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Sample records for 5-min mean-power performance

  1. Validation of functional fetal autonomic brain age score fABAS in 5 min short recordings.

    PubMed

    Hoyer, Dirk; Schneider, Uwe; Kowalski, Eva-Maria; Schmidt, Alexander; Witte, Otto W; Schleußner, Ekkehard; Hatzmann, Wolfgang; Grönemeyer, Dietrich Hw; van Leeuwen, Peter

    2015-11-01

    With the objective of evaluating the functional maturation age and developmental disturbances we have previously introduced the fetal autonomic brain age score (fABAS) using 30 min fetal magnetocardiographic recordings (fMCG, Jena). The score is based on heart rate pattern indices that are related to universal principles of developmental biology. The present work aims at the validation of the fABAS methodology on 5 min recordings from an independent database (fMCG, Bochum).We found high agreement of fABAS obtained from Jena normal fetuses (5 min subsets, n =  364) and Bochum recordings (n =  322, normal fetuses). fABAS of 48 recordings from fetuses with intra-uterine growth restriction (IUGR, Bochum) was reduced in most of the cases, a result consistent with IUGR fetuses from Jena previously reported. fABAS calculated from 5 min snapshots only partly covers the accuracy when compared to fABAS from 30 min recordings. More precise diagnosis requires longer recordings.fABAS obtained from fMCG recordings is a strong candidate for standardized assessment of functional maturation age and developmental disturbances. Even 5 min recordings seem to be valuable for screening for maturation problems.

  2. Observation of additional low-degree 5-min modes of solar oscillation

    NASA Technical Reports Server (NTRS)

    Scherrer, P. H.; Wilcox, J. M.; Christensen-Dalsgaard, J.; Gough, D.

    1982-01-01

    High-order solar oscillations with degrees l=3, 4, and 5 could be detected. The observations were made by measuring the difference between the shifts in the Fe 5,124 spectrum line from light integrated from a central circular portion of the solar disk and from an annular portion exterior to it. The frequencies of the octupole modes agree well with the values obtained from whole-disk measurements at the South Pole. A least-squares fit of the observed frequencies to values interpolated between and extrapolated from the predictions of a sequence of solar models with different chemical compositions selects two models. One, a helium-rich solution, agrees with that of similar analyses of whole-disk data. The extrapolated solution has a relatively deep convection zone, and is thus consistent with analyses of 5-min oscillations of high degree.

  3. The relationship between the 5-min oscillation and 3-min oscillations at the umbral/penumbral sunspot boundary

    NASA Astrophysics Data System (ADS)

    Zhou, Xinping; Liang, Hongfei

    2017-03-01

    Observations of the main sunspot of AR 11692 were carried out with the 1 m New Vacuum Solar Telescope (NVST) located on the Fuxian Solar Observatory (FSO) in Hα on March 13, 2013. The high cadence (up to 12 s) Hα intensity images help us to investigate the relationship between the 5-min oscillation and 3-min oscillation. It is found that running waves, periodically formed at the wave sources within umbra, propagate outward with the shape of partial arcs. The running waves run across the umbra-penumbra boundary and eventually disappear at the edge of penumbra. But there are obvious differences when we measure the period of running waves in different regions of a sunspot. The period is about 150 s when the running waves are located in umbra, which is a typical 3-min oscillation, and the period is about 300 s when the running waves are located in the penumbra, which is a typical 5-min oscillation. On the basis of time-slice images, we conclude that the waves form in the umbral region with the 5-min oscillation period, which can cause the brightness periodicity change in the umbra region with the 3-min period (in fact, is half of 5-min oscillation) and 5-min in the penumbra.

  4. Calculation of guaranteed mean power from wind turbine generators

    NASA Technical Reports Server (NTRS)

    Spera, D. A.

    1981-01-01

    A method for calculating the 'guaranteed mean' power output of a wind turbine generator is proposed. The term 'mean power' refers to the average power generated at specified wind speeds during short-term tests. Correlation of anemometers, the method of bins for analyzing non-steady data, the PROP Code for predicting turbine power, and statistical analysis of deviations in test data from theory are discussed. Guaranteed mean power density for the Clayton Mod-OA system was found to be 8 watts per square meter less than theoretical power density at all power levels, with a confidence level of 0.999. This amounts to 4 percent of rated power.

  5. Estimation of spatial patterns of urban air pollution over a 4-week period from repeated 5-min measurements

    NASA Astrophysics Data System (ADS)

    Gillespie, Jonathan; Masey, Nicola; Heal, Mathew R.; Hamilton, Scott; Beverland, Iain J.

    2017-02-01

    Determination of intra-urban spatial variations in air pollutant concentrations for exposure assessment requires substantial time and monitoring equipment. The objective of this study was to establish if short-duration measurements of air pollutants can be used to estimate longer-term pollutant concentrations. We compared 5-min measurements of black carbon (BC) and particle number (PN) concentrations made once per week on 5 occasions, with 4 consecutive 1-week average nitrogen dioxide (NO2) concentrations at 18 locations at a range of distances from busy roads in Glasgow, UK. 5-min BC and PN measurements (averaged over the two 5-min periods at the start and end of a week) explained 40-80%, and 7-64% respectively, of spatial variation in the intervening 1-week NO2 concentrations for individual weeks. Adjustment for variations in background concentrations increased the percentage of explained variation in the bivariate relationship between the full set of NO2 and BC measurements over the 4-week period from 28% to 50% prior to averaging of repeat measurements. The averages of five 5-min BC and PN measurements made over 5 weeks explained 75% and 33% respectively of the variation in average 1-week NO2 concentrations over the same period. The relatively high explained variation observed between BC and NO2 measured on different time scales suggests that, with appropriate steps to correct or average out temporal variations, repeated short-term measurements can be used to provide useful information on longer-term spatial patterns for these traffic-related pollutants.

  6. Bactericidal efficacy of a 1.5min surgical hand-rubbing protocol under in-use conditions.

    PubMed

    Kac, G; Masmejean, E; Gueneret, M; Rodi, A; Peyrard, S; Podglajen, I

    2009-06-01

    In healthy volunteers, surgical hand rubbing with Sterillium for 1.5min has been shown to be as effective as a 3min procedure. The aim of this study was to assess whether this result was reproducible under in-use conditions. During nine weeks in the ambulatory surgery theatre of a 750-bed tertiary care university hospital, the two surgical hand-rubbing procedures were compared with each other, and with a hand-scrubbing procedure using a povidone-iodine (4%) scrub prior to and after 25 different surgical operations for each. Imprints of the surgeon's dominant hand were taken on culture plates before and within 1min following the end of the hand-rubbing/scrubbing procedures (immediate effect) and at the end of surgery (sustained effect). Plates were incubated aerobically at 37 degrees C for 48h. Colonies were counted at 24h and 48h. Results were expressed as the number of colony-forming units per hand. No significant difference in baseline hand bacterial load was found before the hand-rubbing/scrubbing procedures among the three groups (P=0.19). With respect to immediate and sustained antimicrobial effects, a significantly greater reduction in microbial loads on the hands was achieved with the 3min hand-rubbing protocol as opposed to hand-scrubbing protocol (P=0.04 and P=0.02, respectively), but there was no difference between the reductions obtained with 1.5 and 3min rubbing protocols (P=0.41 and P=0.36, respectively). Surgical hand rubbing with Sterillium using a 1.5min protocol should be considered as an attractive alternative method for surgical hand disinfection.

  7. A novel liquid chromatography/tandem mass spectrometry method for the quantification of glycine as biomarker in brain microdialysis and cerebrospinal fluid samples within 5min.

    PubMed

    Voehringer, Patrizia; Fuertig, René; Ferger, Boris

    2013-11-15

    Glycine is an important amino acid neurotransmitter in the central nervous system (CNS) and a useful biomarker to indicate biological activity of drugs such as glycine reuptake inhibitors (GRI) in the brain. Here, we report how a liquid chromatography/tandem mass spectrometry (LC-MS/MS) method for the fast and reliable analysis of glycine in brain microdialysates and cerebrospinal fluid (CSF) samples has been established. Additionally, we compare this method with the conventional approach of high performance liquid chromatography (HPLC) coupled to fluorescence detection (FD). The present LC-MS/MS method did not require any derivatisation step. Fifteen microliters of sample were injected for analysis. Glycine was detected by a triple quadrupole mass spectrometer in the positive electrospray ionisation (ESI) mode. The total running time was 5min. The limit of quantitation (LOQ) was determined as 100nM, while linearity was given in the range from 100nM to 100μM. In order to demonstrate the feasibility of the LC-MS/MS method, we measured glycine levels in striatal in vivo microdialysates and CSF of rats after administration of the commercially available glycine transporter 1 (GlyT1) inhibitor LY 2365109 (10mg/kg, p.o.). LY 2365109 produced 2-fold and 3-fold elevated glycine concentrations from 1.52μM to 3.6μM in striatal microdialysates and from 10.38μM to 36μM in CSF, respectively. In conclusion, we established a fast and reliable LC-MS/MS method, which can be used for the quantification of glycine in brain microdialysis and CSF samples in biomarker studies.

  8. Rapid (<5 min) Identification of Pathogen in Human Blood by Electrokinetic Concentration and Surface-Enhanced Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    I-Fang Cheng; Chang, Hsien-Chang; Chen, Tzu-Ying; Hu, Chenming; Yang, Fu-Liang

    2013-08-01

    This study reports a novel microfluidic platform for rapid and long-ranged concentration of rare-pathogen from human blood for subsequent on-chip surface-enhanced Raman spectroscopy (SERS) identification/discrimination of bacteria based on their detected fingerprints. Using a hybrid electrokinetic mechanism, bacteria can be concentrated at the stagnation area on the SERS-active roughened electrode, while blood cells were excluded away from this region at the center of concentric circular electrodes. This electrokinetic approach performs isolation and concentration of bacteria in about three minutes; the density factor is increased approximately a thousand fold in a local area of ~5000 μm2 from a low bacteria concentration of 5 × 103 CFU/ml. Besides, three genera of bacteria, S. aureus, E. coli, and P. aeruginosa that are found in most of the isolated infections in bacteremia were successfully identified in less than one minute on-chip without the use of any antibody/chemical immobilization and reaction processes.

  9. Comparison of different synthetic 5-min rainfall time series on the results of rainfall runoff simulations in urban drainage modelling

    NASA Astrophysics Data System (ADS)

    Krämer, Stefan; Rohde, Sophia; Schröder, Kai; Belli, Aslan; Maßmann, Stefanie; Schönfeld, Martin; Henkel, Erik; Fuchs, Lothar

    2015-04-01

    standards. The synthetic and reference long term event time series are used as rainfall input for the hydrodynamic sewer models. For comparison of the synthetic rainfall time series against the reference rainfall and against each other the number of - surcharged manholes, - surcharges per manhole, - and the average surcharge volume per manhole are applied as hydraulic performance criteria. The results are discussed and assessed to answer the following questions: - Are the synthetic rainfall approaches suitable to generate high resolution rainfall series and do they produce, - in combination with numerical rainfall runoff models - valid results for design of urban drainage systems? - What are the bounds of uncertainty in the runoff results depending on the synthetic rainfall model and on the climate region? The work is carried out within the SYNOPSE project, funded by the German Federal Ministry of Education and Research (BMBF).

  10. Timing matters: negative emotion elicited 5 min but not 30 min or 45 min after learning enhances consolidation of internal-monitoring source memory.

    PubMed

    Wang, Bo; Bukuan, Sun

    2015-05-01

    Two experiments examined the time-dependent effects of negative emotion on consolidation of item and internal-monitoring source memory. In Experiment 1, participants (n=121) learned a list of words. They were asked to read aloud half of the words and to think about the remaining half. They were instructed to memorize each word and its associative cognitive operation ("reading" versus "thinking"). Immediately following learning they conducted free recall and then watched a 3-min either neutral or negative video clip when 5 min, 30 min or 45 min had elapsed after learning. Twenty-four hours later they returned to take surprise tests for item and source memory. Experiment 2 was similar to Experiment 1 except that participants, without conducting an immediate test of free recall, took tests of source memory for all encoded words both immediately and 24 h after learning. Experiment 1 showed that negative emotion enhanced consolidation of item memory (as measured by retention ratio of free recall) regardless of delay of emotion elicitation and that negative emotion enhanced consolidation of source memory when it was elicited at a 5 min delay but reduced consolidation of source memory when it was elicited at a 30 min delay; when elicited at a 45 min delay, negative emotion had little effect. Furthermore, Experiment 2 replicated the enhancement effect on source memory in the 5 min delay even when participants were tested on all the encoded words. The current study partially replicated prior studies on item memory and extends the literature by providing evidence for a time-dependent effect of negative emotion on consolidation of source memory based on internal monitoring.

  11. Effect of active warm-up duration on morning short-term maximal performance during Ramadan.

    PubMed

    Baklouti, Hana; Chtourou, Hamdi; Aloui, Asma; Chaouachi, Anis; Souissi, Nizar

    2015-01-01

    Purpose To examine the effect of active warm-up duration on short-term maximal performance assessed during Ramadan in the morning. Methods Twelve healthy active men performed four Wingate tests for measurement of peak power and mean power before and during Ramadan at 09:00 a.m. The tests were performed on separate days, after either a 5-min or a 15-min warm-up. The warm-up consisted in pedaling at 50% of the power output obtained at the last stage of a submaximal multistage cycling test. Oral temperature was measured at rest and after warming-up. Furthermore, ratings of perceived exertion were obtained immediately after the Wingate test. Results Oral temperature was higher after the 15-min warm-up than the 5-min warm-up throughout the study. Moreover, peak power and mean power were higher after the 15-min warm-up than the 5-min warm-up before Ramadan. However, during Ramadan, there was no significant difference between the two warm-up durations. In addition, ratings of perceived exertion were higher after the 15-min warm-up than the 5-min warm-up only during Ramadan. Conclusions There is no need to prolong the warm-up period before short-term maximal exercise performed during Ramadan in the morning.

  12. A study of gravity-wave spectra in the troposphere and stratosphere at 5-min to 5-day periods with the Poker Flat MST radar

    NASA Technical Reports Server (NTRS)

    Bemra, R. S.; Rastogi, P. K.; Balsley, B. B.

    1986-01-01

    An analysis of frequency spectra at periods of about 5 days to 5 min from two 20-day sets of velocity measurements in the stratosphere and troposphere region obtained with the Poker Flat mesosphere-stratosphere-troposphere (MST) radar during January and June, 1984 is presented. A technique based on median filtering and averaged order statistics for automatic editing, smoothing and spectral analysis of velocity time series contaminated with spurious data points or outliers is outlined. The validity of this technique and its effects on the inferred spectral index was tested through simulation. Spectra obtained with this technique are discussed. The measured spectral indices show variability with season and height, especially across the tropopause. The discussion briefly outlines the need for obtaining better climatologies of velocity spectra and for the refinements of the existing theories to explain their behavior.

  13. The Effect of Skinfold on the Assessment of the Mean Power Frequency at the Fatigue Threshold

    PubMed Central

    BANIQUED, ALYSSANDRA N.; ZUNIGA, JORGE M.; STRUNC, THOMAS C.; KEENAN, KATIE M.; BOKEN, AGRINI K.; ANDERSON, JEFFREY J.

    2016-01-01

    The purpose of this study was to determine if the amount of subcutaneous tissue over the quadriceps affects the assessment of mean power frequency at the fatigue threshold (MPFFT). It was hypothesized that greater skinfold values will result in lower power outputs associated to the MPFFT. Fourteen adults (Mean ± SD age = 20.7 ± 0.99; body weight = 72.8 ± 12.6 kg) performed an incremental cycle ergometry test to exhaustion while surface electromyographic (EMG) signals were measured from the vastus lateralis. The skinfold thickness of each leg was taken prior to the test, and skinfold thicknesses were separated into a larger and a smaller groups. The independent t-test showed a significant difference (p = 0.01) between the power outputs associated to the MPFFT of groups with high (Mean ± SD 130.4 ± 34.5 W) versus low skinfold (212.5 ± 61.2 W) values. The results suggested that higher subcutaneous fat may have affected the assessment of MPFFT during cycle ergometry. PMID:27766128

  14. Basic reporting and interpretation of surface EMG amplitude and mean power frequency: a reply to Vitgotsky, Ogborn, and Phillips.

    PubMed

    Jenkins, Nathaniel D M; Housh, Terry J; Bergstrom, Haley C; Cochrane, Kristen C; Hill, Ethan C; Smith, Cory M; Johnson, Glen O; Schmidt, Richard J; Cramer, Joel T

    2016-03-01

    In this response, we addressed the specific issues raised by Vigotsky et al. and clarified (1) our methods and adherence to electromyographic signal reporting standards, (2) our interpretation of EMG amplitude, and (3) our interpretation of EMG mean power frequency.

  15. The influence of electromyographic recording methods and the innervation zone on the mean power frequency-torque relationships.

    PubMed

    Herda, Trent J; Zuniga, Jorge M; Ryan, Eric D; Camic, Clayton L; Bergstrom, Haley C; Smith, Doug B; Weir, Joseph P; Cramer, Joel T; Housh, Terry J

    2015-06-01

    This study examined the effects of electromyographic (EMG) recording methods and innervation zone (IZ) on the mean power frequency (MPF)-torque relationships. Nine subjects performed isometric ramp muscle actions of the leg extensors from 5% to 100% of maximal voluntary contraction with an eight channel linear electrode array over the IZ of the vastus lateralis. The slopes were calculated from the log-transformed monopolar and bipolar EMG MPF-torque relationships for each channel and subject and 95% confidence intervals (CI) were constructed around the slopes for each relationship and the composite of the slopes. Twenty-two to 55% of the subjects exhibited 95% CIs that did not include a slope of zero for the monopolar EMG MPF-torque relationships while 25-75% of the subjects exhibited 95% CIs that did not include a slope of zero for the bipolar EMG MPF-torque relationships. The composite of the slopes from the EMG MPF-torque relationships were not significantly different from zero for any method or channel, however, the method and IZ location slightly influenced the number of significant slopes on a subject-by-subject basis. The log-transform model indicated that EMG MPF-torque patterns were nonlinear regardless of recording method or distance from the IZ.

  16. Muscle contractile properties as an explanation of the higher mean power output in marmosets than humans during jumping.

    PubMed

    Plas, Rogier L C; Degens, Hans; Meijer, J Peter; de Wit, Gerard M J; Philippens, Ingrid H C H M; Bobbert, Maarten F; Jaspers, Richard T

    2015-07-01

    The muscle mass-specific mean power output (PMMS,mean) during push-off in jumping in marmosets (Callithrix jacchus) is more than twice that in humans. In the present study it was tested whether this is attributable to differences in muscle contractile properties. In biopsies of marmoset m. vastus lateralis (VL) and m. gastrocnemius medialis (GM) (N=4), fibre-type distribution was assessed using fluorescent immunohistochemistry. In single fibres from four marmoset and nine human VL biopsies, the force-velocity characteristics were determined. Marmoset VL contained almost exclusively fast muscle fibres (>99.0%), of which 63% were type IIB and 37% were hybrid fibres, fibres containing multiple myosin heavy chains. GM contained 9% type I fibres, 44% type IIB and 47% hybrid muscle fibres. The proportions of fast muscle fibres in marmoset VL and GM were substantially larger than those reported in the corresponding human muscles. The curvature of the force-velocity relationships of marmoset type IIB and hybrid fibres was substantially flatter than that of human type I, IIA, IIX and hybrid fibres, resulting in substantially higher muscle fibre mass-specific peak power (PFMS,peak). Muscle mass-specific peak power output (PMMS,peak) values of marmoset whole VL and GM, estimated from their fibre-type distributions and force-velocity characteristics, were more than twice the estimates for the corresponding human muscles. As the relative difference in estimated PMMS,peak between marmosets and humans is similar to that of PMMS,mean during push-off in jumping, it is likely that the difference in in vivo mechanical output between humans and marmosets is attributable to differences in muscle contractile properties.

  17. Additive effects of beta-alanine and sodium bicarbonate on upper-body intermittent performance.

    PubMed

    Tobias, Gabriel; Benatti, Fabiana Braga; de Salles Painelli, Vitor; Roschel, Hamilton; Gualano, Bruno; Sale, Craig; Harris, Roger C; Lancha, Antonio Herbert; Artioli, Guilherme Gianinni

    2013-08-01

    We examined the isolated and combined effects of beta-alanine (BA) and sodium bicarbonate (SB) on high-intensity intermittent upper-body performance in judo and jiu-jitsu competitors. 37 athletes were assigned to one of four groups: (1) placebo (PL)+PL; (2) BA+PL; (3) PL+SB or (4) BA+SB. BA or dextrose (placebo) (6.4 g day⁻¹) was ingested for 4 weeks and 500 mg kg⁻¹ BM of SB or calcium carbonate (placebo) was ingested for 7 days during the 4th week. Before and after 4 weeks of supplementation, the athletes completed four 30-s upper-body Wingate tests, separated by 3 min. Blood lactate was determined at rest, immediately after and 5 min after the 4th exercise bout, with perceived exertion reported immediately after the 4th bout. BA and SB alone increased the total work done in +7 and 8 %, respectively. The co-ingestion resulted in an additive effect (+14 %, p < 0.05 vs. BA and SB alone). BA alone significantly improved mean power in the 2nd and 3rd bouts and tended to improve the 4th bout. SB alone significantly improved mean power in the 4th bout and tended to improve in the 2nd and 3rd bouts. BA+SB enhanced mean power in all four bouts. PL+PL did not elicit any alteration on mean and peak power. Post-exercise blood lactate increased with all treatments except with PL+PL. Only BA+SB resulted in lower ratings of perceived exertion (p = 0.05). Chronic BA and SB supplementation alone equally enhanced high-intensity intermittent upper-body performance in well-trained athletes. Combined BA and SB promoted a clear additive ergogenic effect.

  18. High-intensity cycle interval training improves cycling and running performance in triathletes.

    PubMed

    Etxebarria, Naroa; Anson, Judith M; Pyne, David B; Ferguson, Richard A

    2014-01-01

    Effective cycle training for triathlon is a challenge for coaches. We compared the effects of two variants of cycle high-intensity interval training (HIT) on triathlon-specific cycling and running. Fourteen moderately-trained male triathletes ([Formula: see text]O2peak 58.7 ± 8.1 mL kg(-1) min(-1); mean ± SD) completed on separate occasions a maximal incremental test ([Formula: see text]O2peak and maximal aerobic power), 16 × 20 s cycle sprints and a 1-h triathlon-specific cycle followed immediately by a 5 km run time trial. Participants were then pair-matched and assigned randomly to either a long high-intensity interval training (LONG) (6-8 × 5 min efforts) or short high-intensity interval training (SHORT) (9-11 × 10, 20 and 40 s efforts) HIT cycle training intervention. Six training sessions were completed over 3 weeks before participants repeated the baseline testing. Both groups had an ∼7% increase in [Formula: see text]O2peak (SHORT 7.3%, ±4.6%; mean, ±90% confidence limits; LONG 7.5%, ±1.7%). There was a moderate improvement in mean power for both the SHORT (10.3%, ±4.4%) and LONG (10.7%, ±6.8%) groups during the last eight 20-s sprints. There was a small to moderate decrease in heart rate, blood lactate and perceived exertion in both groups during the 1-h triathlon-specific cycling but only the LONG group had a substantial decrease in the subsequent 5-km run time (64, ±59 s). Moderately-trained triathletes should use both short and long high-intensity intervals to improve cycling physiology and performance. Longer 5-min intervals on the bike are more likely to benefit 5 km running performance.

  19. Influence of warm-up duration and recovery interval prior to exercise on anaerobic performance

    PubMed Central

    Chaâri, N; Mezghanni, N; Souissi, N

    2016-01-01

    The purpose of the study was to determine the impact of different active warm-up (AWU) durations and the rest interval separating it from exercise on anaerobic performance. Eleven male physical education students (22.6 ± 2.52 years; 179.2 ± 4.3 cm; 82.5 ± 9.7 kg; mean ± SD) participated in a cross-over randomized study, and they all underwent the Wingate test after three AWU durations: 5 min (AWU5), 15 min (AWU15) and 20 min (AWU20), with recovery (WREC) or without a recovery interval (NREC) separating the AWU and anaerobic exercise performance. All the AWUs consisted of pedalling at a constant pace of 60 rpm at 50% of the maximal aerobic power. The rest interval between the end of warm-up and the beginning of exercise was set at 5 min. During the Wingate test, peak power (PP), mean power (MP) and the fatigue index (FI) were recorded and analysed. Oral temperature was recorded at rest and at the end of the warm-up. Likewise, rest, post-warm-up and post-Wingate heart rate (HR) and rating of perceived exertion (RPE) were recorded during each session. The ANOVA showed a significant effect of recovery interval, warm-up duration and measurement point on RPE scores (P<0.001). Although the effect of AWU duration on MP and PP was significant (P<0.05), the effect of the recovery interval on both parameters was not significant (P>0.05). Moreover, the analyses showed a significant interaction between recovery interval and AWU duration (P<0.001 and P<0.05 for MP and PP respectively). The AWU15 duration improves the MP and PP when associated with a recovery interval prior to exercise of 5 min. However, the AWU5 duration allows better improvement of power output when the exercise is applied immediately after the warm-up. Consequently, physically active males, as well as educators and researchers interested in anaerobic exercise, must take into account the duration of warm-up and the following recovery interval when practising or assessing activities requiring powerful lower

  20. Influence of warm-up duration and recovery interval prior to exercise on anaerobic performance.

    PubMed

    Frikha, M; Chaâri, N; Mezghanni, N; Souissi, N

    2016-12-01

    The purpose of the study was to determine the impact of different active warm-up (AWU) durations and the rest interval separating it from exercise on anaerobic performance. Eleven male physical education students (22.6 ± 2.52 years; 179.2 ± 4.3 cm; 82.5 ± 9.7 kg; mean ± SD) participated in a cross-over randomized study, and they all underwent the Wingate test after three AWU durations: 5 min (AWU5), 15 min (AWU15) and 20 min (AWU20), with recovery (WREC) or without a recovery interval (NREC) separating the AWU and anaerobic exercise performance. All the AWUs consisted of pedalling at a constant pace of 60 rpm at 50% of the maximal aerobic power. The rest interval between the end of warm-up and the beginning of exercise was set at 5 min. During the Wingate test, peak power (PP), mean power (MP) and the fatigue index (FI) were recorded and analysed. Oral temperature was recorded at rest and at the end of the warm-up. Likewise, rest, post-warm-up and post-Wingate heart rate (HR) and rating of perceived exertion (RPE) were recorded during each session. The ANOVA showed a significant effect of recovery interval, warm-up duration and measurement point on RPE scores (P<0.001). Although the effect of AWU duration on MP and PP was significant (P<0.05), the effect of the recovery interval on both parameters was not significant (P>0.05). Moreover, the analyses showed a significant interaction between recovery interval and AWU duration (P<0.001 and P<0.05 for MP and PP respectively). The AWU15 duration improves the MP and PP when associated with a recovery interval prior to exercise of 5 min. However, the AWU5 duration allows better improvement of power output when the exercise is applied immediately after the warm-up. Consequently, physically active males, as well as educators and researchers interested in anaerobic exercise, must take into account the duration of warm-up and the following recovery interval when practising or assessing activities requiring powerful lower

  1. Comparison of different synthetic 5-min rainfall time series regarding their suitability for urban drainage modelling

    NASA Astrophysics Data System (ADS)

    van der Heijden, Sven; Callau Poduje, Ana; Müller, Hannes; Shehu, Bora; Haberlandt, Uwe; Lorenz, Manuel; Wagner, Sven; Kunstmann, Harald; Müller, Thomas; Mosthaf, Tobias; Bárdossy, András

    2015-04-01

    For the design and operation of urban drainage systems with numerical simulation models, long, continuous precipitation time series with high temporal resolution are necessary. Suitable observed time series are rare. As a result, intelligent design concepts often use uncertain or unsuitable precipitation data, which renders them uneconomic or unsustainable. An expedient alternative to observed data is the use of long, synthetic rainfall time series as input for the simulation models. Within the project SYNOPSE, several different methods to generate synthetic precipitation data for urban drainage modelling are advanced, tested, and compared. The presented study compares four different approaches of precipitation models regarding their ability to reproduce rainfall and runoff characteristics. These include one parametric stochastic model (alternating renewal approach), one non-parametric stochastic model (resampling approach), one downscaling approach from a regional climate model, and one disaggregation approach based on daily precipitation measurements. All four models produce long precipitation time series with a temporal resolution of five minutes. The synthetic time series are first compared to observed rainfall reference time series. Comparison criteria include event based statistics like mean dry spell and wet spell duration, wet spell amount and intensity, long term means of precipitation sum and number of events, and extreme value distributions for different durations. Then they are compared regarding simulated discharge characteristics using an urban hydrological model on a fictitious sewage network. First results show a principal suitability of all rainfall models but with different strengths and weaknesses regarding the different rainfall and runoff characteristics considered.

  2. Effect of time of day on aerobic contribution to the 30-s Wingate test performance.

    PubMed

    Souissi, Nizar; Bessot, Nicolas; Chamari, Karim; Gauthier, Antoine; Sesboüé, Bruno; Davenne, Damien

    2007-01-01

    The purpose of this study was to evaluate the effects of time of day on aerobic contribution during high-intensity exercise. A group of 11 male physical education students performed a Wingate test against a resistance of 0.087 kg . kg(-1) body mass. Two different times of day were chosen, corresponding to the minimum (06:00 h) and the maximum (18:00 h) levels of power. Oxygen uptake (.VO(2)) was recorded breath by breath during the test (30 sec). Blood lactate concentrations were measured at rest, just after the Wingate test, and again 5 min later. Oral temperature was measured before each test and on six separate occasions at 02:00, 06:00, 10:00, 14:00, 18:00, and 22:00 h. A significant circadian rhythm was found in body temperature with a circadian acrophase at 18:16+/-00:25 h as determined by cosinor analysis. Peak power (P(peak)), mean power (P(mean)), total work done, and .VO(2) increased significantly from morning to afternoon during the Wingate Test. As a consequence, aerobic contribution recorded during the test increased from morning to afternoon. However, no difference in blood lactate concentrations was observed from morning to afternoon. Furthermore, power decrease was greater in the morning than afternoon. Altogether, these results indicate that the time-of-day effect on performances during the Wingate test is mainly due to better aerobic participation in energy production during the test in the afternoon than in the morning.

  3. Are declines in physical performance associated with a reduction in skill-related performance during professional soccer match-play?

    PubMed

    Carling, Christopher; Dupont, Gregory

    2011-01-01

    The aim of this study was to determine whether declines in physical performance in a professional soccer team during match-play were associated with reductions in skill-related performance. Computerized tracking of performance in midfield players (n = 11) showed that total distance and distance covered in high-speed running (>14.4 km · h⁻¹) were greater in the first versus second half of games (both P < 0.001) and in the first versus the final 15 min of play (P < 0.05). Analysis of high-speed running across 5-min periods showed that more distance was covered in the first versus the final game period, and in the peak period of activity compared with the following period and game mean for other periods (all P < 0.05). Analysis of skill-related measures revealed no significant decline between halves, across 15-min intervals or in the 5-min period following that of peak high-speed activity compared with the game mean for other 5-min periods. In contrast, frequencies of passing, ball possessions, and duels were greater in the first 5-min than in the final 5-min period (P < 0.05). Neither physical nor skill-related performance was affected across three consecutive games within a period of ≤7 days. The results suggest that the players were generally able to maintain skill-related performance throughout games and when competing in successive matches within a short time.

  4. High-Intensity Intermittent Training Positively Affects Aerobic and Anaerobic Performance in Judo Athletes Independently of Exercise Mode

    PubMed Central

    Franchini, Emerson; Julio, Ursula F.; Panissa, Valéria L. G.; Lira, Fábio S.; Gerosa-Neto, José; Branco, Braulio H. M.

    2016-01-01

    Purpose: The present study investigated the effects of high-intensity intermittent training (HIIT) on lower- and upper-body graded exercise and high-intensity intermittent exercise (HIIE, four Wingate bouts) performance, and on physiological and muscle damage markers responses in judo athletes. Methods: Thirty-five subjects were randomly allocated to a control group (n = 8) or to one of the following HIIT groups (n = 9 for each) and tested pre- and post-four weeks (2 training d·wk−1): (1) lower-body cycle-ergometer; (2) upper-body cycle-ergometer; (3) uchi-komi (judo technique entrance). All HIIT were constituted by two blocks of 10 sets of 20 s of all out effort interspersed by 10 s set intervals and 5-min between blocks. Results: For the upper-body group there was an increase in maximal aerobic power in graded upper-body exercise test (12.3%). The lower-body group increased power at onset blood lactate in graded upper-body exercise test (22.1%). The uchi-komi group increased peak power in upper- (16.7%) and lower-body (8.5%), while the lower-body group increased lower-body mean power (14.2%) during the HIIE. There was a decrease in the delta blood lactate for the uchi-komi training group and in the third and fourth bouts for the upper-body training group. Training induced testosterone-cortisol ratio increased in the lower-body HIIE for the lower-body (14.9%) and uchi-komi (61.4%) training groups. Conclusion: Thus, short-duration low-volume HIIT added to regular judo training was able to increase upper-body aerobic power, lower- and upper-body HIIE performance. PMID:27445856

  5. Diurnal variation in Wingate test performances: influence of active warm-up.

    PubMed

    Souissi, Nizar; Driss, Tarak; Chamari, Karim; Vandewalle, Henry; Davenne, Damien; Gam, Abdelkader; Fillard, Jean-Robert; Jousselin, Eric

    2010-05-01

    The purpose of the present study was to examine the effects of active warm-up duration on the diurnal fluctuations in anaerobic performances. Twelve physical education students performed a medical stress test (progressive test up to exhaustion) and four Wingate tests (measurement of peak power [P(peak)], mean power [P(mean)], and fatigue index during an all-out 30 s cycling exercise). The tests were performed in separate sessions (minimum interval = 36 h) in a balanced and randomized design at 08:00 and 18:00 h, either after a 5 min (5-AWU) or a 15 min active warm-up (15-AWU). AWU consisted of pedaling at 50% of the power output at the last stage of the stress exhausting test. Rectal temperature was collected throughout the sessions. A two-way ANOVA (warm-up x time of day) revealed a significant interaction for P(peak) (F((1.11)) = 6.48, p < 0.05) and P(mean) (F((1.11)) = 5.84, p < 0.05): the time-of-day effect was significant (p < 0.001) in contrast with the effect of warm-up duration (p > 0.05). P(peak) and P(mean) improved significantly from morning to afternoon after both 5-AWU and 15-AWU, but the effect of warm-up duration was significant in the morning only. Indeed, the values of P(peak) or P(mean) were the same after both warm-up protocols in the afternoon. For rectal temperature, there was no interaction between time-of-day and warm-up duration. Rectal temperature before and after both the warm-up protocols was higher in the afternoon, and the effect of warm-up duration on temperature was similar at 08:00 and 18:00 h. In conclusion, the interpretation of the results of the anaerobic performance tests should take into account time-of-day and warm-up procedures. Longer warm-up protocols are recommended in the morning to minimize the diurnal fluctuations of anaerobic performances.

  6. The Physiological Mechanisms of Performance Enhancement with Sprint Interval Training Differ between the Upper and Lower Extremities in Humans

    PubMed Central

    Zinner, Christoph; Morales-Alamo, David; Ørtenblad, Niels; Larsen, Filip J.; Schiffer, Tomas A.; Willis, Sarah J.; Gelabert-Rebato, Miriam; Perez-Valera, Mario; Boushel, Robert; Calbet, Jose A. L.; Holmberg, Hans-Christer

    2016-01-01

    To elucidate the mechanisms underlying the differences in adaptation of arm and leg muscles to sprint training, over a period of 11 days 16 untrained men performed six sessions of 4–6 × 30-s all-out sprints (SIT) with the legs and arms, separately, with a 1-h interval of recovery. Limb-specific VO2peak, sprint performance (two 30-s Wingate tests with 4-min recovery), muscle efficiency and time-trial performance (TT, 5-min all-out) were assessed and biopsies from the m. vastus lateralis and m. triceps brachii taken before and after training. VO2peak and Wmax increased 3–11% after training, with a more pronounced change in the arms (P < 0.05). Gross efficiency improved for the arms (+8.8%, P < 0.05), but not the legs (−0.6%). Wingate peak and mean power outputs improved similarly for the arms and legs, as did TT performance. After training, VO2 during the two Wingate tests was increased by 52 and 6% for the arms and legs, respectively (P < 0.001). In the case of the arms, VO2 was higher during the first than second Wingate test (64 vs. 44%, P < 0.05). During the TT, relative exercise intensity, HR, VO2, VCO2, VE, and Vt were all lower during arm-cranking than leg-pedaling, and oxidation of fat was minimal, remaining so after training. Despite the higher relative intensity, fat oxidation was 70% greater during leg-pedaling (P = 0.017). The aerobic energy contribution in the legs was larger than for the arms during the Wingate tests, although VO2 for the arms was enhanced more by training, reducing the O2 deficit after SIT. The levels of muscle glycogen, as well as the myosin heavy chain composition were unchanged in both cases, while the activities of 3-hydroxyacyl-CoA-dehydrogenase and citrate synthase were elevated only in the legs and capillarization enhanced in both limbs. Multiple regression analysis demonstrated that the variables that predict TT performance differ for the arms and legs. The primary mechanism of adaptation to SIT by both the arms and legs

  7. Curriculum-Based Measurement in Science Learning: Vocabulary-Matching as an Indicator of Performance and Progress

    ERIC Educational Resources Information Center

    Espin, Christine A.; Busch, Todd W.; Lembke, Erica S.; Hampton, David D.; Seo, Kyounghee; Zukowski, Beth A.

    2013-01-01

    The technical adequacy of curriculum-based measures in the form of short and simple vocabulary-matching probes to predict students' performance and progress in science at the secondary level was investigated. Participants were 198 seventh-grade students from 10 science classrooms. Curriculum-based measurements (CBM) were 5-min vocabulary-matching…

  8. Acute Effects of Classroom Exercise Breaks on Executive Function and Math Performance: A Dose-Response Study

    ERIC Educational Resources Information Center

    Howie, Erin K.; Schatz, Jeffrey; Pate, Russell R.

    2015-01-01

    Purpose: The purpose of this study was to determine the acute dose-response relationship of classroom exercise breaks with executive function and math performance in 9- to 12-year-old children by comparing 5-min, 10-min, or 20-min classroom exercise breaks to 10 min of sedentary classroom activity. Method: This study used a within-subjects…

  9. Does upper body strength and power influence upper body Wingate performance in men and women?

    PubMed

    Lovell, D; Mason, D; Delphinus, E; Eagles, A; Shewring, S; McLellan, C

    2011-10-01

    The aim of this study was to determine the influence of muscular strength and power on upper body Wingate performance in men and women. Muscular strength (1 repetition maximum bench press), muscular power (bench throws) and upper body anaerobic performance (Wingate Anaerobic Test (WAnT)) was assessed in 24 men and 16 women. Men had significantly ( P<0.001) higher absolute and relative peak and mean power and blood lactate concentration during the WAnT compared to their female counterparts. Men also produced significantly ( P<0.001) higher strength and absolute and relative peak and mean power during the bench press and throw, respectively, compared to the female participants. For men body mass and mean power produced during the bench throw explained approximately 84% and 87% of the variance in Wingate peak ( P<0.001 and P=0.039, respectively) and mean ( P<0.001 and P=0.028, respectively) power. For women mean power produced during the bench throw explained approximately 72% and 52% of the variance in Wingate peak ( P=0.002) and mean ( P=0.017) power, respectively. For men body mass and to a lesser extent muscular power best predicts upper body Wingate performance while for women only muscular power predicts upper body Wingate performance.

  10. Soldier Performance and Mood States Following a Strenuous Road March

    DTIC Science & Technology

    1990-01-01

    min after the march). Soldiers jumped as high as possible and marked a board at the highest point of the jump . The highest of 3 trials was recorded...improve shooting accuracy (15, 16). The grenade throw and vertical jump tests were used to evaluate explosive strength or power (6, 17). Under the...appear to affect leg power. Patton et al. (18) found no decline in peak or mean power on the Wingate test when subjects performed a loaded road march task

  11. Fluctuations in running and skill-related performance in elite rugby union match-play.

    PubMed

    Lacome, Mathieu; Piscione, Julien; Hager, Jean-Philippe; Carling, Chris

    2017-03-01

    This study investigated end-game and transient changes in running activities and whether these were concomitantly associated with reductions in skill-related performance in senior international rugby union match-play. Altogether, 18 official matches were analysed (322 individual observations) using computerised video-based tracking and event coding (Amisco Pro(®), SUP, Nice, France). In forwards and backs, trivial to small reductions (% difference: -2.1, ±1.3 to -10.0, ±4.0%) in total distance and that covered at high speeds (>18.0 km h(-1)) occurred in the second- versus the first-half while there were trivial differences in skill-related performance measures (-2.3, ±4.5 to 7.5, ±14.0%). In both positions, small to moderate declines (-42, ±10 to -21, ±7%) occurred in high-speed running in the final 10-min and 5-min periods versus mean values for all other 10-min and 5-min periods throughout the game while only small changes (-18, ±51 to 13, ±41%) in skill-related performance were observed. Trivial changes in running and skill-related performance (-11, ±74 to 7, ±39%) were observed in the 5-min period immediately following the most intense 5-minute periods of play compared to mean performance over the other 5-min periods. These findings suggest that international rugby union players were generally able to maintain skill-related performance over the course of match-play even when declines in running performance occurred.

  12. Acute effects of different volumes of dynamic stretching on vertical jump performance, flexibility and muscular endurance.

    PubMed

    Ryan, Eric D; Everett, Kenneth L; Smith, Doug B; Pollner, Christie; Thompson, Brennan J; Sobolewski, Eric J; Fiddler, Ryan E

    2014-11-01

    The purpose of this study was to examine the acute effects of different volumes of a dynamic stretching routine on vertical jump (VJ) performance, flexibility and muscular endurance (ME). Twenty-six males (age 22.2 ± 1.3 years) performed three separate randomized conditions: (i) a control (CON) condition (5-min jog + 12 min of resting), (ii) a 5-min jog + a dynamic stretching routine (DS1; 6.7 ± 1.3 min) and (iii) a 5-min jog + a dynamic stretching routine with twice the volume (DS2; 12.1 ± 1.6 min). The dynamic stretching routine included 11 exercises targeting the hip and thigh musculature. VJ performance (jump height and velocity) and flexibility were measured prior to and following all conditions, while ME was measured following all conditions. The DS1 and DS2 conditions increased VJ height and velocity (P<0.01), while the CON condition did not change (P>0.05). When compared to the CON condition, the DS1 condition did not improve ME (P>0.05), whereas the DS2 condition resulted in a significant (15.6%) decrease in the number of repetitions completed (P<0.05). Flexibility increased following all conditions (P<0.01), while the DS1 condition was significantly greater (P<0.01) than the CON condition at post-testing. These results suggest that dynamic stretching routines lasting approximately 6-12 min performed following a 5-min jog resulted in similar increases in VJ performance and flexibility. However, longer durations of dynamic stretching routines may impair repetitive high-intensity activities.

  13. Hyperventilation as a strategy for improved repeated sprint performance.

    PubMed

    Sakamoto, Akihiro; Naito, Hisashi; Chow, Chin-Moi

    2014-04-01

    Repeated high-intensity sprints incur substantial anaerobic metabolic challenges and create an acidic muscle milieu that is unfavorable for subsequent performance. Hyperventilation, resulting in respiratory alkalosis, acts as a compensatory mechanism for metabolic acidosis. This study tested the hypothesis that hyperventilation performed during recovery intervals would attenuate performance decrement in repeated sprint pedaling. Thirteen male university athletes performed 10 sets of 10-second maximal pedaling on a cycle ergometer with a 60-second recovery between sets under control (spontaneous breathing) and hyperventilation conditions in a crossover counter-balanced manner. Pedaling load was set at 0.075 × body mass. Peak and mean power outputs were documented for each set to compare performance decrements for 10 sets between conditions. Hyperventilation (60 breaths per minute and end-tidal partial pressure of CO2 maintained at 20-25 mm Hg) was performed 30 seconds before each sprint set. This intervention successfully increased blood pH by 0.03-0.07 but lowered P(CO2) by 1.2-8.4 mm Hg throughout exercise (p < 0.001). The peak and mean power outputs, and blood [La] accumulation were not significantly different between the conditions. However, a significant condition × time interaction existed for peak power (p = 0.035) and mean power (p = 0.023), demonstrating an attenuation in power decrement in later sprint sets with hyperventilation. In conclusion, hyperventilation implemented during recovery intervals of repeated sprint pedaling attenuated performance decrements in later exercise bouts that was associated with substantial metabolic acidosis. The practical implication is that hyperventilation may have a strategic role for enhancing training effectiveness and may give an edge in performance outcomes.

  14. Lunge performance and its determinants.

    PubMed

    Cronin, John; McNair, Peter J; Marshall, Robert N

    2003-01-01

    For activities such as squash, badminton and fencing, the ability to quickly complete a lunge and return to the start or move off in another direction is critical for success. Determining which strength qualities are important predictors of lunge performance was the focus of this study. Thirty-one male athletes performed: (1) a unilateral maximal squat (one-repetition maximum, 1-RM) and unilateral jump squat (50% 1-RM) on an instrumented supine squat machine, and (2) a forward lunge while attached to a linear transducer. We performed stepwise multiple regression analysis with lunge performance as the dependent variable and various strength, flexibility and anthropometric measures as the independent variables. From the many strength and power measures calculated, time to peak force was the best single predictor of lunge performance, which accounted for 55% of the explained variance. The best three-variable model for predicting lunge performance accounted for 76-85% of the explained variance. The models differed, however, according to whether lunge performance was expressed relative to body mass (time to peak force, mean power and relative strength = 76%) or taken as an absolute value (time to peak force, leg length and flexibility = 85%). We conclude that one to two trials were reliable for strength diagnosis and that one strength measure cannot accurately explain functional performance because other factors, such as body mass, flexibility and leg length, have diverse effects on the statistical models.

  15. Effects of general, specific and combined warm-up on explosive muscular performance

    PubMed Central

    Henriquez–Olguín, C; Beltrán, AR; Ramírez, MA; Labarca, C; Cornejo, M; Álvarez, C; Ramírez-Campillo, R

    2015-01-01

    The purpose of this study was to compare the acute effects of general, specific and combined warm-up (WU) on explosive performance. Healthy male (n = 10) subjects participated in six WU protocols in a crossover randomized study design. Protocols were: passive rest (PR; 15 min of passive rest), running (Run; 5 min of running at 70% of maximum heart rate), stretching (STR; 5 min of static stretching exercise), jumping [Jump; 5 min of jumping exercises – 3x8 countermovement jumps (CMJ) and 3x8 drop jumps from 60 cm (DJ60)], and combined (COM; protocols Run+STR+Jump combined). Immediately before and after each WU, subjects were assessed for explosive concentric-only (i.e. squat jump – SJ), slow stretch-shortening cycle (i.e. CMJ), fast stretch-shortening cycle (i.e. DJ60) and contact time (CT) muscle performance. PR significantly reduced SJ performance (p =0.007). Run increased SJ (p =0.0001) and CMJ (p =0.002). STR increased CMJ (p =0.048). Specific WU (i.e. Jump) increased SJ (p =0.001), CMJ (p =0.028) and DJ60 (p =0.006) performance. COM increased CMJ performance (p =0.006). Jump was superior in SJ performance vs. PR (p =0.001). Jump reduced (p =0.03) CT in DJ60. In conclusion, general, specific and combined WU increase slow stretch-shortening cycle (SSC) muscle performance, but only specific WU increases fast SSC muscle performance. Therefore, to increase fast SSC performance, specific fast SSC muscle actions must be included during the WU. PMID:26060335

  16. Laboratory predictors of uphill cycling performance in trained cyclists.

    PubMed

    Bossi, Arthur Henrique; Lima, Pedro; Lima, Jorge Perrout de; Hopker, James

    2016-05-07

    This study aimed to assess the relationship between an uphill time-trial (TT) performance and both aerobic and anaerobic parameters obtained from laboratory tests. Fifteen cyclists performed a Wingate anaerobic test, a graded exercise test (GXT) and a field-based 20-min TT with 2.7% mean gradient. After a 5-week non-supervised training period, 10 of them performed a second TT for analysis of pacing reproducibility. Stepwise multiple regressions demonstrated that 91% of TT mean power output variation (W kg(-1)) could be explained by peak oxygen uptake (ml kg(-1.)min(-1)) and the respiratory compensation point (W kg(-1)), with standardised beta coefficients of 0.64 and 0.39, respectively. The agreement between mean power output and power at respiratory compensation point showed a bias ± random error of 16.2 ± 51.8 W or 5.7 ± 19.7%. One-way repeated-measures analysis of variance revealed a significant effect of the time interval (123.1 ± 8.7; 97.8 ± 1.2 and 94.0 ± 7.2% of mean power output, for epochs 0-2, 2-18 and 18-20 min, respectively; P < 0.001), characterising a positive pacing profile. This study indicates that an uphill, 20-min TT-type performance is correlated to aerobic physiological GXT variables and that cyclists adopt reproducible pacing strategies when they are tested 5 weeks apart (coefficients of variation of 6.3; 1 and 4%, for 0-2, 2-18 and 18-20 min, respectively).

  17. Performativity, Performance and Education

    ERIC Educational Resources Information Center

    Locke, Kirsten

    2015-01-01

    This article explores Lyotard's notion of performativity through an engagement with McKenzie's analysis of performance as a "formation of knowledge and power" that has displaced the notion of discipline as the tool for social evaluation. Through conditions of "performance" capitalism, education is to conform to a…

  18. The Effect of Different Recovery Duration on Repeated Anaerobic Performance in Elite Cyclists

    PubMed Central

    Harbili, Sultan

    2015-01-01

    This study investigated the effect of recovery duration on repeated anaerobic performance in elite cyclists. The study followed a cross-over design protocol. Twelve elite male cyclists were randomly assigned to three groups (with recovery duration of 1, 2 and 3 min, respectively). All the subjects performed 4 repeated Wingate tests (4 × 30 s WT) at 48 h intervals for three different recovery periods. No significant interaction was observed between the effects of recovery duration and repetition (p>0.05), whereas there was a significant main effect of repetition on peak power, mean power, and a fatigue index (p<0.05). Peak power decreased significantly in repeated WTs with 1 and with 2 min recovery duration (p<0.05), but it did not change significantly in a repeated WT with 3 min recovery (p>0.05). In contrast, mean power decreased significantly in repeated WTs with 1, 2 and 3 min recovery duration (p<0.05). The fatigue index increased significantly in a repeated WT with 1 min recovery duration (p<0.05), but no significant difference was observed in the fatigue index in repeated WTs with 2 and 3 min recovery (p>0.05). In a 4 × 30 s WT, peak power decreased in cycles with 1 and 2 min recovery duration, but remained unchanged with 3 min recovery duration, whereas mean power decreased in all recovery duration procedures. The WT with 1 min recovery duration caused greater fatigue. Although recovery duration affected both peak power and mean power, the effect on peak power was greater. PMID:26839617

  19. Relationships Between Anaerobic Performance, Field Tests and Game Performance of Sitting Volleyball Players.

    PubMed

    Marszalek, Jolanta; Molik, Bartosz; Gomez, Miguel Angel; Skučas, Kęstutis; Lencse-Mucha, Judit; Rekowski, Witold; Pokvytyte, Vaida; Rutkowska, Izabela; Kaźmierska-Kowalewska, Kalina

    2015-11-22

    The aim of this study was to evaluate relationships between anaerobic performance, field tests, game performance and anthropometric variables of sitting volleyball players. Twenty elite Polish sitting volleyball players were tested using the 30 s Wingate Anaerobic Test for arm crank ergometer and participated in six physical field tests. Heights in position to block and to spike, as well as arm reach were measured. Players were observed during the game on the court in terms of effectiveness of the serve, block, attack, receive and defense. Pearson analysis and the Spearman's rank correlation coefficient were used. The strongest correlations were found between the chest pass test and mean power and peak power (r=.846; p=.001 and r=.708; p=.0005, respectively), and also between the T-test and peak power (r= -.718; p=.001). Mean power correlated with the 3 m test (r= -.540; p=.014), the 5 m test (r= -.592; p=.006), and the T-test (r= -.582; p=.007). Peak power correlated with the 3 m test (r= -.632; p=.003), the 5 m test (r= -.613; p=.004), speed & agility (r= -.552; p=.012) and speed & endurance (r=-.546; p=.013). Significant correlations were observed between anthropometric parameters and anaerobic performance variables (p≤.001), and also between anthropometric parameters and field tests (p≤.05). Game performance and physical fitness of sitting volleyball players depended on their anthropometric variables: reach of arms, the position to block and to spike. The chest pass test could be used as a non-laboratory field test of anaerobic performance of sitting volleyball players.

  20. Performance, Performance System, and High Performance System

    ERIC Educational Resources Information Center

    Jang, Hwan Young

    2009-01-01

    This article proposes needed transitions in the field of human performance technology. The following three transitions are discussed: transitioning from training to performance, transitioning from performance to performance system, and transitioning from learning organization to high performance system. A proposed framework that comprises…

  1. Effect of active and passive recovery on blood lactate and performance during simulated competition in high level gymnasts.

    PubMed

    Jemni, Monèm; Sands, William A; Friemel, Françoise; Delamarche, Paul

    2003-04-01

    The purpose of this study was to investigate the effect of two recovery strategies between men's gymnastics events on blood lactate removal (BL) and performance as rated by expert "blind" judges. Twelve male gymnasts (21.8 +/- 2.4 years) participated. The sessions were composed of routine performances in the six Olympic events, which were separated by 10 min of recovery. All gymnasts performed two recovery protocols between events on separate days: Rest protocol, 10 min rest in a sitting position; Combined protocol, 5 min rest and 5 min self-selected active recovery. Three blood samples were taken at 2, 5, and 10 min following each event. Gymnasts produced moderate values of BL following each of the six events (2.2 to 11.6 mmol.L-1). There was moderate variability in BL values between events that could not be accounted for by the athlete's event performance. Gymnasts showed higher BL concentration (p > .05) and significantly (p < .05) higher scoring performances (as rated by a panel of certified judges) when they used a combined recovery between gymnastics events rather than a passive recovery (delta BL = 40.51% vs. 28.76% of maximal BL, p < .05, and total score = 47.28 +/- 6.82 vs. 38.39 +/- 7.55, p < .05, respectively).

  2. Dynamic stretching and golf swing performance.

    PubMed

    Moran, K A; McGrath, T; Marshall, B M; Wallace, E S

    2009-02-01

    The aim of the present study was to examine the effect of dynamic stretching, static stretching and no stretching, as part of a general warm-up, on golf swing performance with a five-iron. Measures of performance were taken 0 min, 5 min, 15 min and 30 min after stretching. Dynamic stretching produced significantly greater club head speeds than both static stretching (Delta=1.9m.s (-1); p=0.000) and no stretching (Delta=1.7 m.s (-1); p=0.000), and greater ball speeds than both static stretching (Delta=3.5m.s (-1); p=0.003) and no stretching (Delta=3.3m.s (-1); p=0.001). Dynamic stretching produced significantly straighter swing-paths than both static stretching (Delta=-0.61 degrees , p=0.000) and no stretching (Delta=-0.72 degrees , p=0.01). Dynamic stretching also produced more central impact points than the static stretch (Delta=0.7 cm, p=0.001). For the club face angle, there was no effect of either stretch or time. For all of the variables measured, there was no significant difference between the static stretch and no stretch conditions. All of the results were unaffected by the time of measurement after stretching. The results indicate that dynamic stretching should be used as part of a general warm-up in golf.

  3. Recession on Top of Energy Crisis May Mean Power Boost for Universities

    ERIC Educational Resources Information Center

    Basken, Paul

    2009-01-01

    For many Americans, the confluence of a recession and a growing realization that the nation needs to end its reliance on fossil fuels seems like a double dose of bad news. But for the nation's research universities, it may be an opportunity. A Brookings Institution, a policy-study group with ties to the Democratic leaders now controlling the White…

  4. Sleep deprivation induced anxiety and anaerobic performance.

    PubMed

    Vardar, Selma Arzu; Oztürk, Levent; Kurt, Cem; Bulut, Erdogan; Sut, Necdet; Vardar, Erdal

    2007-01-01

    The aim of this study was to investigate the effects of sleep deprivation induced anxiety on anaerobic performance. Thirteen volunteer male physical education students completed the Turkish version of State Anxiety Inventory and performed Wingate anaerobic test for three times: (1) following a full-night of habitual sleep (baseline measurements), (2) following 30 hours of sleep deprivation, and (3) following partial-night sleep deprivation. Baseline measurements were performed the day before total sleep deprivation. Measurements following partial sleep deprivation were made 2 weeks later than total sleep deprivation measurements. State anxiety was measured prior to each Wingate test. The mean state anxiety following total sleep deprivation was higher than the baseline measurement (44.9 ± 12.9 vs. 27.6 ± 4.2, respectively, p = 0.02) whereas anaerobic performance parameters remained unchanged. Neither anaerobic parameters nor state anxiety levels were affected by one night partial sleep deprivation. Our results suggest that 30 hours continuous wakefulness may increase anxiety level without impairing anaerobic performance, whereas one night of partial sleep deprivation was ineffective on both state anxiety and anaerobic performance. Key pointsShort time total sleep deprivation (30 hours) increases state anxiety without any competition stress.Anaerobic performance parameters such as peak power, mean power and minimum power may not show a distinctive difference from anaerobic performance in a normal sleep day despite the high anxiety level induced by short time sleep deprivation.Partial sleep deprivation does not affect anxiety level and anaerobic performance of the next day.

  5. Different proportions of C/KCu7S4 hybrid structure for high-performance supercapacitors

    NASA Astrophysics Data System (ADS)

    Dai, Shuge; Xi, Yi; Hu, Chenguo; Yue, Xule; Cheng, Lu; Wang, Guo

    2014-10-01

    KCu7S4 has the channel structure and minor resistance. Its double larger channels ensure that the ions can well exchange with other's, at the same time, can shorten the ionic diffusion path and improve the ionic and electronic transport. So KCu7S4 shows good electrochemical property. The paper reports a novel and high performance supercapacitor based on hybrid carbon particles and KCu7S4 (C/KCu7S4) electrode. For the hybrid structure with different proportions of C and KCu7S4, the C/KCu7S4 (1:10) hybrid supercapacitor shows preferable electrochemical performance and large specific capacitance (469 mF cm-2) at high charge-discharge rate (2 mA), still retaining ∼95% of the capacitance over 5000 cycles by charge-discharge process at a fixed current of 10 mA. Three supercapacitor units in series can light 50 light-emitting diodes (LEDs) for 2.5 min, 10 LEDs for 4 min, one LED for 5.5 min. The much-increased capacity, rate capability, and cycling stability may be attributed to the superionic conductive KCu7S4 nanowires and C/KCu7S4 hybrid structure, which improve ionic and electronic transport, enhance the kinetics of redox reactions through the electrode system.

  6. Timing influence of carbohydrate-protein ingestion on muscle soreness and next-day running performance.

    PubMed

    Greer, Beau Kjerulf; Price, Anna; Jones, Brett

    2014-06-01

    The present study investigates timing effects of a carbohydrate-protein (CHO-PROT) beverage on indicators of muscle damage and next day running performance. Nine trained subjects completed three trials of a 30 min downhill run, followed by a 1.5 mile treadmill running time trial 24 hr later in a blinded, crossover design. Either a CHO-PROT or noncaloric placebo beverage was given 30 and 5 min prior to, at the 15 min mark during, immediately after, and 30 min after the downhill running protocol. In the first treatment (T1), a total of 360 kilocalories were given 30 and 5 min prior to downhill running, as well as at the 15 min mark, with placebos used at other time points. In the second treatment (T2), an isocaloric amount was given but only immediately after and 30 min after downhill running, with placebos used at other time points. In the placebo treatment, a placebo was given at all time points. There were no significant differences in the 1.5 mile time trial or soreness between trials (p > .05). Regardless of timing, the ingestion of a CHO-PROT beverage had no effect on next day running performance or muscular soreness versus a placebo.

  7. A comparative study of the performance of different spectral estimation methods for classification of mental tasks.

    PubMed

    Diez, Pablo F; Laciar, Eric; Mut, Vicente; Avila, Enrique; Torres, Abel

    2008-01-01

    In this paper we compare three different spectral estimation techniques for the classification of mental tasks. These techniques are the standard periodogram, the Welch periodogram and the Burg method, applied to electroencephalographic (EEG) signals. For each one of these methods we compute two parameters: the mean power and the root mean square (RMS), in various frequency bands. The classification of the mental tasks was conducted with a linear discriminate analysis. The Welch periodogram and the Burg method performed better than the standard periodogram. The use of the RMS allows better classification accuracy than the obtained with the power of EEG signals.

  8. Investigating the Use of Deep Convective Clouds (DCCT) to Monitor On-orbit Performance of the Geostationary Lightning Mapper (GLM) using Lightning Imaging Sensor (LIS) Measurements

    NASA Technical Reports Server (NTRS)

    Buechler, Dennis E.; Christian, Hugh J.; Koshak, William J.; Goodman, Steven J.

    2013-01-01

    There is a need to monitor the on-orbit performance of the Geostationary Lightning Mapper (GLM) on the Geostationary Operational Environmental Satellite R (GOES-R) for changes in instrument calibration that will affect GLM's lightning detection efficiency. GLM has no onboard calibration so GLM background radiance observations (available every 2.5 min) of Deep Convective Clouds (DCCs) are investigated as invariant targets to monitor GLM performance. Observations from the Lightning Imaging Sensor (LIS) and the Visible and Infrared Scanner (VIRS) onboard the Tropical Rainfall Measuring Mission (TRMM) satellite are used as proxy datasets for GLM and ABI 11 m measurements.

  9. Does Increasing Active Warm-Up Duration Affect Afternoon Short-Term Maximal Performance during Ramadan?

    PubMed Central

    Baklouti, Hana; Aloui, Asma; Chtourou, Hamdi; Briki, Walid; Chaouachi, Anis; Souissi, Nizar

    2015-01-01

    Aim The purpose of this study was to examine the effect of active warm-up duration on short-term maximal performance assessed during Ramadan in the afternoon. Methods Twelve healthy active men took part in the study. The experimental design consisted of four test sessions conducted at 5 p.m., before and during Ramadan, either with a 5-minute or a 15-minute warm-up. The warm-up consisted in pedaling at 50% of the power output obtained at the last stage of a submaximal multistage cycling test. During each session, the subjects performed two vertical jump tests (squat jump and counter movement jump) for measurement of vertical jump height followed by a 30-second Wingate test for measurement of peak and mean power. Oral temperature was recorded at rest and after warming-up. Moreover, ratings of perceived exertion were obtained immediately after the Wingate test. Results Oral temperature was higher before Ramadan than during Ramadan at rest, and was higher after the 15-minute warm-up than the 5-minute warm-up both before and during Ramadan. In addition, vertical jump heights were not significantly different between the two warm-up conditions before and during Ramadan, and were lower during Ramadan than before Ramadan after both warm-up conditions. Peak and mean power were not significantly different between the two warm-up durations before Ramadan, but were significantly higher after the 5-minute warm-up than the 15-minute warm-up during Ramadan. Moreover, peak and mean power were lower during Ramadan than before Ramadan after both warm-up conditions. Furthermore, ratings of perceived exertion were higher after the 15-minute warm-up than the 5-minute warm-up only during Ramadan. Conclusion The prolonged active warm-up has no effect on vertical jump height but impairs anaerobic power assessed during Ramadan in the afternoon. PMID:25646955

  10. Monitoring changes in physical performance with heart rate measures in young soccer players.

    PubMed

    Buchheit, M; Simpson, M B; Al Haddad, H; Bourdon, P C; Mendez-Villanueva, A

    2012-02-01

    The aim of the present study was to verify the validity of using exercise heart rate (HRex), HR recovery (HRR) and post-exercise HR variability (HRV) during and after a submaximal running test to predict changes in physical performance over an entire competitive season in highly trained young soccer players. Sixty-five complete data sets were analyzed comparing two consecutive testing sessions (3-4 months apart) collected on 46 players (age 15.1 ± 1.5 years). Physical performance tests included a 5-min run at 9 km h(-1) followed by a seated 5-min recovery period to measure HRex, HRR and HRV, a counter movement jump, acceleration and maximal sprinting speed obtained during a 40-m sprint with 10-m splits, repeated-sprint performance and an incremental running test to estimate maximal cardiorespiratory function (end test velocity V (Vam-Eval)). Possible changes in physical performance were examined for the players presenting a substantial change in HR measures over two consecutive testing sessions (greater than 3, 13 and 10% for HRex, HRR and HRV, respectively). A decrease in HRex or increase in HRV was associated with likely improvements in V (Vam-Eval); opposite changes led to unclear changes in V (Vam-Eval). Moderate relationships were also found between individual changes in HRR and sprint [r = 0.39, 90% CL (0.07;0.64)] and repeated-sprint performance [r = -0.38 (-0.05;-0.64)]. To conclude, while monitoring HRex and HRV was effective in tracking improvements in V (Vam-Eval), changes in HRR were moderately associated with changes in (repeated-)sprint performance. The present data also question the use of HRex and HRV as systematic markers of physical performance decrements in youth soccer players.

  11. Two percent hypohydration does not impair self-selected high-intensity intermittent exercise performance.

    PubMed

    Yamashita, Naoyuki; Ito, Ryo; Nakano, Masataka; Matsumoto, Takaaki

    2015-01-01

    The level of hypohydration at which power output during intermittent exercise performance starts to decrease is not fully understood. The purpose of this study was to investigate the effects of 2% hypohydration without hyperthermia on intermittent exercise performance. Eight collegiate amateur boxers completed 2 exercise tests. On day 1, subjects hypohydrated by 2% of body mass by exercising in a hot environment, and on day 2, subjects performed intermittent exercise (4 × 2 minute per round [R] separated by 1-minute recovery) under a randomly assigned condition of with (HYP) or without (EUH) hypohydration. Each bout consisted of 8 × 5 seconds of maximal cycling exercise (0.05 kp × body mass) separated by 10 seconds of passive recovery. Mean power output per kilogram (MPO), total power output per kilogram (TPO), energy system relative contribution, and core rectal temperature (Tre) were measured. Changes in body mass before the exercise tests were -2.25 ± 0.18% (HYP) and -0.17 ± 0.19% (EUH) (p < 0.001). Mean power output, TPO, and each energy contribution ratio were not significantly different between the trials, and pre- and postexercise test Tre did not differ significantly between trials. Results demonstrated that approximately 2% hypohydration lies below the point at which power output during intermittent exercise starts to decline.

  12. Caffeine's effect on intermittent sprint cycling performance with different rest intervals.

    PubMed

    Lee, Chia-Lun; Cheng, Ching-Feng; Lin, Jung-Charng; Huang, Hsin-Wei

    2012-06-01

    The purpose of this study was to investigate the effects of caffeine ingestion on the performance of an intermittent sprint cycling test (ISCT) with different rest intervals. Fourteen males with team sport experience consumed 6 mg kg(-1) of caffeine or a placebo 60 min prior to completing two sets of an ISCT with 4-min rest intervals. Each set consisted of 12 × 4-s sprints with 20- or 90-s active recovery intervals at 60-70 rpm. Blood lactate was collected at baseline and immediately following the completion of six sprints in each set. At 20-s recovery intervals, peak power and total work were not significantly different between conditions during the ISCT (P > 0.05); but caffeine reduced 6.31% effort for mean power in Sprint 10 of the later stage, as well as an increased fatigue index and elevated blood lactate levels during the ISCT (P < 0.05). At 90-s recovery intervals, peak power, mean power, and total work under caffeine conditions were significantly higher than under placebo conditions during the ISCT (P < 0.05), but no differences were apparent in fatigue index and blood lactate levels (P > 0.05). In conclusion, caffeine ingestion may be ergolytic, affecting performance and fatigue development in the later stage during a prolonged and intermittent sprint test with a short recovery interval. However, caffeine produces an ergogenic effect in the initial stage of an intermittent sprint performance with a longer recovery interval.

  13. Virulent bacterial infection improves aversive learning performance in Drosophila melanogaster.

    PubMed

    Babin, Aurélie; Kolly, Sylvain; Kawecki, Tadeusz J

    2014-10-01

    Virulent infections are expected to impair learning ability, either as a direct consequence of stressed physiological state or as an adaptive response that minimizes diversion of energy from immune defense. This prediction has been well supported for mammals and bees. Here, we report an opposite result in Drosophila melanogaster. Using an odor-mechanical shock conditioning paradigm, we found that intestinal infection with bacterial pathogens Pseudomonas entomophila or Erwinia c. carotovora improved flies' learning performance after a 1h retention interval. Infection with P. entomophila (but not E. c. carotovora) also improved learning performance after 5 min retention. No effect on learning performance was detected for intestinal infections with an avirulent GacA mutant of P. entomophila or for virulent systemic (hemocoel) infection with E. c. carotovora. Assays of unconditioned responses to odorants and shock do not support a major role for changes in general responsiveness to stimuli in explaining the changes in learning performance, although differences in their specific salience for learning cannot be excluded. Our results demonstrate that the effects of pathogens on learning performance in insects are less predictable than suggested by previous studies, and support the notion that immune stress can sometimes boost cognitive abilities.

