive method in a clinical setting. Nevertheless, both models are an important step in this direction.

  3. Can Mathematical Models Predict the Outcomes of Prostate Cancer Patients Undergoing Intermittent Androgen Deprivation Therapy?

    NASA Astrophysics Data System (ADS)

    Everett, R. A.; Packer, A. M.; Kuang, Y.

    Androgen deprivation therapy is a common treatment for advanced or metastatic prostate cancer. Like the normal prostate, most tumors depend on androgens for proliferation and survival but often develop treatment resistance. Hormonal treatment causes many undesirable side effects which significantly decrease the quality of life for patients. Intermittently applying androgen deprivation in cycles reduces the total duration with these negative effects and may reduce selective pressure for resistance. We extend an existing model which used measurements of patient testosterone levels to accurately fit measured serum prostate specific antigen (PSA) levels. We test the model's predictive accuracy, using only a subset of the data to find parameter values. The results are compared with those of an existing piecewise linear model which does not use testosterone as an input. Since actual treatment protocol is to re-apply therapy when PSA levels recover beyond some threshold value, we develop a second method for predicting the PSA levels. Based on a small set of data from seven patients, our results showed that the piecewise linear model produced slightly more accurate results while the two predictive methods are comparable. This suggests that a simpler model may be more beneficial for a predictive use compared to a more biologically insightful model, although further research is needed in this field prior to implementing mathematical models as a predictive method in a clinical setting. Nevertheless, both models are an important step in this direction.

  4. Influence of intermittent wetting and drying conditions on heavy metal removal by stormwater biofilters.

    PubMed

    Blecken, Godecke-Tobias; Zinger, Yaron; Deletić, Ana; Fletcher, Tim D; Viklander, Maria

    2009-10-01

    Biofiltration is a technology to treat urban stormwater runoff, which conveys pollutants, including heavy metals. However, the variability of metals removal performance in biofiltration systems is as yet unknown. A laboratory study has been conducted with vegetated biofilter mesocosms, partly fitted with a submerged zone at the bottom of the filter combined with a carbon source. The biofilters were dosed with stormwater according to three different dry/wet schemes, to investigate the effect of intermittent wetting and drying conditions on metal removal. Provided that the biofilters received regular stormwater input, metal removal exceeded 95%. The highest metal accumulation occurs in the top layer of the filter media. However, after antecedent drying before a storm event exceeding 3-4 weeks the filters performed significantly worse, although metal removal still remained relatively high. Introducing a submerged zone into the filter improved the performance significantly after extended dry periods. In particular, copper removal in filters equipped with a submerged zone was increased by around 12% (alpha=0.05) both during wet and dry periods and for lead the negative effect of drying could completely be eliminated, with consistently low outflow concentrations even after long drying periods.

  5. Intermittent reservoir daily-inflow prediction using lumped and distributed data multi-linear regression models

    NASA Astrophysics Data System (ADS)

    Magar, R. B.; Jothiprakash, V.

    2011-12-01

    In this study, multi-linear regression (MLR) approach is used to construct intermittent reservoir daily inflow forecasting system. To illustrate the applicability and effect of using lumped and distributed input data in MLR approach, Koyna river watershed in Maharashtra, India is chosen as a case study. The results are also compared with autoregressive integrated moving average (ARIMA) models. MLR attempts to model the relationship between two or more independent variables over a dependent variable by fitting a linear regression equation. The main aim of the present study is to see the consequences of development and applicability of simple models, when sufficient data length is available. Out of 47 years of daily historical rainfall and reservoir inflow data, 33 years of data is used for building the model and 14 years of data is used for validating the model. Based on the observed daily rainfall and reservoir inflow, various types of time-series, cause-effect and combined models are developed using lumped and distributed input data. Model performance was evaluated using various performance criteria and it was found that as in the present case, of well correlated input data, both lumped and distributed MLR models perform equally well. For the present case study considered, both MLR and ARIMA models performed equally sound due to availability of large dataset.

  6. Changes in Drop-Jump Landing Biomechanics During Prolonged Intermittent Exercise

    PubMed Central

    Schmitz, Randy J.; Cone, John C.; Tritsch, Amanda J.; Pye, Michele L.; Montgomery, Melissa M.; Henson, Robert A.; Shultz, Sandra J.

    2014-01-01

    Background: As injury rates rise in the later stages of sporting activities, a better understanding of lower extremity biomechanics in the later phases of gamelike situations may improve training and injury prevention programs. Hypothesis: Lower extremity biomechanics of a drop-jump task (extracted from a principal components analysis) would reveal factors associated with risk of anterior cruciate ligament injury during a 90-minute individualized intermittent exercise protocol (IEP) and for 1 hour following the IEP. Study Design: Controlled laboratory study. Level of Evidence: Level 4. Methods: Fifty-nine athletes (29 women, 30 men) completed 3 sessions. The first session assessed fitness for an IEP designed to simulate the demands of a soccer match. An experimental session assessed drop-jump biomechanics, after a dynamic warm-up, every 15 minutes during the 90-minute IEP, and for 1 hour following the IEP. A control session with no exercise assessed drop-jump performance at the same intervals. Results: Two biomechanical factors early in the first half (hip flexion at initial contact and hip loading; ankle loading and knee shear force) decreased at the end of the IEP and into the 60-minute recovery period, while a third factor (knee loading) decreased only during the recovery period (P ≤ 0.05). Conclusion: The individualized sport-specific IEP may have more subtle effects on landing biomechanics when compared with short-term, exhaustive fatigue protocols. Clinical Relevance: Potentially injurious landing biomechanics may not occur until the later stages of soccer activity. PMID:24587862

  7. MODELING OF THE NON-GAUSSIAN PDFs OF FIELD VARIATIONS AND INTERMITTENCY IN THE TURBULENT SOLAR WIND

    SciTech Connect

    Ragot, B. R.

    2013-03-10

    The probability distribution functions (PDFs) of magnetic field variations display strong scale-dependent non-Gaussianity in the turbulent solar wind. This is a typical signature of intermittent turbulence. Physical modeling of the turbulent field variations based on the characteristics of the observed turbulence, including the variability of its power level, produces, free of parameter adjustment and over a broad range of inertial scales, accurate fits of the non-Gaussian PDFs. The effects of phase randomization and time resolution of the Fourier power spectra are further tested to determine which of the phase correlation or the spectral variability is responsible for the strong non-Gaussianity of the observed PDFs of field variations. The periods of enhanced power level are found to be responsible for the non-Gaussian tails of the PDFs.

  8. Fit Effect of Motorcycle Helmet

    NASA Astrophysics Data System (ADS)

    Chang, Li-Tung; Chang, Chih-Han; Chang, Guan-Liang

    Optimized assessment of the adequacy of fit conditions between a motorcycle helmet and head size in relation to prevention of head injury remains unclear and is complicated by wide variations in the size and shape characteristics of helmet and wearer’s heads. A finite element model (LS-DYNA3D) based on realistic geometric features of a motorcycle helmet was established to simulate the standard shock absorption test for evaluating the dynamic response and fit effects of a helmet. The model was used to simulate crown, rear and side sites impacts of the helmet. The peak acceleration and Head Injury Criterion (HIC) were employed to assess the protective performance of the helmet against head injuries. The results show that this helmet model had various dynamic responses at different impact sites due to its geometric shape, but that the impact-absorbing capability did not vary markedly within these sites. The fit conditions between the headform and the helmet dramatically affected the assessment of the impact-absorbing capability of the helmet in the standard shock absorption test. However, for a motorcyclist, the helmet fit would have only minor influence on the protection against head injuries. This observation suggests that a better fitting helmet with stable fixation should provide more protection against head injury.

  9. Fitting and Interpreting Occupancy Models

    PubMed Central

    Welsh, Alan H.; Lindenmayer, David B.; Donnelly, Christine F.

    2013-01-01

    We show that occupancy models are more difficult to fit than is generally appreciated because the estimating equations often have multiple solutions, including boundary estimates which produce fitted probabilities of zero or one. The estimates are unstable when the data are sparse, making them difficult to interpret, and, even in ideal situations, highly variable. As a consequence, making accurate inference is difficult. When abundance varies over sites (which is the general rule in ecology because we expect spatial variance in abundance) and detection depends on abundance, the standard analysis suffers bias (attenuation in detection, biased estimates of occupancy and potentially finding misleading relationships between occupancy and other covariates), asymmetric sampling distributions, and slow convergence of the sampling distributions to normality. The key result of this paper is that the biases are of similar magnitude to those obtained when we ignore non-detection entirely. The fact that abundance is subject to detection error and hence is not directly observable, means that we cannot tell when bias is present (or, equivalently, how large it is) and we cannot adjust for it. This implies that we cannot tell which fit is better: the fit from the occupancy model or the fit ignoring the possibility of detection error. Therefore trying to adjust occupancy models for non-detection can be as misleading as ignoring non-detection completely. Ignoring non-detection can actually be better than trying to adjust for it. PMID:23326323

  10. Implementation of Health Fitness Exercise Programs.

    ERIC Educational Resources Information Center

    Cundiff, David E., Ed.

    This monograph includes the following articles to aid in implementation of fitness concepts: (1) "Trends in Physical Fitness: A Personal Perspective" (H. Harrison Clarke); (2) "A Total Health-Fitness Life-Style" (Steven N. Blair); (3) "Objectives for the Nation--Physical Fitness and Exercise" (Jack H. Wilmore); (4) "A New Physical Fitness Test"…

  11. Test fittings for dimensionally critical tubes

    NASA Technical Reports Server (NTRS)

    Hagler, R.

