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Sample records for maximal treadmill test

  1. Validation of a Maximal Incremental Skating Test Performed on a Slide Board: Comparison With Treadmill Skating.

    Science.gov (United States)

    Piucco, Tatiane; Diefenthaeler, Fernando; Soares, Rogério; Murias, Juan M; Millet, Guillaume Y

    2017-11-01

    To investigate the criterion validity of a maximal incremental skating test performed on a slide board (SB). Twelve subelite speed skaters performed a maximal skating test on a treadmill and on a SB. Gas exchange threshold (GET), respiratory compensation point (RCP), and maximal variables were determined. Oxygen uptake ([Formula: see text]) (31.0 ± 3.2 and 31.4 ± 4.1 mL·min -1 ·kg -1 ), percentage of maximal [Formula: see text] ([Formula: see text]) (66.3 ± 4 and 67.7 ± 7.1%), HR (153 ± 14 and 150 ±12 bpm), and ventilation (59.8 ± 11.8 and 57.0 ± 10.7 L·min -1 ) at GET, and [Formula: see text] (42.5 ± 4.4 and 42.9 ± 4.8 mL·min -1 ·kg -1 ), percentage of [Formula: see text] (91.1 ± 3.3 and 92.4 ± 2.1%), heart rate (HR) (178 ± 9 and 178 ± 6 bpm), and ventilation (96.5 ± 19.2 and 92.1 ± 12.7 L·min -1 ) at RCP were not different between skating on a treadmill and on a SB. [Formula: see text] (46.7 ± 4.4 vs 46.4 ±6.1 mL·min -1 ·kg -1 ) and maximal HR (195 ± 6 vs 196 ± 10 bpm) were not significantly different and correlated (r = .80 and r = .87, respectively; P  .8) with athletes' best times on 1500 m. The incremental skating test on a SB was capable to distinguish maximal ([Formula: see text] and HR) and submaximal ([Formula: see text], % [Formula: see text], HR, and ventilation) parameters known to determine endurance performance. Therefore, the SB test can be considered as a specific and practical alternative to evaluate speed skaters.

  2. Non-invasive coronary angiography for patients with acute atypical chest pain discharged after negative screening including maximal negative treadmill stress test. A prospective study.

    Science.gov (United States)

    Bonello, L; Armero, S; Jacquier, A; Com, O; Sarran, A; Sbragia, P; Panuel, M; Arques, S; Paganelli, F

    2009-05-01

    Among patients admitted in the emergency department for acute atypical chest pain those with an acute coronary syndrome (ACS) who are mistakenly discharged home have high mortality. A recent retrospective study has demonstrated that multislice computed tomography (MSCT) coronary angiography could improve triage of these patients. We aimed to prospectively confirm these data on patients with a negative screening including maximal treadmill stress. 30 patients discharged from the emergency department after negative screening for an ACS were included. All patients underwent MSCT angiography of the coronary artery. Patients with coronary atheroma on MSCT had an invasive coronary angiography to confirm these findings. Seven patients (23%) had obstructive coronary artery disease on MSCT. Invasive coronary angiography (ICA) confirmed the diagnosis in all patients. In patients with no previously known coronary artery disease admitted to the emergency department with atypical acute chest pain and discharged after negative screening, including maximal treadmill stress test, MSCT coronary angiography is useful for the diagnosis of obstructive coronary artery disease.

  3. Cardiac function and myocardial perfusion immediately following maximal treadmill exercise inside the MRI room

    Directory of Open Access Journals (Sweden)

    Ballinger Michelle R

    2008-01-01

    Full Text Available Abstract Treadmill exercise stress testing is an essential tool in the prevention, detection, and treatment of a broad spectrum of cardiovascular disease. After maximal exercise, cardiac images at peak stress are typically acquired using nuclear scintigraphy or echocardiography, both of which have inherent limitations. Although CMR offers superior image quality, the lack of MRI-compatible exercise and monitoring equipment has prevented the realization of treadmill exercise CMR. It is critical to commence imaging as quickly as possible after exercise to capture exercise-induced cardiac wall motion abnormalities. We modified a commercial treadmill such that it could be safely positioned inside the MRI room to minimize the distance between the treadmill and the scan table. We optimized the treadmill exercise CMR protocol in 20 healthy volunteers and successfully imaged cardiac function and myocardial perfusion at peak stress, followed by viability imaging at rest. Imaging commenced an average of 30 seconds after maximal exercise. Real-time cine of seven slices with no breath-hold and no ECG-gating was completed within 45 seconds of exercise, immediately followed by stress perfusion imaging of three short-axis slices which showed an average time to peak enhancement within 57 seconds of exercise. We observed a 3.1-fold increase in cardiac output and a myocardial perfusion reserve index of 1.9, which agree with reported values for healthy subjects at peak stress. This study successfully demonstrates in-room treadmill exercise CMR in healthy volunteers, but confirmation of feasibility in patients with heart disease is still needed.

  4. The Impact of Firefighter Personal Protective Equipment and Treadmill Protocol on Maximal Oxygen Uptake

    Science.gov (United States)

    Lee, Joo-Young; Bakri, Ilham; Kim, Jung-Hyun; Son, Su-Young; Tochihara, Yutaka

    2015-01-01

    This study investigated the effects of firefighter personal protective equipment (PPE) on the determination of maximal oxygen uptake (VO2max) while using two different treadmill protocols: a progressive incline protocol (PIP) and a progressive speed protocol (PSP), with three clothing conditions (Light-light clothing; Boots-PPE with rubber boots; Shoes-PPE with running shoes). Bruce protocol with Light was performed for a reference test. Results showed there was no difference in VO2max between Bruce Light, PIP Light, and PSP Light. However, VO2max was reduced in Boots and Shoes with shortened maximal performance time (7 and 6 min reduced for PIP Boots and Shoes, respectively; 11 and 9 min reduced for PSP Boots and Shoes, respectively), whereas the increasing rate of VO2 in Boots and Shoes during submaximal exercise was greater compared with Light. Wearing firefighter boots compared with wearing running shoes also significantly affected submaximal VO2 but not VO2max. These results suggest that firefighters’ maximal performance determined from a typical VO2max test without wearing PPE may overestimate the actual performance capability of firefighters wearing PPE. PMID:23668854

  5. Guinea pig maximization test

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner

    1985-01-01

    Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline...

  6. Does treadmill running performance, heart rate and breathing rate response during maximal graded exercise improve after volitional respiratory muscle training?

    Science.gov (United States)

    Radhakrishnan, K; Sharma, V K; Subramanian, S K

    2017-05-10

    Maximal physical exertion in sports usually causes fatigue in the exercising muscles, but not in the respiratory muscles due to triggering of the Respiratory muscle metabo-reflex, a sympathetic vasoconstrictor response leading to preferential increment in blood flow to respiratory muscles. 1 We planned to investigate whether a six week yogic pranayama based Volitional Respiratory Muscle Training (VRMT) can improve maximal Graded Exercise Treadmill Test (GXTT) performance in healthy adult recreational sportspersons. Consecutive, consenting healthy adult recreational sportspersons aged 20.56±2.49 years (n=30), volunteered to 'baseline recording' of resting heart rate (HR), blood pressure (BP), respiratory rate (RR), and Bruce ramp protocol maximal GXTT until volitional exhaustion providing total test time (TTT), derived VO2max, Metabolic Equivalent of Task (METs), HR and BP response during maximal GXTT and drop in recovery HR data. After six weeks of observation, they underwent 'pre-intervention recording' followed by supervised VRMT intervention for 6 weeks (30 minutes a day; 5 days a week) and then 'post-intervention recording'. Repeated measures ANOVA with pairwise t statistical comparison was used to analyse the data. After supervised VRMT, we observed significant decrease in their resting supine RR (prespiratory muscle aerobic capacity, attenuation of respiratory muscle metabo-reflex, increase in cardiac stroke volume and autonomic resetting towards parasympatho-dominance. Yogic Pranayama based VRMT can be used in sports conditioning programme of athletes to further improve their maximal exercise performance, and as part of rehabilitation training during return from injury.

  7. Graded Aerobic Treadmill Testing in Adolescent Traumatic Brain Injury Patients.

    Science.gov (United States)

    Cordingley, Dean M; Girardin, Richard; Morissette, Marc P; Reimer, Karen; Leiter, Jeff; Russell, Kelly; Ellis, Michael J

    2017-11-01

    To examine the safety and tolerability of clinical graded aerobic treadmill testing in recovering adolescent moderate and severe traumatic brain injury (TBI) patients referred to a multidisciplinary pediatric concussion program. We completed a retrospective case series of two moderate and five severe TBI patients (mean age, 17.3 years) who underwent initial Buffalo Concussion Treadmill Testing at a mean time of 71.6 days (range, 55-87) postinjury. Six patients completed one graded aerobic treadmill test each and one patient underwent initial and repeat testing. There were no complications. Five initial treadmill tests were completely tolerated and allowed an accurate assessment of exercise tolerance. Two initial tests were terminated early by the treatment team because of neurological and cardiorespiratory limitations. As a result of testing, two patients were cleared for aerobic exercise as tolerated and four patients were treated with individually tailored submaximal aerobic exercise programs resulting in subjective improvement in residual symptoms and/or exercise tolerance. Repeat treadmill testing in one patient performed after 1 month of treatment with submaximal aerobic exercise prescription was suggestive of improved exercise tolerance. One patient was able to tolerate aerobic exercise following surgery for posterior glottic stenosis. Preliminary results suggest that graded aerobic treadmill testing is a safe, well tolerated, and clinically useful tool to assess exercise tolerance in appropriately selected adolescent patients with TBI. Future prospective studies are needed to evaluate the effect of tailored submaximal aerobic exercise prescription on exercise tolerance and patient outcomes in recovering adolescent moderate and severe TBI patients.

  8. How many electrocardiographic leads are required for exercise treadmill tests

    International Nuclear Information System (INIS)

    Miller, T.D.; Desser, K.B.; Lawson, M.

    1987-01-01

    Forty-four consecutive patients who had perfusion defects on thallium-201 scanning and positive exercise treadmill tests were prospectively studied. Thirty-eight (86%) subjects had diagnostic ST segment changes in lead V5, 37 (84%) in lead V4, and 44 (100%) in either lead V4, V5 or both. Thirty patients had ST segment changes in the inferior leads, 20 in lead aVR, and only four in lead I and/or aVL. All of these latter subjects had diagnostic ST segments in lead V4 and/or V5. It is concluded that: combined electrocardiographic leads V4 and V5 detect the vast majority of ischemic changes during exercise treadmill testing, regardless of the site of perfusion defects detected by thallium-201 scanning; and monitoring the inferior and lateral leads rarely provides more diagnostic information

  9. Establishing a Practical Treadmill Sprint as an Alternative to the Wingate Anaerobic Test

    Science.gov (United States)

    McKie, Greg L.; Islam, Hashim; Townsend, Logan K.; Howe, Greg J.; Hazell, Tom J.

    2018-01-01

    This study examined the validity and reliability of a 30-second running sprint test using two non-motorized treadmills compared to the established Wingate Anaerobic Test. Twenty-four participants completed three sessions in a randomized order on a: (1) manual mode treadmill (Woodway); (2) specialized interval training treadmill (HiTrainer); and…

  10. Hemodynamic Changes After Static and Dynamic Exercises and Treadmill Stress Test; Different Patterns in Patients with Primary Benign Exertional Headache?

    Directory of Open Access Journals (Sweden)

    Mohsen Rostami

    2012-06-01

    Full Text Available The pathophysiology of primary benign exertional headache (EH is not still clearly defined. Some researchers have suggested an impaired vascular response as the etiology of this disorder. In this study we investigated whether there are any differences in blood pressure (BP and heart rate (HR of the subjects in course of the static and dynamic exercises and the treadmill stress test between those with and without EH. From university students, 22 patients with EH (mean age: 19.8 ± 2.10, Female to Male: 7:15 and 20 normal subjects (mean age: 19.3 ± 1.97, Female: Male: 8:12 were recruited. All the subjects performed the static and dynamic exercises at 30 and 20 percent of the maximal voluntary contraction (MVC and Bruce treadmill stress test according to the standard protocols. HR and BP of all the cases at the baseline and during and immediately after each test were measured. No significant difference was found between the mean rise of HR, systolic and diastolic BP of the subjects with and without EH in static and dynamic exercises and also treadmill stress test. It seems that between those with and without EH, there is no significant difference in rise of HR and BP response to static and dynamic exercises and treadmill stress test. Further studies are required to find the pathophysiology and risk factors of EH.

  11. Hemodynamic changes after static and dynamic exercises and treadmill stress test; different patterns in patients with primary benign exertional headache?