  14. Factors limiting anaerobic performance in adolescent males with cystic fibrosis.

    PubMed

    Boas, S R; Joswiak, M L; Nixon, P A; Fulton, J A; Orenstein, D M

    1996-03-01

    Forty-one adolescent males (11.1-18.3 yr) with cystic fibrosis (CF) and 37 healthy adolescent males (11.1-17.9 yr) performed a Wingate Anaerobic Test (WAnT). The group with CF was subdivided by sexual maturity, nutritional status, and degree of airway obstruction. The subjects with CF had lower absolute power outputs than the healthy controls [mean power in Watts (mean +/- SD): 350.2 +/- 135.9 vs 424.5 +/- 120.4, P < 0.001; peak power: 525.2 +/- 178.4 vs 665.9 +/- 191.3, P < 0.001). When absolute power was corrected for lean body mass, the subjects with CF had lower power outputs than the healthy controls (mean power in W.kg-1: 8.9 +/- 1.7 vs 9.6 +/- 0.9, P < 0.05; peak power: 13.4 +/- 2.1 vs 15.0 +/- 1.6, P < 0.05). The subgroup with CF with a higher body mass index (BMI > 17.5 kg.m-2) had higher peak and mean power output than subjects with CF with a lower BMI in both absolute power and when power was expressed per lean body mass. When sexual maturation was considered, subjects with CF with salivary testosterone greater than 4.0 ng.dl-1 had a higher mean and peak power in both absolute terms and relative to lean body mass than subjects with CF with salivary testosterone less than 4.0 ng.dl-1. Multiple regression analysis indicated that the nutritional factor accounted for 70%-80% of the variability in power output in the subjects with CF, while testosterone accounted for 10% of the variability. Pulmonary function was not a significant independent correlate of anaerobic power. Our results suggest that nutritional status, and to a lesser extent maturational factors, may play a more important role than pulmonary function in determining anaerobic fitness in male adolescents with CF.

  15. Impairment of Performance Variables After In-Season Strength-Training Cessation in Elite Cyclists.

    PubMed

    Rønnestad, Bent R; Hansen, Joar; Hollan, Ivana; Spencer, Matt; Ellefsen, Stian

    2016-09-01

    The current study investigated the effects of 8 wk of strength-training cessation after 25 wk of strength training on strength- and cycling-performance characteristics. Elite cyclists were randomly assigned to either 25 wk of endurance training combined with heavy strength training (EXP, n = 7, maximal oxygen uptake [V̇O2max] 77 ± 6 mL . kg(-1) . min(-1); 3 × 4-10 RM, 1 to 2 d/wk) or to endurance training only (CON, n = 7, V̇O2max 73 ± 5 mL . kg(-1) . min(-1)). Thereafter, both groups performed endurance training only for 8 wk, coinciding with the initial part of the competition season. Data were assessed for practical significance using magnitude-based inferences. During the 25-wk preparatory period, EXP had a larger positive impact on maximal isometric half-squat force, squat jump (SJ), maximal aerobic power (Wmax), power output at 4 mmol/L [La], and mean power in 30-s Wingate test than did CON (ES = 0.46-0.74). Conversely, during the 8-wk competition period EXP had a reduction in SJ, Wmax, and mean power in the 30-s Wingate test compared with CON (ES = 0.49-0.84). The present findings suggest rapid decline of adaptations on termination of strength training during the first 8 wk of the competition period in elite cyclists.

  16. Effects of eccentric overload bout on change of direction and performance in soccer players.

    PubMed

    de Hoyo, M; de la Torre, A; Pradas, F; Sañudo, B; Carrasco, L; Mateo-Cortes, J; Domínguez-Cobo, S; Fernandes, O; Gonzalo-Skok, O

    2015-04-01

    The aims of this study were to analyse the effects of eccentric overload training (EOT) on kinetic parameters during change of direction (COD) and performance related to sprinting and jumping abilities. 20 male soccer players performed 2 different protocols: 1) 5-min cycling warm-up and 2) 5-min cycling warm-up+YoYo half-squat exercise. The outcome measured included vertical ground reaction force (vGRF) and propulsive force (PvGRF), time to vGRF (T_vGRF) and propulsive force (T_PvGRF), contact time (CT), eccentric (ECC_IMP), concentric (CONC_IMP) and total (TOT_IMP) impulses and moments (Mx, My and Mz) during 2 COD tasks. Additionally, subjects performed a counter-movement jump (CMJ) and 20 m sprint tests. Results showed a substantial better improvement (likely to almost certainly) in vGRF (ES: 0.84), vAGRF (ES: 0.72), CT (ES: 0.48), My (ES: 0.35), Mz (ES: 0.44) and ECC_IMP (ES: 0.45) during crossover cutting maneuver, whereas during side-step cutting maneuver Time_ECC (ES: 0.68), CT (ES: 0.64), vGRF (ES: 0.48) and My (ES: 0.47) were substantially enhanced (likely). Furthermore, substantial better performance was found in CMJ (ES: 0.47; very likely) and 20 m (ES: 0.20; possibly). In conclusion, EOT produced a better muscle activation during 2 different COD tasks and greater sprinting and jumping performance.

  17. Enhanced charge transport and photovoltaic performance of PBDTTT-C-T/PC70BM solar cells via UV-ozone treatment.

    PubMed

    Adhikary, Prajwal; Venkatesan, Swaminathan; Adhikari, Nirmal; Maharjan, Purna P; Adebanjo, Olusegun; Chen, Jihua; Qiao, Qiquan

    2013-10-21

    In this work, the electron transport layer of PBDTTT-C-T/PC70BM polymer solar cells were subjected to UV-ozone treatment, leading to improved cell performances from 6.46% to 8.34%. The solar cell efficiency reached a maximum of 8.34% after an optimal 5 minute UV-ozone treatment, and then decreased if treated for a longer time. To the best of our knowledge, the mechanism behind the effects of UV-ozone treatment on the improvement of charge transport and cell performance is not fully understood. We have developed a fundamental understanding of the UV-ozone treatment mechanism, which explains both the enhancements in charge transport and photovoltaic performance at an optimal treatment time, and also the phenomenon whereby further treatment time leads to a drop in cell efficiency. Transient photocurrent measurements indicated that the cell charge transport times were 1370 ns, 770 ns, 832 ns, 867 ns, and 1150 ns for the 0 min, 5 min, 10 min, 15 min, and 20 min UV-ozone treatment times, respectively. Therefore the 5 min UV-ozone treatment time led to the shortest transport time and the most efficient charge transport in the cells. The 5 min UV-ozone treated sample exhibited the highest peak intensity (E2) in the Raman spectra of the treated films, at about 437 cm(-1), indicating that it possessed the best wurtzite phase crystallinity of the ZnO films. Further increasing the UV-ozone treatment time from 5 to 20 min induced the formation of p-type defects (e.g. interstitial oxygen atoms), pushing the ZnO Fermi-level further away from the vacuum level, and decreasing the wurtzite crystallinity.

  18. Towards high performance CoFe2O4 isotropic nanocrystalline powder for permanent magnet applications

    NASA Astrophysics Data System (ADS)

    Pedrosa, F. J.; Rial, J.; Golasinski, K. M.; Guzik, M. N.; Quesada, A.; Fernández, J. F.; Deledda, S.; Camarero, J.; Bollero, A.

    2016-11-01

    We report on a comparative study of high performance isotropic cobalt ferrite (CoFe2O4) powder processed by dry and surfactant assisted (wet) ball milling. Milling times as short as 1.5 min (dry) and 6 min (wet) have resulted in a 4-fold increase in coercivity, with a maximum achieved value above 318 kA/m (4 kOe). The use of surfactant is shown to be advantageous in the formation of a more homogeneous structure constituted by non-agglomerated and strained nanoparticles. A record (BH) max value of 18.6 kJ m - 3 (2.34 MGOe) has been obtained for isotropic powder after post-processing annealing. This magnetic performance combined with the required short processing times and the unnecessary requirement of oxygen avoidance in the milling process, makes this CoFe2O4 powder a good candidate for permanent magnet applications.

  19. Effect of sex on torque, recovery, EMG, and MMG responses to fatigue

    PubMed Central

    Hill, E.C.; Housh, T.J.; Smith, C.M.; Cochrane, K.C.; Jenkins, N.D.M.; Cramer, J.T.; Schmidt, R.J.; Johnson, G.O.

    2016-01-01

    Objective: The purpose of the present investigation was to examine the effect of sex on maximal voluntary isometric contraction (MVIC) torque and the EMG and MMG responses as a result of fatiguing, intermittent, submaximal (65% of MVIC), isometric elbow flexion muscle contractions. Methods: Eighteen men and women performed MVIC trials before (pretest), after (posttest), and 5-min after (5-min recovery) performing 50 intermittent, submaximal isometric muscle contractions. Surface electromyographic (EMG) and mechanomyographic (MMG) signals were simultaneously recorded from the biceps brachii muscle. Results: As a result of the fatiguing workbout torque decreased similarly from pretest to posttest for both the men (24.0%) and women (23.3%). After 5-min of recovery, torque had partially recovered for the men, while torque had returned to pretest levels for the women. For both sexes, from pretest to posttest EMG mean power frequency and MMG amplitude decreased, but returned to pretest levels after 5-min of recovery. Conclusions: In the present study, there were sex-related differences in muscle fatigue that were not associated with the EMG or MMG responses. PMID:27973383

  20. Effects of power variation on cycle performance during simulated hilly time-trials.

    PubMed

    Wells, Marc S; Marwood, Simon

    2016-11-01

    It has previously been shown that cyclists are unable to maintain a constant power output during cycle time-trials on hilly courses. The purpose of the present study is therefore to quantify these effects of power variation using a mathematical model of cycling performance. A hypothetical cyclist (body mass: 70 kg, bicycle mass: 10 kg) was studied using a mathematical model of cycling, which included the effects of acceleration. Performance was modelled over three hypothetical 40-km courses, comprising repeated 2.5-km sections of uphill and downhill with gradients of 1%, 3%, and 6%, respectively. Amplitude (5-15%) and distance (0.31-20.00 km) of variation were modelled over a range of mean power outputs (200-600 W) and compared to sustaining a constant power. Power variation was typically detrimental to performance; these effects were augmented as the amplitude of variation and severity of gradient increased. Varying power every 1.25 km was most detrimental to performance; at a mean power of 200 W, performance was impaired by 43.90 s (±15% variation, 6% gradient). However at the steepest gradients, the effect of power variation was relatively independent of the distance of variation. In contrast, varying power in parallel with changes in gradient improved performance by 188.89 s (±15% variation, 6% gradient) at 200 W. The present data demonstrate that during hilly time-trials, power variation that does not occur in parallel with changes in gradient is detrimental to performance, especially at steeper gradients. These adverse effects are substantially larger than those previously observed during flat, windless time-trials.

  1. Performance Improvement.

    ERIC Educational Resources Information Center

    1996

    This document contains four papers presented at a symposium on performance improvement moderated by Edward Schorer at the 1996 conference of the Academy of Human Resource Development (AHRD) "The Organizational Ecology of Ethical Problems: International Case Studies in the Light of HPT [Human Performance Technology]" (Peter J. Dean,…

  2. Pilot performance

    NASA Technical Reports Server (NTRS)

    Nicholls, Jennifer

    1988-01-01

    For many years, the emphasis has been placed on the performance of the aircraft, rather than on those who fly the aircraft. This is largely due to the relative safety of flying. Just in the last few years there have been several major accidents that have shown that flying is not quite as safe as it was thought to be. Sixty-five percent of these accidents are a result of pilot performance decrements, and so it is obvious that there is a need to reduce that figure. A study has been mandated to evaluate the performance of pilots. This includes workload, circadium rhythms, jet lag, and any other factors which might affect a pilot's performance in the cockpit. The purpose of this study is to find out when and why the decrement in a pilot's performance occur and how to remedy the situation.

  3. Device Performance

    SciTech Connect

    Not Available

    2006-06-01

    In the Device Performance group, within the National Center for Photovoltaic's Measurements and Characterization Division, we measure the performance of PV cells and modules with respect to standard reporting conditions--defined as a reference temperature (25 C), total irradiance (1000 Wm-2), and spectral irradiance distribution (IEC standard 60904-3). Typically, these are ''global'' reference conditions, but we can measure with respect to any reference set. To determine device performance, we conduct two general categories of measurements: spectral responsivity (SR) and current versus voltage (I-V). We usually perform these measurements using standard procedures, but we develop new procedures when required by new technologies. We also serve as an independent facility for verifying device performance for the entire PV community. We help the PV community solve its special measurement problems, giving advice on solar simulation, instrumentation for I-V measurements, reference cells, measurement procedures, and anomalous results. And we collaborate with researchers to analyze devices and materials.

  4. Performance tests.

    PubMed Central

    Wetherell, A

    1996-01-01

    This paper discusses the use of psychological performance tests to assess the effects of environmental stressors. The large number and the variety of performance tests are illustrated, and the differences between performance tests and other psychological tests are described in terms of their design, construction, use, and purpose. The stressor emphasis is on the effects of drugs since that is where most performance tests have found their main application, although other stressors, e.g., fatigue, toxic chemicals, are mentioned where appropriate. Diazepam is used as an example. There is no particular performance emphasis since the tests are intended to have wide applicability. However, vehicle-driving performance is discussed because it has been the subject of a great deal of research and is probably one of the most important areas of application. Performance tests are discussed in terms of the four main underlying models--factor analysis, general information processing, multiple resource and strategy models, and processing-stage models--and in terms of their psychometric properties--sensitivity, reliability, and content, criterion, construct, and face validity. Some test taxonomies are presented. Standardization is also discussed with reference to the reaction time, mathematical processing, memory search, spatial processing, unstable tracking, verbal processing, and dual task tests used in the AGARD STRES battery. Some comments on measurement strengths and appropriate study designs and methods are included. PMID:9182033

  5. The Performance of Performance Standards.

    ERIC Educational Resources Information Center

    Heckman, James J.; Heinrich, Carolyn; Smith, Jeffery

    2002-01-01

    A model demonstrating how performance incentives may encourage cream skimming (selecting participants with a high likelihood of success) was applied to data from 16 Job Training Partnership Act training centers. Short-term performance measures were weakly and perversely related to long-term impacts, but efficiency gains/losses from skimming were…

  6. Performance Support for Performance Analysis

    ERIC Educational Resources Information Center

    Schaffer, Scott; Douglas, Ian

    2004-01-01

    Over the past several years, there has been a shift in emphasis in many business, industry, government and military training organizations toward human performance technology or HPT (Rossett, 2002; Dean, 1995). This trend has required organizations to increase the human performance knowledge, skills, and abilities of the training workforce.…

  7. Part A: Assessing the performance of the COMFA outdoor thermal comfort model on subjects performing physical activity

    NASA Astrophysics Data System (ADS)

    Kenny, Natasha A.; Warland, Jon S.; Brown, Robert D.; Gillespie, Terry G.

    2009-09-01

    This study assessed the performance of the COMFA outdoor thermal comfort model on subjects performing moderate to vigorous physical activity. Field tests were conducted on 27 subjects performing 30 min of steady-state activity (walking, running, and cycling) in an outdoor environment. The predicted COMFA budgets were compared to the actual thermal sensation (ATS) votes provided by participants during each 5-min interval. The results revealed a normal distribution in the subjects’ ATS votes, with 82% of votes received in categories 0 (neutral) to +2 (warm). The ATS votes were significantly dependent upon sex, air temperature, short and long-wave radiation, wind speed, and metabolic activity rate. There was a significant positive correlation between the ATS and predicted budgets (Spearman’s rho = 0.574, P < 0.01). However, the predicted budgets did not display a normal distribution, and the model produced erroneous estimates of the heat and moisture exchange between the human body and the ambient environment in 6% of the cases.

  8. Match running performance fluctuations in elite soccer: indicative of fatigue, pacing or situational influences?

    PubMed

    Bradley, Paul S; Noakes, Timothy D

    2013-01-01

    The aims of this study were to: (1) quantify match running performance in 5-min periods to determine if players fatigue or modulate high-intensity running according to a pacing strategy, and (2) examine factors impacting high-intensity running such as score line, match importance and the introduction of substitutes. All players were analysed using a computerised tracking system. Maintaining 'high' levels of activity in the first half resulted in a 12% reduction (P < 0.01) in the second half for high-intensity running (effect size [ES]: 0.8), while no changes were observed in 'moderate' and 'low' groups (ES: 0.0-0.2). The 'high' group covered less (P < 0.01) high-intensity running in the initial 10-min of the second versus first half (ES: 0.6-0.7), but this was not observed in 'moderate' and 'low' groups (ES: 0.2-0.4). After the most intense periods, players demonstrated an 8% drop in high-intensity running (P < 0.05) compared to the match average (ES: 0.2) and this persisted for 5-min before recovering. Players covered similar high-intensity running distances in matches with differing score lines but position-specific trends indicated central defenders covered 17% less (P < 0.01) and attackers 15% more high-intensity running during matches that were heavily won versus lost (ES: 0.9). High-intensity running distances were comparable in matches of differing importance, but between-half trends indicated that only declines (P < 0.01) occurred in the second half of critical matches (ES: 0.2). Substitutes covered 15% more (P < 0.01) high-intensity running versus the same time period when completing a full match (ES: 0.5). The data demonstrate that high-intensity running in the second half is impacted by the activity of the first half and is reduced for 5-min after intense periods. High-intensity running is also influenced by score line and substitutions but not match importance. More research is warranted to establish if fluctuations in match running performance are

  9. Heavy strength training improves running and cycling performance following prolonged submaximal work in well-trained female athletes.

    PubMed

    Vikmoen, Olav; Rønnestad, Bent R; Ellefsen, Stian; Raastad, Truls

    2017-03-01

    The purpose of this study was to investigate the effects of adding heavy strength training to female duathletes' normal endurance training on both cycling and running performance. Nineteen well-trained female duathletes (VO2max cycling: 54 ± 3 ml∙kg(-1)∙min(-1), VO2max running: 53 ± 3 ml∙kg(-1)∙min(-1)) were randomly assigned to either normal endurance training (E, n = 8) or normal endurance training combined with strength training (E+S, n = 11). The strength training consisted of four lower body exercises [3 × 4-10 repetition maximum (RM)] twice a week for 11 weeks. Running and cycling performance were assessed using 5-min all-out tests, performed immediately after prolonged periods of submaximal work (3 h cycling or 1.5 h running). E+S increased 1RM in half squat (45 ± 22%) and lean mass in the legs (3.1 ± 4.0%) more than E Performance during the 5-min all-out test increased in both cycling (7.0 ± 4.5%) and running (4.7 ± 6.0%) in E+S, whereas no changes occurred in E The changes in running performance were different between groups. E+S reduced oxygen consumption and heart rate during the final 2 h of prolonged cycling, whereas no changes occurred in E No changes occurred during the prolonged running in any group. Adding strength training to normal endurance training in well-trained female duathletes improved both running and cycling performance when tested immediately after prolonged submaximal work.

  10. Engineering Performance

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Under Goddard Space Flight Center and Jet Propulsion Laboratory SBIR (Small Business Innovative Research) contracts, AST Engineering Services, Inc. developed a system engineering computer software tool to model how certain applications will affect a proposed system's performance. Quantitative System Engineering (QASE) evaluates system timing, capacity and availability. The system is used to predict performance of proposed real-time, aerospace systems, embedded systems, and/or scientific systems, as well as in support of NASA's EDOS (Earth Observing System (EOS) Data and Operations System) initiative.

  11. Noninvasive measurement of respiratory muscle performance after exhaustive endurance exercise.

    PubMed

    Perret, C; Pfeiffer, R; Boutellier, U; Wey, H M; Spengler, C M

    1999-08-01

    The use of noninvasive techniques to measure respiratory muscle performance after different types of endurance exercise has not been entirely successful, as the results have not consistently indicated diminished performance for similar types of exercise. The aim of the present study was 1) to compare different, noninvasive methods to assess respiratory muscle performance before and after an exhaustive cycling endurance test (which has previously been shown to induce diaphragmatic fatigue) and 2) to determine which of the tests best reflect published results of measurements of diaphragmatic fatigue. Twelve healthy subjects participated in the study and performed three different test series in a random order on three different days. These tests were performed before, and 5, 40 and 75 min after an exhausting task (a cycling endurance run at 85% of maximal oxygen uptake (V'O2,max)). The tests of the three test series were 1) breathing against a constant inspiratory resistance to task failure, 2) determination of 12-min sustained ventilatory capacity, and 3) spirometric and maximal inspiratory and expiratory mouth pressure measurements. The only measurement that was affected by exhaustive cycling was the time to task failure breathing against inspiratory resistance. It was significantly reduced from (mean+/-sD) 364+/-88 s before exercise to 219+/-122 s at 5 min after cessation of exercise. It is concluded that the constant-load resistive breathing test to task failure is the only noninvasive respiratory muscle performance test evaluated in this study which shows a decrease in respiratory muscle performance after exhaustive endurance exercise.

  12. Performance of zigzag corrugated furrows in Bolivia

    NASA Astrophysics Data System (ADS)

    Roldán Cañas, J.; Chipana, R.; Moreno-Pérez, M. F.; Chipana, G.

    2012-04-01

    In Bolivia, irrigation area is estimated in more than 250000 ha, being surface irrigation the most common method. In highland areas (Altiplano) and in interandean valleys, traditional and ancestral irrigation systems such as flood irrigation, contour furrows, zigzag corrugated furrows, suka kollus and irrigation by kanis, are the most important. In the case of very steep terrains and shallow soils, the zigzag corrugated irrigation method is very frequent. This irrigation method has been used for a long time but their low application efficiency and the shortage of water justify this work devoted to their characterization and to study their performance. The experimental study was conducted southeast of the city of La Paz in the community of Cebollino located at 2600 meters above sea level. Furrow characteristics vary in function of crop type and soil slope, so that the larger the slope the greater the separation between furrows. In our case, the crop chosen was the lettuce and the experimental plot had an area of 800 m2 with a slope ranging between 14 and 18%. Blocks of corrugated furrows were identified and experimental measures were made during each irrigation, once per week, in the central blocks to avoid border effects. To determine advance curves 15 stations were used spaced 18 m. At each station, advance and recession time and infiltration depth were measured. Inlet and outlet flow were controlled each 5 min. To calculate the reference evapotranspiration, the Hargraves-Samani equation was used. Due to the very high terrain slopes, the advance curve takes a linear form rather than the typical exponential form. This hinders the proper calculation of the parameters of the Kostiakov-Lewis equation used to determine the infiltrated depth values. The inlet flow range, along irrigation events, between 0.01 and 0.085 L/s due to the uncontrolled use of water in fields located upstream. The large variability of inflow flow difficult irrigation management especially in

  13. Good Performers

    ERIC Educational Resources Information Center

    Bennett, Bob

    2009-01-01

    Soaring energy prices and tightening school budgets don't mix well. In fact, millions of children across the United States are being educated in energy-leaking, unhealthful facilities in dire need of physical upgrade and systems modernization. Increasing numbers of K-12 districts and institutions of higher learning are turning to performance-based…

  14. Performing Resistance

    ERIC Educational Resources Information Center

    Garoian, Charles R.; Gaudelius, Yvonne M.

    2004-01-01

    Many contemporary artists, critical theorists, and educators challenge the cultural assumptions that are embedded in our understandings of technology and its relationship to art, the body, and human life. In this article, we discuss the performance artworks of osseus labyrint, Goat Island, and Guillermo Gomez-Pena, Roberto Sifuentes, and Juan…

  15. Acute antioxidant supplementation improves endurance performance in trained athletes.

    PubMed

    Bentley, David J; Dank, Steven; Coupland, Rory; Midgley, Adrian; Spence, Ian

    2012-01-01

    This study examined the acute effects of a single dose of an antioxidant (AO; Lactaway® containing pycnogenol) on time to fatigue (TTF). Nine trained cyclists [mean ± SD age 35 ± 10 yrs; body mass 71.6 ± 10.2 kg; VO2 peak 63 ± 11 ml/kg/min] performed on two separate occasions a continuous protocol of 5 min at 50% of peak power output (PPO), 8 min at 70% of PPO, and then cycled to fatigue at 95% PPO. Four hours prior to the exercise protocol, the subjects consumed the supplement or a placebo (counterbalanced, double blind protocol). Cyclists, on average, rode for 80 s more in the Lactaway trial than they did in the placebo trial. There was considerable evidence (chances ≥94.5%) for substantial positive treatment effects for TTF and the other performance-related variables (excluding [BLa] at 95% PPO). Other studies are necessary to confirm these results and identify the mechanisms underlying the observed effects.

  16. Postexercise cold-water immersion improves intermittent high-intensity exercise performance in normothermia.

    PubMed

    McCarthy, Avina; Mulligan, James; Egaña, Mikel

    2016-11-01

    A brief cold water immersion between 2 continuous high-intensity exercise bouts improves the performance of the latter compared with passive recovery in the heat. We investigated if this effect is apparent in normothermic conditions (∼19 °C), employing an intermittent high-intensity exercise designed to reflect the work performed at the high-intensity domain in team sports. Fifteen young active men completed 2 exhaustive cycling protocols (Ex1 and Ex2: 12 min at 85% ventilatory threshold (VT) and then an intermittent exercise alternating 30-s at 40% peak power (Ppeak) and 30 s at 90% Ppeak to exhaustion) separated by 15 min of (i) passive rest, (ii) 5-min cold-water immersion at 8 °C, and (iii) 10-min cold-water immersion at 8 °C. Core temperature, heart rate, rates of perceived exertion, and oxygen uptake kinetics were not different during Ex1 among conditions. Time to failure during the intermittent exercise was significantly (P < 0.05) longer during Ex2 following the 5- and 10-min cold-water immersions (7.2 ± 3.5 min and 7.3 ± 3.3 min, respectively) compared with passive rest (5.8 ± 3.1 min). Core temperature, heart rate, and rates of perceived exertion were significantly (P < 0.05) lower during most periods of Ex2 after both cold-water immersions compared with passive rest. The time constant of phase II oxygen uptake response during the 85% VT bout of Ex2 was not different among the 3 conditions. A postexercise, 5- to 10-min cold-water immersion increases subsequent intermittent high-intensity exercise compared with passive rest in normothermia due, at least in part, to reductions in core temperature, circulatory strain, and effort perception.

  17. Anaerobic energy provision does not limit Wingate exercise performance in endurance-trained cyclists.

    PubMed

    Calbet, J A L; De Paz, J A; Garatachea, N; Cabeza de Vaca, S; Chavarren, J

    2003-02-01

    The aim of this study was to evaluate the effects of severe acute hypoxia on exercise performance and metabolism during 30-s Wingate tests. Five endurance- (E) and five sprint- (S) trained track cyclists from the Spanish National Team performed 30-s Wingate tests in normoxia and hypoxia (inspired O(2) fraction = 0.10). Oxygen deficit was estimated from submaximal cycling economy tests by use of a nonlinear model. E cyclists showed higher maximal O(2) uptake than S (72 +/- 1 and 62 +/- 2 ml x kg(-1) x min(-1), P < 0.05). S cyclists achieved higher peak and mean power output, and 33% larger oxygen deficit than E (P < 0.05). During the Wingate test in normoxia, S relied more on anaerobic energy sources than E (P < 0.05); however, S showed a larger fatigue index in both conditions (P < 0.05). Compared with normoxia, hypoxia lowered O(2) uptake by 16% in E and S (P < 0.05). Peak power output, fatigue index, and exercise femoral vein blood lactate concentration were not altered by hypoxia in any group. Endurance cyclists, unlike S, maintained their mean power output in hypoxia by increasing their anaerobic energy production, as shown by 7% greater oxygen deficit and 11% higher postexercise lactate concentration. In conclusion, performance during 30-s Wingate tests in severe acute hypoxia is maintained or barely reduced owing to the enhancement of the anaerobic energy release. The effect of severe acute hypoxia on supramaximal exercise performance depends on training background.

  18. Effects of Early and Late Rest Intervals on Performance and Overnight Consolidation of a Keyboard Sequence

    ERIC Educational Resources Information Center

    Cash, Carla Davis

    2009-01-01

    Thirty-six nonmusicians practiced a five-element key-press sequence on a digital piano, repeating the sequence as quickly and accurately as possible during twelve 30-s practice blocks alternating with 30-s pauses. Twelve learners rested for 5 min between Blocks 3 and 4, another 12 learners rested for 5 min between Blocks 9 and 10, and the…

  19. Performance Testing

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Systems Technology, Inc., Hawthorne, CA, developed an electronic Critical Tracking Task (CTT) system that analyzes and rates a subject's visual/motor responses for Ames Research Center. Originally applied to measuring the effects of long term confinement in the mid 1960's, the CTT system is now marketed as FACTOR 1000 by Performance Factors, Inc. Alameda, CA, under a licensing agreement with Systems Technology. The system is a non-invasive, self-administered test that takes less than a minute and detects impairment from a broad range of causes, including stress, fatigue, illness, drugs, or alcohol. It is used daily by Old Town Trolley Tours, San Diego, CA, to assess each driver's physical coordination skills prior to the start of each shift. FACTOR 1000 reduces liabilities and costs related to accidents, and costs less than one dollar per day per employee. Performance Factors is now BioFactors, Inc.

  20. Magnetic molecularly imprinted polymer for the efficient and selective preconcentration of diazinon before its determination by high-performance liquid chromatography.

    PubMed

    Zare, Fahimeh; Ghaedi, Mehrorang; Daneshfar, Ali; Ostovan, Abbas

    2015-08-01

    A molecularly imprinted polymer was selectively applied for solid-phase extraction and diazinon residues enrichment before high-performance liquid chromatography. Diazinon was thermally copolymerized with Fe3 O4 @polyethyleneglycol nanoparticles, methacrylic acid (functional monomer), 2-hydroxyethyl methacrylate (co-monomer), and ethylene glycol dimethacrylate (cross-linking monomer) in the presence of acetonitrile (porogen) and 2,2-azobisisobutyronitrile (initiator). Then, the imprinted diazinon was reproducibly eluted with methanol/acetic acid (9:1, v/v). The sorbent particles were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The comprehensive study of variables through experimental design showed that the maximum performance was achieved under these conditions: pH 7, 10 mL sample volume, 15 mg sorbent, 10 min vortex time, 5 min ultrasonic time, 200 μL methanol/acetic acid (9:1, v/v) as eluent, and 5 min desorption time. Under optimized conditions, the molecularly imprinted polymer solid-phase extraction method demonstrated a linear range (0.02-5 g/mL), a correlation coefficient of 0.997, and 0.005 g/mL detection limit.

  1. Performance Assessment: Lessons from Performers

    ERIC Educational Resources Information Center

    Parkes, Kelly A.

    2010-01-01

    The performing arts studio is a highly complex learning setting, and assessing student outcomes relative to reliable and valid standards has presented challenges to this teaching and learning method. Building from the general international higher education literature, this article illustrates details, processes, and solutions, drawing on…

  2. Pay for Performance: Whose Performance?

    ERIC Educational Resources Information Center

    Tienken, Christopher H.

    2011-01-01

    Education reform proposals are not in short supply. Recent issues of the "Kappa Delta Pi Record" examined two of these: Common Core State Standards (Winter 2011) and Charter Schools (Spring 2011). Teacher pay for performance is another policy gaining traction in state legislatures and at the federal level. The Race to the Top (RTTT)…

  3. Prediction of sprint triathlon performance from laboratory tests.

    PubMed

    Van Schuylenbergh, R; Eynde, B Vanden; Hespel, P

    2004-01-01

    This study investigated whether sprint triathlon performance can be adequately predicted from laboratory tests. Ten triathletes [mean (SEM), age 21.8 (0.3) years, height 179 (2) cm, body mass 67.5 (2.5) kg] performed two graded maximal exercise test in random order, either on their own bicycle which was mounted on an ergometer or on a treadmill, to determine their peak oxygen consumption ( VO(2)peak). Furthermore, they participated in two to three 30-min constant-load tests in both swimming, cycling and running to establish their maximal lactate steady state (MLSS) in each exercise mode. Swim tests were performed in a 25-m swimming pool (water temperature 27 degrees C). During each test heart rate (HR), power output (PO) or running/swimming speed and blood lactate concentration (BLC) were recorded at regular intervals. Oxygen uptake ( VO(2)) was continuously measured during the graded tests. Two weeks after the laboratory tests all subjects competed in a triathlon race (500 m swim, 20-km bike, 5-km run) [1 h 4 min 45 s (1 min 38 s)]. Peak HR was 7 beats.min(-1) lower in the graded cycle test than in the treadmill test ( p<0.05) at similar peak BLC (approximately 10 mmol.l(-1)) and VO(2)peak (approximately 5 L.min(-1)). High correlations were found between VO(2)peak during cycling ( r=-0.71, p<0.05) or running ( r=-0.69, p<0.05) and triathlon performance. Stepwise multiple regression analysis showed that running speed and swimming speed at MLSS, together with BLC in running at MLSS, yielded the best prediction of performance [1 h 5 min 18 s (1 min 49 s)]. Thus, our data indicate that exercise tests aimed to determine MLSS in running and swimming allow for a precise estimation of sprint triathlon performance.

  4. Quantification of urinary uric acid in the presence of thymol and thimerosal by high-performance liquid chromatography

    NASA Technical Reports Server (NTRS)

    Chen, Y.; Pietrzyk, R. A.; Whitson, P. A.

    1997-01-01

    A high-performance liquid chromatographic method was developed as an alternative to automated enzymatic analysis of uric acid in human urine preserved with thymol and/or thimerosal. Uric acid (tR = 10 min) and creatinine (tR = 5 min) were separated and quantified during isocratic elution (0.025 M acetate buffer, pH 4.5) from a mu Bondapak C18 column. The uric-acid peak was identified chemically by incubating urine samples with uricase. The thymol/thimerosal peak appeared at 31 min during the washing step and did not interfere with the analysis. We validated the high-performance liquid chromatographic method for linearity, precision and accuracy, and the results were found to be excellent.

  5. Stress and its Impact on the Neurocognitive Performance of Australian Nurses.

    PubMed

    Lees, Ty; Lal, Sara

    2017-02-01

    Nurses function inside a particularly stressful occupation that requires the provision of continuous care to individuals who are often in great need. Stress has been shown to impair performance and specifically shown to impair nursing quality. However, we do not yet know how stress influences the cognitive performance of nurses, and hence, the present study investigated the associations between stress and cognitive performance in nurses using electroencephalography and administered cognitive assessments. Thirty-six nurses (34 women) of mean age 37.77 ± 11.40 years were recruited. Stress was examined using the Lifestyle Appraisal Questionnaire. Broad spectrum electroencephalogram activity at positions Fp1, Fp2, C3 and C4 was recorded for a 5-min baseline and active phase to physiologically assess cognitive performance. Additionally, the Mini-Mental State Exam and Cognistat were also used to measure cognitive performance. Assessed cognitive performance was not associated to stress, however, lifestyle factors, as well as a number of the examined cognitive electroencephalographic variables including changes in theta, alpha activity and gamma reactivity were. Definitively determining how stress affects the cognitive performance of nurses requires additional research; the present study forms a foundation from which future research can further expand the examination of stress exposure in nurses. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Effects of combined creatine and sodium bicarbonate supplementation on repeated sprint performance in trained men.

    PubMed

    Barber, James J; McDermott, Ann Y; McGaughey, Karen J; Olmstead, Jennifer D; Hagobian, Todd A

    2013-01-01

    Creatine and sodium bicarbonate supplementation independently increase exercise performance, but it remains unclear whether combining these 2 supplements is more beneficial on exercise performance. The purpose of this study was to evaluate the impact of combining creatine monohydrate and sodium bicarbonate supplementation on exercise performance. Thirteen healthy, trained men (21.1 ± 0.6 years, 23.5 ± 0.5 kg·m(-2), 66.7 ± 5.7 ml·(kg·m)(-1) completed 3 conditions in a double-blinded, crossover fashion: (a) Placebo (Pl; 20 g maltodextrin + 0.5 g·kg(-1) maltodextrin), (b) Creatine (Cr; 20 g + 0.5 g·kg(-1) maltodextrin), and (c) Creatine plus sodium bicarbonate (Cr + Sb; 20 g + 0.5 g·kg(-1) sodium bicarbonate). Each condition consisted of supplementation for 2 days followed by a 3-week washout. Peak power, mean power, relative peak power, and bicarbonate concentrations were assessed during six 10-second repeated Wingate sprint tests on a cycle ergometer with a 60-second rest period between each sprint. Compared with Pl, relative peak power was significantly higher in Cr (4%) and Cr + Sb (7%). Relative peak power was significantly lower in sprints 4-6, compared with that in sprint 1, in both Pl and Cr. However, in Cr + Sb, sprint 6 was the only sprint significantly lower compared with sprint 1. Pre-Wingate bicarbonate concentrations were significantly higher in Cr + Sb (10%), compared with in Pl and Cr, and mean concentrations remained higher after sprint 6, although not significantly. Combining creatine and sodium bicarbonate supplementation increased peak and mean power and had the greatest attenuation of decline in relative peak power over the 6 repeated sprints. These data suggest that combining these 2 supplements may be advantageous for athletes participating in high-intensity, intermittent exercise.

  7. Morning anaerobic performance is not altered by vigilance impairment.

    PubMed

    Lericollais, Romain; Gauthier, Antoine; Bessot, Nicolas; Zouabi, Amira; Davenne, Damien

    2013-01-01

    The aim of this study was to determine the role played by vigilance on the anaerobic performance recorded during a Wingate test performed at the bathyphase (nadir) of the circadian rhythmicity. Twenty active male participants performed a 60-s Wingate test at 6 a.m. during 3 test sessions in counter-balanced order the day after either (i) a normal reference night, (ii) a total sleep deprivation night, or (iii) a total sleep deprivation night associated with an extended simulated driving task from 9 p.m. to 5 a.m. During this task, the number of inappropriate line crossings (ILCs) was used to control and quantify the effective decrease in the level of vigilance. The main findings show that (i) vigilance of each participant was significantly altered (i.e., a drastic and progressive increase in ILCs is shown during the 7.5 hours of driving) by the sleep deprivation night associated with an extended driving task; (ii) the subjective evaluation of vigilance performed by self-rated scale revealed an increased impairment of the vigilance level between the normal reference night, the total sleep deprivation night and the total sleep deprivation night associated with an extended driving task; and (iii) the morning following this last condition, during the Wingate test, the recorded cycling biomechanical parameters (peak power, mean power and fatigue index values, power decrease, and cycling kinetic and kinematic patterns) were not significantly different from the two other conditions. Consequently, these results show that anaerobic performances recorded during a Wingate test performed at the bathyphase of the circadian rhythmicity are not altered by a drastic impairment in vigilance. These findings seem to indicate that vigilance is probably not a factor that contributes to circadian variations in anaerobic performance.

  8. Exercise Performance and Corticospinal Excitability during Action Observation

    PubMed Central

    Wrightson, James G.; Twomey, Rosie; Smeeton, Nicholas J.

    2016-01-01

    Purpose: Observation of a model performing fast exercise improves simultaneous exercise performance; however, the precise mechanism underpinning this effect is unknown. The aim of the present study was to investigate whether the speed of the observed exercise influenced both upper body exercise performance and the activation of a cortical action observation network (AON). Method: In Experiment 1, 10 participants completed a 5 km time trial on an arm-crank ergometer whilst observing a blank screen (no-video) and a model performing exercise at both a typical (i.e., individual mean cadence during baseline time trial) and 15% faster than typical speed. In Experiment 2, 11 participants performed arm crank exercise whilst observing exercise at typical speed, 15% slower and 15% faster than typical speed. In Experiment 3, 11 participants observed the typical, slow and fast exercise, and a no-video, whilst corticospinal excitability was assessed using transcranial magnetic stimulation. Results: In Experiment 1, performance time decreased and mean power increased, during observation of the fast exercise compared to the no-video condition. In Experiment 2, cadence and power increased during observation of the fast exercise compared to the typical speed exercise but there was no effect of observation of slow exercise on exercise behavior. In Experiment 3, observation of exercise increased corticospinal excitability; however, there was no difference between the exercise speeds. Conclusion: Observation of fast exercise improves simultaneous upper-body exercise performance. However, because there was no effect of exercise speed on corticospinal excitability, these results suggest that these improvements are not solely due to changes in the activity of the AON. PMID:27014037

  9. Effects of intermittent hypoxia training on exercise performance, hemodynamics, and ventilation in healthy senior men.

    PubMed

    Shatilo, Valeriy B; Korkushko, Oleg V; Ischuk, Vadim A; Downey, H Fred; Serebrovskaya, Tatiana V

    2008-01-01

    The efficacy and safety of intermittent hypoxia training (IHT) were investigated in healthy, 60- to 74-yr-old men. Fourteen men (Gr 1) who routinely exercised daily for 20 to 30 min were compared with 21 (Gr 2) who avoided exercise. Their submaximal work-load power values before the IHT training were 94 +/- 3.7 and 66 +/- 3.1, respectively. Before and after 10 days of IHT, the ventilatory response to sustained hypoxia (SH; 12% O(2) for 10 min), work capacity (bicycle ergometer), and forearm cutaneous perfusion (laser Doppler) were determined. During SH, no negative electrocardiogram (ECG) changes were observed in either group, and the ventilatory response to SH was unaltered by IHT. In Gr 1, IHT (normobaric rebreathing for 5 min, final Sa(O(2)) = 85% to 86%, followed by 5 min normoxia, 4/day) produced no changes in hemodynamic indixes and work capacity. In Gr 2, IHT decreased blood pressure (BP) by 7.9 +/- 3.1 mmHg (p < 0.05) and increased submaximal work by 11.3% (p < 0.05) and anaerobic threshold by 12.7% (p < 0.05). The increase in HR and BP caused by a 55 W-work load was reduced by 5% and 6.5%, respectively (p < 0.05). Cutaneous perfusion increased by 0.06 +/- 0.04 mL/min/100 g in Gr 1 and by 0.11 +/- 0.04 mL/min/100 g in Gr 2 (p < 0.05). Hyperemia recovery time increased significantly by 15.3 +/- 4.6 sec in Gr 1 and by 25.2 +/- 11.2 sec in Gr 2. Thus, healthy senior men well tolerate IHT as performed in this investigation. In untrained, healthy senior men, IHT had greater positive effects on hemodynamics, microvascular endothelial function, and work capacity.

  10. Effects of load on wingate test performances and reliability.

    PubMed

    Jaafar, Hamdi; Rouis, Majdi; Coudrat, Laure; Attiogbé, Elvis; Vandewalle, Henry; Driss, Tarak

    2014-12-01

    The purpose of this study was to examine the effects of 2 braking forces (8.7 and 11% of body mass, BM) on Wingate test performance, peak lactate ([La]pk), peak heart rate (HRpk), and rate of perceived exertion (RPE). Sixteen male physical education students (age: 22.7 ± 1.3 years, height: 1.81 ± 0.07 m, BM: 74.3 ± 9.6 kg) performed, in a randomized order, 2 Wingate tests at 8.7% BM and 2 Wingate tests at 11% BM on a Monark cycle ergometer on 4 separate sessions. The results showed that the reliability level of mechanical measures was not affected by the braking force and was relatively similar for each variable in both braking forces (0.886 < ICC < 0.985). In addition, peak power, mean power, fatigue slope, and RPE were significantly higher (8.2, 7.0, 11.9, and 4.1%, respectively, all < 0.05) using a braking force of 11% BM compared with 8.7% BM, whereas there was no significant effect of braking force on [La]pk and HRpk. In conclusion, the results of this study suggested that the reliability of the Wingate test does not depend on the used load, and a braking force of 11% BM is more optimal for power output during Wingate test in active adults.

  11. Effects of a selective sleep deprivation on subsequent anaerobic performance.

    PubMed

    Mougin, F; Bourdin, H; Simon-Rigaud, M L; Didier, J M; Toubin, G; Kantelip, J P

    1996-02-01

    The aim of the study was to investigate the effects of a partial sleep deprivation on a subsequent supramaximal exercise evaluated from the 30 second Wingate test, and on the following recovery. To take into account the active muscle mass, the Wingate test was performed against a constant braking force related to the data of a force-velocity test conducted on a Monark cycle ergometer (Model 814 E with weights) one week before the experimental test. Eight highly trained athletes were enrolled for this study. The changes in ventilatory and metabolic responses were analyzed during and upon completion of physical 30 second exercise, taking place after two nights, in other words, after a reference night and after a night with reduced sleep. Partial sleep deprivation was obtained by delaying bedtime until 3 a.m. The 30 second Wingate test was performed between 9 a.m. and noon the following days, using a Monark ergometer (Model 814 F). The analyses of change scores disclosed that there were no main significant effects for measures of ventilation, lactates and pH(v) levels under the two experimental conditions. The peak power, the mean power output and the peak velocity recorded after partial sleep deprivation were not modified in comparison with the values obtained after the reference night. These findings suggest that acute sleep loss did not contribute to alterations in supramaximal exercise.

  12. Acute Beetroot Juice Supplementation Does Not Improve Cycling Performance in Normoxia or Moderate Hypoxia.

    PubMed

    MacLeod, Kristin E; Nugent, Sean F; Barr, Susan I; Koehle, Michael S; Sporer, Benjamin C; MacInnis, Martin J

    2015-08-01

    Beetroot juice (BR) has been shown to lower the oxygen cost of exercise in normoxia and may have similar effects in hypoxia. We investigated the effect of BR on steady-state exercise economy and 10-km time trial (TT) performance in normoxia and moderate hypoxia (simulated altitude: ~2500 m). Eleven trained male cyclists (VO 2peak ≥ 60 ml · kg(-1) · min(-1)) completed four exercise trials. Two hours before exercise, subjects consumed 70 mL BR (~6 mmol nitrate) or placebo (nitrate-depleted BR) in a randomized, double-blind manner. Subjects then completed a 15-min self-selected cycling warm-up, a 15-min steady-state exercise bout at 50% maximum power output, and a 10-km time trial (TT) in either normoxia or hypoxia. Environmental conditions were randomized and single-blind. BR supplementation increased plasma nitrate concentration and fraction of exhaled nitric oxide relative to PL (p < .05 for both comparisons). Economy at 50% power output was similar in hypoxic and normoxic conditions (p > .05), but mean power output was greater in the normoxic TT relative to the hypoxic TT (p < .05). BR did not affect economy, steady-state SpO2, mean power output, or 10-km TT completion time relative to placebo in either normoxia or hypoxia (p > .05 in all comparisons). In conclusion, BR did not lower the oxygen cost of steady-state exercise or improve exercise performance in normoxia or hypoxia in a small sample of well-trained male cyclists.

  13. Effects of active vs. passive recovery on work performed during serial supramaximal exercise tests.

    PubMed

    Spierer, D K; Goldsmith, R; Baran, D A; Hryniewicz, K; Katz, S D

    2004-02-01

    The current investigation was undertaken to determine the effects of active versus passive recovery on work performance during repeated bouts of supramaximal exercise. Six healthy sedentary subjects and 9 moderately trained healthy hockey players performed serial 30-second Wingate anaerobic power tests (WAnT) on a bicycle ergometer interposed with 4 minutes of active recovery at a work rate corresponding to 28 % of VO(2)max or passive recovery at rest. Peak power, mean power, total work achieved, and fatigue index were calculated for the serial WAnT. Capillary blood lactate was determined at 5-minute intervals after the last WAnT during 30 minutes of active or passive recovery. Mean power was significantly greater during active recovery in sedentary subjects when compared with passive recovery (388 +/- 42 vs. 303 +/- 37 W, p < 0.05), but did not differ according to recovery mode in moderately trained hockey players (589 +/- 22 W active vs. 563 +/- 26 W passive, p = 0.14). Total work achieved significantly increased during active when compared with passive recovery in sedentary subjects (34 890 +/- 3768 vs. 27 260 +/- 3364 J, p < 0.02) and moderately trained hockey players (86 763 +/- 9151 vs. 75 357 +/- 8281 J, p < 0.05). Capillary blood lactate levels did not differ during active when compared with passive recovery in sedentary subjects but were significantly lower during active when compared with passive recovery in moderately trained hockey players. These data demonstrate that active recovery at a work rate corresponding to 28 % of VO(2)max increases total work achieved during repeated WAnT when compared with passive recovery in sedentary subjects and moderately trained hockey players.

  14. AMP deaminase deficiency is associated with lower sprint cycling performance in healthy subjects.

    PubMed

    Fischer, Heléne; Esbjörnsson, Mona; Sabina, Richard L; Strömberg, Anna; Peyrard-Janvid, Myriam; Norman, Barbara

    2007-07-01

    AMP deaminase (AMPD) deficiency is an inherited disorder of skeletal muscle found in approximately 2% of the Caucasian population. Although most AMPD-deficient individuals are asymptomatic, a small subset has exercise-related cramping and pain without any other identifiable neuromuscular complications. This heterogeneity has raised doubts about the physiological significance of AMPD in skeletal muscle, despite evidence for disrupted adenine nucleotide catabolism during exercise in deficient individuals. Previous studies have evaluated the effect of AMPD deficiency on exercise performance with mixed results. This study was designed to circumvent the perceived limitations in previous reports by measuring exercise performance during a 30-s Wingate test in 139 healthy, physically active subjects of both sexes, with different AMPD1 genotypes, including 12 AMPD-deficient subjects. Three of the deficient subjects were compound heterozygotes characterized by the common c.34C>T mutation in one allele and a newly discovered AMPD1 mutation, c.404delT, in the other. While there was no significant difference in peak power across AMPD1 genotypes, statistical analysis revealed a faster power decrease in the AMPD-deficient group and a difference in mean power across the genotypes (P = 0.0035). This divergence was most striking at 15 s of the 30-s cycling. Assessed by the fatigue index, the decrease in power output at 15 s of exercise was significantly greater in the deficient group compared with the other genotypes (P = 0.0006). The approximate 10% lower mean power in healthy AMPD-deficient subjects during a 30-s Wingate cycling test reveals a functional role for the AMPD1 enzyme in sprint exercise.

  15. Validity of the running anaerobic sprint test for assessing anaerobic power and predicting short-distance performances.

    PubMed

    Zagatto, Alessandro M; Beck, Wladimir R; Gobatto, Claudio A

    2009-09-01

    The purpose of this study was to investigate the reliability and validity of the running anaerobic sprint test (RAST) in anaerobic assessment and predicting short-distance performance. Forty members of the armed forces were recruited for this study (age 19.78 +/- 1.18 years; body mass 70.34 +/- 8.10 kg; height 1.76 +/- 0.53 m; body fat 15.30 +/- 5.65 %). The RAST test was applied to six 35-meter maximal running performances with a 10-second recovery between each run; the peak power, mean power, and the fatigue index were measured. The study was divided in two stages. The first stage investigated the reliability of the RAST using a test-retest method; the second stage aimed to evaluate the validity of the RAST comparing the results with the Wingate test and running performances of 35, 50, 100, 200, and 400 m. There were not significant differences between test-retest scores in the first stage of the study (p > 0.05) and were found significant correlations between these variables (intraclass correlation coefficient approximately = 0.88). The RAST had significant correlations with the Wingate test (peak power r = 0.46; mean power r = 0.53; fatigue index r = 0.63) and 35, 50, 100, 200, and 400 m performances scores (p < 0.05). The advantage of using the RAST for measuring anaerobic power is that it allows for the execution of movements more specific to sporting events that use running as the principal style of locomotion, is easily applied and low cost, and due to its simplicity can easily be incorporated into routine training. We concluded that this procedure is reliable and valid, and can be used to measure running anaerobic power and predict short-distance performances.

  16. Rapid weight loss followed by recovery time does not affect judo-related performance.

    PubMed

    Artioli, Guilherme G; Iglesias, Rodrigo T; Franchini, Emerson; Gualano, Bruno; Kashiwagura, Daniel B; Solis, Marina Y; Benatti, Fabiana B; Fuchs, Marina; Lancha Junior, Antonio H

    2010-01-01

    In this study, we investigated the effects of rapid weight loss followed by a 4-h recovery on judo-related performance. Seven weight-cycler athletes were assigned to a weight loss group (5% body weight reduction by self-selected regime) and seven non-weight-cyclers to a control group (no weight reduction). Body composition, performance, glucose, and lactate were assessed before and after weight reduction (5-7 days apart; control group kept weight stable). The weight loss group had 4 h to re-feed and rehydrate after the weigh-in. Food intake was recorded during the weight loss period and recovery after the weigh-in. Performance was evaluated through a specific judo exercise, followed by a 5-min judo combat and by three bouts of the Wingate test. Both groups significantly improved performance after the weight loss period. No interaction effects were observed. The energy and macronutrient intake of the weight loss group were significantly lower than for the control group. The weight loss group consumed large amounts of food and carbohydrate during the 4-h recovery period. No changes were observed in lactate concentration, but a significant decrease in glucose during rest was observed in the weight loss group. In conclusion, rapid weight loss did not affect judo-related performance in experienced weight-cyclers when the athletes had 4 h to recover. These results should not be extrapolated to inexperienced weight-cyclers.

  17. Sensitive and rapid high-performance liquid chromatography tandem mass spectrometry method for estimation of fulvestrant in rabbit plasma.

    PubMed

    Balaram, Varanasi Murali; Parmar, Dharmesh; Teja, Bulusu B; Rathnam, Shivprakash; Rao, Jangala Venkateswara; Dasandi, Bhavesh

    2010-08-01

    A rapid and sensitive high-performance liquid chromatography and electrospray tandem mass spectrometry method was developed and validated for estimation of fulvestrant in rabbit plasma using liquid-liquid extraction. The separation and quantification of fulvestrant were achieved by reverse-phase chromatography on a Sunfire C18 column (50 x 2.1. i.d., 3.5 microm) with isocratic elution at a flow rate of 300 microL/min using norethistrone as an internal standard from 500 microL plasma sample. The method was validated over the concentration range from 0.092 to 16.937 ng/mL with a lower limit of detection of 0.023 ng/mL. The intra-day and inter-day accuracy and precision were within 10%. The recovery was 85 and 90% for fulvestrant and norethistrone respectively. The chromatographic run time was only 2.5 min.

  18. Comparison of coagulation performance and floc properties of a novel zirconium-glycine complex coagulant with traditional coagulants.

    PubMed

    Zhang, Zhilin; Wu, Chunde; Wu, Yue; Hu, Caixia

    2014-05-01

    A new inorganic-organic hybrid material zirconium-glycine complex (ZGC) was firstly used as a coagulant in a coagulation process to treat Pearl River raw water. Its coagulation performance was compared with commonly used aluminum (Al) coagulants such as aluminum sulfate (Al2(SO4)3) and polyaluminum chloride (PAC), in terms of water quality parameters and floc properties. ZGC coagulation achieved higher removal of turbidity (93.8%) than other traditional coagulants. Charge neutralization was proven to act as a dominant mechanism during ZGC coagulation. The aggregated flocs with ZGC showed the fastest growth rate and good recovery ability compared with the other coagulants and achieved the largest floc size within 5 min. The ZGC coagulant can decrease the hydraulic retention time and increase removal efficiency.

  19. A new physical performance classification system for elite handball players: cluster analysis.

    PubMed

    Bautista, Iker J; Chirosa, Ignacio J; Robinson, Joseph E; van der Tillaar, Roland; Chirosa, Luis J; Martín, Isidoro Martínez

    2016-06-01

    The aim of the present study was to identify different cluster groups of handball players according to their physical performance level assessed in a series of physical assessments, which could then be used to design a training program based on individual strengths and weaknesses, and to determine which of these variables best identified elite performance in a group of under-19 [U19] national level handball players. Players of the U19 National Handball team (n=16) performed a set of tests to determine: 10 m (ST10) and 20 m (ST20) sprint time, ball release velocity (BRv), countermovement jump (CMJ) height and squat jump (SJ) height. All players also performed an incremental-load bench press test to determine the 1 repetition maximum (1RMest), the load corresponding to maximum mean power (LoadMP), the mean propulsive phase power at LoadMP (PMPPMP) and the peak power at LoadMP (PPEAKMP). Cluster analyses of the test results generated four groupings of players. The variables best able to discriminate physical performance were BRv, ST20, 1RMest, PPEAKMP and PMPPMP. These variables could help coaches identify talent or monitor the physical performance of athletes in their team. Each cluster of players has a particular weakness related to physical performance and therefore, the cluster results can be applied to a specific training programmed based on individual needs.

  20. A new physical performance classification system for elite handball players: cluster analysis

    PubMed Central

    Chirosa, Ignacio J.; Robinson, Joseph E.; van der Tillaar, Roland; Chirosa, Luis J.; Martín, Isidoro Martínez

    2016-01-01

    Abstract The aim of the present study was to identify different cluster groups of handball players according to their physical performance level assessed in a series of physical assessments, which could then be used to design a training program based on individual strengths and weaknesses, and to determine which of these variables best identified elite performance in a group of under-19 [U19] national level handball players. Players of the U19 National Handball team (n=16) performed a set of tests to determine: 10 m (ST10) and 20 m (ST20) sprint time, ball release velocity (BRv), countermovement jump (CMJ) height and squat jump (SJ) height. All players also performed an incremental-load bench press test to determine the 1 repetition maximum (1RMest), the load corresponding to maximum mean power (LoadMP), the mean propulsive phase power at LoadMP (PMPPMP) and the peak power at LoadMP (PPEAKMP). Cluster analyses of the test results generated four groupings of players. The variables best able to discriminate physical performance were BRv, ST20, 1RMest, PPEAKMP and PMPPMP. These variables could help coaches identify talent or monitor the physical performance of athletes in their team. Each cluster of players has a particular weakness related to physical performance and therefore, the cluster results can be applied to a specific training programmed based on individual needs. PMID:28149376

  1. On Using a Pilot Sample Variance for Sample Size Determination in the Detection of Differences between Two Means: Power Consideration

    ERIC Educational Resources Information Center

    Shieh, Gwowen

    2013-01-01

    The a priori determination of a proper sample size necessary to achieve some specified power is an important problem encountered frequently in practical studies. To establish the needed sample size for a two-sample "t" test, researchers may conduct the power analysis by specifying scientifically important values as the underlying population means…

  2. High-resolution high-performance liquid chromatography with electrospray ionization mass spectrometry and tandem mass spectrometry characterization of a new isoform of human salivary acidic proline-rich proteins named Roma-Boston Ser22(Phos) → Phe variant

    PubMed Central

    Iavarone, Federica; D’Alessandro, Alfredo; Tian, Na; Cabras, Tiziana; Messana, Irene; Helmerhorst, Eva J.; Oppenheim, Frank G.; Castagnola, Massimo

    2015-01-01

    During a survey of human saliva by a top-down reversed-phase high-performance liquid chromatography with electrospray ionization mass spectrometry approach, two proteins eluting at 27.4 and 28.4 min, with average masses of 15 494 ± 1 and 11 142 ± 1 Da, were detected in a subject from Boston. The Δmass value (4352 Da) of the two proteins was similar to the difference in mass values between intact (150 amino acids, [a.a.]) and truncated acidic proline-rich proteins (aPRPs; 106 a.a.) suggesting an a.a. substitution in the first 106 residues resulting in a strong reduction in polarity, since under the same experimental conditions aPRPs eluted at ~22.5 min (intact) and 23.5 min (truncated forms). Manual inspection of the high-resolution high-performance liquid chromatography with electrospray ionization tandem mass spectra of the truncated isoform showed the replacement of the phosphorylated Ser-22 in PRP-3 with a Phe residue. Inspection of the tandem mass spectra of the intact isoform confirmed the substitution, which is allowed by the code transition TCT→TTT and is in agreement with the dramatic increase in elution time. The isoform was also detected in two other subjects, one from Boston (unrelated to the previous) and one from Rome. For this reason we propose to name this variant PRP-1 (PRP-3) RB (Roma-Boston) Ser22(phos)→Phe. PMID:24771659

  3. Caffeine and 3-km cycling performance: Effects of mouth rinsing, genotype, and time of day.

    PubMed

    Pataky, M W; Womack, C J; Saunders, M J; Goffe, J L; D'Lugos, A C; El-Sohemy, A; Luden, N D

    2016-06-01

    We assessed the efficacy of caffeine mouth rinsing on 3-km cycling performance and determined whether caffeine mouth rinsing affects performance gains influenced by the CYP1A2 polymorphism. Thirty-eight recreational cyclists completed four simulated 3-km time trials (TT). Subjects ingested either 6 mg/kg BW of caffeine or placebo 1 h prior to each TT. Additionally, 25 mL of 1.14% caffeine or placebo solution were mouth rinsed before each TT. The treatments were Placebo, caffeine Ingestion, caffeine Rinse and Ingestion+Rinse. Subjects were genotyped and classified as AA homozygotes or AC heterozygotes for the rs762551 polymorphism of the CYP1A2 gene involved in caffeine metabolism. Magnitude-based inferences were used to evaluate treatment differences in mean power output based on a predetermined meaningful treatment effect of 1.0%. AC heterozygotes (4.1%) and AA homozygotes (3.4%) benefited from Ingestion+Rinse, but only AC performed better with Ingestion (6.0%). Additionally, Rinse and Ingestion+Rinse elicited better performance relative to Placebo among subjects that performed prior to 10:00 h (Early) compared with after 10:00 h (Late). The present study provides additional evidence of genotype and time of day factors that affect the ergogenic value of caffeine intake that may allow for more personalized caffeine intake strategies to maximize performance.

  4. 10 weeks of heavy strength training improves performance-related measurements in elite cyclists.

    PubMed

    Rønnestad, Bent R; Hansen, Joar; Nygaard, Håvard

    2016-08-02

    Elite cyclists have often a limited period of time available during their short preparation phase to focus on development of maximal strength; therefore, the purpose of the present study was to investigate the effect of 10-week heavy strength training on lean lower-body mass, leg strength, determinants of cycling performance and cycling performance in elite cyclists. Twelve cyclists performed heavy strength training and normal endurance training (E&S) while 8 other cyclists performed normal endurance training only (E). Following the intervention period E&S had a larger increase in maximal isometric half squat, mean power output during a 30-s Wingate sprint (P < 0.05) and a tendency towards larger improvement in power output at 4 mmol ∙ L(-1) [la(-)] than E (P = 0.068). There were no significant difference between E&S and E in changes in 40-min all-out trial (4 ± 6% vs. -1 ± 6%, respectively, P = 0.13). These beneficial effects may encourage elite cyclists to perform heavy strength training and the short period of only 10 weeks should make it executable even in the compressed training and competition schedule of elite cyclists.

  5. Physiological responses to 1000-m ergometer time-trial performance in outrigger canoeing.

    PubMed

    Kerr, Rebecca; Spinks, Warwick; Leicht, Anthony; Sinclair, Wade; Woodside, Louise

    2008-09-01

    Graded exercise tests are commonly used to assess peak physiological capacities of athletes. However, unlike time trials, these tests do not provide performance information. The aim of this study was to examine the peak physiological responses of female outrigger canoeists to a 1000-m ergometer time trial and compare the time-trial performance to two graded exercise tests performed at increments of 7.5 W each minute and 15 W each two minutes respectively. 17 trained female outrigger canoeists completed the time trial on an outrigger canoe ergometer with heart rate (HR), stroke rate, power output, and oxygen consumption (VO2) determined every 15 s. The mean (+/- s) time-trial time was 359 +/- 33 s, with a mean power output of 65 +/- 16 W and mean stroke rate of 56 +/- 4 strokes min(-1). Mean values for peak VO2, peak heart rate, and mean heart rate were 3.17 +/- 0.67 litres min(-1), 177 +/- 11 beats min(-1), and 164 +/- 12 beats min(-1) respectively. Compared with the graded exercise tests, the time-trial elicited similar values for peak heart rate, peak power output, peak blood lactate concentration, and peak VO2. As a time trial is sport-specific and can simultaneously quantify sprint performance and peak physiological responses in outrigger canoeing, it is suggested that a time trial be used by coaches for crew selection as it doubles as a reliable performance measure and a protocol for monitoring peak aerobic capacity of female outrigger canoeists.

  6. Effects of Acute Beta-Alanine Supplementation on Anaerobic Performance in Trained Female Cyclists.

    PubMed

    Glenn, Jordan M; Smith, Keyona; Moyen, Nicole E; Binns, Ashley; Gray, Michelle

    2015-01-01

    Longitudinal beta-alanine (BA) supplementation can improve exercise performance in males through increases in carnosine; however, females experience greater relative increases in carnosine compared to males. This potentially allows females to benefit from acute BA doses; however, effects of an acute BA dose on performance in females remain unknown. The purpose of this investigation was to evaluate how an acute dose of 1.6 g BA affects anaerobic performance in female cyclists. Twelve females (age=26.6±1.3 y) volunteered to participate in this randomized, double-blind study. All participants completed two supplement trials: 1) Placebo=34 g dextrose and 2) BA=1.6 g BA + 34 g dextrose. Thirty-minutes after supplementation, participants performed three repeated Wingate cycling tests with 2 min of active rest after each. Fatigue index, mean power, and peak power were measured during each Wingate. Lactate, heart rate, and rating of perceived exertion (RPE) were measured at rest, immediately after each Wingate, and after each active rest period. RPE significantly decreased (p<0.001) immediately following Wingates 1 and 2 and after each 2-min rest period for the BA trials; however, no differences were observed immediately after Wingate 3 (p>0.05). No significant supplementation effect was observed for any performance or physiological variable (p>0.05 for all variables). Findings suggest that an acute dose of BA (1.6 g) decreases RPE during anaerobic power activities in trained female cyclists.

  7. C₁₈-bound porous silica monolith particles as a low-cost high-performance liquid chromatography stationary phase with an excellent chromatographic performance.

    PubMed

    Ali, Faiz; Cheong, Won Jo

    2014-12-01

    Ground porous silica monolith particles with an average particle size of 2.34 μm and large pores (363 Å) exhibiting excellent chromatographic performance have been synthesized on a relatively large scale by a sophisticated sol-gel procedure. The particle size distribution was rather broad, and the d(0.1)/d(0.9) ratio was 0.14. The resultant silica monolith particles were chemically modified with chlorodimethyloctadecylsilane and end-capped with a mixture of hexamethyldisilazane and chlorotrimethylsilane. Very good separation efficiency (185,000/m) and chromatographic resolution were achieved when the C18 -bound phase was evaluated for a test mixture of five benzene derivatives after packing in a stainless-steel column (1.0 mm × 150 mm). The optimized elution conditions were found to be 70:30 v/v acetonitrile/water with 0.1% trifluoroacetic acid at a flow rate of 25 μL/min. The column was also evaluated for fast analysis at a flow rate of 100 μL/min, and all the five analytes were eluted within 3.5 min with reasonable efficiency (ca. 60,000/m) and resolution. The strategy of using particles with reduced particle size and large pores (363 Å) combined with C18 modification in addition to partial-monolithic architecture has resulted in a useful stationary phase (C18 -bound silica monolith particles) of low production cost showing excellent chromatographic performance.

  8. Greater volumes of static and dynamic stretching within a warm-up do not impair star excursion balance performance.

    PubMed

    Belkhiria-Turki, L; Chaouachi, A; Turki, O; Hammami, R; Chtara, M; Amri, M; Drinkwater, E J; Behm, D G

    2014-06-01

    Based on the conflicting static stretching (SS) literature and lack of dynamic stretching (DS) literature regarding the effects of differing volumes of stretching on balance, the present study investigated the effects of 4, 8, and 12 sets of SS and DS following a 5 min aerobic running warm-up on the star excursion balance test (SEBT). The objective was to examine an optimal stretch modality and volume to enhance dynamic balance. A randomized, within-subjects experimental design with repeated measures for stretching (SS and DS) versus no-stretching treatment was used to examine the acute effects of 10 (4 sets), 20 (8 sets), and 30 (12 sets) min, of 15s repetitions per muscle of SS and/or DS following a 5 min aerobic warm-up on the performance of the SEBT. Results indicated that a warm-up employing either SS or DS of any volume generally improves SEBT by a "small" amount with effect sizes ranging from 0.06 to 0.50 (11 of 18 conditions>75% likely to exceed the 1.3-1.9% smallest worthwhile change). Secondly, the difference between static and dynamic warm-up on this observed improvement with warm-up improvement was "trivial" to "moderate" (d=0.04 to 0.57) and generally "unclear" (only two of nine conditions>75% likely to exceed the smallest worthwhile change). Finally, the effect of increasing the volume of warm-up on the observed improvement with a warm-up is "trivial" to "small" (d<0.40) and generally "unclear" (only three of 12 conditions>75% likely to exceed the smallest worthwhile change). In summary, an aerobic running warm-up with stretching that increases core and muscle temperature whether it involves SS or DS may be expected to provide small improvements in the SEBT.