    1980-01-01

    Method using lightweight fitting protects tubes and tube stubs during testing and through to final welding. Fitting does not interfere with final welding or brazing like temporary test fittings, and is not heavy like machined-on integral fittings with face-seal 0-rings. Fitting approach is adaptable to many types of components, including valves, transducers, and filters.

  12. Intermittent bursts induced by double tearing mode reconnection

    SciTech Connect

    Wei, Lai; Wang, Zheng-Xiong

    2014-06-15

    Reversed magnetic shear (RMS) configuration is assumed to be the steady-state operation scenario for the future advanced tokamaks like International Thermonuclear Experimental Reactor. In this work, we numerically discover a phenomenon of violent intermittent bursts induced by self-organized double tearing mode (DTM) reconnection in the RMS configuration during the very long evolution, which may continuously lead to annular sawtooth crashes and thus badly impact the desired steady-state operation of the future advanced RMS tokamaks. The key process of the intermittent bursts in the off-axis region is similar to that of the typical sawtooth relaxation oscillation in the positive magnetic shear configuration. It is interestingly found that in the decay phase of the DTM reconnection, the zonal field significantly counteracts equilibrium field to make the magnetic shear between the two rational surfaces so weak that the residual self-generated vortices of the previous DTM burst are able to trigger a reverse DTM reconnection by curling the field lines.

  13. Intermittent flow regimes near the convection threshold in ferromagnetic nanofluids.

    PubMed

    Krauzina, Marina T; Bozhko, Alexandra A; Putin, Gennady F; Suslov, Sergey A

    2015-01-01

    The onset and decay of convection in a spherical cavity filled with ferromagnetic nanofluid and heated from below are investigated experimentally. It is found that, unlike in a single-component Newtonian fluid where stationary convection sets in as a result of supercritical bifurcation and where convection intensity increases continuously with the degree of supercriticality, convection in a multicomponent ferromagnetic nanofluid starts abruptly and has an oscillatory nature. The hysteresis is observed in the transition between conduction and convection states. In moderately supercritical regimes, the arising fluid motion observed at a fixed temperature difference intermittently transitions from quasiharmonic to essentially irregular oscillations that are followed by periods of a quasistationary convection. The observed oscillations are shown to result from the precession of the axis of a convection vortex in the equatorial plane. When the vertical temperature difference exceeds the convection onset value by a factor of 2.5, the initially oscillatory convection settles to a steady-state regime with no intermittent behavior detected afterward. The performed wavelet and Fourier analyses of thermocouple readings indicate the presence of various oscillatory modes with characteristic periods ranging from one hour to several days. PMID:25679711

  14. Emission Enhancement and Intermittency in Polycrystalline Organolead Halide Perovskite Films.

    PubMed

    Li, Cheng; Zhong, Yu; Luna, Carlos Andres Melo; Unger, Thomas; Deichsel, Konstantin; Gräser, Anna; Köhler, Jürgen; Köhler, Anna; Hildner, Richard; Huettner, Sven

    2016-01-01

    Inorganic-organic halide organometal perovskites have demonstrated very promising performance for opto-electronic applications, such as solar cells, light-emitting diodes, lasers, single-photon sources, etc. However, the little knowledge on the underlying photophysics, especially on a microscopic scale, hampers the further improvement of devices based on this material. In this communication, correlated conventional photoluminescence (PL) characterization and wide-field PL imaging as a function of time are employed to investigate the spatially- and temporally-resolved PL in CH₃NH₃PbI3-xClx perovskite films. Along with a continuous increase of the PL intensity during light soaking, we also observe PL blinking or PL intermittency behavior in individual grains of these films. Combined with significant suppression of PL blinking in perovskite films coated with a phenyl-C61-butyric acid methyl ester (PCBM) layer, it suggests that this PL intermittency is attributed to Auger recombination induced by photoionized defects/traps or mobile ions within grains. These defects/traps are detrimental for light conversion and can be effectively passivated by the PCBM layer. This finding paves the way to provide a guideline on the further improvement of perovskite opto-electronic devices. PMID:27548128

  15. Intermittency measurement in two-dimensional bacterial turbulence

    NASA Astrophysics Data System (ADS)

    Qiu, Xiang; Ding, Long; Huang, Yongxiang; Chen, Ming; Lu, Zhiming; Liu, Yulu; Zhou, Quan

    2016-06-01

    In this paper, an experimental velocity database of a bacterial collective motion, e.g., Bacillus subtilis, in turbulent phase with volume filling fraction 84 % provided by Professor Goldstein at Cambridge University (UK), was analyzed to emphasize the scaling behavior of this active turbulence system. This was accomplished by performing a Hilbert-based methodology analysis to retrieve the scaling property without the β -limitation. A dual-power-law behavior separated by the viscosity scale ℓν was observed for the q th -order Hilbert moment Lq(k ) . This dual-power-law belongs to an inverse-cascade since the scaling range is above the injection scale R , e.g., the bacterial body length. The measured scaling exponents ζ (q ) of both the small-scale (k >kν ) and large-scale (k intermittency parameters are μS=0.26 and μL=0.17 , respectively, for the small- and large-scale motions. It implies that the former cascade is more intermittent than the latter one, which is also confirmed by the corresponding singularity spectrum f (α ) versus α . Comparison with the conventional two-dimensional Ekman-Navier-Stokes equation, a continuum model indicates that the origin of the multifractality could be a result of some additional nonlinear interaction terms, which deservers a more careful investigation.

  16. Intermittent Water Supply: Prevalence, Practice, and Microbial Water Quality.

    PubMed

    Kumpel, Emily; Nelson, Kara L

    2016-01-19

    Intermittent water supplies (IWS), in which water is provided through pipes for only limited durations, serve at least 300 million people around the world. However, providing water intermittently can compromise water quality in the distribution system. In IWS systems, the pipes do not supply water for periods of time, supply periods are shortened, and pipes experience regular flow restarting and draining. These unique behaviors affect distribution system water quality in ways that are different than during normal operations in continuous water supplies (CWS). A better understanding of the influence of IWS on mechanisms causing contamination can help lead to incremental steps that protect water quality and minimize health risks. This review examines the status and nature of IWS practices throughout the world, the evidence of the effect of IWS on water quality, and how the typical contexts in which IWS systems often exist-low-income countries with under-resourced utilities and inadequate sanitation infrastructure-can exacerbate mechanisms causing contamination. We then highlight knowledge gaps for further research to improve our understanding of water quality in IWS.

  17. Horizontal visibility graphs generated by type-I intermittency

    NASA Astrophysics Data System (ADS)

    Núñez, Ángel M.; Luque, Bartolo; Lacasa, Lucas; Gómez, Jose Patricio; Robledo, Alberto

    2013-05-01

    The type-I intermittency route to (or out of) chaos is investigated within the horizontal visibility (HV) graph theory. For that purpose, we address the trajectories generated by unimodal maps close to an inverse tangent bifurcation and construct their associated HV graphs. We show how the alternation of laminar episodes and chaotic bursts imprints a fingerprint in the resulting graph structure. Accordingly, we derive a phenomenological theory that predicts quantitative values for several network parameters. In particular, we predict that the characteristic power-law scaling of the mean length of laminar trend sizes is fully inherited by the variance of the graph degree distribution, in good agreement with the numerics. We also report numerical evidence on how the characteristic power-law scaling of the Lyapunov exponent as a function of the distance to the tangent bifurcation is inherited in the graph by an analogous scaling of block entropy functionals defined on the graph. Furthermore, we are able to recast the full set of HV graphs generated by intermittent dynamics into a renormalization-group framework, where the fixed points of its graph-theoretical renormalization-group flow account for the different types of dynamics. We also establish that the nontrivial fixed point of this flow coincides with the tangency condition and that the corresponding invariant graph exhibits extremal entropic properties.

  18. Intermittent Demand Forecasting in a Tertiary Pediatric Intensive Care Unit.

    PubMed

    Cheng, Chen-Yang; Chiang, Kuo-Liang; Chen, Meng-Yin

    2016-10-01

    Forecasts of the demand for medical supplies both directly and indirectly affect the operating costs and the quality of the care provided by health care institutions. Specifically, overestimating demand induces an inventory surplus, whereas underestimating demand possibly compromises patient safety. Uncertainty in forecasting the consumption of medical supplies generates intermittent demand events. The intermittent demand patterns for medical supplies are generally classified as lumpy, erratic, smooth, and slow-moving demand. This study was conducted with the purpose of advancing a tertiary pediatric intensive care unit's efforts to achieve a high level of accuracy in its forecasting of the demand for medical supplies. On this point, several demand forecasting methods were compared in terms of the forecast accuracy of each. The results confirm that applying Croston's method combined with a single exponential smoothing method yields the most accurate results for forecasting lumpy, erratic, and slow-moving demand, whereas the Simple Moving Average (SMA) method is the most suitable for forecasting smooth demand. In addition, when the classification of demand consumption patterns were combined with the demand forecasting models, the forecasting errors were minimized, indicating that this classification framework can play a role in improving patient safety and reducing inventory management costs in health care institutions. PMID:27562485

  19. Intermittent Demand Forecasting in a Tertiary Pediatric Intensive Care Unit.

    PubMed

    Cheng, Chen-Yang; Chiang, Kuo-Liang; Chen, Meng-Yin

    2016-10-01

    Forecasts of the demand for medical supplies both directly and indirectly affect the operating costs and the quality of the care provided by health care institutions. Specifically, overestimating demand induces an inventory surplus, whereas underestimating demand possibly compromises patient safety. Uncertainty in forecasting the consumption of medical supplies generates intermittent demand events. The intermittent demand patterns for medical supplies are generally classified as lumpy, erratic, smooth, and slow-moving demand. This study was conducted with the purpose of advancing a tertiary pediatric intensive care unit's efforts to achieve a high level of accuracy in its forecasting of the demand for medical supplies. On this point, several demand forecasting methods were compared in terms of the forecast accuracy of each. The results confirm that applying Croston's method combined with a single exponential smoothing method yields the most accurate results for forecasting lumpy, erratic, and slow-moving demand, whereas the Simple Moving Average (SMA) method is the most suitable for forecasting smooth demand. In addition, when the classification of demand consumption patterns were combined with the demand forecasting models, the forecasting errors were minimized, indicating that this classification framework can play a role in improving patient safety and reducing inventory management costs in health care institutions.