    Science.gov (United States)

    Kordi, Ramin; Mazaheri, Reza; Rostami, Mohsen; Mansournia, Mohammad Ali

    2012-01-01

    The pathophysiology of primary benign exertional headache (EH) is not still clearly defined. Some researchers have suggested an impaired vascular response as the etiology of this disorder. In this study we investigated whether there are any differences in blood pressure (BP) and heart rate (HR) of the subjects in course of the static and dynamic exercises and the treadmill stress test between those with and without EH. From university students, 22 patients with EH (mean age: 19.8 ± 2.10, Female to Male: 7:15) and 20 normal subjects (mean age: 19.3 ± 1.97, Female: Male: 8:12) were recruited. All the subjects performed the static and dynamic exercises at 30 and 20 percent of the maximal voluntary contraction (MVC) and Bruce treadmill stress test according to the standard protocols. HR and BP of all the cases at the baseline and during and immediately after each test were measured. No significant difference was found between the mean rise of HR, systolic and diastolic BP of the subjects with and without EH in static and dynamic exercises and also treadmill stress test. It seems that between those with and without EH, there is no significant difference in rise of HR and BP response to static and dynamic exercises and treadmill stress test. Further studies are required to find the pathophysiology and risk factors of EH.

  12. An electromyographic-based test for estimating neuromuscular fatigue during incremental treadmill running

    International Nuclear Information System (INIS)

    Camic, Clayton L; Kovacs, Attila J; Hill, Ethan C; Calantoni, Austin M; Yemm, Allison J; Enquist, Evan A; VanDusseldorp, Trisha A

    2014-01-01

    The purposes of the present study were two fold: (1) to determine if the model used for estimating the physical working capacity at the fatigue threshold (PWC FT ) from electromyographic (EMG) amplitude data during incremental cycle ergometry could be applied to treadmill running to derive a new neuromuscular fatigue threshold for running, and (2) to compare the running velocities associated with the PWC FT , ventilatory threshold (VT), and respiratory compensation point (RCP). Fifteen college-aged subjects (21.5  ±  1.3 y, 68.7  ±  10.5 kg, 175.9  ±  6.7 cm) performed an incremental treadmill test to exhaustion with bipolar surface EMG signals recorded from the vastus lateralis. There were significant (p < 0.05) mean differences in running velocities between the VT (11.3  ±  1.3 km h −1 ) and PWC FT (14.0  ±  2.3 km h −1 ), VT and RCP (14.0  ±  1.8 km h −1 ), but not the PWC FT and RCP. The findings of the present study indicated that the PWC FT model could be applied to a single continuous, incremental treadmill test to estimate the maximal running velocity that can be maintained prior to the onset of neuromuscular fatigue. In addition, these findings suggested that the PWC FT , like the RCP, may be used to differentiate the heavy from severe domains of exercise intensity. (paper)

  13. A Comparison of Aerobic Fitness Testing on a Swim Bench and Treadmill in a Recreational Surfing Cohort: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Hamzeh Khundaqji

    2018-06-01

    Full Text Available The intermittent manner of surfing accentuates the importance of both the aerobic and anaerobic energy systems. Currently, the optimal method of assessing surfing-specific aerobic fitness is using a swim bench (SWB ergometer; however, their limited availability presents a barrier to surfers wanting to know their maximal aerobic power (VO2peak. As a result, the aims of this pilot study were to determine the VO2peak of recreational surfers using a new commercial SWB ergometer and to propose and examine the feasibility of a regression model to predict SWB ergometer VO2peak values. A total of nine recreational surfers were assessed where body measurements were conducted followed by maximal aerobic capacity testing (swim bench and treadmill to profile the cohort. Findings demonstrated that VO2peak values were significantly greater (p < 0.001 on the treadmill compared to the SWB ergometer (M = 66.01 ± 8.23 vs. 37.41 ± 8.73 mL/kg/min. Peak heart rate was also significantly greater on the treadmill compared to the SWB ergometer. Multiple regression analysis was used to produce a model which predicted SWB VO2peak values with an R2 value of 0.863 and an adjusted R2 value of 0.726. The physiological profiling of the recreational cohort coupled with a surfer’s predicted SWB VO2peak value will allow for identification of surfing-specific aerobic fitness levels and evidence-based training recommendations.

  14. A comparison of VO2max and metabolic variables between treadmill running and treadmill skating.

    Science.gov (United States)

    Koepp, Kriston K; Janot, Jeffrey M

    2008-03-01

    The purpose of this study was to determine differences in VO2max and metabolic variables between treadmill running and treadmill skating. This study also examined VO2max responses during a continuous skating treadmill protocol and a discontinuous skating treadmill protocol. Sixteen male high school hockey players, who had a mean age of 16 +/- 1 years and were of an above-average fitness level, participated in this study. All subjects completed 4 exercise trials: a 1-hour skating treadmill familiarization trial, a treadmill running trial, and 2 randomized skating treadmill trials. Minute ventilation (VE), oxygen consumption VO2), carbon dioxide production VCO2), respiratory exchange ratio (RER), and heart rate were averaged every 15 seconds up to VO2max for each exercise test. The results showed that there was a significant difference (P skating treadmill protocol. There was also a significant difference for maximal RER between the discontinuous and continuous skating treadmill protocol and between the discontinuous skating treadmill protocol and running treadmill protocol. In conclusion, the running treadmill elicited a greater VO2max (mL.kg.min) than the skating treadmill did, but when it comes to specificity of ice skating, the skating treadmill may be ideal. Also, there was no significant difference between the discontinuous and continuous skating treadmill protocols. Therefore, a continuous protocol is possible on the skating treadmill without compromising correct skating position and physiologic responses. However, the continuous skating treadmill protocol should undergo validation before other scientists, coaches, and strength and conditioning professionals can apply it correctly.

  15. Freqüência cardíaca máxima em testes de exercício em esteira rolante e em cicloergômetro de membros inferiores Maximal heart rate in exercise tests on treadmill and in a cycloergometer of lower limbs

    Directory of Open Access Journals (Sweden)

    Claudio Gil Soares de Araújo

    2005-07-01

    Full Text Available OBJETIVO: Comparar, retrospectivamente, os valores de freqüência cardíaca máxima (FCM e o descenso da freqüência cardíaca no primeiro minuto da recuperação (dFC, obtidos em teste de exercício (TE realizados em dois ergômetros e momentos distintos. MÉTODOS: Sessenta indivíduos (29 a 80 anos de idade, submetidos a TE cardiopulmonar em ciclo de membros inferiores (CMI em nosso laboratório e que possuíam TE prévio (até 36 meses em esteira (EST em outros laboratórios, nas condições idênticas de medicações de ação cronotrópica negativa. RESULTADOS: FCM foi semelhante no CMI: 156±3 e EST: 154±2 bpm (p=0,125, enquanto o dFC foi maior em CMI: 33±2, EST: 26±3 bpm (média ± erro padrão da média (pOBJECTIVE: To compare, retrospectively, the values of maximum heart rate (MHR and the decrease of the heart rate at the first minute of recovery, which were obtained in an exercise test (ET performed in two different ergometers and at different moments. METHODS: Sixty individuals (from 29 to 80 years old, submitted to cardiopulmonary ET in a cycle of lower limbs (CLL in our laboratory and who had previous ET (up to 36 months in a treadmill (TRM in other laboratories, under identical conditions of medications of negative chronotropic action. RESULTS: MHR was similar in CLL: 156±3 and TRM: 154±2 bpm (p=0.125, whereas dHR was higher in CLL: 33±2, EST: 26±3 bpm (mean ± standard error of the mean (p<0.001. In hemodynamic variables studied, the systolic blood pressure and the double product were higher in the ET-CLL (p<0.001. The electrocardiogram (ECG was similar in both ETs, except due to more frequent supraventricular arrhythmias in CLL. CONCLUSION: a With some diligence from the examiner and previous knowledge of MHR in a previous ET it is possible to obtain high levels of MHR in an ET-CLL; b interrupting the MHR-based ET forecast through equations tends to lead to sub-maximum efforts; c dHR differs in active and passive

  16. Exercise testing of pre-school children using the Bruce treadmill protocol: new reference values

    NARCIS (Netherlands)

    M.H.M. van der Cammen-van Zijp (Monique); H. IJsselstijn (Hanneke); T. Takken (Tim); S.P. Willemsen (Sten); D. Tibboel (Dick); H.J. Stam (Henk); H.J.G. van den Berg-Emons (Rita)

    2010-01-01

    textabstractThe Bruce treadmill protocol is an often-used exercise test for children and adults. Few and mainly old normative data are available for young children. In this cross-sectional observational study we determined new reference values for the original Bruce protocol in children aged 4 and 5

  17. A prospective comparison of pedal ergometry with conventional treadmill testing in the investigation of lower extremity pain.

    LENUS (Irish Health Repository)

    Manning, B J

    2012-02-03

    BACKGROUND: Investigation of lower extremity pain is compromised by comorbid disorders that may interfere with conventional testing. AIMS: To compare pedal ergometry with conventional treadmill testing. METHODS: A prospective study was performed where patients presenting with a diagnosis of intermittent claudication were assessed by both methods of testing. RESULTS: Of 78 patients studied with both tests, no exercise-induced ankle pressure changes occurred in 26, two were unable to complete either test despite normal pressure measurements, while 24 had exercise-induced pressure drop detected by both tests. Of patients who completed pedal ergometry, 21 were unable to complete the treadmill test, 14 of whom had negative ergometry, while seven had a pressure drop detected by pedal ergometry. Three had pressure changes with pedal ergometry, but not with treadmill testing and two had pressure changes on the treadmill not reproduced by pedal ergometry. CONCLUSIONS: Pedal ergometer is more sensitive than treadmill testing in detecting arterial insufficiency, as indicated by a 20% or greater fall in ankle pressure, and more suitable in a subgroup of patients unable to tolerate conventional treadmill testing.

  18. Peak Cardiorespiratory Responses of Patients with Subacute Stroke During Land and Aquatic Treadmill Exercise.

    Science.gov (United States)

    Lee, Yong Ki; Kim, Bo Ryun; Han, Eun Young

    2017-05-01

    The aim of this work was to investigate the cardiorespiratory responses of patients with subacute stroke to exercise stress tests with aquatic and land treadmills. Twenty-one consecutive patients who presented with first-ever subacute stroke in 2013-2015. All subjects underwent symptom-limited incremental exercise testing with aquatic and land treadmills. Land treadmill speed started at 1.5 km/h and increased 0.5 km/h every 1 to 2 minutes until maximal tolerable speed was achieved. Thereafter, the grade was elevated by 2% every 2 minutes. In the aquatic treadmill test, subjects were submerged to the xiphoid in 28°C water. Treadmill speed started at 1.5 km/h and was increased 0.5 km/h every 2 minutes thereafter. Cardiorespiratory responses were recorded with aquatic and land treadmills. Compared to land treadmill exercise, aquatic treadmill exercise achieved significantly better peak VO2 (22.0 vs 20.0; P = 0.02), peak metabolic equivalents (6.3 vs 5.8; P = 0.02), and peak rating of perceived exertion (17.6 vs 18.4, P = 0.01). Heart rate and VO2 correlated significantly during both tests (land treadmill: r = 0.96, P aquatic treadmill: r = 0.99, P Aquatic treadmill exercise elicited significantly better peak cardiorespiratory responses than land treadmill exercise and may be as effective for early intensive aerobic training in subacute stroke patients.

  19. A comparison of two Shuttle launch and entry suits - Reach envelope, isokinetic strength, and treadmill tests

    Science.gov (United States)

    Schafer, Lauren E.; Rajulu, Sudhakar L.; Klute, Glenn K.

    1992-01-01

    A quantification has been conducted of any existing differences between the performance, in operational conditions, of the Space Shuttle crew Launch Entry Suit (LES) and the new Advanced Crew Escape Suit (ACES). While LES is a partial-pressure suit, the ACES system which is being considered as a replacement for LES is a full-pressure suit. Three tests have been conducted with six subjects to ascertain the suits' reach envelope, strength, and treadmill performance. No significant operational differences were found between the two suit designs.