  9. The effect of including a series of isometric conditioning contractions to the rowing warm-up on 1,000-m rowing ergometer time trial performance.

    PubMed

    Feros, Simon A; Young, Warren B; Rice, Anthony J; Talpey, Scott W

    2012-12-01

    Rowing requires strength, power, and strength-endurance for optimal performance. A rowing-based warm-up could be enhanced by exploiting the postactivation potentiation (PAP) phenomenon, acutely enhancing power output at the beginning of a race where it is needed most. Minimal research has investigated the effects of PAP on events of longer duration (i.e. 1,000-m rowing). The purpose of this research was to investigate the effects of PAP on 1,000-m rowing ergometer performance through the use of 2 different warm-up procedures: (a) a rowing warm-up combined with a series of isometric conditioning contractions, known as the potentiated warm-up (PW), and (b) a rowing warm-up only (NW). The isometric conditioning contractions in the PW were performed by "pulling" an immovable handle on the rowing ergometer, consisting of 5 sets of 5 seconds (2 seconds at submaximal intensity, and 3 seconds at maximal intensity), with a 15-second recovery between sets. The 1,000-m rowing ergometer time trial was performed after each warm-up condition, whereby mean power output, mean stroke rate, and split time were assessed every 100 m. Ten Australian national level rowers served as the subjects and performed both conditions in a counterbalanced order on separate days. The PW reduced 1,000-m time by 0.8% (p > 0.05). The PW improved mean power output by 6.6% (p < 0.01) and mean stroke rate by 5.2% (p < 0.01) over the first 500 m; resulting in a reduction of 500-m time by 1.9% (p < 0.01), compared with the NW. It appears that the inclusion of isometric conditioning contractions to the rowing warm-up enhance short-term rowing ergometer performance (especially at the start of a race) to a greater extent than a rowing warm-up alone.

  10. Substrate Utilization and Cycling Performance Following Palatinose™ Ingestion: A Randomized, Double-Blind, Controlled Trial.

    PubMed

    König, Daniel; Zdzieblik, Denise; Holz, Anja; Theis, Stephan; Gollhofer, Albert

    2016-06-23

    (1) OBJECTIVE: To compare the effects of isomaltulose (Palatinose™, PSE) vs. maltodextrin (MDX) ingestion on substrate utilization during endurance exercise and subsequent time trial performance; (2) METHODS: 20 male athletes performed two experimental trials with ingestion of either 75 g PSE or MDX 45 min before the start of exercise. The exercise protocol consisted of 90 min cycling (60% VO₂max) followed by a time trial; (3) RESULTS: Time trial finishing time (-2.7%, 90% CI: ±3.0%, 89% likely beneficial; p = 0.147) and power output during the final 5 min (+4.6%, 90% CI: ±4.0%, 93% likely beneficial; p = 0.053) were improved with PSE compared with MDX. The blood glucose profile differed between trials (p = 0.013) with PSE resulting in lower glycemia during rest (95%-99% likelihood) and higher blood glucose concentrations during exercise (63%-86% likelihood). In comparison to MDX, fat oxidation was higher (88%-99% likelihood; p = 0.005) and carbohydrate oxidation was lower following PSE intake (85%-96% likelihood; p = 0.002). (4) CONCLUSION: PSE maintained a more stable blood glucose profile and higher fat oxidation during exercise which resulted in improved cycling performance compared with MDX. These results could be explained by the slower availability and the low-glycemic properties of Palatinose™ allowing a greater reliance on fat oxidation and sparing of glycogen during the initial endurance exercise.

  11. Substrate Utilization and Cycling Performance Following Palatinose™ Ingestion: A Randomized, Double-Blind, Controlled Trial

    PubMed Central

    König, Daniel; Zdzieblik, Denise; Holz, Anja; Theis, Stephan; Gollhofer, Albert

    2016-01-01

    (1) Objective: To compare the effects of isomaltulose (Palatinose™, PSE) vs. maltodextrin (MDX) ingestion on substrate utilization during endurance exercise and subsequent time trial performance; (2) Methods: 20 male athletes performed two experimental trials with ingestion of either 75 g PSE or MDX 45 min before the start of exercise. The exercise protocol consisted of 90 min cycling (60% VO2max) followed by a time trial; (3) Results: Time trial finishing time (−2.7%, 90% CI: ±3.0%, 89% likely beneficial; p = 0.147) and power output during the final 5 min (+4.6%, 90% CI: ±4.0%, 93% likely beneficial; p = 0.053) were improved with PSE compared with MDX. The blood glucose profile differed between trials (p = 0.013) with PSE resulting in lower glycemia during rest (95%–99% likelihood) and higher blood glucose concentrations during exercise (63%–86% likelihood). In comparison to MDX, fat oxidation was higher (88%–99% likelihood; p = 0.005) and carbohydrate oxidation was lower following PSE intake (85%–96% likelihood; p = 0.002). (4) Conclusion: PSE maintained a more stable blood glucose profile and higher fat oxidation during exercise which resulted in improved cycling performance compared with MDX. These results could be explained by the slower availability and the low-glycemic properties of Palatinose™ allowing a greater reliance on fat oxidation and sparing of glycogen during the initial endurance exercise. PMID:27347996

  12. Performance Monitoring Based on UML Performance Profile

    NASA Astrophysics Data System (ADS)

    Kim, Dong Kwan; Kim, Chul Jin; Cho, Eun Sook

    In this paper we propose a way of measuring software performance metrics such as response time, throughput, and resource utilization. It is obvious that performance-related Quality of Service (QoS) is one of the important factors which are satisfied for users' needs. The proposed approach uses UML performance profile for the performance specification and aspect-oriented paradigm for the performance measurement. Code instrumentation in AOP is a mechanism to insert source code for performance measurement into business logic code. We used AspectJ, an aspect-oriented extension to the Java. AspectJ code for performance measurement is separated from Java code for functional requirements. Both AspectJ and Java code can be woven together for the performance measurement. The key component of the proposed approach is an AspectJ code generator. It creates AspectJ code for the performance measurement from the UML [1] models containing performance profile.

  13. Performance and physiological responses to repeated-sprint exercise: a novel multiple-set approach.

    PubMed

    Serpiello, Fabio R; McKenna, Michael J; Stepto, Nigel K; Bishop, David J; Aughey, Robert J

    2011-04-01

    We investigated the acute and chronic responses to multiple sets of repeated-sprint exercise (RSE), focusing on changes in acceleration, intermittent running capacity and physiological responses. Ten healthy young adults (7 males, 3 females) performed an incremental test, a Yo-Yo intermittent recovery test level1 (Yo-Yo IR1), and one session of RSE. RSE comprised three sets of 5 × 4-s maximal sprints on a non-motorised treadmill, with 20 s of passive recovery between repetitions and 4.5 min of passive recovery between sets. After ten repeated-sprint training sessions, participants repeated all tests. During RSE, performance was determined by measuring acceleration, mean and peak power/velocity. Recovery heart rate (HR), HR variability, and finger-tip capillary lactate concentration ([Lac(-)]) were measured. Performance progressively decreased across the three sets of RSE, with the indices of repeated-sprint ability being impaired to a different extent before and after training. Training induced a significant increase (p < 0.05) in all indices of performance, particularly acceleration (21.9, 14.7 and 15.2% during sets 1, 2 and 3, respectively). Training significantly increased Yo-Yo IR1 performance by 8% and decreased Δ[Lac(-)]/work ratio (-15.2, -15.5, -9.4% during sets 1, 2 and 3, respectively) and recovery HR during RSE. There were strong correlations between Yo-Yo IR1 performance and indices of RSE performance, especially acceleration post-training (r = 0.88, p = 0.004). Repeated-sprint training, comprising only 10 min of exercise overall, effectively improved performance during multiple-set RSE. This exercise model better reflects team-sport activities than single-set RSE. The rapid training-induced improvement in acceleration, quantified here for the first time, has wide applications for professional and recreational sport activities.

  14. Simulated rugby performance at 1550-m altitude following adaptation to intermittent normobaric hypoxia.

    PubMed

    Hamlin, Michael J; Hinckson, Erica A; Wood, Matthew R; Hopkins, Will G

    2008-11-01

    Team-sport athletes who normally reside at sea level occasionally play games at altitudes sufficient to impair endurance performance. To investigate the effect of intermittent normobaric hypoxic exposure on performance in generic and game-specific tests at altitude, 22 senior club level rugby players performed baseline tests before single-blind random assignment to one of three groups: hypoxia-altitude (n=9), normoxia-altitude (n=6), and normoxia-sea level (n=7). The hypoxia-altitude group underwent 9-13 sessions of intermittent hypoxic exposure (concentration of inspired oxygen=13-10%) over 15 days, then repeated the performance tests within 12h of travelling to 1550m. The normoxia-altitude group underwent placebo exposures by breathing room air before repeating the tests at altitude, whereas the normoxia-sea level group underwent placebo exposures before repeating the tests at sea level. Hypoxic exposure consisted of alternately breathing 6min hypoxic gas and 4min ambient air for 1h at rest. Performance measures gathered at each testing session were maximum speed, sub-maximum heart-rate speed and sub-maximum lactate speed during a 20-m incremental running test, mean time in six 70-m sprints, repetitive explosive power and other measures from seven 5.5-min circuits of a rugby simulation. Repetitive explosive power ( approximately -16%) and 20-m shuttle performance ( approximately -3%) decreased substantially at altitude compared to sea level. Acclimatisation to hypoxia had a beneficial effect on sub-maximum heart rate and lactate speed but little effect on other performance measures. In conclusion, 1550-m altitude substantially impaired some measures of performance and the effects of prior adaptation via 9-13 sessions of intermittent hypoxia were mostly unclear.

  15. Asserting Performance Expectations (Formerly Performance Assertions: A Performance Diagnosis Tool)

    SciTech Connect

    Vetter, J S; Worley, P

    2002-07-24

    Traditional techniques for performance analysis provide a means for extracting and analyzing raw performance information from applications. Users then reason about and compare this raw performance data to their performance expectations for important application constructs. This comparison can be tedious, difficult, and error-prone for the scale and complexity of today's architectures and software systems. To address this situation, we present a methodology and prototype that allows users to assert performance expectations explicitly in their source code using performance assertions. As the application executes, each performance assertion in the application collects data implicitly to verify the assertion. By allowing the user to specify a performance expectation with individual code segments, the runtime system can jettison raw data for measurements that pass their expectation, while reacting to failures with a variety of responses. We present several compelling uses of performance assertions with our operational prototype including raising a performance exception, validating a performance model, and adapting an algorithm to an architecture empirically at runtime.

  16. Analysis of performance of prepubertal swimmers assessed from anthropometric and bio-energetic characteristics.

    PubMed

    Duché, P; Falgairette, G; Bedu, M; Lac, G; Robert, A; Coudert, J

    1993-01-01

    The relationship between anthropometric and bio-energetic data and timed performance over 50 to 400 m was studied in 25 young male swimmers [11.3 (SD 1) years]. Anthropometric measurements included height, body mass, body fat mass, body area, thoracic section area (Ats) thoracic circumferences, lengths of upper limb, bi-acromial and bi-iliac diameters. Maximal oxygen consumption (VO2max; direct method), maximal anaerobic power (W(an),max; force-velocity test) and mean power in 30 s sprint (W30 s; Wingate test) were also measured. Each of these bio-energetic variables was expressed in absolute terms, relating to body mass, body area and Ats. The stepwise regression method was used to determine contribution of the variables (anthropometric and/or bio-energetic) of the time achieved over the distance. The W30 s/Ats accounted for 46% of the time over 50 m (negative correlation). The VO2max/Ats and height were negatively correlated with the times of performances over 100 m, 200 m and 400 m, these two variables accounted for 71% to 77% of the performance. These results would indicate that even in young boys, anthropometric and bio-energetic characteristics are both important in swimming performance, particularly the bio-energetic variables expressed per Ats.

  17. Effects of salbutamol and caffeine ingestion on exercise metabolism and performance.

    PubMed

    Collomp, K; Candau, R; Millet, G; Mucci, P; Borrani, F; Préfaut, C; De Ceaurriz, J

    2002-11-01

    This study was designed to assess the effects of acute oral salbutamol and caffeine intake on performance and metabolism during short-term endurance exercise. Eight healthy volunteers participated in the double-blind placebo-controlled randomized cross-over study. Two 10 min cycling trials were performed at a power corresponding to 90 % VO 2 max for the first and a mock test for the second, separated by 10 min of passive recovery after ingestion of placebo (Pla), salbutamol (Sal, 6 mg) and caffeine (Caf, 250 mg). Performance (mean power during the mock test) was not statistically significant between the 3 treatments. Blood lactate was significantly increased after Sal compared to Pla at rest and until the end of the mock test whereas it appeared significantly increased after Caf compared to Pla at the end of the two exercises. Sal increased basal blood glucose and both Sal and Caf induced significant higher plasma insulin concentrations at rest, at the end of the mock test and during the recovery compared to Pla. No significant changes were found in these three variables between the Sal and the Caf treatments. Plasma growth hormone was significantly decreased after Sal after the mock test compared to the two other treatments. In conclusion, under the conditions of this study, neither oral salbutamol nor caffeine intake produce enhancement of short-term performance in non-specific trained subjects despite the substantial shifts in metabolic and hormonal parameters which were found.

  18. Effects of caffeine chewing gum on race performance and physiology in male and female cyclists.

    PubMed

    Paton, Carl; Costa, Vitor; Guglielmo, Luiz

    2015-01-01

    This investigation reports the effects of chewing caffeinated gum on race performance with trained cyclists. Twenty competitive cyclists completed two 30-km time trials that included a maximal effort 0.2-km sprint each 10-km. Caffeine (~3-4 mg · kg(-1)) or placebo was administered double-blind via chewing gum at the 10-km point following completion of the first sprint. Measures of power output, oxygen uptake, heart rate, lactate and perceived exertion were taken at set intervals during the time trial. Results indicated no substantial differences in any measured variables between caffeine and placebo conditions during the first 20-km of the time trial. Caffeine gum did however lead to substantial enhancements (mean ± 90% confidence limits (CLs)) in mean power during the final 10-km (3.8% ± 2.3%), and sprint power at 30-km (4.0% ± 3.6%). The increases in performance over the final 10-km were associated with small increases in heart rate and blood lactate (effect size of 0.24 and 0.28, respectively). There were large inter-individual variations in the response to caffeine, and apparent gender related differences in sprint performance. Chewing caffeine gum improves mean and sprint performance power in the final 10-km of a 30-km time trial in male and female cyclists most likely through an increase in nervous system activation.

  19. Transference of Traditional Versus Complex Strength and Power Training to Sprint Performance

    PubMed Central

    Loturco, Irineu; Tricoli, Valmor; Roschel, Hamilton; Nakamura, Fabio Yuzo; Cal Abad, Cesar Cavinato; Kobal, Ronaldo; Gil, Saulo; González-Badillo, Juan José

    2014-01-01

    The purpose of this study was to determine the effects of two different strength-power training models on sprint performance. Forty-eight soldiers of the Brazilian brigade of special operations with at least one year of army training experience were divided into a control group (CG: n = 15, age: 20.2 ± 0.7 years, body height: 1.74 ± 0.06 m, and body mass: 66.7 ± 9.8 kg), a traditional training group (TT: n = 18, age: 20.1 ± 0.7 years, body height: 1.71 ± 0.05 m, and body mass: 64.2 ± 4.7 kg), and a complex training group (CT: n = 15, age: 20.3 ± 0.8 years, body height: 1.71 ± 0.07 m; and body mass: 64.0 ± 8.8 kg). Maximum strength (25% and 26%), CMJ height (36% and 39%), mean power (30% and 35%) and mean propulsive power (22% and 28%) in the loaded jump squat exercise, and 20-m sprint speed (16% and 14%) increased significantly (p≤0.05) following the TT and CT, respectively. However, the transfer effect coefficients (TEC) of strength and power performances to 20-m sprint performance following the TT were greater than the CT throughout the 9-week training period. Our data suggest that TT is more effective than CT to improve sprint performance in moderately trained subjects. PMID:25114753

  20. Improved solvent extraction procedure and high-performance liquid chromatography-evaporative light-scattering detector method for analysis of polar lipids from dairy materials.

    PubMed

    Le, Thien Trung; Miocinovic, Jelena; Nguyen, Tuyet Mai; Rombaut, Roeland; van Camp, John; Dewettinck, Koen

    2011-10-12

    A normal-phase high-performance liquid chromatography-evaporative light-scattering detector method employing dichloromethane, methanol, and acetic acid/triethylamine buffer as the mobile phase was developed for analysis of polar lipids (PLs). This method was applicable for analysis of PLs from both dairy materials and soy lecithin. All of the PLs of interest such as glycolipids, phospholipids, and sphingomyelin were well separated with a total run time of 22.5 min and without necessitating the removal of neutral lipids beforehand. Peak retention times were stable, and the method was reproducible. In this study, a modified method of using solvents for extraction of PLs from dairy matrices was also investigated. The modified method offered higher extraction efficiency, consumed less time, and in some cases saved solvent use.

  1. Vitamin E analysis by ultra-performance convergence chromatography and structural elucidation of novel α-tocodienol by high-resolution mass spectrometry.

    PubMed

    Gee, Ping Tou; Liew, Chen Yee; Thong, Meng Chil; Gay, Melvin C L

    2016-04-01

    We have developed a method for analysing vitamin E using ultra-performance convergence chromatography with a chromatographic runtime of 5.5 min. A well-resolved chromatogram with excellent precision in retention time revealed seven vitamin E components in the palm oil derived tocotrienol-rich fraction. The major vitamin E components were α-tocopherol, α-tocotrienol, γ-tocotrienol and δ-tocotrienol whereas the minor vitamin E components were α-tocomonoenol, β-tocotrienol and an unreported trace component. The new component was positively identified by high-resolution mass spectrometry as 2-methyl-2(4',8',12'-trimethyltrideca-7',11'-dienyl)5,7,8-trimethylchroman-6-ol or α-tocodienol.

  2. Simultaneous extraction and analysis by high performance liquid chromatography coupled to diode array and mass spectrometric detectors of bixin and phenolic compounds from annatto seeds.

    PubMed

    Chisté, Renan Campos; Yamashita, Fábio; Gozzo, Fábio Cesar; Mercadante, Adriana Zerlotti

    2011-01-07

    This study was designed to identify and quantify the carotenoids and phenolic compounds from annatto seeds using high performance liquid chromatography coupled to diode array and mass spectrometer detectors (HPLC-DAD-MS/MS). Furthermore, using response surface methodology, an optimized procedure for simultaneous extraction of these compounds was established. In addition to bixin, known to be the main carotenoid in annatto seeds, hypolaetin and a caffeoyl acid derivative were identified as the main phenolic compounds. The optimized procedure involved 15 extractions using acetone:methanol:water (50:40:10, v/v/v) as solvent, a solid-liquid ratio of 1:9 (m/v) and an extraction time of 5 min. Validation data indicated that the HPLC method proposed provided good linearity, sensitivity, procedure accuracy, system precision and suggested its suitability for the simultaneous analysis of phenolic compounds and carotenoids in annatto seeds.

  3. 4-Nitrophenol in 4-nitrophenyl phosphate, a substrate for alkaline phosphatase, as measured by paired-ion high-performance liquid chromatography.

    PubMed

    Culbreth, P H; Duncan, I W; Burtis, C A

    1977-12-01

    We used paired-ion high-performance liquid chromatography to determine the 4-nitrophenol content of 4-nitrophenyl phosphate, a substrate for alkaline phosphatase analysis. This was done on a reversed-phase column with a mobile phase of methanol/water, 45/55 by vol, containing 3 ml of tetrabutylammonium phosphate reagent per 200 ml of solvent. At a flow rate of 1 ml/min, 4-nitrophenol was eluted at 9 min and monitored at 404 nm; 4-nitrophenyl phosphate was eluted at 5 min and could be monitored at 311 nm. Samples of 4-nitrophenyl phosphate obtained from several sources contained 0.3 to 7.8 mole of 4-nitrophenol per mole of 4-nitrophenyl phosphate.

  4. Extraction of amphetamines and methylenedioxyamphetamines from urine using a monolithic silica disk-packed spin column and high-performance liquid chromatography-diode array detection.

    PubMed

    Namera, Akira; Nakamoto, Akihiro; Nishida, Manami; Saito, Takeshi; Kishiyama, Izumi; Miyazaki, Shota; Yahata, Midori; Yashiki, Mikio; Nagao, Masataka

    2008-10-24

    To overcome the limitations of solid-phase extraction, we developed a device comprising a spin column packed with octadecyl silane-bonded monolithic silica for extracting amphetamines and methylenedioxyamphetamines from urine. Urine (0.5mL), buffer (0.4mL), and methoxyphenamine (internal standard) were directly put into the preactivated column. The column was centrifuged (3000rpm, 5min) for sample loading and washed. The adsorbed analytes were eluted and analyzed by high-performance liquid chromatography, without evaporation. The results were as follows: linear curves (drug concentrations of 0.2-20microg/mL); correlation coefficients >0.99; detection limit, 0.1microg/mL. The proposed method is not only useful for drugs from biological materials but also highly reproducible for the analysis of these drugs in urine.

  5. Effect of sonic driving on maximal aerobic performance.

    PubMed

    Brilla, L.R.; Hatcher, Stefanie

    2000-07-01

    The study purpose was to evaluate antecedent binaural stimulation (ABS) on maximal aerobic physical performance. Twenty-two healthy, physically active subjects, 21-34 years, randomly received one of two preparations for each session: 15 min of quiet (BLANK) or percussive sonic driving at 200+ beats per minute (bpm) using a recorded compact disc (FSS, Mill Valley, CA) with headphones (ABS). Baseline HR, blood pressure (BP), and breathing frequency (f(br)) were obtained. During each condition, HR and f(br) were recorded at 3-min intervals. The graded maximal treadmill testing was administered immediately postpreparation session on separate days, with at least 48 h rest between sessions. There were significant differences in the antecedent period means between the two conditions, ABS (HR: 70.2 +/- 10.7 bpm; f(br): 18.5 +/- 3.3 br min(-1); BP: 134.5/87.9 +/- 13.6/9.2 mm Hg) and BLANK (HR: 64.6 +/- 7.9; f(br): 14.3 +/- 2.9; BP: 126.7/80.3 +/- 12.1/8.6). Differences were noted for each 3-min interval and pre- postantecedent period. The maximal graded exercise test (GXT) results showed that there was a small but significant (P < 0.05), increase in maximal VO(2) in the ABS (49.8 +/- 6.8 ml. kg(-1). min(-1)) vs. BLANK (46.7 +/- 8.7) conditions. Related to that finding was a slight increase (0.5 min) in time to exhaustion (P < 0.05). There were no significant differences in HR or RPE (P > 0.05). There may be a latency to ABS related to entrainment or imagery-enhanced warm-up. Am. J. Hum. Biol. 12:558-565, 2000. Copyright 2000 Wiley-Liss, Inc.

  6. The Performer as Writer.

    ERIC Educational Resources Information Center

    Gentile, John S.

    Most performer-writers accept the writing process simply as a means to an end: the shared performance event with a live audience. While writer-performers regard a script as more important than the performance, a solo performance is, however, a showcase of the artist's talent, and creating one's own text offers the performer artistic control. Some…

  7. High Performance Work Practices and Firm Performance.

    ERIC Educational Resources Information Center

    Department of Labor, Washington, DC. Office of the American Workplace.

    A literature survey established that a substantial amount of research has been conducted on the relationship between productivity and the following specific high performance work practices: employee involvement in decision making, compensation linked to firm or worker performance, and training. According to these studies, high performance work…

  8. Performance of Pain, Performance of Beauty

    ERIC Educational Resources Information Center

    Thompson, James

    2006-01-01

    "Performance of pain, performance of beauty" explores performance projects in war zones using Elaine Scarry's definitions of "pain" and "beauty" as a starting point. The way in which pain constricts the body and the experience that beauty can take a person beyond the body become a contested framework for considering…

  9. Neck-cooling improves repeated sprint performance in the heat

    PubMed Central

    Sunderland, Caroline; Stevens, Ryan; Everson, Bethan; Tyler, Christopher J.

    2015-01-01

    The present study evaluated the effect of neck-cooling during exercise on repeated sprint ability in a hot environment. Seven team-sport playing males completed two experimental trials involving repeated sprint exercise (5 × 6 s) before and after two 45 min bouts of a football specific intermittent treadmill protocol in the heat (33.0 ± 0.2°C; 53 ± 2% relative humidity). Participants wore a neck-cooling collar in one of the trials (CC). Mean power output and peak power output declined over time in both trials but were higher in CC (540 ± 99 v 507 ± 122 W, d = 0.32; 719 ± 158 v 680 ± 182 W, d = 0.24 respectively). The improved power output was particularly pronounced (d = 0.51–0.88) after the 2nd 45 min bout but the CC had no effect on % fatigue. The collar lowered neck temperature and the thermal sensation of the neck (P < 0.001) but had no effect on heart rate, fluid loss, fluid consumption, lactate, glucose, plasma volume change, cortisol, or thermal sensation (P > 0.05). There were no trial differences but interaction effects were demonstrated for prolactin concentration and rating of perceived exertion (RPE). Prolactin concentration was initially higher in the collar cold trial and then was lower from 45 min onwards (interaction trial × time P = 0.04). RPE was lower during the football intermittent treadmill protocol in the collar cold trial (interaction trial × time P = 0.01). Neck-cooling during exercise improves repeated sprint performance in a hot environment without altering physiological or neuroendocrinological responses. RPE is reduced and may partially explain the performance improvement. PMID:26594177

  10. Neck-cooling improves repeated sprint performance in the heat.

    PubMed

    Sunderland, Caroline; Stevens, Ryan; Everson, Bethan; Tyler, Christopher J

    2015-01-01

    The present study evaluated the effect of neck-cooling during exercise on repeated sprint ability in a hot environment. Seven team-sport playing males completed two experimental trials involving repeated sprint exercise (5 × 6 s) before and after two 45 min bouts of a football specific intermittent treadmill protocol in the heat (33.0 ± 0.2°C; 53 ± 2% relative humidity). Participants wore a neck-cooling collar in one of the trials (CC). Mean power output and peak power output declined over time in both trials but were higher in CC (540 ± 99 v 507 ± 122 W, d = 0.32; 719 ± 158 v 680 ± 182 W, d = 0.24 respectively). The improved power output was particularly pronounced (d = 0.51-0.88) after the 2nd 45 min bout but the CC had no effect on % fatigue. The collar lowered neck temperature and the thermal sensation of the neck (P < 0.001) but had no effect on heart rate, fluid loss, fluid consumption, lactate, glucose, plasma volume change, cortisol, or thermal sensation (P > 0.05). There were no trial differences but interaction effects were demonstrated for prolactin concentration and rating of perceived exertion (RPE). Prolactin concentration was initially higher in the collar cold trial and then was lower from 45 min onwards (interaction trial × time P = 0.04). RPE was lower during the football intermittent treadmill protocol in the collar cold trial (interaction trial × time P = 0.01). Neck-cooling during exercise improves repeated sprint performance in a hot environment without altering physiological or neuroendocrinological responses. RPE is reduced and may partially explain the performance improvement.

  11. Exploring the performance reserve: Effect of different magnitudes of power output deception on 4,000 m cycling time-trial performance

    PubMed Central

    Stone, Mark R.; Thomas, Kevin; Wilkinson, Michael; Stevenson, Emma; St. Clair Gibson, Alan; Jones, Andrew M.; Thompson, Kevin G.

    2017-01-01

    Purpose The aim of the present study was to investigate whether a magnitude of deception of 5% in power output would lead to a greater reduction in the amount of time taken for participants to complete a 4000 m cycling TT than a magnitude of deception of 2% in power output, which we have previously shown can lead to a small change in 4000 m cycling TT performance. Methods Ten trained male cyclists completed four, 4000 m cycling TTs. The first served as a habituation and the second as a baseline for future trials. During trials three and four participants raced against a pacer which was set, in a randomized order, at a mean power output equal to 2% (+2% TT) or 5% (+5% TT) higher than their baseline performance. However participants were misled into believing that the power output of the pacer was an accurate representation of their baseline performance on both occasions. Cardiorespiratory responses were recorded throughout each TT, and used to estimate energy contribution from aerobic and anaerobic metabolism. Results Participants were able to finish the +2% TT in a significantly shorter duration than at baseline (p = 0.01), with the difference in performance likely attributable to a greater anaerobic contribution to total power output (p = 0.06). There was no difference in performance between the +5% TT and +2% TT or baseline trials. Conclusions Results suggest that a performance reserve is conserved, involving anaerobic energy contribution, which can be utilised given a belief that the exercise will be sustainable however there is an upper limit to how much deception can be tolerated. These findings have implications for performance enhancement in athletes and for our understanding of the nature of fatigue during high-intensity exercise. PMID:28278174

  12. Long-term effects of graduated compression stockings on cardiorespiratory performance.

    PubMed

    Priego, J I; Lucas-Cuevas, A G; Aparicio, I; Giménez, J V; Cortell-Tormo, J M; Pérez-Soriano, P

    2015-09-01

    The use of graduated compression stockings (GCS) in sport has been increasing in the last years due to their potential positive effects for athletes. However, there is little evidence to support whether these types of garments actually improve cardiorespiratory performance. The aim of this study was to examine the cardiorespiratory responses of GCS during running after three weeks of regular use. Twenty recreational runners performed three tests on different days: test 1) - a 5-min maximal effort run in order to determine the participants' maximal aerobic speed; and tests 2) and 3) - a fatigue running test of 30 minutes at 80% of their maximal aerobic speed with either GCS or PLACEBO stockings at random. Cardiorespiratory parameters (minute ventilation, heart rate, relative oxygen consumption, relative carbon dioxide production, ventilatory equivalents for oxygen and carbon dioxide, and oxygen pulse) were measured. Before each test in the laboratory, the participants trained with the randomly assigned stockings (GCS or PLACEBO) for three weeks. No significant differences between GCS and PLACEBO were found in any of the cardiorespiratory parameters. In conclusion, the present study provides evidence that running with GCS for three weeks does not influence cardiorespiratory parameters in recreational runners.

  13. Long-term effects of graduated compression stockings on cardiorespiratory performance

    PubMed Central

    Lucas-Cuevas, AG; Aparicio, I; Giménez, JV; Cortell-Tormo, JM; Pérez-Soriano, P

    2015-01-01

    The use of graduated compression stockings (GCS) in sport has been increasing in the last years due to their potential positive effects for athletes. However, there is little evidence to support whether these types of garments actually improve cardiorespiratory performance. The aim of this study was to examine the cardiorespiratory responses of GCS during running after three weeks of regular use. Twenty recreational runners performed three tests on different days: test 1) – a 5-min maximal effort run in order to determine the participants’ maximal aerobic speed; and tests 2) and 3) – a fatigue running test of 30 minutes at 80% of their maximal aerobic speed with either GCS or PLACEBO stockings at random. Cardiorespiratory parameters (minute ventilation, heart rate, relative oxygen consumption, relative carbon dioxide production, ventilatory equivalents for oxygen and carbon dioxide, and oxygen pulse) were measured. Before each test in the laboratory, the participants trained with the randomly assigned stockings (GCS or PLACEBO) for three weeks. No significant differences between GCS and PLACEBO were found in any of the cardiorespiratory parameters. In conclusion, the present study provides evidence that running with GCS for three weeks does not influence cardiorespiratory parameters in recreational runners. PMID:26424925

  14. Effect of Regular Yoga Practice on Respiratory Regulation and Exercise Performance

    PubMed Central

    Beutler, Eveline; Beltrami, Fernando G.; Boutellier, Urs; Spengler, Christina M.

    2016-01-01

    Yoga alters spontaneous respiratory regulation and reduces hypoxic and hypercapnic ventilatory responses. Since a lower ventilatory response is associated with an improved endurance capacity during whole-body exercise, we tested whether yogic subjects (YOGA) show an increased endurance capacity compared to matched non-yogic individuals (CON) with similar physical activity levels. Resting ventilation, the ventilatory response to hypercapnia, passive leg movement and exercise, as well as endurance performance were assessed. YOGA (n = 9), compared to CONTROL (n = 6), had a higher tidal volume at rest (0.7±0.2 vs. 0.5±0.1 l, p = 0.034) and a reduced ventilatory response to hypercapnia (33±15 vs. 47±15 l·min-1, p = 0.048). A YOGA subgroup (n = 6) with maximal performance similar to CONTROL showed a blunted ventilatory response to passive cycling (11±2 vs. 14±2 l·min-1, p = 0.039) and a tendency towards lower exercise ventilation (33±2 vs. 36±3 l·min-1, p = 0.094) while cycling endurance (YOGA: 17.3±3.3; CON: 19.6±8.5 min, p = 0.276) did not differ. Thus, yoga practice was not associated with improved exercise capacity nor with significant changes in exercise ventilation despite a significantly different respiratory regulation at rest and in response to hypercapnia and passive leg movement. PMID:27055287

  15. Effect of Regular Yoga Practice on Respiratory Regulation and Exercise Performance.

    PubMed

    Beutler, Eveline; Beltrami, Fernando G; Boutellier, Urs; Spengler, Christina M

    2016-01-01

    Yoga alters spontaneous respiratory regulation and reduces hypoxic and hypercapnic ventilatory responses. Since a lower ventilatory response is associated with an improved endurance capacity during whole-body exercise, we tested whether yogic subjects (YOGA) show an increased endurance capacity compared to matched non-yogic individuals (CON) with similar physical activity levels. Resting ventilation, the ventilatory response to hypercapnia, passive leg movement and exercise, as well as endurance performance were assessed. YOGA (n = 9), compared to CONTROL (n = 6), had a higher tidal volume at rest (0.7±0.2 vs. 0.5±0.1 l, p = 0.034) and a reduced ventilatory response to hypercapnia (33±15 vs. 47±15 l·min(-1), p = 0.048). A YOGA subgroup (n = 6) with maximal performance similar to CONTROL showed a blunted ventilatory response to passive cycling (11±2 vs. 14±2 l·min(-1), p = 0.039) and a tendency towards lower exercise ventilation (33±2 vs. 36±3 l·min(-1), p = 0.094) while cycling endurance (YOGA: 17.3±3.3; CON: 19.6±8.5 min, p = 0.276) did not differ. Thus, yoga practice was not associated with improved exercise capacity nor with significant changes in exercise ventilation despite a significantly different respiratory regulation at rest and in response to hypercapnia and passive leg movement.

  16. Effects of intermittent hypoxic training on aerobic and anaerobic performance.

    PubMed

    Morton, James Peter; Cable, Nigel Tim

    The aim of the present study was to determine whether short-term intermittent hypoxic training would enhance sea level aerobic and anaerobic performance over and above that occurring with equivalent sea level training. Over a 4-week period, two groups of eight moderately trained team sports players performed 30 min of cycling exercise three times per week. One group trained in normobaric hypoxia at a simulated altitude of 2750 m (F(I)O2= 0.15), the other group trained in a laboratory under sea level conditions. Each training session consisted of ten 1-min bouts at 80% maximum workload maintained for 2 min (Wmax) during the incremental exercise test at sea level separated by 2-min active recovery at 50% Wmax. Training intensities were increased by 5% after six training sessions and by a further 5% (of original Wmax) after nine sessions. Pre-training assessments of VO(2max), power output at onset of 4 mM blood lactate accumulation (OBLA), Wmax and Wingate anaerobic performance were performed on a cycle ergometer at sea level and repeated 4-7 d following the training intervention. Following training there were significant increases (p < 0.01) in VO(2max) (7.2 vs. 8.0%), Wmax (15.5 vs. 17.8%), OBLA (11.1 vs. 11.9%), mean power (8.0 vs. 6.5%) and peak power (2.9 vs. 9.3%) in both the hypoxic and normoxic groups respectively. There were no significant differences between the increases in any of the above-mentioned performance parameters in either training environment (p > 0.05). In addition, neither haemoglobin concentration nor haematocrit were significantly changed in either group (p > 0.05). It is concluded that acute exposure of moderately trained subjects to normobaric hypoxia during a short-term training programme consisting of moderate- to high-intensity intermittent exercise has no enhanced effect on the degree of improvement in either aerobic or anaerobic performance. These data suggest that if there are any advantages to training in hypoxia for sea level

  17. Performing Surgery: Commonalities with Performers Outside Medicine

    PubMed Central

    Kneebone, Roger L.

    2016-01-01

    This paper argues for the inclusion of surgery within the canon of performance science. The world of medicine presents rich, complex but relatively under-researched sites of performance. Performative aspects of clinical practice are overshadowed by a focus on the processes and outcomes of medical care, such as diagnostic accuracy and the results of treatment. The primacy of this “clinical” viewpoint—framed by clinical professionals as the application of medical knowledge—hides resonances with performance in other domains. Yet the language of performance is embedded in the culture of surgery—surgeons “perform” operations, work in an operating “theater” and use “instruments.” This paper asks what might come into view if we take this performative language at face value and interrogate surgery from the perspective of performance science. PMID:27630587

  18. Photocatalytic performance of the SiO2 sphere/ n-type TiO2/ p-type CuBiS2 composite catalysts coated with different contents of Ag nanoparticles under ultraviolet and visible light irradiations

    NASA Astrophysics Data System (ADS)

    Abdullah, Hairus; Kuo, Dong-Hau

    2016-08-01

    Photocatalytic performance of the SiO2 sphere/ n-type TiO2/ p-type CuBiS2 composite catalysts with different contents of silver nanoparticles (abbreviated as SiO2/ n-TiO2/ p-CuBiS2/Ag) toward the photodegradation of Acid Black 1 ( AB 1) dye under ultraviolet (UV) and visible light was investigated. The composite catalyst spheres were analyzed their crystal structure, microstructure, optical absorbance capabilities, and photodegradation capabilities of AB 1 dye. The best photodegradation performances of the 20 mg composite powder with only ~5 mg photoactive catalysts showed the degradation of AB 1 dye in 5 min under UV and 60 min under visible light irradiations. The concept of composite catalyst with numerous nano p- n diodes and its photodegradation mechanism were proposed.

  19. Ultra performance liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry for high-sensitivity and high-throughput analysis of U.S. Environmental Protection Agency 16 priority pollutants polynuclear aromatic hydrocarbons.

    PubMed

    Cai, Sheng-Suan; Syage, Jack A; Hanold, Karl A; Balogh, Michael P

    2009-03-15

    In this work, we demonstrate the utility of ultra performance liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry (UPLC-APPI-MS/MS) for high-sensitivity and high-throughput analysis of United States Environmental Protection Agency (U.S. EPA) 16 priority pollutants polycyclic aromatic hydrocarbons (PAHs). Analyses were performed on a Waters Acquity-TQD equipped with Syagen's PhotoMate APPI source. All 16 PAHs were analyzed on column in approximately 3.5 min with excellent chromatographic separation for all PAH isomers and with low picogram detection limits on column for all analytes using chlorobenzene as a dopant. Dynamic linear ranges were evaluated and found to cover at least 3-4 orders of magnitude. In comparison with the existing U.S. EPA methods, this approach improves instrument sample throughput by at least 10-fold.

  20. The effect of music on 10-km cycle time-trial performance.

    PubMed

    Hagen, Jana; Foster, Carl; Rodríguez-Marroyo, Jose; de Koning, Jos J; Mikat, Richard P; Hendrix, Charles R; Porcari, John P

    2013-01-01

    Music is widely used as an ergogenic aid in sport, but there is little evidence of its effectiveness during closed-loop athletic events. In order to determine the effectiveness of music as an ergogenic aid, well-trained and task-habituated cyclists performed 10-km cycle time trials either while listening to self-selected motivational music or with auditory input blocked. There were no statistically significant differences in performance time or physiological or psychological markers related to music (time-trial duration17.75 ± 2.10 vs 17.81 ± 2.06 min, mean power output 222 ± 66 vs 220 ± 65 W, peak heart rate184 ± 9 vs 183 ± 8 beats/min, peak blood lactate12.1 ± 2.6 vs 11.9 ± 2.1 mmol/L, and final rating of perceived exertion 8.4 ± 1.5 vs 8.5 ± 1.6). It is concluded that during exercise at competitive intensity, there is no meaningful effect of music on either performance or physiology.

  1. The effect of mountain bike wheel size on cross-country performance.

    PubMed

    Hurst, Howard Thomas; Sinclair, Jonathan; Atkins, Stephen; Rylands, Lee; Metcalfe, John

    2016-08-01

    The purpose of this study was to determine the influence of different wheel size diameters on indicators of cross-country mountain bike time trial performance. Nine competitive male mountain bikers (age 34.7 ± 10.7 years; stature 177.7 ± 5.6 cm; body mass 73.2 ± 8.6 kg) performed 1 lap of a 3.48 km mountain bike (MTB) course as fast as possible on 26″, 27.5″ and 29″ wheeled MTB. Time (s), mean power (W), cadence (revs · min(-1)) and velocity (km · h(-1)) were recorded for the whole lap and during ascent and descent sections. One-way repeated measure ANOVA was used to determine significant differences. Results revealed no significant main effects for any variables by wheel size during all trials, with the exception of cadence during the descent (F(2, 16) = 8.96; P = .002; P(2) = .53). Post hoc comparisons revealed differences lay between the 26″ and 29″ wheels (P = .02). The findings indicate that wheel size does not significantly influence performance during cross-country when ridden by trained mountain bikers, and that wheel choice is likely due to personal choice or sponsorship commitments.

  2. Acute effects of three different stretching protocols on the wingate test performance.

    PubMed

    Franco, Bruno L; Signorelli, Gabriel R; Trajano, Gabriel S; Costa, Pablo B; de Oliveira, Carlos G

    2012-01-01

    The purpose of this study was to examine the acute effects of different stretching exercises on the performance of the traditional Wingate test (WT). Fifteen male participants performed five WT; one for familiarization (FT), and the remaining four after no stretching (NS), static stretching (SS), dynamic stretching (DS), and proprioceptive neuromuscular facilitation (PNF). Stretches were targeted for the hamstrings, quadriceps, and calf muscles. Peak power (PP), mean power (MP), and the time to reach PP (TP) were calculated. The MP was significantly lower when comparing the DS (7.7 ± 0.9 W/kg) to the PNF (7.3 ± 0.9 W/kg) condition (p < 0.05). For PP, significant differences were observed between more comparisons, with PNF stretching providing the lowest result. A consistent increase of TP was observed after all stretching exercises when compared to NS. The results suggest the type of stretching, or no stretching, should be considered by those who seek higher performance and practice sports that use maximal anaerobic power.

  3. Effect of step aerobics training on anaerobic performance of men and women.

    PubMed

    Kin-Isler, Ayse; Kosar, Sukran Nazan

    2006-05-01

    The purpose of this study was to investigate the effects of 10 weeks of step aerobics training on anaerobic performance of men and women. College-age volunteers (64 women and 54 men) were divided into step aerobics (33 women, 27 men) and control (31 women, 27 men) groups. Before and after the 10-week period, the subjects' body composition, muscular strength, Wingate anaerobic performance, and vertical jump anaerobic performance were determined. The step aerobics group participated in step aerobics sessions of 50 minutes per day, 3 days per week for 10 weeks, at 60-80% of their heart rate reserve. Results of 2 x 2 analysis of covariance with repeated measures indicated significant sex differences in percentage body fat, lean body mass, muscular strength, and in all of the measured indices of the Wingate Anaerobic Test. The step aerobics group showed significant improvement only in mean power relative to body weight compared with the control group and women showed significant improvement only in anaerobic power of vertical jump when compared with men. It can be concluded that 10 weeks of step aerobics was not effective in improving all of the measured anaerobic indices in men and women.

  4. Analysis of Classical Time-Trial Performance and Technique-Specific Physiological Determinants in Elite Female Cross-Country Skiers

    PubMed Central

    Sandbakk, Øyvind; Losnegard, Thomas; Skattebo, Øyvind; Hegge, Ann M.; Tønnessen, Espen; Kocbach, Jan

    2016-01-01

    The present study investigated the contribution of performance on uphill, flat, and downhill sections to overall performance in an international 10-km classical time-trial in elite female cross-country skiers, as well as the relationships between performance on snow and laboratory-measured physiological variables in the double poling (DP) and diagonal (DIA) techniques. Ten elite female cross-country skiers were continuously measured by a global positioning system device during an international 10-km cross-country skiing time-trial in the classical technique. One month prior to the race, all skiers performed a 5-min submaximal and 3-min self-paced performance test while roller skiing on a treadmill, both in the DP and DIA techniques. The time spent on uphill (r = 0.98) and flat (r = 0.91) sections of the race correlated most strongly with the overall 10-km performance (both p < 0.05). Approximately 56% of the racing time was spent uphill, and stepwise multiple regression revealed that uphill time explained 95.5% of the variance in overall performance (p < 0.001). Distance covered during the 3-min roller-skiing test and body-mass normalized peak oxygen uptake (VO2peak) in both techniques showed the strongest correlations with overall time-trial performance (r = 0.66–0.78), with DP capacity tending to have greatest impact on the flat and DIA capacity on uphill terrain (all p < 0.05). Our present findings reveal that the time spent uphill most strongly determine classical time-trial performance, and that the major portion of the performance differences among elite female cross-country skiers can be explained by variations in technique-specific aerobic power. PMID:27536245

  5. Analysis of Classical Time-Trial Performance and Technique-Specific Physiological Determinants in Elite Female Cross-Country Skiers.

    PubMed

    Sandbakk, Øyvind; Losnegard, Thomas; Skattebo, Øyvind; Hegge, Ann M; Tønnessen, Espen; Kocbach, Jan

    2016-01-01

    The present study investigated the contribution of performance on uphill, flat, and downhill sections to overall performance in an international 10-km classical time-trial in elite female cross-country skiers, as well as the relationships between performance on snow and laboratory-measured physiological variables in the double poling (DP) and diagonal (DIA) techniques. Ten elite female cross-country skiers were continuously measured by a global positioning system device during an international 10-km cross-country skiing time-trial in the classical technique. One month prior to the race, all skiers performed a 5-min submaximal and 3-min self-paced performance test while roller skiing on a treadmill, both in the DP and DIA techniques. The time spent on uphill (r = 0.98) and flat (r = 0.91) sections of the race correlated most strongly with the overall 10-km performance (both p < 0.05). Approximately 56% of the racing time was spent uphill, and stepwise multiple regression revealed that uphill time explained 95.5% of the variance in overall performance (p < 0.001). Distance covered during the 3-min roller-skiing test and body-mass normalized peak oxygen uptake (VO2peak) in both techniques showed the strongest correlations with overall time-trial performance (r = 0.66-0.78), with DP capacity tending to have greatest impact on the flat and DIA capacity on uphill terrain (all p < 0.05). Our present findings reveal that the time spent uphill most strongly determine classical time-trial performance, and that the major portion of the performance differences among elite female cross-country skiers can be explained by variations in technique-specific aerobic power.

  6. Distributed performance counters

    DOEpatents

    Davis, Kristan D; Evans, Kahn C; Gara, Alan; Satterfield, David L

    2013-11-26

    A plurality of first performance counter modules is coupled to a plurality of processing cores. The plurality of first performance counter modules is operable to collect performance data associated with the plurality of processing cores respectively. A plurality of second performance counter modules are coupled to a plurality of L2 cache units, and the plurality of second performance counter modules are operable to collect performance data associated with the plurality of L2 cache units respectively. A central performance counter module may be operable to coordinate counter data from the plurality of first performance counter modules and the plurality of second performance modules, the a central performance counter module, the plurality of first performance counter modules, and the plurality of second performance counter modules connected by a daisy chain connection.

  7. High Performance Work Systems and Firm Performance.

    ERIC Educational Resources Information Center

    Kling, Jeffrey

    1995-01-01

    A review of 17 studies of high-performance work systems concludes that benefits of employee involvement, skill training, and other high-performance work practices tend to be greater when new methods are adopted as part of a consistent whole. (Author)

  8. Endurance training of respiratory muscles improves cycling performance in fit young cyclists

    PubMed Central

    Holm, Paige; Sattler, Angela; Fregosi, Ralph F

    2004-01-01

    Background Whether or not isolated endurance training of the respiratory muscles improves whole-body endurance exercise performance is controversial, with some studies reporting enhancements of 50 % or more, and others reporting no change. Twenty fit (VO2 max 56.0 ml/kg/min), experienced cyclists were randomly assigned to three groups. The experimental group (n = 10) trained their respiratory muscles via 20, 45 min sessions of hyperpnea. The placebo group (n = 4) underwent "sham" training (20, 5 min sessions), and the control group (n = 6) did no training. Results After training, the experimental group increased their respiratory muscle endurance capacity by 12 %. Performance on a bicycle time trial test designed to last about 40 min improved by 4.7 % (9 of 10 subjects showed improvement). There were no test-re-test improvements in either respiratory muscle or bicycle exercise endurance performance in the placebo group, nor in the control group. After training, the experimental group had significantly higher ventilatory output and VO2, and lower PCO2, during constant work-rate exercise; the placebo and control groups did not show these changes. The perceived respiratory effort was unchanged in spite of the higher ventilation rate after training. Conclusions The results suggest that respiratory muscle endurance training improves cycling performance in fit, experienced cyclists. The relative hyperventilation with no change in respiratory effort sensations suggest that respiratory muscle training allows subjects to tolerate the higher exercise ventilatory response without more dyspnea. Whether or not this can explain the enhanced performance is unknown. PMID:15132753

  9. Effect of drink temperature on core temperature and endurance cycling performance in warm, humid conditions.

    PubMed

    Burdon, Catriona; O'Connor, Helen; Gifford, Janelle; Shirreffs, Susan; Chapman, Phillip; Johnson, Nathan

    2010-09-01

    The aims of this study were to determine the effect of cold (4 °C) and thermoneutral (37 °C) beverages on thermoregulation and performance in the heat and to explore sensory factors associated with ingesting a cold stimulus. Seven males (age 32.8 ± 6.1 years, [V(.)]O(2peak) 59.4 ± 6.6 ml x kg(-1) x min(-1)) completed cold, thermoneutral, and thermoneutral + ice trials in randomized order. Participants cycled for 90 min at 65%[V(.)]O(2peak) followed by a 15-min performance test at 28 °C and 70% relative humidity. They ingested 2.3 ml x kg(-1) of a 7.4% carbohydrate-electrolyte solution every 10 min during the 90-min steady-state exercise including 30 ml ice puree every 5 min in the ice trial. Absolute changes in skin temperature (0.22 ± 1.1 °C vs. 1.14 ± 0.9 °C; P = 0.02), mean body temperature (1.2 ± 0.3 vs. 1.6 ± 0.3 °C; P = 0.03), and heat storage were lower across the 90-min exercise bout for the cold compared with the thermoneutral trial. Significant improvements (4.9 ± 2.4%, P < 0.01) in performance were observed with cold but no significant differences were detected with ice. Consumption of cold beverages during prolonged exercise in the heat improves body temperature measures and performance. Consumption of ice did not reveal a sensory response, but requires further study. Beverages consumed by athletes exercising in the heat should perhaps be cold for performance and safety reasons.

  10. The effect of an intermittent, high-intensity warm-up on supramaximal kayak ergometer performance.

    PubMed

    Bishop, David; Bonetti, Darrel; Spencer, Matthew

    2003-01-01

    It has previously been shown that the metabolic acidaemia induced by a continuous warm-up at the 'lactate threshold' is associated with a reduced accumulated oxygen deficit and decreased supramaximal performance. The aim of this study was to determine if an intermittent, high-intensity warm-up could increase oxygen uptake (VO2) without reducing the accumulated oxygen deficit, and thus improve supramaximal performance. Seven male 500 m kayak paddlers, who had represented their state, volunteered for this study. Each performed a graded exercise test to determine VO2max and threshold parameters. On subsequent days and in a random, counterbalanced order, the participants then performed a continuous or intermittent, high-intensity warm-up followed by a 2 min, all-out kayak ergometer test. The continuous warm-up consisted of 15 min of exercise at approximately 65% VO2max. The intermittent, high-intensity warm-up was similar, except that the last 5 min was replaced with five 10 s sprints at 200% VO2max, separated by 50 s of recovery at approximately 55% VO2max. Significantly greater (P < 0.05) peak power (intermittent vs continuous: 629 +/- 199 vs 601 +/- 204 W) and average power (intermittent vs continuous: 328 +/- 39.0 vs 321 +/- 42.4 W) were recorded after the intermittent warm-up. There was no significant difference between conditions for peak VO2, total VO2 or the accumulated oxygen deficit. The results of this study indicate that 2 min all-out kayak ergometer performance is significantly better after an intermittent rather than a continuous warm-up.

  11. Initial Cognitive Performance Predicts Longitudinal Aviator Performance

    PubMed Central

    Jo, Booil; Adamson, Maheen M.; Kennedy, Quinn; Noda, Art; Hernandez, Beatriz; Zeitzer, Jamie M.; Friedman, Leah F.; Fairchild, Kaci; Scanlon, Blake K.; Murphy, Greer M.; Taylor, Joy L.

    2011-01-01

    Objectives. The goal of the study was to improve prediction of longitudinal flight simulator performance by studying cognitive factors that may moderate the influence of chronological age. Method. We examined age-related change in aviation performance in aircraft pilots in relation to baseline cognitive ability measures and aviation expertise. Participants were aircraft pilots (N = 276) aged 40–77.9. Flight simulator performance and cognition were tested yearly; there were an average of 4.3 (± 2.7; range 1–13) data points per participant. Each participant was classified into one of the three levels of aviation expertise based on Federal Aviation Administration pilot proficiency ratings: least, moderate, or high expertise. Results. Addition of measures of cognitive processing speed and executive function to a model of age-related change in aviation performance significantly improved the model. Processing speed and executive function performance interacted such that the slowest rate of decline in flight simulator performance was found in aviators with the highest scores on tests of these abilities. Expertise was beneficial to pilots across the age range studied; however, expertise did not show evidence of reducing the effect of age. Discussion. These data suggest that longitudinal performance on an important real-world activity can be predicted by initial assessment of relevant cognitive abilities. PMID:21586627

  12. Conceptualising Research Performance

    ERIC Educational Resources Information Center

    Bazeley, Pat

    2010-01-01

    In a context of increasing emphasis on academic performance and accountability, data from a structured survey in which academics elaborated on eight different attributes of high-performing researchers were used to build a conceptual model of research performance. Research performance was seen to comprise two basic components, with six secondary…

  13. Obstacle Avoidance, Visual Detection Performance, and Eye-Scanning Behavior of Glaucoma Patients in a Driving Simulator: A Preliminary Study

    PubMed Central

    Prado Vega, Rocío; van Leeuwen, Peter M.; Rendón Vélez, Elizabeth; Lemij, Hans G.; de Winter, Joost C. F.

    2013-01-01

    The objective of this study was to evaluate differences in driving performance, visual detection performance, and eye-scanning behavior between glaucoma patients and control participants without glaucoma. Glaucoma patients (n = 23) and control participants (n = 12) completed four 5-min driving sessions in a simulator. The participants were instructed to maintain the car in the right lane of a two-lane highway while their speed was automatically maintained at 100 km/h. Additional tasks per session were: Session 1: none, Session 2: verbalization of projected letters, Session 3: avoidance of static obstacles, and Session 4: combined letter verbalization and avoidance of static obstacles. Eye-scanning behavior was recorded with an eye-tracker. Results showed no statistically significant differences between patients and control participants for lane keeping, obstacle avoidance, and eye-scanning behavior. Steering activity, number of missed letters, and letter reaction time were significantly higher for glaucoma patients than for control participants. In conclusion, glaucoma patients were able to avoid objects and maintain a nominal lane keeping performance, but applied more steering input than control participants, and were more likely than control participants to miss peripherally projected stimuli. The eye-tracking results suggest that glaucoma patients did not use extra visual search to compensate for their visual field loss. Limitations of the study, such as small sample size, are discussed. PMID:24146975

  14. Not self-focused attention but negative beliefs affect poor social performance in social anxiety: an investigation of pathways in the social anxiety-social rejection relationship.

    PubMed

    Voncken, Marisol J; Dijk, Corine; de Jong, Peter J; Roelofs, Jeffrey

    2010-10-01

    Patients with social anxiety disorder (SAD) not only fear negative evaluation but are indeed less likeable than people without SAD. Previous research shows social performance to mediate this social anxiety-social rejection relationship. This study studied two pathways hypothesized to lead to poor social performance in social anxiety: increased self-focused attention and negative beliefs. State social anxiety was experimentally manipulated in high and low-blushing-fearful individuals by letting half of the participants believe that they blushed intensely during a 5 min getting-acquainted interaction with two confederates. Participants rated their state social anxiety, self-focused attention, and level of negative beliefs. Two confederates and two video-observers rated subsequently likeability (i.e., social rejection) and social performance of the participants. In both groups, the social anxiety-social rejection relationship was present. Although state social anxiety was related to heightened self-focused attention and negative beliefs, only negative beliefs were associated with relatively poor social performance. In contrast to current SAD models, self-focused attention did not play a key-role in poor social performance but seemed to function as a by-product of state social anxiety. Beliefs of being negatively evaluated seem to elicit changes in behavioral repertoire resulting in a poor social performance and subsequent rejection.

  15. [Determination of histamine in canned fish by high performance liquid chromatography with pre-column derivatization].

    PubMed

    Jin, Gaowa; Cai, Youqiong; Yu, Huijuan; Qian, Beilei

    2010-11-01

    A pre-column derivatization-high performance liquid chromatographic (HPLC) method has been developed for the determination of histamine in canned fish. The homogenated samples were ultrasonically extracted with perchloric acid aqueous solution, derivatized with dansyl chloride and diluted with acetonitrile to a desired volume. The samples were determined by HPLC with ultraviolet detector and quantified by external standard method. Adopting a C18 column with 1.8 microm stationary phase particles, the analysis time for each sample was smaller than 5 min with the flow rate of 0.3 mL/min. It can decrease the consumption of the mobile phase and save the cost. The linear range was 0.08-8.00 mg/L for histamine. The correlation coefficient was 0.999 98. The average recoveries of histamine at different concentration levels in spiked samples were greater than 96% and the relative standard deviations (RSDs) were smaller than 2.5%. The quantitation limit was 5.00 mg/kg for histamine in canned fish by HPLC. The results indicated that this HPLC method is fast, sensitive, reproducible and practical for the routine analysis of histamine in canned fish.

  16. A new device for performing reference point indentation without a reference probe

    NASA Astrophysics Data System (ADS)

    Bridges, Daniel; Randall, Connor; Hansma, Paul K.

    2012-04-01

    Here we describe a novel, hand-held reference point indentation (RPI), instrument that is designed for clinical measurements of bone material properties in living patients. This instrument differs from previous RPI instruments in that it requires neither a reference probe nor removal of the periosteum that covers the bone, thus significantly simplifying its use in patient testing. After describing the instrument, we discuss five guidelines for optimal and reproducible results. These are: (1) the angle between the normal to the surface and the axis of the instrument should be less than 10°, (2) the compression of the main spring to trigger the device must be performed slowly (>1 s), (3) the probe tip should be sharper than 10 μm; however, a normalized parameter with a calibration phantom can correct for dull tips up to a 100 μm radius, (4) the ambient room temperature should be between 4 °C and 37 °C, and (5) the effective mass of the bone or material under test must exceed 1 kg, or if under 1 kg, the specimen should be securely anchored in a fixation device with sufficient mass (which is not a requirement of previous RPI instruments). Our experience is that a person can be trained with these guidelines in about 5 min and thereafter obtain accurate and reproducible results. The portability, ease of use, and minimal training make this instrument suitable to measure bone material properties in a clinical setting.

  17. Impact of Center-of-Mass Acceleration on the Performance of Ultramarathon Runners

    PubMed Central

    Lin, Shun-Ping; Sung, Wen-Hsu; Kuo, Fon-Chu; Kuo, Terry B.J.; Chen, Jin-Jong

    2014-01-01

    Ultramarathon races are rapidly gaining popularity in several countries, raising interest for the improvement of training programs. The aim of this study was to use a triaxial accelerometer to compare the three-dimensional center-of-mass accelerations of two groups of ultramarathon runners with distinct performances during different running speeds and distances. Ten runners who participated in the 12-h Taipei International Ultramarathon Race underwent laboratory treadmill testing one month later. They were divided into an elite group (EG; n = 5) and a sub-elite group (SG; n = 5). The triaxial center-of-mass acceleration recorded during a level-surface progressive intensity running protocol (3, 6, 8, 9, 10, and 12 km/h; 5 min each) was used for correlation analyses with running distance during the ultramarathon. The EG showed negative correlations between mediolateral (ML) acceleration (r = −0.83 to −0.93, p < 0.05), and between anterior–posterior (AP) acceleration and running distance (r = −0.8953 to −0.9653, p < 0.05), but not for vertical control of the center of mass. This study suggests that runners reduce stride length to minimize mediolateral sway and the effects of braking on the trunk; moreover, cadence must be increased to reduce braking effects and enhance impetus. Consequently, the competition level of ultramarathons can be elevated. PMID:25713664

  18. [Determination of penicillin intermediate and three penicillins in milk by high performance capillary electrophoresis].

    PubMed

    Tian, Chunqiu; Tan, Huarong; Gao, Liping; Shen, Huqin; Qi, Kezong

    2011-11-01

    A high performance capillary electrophoresis (HPCE) method was developed for the simultaneous determination of penicillin intermediate and penicillins in milk, including 6-amino-penicillanic acid (6-APA), penicillin G (PEN), ampicillin (AMP) and amoxicillin (AMO). The main parameters including the ion concentration and pH value of running buffer, separation voltage and column temperature were optimized systematically by orthogonal test. The four penicillins (PENs) were baseline separated within 4.5 min with the running buffer of 40 mmol/L potassium dihydrogen phosphate-20 mmol/L borax solution (pH 7.8), separation voltage of 28 kV and column temperature of 30 degrees C. The calibration curves showed good linearity in the range of 1.56 - 100 mg/L, and the correlation coefficients (r2) were between 0.9979 and 0.9998. The average recoveries at three spiked levels were in the range of 84.91% - 96.72% with acceptable relative standard deviations (RSDs) of 1.11% - 9.11%. The method is simple, fast, accurate and suitable for the determination of penicillins in real samples.

  19. Tail loss, body condition and swimming performances in tiger snakes, Notechis ater occidentalis.

    PubMed

    Aubret, Fabien; Bonnet, Xavier; Maumelat, Stéphanie

    2005-10-01

    In limbless tetrapods such as snakes, propulsive forces are generated by lateral undulations of the body and of the tail. In a large population of tiger snakes from Western Australia, tail loss was extremely common (58% of the individuals) and often very severe (more than two-thirds of the tail was missing in 14% of the cases, and in some instances, the tail was totally lost). Tail loss was not however correlated with body size, mass or body condition of wild individuals, and hence did not influence their abilities to acquire resources. These large venomous snakes exhibit marked aquatic habits. Locomotor tests in controlled conditions revealed that tail loss had a significant negative influence on burst swimming performances. However, no effect was found on routine swimming speed and total distance travelled over 5 min. These results suggest that a long and slender tail, although important for maximal speed, is not necessarily relevant for the locomotor abilities required for successful hunting. Tail-damaged individuals outnumbered intact snakes, suggesting that tail loss did not severely compromise survival. Overall, in this species, a slight deterioration of maximal speed due to severe tail loss probably has a low (undetectable) ecological impact, at least for adults.

  20. Upper lifting performance of healthy young adults in functional capacity evaluations: a comparison of two protocols.

    PubMed

    IJmker, S; Gerrits, E H; Reneman, M F

    2003-12-01

    The objectives of this study were to explore the concurrent validity of test results of upper lifting tasks of the Ergo-Kit FCE and the Isernhagen Work Systems (IWS) FCE. Seventy-one healthy young adults performed 5 upper lifting tests with at least 5 min of rest in between. The lifting tests included 3 standard protocols and 2 modified protocols. Three criteria for concurrent validity were established: 1) Pearson correlation higher than .75, 2) nonsignificant two-tailed t test, and 3) mean difference smaller than 5 kg. The results showed that none of the criteria were met for the standard protocols. For the modified protocols criteria 2 and 3 were not met. Individual differences larger than 10 kg were found for both standard and modified protocols. It was concluded that the standard protocols for upper lifting tasks of the Ergo-Kit FCE and the IWS FCE do not meet the criteria for concurrent validity and can, therefore, not be used interchangeably.

  1. Rapid determination of lamivudine in human plasma by high-performance liquid chromatography.

    PubMed

    Alebouyeh, Mahmoud; Amini, Hossein

    2015-01-15

    A simple and rapid high-performance liquid chromatographic method with spectrophotometric detection was developed for the determination of lamivudine in human plasma. Sample preparation was accomplished through protein precipitation with acetonitrile followed by aqueous phase separation using dichloromethane. Lamivudine and the internal standard acyclovir were well separated from endogenous plasma peaks on a Chromolith RP-18e column under isocratic elution with 50 mM sodium dihydrogen phosphate-triethylamine (996:4, v/v), pH 3.2 at 20 °C. Total run time at a flow-rate of 1.5 ml/min was less than 5 min. Detection was made at 278 nm. The method was specific and sensitive, with a lower quantification limit of 40 ng/ml and a detection limit of 10 ng/ml. The absolute recovery was 97.7%, while the within- and between-day coefficient of variation and percent error values of the assay method were all less than 7%. The linearity was assessed in the range of 40-2560 in plasma, with a correlation coefficient of greater than 0.999. The method was successfully applied to a bioequivalence study in healthy volunteers.

  2. Removal of fluoride by hydrous manganese oxide-coated alumina: performance and mechanism.

    PubMed

    Teng, Shao-Xiang; Wang, Shu-Guang; Gong, Wen-Xin; Liu, Xian-Wei; Gao, Bao-Yu

    2009-09-15

    A novel hydrous-manganese-oxide-coated alumina (HMOCA) material was prepared through a redox process. The adsorbent was characterized by SEM, BET surface area measurement, XRD, pH(PZC) measurement, FTIR spectroscopy, and XPS. The manganese oxides were amorphous and manganese existed mainly in the +IV oxidation state. Batch and column experiments were carried out to investigate the adsorption potential of the adsorbent. Fluoride adsorption onto HMOCA followed the pseudo-second-order equation well with a correlation coefficient greater than 0.99. Both external and intraparticle diffusion contributed to the rate of transfer and removal. The adsorption of fluoride was thought to take place mainly by ion-exchange. Optimum removal of fluoride occurred in a pH range of 4.0-6.0. The maximum adsorption capacity calculated from the Langmuir model was 7.09 mg/g. The presence of HCO(3)(-), SO(4)(2-) and PO(4)(3-) had negative effects on the adsorption of fluoride. The adsorbed fluoride can be released by alkali solution. Column studies were performed and 669 bed volumes were treated with the effluent fluoride under 1.0mg/L at an influent F(-) concentration of 5.0mg/L and flow rate of 2.39 m(3)/(m(2)h) (empty bed contact time=7.5 min).

  3. Simultaneous determination of 21 preservatives in cosmetics by ultra performance liquid chromatography.

    PubMed

    Wu, T; Wang, C; Wang, X; Ma, Q

    2008-10-01

    An ultra performance liquid chromatography (UPLC) method has been developed for the simultaneous determination of 21 preservatives: 2-methyl-4-isothiazoline-3-ketone, bronopol, 5-chloro-2-methyl-4-isothiazoline-3-ketone, benzyl alcohol, 2-phenoxyethanol, methyl-p-hydroxy benzoate, ethyl-p-hydroxy benzoate, methyl benzoate, 4-hydroxybenzoic acid iso-propyl ester, propyl-p-hydroxy benzoate, 4-chloro-3-methylphenol, ethyl benzoate, 2-phenylphenol, 4-hydroxybenzoic acid iso-butyl ester, butyl-p-hydroxy benzoate, 4-chloro-3,5-dimethylphenol, phenyl benzoate, 2,4-dichloro-3,5-dimethylphenol, 2-benzyl-4-chlorophenol, triclocarban and triclosan in cosmetics. A Waters ACQUITY UPLC BEH C(18) column was used with 0.1% formic acid solution as the mobile phase under the condition of gradient elution. Preservatives were extracted with methanol by ultrasonicator, and then they were analysed by UPLC-PDA detector. All these preservatives were baseline separated in 8.5 min. The pre-treatment method of samples and the chromatographic condition of analysis were critically examined in this study. The recoveries ranged from 90.5 to 97.8%, with RSD values below 3.2%, and all correlation coefficients (r) were no less than 0.9997. Thus, this method could be used for analysing the preservatives in cosmetic products.

  4. A new device for performing reference point indentation without a reference probe

    PubMed Central

    Bridges, Daniel; Randall, Connor; Hansma, Paul K.