  20. Intermittent filtration of bacteria and colloids in porous media

    NASA Astrophysics Data System (ADS)

    Auset, Maria; Keller, Arturo A.; Brissaud, FrançOis; Lazarova, Valentina

    2005-09-01

    Intermittent filtration through porous media used for water and wastewater treatment can achieve high pathogen and colloid removal efficiencies. To predict the removal of bacteria, the effects of cyclic infiltration and draining events (transient unsaturated flow) were investigated. Using physical micromodels, we visualized the intermittent transport of bacteria and other colloids in unsaturated porous media. Column experiments provided quantitative measurements of the phenomena observed at the pore scale. Tagged Escherichia coli and a conservative tracer (NaI) were introduced in an initial pulse into a 1.5 m sand column. Subsequent hydraulic flushes without tagged bacteria or tracer were repeated every 4 hours for the next 4 days, during which outflow concentrations were monitored. Breakthrough behavior between colloids and dissolved tracer differed significantly, reflecting the differences in transport processes. Advancement of the wetting front remobilized bacteria which were held in thin water films, attached to the air-water interface (AWI), or entrapped in stagnant pore water between gas bubbles. In contrast, the tracer was only remobilized by diffusion from immobile to mobile water. Remobilization led to successive concentration peaks of bacteria and tracer in the effluent but with significant temporal differences. Observations at the pore-scale indicated that the colloids were essentially irreversibly attached to the solid-water interface, which explained to some extent the high removal efficiency of microbes in the porous media. Straining, cluster filtration, cell lysis, protozoa grazing, and bacteriophage parasitism could also contribute to the removal efficiency of bacteria.

  1. Horizontal visibility graphs generated by type-I intermittency.

    PubMed

    Núñez, Ángel M; Luque, Bartolo; Lacasa, Lucas; Gómez, Jose Patricio; Robledo, Alberto

    2013-05-01

    The type-I intermittency route to (or out of) chaos is investigated within the horizontal visibility (HV) graph theory. For that purpose, we address the trajectories generated by unimodal maps close to an inverse tangent bifurcation and construct their associated HV graphs. We show how the alternation of laminar episodes and chaotic bursts imprints a fingerprint in the resulting graph structure. Accordingly, we derive a phenomenological theory that predicts quantitative values for several network parameters. In particular, we predict that the characteristic power-law scaling of the mean length of laminar trend sizes is fully inherited by the variance of the graph degree distribution, in good agreement with the numerics. We also report numerical evidence on how the characteristic power-law scaling of the Lyapunov exponent as a function of the distance to the tangent bifurcation is inherited in the graph by an analogous scaling of block entropy functionals defined on the graph. Furthermore, we are able to recast the full set of HV graphs generated by intermittent dynamics into a renormalization-group framework, where the fixed points of its graph-theoretical renormalization-group flow account for the different types of dynamics. We also establish that the nontrivial fixed point of this flow coincides with the tangency condition and that the corresponding invariant graph exhibits extremal entropic properties.

  2. Optimization via intermittency with a self-organizing neural network.

    PubMed

    Kwok, Terence; Smith, Kate A

    2005-11-01

    One of the major obstacles in using neural networks to solve combinatorial optimization problems is the convergence toward one of the many local minima instead of the global minima. In this letter, we propose a technique that enables a self-organizing neural network to escape from local minima by virtue of the intermittency phenomenon. It gives rise to novel search dynamics that allow the system to visit multiple global minima as meta-stable states. Numerical experiments performed suggest that the phenomenon is a combined effect of Kohonen-type competitive learning and the iterated softmax function operating near bifurcation. The resultant intermittent search exhibits fractal characteristics when the optimization performance is at its peak in the form of 1/f signals in the time evolution of the cost, as well as power law distributions in the meta-stable solution states. TheN-Queens problem is used as an example to illustrate the meta-stable convergence process that sequentially generates, in a single run, 92 solutions to the 8-Queens problem and 4024 solutions to the 17-Queens problem.

  3. Thymic Selection of T Cells as Diffusion with Intermittent Traps

    NASA Astrophysics Data System (ADS)

    Košmrlj, Andrej

    2011-04-01

    T cells orchestrate adaptive immune responses by recognizing short peptides derived from pathogens, and by distinguishing them from self-peptides. To ensure the latter, immature T cells (thymocytes) diffuse within the thymus gland, where they encounter an ensemble of self-peptides presented on (immobile) antigen presenting cells. Potentially autoimmune T cells are eliminated if the thymocyte binds sufficiently strongly with any such antigen presenting cell. We model thymic selection of T cells as a random walker diffusing in a field of immobile traps that intermittently turn "on" and "off". The escape probability of potentially autoimmune T cells is equivalent to the survival probability of such a random walker. In this paper we describe the survival probability of a random walker on a d-dimensional cubic lattice with randomly placed immobile intermittent traps, and relate it to the result of a well-studied problem where traps are always "on". Additionally, when switching between the trap states is slow, we find a peculiar caging effect for the survival probability.

  4. Intermittent transport of nonlinear reduced models in tokomak plasmas turbulence

    NASA Astrophysics Data System (ADS)

    Belgherras, S.; Benouaz, T.; Bekkouche, S. M. A.; Bekkouche

    2012-12-01

    Understanding the origin and nature of turbulent transport in tokomak plasmas is one of the major challenges of a successful magnetic confinement fusion. The aim of this work is to study instability associated with the ion-temperature gradient (ITG)-driven turbulence in the core of the plasma, which is the seat of fusion reactions. We used a low degree of freedom model composed of 18 ordinary differential equations. When the system is slightly above the stability threshold of the ITG mode, it is considered to be in the convection regime and convective heat transport of the system is time-independent, or oscillates periodically. As ITG is increased further, the system bifurcates to the turbulent regime. In a strongly turbulent regime, intermittent bursts (the so-called avalanches) are observed. This intermittency is a result of the competition among the following three factors: generation of sheared flows and suppression of ITG turbulence, gradual reduction of the sheared flows due to viscosity, and rapid regrowth of ITG modes due to reduction of sheared flows.

  5. Optimization via intermittency with a self-organizing neural network.

    PubMed

    Kwok, Terence; Smith, Kate A

    2005-11-01

    One of the major obstacles in using neural networks to solve combinatorial optimization problems is the convergence toward one of the many local minima instead of the global minima. In this letter, we propose a technique that enables a self-organizing neural network to escape from local minima by virtue of the intermittency phenomenon. It gives rise to novel search dynamics that allow the system to visit multiple global minima as meta-stable states. Numerical experiments performed suggest that the phenomenon is a combined effect of Kohonen-type competitive learning and the iterated softmax function operating near bifurcation. The resultant intermittent search exhibits fractal characteristics when the optimization performance is at its peak in the form of 1/f signals in the time evolution of the cost, as well as power law distributions in the meta-stable solution states. TheN-Queens problem is used as an example to illustrate the meta-stable convergence process that sequentially generates, in a single run, 92 solutions to the 8-Queens problem and 4024 solutions to the 17-Queens problem. PMID:16156935

  6. Hydrology and Geomorphology of Tallgrass Prairie Intermittent Headwater Streams

    NASA Astrophysics Data System (ADS)

    Daniels, M. D.; Grudzinski, B.

    2011-12-01

    The arid to semi-arid Great Plains region of the United States covers more than 1 million km2, yet virtually nothing is known about the geomorphology of its intermittent headwater streams. These streams and the perennial rivers they feed support a unique and increasingly endangered assemblage of endemic fish species. While human impacts in the region are not at first glace significant, the reality is that the Great Plains are an intensively managed landscape, with pervasive cattle grazing, channelization, and groundwater over-pumping affecting these systems. These stresses will only increase with potential climate and related land use changes. Few natural remnants of native grassland remain today, limiting opportunities to study the natural dynamics of these systems in contrast to the anthropogenically modified systems. This paper presents a review of the existing geomorphological and hydrological knowledge of Great Plains headwater streams and presents the initial analysis of an 18 year intermittent headwater stream record from the tallgrass Konza Prairie LTER, Kansas. Results suggest that fire frequency and grazing and the resultant riparian vegetation composition strongly influence stream flow dynamics as well as stream geomorphology.