  20. Metabolic and clinical comparative analysis of treadmill six-minute walking test and cardiopulmonary exercise testing in obese and eutrophic women

    Directory of Open Access Journals (Sweden)

    Luciana Di Thommazo-Luporini

    Full Text Available BACKGROUND: Impaired exercise tolerance is directly linked to decreased functional capacity as a consequence of obesity. OBJECTIVES: To analyze and compare the cardiopulmonary, metabolic, and perceptual responses during a cardiopulmonary exercise test (CPX and a treadmill six-minute walking test (tread6MWT in obese and eutrophic women. METHOD: Twenty-nine female participants, aged 20-45 years were included. Fourteen were allocated to the obese group and 15 to the eutrophic group. Anthropometric measurements and body composition assessment were performed. RESULTS: In both tests, obese women presented with significantly higher absolute oxygen uptake, minute ventilation, and systolic and diastolic blood pressure; they also presented with lower speed, distance walked, and oxygen uptake corrected by the weight compared to eutrophics. During the maximal exercise test, perceived dyspnea was greater and the respiratory exchange ratio was lower in obese subjects compared to eutrophics. During the submaximal test, carbon dioxide production, tidal volume, and heart rate were higher in obese subjects compared to eutrophic women. When analyzing possible correlations between the CPX and the tread6MWT at peak, there was a strong correlation for the variable heart rate and a moderate correlation for the variable oxygen uptake. The heart rate obtained in the submaximal test was able to predict the one obtained in the maximal test. Bland-Altman plots demonstrated the agreement between both tests to identify metabolic and physiological parameters at peak exercise. CONCLUSIONS: The six-minute walking test induced ventilatory, metabolic, and cardiovascular responses in agreement with the maximal testing. Thus, the six-minute walking test proves to be important for functional evaluation in the physical therapy routine.

  1. Maximal Strength Testing in Healthy Children.

    Science.gov (United States)

    Faigenbaum, Avery D.; Milliken, Laurie A.; Westcott, Wayne L.

    2003-01-01

    Evaluated the safety and efficacy of 1 repetition maximum (1RM) strength testing in healthy children age 6-12 years. Data were collected on 96 children who performed a 1RM test on one upper body and one lower body exercise using child-sized weight machines. Findings indicated that children could safely perform 1RM strength tests provided…

  2. Twitch interpolation technique in testing of maximal muscle strength

    DEFF Research Database (Denmark)

    Bülow, P M; Nørregaard, J; Danneskiold-Samsøe, B

    1993-01-01

    The aim was to study the methodological aspects of the muscle twitch interpolation technique in estimating the maximal force of contraction in the quadriceps muscle utilizing commercial muscle testing equipment. Six healthy subjects participated in seven sets of experiments testing the effects...

  3. The Oxidant-Antioxidant Equilibrium and Inflammatory Process Indicators after an Exercise Test on the AlterG Antigravity Treadmill in Young Amateur Female Athletes.

    Science.gov (United States)

    Sielski, Łukasz; Sutkowy, Paweł; Skopowska, Agnieszka; Pawlak-Osińska, Katarzyna; Augustyńska, Zofia; Hewelt, Katarzyna; Drapała, Radosław; Woźniak, Alina

    2018-01-01

    The AlterG antigravity treadmill allows running with a considerable weight reduction. Physical exercise practiced on this treadmill is an innovative method supporting the treatment of injuries in sports and rehabilitation of patients. The aim of the study was to investigate the effect of a 30 min run on the AlterG treadmill with 80% body weight reduction comparing the effect to the similar effort on the classic treadmill on the redox equilibrium and the activity of selected lysosomal enzymes and a serine protease inhibitor in the blood of amateur minor female volleyball players. Venous blood samples were taken before the exercise and 30 minutes and 24 hours after its completion. The obtained results were analysed using Tukey's test and Pearson's linear correlations were calculated. 24 h after the running test on classic treadmill, the erythrocytic superoxide dismutase activity was higher than before and 30 min after it, as well as compared to the run on AlterG treadmill ( p < 0.001). The erythrocytic-conjugated diene concentration 24 h after the exercise on the classic treadmill was meaningly higher compared to that after the exercise on the AlterG treadmill ( p < 0.001). The cathepsin D activity was significantly lower after the exercise in AlterG conditions compared to the baseline value and that measured after the exercise on classic treadmill ( p < 0.001). It seems that the exercise on the AlterG treadmill keeps the oxidant-antioxidant equilibrium and stabilizes lysosomal membranes in young, physically active women in contrast to the exercise on the classic treadmill. This trial is registered with CTRI/2018/01/011344.

  4. The Oxidant–Antioxidant Equilibrium and Inflammatory Process Indicators after an Exercise Test on the AlterG Antigravity Treadmill in Young Amateur Female Athletes

    Science.gov (United States)

    Sielski, Łukasz; Skopowska, Agnieszka; Pawlak-Osińska, Katarzyna; Augustyńska, Zofia; Hewelt, Katarzyna; Drapała, Radosław

    2018-01-01

    The AlterG antigravity treadmill allows running with a considerable weight reduction. Physical exercise practiced on this treadmill is an innovative method supporting the treatment of injuries in sports and rehabilitation of patients. The aim of the study was to investigate the effect of a 30 min run on the AlterG treadmill with 80% body weight reduction comparing the effect to the similar effort on the classic treadmill on the redox equilibrium and the activity of selected lysosomal enzymes and a serine protease inhibitor in the blood of amateur minor female volleyball players. Venous blood samples were taken before the exercise and 30 minutes and 24 hours after its completion. The obtained results were analysed using Tukey's test and Pearson's linear correlations were calculated. 24 h after the running test on classic treadmill, the erythrocytic superoxide dismutase activity was higher than before and 30 min after it, as well as compared to the run on AlterG treadmill (p < 0.001). The erythrocytic-conjugated diene concentration 24 h after the exercise on the classic treadmill was meaningly higher compared to that after the exercise on the AlterG treadmill (p < 0.001). The cathepsin D activity was significantly lower after the exercise in AlterG conditions compared to the baseline value and that measured after the exercise on classic treadmill (p < 0.001). It seems that the exercise on the AlterG treadmill keeps the oxidant–antioxidant equilibrium and stabilizes lysosomal membranes in young, physically active women in contrast to the exercise on the classic treadmill. This trial is registered with CTRI/2018/01/011344. PMID:29765494

  5. The Oxidant–Antioxidant Equilibrium and Inflammatory Process Indicators after an Exercise Test on the AlterG Antigravity Treadmill in Young Amateur Female Athletes

    Directory of Open Access Journals (Sweden)

    Łukasz Sielski

    2018-01-01

    Full Text Available The AlterG antigravity treadmill allows running with a considerable weight reduction. Physical exercise practiced on this treadmill is an innovative method supporting the treatment of injuries in sports and rehabilitation of patients. The aim of the study was to investigate the effect of a 30 min run on the AlterG treadmill with 80% body weight reduction comparing the effect to the similar effort on the classic treadmill on the redox equilibrium and the activity of selected lysosomal enzymes and a serine protease inhibitor in the blood of amateur minor female volleyball players. Venous blood samples were taken before the exercise and 30 minutes and 24 hours after its completion. The obtained results were analysed using Tukey’s test and Pearson’s linear correlations were calculated. 24 h after the running test on classic treadmill, the erythrocytic superoxide dismutase activity was higher than before and 30 min after it, as well as compared to the run on AlterG treadmill (p<0.001. The erythrocytic-conjugated diene concentration 24 h after the exercise on the classic treadmill was meaningly higher compared to that after the exercise on the AlterG treadmill (p<0.001. The cathepsin D activity was significantly lower after the exercise in AlterG conditions compared to the baseline value and that measured after the exercise on classic treadmill (p<0.001. It seems that the exercise on the AlterG treadmill keeps the oxidant–antioxidant equilibrium and stabilizes lysosomal membranes in young, physically active women in contrast to the exercise on the classic treadmill. This trial is registered with CTRI/2018/01/011344.

  6. Does the incremental shuttle walk test require maximal effort in young obese women?

    Directory of Open Access Journals (Sweden)

    S.P. Jürgensen

    2016-01-01

    Full Text Available Obesity is a chronic disease with a multifaceted treatment approach that includes nutritional counseling, structured exercise training, and increased daily physical activity. Increased body mass elicits higher cardiovascular, ventilatory and metabolic demands to varying degrees during exercise. With functional capacity assessment, this variability can be evaluated so individualized guidance for exercise training and daily physical activity can be provided. The aim of the present study was to compare cardiovascular, ventilatory and metabolic responses obtained during a symptom-limited cardiopulmonary exercise test (CPX on a treadmill to responses obtained by the incremental shuttle walk test (ISWT in obese women and to propose a peak oxygen consumption (VO2 prediction equation through variables obtained during the ISWT. Forty obese women (BMI ≥30 kg/m2 performed one treadmill CPX and two ISWTs. Heart rate (HR, arterial blood pressure (ABP and perceived exertion by the Borg scale were measured at rest, during each stage of the exercise protocol, and throughout the recovery period. The predicted maximal heart rate (HRmax was calculated (210 – age in years (16 and compared to the HR response during the CPX. Peak VO2 obtained during CPX correlated significantly (P<0.05 with ISWT peak VO2 (r=0.79 as well as ISWT distance (r=0.65. The predictive model for CPX peak VO2, using age and ISWT distance explained 67% of the variability. The current study indicates the ISWT may be used to predict aerobic capacity in obese women when CPX is not a viable option.

  7. State adaptation reserves cardiorespiratory system first-year students with varying degrees of physical fitness in terms of treadmill test

    Directory of Open Access Journals (Sweden)

    V.A. Levchenko

    2014-05-01

    Full Text Available Purpose : to examine the state of the cardiorespiratory system in terms of the stress test in first-year students with different levels of fitness. Material : the study involved 43 students, of which 18 boys and 25devushek basic medical group. The study used a treadmill, a pulse oximeter, spirometer. Results : more adjustment disorders were detected in students that are not involved in physical education at school. Decreased ability of the cardiorespiratory system to maintain proper oxygen supply of the organism in the stress test. This is not observed in students who were attending school in addition sports clubs. Found that students with low tolerance to physical exercise need a separate program of physical training, the dynamic control of the teachers and the need for additional medical examination. Conclusions : the treadmill test is an ideal way of revealing hidden maladjustment cardiorespiratory system in adolescence.

  8. Assessment of ventilatory thresholds from heart rate variability in five incremental treadmill tests in cross country skiers

    OpenAIRE

    Mendia Iztueta, Ibai

    2014-01-01

    Incremental treadmill tests are widely used in the field of exercise physiology for the assessment of Ventilatory Thresholds for clinical and sport oriented issues. The assessment of Ventilatory Thresholds (VTs) from Heart Rate Variability (HRV) is a relatively new approach with increasing popularity because it is a non-invasive and economical method. Nevertheless, this has not been used in Cross Country (XC) Skiing, an endurance sport where the knowledge of VTs holds special importance. The ...

  9. Cardiorespiratory performance of coronary artery disease patients on land versus underwater treadmill tests: a comparative study.

    Science.gov (United States)

    Garcia, Mauricio Koprowski; Rizzo, Limanara; Yazbek-Júnior, Paulo; Yutiyama, Daniela; Silva, Fabiola Jomar da; Matheus, Denise; Mastrocolla, Luiz Eduardo; Massad, Eduardo

    2017-11-01

    To compare responses to a cardiopulmonary exercise test on land versus on an underwater treadmill, to assess the cardiorespiratory performance of coronary artery disease patients while immersed in warm water and to compare with the performance of healthy individuals. The sample population consisted of 40 subjects, which included 20 coronary artery disease patients aged 63.7±8.89 years old, functional class I and II, according to the New York Hearth Association, and 20 healthy subjects aged 64.7±7.09 years old. The statistical significances were calculated through an ANOVA test with a (1 - β) power of 0.861. ClinicalTrials.gov: NCT00989248 (22). Significant differences were uncovered in coronary artery disease group regarding the variables heart beats (HB), (p>0.01), oxygen consumption (VO2), (p>0.01) and carbon dioxide production (VCO2) (p<0.01). Also, for the same group, in relation to the environment, water versus on land for HB, VO2, VCO2 and oxygen for each heart beat (VO2/HB) all of than (p<0.01). The stages for data collected featured the subject's performance throughout the experiment, and within the given context, variables rating of perceived exertion (RPE), HB, VO2, VCO2 and VO2/HB (p<0.01) showed significant interactions between test stages and environment. Additionally, there was a significant interaction between the etiology and the test stages for the variables HB, VO2 and VCO2 (p<0.01). Electrocardiographic changes compatible with myocardial ischemia or arrhythmia were not observed. The subjects exhibited lower scores on Borg's perceived exertion scale in the water than at every one of the test stages on land (p<0.01). This study show that a cardiopulmonary exercise test can be safely conducted in subjects in immersion and that the procedures, resources and equipment used yielded replicable and reliable data. Significant differences observed in water versus on land allow us to conclude that coronary artery disease patients are able to do physical

  10. Cardiorespiratory performance of coronary artery disease patients on land versus underwater treadmill tests: a comparative study

    Directory of Open Access Journals (Sweden)

    Mauricio Koprowski Garcia

    Full Text Available OBJECTIVE: To compare responses to a cardiopulmonary exercise test on land versus on an underwater treadmill, to assess the cardiorespiratory performance of coronary artery disease patients while immersed in warm water and to compare with the performance of healthy individuals. METHODS: The sample population consisted of 40 subjects, which included 20 coronary artery disease patients aged 63.7±8.89 years old, functional class I and II, according to the New York Hearth Association, and 20 healthy subjects aged 64.7±7.09 years old. The statistical significances were calculated through an ANOVA test with a (1 - β power of 0.861. ClinicalTrials.gov: NCT00989248 (22. RESULTS: Significant differences were uncovered in coronary artery disease group regarding the variables heart beats (HB, (p>0.01, oxygen consumption (VO2, (p>0.01 and carbon dioxide production (VCO2 (p<0.01. Also, for the same group, in relation to the environment, water versus on land for HB, VO2, VCO2 and oxygen for each heart beat (VO2/HB all of than (p<0.01. The stages for data collected featured the subject’s performance throughout the experiment, and within the given context, variables rating of perceived exertion (RPE, HB, VO2, VCO2 and VO2/HB (p<0.01 showed significant interactions between test stages and environment. Additionally, there was a significant interaction between the etiology and the test stages for the variables HB, VO2 and VCO2 (p<0.01. Electrocardiographic changes compatible with myocardial ischemia or arrhythmia were not observed. The subjects exhibited lower scores on Borg’s perceived exertion scale in the water than at every one of the test stages on land (p<0.01. CONCLUSION: This study show that a cardiopulmonary exercise test can be safely conducted in subjects in immersion and that the procedures, resources and equipment used yielded replicable and reliable data. Significant differences observed in water versus on land allow us to conclude that

  11. The reliability and validity of a soccer-specific nonmotorised treadmill simulation (intermittent soccer performance test).