    2012-01-01

    Here we describe a novel, hand-held reference point indentation (RPI), instrument that is designed for clinical measurements of bone material properties in living patients. This instrument differs from previous RPI instruments in that it requires neither a reference probe nor removal of the periosteum that covers the bone, thus significantly simplifying its use in patient testing. After describing the instrument, we discuss five guidelines for optimal and reproducible results. These are: (1) the angle between the normal to the surface and the axis of the instrument should be less than 10°, (2) the compression of the main spring to trigger the device must be performed slowly (>1 s), (3) the probe tip should be sharper than 10 μm; however, a normalized parameter with a calibration phantom can correct for dull tips up to a 100 μm radius, (4) the ambient room temperature should be between 4 °C and 37 °C, and (5) the effective mass of the bone or material under test must exceed 1 kg, or if under 1 kg, the specimen should be securely anchored in a fixation device with sufficient mass (which is not a requirement of previous RPI instruments). Our experience is that a person can be trained with these guidelines in about 5 min and thereafter obtain accurate and reproducible results. The portability, ease of use, and minimal training make this instrument suitable to measure bone material properties in a clinical setting. PMID:22559552

  5. A new device for performing reference point indentation without a reference probe.

    PubMed

    Bridges, Daniel; Randall, Connor; Hansma, Paul K

    2012-04-01

    Here we describe a novel, hand-held reference point indentation (RPI), instrument that is designed for clinical measurements of bone material properties in living patients. This instrument differs from previous RPI instruments in that it requires neither a reference probe nor removal of the periosteum that covers the bone, thus significantly simplifying its use in patient testing. After describing the instrument, we discuss five guidelines for optimal and reproducible results. These are: (1) the angle between the normal to the surface and the axis of the instrument should be less than 10°, (2) the compression of the main spring to trigger the device must be performed slowly (>1 s), (3) the probe tip should be sharper than 10 μm; however, a normalized parameter with a calibration phantom can correct for dull tips up to a 100 μm radius, (4) the ambient room temperature should be between 4 °C and 37 °C, and (5) the effective mass of the bone or material under test must exceed 1 kg, or if under 1 kg, the specimen should be securely anchored in a fixation device with sufficient mass (which is not a requirement of previous RPI instruments). Our experience is that a person can be trained with these guidelines in about 5 min and thereafter obtain accurate and reproducible results. The portability, ease of use, and minimal training make this instrument suitable to measure bone material properties in a clinical setting.

  6. Diurnal variation in Wingate-test performance and associated electromyographic parameters.

    PubMed

    Chtourou, Hamdi; Zarrouk, Nidhal; Chaouachi, Anis; Dogui, Mohamed; Behm, David G; Chamari, Karim; Hug, François; Souissi, Nizar

    2011-10-01

    The present study was designed to evaluate time-of-day effects on electromyographic (EMG) activity changes during a short-term intense cycling exercise. In a randomized order, 22 male subjects were asked to perform a 30-s Wingate test against a constant braking load of 0.087 kg·kg(-1) body mass during two experimental sessions, which were set up either at 07:00 or 17:00 h. During the test, peak power (P(peak)), mean power (P(mean)), fatigue index (FI; % of decrease in power output throughout the 30 s), and evolution of power output (5-s span) throughout the exercise were analyzed. Surface EMG activity was recorded in both the vastus lateralis and vastus medialis muscles throughout the test and analyzed over a 5-s span. The root mean square (RMS) and mean power frequency (MPF) of EMG were calculated. Neuromuscular efficiency (NME) was estimated from the ratio of power to RMS. Resting core temperature, P(peak), P(mean), and FI were significantly higher (p < .05) in the evening than morning test (e.g., P(peak): 11.6 ± 0.8 vs. 11.9 ± 1 W·kg(-1)). The results showed that power output decreased following two phases. During the first phase (first 20s), power output decreased rapidly and values were higher (p < .05) in the evening than in the morning. During the second phase (last 10s), power decreased slightly and appeared independent of the time of day of testing. This power output decrease was paralleled by evolution of the MPF and NME. During the first phase, NME and MPF were higher (p < .05) in the evening. During the second phase, NME and MPF were independent of time of day. In addition, no significant differences were noticed between 7:00 and 17:00 h for EMG RMS during the whole 30 s. Taken together, these results suggest that peripheral mechanisms (i.e., muscle power and fatigue) are more likely the cause of the diurnal variation of the Wingate-test performance rather than central mechanisms.

  7. Preseason changes in markers of lower body fatigue and performance in young professional rugby union players.

    PubMed

    Roe, Gregory A B; Darrall-Jones, Joshua D; Till, Kevin; Jones, Ben

    2016-11-01

    This study investigated the changes in measures of neuromuscular fatigue and physical performance in young professional rugby union players during a preseason training period. Fourteen young (age: 19.1 ± 1.2 years) professional rugby union players participated in the study. Changes in measures of lower body neuromuscular fatigue (countermovement jump (CMJ) mean power, mean force, flight-time) and physical performance (lower body strength, 40 m sprint velocity) were assessed during an 11-week preseason period using magnitude-based inferences. CMJ mean power was likely to very likely decreased during week 2 (-8.1 ± 5.5% to -12.5 ± 6.8%), and likely to almost certainly decreased from weeks 5 to 11 (-10 ± 4.3% to -14.7 ± 6.9%), while CMJ flight-time demonstrated likely to very likely decreases during weeks 2, and weeks 4-6 (-2.41 ± 1% to -3.3 ± 1.3%), and weeks 9-10 (-1.9 ± 0.9% to -2.2 ± 1.5%). Despite this, possible improvements in lower body strength (5.8 ± 2.7%) and very likely improvements in 40 m velocity (5.5 ± 3.6%) were made. Relationships between changes in CMJ metrics and lower body strength or 40 m sprint velocity were trivial or small (<0.22). Increases in lower body strength and 40 m velocity occurred over the course of an 11-week preseason despite the presence of neuromuscular fatigue (as measured by CMJ). The findings of this study question the usefulness of CMJ for monitoring fatigue in the context of strength and sprint velocity development. Future research is needed to ascertain the consequences of negative changes in CMJ in the context of rugby-specific activities to determine the usefulness of this test as a measure of fatigue in this population.

  8. A comparison of caffeine versus pseudoephedrine on cycling time-trial performance.

    PubMed

    Spence, Angela L; Sim, Marc; Landers, Grant; Peeling, Peter

    2013-10-01

    Both caffeine (CAF) and pseudoephedrine (PSE) are proposed to be central nervous system stimulants. However, during competition, CAF is a permitted substance, whereas PSE is a banned substance at urinary levels >150 μg · ml(-1). As a result, this study aimed to compare the effect of CAF versus PSE use on cycling time trial (TT) performance to explore whether the legal stimulant was any less ergogenic than the banned substance. Here, 10 well-trained male cyclists or triathletes were recruited for participation. All athletes were required to attend the laboratory on four separate occasions--including a familiarization trial and three experimental trials, which required participants to complete a simulated 40 km (1,200 kJ) cycling TT after the ingestion of either 200 mg CAF, 180 mg PSE or a nonnutritive placebo (PLA). The results showed that the total time taken and the mean power produced during each TT was not significantly different (p > .05) between trials, despite a 1.3% faster overall time (~57 s) after CAF consumption. Interestingly, the time taken to complete the second half of the TT was significantly faster (p < .05) in CAF as compared with PSE (by 99 s), with magnitude based inferences suggesting a 91% beneficial effect of CAF during the second half of the TT. This investigation further confirms the ergogenic benefits of CAF use during TT performances and further suggests this legal CNS stimulant has a better influence than a supra-therapeutic dose of PSE.

  9. Variations in Hypoxia Impairs Muscle Oxygenation and Performance during Simulated Team-Sport Running

    PubMed Central

    Sweeting, Alice J.; Billaut, François; Varley, Matthew C.; Rodriguez, Ramón F.; Hopkins, William G.; Aughey, Robert J.

    2017-01-01

    Purpose: To quantify the effect of acute hypoxia on muscle oxygenation and power during simulated team-sport running. Methods: Seven individuals performed repeated and single sprint efforts, embedded in a simulated team-sport running protocol, on a non-motorized treadmill in normoxia (sea-level), and acute normobaric hypoxia (simulated altitudes of 2,000 and 3,000 m). Mean and peak power was quantified during all sprints and repeated sprints. Mean total work, heart rate, blood oxygen saturation, and quadriceps muscle deoxyhaemoglobin concentration (assessed via near-infrared spectroscopy) were measured over the entire protocol. A linear mixed model was used to estimate performance and physiological effects across each half of the protocol. Changes were expressed in standardized units for assessment of magnitude. Uncertainty in the changes was expressed as a 90% confidence interval and interpreted via non-clinical magnitude-based inference. Results: Mean total work was reduced at 2,000 m (−10%, 90% confidence limits ±6%) and 3,000 m (−15%, ±5%) compared with sea-level. Mean heart rate was reduced at 3,000 m compared with 2,000 m (−3, ±3 min−1) and sea-level (−3, ±3 min−1). Blood oxygen saturation was lower at 2,000 m (−8, ±3%) and 3,000 m (−15, ±2%) compared with sea-level. Sprint mean power across the entire protocol was reduced at 3,000 m compared with 2,000 m (−12%, ±3%) and sea-level (−14%, ±4%). In the second half of the protocol, sprint mean power was reduced at 3,000 m compared to 2,000 m (−6%, ±4%). Sprint mean peak power across the entire protocol was lowered at 2,000 m (−10%, ±6%) and 3,000 m (−16%, ±6%) compared with sea-level. During repeated sprints, mean peak power was lower at 2,000 m (−8%, ±7%) and 3,000 m (−8%, ±7%) compared with sea-level. In the second half of the protocol, repeated sprint mean power was reduced at 3,000 m compared to 2,000 m (−7%, ±5%) and sea-level (−9%, ±5%). Quadriceps muscle

  10. Endurance capacity and high-intensity exercise performance responses to a high fat diet.

    PubMed

    Fleming, Jesse; Sharman, Matthew J; Avery, Neva G; Love, Dawn M; Gómez, Ana L; Scheett, Timothy P; Kraemer, William J; Volek, Jeff S

    2003-12-01

    The effects of adaptation to a high-fat diet on endurance performance are equivocal, and there is little data regarding the effects on high-intensity exercise performance. This study examined the effects of a high-fat/moderate protein diet on submaximal, maximal, and supramaximal performance. Twenty non-highly trained men were assigned to either a high-fat/moderate protein (HFMP; 61% fat diet) (n = 12) or a control (C; 25% fat) group (n = 8). A maximal oxygen consumption test, two 30-s Wingate anaerobic tests, and a 45-min timed ride were performed before and after 6 weeks of diet and training. Body mass decreased significantly (-2.2 kg; p < or = .05) in HFMP subjects. Maximal oxygen consumption significantly decreased in the HFMP group (3.5 +/- 0.14 to 3.27 +/- 0.09 L x min(-1)) but was unaffected when corrected for body mass. Perceived exertion was significantly higher during this test in the HFMP group. Main time effects indicated that peak and mean power decreased significantly during bout 1 of the Wingate sprints in the HFMP (-10 and -20%, respectively) group but not the C (-8 and -16%, respectively) group. Only peak power was lower during bout 1 in the HFMP group when corrected for body mass. Despite significantly reduced RER values in the HFMP group during the 45-min cycling bout, work output was significantly decreased (-18%). Adaptation to a 6-week HFMP diet in non-highly trained men resulted in increased fat oxidation during exercise and small decrements in peak power output and endurance performance. These deleterious effects on exercise performance may be accounted for in part by a reduction in body mass and/or increased ratings of perceived exertion.

  11. Performing Gram stain directly on catheter tips: assessment of the quality of the observation process.

    PubMed

    Guembe, M; Pérez-Granda, M J; Rivera, M L; Martín-Rabadán, P; Bouza, E

    2015-06-01

    A previous study performed in our institution showed that catheter tip (CT) staining by combining acridine orange and Gram stain (GS) before culture anticipated catheter colonization with exhaustive and careful observation by a highly trained technician. Our objective was to assess the validity values of GS without acridine orange on an external smear of CT for predicting catheter colonization and catheter-related bloodstream infection (C-RBSI). We compared different periods of observation and the results of two technicians with different levels of professional experience. Over a 5-month period, the roll-plate technique was preceded by direct GS of all CTs sent to the microbiology laboratory. The reading was taken at ×100 by two observers with different skill levels. Each observer performed a routine examination (3 min along three longitudinal lines) and an exhaustive examination (5 min along five longitudinal lines). The presence of at least one cell was considered positive. All slides were read before culture results were known. We included a total of 271 CTs from 209 patients. The prevalence of catheter colonization and C-RBSI was 16.2 % and 5.1 %, respectively. Routine and exhaustive examinations revealed only 29.5 % and 40.9 % of colonized catheters, respectively (p < 0.001). In contrast, they revealed high negative predictive values for C-RBSI (96.5 % and 96.3 %, respectively). Our study shows that the yield of GS performed directly on CTs is greater when staining is performed exhaustively. However, the decision to implement this approach in daily routine will depend on the prevalence rate of catheter colonization at each institution.

  12. Nighttime feeding likely alters morning metabolism but not exercise performance in female athletes.

    PubMed

    Ormsbee, Michael J; Gorman, Katherine A; Miller, Elizabeth A; Baur, Daniel A; Eckel, Lisa A; Contreras, Robert J; Panton, Lynn B; Spicer, Maria T

    2016-07-01

    The timing of morning endurance competition may limit proper pre-race fueling and resulting performance. A nighttime, pre-sleep nutritional strategy could be an alternative method to target the metabolic and hydrating needs of the early morning athlete without compromising sleep or gastrointestinal comfort during exercise. Therefore, the purpose of this investigation was to examine the acute effects of pre-sleep chocolate milk (CM) ingestion on next-morning running performance, metabolism, and hydration status. Twelve competitive female runners and triathletes (age, 30 ± 7 years; peak oxygen consumption, 53 ± 4 mL·kg(-1)·min(-1)) randomly ingested either pre-sleep CM or non-nutritive placebo (PL) ∼30 min before sleep and 7-9 h before a morning exercise trial. Resting metabolic rate (RMR) was assessed prior to exercise. The exercise trial included a warm-up, three 5-min incremental workloads at 55%, 65%, and 75% peak oxygen consumption, and a 10-km treadmill time trial (TT). Physiological responses were assessed prior, during (incremental and TT), and postexercise. Paired t tests and magnitude-based inferences were used to determine treatment differences. TT performances were not different ("most likely trivial" improvement with CM) between conditions (PL: 52.8 ± 8.4 min vs CM: 52.8 ± 8.0 min). RMR was "likely" increased (4.8%) and total carbohydrate oxidation (g·min(-1)) during exercise was "possibly" or likely increased (18.8%, 10.1%, 9.1% for stage 1-3, respectively) with CM versus PL. There were no consistent changes to hydration indices. In conclusion, pre-sleep CM may alter next-morning resting and exercise metabolism to favor carbohydrate oxidation, but effects did not translate to 10-km running performance improvements.

  13. How Performance Improves

    SciTech Connect

    Jerry L. Harbour; Julie L. Marble

    2005-09-01

    Countless articles and books have been written about and numerous programs have been developed to improve performance. Despite this plethora of activity on how to improve performance, we have largely failed to address the more fundamental question of how performance actually improves. To begin exploring this more basic question, we have plotted some 1,200 performance records to date and found that irrespective of venue, industry, or business, there seems to be a fundamental and repeatable set of concepts regarding how performance improves over time. Such gained insights represent both opportunities and challenges to the performance technologist. Differences in performance outcomes may, for example, be as much a function of the life cycle stage of a performance system as the efficacy of the selected improvement method itself. Accordingly, it may be more difficult to compare differing performance improvement methods than previously thought.

  14. Kinesics and Performance

    ERIC Educational Resources Information Center

    Schechner, Richard; Mintz, Cynthia

    1973-01-01

    Current teaching and thinking about theatre performances tend to ignore kinesics. Kinesics study answers the need for consideration of analogical thinking and nonverbal communication distinctive to theatrical performance. (CH)

  15. Performing Narrative Medicine

    ERIC Educational Resources Information Center

    Langellier, Kristin M.

    2009-01-01

    In this article, the author weaves narrative medicine and performance together to consider what might it mean to call narrative medicine a performance. To name narrative medicine as performance is to recognize the texts and bodies, the stories and selves, that participate in its practice--patients' and physicians' embodied stories as well as the…

  16. Integrating Learning and Performance.

    ERIC Educational Resources Information Center

    1998

    This document contains four papers from a symposium on integrating learning and performance in human resource development (HRD). "Action Imperatives that Impact Knowledge Performance and Financial Performance in the Learning Organization: An Exploratory Model" (Gary L. Selden, Karen E. Watkins, Thomas Valentine, Victoria J. Marsick)…

  17. IR DIAL performance modeling

    SciTech Connect

    Sharlemann, E.T.

    1994-07-01

    We are developing a DIAL performance model for CALIOPE at LLNL. The intent of the model is to provide quick and interactive parameter sensitivity calculations with immediate graphical output. A brief overview of the features of the performance model is given, along with an example of performance calculations for a non-CALIOPE application.

  18. Teaching Tips: Performance Literacy

    ERIC Educational Resources Information Center

    Dillingham, Brett

    2005-01-01

    As educators struggle to find ways to engage students in literacy development and content area exploration, performance literacy is emerging as an important pedagogical tool. This article defines performance literacy as the process of teaching students to write and perform stories. The author lists the five major components in the development of…

  19. Seven Performance Drivers.

    ERIC Educational Resources Information Center

    Ross, Linda

    2003-01-01

    Recent work with automotive e-commerce clients led to the development of a performance analysis methodology called the Seven Performance Drivers, including: standards, incentives, capacity, knowledge and skill, measurement, feedback, and analysis. This methodology has been highly effective in introducing and implementing performance improvement.…

  20. Performance Support in Perspective.

    ERIC Educational Resources Information Center

    Banerji, Ashok

    1999-01-01

    Discusses the integrated concept of electronic performance support systems (EPSS) as a solution to meet performance needs of knowledge-rich workplaces where information overload is often a problem. Considers the adoption of information technology, task performance time, and support functions, and gives an example of an EPSS for marine shipping…

  1. Nutrition and Mental Performance

    ERIC Educational Resources Information Center

    Stein, Zena; And Others

    1972-01-01

    Prenatal exposure to the Dutch famine of 1944-45 had no detectable effects on the adult mental performance of surviving male offspring; birth weight was not related to mental performance; and the association of social class with mental performance was strong. (AL)

  2. Rhythms of Mental Performance

    ERIC Educational Resources Information Center

    Valdez, Pablo; Reilly, Thomas; Waterhouse, Jim

    2008-01-01

    Cognitive performance is affected by an individual's characteristics and the environment, as well as by the nature of the task and the amount of practice at it. Mental performance tests range in complexity and include subjective estimates of mood, simple objective tests (reaction time), and measures of complex performance that require decisions to…

  3. Performance Measurement Redux.

    ERIC Educational Resources Information Center

    Feller, Irwin

    2002-01-01

    Continues the exploration of the effective use and misuse of performance indicators that has been conducted by various authors in this journal. Identifies some further limitations on the use of performance measurement and notes that many performance measurement undertakings make no provision for evaluating the impact of the undertakings…

  4. Performance Improvement Assuming Complexity

    ERIC Educational Resources Information Center

    Rowland, Gordon

    2007-01-01

    Individual performers, work teams, and organizations may be considered complex adaptive systems, while most current human performance technologies appear to assume simple determinism. This article explores the apparent mismatch and speculates on future efforts to enhance performance if complexity rather than simplicity is assumed. Included are…

  5. Chemical profiling and quantification of Gua-Lou-Gui-Zhi decoction by high performance liquid chromatography/quadrupole-time-of-flight mass spectrometry and ultra-performance liquid chromatography/triple quadrupole mass spectrometry.

    PubMed

    Xu, Wen; Huang, Mingqing; Li, Huang; Chen, Xianwen; Zhang, Yuqin; Liu, Jie; Xu, Wei; Chu, Kedan; Chen, Lidian

    2015-04-01

    Gua-Lou-Gui-Zhi decoction (GLGZD) is a classical formula of traditional Chinese medicine, which has been commonly used to treat dysfunction after stroke, epilepsy and spinal cord injury. In this study, a systematic method was established for chemical profiling and quantification analysis of the major constituents in GLGZD. For qualitative analysis, a method of high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (Q-TOF MS) was developed. 106 compounds, including monoterpene glycosides, galloyl glucoses, phenolic acids, flavonoids, gingerols and triterpene saponins were identified or tentatively presumed by comparison with reference standards or literature data. According to the qualitative results, a new quantitative analysis method of ultra-performance liquid chromatography/triple quadrupole mass spectrometry (QqQ-MS) was established. 24 representative compounds were simultaneously detected in 10 batches of GLGZD samples in 7.5 min. The calibration curves for all analytes showed good linearity (r>0.9959) within the test ranges. The LODs and the LOQs were less than 30.6 and 70.9 ng/mL, respectively. The RSDs of intra- and inter-day precision, repeatability and stability were below 3.64%, 4.85%, 4.84% and 3.87%, respectively. The overall recoveries ranged from 94.94% to 103.66%, with the RSDs within 5.12%. This study established a high sensitive and efficient method for the integrating quality control, including identification and quantification of Chinese medicinal preparation.

  6. Effects of caffeine and carbohydrate mouth rinses on repeated sprint performance.

    PubMed

    Beaven, C Martyn; Maulder, Peter; Pooley, Adrian; Kilduff, Liam; Cook, Christian

    2013-06-01

    Our purpose was to examine the effectiveness of carbohydrate and caffeine mouth rinses in enhancing repeated sprint ability. Previously, studies have shown that a carbohydrate mouth rinse (without ingestion) has beneficial effects on endurance performance that are related to changes in brain activity. Caffeine ingestion has also demonstrated positive effects on sprint performance. However, the effects of carbohydrate or caffeine mouth rinses on intermittent sprints have not been examined previously. Twelve males performed 5 × 6-s sprints interspersed with 24 s of active recovery on a cycle ergometer. Twenty-five milliliters of either a noncaloric placebo, a 6% glucose, or a 1.2% caffeine solution was rinsed in the mouth for 5 s prior to each sprint in a double-blinded and balanced cross-over design. Postexercise maximal heart rate and perceived exertion were recorded, along with power measures. A second experiment compared a combined caffeine-carbohydrate rinse with carbohydrate only. Compared with the placebo mouth rinse, carbohydrate substantially increased peak power in sprint 1 (22.1 ± 19.5 W; Cohen's effect size (ES), 0.81), and both caffeine (26.9 ± 26.9 W; ES, 0.71) and carbohydrate (39.1 ± 25.8 W; ES, 1.08) improved mean power in sprint 1. Experiment 2 demonstrated that a combination of caffeine and carbohydrate improved sprint 1 power production compared with carbohydrate alone (36.0 ± 37.3 W; ES, 0.81). We conclude that carbohydrate and (or) caffeine mouth rinses may rapidly enhance power production, which could have benefits for specific short sprint exercise performance. The ability of a mouth-rinse intervention to rapidly improve maximal exercise performance in the absence of fatigue suggests a central mechanism.

  7. Prolonged self-paced exercise in the heat – environmental factors affecting performance

    PubMed Central

    Junge, Nicklas; Jørgensen, Rasmus; Flouris, Andreas D.; Nybo, Lars

    2016-01-01

    ABSTRACT In this review we examine how self-paced performance is affected by environmental heat stress factors during cycling time trial performance as well as considering the effects of exercise mode and heat acclimatization. Mean power output during prolonged cycling time trials in the heat (≥30°C) was on average reduced by 15% in the 14 studies that fulfilled the inclusion criteria. Ambient temperature per se was a poor predictor of the integrated environmental heat stress and 2 of the prevailing heat stress indices (WBGT and UTCI) failed to predict the environmental influence on performance. The weighing of wind speed appears to be too low for predicting the effect for cycling in trained acclimatized subjects, where performance may be maintained in outdoor time trials at ambient temperatures as high as 36°C (36°C UTCI; 28°C WBGT). Power output during indoor trials may also be maintained with temperatures up to at least 27°C when humidity is modest and wind speed matches the movement speed generated during outdoor cycling, whereas marked reductions are observed when air movement is minimal. For running, representing an exercise mode with lower movement speed and higher heat production for a given metabolic rate, it appears that endurance is affected even at much lower ambient temperatures. On this basis we conclude that environmental heat stress impacts self-paced endurance performance. However, the effect is markedly modified by acclimatization status and exercise mode, as the wind generated by the exercise (movement speed) or the environment (natural or fan air movement) exerts a strong influence. PMID:28090557

  8. Off-Ice Anaerobic Power Does Not Predict On-Ice Repeated Shift Performance in Hockey.

    PubMed

    Peterson, Ben J; Fitzgerald, John S; Dietz, Calvin C; Ziegler, Kevin S; Baker, Sarah E; Snyder, Eric M

    2016-09-01

    Peterson, BJ, Fitzgerald, JS, Dietz, CC, Ziegler, KS, Baker, SE, and Snyder, EM. Off-ice anaerobic power does not predict on-ice repeated shift performance in hockey. J Strength Cond Res 30(9): 2375-2381, 2016-Anaerobic power is a significant predictor of acceleration and top speed in team sport athletes. Historically, these findings have been applied to ice hockey although recent research has brought their validity for this sport into question. As ice hockey emphasizes the ability to repeatedly produce power, single bout anaerobic power tests should be examined to determine their ability to predict on-ice performance. We tested whether conventional off-ice anaerobic power tests could predict on-ice acceleration, top speed, and repeated shift performance. Forty-five hockey players, aged 18-24 years, completed anthropometric, off-ice, and on-ice tests. Anthropometric and off-ice testing included height, weight, body composition, vertical jump, and Wingate tests. On-ice testing consisted of acceleration, top speed, and repeated shift fatigue tests. Vertical jump (VJ) (r = -0.42; r = -0.58), Wingate relative peak power (WRPP) (r = -0.32; r = -0.43), and relative mean power (WRMP) (r = -0.34; r = -0.48) were significantly correlated (p ≤ 0.05) to on-ice acceleration and top speed, respectively. Conversely, none of the off-ice tests correlated with on-ice repeated shift performance, as measured by first gate, second gate, or total course fatigue; VJ (r = 0.06; r = 0.13; r = 0.09), WRPP (r = 0.06; r = 0.14; r = 0.10), or WRMP (r = -0.10; r = -0.01; r = -0.01). Although conventional off-ice anaerobic power tests predict single bout on-ice acceleration and top speed, they neither predict the repeated shift ability of the player, nor are good markers for performance in ice hockey.

  9. Relationship of body mass status with running and jumping performances in young basketball players

    PubMed Central

    Nikolaidis, Pantelis Theodoros; Asadi, Abbas; Santos, Eduardo J.A.M.; Calleja-González, Julio; Padulo, Johnny; Chtourou, Hamdi; Zemkova, Erika

    2015-01-01

    Summary Purpose the main purpose of this study was to examine the relationship of body mass (BM) status with running and jumping performances in young male basketball players. Methods basketball players (n=72, age 12.9±2.8 yrs), who were grouped into U-12 (9–12 yrs), U-15 (12–15 yrs) and U-18 (15–18 yrs), performed a battery of anthropometric, running and jumping tests. We examined differences among age groups, and between normal weight and overweight players. Results the results indicated significant and large differences among age groups in BM, height, body mass index (BMI), fat mass (FM), fat-free mass, speed, endurance, standing long jump, countermovement jump (CMJ), mean power in 30 s jumping test (Pmean) (p<0.001, η2≥0.23) with older players presenting higher values. Within each age group, overweight players had higher BM, BMI, body fat percentage and FM (p<0.05) than their normal weight counterparts. Overweight players had worst performance in running (sprint and endurance) and jumping (CMJ and Pmean) in U-12, and worst endurance in U-18 (p<0.05, |d|≥0.82) than normal-weight players, whereas there was no difference in U-15. Conclusions it was concluded that the relationship of BMI with running and jumping performances varied according to age. Based on these findings, trainers and coaches should focus on special intervention exercise and nutrition programs targeting optimal body mass especially in young basketball players, where the excess of body mass seemed to have the most detrimental effect on running and jumping performances. PMID:26605193

  10. Prolonged self-paced exercise in the heat - environmental factors affecting performance.

    PubMed

    Junge, Nicklas; Jørgensen, Rasmus; Flouris, Andreas D; Nybo, Lars

    2016-01-01

    In this review we examine how self-paced performance is affected by environmental heat stress factors during cycling time trial performance as well as considering the effects of exercise mode and heat acclimatization. Mean power output during prolonged cycling time trials in the heat (≥30°C) was on average reduced by 15% in the 14 studies that fulfilled the inclusion criteria. Ambient temperature per se was a poor predictor of the integrated environmental heat stress and 2 of the prevailing heat stress indices (WBGT and UTCI) failed to predict the environmental influence on performance. The weighing of wind speed appears to be too low for predicting the effect for cycling in trained acclimatized subjects, where performance may be maintained in outdoor time trials at ambient temperatures as high as 36°C (36°C UTCI; 28°C WBGT). Power output during indoor trials may also be maintained with temperatures up to at least 27°C when humidity is modest and wind speed matches the movement speed generated during outdoor cycling, whereas marked reductions are observed when air movement is minimal. For running, representing an exercise mode with lower movement speed and higher heat production for a given metabolic rate, it appears that endurance is affected even at much lower ambient temperatures. On this basis we conclude that environmental heat stress impacts self-paced endurance performance. However, the effect is markedly modified by acclimatization status and exercise mode, as the wind generated by the exercise (movement speed) or the environment (natural or fan air movement) exerts a strong influence.

  11. Fiscal Year 2009 Performance Budget: Performance Plan

    ERIC Educational Resources Information Center

    US Department of Education, 2008

    2008-01-01

    The U.S. Department of Education set the following goals as measures of their annual performance: (1) Improve student achievement, with a focus on bringing all students to grade level in reading and mathematics by 2014; (2) Increase the academic achievement of all high school students; and (3) Ensure the accessibility, affordability and…

  12. Algorithm performance evaluation

    NASA Astrophysics Data System (ADS)

    Smith, Richard N.; Greci, Anthony M.; Bradley, Philip A.

    1995-03-01

    Traditionally, the performance of adaptive antenna systems is measured using automated antenna array pattern measuring equipment. This measurement equipment produces a plot of the receive gain of the antenna array as a function of angle. However, communications system users more readily accept and understand bit error rate (BER) as a performance measure. The work reported on here was conducted to characterize adaptive antenna receiver performance in terms of overall communications system performance using BER as a performance measure. The adaptive antenna system selected for this work featured a linear array, least mean square (LMS) adaptive algorithm and a high speed phase shift keyed (PSK) communications modem.

  13. Pharmacokinetics of honokiol after intravenous guttae in beagle dogs assessed using ultra-performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Liang, Yi; Cui, Gang; Wang, Xiaoxue; Zhang, Wei; An, Quan; Lin, Zongtao; Wang, Hong; Chen, Shizhong

    2014-10-01

    A simple, rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of honokiol in beagle dog plasma after intravenous guttae. With addition of the internal standard magnolol, plasma samples were precipitated with methanol and separated on a Shim-pack XR-ODS II (2.0 × 100 mm, 2.2 µm) with isocratic elution of methanol and water (80:20) solution at a flow rate of 0.2 mL/min. A good separation of honokiol was achieved within 3.5 min. Quantification was performed on a Waters Quattro Premier XE triple quadrupole mass spectrometer with electrospray ionization inlet in the negative multiple reaction monitoring mode. Good linearity was obtained over the concentration range of 5.12-15580 ng/mL (r(2) > 0.998). Intra- and inter-day precisions were <13.10%, and accuracy ranged from 89.21 to 99.92%. The lower limit of quantification for honokiol was 5.12 ng/mL, and honokiol was stable under various conditions (three freeze-thaw cycles, short-term temperature, post-preparative and long-term temperature conditions.). This validated method was successfully applied to the pharmacokinetic study of honokiol in dogs by intravenous guttae.

  14. Performance of cellulose acetate - polyethersulphone blend membrane prepared using microwave heating for palm oil mill effluent treatment.

    PubMed

    Idris, A; Ahmed, I; Jye, H W

    2007-01-01

    The objective of this research is to investigate the performance of blend cellulose acetate (CA)-polyethersulphone (PES) membranes prepared using microwave heating (MWH) techniques and then compare it with blend CA-PES membranes prepared using conventional heating (CH) methods using bovine serum albumin solution. The superior membranes were then used in the treatment of palm oil mill effluent (POME). Various blends of CA-PES have been blended with PES in the range of 1-5 wt%. This distinctive series of dope formulations of blend CA/PES and pure CA was prepared using N, N-dimethylformamide (DMF) as solvent. The dope solution was prepared by MW heating for 5 min at a high pulse and the membranes were prepared by phase inversion method. The performances of these membranes were evaluated in terms of pure water and permeate flux, percentage removal of total suspended solids (TSS), chemical oxygen demand (COD) and biochemical oxygen demand (BOD). The results indicate that blend membranes prepared using the microwave technique is far more superior compared to that prepared using CH. Blend membranes with 19% CA, 1-3% PES and 80% of DMF solvent were found to be the best membrane formulation.

  15. European athletes dominate performances in Double Iron ultra-triathlons--a retrospective data analysis from 1985 to 2010.

    PubMed

    Rüst, Christoph Alexander; Knechtle, Beat; Knechtle, Patrizia; Lepers, Romuald; Rosemann, Thomas; Onywera, Vincent

    2014-01-01

    We investigated the participation and performance trends of ultra-endurance triathletes from all nationalities competing in a Double Iron ultra-triathlon (7.6-km swim, 360-km cycle and 84.4-km run) from 1985 to 2010. A total of 1854 athletes participated in 92 Double Iron ultra-triathlons. The majority of the winners came from Europe with 72 victories, followed by North America with 17 victories. The race time for the European ultra-triathletes was 1340 (s=95.3) min, decreasing highly significantly (r (2)=0.28; P<0.0001) across the years. North American ultra-triathletes finished the races within 1556 (s=124.5) min; their race time showed no changes across the years (r (2)=0.045; P=0.07). The race time for the Europeans was highly significantly faster compared to the North Americans (P<0.0001). Future studies should investigate each country in Europe and North America in order to find the country with the largest participation of athletes and their best performance.

  16. Effect of Heat and Heat Acclimatization on Cycling Time Trial Performance and Pacing

    PubMed Central

    RACINAIS, SEBASTIEN; PÉRIARD, JULIEN D.; KARLSEN, ANDERS; NYBO, LARS

    2015-01-01

    ABSTRACT Purpose This study aimed to determine the effects of heat acclimatization on performance and pacing during outdoor cycling time trials (TT, 43.4 km) in the heat. Methods Nine cyclists performed three TT in hot ambient conditions (TTH, approximately 37°C) on the first (TTH-1), sixth (TTH-2), and 14th (TTH-3) days of training in the heat. Data were compared with the average of two TT in cool condition (approximately 8°C) performed before and after heat acclimatization (TTC). Results TTH-1 (77 ± 6 min) was slower (P = 0.001) than TTH-2 (69 ± 5 min), and both were slower (P < 0.01) than TTC and TTH-3 (66 ± 3 and 66 ± 4 min, respectively), without differences between TTC and TTH-3 (P > 0.05). The cyclists initiated the first 20% of all TT at a similar power output, irrespective of climate and acclimatization status; however, during TTH-1, they subsequently had a marked decrease in power output, which was partly attenuated after 6 d of acclimatization and was further reduced after 14 d. HR was higher during the first 20% of TTH-1 than that in the other TT (P < 0.05), but there were no differences between conditions from 30% onward. Final rectal temperature was similar in all TTH (40.2°C ± 0.4°C, P = 1.000) and higher than that in TTC (38.5°C ± 0.6°C, P < 0.001). Conclusions After 2 wk of acclimatization, trained cyclists are capable of completing a prolonged TT in a similar time in the heat compared with cool conditions, whereas in the unacclimatized state, they experienced a marked decrease in power output during the TTH. PMID:24977692

  17. Predictive performance models and multiple task performance

    NASA Technical Reports Server (NTRS)

    Wickens, Christopher D.; Larish, Inge; Contorer, Aaron

    1989-01-01

    Five models that predict how performance of multiple tasks will interact in complex task scenarios are discussed. The models are shown in terms of the assumptions they make about human operator divided attention. The different assumptions about attention are then empirically validated in a multitask helicopter flight simulation. It is concluded from this simulation that the most important assumption relates to the coding of demand level of different component tasks.

  18. How 100-m event analyses improve our understanding of world-class men's and women's sprint performance.

    PubMed

    Slawinski, J; Termoz, N; Rabita, G; Guilhem, G; Dorel, S; Morin, J-B; Samozino, P

    2017-01-01

    This study aimed to compare the force (F)-velocity (v)-power (P)-time (t) relationships of female and male world-class sprinters. A total of 100 distance-time curves (50 women and 50 men) were computed from international 100-m finals, to determine the acceleration and deceleration phases of each race: (a) mechanical variables describing the velocity, force, and power output; and (b) F-P-v relationships and associated maximal power output, theoretical force and velocity produced by each athlete (Pmax , F0 , and V0 ). The results showed that the maximal sprint velocity (Vmax ) and mean power output (W/kg) developed over the entire 100 m strongly influenced 100-m performance (r > -0.80; P ≤ 0.001). With the exception of mean force (N/kg) developed during the acceleration phase or during the entire 100 m, all of the mechanicals variables observed over the race were greater in men. Shorter acceleration and longer deceleration in women may explain both their lower Vmax and their greater decrease in velocity, and in turn their lower performance level, which can be explained by their higher V0 and its correlation with performance. This highlights the importance of the capability to keep applying horizontal force to the ground at high velocities.

  19. Developing Human Performance Measures

    SciTech Connect

    Jeffrey Joe; Bruce Hallbert; Larry Blackwood; Donald Dudehoeffer; Kent Hansen

    2006-05-01

    Through the reactor oversight process (ROP), the U.S. Nuclear Regulatory Commission (NRC) monitors the performance of utilities licensed to operate nuclear power plants. The process is designed to assure public health and safety by providing reasonable assurance that licensees are meeting the cornerstones of safety and designated crosscutting elements. The reactor inspection program, together with performance indicators (PIs), and enforcement activities form the basis for the NRC’s risk-informed, performance based regulatory framework. While human performance is a key component in the safe operation of nuclear power plants and is a designated cross-cutting element of the ROP, there is currently no direct inspection or performance indicator for assessing human performance. Rather, when human performance is identified as a substantive cross cutting element in any 1 of 3 categories (resources, organizational or personnel), it is then evaluated for common themes to determine if follow-up actions are warranted. However, variability in human performance occurs from day to day, across activities that vary in complexity, and workgroups, contributing to the uncertainty in the outcomes of performance. While some variability in human performance may be random, much of the variability may be attributed to factors that are not currently assessed. There is a need to identify and assess aspects of human performance that relate to plant safety and to develop measures that can be used to successfully assure licensee performance and indicate when additional investigation may be required. This paper presents research that establishes a technical basis for developing human performance measures. In particular, we discuss: 1) how historical data already gives some indication of connection between human performance and overall plant performance, 2) how industry led efforts to measure and model human performance and organizational factors could serve as a data source and basis for a

  20. Wind potential assessment to estimate performance of selected wind turbines in Pandansimo Beach-Yogyakarta

    NASA Astrophysics Data System (ADS)

    Tjahjana, D. D. D. P.; Al-Masuun, I. K.; Gustiantono, A.

    2016-03-01

    This paper presents the characteristics of wind speed and wind energy potential in the Pandansimo Beach-Yogyakarta based on Weibull distribution analysis. Ten-min average time series wind-speed data for a period of 2 year, measured at a height 50 m, are used in this study. The continuously recorded wind speed data were averaged over 10 minutes and stored in data logger. The results showed that the annual mean wind speed at location is 6.249 m/s, while the annual mean power densities is 264 W/m². It was further shown that the mean annual value of the most probable wind speed is 5.5 m/s and the mean annual value of the wind speed carrying maximum energy is 9.608 m/s. The performance of selected commercial wind turbine models designed for electricity generation in the site was examined. The wind turbine with the highest value of capacity factor is VESTAS V-110 with 33.97% and can produce 5951.04 M Wh/year.

  1. Lower and upper body anaerobic performance in male and female adolescent athletes.

    PubMed

    Nindl, B C; Mahar, M T; Harman, E A; Patton, J F

    1995-02-01

    Little data exist for upper and lower body mechanical power capability of adolescent athletes. This study compared arm (A) and leg (L) anaerobic peak and mean power (PP and MP) of 20 male and 20 female adolescent athletes after normalization for body mass (BM), fat-free mass (FFM), and lean A and L cross-sectional area (CSA). Power outputs were assessed by the Wingate anaerobic test. FFM and CSA were estimated via anthropometry. No significant (P > 0.05) differences existed between the sexes in Tanner sexual maturity, chronological age, or overall training activity. Males had higher (P < 0.001) absolute PP (W) (L 694 vs 442; A 494 vs 309) and MP (L 548 vs 307; A 337 vs 214). Ratio normalization and ANCOVA were used to remove the influence of body size differences. Ratio normalization showed that males had greater leg PP/BM, MP/BM, MP/FFM, MP/CSA, as well as arm PP/BM and MP/BM, whereas all leg and arm PP and MP ANCOVA adjusted means for BM, FFM, and CSA, except arm MP adjusted for FFM, were significantly (P < 0.01) higher for males than females. We conclude that factors other than muscle mass, possibly qualitative in nature, are responsible for the sex difference in anaerobic performance of adolescent athletes.

  2. The Effect of Prior Upper Body Exercise on Subsequent Wingate Performance

    PubMed Central

    Grant, Marie Clare; Robergs, Robert; Baird, Marianne Findlay; Baker, Julien S.

    2014-01-01

    It has been reported previously that the upper body musculature is continually active during high intensity cycle ergometry. The aim of this study was to examine the effects of prior upper body exercise on subsequent Wingate (WAnT) performance. Eleven recreationally active males (20.8 ± 2.2 yrs; 77.7 ± 12.0 kg; 1.79 ± 0.04 m) completed two trials in a randomised order. In one trial participants completed 2 × 30 s WAnT tests (WAnT1 and WAnT2) with a 6 min recovery period; in the other trial, this protocol was preceded with 4 sets of biceps curls to induce localised arm fatigue. Prior upper body exercise was found to have a statistically significant detrimental effect on peak power output (PPO) during WAnT1 (P < 0.05) but no effect was observed for mean power output (MPO) (P > 0.05). Handgrip (HG) strength was also found to be significantly lower following the upper body exercise. These results demonstrate that the upper body is meaningfully involved in the generation of leg power during intense cycling. PMID:24895566

  3. High performance polymer development

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M.

    1991-01-01

    The term high performance as applied to polymers is generally associated with polymers that operate at high temperatures. High performance is used to describe polymers that perform at temperatures of 177 C or higher. In addition to temperature, other factors obviously influence the performance of polymers such as thermal cycling, stress level, and environmental effects. Some recent developments at NASA Langley in polyimides, poly(arylene ethers), and acetylenic terminated materials are discussed. The high performance/high temperature polymers discussed are representative of the type of work underway at NASA Langley Research Center. Further improvement in these materials as well as the development of new polymers will provide technology to help meet NASA future needs in high performance/high temperature applications. In addition, because of the combination of properties offered by many of these polymers, they should find use in many other applications.

  4. Cognitive aspects of performance.

    PubMed Central

    Kane, J. E.

    1978-01-01

    The study of cognitive structures and processes in the control of skilled performance is considered and reviewed with special reference to a proposed hierarchical system incorporating levels of motor integration. Cognitive styles and dispositions of general behaviour are suggested as factors which may determine performance levels. The relative importance of these personal factors and stronger personality traits in accounting for variance in performance is considered in the light of a critique of the current interactional controversy. PMID:444808

  5. Behavioral Health & Performance

    NASA Video Gallery

    Summary of the Behavioral Health and Performance Operations Group’s work including an overview of astronaut selection, behavioral health services provided to astronauts, the psychological aspects o...

  6. Photovoltaic array performance model.

    SciTech Connect

    Kratochvil, Jay A.; Boyson, William Earl; King, David L.

    2004-08-01

    This document summarizes the equations and applications associated with the photovoltaic array performance model developed at Sandia National Laboratories over the last twelve years. Electrical, thermal, and optical characteristics for photovoltaic modules are included in the model, and the model is designed to use hourly solar resource and meteorological data. The versatility and accuracy of the model has been validated for flat-plate modules (all technologies) and for concentrator modules, as well as for large arrays of modules. Applications include system design and sizing, 'translation' of field performance measurements to standard reporting conditions, system performance optimization, and real-time comparison of measured versus expected system performance.

  7. Acute Citrulline-Malate Supplementation and High-Intensity Cycling Performance.

    PubMed

    Cunniffe, Brian; Papageorgiou, Maria; OʼBrien, Barbara; Davies, Nathan A; Grimble, George K; Cardinale, Marco

    2016-09-01

    Cunniffe, B, Papageorgiou, M, O'Brien, B, Davies, NA, Grimble, GK, and Cardinale, M. Acute citrulline-malate supplementation and high-intensity cycling performance. J Strength Cond Res 30(9): 2638-2647, 2016-Dietary L-citrulline-malate (CM) consumption has been suggested to improve skeletal muscle metabolism and contractile efficiency, which would be expected to predispose exercising individuals to greater fatigue resistance. The purpose of this study was to examine the effects of CM supplementation on acid-base balance and high-intensity exercise performance. In a double-blind, placebo-controlled, crossover study, 10 well-trained males consumed either 12 g of CM (in 400 ml) or lemon sugar-free cordial (placebo [PL]) 60 minutes before completion of 2 exercise trials. Each trial consisted of subjects performing 10 (×15 seconds) maximal cycle sprints (with 30-second rest intervals) followed by 5 minutes recovery before completing a cycle time-to-exhaustion test (TTE) at 100% of individual peak power (PP). Significant increases in plasma concentrations of citrulline (8.8-fold), ornithine (3.9-fold), and glutamine (1.3-fold) were observed 60 minutes after supplementation in the CM trial only (p ≤ 0.05) and none of the subjects experienced gastrointestinal side-effects during testing. Significantly higher exercise heart rates were observed in CM condition (vs. PL) although no between trial differences in performance related variables (TTE: [120 ± 61 seconds CM vs. 113 ± 50 seconds PL]), PP or mean power, ([power fatigue index: 36 ± 16% CM vs. 28 ± 18% PL]), subjective rating of perceived exertion or measures of acid-base balance (pH, lactate, bicarbonate, base-excess) were observed (p > 0.05). This study demonstrated that acute supplementation of 12 g CM does not provide acute ergogenic benefits using the protocol implemented in this study in well-trained males.

  8. Disinfecting properties of performic acid against bacteriophage phi X 174 as a model of small envelope--free viruses.

    PubMed

    Bydzovská, O; Mĕrka, V

    1981-01-01

    Performic acid HCOOH (PFA) is a wide-spectrum disinfectant. It inactivates viruses, bacteria and bacterial spores, mycobacteria as well as microscopic fungi. Its main drawback is its instability, which makes it a logical necessity that it is to be prepared prior to use from its components HCOOH and H2O2. The mixing of 8 ml HCOOH of the concentration 850 ml/l and 17 ml H2O2 of the concentration 300 ml/l in a 100 ml-volume reagent bottle with a ground-in glass stopper gives, after an 1-hour rest at room temperature and after another 1 hour in a refrigerator, a stock solution that contains about 50 ml/l of PFA the actual concentration of which is determined iodometrically. Bacteriophage phi X 174 (host E. coli C) is characterized by cubic ikosahedral-type symmetry of particles free of envelope, has 27 mm in diameter and contains single-strand cyclic DNA; formerly was classed among Parvoviridae. The possibility of plaque assay-based quantitative determination of the number of infectious particles makes if it a feasible model for assessing disinfectant action on small hydrophilic viruses under conditions close to those of practical disinfection procedures. PFA stock solution diluted to 1 X 10(-3) (0.05 ml/l of effective component) inactivates the model virus of a concentration 10(8) pfu/ml aqueous suspension within 5 min so that no virus is detectable; the drop in the number of pfu amounts to 7 log orders of magnitude. In the presence of 400 ml/l of serum, the identical effect is achieved within 5 min by PFA stock solution diluted to 5 X 10(-3). The lowest PFA concentration that reliably inactivates bacteriophage phi X 174 in aqueous suspension is identical with the lowest concentration inactivating Coxsackie B 1 virus in tissue cultures. On textile, glass, plastic, rubber and metal carriers contaminated by swabbing or by a dried drop of bacteriophage suspension containing about 1 X 10(9) pfu/ml, the lowest reliably effective concentrations of PFA range within 0

  9. OLEM Performance Assessment Information

    EPA Pesticide Factsheets

    This asset includes a variety of data sets that measure the performance of Office of Land and Emergency Management (OLEM) programs in support of the Office of the Chief Financial Officer's Annual Commitment System (ACS) and Performance Evaluation Reporting System (PERS). Information is drawn from OLEM's ACRES, RCRAInfo, CERCLIS/SEMS, ICIS, and LUST4 systems, as well as input manually by authorized individuals in OLEM's program offices. Information is reviewed by OLEM program staff prior to being pushed to ACS and entered into PERS. This data asset also pulls in certain performance information input directly by Regional Office staff into ACS. Information is managed by the Performance Assessment Tool (PAT) and displayed in the PAT Dashboard.Information in this asset include:--Government Performance and Results Act (GPRA) of 1993: Measures reported for Innovations, Partnerships and Communications Office (IPCO), the Office of Brownfields and Land Revitalization (OBLR), the Office of Emergency Management (OEM), the Office of Resource Conservation and Recovery (ORCR), the Office of Superfund Remediation and Technology Innovation (OSRTI), and the Office of Underground Storage Tanks (OUST).-- Performance and Environmental Results System (PERS): Includes OLEM's information on performance results and baselines for the EPA Annual Plan and Budget.--Key Performance Indicators: OLEM has identified five KPIs that are tracked annually.--Integrated Cleanup Initiative: A pilot pe

  10. Managing employee performance.

    PubMed

    McConnell, Charles R

    2004-01-01

    Performance management consists of significantly more than periodic evaluation of performance. It is the art and science of dealing with employees in a manner intended to positively influence their thinking and behavior to achieve a desired level of performance. It is essential for the manager to always model positive behavior concerning performance; what one does or says as a manager always has an influence on others. The kinds of employee behavior most likely encountered relative to performance management efforts stem from resistance to change and lack of complete understanding of what is expected. Employee participation must be elicited whenever possible for performance improvement; as far as the inner working details of a specific job are concerned, there is no one who knows the job better than the person who does it everyday. For each task to be done, an employee needs to know what output is expected, how this output will be measured, and what standards are applied in assessing the output. Managing employee performance requires ongoing contact with each employee, regular feedback, and whatever coaching, counseling, and training are necessary to bring an employee back on track when a problem appears. Sustaining efficient and effective employee performance requires the manager's ongoing attention and involvement.

  11. Performance Improvement [in HRD].

    ERIC Educational Resources Information Center

    1995

    These four papers are from a symposium that was facilitated by Richard J. Torraco at the 1995 conference of the Academy of Human Resource Development (HRD). "Performance Technology--Isn't It Time We Found Some New Models?" (William J. Rothwell) reviews briefly two classic models, describes criteria for the high performance workplace…

  12. Technology Performance Exchange

    SciTech Connect

    2015-09-01

    To address the need for accessible, high-quality data, the Department of Energy has developed the Technology Performance Exchange (TPEx). TPEx enables technology suppliers, third-party testing laboratories, and other entities to share product performance data. These data are automatically transformed into a format that technology evaluators can easily use in their energy modeling assessments to inform procurement decisions.

  13. Developing Effective Performance Measures

    DTIC Science & Technology

    2014-10-14

    center (after receiving the training). 5. Post -course survey results of veterans that took the training. 38 Developing Effective Performance...PV)) Estimate at Completion (EAC) Budget at Completion ( BAC ) Budgeted Cost of Work Performed (BCWP) Schedule Variance (SV) at time t1 Cost

  14. Performance Measurement at OIT

    DTIC Science & Technology

    2014-08-01

    after receiving the training). 5. Post -course survey results of veterans that took the training. 27 Performance Measurement at OIT Mark Kasunic...EAC) Budget at Completion ( BAC ) Budgeted Cost of Work Performed (BCWP) Schedule Variance (SV) at time t1 Cost Variance (CV) at time t1 (a.k.a. EV

  15. Performance Simulation: The Method.

    ERIC Educational Resources Information Center

    Rucker, Lance M.

    A logical, performer-based approach to teaching psychomotor skills is described. Four phases of surgical psychomotor skills training are identified, using an example from a dental preclinical training curriculum: (1) dental students are acquainted with the postural and positional parameters of balanced psychomotor performances; (2) students learn…

  16. Apprentice Performance Evaluation.

    ERIC Educational Resources Information Center

    Gast, Clyde W.

    The Granite City (Illinois) Steel apprentices are under a performance evaluation from entry to graduation. Federally approved, the program is guided by joint apprenticeship committees whose monthly meetings include performance evaluation from three information sources: journeymen, supervisors, and instructors. Journeymen's evaluations are made…

  17. Test and Performance Anxiety

    ERIC Educational Resources Information Center

    Huberty, Thomas J.

    2010-01-01

    Test and performance anxiety is not recognized easily in schools, in large part because adolescents rarely refer themselves for emotional concerns. Not wanting to risk teasing or public attention, anxious adolescents suffer in silence and under perform on school-related tasks. In school, anxiety is experienced often by students when being…

  18. Untangling Performance from Success

    NASA Astrophysics Data System (ADS)

    Yucesoy, Burcu; Barabasi, Albert-Laszlo

    Fame, popularity and celebrity status, frequently used tokens of success, are often loosely related to, or even divorced from professional performance. This dichotomy is partly rooted in the difficulty to distinguish performance, an individual measure that captures the actions of a performer, from success, a collective measure that captures a community's reactions to these actions. Yet, finding the relationship between the two measures is essential for all areas that aim to objectively reward excellence, from science to business. Here we quantify the relationship between performance and success by focusing on tennis, an individual sport where the two quantities can be independently measured. We show that a predictive model, relying only on a tennis player's performance in tournaments, can accurately predict an athlete's popularity, both during a player's active years and after retirement. Hence the model establishes a direct link between performance and momentary popularity. The agreement between the performance-driven and observed popularity suggests that in most areas of human achievement exceptional visibility may be rooted in detectable performance measures. This research was supported by Air Force Office of Scientific Research (AFOSR) under agreement FA9550-15-1-0077.

  19. Holley Stick Performance Analysis

    DTIC Science & Technology

    2013-04-01

    TECHNICAL REPORT 2015 April 2013 Holley Stick Performance Analysis Steven T. Holste , Ph.D Jeffrey J. Person...Performance Analysis Steven T. Holste , PhD. Jeffrey J. Person Approved for public release...IEDs on U.S. and coalition forces. Figure 2 depicts OEF casualties from 2008 through 2012, indicating Total and IED-caused Killed in Action (KIA

  20. Performance Teaching in ELT.

    ERIC Educational Resources Information Center

    Crouch, Christopher

    1989-01-01

    Reports the effects on student classroom behavior of a performance teaching strategy in which teacher trainees of English as a second language "perform" to better engage students. Students paid attention more immediately and sustained attention longer, engaged more willingly in subsequent tasks, and appeared to enjoy the lesson more.…

  1. Emotions and Golf Performance

    ERIC Educational Resources Information Center

    Cohen, Alexander B.; Tenenbaum, Gershon; English, R. William

    2006-01-01

    A multiple case study investigation is reported in which emotions and performance were assessed within the probabilistic individual zone of optimal functioning (IZOF) model (Kamata, Tenenbaum, & Hanin, 2002) to develop idiosyncratic emotion-performance profiles. These profiles were incorporated into a psychological skills training (PST)…

  2. Infiniband Performance Testing

    SciTech Connect

    Minich, M

    2005-10-13

    A look at the performance of the infiniband interconnect using the Voltaire host stack. This will attempt to compare not only infiniband to other high-performance interconnects, but will also take a look at comparing some of the different hardware choices available at the time of writing (e.g. Opteron, EM64T, pci-express and pci-x).

  3. Measuring Clerical Job Performance

    ERIC Educational Resources Information Center

    Ronan, William W.; And Others

    1976-01-01

    Describes research which attempts to provide a solution to the performance criterion problem, concluding that is seems possible to measure many aspects of clerical work using psychometric measures that are highly job related; recommends that such devices be used to supplement ratings in the performance evaluation process.

  4. Performance Improvement Processes.

    ERIC Educational Resources Information Center

    1997

    This document contains four papers from a symposium on performance improvement processes. In "Never the Twain Shall Meet?: A Glimpse into High Performance Work Practices and Downsizing" (Laurie J. Bassi, Mark E. Van Buren) evidence from a national cross-industry of more than 200 establishments is used to demonstrate that high-performance…

  5. Music and academic performance.

    PubMed

    Arnaud Cabanac; Perlovsky, Leonid; Bonniot-Cabanac, Marie-Claude; Cabanac, Michel

    2013-11-01

    In a previous study we demonstrated that listening to a pleasant music while performing an academic test helped students to overcome stress, to devote more time to more stressful and more complicated task and the grades were higher. Yet, there remained ambiguities as for the causes of the higher test performance of these students: do they perform better because they hear music during their examinations, or would they perform better anyway because they are more gifted/motivated? This motivated the current study as a preliminary step toward that general question: Do students who like/perform music have better grades than the others? Our results confirmed this hypothesis: students studying music have better grades in all subjects.

  6. The Gravity-Loading countermeasure Skinsuit (GLCS) and its effect upon aerobic exercise performance

    NASA Astrophysics Data System (ADS)

    Attias, Julia; Philip, A. T. Carvil; Waldie, James; Russomano, Thais; Simon, N. Evetts; David, A. Green

    2017-03-01

    The Russian Pingvin suit is employed as a countermeasure to musculoskeletal atrophy in microgravity, though its 2-stage loading regime is poorly tolerated. The Gravity-Loading Countermeasure Skinsuit (GLCS) has been devised to comfortably compress the body via incrementally increasing longitudinal elastic-fibre tensions from the shoulders to the feet. We tested whether the Mk III GLCS was a feasible adjunct to sub-maximal aerobic exercise and resulting VO2Max predictions. Eight healthy subjects (5♂, 28±6 yr) performed cycle ergometry at 75% VO2Max (derived from an Astrand-Rhyming protocol) whilst wearing a GLCS and gym clothing (GYM). Ventilatory parameters, heart rate (HR), core temperature (TC), and blood lactate (BL) were recorded along with subjective perceived exertion, thermal comfort, movement discomfort and body control. Physiological and subjective responses were compared over TIME and between GYM and GLCS (ATTIRE) with 2-way repeated measures ANOVA and Wilcoxon tests respectively. Resultant VO2Max predictions were compared with paired t-tests between ATTIRE. The GLCS induced greater initial exercise ventilatory responses which stabilised by 20 min. HR and TC continued to rise from 5 min irrespective of ATTIRE, whereas BL was greater in the GLCS at 20 min. Predicted V O2Max did not differ with ATTIRE, though some observed differences in HR were noteworthy. All subjective ratings were exacerbated in the GLCS. Despite increased perception of workload and initial ventilatory augmentations, submaximal exercise performance was not impeded. Whilst predicted VO2Max did not differ, determination of actual VO2Max in the GLCS is warranted due to apparent modulation of the linear HR-VO2 relationship. The GLCS may be a feasible adjunct to exercise and potential countermeasure to unloaded-induced physiological deconditioning on Earth or in space.

  7. Effects of an amino acid carbohydrate drink on exercise performance after consecutive-day exercise bouts.

    PubMed

    Skillen, Rebecca A; Testa, Massimo; Applegate, Elizabeth A; Heiden, Eric A; Fascetti, Andrea J; Casazza, Gretchen A

    2008-10-01

    This study examined the effect of amino acids in a carbohydrate beverage on cycling performance. Twelve male athletes (28.5 +/- 2.1 yr) cycled at 75% VO2peak for 90 min followed by a ride to exhaustion at 85% VO2peak, before (T1) and on 2 consecutive days (T2 and T3) after 2 weeks of supplementation with 3.6% carbohydrate plus 1% amino acids (AA) or 4.6% carbohydrate-only (CHO) isocaloric beverages. Muscle damage was assessed by plasma creatine kinase (CK), and muscle fatigue by changes in vertical jump pre- to postexercise. Muscle soreness, overall fatigue, and changes in mood state were assessed using questionnaires. Plasma CK was lower for AA in T3 (214.0 +/- 13.5 vs. 485.9 +/- 191.4 U/L immediately post, 213.9 +/- 13.1 vs. 492.0 +/- 199.4 U/L 5 hr post, and 194.9 +/- 17.9 vs. 405.9 +/- 166.6 U/L 24 hr postexercise in AA and CHO, respectively). Time to exhaustion decreased from T2 to T3 only in CHO (10.9 +/- 2.5 to 12.6 +/- 3.2 vs. 13.8 +/- 2.8 to 7.8 +/- 1.5 min in AA and CHO, respectively). Vertical-jump change from pre- to postexercise was greater in T3 for the CHO treatment. Total fatigue score and mood disturbance decreased significantly only with AA in T3. The addition of AA to a carbohydrate beverage after consecutive-day exercise bouts reduced muscle damage as indicated by CK levels, decreased fatigue, and maintained exercise performance compared with consuming carbohydrate alone.

  8. Impact of a motivated performance task on autonomic and hemodynamic cardiovascular reactivity.

    PubMed

    May, Ross W; Sanchez-Gonzalez, Marcos A; Seibert, Gregory S; Samaan, John S; Fincham, Frank D

    2016-05-01

    Motivated performance (MP) tasks include mental stressors characterized by a high degree of motivation, individual engagement, and sympathetic overstimulation. It is therefore important to document the independent influence of motivation apart from engagement on markers of cardiovascular autonomic modulation, including vasomotor tone (low-frequency systolic blood pressure, LFSBP), blood pressure homeostasis (baroreflex sensitivity, BRS), and myocardial oxygen consumption (rate pressure product, RPP). Accordingly, an arithmetic task (AT) was used to manipulate motivation to evaluate its impact on cardiovascular reactivity. Forty-two young adults (Mage = 20.21 years, SD = 2.09) qualified for the study. After a 10-min resting period, electrocardiogram and finger beat-to-beat blood pressure were recorded at three distinct 5-min stages: baseline (BASE), AT, and recovery (REC). Prior to AT initiation, participants were randomized into two groups based on directions stating that the AT task was either designed to be entertaining and fun (low MP, LMP) or a test diagnostic of one's intelligence (high MP, HMP). Independent of task engagement ratings, motivation to complete the AT task as well as solution success was significantly greater in the HMP than the LMP condition. Regarding physiological parameters, two (LMP vs. HMP) × three (BASE, AT, REC) repeated measures ANOVAs revealed no significant baseline differences but a significant higher order interaction indicating that in comparison to LMP, individuals in the HMP condition had significantly higher vasomotor tone and myocardial oxygen consumption but not BRS. Greater motivation during a performance task may provide the substrate for the development of adverse cardiovascular events by increasing sympathetic activity and ultimately increasing myocardial oxygen demand which could lead to acute coronary syndromes.

  9. 10 km running performance predicted by a multiple linear regression model with allometrically adjusted variables

    PubMed Central

    Abad, Cesar C. C.; Barros, Ronaldo V.; Bertuzzi, Romulo; Gagliardi, João F. L.; Lima-Silva, Adriano E.; Lambert, Mike I.

    2016-01-01

    Abstract The aim of this study was to verify the power of VO2max, peak treadmill running velocity (PTV), and running economy (RE), unadjusted or allometrically adjusted, in predicting 10 km running performance. Eighteen male endurance runners performed: 1) an incremental test to exhaustion to determine VO2max and PTV; 2) a constant submaximal run at 12 km·h−1 on an outdoor track for RE determination; and 3) a 10 km running race. Unadjusted (VO2max, PTV and RE) and adjusted variables (VO2max0.72, PTV0.72 and RE0.60) were investigated through independent multiple regression models to predict 10 km running race time. There were no significant correlations between 10 km running time and either the adjusted or unadjusted VO2max. Significant correlations (p < 0.01) were found between 10 km running time and adjusted and unadjusted RE and PTV, providing models with effect size > 0.84 and power > 0.88. The allometrically adjusted predictive model was composed of PTV0.72 and RE0.60 and explained 83% of the variance in 10 km running time with a standard error of the estimate (SEE) of 1.5 min. The unadjusted model composed of a single PVT accounted for 72% of the variance in 10 km running time (SEE of 1.9 min). Both regression models provided powerful estimates of 10 km running time; however, the unadjusted PTV may provide an uncomplicated estimation. PMID:28149382

  10. Repeated Sprint Performance in Male and Female College Athletes Matched for VO2max Relative to Fat Free Mass.

    PubMed

    Mageean, Amanda L; Alexander, Ryan P; Mier, Constance M

    The purpose of this study was to examine gender differences in repeated sprint exercise (RSE) performance among male and female athletes matched for VO2max relative to FFM (VO2max FFM). Thirty nine male and female college athletes performed a graded exercise test for VO2max and hydrostatic weighing to determine FFM. From the results, 11 pairs of males and females matched for VO2max FFM (mean ± SD; 58.3 ± 4.3 and 58.9 ± 4.6 ml·kg FFM(-1)·min(-1); men and women, respectively) were identified. On a separate day, matched participants performed a RSE protocol that consisted of five 6-sec cycle sprints with 30-sec recovery periods, followed by 5-min active recovery and a 30-sec all-out sprint. Repeated 6-sec sprint performance did not differ between men and women; both maintained power output (PO) until sprint 4. POFFM (W·kg(-1) FFM) did not differ between men and women during the five sprints. During the 30-sec sprint, men achieved a lower peak POFFM than women (11.7 ± 1.5 vs 13.2 ± 1.2); however, the decline in POFFM over 30 sec was greater in women. VO2 (ml·kg FFM(-1)·min(-1)) was lower in men during recovery (24.4 ± 3.8 vs 28.7 ± 5.7) and at the beginning (29.2 ± 4.0 vs 34.7 ± 4.9) and end (49.4 ± 5.0 vs 52.3 ± 4.0). of the 30-sec sprint. These data indicate that men and women with similar aerobic capacities do not respond differently to short repeated sprints but may differ in their ability to recover and perform sprints of longer duration.

  11. Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review.

    PubMed

    Behm, David G; Blazevich, Anthony J; Kay, Anthony D; McHugh, Malachy

    2016-01-01

    Recently, there has been a shift from static stretching (SS) or proprioceptive neuromuscular facilitation (PNF) stretching within a warm-up to a greater emphasis on dynamic stretching (DS). The objective of this review was to compare the effects of SS, DS, and PNF on performance, range of motion (ROM), and injury prevention. The data indicated that SS- (-3.7%), DS- (+1.3%), and PNF- (-4.4%) induced performance changes were small to moderate with testing performed immediately after stretching, possibly because of reduced muscle activation after SS and PNF. A dose-response relationship illustrated greater performance deficits with ≥60 s (-4.6%) than with <60 s (-1.1%) SS per muscle group. Conversely, SS demonstrated a moderate (2.2%) performance benefit at longer muscle lengths. Testing was performed on average 3-5 min after stretching, and most studies did not include poststretching dynamic activities; when these activities were included, no clear performance effect was observed. DS produced small-to-moderate performance improvements when completed within minutes of physical activity. SS and PNF stretching had no clear effect on all-cause or overuse injuries; no data are available for DS. All forms of training induced ROM improvements, typically lasting <30 min. Changes may result from acute reductions in muscle and tendon stiffness or from neural adaptations causing an improved stretch tolerance. Considering the small-to-moderate changes immediately after stretching and the study limitations, stretching within a warm-up that includes additional poststretching dynamic activity is recommended for reducing muscle injuries and increasing joint ROM with inconsequential effects on subsequent athletic performance.

  12. PPC750 Performance Monitor

    NASA Technical Reports Server (NTRS)

    Meyer, Donald; Uchenik, Igor

    2007-01-01

    The PPC750 Performance Monitor (Perfmon) is a computer program that helps the user to assess the performance characteristics of application programs running under the Wind River VxWorks real-time operating system on a PPC750 computer. Perfmon generates a user-friendly interface and collects performance data by use of performance registers provided by the PPC750 architecture. It processes and presents run-time statistics on a per-task basis over a repeating time interval (typically, several seconds or minutes) specified by the user. When the Perfmon software module is loaded with the user s software modules, it is available for use through Perfmon commands, without any modification of the user s code and at negligible performance penalty. Per-task run-time performance data made available by Perfmon include percentage time, number of instructions executed per unit time, dispatch ratio, stack high water mark, and level-1 instruction and data cache miss rates. The performance data are written to a file specified by the user or to the serial port of the computer

  13. Precision performance lamp technology

    NASA Astrophysics Data System (ADS)

    Bell, Dean A.; Kiesa, James E.; Dean, Raymond A.