  7. Mechanisms affecting water quality in an intermittent piped water supply.

    PubMed

    Kumpel, Emily; Nelson, Kara L

    2014-01-01

    Drinking water distribution systems throughout the world supply water intermittently, leaving pipes without pressure between supply cycles. Understanding the multiple mechanisms that affect contamination in these intermittent water supplies (IWS) can be used to develop strategies to improve water quality. To study these effects, we tested water quality in an IWS system with infrequent and short water delivery periods in Hubli-Dharwad, India. We continuously measured pressure and physicochemical parameters and periodically collected grab samples to test for total coliform and E. coli throughout supply cycles at 11 sites. When the supply was first turned on, water with elevated turbidity and high concentrations of indicator bacteria was flushed out of pipes. At low pressures (<10 psi), elevated indicator bacteria were frequently detected even when there was a chlorine residual, suggesting persistent contamination had occurred through intrusion or backflow. At pressures between 10 and 17 psi, evidence of periodic contamination suggested that transient intrusion, backflow, release of particulates, or sloughing of biofilms from pipe walls had occurred. Few total coliform and no E. coli were detected when water was delivered with a chlorine residual and at pressures >17 psi.

  8. Twist-induced Magnetosphere Reconfiguration for Intermittent Pulsars

    NASA Astrophysics Data System (ADS)

    Huang, Lei; Yu, Cong; Tong, Hao

    2016-08-01

    We propose that the magnetosphere reconfiguration induced by magnetic twists in the closed field line region can account for the mode switching of intermittent pulsars. We carefully investigate the properties of axisymmetric force-free pulsar magnetospheres with magnetic twists in closed field line regions around the polar caps. The magnetosphere with twisted closed lines leads to enhanced spin-down rates. The enhancement in spin-down rate depends on the size of the region with twisted closed lines. Typically, it is increased by a factor of ˜2, which is consistent with the intermittent pulsars’ spin-down behavior during the “off” and “on” states. We find that there is a threshold of maximal twist angle {{Δ }}{φ }{{thres}}˜ 1. The magnetosphere is stable only if the closed line twist angle is less than {{Δ }}{φ }{{thres}}. Beyond this value, the magnetosphere becomes unstable and gets untwisted. The spin-down rate would reduce to its off-state value. The quasi-periodicity in spin-down rate change can be explained by long-term activities in the star’s crust and the untwisting induced by MHD instability. The estimated duration of on-state is about 1 week, consistent with observations. Due to the MHD instability, there exists an upper limit for the spin-down ratio (f˜ 3) between the on-state and the off-state, if the Y-point remains at the light cylinder.

  9. Intermittent collective dynamics emerge from conflicting imperatives in sheep herds

    PubMed Central

    Ginelli, Francesco; Peruani, Fernando; Pillot, Marie-Helène; Chaté, Hugues; Theraulaz, Guy; Bon, Richard

    2015-01-01

    Among the many fascinating examples of collective behavior exhibited by animal groups, some species are known to alternate slow group dispersion in space with rapid aggregation phenomena induced by a sudden behavioral shift at the individual level. We study this phenomenon quantitatively in large groups of grazing Merino sheep under controlled experimental conditions. Our analysis reveals strongly intermittent collective dynamics consisting of fast, avalanche-like regrouping events distributed on all experimentally accessible scales. As a proof of principle, we introduce an agent-based model with individual behavioral shifts, which we show to account faithfully for all collective properties observed. This offers, in turn, an insight on the individual stimulus/response functions that can generate such intermittent behavior. In particular, the intensity of sheep allelomimetic behavior plays a key role in the group’s ability to increase the per capita grazing surface while minimizing the time needed to regroup into a tightly packed configuration. We conclude that the emergent behavior reported probably arises from the necessity to balance two conflicting imperatives: (i) the exploration of foraging space by individuals and (ii) the protection from predators offered by being part of large, cohesive groups. We discuss our results in the context of the current debate about criticality in biology. PMID:26417082

  10. INTERMITTENT CONVECTION IN THE BOUNDARY OF DIII-D

    SciTech Connect

    J.A. BOEDO; D.L. RUDAKOV; R.J. COLCHIN; R.A. MOYER; S. KRASHENINNIKOV; D.G. WHYTE; G.R. McKEE; M.J. SCHAFFER; P.C. STANGEBY; W.P. WEST; S.L. ALLEN; A.W. LEONARD

    2002-06-01

    Intermittent plasma objects (IPOs) featuring higher pressure than the surrounding plasma, and responsible for {approx}50% of the E x B{sub T} radial transport, are observed in the scrape-off layer (SOL) and edge of the DIII-D tokamak. The skewness of probe and BES intermittent data suggest IPO formation at or near the last closed flux surface (LCFS) and the existence of hole-IPO pairs. The particle content of the IPOs at the LCFS is linearly dependent on the discharge density, however, when normalized to the local averaged density, it is fairly insensitive to density variations. It is also shown that the IPOs thermalize with the background plasma within 1 cm of the LCFS. The IPOs appear in the SOL of both L and H mode discharges carrying {approx}50% of the total SOL radial E x B{sub T} transport at all radii. However, the total flux and the IPO contribution, are highly reduced in H-mode conditions due to the increased confinement.

  11. Enhancement of Nitrogen Removal in an Intermittent Aeration Membrane Bioreactor

    NASA Astrophysics Data System (ADS)

    He, Xiaojuan; Wisniewski, Christelle; Li, Xudong; Zhou, Qi

    2010-11-01

    An intermittent aerated membrane bioreactor was applied in laboratory scale to treat synthetic household wastewater. The system organic load and nitrogen load were 0.34 kgCODṡm-3ṡd-1 and 0.06 kgTNṡm-3ṡd-1, respectively. The hydraulic residence time was equal to 12 h and very long sludge residence times were imposed. Intermittent aeration, with anoxic-aerobic cycle of 30/60 minutes, was employed in the system. The results showed that 100% SS and >90% COD could be removed. The average removal efficiency of NH4-N and TN was 99.7% and 80%, respectively. A linear relationship between the fouling rate and the MLSS, MLVSS concentration was founded. The denitrification seemed to be the rate-limiting step for nitrogen removal. To enhance denitrification, the following strategies could be considered: 1) to select suitable aeration/non-aeration cycle, 2) to control the aeration intensity, 3) to feed the system at the beginning of non-aeration period, 4) to maintain high MLSS concentration.

  12. Reactive Oxygen Species and Respiratory Plasticity Following Intermittent Hypoxia

    PubMed Central

    MacFarlane, P.M.; Wilkerson, J.E.R.; Lovett-Barr, M.R.; Mitchell, G.S.

    2008-01-01

    The neural network controlling breathing exhibits plasticity in response to environmental or physiological challenges. For example, while hypoxia initiates rapid and robust increases in respiratory motor output to defend against hypoxemia, it also triggers persistent changes, or plasticity, in chemosensory neurons and integrative pathways that transmit brainstem respiratory activity to respiratory motor neurons. Frequently studied models of hypoxia-induced respiratory plasticity include: 1) carotid chemosensory plasticity and metaplasticity induced by chronic intermittent hypoxia (CIH), and 2) acute intermittent hypoxia (AIH) induced phrenic long-term facilitation (pLTF) in naïve and CIH preconditioned rats. These forms of plasticity share some mechanistic elements, although they differ in anatomical location and the requirement for CIH preconditioning. Both forms of plasticity require serotonin receptor activation and formation of reactive oxygen species (ROS). While the cellular sources and targets of ROS are not well known, recent evidence suggests that ROS modify the balance of protein phosphatase and kinase activities, shifting the balance towards net phosphorylation and favoring cellular reactions that induce and/or maintain plasticity. Here, we review possible sources of ROS, and the impact of ROS on phosphorylation events relevant to respiratory plasticity. PMID:18692605

  13. Molecular Mechanisms of Chronic Intermittent Hypoxia and Hypertension

    PubMed Central

    Sunderram, J.; Androulakis, I.P.

    2013-01-01

    Obstructive sleep apnea (OSA) is characterized by episodes of repeated airway obstruction resulting in cessation (apnea) or reduction (hypopnea) in airflow during sleep. These events lead to intermittent hypoxia and hypercapnia, sleep fragmentation, and changes in intrathoracic pressure, and are associated with a marked surge in sympathetic activity and an abrupt increase in blood pressure. Blood pressure remains elevated during wakefulness despite the absence of obstructive events resulting in a high prevalence of hypertension in patients with OSA. There is substantial evidence that suggests that chronic intermittent hypoxia (CIH) leads to sustained sympathoexcitation during the day and changes in vasculature resulting in hypertension in patients with OSA. Mechanisms of sympathoexcitation include augmentation of peripheral chemoreflex sensitivity and a direct effect on central sites of sympathetic regulation. Interestingly, the vascular changes that occur with CIH have been ascribed to the same molecules that have been implicated in the augmented sympathetic tone in CIH. This review will discuss the hypothesized molecular mechanisms involved in the development of hypertension with CIH, will build a conceptual model for the development of hypertension following CIH, and will propose a systems biology approach in further elucidating the relationship between CIH and the development of hypertension. PMID:23140119

  14. The Development of Myopia Among Children With Intermittent Exotropia

    PubMed Central

    EKDAWI, NOHA S.; NUSZ, KEVIN J.; DIEHL, NANCY N.; MOHNEY, BRIAN G.