    Science.gov (United States)

    Aldous, Jeffrey W F; Akubat, Ibrahim; Chrismas, Bryna C R; Watkins, Samuel L; Mauger, Alexis R; Midgley, Adrian W; Abt, Grant; Taylor, Lee

    2014-07-01

    This study investigated the reliability and validity of a novel nonmotorised treadmill (NMT)-based soccer simulation using a novel activity category called a "variable run" to quantify fatigue during high-speed running. Twelve male University soccer players completed 3 familiarization sessions and 1 peak speed assessment before completing the intermittent soccer performance test (iSPT) twice. The 2 iSPTs were separated by 6-10 days. The total distance, sprint distance, and high-speed running distance (HSD) were 8,968 ± 430 m, 980 ± 75 m and 2,122 ± 140 m, respectively. No significant difference (p > 0.05) was found between repeated trials of the iSPT for all physiological and performance variables. Reliability measures between iSPT1 and iSPT2 showed good agreement (coefficient of variation: 0.80). Furthermore, the variable run phase showed HSD significantly decreased (p ≤ 0.05) in the last 15 minutes (89 ± 6 m) compared with the first 15 minutes (85 ± 7 m), quantifying decrements in high-speed exercise compared with the previous literature. This study validates the iSPT as a NMT-based soccer simulation compared with the previous match-play data and is a reliable tool for assessing and monitoring physiological and performance variables in soccer players. The iSPT could be used in a number of ways including player rehabilitation, understanding the efficacy of nutritional interventions, and also the quantification of environmentally mediated decrements on soccer-specific performance.

  12. Commercial Motion Sensor Based Low-Cost and Convenient Interactive Treadmill

    Directory of Open Access Journals (Sweden)

    Jonghyun Kim

    2015-09-01

    Full Text Available Interactive treadmills were developed to improve the simulation of overground walking when compared to conventional treadmills. However, currently available interactive treadmills are expensive and inconvenient, which limits their use. We propose a low-cost and convenient version of the interactive treadmill that does not require expensive equipment and a complicated setup. As a substitute for high-cost sensors, such as motion capture systems, a low-cost motion sensor was used to recognize the subject’s intention for speed changing. Moreover, the sensor enables the subject to make a convenient and safe stop using gesture recognition. For further cost reduction, the novel interactive treadmill was based on an inexpensive treadmill platform and a novel high-level speed control scheme was applied to maximize performance for simulating overground walking. Pilot tests with ten healthy subjects were conducted and results demonstrated that the proposed treadmill achieves similar performance to a typical, costly, interactive treadmill that contains a motion capture system and an instrumented treadmill, while providing a convenient and safe method for stopping.

  13. Exaggerated Exercise Blood Pressure Response During Treadmill Testing as a Predictor of Future Hypertension in Men: A Longitudinal Study.

    Science.gov (United States)

    Jae, Sae Young; Franklin, Barry A; Choo, Jina; Choi, Yoon-Ho; Fernhall, Bo

    2015-11-01

    The purpose of this study was to evaluate receiver operating characteristic curves to identify optimal cutoff values of exercise systolic blood pressure (SBP) using both peak SBP and relative SBP (peak SBP minus resting SBP) as predictors of future hypertension (HTN). Participants were 3,742 healthy normotensive men who underwent symptom-limited treadmill testing at baseline. Incident HTN was defined as SBP/diastolic blood pressure greater than 140/90 mm Hg and/or diagnosed HTN by a physician. During an average 5-year follow-up, 364 (9.7%) new cases of HTN were observed. The most discriminatory cutoff values for peak SBP and relative SBP for predicting incident HTN were 181 mm Hg (areas under the curve (AUC) = 0.644, sensitivity = 54%, and specificity = 69%) and 52 mm Hg (AUC = 0.549, sensitivity = 64.3%, and specificity = 44.6%), respectively. Participants with peak SBP greater than 181 mm Hg and relative SBP greater than 52 mm Hg had 1.54-fold (95% CI: 1.23-1.93) and 1.44-fold (95% CI: 1.16-1.80) risks of developing HTN after adjusting for potential confounding variables. When these 2 variables were entered simultaneously into the Cox proportional hazards regression model with adjustment for potential confounding variables, only peak SBP (relative risk: 1.39, 95% CI: 1.02-1.89) was a predictor of the development of HTN. The most accurate discriminators for peak and relative SBP during treadmill exercise testing to predict incident HTN were greater than 181 and 52 mm Hg, respectively, in normotensive men. A peak SBP greater than 181 mm Hg during treadmill exercise testing may provide a useful predictor for the development of HTN in clinical practice. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. The effect of vocal and instrumental music on cardio respiratory variables, energy expenditure and exertion levels during sub maximal treadmill exercise.

    Science.gov (United States)

    Savitha, D; Sejil, T V; Rao, Shwetha; Roshan, C J; Roshan, C J

    2013-01-01

    The purpose of the study was to investigate the effect of vocal and instrumental music on various physiological parameters during submaximal exercise. Each subject underwent three sessions of exercise protocol without music, with vocal music, and instrumental versions of same piece of music. The protocol consisted of 10 min treadmill exercise at 70% HR(max) and 20 min of recovery. Minute to minute heart rate and breath by breath recording of respiratory parameters, rate of energy expenditure and perceived exertion levels were measured. Music, irrespective of the presence or absence of lyrics, enabled the subjects to exercise at a significantly lower heart rate and oxygen consumption, reduced the metabolic cost and perceived exertion levels of exercise (P Music having a relaxant effect could have probably increased the parasympathetic activation leading to these effects.

  15. Maximal lattice free bodies, test sets and the Frobenius problem

    DEFF Research Database (Denmark)

    Jensen, Anders Nedergaard; Lauritzen, Niels; Roune, Bjarke Hammersholt

    Maximal lattice free bodies are maximal polytopes without interior integral points. Scarf initiated the study of maximal lattice free bodies relative to the facet normals in a fixed matrix. In this paper we give an efficient algorithm for computing the maximal lattice free bodies of an integral m...... method is inspired by the novel algorithm by Einstein, Lichtblau, Strzebonski and Wagon and the Groebner basis approach by Roune....

  16. Associations of maximal strength and muscular endurance test scores with cardiorespiratory fitness and body composition.

    Science.gov (United States)

    Vaara, Jani P; Kyröläinen, Heikki; Niemi, Jaakko; Ohrankämmen, Olli; Häkkinen, Arja; Kocay, Sheila; Häkkinen, Keijo

    2012-08-01

    The purpose of the present study was to assess the relationships between maximal strength and muscular endurance test scores additionally to previously widely studied measures of body composition and maximal aerobic capacity. 846 young men (25.5 ± 5.0 yrs) participated in the study. Maximal strength was measured using isometric bench press, leg extension and grip strength. Muscular endurance tests consisted of push-ups, sit-ups and repeated squats. An indirect graded cycle ergometer test was used to estimate maximal aerobic capacity (V(O2)max). Body composition was determined with bioelectrical impedance. Moreover, waist circumference (WC) and height were measured and body mass index (BMI) calculated. Maximal bench press was positively correlated with push-ups (r = 0.61, p strength (r = 0.34, p strength correlated positively (r = 0.36-0.44, p test scores were related to maximal aerobic capacity and body fat content, while fat free mass was associated with maximal strength test scores and thus is a major determinant for maximal strength. A contributive role of maximal strength to muscular endurance tests could be identified for the upper, but not the lower extremities. These findings suggest that push-up test is not only indicative of body fat content and maximal aerobic capacity but also maximal strength of upper body, whereas repeated squat test is mainly indicative of body fat content and maximal aerobic capacity, but not maximal strength of lower extremities.

  17. Transient left ventricular apical ballooning and exercise induced hypertension during treadmill exercise testing: is there a common hypersympathetic mechanism?

    Directory of Open Access Journals (Sweden)

    Oh Jae K

    2008-07-01

    Full Text Available Abstract Objective To describe two cases of Takotsubo like myocardial contractile pattern during exercise stress test secondary to hypertensive response. Background Treadmill exercise testing is known to cause sympathetic stimulation, leading to increased levels of catecholamine, resulting in alteration in vascular tone. Hypertensive response during exercise testing can cause abnormal consequences, resulting in false positive results. Cases We present the cases of two patients experiencing apical and basal akinesis during exercise stress echocardiography, in whom normal wall motion response was observed on subsequent pharmacologic stress testing. The first patient developed transient left ventricular (LV apical akinesis during exercise stress echocardiography. Due to high suspicion that this abnormality might be secondary to hypertensive response, pharmacologic stress testing was performed after three days, which was completely normal and showed no such wall motion abnormality. Qualitative assessment of myocardial perfusion using contrast was also performed, which showed good myocardial blood flow, indicating low probability for significant obstructive coronary artery disease. The second patient developed LV basal akinesis as a result of hypertensive response during exercise testing. Coronary angiogram was not performed in either patient due to low suspicion for coronary artery disease, and subsequently negative stress studies. Results Transient stress induced cardiomyopathy can develop secondary to hypertensive response during exercise stress testing. Conclusion These cases provide supporting evidence to the hyper-sympathetic theory of left ventricular ballooning syndrome.

  18. Chest tcpO2 changes during constant-load treadmill walking tests in patients with claudication

    International Nuclear Information System (INIS)

    Ouedraogo, N; Leftheriotis, G; Abraham, P; Feuilloy, M; Mahe, G; Saumet, J-L

    2011-01-01

    Changes in chest transcutaneous-pO 2 at rest (ΔtcpO 2 ) mimic absolute changes in arterial-pO 2 during moderate exercise, although the absolute starting values may dramatically differ. We retrospectively studied 485 patients (group 1), prospectively studied 292 new patients (group 2) and estimated the intra-test and the test–retest reproducibility of ΔtcpO 2 during constant-load treadmill tests: 3.2 km h −1 , 10% grade, using the cross correlation technique. Patients were classified into groups according to their best fit to nine pre-defined mathematic models. Respectively, 71% and 76% of patients of groups 1 and 2 fitted with a model showing a ΔtcpO 2 increase during and a decrease following exercise. Another 18% and 12% of the patients of groups 1 and 2 respectively fitted with a model that showed an abrupt decrease at exercise onset, a slow increase during walking and an overshoot in the recovery period, referred here as a walking-induced transcutaneous hack (WITH) profile. The mean r max value for the cross-correlation analysis was 0.919 ± 0.091 and 0.800 ± 0.129 for intra-test and test–retest reproducibility. Most profiles show the expected ΔtcpO 2 exercise-induced increase. Future studies are needed to confirm and explain the WITH profiles that we found, and screen for potential-associated diseases

  19. Prediction of 6-year prognosis for cardiac event by thallium-201 single-photon emission computed tomography (SPECT) with treadmill exercise test

    International Nuclear Information System (INIS)