    1997-09-01

    A principal function of a lamp is to produce light output with designated spectra, intensity, and/or geometric radiation patterns. The function of a precision performance lamp is to go beyond these parameters and into the precision repeatability of performance. All lamps are not equal. There are a variety of incandescent lamps, from the vacuum incandescent indictor lamp to the precision lamp of a blood analyzer. In the past the definition of a precision lamp was described in terms of wattage, light center length (LCL), filament position, and/or spot alignment. This paper presents a new view of precision lamps through the discussion of a new segment of lamp design, which we term precision performance lamps. The definition of precision performance lamps will include (must include) the factors of a precision lamp. But what makes a precision lamp a precision performance lamp is the manner in which the design factors of amperage, mscp (mean spherical candlepower), efficacy (lumens/watt), life, not considered individually but rather considered collectively. There is a statistical bias in a precision performance lamp for each of these factors; taken individually and as a whole. When properly considered the results can be dramatic to the system design engineer, system production manage and the system end-user. It can be shown that for the lamp user, the use of precision performance lamps can translate to: (1) ease of system design, (2) simplification of electronics, (3) superior signal to noise ratios, (4) higher manufacturing yields, (5) lower system costs, (6) better product performance. The factors mentioned above are described along with their interdependent relationships. It is statistically shown how the benefits listed above are achievable. Examples are provided to illustrate how proper attention to precision performance lamp characteristics actually aid in system product design and manufacturing to build and market more, market acceptable product products in the

  14. Deodorants, value, and performance.

    PubMed

    Newcomer, L N

    1997-11-01

    For the health-care market, like the deodorant market, the message is clear: Add value or your product will not be competitive. For physicians of all specialties, the best way to add value is to measure and improve performance. Performance measurement is critical to improvement in health care. Without measurement, there can be no improvement in quality. Without improvement in quality, there is no added value. Oncologists can take at least two actions to add value for their health plans: (1) measure practice performance and demonstrate a quality improvement; and (2) become the personal-care physician for cancer patients.

  15. Performance Management Plan

    SciTech Connect

    IT Corporation, Las Vegas, NV

    2002-08-21

    This Performance Management Plan describes the approach for accelerating cleanup activities of U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Operations Office (NNSA/NV) Environmental Management (EM) Program. This approach accelerates the reduction of risk at NNSA/NV sites while performing the work responsibly, effectively, and more efficiently. In May 2002, NNSA/NV EM and the Nevada Division of Environmental Protection signed a Letter of Intent formalizing an agreement to pursue accelerated risk reduction and cleanup for activities within the State of Nevada. This Performance Management Plan provides the strategic direction for implementing the Letter of Intent.

  16. Evaluating Performance of Components

    NASA Technical Reports Server (NTRS)

    Katz, Daniel; Tisdale, Edwin; Norton, Charles

    2004-01-01

    Parallel Component Performance Benchmarks is a computer program developed to aid the evaluation of the Common Component Architecture (CCA) - a software architecture, based on a component model, that was conceived to foster high-performance computing, including parallel computing. More specifically, this program compares the performances (principally by measuring computing times) of componentized versus conventional versions of the Parallel Pyramid 2D Adaptive Mesh Refinement library - a software library that is used to generate computational meshes for solving physical problems and that is typical of software libraries in use at NASA s Jet Propulsion Laboratory.

  17. Neoliberalism, Performativity and Research

    NASA Astrophysics Data System (ADS)

    Roberts, Peter

    2007-07-01

    This paper provides a critical analysis of New Zealand's Performance Based Research Fund (PBRF). The first section sketches the development and implementation of the PBRF. The second section evaluates the scheme, concentrating on three themes: the relationship between privatization, competition and research performance; the standardization of research; and motivations for research. The paper acknowledges the thorough work completed by the Tertiary Education Advisory Commission and other policy groups in laying the foundation for the adoption of performance-based research funding in New Zealand. It is argued, however, that when viewed in its larger context, the PBRF constitutes a continuation of neoliberal trends already well established in New Zealand's tertiary education system.

  18. Performance and Accountability Report

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The NASA Fiscal Year 2002 Performance and Accountability Report is presented. Over the past year, significant changes have been implemented to greatly improve NASA's management while continuing to break new ground in science and technology. Excellent progress has been made in implementing the President's Management Agenda. NASA is leading the government in its implementation of the five government-wide initiatives. NASA received an unqualified audit opinion on FY 2002 financial statements. The vast majority of performance goals have been achieved, furthering each area of NASA's mission. The contents include: 1) NASA Vision and Mission; 2) Management's Discussion and Analysis; 3) Performance; and 4) Financial.

  19. Breakfast and performance.

    PubMed

    Cueto, S

    2001-12-01

    Evidence suggests that the effect of fasting on performance is not uniform, but it is dependent on the basal nutritional status of the subject. Breakfast consumption has a short-term effect in improving selected learning skills, especially work memory. School breakfast programmes have a positive effect on the nutritional status of children, on school attendance and probably on dropout rates. The effect of breakfast consumption on school performance depends on the interaction between the programme, student characteristics (malnutrition) and school organisation. Unless the school setting guarantees a minimum quality standard, the benefits of breakfast consumption will not be evident in performance in complex areas like language or maths.

  20. Development of a gradient high performance liquid chromatography assay for simultaneous analysis of hydrophilic gemcitabine and lipophilic curcumin using a central composite design and its application in liposome development.

    PubMed

    Xu, Hongtao; Paxton, James; Lim, Joanne; Li, Yan; Wu, Zimei

    2014-09-01

    A rapid and reliable gradient high performance liquid chromatography (HPLC) method was developed for the simultaneous analysis of a hydrophilic anticancer drug, gemcitabine, and a lipophilic phytochemical, curcumin. A central composite design (CCD) was employed to optimize the gradient elution programme to obtain an acceptable retention time and peak width for curcumin with the aid of the desirability function (DF). Dual wavelengths (gemcitabine, 270nm; curcumin, 420nm) were selected to give maximal specific detection using a diode-array detector. The optimized DF was obtained with a mobile phase (water:acetonitrile) of 95:5 for 4.5min, followed by 30:70 for 5min, which gave retention times within 11min with peak widths <0.10min, respectively. No interference from the formulation ingredients was detected. The method was linear over the range of 0.125-5μM for gemcitabine, and 1.25-50μM for curcumin. The intra-day and inter-day variability were less than 5%, with accuracies between 90 and 110% of the true values. The limit of detection (LOD) for gemcitabine and curcumin was 0.04μM and 0.03μM, respectively. Using this method, release study for a dual-drug loaded formulation revealed a Fickian diffusion process for both. The stability of curcumin was pH dependent in aqueous solutions with a half-life of 3h at 25°C and pH 7.4. This was significantly improved after incorporation into the liposomes with no degradation for at least 3 months. In conclusion, the combination of CCD and DF offers a new approach to optimize a gradient HPLC method with high efficiency. A liposomal carrier system may provide an option for tumour dual-drug therapy with the additional advantage of chemical stabilization of the encapsulated compound.

  1. Sonic spray ionization technology: performance study and application to a LC/MS analysis on a monolithic silica column for heroin impurity profiling.

    PubMed

    Dams, Riet; Benijts, Tom; Günther, Wolfgang; Lambert, Willy; De Leenheer, André

    2002-07-01

    Sonic spray (SS) ionization is a relatively novel atmospheric pressure ionization technique for LC/MS, based on the principle of "spray ionization", which only recently became commercially available. In this paper, we evaluate the performance of this ion source as an interface for LC/MS in comparison with the more traditional and better studied pneumatically assisted electrospray or ion spray (IS). The effect of organic modifiers, volatile acids, and buffer systems in the LC eluent on the ionization efficiency of both interfaces is described and some possible explanations for the observed phenomena are highlighted. We could conclude that the presence of organic solvents gradually increased the ionization efficiency for IS and SS, while volatile acids or buffers gave a significant signal suppression. Furthermore, we present the application of the sonic spray interface to a fast LC/MS analysis, for the simultaneous determination of the seven prime opium alkaloids in heroin impurity profiling. Chromatographic separation is performed in 5 min on a monolithic silica column (Chromolith Performance) with a gradient elution system and an optimized flow of 5 mL/min. By means of a postcolumn split of approximately 1/20, a coupling between the fast LC system and the mass spectrometer is made. The method is validated and successfully applied to the analysis of real-time seized heroin street samples.

  2. Porous, one-dimensional and high aspect ratio nanofibric network of cobalt manganese oxide as a high performance material for aqueous and solid-state supercapacitor (2 V)

    NASA Astrophysics Data System (ADS)

    Bhagwan, Jai; Sivasankaran, V.; Yadav, K. L.; Sharma, Yogesh

    2016-09-01

    Porous nanofibric network of spinel CoMn2O4 (CMO) are fabricated by facile electrospinning process and characterized by XRD, BET, TGA, FTIR, FESEM, TEM, XPS techniques. CMO nanofibers are employed as supercapacitor electrode for first time which exhibits high specific capacitance (Cs) of 320(±5) F g-1 and 270(±5) F g-1 at 1 A g-1 and 5 A g-1, respectively in 1 M H2SO4. CMO nanofibers exhibit excellent cyclability (till 10,000 cycles @ 5 A g-1). To examine practical performance, solid-state symmetric supercapacitor (SSSC) is also fabricated using PVA-H2SO4 as gel electrolyte. The SSSC evinces high energy density of 75 W h kg-1 (comparable to Pb-acid and Ni-MH battery) along with high power density of 2 kW kg-1. Furthermore, a red colored LED (1.8 V @ current 20 mA) was lit for 5 min using single SSSC device supporting its output voltage of 2 V. This high performance of CMO in both aqueous and SSSC is attributed to one dimensional nanofibers consisting of voids/gaps with minimum inter-particle resistance that facilitates smoother transportation of electrons/ions. These voids/gaps in CMO (structural as well as morphological) act as intercalation/de-intercalation sites for extra storage performance, and also works as buffering space to accommodate stress/strain produced while long term cyclings.

  3. Effect of caffeine ingestion after creatine supplementation on intermittent high-intensity sprint performance.

    PubMed

    Lee, Chia-Lun; Lin, Jung-Charng; Cheng, Ching-Feng

    2011-08-01

    The aim of this study was to investigate the effects of acute caffeine ingestion on intermittent high-intensity sprint performance after 5 days of creatine loading. After completing a control trial (no ergogenic aids, CON), twelve physically active men were administered in a double-blind, randomized crossover protocol to receive CRE + PLA (0.3 g kg(-1) day(-1) of creatine for 5 days then followed by 6 mg kg(-1) of placebo) and CRE + CAF (0.3 g kg(-1) day(-1) of creatine for 5 days and followed by 6 mg kg(-1) of caffeine), after which they performed a repeated sprint test. Each test consisted of six 10-s intermittent high-intensity sprints on a cycling ergometer, with 60-s rest intervals between sprints. Mean power, peak power, rating of perceived exertion (RPE), and heart rates were measured during the test. Blood samples for lactate, glucose, and catecholamine concentrations were drawn at specified intervals. The mean and peak power observed in the CRE + CAF were significantly higher than those found in the CON during Sprints 1 and 3; and the CRE + CAF showed significantly higher mean and peak power than that in the CRE + PLA during Sprints 1 and 2. The mean and peak power during Sprint 3 in the CRE + PLA was significantly greater than that in the CON. Heart rates, plasma lactate, and glucose increased significantly with CRE + CAF during most sprints. No significant differences were observed in the RPE among the three trials. The present study determined that caffeine ingestion after creatine supplements augmented intermittent high-intensity sprint performance.

  4. The effect of ice ingestion on female athletes performing intermittent exercise in hot conditions.

    PubMed

    Zimmermann, Matthew Robert; Landers, Grant Justin

    2015-01-01

    Studies have reported the benefits of pre-cooling prior to exercise in the heat for male athletes, but at this time no research has investigated female athletes. The aim of the following study was to test the effects of pre-cooling on female repeat sprint performance in hot, humid conditions; namely is ice ingestion effective in reducing core temperature (Tc) and does this reduced Tc lead to improved repeat sprint performance in female athletes? Nine female team sport athletes with mean age (21.0 ± 1.2 y), height (169.8 ± 4.1 cm) and body mass (62.3 ± 5.0 kg) participated in this study. Participants completed 72 min of an intermittent sprint protocol (ISP) consisting of 2 × 36 min halves in hot, humid conditions (33.1 ± 0.1 °C, 60.3 ± 1.5% RH) on a cycle ergometer. This was preceded by 30 min of either ice ingestion (ICE) or water consumption (CON) in a randomised order. At the end of the pre-cooling period, Tc significantly decreased following ICE (-0.7 ± 0.3 °C) compared to CON (-0.1 ± 0.2 °C; p = 0.001). Tc also remained lower in ICE compared to CON during the ISP (p = 0.001). Ratings of perceived thermal sensation were lower in ICE compared to CON (p = 0.032) at the beginning (p = 0.022) and mid-point (p = 0.035) of the second half. No differences in work, mean power, peak power, rating of perceived exertion, heart rate or sweat loss between conditions were recorded (p > 0.05). Ice ingestion significantly reduced female Tc prior to intermittent exercise in the heat and reduced thermal sensation; however, this did not coincide with improved performance.

  5. Pressure and coverage effects of sporting compression garments on cardiovascular function, thermoregulatory function, and exercise performance.

    PubMed

    MacRae, Braid A; Laing, Raechel M; Niven, Brian E; Cotter, James D

    2012-05-01

    Sporting compression garments (CG) are used widely during exercise despite little evidence of benefits. The purpose of this study was to investigate coverage and pressure effects of full-body CG on cardiovascular and thermoregulatory function at rest and during prolonged exercise, and on exercise performance. Twelve recreationally trained male cyclists [mean (SD) age, 26 (7) years; VO(2 max), 53 (8) mL kg(-1) min(-1)] completed three sessions (counterbalanced order), wearing either correctly-sized CG (CSG; 11-15 mmHg), over-sized CG (OSG; 8-13 mmHg), or gym shorts (CONT). Test sessions were conducted in temperate conditions [24 (1)°C, 60 (4)% relative humidity; ~2 m s(-1) air velocity during exercise], consisting of resting on a chair then on a cycle ergometer, before 60-min fixed-load cycling at ~65% VO(2 max) and a 6-km time trial. Wearing CG (CSG or OSG) did not mitigate cardiovascular strain during mild orthostatic stress at rest (p = 0.20-0.93 for garment effects). During exercise, cardiac output was ~5% higher in the CG conditions (p < 0.05), which appears to be accounted for via non-significant higher end-exercise heart rate (~4-7%, p = 0.30; p = 0.06 for greater heart rate drift in CSG); other cardiovascular variables, including stroke volume, were similar among conditions (p = 0.23-0.91). Covered-skin temperature was higher in CG conditions (p < 0.001) but core (oesophageal) temperature was not (p = 0.79). Time-trial performance (mean power, time taken) was similar with or without CG (p = 0.24-0.44). In conclusion, any demonstrable physiological or psychophysical effects of full-body CG were mild and seemingly reflective more of surface coverage than pressure. No benefit was evident for exercise performance.

  6. Energy system contributions and determinants of performance in sprint cross-country skiing.

    PubMed

    Andersson, E; Björklund, G; Holmberg, H-C; Ørtenblad, N

    2017-04-01

    To improve current understanding of energy contributions and determinants of sprint-skiing performance, 11 well-trained male cross-country skiers were tested in the laboratory for VO2max , submaximal gross efficiency (GE), maximal roller skiing velocity, and sprint time-trial (STT) performance. The STT was repeated four times on a 1300-m simulated sprint course including three flat (1°) double poling (DP) sections interspersed with two uphill (7°) diagonal stride (DS) sections. Treadmill velocity and VO2 were monitored continuously during the four STTs and data were averaged. Supramaximal GE during the STT was predicted from the submaximal relationships for GE against velocity and incline, allowing computation of metabolic rate and O2 deficit. The skiers completed the STT in 232 ± 10 s (distributed as 55 ± 3% DP and 45 ± 3% DS) with a mean power output of 324 ± 26 W. The anaerobic energy contribution was 18 ± 5%, with an accumulated O2 deficit of 45 ± 13 mL/kg. Block-wise multiple regression revealed that VO2 , O2 deficit, and GE explained 30%, 15%, and 53% of the variance in STT time, respectively (all P < 0.05). This novel GE-based method of estimating the O2 deficit in simulated sprint-skiing has demonstrated an anaerobic energy contribution of 18%, with GE being the strongest predictor of performance.

  7. High-performance liquid chromatographic method for sensitive determination of the alkylating agent CB1954 in human plasma.

    PubMed

    Anderson, D; Ferry, D R; Knox, R J; Andrews, S J; Downes, A J; Kerr, D J; Seymour, L W

    1999-08-20

    A high-performance liquid chromatography (HPLC) method is described for the measurement of the weak alkylating agent CB1954 in human plasma. CB1954 can be used as an innocuous prodrug designed for activation by bacterial nitroreductases in strategies of gene-directed enzyme-prodrug therapy, and becomes activated to a potent bifunctional alkylating agent. The HPLC method involves precipitation and solvent extraction and uses Mitomycin C (MMC) as an internal standard, with a retention time for MMC of 5.85 +/- 0.015 min, and for CB1954 of 10.72 +/- 0.063 min. The limit of detection for CB1954 is 2.9 ng/ml, and this compares favourably with systems involving direct analysis of plasma (limit of detection 600 ng/ml, approximately). The method is now being used for pharmacokinetic measurements in plasma samples from cancer patients entering phase I clinical trials of CB1954. Results using serial plasma samples from one patient are presented. The patient was treated intravenously with CB1954 (6 mg/m2), and plasma clearance of the drug showed biphasic kinetics with alpha half-life 14.6 min, and beta half-life 170.5 min.

  8. Speciation of vanadium in oilsand coke and bacterial culture by high performance liquid chromatography inductively coupled plasma mass spectrometry.

    PubMed

    Li, X Sherry; Glasauer, Susan; Le, X Chris

    2007-10-17

    A simple and sensitive method for the speciation of vanadium(III), (IV), and (V) was developed by using high performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICPMS). The EDTA-complexed vanadium species were separated on a strong anion exchange column with an eluent containing 2 mM EDTA, 3% acetonitrile, and 80 mM ammonium bicarbonate at pH 6. Each analysis was complete in 5 min. The detection limits were 0.6, 0.7 and 1.0 microg L(-1) for V(III), V(IV), and V(V), respectively. The method was applied to coke pore water samples from an oilsand processing/upgrading site in Fort McMurray, Alberta, Canada and to Shewanella putrefaciens CN32 bacterial cultures incubated with V(V). In the coke pore water samples, V(IV) and V(V) were found to be the major species. For the first time, V(III) was detected in the bacterial cultures incubated with V(V).

  9. Simultaneous determination of niflumic acid and its prodrug, talniflumate in human plasma by high performance liquid chromatography.

    PubMed

    Jang, Dong-Jin; Park, Jeong-Sook; Ko, Hye-Ran; Jee, Jun-Pil; Kim, Jin-Ki; Kim, Sung Tae; Kim, Chong-Kook

    2005-01-01

    A high-performance liquid chromatographic (HPLC) method has been developed for the simultaneous determination of niflumic acid and its prodrug, talniflumate, in human plasma. Niflumic acid and talniflumate were eluted isocratically with methanol-water (73:27, v/v, adjusted to pH 3.5 by acetic acid) at a fl ow rate of 1 mL/min. Indomethacin was used as an internal standard. Signals were monitored by an UV detector at 288 nm. Retention times of indomethacin, niflumic acid and talniflumate were 5.9, 7.2 and 13.5 min, respectively. Calibration plots were linear over the range 50-5000 ng/mL for niflumic acid and 100-5000 ng/mL for talniflumate. The limits of quantitation were 50 ng/mL for niflumic acid and 100 ng/mL for talniflumate. The intra- and inter-day relative standard deviations (RSD) of niflumic acid and talniflumate were less than 10% and the accuracies were higher than 90%. This method is rapid, sensitive and reproducible for the determination of niflumic acid and talniflumate in human plasma.

  10. Separation and determination of organic acids and phenolic compounds in fruit juices and drinks by high-performance liquid chromatography.

    PubMed

    Shui, Guanghou; Leong, Lai Peng

    2002-11-15

    A high-performance liquid chromatographic (HPLC) separation method with photo-diode array detection has been developed for the simultaneous determination of organic acids and phenolic compounds in juices and drinks. The chromatographic analysis of organic acids and phenolic compounds was carried out after their elution with sulphuric acid solution (pH 2.5) and methanol from C18 stationary phase. The mobile phase employed was sulphuric acid solution working at a flow-rate of 0.35 ml min(-1) for the whole run, while methanol was linearly increased to 0.45 ml min(-1) from 15 to 75 min followed by a 5-min isocratic elution. Ten organic acid acids were eluted in 30 min and 21 phenolic compounds, which include phenolic acids and flavonoids, were eluted in the following 50 min. Target compounds were detected at 215 nm. The repeatability (n=3) and between day precision of peak area (n=3) were all within 5.0% RSD. The within-day repeatability (n=3) and between-day precision (n=10) of retention times were within 0.3 and 1.6% relative standard deviation (RSD), respectively. The accuracy of the method was confirmed with an average recovery ranging between 85 and 106%. The method was successfully used to measure a variety of organic acids and phenolic compounds in juices and beverages. This method could also be used to evaluate the authenticity, spoilage or micronutrient contents of juices.

  11. Chemometrics-enhanced high performance liquid chromatography-ultraviolet detection of bioactive metabolites from phytochemically unknown plants.

    PubMed

    Alvarez-Zapata, Radamés; Sánchez-Medina, Alberto; Chan-Bacab, Manuel; García-Sosa, Karlina; Escalante-Erosa, Fabiola; García-Rodríguez, Rosa Virginia; Peña-Rodríguez, Luis Manuel

    2015-11-27

    This work describes the use of Colubrina greggii as a model to investigate the use of chemometric analysis combined with data from a leishmanicidal bioassay, using Principal Component Analysis (PCA) and Orthogonal Projections to Latent Structures (O-PLS), to detect biologically active natural products in crude extracts from plants having little or no phytochemical information. A first analysis of the HPLC-UV profiles of the extract and its semi-purified fractions using both Principal Component Analysis (PCA) and Orthogonal Partial Least Squares (O-PLS) indicated that the components at tR 48.2, 48.7, 51.8min correlated with the variation in bioactivity. However, a further O-PLS analysis of the HPLC-UV profiles of fractions obtained through a final semi-preparative HPLC purification showed two components at tR 48.7 and 49.5min which correlated with the variation of the bioactivity in a high performance predictive model, with high determination coefficient, high correlation coefficient values (R(2) and Q(2)=0.99) and a low root mean square error (RMSE=0.018). This study demonstrates that the association of chemometric analysis with bioassay results can be an excellent strategy for the detection and isolation of bioactive metabolites from phytochemically unknown plant crude extracts.

  12. Fast and direct quantification of underivatized muscone by ultra performance liquid chromatography coupled with evaporative light scattering detection.

    PubMed

    Jin, Cheng; Yan, Chunxia; Luo, Yun; Li, Baocai; He, Jing; Xiao, Xiaohe

    2013-06-01

    A new reversed phase ultra performance liquid chromatography coupled with evaporative light scattering detection is developed for the fast and direct quantification of underivatized muscone in precious herbal medicine musk. Separation of muscone was achieved on a Waters Acquity BEH C18 (50 × 2.1 mm id, 1.7 μm) column. The runtime was as short as 5 min. The mode of evaporative light scattering detection was set at Impact On. The influence of evaporative light scattering detection condition on sensitivity was investigated. The optimized condition was: drift tube temperature at 30°C, gas flow rate 4.2 L/min. The method was validated with respect to the precision, sensitivity, accuracy, linearity, stability, and robustness were measured in this paper. The calibration curves showed good linear regression (r = 0.9914) within the test range. The recovery rate was 98.6%. The limit of detection for muscone was 2.0 ng. The validated method was rapid, simple, reproducible, and convenient for the quantification of muscone in musk and the related products.

  13. Comprehensive ultra-performance liquid chromatographic separation and mass spectrometric analysis of eicosanoid metabolites in human samples.

    PubMed

    Wang, Yan; Armando, Aaron M; Quehenberger, Oswald; Yan, Chao; Dennis, Edward A

    2014-09-12

    Over the past decade, the number of known eicosanoids has expanded immensely and we have now developed an ultra-performance liquid chromatography-electrospray ionization triple quadrupole mass spectrometric (UPLC-QTRAP/MS/MS) method to monitor and quantify numerous eicosanoids. The UPLC-QTRAP/MS/MS approach utilizes scheduled multiple reaction monitoring (MRM) to optimize sensitivity, number of metabolites that can be analyzed and the time requirement of the analysis. A total of 184 eicosanoids including 26 deuterated internal standards can be separated and monitored in a single 5min UPLC run. To demonstrate a practical application, human plasma samples were analyzed following solid-phase extraction (SPE) and the recovery rate and matrix effects were determined for the 26 deuterated internal standards added to the plasma. The method was validated and shown to be sensitive with the limit of quantitation at pg levels for most compounds, accurate with recovery rates of 70-120%, and precise with a CV<30 for all compounds. Also, the method showed a linear response over a range spanning several orders of magnitude. In a QC human plasma sample, we identified and rigorously quantified over 120 eicosanoids.

  14. Design and performance of a fast thermal response miniature Chromium Potassium Alum (CPA) salt pill for use in a millikelvin cryocooler

    NASA Astrophysics Data System (ADS)

    Bartlett, J.; Hardy, G.; Hepburn, I. D.

    2015-01-01

    The design and performance of a fast thermal response miniature (24 mm outer diameter by 30 mm long) Chromium Potassium Alum (CPA) salt pill is described. The need for a fast thermal response has been driven by the development of a continuously operating millikelvin cryocooler (mKCC) which uses 2 T superconducting magnets that can be ramped to full field in 30 s. The consequence of magnetising and demagnetising the CPA pill in such a short time is that thermal boundary resistance and eddy current heating have a significant impact on the performance of the pill, which was investigated in detail using modelling. The complete design of a prototype CPA pill is described in this paper, including the methods used to minimise thermal boundary resistance and eddy current heating as well as the manufacturing and assembly processes. The performance of the prototype CPA pill operated from a 3.6 K bath is presented, demonstrating that a complete CPA cycle (magnetising, cooling to bath and demagnetising) can be accomplished in under 2.5 min, with magnetisation and demagnetisation taking just 30 s each. The cold finger base temperature of the prototype varies with demagnetisation speed as a consequence of eddy current heating; for a 30 s demagnetisation, a base temperature of 161 mK is obtained, whilst for a 5 min demagnetisation, a base temperature of 149 mK was measured (both from a 3.6 K and 2 T starting position). The measured hold times of the CPA pill at 200 mK, 300 mK, and 1 K are given, proving that the hold time far exceeds the recycle time and demonstrating the potential for continuous operation when two ADRs are used in a tandem configuration. The ease and speed at which the CPA pill temperature can be changed and controlled when stepping between operating temperatures in the range of 200 mK to 4 K using a servo control program is also shown, once again highlighting the excellent thermal response of the pill. All of the test results are in good agreement with the

  15. Measures of rowing performance.

    PubMed

    Smith, T Brett; Hopkins, Will G

    2012-04-01

    Accurate measures of performance are important for assessing competitive athletes in practi~al and research settings. We present here a review of rowing performance measures, focusing on the errors in these measures and the implications for testing rowers. The yardstick for assessing error in a performance measure is the random variation (typical or standard error of measurement) in an elite athlete's competitive performance from race to race: ∼1.0% for time in 2000 m rowing events. There has been little research interest in on-water time trials for assessing rowing performance, owing to logistic difficulties and environmental perturbations in performance time with such tests. Mobile ergometry via instrumented oars or rowlocks should reduce these problems, but the associated errors have not yet been reported. Measurement of boat speed to monitor on-water training performance is common; one device based on global positioning system (GPS) technology contributes negligible extra random error (0.2%) in speed measured over 2000 m, but extra error is substantial (1-10%) with other GPS devices or with an impeller, especially over shorter distances. The problems with on-water testing have led to widespread use of the Concept II rowing ergometer. The standard error of the estimate of on-water 2000 m time predicted by 2000 m ergometer performance was 2.6% and 7.2% in two studies, reflecting different effects of skill, body mass and environment in on-water versus ergometer performance. However, well trained rowers have a typical error in performance time of only ∼0.5% between repeated 2000 m time trials on this ergometer, so such trials are suitable for tracking changes in physiological performance and factors affecting it. Many researchers have used the 2000 m ergometer performance time as a criterion to identify other predictors of rowing performance. Standard errors of the estimate vary widely between studies even for the same predictor, but the lowest

  16. Identity verifier performance

    SciTech Connect

    Maxwell, R.

    1987-01-01

    This report is a transcript of a paper given at the Smart Card Applications and Technologies Conference, October 14, 1987. Identity verification techniques are identified and discussed, and statistical performance data is given. 20 figs. (JF)

  17. Desalination processes and performance

    SciTech Connect

    Summers, L. J.

    1995-06-01

    Different desalination processes are evaluated for feed, capacity, performance, energy requirements, and cost. These include distillation, reverse osmosis, or electrodialysis. Detailed information is given on distillation processes and membrane processes.

  18. DAS performance analysis

    SciTech Connect

    Bates, G.; Bodine, S.; Carroll, T.; Keller, M.

    1984-02-01

    This report begins with an overview of the Data Acquisition System (DAS), which supports several of PPPL's experimental devices. Performance measurements which were taken on DAS and the tools used to make them are then described.

  19. On Time Performance Pressure

    NASA Technical Reports Server (NTRS)

    Connell, Linda; Wichner, David; Jakey, Abegael

    2013-01-01

    Within many operations, the pressures for on-time performance are high. Each month, on-time statistics are reported to the Department of Transportation and made public. There is a natural tendency for employees under pressure to do their best to meet these objectives. As a result, pressure to get the job done within the allotted time may cause personnel to deviate from procedures and policies. Additionally, inadequate or unavailable resources may drive employees to work around standard processes that are seen as barriers. However, bypassing practices to enable on-time performance may affect more than the statistics. ASRS reports often highlight on-time performance pressures which may result in impact across all workgroups in an attempt to achieve on-time performance. Reporters often provide in-depth insights into their experiences which can be used by industry to identify and focus on the implementation of systemic fixes.

  20. GPS Timing Performance

    DTIC Science & Technology

    2014-01-01

    U.S. Naval Observatory (USNO) [1]. Interoperability with Galileo, and perhaps someday with other Global Navigation Satellite Systems ( GNSS ), is to...be established through transmission of the differences between the GNSS system times. This paper describes the performance of the GPS system, which...interoperable GNSS systems will benefit from the additional satellites, and in certain situations markedly so. 2. Current Performance Under Optimal

  1. Roller drive materials performance

    NASA Technical Reports Server (NTRS)

    Rohn, Douglas A.

    1988-01-01

    Roller traction performance basics, a test program to measure performance, and the need for and typical use of the information are outlined. A test rig was designed and fabricated to develop this information. Parametric conditions and specimen materials were chosen so that the resulting data will be valuable to the design and development of advanced, roller-driven space mechanisms, from precision positioning devices to telerobot joints.

  2. Embarking on performance improvement.

    PubMed

    Brown, Bobbi; Falk, Leslie Hough

    2014-06-01

    Healthcare organizations should approach performance improvement as a program, not a project. The program should be led by a guidance team that identifies goals, prioritizes work, and removes barriers to enable clinical improvement teams and work groups to realize performance improvements. A healthcare enterprise data warehouse can provide the initial foundation for the program analytics. Evidence-based best practices can help achieve improved outcomes and reduced costs.

  3. Intellectual Performance Under Stress

    DTIC Science & Technology

    1976-09-01

    Jeffery Miller - Asst. Prof. Univ. Cal. San Diego Donald Polzella Asst. Prof. Univ. of Dayton Andrew Rose American Institute of Research Douglas Stokes...Research, 1974, 71, 39!-400. (0l0588—26-J) Polzella , D.J. The effect of sleep-deprivation on short-term recognition memory. Human Performance Center...Technical Report No. 47, April, 1974. (010588-19-1’) Polzella , D.J. Remembering the functional sentence. Human Performance Center Technical Report No

  4. Examples Performance Testing Templates.

    SciTech Connect

    Siple, Bud H.

    2014-07-01

    The purpose of this Performance Testing Program Plan is to identify the process and phased approach that will be implemented at Site XYZ . The purpose of the testing program at Site XYZ is specifically designed to evaluate the effectiveness of systems that are employed at this site. This plan defines tasks to be accomplished to ensure that performance testing is conducted as effectively and efficiently as possible.

  5. High Performance Polymers

    NASA Technical Reports Server (NTRS)

    Venumbaka, Sreenivasulu R.; Cassidy, Patrick E.

    2003-01-01

    This report summarizes results from research on high performance polymers. The research areas proposed in this report include: 1) Effort to improve the synthesis and to understand and replicate the dielectric behavior of 6HC17-PEK; 2) Continue preparation and evaluation of flexible, low dielectric silicon- and fluorine- containing polymers with improved toughness; and 3) Synthesis and characterization of high performance polymers containing the spirodilactam moiety.

  6. Effects of pre-exercise listening to slow and fast rhythm music on supramaximal cycle performance and selected metabolic variables.

    PubMed

    Yamamoto, T; Ohkuwa, T; Itoh, H; Kitoh, M; Terasawa, J; Tsuda, T; Kitagawa, S; Sato, Y

    2003-07-01

    We examined the effect of listening to two different types of music (with slow and fast rhythm), prior to supramaximal cycle exercise, on performance, heart rate, the concentration of lactate and ammonia in blood, and the concentration of catecholamines in plasma. Six male students participated in this study. After listening to slow rhythm or fast rhythm music for 20 min, the subjects performed supramaximal exercise for 45 s using a cycle ergometer. Listening to slow and fast rhythm music prior to supramaximal exercise did not significantly affect the mean power output. The plasma norepinephrine concentration immediately before the end of listening to slow rhythm music was significantly lower than before listening (p < 0.05). The plasma epinephrine concentration immediately before the end of listening to fast rhythm music was significantly higher than before listening (p < 0.05). The type of music had no effect on blood lactate and ammonia levels or on plasma catecholamine levels following exercise. In conclusion, listening to slow rhythm music decreases the plasma norepinephrine level, and listening to fast rhythm music increases the plasma epinephrine level. The type of music has no impact on power output during exercise.

  7. Effects of heat exposure and 3% dehydration achieved via hot water immersion on repeated cycle sprint performance.

    PubMed

    Kraft, Justin A; Green, James M; Bishop, Phillip A; Richardson, Mark T; Neggers, Yasmin H; Leeper, James D

    2011-03-01

    This study examined effects of heat exposure with and without dehydration on repeated anaerobic cycling. Males (n = 10) completed 3 trials: control (CT), water-bath heat exposure (∼39°C) to 3% dehydration (with fluid replacement) (HE), and similar heat exposure to 3% dehydration (DEHY). Hematocrit increased significantly from pre to postheat immersion in both HE and DEHY. Participants performed 6 × 15s cycle sprints (30s active recovery). Mean Power (MP) was significantly lower vs. CT (596 ± 66 W) for DEHY (569 ± 72 W), and the difference approached significance for HE (582 ± 76 W, p = 0.07). Peak Power (PP) was significantly lower vs. CT (900 ± 117 W) for HE (870 ± 128 W) and approached significance for DEHY (857 ± 145 W, p = 0.07). Postsprint ratings of perceived exertion was higher during DEHY (6.4 ± 2.0) and HE (6.3 ± 1.6) than CT (5.7 ± 2.1). Combined heat and dehydration impaired MP and PP (decrements greatest in later bouts) with HE performance intermediate to CT and DEHY.

  8. Performance assurance program plan

    SciTech Connect

    Rogers, B.H.

    1997-11-06

    B and W Protec, Inc. (BWP) is responsible for implementing the Performance Assurance Program for the Project Hanford Management Contract (PHMC) in accordance with DOE Order 470.1, Safeguards and Security Program (DOE 1995a). The Performance Assurance Program applies to safeguards and security (SAS) systems and their essential components (equipment, hardware, administrative procedures, Protective Force personnel, and other personnel) in direct support of Category I and H special nuclear material (SNM) protection. Performance assurance includes several Hanford Site activities that conduct performance, acceptance, operability, effectiveness, and validation tests. These activities encompass areas of training, exercises, quality assurance, conduct of operations, total quality management, self assessment, classified matter protection and control, emergency preparedness, and corrective actions tracking and trending. The objective of the Performance Assurance Program is to capture the critical data of the tests, training, etc., in a cost-effective, manageable program that reflects the overall effectiveness of the program while minimizing operational impacts. To aid in achieving this objective, BWP will coordinate the Performance Assurance Program for Fluor Daniel Hanford, Inc. (FDH) and serve as the central point for data collection.

  9. Repository performance confirmation.

    SciTech Connect

    Hansen, Francis D.

    2011-09-01

    Repository performance confirmation links the technical bases of repository science and societal acceptance. This paper explores the myriad aspects of what has been labeled performance confirmation in U.S. programs, which involves monitoring as a collection of distinct activities combining technical and social significance in radioactive waste management. This paper is divided into four parts: (1) A distinction is drawn between performance confirmation monitoring and other testing and monitoring objectives; (2) A case study illustrates confirmation activities integrated within a long-term testing and monitoring strategy for Yucca Mountain; (3) A case study reviews compliance monitoring developed and implemented for the Waste Isolation Pilot Plant; and (4) An approach for developing, evaluating and implementing the next generation of performance confirmation monitoring is presented. International interest in repository monitoring is exhibited by the European Commission Seventh Framework Programme 'Monitoring Developments for Safe Repository Operation and Staged Closure' (MoDeRn) Project. The MoDeRn partners are considering the role of monitoring in a phased approach to the geological disposal of radioactive waste. As repository plans advance in different countries, the need to consider monitoring strategies within a controlled framework has become more apparent. The MoDeRn project pulls together technical and societal experts to assimilate a common understanding of a process that could be followed to develop a monitoring program. A fundamental consideration is the differentiation of confirmation monitoring from the many other testing and monitoring activities. Recently, the license application for Yucca Mountain provided a case study including a technical process for meeting regulatory requirements to confirm repository performance as well as considerations related to the preservation of retrievability. The performance confirmation plan developed as part of the

  10. Influence of crank length on cycle ergometry performance of well-trained female cross-country mountain bike athletes.

    PubMed

    Macdermid, Paul William; Edwards, Andrew M

    2010-01-01

    The aim of this study was to determine the differential effects of three commonly used crank lengths (170, 172.5 and 175 mm) on performance measures relevant to female cross-country mountain bike athletes (n = 7) of similar stature. All trials were performed in a single blind and balanced order with a 5- to 7-day period between trials. Both saddle height and fore-aft position to pedal axle distance at a crank angle of 90 degrees was controlled across all trials. The laboratory tests comprised a supra-maximal (peak power-cadence); an isokinetic (50 rpm) test; and a maximal test of aerobic capacity. The time to reach supra-maximal peak power was significantly (P < 0.05) shorter in the 170 mm (2.57 +/- 0.79 s) condition compared to 175 mm (3.29 +/- 0.76 s). This effect represented a mean performance advantage of 27.8% for 170 mm compared to 175 mm. There was no further inter-condition differences between performance outcome measurements derived for the isokinetic (50 rpm) maximum power output, isokinetic (50 rpm) mean power output or indices of endurance performance. The decreased time to peak power with the greater rate of power development in the 170 mm condition suggests a race advantage may be achieved using a shorter crank length than commonly observed. Additionally, there was no impediment to either power output produced at low cadences or indices of endurance performance using the shorter crank length and the advantage of being able to respond quickly to a change in terrain could be of strategic importance to elite athletes.

  11. Caffeine ingestion after rapid weight loss in judo athletes reduces perceived effort and increases plasma lactate concentration without improving performance.

    PubMed

    Lopes-Silva, Joao P; Felippe, Leandro J C; Silva-Cavalcante, Marcos D; Bertuzzi, Romulo; Lima-Silva, Adriano E

    2014-07-22

    The objective of this study was to examine the effect of caffeine on judo performance, perceived exertion, and plasma lactate response when ingested during recovery from a 5-day weight loss period. Six judokas performed two cycles of a 5-day rapid weight loss procedure to reduce their body weight by ~5%. After weigh-in, subjects re-fed and rehydrated over a 4-h recovery period. In the third hour of this "loading period", subjects ingested a capsule containing either caffeine (6 mg·kg-1) or placebo. One hour later, participants performed three bouts of a judo fitness test with 5-min recovery periods. Perceived exertion and plasma lactate were measured before and immediately after each test bout. Body weight was reduced in both caffeine and placebo conditions after the weight loss period (-3.9% ± 1.6% and -4.0% ± 2.3% from control, respectively, p < 0.05). At three hours after weigh-in, body weight had increased with both treatments but remained below the control (-3.0% ± 1.3% and -2.7% ± 2.2%). There were no significant differences in the number of throws between the control, caffeine or placebo groups. However, plasma lactate was systemically higher and perceived exertion lower in the subjects who ingested caffeine compared to either the control or placebo subjects (p < 0.05). In conclusion, caffeine did not improve performance during the judo fitness test after a 5-day weight loss period, but reduced perceived exertion and increased plasma lactate.

  12. Metabolic consequences of β-alanine supplementation during exhaustive supramaximal cycling and 4000-m time-trial performance.

    PubMed

    Bellinger, Phillip M; Minahan, Clare L

    2016-08-01

    The present study investigated the effects of β-alanine supplementation on the resultant blood acidosis, lactate accumulation, and energy provision during supramaximal-intensity cycling, as well as the aerobic and anaerobic contribution to power output during a 4000-m cycling time trial (TT). Seventeen trained cyclists (maximal oxygen uptake = 4.47 ± 0.55 L·min(-1)) were administered 6.4 g of β-alanine (n = 9) or placebo (n = 8) daily for 4 weeks. Participants performed a supramaximal cycling test to exhaustion (equivalent to 120% maximal oxygen uptake) before (PreExh) and after (PostExh) the 4-week supplementation period, as well as an additional postsupplementation supramaximal cycling test identical in duration and power output to PreExh (PostMatch). Anaerobic capacity was quantified and blood pH, lactate, and bicarbonate concentrations were measured pre-, immediately post-, and 5 min postexercise. Subjects also performed a 4000-m cycling TT before and after supplementation while the aerobic and anaerobic contributions to power output were quantified. β-Alanine supplementation increased time to exhaustion (+12.8 ± 8.2 s; P = 0.041) and anaerobic capacity (+1.1 ± 0.7 kJ; P = 0.048) in PostExh compared with PreExh. Performance time in the 4000-m TT was reduced following β-alanine supplementation (-6.3 ± 4.6 s; P = 0.034) and the mean anaerobic power output was likely to be greater (+6.2 ± 4.5 W; P = 0.035). β-Alanine supplementation increased time to exhaustion concomitant with an augmented anaerobic capacity during supramaximal intensity cycling, which was also mirrored by a meaningful increase in the anaerobic contribution to power output during a 4000-m cycling TT, resulting in an enhanced overall performance.

  13. Fasting improves static apnea performance in elite divers without enhanced risk of syncope.

    PubMed

    Schagatay, Erika; Lodin-Sundström, Angelica

    2014-01-01

    In competitive apnea divers, the nutritional demands may be essentially different from those of, for example, endurance athletes, where energy resources need to be maximised for successful performance. In competitive apnea, the goal is instead to limit metabolism, as the length of the sustainable apneic period will depend to a great extent on minimising oxygen consumption. Many but not all elite divers fast before performing static apnea in competition. This may increase oxygen consumption as mainly lipid stores are metabolised but could also have beneficial effects on apneic duration. Our aim was to determine the effect of over-night fasting on apnea performance. Six female and seven male divers performed a series of three apneas after eating and fasting, respectively. The series consisted of two 2-min apneas spaced by 3 min rest and, after 5 min rest, one maximal effort apnea. Apneas were performed at supine rest and preceded by normal respiration and maximal inspiration. Mean (± SD) time since eating was 13 h (± 2 h 43 min) for the fasting and 1 h 34 min (± 33 min) for the eating condition (P < 0.001). Mean blood glucose was 5.1 (± 0.4) mmol/L after fasting and 5.9 (± 0.7) mmol/L after eating (P<0.01). Lung volumes were similar in both conditions (NS). For the 2-min apneas, nadir SaO2 during fasting was 95 (± 1)% and 92 (± 2)% (P < 0.001) on eating and ETCO2 was lower in the fasting condition (P < 0.01) while heart rate (HR) during apnea was 74 (± 10) bpm for fasting and 80 (± 10) bpm for eating conditions (P < 0.01). Maximal apnea durations were 4 min 41 s (± 43 s) during fasting and 3 min 51 s (± 37 s) after eating (P < 0.001), and time without respiratory contractions was 31 s (25%) longer after fasting (P < 0.01). At maximal apnea termination, SaO2 and ETCO2 were similar in both conditions (NS) and apneic HR was 63 (± 9) bpm for fasting and 70 (± 10) bpm for eating (P < 0.01). The 22% longer apnea duration after fasting with analogous end apnea

  14. EVA Performance Prediction

    NASA Technical Reports Server (NTRS)

    Peacock, Brian; Maida, James; Rajulu, Sudhakar

    2004-01-01

    Astronaut physical performance capabilities in micro gravity EV A or on planetary surfaces when encumbered by a life support suit and debilitated by a long exposure to micro gravity will be less than unencumbered pre flight capabilities. The big question addressed by human factors engineers is: what can the astronaut be expected to do on EVA or when we arrive at a planetary surface? A second question is: what aids to performance will be needed to enhance the human physical capability? These questions are important for a number of reasons. First it is necessary to carry out accurate planning of human physical demands to ensure that time and energy critical tasks can be carried out with confidence. Second it is important that the crew members (and their ground or planetary base monitors) have a realistic picture of their own capabilities, as excessive fatigue can lead to catastrophic failure. Third it is important to design appropriate equipment to enhance human sensory capabilities, locomotion, materials handling and manipulation. The evidence from physiological research points to musculoskeletal, cardiovascular and neurovestibular degradation during long duration exposure to micro gravity . The evidence from the biomechanics laboratory (and the Neutral Buoyancy Laboratory) points to a reduction in range of motion, strength and stamina when encumbered by a pressurized suit. The evidence from a long history of EVAs is that crewmembers are indeed restricted in their physical capabilities. There is a wealth of evidence in the literature on the causes and effects of degraded human performance in the laboratory, in sports and athletics, in industry and in other physically demanding jobs. One approach to this challenge is through biomechanical and performance modeling. Such models must be based on thorough task analysis, reliable human performance data from controlled studies, and functional extrapolations validated in analog contexts. The task analyses currently carried

  15. Instrument performance evaluation

    SciTech Connect

    Swinth, K.L.

    1993-03-01

    Deficiencies exist in both the performance and the quality of health physics instruments. Recognizing the implications of such deficiencies for the protection of workers and the public, in the early 1980s the DOE and the NRC encouraged the development of a performance standard and established a program to test a series of instruments against criteria in the standard. The purpose of the testing was to establish the practicality of the criteria in the standard, to determine the performance of a cross section of available instruments, and to establish a testing capability. Over 100 instruments were tested, resulting in a practical standard and an understanding of the deficiencies in available instruments. In parallel with the instrument testing, a value-impact study clearly established the benefits of implementing a formal testing program. An ad hoc committee also met several times to establish recommendations for the voluntary implementation of a testing program based on the studies and the performance standard. For several reasons, a formal program did not materialize. Ongoing tests and studies have supported the development of specific instruments and have helped specific clients understand the performance of their instruments. The purpose of this presentation is to trace the history of instrument testing to date and suggest the benefits of a centralized formal program.

  16. The performance measurement manifesto.

    PubMed

    Eccles, R G

    1991-01-01

    The leading indicators of business performance cannot be found in financial data alone. Quality, customer satisfaction, innovation, market share--metrics like these often reflect a company's economic condition and growth prospects better than its reported earnings do. Depending on an accounting department to reveal a company's future will leave it hopelessly mired in the past. More and more managers are changing their company's performance measurement systems to track nonfinancial measures and reinforce new competitive strategies. Five activities are essential: developing an information architecture; putting the technology in place to support this architecture; aligning bonuses and other incentives with the new system; drawing on outside resources; and designing an internal process to ensure the other four activities occur. New technologies and more sophisticated databases have made the change to nonfinancial performance measurement systems possible and economically feasible. Industry and trade associations, consulting firms, and public accounting firms that already have well-developed methods for assessing market share and other performance metrics can add to the revolution's momentum--as well as profit from the business opportunities it presents. Every company will have its own key measures and distinctive process for implementing the change. But making it happen will always require careful preparation, perseverance, and the conviction of the CEO that it must be carried through. When one leading company can demonstrate the long-term advantage of its superior performance on quality or innovation or any other nonfinancial measure, it will change the rules for all its rivals forever.

  17. Cognitive performance and dehydration.

    PubMed

    Adan, Ana

    2012-04-01

    No matter how mild, dehydration is not a desirable condition because there is an imbalance in the homeostatic function of the internal environment. This can adversely affect cognitive performance, not only in groups more vulnerable to dehydration, such as children and the elderly, but also in young adults. However, few studies have examined the impact of mild or moderate dehydration on cognitive performance. This paper reviews the principal findings from studies published to date examining cognitive skills. Being dehydrated by just 2% impairs performance in tasks that require attention, psychomotor, and immediate memory skills, as well as assessment of the subjective state. In contrast, the performance of long-term and working memory tasks and executive functions is more preserved, especially if the cause of dehydration is moderate physical exercise. The lack of consistency in the evidence published to date is largely due to the different methodology applied, and an attempt should be made to standardize methods for future studies. These differences relate to the assessment of cognitive performance, the method used to cause dehydration, and the characteristics of the participants.

  18. Establishing maintenance performance indicators

    SciTech Connect

    Baca, B.

    1994-10-01

    Maintenance Performance Indicators (PI) specify where the maintenance department is and which direction it is going allowing for a quick and accurate assessment of the performance of the Maintenance Management Program (MMP). Establishing PI`s for the maintenance department will allow a measure of productivity and a means of feedback for methods improvement. Effective performance of the maintenance department directly effects plant profitability. Improvements in the quality and productivity of the maintenance work force will significantly reduce maintenance costs. The level of performance attained by the maintenance work force is usually guessed at. Guessing will not identify areas needing improvement or help to initiate a corrective action. Maintenance PI`s are required for maintenance departments whose goal is to control maintenance costs while increasing productivity. The application of basic statistical methods will allow a maintenance department to know where they are and which direction they are going. The data presented in this paper is a representation of indicators used in industry as well as developed indicators to establish a complete maintenance performance indicator program. The methodology used in developing this program can be used as a way to manage a cost effective maintenance management program.

  19. Internet Performance to Africa

    SciTech Connect

    Cottrell, L

    2003-10-01

    We report the first results ever for real-time Internet performance to Africa using the PingER methodology. Multiple monitoring hosts were used to enable comparisons with performance from different parts of the world. From these preliminary measurements, we have found that Internet packet losses to some African sites in recent months range from very poor to bad (> 12%), some getting better, others are holding steady or getting worse. This, together with the average monthly Round Trip Times, imply end-to-end maximum TCP throughputs that are order of magnitudes different between countries in the region. Africa is shown to be far from the Internet performance in industrialized nations due to the poor infrastructure in place today. These monitoring efforts can provide valuable information to analyze the relative rates of future improvement and today they help us to quantify the digital divide and can provide quantitative information to policy makers.

  20. Cyclone performance and optimization

    SciTech Connect

    Leith, D.

    1989-06-15

    The objectives of this project are: to characterize the gas flow pattern within cyclones, to revise the theory for cyclone performance on the basis of these findings, and to design and test cyclones whose dimensions have been optimized using revised performance theory. This work is important because its successful completion will aid in the technology for combustion of coal in pressurized, fluidized beds. We have now received all the equipment necessary for the flow visualization studies described over the last two progress reports. We have begun more detailed studies of the gas flow pattern within cyclones as detailed below. Third, we have begun studies of the effect of particle concentration on cyclone performance. This work is critical to application of our results to commercial operations. 1 fig.

  1. High performance steam development

    SciTech Connect

    Duffy, T.; Schneider, P.

    1995-12-31

    DOE has launched a program to make a step change in power plant to 1500 F steam, since the highest possible performance gains can be achieved in a 1500 F steam system when using a topping turbine in a back pressure steam turbine for cogeneration. A 500-hour proof-of-concept steam generator test module was designed, fabricated, and successfully tested. It has four once-through steam generator circuits. The complete HPSS (high performance steam system) was tested above 1500 F and 1500 psig for over 102 hours at full power.

  2. Human performance during spaceflight.

    PubMed

    Manzey, D; Lorenz, B

    1999-04-01

    The paper focuses on three different questions: (1) What attributes cause space to be an extreme environment for humans? (2) What do we know about mental performance during spaceflight? (3) What kinds of psychological countermeasures are currently applied and/or conceivable for prolonged spaceflight which might help maintain mental efficiency and stabilize the emotional state of astronauts? Topics discussed include stressors that originate in the space environment, stressors related to the space habitat and its life-support system, stressors related to the mission specific workload of astronauts, stressors that arise from the psychosocial situation in a space habitat, manual performance during spaceflight, and psychological countermeasures for prolonged spaceflight.

  3. Photovoltaic lighting system performance

    SciTech Connect

    Harrington, S.R.; Hund, T.D.

    1996-06-01

    The performance of 21 PV-powered low pressure sodium lighting systems on a multi-use has been documented in this paper. Specific areas for evaluation include the vandal resistant PV modules, constant voltage and on/off PV charge controllers, flooded deep-cycle lead-antimony and valve regulated lead-acid (VLRA) gel batteries, and low pressure sodium ballasts and lights. The PV lighting system maintenance intervals and lessons learned have been documented over the past 2.5 years. The above performance data has shown that with careful hardware selection, installation, and maintenance intervals the PV lighting systems will operate reliably.

  4. Dependability and performability analysis

    NASA Technical Reports Server (NTRS)

    Trivedi, Kishor S.; Ciardo, Gianfranco; Malhotra, Manish; Sahner, Robin A.

    1993-01-01

    Several practical issues regarding specifications and solution of dependability and performability models are discussed. Model types with and without rewards are compared. Continuous-time Markov chains (CTMC's) are compared with (continuous-time) Markov reward models (MRM's) and generalized stochastic Petri nets (GSPN's) are compared with stochastic reward nets (SRN's). It is shown that reward-based models could lead to more concise model specifications and solution of a variety of new measures. With respect to the solution of dependability and performability models, three practical issues were identified: largeness, stiffness, and non-exponentiality, and a variety of approaches are discussed to deal with them, including some of the latest research efforts.

  5. Human target acquisition performance

    NASA Astrophysics Data System (ADS)

    Teaney, Brian P.; Du Bosq, Todd W.; Reynolds, Joseph P.; Thompson, Roger; Aghera, Sameer; Moyer, Steven K.; Flug, Eric; Espinola, Richard; Hixson, Jonathan

    2012-06-01

    The battlefield has shifted from armored vehicles to armed insurgents. Target acquisition (identification, recognition, and detection) range performance involving humans as targets is vital for modern warfare. The acquisition and neutralization of armed insurgents while at the same time minimizing fratricide and civilian casualties is a mounting concern. U.S. Army RDECOM CERDEC NVESD has conducted many experiments involving human targets for infrared and reflective band sensors. The target sets include human activities, hand-held objects, uniforms & armament, and other tactically relevant targets. This paper will define a set of standard task difficulty values for identification and recognition associated with human target acquisition performance.

  6. Performance of gigabit FDDI

    NASA Technical Reports Server (NTRS)

    Game, David; Maly, Kurt J.

    1990-01-01

    Great interest exists in developing high speed protocols which will be able to support data rates at gigabit speeds. Hardware currently exists which can experimentally transmit at data rates exceeding a gigabit per second, but it is not clear as to what types of protocols will provide the best performance. One possibility is to examine current protocols and their extensibility to these speeds. Scaling of Fiber Distributed Data Interface (FDDI) to gigabit speeds is studied. More specifically, delay statistics are included to provide insight as to which parameters (network length, packet length or number of nodes) have the greatest effect on performance.

  7. Human Performance Assessment Methods

    DTIC Science & Technology

    1989-05-01

    deja aborde let problmes souleves par e’tude des performances humaines en situation op ~ rationnelle mais tr~s souvent il t’est av&r impossiblc de faire...La mission dii Groupe fit dl󈨁abortr inc batterie standardiq~e de tests et de rechercher et crs~er unc structure pour I𔄀change de donnees. La...fit de compiler ct dc publier in Annusire international des 6quipes de recherche en performances humaines. Cette publication. quoique loin d

  8. Can cycling performance in an early morning, laboratory-based cycle time-trial be improved by morning exercise the day before?

    PubMed

    Edwards, B J; Edwards, W; Waterhouse, J; Atkinson, G; Reilly, T

    2005-10-01

    The normal circadian rhythm in exercise performance may be altered by the habitual timing of training. We have investigated if morning time trial performance is affected by the time at which moderate exercise is performed on the previous day. Eight male cyclists undertook two separate exercise sessions of sub-maximal cycle ergometry (60% V.O2peak for 30 min) at 07:00 h and 12:00 h the day before a 16.1-km time trial at 07:00 h. Heart rate, power output, ratings of perceived exertion, and rectal temperature were measured at rest and every 5 min in the pre-time trial exercises, and every 1.61 km during the time trial. Blood samples were taken at rest and immediately after the time trial for the measurement of lactate concentration. The time trial performed the day after the 07:00 h sub-maximal exercise was completed in 1672+/-135 s, compared to 1706+/-159 s for the time trial performed the day after the noon pre-time trial exercise (p=0.027). The time trial after exercise the previous morning was associated with higher work-rates (p=0.031), a higher net lactate accumulation after the time trial (p=0.018), and a trend for higher heart rates (p=0.093) compared to the time trial after exercise the previous noon. These findings suggest that cycling performance in an early morning time trial is improved if an athlete participates in early-morning rather than noontime moderate exercise the day before. This finding cannot be attributed to the physiological responses to the exercise on the pre-time trial day or to environmental factors. It is suggested that it might partly reflect an advantage gained by performing exercise in the day(s) immediately beforehand at the same time as the competition.

  9. Design and performance evaluation of a microfluidic ion-suppression module for anion-exchange chromatography.

    PubMed

    Wouters, Sam; Wouters, Bert; Jespers, Sander; Desmet, Gert; Eghbali, Hamed; Bruggink, Cees; Eeltink, Sebastiaan

    2014-08-15

    A microfluidic membrane suppressor has been constructed to suppress ions of alkaline mobile-phases via an acid-base reaction across a sulfonated poly(tetrafluoroethylene)-based membrane and was evaluated for anion-exchange separations using conductivity detection. The membrane was clamped between two chip substrates, accommodating rectangular microchannels for the eluent and regenerant flow, respectively. Additionally, a clamp-on chip holder has been constructed which allows the alignment and stacking of different chip modules. The response and efficacy of the microfluidic chip suppressor was assessed for a wide range of eluent (KOH) concentrations, using 127 and 183μm thick membranes, while optimizing the flow rate and concentration of the regenerant solution (H2SO4). The optimal operating eluent flow rate was determined at 5μL/min, corresponding to the optimal van-Deemter flow velocity of commercially-available column technology, i.e. a 0.4mm i.d.×250mm long column packed with 7.5μm anion-exchange particles. When equilibrated at 10mM KOH, a 99% decrease in conductivity signal could be obtained within 5min when applying 10mM H2SO4 regenerant at 75μL/min. A background signal as low as 1.2μS/cm was obtained, which equals the performance of a commercially-available electrolytic hollow-fiber suppressor. When increasing the temperature of the membrane suppressor from 15 to 20°C, ion suppression was significantly improved allowing the application of 75mM KOH. The applicability of the chip suppressor has been demonstrated with an isocratic baseline separation of a mixture of seven inorganic ions, yielding plate numbers between 5300 and 10,600 and with a gradient separation of a complex ion mixture.

  10. Performance and mechanism of low-frequency ultrasound to regenerate the biological activated carbon.

    PubMed

    Liu, Cheng; Sun, Yakun; Wang, Dongying; Sun, Zhehao; Chen, Ming; Zhou, Zhi; Chen, Wei

    2017-01-01

    Biological activated carbon (BAC) filter has been widely used as an effective water treatment but regenerations of BAC are costly. Ultrasound has been successfully applied for regeneration of activated carbon but has been less frequently applied to the regenerate the BAC. In this study, bench-scale and pilot-scale experiments were conducted to evaluate the regeneration performance and mechanism of BAC with low-frequency ultrasound. Adsorption indices, microbiological parameters, pore structure and removal efficiencies were further investigated. The results showed that low-frequency ultrasound could regenerate the BAC effectively. The regeneration effects were significantly affected by the frequency, sonication intensity, sonication time, and water temperature, but not the usage time of the BAC. The optimized conditions were identified as 40kHz of frequency, 115×10(-3)W/cm(3) of sonication intensity, 25-30°C of water temperature and 5min of sonication time. The iodine value and methylene blue value increased from 480mg/g and 100mg/g to 680mg/g and 133mg/g respectively, the biomass decreased from 310nmolP/gC to 245nmolP/gC, while the biological activity increased from 0.03mg O2/hgC to 0.0355mg O2/hgC under the optimized condition. After three months of continuous operation, removal efficiencies of regenerated BAC were still high for the removal of organic contaminants, atrazine, and 2-MIB. Analysis of pore structure, BET surface area, and scanning electron microscopy indicated that ultrasound mainly acted on surface and macro-pores of BAC through the high-speed microjets and high-pressure microstreams resulted from the collapse of cavitation bubbles.

  11. New rapid methods for determination of total LAS in sewage sludge by high performance liquid chromatography (HPLC) and capillary electrophoresis (CE).

    PubMed

    Villar, M; Callejón, M; Jiménez, J C; Alonso, E; Guiraúm, A

    2009-02-23

    Linear alkylbenzene sulfonates (LAS) are the most common synthetic anionic surfactant used in domestic and industrial detergents, with a global production of 2.4x10(6) t year(-1). After use and disposal, LAS may enter the environment by one of the several routes, including by direct discharge to surface water or discharge to water from sewage treatment plants. Sewage treatment plants break down LAS only partly: some of them remain in effluent and other fraction is adsorbed in sewage solid. New and rapid methods for determination of total LAS from sewage sludge based on microwave assisted extraction and HPLC-FL and CE-DAD determination are proposed. The extraction of total LAS is carried out by using microwaves energy, an extraction time of 10 min and 5 mL of methanol. For HPLC-FL determination, mobile phase acetonitrile-water was used, comprising 60% (v/v) from 0 to 1 min and a flow rate of 1 mL min(-1) programmed to 100% acetonitrile between 1 and 2 min and a flow rate of 2 mL min(-1). The final composition was maintained for a further 5 min. The determination of total LAS by CE-DAD was performed in a phosphate buffer (10 mM, pH 9). The separation voltage was 25 kV and the temperature of the capillary was 30 degrees C. Injections were performed in the pressure mode and the injection time was set at 12 s. The determination of total LAS is carried out in less than 5 min. The methods did not require clean-up or preconcentration steps. Detection limit for total LAS in the sludge was 3.03 mg kg(-1) using HPLC-FL and 21.0 mg kg(-1) using CE-DAD, and recoveries were >85% using both determination methods. Concentrations of total LAS obtained using both methods were compared with the sum of concentrations of homologues LAS C-10, LAS C-11, LAS C-12 and LAS C-13 obtained using microwaves assisted extraction and HPLC-FL and CE-DAD determination.

  12. MIND performance and prototyping

    SciTech Connect

    Cervera-Villanueva, A.

    2008-02-21

    The performance of MIND (Magnetised Iron Neutrino Detector) at a neutrino factory has been revisited in a new analysis. In particular, the low neutrino energy region is studied, obtaining an efficiency plateau around 5 GeV for a background level below 10{sup -3}. A first look has been given into the detector optimisation and prototyping.

  13. Cyclone performance by velocity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cyclones are used almost exclusively in the US cotton ginning industry for emission abatement on pneumatic conveying system exhausts because of their high efficiency, and low capital and operating cost.. Cyclone performance is improved by increasing collection effectiveness or decreasing energy cons...

  14. Ion thruster performance model

    NASA Technical Reports Server (NTRS)

    Brophy, J. R.

    1984-01-01

    A model of ion thruster performance is developed for high flux density, cusped magnetic field thruster designs. This model is formulated in terms of the average energy required to produce an ion in the discharge chamber plasma and the fraction of these ions that are extracted to form the beam. The direct loss of high energy (primary) electrons from the plasma to the anode is shown to have a major effect on thruster performance. The model provides simple algebraic equations enabling one to calculate the beam ion energy cost, the average discharge chamber plasma ion energy cost, the primary electron density, the primary-to-Maxwellian electron density ratio and the Maxwellian electron temperature. Experiments indicate that the model correctly predicts the variation in plasma ion energy cost for changes in propellant gas (Ar, Kr and Xe), grid transparency to neutral atoms, beam extraction area, discharge voltage, and discharge chamber wall temperature. The model and experiments indicate that thruster performance may be described in terms of only four thruster configuration dependent parameters and two operating parameters. The model also suggests that improved performance should be exhibited by thruster designs which extract a large fraction of the ions produced in the discharge chamber, which have good primary electron and neutral atom containment and which operate at high propellant flow rates.

  15. Enhancing Workgroup Performance.

    ERIC Educational Resources Information Center

    1998

    This document contains four papers from a symposium on enhancing workgroup performance in human resource development (HRD). "Formation of Cross-Cultural Global Teams: Making Informed Choices on Team Composition" (Robert L. Dilworth) describes how a mixed class of U.S. and international students identified their cultural and learning…

  16. Improving Surface Irrigation Performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface irrigation systems often have a reputation for poor performance. One key feature of efficient surface irrigation systems is precision (e.g. laser-guided) land grading. Poor land grading can make other improvements ineffective. An important issue, related to land shaping, is developing the pr...

  17. Confronting Poor Performance.

    ERIC Educational Resources Information Center

    Dennis, Bruce L.

    Responsible and effective administrative leadership requires confronting those members of the teaching staff who are a negative influence on the institution. Importantly, the absence of expressed appreciation for good work can have a devastating impact on a principal's image if he or she suddenly begins to confront poor performances. Actually, the…

  18. Performance Measurement Revisited

    ERIC Educational Resources Information Center

    Axford, H. William

    1973-01-01

    Performance measurement, through unit-cost study programs, can be a step toward evaluating the value of systems. This article reports the application of unit-cost studies in technical service functions at a large state university, and presents three tables for labor costs in terms of minutes and dollars per volume. (4 references) (Author/SJ)

  19. Women and Performance Issue.

    ERIC Educational Resources Information Center

    Kirby, Michael, Ed.

    1980-01-01

    The diversity of important work being done by women in many aspects of theatrical performance in the United States is illustrated in this journal issue. The nine articles provide discussions of the following: (1) women's careers, images, and movements in the American theatre; (2) the evolution of La Mama, an off-off-Broadway theatre group begun in…

  20. Performing Arts Annual 1987.

    ERIC Educational Resources Information Center

    Newsom, Iris, Ed.

    Liberally illustrated with photographs and drawings, this book is comprised of articles on the history of the performing arts at the Library of Congress. The articles, listed with their authors, are (1) "Stranger in Paradise: The Writer in Hollywood" (Virginia M. Clark); (2) "Live Television Is Alive and Well at the Library of…

  1. High performance systems

    SciTech Connect

    Vigil, M.B.

    1995-03-01

    This document provides a written compilation of the presentations and viewgraphs from the 1994 Conference on High Speed Computing given at the High Speed Computing Conference, {open_quotes}High Performance Systems,{close_quotes} held at Gleneden Beach, Oregon, on April 18 through 21, 1994.

  2. Performance Pay for Teachers

    ERIC Educational Resources Information Center

    Protheroe, Nancy

    2011-01-01

    During the past few years, interest in shifting at least a portion of what teachers are paid away from a reliance on a traditional salary schedule to one that incorporates a pay for performance component has reached a new high. Proponents of the approach view it as a way to improve teacher quality by both motivating teachers and--through higher…

  3. Performance, Accountability, and Results.

    ERIC Educational Resources Information Center

    Drucker, Peter F.

    1992-01-01

    Although technology might greatly increase school performance, the economics will be hard to manage and explain to a tax-paying public. As in hospitals, technology is an expensive investment that will not replace people. Schooling's true challenge is not handling machinery but creating a multicultural society. To succeed, schools must emphasize…

  4. Cooperative Performance Incentive Plans.

    ERIC Educational Resources Information Center

    Raham, Helen

    2000-01-01

    Discusses what is known about cooperative performance incentive (CPI) plans, which are award programs that offer teachers and other school staff pay bonuses for achievement of specific schoolwide educational objectives. The paper describes and compares existing CPI models worldwide, analyzes their impact on student learning and school practices,…

  5. Functional performance of pyrovalves

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.