    2013-01-01

    PURPOSE To describe the long-term refractive error changes in children diagnosed with intermittent exotropia (IXT) in a defined population. DESIGN Retrospective, population-based observational study. METHODS Using the resources of the Rochester Epidemiology Project, the medical records of all children (<19 years) diagnosed with IXT as residents of Olmsted County, Minnesota, from January 1, 1975 through December 31, 1994 were retrospectively reviewed for any change in refractive error over time. RESULTS One hundred eighty-four children were diagnosed with IXT during the 20-year study period; 135 (73.4%) had 2 or more refractions separated by a mean of 10 years (range, 1–27 years). The Kaplan-Meier rate of developing myopia in this population was 7.4% by 5 years of age, 46.5% by 10 years, and 91.1% by 20 years. There were 106 patients with 2 or more refractions separated by at least 1 year through 21 years of age, of which 43 underwent surgery and 63 were observed. The annual overall progression was −0.26 diopters (SD ± 0.24) without a statistically significant difference between the observed and surgical groups (P = .59). CONCLUSION In this population-based study of children with intermittent exotropia, myopia was calculated to occur in more than 90% of patients by 20 years of age. Observation versus surgical correction did not alter the refractive outcome. PMID:20172074

  15. Adrenocortical adaptation to chronic intermittent stress in hemispherectomized pigeon.

    PubMed

    Ramade, F; Bayle, J D

    1984-07-01

    Hemispherectomized pigeons were exposed daily to electrical footshocks delivered for 15 sec, at the same hour, for 8 weeks. Serial blood samples were obtained through a chronic vascular catheter. The adrenocortical response to chronic intermittent stress was measured kinetically at one week intervals. The initial response including several successive peaks of plasma corticosterone progressively adapted: Late peaks disappeared and only the first one subsisted 12-14 min after stressor application; this first peak diminished in magnitude; furthermore, an anticipatory peak occurred, starting 14 min before stress. In pigeons lesioned in the anterior dorsomedial thalamus, the only response to the stressor was of the single peak (12-14 min) type without any development of anticipatory conditioned response. This phenomenon was consistant all over the experimental period. Thalamic-hypothalamic interrelationships may be suggested to provide neuronal loops that underlie the long lasting, pulsatile repetitive components of the adrenocortical response to acute stress and also the adaptative process of such a response to chronic intermittent stress, including a conditioned, anticipatory endocrine activation. PMID:6505055

  16. Physical fitness of militia forces.

    PubMed

    Song, T M; Moore, J

    1989-09-01

    Anthropometry and physical fitness of Canadian militia infantry (n = 19) and militia service battalion (SVC, n = 27) men, ranging in age from 17 to 21 years, were examined and were compared with recent Canadian fitness norms. The height of the infantry was taller (p less than 0.05) than that of civilians. There was no difference between the two groups for the body mass index (BMI), skinfolds, grip strength, and maximum oxygen consumption rate. Flexibility and muscular endurance (sit-ups) of the infantry were greater (p less than 0.01) than those of the militia service battalion. Skinfolds and muscular endurance of the militia were above the average, and BMI and maximum oxygen consumption rate of the militia were below the average for civilians. Further study is needed to establish the fitness criteria that should be met by the militia in the future.

  17. The Soldier Fitness Tracker: Global Delivery of Comprehensive Soldier Fitness

    ERIC Educational Resources Information Center

    Fravell, Mike; Nasser, Katherine; Cornum, Rhonda

    2011-01-01

    Carefully implemented technology strategies are vital to the success of large-scale initiatives such as the U.S. Army's Comprehensive Soldier Fitness (CSF) program. Achieving the U.S. Army's vision for CSF required a robust information technology platform that was scaled to millions of users and that leveraged the Internet to enable global reach.…

  18. Self-Sealing Cryogenic Fitting

    NASA Technical Reports Server (NTRS)

    Jia, Lin Xiang; Chow, Wen Lung; Moslemian, Davood; Lin, Gary; Melton, Greg

    1994-01-01

    Self-sealing fitting for cryogenic tubes remains free of leakage from room temperature to liquid-helium temperature even at internal pressure as high as 2.7 MPa. Fitting comprises parts made of materials with different coefficients of thermal expansion to prevent leakage gaps from forming as temperature decreases. Consists of coupling nut, two flared tube ends, and flared O-ring spacer. Spacer contracts more than tube ends do as temperature decreases. This greater contraction seals tube ends more tightly, preventing leakage.

  19. Intermittency in the photosphere and corona as derived from the Hinode data

    NASA Astrophysics Data System (ADS)

    Abramenko, V.; Yurchyshyn, V.; Wang, H.

    2008-05-01

    Recent studies undoubtedly demonstrate that the magnetic fields in the photosphere and corona are strongly non-Gaussian and can be represented as intermittent structures, which offers new views on the underlying physics. In particular, such problems as the existence in the corona of localized areas with extremely strong resistivity (required to explain magnetic reconnection of all scales) and the interchange between small and large scales (required in study of the photosphere/corona coupling), to name a few, can be easily captured by the concept of intermittency. This study is focused on simultaneous time variations of intermittency properties derived in the photosphere, chromosphere and corona. We analyzed data for NOAA AR 10930 acquired between Dec 08, 2006 12:00 UT and Dec 13, 2006 18:45 UT. Photospheric intermittency was inferred from Hinode magnetic field measurements, while intermittency in the transition region and corona was derived from Nobeyama 9 GHz radio polarization measurements, high cadence Hinode/XRT/Be-thin data as well as GOES 1-8Å~ flux. Photospheric dynamics and its possible relationship with the intermittency variations were also analyzed by calculating the kinetic vorticity. For this case study we found the following chain of events. Intermittency of the photospheric magnetic field peaked after the specific kinetic vorticity of plasma flows in the AR reached its maximum level (4 hour time delay). In turn, gradual increase of coronal intermittency occurred after the peak of the photospheric intermittency. The time delay between the peak of photospheric intermittency and the occurrence of the first strong (X3.4) flare was approximately 1.3 days. Our analysis seems to suggest that the enhancement of intermittency/complexity first occurs in the photosphere and is later transported toward the corona.

  20. Designing the Fitness Testing Environment.

    ERIC Educational Resources Information Center

    Petray, Clayre; And Others

    1989-01-01

    This article provides teachers with strategies for planning and organizing a positive, efficient physical fitness testing environment for K-12 students, including students with special needs. Methods of class organization and scheduling suggestions are presented. Sample record and score sheets are included. (IAH)

  1. Aerobic Fitness and School Children.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1997-01-01

    Provides school counselors with information on aerobic exercise (specifically running) and the psychological, behavioral, and physical benefits children obtained by participating in fitness programs. Recommends collaboration between school counselors and physical education teachers and gives a preliminary discussion of aerobic running and its…

  2. Aerobic Fitness and School Children.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1992-01-01

    Provides school counselors with information regarding aerobic exercise (specifically running), and the psychological, behavioral, and physical benefits children obtain by participating in fitness programs. Presents methods of collaboration between school counselors and physical education teachers. Offers preliminary discussion of aerobic running…

  3. A YOUNG GIRL WITH FITS.

    PubMed

    Ahmed, Imran; Ahmed, Ejaz; Zaidi, Badshah Hussain; Ansari, Jawad Khaliq; Nisar, Shazia

    2015-01-01

    A young girl presented with fits vomiting and epigastric pain. Investigations including CT-Scan brain, MRI brain, MRV brain and cerebrospinal fluid (CSF) examination were normal. Her urine was screened for porphobilinogen which was positive. She responded to intravenous dextrose and hypercaloric diet

  4. Current Issues in Flexibility Fitness.

    ERIC Educational Resources Information Center

    Knudson, Duane V.; Magnusson, Peter; McHugh, Malachy

    2000-01-01

    Physical activity is extremely important in maintaining good health. Activity is not possible without a certain amount of flexibility. This report discusses issues related to flexibility fitness. Flexibility is a property of the musculoskeletal system that determines the range of motion achievable without injury to the joints. Static flexibility…

  5. Standardizing Documentation of FITS Headers

    NASA Astrophysics Data System (ADS)

    Hourcle, Joseph

    2014-06-01

    Although the FITS file format[1] can be self-documenting, human intervention is often needed to read the headers to write the necessary transformations to make a given instrument team's data compatible with our preferred analysis package. External documentation may be needed to determine what the values are of coded values or unfamiliar acronyms.Different communities have interpreted keywords slightly differently. This has resulted in ambiguous fields such as DATE-OBS, which could be either the start or mid-point of an observation.[2]Conventions for placing units and additional information within the comments of a FITS card exist, but they require re-writing the FITS file. This operation can be quite costly for large archives, and should not be taken lightly when dealing with issues of digital preservation.We present what we believe is needed for a machine-actionable external file describing a given collection of FITS files. We seek comments from data producers, archives, and those writing software to help develop a single, useful, implementable standard.References:[1] Pence, et.al. 2010, http://dx.doi.org/10.1051/0004-6361/201015362[2] Rots, et.al, (in preparation), http://hea-www.cfa.harvard.edu arots/TimeWCS/

  6. Coaches as Fitness Role Models

    ERIC Educational Resources Information Center

    Nichols, Randall; Zillifro, Traci D.; Nichols, Ronald; Hull, Ethan E.