    Hayashi, Katsumi; Ohsuzu, Fumitaka; Kosuda, Shigeru; Nakamura, Haruo

    1997-01-01

    To examine thallium-201 single-photon emission computed tomography (SPECT) with a treadmill exercise test can predict the long-term prognosis of patients with coronary artery disease, 95 patients (71 men, 24 women) who underwent a treadmill exercise test with thallium-201 SPECT from April to December 1986 were followed for 6 years. Three short-axis slices at the apical, mid- and basal-level were selected, and each slice was divided into eight segments. Each segment count was assigned a score according to the count range in the slice (score 0, count range 76-100%; 1, 51-75%; 2, 26-50%; 3, 1-25%; 4, 0%) by evaluating the mean value of the slice. The total Tl defect score of each segment in 3 slices was summed (ΣTl defect score). The 'early ΣTl defect score' was the ΣTl defect score 5 min after treadmill exercise, and the 'late ΣTl defect score' was ΣTl defect score measured 4 h after treadmill exercise. Cardiac events occurred in 27 of the 95 patients: cardiac death 3; myocardial infarction 1; percutaneous transluminal angioplasty 16; coronary artery bypass graft 5; congestive heart failure 3. Univariate analysis showed that previous myocardial infarction (p<0.01), exercise work load (p<0.05), early ΣTl defect score (p<0.0l) and late ΣTl defect score (p<0.01) were independent predictors of the prognosis. These results suggest that thallium-201 SPECT with the treadmill exercise test could be applicable and useful to predict long term prognosis. (author)

  20. Cardiac Autonomic Function during Submaximal Treadmill Exercise in Adults with Down Syndrome

    Science.gov (United States)

    Mendonca, Goncalo V.; Pereira, Fernando D.; Fernhall, Bo

    2011-01-01

    This study determined whether the cardiac autonomic function of adults with Down syndrome (DS) differs from that of nondisabled persons during submaximal dynamic exercise. Thirteen participants with DS and 12 nondisabled individuals performed maximal and submaximal treadmill tests with metabolic and heart rate (HR) measurements. Spectral analysis…

  1. Multistage treadmill exercise testing with a multiple unipolar precordial lead system in the evaluation of effort angina pectoris

    International Nuclear Information System (INIS)

    Shiki, Kazuhito; Tsuzuki, Masato; Kawai, Naoki; Kondo, Teruo; Sotobata, Iwao

    1984-01-01

    Sixty-one patients who had angina pectoris without prior myocardial infarction and 24 healthy men were studied by multistage treadmill exercise testing with 20 unipolar leads covering the left anterolateral hemithorax. Exercise-induced ST- segment changes were compared with the results of stress thallium-201 myocardial images and also with coronary arteriographic fingings. All patients had more than 75% narrowing of at least one major coronary artery. Fifty-one of the 61 patients had diagnostically significant exercise-induced ischemic ST-segment depression (sensitivity 83.6%) and all of the 24 controls showed a negative exercise test (specificity 100%). The exercise-induced ST-segment depressions appeared most often in the area just below V 5 . The number of leads with ST-segment depression and the sum of the depths of ST-segment depressions significantly correlated with the number of regions-of-interest of stress-induced hypoperfusion of myocardial scintigraphy (r = 0.62 and r = 0.61, respectively). These parameters increased as the number of diseased coronary arteries increased, but were not influenced by the presence or absence of coronary collateral circulation. The maximum depth of ST-segment depression was greater in triple vessel disease than in single or double vessel disease (p 5 . (J.P.N.)

  2. Assessment of Heart Rate Variability Thresholds from Incremental Treadmill Tests in Five Cross-Country Skiing Techniques.

    Directory of Open Access Journals (Sweden)

    Ibai Mendia-Iztueta

    Full Text Available The assessment of heart rate variability (HRV thresholds (HRVTs as an alternative of Ventilatory thresholds (VTs is a relatively new approach with increasing popularity which has not been conducted in cross-country (XC skiing yet. The main purpose of the present study was to assess HRVTs in the five main XC skiing-related techniques, double poling (DP, diagonal striding (DS, Nordic walking (NW, V1 skating (V1, and V2 skating (V2.Ten competitive skiers completed these incremental treadmill tests until exhaustion with a minimum of one to two recovery days in between each test. Ventilatory gases, HRV and poling frequencies were measured. The first HRV threshold (HRVT1 was assessed using two time-domain analysis methods, and the second HRV threshold (HRVT2 was assessed using two non-time varying frequency-domain analysis methods. HRVT1 was assessed by plotting the mean successive difference (MSD and standard deviation (SD of normalized R-R intervals to workload. HRVT1 was assessed by plotting high frequency power (HFP and the HFP relative to respiratory sinus arrhythmia (HFPRSA with workload. HRVTs were named after their methods (HRVT1-SD; HRVT1-MSD; HRVT2-HFP; HRVT2-HFP-RSA. The results showed that the only cases where the proposed HRVTs were good assessors of VTs were the HRVT1-SD of the DS test, the HRVT1-MSD of the DS and V2 tests, and the HRVT2-HFP-RSA of the NW test. The lack of a wider success of the assessment of HRVTs was reasoned to be mostly due to the high entrainment between the breathing and poling frequencies. As secondary finding, a novel Cardiolocomotor coupling mode was observed in the NW test. This new Cardiolocoomtor coupling mode corresponded to the whole bilateral poling cycle instead of corresponding to each poling action as it was reported to the date by the existing literature.

  3. Comparison of the sensitivities of the Buehler test and the guinea pig maximization test for predictive testing of contact allergy

    DEFF Research Database (Denmark)

    Frankild, S; Vølund, A; Wahlberg, J E

    2001-01-01

    International test guidelines, such as the Organisation for Economic Cooperation and Development (OECD) guideline #406, recommend 2 guinea pig methods for testing of the contact allergenic potential of chemicals: the Guinea Pig Maximization Test (GPMT) and the Buehler test. Previous comparisons...

  4. Gender differences in the variables of exercise treadmill test in type ...

    African Journals Online (AJOL)

    Background: Exercise capacity, like some other variables of exercise stress test, is a strong predictor of cardiovascular and overall ..... plan, and guide cardiac rehabilitation. .... peripheral vascular disease, peripheral neuropathy, physical ...

  5. Influence of regression model and initial intensity of an incremental test on the relationship between the lactate threshold estimated by the maximal-deviation method and running performance.

    Science.gov (United States)

    Santos-Concejero, Jordan; Tucker, Ross; Granados, Cristina; Irazusta, Jon; Bidaurrazaga-Letona, Iraia; Zabala-Lili, Jon; Gil, Susana María

    2014-01-01

    This study investigated the influence of the regression model and initial intensity during an incremental test on the relationship between the lactate threshold estimated by the maximal-deviation method and performance in elite-standard runners. Twenty-three well-trained runners completed a discontinuous incremental running test on a treadmill. Speed started at 9 km · h(-1) and increased by 1.5 km · h(-1) every 4 min until exhaustion, with a minute of recovery for blood collection. Lactate-speed data were fitted by exponential and polynomial models. The lactate threshold was determined for both models, using all the co-ordinates, excluding the first and excluding the first and second points. The exponential lactate threshold was greater than the polynomial equivalent in any co-ordinate condition (P performance and is independent of the initial intensity of the test.

  6. Treadmill exercise testing of asymptomatic men and women without evidence of heart disease

    Directory of Open Access Journals (Sweden)

    W.A. Chalela

    2009-12-01

    Full Text Available The aim of this study was to test the hypothesis of differences in performance including differences in ST-T wave changes between healthy men and women submitted to an exercise stress test. Two hundred (45.4% men and 241 (54.6% women (mean age: 38.7 ± 11.0 years were submitted to an exercise stress test. Physiologic and electrocardiographic variables were compared by the Student t-test and the chi-square test. To test the hypothesis of differences in ST-segment changes, data were ranked with functional models based on weighted least squares. To evaluate the influence of gender and age on the diagnosis of ST-segment abnormality, a logistic model was adjusted; P < 0.05 was considered to be significant. Rate-pressure product, duration of exercise and estimated functional capacity were higher in men (P < 0.05. Sixteen (6.7% women and 9 (4.5% men demonstrated ST-segment upslope ≥0.15 mV or downslope ≥0.10 mV; the difference was not statistically significant. Age increase of one year added 4% to the chance of upsloping of segment ST ≥0.15 mV or downsloping of segment ST ≥0.1 mV (P = 0.03; risk ratio = 1.040, 95% confidence interval (CI = 1.002-1.080. Heart rate recovery was higher in women (P < 0.05. The chance of women showing an increase of systolic blood pressure ≤30 mmHg was 85% higher (P = 0.01; risk ratio = 1.85, 95%CI = 1.1-3.05. No significant difference in the frequency of ST-T wave changes was observed between men and women. Other differences may be related to different physical conditioning.

  7. Characterization of the heart rate curve during a maximum incremental test on a treadmill. DOI: 10.5007/1980-0037.2011v13n4p285

    Directory of Open Access Journals (Sweden)

    Eduardo Marcel Fernandes Nascimento

    2011-08-01

    Full Text Available The objective of this study was to analyze the heart rate (HR profile plotted against incremental workloads (IWL during a treadmill test using three mathematical models [linear, linear with 2 segments (Lin2, and sigmoidal], and to determine the best model for the identification of the HR threshold that could be used as a predictor of ventilatory thresholds (VT1 and VT2. Twenty-two men underwent a treadmill incremental test (retest group: n=12 at an initial speed of 5.5 km.h-1, with increments of 0.5 km.h-1 at 1-min intervals until exhaustion. HR and gas exchange were continuously measured and subsequently converted to 5-s and 20-s averages, respectively. The best model was chosen based on residual sum of squares and mean square error. The HR/IWL ratio was better fitted with the Lin2 model in the test and retest groups (p0.05. During a treadmill incremental test, the HR/IWL ratio seems to be better fitted with a Lin2 model, which permits to determine the HR threshold that coincides with VT1.

  8. Beneficial Effects of New Zealand Blackcurrant Extract on Maximal Sprint Speed during the Loughborough Intermittent Shuttle Test

    Directory of Open Access Journals (Sweden)

    Mark ET Willems

    2016-08-01

    Full Text Available New Zealand blackcurrant (NZBC extract has been shown to enhance high-intensity intermittent treadmill running. We examined the effects of NZBC extract during the Loughborough Intermittent Shuttle Test (LIST which involves 5 × 15 min blocks with intermittent 15-m maximal sprints, interspersed by moderate and high-intensity running to simulate team sport activity, and a subsequent run to exhaustion. Thirteen males (age: 22 ± 1 year, V ˙ O 2 max : 50 ± 5 mL·kg−1·min−1 participated in three indoor sessions (T: 24 ± 3 °C, humidity: 52% ± 9%. In the first session, a multistage fitness test was completed to determine peak running speed and estimate V ˙ O 2 max . Participants consumed NZBC extract in capsules (300 mg·day−1 CurraNZ™ or placebo (PL (300 mg·day−1 microcrystalline cellulose M102 for seven days in a double-blind, randomized, cross-over design (wash-out at least seven days. NZBC extract did not affect average 15-m sprint times in each block. NZBC reduced slowing of the fastest sprint between block 1 and 5 (PL: 0.12 ± 0.07 s; NZBC: 0.06 ± 0.12 s; p < 0.05. NZBC extract had no effect on heart rate, vertical jump power, lactate and time to exhaustion (PL: 13.44 ± 8.09 min, NZBC: 15.78 ± 9.40 min, p > 0.05. However, eight participants had higher running times to exhaustion when consuming NZBC extract. New Zealand blackcurrant extract may enhance performance in team sports with repeated maximal sprints.

  9. Reliability of Maximal Strength Testing in Novice Weightlifters

    Science.gov (United States)

    Loehr, James A.; Lee, Stuart M. C.; Feiveson, Alan H.; Ploutz-Snyder, Lori L.