    1996-01-01

    Following several flight and ground test failures of spacecraft systems using single-shot, 'normally closed' pyrotechnically actuated valves (pyrovalves), a Government/Industry cooperative program was initiated to assess the functional performance of five qualified designs. The goal of the program was to provide information on functional performance of pyrovalves to allow users the opportunity to improve procurement requirements. Specific objectives included the demonstration of performance test methods, the seating; these gases/particles entered the fluid path of measurement of 'blowby' (the passage of gases from the pyrotechnic energy source around the activating piston into the valve's fluid path), and the quantification of functional margins for each design. Experiments were conducted at NASA's Langley Research Center on several units for each of the five valve designs. The test methods used for this program measured the forces and energies required to actuate the valves, as well as the energies and the pressures (where possible) delivered by the pyrotechnic sources. Functional performance ranged widely among the designs. Blowby cannot be prevented by o-ring seals; metal-to-metal seals were effective. Functional margin was determined by dividing the energy delivered by the pyrotechnic sources in excess to that required to accomplish the function by the energy required for that function. Two of the five designs had inadequate functional margins with the pyrotechnic cartridges evaluated.

  6. Functional Performance of Pyrovalves

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.

    1996-01-01

    Following several flight and ground test failures of spacecraft systems using single-shot, 'normally closed' pyrotechnically actuated valves (pyrovalves), a government/industry cooperative program was initiated to assess the functional performance of five qualified designs. The goal of the program was to improve performance-based requirements for the procurement of pyrovalves. Specific objectives included the demonstration of performance test methods, the measurement of 'blowby' (the passage of gases from the pyrotechnic energy source around the activating piston into the valve's fluid path), and the quantification of functional margins for each design. Experiments were conducted in-house at NASA on several units each of the five valve designs. The test methods used for this program measured the forces and energies required to actuate the valves, as well as the energies and the pressures (where possible) delivered by the pyrotechnic sources. Functional performance ranged widely among the designs. Blowby cannot be prevented by o-ring seals; metal-to-metal seals were effective. Functional margin was determined by dividing the energy delivered by the pyrotechnic sources in excess to that required to accomplish the function by the energy required for that function. All but two designs had adequate functional margins with the pyrotechnic cartridges evaluated.

  7. Antenna performance and resolution

    NASA Technical Reports Server (NTRS)

    Carney, J. J.

    1974-01-01

    The performance of the antenna throughout SL-2, SL-3, and SL-4 was investigated along with the antenna resolution of brightness temperature during flight. The target area selected for the test flights was the Gulf of California, as it offered land/water interface. The coordinate transformations and antenna orientation, flight path simulation, and integration over the radiometric target are discussed.

  8. Performing arts medicine.

    PubMed Central

    Ostwald, P F; Baron, B C; Byl, N M; Wilson, F R

    1994-01-01

    Arts medicine has come of age, resulting from 3 important developments over the past decade: improved methods of diagnosis and treatment, an awareness that artists suffer from special problems related to their occupation and lifestyle, and the establishment of health programs emphasizing an interdisciplinary approach to these patients. We focus on the patterns of illness afflicting performing artists, specifically dancers, singers, actors, and instrumental musicians, and explain some of the things a health care team can do in treating these patients. The conditions governing these patients' lives--early exposure to high expectations of excellence, incessant demands for perfection, long periods of intense practicing, fierce competition, high levels of anxiety associated with performance, and uncertain careers--need to be understood. Levels of disease and disability are remarkably high, but artists often ignore symptoms. We discuss the musculoskeletal, neurologic, vocal, psychological, and other syndromes found among performers and some of the difficulties in treating them. The prevention of injury, conservative management, collaboration with teachers, and a psychotherapeutic approach are desirable. Arts medicine programs for professional consultation exist in several major cities of the United States and abroad. Although research is needed regarding the effectiveness of health care services for performing artists, the scientific literature devoted to this field is growing. PMID:8128702

  9. High performance parallel architectures

    SciTech Connect

    Anderson, R.E. )

    1989-09-01

    In this paper the author describes current high performance parallel computer architectures. A taxonomy is presented to show computer architecture from the user programmer's point-of-view. The effects of the taxonomy upon the programming model are described. Some current architectures are described with respect to the taxonomy. Finally, some predictions about future systems are presented. 5 refs., 1 fig.

  10. High-Performance Happy

    ERIC Educational Resources Information Center

    O'Hanlon, Charlene

    2007-01-01

    Traditionally, the high-performance computing (HPC) systems used to conduct research at universities have amounted to silos of technology scattered across the campus and falling under the purview of the researchers themselves. This article reports that a growing number of universities are now taking over the management of those systems and…

  11. Assessing Scientific Performance.

    ERIC Educational Resources Information Center

    Weiner, John M.; And Others

    1984-01-01

    A method for assessing scientific performance based on relationships displayed numerically in published documents is proposed and illustrated using published documents in pediatric oncology for the period 1979-1982. Contributions of a major clinical investigations group, the Childrens Cancer Study Group, are analyzed. Twenty-nine references are…

  12. Defining performance of organizations.

    PubMed

    1993-07-01

    Quality is and always has been in the beholder's eye. It is therefore necessary, as argued in this excerpt from The Measurement Mandate, the latest text on the Joint Commission's Agenda for Change indicator development and testing methodology, to concentrate on the best ways to measure, assess, and improve the discernible, quantifiable dimensions of an organization's performance.

  13. The Power To Perform.

    ERIC Educational Resources Information Center

    Education Next, 2003

    2003-01-01

    Argues that attracting nontraditional leaders to school administration requires the adoption of results-based practices tying compensation to performance. Includes profiles of two nontraditional leaders: Jennifer Henry, executive director of the Academy for Urban School Leadership in Chicago and Paula Dawning, superintendent of the Benton Harbor…

  14. New Source Performance Standards

    ERIC Educational Resources Information Center

    Jenkins, Richard E.; McCutchen, Gary D.

    1972-01-01

    This feature article outlines the concept and procedures followed in establishing performance standards for new emission sources and summarizes the standards that have been established to date. Five source catagories are enumerated: fossil fuel-fired steam generators, municipal incinerators, Portland cement plants, nitric acid plants, and sulfuric…

  15. PREVAPORATION PERFORMANCE PREDICTION SOFTWARE

    EPA Science Inventory

    The Pervaporation, Performance, Prediction Software and Database (PPPS&D) computer software program is currently being developed within the USEPA, NRMRL. The purpose of the PPPS&D program is to educate and assist potential users in identifying opportunities for using pervaporati...

  16. High Performance Window Retrofit

    SciTech Connect

    Shrestha, Som S; Hun, Diana E; Desjarlais, Andre Omer

    2013-12-01

    The US Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) and Traco partnered to develop high-performance windows for commercial building that are cost-effective. The main performance requirement for these windows was that they needed to have an R-value of at least 5 ft2 F h/Btu. This project seeks to quantify the potential energy savings from installing these windows in commercial buildings that are at least 20 years old. To this end, we are conducting evaluations at a two-story test facility that is representative of a commercial building from the 1980s, and are gathering measurements on the performance of its windows before and after double-pane, clear-glazed units are upgraded with R5 windows. Additionally, we will use these data to calibrate EnergyPlus models that we will allow us to extrapolate results to other climates. Findings from this project will provide empirical data on the benefits from high-performance windows, which will help promote their adoption in new and existing commercial buildings. This report describes the experimental setup, and includes some of the field and simulation results.

  17. Low power arcjet performance

    NASA Technical Reports Server (NTRS)

    Curran, Francis M.; Sarmiento, Charles J.

    1990-01-01

    An experimental investigation was performed to evaluate arc jet operation at low power. A standard, 1 kW, constricted arc jet was run using nozzles with three different constrictor diameters. Each nozzle was run over a range of current and mass flow rates to explore stability and performance in the low power engine. A standard pulse-width modulated power processor was modified to accommodate the high operating voltages required under certain conditions. Stable, reliable operation at power levels below 0.5 kW was obtained at efficiencies between 30 and 40 percent. The operating range was found to be somewhat dependent on constrictor geometry at low mass flow rates. Quasi-periodic voltage fluctuations were observed at the low power end of the operating envelope, The nozzle insert geometry was found to have little effect on the performance of the device. The observed performance levels show that specific impulse levels above 350 seconds can be obtained at the 0.5 kW power level.

  18. MCNP Progress & Performance Improvements

    SciTech Connect

    Brown, Forrest B.; Bull, Jeffrey S.; Rising, Michael Evan

    2015-04-14

    Twenty-eight slides give information about the work of the US DOE/NNSA Nuclear Criticality Safety Program on MCNP6 under the following headings: MCNP6.1.1 Release, with ENDF/B-VII.1; Verification/Validation; User Support & Training; Performance Improvements; and Work in Progress. Whisper methodology will be incorporated into the code, and run speed should be increased.

  19. Performance Management and Reward

    NASA Astrophysics Data System (ADS)

    Yiannis, Triantafyllopoulos; Ioannis, Seimenis; Nikolaos, Konstantopoulos

    2009-08-01

    The article aims to examine, current Performance Management practices on Reward, financial or non-financial using lessons from the literature and the results of a qualitative analysis as these revealed from the interview of some executive members of Greek companies.

  20. Nuclear Enterprise Performance Measurement

    DTIC Science & Technology

    2011-03-01

    sustainability metrics ( Sikdar , 2009). It is used by the Environmental Protection Agency to help determine which biofuels are most sustainable. The method... Sikdar , 2009). ∏ / / (3) This method is...performance metrics. Aggregation metric D is a method developed to aggregate environmental sustainability metrics ( Sikdar , 2009). It is used by the

  1. Performance Evaluation Process.

    ERIC Educational Resources Information Center

    1998

    This document contains four papers from a symposium on the performance evaluation process and human resource development (HRD). "Assessing the Effectiveness of OJT (On the Job Training): A Case Study Approach" (Julie Furst-Bowe, Debra Gates) is a case study of the effectiveness of OJT in one of a high-tech manufacturing company's product…

  2. Performance Theory: Southeast Asia.

    ERIC Educational Resources Information Center

    Kirby, Michael, Ed.

    1979-01-01

    Focusing on the contemporary theatre in Southeast Asia, this journal issue sheds light on the intercultural relationships that exist between that part of the world and the Western world. In addition to a transcript of a Balinese "topeng" (storytelling) performance, the journal contains eight articles that provide information on the…

  3. Amphetamines and Sports Performance.

    ERIC Educational Resources Information Center

    Cooter, G. Rankin

    1980-01-01

    A large number of athletes have resorted to drugs to improve performance in competition. Research literature on the use of amphetamines, both pro and con, is currently confounded with poor research designs and lack of controls, and further research is needed. (CJ)

  4. TRAC performance estimates

    NASA Technical Reports Server (NTRS)

    Everett, L.

    1992-01-01

    This report documents the performance characteristics of a Targeting Reflective Alignment Concept (TRAC) sensor. The performance will be documented for both short and long ranges. For long ranges, the sensor is used without the flat mirror attached to the target. To better understand the capabilities of the TRAC based sensors, an engineering model is required. The model can be used to better design the system for a particular application. This is necessary because there are many interrelated design variables in application. These include lense parameters, camera, and target configuration. The report presents first an analytical development of the performance, and second an experimental verification of the equations. In the analytical presentation it is assumed that the best vision resolution is a single pixel element. The experimental results suggest however that the resolution is better than 1 pixel. Hence the analytical results should be considered worst case conditions. The report also discusses advantages and limitations of the TRAC sensor in light of the performance estimates. Finally the report discusses potential improvements.

  5. Assessing Team Performance.

    ERIC Educational Resources Information Center

    Trimble, Susan; Rottier, Jerry

    Interdisciplinary middle school level teams capitalize on the idea that the whole is greater than the sum of its parts. Administrators and team members can maximize the advantages of teamwork using team assessments to increase the benefits for students, teachers, and the school environment. Assessing team performance can lead to high performing…

  6. Performance Funding in Pennsylvania

    ERIC Educational Resources Information Center

    Cavanaugh, John C.; Garland, Peter

    2012-01-01

    Greater accountability in public higher education systems is a fact of life in the current political climate. Increasingly, one form this accountability takes is performance funding, which arises from elected officials' need for assurance that taxpayer funds are not only being invested and used properly but are resulting in desired outcomes at…

  7. Speaking "over" Performativity

    ERIC Educational Resources Information Center

    White, Julie

    2010-01-01

    In a time where standards and accountability override trust in teachers and principals, mandated versions of pedagogy have recently appeared in the Australian landscape. This article critiques one pedagogical reform initiative and suggests that in performative times, it may be preferable for principals and teachers to speak "over" reform…

  8. Structuralist Performance Issue.

    ERIC Educational Resources Information Center

    Kirby, Michael, Ed.

    1979-01-01

    Defining structuralism as an unannounced aesthetic movement that involves not only the theatre but all arts, this journal issue focuses on structuralist performance. The nine articles provide information on the following topics: the French theatre group, Atelier Theatre et Musique; "Tell Me," a play by Guy de Cointet; patterning in "Five…

  9. Inspiratory resistive loading after all-out exercise improves subsequent performance.

    PubMed

    Chiappa, Gaspar R; Ribeiro, Jorge P; Alves, Cristiano N; Vieira, Paulo J C; Dubas, João; Queiroga, Fernando; Batista, Laura D; Silva, Antonio C; Neder, J Alberto

    2009-05-01

    We have previously shown that post-exercise inspiratory resistive loading (IRL) reduces blood lactate ([Lac(b)(-)]). In this study, we tested the hypothesis that IRL during recovery could improve subsequent exercise performance. Eight healthy men underwent, on different days, two sequential 30-s, cycle ergometer Wingate tests. During the 10-min recovery period from test 1, subjects breathed freely or through an inspiratory resistance (15 cm H(2)O) with passive leg recovery. Arterialized [Lac(b)(-)] values, perceptual scores (Borg), cardiac output by impedance cardiography (QT), and changes in the deoxygenation status of the M. vastus lateralis by near-infrared spectroscopy (DeltaHHb), were recorded. [Lac(b)(-)] was significantly reduced after 4 min of recovery with IRL (peak [Lac(b)(-)] 12.5 +/- 2.3 mmol l(-1) with free-breathing vs. 9.8 +/- 1.5 mmol l(-1) with IRL). Effort perception was reduced during late recovery with IRL compared with free-breathing. Cardiac work was increased with IRL, since heart rate and QT were elevated during late recovery. Peripheral muscle reoxygenation, however, was significantly impaired with IRL, suggesting that post-exercise convective O(2) delivery to the lower limbs was reduced. Importantly, IRL had a dual effect on subsequent performance, i.e., improvement in peak and mean power, but increased fatigue index (P < 0.05). Our data demonstrate that IRL after a Wingate test reduces post-exercise effort perception and improves peak power on subsequent all-out maximal-intensity exercise.

  10. Anthropometric, physiological, performance, and nutritional profile of the Brazil National Canoe Polo Team.

    PubMed

    Alves, Christiano Robles Rodrigues; Pasqua, Leonardo; Artioli, Guilherme Gianinni; Roschel, Hamilton; Solis, Marina; Tobias, Gabriel; Klansener, Christian; Bertuzzi, Rômulo; Franchini, Emerson; Lancha Junior, Antonio Herbert; Gualano, Bruno

    2012-01-01

    The purpose of this study was to determine the physiological, anthropometric, performance, and nutritional characteristics of the Brazil Canoe Polo National Team. Ten male canoe polo athletes (age 26.7 ± 4.1 years) performed a battery of tests including assessments of anthropometric parameters, upper-body anaerobic power (Wingate), muscular strength, aerobic power, and nutritional profile. In addition, we characterized heart rate and plasma lactate responses and the temporal pattern of the effort/recovery during a simulated canoe polo match. The main results are as follows: body fat, 12.3 ± 4.0%; upper-body peak and mean power, 6.8 ± 0.5 and 4.7 ± 0.4 W · kg(-1), respectively; 1-RM bench press, 99.1 ± 11.7 kg; peak oxygen uptake, 44.3 ± 5.8 mL · kg(-1) · min(-1); total energy intake, 42.8 ± 8.6 kcal · kg(-1); protein, carbohydrate, and fat intakes, 1.9 ± 0.1, 5.0 ± 1.5, and 1.7 ± 0.4 g · kg(-1), respectively; mean heart rate, 146 ± 11 beats · min(-1); plasma lactate, 5.7 ± 3.8 mmol · L(-1) at half-time and 4.6 ± 2.2 mmol · L(-1) at the end of the match; effort time (relative to total match time), 93.1 ± 3.0%; number of sprints, 9.6 ± 4.4. The results of this study will assist coaches, trainers, and nutritionists in developing more adequate training programmes and dietary interventions for canoe polo athletes.

  11. Aerobic and anaerobic contribution to Wingate test performance in sprint and middle-distance runners.

    PubMed

    Granier, P; Mercier, B; Mercier, J; Anselme, F; Préfaut, C

    1995-01-01

    We investigated the aerobic and anaerobic contributions to performance during the Wingate test in sprint and middle-distance runners and whether they were related to the peak aerobic and anaerobic performances determined by two commonly used tests: the force-velocity test and an incremental aerobic exercise test. A group of 14 male competitive runners participated: 7 sprinters, aged 20.7 (SEM 1.3) years, competing in 50, 100 and 200-m events and 7 middle-distance runners, aged 20.0 (SEM 1.0) years, competing in 800, 1,000 and 1,500 m-events. The oxygen uptake (VO2) was recorded breath-by-breath during the test (30 s) and during the first 20 s of recovery. Blood samples for venous plasma lactate concentrations were drawn at rest before the start of the test and during the 20-min recovery period. During the Wingate test mean power (W) was determined and three values of mechanical efficiency, one individual and two arbitrary, 16% and 25%, were used to calculate the contributions of work by aerobic (Waer,ind,16%,25%) and anaerobic (Wan,ind,16%,25%) processes. Peak anaerobic power (Wan,peak) was estimated by the force-velocity test and maximal aerobic energy expenditure (Waer,peak) was determined during an incremental aerobic exercise test. During the Wingate test, the middle-distance runners had a significantly greater VO2 than the sprinters (P < 0.001), who had significantly greater venous plasma lactate concentrations (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Effect of a carbohydrate mouth rinse on simulated cycling time-trial performance commenced in a fed or fasted state.

    PubMed

    Lane, Stephen C; Bird, Stephen R; Burke, Louise M; Hawley, John A

    2013-02-01

    It is presently unclear whether the reported ergogenic effect of a carbohydrate (CHO) mouth rinse on cycling time-trial performance is affected by the acute nutritional status of an individual. Hence, the aim of this study was to investigate the effect of a CHO mouth rinse on a 60-min simulated cycling time-trial performance commenced in a fed or fasted state. Twelve competitive male cyclists each completed 4 experimental trials using a double-blinded Latin square design. Two trials were commenced 2 h after a meal that contained 2.5 g·kg(-1) body mass of CHO (FED) and 2 after an overnight fast (FST). Prior to and after every 12.5% of total time during a performance ride, either a 10% maltodextrin (CHO) or a taste-matched placebo (PLB) solution was mouth rinsed for 10 s then immediately expectorated. There were significant main effects for both pre-ride nutritional status (FED vs. FST; p < 0.01) and CHO mouth rinse (CHO vs. PLB; p < 0.01) on power output with an interaction evident between the interventions (p < 0.05). The CHO mouth rinse improved mean power to a greater extent after an overnight fast (282 vs. 273 W, 3.4%; p < 0.01) compared with a fed state (286 vs. 281 W, 1.8%; p < 0.05). We concluded that a CHO mouth rinse improved performance to a greater extent in a fasted compared with a fed state; however, optimal performance was achieved in a fed state with the addition of a CHO mouth rinse.

  13. Asymptotic Parachute Performance Sensitivity

    NASA Technical Reports Server (NTRS)

    Way, David W.; Powell, Richard W.; Chen, Allen; Steltzner, Adam D.

    2006-01-01

    In 2010, the Mars Science Laboratory mission will pioneer the next generation of robotic Entry, Descent, and Landing systems by delivering the largest and most capable rover to date to the surface of Mars. In addition to landing more mass than any other mission to Mars, Mars Science Laboratory will also provide scientists with unprecedented access to regions of Mars that have been previously unreachable. By providing an Entry, Descent, and Landing system capable of landing at altitudes as high as 2 km above the reference gravitational equipotential surface, or areoid, as defined by the Mars Orbiting Laser Altimeter program, Mars Science Laboratory will demonstrate sufficient performance to land on 83% of the planet s surface. By contrast, the highest altitude landing to date on Mars has been the Mars Exploration Rover at 1.3 km below the areoid. The coupling of this improved altitude performance with latitude limits as large as 60 degrees off of the equator and a precise delivery to within 10 km of a surface target, will allow the science community to select the Mars Science Laboratory landing site from thousands of scientifically interesting possibilities. In meeting these requirements, Mars Science Laboratory is extending the limits of the Entry, Descent, and Landing technologies qualified by the Mars Viking, Mars Pathfinder, and Mars Exploration Rover missions. Specifically, the drag deceleration provided by a Viking-heritage 16.15 m supersonic Disk-Gap-Band parachute in the thin atmosphere of Mars is insufficient, at the altitudes and ballistic coefficients under consideration by the Mars Science Laboratory project, to maintain necessary altitude performance and timeline margin. This paper defines and discusses the asymptotic parachute performance observed in Monte Carlo simulation and performance analysis and its effect on the Mars Science Laboratory Entry, Descent, and Landing architecture.

  14. EMU Suit Performance Simulation

    NASA Technical Reports Server (NTRS)

    Cowley, Matthew S.; Benson, Elizabeth; Harvill, Lauren; Rajulu, Sudhakar

    2014-01-01

    Introduction: Designing a planetary suit is very complex and often requires difficult trade-offs between performance, cost, mass, and system complexity. To verify that new suit designs meet requirements, full prototypes must be built and tested with human subjects. However, numerous design iterations will occur before the hardware meets those requirements. Traditional draw-prototype-test paradigms for research and development are prohibitively expensive with today's shrinking Government budgets. Personnel at NASA are developing modern simulation techniques that focus on a human-centric design paradigm. These new techniques make use of virtual prototype simulations and fully adjustable physical prototypes of suit hardware. This is extremely advantageous and enables comprehensive design down-selections to be made early in the design process. Objectives: The primary objective was to test modern simulation techniques for evaluating the human performance component of two EMU suit concepts, pivoted and planar style hard upper torso (HUT). Methods: This project simulated variations in EVA suit shoulder joint design and subject anthropometry and then measured the differences in shoulder mobility caused by the modifications. These estimations were compared to human-in-the-loop test data gathered during past suited testing using four subjects (two large males, two small females). Results: Results demonstrated that EVA suit modeling and simulation are feasible design tools for evaluating and optimizing suit design based on simulated performance. The suit simulation model was found to be advantageous in its ability to visually represent complex motions and volumetric reach zones in three dimensions, giving designers a faster and deeper comprehension of suit component performance vs. human performance. Suit models were able to discern differing movement capabilities between EMU HUT configurations, generic suit fit concerns, and specific suit fit concerns for crewmembers based

  15. Hypoxic Repeat Sprint Training Improves Rugby Player's Repeated Sprint but Not Endurance Performance.

    PubMed

    Hamlin, Michael J; Olsen, Peter D; Marshall, Helen C; Lizamore, Catherine A; Elliot, Catherine A

    2017-01-01

    This study aims to investigate the performance changes in 19 well-trained male rugby players after repeat-sprint training (six sessions of four sets of 5 × 5 s sprints with 25 s and 5 min of active recovery between reps and sets, respectively) in either normobaric hypoxia (HYP; n = 9; FIO2 = 14.5%) or normobaric normoxia (NORM; n = 10; FIO2 = 20.9%). Three weeks after the intervention, 2 additional repeat-sprint training sessions in hypoxia (FIO2 = 14.5%) was investigated in both groups to gauge the efficacy of using "top-up" sessions for previously hypoxic-trained subjects and whether a small hypoxic dose would be beneficial for the previously normoxic-trained group. Repeated sprint (8 × 20 m) and Yo-Yo Intermittent Recovery Level 1 (YYIR1) performances were tested twice at baseline (Pre 1 and Pre 2) and weekly after (Post 1-3) the initial intervention (intervention 1) and again weekly after the second "top-up" intervention (Post 4-5). After each training set, heart rate, oxygen saturation, and rate of perceived exertion were recorded. Compared to baseline (mean of Pre 1 and Pre 2), both the hypoxic and normoxic groups similarly lowered fatigue over the 8 sprints 1 week after the intervention (Post 1: -1.8 ± 1.6%, -1.5 ± 1.4%, mean change ± 90% CI in HYP and NORM groups, respectively). However, from Post 2 onwards, only the hypoxic group maintained the performance improvement compared to baseline (Post 2: -2.1 ± 1.8%, Post 3: -2.3 ± 1.7%, Post 4: -1.9 ± 1.8%, and Post 5: -1.2 ± 1.7%). Compared to the normoxic group, the hypoxic group was likely to have substantially less fatigue at Post 3-5 (-2.0 ± 2.4%, -2.2 ± 2.4%, -1.6 ± 2.4% Post 3, Post 4, Post 5, respectively). YYIR1 performances improved throughout the recovery period in both groups (13-37% compared to baseline) with unclear differences found between groups. The addition of two sessions of "top-up" training after intervention 1, had little effect on either group. Repeat-sprint training in

  16. Hypoxic Repeat Sprint Training Improves Rugby Player's Repeated Sprint but Not Endurance Performance

    PubMed Central

    Hamlin, Michael J.; Olsen, Peter D.; Marshall, Helen C.; Lizamore, Catherine A.; Elliot, Catherine A.

    2017-01-01

    This study aims to investigate the performance changes in 19 well-trained male rugby players after repeat-sprint training (six sessions of four sets of 5 × 5 s sprints with 25 s and 5 min of active recovery between reps and sets, respectively) in either normobaric hypoxia (HYP; n = 9; FIO2 = 14.5%) or normobaric normoxia (NORM; n = 10; FIO2 = 20.9%). Three weeks after the intervention, 2 additional repeat-sprint training sessions in hypoxia (FIO2 = 14.5%) was investigated in both groups to gauge the efficacy of using “top-up” sessions for previously hypoxic-trained subjects and whether a small hypoxic dose would be beneficial for the previously normoxic-trained group. Repeated sprint (8 × 20 m) and Yo-Yo Intermittent Recovery Level 1 (YYIR1) performances were tested twice at baseline (Pre 1 and Pre 2) and weekly after (Post 1–3) the initial intervention (intervention 1) and again weekly after the second “top-up” intervention (Post 4–5). After each training set, heart rate, oxygen saturation, and rate of perceived exertion were recorded. Compared to baseline (mean of Pre 1 and Pre 2), both the hypoxic and normoxic groups similarly lowered fatigue over the 8 sprints 1 week after the intervention (Post 1: −1.8 ± 1.6%, −1.5 ± 1.4%, mean change ± 90% CI in HYP and NORM groups, respectively). However, from Post 2 onwards, only the hypoxic group maintained the performance improvement compared to baseline (Post 2: −2.1 ± 1.8%, Post 3: −2.3 ± 1.7%, Post 4: −1.9 ± 1.8%, and Post 5: −1.2 ± 1.7%). Compared to the normoxic group, the hypoxic group was likely to have substantially less fatigue at Post 3–5 (−2.0 ± 2.4%, −2.2 ± 2.4%, −1.6 ± 2.4% Post 3, Post 4, Post 5, respectively). YYIR1 performances improved throughout the recovery period in both groups (13–37% compared to baseline) with unclear differences found between groups. The addition of two sessions of “top-up” training after intervention 1, had little effect on either

  17. Development and validation of an ultra high performance liquid chromatography electrospray ionization tandem mass spectrometry method for the simultaneous determination of selected flavonoids in Ginkgo biloba.

    PubMed

    Pandey, Renu; Chandra, Preeti; Arya, Kamal Ram; Kumar, Brijesh

    2014-12-01

    A rapid and sensitive ultra high performance liquid chromatography electrospray ionization tandem mass spectrometry method was developed and validated for the simultaneous determination of 13 flavonoids in leaf, stem, and fruit extracts of male and female trees of Ginkgo biloba to investigate gender- and age-related variations of flavonoids content. Chromatographic separation was accomplished on an Acquity UPLC BEH C18 column (50 mm × 2.1 mm id, 1.7 μm) in 5 min. Quantitation was performed using negative electrospray ionization mass spectrometry in multiple reaction monitoring mode. The calibration curves of all analytes showed a good linear relationship (r(2) ≥ 0.9977) over the concentration range of 1-1000 ng/mL. The precision evaluated by an intra- and interday study showed RSD ≤ 1.98% and good accuracy with overall recovery in the range from 97.90 to 101.09% (RSD ≤ 1.67%) for all analytes. The method sensitivity expressed as the limit of quantitation was typically 0.25-3.57 ng/mL. The results showed that the total content of 13 flavonoids was higher in the leaf extract of an old male Ginkgo tree compared to young female Ginkgo trees.

  18. Simultaneous determination of irbesartan and hydrochlorothiazide in human plasma by ultra high performance liquid chromatography tandem mass spectrometry and its application to a bioequivalence study.

    PubMed

    Qiu, Xiangjun; Wang, Zhe; Wang, Bing; Zhan, Hui; Pan, Xiaofeng; Xu, Ren-ai

    2014-04-15

    An ultra high performance liquid chromatography tandem mass spectrometry (U-HPLC-MS/MS) method was developed and validated to determine irbesartan (IRB) and hydrochlorothiazide (HCTZ) in human plasma simultaneously. Plasma samples were prepared using protein precipitation with acetonitrile, the two analytes and the internal standard losartan were separated on an Acquity U-HPLC BEH C18 column and mass spectrometric analysis was performed using a QTrap5500 mass spectrometer coupled with an electro-spray ionization (ESI) source in the negative ion mode. The MRM transitions of m/z 427.2→206.9 and m/z 296.1→204.9 were used to quantify for IRB and HCTZ, respectively. The linearity of this method was found to be within the concentration range of 5-3000ng/mL for IRB, and 0.5-300ng/mL for HCTZ in human plasma, respectively. The lower limit of quantification (LLOQ) was 5ng/mL and 0.5ng/mL for IRB and HCTZ in human plasma, respectively. The relative standard deviations (RSD) of intra and inter precision were less than 12% for both IRB and HCTZ. The analysis time of per sample was 2.5min. The developed and validated method was successfully applied to a bioequivalence study of IRB (300mg) with HCTZ (12.5mg) tablet in Chinese healthy volunteers (N=20).

  19. Determination of liquiritigenin by ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometry: Application to a linear pharmacokinetic study of liquiritigenin in rat plasma.

    PubMed

    Gu, Jie; Li, Huan; Pei, Ke; Cai, Hui; Qin, Kunming; Zhang, Xinghai; Zheng, Lijuan; Liu, Xiao; Cai, Yunqing; Cai, Baochang

    2014-09-17

    A simple, sensitive and rapid ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method has been developed and validated for the quantification of liquiritigenin, a promising anti-tumor agent. Liquiritigenin and the internal standard were separated on an Agilent Extend C18 column and eluted with a gradient mobile phase system of acetonitrile and water. The analysis was performed on a negative ionization electrospray mass spectrometer via multiple reaction monitoring (MRM). Transitions of m/z 255.0→119.0 for liquiritigenin and m/z 269.0→117.0 for the IS were monitored. One-step protein precipitation with acetonitrile was used to remove impurities and extract the analytes from plasma. The method had a chromatographic run time of 4.5min and a good linearity in the range of 1-1000ng/mL. The precision (R.S.D.) of intra-day and inter-day ranged from 4.54 to 10.65% and 5.94 to 13.81%, respectively; while the accuracy of intra-day and inter-day ranged from 104.06 to 109.28% and 94.98 to 112.05%. The recovery and stability were also within the acceptable limits. The validated method was applied to a linear pharmacokinetic study of liquiritigenin in rat plasma for the first time.

  20. Determination of alpha-solanine and alpha-chaconine in potatoes by high-performance thin-layer chromatography/densitometry.

    PubMed

    Bodart, P; Kabengera, C; Noirfalise, A; Hubert, P; Angenot, L

    2000-01-01

    A high-performance thin-layer chromatographic (HPTLC) method was used to determine the glycoalkaloids alpha-solanine and alpha-chaconine in potatoes. Alpha-solanine and alpha-chaconine are extracted from dehydrated potatoes with boiling methanol-acetic acid (95 + 5, v/v). The analytes are separated on a Silica Gel 60 F254 HPTLC plate by a saturated mixture of dichloromethane-methanol-water-concentrated ammonium hydroxide (70 + 30 + 4 + 0.4, v/v), which is used for vertical development of the plate up to a distance of 85 mm. For visualization, the plate is dipped 3 times into a modified Carr-Price reagent, 20% (w/v) antimony(III) chloride in acetic acid-dichloromethane (1 + 3, v/v), and subsequently heated on a hot plate at 105 degrees C for 5 min. The glycoalkaloids all appear as red chromatographic zones on a colorless background. Densitometric quantification is performed at 507 nm by reflectance scanning. After determination of the appropriate response function, the proposed method was validated. Good results with respect to linearity, accuracy, and precision were obtained in the concentration range studied.

  1. High-resolution high-performance liquid chromatography with electrospray ionization mass spectrometry and tandem mass spectrometry characterization of a new isoform of human salivary acidic proline-rich proteins named Roma-Boston Ser₂₂ (Phos) → Phe variant.

    PubMed

    Iavarone, Federica; D'Alessandro, Alfredo; Tian, Na; Cabras, Tiziana; Messana, Irene; Helmerhorst, Eva J; Oppenheim, Frank G; Castagnola, Massimo

    2014-07-01

    During a survey of human saliva by a top-down reversed-phase high-performance liquid chromatography with electrospray ionization mass spectrometry approach, two proteins eluting at 27.4 and 28.4 min, with average masses of 15 494 ± 1 and 11 142 ± 1 Da, were detected in a subject from Boston. The Δmass value (4352 Da) of the two proteins was similar to the difference in mass values between intact (150 amino acids, [a.a.]) and truncated acidic proline-rich proteins (aPRPs; 106 a.a.) suggesting an a.a. substitution in the first 106 residues resulting in a strong reduction in polarity, since under the same experimental conditions aPRPs eluted at ∼22.5 min (intact) and 23.5 min (truncated forms). Manual inspection of the high-resolution high-performance liquid chromatography with electrospray ionization tandem mass spectra of the truncated isoform showed the replacement of the phosphorylated Ser-22 in PRP-3 with a Phe residue. Inspection of the tandem mass spectra of the intact isoform confirmed the substitution, which is allowed by the code transition TCT→TTT and is in agreement with the dramatic increase in elution time. The isoform was also detected in two other subjects, one from Boston (unrelated to the previous) and one from Rome. For this reason we propose to name this variant PRP-1 (PRP-3) RB (Roma-Boston) Ser22 (phos)→Phe.

  2. Acute Effects of Two Different Warm-Up Protocols on Flexibility and Lower Limb Explosive Performance in Male and Female High Level Athletes

    PubMed Central

    Tsolakis, Charilaos; Bogdanis, Gregory C.

    2012-01-01

    This study examined the effects of two different warm-up protocols on lower limb power and flexibility in high level athletes. Twenty international level fencers (10 males and 10 females) performed two warm-up protocols that included 5-min light jogging and either short (15s) or long (45s) static stretching exercises for each of the main leg muscle groups (quadriceps, hamstrings and triceps surae), followed by either 3 sets of 3 (short stretching treatment), or 3 sets of 5 tuck jumps (long stretching treatment), in a randomized crossover design with one week between treatments. Hip joint flexion was measured with a Lafayette goniometer before and after the 5-min warm-up, after stretching and 8 min after the tuck jumps, while counter movement jump (CMJ) performance was evaluated by an Ergojump contact platform, before and after the stretching treatment, as well as immediately after and 8 minutes after the tuck jumps. Three way ANOVA (condition, time, gender) revealed significant time (p < 0.001) and gender (p < 0.001) main effects for hip joint flexion, with no interaction between factors. Flexibility increased by 6. 8 ± 1.1% (p < 0.01) after warm-up and by another 5.8 ± 1.6% (p < 0.01) after stretching, while it remained increased 8 min after the tuck jumps. Women had greater ROM compared with men at all time points (125 ± 8° vs. 94 ± 4° p<0.01 at baseline), but the pattern of change in hip flexibility was not different between genders. CMJ performance was greater in men compared with women at all time points (38.2 ± 1.9 cm vs. 29.8 ± 1.2 cm p < 0.01 at baseline), but the percentage of change CMJ performance was not different between genders. CMJ performance remained unchanged throughout the short stretching protocol, while it decreased by 5.5 ± 0.9% (p < 0.01) after stretching in the long stretching protocol However, 8 min after the tuck jumps, CMJ performance was not different from the baseline value (p = 0.075). In conclusion, lower limb power may be

  3. System Performance Characterization

    SciTech Connect

    van Dam, M A

    2004-05-26

    Characterizing an adaptive optics (AO) system refers to understanding its performance and limitations. The goal of an AO system is to correct wavefront aberrations. The uncorrected aberrations, called the residual errors and referred to in what follows simply as the errors, degrade the image quality in the science camera. Understanding the source of these errors is a great aid in designing an AO system and optimizing its performance. This chapter explains how to estimate the wavefront error terms and the relationship between the wavefront error and the degradation of the image. The analysis deals with the particular case of a HartmannShack wavefront sensor (WFS) and a continuous deformable mirror (DM), although the principles involved can be applied to any AO system.

  4. Cyclone performance and optimization

    SciTech Connect

    Leith, D.

    1990-06-15

    The objectives of this project are: to characterize the gas flow pattern within cyclones, to revise the theory for cyclone performance on the basis of these findings, and to design and test cyclones whose dimensions have been optimized using revised performance theory. This work is important because its successful completion will aid in the technology for combustion of coal in pressurized, fluidized beds. During the past quarter, we have nearly completed modeling work that employs the flow field measurements made during the past six months. In addition, we have begun final work using the results of this project to develop improved design methods for cyclones. This work involves optimization using the Iozia-Leith efficiency model and the Dirgo pressure drop model. This work will be completed this summer. 9 figs.

  5. NCCDS performance model

    NASA Technical Reports Server (NTRS)

    Richmond, Eric; Vallone, Antonio

    1994-01-01

    The NASA/GSFC Network Control Center (NCC) provides communication services between ground facilities and spacecraft missions in near-earth orbit that use the Space Network. The NCC Data System (NCCDS) provides computational support and is expected to be highly utilized by the service requests needed in the future years. A performance model of the NCCDS has been developed to assess the future workload and possible enhancements. The model computes message volumes from mission request profiles and SN resource levels and generates the loads for NCCDS configurations as a function of operational scenarios and processing activities. The model has been calibrated using the results of benchmarks performed on the operational NCCDS facility and used to assess some future SN service request scenarios.

  6. Human Performance in Space

    NASA Technical Reports Server (NTRS)

    Jones, Patricia M.; Fiedler, Edna

    2010-01-01

    Human factors is a critical discipline for human spaceflight. Nearly every human factors research area is relevant to space exploration -- from the ergonomics of hand tools used by astronauts, to the displays and controls of a spacecraft cockpit or mission control workstation, to levels of automation designed into rovers on Mars, to organizational issues of communication between crew and ground. This chapter focuses more on the ways in which the space environment (especially altered gravity and the isolated and confined nature of long-duration spaceflight) affects crew performance, and thus has specific novel implications for human factors research and practice. We focus on four aspects of human performance: neurovestibular integration, motor control and musculo-skeletal effects, cognitive effects, and behavioral health. We also provide a sampler of recent human factors studies from NASA.

  7. High Performance, Dependable Multiprocessor

    NASA Technical Reports Server (NTRS)

    Ramos, Jeremy; Samson, John R.; Troxel, Ian; Subramaniyan, Rajagopal; Jacobs, Adam; Greco, James; Cieslewski, Grzegorz; Curreri, John; Fischer, Michael; Grobelny, Eric; George, Alan; Aggarwal, Vikas; Patel, Minesh; Some, Raphael

    2006-01-01

    With the ever increasing demand for higher bandwidth and processing capacity of today's space exploration, space science, and defense missions, the ability to efficiently apply commercial-off-the-shelf (COTS) processors for on-board computing is now a critical need. In response to this need, NASA's New Millennium Program office has commissioned the development of Dependable Multiprocessor (DM) technology for use in payload and robotic missions. The Dependable Multiprocessor technology is a COTS-based, power efficient, high performance, highly dependable, fault tolerant cluster computer. To date, Honeywell has successfully demonstrated a TRL4 prototype of the Dependable Multiprocessor [I], and is now working on the development of a TRLS prototype. For the present effort Honeywell has teamed up with the University of Florida's High-performance Computing and Simulation (HCS) Lab, and together the team has demonstrated major elements of the Dependable Multiprocessor TRLS system.

  8. MIR Performance Analysis

    SciTech Connect

    Hazen, Damian; Hick, Jason

    2012-06-12

    We provide analysis of Oracle StorageTek T10000 Generation B (T10KB) Media Information Record (MIR) Performance Data gathered over the course of a year from our production High Performance Storage System (HPSS). The analysis shows information in the MIR may be used to improve tape subsystem operations. Most notably, we found the MIR information to be helpful in determining whether the drive or tape was most suspect given a read or write error, and for helping identify which tapes should not be reused given their history of read or write errors. We also explored using the MIR Assisted Search to order file retrieval requests. We found that MIR Assisted Search may be used to reduce the time needed to retrieve collections of files from a tape volume.

  9. High performance collectors

    NASA Astrophysics Data System (ADS)

    Ogawa, H.; Hozumi, S.; Mitsumata, T.; Yoshino, K.; Aso, S.; Ebisu, K.

    1983-04-01

    Materials and structures used for flat plate solar collectors and evacuated tubular collectors were examined relative to their overall performance to project effectiveness for building heating and cooling and the feasibility of use for generating industrial process heat. Thermal efficiencies were calculated for black paint single glazed, selective surface single glazed, and selective surface double glazed flat plate collectors. The efficiencies of a single tube and central tube accompanied by two side tube collectors were also studied. Techniques for extending the lifetimes of the collectors were defined. The selective surface collectors proved to have a performance superior to other collectors in terms of the average annual energy delivered. Addition of a black chrome-coated fin system to the evacuated collectors produced significant collection efficiency increases.

  10. Environmental Performance Report 2015

    SciTech Connect

    2016-07-01

    The National Renewable Energy Laboratory's (NREL's) Environmental Performance Report provides a description of the laboratory's environmental management activities for 2015, including information on environmental and sustainability performance, environmental compliance activities and status, and environmental protection programs, highlights, and successes. The purpose of this report is to ensure that U.S. Department of Energy (DOE) and the public receive timely, accurate information about events that have affected or could adversely affect the health, safety, and security of the public or workers; the environment; or the operations of DOE facilities. This report meets the requirements of the Annual Site Environmental Report and is prepared in accordance with the DOE Order 231.1B, Environment, Safety and Health Reporting.

  11. Enhancing Decision Performance

    DTIC Science & Technology

    2002-07-09

    The first is temporary storage of information, as proposed by Atkinson and Shiffrin (1968) in their model of short term memory . The second demand...Reference: Atkinson , R.C., & Shiffrin , R.M. (1968). Human memory : A proposed system and its control processes. In K.W. Spence (Ed.), The psychology of...Flexiablity in Performance Study 2: Use and Memory of Configural and Holistic Information Study 3: Time Pressure REPORT DOCUMENTATION PAGE Form Approved

  12. Distributed Explosive Performance Model

    DTIC Science & Technology

    1998-01-01

    18 Analytic Code ( DEPAC ). DEPAC is a restructured and an upgraded one-stop code of the previous version of the Linear Explosive Array Performance...findings1. 3. Developed the initial version of DEPAC (LEAP and LAM) 3. 4. Released three Technical Results (TRs). 5. Established the methodology for quick...the input files for each run for CTH, process the data generated by CTH, and create the input database files for DEPAC . The line charge is composed of

  13. DART AVGS Performance

    NASA Technical Reports Server (NTRS)

    Howard, Richard T.; Bryan, Thomas C.

    2007-01-01

    The Advanced Video Guidance Sensor (AVGS) was designed to be the proximity operations sensor for the Demonstration of Autonomous Rendezvous Technologies (DART). The DART mission flew in April of2005 and was a partial success. The AVGS did not get the opportunity to operate in every mode in orbit, but those modes in which it did operate were completely successful. This paper will detail the development, testing, and on-orbit performance of the AVGS.

  14. High performance polymeric foams

    SciTech Connect

    Gargiulo, M.; Sorrentino, L.; Iannace, S.

    2008-08-28

    The aim of this work was to investigate the foamability of high-performance polymers (polyethersulfone, polyphenylsulfone, polyetherimide and polyethylenenaphtalate). Two different methods have been used to prepare the foam samples: high temperature expansion and two-stage batch process. The effects of processing parameters (saturation time and pressure, foaming temperature) on the densities and microcellular structures of these foams were analyzed by using scanning electron microscopy.

  15. CF6 performance improvement

    NASA Technical Reports Server (NTRS)

    Lennard, D. J.

    1978-01-01

    Potential CF6 engine performance improvements directed at reduced fuel consumption were identified and screened relative to airline acceptability and are reviewed. The screening process developed to provide evaluations of fuel savings and economic factors including return on investment and direct operating cost is described. In addition, assessments of development risk and production potential are made. Several promising concepts selected for full-scale development based on a ranking involving these factors are discussed.

  16. Evaluating steam trap performance

    SciTech Connect

    Fuller, N.Y.

    1985-08-08

    This paper presents a method for evaluating the performance level of steam traps by preparing an economic analysis of several types to determine the equivalent uniform annual cost. A series of tests on steam traps supplied by six manufacturers provided data for determining the relative efficiencies of each unit. The comparison was made using a program developed for the Texas Instruments T1-59 programmable calculator to evaluate overall steam trap economics.

  17. Cyclone performance and optimization

    SciTech Connect

    Leith, D.

    1990-09-15

    The objectives of this project are: to characterize the gas flow pattern within cyclones, to revise the theory for cyclone performance on the basis of these findings, and to design and test cyclones whose dimensions have been optimized using revised performance theory. This work is important because its successful completion will aid in the technology for combustion of coal in pressurized, fluidized beds. This quarter, an empirical model for predicting pressure drop across a cyclone was developed through a statistical analysis of pressure drop data for 98 cyclone designs. The model is shown to perform better than the pressure drop models of First (1950), Alexander (1949), Barth (1956), Stairmand (1949), and Shepherd-Lapple (1940). This model is used with the efficiency model of Iozia and Leith (1990) to develop an optimization curve which predicts the minimum pressure drop and the dimension rations of the optimized cyclone for a given aerodynamic cut diameter, d{sub 50}. The effect of variation in cyclone height, cyclone diameter, and flow on the optimization curve is determined. The optimization results are used to develop a design procedure for optimized cyclones. 37 refs., 10 figs., 4 tabs.

  18. High Performance Buildings Database

    DOE Data Explorer

    The High Performance Buildings Database is a shared resource for the building industry, a unique central repository of in-depth information and data on high-performance, green building projects across the United States and abroad. The database includes information on the energy use, environmental performance, design process, finances, and other aspects of each project. Members of the design and construction teams are listed, as are sources for additional information. In total, up to twelve screens of detailed information are provided for each project profile. Projects range in size from small single-family homes or tenant fit-outs within buildings to large commercial and institutional buildings and even entire campuses. The database is a data repository as well. A series of Web-based data-entry templates allows anyone to enter information about a building project into the database. Once a project has been submitted, each of the partner organizations can review the entry and choose whether or not to publish that particular project on its own Web site.

  19. Diet and physical performance.

    PubMed

    Montain, Scott J; Young, Andrew J

    2003-06-01

    This paper provides a historical summary of military nutrition research into the role of diet for sustaining soldier physical performance. Studies of underfeeding document that physical performance is preserved during several days of underfeeding provided sufficient carbohydrate and minerals are consumed to minimize the diuresis associated with semi-starvation diets and serial intake of carbohydrate is available to support metabolism during prolonged work. The Military Recommended Dietary Allowances, AR 40-25, currently recommends that when restricted rations are required, that the ration contain at least 1,100-1,500 kcal, 50-70 g of protein, and a minimum of 100 g of carbohydrate on a daily basis. This low energy diet, however, is not recommended for subsistence for longer than 10 consecutive days. Dietary carbohydrate intakes of approximately 300-400 g will more closely match the quantity of carbohydrate oxidized to meet daily energy requirements during field operations. Research into the potential advantages of dietary supplements has generally not proved advantageous when compared to eating a well balanced diet. Future investigations of the role of diet for sustaining soldier health and performance should be directed toward a better understanding of the influence of energy intake and macro-nutrient composition for preserving lean body mass, reducing susceptibility to illness and injury and enhancing recovery during and after sustained operations.

  20. ATR performance modeling concepts

    NASA Astrophysics Data System (ADS)

    Ross, Timothy D.; Baker, Hyatt B.; Nolan, Adam R.; McGinnis, Ryan E.; Paulson, Christopher R.

    2016-05-01

    Performance models are needed for automatic target recognition (ATR) development and use. ATRs consume sensor data and produce decisions about the scene observed. ATR performance models (APMs) on the other hand consume operating conditions (OCs) and produce probabilities about what the ATR will produce. APMs are needed for many modeling roles of many kinds of ATRs (each with different sensing modality and exploitation functionality combinations); moreover, there are different approaches to constructing the APMs. Therefore, although many APMs have been developed, there is rarely one that fits a particular need. Clarified APM concepts may allow us to recognize new uses of existing APMs and identify new APM technologies and components that better support coverage of the needed APMs. The concepts begin with thinking of ATRs as mapping OCs of the real scene (including the sensor data) to reports. An APM is then a mapping from explicit quantized OCs (represented with less resolution than the real OCs) and latent OC distributions to report distributions. The roles of APMs can be distinguished by the explicit OCs they consume. APMs used in simulations consume the true state that the ATR is attempting to report. APMs used online with the exploitation consume the sensor signal and derivatives, such as match scores. APMs used in sensor management consume neither of those, but estimate performance from other OCs. This paper will summarize the major building blocks for APMs, including knowledge sources, OC models, look-up tables, analytical and learned mappings, and tools for signal synthesis and exploitation.

  1. NASA Performance Plan

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The Government Performance and Results Act (GPRA) passed by Congress and signed by the President in 1993 provides a new tool to improve the efficiency of all Federal agencies. The goals of GPRA are to: Improve citizen confidence in Government performance; Improve Federal program management, effectiveness, and public accountability; and Improve congressional decisionmaking on where to commit the Nation's financial and human resources. The Act directs Executive Branch agencies to develop a customer-focused strategic plan that aligns activities with concrete missions and goals. The first plans were submitted in September 1998 as part of the Fiscal Year 1999 (FY99) budget process. These budget submissions were expected to support the goals expressed in the agency strategic plans. The Act also directs agencies to manage and measure results to justify congressional appropriations and authorizations. Six months after the completion of the fiscal year, agencies will report on the degree of success in achieving the goals and evaluation measures defined in the strategic and performance plans. The plans required by GPRA have been submitted to the Office of Management and Budget (OMB) and to Congress. Copies of NASA plans are available from the Office of Policy and Plans at NASA Headquarters and can be accessed on the i nterinet web sites identified in the Appendix.

  2. Behavior and Performance Project

    NASA Technical Reports Server (NTRS)

    Washburn, David A.; Rumbaugh, Duane M.; Shlyk, Galina; Vassilieva, Oxana; Richardson, W. Kirk

    1998-01-01

    Behavior is an overt manifestation of underlying biology. As such, alterations in biological systems that result from spaceflight would be expected to evidence themselves in subtle or even pronounced changes in the behavior of that organism. These alterations in visible behavior may then indicate or even be diagnostic of alterations in the physical well-being of humans and other animals as they adapt to space environments or readapt to Earth--alterations that might not otherwise be detected without relatively invasive and frequently expensive procedures. Moreover, behavior and performance constitute the central standard for evaluating the mission success of spaceflight ventures. The success or failure of any excursion into space is primarily indexed by the ability of astronauts and cosmonauts to perform the tasks and experiments of any particular mission, to land a re-entry vehicle after extended exposure to microgravity (as with the space shuttle), or to make time-critical and life-saving repairs or other decisions while in orbit (as with the recent Mir events). Thus, understanding the effects spaceflight on behavior and performance is inherently important, in addition to those insights that behavior can provide about the physiological consequences of space adaptation.

  3. Mentoring Human Performance - 12480

    SciTech Connect

    Geis, John A.; Haugen, Christian N.

    2012-07-01

    Although the positive effects of implementing a human performance approach to operations can be hard to quantify, many organizations and industry areas are finding tangible benefits to such a program. Recently, a unique mentoring program was established and implemented focusing on improving the performance of managers, supervisors, and work crews, using the principles of Human Performance Improvement (HPI). The goal of this mentoring was to affect behaviors and habits that reliably implement the principles of HPI to ensure continuous improvement in implementation of an Integrated Safety Management System (ISMS) within a Conduct of Operations framework. Mentors engaged with personnel in a one-on-one, or one-on-many dialogue, which focused on what behaviors were observed, what factors underlie the behaviors, and what changes in behavior could prevent errors or events, and improve performance. A senior management sponsor was essential to gain broad management support. A clear charter and management plan describing the goals, objectives, methodology, and expected outcomes was established. Mentors were carefully selected with senior management endorsement. Mentors were assigned to projects and work teams based on the following three criteria: 1) knowledge of the work scope; 2) experience in similar project areas; and 3) perceived level of trust they would have with project management, supervision, and work teams. This program was restructured significantly when the American Reinvestment and Recovery Act (ARRA) and the associated funding came to an end. The program was restructured based on an understanding of the observations, attributed successes and identified shortfalls, and the consolidation of those lessons. Mentoring the application of proven methods for improving human performance was shown effective at increasing success in day-to-day activities and increasing confidence and level of skill of supervisors. While mentoring program effectiveness is difficult to

  4. Functional Performance Evaluation

    NASA Technical Reports Server (NTRS)

    Greenisen, Michael C.; Hayes, Judith C.; Siconolfi, Steven F.; Moore, Alan D.

    1999-01-01

    The Extended Duration Orbiter Medical Project (EDOMP) was established to address specific issues associated with optimizing the ability of crews to complete mission tasks deemed essential to entry, landing, and egress for spaceflights lasting up to 16 days. The main objectives of this functional performance evaluation were to investigate the physiological effects of long-duration spaceflight on skeletal muscle strength and endurance, as well as aerobic capacity and orthostatic function. Long-duration exposure to a microgravity environment may produce physiological alterations that affect crew ability to complete critical tasks such as extravehicular activity (EVA), intravehicular activity (IVA), and nominal or emergency egress. Ultimately, this information will be used to develop and verify countermeasures. The answers to three specific functional performance questions were sought: (1) What are the performance decrements resulting from missions of varying durations? (2) What are the physical requirements for successful entry, landing, and emergency egress from the Shuttle? and (3) What combination of preflight fitness training and in-flight countermeasures will minimize in-flight muscle performance decrements? To answer these questions, the Exercise Countermeasures Project looked at physiological changes associated with muscle degradation as well as orthostatic intolerance. A means of ensuring motor coordination was necessary to maintain proficiency in piloting skills, EVA, and IVA tasks. In addition, it was necessary to maintain musculoskeletal strength and function to meet the rigors associated with moderate altitude bailout and with nominal or emergency egress from the landed Orbiter. Eight investigations, referred to as Detailed Supplementary Objectives (DSOs) 475, 476, 477, 606, 608, 617, 618, and 624, were conducted to study muscle degradation and the effects of exercise on exercise capacity and orthostatic function (Table 3-1). This chapter is divided into

  5. Pre-Exercise Hyperpnea Attenuates Exercise-Induced Bronchoconstriction Without Affecting Performance

    PubMed Central

    Eichenberger, Philipp A.; Scherer, Thomas A.; Spengler, Christina M.

    2016-01-01

    Whole-body warm-up exercises were shown to attenuate exercise-induced bronchoconstriction (EIB). Whether intense pre-exercise hyperpnea offers similar protection and whether this might negatively affect exercise performance is unknown. Nine subjects with EIB (25±5 yrs; forced expiratory volume in 1s [FEV1], 104±15% predicted) performed an exercise challenge (ECh) followed—after 30min—by a constant-load cycling test to exhaustion. The ECh was preceded by one of four conditions: by i) control warm-up (CON) or by 10min of normocapnic hyperpnea with partial rebreathing at either ii) 50% (WU50) or iii) variable intensity (8x 30s-80%/45s-30%; WU80/30), or at iv) 70% (WU70) of maximal voluntary ventilation. FEV1 was measured at baseline and in 5-min intervals until 15min after CON/warm-up and 30min after ECh. None of the warm-up conditions induced EIB. The maximal post-ECh decrease in FEV1 was -13.8±3.1% after CON, −9.3±5.0% after WU50 (p = 0.081 vs. CON), −8.6±7.5% after WU80/30 (p = 0.081 vs. CON) and −7.2±5.0% after WU70 (p = 0.006 vs. CON), and perception of respiratory exertion was significantly attenuated (all p≤0.048), with no difference between warm-up conditions. Only after CON, FEV1 remained significantly reduced up to the start of the cycling endurance test (−8.0±4.3%, p = 0.004). Cycling performance did not differ significantly between test days (CON: 13±7min; WU50: 14±9min; WU80/30: 13±9min; WU70: 14±7min; p = 0.582). These data indicate that intense hyperpnea warm-up is effective in attenuating EIB severity and accelerating lung function recovery while none of the warm-up condition do compromise cycling performance. PMID:27898744

  6. Mechanically versus electro-magnetically braked cycle ergometer: performance and energy cost of the Wingate Anaerobic Test.

    PubMed

    Micklewright, D; Alkhatib, A; Beneke, R

    2006-04-01

    Performance and metabolic profiles of the Wingate Anaerobic Test (WAnT) were compared between a mechanically resisted (ME) and an electro-magnetically braked (EE) cycle ergometer. Fifteen healthy subjects (24.0+/-3.5 years, 180.5+/-6.1 cm, 75.4+/-11.9 kg) performed a WAnT on ME, and EE 3 days apart. Performance was measured as peak power (PP), minimum power (MP), mean power (AP), time to PP (TTPP), fatigue rate (FR), and maximum cadence (RPM(MAX)). Lactic (W (LAC)) and alactic (W (PCR)) anaerobic energy were calculated from net lactate appearance and the fast component of post-exercise oxygen uptake. Aerobic metabolism (W (AER)) was calculated from oxygen uptake during the WAnT. Total energy cost (W (TOT)) was calculated as the sum of W (LAC), W (PCR), and W (AER). There was no difference between ME and EE in PP (873+/-159 vs. 931+/-193 W) or AP (633+/-89 vs. 630+/-89 W). In the EE condition TTPP (2.3+/-0.7 vs. 4.3+/-0.7 s) was longer (P<0.001), MP (464+/-78 vs. 388+/-57 W) was lower (P<0.001), FR (15.2+/-5.2 vs. 20.5+/-6.8%) was higher (P<0.005), and RPM(MAX) (168+/-18 vs. 128+/-15 rpm) was slower (P<0.001). There was no difference in W (TOT) (1,331+/-182 vs. 1,373+/-120 J kg(-1)), W (AER) (292+/-76 vs. 309+/-72 J kg(-1)), W (PCR) (495+/-153 vs. 515+/-111 J kg(-1)) or W (LAC) (545+/-132 vs. 549+/-141 J kg(-1)) between ME and EE devices. The EE produces distinctly different performance measures but valid metabolic WAnT results that may be used to evaluate anaerobic fitness.

  7. Effectiveness of a dry-land resistance training program on strength, power, and swimming performance in paralympic swimmers.

    PubMed

    Dingley, Andrew A; Pyne, David B; Youngson, Jamie; Burkett, Brendan

    2015-03-01

    This study evaluated the effectiveness of a dry-land resistance training program in Paralympic swimmers to increase swimming power and strength measures, and how these changes affect swimming performance. Seven elite-level Paralympic swimmers (1 man and 6 women; age: 19.4 ± 6.5 years; body mass: 57 ± 12 kg; height: 1.66 ± 0.21 m) performed a 6-week coach-prescribed strength training intervention program designed to improve power, flexibility, and postural control. Exercises targeted the main swimming movements: the start and turn, postural control in the water, and the pull and kick focusing on the gluteals, upper body, and trunk. Swimming-specific tests, involving a 50-m time trial, and timed dive starts were conducted at baseline and after the 6-week program. A bilateral swim-bench ergometer and jump tests were conducted to quantify arm and leg strength and power. After the 6-week intervention, 50-m time trials improved by 1.2%, ± 1.5% (mean, ± 90% confidence limits). Increases in both mean power (6.1%, ± 5.9%) and acceleration (3.7%, ± 3.7%) generated during the dive start enabled swimmers to substantially improve start times to the 5-m (5.5%, ± 3.2) and 15-m (1.8%, ± 1.1%) marks. The resistance training intervention resulted in a very large (r = 0.78, ± 0.37) correlation between dive start velocity and the counter movement jump mean velocity. The 6-week resistance training program for Paralympic swimmers yielded substantial improvements in dry-land measures that corresponded with improvements in both timed dive starts and 50-m time trial performance, thus highlighting the usefulness of dry-land training for enhancing swimming performance in Paralympic swimming.

  8. Effects of sodium bicarbonate ingestion on performance and perceptual responses in a laboratory-simulated BMX cycling qualification series.

    PubMed

    Zabala, Mikel; Requena, Bernardo; Sánchez-Muñoz, Cristóbal; González-Badillo, Juan José; García, Inmaculada; Oöpik, Vahur; Pääsuke, Mati

    2008-09-01

    The objective of this study was to examine the effect of sodium bicarbonate (NaHCO3-) ingestion on performance and perceptual responses in a laboratory-simulated bicycle motocross (BMX) qualification series. Nine elite BMX riders volunteered to participate in this study. After familiarization, subjects undertook two trials involving repeated sprints (3 x Wingate tests [WTs] separated by 30 minutes of recovery; WT1, WT2, WT3). Ninety minutes before each trial, subjects ingested either NaHCO3- or placebo in a counterbalanced, randomly assigned, double-blind manner. Each trial was separated by 4 days. Performance variables of peak power, mean power, time to peak power, and fatigue index were calculated for each sprint. Ratings of perceived exertion were obtained after each sprint, and ratings of perceived readiness were obtained before each sprint. No significant differences were observed in performance variables between successive sprints or between trials. For the NaHCO3- trial, peak blood lactate during recovery was greater after WT2 (p < 0.05) and tended to be greater after WT3 (p = 0.07), and ratings of perceived exertion were not influenced. However, improved ratings of perceived readiness were observed before WT2 and WT3 (p < 0.05). In conclusion, NaHCO3- ingestion had no effect on performance and RPE during a series of three WT simulating a BMX qualification series, possibly because of the short duration of each effort and the long recovery time used between the three WTs. On the contrary, NaHCO3- ingestion improved perceived readiness before each WT.

  9. Caffeine and sports performance.

    PubMed

    Burke, Louise M

    2008-12-01

    Athletes are among the groups of people who are interested in the effects of caffeine on endurance and exercise capacity. Although many studies have investigated the effect of caffeine ingestion on exercise, not all are suited to draw conclusions regarding caffeine and sports performance. Characteristics of studies that can better explore the issues of athletes include the use of well-trained subjects, conditions that reflect actual practices in sport, and exercise protocols that simulate real-life events. There is a scarcity of field-based studies and investigations involving elite performers. Researchers are encouraged to use statistical analyses that consider the magnitude of changes, and to establish whether these are meaningful to the outcome of sport. The available literature that follows such guidelines suggests that performance benefits can be seen with moderate amounts (~3 mg.kg-1 body mass) of caffeine. Furthermore, these benefits are likely to occur across a range of sports, including endurance events, stop-and-go events (e.g., team and racquet sports), and sports involving sustained high-intensity activity lasting from 1-60 min (e.g., swimming, rowing, and middle and distance running races). The direct effects on single events involving strength and power, such as lifts, throws, and sprints, are unclear. Further studies are needed to better elucidate the range of protocols (timing and amount of doses) that produce benefits and the range of sports to which these may apply. Individual responses, the politics of sport, and the effects of caffeine on other goals, such as sleep, hydration, and refuelling, also need to be considered.

  10. Spaceport Performance Measures

    NASA Technical Reports Server (NTRS)

    Finger, G. Wayne

    2010-01-01

    Spaceports have traditionally been characterized by performance measures associated with their site characteristics. Measures such as "Latitude" (proximity to the equator), "Azimuth" (range of available launch azimuths) and "Weather" (days of favorable weather) are commonly used to characterize a particular spaceport. However, other spaceport performance measures may now be of greater value. These measures can provide insight into areas of operational differences between competing spaceports and identify areas for improving the performance of spaceports. This paper suggests Figures of Merit (FOMs) for spaceport "Capacity" (number of potential launch opportunities per year and / or potential mass' to low earth orbit (LEO) per year); "Throughput" (actual mass to orbit per year compared to capacity); "Productivity" (labor effort hours per unit mass to orbit); "Energy Efficiency" (joules expended at spaceport per unit mass to orbit); "Carbon Footprint" tons CO2 per unit mass to orbit). Additional FOMS are investigated with regards to those areas of special interest to commercial launch operators, such as "Assignment Schedule" (days required for a binding assignment of a launch site from the spaceport); "Approval Schedule" (days to complete a range safety assessment leading to an approval or disapproval of a launch vehicle); "Affordability" (cost for a spaceport to assess a new launch vehicle); "Launch Affordability" (fixed range costs per launch); "Reconfigure Time" (hours to reconfigure the range from one vehicle's launch ready configuration to another vehicle's configuration); "Turn,Around Time" (minimum range hours required between launches of an identical type launch vehicle). Available or notional data is analyzed for the KSC/CCAFS area and other spaceports. Observations regarding progress over the past few decades are made. Areas where improvement are needed or indicated are suggested.

  11. Performance analysis in saber.

    PubMed

    Aquili, Andrea; Tancredi, Virginia; Triossi, Tamara; De Sanctis, Desiree; Padua, Elvira; DʼArcangelo, Giovanna; Melchiorri, Giovanni

    2013-03-01

    Fencing is a sport practiced by both men and women, which uses 3 weapons: foil, épée, and saber. In general, there are few scientific studies available in international literature; they are limited to the performance analysis of fencing bouts, yet there is nothing about saber. There are 2 kinds of competitions in the World Cup for both men and women: the "FIE GP" and "A." The aim of this study was to carry out a saber performance analysis to gain useful indicators for the definition of a performance model. In addition, it is expected to verify if it could be influenced by the type of competition and if there are differences between men and women. Sixty bouts: 33 FIE GP and 27 "A" competitions (35 men's and 25 women's saber bouts) were analyzed. The results indicated that most actions are offensive (55% for men and 49% for women); the central area of the piste is mostly used (72% for men and 67% for women); the effective fighting time is 13.6% for men and 17.1% for women, and the ratio between the action and break times is 1:6.5 for men and 1:5.1 for women. A lunge is carried out every 23.9 seconds by men and every 20 seconds by women, and a direction change is carried out every 65.3 seconds by men and every 59.7 seconds by women. The data confirm the differences between the saber and the other 2 weapons. There is no significant difference between the data of the 2 different kinds of competitions.

  12. Should Aid Reward Performance?

    PubMed Central

    Olken, Benjamin A.; Onishi, Junko; Wong, Susan

    2014-01-01

    We report an experiment in 3,000 villages that tested whether incentives improve aid efficacy. Villages received block grants for maternal and child health and education that incorporated relative performance incentives. Subdistricts were randomized into incentives, an otherwise identical program without incentives, or control. Incentives initially improved preventative health indicators, particularly in underdeveloped areas, and spending efficiency increased. While school enrollments improved overall, incentives had no differential impact on education, and incentive health effects diminished over time. Reductions in neonatal mortality in non-incentivized areas did not persist with incentives. We find no systematic scoring manipulation nor funding reallocation toward richer areas. PMID:25485039

  13. High Performance Liquid Chromatography

    NASA Astrophysics Data System (ADS)

    Talcott, Stephen

    High performance liquid chromatography (HPLC) has many applications in food chemistry. Food components that have been analyzed with HPLC include organic acids, vitamins, amino acids, sugars, nitrosamines, certain pesticides, metabolites, fatty acids, aflatoxins, pigments, and certain food additives. Unlike gas chromatography, it is not necessary for the compound being analyzed to be volatile. It is necessary, however, for the compounds to have some solubility in the mobile phase. It is important that the solubilized samples for injection be free from all particulate matter, so centrifugation and filtration are common procedures. Also, solid-phase extraction is used commonly in sample preparation to remove interfering compounds from the sample matrix prior to HPLC analysis.

  14. WFIRST Observatory Performance

    NASA Technical Reports Server (NTRS)

    Kruk, Jeffrey W.