    2012-01-01

    The lack of physical activity, low fitness levels, and elevated obesity rates as high as 32% of today's youth are well documented. Many strategies and grants have been developed at the national, regional, and local levels to help counteract these current trends. Strategies have been developed and implemented for schools, households (parents), and…

  7. Physical Performance, Fitness and Diet.

    ERIC Educational Resources Information Center

    Young, Donald R.

    This book deals principally with the relationships between diet, fitness, and physical work capacity. The extreme nutritional states of obesity and chronic food deprivation are considered, and the effect of supplementation and modification of normal dietaries on work capacity are discussed. Figures and data tables provide information regarding…

  8. Color Coding Childrens' Fitness Performance.

    ERIC Educational Resources Information Center

    West, Barbara H.; And Others

    1987-01-01

    A program of the Salt Lake City School District and the University of Utah, Operation C.H.A.M.P. (Children's Health and Movement Program), was designed to motivate elementary school children to do their best in physical education and fitness testing. The program is described. (MT)

  9. Hotels Make Room for Fitness.

    ERIC Educational Resources Information Center

    Koszuta, Laurie Einstein

    1986-01-01

    Hotels, in hopes of gaining a competitive edge, are offering workout rooms, exercise equipment, fitness trails, and jogging tracks, but no standards have been set for safety of the facilities or staff preparedness in exercise screening, equipment use, injury prevention, or first aid. (MT)

  10. National Adult Physical Fitness Survey.

    ERIC Educational Resources Information Center

    President's Council on Physical Fitness and Sports Newsletter, 1973

    1973-01-01

    This report of a personal interview research survey conducted for the President's Council on Physical Fitness and Sports in 1972 presents the following findings: (a) 45 percent of all adult Americans do not engage in any form of exercise; (b) walking is the most popular form of exercise, followed by bicycle riding, swimming, calisthenics, bowling,…

  11. Factors Influencing Physical Fitness Evaluation.

    ERIC Educational Resources Information Center

    Haarer, Barbara G.

    This annotated bibliography focuses on works that examine areas in which the physical educator can improve the administration of physical fitness tests in the elementary and secondary schools. The first part contains annotations that examine modifications of existing components which measure aspects of muscular and cardiovascular endurance. The…

  12. Preparation of Police Fitness Instructors.

    ERIC Educational Resources Information Center

    Collingwood, Thomas R.; And Others

    1979-01-01

    Concern about the declining level of physical fitness of police officers has led the Bureau of Training of the Kentucky Department of Justice and the Department of Physical Education at Eastern Kentucky University to implement a training course for police instructors. (LH)

  13. Physical Therapist Assistant Fitness Lab.

    ERIC Educational Resources Information Center

    Backstrom, Kurt; And Others

    Colby Community College's (CCC) Fitness Lab was established to provide the Physical Therapist Assistant (PTA) Program with a learning laboratory in which students can practice classroom-acquired skills, while at the same time promoting the physical, emotional, social, and intellectual well-being of CCC students and staff, and community members. A…

  14. Fitness profiling of elite level adolescent Gaelic football players.

    PubMed

    Cullen, Bryan D; Cregg, Cathal J; Kelly, David T; Hughes, Sarah M; Daly, Pat G; Moyna, Niall M

    2013-08-01

    The purpose of this study was to evaluate the anthropometric characteristics and fitness levels of elite level under 18 (U-18) Gaelic football players to establish normative centile scores for selected fitness parameters and to compare the physical and fitness characteristics relative to each playing position. A total of 265 male U-18 Gaelic football players (age: 16.96 ± 0.7 years; height: 178.11 ± 6.27 cm; weight: 72.07 ± 8.68 kg) participated in the study. According to positional roles, players were categorized as goalkeepers (n = 13), defenders (n = 113), midfielders (n = 30), and forwards (n = 109). Height and weight were measured, and skinfolds were taken before participants sequentially performed a sit and reach test (S&R), countermovement jump (CMJ), standing long jump (SLJ), 5- and 20-m speed test, and the Yo-Yo Intermittent Recovery Test Level 1 (YYIRT1). The percentage body fat was higher (p < 0.01) in goalkeepers than the other playing positions. Goalkeepers had a higher body mass index than defenders (p < 0.05) and forwards (p < 0.01). Midfielders and goalkeepers were taller (p < 0.01) and heavier (p < 0.01) than defenders and forwards. The total distance covered in the YYIRT1 was significantly lower (p < 0.01) in goalkeepers than the other playing positions. There was no significant positional difference in the performance scores in the S&R test, CMJ, SLJ, and 5- and 20-m running speed. The study findings indicate minimal differences in the anthropometric and physiological characteristics between playing positions in elite youth level Gaelic football players. The norm-referenced percentile scores will enable conditioning coaches to benchmark elite performance and design training programs.

  15. The fitness value of information

    PubMed Central

    Donaldson-Matasci, Matina C.; Bergstrom, Carl T.; Lachmann, Michael

    2013-01-01

    Communication and information are central concepts in evolutionary biology. In fact, it is hard to find an area of biology where these concepts are not used. However, quantifying the information transferred in biological interactions has been difficult. How much information is transferred when the first spring rainfall hits a dormant seed, or when a chick begs for food from its parent? One measure that is commonly used in such cases is fitness value: by how much, on average, an individual’s fitness would increase if it behaved optimally with the new information, compared to its average fitness without the information. Another measure, often used to describe neural responses to sensory stimuli, is the mutual information—a measure of reduction in uncertainty, as introduced by Shannon in communication theory. However, mutual information has generally not been considered to be an appropriate measure for describing developmental or behavioral responses at the organismal level, because it is blind to function; it does not distinguish between relevant and irrelevant information. In this paper we show that there is in fact a surprisingly tight connection between these two measures in the important context of evolution in an uncertain environment. In this case, a useful measure of fitness benefit is the increase in the long-term growth rate, or the fold increase in number of surviving lineages. We show that in many cases the fitness value of a developmental cue, when measured this way, is exactly equal to the reduction in uncertainty about the environment, as described by the mutual information. PMID:25843980

  16. Accelerated Fitting of Stellar Spectra

    NASA Astrophysics Data System (ADS)

    Ting, Yuan-Sen; Conroy, Charlie; Rix, Hans-Walter

    2016-07-01

    Stellar spectra are often modeled and fitted by interpolating within a rectilinear grid of synthetic spectra to derive the stars’ labels: stellar parameters and elemental abundances. However, the number of synthetic spectra needed for a rectilinear grid grows exponentially with the label space dimensions, precluding the simultaneous and self-consistent fitting of more than a few elemental abundances. Shortcuts such as fitting subsets of labels separately can introduce unknown systematics and do not produce correct error covariances in the derived labels. In this paper we present a new approach—Convex Hull Adaptive Tessellation (chat)—which includes several new ideas for inexpensively generating a sufficient stellar synthetic library, using linear algebra and the concept of an adaptive, data-driven grid. A convex hull approximates the region where the data lie in the label space. A variety of tests with mock data sets demonstrate that chat can reduce the number of required synthetic model calculations by three orders of magnitude in an eight-dimensional label space. The reduction will be even larger for higher dimensional label spaces. In chat the computational effort increases only linearly with the number of labels that are fit simultaneously. Around each of these grid points in the label space an approximate synthetic spectrum can be generated through linear expansion using a set of “gradient spectra” that represent flux derivatives at every wavelength point with respect to all labels. These techniques provide new opportunities to fit the full stellar spectra from large surveys with 15–30 labels simultaneously.

  17. Accelerated Fitting of Stellar Spectra

    NASA Astrophysics Data System (ADS)

    Ting, Yuan-Sen; Conroy, Charlie; Rix, Hans-Walter

    2016-07-01

    Stellar spectra are often modeled and fitted by interpolating within a rectilinear grid of synthetic spectra to derive the stars’ labels: stellar parameters and elemental abundances. However, the number of synthetic spectra needed for a rectilinear grid grows exponentially with the label space dimensions, precluding the simultaneous and self-consistent fitting of more than a few elemental abundances. Shortcuts such as fitting subsets of labels separately can introduce unknown systematics and do not produce correct error covariances in the derived labels. In this paper we present a new approach—Convex Hull Adaptive Tessellation (chat)—which includes several new ideas for inexpensively generating a sufficient stellar synthetic library, using linear algebra and the concept of an adaptive, data-driven grid. A convex hull approximates the region where the data lie in the label space. A variety of tests with mock data sets demonstrate that chat can reduce the number of required synthetic model calculations by three orders of magnitude in an eight-dimensional label space. The reduction will be even larger for higher dimensional label spaces. In chat the computational effort increases only linearly with the number of labels that are fit simultaneously. Around each of these grid points in the label space an approximate synthetic spectrum can be generated through linear expansion using a set of “gradient spectra” that represent flux derivatives at every wavelength point with respect to all labels. These techniques provide new opportunities to fit the full stellar spectra from large surveys with 15-30 labels simultaneously.