    2009-01-01

    The one repetition maximum (1RM) is a criterion measure of muscle strength. However, the reliability of 1RM testing in novice subjects has received little attention. Understanding this information is crucial to accurately interpret changes in muscle strength. To evaluate the test-retest reliability of a squat (SQ), heel raise (HR), and deadlift (DL) 1RM in novice subjects. Twenty healthy males (31 plus or minus 5 y, 179.1 plus or minus 6.1 cm, 81.4 plus or minus 10.6 kg) with no weight training experience in the previous six months participated in four 1RM testing sessions, with each session separated by 5-7 days. SQ and HR 1RM were conducted using a smith machine; DL 1RM was assessed using free weights. Session 1 was considered a familiarization and was not included in the statistical analyses. Repeated measures analysis of variance with Tukey fs post-hoc tests were used to detect between-session differences in 1RM (p.0.05). Test-retest reliability was evaluated by intraclass correlation coefficients (ICC). During Session 2, the SQ and DL 1RM (SQ: 90.2 }4.3, DL: 75.9 }3.3 kg) were less than Session 3 (SQ: 95.3 }4.1, DL: 81.5 plus or minus 3.5 kg) and Session 4 (SQ: 96.6 }4.0, DL: 82.4 }3.9 kg), but there were no differences between Session 3 and Session 4. HR 1RM measured during Session 2 (150.1 }3.7 kg) and Session 3 (152.5 }3.9 kg) were not different from one another, but both were less than Session 4 (157.5 }3.8 kg). The reliability (ICC) of 1RM measures for Sessions 2-4 were 0.88, 0.83, and 0.87, for SQ, HR, and DL, respectively. When considering only Sessions 3 and 4, the reliability was 0.93, 0.91, and 0.86 for SQ, HR, and DL, respectively. One familiarization session and 2 test sessions (for SQ and DL) were required to obtain excellent reliability (ICC greater than or equal to 0.90) in 1RM values with novice subjects. We were unable to attain this level of reliability following 3 HR testing sessions therefore additional sessions may be required to obtain an

  10. Testing Gravity via Lunar Laser Ranging: Maximizing Data Quality

    Science.gov (United States)

    Murphy, Thomas

    We propose to continue leading-edge observations with the Apache Point Observatory Lunar Laser-ranging Operation (APOLLO), in an effort to subject gravity to the most stringent tests yet. APOLLO has delivered a dramatic improvement in the measurement of the lunar orbit: now at the millimeter level. Yet incomplete models are thus far unable to confirm the accuracy. We therefore seek to build a calibration system to ensure that APOLLO meets its millimeter measurement goal. Gravity--the most evident force of nature--is in fact the weakest of the fundamental forces, and consequently the most poorly tested. Einstein’s general relativity, which is currently our best description of gravity, is fundamentally incompatible with quantum mechanics and is likely to be replaced by a more complete theory in the future. A modified theory would predict small deviations in the solar system that could have profound consequences for our understanding of the Universe as a whole. Lunar laser ranging (LLR), in which short laser pulses launched from a telescope are bounced off of reflectors placed on the Moon by U.S. astronauts and Soviet landers, has for decades produced some of the leading tests of gravity by mapping the shape of the lunar orbit to high precision. These include tests of the strong equivalence principle, the time-rate-ofchange of Newton’s gravitational constant, gravitomagnetism, the inverse-square law, and many others. Among the attributes that contribute to APOLLO’s superior observations, routine ranging to all five lunar reflectors on timescales of minutes dramatically improves our ability to gauge lunar orientation and body distortion. This information produces insights into the interior structure and dynamics of the Moon, allowing a more precise determination of the path for the Moon’s center of mass, lending to tests of fundamental gravity. Simultaneously, higher precision range measurements, together with data from a superconducting gravimeter at the

  11. Impact of training status on maximal oxygen uptake criteria ...

    African Journals Online (AJOL)

    Peak treadmill running speed was significantly faster and total test time significantly longer in the trained group. In contrast, peak lactate, although maximal for both groups, was significantly higher in the untrained group (13.5 mmol.l-1 compared with 10.3 mmol.l-1). The other responses were not different between the groups ...

  12. Predischarge maximal exercise test identifies risk for cardiac death in patients with acute myocardial infarction

    DEFF Research Database (Denmark)

    Nielsen, J R; Mickley, H; Damsgaard, E M

    1990-01-01

    A maximal exercise test was performed in 54 patients with acute myocardial infarction (AMI) before discharge and in 49 age-matched control subjects. The long-term prognosis was assessed after an average follow-up of 7.6 years in AMI patients and 5.8 years in control subjects. The maximal work...... capacity and systolic blood pressure increase in AMI patients was 59% that of control subjects (p less than 0.001). Seventeen AMI patients had significant ST-segment shifts, 13 with ST depression and 4 with ST elevation. In AMI patients experiencing a cardiac death during follow-up the maximal work...... were of no significant value. In this study maximal work capacity turned out to be the best single exercise variable for identifying groups of AMI patients with very low and relative high risk of cardiac death. When all 3 exercise variables were combined, the predischarge maximal exercise test...

  13. Clinical value and severity of myocardial perfusion defects in asymptomatic diabetic patients with negative or weakly positive exercise treadmill test

    International Nuclear Information System (INIS)

    Zakavi, Seyed Rasoul; Taherpour, Mehdi; Moossavi, Zohreh; Sadeghi, Ramin; Kakhki, Vahidreza Dabbagh; Rokni, Haleh

    2013-01-01

    Although coronary artery disease (CAD) is the leading cause of death in type 2 diabetic patients, it is frequently asymptomatic. Myocardial perfusion imaging (MPI) is reported to show ischemia in a significant number of asymptomatic diabetic patients. We studied the prevalence and severity of myocardial perfusion defects in asymptomatic diabetic patients and its clinical impact. One hundred thirty consecutive asymptomatic patients, aged 35-65 years with type 2 diabetes mellitus and with no history of CAD and no cardiac symptoms were recruited in the study. Echocardiography, electrocardiography (ECG), routine laboratory tests and exercise treadmill test (ETT) were performed and patients with weakly positive or negative ETT underwent Dipyridamole MPI. Patients with positive ETT were referred to coronary angiography. Patients were followed for at least 17 months (mean 21.7 months) and any cardiac event was recorded. We studied 81 female and 49 male patients with mean age of 51.8 years. Negative, weakly positive and positive ETT result was noted in 74.3%, 15% and 10.7% respectively. 75% of patients with positive ETT had coronary artery disease in angiography. Gated myocardial perfusion SPECT was done in 106 patients. MPI showed reversible defect in 26.9% of the patients with a mean summed stress score of 3.3±1.8. Follow up completed in 112 patients and only one patient with abnormal MPI underwent coronary angiography followed by PTCA. No cardiac death, MI, UA or hospital admission occurred among our patients during follow up (17-26 months). Mean stress end diastolic volume (EDV) was significantly higher in patients with reversible defect compared to patients without reversible defect based on MPI findings (62.0±31.6 Vs 48.5±18.4 ml, P=0.04). Blood glucose and HbA1c were significantly higher in patients with ischemia compared to patients without ischemia (P<0.05). Meanwhile the ratio of TG to HDL was 6.06±3.2 in ischemic patients compared to 4.8±2.3 in normal

  14. Homocysteine, visceral adiposity-related novel cardiometabolic risk factors, and exaggerated blood pressure response to the exercise treadmill test.

    Science.gov (United States)

    Türker Duyuler, Pinar; Duyuler, Serkan; Demir, Mevlüt; Uçar Elalmiş, Özgül; Güray, Ümit; İleri, Mehmet

    2017-12-01

    Exaggerated blood pressure response to exercise is a risk factor for the development of future hypertension. In this study, we aimed to investigate the association between homocysteine, epicardial fat thickness, nonalcoholic hepatic steatosis, and exaggerated blood pressure response to exercise. We included 44 normotensive and 40 patients with exaggerated blood pressure response to exercise who have normal resting blood pressure and without a previous diagnosis of hypertension. All patients underwent treadmill exercise test and clinical, ultrasonographic, and echocardiographic evaluation. Exaggerated blood pressure response to exercise is defined as peak exercise systolic blood pressure of at least 210 mmHg in men and at least 190 mmHg in women. Homocysteine and other biochemical parameters were determined with standardized automated laboratory tests. Mean age of all participants is 47.9±8.5 years, and 36 of 84 participants were female. The frequency of diabetes mellitus in both groups was similar (P=0.250). Homeostasis model assessment index-insulin resistance had a statistically insignificant trend to be higher in a patient with exercise hypertension (P=0.058). The nonalcoholic fatty liver was more frequent in patients with exercise hypertension (13.6 vs. 47.5%, P=0.002). Epicardial fat thickness was increased in patients with exercise hypertension (5.5±1.5 vs. 7.3±1.1 mm; P=0.001). However, homocysteine levels did not significantly differ between normotensive and exercise hypertensive patients [12.3 μmol/l (5.7-16.9 μmol/l) vs. 13 μmol/l (5.9-28.3 μmol/l); P=0.883]. In our study, homocysteine levels were not associated with exaggerated blood pressure response to exercise; however, fatty liver and epicardial fat thickness as visceral adiposity-related cardiometabolic risk factors were significantly related with exaggerated blood pressure response to exercise in patients without a previous diagnosis of hypertension.

  15. Estimation of maximal oxygen uptake without exercise testing in Korean healthy adult workers.

    Science.gov (United States)

    Jang, Tae-Won; Park, Shin-Goo; Kim, Hyoung-Ryoul; Kim, Jung-Man; Hong, Young-Seoub; Kim, Byoung-Gwon

    2012-08-01

    Maximal oxygen uptake is generally accepted as the most valid and reliable index of cardiorespiratory fitness and functional aerobic capacity. The exercise test for measuring maximal oxygen uptake is unsuitable for screening tests in public heath examinations, because of the potential risks of exercise exertion and time demands. We designed this study to determine whether work-related physical activity is a potential predictor of maximal oxygen uptake, and to develop a maximal oxygen uptake equation using a non-exercise regression model for the cardiorespiratory fitness test in Korean adult workers. Study subjects were adult workers of small-sized companies in Korea. Subjects with history of disease such as hypertension, diabetes, asthma and angina were excluded. In total, 217 adult subjects (113 men of 21-55 years old and 104 women of 20-64 years old) were included. Self-report questionnaire survey was conducted on study subjects, and maximal oxygen uptake of each subject was measured with the exercise test. The statistical analysis was carried out to develop an equation for estimating maximal oxygen uptake. The predictors for estimating maximal oxygen uptake included age, gender, body mass index, smoking, leisure-time physical activity and the factors representing work-related physical activity. The work-related physical activity was identified to be a predictor of maximal oxygen uptake. Moreover, the equation showed high validity according to the statistical analysis. The equation for estimating maximal oxygen uptake developed in the present study could be used as a screening test for assessing cardiorespiratory fitness in Korean adult workers.

  16. PENGARUH LATIHAN FARTLEK DENGAN TREADMILL DAN LARI DI LAPANGAN TERHADAP DAYA TAHAN KARDIORESPIRASI

    Directory of Open Access Journals (Sweden)

    Maya Kurnia

    2013-04-01

    Abstract The objective of this study is to reveal the effect of fartlek with treadmill, running, and vital lung capacity on respiratory endurance. The study used the experiment factorial 2x2 block design. The data were collected using the respiratory endurance test (using the twelve minutes by Cooper’s test with maximal distance which can be taken within twelve minutes. The results of this study are as follows: (1 There is a difference in respiratory endurance between those who were involved in fartlek with treadmill with those who ran. The respiratory endurance is better for those who ran than those who used treadmill. (2 There is a difference in respiratory endurance between those who have low vital lung capacity with those who have high vital lung capacity. The respiratory endurance is better for those who have high vital lung capacity than those who have low vital lung capacity. (3 There is no interaction between those who were involved in fartlek with treadmill, running, and vital lung capacity in respiratory endurance. Members who were involved in fartlek with ran and have low vital lung capacity, who were involved in fartlek with treadmill and have high vital lung capacity, and who were involved in fartlek with ran and have high vital lung capacity is not different significance. Keywords: fartlek training, vital lung capacity, respiratory endurance.

  17. Phototherapy during treadmill training improves quadriceps performance in postmenopausal women.

    Science.gov (United States)

    Paolillo, F R; Corazza, A V; Paolillo, A R; Borghi-Silva, A; Arena, R; Kurachi, C; Bagnato, V S

    2014-06-01

    To evaluate the effects of infrared-light-emitting diode (LED) during treadmill training on functional performance. Thirty postmenopausal women aged 50-60 years were randomly assigned to one of three groups and successfully completed the full study. The three groups were: (1) the LED group, which performed treadmill training associated with phototherapy (n = 10); (2) the exercise group, which carried out treadmill training only (n = 10); and (3) the sedentary group, which neither performed physical training nor underwent phototherapy (n = 10). Training was performed over a period of 6 months, twice a week for 45 min per session at 85-90% of maximal heart rate, which was obtained during progressive exercise testing. The irradiation parameters were 100 mW, 39 mW/cm(2) and 108 J/cm(2) for 45 min. Quadriceps performance was measured during isokinetic exercise testing at 60°/s and 300°/s. Peak torque did not differ amongst the groups. However, the results showed significantly higher values of power and total work for the LED group (∆ = 21 ± 6 W and ∆ = 634 ± 156 J, p women.