    2012-01-01

    The WFIRST observatory will be a powerful and flexible wide-field near-infrared facility. The planned surveys will provide data applicable to an enormous variety of astrophysical science. This presentation will provide a description of the observatory and its performance characteristics. This will include a discussion of the point spread function, signal-to-noise budgets for representative observing scenarios and the corresponding limiting sensitivity. Emphasis will be given to providing prospective Guest Observers with information needed to begin thinking about new observing programs.

  15. Predicting photothermal field performance

    NASA Technical Reports Server (NTRS)

    Gonzalez, C. C.; Ross, R. G., Jr.

    1984-01-01

    Photothermal field performance in flat plate solar collectors was predicted. An analytical model which incorporates the measured dependency between transmittance loss and UV and temperature exposure levels was developed. The model uses SOLMET weather data extrapolated to 30 years for various sites and module mounting configurations. It is concluded that the temperature is the key to photothermally induced transmittance loss. The sensitivity of transmittance loss to UV level is nonlinear with minimum in curve near one sun. The ethylene vinyl acetate (EVA) results are consistent with 30 year life allocation.

  16. Performance of Dental Ceramics

    PubMed Central

    Rekow, E.D.; Silva, N.R.F.A.; Coelho, P.G.; Zhang, Y.; Guess, P.; Thompson, V.P.

    2011-01-01

    The clinical success of modern dental ceramics depends on an array of factors, ranging from initial physical properties of the material itself, to the fabrication and clinical procedures that inevitably damage these brittle materials, and the oral environment. Understanding the influence of these factors on clinical performance has engaged the dental, ceramics, and engineering communities alike. The objective of this review is to first summarize clinical, experimental, and analytic results reported in the recent literature. Additionally, it seeks to address how this new information adds insight into predictive test procedures and reveals challenges for future improvements. PMID:21224408

  17. High performance cyclone development

    SciTech Connect

    Giles, W.B.

    1981-01-01

    The results of cold flow experiments at atmospheric conditions of an air-shielded 18 in-dia electrocyclone with a central cusped electrode are reported using fine test dusts of both flyash and nickel powder. These results are found to confirm expectations of enhanced performance, similar to earlier work on a 12 in-dia model. An analysis of the combined inertial-electrostatic force field is also presented which identifies general design goals and scaling laws. From this, it is found that electrostatic enhancement will be particularly beneficial for fine dusts in large cyclones. Recommendations for further improvement in cyclone collection efficiency are proposed.

  18. LISA Instrument Performance

    NASA Technical Reports Server (NTRS)

    Livas, Jeffrey C.; Thorpe, James Ira

    2008-01-01

    Laser Interferometer Space Antenna (LISA) is designed to observe gravitational waves in the frequency band from 10(exp -1) to 10(exp -4) Hz where a rich spectrum of sources is expected. The measurements must be made from space to avoid the large motions of the earth that prevent the current generations (eg. LIGO) from operating at these freq8uencies. The technology and expected performance behind this measurement capability will be reviewed with an emphasis on the interferometric measurement system., including recent laboratory results showing a novel tunable frequency stabilized laser.

  19. High Performance FORTRAN

    NASA Technical Reports Server (NTRS)

    Mehrotra, Piyush

    1994-01-01

    High performance FORTRAN is a set of extensions for FORTRAN 90 designed to allow specification of data parallel algorithms. The programmer annotates the program with distribution directives to specify the desired layout of data. The underlying programming model provides a global name space and a single thread of control. Explicitly parallel constructs allow the expression of fairly controlled forms of parallelism in particular data parallelism. Thus the code is specified in a high level portable manner with no explicit tasking or communication statements. The goal is to allow architecture specific compilers to generate efficient code for a wide variety of architectures including SIMD, MIMD shared and distributed memory machines.

  20. Loudspeaker Performance Aid

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Many manufacturers of loudspeakers are now using a magnetic liquid cooling agent known as ferrofluid. Commercialized by Ferrofluids Corporation, ferrofluid is a liquid material in which sub-microscopic particles of iron oxide are permanently suspended. Injected into the voice coil segment of speaker system, magnetic liquid serves as superior heat transfer medium for cooling the voice coil, thus substantially increasing the system's ability to handle higher power levels and decreasing chance of speaker failure. Ferrofluid offers several additional advantages which add up to improved speaker performance, lower manufacturing costs and fewer rejects.

  1. Development and validation of ultra-high performance supercritical fluid chromatography method for determination of illegal dyes and comparison to ultra-high performance liquid chromatography method.

    PubMed

    Khalikova, Maria A; Šatínský, Dalibor; Solich, Petr; Nováková, Lucie

    2015-05-18

    A novel simple, fast and efficient ultra-high performance supercritical fluid chromatography (UHPSFC) method was developed and validated for the separation and quantitative determination of eleven illegal dyes in chili-containing spices. The method involved a simple ultrasound-assisted liquid extraction of illegal compounds with tetrahydrofuran. The separation was performed using a supercritical fluid chromatography system and CSH Fluoro-Phenyl stationary phase at 70°C. The mobile phase was carbon dioxide and the mixture of methanol:acetonitrile (1:1, v/v) with 2.5% formic acid as an additive at the flow rate 2.0 mL min(-1). The UV-vis detection was accomplished at 500 nm for seven compounds and at 420 nm for Sudan Orange G, Butter Yellow, Fast Garnet GBC and Methyl Red due to their maximum of absorbance. All eleven compounds were separated in less than 5 min. The method was successfully validated and applied using three commercial samples of chili-containing spices - Chili sauce (Indonesia), Feferony sauce (Slovakia) and Mojo sauce (Spain). The linearity range of proposed method was 0.50-9.09 mg kg(-1) (r ≥ 0.995). The detection limits were determined as signal to noise ratio of 3 and were ranged from 0.15 mg kg(-1) to 0.60 mg kg(-1) (1.80 mg kg(-1) for Fast Garnet) for standard solution and from 0.25 mg kg(-1) to 1.00 mg kg(-1) (2.50 mg kg(-1) for Fast Garnet, 1.50 mg kg(-1) for Sudan Red 7B) for chili-containing samples. The recovery values were in the range of 73.5-107.2% and relative standard deviation ranging from 0.1% to 8.2% for within-day precision and from 0.5% to 8.8% for between-day precision. The method showed potential for being used to monitor forbidden dyes in food constituents. The developed UHPSFC method was compared to the UHPLC-UV method. The orthogonality of Sudan dyes separation by these two methods was demonstrated. Benefits and drawbacks were discussed showing the reliability of both methods for monitoring of studied illegal dyes in real

  2. Altair performance and upgrades

    NASA Astrophysics Data System (ADS)

    Lai, Olivier; Véran, Jean-Pierre; Herriot, Glen; White, John; Ball, Jesse; Trujillo, Chad

    2014-07-01

    Altair is the facility single conjugate AO system for Gemini North. Although it has been in operation for more than 10 years (and upgraded to LGS in 2007), Altair's performance is degraded by three main issues: vibrations of the telescope and instrument support structure, spatial aliasing on centroid offsets from the M2 support structure print-through on the optical surface and static non-common path aberrations. Monte-Carlo simulations can reproduce the behavior of Altair when including these three effects and they are roughly of the same order of magnitude. Solutions or mitigations are being investigated to overcome these nefarious effects and restore Altair's performance to its nominal level. A simplex algorithm as well as a phase diversity approach are being investigated to measure and correct for static aberrations. A high accuracy phase map of the M2 print-through has been obtained and is being used to calibrate and/or filter centroids affected by aliasing. A new real time computer is under consideration, to be able to handle more advanced controllers, especially notch filters to combat vibrations. In this paper we will report on the various simulations and on-sky results of this rejuvenation of one of Gemini's workhorse instruments.

  3. Cyclone performance and optimization

    SciTech Connect

    Leith, D.

    1989-03-15

    The objectives of this project are: to characterize the gas flow pattern within cyclones, to revise the theory for cyclone performance on the basis of these findings, and to design and test cyclones whose dimensions have been optimized using revised performance theory. This work is important because its successful completion will aid in the technology for combustion of coal in pressurized, fluidized beds. This quarter, we have been hampered somewhat by flow delivery of the bubble generation system and arc lighting system placed on order last fall. This equipment is necessary to map the flow field within cyclones using the techniques described in last quarter's report. Using the bubble generator, we completed this quarter a study of the natural length'' of cyclones of 18 different configurations, each configuration operated at five different gas flows. Results suggest that the equation by Alexander for natural length is incorrect; natural length as measured with the bubble generation system is always below the bottom of the cyclones regardless of the cyclone configuration or gas flow, within the limits of the experimental cyclones tested. This finding is important because natural length is a term in equations used to predict cyclone efficiency. 1 tab.

  4. Anaerobic performance at altitude.

    PubMed

    Coudert, J

    1992-10-01

    Anaerobic metabolism is usually evaluated by the determination of the anaerobic capacity and the maximal anaerobic mechanical external power (Wmax). Conflicting results are reported on anaerobic capacity evaluated by maximal oxygen deficit and debt, and maximal blood lactate concentration during acute or chronic hypoxia (acclimatized subjects). Data on muscle biopsies (lactate concentration, changes in ATP, phosphocreatine and glycogen stores, glycolytic enzyme activities) and the few studies on lactate flux give in most cases evidence of a non-alteration of the anaerobic capacity for altitudes up to 5,500 m. No differences are observed in Wmax measured at high altitudes up to 5,200 m during intense short-term exercises: (1) jumps on a force platform which is a good indicator of alactic Wmax, and (2) 7-10 s sprints (i.e. force-velocity test) which solicit alactic metabolism but also lactic pathway. For exercises of duration equal or more than 30 s (i.e. Wingate test), there are conflicting results because a lower participation of aerobic metabolism during this test at high altitude can interfere with anaerobic performance. In conclusion, we can admit that anaerobic performances are not altered by high altitudes up to 5,200 m if the length of exposure does not exceed 5 weeks. After this period, muscle mass begins to decrease.

  5. Assessment of sensor performance

    NASA Astrophysics Data System (ADS)

    Waldmann, C.; Tamburri, M.; Prien, R. D.; Fietzek, P.

    2010-02-01

    There is an international commitment to develop a comprehensive, coordinated and sustained ocean observation system. However, a foundation for any observing, monitoring or research effort is effective and reliable in situ sensor technologies that accurately measure key environmental parameters. Ultimately, the data used for modelling efforts, management decisions and rapid responses to ocean hazards are only as good as the instruments that collect them. There is also a compelling need to develop and incorporate new or novel technologies to improve all aspects of existing observing systems and meet various emerging challenges. Assessment of Sensor Performance was a cross-cutting issues session at the international OceanSensors08 workshop in Warnemünde, Germany, which also has penetrated some of the papers published as a result of the workshop (Denuault, 2009; Kröger et al., 2009; Zielinski et al., 2009). The discussions were focused on how best to classify and validate the instruments required for effective and reliable ocean observations and research. The following is a summary of the discussions and conclusions drawn from this workshop, which specifically addresses the characterisation of sensor systems, technology readiness levels, verification of sensor performance and quality management of sensor systems.

  6. Thermal Performance Benchmarking

    SciTech Connect

    Feng, Xuhui; Moreno, Gilbert; Bennion, Kevin

    2016-06-07

    The goal for this project is to thoroughly characterize the thermal performance of state-of-the-art (SOA) in-production automotive power electronics and electric motor thermal management systems. Information obtained from these studies will be used to: evaluate advantages and disadvantages of different thermal management strategies; establish baseline metrics for the thermal management systems; identify methods of improvement to advance the SOA; increase the publicly available information related to automotive traction-drive thermal management systems; help guide future electric drive technologies (EDT) research and development (R&D) efforts. The thermal performance results combined with component efficiency and heat generation information obtained by Oak Ridge National Laboratory (ORNL) may then be used to determine the operating temperatures for the EDT components under drive-cycle conditions. In FY16, the 2012 Nissan LEAF power electronics and 2014 Honda Accord Hybrid power electronics thermal management system were characterized. Comparison of the two power electronics thermal management systems was also conducted to provide insight into the various cooling strategies to understand the current SOA in thermal management for automotive power electronics and electric motors.

  7. High Performance Parallel Architectures

    NASA Technical Reports Server (NTRS)

    El-Ghazawi, Tarek; Kaewpijit, Sinthop

    1998-01-01

    Traditional remote sensing instruments are multispectral, where observations are collected at a few different spectral bands. Recently, many hyperspectral instruments, that can collect observations at hundreds of bands, have been operational. Furthermore, there have been ongoing research efforts on ultraspectral instruments that can produce observations at thousands of spectral bands. While these remote sensing technology developments hold great promise for new findings in the area of Earth and space science, they present many challenges. These include the need for faster processing of such increased data volumes, and methods for data reduction. Dimension Reduction is a spectral transformation, aimed at concentrating the vital information and discarding redundant data. One such transformation, which is widely used in remote sensing, is the Principal Components Analysis (PCA). This report summarizes our progress on the development of a parallel PCA and its implementation on two Beowulf cluster configuration; one with fast Ethernet switch and the other with a Myrinet interconnection. Details of the implementation and performance results, for typical sets of multispectral and hyperspectral NASA remote sensing data, are presented and analyzed based on the algorithm requirements and the underlying machine configuration. It will be shown that the PCA application is quite challenging and hard to scale on Ethernet-based clusters. However, the measurements also show that a high- performance interconnection network, such as Myrinet, better matches the high communication demand of PCA and can lead to a more efficient PCA execution.

  8. Sensitive screening of abused drugs in dried blood samples using ultra-high-performance liquid chromatography-ion booster-quadrupole time-of-flight mass spectrometry.

    PubMed

    Chepyala, Divyabharathi; Tsai, I-Lin; Liao, Hsiao-Wei; Chen, Guan-Yuan; Chao, Hsi-Chun; Kuo, Ching-Hua

    2017-03-31

    An increased rate of drug abuse is a major social problem worldwide. The dried blood spot (DBS) sampling technique offers many advantages over using urine or whole blood sampling techniques. This study developed a simple and efficient ultra-high-performance liquid chromatography-ion booster-quadrupole time-of-flight mass spectrometry (UHPLC-IB-QTOF-MS) method for the analysis of abused drugs and their metabolites using DBS. Fifty-seven compounds covering the most commonly abused drugs, including amphetamines, opioids, cocaine, benzodiazepines, barbiturates, and many other new and emerging abused drugs, were selected as the target analytes of this study. An 80% acetonitrile solvent with a 5-min extraction by Geno grinder was used for sample extraction. A Poroshell column was used to provide efficient separation, and under optimal conditions, the analytical times were 15 and 5min in positive and negative ionization modes, respectively. Ionization parameters of both electrospray ionization source and ion booster (IB) source containing an extra heated zone were optimized to achieve the best ionization efficiency of the investigated abused drugs. In spite of their structural diversity, most of the abused drugs showed an enhanced mass response with the high temperature ionization from an extra heated zone of IB source. Compared to electrospray ionization, the ion booster (IB) greatly improved the detection sensitivity for 86% of the analytes by 1.5-14-fold and allowed the developed method to detect trace amounts of compounds on the DBS cards. The validation results showed that the coefficients of variation of intra-day and inter-day precision in terms of the signal intensity were lower than 19.65%. The extraction recovery of all analytes was between 67.21 and 115.14%. The limits of detection of all analytes were between 0.2 and 35.7ngmL(-1). The stability study indicated that 7% of compounds showed poor stability (below 50%) on the DBS cards after 6 months of storage at

  9. Usability and performance of a wearable tele-echography robot for focused assessment of trauma using sonography.

    PubMed

    Ito, Keiichiro; Sugano, Shigeki; Takeuchi, Ryohei; Nakamura, Kyota; Iwata, Hiroyasu

    2013-02-01

    Focused Assessment with Sonography for Trauma (FAST) is widely used as a first lifesaving step for patients suffering from internal bleeding. Because it may take a long time to transport such patients to a hospital, a wearable and portable tele-echography robot that a paramedic can attach to the patient has been developed. In the current study, experiments were conducted to evaluate the usability and performance of attached FAST. The proposed robot must be attached to 4 areas to perform FAST. The time required for attachment and the positions of attachment completed by 9 non-medical staff members, as well as the time it took for the FAST to reach a medical doctor, were measured. The echo images obtained when the patient's body was in motion were evaluated by a medical doctor. The robot could be attached to all 4 areas within approximately 5min, and the maximum gap was 4.8cm. This indicates that a paramedic who has received training in emergency medical care should be able to attach the robot to a patient quickly and accurately. Additionally, it was confirmed that the robot could be used to complete FAST under a doctor's control within 9min and that the extracted echo images were suitable for FAST. A comparison of the results with current ambulance transportation time confirmed that FAST could be completed approximately 14min before the patient reached the hospital. The results of the current study indicate that the robot is worth using, is suitable for FAST, and will be effective in emergency medical care.

  10. Analysis of drugs of abuse in human plasma using microextraction by packed sorbents and ultra-high-performance liquid chromatography.

    PubMed

    Fernández, P; González, M; Regenjo, M; Ares, A M; Fernández, A M; Lorenzo, R A; Carro, A M

    2017-02-17

    A miniaturized and simple method based on digitally programmed microextraction by packed sorbent (eVol(®)-MEPS) coupled to ultra-performance liquid chromatography (UPLC) has been developed for quantitative determination of three synthetic cathinones and seven conventional drugs of abuse and metabolites. The influence of several extraction parameters, such as washing and elution solvents were tested. In addition important variables affecting MEPS performance, namely sample volume, sorbent drying time, washing solvent volume, elution volume, number of extraction cycles, sorbent phase and pH, were evaluated using an asymmetrical screening design. The optimal experimental conditions involved 300μL of plasma, loading 10×100μL of sample through a C8/SCX sorbent in a MEPS syringe placed in the semi-automatic eVol(®) system, washing using 150μL H2O:MeOH (90:10, v/v), drying for 0.5min and elution using 200μL dichloromethane:2-propanol:ammonium hydroxide (78:20:2, v/v/v). The drugs separation was achieved using an ACQUITY BEH Shield RP18 column (2.1mm×100mm×1.7μm) in 3min. Under optimized conditions the proposed method was validated in terms of selectivity, linearity, limits of detection (LOD) and quantitation (LOQ), precision and matrix effect, using standard addition calibration. The combination of MEPS and UPLC provides a method for the primary screening of the analytes in 18min with excellent recoveries at three concentration levels, ranging between 80 and 104% (relative standard deviation <11%). The developed methodology has been successfully applied to plasma samples from polydrug abusers.

  11. Concurrent Verbal Encouragement and Wingate Anaerobic Cycle Test Performance in Females: Athletes vs. Non-Athletes.

    PubMed

    Bullinger, Dyana L; Hearon, Christopher M; Gaines, Stacey A; Daniel, Michael L

    To examine the effect of concurrent verbal encouragement on the performance of the WAnT in female athletes vs. female non-athletes. College-age female subjects were recruited where ten of the subjects were intercollegiate athletes (ATH, n1 =10) and the nine were non-athletes (NON, n2 =9). The WAnT was novel to all subjects and the subjects were blinded to the study's purpose. Prior to the experimental trials, subjects were measured for body composition and performed a familiarity WAnT trial without verbal encouragement. Subjects then performed the WAnT twice, once with concurrent verbal encouragement (VE) and once without (NVE), in a balanced cross-over design. Peak (PP) and mean power (MP), and total work (TW) were compared between ATH and NON across VE and NVE using an ANOVA (1 between, 1 within), α=0.05. ATH and NON did not differ (p>0.05) in age or body composition with the exception of fat-free mass which differed significantly (ATH=53.7±6.6, NON=46.1±5.7 kg) (p<0.05). A significant (p<0.05) main effect for ATH/NON was observed where ATH outperformed NON when pooled across VE/NVE trials for PP (ATH=13.0±1.4, NON=11.3±1.7 W·kg(-1)), MP (ATH=7.7±1.1, NON=6.7±0.9 W·kg-1) and TW (ATH=232±35, NON=201±26 J·kg(-1)). When pooled across all subjects (ATH and NON), the VE/NVE trials did not differ (p>0.05) for PP (VE=12.4±1.7, NVE=12.0±1.9 W·kg(-1)), MP (VE=7.3±1.1, NVE=7.2±1.2 W·kg(-1)) and TW (VE=219±33, NVE=215±35 J·kg(-1)). The ATH/NON interaction with VE/NVE was not significant (p>0.05). Concurrent verbal encouragement does not affect performance on the WAnT in females, nor does it affect WAnT performance in female athletes and non-athletes differently.

  12. Warming-Up Affects Performance and Lactate Distribution between Plasma and Red Blood Cells

    PubMed Central

    Wahl, Patrick; Zinner, Christoph; Yue, Zengyuan; Bloch, Wilhelm; Mester, Joachim

    2010-01-01

    Warming-up (WU) is a widely used preparation for training and competition. However, little is known about the potential mechanisms of WU on performance and on the lactate distribution in the blood compartment. The purpose of the present study was to investigate whether different WU procedures affect performance and lactate distribution between plasma and red blood cells (RBCs) after maximal exercise. At three different occasions eleven subjects performed one 30 s maximal effort exercise on a cycle ergometer. Before each exercise, subjects warmed up at different intensities: 1. no WU (NWU); 2. extensive WU (EWU); 3. intensive WU (IWU). Blood samples were taken under resting conditions, after WU, and in 1 minute intervals during recovery to determine lactate concentrations [LA] in whole blood ([LA]WB), plasma ([LA]plasma) and erythrocytes ([LA]RBC). Mean power output was +58 Watt (EWU) and +60 Watt (IWU) higher compared to NWU. For each WU condition [LA]plasma and [LA]RBC differed significantly at any time point, showing greater [LA]plasma compared to [LA]RBC. The maximal effort exercise caused a rapid decrease of the [LA]RBC/[LA]plasma ratio. [LA]RBC reached the peak 3-5 minutes later than [LA]plasma depending on the WU condition. The initial increments in [LA]RBC were 10-16% lower after IWU compared to NWU and EWU. The lower increment of [LA]RBC after IWU might be due to a “higher preloading” with lactate before exercise, causing a smaller initial [LA] gradient between plasma and RBCs. It seems that the influx decreases with increasing intracellular [LA]. Another possibility one could speculate about is, that the extracellular increase in [LA] inhibits the outflux of lactate produced by the RBC itself. This inhibited export of lactate from RBCs may lead to an intracellular lactate accumulation. But the relatively fast increase in [LA]RBC and other investigations partly contradicts this possibility. Key points Warm-up significantly improves performance during 30

  13. High performing micromachined retroreflector

    NASA Astrophysics Data System (ADS)

    Lundvall, Axel; Nikolajeff, Fredrik; Lindstrom, Tomas

    2003-10-01

    This paper reports on the realization of a type of micromachined retroreflecting sheeting material. The geometry presented has high reflection efficiency even at large incident angles, and it can be manufactured through polymer replication techniques. The paper consists of two parts: A theoretical section outlining the design parameters and their impact on the optical performance, and secondly, an experimental part comprising both manufacturing and optical evaluation for a candidate retroreflecting sheet material in traffic control devices. Experimental data show that the retroreflecting properties are promising. The retroreflector consists of a front layer of densely packed spherical microlenses, a back surface of densely packed spherical micromirrors, and a transparent spacer layer. The thickness of the spacer layer determines in part the optical characteristics of the retroreflector.

  14. RLV Turbine Performance Optimization

    NASA Technical Reports Server (NTRS)

    Griffin, Lisa W.; Dorney, Daniel J.

    2001-01-01

    A task was developed at NASA/Marshall Space Flight Center (MSFC) to improve turbine aerodynamic performance through the application of advanced design and analysis tools. There are four major objectives of this task: 1) to develop, enhance, and integrate advanced turbine aerodynamic design and analysis tools; 2) to develop the methodology for application of the analytical techniques; 3) to demonstrate the benefits of the advanced turbine design procedure through its application to a relevant turbine design point; and 4) to verify the optimized design and analysis with testing. Final results of the preliminary design and the results of the two-dimensional (2D) detailed design of the first-stage vane of a supersonic turbine suitable for a reusable launch vehicle (R-LV) are presented. Analytical techniques for obtaining the results are also discussed.

  15. System performance conclusions

    NASA Technical Reports Server (NTRS)

    Arndt, G. D.

    1980-01-01

    The advantages and disadvantages of reducing power levels and using antennas with diameters smaller than 1 Km were evaluated if rectenna costs and land usage requirements become major factors, operating at 5800 megahertz should be considered. Three sequences (random, incoherent phasing, and concentric rings - center to edge) provided satisfactory performance in that the resultant sidelobe levels during startup/ shutdown were lower than the steady-state levels present during normal operations. Grating lobe peaks and scattered power levels were used to determine the array/subarray mechanical alignment requirements. The antenna alignment requirement is 1 min or 3 min depending on phase control configuration. System error parameters were defined to minimize scattered microwave power.

  16. Trust in performance indicators?

    PubMed Central

    Davies, H. T.; Lampel, J.

    1998-01-01

    The 1980s and 90s have seen the proliferation of all forms of performance indicators as part of attempts to command and control health services. The latest area to receive attention is health outcomes. Published league tables of mortality and other health outcomes have been available in the United States for some time and in Scotland since the early 1990s; they have now been developed for England and Wales. Publication of these data has proceeded despite warnings as to their limited meaningfulness and usefulness. The time has come to ask whether the remedy is worse than the malady: are published health outcomes contributing to quality efforts or subverting more constructive approaches? This paper argues that attempts to force improvements through publishing health outcomes can be counterproductive, and outlines an alternative approach which involves fostering greater trust in professionalism as a basis for quality enhancements. PMID:10185142

  17. RTA gun performance

    SciTech Connect

    Andersen, D E; Eylon, S; Henestroza, E; Houck, T L; Lidia, S M; Vanecek, D L; Westenskow, G A; Yu, S S

    1998-08-10

    The technical challenge for making two-beam accelerators into realizable power sources for high-energy colliders lie in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have constructed a 1.2-kA, 1-MeV, electron induction injector for the RTA accelerator. The electron source will be a 8.9 cm diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. The injector's pulse length should be over 120-ns flat top (1% energy variation) with a normalized edge emittance of less than 200 π-mm-mr. Details of the design and performance of the injector, beam line, and diagnostics will be presented.

  18. Krypton ion thruster performance

    NASA Technical Reports Server (NTRS)

    Patterson, Michael J.; Williams, George J., Jr.

    1992-01-01

    Preliminary data were obtained from a 30 cm ion thruster operating on krypton propellant over the input power range of 0.4-5.5 kW. The data are presented, and compared and contrasted to those obtained with xenon propellant over the same input power envelope. Typical krypton thruster efficiency was 70 percent at a specific impulse of approximately 5000 s, with a maximum demonstrated thrust-to-power ratio of approximately 42 mN/kW at 2090 s specific impulse and 1580 watts input power. Critical thruster performance and component lifetime issues were evaluated. Order-of-magnitude power throttling was demonstrated using a simplified power-throttling strategy.

  19. Krypton Ion Thruster Performance

    NASA Technical Reports Server (NTRS)

    Patterson, Michael J.; Williams, George J.

    1992-01-01

    Preliminary data were obtained from a 30 cm ion thruster operating on krypton propellant over the input power range of 0.4 to 5.5 kW. The data presented are compared and contrasted to the data obtained with xenon propellant over the same input power envelope. Typical krypton thruster efficiency was 70 percent at a specific impulse of approximately 5000 s, with a maximum demonstrated thrust to power ratio of approximately 42 mN/kW at 2090 s specific impulse and 1580 watts input power. Critical thruster performance and component lifetime issues were evaluated. Order of magnitude power throttling was demonstrated using a simplified power-throttling strategy.

  20. Determining structural performance

    NASA Technical Reports Server (NTRS)

    Ernst, Michael A.; Kiraly, Louis J.

    1987-01-01

    An overview is given of the methods and concepts developed to enhance and predict structural dynamic characteristics of advanced aeropropulsion systems. Aeroelasticity, Vibration Control, Dynamic Systems, and Computational Structural Methods are four disciplines that make up the research program at NASA/Lewis Research Center. The Aeroelasticity program develops analytical and experimental methods to minimize flutter and forced vibration of aerospace propulsion systems. Both frequency domain and time domain methods have been developed for applications on the turbofan, turbopump, and advanced turboprop. To improve life and performance, the Vibration Control program conceives, analyzes, develops, and demonstrates new methods to control vibrations in aerospace systems. Active and passive vibration control is accomplished with electromagnetic dampers, magnetic bearings, and piezoelectric crystals to control rotor vibrations. The Dynamic Systems program analyzes and verifies the dynamics of interacting systems, as well as develops concepts and methods for high-temperature dynamic seals. The Computational Structural Methods program uses computer science to improve solutions of structural problems.

  1. Mod II engine performance

    NASA Technical Reports Server (NTRS)

    Richey, Albert E.; Huang, Shyan-Cherng

    1987-01-01

    The testing of a prototype of an automotive Stirling engine, the Mod II, is discussed. The Mod II is a one-piece cast block with a V-4 single-crankshaft configuration and an annular regenerator/cooler design. The initial testing of Mod II concentrated on the basic engine, with auxiliaries driven by power sources external to the engine. The performance of the engine was tested at 720 C set temperature and 820 C tube temperature. At 720 C, it is observed that the power deficiency is speed dependent and linear, with a weak pressure dependency, and at 820 C, the power deficiency is speed and pressure dependent. The effects of buoyancy and nozzle spray pattern on the heater temperature spread are investigated. The characterization of the oil pump and the operating cycle and temperature spread tests are proposed for further evaluation of the engine.

  2. Improvements in Cycling but Not Handcycling 10 km Time Trial Performance in Habitual Caffeine Users.

    PubMed

    Graham-Paulson, Terri; Perret, Claudio; Goosey-Tolfrey, Victoria

    2016-06-25

    Caffeine supplementation during whole-/lower-body exercise is well-researched, yet evidence of its effect during upper-body exercise is equivocal. The current study explored the effects of caffeine on cycling/handcycling 10 km time trial (TT) performance in habitual caffeine users. Eleven recreationally trained males (mean (SD) age 24 (4) years, body mass 85.1 (14.6) kg, cycling/handcycling peak oxygen uptake ( V · peak) 42.9 (7.3)/27.6 (5.1) mL∙kg∙min(-1), 160 (168) mg/day caffeine consumption) completed two maximal incremental tests and two familiarization sessions. During four subsequent visits, participants cycled/handcycled for 30 min at 65% mode-specific V · peak (preload) followed by a 10 km TT following the ingestion of 4 mg∙kg(-1) caffeine (CAF) or placebo (PLA). Caffeine significantly improved cycling (2.0 (2.0)%; 16:35 vs. 16:56 min; p = 0.033) but not handcycling (1.8 (3.0)%; 24:10 vs. 24:36 min; p = 0.153) TT performance compared to PLA. The improvement during cycling can be attributed to the increased power output during the first and last 2 km during CAF. Higher blood lactate concentration (Bla) was reported during CAF compared to PLA (p < 0.007) and was evident 5 min post-TT during cycling (11.2 ± 2.6 and 8.8 ± 3.2 mmol/L; p = 0.001) and handcycling (10.6 ± 2.5 and 9.2 ± 2.9 mmol/L; p = 0.006). Lower overall ratings of perceived exertion (RPE) were seen following CAF during the preload (p < 0.05) but not post-TT. Lower peripheral RPE were reported at 20 min during cycling and at 30 min during handcycling, and lower central RPE was seen at 30 min during cycling (p < 0.05). Caffeine improved cycling but not handcycling TT performance. The lack of improvement during handcycling may be due to the smaller active muscle mass, elevated (Bla) and/or participants' training status.

  3. Caffeine intake improves intense intermittent exercise performance and reduces muscle interstitial potassium accumulation.

    PubMed

    Mohr, Magni; Nielsen, Jens Jung; Bangsbo, Jens

    2011-11-01

    The effect of oral caffeine ingestion on intense intermittent exercise performance and muscle interstitial ion concentrations was examined. The study consists of two studies (S1 and S2). In S1, 12 subjects completed the Yo-Yo intermittent recovery level 2 (Yo-Yo IR2) test with prior caffeine (6 mg/kg body wt; CAF) or placebo (PLA) intake. In S2, 6 subjects performed one low-intensity (20 W) and three intense (50 W) 3-min (separated by 5 min) one-legged knee-extension exercise bouts with (CAF) and without (CON) prior caffeine supplementation for determination of muscle interstitial K(+) and Na(+) with microdialysis. In S1 Yo-Yo IR2 performance was 16% better (P < 0.05) in CAF compared with PLA. In CAF, plasma K(+) at the end of the Yo-Yo IR2 test was 5.2 ± 0.1 mmol/l with no difference between the trials. Plasma free fatty acids (FFA) were higher (P < 0.05) in CAF than PLA at rest and remained higher (P < 0.05) during exercise. Peak blood glucose (8.0 ± 0.6 vs. 6.2 ± 0.4 mmol/l) and plasma NH(3) (137.2 ± 10.8 vs. 113.4 ± 13.3 μmol/l) were also higher (P < 0.05) in CAF compared with PLA. In S2 interstitial K(+) was 5.5 ± 0.3, 5.7 ± 0.3, 5.8 ± 0.5, and 5.5 ± 0.3 mmol/l at the end of the 20-W and three 50-W periods, respectively, in CAF, which were lower (P < 0.001) than in CON (7.0 ± 0.6, 7.5 ± 0.7, 7.5 ± 0.4, and 7.0 ± 0.6 mmol/l, respectively). No differences in interstitial Na(+) were observed between CAF and CON. In conclusion, caffeine intake enhances fatigue resistance and reduces muscle interstitial K(+) during intense intermittent exercise.

  4. Improvements in Cycling but Not Handcycling 10 km Time Trial Performance in Habitual Caffeine Users

    PubMed Central

    Graham-Paulson, Terri; Perret, Claudio; Goosey-Tolfrey, Victoria

    2016-01-01

    Caffeine supplementation during whole-/lower-body exercise is well-researched, yet evidence of its effect during upper-body exercise is equivocal. The current study explored the effects of caffeine on cycling/handcycling 10 km time trial (TT) performance in habitual caffeine users. Eleven recreationally trained males (mean (SD) age 24 (4) years, body mass 85.1 (14.6) kg, cycling/handcycling peak oxygen uptake (V·peak) 42.9 (7.3)/27.6 (5.1) mL∙kg∙min−1, 160 (168) mg/day caffeine consumption) completed two maximal incremental tests and two familiarization sessions. During four subsequent visits, participants cycled/handcycled for 30 min at 65% mode-specific V·peak (preload) followed by a 10 km TT following the ingestion of 4 mg∙kg−1 caffeine (CAF) or placebo (PLA). Caffeine significantly improved cycling (2.0 (2.0)%; 16:35 vs. 16:56 min; p = 0.033) but not handcycling (1.8 (3.0)%; 24:10 vs. 24:36 min; p = 0.153) TT performance compared to PLA. The improvement during cycling can be attributed to the increased power output during the first and last 2 km during CAF. Higher blood lactate concentration (Bla) was reported during CAF compared to PLA (p < 0.007) and was evident 5 min post-TT during cycling (11.2 ± 2.6 and 8.8 ± 3.2 mmol/L; p = 0.001) and handcycling (10.6 ± 2.5 and 9.2 ± 2.9 mmol/L; p = 0.006). Lower overall ratings of perceived exertion (RPE) were seen following CAF during the preload (p < 0.05) but not post-TT. Lower peripheral RPE were reported at 20 min during cycling and at 30 min during handcycling, and lower central RPE was seen at 30 min during cycling (p < 0.05). Caffeine improved cycling but not handcycling TT performance. The lack of improvement during handcycling may be due to the smaller active muscle mass, elevated (Bla) and/or participants’ training status. PMID:27348000

  5. Fresh Pathways to Performance Management

    ERIC Educational Resources Information Center

    Foran, Colleen; Doylend, Colleen

    2004-01-01

    For anyone in a leadership position, responsible for the performance of others, there is always an obvious concern with the quality of the work performed and the adherence to the mission, vision, values and culture of the organization. Traditional methods of assuring quality performance include some form of performance appraisal, giving feedback…

  6. Designing Electronic Performance Support Systems.

    ERIC Educational Resources Information Center

    Barker, Philip; Banerji, Ashok

    1995-01-01

    Outlines the basic nature of performance support and describes a generic model that can be used to facilitate electronic performance support system (EPSS) development. Performance measures are discussed; performance support guidelines are summarized; and a case study of the use of an EPSS is presented. (LRW)

  7. The effects of creatine loading on thermoregulation and intermittent sprint exercise performance in a hot humid environment.

    PubMed

    Wright, Glenn A; Grandjean, Peter W; Pascoe, David D

    2007-08-01

    The purpose of this study was to determine the effects creatine (Cr) loading may have on thermoregulatory responses during intermittent sprint exercise in a hot/humid environment. Ten physically active, heat-acclimatized men performed 2 familiarization sessions of an exercise test consisting of a 30-minute low-intensity warm-up followed by 6 x 10 second maximal sprints on a cycle ergometer in the heat (35 degrees C, 60% relative humidity). Subjects then participated in 2 different weeks of supplementation. The first week, subjects ingested 5 g of a placebo (P, maltodextrin) in 4 flavored drinks (20 g total) per day for 6 days and were retested on day 7. The second week was similar to the first except a similar dose (4 x 5 g/day) of creatine monohydrate (Cr) replaced maltodextrin in the flavored drinks. Six days of Cr supplementation produced a significant increase in body weight (+1.30 +/- 0.63 kg), whereas the P did not (+0.11 +/- 0.52 kg). Compared to preexercise measures, the exercise test in the heat produced a significant increase in core temperature, a loss of body water determined by body weight change during exercise, and a relative change in plasma volume (%PVC); however, these were not significantly different between P and Cr. Sprint performance was enhanced by Cr loading. Peak power and mean power were significantly higher during the intermittent sprint exercise test following 6 days of Cr supplementation. It appears that ingestion of Cr for 6 days does not produce any different thermoregulatory responses to intermittent sprint exercise and may augment sprint exercise performance in the heat.

  8. Dairy-based preexercise meal does not affect gut comfort or time-trial performance in female cyclists.

    PubMed

    Haakonssen, Eric C; Ross, Megan L; Cato, Louise E; Nana, Alisa; Knight, Emma J; Jenkins, David G; Martin, David T; Burke, Louise M

    2014-10-01

    Some athletes avoid dairy in the meal consumed before exercise due to fears about gastrointestinal discomfort. Regular exclusion of dairy foods may unnecessarily reduce intake of high quality proteins and calcium with possible implications for body composition and bone health. This study compared the effects of meals that included (Dairy) or excluded (Control) dairy foods on gastric comfort and subsequent cycling performance. Well-trained female cyclists (n = 32; mean ± SD; 24.3 ± 4.1 y; VO(2peak) 57.1 ± 4.9 ml/kg/min) completed two trials (randomized cross-over design) in which they consumed a meal (2 g/kg carbohydrate and 54 kJ/kg) 2 hr before a 90-min cycle session (80 min at 60% maximal aerobic power followed by a 10-min time trial; TT). The dairy meal contained 3 servings of dairy foods providing ~1350 mg calcium. Gut comfort and palatability were measured using questionnaires. Performance was measured as maximum mean power during the TT (MMP10(min)). There was no statistical or clinical evidence of an effect of meal type on MMP10(min) with a mean difference (Dairy - Control) of 4 W (95% CI [-2, 9]). There was no evidence of an association between pretrial gut comfort and meal type (p = .15) or between gut comfort delta scores and meal type postmeal (p = .31), preexercise (p = .17) or postexercise (p = .80). There was no statistical or clinical evidence of a difference in palatability between meal types. In summary, substantial amounts of dairy foods can be included in meals consumed before strenuous cycling without impairing either gut comfort or performance.

  9. Effect of transportation duration of 1-day-old chicks on postplacement production performances and pododermatitis of broilers up to slaughter age.

    PubMed

    Bergoug, H; Guinebretière, M; Tong, Q; Roulston, N; Romanini, C E B; Exadaktylos, V; Berckmans, D; Garain, P; Demmers, T G M; McGonnell, I M; Bahr, C; Burel, C; Eterradossi, N; Michel, V

    2013-12-01

    This experiment studied the effect of transportation duration of 1-d-old chicks on dehydration, mortality, production performance, and pododermatitis during the growout period. Eggs from the same breeder flock (Ross PM3) were collected at 35, 45, and 56 wk of age, for 3 successive identical experiments. In each experiment, newly hatched chicks received 1 of 3 transportation duration treatments from the hatchery before placement in the on-site rearing facility: no transportation corresponding to direct placement in less than 5 min (T00), or 4 (T04) or 10 h (T10) of transportation. The chicks were housed in 35-m(2) pens (650 birds each) and reared until 35 d old. Hematocrit and chick BW were measured on sample chicks before and after transportation. During the growout period, bird weight, feed uptake, and feed conversion ratio were measured weekly until slaughter. Transportation duration affected BW; T00 groups had a significantly higher BW than T04 and T10 transported birds but this effect lasted only until d 21. No clear effect on hematocrit, feed uptake, feed conversion ratio, or mortality was observed for birds transported up to 10 h. The decrease in weight in T10 birds was associated with less severe pododermatitis. Increasing age of the breeder flock was correlated with reduced egg fertility and hatchability, and also with higher quality and BW of hatched chicks. Chicks from older breeders also exhibited reduced mortality during the growout period.

  10. Quantification of levoglucosan and its isomers by High Performance Liquid Chromatography - Electrospray Ionization tandem Mass Spectrometry and its applications to atmospheric and soil samples

    NASA Astrophysics Data System (ADS)

    Piot, C.; Jaffrezo, J.-L.; Cozic, J.; Pissot, N.; El Haddad, I.; Marchand, N.; Besombes, J.-L.

    2011-07-01

    The determination of atmospheric concentrations of levoglucosan and its two isomers, unambiguous tracers of biomass burning emissions, became even more important with the development of wood as renewable energy for domestic heating. Many researches demonstrated the increase during recent years of atmospheric particulate matter load due to domestic biomass combustion in developed countries. Analysis of biomass burning tracers is traditionally performed with Gas Chromatography-Mass Spectrometry (GC-MS) technique after derivatization and requires an organic solvent extraction. A simpler and faster technique using Liquid Chromatography - Electrospray Ionisation - tandem Mass Spectrometry (LC-ESI-MS/MS) was optimized for the analysis of levoglucosan, mannosan and galactosan isomers after an aqueous extraction. This technique allows a good separation between the three compounds in a very reduced time (runtime ~5 min). LOD and LOQ of this method are 30 μg l-1 and 100 μg l-1 respectively, allowing the use of filters from low-volume sampler (as commonly used in routine campaigns). A comparison of simultaneous levoglucosan measurements by GC-MS and LC-ESI-MS/MS for about 50 samples coming from different types of sampling sites and seasons was realized and shows very good agreement between the two methods. Therefore LC-ESI-MS/MS method can be used as an alternative to GC-MS particularly for measurement campaigns in routine where analysis time is important and detection limit is reduced. This paper shows that this method is also applicable to other environmental sample types like soil.

  11. Quantification of levoglucosan and its isomers by High Performance Liquid Chromatography - Electrospray Ionization tandem Mass Spectrometry and its applications to atmospheric and soil samples

    NASA Astrophysics Data System (ADS)

    Piot, C.; Jaffrezo, J.-L.; Cozic, J.; Pissot, N.; El Haddad, I.; Marchand, N.; Besombes, J.-L.

    2012-01-01

    The determination of atmospheric concentrations of levoglucosan and its two isomers, unambiguous tracers of biomass burning emissions, became even more important with the development of wood as renewable energy for domestic heating. Many researches demonstrated the increase during recent years of atmospheric particulate matter load due to domestic biomass combustion in developed countries. Analysis of biomass burning tracers is traditionally performed with Gas Chromatography-Mass Spectrometry (GC-MS) technique after derivatization and requires an organic solvent extraction. A simpler and faster technique using Liquid Chromatography - Electrospray Ionisation - tandem Mass Spectrometry (LC-ESI-MS/MS) was optimized for the analysis of levoglucosan, mannosan and galactosan isomers after an aqueous extraction. This technique allows a good separation between the three compounds in a very reduced time (runtime ~5 min). LOD and LOQ of this method are 30 μg l-1 and 100 μg l-1 respectively, allowing the use of filters from low-volume sampler (as commonly used in routine campaigns). A comparison of simultaneous levoglucosan measurements by GC-MS and LC-ESI-MS/MS for about 50 samples coming from different types of sampling sites and seasons was realized and shows very good agreement between the two methods. Therefore LC-ESI-MS/MS method can be used as an alternative to GC-MS particularly for measurement campaigns in routine where analysis time is important and detection limit is reduced. This paper shows that this method is also applicable to other environmental sample types like soil.

  12. Determination of MKT-077, a novel antineoplastic agent, in plasma samples by high-performance liquid chromatography and its application to pharmacokinetics in rats.

    PubMed

    Tatsuta, N; Suzuki, N; Koya, K; Kawakami, M; Shishido, T; Chen, L B

    1999-03-01

    A simple high-performance liquid chromatographic method was developed for determination of a novel antineoplastic agent MKT-077 in plasma. MKT-077 was extracted from 50 microl of plasma with acetonitrile containing 1 ml trifluoroacetic acid per liter. Chromatographic separation was achieved within 13.5 min using a reverse-phase Puresil C18 analytical column. A visible detector operated at 490 nm was used. The linearity of the calibration curve was obtained (r2 = 0.99986) over the analytical range of 10-500 ng/ml(-1). The intra- and inter-assay precision was in the range of 0.9-11.1 and 0.3-4.4%, respectively. The intra- and inter-assay bias ranged from -7.3 to 11.1% and from 0.4 to 11.6%, respectively. The utility of this assay was demonstrated after the administration of a single dose of MKT-077 to rats. The plasma elimination half-life of MKT-077 was 1.8-4 h.

  13. Determination of triazole fungicides in environmental water samples by high performance liquid chromatography with cloud point extraction using polyethylene glycol 600 monooleate.

    PubMed

    Tang, Tao; Qian, Kun; Shi, Tianyu; Wang, Fang; Li, Jianqiang; Cao, Yongsong

    2010-11-08

    A preconcentration technique known as cloud point extraction was developed for the determination of trace levels of triazole fungicides tricyclazole, triadimefon, tebuconazole and diniconazole in environmental waters. The triazole fungicides were extracted and preconcentrated using polyethylene glycol 600 monooleate (PEG600MO) as a low toxic and environmentally benign nonionic surfactant, and determined by high performance liquid chromatography/ultraviolet detection (HPLC-UV). The extraction conditions were optimized for the four triazole fungicides as follows: 2.0 wt% PEG600MO, 2.5 wt% Na(2)SO(4), equilibration at 45°C for 10 min, and centrifugation at 2000 rpm (533 × g) for 5 min. The triazole fungicides were well separated on a reversed-phase kromasil ODS C(18) column (250 mm × 4.6 mm, 5 μm) with gradient elution at ambient temperature and detected at 225 nm. The calibration range was 0.05-20 μg L(-1) for tricyclazole and 0.5-20 μg L(-1) for the other three classes of analytes with the correlation coefficients over 0.9992. Preconcentration factors were higher than 60-fold for the four selected fungicides. The limits of detection were 6.8-34.5 ng L(-1) (S/N=3) and the recoveries were 82.0-96.0% with the relative standard deviations of 2.8-7.8%.

  14. Ultra-performance liquid chromatography MS/MS method for the determination of parabens in compost from sewage sludge: comparison of the efficiency of two extraction techniques.

    PubMed

    Benítez-Villalba, Julio César; Zafra-Gómez, Alberto; Dorival-García, Noemí; Camino-Sánchez, Francisco Javier; Cantarero, Samuel; Vílchez, José Luis

    2013-08-01

    The efficiency of two extraction techniques--ultrasound-assisted extraction and pressurized liquid extraction--are compared and evaluated in the determination of parabens in compost samples. The extraction parameters for each technique were accurately optimized. The selected compounds were detected and quantified using ultra-performance LC MS/MS, operating in negative ESI and in SRM mode. The analytes were separated in less than 5 min. Ethylparaben (ring-(13)C6 labeled) was used as an internal standard. Two selective, sensitive, and accurate analytical methods were developed and validated. The LODs of the methods ranged from 3 to 7 ng/g and the LOQs from 10 to 23 ng/g, while inter- and intraday variability was under 6% in all cases. The methods were validated separately by using matrix-matched calibration and recovery assays with spiked samples. Recovery rates ranged from 94.0 to 105.0%. Compost samples were taken from different composting plants. Although the statistical comparison demonstrated no statistically significant differences between the two extraction techniques, the method based on pressurized liquid extraction was more sensitive than the ultrasound extraction based method.

  15. Simultaneous determination of six synthetic phenolic antioxidants in edible oils using dispersive liquid-liquid microextraction followed by high-performance liquid chromatography with diode array detection.

    PubMed

    Xu, Shuangjiao; Liu, Liangliang; Wang, Yanqin; Zhou, Dayun; Kuang, Meng; Fang, Dan; Yang, Weihua; Wei, Shoujun; Xiao, Aiping; Ma, Lei

    2016-08-01

    A simple, rapid, organic-solvent- and sample-saving pretreatment technique, called dispersive liquid-liquid microextraction, was developed for the determination of six synthetic phenolic antioxidants from edible oils before high-performance liquid chromatography with diode array detection. The entire procedure was composed of a two-step microextraction and a centrifugal process and could be finished in about 5 min, only consuming only 25 mg of sample and 1 mL of the organic solvent for each extraction. The influences of several important parameters on the microextraction efficiency were thoroughly investigated. Recovery assays for oil samples were spiked at three concentration levels, 50, 100 and 200 mg/kg, and provided recoveries in the 86.3-102.5% range with a relative standard deviation below 3.5%. The intra-day and inter-day precisions for the analysis were less than 3.8%. The proposed method was successfully applied for the determination of synthetic phenolic antioxidants in different oil samples, and satisfactory results were obtained. Thus, the developed method represents a viable alternative for the quality control of synthetic phenolic antioxidant concentrations in edible oils.

  16. Performance of chromID Clostridium difficile agar compared with BBL C. difficile selective agar for detection of C. difficile in stool specimens.

    PubMed

    Han, Sang Bong; Chang, Jiyoung; Shin, Sang Hyun; Park, Kang Gyun; Lee, Gun Dong; Park, Yong Gyu; Park, Yeon-Joon

    2014-09-01

    We evaluated the performance of a new chromogenic medium for detection of Clostridium difficile, chromID C. difficile agar (CDIF; bioMérieux, France), by comparison with BBL C. difficile Selective Agar (CDSA; Becton Dickinson and Company, USA). After heat pre-treatment (80℃, 5 min), 185 diarrheal stool samples were inoculated onto the two media types and incubated anaerobically for 24 hr and 48 hr for CDIF and for 48 hr and 72 hr for CDSA. All typical colonies on each medium were examined by Gram staining, and the gram-positive rods confirmed to contain the tpi gene by PCR were identified as C. difficile. C. difficile was recovered from 36 samples by using a combination of the two media. The sensitivity with CDIF 48 hr was highest (100%) and was significantly higher than that with CDIF 24 hr (58.3%; P<0.001), because samples with a low burden of C. difficile tended to require prolonged incubation up to 48 hr (P<0.001). The specificity of CDIF 24 hr and CDIF 48 hr (99.3% and 90.6%, respectively) was significantly higher than that of CDSA 48 hr and CDSA 72 hr (72.5% and 67.1%, respectively; P<0.001). CDIF was effective for detecting C. difficile in heat-pretreated stool specimens, thus reducing unnecessary testing for toxin production in non-C. difficile isolates and turnaround time.

  17. Simultaneous determination of steroidal and phenolic endocrine disrupting chemicals in fish by ultra-high-performance liquid chromatography-mass spectrometry/mass spectrometry.

    PubMed

    Ye, Aili; Yang, Yi; Zhang, Jing; Liu, Min; Hou, Lijun; Zhou, Jun Liang

    2013-02-22

    A sensitive and reliable analytical method based on pressurized liquid extraction (PLE) and ultra-high-performance liquid chromatography equipped with tandem mass spectrometry (UHPLC-MS/MS) has been developed for simultaneously determining the steroidal and phenolic endocrine disrupting chemicals (EDCs) in fish. The most effective extraction of the target EDCs is achieved by using PLE with on-line purification and the parameters have been optimized as follows: extraction solvent - methanol-acetonitrile (1:1, v/v), on-line purification material - 5 g alumina (5% water), extraction - 3 cycles, static extraction time - 5 min and extraction temperature - 60°C. Compared to the Oasis hydrophilic-lipophilic balance (HLB) solid phase extraction (SPE), freezing-lipid filtration combined with n-hexane defatting clean-up obtains much better recoveries of the target compounds and provide cleaner extracts. The matrix effect (ME) is generally eliminated by using an internal standard method. At spiking levels of 5, 50, and 100 ng/g, the mean recoveries vary from 71.2% to 108% for the target EDCs with a relative standard deviation (RSD) less than 16%. The method limit of detection (LOD) and limit of quantitation (LOQ) are 0.04-0.08 ng/gdw and 0.07-0.27 ng/gdw, respectively. The established method has been successfully applied to fish samples from the local market to determine the target EDCs.

  18. Simultaneous determination of salidroside and tyrosol in extracts of Rhodiola L. by microwave assisted extraction and high-performance liquid chromatography.

    PubMed

    Mao, Yu; Li, Yan; Yao, Ning

    2007-11-05

    Rhodiola L. has a long history of use in traditional Chinese medicine (TCM) and has shown great promise in recent clinical trials. Salidroside and tyrosol are two important active compounds present in this TCM. In this work, microwave-assisted extraction (MAE) followed by high performance liquid chromatography (HPLC) with a photodiode array detector (DAD) was developed for quantitative analysis of salidroside and tyrosol in Rhodiola L. samples. After systematical investigation, the optimal experimental parameters of soak time (60 min), extraction solvent volume (1g sample, 5 mL), extract solvent composition (50% methanol/water), microwave power (400 W) and extraction time (5 min) were investigated. The optimized method provided satisfactory precision (R.S.D. values less than 7.5%), good recovery (from 94.4 to 123%), and good linear relation in the range of 5.0-500 microg/mL for salidroside and 1.0-100 microg/mL for tyrosol (R2>0.999). The proposed method was applied to quantitative analysis of salidroside and tyrosol in Rhodiola L. samples from five different growing areas. To demonstrate the method feasibility, recirculation was also used to analyze salidroside and tyrosol in Rhodiola L. samples. The proposed MAE-HPLC-DAD is a simple, rapid and low-cost method for quantitative analysis of salidroside and tyrosol, and a potential tool for quality assessment of Rhodiola L. sample.

  19. Simultaneous determination of thiamethoxam, clothianidin, and metazachlor residues in soil by ultrahigh performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

    PubMed

    Valverde, Silvia; Ares, Ana M; Bernal, José Luis; Nozal, María Jesús; Bernal, José

    2017-03-01

    A rapid pioneering method has been developed to simultaneously determine residues of three pesticides (thiamethoxam, clothianidin, and metazachlor) in soil by ultrahigh performance liquid chromatography coupled to a mass spectrometry detector (quadrupole time-of-flight). An efficient extraction procedure (90-105% average analyte recoveries) has also been proposed, involving solid-liquid extraction by a mixture of water and methanol (60:40, v/v), centrifugation, and concentration. A chromatographic analysis of the compounds was achieved in 5.5 min by means of a core-shell technology based column (Kinetex(®) EVO C18 , 50 × 2.1 mm, 1.7 μm, 100 Å). The mobile phase (0.3 mL/min, gradient elution mode) consisted of 0.1% v/v formic acid in water and 0.1% v/v formic acid in acetonitrile. The method was fully validated in terms of selectivity, detection and quantification limits, matrix effect, linearity, trueness, and precision. Low limits of detection and quantification were obtained, ranging from 0.2 to 3.0 μg/kg, which are similar to those published in previous studies, while the absence of a significant matrix effect allowed quantification of the pesticides with standard calibration curves. The proposed method was applied for an analysis of pesticides in several soil samples from experimental fields dedicated to oilseed rape cultivars.

  20. Highly efficient hybrid solar cell using ZnO nanorods and assessment of changes in cell performance by varying the growth period

    NASA Astrophysics Data System (ADS)

    Mehrabian, Masood; Aslyousefzadeh, Sonya; Maleki, M. Hadi

    2015-05-01

    Zinc oxide nanorod arrays (ZnO NRs) were grown from ZnO seed-coated substrates in an aqueous solution by using the hydrothermal method for different growth periods varying from 5 min to 1 hour. The influence of the growth period of the ZnO nanorods on photovoltaic applications was studied in detail. Experimental results showed that utilization of the nanorod arrays lead to an enhanced the cell performance by increasing of light absorption and creation of a vertical direction for electron transport in the solar cells. A power conversion efficiency of 3.33% with an opencircuit voltage of V OC = 0.58 V, a short-circuit current of J SC = 10.05 mA/cm2 and a fill factor of FF = 54.35% was achieved for solar cells based on ZnO NRs with growth period of 20 min. Such solar cells with an optimal growth period are effective in light trapping, which leads to a significant enhancement in the absorption of light, and thereby, show an obvious increase in the power conversion efficiency.

  1. Size exclusion and reversed-phase high-performance liquid chromatography/UV for routine control of thermal processing of cows' and donkey milk major proteins.

    PubMed

    Pinho, Carina; Martins, Zita E; Petisca, Catarina; Figurska, Agata M; Pinho, Olívia; Ferreira, Isabel M P L V O

    2012-05-01

    Cows' and donkey milks (raw and thermally processed) and respective whey were analysed for quantification of major proteins. Two different chromatographic approaches, size exclusion (SE-HPLC) and reversed-phase high performance liquid chromatography (RP-HPLC) both coupled to UV detection were used. Usefulness of these methods for routine control of the effect of thermal processing was evaluated. The external standard method was used to calibrate the SE-HPLC and RP-HPLC systems. Concerning quantification of β-lactoglobulin (β-lg), α-lactalbumin (α-la), lysozyme (lys), and total casein (cn), no significant differences between results obtained by SE-HPLC and by RP-HPLC (t-test, P>0·05) were observed for raw milks and whey. Heating of cows' milk promoted aggregation of denatured proteins as observed by SE-HPLC, whereas α-la and β-lg from donkey milk were stable to thermal processing at 100 °C (5 min). Lys was quantified in donkey raw milk and whey however, in thermally processed donkey milk lys was denatured and could not be quantified by HPLC.

  2. Rapid and sensitive determination of levofloxacin in microsamples of human plasma by high-performance liquid chromatography and its application in a pharmacokinetic study.

    PubMed

    Aguilar-Carrasco, José Carlos; Hernández-Pineda, Jessica; Jiménez-Andrade, Juan Miguel; Flores-Murrieta, Francisco Javier; Carrasco-Portugal, Miriam Del Carmen; López-Canales, Jorge Skiold

    2015-03-01

    A rapid, sensitive and simple high-performance liquid chromatographic assay with ultraviolet detection was developed for the quantification of levofloxacin in microsamples (100 μL) of human plasma. The extraction procedure included a protein precipitation technique and a short chromatographic running time (4.5 min). Analyses were carried out on a Symmetry C18 column using a mixture of acetonitrile and 0.01 m potassium dihydrogen aqueous solution (pH 3.4; 14:86 v/v) as mobile phase. The method provided specificity and was linear (r ≥ 0.9992) over the concentration range 0.1-12 µg/mL. The average absolute recovery was 93.59%. The intra- and inter-day coefficients of variation were <6%. Additionally, levofloxacin was stable in all evaluations. The usefulness of this method was demonstrated in a pharmacokinetic study of levofloxacin in healthy adult volunteers. The present method offers two main advantages: (a) the use of microsamples reduces the total volume of blood to be collected from patients; and (b) it provides a good cost-effectiveness ratio. It is concluded that the method is rapid, simple, sensitive, economical and suitable for the determination of levofloxacin in human plasma using a small volume of sample.

  3. Research Performance Progress Report

    SciTech Connect

    Park, Hye -Sook

    2014-09-10

    The major goals of this project is to develop a suite of diagnostics to probe magnetic fields generated by the dynamics of high velocity interpenetrating plasma flows relevant to astrophysical collisionless shocks. Collisionless shocks are common in the universe and are responsible for decelerating and thermalizing supersonic plasma flows and accelerating a fraction of the incident particles to high energies. When high velocity, low density, plasma flows interact in astrophysics, turbulent electrostatic and electromagnetic waves are generated due to plasma instabilities, such as the Weibel instability. This can lead to localized pockets of very strong magnetic field generation. The net result is that the plasmas stagnate in what is called a collisionless shock. Understanding these enigmatic interactions requires well-controlled laboratory experiments able to validate the theory and the simulations. Time and spatially resolved magnetic field diagnostics are key to probing these frontier plasma dynamics, relevant to both astrophysics and laboratory applications of plasma physics. This project will enable us to develop the necessary diagnostics for this experiment on NIF. Our team has vast experience in performing laser experiments, theory, simulations and diagnostic development and is ideally suited for carrying out this work.

  4. High performance sapphire windows

    NASA Technical Reports Server (NTRS)

    Bates, Stephen C.; Liou, Larry

    1993-01-01

    High-quality, wide-aperture optical access is usually required for the advanced laser diagnostics that can now make a wide variety of non-intrusive measurements of combustion processes. Specially processed and mounted sapphire windows are proposed to provide this optical access to extreme environment. Through surface treatments and proper thermal stress design, single crystal sapphire can be a mechanically equivalent replacement for high strength steel. A prototype sapphire window and mounting system have been developed in a successful NASA SBIR Phase 1 project. A large and reliable increase in sapphire design strength (as much as 10x) has been achieved, and the initial specifications necessary for these gains have been defined. Failure testing of small windows has conclusively demonstrated the increased sapphire strength, indicating that a nearly flawless surface polish is the primary cause of strengthening, while an unusual mounting arrangement also significantly contributes to a larger effective strength. Phase 2 work will complete specification and demonstration of these windows, and will fabricate a set for use at NASA. The enhanced capabilities of these high performance sapphire windows will lead to many diagnostic capabilities not previously possible, as well as new applications for sapphire.

  5. ASTER DEM performance

    USGS Publications Warehouse

    Fujisada, H.; Bailey, G.B.; Kelly, Glen G.; Hara, S.; Abrams, M.J.

    2005-01-01

    The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument onboard the National Aeronautics and Space Administration's Terra spacecraft has an along-track stereoscopic capability using its a near-infrared spectral band to acquire the stereo data. ASTER has two telescopes, one for nadir-viewing and another for backward-viewing, with a base-to-height ratio of 0.6. The spatial resolution is 15 m in the horizontal plane. Parameters such as the line-of-sight vectors and the pointing axis were adjusted during the initial operation period to generate Level-1 data products with a high-quality stereo system performance. The evaluation of the digital elevation model (DEM) data was carried out both by Japanese and U.S. science teams separately using different DEM generation software and reference databases. The vertical accuracy of the DEM data generated from the Level-1A data is 20 m with 95% confidence without ground control point (GCP) correction for individual scenes. Geolocation accuracy that is important for the DEM datasets is better than 50 m. This appears to be limited by the spacecraft position accuracy. In addition, a slight increase in accuracy is observed by using GCPs to generate the stereo data.

  6. Performance of Waterless Concrete

    NASA Technical Reports Server (NTRS)

    Toutanji, Houssam; Evans, Steve; Grugel, Richard N.

    2010-01-01

    The development of permanent lunar bases is constrained by performance of construction materials and availability of in-situ resources. Concrete seems a suitable construction material for the lunar environment, but water, one of its major components, is an extremely scarce resource on the Moon. This study explores an alternative to hydraulic concrete by replacing the binding mix of concrete (cement and water) with sulfur. Sulfur is a volatile element on the lunar surface that can be extracted from lunar soils by heating. Sulfur concrete mixes were prepared to investigate the effect of extreme environmental conditions on the properties of sulfur concrete. A hypervelocity impact test was conducted, having as its target a 5-cm cubic sample of sulfur concrete. This item consisted of JSC-1 lunar regolith simulant (65%) and sulfur (35%). The sample was placed in the MSFC Impact Test Facility s Micro Light Gas Gun target chamber, and was struck by a 1-mm diameter (1.4e-03 g) aluminum projectile at 5.85 km/s. In addition, HZTERN code, provided by NASA was used to study the effectiveness of sulfur concrete when subjected to space radiation.

  7. Final Performance Report

    SciTech Connect

    Hsieh, S. T.

    2013-08-31

    U.S./China Energy and Environmental Technology Center (EETC), Payson Center for International Development, Law School of Tulane University was officially established in 1997 with initial funds from private sector, US Environmental Protection Agency and the US Department of Energy (DOE.) Lately, DOE has provided EETC funds for operations with cost share from the Ministry of Science and Technology, China. EETC was created to facilitate the development of friendly, broad-based U.S./China relations. Tulane University signed the Memorandum of Understanding (MOU) with the Chinese People’s Institute of Foreign Affairs (1995) to promote the formation of Chinese partners for EETC. EETC’s original goal is to enhance the competitiveness of US clean fossil energy technology in China so that, as her economy expands, local and global environment are well protected. Specifically, through the demonstration and broadly deployment of US developed clean coal technology for power generation, transmission, and emission reductions in China. EETC is also focused on US industry partnerships for local economic development. One of the main the objectives of the EETC is to promote the efficient, responsible production and utilization of energy with a focus on clean fossil energy, promote US clean energy and environmental technologies, and encourage environmental performance while improving the quality of life in China. Another objective is to assist China with environmental and energy policy development and provide supports for China’s development with expertise (best practices) from US industry.

  8. Biological Performance Assessment

    SciTech Connect

    2013-07-09

    The BioPA provides turbine designers with a set of tools that can be used to assess biological risks of turbines during the design phase, before expensive construction begins. The toolset can also be used to assess existing installations under a variety of operating conditions, supplementing data obtained through expensive field testing. The BioPA uses computational fluid dynamics (CFD) simulations of a turbine design to quantify the exposure of passing fish to a set of known injury mechanisms. By appropriate sampling of the fluid domain, the BioPA assigns exposure probabilities to each mechanism. The exposure probabilities are combined with dose-response data from laboratory stress studies of fish to produce a set of biological BioPA Scores. These metrics provide an objective measure that can be used to compare competing turbines or to refine a new design. The BioPA process can be performed during the turbine design phase and is considerably less expensive than prototype-scale field testing.

  9. Optimizing rotary drill performance

    SciTech Connect

    Schivley, G.P. Jr.

    1995-12-31

    Data is presented showing Penetration Rate (PR) versus Force-on-the-Bit (FB) and Bit Angular Speed (N). Using this data, it is shown how FB and N each uniquely contribute to the PR for any particular drilling situation. This data represents many mining situations; including coal, copper, gold, iron ore and limestone quarrying. The important relationship between Penetration per Revolution (P/R) and the height of the cutting elements of the bit (CH) is discussed. Drill performance is then reviewed, considering the effect of FB and N on bit life. All this leads to recommendations for the operating values of FB and N for drilling situations where the rock is not highly abrasive and bit replacements are because of catastrophic failure of the bit cone bearings. The contribution of compressed air to the drilling process is discussed. It is suggested that if the air issuing from the bit jets is supersonic that may enhance the sweeping of the hole bottom. Also, it is shown that not just uphole air velocity is enough to provide adequate transport of the rock cuttings up the annulus of a drilled hole. In addition, air volume flow rate must be considered to assure there is adequate particle spacing so the mechanism of aerodynamic drag can effectively lift the cuttings up and out of the hole annulus.

  10. Laser Lightcraft Performance

    NASA Technical Reports Server (NTRS)

    Chen, Yen-Sen; Liu, Jiwen; Wei, Hong

    2000-01-01

    The purpose of this study is to establish the technical ground for modeling the physics of laser powered pulse detonation phenomenon. The principle of the laser power propulsion is that when high-powered laser is focused at a small area near the surface of a thruster, the intense energy causes the electrical breakdown of the working fluid (e.g. air) and forming high speed plasma (known as the inverse Bremsstrahlung, IB, effect). The intense heat and high pressure created in the plasma consequently causes the surrounding to heat up and expand until the thrust producing shock waves are formed. This complex process of gas ionization, increase in radiation absorption and the forming of plasma and shock waves will be investigated in the development of the present numerical model. In the first phase of this study, laser light focusing, radiation absorption and shock wave propagation over the entire pulsed cycle are modeled. The model geometry and test conditions of known benchmark experiments such as those in Myrabo's experiment will be employed in the numerical model validation simulations. The calculated performance data will be compared to the test data.