  18. Self-Fitting Hearing Aids

    PubMed Central

    Convery, Elizabeth

    2016-01-01

    A self-contained, self-fitting hearing aid (SFHA) is a device that enables the user to perform both threshold measurements leading to a prescribed hearing aid setting and fine-tuning, without the need for audiological support or access to other equipment. The SFHA has been proposed as a potential solution to address unmet hearing health care in developing countries and remote locations in the developed world and is considered a means to lower cost and increase uptake of hearing aids in developed countries. This article reviews the status of the SFHA and the evidence for its feasibility and challenges and predicts where it is heading. Devices that can be considered partly or fully self-fitting without audiological support were identified in the direct-to-consumer market. None of these devices are considered self-contained as they require access to other hardware such as a proprietary interface, computer, smartphone, or tablet for manipulation. While there is evidence that self-administered fitting processes can provide valid and reliable results, their success relies on user-friendly device designs and interfaces and easy-to-interpret instructions. Until these issues have been sufficiently addressed, optional assistance with the self-fitting process and on-going use of SFHAs is recommended. Affordability and a sustainable delivery system remain additional challenges for the SFHA in developing countries. Future predictions include a growth in self-fitting products, with most future SFHAs consisting of earpieces that connect wirelessly with a smartphone and providers offering assistance through a telehealth infrastructure, and the integration of SFHAs into the traditional hearing health-care model. PMID:27072929

  19. Gaussianity versus intermittency in solar system plasma turbulence

    NASA Astrophysics Data System (ADS)

    Echim, M.

    2014-12-01

    Statistical properties of plasma and magnetic field fluctuations exhibit features linked with the dynamics of the targeted system and sometimes with the physical processes that are at the origin of these fluctuations. Intermittency is sometimes discussed in terms of non-Gaussianity of the Probability Distribution Functions (PDFs) of fluctuations for ranges of spatio/temporal scales. Some examples of self-similarity have been however shown for PDFs whose wings are not Gaussian. In this study we discuss intermittency in terms of non-Gaussianity as well as scale dependence of the higher order moments of PDFs, in particular the flatness. We use magnetic field and plasma data from several space missions, in the solar wind (Ulysses, Cluster, and Venus Express), and in the planetary magnetosheaths (Cluster and Venus Express). We analyze Ulysses data that satisfy a consolidated set of selection criteria able to identify "pure" fast and slow wind. We investigate Venus Express data close to the orbital apogee, in the solar wind, at 0.72 AU, and in the Venus magnetosheath. We study Cluster data in the solar wind (for time intervals not affected by planetary ions effects), and the magnetosheath. We organize our results in three solar wind data bases (one for the solar maximum, 1999-2001, two for the solar minimum, 1997-1998 and respectively, 2007-2008), and two planetary databases (one for the solar maximum, 2000-2001, that includes PDFs obtained in the terrestrial magnetosphere, and one for the solar minimum, 2007-2008, that includes PDFs obtained in the terrestrial and Venus magnetospheres and magnetosheaths). In addition to investigating the statistical properties of fluctuations for the minimum and maximum of the solar cycle we also analyze the similarities and differences between fast and slow wind. We emphasize the importance of our data survey and analysis in the context of understanding the solar wind turbulence and complexity, and the exploitation of data bases and as

  20. Affecting Factors and Outcome on Intermittent Internet Pulling Behavior in Taiwan's Undergraduate Students

    ERIC Educational Resources Information Center

    Yang, Hui-Jen; Lay, Yun-Long

    2011-01-01

    Nowadays people's lives heavily rely on Internet facilities. Internet users generally have constant Internet connectivity and intermittently click on sites they want to access even amidst studying or working. In this study, we sought to examine the factors affecting intermittent Internet pulling behavior on undergraduate students. Furthermore, the…

  1. Intermittency in {sup 32}S + S and {sup 32}S + Au collisions at the CERN SPS

    SciTech Connect

    Bloomer, M.A.; Jacobs, P.; WA80 Collaboration

    1991-12-01

    Nonstatistical or ``intermittent`` fluctuations of charged particle multiplicities have been investigated at the CERN SPS with the WA80 multiplicity array for {sup 32}S+S and {sup 32}S+Au collisions of varying centrality. Within the phase space domain studied there is no evidence for intermittency in these collisions beyond that accounted for by FRITIOF filtered through a full detector simulation.

  2. Intermittency in sup 32 S + S and sup 32 S + Au collisions at the CERN SPS

    SciTech Connect

    Bloomer, M.A.; Jacobs, P.

    1991-12-01

    Nonstatistical or intermittent'' fluctuations of charged particle multiplicities have been investigated at the CERN SPS with the WA80 multiplicity array for {sup 32}S+S and {sup 32}S+Au collisions of varying centrality. Within the phase space domain studied there is no evidence for intermittency in these collisions beyond that accounted for by FRITIOF filtered through a full detector simulation.

  3. Radial evolution of the intermittency of density fluctuations in the fast solar wind

    SciTech Connect

    Bruno, R.; D'Amicis, R.; Telloni, D.; Primavera, L.; Sorriso-Valvo, L.; Carbone, V.; Malara, F.; Veltri, P.

    2014-05-01

    We study the radial evolution of the intermittency of density fluctuations in the fast solar wind. The study is performed by analyzing the plasma density measurements provided by Helios 2 in the inner heliosphere between 0.3 and 0.9 AU. The analysis is carried out by means of a complete set of diagnostic tools, including the flatness factor at different timescales to estimate intermittency, the Kolmogorov-Smirnov test to estimate the degree of intermittency, and the Fourier transform to estimate the power spectral densities of these fluctuations. Density fluctuations within the fast wind are rather intermittent and their level of intermittency, together with the amplitude of intermittent events, decreases with the distance from the Sun, at odds with the intermittency of both magnetic field and all other plasma parameters. Furthermore, the intermittent events are strongly correlated, exhibiting temporal clustering. This indicates that the mechanism underlying their generation departs from a time-varying Poisson process. A remarkable, qualitative similarity with the behavior of plasma density fluctuations obtained from a numerical study of the nonlinear evolution of parametric instability in the solar wind supports the idea that this mechanism has an important role in governing density fluctuations in the inner heliosphere.

  4. Simultaneous Infrared Dry-Blanching and Dehydration of apple slices Controlled by Intermittent Heating Mode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infrared heating controlled by intermittent heating mode was found to be able to achieve simultaneous dry-blanching and dehydration of apple slices with a desirable quality. In order to better understand the performance of intermittent heating for simultaneous dry-blanching and dehydration (SIDBD),...

  5. 29 CFR 825.203 - Scheduling of intermittent or reduced schedule leave.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993 Employee Leave Entitlements Under the Family and Medical Leave Act § 825.203 Scheduling of intermittent or reduced schedule leave. Eligible... 29 Labor 3 2014-07-01 2014-07-01 false Scheduling of intermittent or reduced schedule......

  6. 29 CFR 825.203 - Scheduling of intermittent or reduced schedule leave.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993 Employee Leave Entitlements Under the Family and Medical Leave Act § 825.203 Scheduling of intermittent or reduced schedule leave. Eligible... 29 Labor 3 2010-07-01 2010-07-01 false Scheduling of intermittent or reduced schedule......

  7. 29 CFR 825.203 - Scheduling of intermittent or reduced schedule leave.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993 Employee Leave Entitlements Under the Family and Medical Leave Act § 825.203 Scheduling of intermittent or reduced schedule leave. Eligible... 29 Labor 3 2012-07-01 2012-07-01 false Scheduling of intermittent or reduced schedule......

  8. 29 CFR 825.203 - Scheduling of intermittent or reduced schedule leave.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993 Employee Leave Entitlements Under the Family and Medical Leave Act § 825.203 Scheduling of intermittent or reduced schedule leave. Eligible... 29 Labor 3 2013-07-01 2013-07-01 false Scheduling of intermittent or reduced schedule......

  9. 29 CFR 825.203 - Scheduling of intermittent or reduced schedule leave.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993 Employee Leave Entitlements Under the Family and Medical Leave Act § 825.203 Scheduling of intermittent or reduced schedule leave. Eligible... 29 Labor 3 2011-07-01 2011-07-01 false Scheduling of intermittent or reduced schedule......

  10. Assessing the Long-Term System Value of Intermittent Electric Generation Technologies

    SciTech Connect

    Lamont, A D

    2005-08-24

    This research investigates the economic penetration and system-wide effects of large-scale intermittent technologies in an electric generation system. The research extends the standard screening curve analysis to optimize the penetration and system structure with intermittent technologies. The analysis is based on hour-by-hour electric demands and intermittent generation. A theoretical framework is developed to find an expression for the marginal value of an intermittent technology as a function of the average system marginal cost, the capacity factor of the generator, and the covariance between the generator's hourly production and the hourly system marginal cost. A series of model runs are made examining the penetration of wind and photovoltaic in a simple electric generation system. These illustrate the conclusions in the theoretical analysis and illustrate the effects that large-scale intermittent penetration has on the structure of the generation system. In the long-term, adding intermittent generation to a system allows us to restructure the dispatchable generation capacity to a mix with lower capital cost. It is found that large scale intermittent generation tends to reduce the optimal capacity and production of baseload generators and increase the capacity and production of intermediate generators, although the extent to which this occurs depends strongly on the pattern of production from the intermediate generators. It is also shown that the marginal value of intermittent generation declines as it penetrates. The analysis investigates the specific mechanism through which this occurs.