  18. Comparison of adenosine and treadmill exercise thallium-201 stress tests for the detection of coronary artery disease

    International Nuclear Information System (INIS)

    Abe, Shinya; Takeishi, Yasuchika; Chiba, Junya; Ikeda, Kozue; Tomoike, Hitonobu

    1993-01-01

    To determine the clinical usefulness of adenosine Tl-201 imaging for the evaluation of coronary artery disease, 22 patients with suspected coronary artery disease who underwent adenosine and exercise Tl-201 single photon emission computed tomography (SPECT) were studied. The peak levels of heart rate (83 vs 123 bpm, p<0.001), systolic blood pressure (124 vs 164 mmHg, p<0.001), diastolic blood pressure (70 vs 86 mmHg, p<0.01) and rate pressure products (10220 vs 20410 bpm x mmHg, p<0.001) were markedly smaller during adenosine infusion than during exercise. Segmental agreements between adenosine and exercise tests were 90% (218 of 242 segments) regarding the presence of perfusion defects and 89% (215 of 242 segments) regarding the presence of redistribution. Regional Tl-201 uptake (r=0.85, p<0.001) and the extent (r=0.75, p<0.001) and intensity (r=0.83, p<0.001) of Tl-201 defects during adenosine testing were closely correlated with those of exercise testing. Adenosine and exercise tests showed similar sensitivities for the identification of individual coronary stenosis (85% vs 78%). However, in patients who were unable to perform adequate exercise (maximal heart rate<120 bpm), the sensitivity of adenosine imaging tended to be higher than that of exercise imaging (92% vs 69%, p=0.07). Adenosine Tl-201 imaging is an alternative to the exercise test for assessing the severity and loci of coronary artery disease, especially in patients who are unable to perform adequate physical exercise. (author)

  19. Physiological responses of horses to a treadmill simulated speed and endurance test in high heat and humidity before and after humid heat acclimation.

    Science.gov (United States)

    Marlin, D J; Scott, C M; Schroter, R C; Harris, R C; Harris, P A; Roberts, C A; Mills, P C

    1999-01-01

    To investigate whether horses were able to acclimate to conditions of high temperature and humidity, 5 horses of different breeds were trained for 80 min on 15 consecutive days on a treadmill at 30 degrees C and 80%RH. Training consisted of a combination of long duration low-intensity exercise, medium duration medium intensity exercise and short duration high intensity exercise. Between training sessions the horses were maintained at 11+/-3 degrees C and 74+/-2%RH. Before (PRE-ACC) and after acclimation (POST-ACC) the horses undertook a simulated Competition Exercise Test (CET), designed to represent the Speed and Endurance Test of a 3-day event, at 30 degrees C/80%RH. Maximal oxygen uptake (VO2PEAK) was not changed following acclimation (PRE-ACC 141+/-8 ml/min/kg bwt vs. POST-ACC 145+/-9 ml/min/kg bwt [STPD], P>0.05). Following acclimation, 4 of the 5 horses were able to complete a significantly greater amount of Phase D in the CET (PRE-ACC 6.3+/-0.3 min vs. POST-ACC 7.3+/-0.3 min, P<0.05; target time = 8 min). Resting body temperatures (pulmonary artery [TPA], rectal [TREC] and tail-skin [TTSK] temperatures) were all significantly lower following acclimation. During exercise, metabolic heat production (M) and heat dissipation (HD), for the same exercise duration, were both significantly lower following acclimation (P<0.05), although heat storage (HS) was significantly higher (P<0.05). The higher heat storage following acclimation was associated with a lower TTSK for a given TPA and a decreased total fluid loss (% bodyweight, P<0.05). Plasma volume was not changed following acclimation. The relationship of sweating rate (SR) to TPA or TTSK on either the neck or the gluteal region was not significantly altered by acclimation, although the onset of sweating occurred at a lower TPA or TTSK following acclimation (P<0.05). The horses in the present study showed a number of physiological adaptations to a period of 15 days of exposure to high heat and humidity consistent

  20. Vitamin D status and V[combining dot above]O2peak during a skate treadmill graded exercise test in competitive ice hockey players.

    Science.gov (United States)

    Fitzgerald, John S; Peterson, Ben J; Warpeha, Joseph M; Wilson, Patrick B; Rhodes, Greg S; Ingraham, Stacy J

    2014-11-01

    Vitamin D status has been associated with cardiorespiratory fitness (CRF) in cross-sectional investigations in the general population. Data characterizing the association between 25-hydroxyvitamin D (25(OH)D) concentration and CRF in athletes are lacking. Junior and collegiate ice hockey players were recruited from the Minneapolis, MN (44.9° N), area during the off-season period (May 16-June 28). The purpose of this study was to examine the cross-sectional association between 25(OH)D concentration and CRF in a sample population of competitive ice hockey players. Circulating 25(OH)D level was assessed from a capillary blood sample analyzed using liquid chromatography-tandem mass spectrometry. V[Combining Dot Above]O2peak during a skate treadmill graded exercise test (GXT) was used to assess CRF. Data on both 25(OH)D concentration and V[Combining Dot Above]O2peak were available for 52 athletes. Insufficient 25(OH)D concentrations were found in 37.7% of the athletes (skate treadmill GXT.

  1. The guinea pig maximization test--with a multiple dose design

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Vølund, A; Frankild, S

    1995-01-01

    The guinea pig maximization test (GPMT) is usually performed with one moderately irritant induction dose of the allergen and gives a qualitative assessment-hazard identification-of the allergenicity of the chemical. We refined the GPMT by applying a multiple dose design and used 30 guinea pigs in...

  2. MAXIMIZING GROWTH AND SEXUAL MATURATION OF SHEEPSHEAD MINNOWS IN SUPPORT OF MULTI-GENERATION TEST DEVELOPMENT

    Science.gov (United States)

    Hemmer, R.L., G.M. Cripe and L.R. Goodman. In press. Maximizing Growth and Sexual Maturation of Sheepshead Minnows (Cyprinodon variegatus) in Support of Multi-Generation Test Development (Abstract). To be presented at the SETAC Fourth World Congress, 14-18 November 2004, Portland...

  3. Nickel-sulphate-induced contact dermatitis in the guinea pig maximization test

    DEFF Research Database (Denmark)

    Rohold, A E; Nielsen, G D; Andersen, Klaus Ejner

    1991-01-01

    Nickel sulphate is a sensitizer in guinea pigs, but the frequency of sensitization varies from study to study. The dose-response relationship for NiSO4.6H2O was evaluated in the guinea pig maximization test in this study. 6 intradermal (0.01%-3.0% aq.) and 6 topical (0.25%-10.0% pet.) concentrati...

  4. The value and limitations of rechallenge in the guinea pig maximization test

    DEFF Research Database (Denmark)

    Frankild, S; Basketter, D A; Andersen, Klaus Ejner

    1996-01-01

    The guinea pig maximization test (GPMT) has played a primary rôle in the evaluation of potential skin contact sensitizers for 25 years. In the OECD Guideline 406 from 1993, it is specifically suggested that equivocal results from the initial challenge in the GPMT should be evaluated further...

  5. The guinea pig maximization test--with a multiple dose design

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Vølund, A; Frankild, S

    1995-01-01

    The guinea pig maximization test (GPMT) is usually performed with one moderately irritant induction dose of the allergen and gives a qualitative assessment-hazard identification-of the allergenicity of the chemical. We refined the GPMT by applying a multiple dose design and used 30 guinea pigs...

  6. Paediatric treadmill friction injuries.

    Science.gov (United States)

    Jeremijenko, Luke; Mott, Jonathan; Wallis, Belinda; Kimble, Roy

    2009-05-01

    The aim of this study was to report on the severity and incidence of children injured by treadmills and to promote the implementation of safety standards. This retrospective review of children with treadmill friction injuries was conducted in a single tertiary-level burns centre in Australia between January 1997 and June 2007. The study revealed 37 children who sustained paediatric treadmill friction injuries. This was a presentation of 1% of all burns. Thirty-three (90%) of the injuries occurred in the last 3.5 years (January 2004 to June 2007). The modal age was 3.2 years. Thirty-three (90%) injuries were either full thickness or deep partial friction burns. Eleven (30%) required split thickness skin grafts. Of those who became entrapped, 100% required skin grafting. This study found that paediatric treadmill friction injuries are severe and increasing in incidence. Australian standards should be developed, implemented and mandated to reduce this preventable and severe injury.

  7. Prediction of maximal lactate steady state in runners with an incremental test on the field.

    Science.gov (United States)

    Leti, Thomas; Mendelson, Monique; Laplaud, David; Flore, Patrice

    2012-01-01

    During a maximal incremental ergocycle test, the power output associated with Respiratory Exchange Ratio equal to 1.00 (RER = 1.00) predicts maximal lactate steady state (MLSS). We hypothesised that these results are transferable for runners on the field. Fourteen runners performed a maximal progressive test, to assess the speed associated with RER = 1.00, and several 30 minutes constant velocity tests to determine the speed at MLSS. We observed that the speeds at RER = 1.00, at the second ventilatory threshold (VT2) and at MLSS did not differ (15.7 ± 1.1 km · h⁻¹, 16.2 ± 1.4 km · h⁻¹, 15.5 ± 1.1 km · h⁻¹ respectively). The speed associated with RER = 1.00 was better correlated with that at MLSS (r = 0.79; p = 0.0008) than that at VT2 (r = 0.73; p = 0.002). Neither the concentration of blood lactate nor the heart rate differed between the speed at RER = 1.00 and that at MLSS from the 10th and the 30th minute of the constant velocity test. Bland and Altman analysis showed a fair agreement between the speed at MLSS and that at RER (0.2 ± 1.4 km · h⁻¹). This study demonstrated that the speed associated with RER = 1.00 determined during maximal progressive track running allows a fair estimation of the speed associated with MLSS, markedly decreasing the burden of numerous invasive tests required to assess it.

  8. The slack test does not assess maximal shortening velocity of muscle fascicle in human.

    Science.gov (United States)

    Hager, Robin; Dorel, Sylvain; Nordez, Antoine; Rabita, Giuseppe; Couturier, Antoine; Hauraix, Hugo; Duchateau, Jacques; Guilhem, Gaël

    2018-06-14

    The application of a series of extremely high accelerative motor-driven quick releases while muscles contract isometrically (i.e. slack test) has been proposed to assess unloaded velocity in human muscle. This study aimed to measure gastrocnemius medialis fascicle (V F ) and tendinous tissues shortening velocity during motor-driven quick releases performed at various activation levels to assess the applicability of the slack test method in human. Maximal fascicle shortening velocity and joint velocity recorded during quick releases and during fast contraction without external load (ballistic condition) were compared. Gastrocnemius medialis fascicle behaviour was investigated from 25 participants using high-frame rate ultrasound during quick releases performed at various activation levels (from 0% to 60% of maximal voluntary isometric torque) and ballistic contractions. Unloaded joint velocity calculated using the slack test method increased whereas V F decreased with muscle activation level (P≤0.03). Passive and low-level quick releases elicited higher V F values (≥ 41.4±9.7 cm.s -1 ) compared to ballistic condition (36.3±8.7 cm.s -1 ), while quick releases applied at 60% of maximal voluntary isometric torque produced the lowest V F These findings suggest that initial fascicle length, complex fascicle-tendon interactions, unloading reflex and motor-driven movement pattern strongly influence and limit the shortening velocity achieved during the slack test. Furthermore, V F elicited by quick releases is likely to reflect substantial contributions of passive processes. Therefore, the slack test is not appropriate to assess maximal muscle shortening velocity in vivo. © 2018. Published by The Company of Biologists Ltd.

  9. Influence of regression model and incremental test protocol on the relationship between lactate threshold using the maximal-deviation method and performance in female runners.

    Science.gov (United States)

    Machado, Fabiana Andrade; Nakamura, Fábio Yuzo; Moraes, Solange Marta Franzói De

    2012-01-01

    This study examined the influence of the regression model and initial intensity of an incremental test on the relationship between the lactate threshold estimated by the maximal-deviation method and the endurance performance. Sixteen non-competitive, recreational female runners performed a discontinuous incremental treadmill test. The initial speed was set at 7 km · h⁻¹, and increased every 3 min by 1 km · h⁻¹ with a 30-s rest between the stages used for earlobe capillary blood sample collection. Lactate-speed data were fitted by an exponential-plus-constant and a third-order polynomial equation. The lactate threshold was determined for both regression equations, using all the coordinates, excluding the first and excluding the first and second initial points. Mean speed of a 10-km road race was the performance index (3.04 ± 0.22 m · s⁻¹). The exponentially-derived lactate threshold had a higher correlation (0.98 ≤ r ≤ 0.99) and smaller standard error of estimate (SEE) (0.04 ≤ SEE ≤ 0.05 m · s⁻¹) with performance than the polynomially-derived equivalent (0.83 ≤ r ≤ 0.89; 0.10 ≤ SEE ≤ 0.13 m · s⁻¹). The exponential lactate threshold was greater than the polynomial equivalent (P performance index that is independent of the initial intensity of the incremental test and better than the polynomial equivalent.

  10. Evaluation of Maxim Module-Integrated Electronics at the DOE Regional Test Centers: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Deline, C.; Sekulic, B.; Stein, J.; Barkaszi, S.; Yang, J.; Kahn, S.