  11. Determining structural performance

    NASA Technical Reports Server (NTRS)

    Ernst, Michael A. (Editor); Brown, Gerald; Dirusso, Eliseo; Fleming, David; Janetzke, David; Kascak, Albert; Kaza, Krishna; Kielb, Robert; Kiraly, Louis J.; Lawrence, Charles

    1990-01-01

    An overview of the methods and concepts developed to enhance and predict structural dynamic characteristics of advanced aeropropulsion systems is presented. Aeroelasticity, vibration control, dynamic systems, and computational structural methods are four disciplines that make up the structural dynamic effort at LeRC. The aeroelasticity program develops analytical and experimental methods for minimizing flutter and forced vibration of aerospace propulsion systems. Both frequency domain and time domain methods were developed for applications on the turbofan, turbopump, and advanced turboprop. In order to improve life and performance, the vibration control program conceives, analyzes, develops, and demonstrates new methods for controlling vibrations in aerospace systems. Active and passive vibration control is accomplished with electromagnetic dampers, magnetic bearings, and piezoelectric crystals to control rotor vibrations. The dynamic systems program analyzes and verifies the dynamics of interacting systems, as well as develops concepts and methods for high-temperature dynamic seals. Work in this field involves the analysis and parametric identification of large, nonlinear, damped, stochastic systems. The computational structural methods program exploits modern computer science as an aid to the solutions of structural problems.

  12. Influence of Prior Intense Exercise and Cold Water Immersion in Recovery for Performance and Physiological Response during Subsequent Exercise

    PubMed Central

    Christensen, Peter M.; Bangsbo, Jens

    2016-01-01

    Athletes in intense endurance sports (e.g., 4000-m track cycling) often perform maximally (~4 min) twice a day due to qualifying and finals being placed on the same day. The purpose of the present study was to evaluate repeated performance on the same day in a competitive setting (part A) and the influence from prior intense exercise on subsequent performance and physiological response to moderate and maximal exercise with and without the use of cold water immersion (CWI) in recovery (part B). In part A, performance times during eight World championships for male track cyclists were extracted from the qualifying and final races in 4000-m individual pursuit. In part B, twelve trained cyclists with an average (±SD) ⩒O2-peak of 67 ± 5 mL/min/kg performed a protocol mimicking a qualifying race (QUAL) followed 3 h later by a performance test (PT) with each exercise period encompassing intense exercise for ~4 min preceded by an identical warm-up period in both a control setting (CON) and using cold water immersion in recovery (CWI; 15 min at 15°C). Performance was lowered (P < 0.001) from qualification to finals (259 ± 3 vs. 261 ± 3 s) for the track cyclists during World championships in part A. In part B, mean power in PT was not different in CWI relative to CON (406 ± 43 vs. 405 ± 38 W). Peak ⩒O2 (5.04 ± 0.50 vs. 5.00 ± 0.49 L/min) and blood lactate (13 ± 3 vs. 14 ± 3 mmol/L) did not differ between QUAL and PT and cycling economy and potassium handling was not impaired by prior intense exercise. In conclusion, performance is reduced with repeated maximal exercise in world-class track cyclists during 4000-m individual pursuit lasting ~4 min, however prior intense exercise do not appear to impair peak ⩒O2, peak lactate, cycling economy, or potassium handling in trained cyclists and CWI in recovery does not improve subsequent performance. PMID:27445857

  13. Influence of Prior Intense Exercise and Cold Water Immersion in Recovery for Performance and Physiological Response during Subsequent Exercise.

    PubMed

    Christensen, Peter M; Bangsbo, Jens

    2016-01-01

    Athletes in intense endurance sports (e.g., 4000-m track cycling) often perform maximally (~4 min) twice a day due to qualifying and finals being placed on the same day. The purpose of the present study was to evaluate repeated performance on the same day in a competitive setting (part A) and the influence from prior intense exercise on subsequent performance and physiological response to moderate and maximal exercise with and without the use of cold water immersion (CWI) in recovery (part B). In part A, performance times during eight World championships for male track cyclists were extracted from the qualifying and final races in 4000-m individual pursuit. In part B, twelve trained cyclists with an average (±SD) ⩒O2-peak of 67 ± 5 mL/min/kg performed a protocol mimicking a qualifying race (QUAL) followed 3 h later by a performance test (PT) with each exercise period encompassing intense exercise for ~4 min preceded by an identical warm-up period in both a control setting (CON) and using cold water immersion in recovery (CWI; 15 min at 15°C). Performance was lowered (P < 0.001) from qualification to finals (259 ± 3 vs. 261 ± 3 s) for the track cyclists during World championships in part A. In part B, mean power in PT was not different in CWI relative to CON (406 ± 43 vs. 405 ± 38 W). Peak ⩒O2 (5.04 ± 0.50 vs. 5.00 ± 0.49 L/min) and blood lactate (13 ± 3 vs. 14 ± 3 mmol/L) did not differ between QUAL and PT and cycling economy and potassium handling was not impaired by prior intense exercise. In conclusion, performance is reduced with repeated maximal exercise in world-class track cyclists during 4000-m individual pursuit lasting ~4 min, however prior intense exercise do not appear to impair peak ⩒O2, peak lactate, cycling economy, or potassium handling in trained cyclists and CWI in recovery does not improve subsequent performance.

  14. Caffeine improves muscular performance in elite Brazilian Jiu-jitsu athletes.

    PubMed

    Diaz-Lara, Francisco Javier; Del Coso, Juan; García, Jose Manuel; Portillo, Luis J; Areces, Francisco; Abián-Vicén, Javier

    2016-11-01

    Scientific information about the effects of caffeine intake on combat sport performance is scarce and controversial. The aim of this study was to investigate the effectiveness of caffeine to improve Brazilian Jiu-jitsu (BJJ)-specific muscular performance. Fourteen male and elite BJJ athletes (29.2 ± 3.3 years; 71.3 ± 9.1 kg) participated in a randomized double-blind, placebo-controlled and crossover experiment. In two different sessions, BJJ athletes ingested 3 mg kg(-1) of caffeine or a placebo. After 60 min, they performed a handgrip maximal force test, a countermovement jump, a maximal static lift test and bench-press tests consisting of one-repetition maximum, power-load, and repetitions to failure. In comparison to the placebo, the ingestion of the caffeine increased: hand grip force in both hands (50.9 ± 2.9 vs. 53.3 ± 3.1 kg; respectively p < .05), countermovement jump height (40.6 ± 2.6 vs. 41.7 ± 3.1 cm; p = .02), and time recorded in the maximal static lift test (54.4 ± 13.4 vs. 59.2 ± 11.9 s; p < .01).The caffeine also increased the one-repetition maximum (90.5 ± 7.7 vs. 93.3 ± 7.5 kg; p = .02), maximal power obtained during the power-load test (750.5 ± 154.7 vs. 826.9 ± 163.7 W; p < .01) and mean power during the bench-press exercise test to failure (280.2 ± 52.5 vs. 312.2 ± 78.3 W; p = .04). In conclusion, the pre-exercise ingestion of 3 mg kg(-1) of caffeine increased dynamic and isometric muscular force, power, and endurance strength in elite BJJ athletes. Thus, caffeine might be an effective ergogenic aid to improve physical performance in BJJ.

  15. Sildenafil does not improve steady state cardiovascular hemodynamics, peak power, or 15-km time trial cycling performance at simulated moderate or high altitudes in men and women.

    PubMed

    Kressler, Jochen; Stoutenberg, Mark; Roos, Bernard A; Friedlander, Anne L; Perry, Arlette C; Signorile, Joseph F; Jacobs, Kevin A

    2011-12-01

    Sildenafil improves oxygen delivery and maximal exercise capacity at very high altitudes (≥ 4,350 m), but it is unknown whether sildenafil improves these variables and longer-duration exercise performance at moderate and high altitudes where competitions are more common. The purpose of this study was to determine the effects of sildenafil on cardiovascular hemodynamics, arterial oxygen saturation (SaO(2)), peak exercise capacity (W (peak)), and 15-km time trial performance in endurance-trained subjects at simulated moderate (MA; ~2,100 m, 16.2% F(I)O(2)) and high (HA; ~3,900 m, 12.8% F(I)O(2)) altitudes. Eleven men and ten women completed two HA W (peak) trials after ingesting placebo or 50 mg sildenafil. Subjects then completed four exercise trials (30 min at 55% of altitude-specific W (peak) + 15-km time trial) at MA and HA after ingesting placebo or 50 mg sildenafil. All trials were performed in randomized, counterbalanced, and double-blind fashion. Sildenafil had little influence on cardiovascular hemodynamics at MA or HA, but did result in higher SaO(2) values (+3%, p < 0.05) compared to placebo during steady state and time trial exercise at HA. W (peak) at HA was 19% lower than SL (p < 0.001) and was not significantly affected by sildenafil. Similarly, the significantly slower time trial performance at MA (28.1 ± 0.5 min, p = 0.016) and HA (30.3 ± 0.6 min, p < 0.001) compared to SL (27.5 ± 0.6 min) was unaffected by sildenafil. We conclude that sildenafil is unlikely to exert beneficial effects at altitudes <4,000 m for a majority of the population.

  16. Using Technical Performance Measures

    NASA Technical Reports Server (NTRS)

    Garrett, Christopher J.; Levack, Daniel J. H.; Rhodes, Russel E.

    2011-01-01

    All programs have requirements. For these requirements to be met, there must be a means of measurement. A Technical Performance Measure (TPM) is defined to produce a measured quantity that can be compared to the requirement. In practice, the TPM is often expressed as a maximum or minimum and a goal. Example TPMs for a rocket program are: vacuum or sea level specific impulse (lsp), weight, reliability (often expressed as a failure rate), schedule, operability (turn-around time), design and development cost, production cost, and operating cost. Program status is evaluated by comparing the TPMs against specified values of the requirements. During the program many design decisions are made and most of them affect some or all of the TPMs. Often, the same design decision changes some TPMs favorably while affecting other TPMs unfavorably. The problem then becomes how to compare the effects of a design decision on different TPMs. How much failure rate is one second of specific impulse worth? How many days of schedule is one pound of weight worth? In other words, how to compare dissimilar quantities in order to trade and manage the TPMs to meet all requirements. One method that has been used successfully and has a mathematical basis is Utility Analysis. Utility Analysis enables quantitative comparison among dissimilar attributes. It uses a mathematical model that maps decision maker preferences over the tradeable range of each attribute. It is capable of modeling both independent and dependent attributes. Utility Analysis is well supported in the literature on Decision Theory. It has been used at Pratt & Whitney Rocketdyne for internal programs and for contracted work such as the J-2X rocket engine program. This paper describes the construction of TPMs and describes Utility Analysis. It then discusses the use of TPMs in design trades and to manage margin during a program using Utility Analysis.

  17. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more that two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  18. 24 CFR 115.206 - Performance assessments; Performance standards.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Performance assessments; Performance standards. 115.206 Section 115.206 Housing and Urban Development Regulations Relating to Housing... AGENCIES Certification of Substantially Equivalent Agencies § 115.206 Performance assessments;...

  19. 24 CFR 115.206 - Performance assessments; Performance standards.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Performance assessments; Performance standards. 115.206 Section 115.206 Housing and Urban Development Regulations Relating to Housing... AGENCIES Certification of Substantially Equivalent Agencies § 115.206 Performance assessments;...

  20. Music Performance Trust Funds: Bringing Professional Performances to School.

    ERIC Educational Resources Information Center

    Patchen, Jeffrey H.

    1985-01-01

    The Music Performance Trust Funds (MPTF) is a national agency that sponsors live musical performances in schools, hospitals, clinics, senior citizen centers, penal institutions, and the like. In this interview a trustee for MPTF talks about the group's history and its commitment to quality performances in the schools. (RM)

  1. Performance Evaluation and the Internet 2 Performance Initiative.

    ERIC Educational Resources Information Center

    Simco, Greg

    2001-01-01

    Explains the Internet 2 collaborative end-to-end performance initiative that focuses on performance measurement, analysis, and improvements that lead to a standard set of network capabilities and limitations. Discusses results of this performance initiative, including providing direction for current and future network development. (Author/LRW)

  2. Analysis of some selected catechins and caffeine in green tea by high performance liquid chromatography.

    PubMed

    El-Shahawi, M S; Hamza, A; Bahaffi, S O; Al-Sibaai, A A; Abduljabbar, T N

    2012-10-15

    Green tea seems to have a positive impact on health due to the catechins-found as flavanols. Thus, the present study was aimed to develop a low cost reversed phase high performance liquid chromatographic (HPLC) method for simultaneous determination of flavanol contents, namely catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin 3-gallate (ECG) and epigallocatechin 3-gallate (EGCG) and caffeine in 29 commercial green tea samples available in a Saudi Arabian local market. A C-18 reversed-phase column, acetonitrile-trifluoroacetic acid as a mobile phase, coupled with UV detector at 205 nm, was successfully used for precise analysis of the tested analytes in boiled water of digested tea leaves. The average values of N (No. of theoretical plates), HETP (height equivalent of theoretical plates) and R(s) (separation factor) (at 10 μg ml(-1) of the catechins EC, EGC, EGCG and ECG) were 2.6×10(3)±1.2×10(3), 1.7×10(-3)±4.7×10(-4) cm and 1.7±5.53×10(-2), respectively. The developed HPLC method demonstrated excellent performance, with low limits of detection (LOD) and quantification (LOQ) of the tested catechins of 0.004-0.05 μg ml(-1) and 0.01-0.17 μg ml(-1), respectively, and recovery percentages of 96-101%. The influence of infusion time (5-30 min) and temperature on the content of the flavanols was investigated by HPLC. After a 5 min infusion of the tea leaves, the average concentrations of caffeine, catechin, EC, EGC, ECG and EGCG were found to be in the ranges 0.086-2.23, 0.113-2.94, 0.58-10.22, 0.19-24.9, 0.22-13.9 and 1.01-43.3 mg g(-1), respectively. The contents of caffeine and catechins followed the sequence: EGCG>EGC>ECG>EC>C>caffeine. The method was applied satisfactorily for the analysis of (+)-catechin, even at trace and ultra trace concentrations of catechins. The method was rapid, accurate, reproducible and ideal for routine analysis.

  3. Late-gestation heat stress abatement on performance and behavior of Holstein dairy cows.

    PubMed

    Karimi, M T; Ghorbani, G R; Kargar, S; Drackley, J K

    2015-10-01

    The objective of this study was to evaluate cooling to lessen the effects of heat stress during the last 3 wk of gestation on performance and behavior of multiparous Holstein cows. Twenty nonlactating cows were randomly assigned to treatments approximately 21 d before their expected calving date based on mature equivalent milk production and parity. Treatments were only imposed during the last 3 wk of gestation and included heat stress (HT; n=10) and cooling (CL; n=10), both under a similar photoperiod (14 h of light and 10 h of dark). Dry cows were housed in a sand-bedded stall with the stall areas for CL cows equipped with sprinklers and fans that were on from 0700 to 1900 h, whereas those for the HT cows were not. After parturition, all cows were housed in a barn with cooling devices. Rectal temperatures were measured daily at 1400 h and respiration rates were recorded by counting the flank movements for 1 min at 1500 h on odd days over the last 3 wk of gestation to calving. Daily dry matter intake was measured from -21 d relative to expected calving to 21 d after calving and milk production was recorded daily up to 180 d in milk. Behavioral changes of dry cows were studied continuously for 24 h at -10 d relative to expected calving. The average temperature-humidity index during the last 3 wk of gestation was 69.7 and was not significantly different between treatments. Heat-stressed cows exhibited greater rectal temperatures (39.5 vs. 39.2°C), greater respiration rates (70.4 vs. 63.3 breaths/min), and decreased dry matter intake (13.7 vs. 15.5 kg/d) compared with CL cows. Compared with HT cows, CL cows produced more milk during 180 d in milk (40.5 vs. 44.6 kg/d). Heat stress decreased ruminating (243.2 vs. 282.5 min/d) and chewing times (390.6 vs. 448.7 min/d) at -10 d before calving. The CL cows had shorter standing times than their HT counterparts (390.4 vs. 474.0 min/d). These results confirm that heat stress abatement in the late gestation period improves

  4. FY 2015 Annual Performance Report

    EPA Pesticide Factsheets

    Presents detailed performance results, as measured against the targets established in EPA’s FY 2015 Annual Plan and Budget. The Executive Overview section analyzes key performance outcomes and links to FY 2015 program evaluations.

  5. Annual Performance Report - FY 2011

    EPA Pesticide Factsheets

    This report summarizes OIG activity, performance, results, and challenges, and provides a financial accounting of resources for fiscal year (FY) 2011 compared to our FY 2011 annual performance targets.

  6. Supporting Reform through Performance Assessment.

    ERIC Educational Resources Information Center

    Kitchen, Richard; Cherrington, April; Gates, Joanne; Hitchings, Judith; Majka, Maria; Merk, Michael; Trubow, George

    2002-01-01

    Describes the impact of a performance assessment project on six teachers' teaching at Borel Middle School in the San Mateo/Foster City School District in California. Reports positive gains in student performance on the tasks over three years. (YDS)

  7. Trinity Acceptance Tests Performance Summary.

    SciTech Connect

    Rajan, Mahesh

    2015-12-01

    Ensuring Real Applications perform well on Trinity is key to success. Four components: ASC applications, Sustained System Performance (SSP), Extra-Large MiniApplications problems, and Micro-benchmarks.

  8. Prediction of ducted fan performance

    NASA Technical Reports Server (NTRS)

    Mendenhall, M. R.; Spangler, S. B.

    1972-01-01

    Computer program to predict performance of ducted fan combination at specified advance ratio and angle of attack is described. Parameters affecting performance of ducted fan are presented. Information obtained from computer program is explained for various conditions considered.

  9. Limits to Open Class Performance?

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H.

    2007-01-01

    This viewgraph presentation describes the limits to open class performance. The contents include: 1) Standard Class; 2) 15m/Racing Class; 3) Open Class; and 4) Design Solutions associated with assumptions, limiting parameters, airfoil performance, current trends, and analysis.

  10. Tough high performance composite matrix

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H. (Inventor); Johnston, Norman J. (Inventor)

    1994-01-01

    This invention is a semi-interpentrating polymer network which includes a high performance thermosetting polyimide having a nadic end group acting as a crosslinking site and a high performance linear thermoplastic polyimide. Provided is an improved high temperature matrix resin which is capable of performing in the 200 to 300 C range. This resin has significantly improved toughness and microcracking resistance, excellent processability, mechanical performance, and moisture and solvent resistances.

  11. Commoditization of High Performance Storage

    SciTech Connect

    Studham, Scott S.

    2004-04-01

    The commoditization of high performance computers started in the late 80s with the attack of the killer micros. Previously, high performance computers were exotic vector systems that could only be afforded by an illustrious few. Now everyone has a supercomputer composed of clusters of commodity processors. A similar commoditization of high performance storage has begun. Commodity disks are being used for high performance storage, enabling a paradigm change in storage and significantly changing the price point of high volume storage.

  12. Memory performance of Prolog architectures

    SciTech Connect

    Tick, E.

    1988-01-01

    Memory Performance of Prolog Architectures addresses these problems and reports dynamic data and instruction referencing characteristics of both sequential and parallel prolog architectures and corresponding uni-processor and multi-processor memory-hierarchy performance tradeoffs. Computer designers and logic programmers will find this work to be a valuable reference with many practical applications. Memory Performance of Prolog Architectures will also serve as an important textbook for graduate level courses in computer architecture and/or performance analysis.

  13. Performance of static positioning for medium distances based on data from a virtual reference station and ASG-PL Network

    NASA Astrophysics Data System (ADS)

    Bakula, M.

    The use of a network of reference stations instead of a single reference station allows the modelling of some systematic errors in a region and allows a user to increase the distance between the rover receiver and reference stations. In some countries, GPS reference stations exist and GPS observations are available for users in real-time mode and in post-processing. Observations from several GPS reference stations in a regional network enable modelling spatially-correlated errors and their modelling on an epoch-by-epoch and satellite-by-satellite basis. As a result, observations of a virtual reference station can be created at a rover's approximate position and its observations can be used in the precise baseline positioning of the rover. This paper presents the performance of the static positioning of a rover station, its quality and reliability for two different baselines. Single-baseline and network static solutions are presented and compared. Network solutions are based on data from a virtual reference station (VRS) obtained by the Wasoft/Virtuall software. In both cases, the same strategy of ambiguity resolution was used. These approaches have been tested with the use of 24-hour GPS data from the Polish Active Geodetic Network (ASG-PL). The data from three reference stations with medium-range separation were used in the process of generating VRS data. GPS data of the rover station were divided into 20, 10 and 5-min. sessions with a sampling interval of 5 sec. Practical calculations and analyses of horizontal and vertical accuracy of coordinates clearly show the improvement of static positioning in terms of time observation span and ambiguity reliability.

  14. Analysis of drugs of abuse in human plasma by dispersive liquid-liquid microextraction and high-performance liquid chromatography.

    PubMed

    Fernández, P; Regenjo, M; Bermejo, A M; Fernández, A M; Lorenzo, R A; Carro, A M

    2015-04-01

    Opioids and cocaine are widely used at present, both for recreational purposes and as drugs of abuse. This raises the need to develop new analytical methods specifically designed for the simultaneous detection of several drugs of abuse in biological samples. In this work, dispersive liquid-liquid microextraction (DLLME) was assessed as a new sample treatment for the simultaneous extraction of morphine (MOR), 6-acetylmorphine (6AM), cocaine (COC), benzoylecgonine (BZE) and methadone (MET) from human plasma. Preliminary assays were done before developing an experimental design based on a Uniform Network Doehlert which allowed the optimum extraction conditions to be identified, namely: a volume of extractant solvent (chloroform) and dispersant solvent (acetonitrile) of 220 µl and 3.2 ml, respectively; 0.2 g of NaCl as a salting-out additive; pH 10.6 and ultrasound stirring for 3.5 min. The resulting extracts were analyzed by high-performance liquid chromatography with photodiode array detection (HPLC-PDA), using an XBridge® RP18 column (250 × 4.6 mm i.d., 5 µm particle size). Calibration graphs were linear over the concentration range 0.1-10 µg ml⁻¹, and detection limits ranged from 13.9 to 28.5 ng ml⁻¹. Precision calculated at three different concentration levels in plasma was included in the range 0.1-6.8% RSD. Recoveries of the five drugs were all higher than 84% on average. Finally the proposed method was successfully applied to 22 plasma samples from heroin, cocaine and/or methadone users, and the most frequently detected drug was benzoylecgonine, followed by methadone, cocaine and morphine.

  15. Modelling Performance: Opening Pandora's Box.

    ERIC Educational Resources Information Center

    McNamara, T. F.

    1995-01-01

    This paper argues that it is necessary for researchers and test developers in the area of language performance testing to have a clear understanding of the role of underlying performance capacities in second language performance. It critically evaluates the models proposed by Hymes, Canale and Swain, and Bachman. (71 references) (MDM)

  16. Performance-Based Funding Brief

    ERIC Educational Resources Information Center

    Washington Higher Education Coordinating Board, 2011

    2011-01-01

    A number of states have made progress in implementing performance-based funding (PFB) and accountability. This policy brief summarizes main features of performance-based funding systems in three states: Tennessee, Ohio, and Indiana. The brief also identifies key issues that states considering performance-based funding must address, as well as…

  17. Creating an Expressive Performance Mindset

    ERIC Educational Resources Information Center

    Broomhead, Paul; Skidmore, Jon B.

    2014-01-01

    Students in performance situations sometimes experience physiological symptoms that inhibit their ability to perform as expressively as they otherwise might possess the understanding and ability to do. As students set out to perform with an expressive mindset, the brain's limbic system may detect some perceived danger in the situation and…

  18. Federal Supervisors and Poor Performers

    DTIC Science & Technology

    1999-07-01

    This report looks at the prevalence of poor performance in the Federal workplace from the perspective of employees and supervisors. The report also...examines what supervisors do about poor performers, the effects of supervisors’ actions, and the factors that influence supervisors’ decisions about how they will handle inadequate performance.

  19. Human Performance Technology and HRD

    ERIC Educational Resources Information Center

    Carliner, Saul

    2014-01-01

    Performance--the achievement of results--is central to definitions of HRD. Performance Technology (HPT) refers to a systematic methodology for developing performance in individuals and organizations. Through a systematic process, HPT explores issues at the organizational, unit, and individual level, and with skills and knowledge, resources, and…

  20. Diet Quality and Academic Performance

    ERIC Educational Resources Information Center

    Florence, Michelle D.; Asbridge, Mark; Veugelers, Paul J.

    2008-01-01

    Background: Although the effects of nutrition on health and school performance are often cited, few research studies have examined the effect of diet quality on the academic performance of children. This study examines the association between overall diet quality and academic performance. Methods: In 2003, 5200 grade 5 students in Nova Scotia,…

  1. Technology Performance Exchange (Fact Sheet)

    SciTech Connect

    Not Available

    2012-10-01

    This fact sheet, 'The Technology Performance Exchange' will be presented at the ET Summit, held at the Pasadena Convention Center on October 15-17, 2012. The Technology Performance Exchange will be a centralized, Web-based portal for finding and sharing energy performance data for commercial building technologies.

  2. Teaching as a Performing Art.

    ERIC Educational Resources Information Center

    Gillis, Don

    Teaching as a Performing Art is a teacher education program developed for the College of Education at the University of South Carolina. It is a methodology designed to elicit better teacher performance in order to produce more effective student performance. Designed for closed-circuit television or resource center access, the course consists of 52…

  3. Single and Combined Effects of Beetroot Crystals and Sodium Bicarbonate on 4-km Cycling Time Trial Performance.

    PubMed

    Callahan, Marcus J; Parr, Evelyn B; Hawley, John A; Burke, Louise M

    2016-11-11

    When ingested alone, beetroot juice and sodium bicarbonate are ergogenic for high-intensity exercise performance. This study sought to determine the independent and combined effects of these supplements. Eight endurance trained (V̇O2max 65 mL·kg·min(-1)) male cyclists completed four x 4-km time trials (TT) in a double-blind Latin square design supplementing with beetroot crystals (BC) for 3 days (15 g.day(-1) + 15 g 1 h prior to TT, containing 300 mg nitrate per 15 g), bicarbonate (Bi 0.3 g·kg(-1) body mass [BM] in 5 doses every 15 min from 2.5 h prior to TT); BC+Bi or placebo (PLA). Subjects completed TTs on a Velotron cycle ergometer under standardized lab conditions. Plasma nitrite concentrations were significantly elevated only in the BC+Bi trial prior to the TT (1520 ± 786 nmol.L(-1)) compared to baseline (665 ± 535 nmol.L(-1), p = 0.02) and the Bi and PLA conditions (Bi: 593 ± 203 nmol.L(-1), p < 0.01; PLA: 543 ± 369 nmol.L(-1), p< 0.01). Plasma nitrite concentrations were not elevated in the BC trial prior to the TT (1102 ± 218 nmol.L(-1)) compared to baseline (975 ± 607 nmol.L(-1), p > 0.05). Blood bicarbonate concentrations were increased in the BC+Bi and Bi trials prior to the TT (BC+Bi: 30.9 ± 2.8 mmol.L(-1); Bi: 31.7 ± 1.1 mmol.L(-1)). There were no differences in mean power output (386 - 394 W) or the time taken to complete the TT (335.8 - 338.1 s) between any conditions. Under the conditions of this study, supplementation was not ergogenic for 4-km TT performance.

  4. Effects of negative air ions on oxygen uptake kinetics, recovery and performance in exercise: a randomized, double-blinded study

    NASA Astrophysics Data System (ADS)

    Nimmerichter, Alfred; Holdhaus, Johann; Mehnen, Lars; Vidotto, Claudia; Loidl, Markus; Barker, Alan R.

    2014-09-01

    Limited research has suggested that acute exposure to negatively charged ions may enhance cardio-respiratory function, aerobic metabolism and recovery following exercise. To test the physiological effects of negatively charged air ions, 14 trained males (age: 32 ± 7 years; : 57 ± 7 mL min-1 kg-1) were exposed for 20 min to either a high-concentration of air ions (ION: 220 ± 30 × 103 ions cm-3) or normal room conditions (PLA: 0.1 ± 0.06 × 103 ions cm-3) in an ionization chamber in a double-blinded, randomized order, prior to performing: (1) a bout of severe-intensity cycling exercise for determining the time constant of the phase II response ( τ) and the magnitude of the slow component (SC); and (2) a 30-s Wingate test that was preceded by three 30-s Wingate tests to measure plasma [adrenaline] (ADR), [nor-adrenaline] (N-ADR) and blood [lactate] (BLac) over 20 min during recovery in the ionization chamber. There was no difference between ION and PLA for the phase II τ (32 ± 14 s vs. 32 ± 14 s; P = 0.7) or SC (404 ± 214 mL vs 482 ± 217 mL; P = 0.17). No differences between ION and PLA were observed at any time-point for ADR, N-ADR and BLac as well as on peak and mean power output during the Wingate tests (all P > 0.05). A high-concentration of negatively charged air ions had no effect on aerobic metabolism during severe-intensity exercise or on performance or the recovery of the adrenergic and metabolic responses after repeated-sprint exercise in trained athletes.

  5. Validity, Reliability, and Performance Determinants of a New Job-Specific Anaerobic Work Capacity Test for the Norwegian Navy Special Operations Command.

    PubMed

    Angeltveit, Andreas; Paulsen, Gøran; Solberg, Paul A; Raastad, Truls

    2016-02-01

    Operators in Special Operation Forces (SOF) have a particularly demanding profession where physical and psychological capacities can be challenged to the extremes. The diversity of physical capacities needed depend on the mission. Consequently, tests used to monitor SOF operators' physical fitness should cover a broad range of physical capacities. Whereas tests for strength and aerobic endurance are established, there is no test for specific anaerobic work capacity described in the literature. The purpose of this study was therefore to evaluate the reliability, validity, and to identify performance determinants of a new test developed for testing specific anaerobic work capacity in SOF operators. Nineteen active young students were included in the concurrent validity part of the study. The students performed the evacuation (EVAC) test 3 times and the results were compared for reliability and with performance in the Wingate cycle test, 300-m sprint, and a maximal accumulated oxygen deficit (MAOD) test. In part II of the study, 21 Norwegian Navy Special Operations Command operators conducted the EVAC test, anthropometric measurements, a dual x-ray absorptiometry scan, leg press, isokinetic knee extensions, maximal oxygen uptake test, and countermovement jump (CMJ) test. The EVAC test showed good reliability after 1 familiarization trial (intraclass correlation = 0.89; coefficient of variance = 3.7%). The EVAC test correlated well with the Wingate test (r = -0.68), 300-m sprint time (r = 0.51), and 300-m mean power (W) (r = -0.67). No significant correlation was found with the MAOD test. In part II of the study, height, body mass, lean body mass, isokinetic knee extension torque, maximal oxygen uptake, and maximal power in a CMJ was significantly correlated with performance in the EVAC test. The EVAC test is a reliable and valid test for anaerobic work capacity for SOF operators, and muscle mass, leg strength, and leg power seem to be the most important determinants

  6. Effect of creatine supplementation on metabolism and performance in humans during intermittent sprint cycling.

    PubMed

    Finn, J P; Ebert, T R; Withers, R T; Carey, M F; Mackay, M; Phillips, J W; Febbraio, M A

    2001-03-01

    This double blind study investigated the effect of oral creatine supplementation (CrS) on 4 x 20 s of maximal sprinting on an air-braked cycle ergometer. Each sprint was separated by 20 s of recovery. A group of 16 triathletes [mean age 26.6 (SD 5.1) years. mean body mass 77.0 (SD 5.8) kg, mean body fat 12.9 (SD 4.6)%, maximal oxygen uptake 4.86 (SD 0.7) l.min-1] performed an initial 4 x 20 s trial after a muscle biopsy sample had been taken at rest. The subjects were then matched on their total intramuscular creatine content (TCr) before being randomly assigned to groups to take by mouth either a creatine supplement (CRE) or a placebo (CON) before a second 4 x 20 s trial. A muscle biopsy sample was also taken immediately before this second trial. The CrS of 100 g comprised 4 x 5 g for 5 days. The initial mean TCr were 112.5 (SD 8.7) and 112.5 (SD 10.7) mmol.kg-1 dry mass for CRE and CON, respectively. After creatine loading and placebo ingestion respectively, CRE [128.7 (SD 11.8) mmol.kg-1 dry mass] had a greater (P = 0.01) TCr than CON [112.0 (SD 10.0) mmol.kg-1 dry mass]. While the increase in free creatine for CRE was statistically significant (P = 0.034), this was not so for the changes in phosphocreatine content [trial 1: 75.7 (SD 6.9), trial 2: 84.7 (SD 11.0) mmol.kg-1 dry mass, P = 0.091]. There were no significant differences between CRE and CON for citrate synthase activity (P = 0.163). There was a tendency towards improved performance in terms of 1 s peak power (in watts P = 0.07; in watts per kilogram P = 0.05), 5 s peak power (in watts P = 0.08) and fatigue index (P = 0.08) after CrS for sprint 1 of the second trial. However, there was no improvement for mean power (in watts P = 0.15; in watts per kilogram P = 0.1) in sprint 1 or for any performance values in subsequent sprints. Our results suggest that, while CrS elevates the intramuscular stores of free creatine, this does not have an ergogenic effect on 4 x 20 s all-out cycle sprints with

  7. Caffeine, but not bicarbonate, improves 6 min maximal performance in elite rowers.

    PubMed

    Christensen, Peter M; Petersen, Mads H; Friis, Signe N; Bangsbo, Jens

    2014-09-01

    This study examined the ergogenic effects in a 6 min maximal performance test (PT) on 12 elite rowers: 6 open-weight (mean ± SD; 25 ± 1 years, and 92 ± 3 kg) and 6 light-weight (25 ± 3 years, and 73 ± 6 kg), following supplementation with caffeine (CAF), sodium bicarbonate (SB), and the combination of both, in a double-blind randomized placebo (PLA) controlled design. PT was executed on 4 occasions, on separate days within a week, and in a non-fasted state, with standardized training being performed the day before PT. Protocols were as follows: (i) CAF, 3 mg/kg, 45 min prior to PT + calcium as SB-PLA; (ii) SB, 0.3 g/kg, 75 min prior to PT + dextrose as CAF-PLA; (iii) CAF + SB; and (iv) PLA; CAF-PLA + SB-PLA. The total distance in the CAF (1878 ± 97 m) and CAF + SB (1877 ± 97 m) was longer than in the PLA (1865 ± 104 m; P < 0.05) and SB (1860 ± 96 m; P < 0.01). The mean power in CAF (400 ± 58 W) and CAF + SB (400 ± 58 W) was higher than the PLA (393 ± 61 W; P < 0.05) and SB (389 ± 57 W; P < 0.01). In CAF and CAF + SB, power was higher (P < 0.05) relative to PLA in the last half (4-6 min) of PT. Trials with CAF were more effective in light-weight rowers (1.0% ± 0.8% improvement in distance; P < 0.05) than in open-weight rowers (0.3% ± 0.8%; P > 0.05). No difference between interventions was observed for readiness and stomach comfort before PT and perceived exertion during PT. This study demonstrates that caffeine ingestion does improve performance in elite rowing. In contrast sodium bicarbonate does not appear to be ergogenic, but it does not abolish the ergogenic effect of caffeine.

  8. Thermal Performance Data Services (TPDS)

    NASA Technical Reports Server (NTRS)

    French, Richard T.; Wright, Michael J.

    2013-01-01

    Initiated as a NASA Engineering and Safety Center (NESC) assessment in 2009, the Thermal Performance Database (TPDB) was a response to the need for a centralized thermal performance data archive. The assessment was renamed Thermal Performance Data Services (TPDS) in 2012; the undertaking has had two fronts of activity: the development of a repository software application and the collection of historical thermal performance data sets from dispersed sources within the thermal performance community. This assessment has delivered a foundational tool on which additional features should be built to increase efficiency, expand the protection of critical Agency investments, and provide new discipline-advancing work opportunities. This report contains the information from the assessment.

  9. HST Replacement Battery Initial Performance

    NASA Technical Reports Server (NTRS)

    Krol, Stan; Waldo, Greg; Hollandsworth, Roger

    2009-01-01

    The Hubble Space Telescope (HST) original Nickel-Hydrogen (NiH2) batteries were replaced during the Servicing Mission 4 (SM4) after 19 years and one month on orbit.The purpose of this presentation is to highlight the findings from the assessment of the initial sm4 replacement battery performance. The batteries are described, the 0 C capacity is reviewed, descriptions, charts and tables reviewing the State Of Charge (SOC) Performance, the Battery Voltage Performance, the battery impedance, the minimum voltage performance, the thermal performance, the battery current, and the battery system recharge ratio,

  10. Truss Performance and Packaging Metrics

    NASA Technical Reports Server (NTRS)

    Mikulas, Martin M.; Collins, Timothy J.; Doggett, William; Dorsey, John; Watson, Judith

    2006-01-01

    In the present paper a set of performance metrics are derived from first principals to assess the efficiency of competing space truss structural concepts in terms of mass, stiffness, and strength, for designs that are constrained by packaging. The use of these performance metrics provides unique insight into the primary drivers for lowering structural mass and packaging volume as well as enabling quantitative concept performance evaluation and comparison. To demonstrate the use of these performance metrics, data for existing structural concepts are plotted and discussed. Structural performance data is presented for various mechanical deployable concepts, for erectable structures, and for rigidizable structures.

  11. Determination of carnitine and acylcarnitines in human urine by means of microextraction in packed sorbent and hydrophilic interaction chromatography-ultra-high-performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Magiera, Sylwia; Baranowski, Jacek

    2015-05-10

    A method using semi-automatic microextraction by packed sorbent (eVol®-MEPS) and hydrophilic interaction chromatography-ultra-high-performance liquid chromatography-tandem mass spectrometry (HILIC-UHPLC-MS/MS) was described for the simultaneous determination of carnitine and acylcarnitines in human urine. The optimal conditions of MEPS extraction were obtained using C2 of M1 (C8+SCX) phase as a sorbent. Chromatographic separation of the analytes was achieved within 2.5min on Acquity UPLC BEH HILIC column using a gradient elution program with water containing 5mM ammonium acetate and acetonitrile as the mobile phase. The detection was performed on a triple-quadrupole tandem mass spectrometer in a positive ion mode via electrospray ionization (ESI). The linearity of the calibration curves for all compounds was found over a range from 0.1ng/mL to 500ng/mL. The method afforded satisfactory results in terms of sensitivity, specificity, precision, accuracy, recovery as well as stability of the analyte under various conditions. The method was used successfully for determination of carnitine and acylcarnitines in human urine.

  12. Simultaneous determination of three herbicides in wheat, wheat straw, and soil using a quick, easy, cheap, effective, rugged, and safe method with ultra high performance liquid chromatography and tandem mass spectrometry.

    PubMed

    Zhao, Huanhuan; Xu, Jun; Dong, Fengshou; Liu, Xingang; Wu, Yanbing; Wu, Xiaohu; Zheng, Yongquan

    2015-04-01

    In this study, a sensitive and effective analytical method for the extraction and detection of three herbicide residues (florasulam, fluroxypyr, and halauxifen-methyl) in wheat and soil was developed. Samples were extracted with acetonitrile/water followed by salting out, dispersive solid-phase extraction cleanup, and detection using ultra high performance liquid chromatography coupled with tandem mass spectrometry. The target analytes were detected within a 5 min runtime using an ultra high performance liquid chromatography high-strength silica trifunctional column connected to an electrospray ionization source in positive mode. The method was validated in five replicates at three fortification concentrations in each matrix. Adequate pesticide quantification and identity confirmation were attained, even at the lowest concentration levels. The method showed very good accuracy and precision. Good recoveries were observed for the three herbicides and mostly ranged between 75.8 and 114.6%, with intraday relative standard deviations <6.01% and interday relative standard deviations <4.02%. The limits of quantification ranged between 0.14 and 7.68 μg/kg for each herbicide. The method was successfully applied for the simultaneous analysis of the three herbicides in actual trial samples, and the results proved that the proposed method was effective in detecting these three herbicides.

  13. Fast determination of neonicotinoid insecticides in bee pollen using QuEChERS and ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

    PubMed

    Valverde, Silvia; Bernal, José Luis; Martín, María Teresa; Nozal, María Jesús; Bernal, José

    2016-10-01

    In this study, a new method has been developed to determine seven neonicotinoid insecticides (acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid and thiamethoxam) in bee pollen using ultra-high performance liquid chromatography coupled to a selective MS detector (qTOF). An efficient sample treatment involving an optimized quick, easy, cheap, effective, rugged and safe method was proposed. In all cases, average analyte recoveries were between 91 and 105%, and no matrix effect was observed. Chromatographic analysis (6.5 min) was performed on a core-shell technology based column (Kinetex® EVO C18 , 50×2.1 mm, 1.7 μm, 100 Å). The mobile phase consisted of 0.1% formic acid in water and 0.1% of formic acid in ACN, with a flow rate of 0.3 mL/min in gradient elution mode. The fully validated method was selective, linear from LOQ to 500 μg/kg, precise and accurate; relative standard deviation and relative error values were below 8%. Low limits LODs and LOQs were obtained, ranging from 0.6 to 1.3 μg/kg (LODs) and 2.1 to 4.0 μg/kg (LOQs). The method was applied to neonicotinoid analysis in several commercial bee pollen samples from different Spanish regions.

  14. Rapid residue analysis of oxathiapiprolin and its metabolites in typical Chinese soil, water, and sediments by a modified quick, easy, cheap, effective, rugged, and safe method with ultra high performance liquid chromatography and tandem mass spectrometry.

    PubMed

    Ju, Chao; Dong, Fengshou; Liu, Xingang; Wu, Xiaohu; Zhao, Huanhuan; Zheng, Yongquan; Xu, Jun

    2015-03-01

    A sensitive and effective method for the simultaneous determination of residues from a new fungicide, oxathiapiprolin, and its metabolites (IN-E8S72 and IN-WR791) in soil, water, and sediment, was developed using ultra high performance liquid chromatography with tandem mass spectrometry. Three compounds were extracted from water, soil, and sediment by using acetonitrile and different proportions of formic acid aqueous solution (1% v/v for water; 2% v/v for soil; and sediment), and were cleaned with octadecylsilane. The target compounds were determined within 5 min using an electrospray ionization source in the positive mode for oxathiapiprolin and in the negative mode for the two metabolites. The limits of quantification for all the three compounds were 0.1 μg/kg in water and 1 μg/kg in soil and sediment. Recovery studies were performed using three spiked levels (0.1, 1, and 10 μg/kg for water; 1, 10, and 50 μg/kg for soil and sediment). The overall average recoveries ranged from 64.8 to 112.7% with all intra- and interday relative standard deviation values below 19.4 and 19.1%, respectively. The method validation confirmed that the proposed method was convenient and reliable for determining residual oxathiapiprolin and its metabolites in soil, water, and sediments.

  15. Metabolism and performance during extended high-intensity intermittent exercise after consumption of low- and high-glycaemic index pre-exercise meals.

    PubMed

    Bennett, Christine B; Chilibeck, Philip D; Barss, Trevor; Vatanparast, Hassanali; Vandenberg, Albert; Zello, Gordon A

    2012-08-01

    The metabolic and performance benefits of prior consumption of low-glycaemic index (GI) meals v. high-GI meals were determined in extended high-intensity intermittent exercise. Participants (ten males and four females, aged 25·8 (sd 7·3) years) completed two testing days (each consisting of back-to-back 90-min intermittent high-intensity treadmill running protocols separated by 3 h) spaced by at least 7 d. Using a randomised counterbalanced cross-over design, low-GI, lentil-based meals (GI about 42) or high-GI, potato-based meals (GI about 78) matched for energy value were consumed 2 h before, and within 1 h after, the first exercise session. Performance was measured by the distance covered during five 1-min sprints (separated by 2·5 min walking) at the end of each exercise session. Peak postprandial blood glucose was higher by 30·8 % in the high-GI trial compared with the low-GI trial, as was insulin (P = 0·039 and P = 0·003, respectively). Carbohydrate oxidation was lower by 5·5 % during the low-GI trials compared with the high-GI trials at the start of the first exercise session (P < 0·05). Blood lactate was significantly higher (6·1 v. 2·6 mmol/l; P = 0·019) and blood glucose significantly lower (4·8 v. 5·4 mmol/l; P = 0·039) at the end of the second exercise session during the high-GI trial compared with the low-GI trial. Sprint distance was not significantly different between conditions. A low-GI meal improved the metabolic profile before and during extended high-intensity intermittent exercise, but did not affect performance. Improvements in metabolic responses when consuming low-GI meals before exercise may be beneficial to the long-term health of athletes.

  16. Social Memory Formation Rapidly and Differentially Affects the Motivation and Performance of Vocal Communication Signals in the Bengalese Finch (Lonchura striata var. domestica)

    PubMed Central

    Toccalino, Danielle C.; Sun, Herie; Sakata, Jon T.

    2016-01-01

    Cognitive processes like the formation of social memories can shape the nature of social interactions between conspecifics. Male songbirds use vocal signals during courtship interactions with females, but the degree to which social memory and familiarity influences the likelihood and structure of male courtship song remains largely unknown. Using a habituation-dishabituation paradigm, we found that a single, brief (<30 s) exposure to a female led to the formation of a short-term memory for that female: adult male Bengalese finches were significantly less likely to produce courtship song to an individual female when re-exposed to her 5 min later (i.e., habituation). Familiarity also rapidly decreased the duration of courtship songs but did not affect other measures of song performance (e.g., song tempo and the stereotypy of syllable structure and sequencing). Consistent with a contribution of social memory to the decrease in courtship song with repeated exposures to the same female, the likelihood that male Bengalese finches produced courtship song increased when they were exposed to a different female (i.e., dishabituation). Three consecutive exposures to individual females also led to the formation of a longer-term memory that persisted over days. Specifically, when courtship song production was assessed 2 days after initial exposures to females, males produced fewer and shorter courtship songs to familiar females than to unfamiliar females. Measures of song performance, however, were not different between courtship songs produced to familiar and unfamiliar females. The formation of a longer-term memory for individual females seemed to require at least three exposures because males did not differentially produce courtship song to unfamiliar females and females that they had been exposed to only once or twice. Taken together, these data indicate that brief exposures to individual females led to the rapid formation and persistence of social memories and support the

  17. Diurnal variations of plasma homocysteine, total antioxidant status, and biological markers of muscle injury during repeated sprint: effect on performance and muscle fatigue--a pilot study.

    PubMed

    Hammouda, Omar; Chtourou, Hamdi; Chahed, Henda; Ferchichi, Salyma; Kallel, Choumous; Miled, Abdelhedi; Chamari, Karim; Souissi, Nizar

    2011-12-01

    The aim of this study was (i) to evaluate whether homocysteine (Hcy), total antioxidant status (TAS), and biological markers of muscle injury would be affected by time of day (TOD) in football players and (ii) to establish a relationship between diurnal variation of these biomarkers and the daytime rhythm of power and muscle fatigue during repeated sprint ability (RSA) exercise. In counterbalanced order, 12 football (soccer) players performed an RSA test (5 x[6 s of maximal cycling sprint + 24 s of rest]) on two different occasions: 07:00-08:30 h and 17:00-18:30 h. Fasting blood samples were collected from a forearm vein before and 3-5 min after each RSA test. Core temperature, rating of perceived exertion, and performances (i.e., Sprint 1, Sprint 2, and power decrease) during the RSA test were significantly higher at 17:00 than 07:00 h (p < .001, p < .05, and p < .05, respectively). The results also showed significant diurnal variation of resting Hcy levels and all biological markers of muscle injury with acrophases (peak times) observed at 17:00 h. These fluctuations persisted after the RSA test. However, biomarkers of antioxidant status' resting levels (i.e., total antioxidant status, uric acid, and total bilirubin) were higher in the morning. This TOD effect was suppressed after exercise for TAS and uric acid. In conclusion, the present study confirms diurnal variation of Hcy, selected biological markers of cellular damage, and antioxidant status in young football players. Also, the higher performances and muscle fatigue showed in the evening during RSA exercise might be due to higher levels of biological markers of muscle injury and lower antioxidant status at this TOD.

  18. Total replacement of corn by mesquite pod meal considering nutritional value, performance, feeding behavior, nitrogen balance, and microbial protein synthesis of Holstein-Zebu crossbred dairy steers.

    PubMed

    de Oliveira Moraes, Gláucia Sabrine; de Souza, Evaristo Jorge Oliveira; Véras, Antonia Sherlânea Chaves; de Paula Almeida, Marina; da Cunha, Márcio Vieira; Torres, Thaysa Rodrigues; da Silva, Camila Sousa; Pereira, Gerfesson Felipe Cavalcanti

    2016-10-01

    The objective of the present study to assess the effects of mesquite pod addition replacing corn (0, 250, 500, 750, and 1000 g/kg in the dry matter basis) on nutrient intake, animal performance, feeding behavior, nutrient digestibility, nitrogen balance, and microbial protein synthesis. Twenty-five Holstein-Zebu crossbred dairy steers at 219 ± 22 kg initial body weight and 18 months of age were used. The experiment lasted 84 days, divided into three periods of 28 days. A completely randomized design was used, and data were submitted to analysis using PROC GLM for analysis of variance and PROC REG for regression analysis using the software Statistical Analysis Systems version 9.1. Experimental diets were composed of Tifton 85 hay, soybean meal, ground corn, mesquite pod meal, and mineral salt. Samples of food offered were collected during the last 3 days of each period, and the leftovers were collected daily, with samples bulked per week. At the end of each 28-day period, the remaining animals were weighed to determine total weight gain and average daily gain. The assessment of behavioral patterns was performed through instantaneous scans in 5-min intervals for three consecutive 12-h days. A single urine sample from each animal was collected on the last day of each collection period at about 4 h after the first feeding. The replacement of corn by mesquite pod meal did not significantly influence treatments regarding nutrients intake, animal performance, and feeding behavior. Retained and consumed nitrogen ratio did not statistically differ between replacement levels. Likewise, there were no statistical differences regarding microbial protein synthesis and efficiency between replacement levels. Mesquite pod meal can be used in Holstein-Zebu crossbred dairy steers' diet with total corn replacement.

  19. Visualizing Parallel Computer System Performance

    NASA Technical Reports Server (NTRS)

    Malony, Allen D.; Reed, Daniel A.

    1988-01-01

    Parallel computer systems are among the most complex of man's creations, making satisfactory performance characterization difficult. Despite this complexity, there are strong, indeed, almost irresistible, incentives to quantify parallel system performance using a single metric. The fallacy lies in succumbing to such temptations. A complete performance characterization requires not only an analysis of the system's constituent levels, it also requires both static and dynamic characterizations. Static or average behavior analysis may mask transients that dramatically alter system performance. Although the human visual system is remarkedly adept at interpreting and identifying anomalies in false color data, the importance of dynamic, visual scientific data presentation has only recently been recognized Large, complex parallel system pose equally vexing performance interpretation problems. Data from hardware and software performance monitors must be presented in ways that emphasize important events while eluding irrelevant details. Design approaches and tools for performance visualization are the subject of this paper.

  20. High Performance Computing at NASA

    NASA Technical Reports Server (NTRS)

    Bailey, David H.; Cooper, D. M. (Technical Monitor)

    1994-01-01

    The speaker will give an overview of high performance computing in the U.S. in general and within NASA in particular, including a description of the recently signed NASA-IBM cooperative agreement. The latest performance figures of various parallel systems on the NAS Parallel Benchmarks will be presented. The speaker was one of the authors of the NAS (National Aerospace Standards) Parallel Benchmarks, which are now widely cited in the industry as a measure of sustained performance on realistic high-end scientific applications. It will be shown that significant progress has been made by the highly parallel supercomputer industry during the past year or so, with several new systems, based on high-performance RISC processors, that now deliver superior performance per dollar compared to conventional supercomputers. Various pitfalls in reporting performance will be discussed. The speaker will then conclude by assessing the general state of the high performance computing field.

  1. Airfoil Design and Rotorcraft Performance

    NASA Technical Reports Server (NTRS)

    Bousman, William G.

    2003-01-01

    The relationship between global performance of a typical helicopter and the airfoil environment, as represented by the airfoil angles of attack and Mach number, has been examined using the comprehensive analysis CAMRAD II. A general correspondence is observed between global performance parameters, such as rotor L/D, and airfoil performance parameters, such as airfoil L/D, the drag bucket boundaries, and the divergence Mach number. Effects of design parameters such as blade twist and rotor speed variation have been examined and, in most cases, improvements observed in global performance are also observed in terms of airfoil performance. The relations observed between global Performance and the airfoil environment suggests that the emphasis in airfoil design should be for good L/D, while the maximum lift coefficient performance is less important.

  2. A Catalog of Performance Objectives, Performance Conditions, and Performance Guides for Machine Tool Operations.

    ERIC Educational Resources Information Center

    Stadt, Ronald; And Others

    This catalog provides performance objectives, tasks, standards, and performance guides associated with current occupational information relating to the job content of machinists, specifically tool grinder operators, production lathe operators, and production screw machine operators. The catalog is comprised of 262 performance objectives, tool and…

  3. Performance Basis for Airborne Separation

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    2008-01-01

    Emerging applications of Airborne Separation Assistance System (ASAS) technologies make possible new and powerful methods in Air Traffic Management (ATM) that may significantly improve the system-level performance of operations in the future ATM system. These applications typically involve the aircraft managing certain components of its Four Dimensional (4D) trajectory within the degrees of freedom defined by a set of operational constraints negotiated with the Air Navigation Service Provider. It is hypothesized that reliable individual performance by many aircraft will translate into higher total system-level performance. To actually realize this improvement, the new capabilities must be attracted to high demand and complexity regions where high ATM performance is critical. Operational approval for use in such environments will require participating aircraft to be certified to rigorous and appropriate performance standards. Currently, no formal basis exists for defining these standards. This paper provides a context for defining the performance basis for 4D-ASAS operations. The trajectory constraints to be met by the aircraft are defined, categorized, and assessed for performance requirements. A proposed extension of the existing Required Navigation Performance (RNP) construct into a dynamic standard (Dynamic RNP) is outlined. Sample data is presented from an ongoing high-fidelity batch simulation series that is characterizing the performance of an advanced 4D-ASAS application. Data of this type will contribute to the evaluation and validation of the proposed performance basis.

  4. 34 CFR 361.86 - Performance levels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Standards and Performance Indicators § 361.86 Performance levels. (a) General. (1) Paragraph (b) of this..., new performance levels. (b) Performance levels for each performance indicator. (1)(i) The performance levels for Performance Indicators 1.1 through 1.6 are— Performance indicator Performance level by type...

  5. Development of programmatic performance indicators

    SciTech Connect

    Olson, J.; Chockie, A.D.; Geisendorfer, C.L.; Vallario, R.W.; Mullen, M.F.

    1988-10-01

    This report summarizes a series of analyses of available plant performance data to determine if the data can be used to construct indicators of performance for several important plant functions. Data concerning the backlog of generic safety issues, operator examination scores, causes of events, and repeat equipment failures are reviewed and analyzed. The analysis indicates that generic safety issue backlog data can be used to assess some aspects of management performance. Operator exam scores do not appear to constitute good summary measures of the quality of training. Licensee Event Reports were found to be codable through the Sequence Coding and Search System into meaningful and useful cause codes for assessing performance in several programmatic areas. Available data on repeat equipment failures were found to be inadequate for establishing a clear measure of maintenance performance. The report concludes that additional data are necessary to assure the valid and reliable assessment of programmatic performance. 13 refs., 12 figs., 39 tabs.

  6. Communication variations and aircrew performance

    NASA Technical Reports Server (NTRS)

    Kanki, Barbara G.; Folk, Valerie G.; Irwin, Cheryl M.

    1991-01-01

    The relationship between communication variations and aircrew performance (high-error vs low-error performances) was investigated by analyzing the coded verbal transcripts derived from the videotape records of 18 two-person air transport crews who participated in a high-fidelity, full-mission flight simulation. The flight scenario included a task which involved abnormal operations and required the coordinated efforts of all crew members. It was found that the best-performing crews were characterized by nearly identical patterns of communication, whereas the midrange and poorer performing crews showed a great deal of heterogeneity in their speech patterns. Although some specific speech sequences can be interpreted as being more or less facilitative to the crew-coordination process, predictability appears to be the key ingredient for enhancing crew performance. Crews communicating in highly standard (hence predictable) ways were better able to coordinate their task, whereas crews characterized by multiple, nonstandard communication profiles were less effective in their performance.

  7. High Performance Flexible Thermal Link

    NASA Astrophysics Data System (ADS)

    Sauer, Arne; Preller, Fabian

    2014-06-01

    The paper deals with the design and performance verification of a high performance and flexible carbon fibre thermal link.Project goal was to design a space qualified thermal link combining low mass, flexibility and high thermal conductivity with new approaches regarding selected materials and processes. The idea was to combine the advantages of existing metallic links regarding flexibility and the thermal performance of high conductive carbon pitch fibres. Special focus is laid on the thermal performance improvement of matrix systems by means of nano-scaled carbon materials in order to improve the thermal performance also perpendicular to the direction of the unidirectional fibres.One of the main challenges was to establish a manufacturing process which allows handling the stiff and brittle fibres, applying the matrix and performing the implementation into an interface component using unconventional process steps like thermal bonding of fibres after metallisation.This research was funded by the German Federal Ministry for Economic Affairs and Energy (BMWi).

  8. Contribution of core body temperature, prior wake time, and sleep stages to cognitive throughput performance during forced desynchrony.

    PubMed

    Darwent, David; Ferguson, Sally A; Sargent, Charli; Paech, Gemma M; Williams, Louise; Zhou, Xuan; Matthews, Raymond W; Dawson, Drew; Kennaway, David J; Roach, Greg D

    2010-07-01

    Shiftworkers are often required to sleep at inappropriate phases of their circadian timekeeping system, with implications for the dynamics of ultradian sleep stages. The independent effects of these changes on cognitive throughput performance are not well understood. This is because the effects of sleep on performance are usually confounded with circadian factors that cannot be controlled under normal day/night conditions. The aim of this study was to assess the contribution of prior wake, core body temperature, and sleep stages to cognitive throughput performance under conditions of forced desynchrony (FD). A total of 11 healthy young adult males resided in a sleep laboratory in which day/night zeitgebers were eliminated and ambient room temperature, lighting levels, and behavior were controlled. The protocol included 2 training days, a baseline day, and 7 x 28-h FD periods. Each FD period consisted of an 18.7-h wake period followed by a 9.3-h rest period. Sleep was assessed using standard polysomnography. Core body temperature and physical activity were assessed continuously in 1-min epochs. Cognitive throughput was measured by a 5-min serial addition and subtraction (SAS) task and a 90-s digit symbol substitution (DSS) task. These were administered in test sessions scheduled every 2.5 h across the wake periods of each FD period. On average, sleep periods had a mean (+/- standard deviation) duration of 8.5 (+/-1.2) h in which participants obtained 7.6 (+/-1.4) h of total sleep time. This included 4.2 (+/-1.2) h of stage 1 and stage 2 sleep (S1-S2 sleep), 1.6 (+/-0.6) h of slow-wave sleep (SWS), and 1.8 (+/-0.6) h of rapid eye movement (REM) sleep. A mixed-model analysis with five covariates indicated significant fixed effects on cognitive throughput for circadian phase, prior wake time, and amount of REM sleep. Significant effects for S1-S2 sleep and SWS were not found. The results demonstrate that variations in core body temperature, time awake, and amount of

  9. Perform or Else: The Performative Enhancement of Teacher Professionalism

    ERIC Educational Resources Information Center

    Liew, Warren Mark

    2012-01-01

    The Singapore Ministry of Education's Enhanced Performance Management System (EPMS) was instituted in 2005 as a system of professional accountability to enhance the standards and stakes of teacher professionalism in schools. This essay explores how the EPMS, with its underlying paradigm of performance management, functions as a "technology of…

  10. Performing Leadership: Use of Performative Inquiry in Teaching Organizational Theories

    ERIC Educational Resources Information Center

    Nilson, Michelle; Fels, Lynn; Gopaul, Bryan

    2016-01-01

    This research explores the various ways in which performative inquiry was implemented in a graduate organizational theories course within an educational leadership cohort at a medium-sized urban Canadian research university. Drawing on Fink's framework for significant learning experiences, the researchers used performative inquiry to enact the…

  11. The Effect of Performance Support and Training as Performance Interventions

    ERIC Educational Resources Information Center

    Nguyen, Frank; Klein, James D.

    2008-01-01

    For decades, training has been one of the most common interventions used by organizations to improve the performance of their employees and teach them new ideas and skills. But owing to the cost of developing and delivering training, organizations have adopted alternative ways to enable employee performance while reducing the cost and minimizing…

  12. On Performance in Higher Education: Towards Performance Governance

    ERIC Educational Resources Information Center

    Sarrico, Claudia S.

    2010-01-01

    The paper has a conceptual nature, and will depart from the literatures on performance management in general and public management in particular and confront them with the literature on higher education studies. Higher education mirrors the developments of other sectors, such as the increasing interest in performance measurement and the continuous…

  13. Prediction of pump cavitation performance

    NASA Technical Reports Server (NTRS)

    Moore, R. D.

    1974-01-01

    A method for predicting pump cavitation performance with various liquids, liquid temperatures, and rotative speeds is presented. Use of the method requires that two sets of test data be available for the pump of interest. Good agreement between predicted and experimental results of cavitation performance was obtained for several pumps operated in liquids which exhibit a wide range of properties. Two cavitation parameters which qualitatively evaluate pump cavitation performance are also presented.

  14. High Performance Fortran: An overview

    SciTech Connect

    Zosel, M.E.

    1992-12-23

    The purpose of this paper is to give an overview of the work of the High Performance Fortran Forum (HPFF). This group of industry, academic, and user representatives has been meeting to define a set of extensions for Fortran dedicated to the special problems posed by a very high performance computers, especially the new generation of parallel computers. The paper describes the HPFF effort and its goals and gives a brief description of the functionality of High Performance Fortran (HPF).

  15. Performance Degradation of LSCF Cathodes

    SciTech Connect

    Alinger, Matthew

    2013-09-30

    This final report summarizes the progress made during the October 1, 2008 - September 30, 2013 period under Cooperative Agreement DE-NT0004109 for the U. S. Department of Energy/National Energy Technology Laboratory (USDOE/NETL) entitled “Performance Degradation of LSCF Cathodes”. The primary objective of this program is to develop a performance degradation mitigation path for high performing, cost-effective solid oxide fuel cells (SOFCs). Strategies to mitigate performance degradation are developed and implemented. In addition, thermal spray manufacturing of SOFCs is explored. Combined, this work establishes a basis for cost-effective SOFC cells.

  16. Lactate, fructose and glucose oxidation profiles in sports drinks and the effect on exercise performance.

    PubMed

    Azevedo, John L; Tietz, Emily; Two-Feathers, Tashena; Paull, Jeff; Chapman, Kenneth

    2007-09-26

    Exogenous carbohydrate oxidation was assessed in 6 male Category 1 and 2 cyclists who consumed CytoMax (C) or a leading sports drink (G) before and during continuous exercise (CE). C contained lactate-polymer, fructose, glucose and glucose polymer, while G contained fructose and glucose. Peak power output and VO2 on a cycle ergometer were 408+/-13 W and 67.4+/-3.2 mlO2 x kg(-1) x min(-1). Subjects performed 3 bouts of CE with C, and 2 with G at 62% VO2peak for 90 min, followed by high intensity (HI) exercise (86% VO(2)peak) to volitional fatigue. Subjects consumed 250 ml fluid immediately before (-2 min) and every 15 min of cycling. Drinks at -2 and 45 min contained 100 mg of [U-(13)C]-lactate, -glucose or -fructose. Blood, pulmonary gas samples and 13CO2 excretion were taken prior to fluid ingestion and at 5,10,15,30,45,60,75, and 90 min of CE, at the end of HI, and 15 min of recovery. HI after CE was 25% longer with C than G (6.5+/-0.8 vs. 5.2+/-1.0 min, P<0.05). 13CO2 from the -2 min lactate tracer was significantly elevated above rest at 5 min of exercise, and peaked at 15 min. 13CO2 from the -2 min glucose tracer peaked at 45 min for C and G. 13CO2 increased rapidly from the 45 min lactate dose, and by 60 min of exercise was 33% greater than glucose in C or G, and 36% greater than fructose in G. 13CO2 production following tracer fructose ingestion was greater than glucose in the first 45 minutes in C and G. Cumulative recoveries of tracer during exercise were: 92%+/-5.3% for lactate in C and 25+/-4.0% for glucose in C or G. Recoveries for fructose in C and G were 75+/-5.9% and 26+/-6.6%, respectively. Lactate was used more rapidly and to a greater extent than fructose or glucose. CytoMax significantly enhanced HI.

  17. Comparison of behaviour, performance and mortality in restricted and ad libitum-fed growing rabbits.

    PubMed

    Dalmau, A; Abdel-Khalek, A M; Ramon, J; Piles, M; Sanchez, J P; Velarde, A; Rafel, O

    2015-07-01

    The objective of this study was to determine whether rabbits fed in a restricted regimen (75%) showed increased competition for feeding, drinking and use of specific areas of the cages as compared with those provided feed ad libitum. This evaluation was carried out by measuring their space utilisation in the cage, the incidence of agonistic behaviour and rates of mortality. In total, 504 rabbits between 31 and 66 days of age were used in this study. A total of 200 heavy-weight rabbits and 56 light-weight rabbits were randomly housed in 32 cages, each cage containing eight rabbits: 25 cages housing heavy rabbits and seven cages housing the light-weight ones. They were all fed ad libitum (AD). In addition, a total of 208 heavy-weight rabbits and 40 light-weight rabbits were randomly housed in 31 cages, each of them containing eight rabbits: 26 cages housing heavy weight rabbits and five cages housing light-weight ones. They were all fed a restricted diet (R) regimen. The restriction was calculated to be 75% of the feed consumed by the AD group. The total space available in the cage was 3252 cm(2), with a stocking density of 24.6 animals/m(2). Animals between 32 and 60 days of age from 20 different cages were observed nine times per week (morning or afternoon) by means of scan and focal sampling by one observer. During each period, cages were assessed for 5 min, registering every minute the position of all the animals in relation to Area A (feeder), Area B (central part) or Area C (back and drinker area). The incidence of agonistic behaviour such as displacement, biting and jumping on each other was also assessed. Performance variables such as daily gain and feed conversion ratio, in addition to general health status and mortality rates, were recorded for all rabbits. When the rabbits were under restricted feeding, the competition for feed and drink increased with clear signs of agonistic behaviour such as biting, displacement and animals jumping on top of each other

  18. Warm-up effects on muscle oxygenation, metabolism and sprint cycling performance.

    PubMed

    Wittekind, Anna; Cooper, Chris E; Elwell, Clare E; Leung, Terence S; Beneke, Ralph

    2012-08-01

    To investigate the effects of warm-up intensity on all-out sprint cycling performance, muscle oxygenation and metabolism, 8 trained male cyclists/triathletes undertook a 30-s sprint cycling test preceded by moderate, heavy or severe warm up and 10-min recovery. Muscle oxygenation was measured by near-infrared spectroscopy, with deoxyhaemoglobin ([HHb]) during the sprint analysed with monoexponential models with time delay. Aerobic, anaerobic-glycolytic and phosphocreatine energy provision to the sprint were estimated from oxygen uptake and lactate production. Immediately prior to the sprint, blood [lactate] was different for each warm up and higher than resting for the heavy and severe warm ups (mod. 0.94 ± 0.36, heavy 1.92 ± 0.64, severe 4.37 ± 0.93 mmol l(-1) P < 0.05), although muscle oxygenation was equally raised above rest. Mean power during the sprint was lower following severe compared to moderate warm up (mod. 672 ± 54, heavy 666 ± 56, severe 655 ± 59 W, P < 0.05). The [HHb] kinetics during the sprint were not different among conditions, although the time delay before [HHb] increased was shorter for severe versus moderate warm up (mod. 5.8 ± 0.6, heavy 5.6 ± 0.9, severe 5.2 ± 0.7 s, P < 0.05). The severe warm up was without effect on estimated aerobic metabolism, but increased estimated phosphocreatine hydrolysis, the latter unable to compensate for the reduction in estimated anaerobic-glycolytic metabolism. It appears that despite all warm ups equally increasing muscle oxygenation, and indicators of marginally faster oxygen utilisation at the start of exercise following a severe-intensity warm up, other energy sources may not be able to fully compensate for a reduced glycolytic rate in sprint exercise with potential detrimental effects on performance.

  19. Evaluating and Improving Teacher Performance.

    ERIC Educational Resources Information Center

    Manatt, Richard P.

    This workbook, coordinated with Manatt Teacher Performance Evaluation (TPE) workshops, summarizes large group presentation in sequence with the transparancies used. The first four modules of the workbook deal with the state of the art of evaluating and improving teacher performance; the development of the TPE system, including selection of…

  20. Improving Reading Performance through Hypnosis.

    ERIC Educational Resources Information Center

    Fillmer, H. Thompson; And Others

    1981-01-01

    Describes a study investigating the effects of group hypnosis on the reading performance of university students in a reading and writing center. Discusses study procedures and presents data on pretest scores and gains in vocabulary and comprehension scores. Concludes that regular use of self-hypnosis significantly improved performance. (DMM)