  11. Sound-wave coherence in atmospheric turbulence with intrinsic and global intermittency.

    PubMed

    Wilson, D Keith; Ostashev, Vladimir E; Goedecke, George H

    2008-08-01

    The coherence function of sound waves propagating through an intermittently turbulent atmosphere is calculated theoretically. Intermittency mechanisms due to both the turbulent energy cascade (intrinsic intermittency) and spatially uneven production (global intermittency) are modeled using ensembles of quasiwavelets (QWs), which are analogous to turbulent eddies. The intrinsic intermittency is associated with decreasing spatial density (packing fraction) of the QWs with decreasing size. Global intermittency is introduced by allowing the local strength of the turbulence, as manifested by the amplitudes of the QWs, to vary in space according to superimposed Markov processes. The resulting turbulence spectrum is then used to evaluate the coherence function of a plane sound wave undergoing line-of-sight propagation. Predictions are made by a general simulation method and by an analytical derivation valid in the limit of Gaussian fluctuations in signal phase. It is shown that the average coherence function increases as a result of both intrinsic and global intermittency. When global intermittency is very strong, signal phase fluctuations become highly non-Gaussian and the average coherence is dominated by episodes with weak turbulence. PMID:18681567

  12. Stability of College Students' Fit with Their Academic Major and the Relationship between Academic Fit and Occupational Fit

    ERIC Educational Resources Information Center

    Ghandour, Louma

    2013-01-01

    This study examines the fit between students' interests and their academic choices at different stages of their college careers. Using image theory (Beach, 1990) as an integrated theory of person-vocation fit, this investigation focuses on the stability of academic fit during college and the relationship between fit with academic choice and fit…

  13. Robust, low-cost data loggers for stream temperature, flow intermittency, and relative conductivity monitoring

    USGS Publications Warehouse

    Chapin, Thomas; Todd, Andrew S.; Zeigler, Matthew P.

    2014-01-01

    Water temperature and streamflow intermittency are critical parameters influencing aquatic ecosystem health. Low-cost temperature loggers have made continuous water temperature monitoring relatively simple but determining streamflow timing and intermittency using temperature data alone requires significant and subjective data interpretation. Electrical resistance (ER) sensors have recently been developed to overcome the major limitations of temperature-based methods for the assessment of streamflow intermittency. This technical note introduces the STIC (Stream Temperature, Intermittency, and Conductivity logger); a robust, low-cost, simple to build instrument that provides long-duration, high-resolution monitoring of both relative conductivity (RC) and temperature. Simultaneously collected temperature and RC data provide unambiguous water temperature and streamflow intermittency information that is crucial for monitoring aquatic ecosystem health and assessing regulatory compliance. With proper calibration, the STIC relative conductivity data can be used to monitor specific conductivity.

  14. Coexistence of intermittencies in the neuronal network of the epileptic brain.

    PubMed

    Koronovskii, Alexey A; Hramov, Alexander E; Grubov, Vadim V; Moskalenko, Olga I; Sitnikova, Evgenia; Pavlov, Alexey N

    2016-03-01

    Intermittent behavior occurs widely in nature. At present, several types of intermittencies are known and well-studied. However, consideration of intermittency has usually been limited to the analysis of cases when only one certain type of intermittency takes place. In this paper, we report on the temporal behavior of the complex neuronal network in the epileptic brain, when two types of intermittent behavior coexist and alternate with each other. We prove the presence of this phenomenon in physiological experiments with WAG/Rij rats being the model living system of absence epilepsy. In our paper, the deduced theoretical law for distributions of the lengths of laminar phases prescribing the power law with a degree of -2 agrees well with the experimental neurophysiological data. PMID:27078357

  15. Intermittency, nonlinear dynamics and dissipation in the solar wind and astrophysical plasmas.

    PubMed

    Matthaeus, W H; Wan, Minping; Servidio, S; Greco, A; Osman, K T; Oughton, S; Dmitruk, P

    2015-05-13

    An overview is given of important properties of spatial and temporal intermittency, including evidence of its appearance in fluids, magnetofluids and plasmas, and its implications for understanding of heliospheric plasmas. Spatial intermittency is generally associated with formation of sharp gradients and coherent structures. The basic physics of structure generation is ideal, but when dissipation is present it is usually concentrated in regions of strong gradients. This essential feature of spatial intermittency in fluids has been shown recently to carry over to the realm of kinetic plasma, where the dissipation function is not known from first principles. Spatial structures produced in intermittent plasma influence dissipation, heating, and transport and acceleration of charged particles. Temporal intermittency can give rise to very long time correlations or a delayed approach to steady-state conditions, and has been associated with inverse cascade or quasi-inverse cascade systems, with possible implications for heliospheric prediction. PMID:25848085

  16. Intermittency, nonlinear dynamics and dissipation in the solar wind and astrophysical plasmas.

    PubMed

    Matthaeus, W H; Wan, Minping; Servidio, S; Greco, A; Osman, K T; Oughton, S; Dmitruk, P

    2015-05-13

    An overview is given of important properties of spatial and temporal intermittency, including evidence of its appearance in fluids, magnetofluids and plasmas, and its implications for understanding of heliospheric plasmas. Spatial intermittency is generally associated with formation of sharp gradients and coherent structures. The basic physics of structure generation is ideal, but when dissipation is present it is usually concentrated in regions of strong gradients. This essential feature of spatial intermittency in fluids has been shown recently to carry over to the realm of kinetic plasma, where the dissipation function is not known from first principles. Spatial structures produced in intermittent plasma influence dissipation, heating, and transport and acceleration of charged particles. Temporal intermittency can give rise to very long time correlations or a delayed approach to steady-state conditions, and has been associated with inverse cascade or quasi-inverse cascade systems, with possible implications for heliospheric prediction.

  17. Intermittency, nonlinear dynamics and dissipation in the solar wind and astrophysical plasmas

    PubMed Central

    Matthaeus, W. H.; Wan, Minping; Servidio, S.; Greco, A.; Osman, K. T.; Oughton, S.; Dmitruk, P.

    2015-01-01

    An overview is given of important properties of spatial and temporal intermittency, including evidence of its appearance in fluids, magnetofluids and plasmas, and its implications for understanding of heliospheric plasmas. Spatial intermittency is generally associated with formation of sharp gradients and coherent structures. The basic physics of structure generation is ideal, but when dissipation is present it is usually concentrated in regions of strong gradients. This essential feature of spatial intermittency in fluids has been shown recently to carry over to the realm of kinetic plasma, where the dissipation function is not known from first principles. Spatial structures produced in intermittent plasma influence dissipation, heating, and transport and acceleration of charged particles. Temporal intermittency can give rise to very long time correlations or a delayed approach to steady-state conditions, and has been associated with inverse cascade or quasi-inverse cascade systems, with possible implications for heliospheric prediction. PMID:25848085

  18. Effects of intermittent aeration on pollutants removal in subsurface wastewater infiltration system.

    PubMed

    Pan, Jing; Fei, Hexin; Song, Siyu; Yuan, Fang; Yu, Long

    2015-09-01

    In this study, the pollutant removal performances in two pilot-scale subsurface wastewater infiltration systems (SWISs) with and without intermittent aeration were investigated. Matrix oxidation reduction potential (ORP) results showed that intermittent aeration well developed aerobic conditions in upper matrix and anoxic or anaerobic conditions in the subsequent sections, which resulted in high NH4(+)-N and TN removal. Moreover, intermittent aeration increased removal rates of COD and TP. Microbial populations and enzyme activities analysis proved that intermittent aeration not only obviously boosted the growth and reproduction of bacteria, fungus, actinomyces, nitrifying bacteria and denitrifying bacteria, but also successfully increased nitrate reductase (NR) and nitrite reductase (NIR) in the depth of 80 and 110 cm. The results suggest that the intermittent aeration could be a widespread research and application strategy for achieving the high removal performance in SWISs.

  19. Dynamic resetting of the human circadian pacemaker by intermittent bright light

    NASA Technical Reports Server (NTRS)

    Rimmer, D. W.; Boivin, D. B.; Shanahan, T. L.; Kronauer, R. E.; Duffy, J. F.; Czeisler, C. A.

    2000-01-01

    In humans, experimental studies of circadian resetting typically have been limited to lengthy episodes of exposure to continuous bright light. To evaluate the time course of the human endogenous circadian pacemaker's resetting response to brief episodes of intermittent bright light, we studied 16 subjects assigned to one of two intermittent lighting conditions in which the subjects were presented with intermittent episodes of bright-light exposure at 25- or 90-min intervals. The effective duration of bright-light exposure was 31% or 63% compared with a continuous 5-h bright-light stimulus. Exposure to intermittent bright light elicited almost as great a resetting response compared with 5 h of continuous bright light. We conclude that exposure to intermittent bright light produces robust phase shifts of the endogenous circadian pacemaker. Furthermore, these results demonstrate that humans, like other species, exhibit an enhanced sensitivity to the initial minutes of bright-light exposure.

  20. Coexistence of intermittencies in the neuronal network of the epileptic brain

    NASA Astrophysics Data System (ADS)

    Koronovskii, Alexey A.; Hramov, Alexander E.; Grubov, Vadim V.; Moskalenko, Olga I.; Sitnikova, Evgenia; Pavlov, Alexey N.

    2016-03-01

    Intermittent behavior occurs widely in nature. At present, several types of intermittencies are known and well-studied. However, consideration of intermittency has usually been limited to the analysis of cases when only one certain type of intermittency takes place. In this paper, we report on the temporal behavior of the complex neuronal network in the epileptic brain, when two types of intermittent behavior coexist and alternate with each other. We prove the presence of this phenomenon in physiological experiments with WAG/Rij rats being the model living system of absence epilepsy. In our paper, the deduced theoretical law for distributions of the lengths of laminar phases prescribing the power law with a degree of -2 agrees well with the experimental neurophysiological data.