    2014-07-01

    Module-embedded power electronics developed by Maxim Integrated are under evaluation through a partnership with the Department of Energy's Regional Test Center (RTC) program. Field deployments of both conventional modules and electronics-enhanced modules are designed to quantify the performance advantage of Maxim's products under different amounts of inter-row shading, and their ability to be deployed at a greater ground-coverage-ratio than conventional modules. Simulations in PVSYST have quantified the predicted performance difference between conventional modules and Maxim's modules from inter-row shading. Initial performance results have identified diffuse irradiance losses at tighter row spacing for both the Maxim and conventional modules. Comparisons with published models show good agreement with models predicting the greatest diffuse irradiance losses. At tighter row spacing, all of the strings equipped with embedded power electronics outperformed their conventional peers. An even greater performance advantage is predicted to occur in the winter months when the amount of inter-row shading mismatch is at a maximum.

  11. Human treadmill walking needs attention

    Directory of Open Access Journals (Sweden)

    Daniel Olivier

    2006-08-01

    Full Text Available Abstract Background The aim of the study was to assess the attentional requirements of steady state treadmill walking in human subjects using a dual task paradigm. The extent of decrement of a secondary (cognitive RT task provides a measure of the attentional resources required to maintain performance of the primary (locomotor task. Varying the level of difficulty of the reaction time (RT task is used to verify the priority of allocation of attentional resources. Methods 11 healthy adult subjects were required to walk while simultaneously performing a RT task. Participants were instructed to bite a pressure transducer placed in the mouth as quickly as possible in response to an unpredictable electrical stimulation applied on the back of the neck. Each subject was tested under five different experimental conditions: simple RT task alone and while walking, recognition RT task alone and while walking, walking alone. A foot switch system composed of a pressure sensitive sensor was placed under the heel and forefoot of each foot to determine the gait cycle duration. Results Gait cycle duration was unchanged (p > 0.05 by the addition of the RT task. Regardless of the level of difficulty of the RT task, the RTs were longer during treadmill walking than in sitting conditions (p 0.05 was found between the attentional demand of the walking task and the decrement of performance found in the RT task under varying levels of difficulty. This finding suggests that the healthy subjects prioritized the control of walking at the expense of cognitive performance. Conclusion We conclude that treadmill walking in young adults is not a purely automatic task. The methodology and outcome measures used in this study provide an assessment of the attentional resources required by walking on the treadmill at a steady state.

  12. Guinea pig maximization tests with formaldehyde releasers. Results from two laboratories

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Boman, A; Hamann, K

    1984-01-01

    The guinea pig maximization test was used to evaluate the sensitizing potential of formaldehyde and 6 formaldehyde releasers (Forcide 78, Germall 115, Grotan BK, Grotan OX, KM 200 and Preventol D2). The tests were carried out in 2 laboratories (Copenhagen and Stockholm), and although we intended...... the procedures to be the same, discrepancies were observed, possibly due to the use of different animal strains, test concentrations and vehicles. The sensitizing potential was in general found to be stronger in Stockholm compared to Copenhagen: formaldehyde sensitized 50% of the guinea pigs in Copenhagen and 95...

  13. Comparison of early exercise treadmill test and oral dipyridamole thallium-201 tomography for the identification of jeopardized myocardium in patients receiving thrombolytic therapy for acute Q-wave myocardial infarction

    International Nuclear Information System (INIS)

    Jain, A.; Hicks, R.R.; Frantz, D.M.; Myers, G.H.; Rowe, M.W.

    1990-01-01

    Thrombolytic therapy has become the treatment of choice for patients with acute myocardial infarction. Researchers are not yet able to identify patients with salvage of myocardium who are at risk for recurrent coronary events. Thus, a prospective trial was performed in 46 patients with myocardial infarction (28 anterior and 18 inferior) who received thrombolytic therapy to determine if early thallium tomography (4.7 days) using oral dipyridamole would identify more patients with residual ischemia than early symptom-limited exercise treadmill tests (5.5 days). There were no complications during the exercise treadmill tests or oral dipyridamole thallium tomography. Mean duration of exercise was 11 +/- 3 minutes and the peak heart rate was 126 beats/min. Thirteen patients had positive test results. After oral dipyridamole all patients had abnormal thallium uptake on the early images. Positive scans with partial filling in of the initial perfusion defects were evident in 34 patients. Angina developed in 13 patients and was easily reversed with intravenous aminophylline. Both symptom-limited exercise treadmill tests and thallium tomography using oral dipyridamole were safely performed early after myocardial infarction in patients receiving thrombolytic therapy. Thallium tomography identified more patients with residual ischemia than exercise treadmill tests (74 vs 28%). Further studies are required to determine whether the results of thallium tomography after oral dipyridamole can be used to optimize patient management and eliminate the need for coronary angiography in some patients

  14. Comparison of vertical ground reaction forces during overground and treadmill running. A validation study

    Directory of Open Access Journals (Sweden)

    Kluitenberg Bas

    2012-11-01

    Full Text Available Abstract Background One major drawback in measuring ground-reaction forces during running is that it is time consuming to get representative ground-reaction force (GRF values with a traditional force platform. An instrumented force measuring treadmill can overcome the shortcomings inherent to overground testing. The purpose of the current study was to determine the validity of an instrumented force measuring treadmill for measuring vertical ground-reaction force parameters during running. Methods Vertical ground-reaction forces of experienced runners (12 male, 12 female were obtained during overground and treadmill running at slow, preferred and fast self-selected running speeds. For each runner, 7 mean vertical ground-reaction force parameters of the right leg were calculated based on five successful overground steps and 30 seconds of treadmill running data. Intraclass correlations (ICC(3,1 and ratio limits of agreement (RLOA were used for further analysis. Results Qualitatively, the overground and treadmill ground-reaction force curves for heelstrike runners and non-heelstrike runners were very similar. Quantitatively, the time-related parameters and active peak showed excellent agreement (ICCs between 0.76 and 0.95, RLOA between 5.7% and 15.5%. Impact peak showed modest agreement (ICCs between 0.71 and 0.76, RLOA between 19.9% and 28.8%. The maximal and average loading-rate showed modest to excellent ICCs (between 0.70 and 0.89, but RLOA were higher (between 34.3% and 45.4%. Conclusions The results of this study demonstrated that the treadmill is a moderate to highly valid tool for the assessment of vertical ground-reaction forces during running for runners who showed a consistent landing strategy during overground and treadmill running. The high stride-to-stride variance during both overground and treadmill running demonstrates the importance of measuring sufficient steps for representative ground-reaction force values. Therefore, an

  15. Maximal exercise testing of men with prostate cancer being treated with androgen deprivation therapy.

    Science.gov (United States)

    Wall, Bradley A; Galvão, Daniel A; Fatehee, Naeem; Taaffe, Dennis R; Spry, Nigel; Joseph, David; Newton, Robert U

    2014-12-01

    Exercise is being increasingly established as a key adjuvant therapy in clinical oncology. As research has demonstrated the beneficial effect of exercise for cancer management, a growing number of patients with cancer are undertaking structured exercise programs. This study aimed to determine the safety and feasibility of formal exercise testing in clinical settings as it is becoming increasingly used as a screening tool and for exercise prescription purposes. One hundred and twelve patients with prostate cancer undergoing androgen deprivation therapy (ADT) took part in a physician-supervised multistage maximal stress test (Bruce protocol). Sixty patients had been on ADT for 3 months (chronic). Of these men, 85% were able to meet the criteria for the attainment of V˙O2max, whereas three positive tests (3.2%) were observed. The three participants who recorded a positive stress test underwent further medical examination and were subsequently cleared of clinically significant cardiovascular disease. Apart from the relatively low V˙O2max (24.7 ± 6.0 mL·kg·min, 10th-15th percentile), compared with normative data in healthy age-matched controls, the cardiovascular response to exercise was similar in this cancer population. Moreover, treatment duration did not seem to influence cardiovascular responses to exercise. This early evidence suggests that risk of adverse events during maximal exercise testing is relatively low in this population and certainly no higher than that in ages-matched, apparently healthy individuals. Maximal exercise testing was demonstrated to be feasible and safe, providing a direct assessment of V˙O2max. The relatively low number of positive tests in this study suggests that the risk of adverse events is relatively low in this population and certainly no higher than that in age-matched, apparently healthy individuals.

  16. CISO's guide to penetration testing a framework to plan, manage, and maximize benefits

    CERN Document Server

    Tiller, James S

    2011-01-01

    CISO's Guide to Penetration Testing: A Framework to Plan, Manage, and Maximize Benefits details the methodologies, framework, and unwritten conventions penetration tests should cover to provide the most value to your organization and your customers. Discussing the process from both a consultative and technical perspective, it provides an overview of the common tools and exploits used by attackers along with the rationale for why they are used. From the first meeting to accepting the deliverables and knowing what to do with the results, James Tiller explains what to expect from all phases of th

  17. Selection of patients from myocardial perfusion scintigraphy based on fuzzy sets theory applied to clinical-epidemiological data and treadmill test results

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, P.S. [Fleury - Centro de Medicina Diagnostica, Sao Paulo, SP (Brazil). Secao de Medicina Nuclear]. E-mail: paulo.duarte@fleury.com.br; Mastrocolla, L.E.; Farsky, P.S.; Sampaio, C.R.E.P.S. [Fleury - Centro de Medicina Diagnostica, Sao Paulo, SP (Brazil). Secao de Cardiologia; Tonelli, P.A. [Sao Paulo Univ., SP (Brazil). Inst. de Matematica e Estatistica; Barros, L.C. [Universidade Estadual de Campinas , SP (Brazil). Inst. de Matematica, Estatistica e Computacao Cientifica; Ortega, N.R. [Sao Paulo Univ., SP (Brazil). Informatica Medica; Pereira, J.C.R. [Sao Paulo Univ., SP (Brazil). Faculdade de Saude Publica. Dept. de Epidemiologia

    2006-01-15

    Coronary artery disease (CAD) is a worldwide leading cause of death. The standard method for evaluating critical partial occlusions is coronary arteriography, a catheterization technique which is invasive, time consuming, and costly. There are noninvasive approaches for the early detection of CAD. The basis for the noninvasive diagnosis of CAD has been laid in a sequential analysis of the risk factors, and the results of the treadmill test and myocardial perfusion scintigraphy (MPS). Many investigators have demonstrated that the diagnostic applications of MPS are appropriate for patients who have an intermediate likelihood of disease. Although this information is useful, it is only partially utilized in clinical practice due to the difficulty to properly classify the patients. Since the seminal work of Lotfi Zadeh, fuzzy logic has been applied in numerous areas. In the present study, we proposed and tested a model to select patients for MPS based on fuzzy sets theory. A group of 1053 patients was used to develop the model and another group of 1045 patients was used to test it. Receiver operating characteristic curves were used to compare the performance of the fuzzy model against expert physician opinions, and showed that the performance of the fuzzy model was equal or superior to that of the physicians. Therefore, we conclude that the fuzzy model could be a useful tool to assist the general practitioner in the selection of patients for MPS. (author)

  18. Selection of patients from myocardial perfusion scintigraphy based on fuzzy sets theory applied to clinical-epidemiological data and treadmill test results

    International Nuclear Information System (INIS)

    Duarte, P.S.; Mastrocolla, L.E.; Farsky, P.S.; Sampaio, C.R.E.P.S.; Tonelli, P.A.; Barros, L.C.; Ortega, N.R.; Pereira, J.C.R.

    2006-01-01

    Coronary artery disease (CAD) is a worldwide leading cause of death. The standard method for evaluating critical partial occlusions is coronary arteriography, a catheterization technique which is invasive, time consuming, and costly. There are noninvasive approaches for the early detection of CAD. The basis for the noninvasive diagnosis of CAD has been laid in a sequential analysis of the risk factors, and the results of the treadmill test and myocardial perfusion scintigraphy (MPS). Many investigators have demonstrated that the diagnostic applications of MPS are appropriate for patients who have an intermediate likelihood of disease. Although this information is useful, it is only partially utilized in clinical practice due to the difficulty to properly classify the patients. Since the seminal work of Lotfi Zadeh, fuzzy logic has been applied in numerous areas. In the present study, we proposed and tested a model to select patients for MPS based on fuzzy sets theory. A group of 1053 patients was used to develop the model and another group of 1045 patients was used to test it. Receiver operating characteristic curves were used to compare the performance of the fuzzy model against expert physician opinions, and showed that the performance of the fuzzy model was equal or superior to that of the physicians. Therefore, we conclude that the fuzzy model could be a useful tool to assist the general practitioner in the selection of patients for MPS. (author)

  19. Sub-maximal and maximal Yo-Yo intermittent endurance test level 2: heart rate response, reproducibility and application to elite soccer

    DEFF Research Database (Denmark)

    Bradley, Paul S; Mohr, Magni; Bendiksen, Mads

    2011-01-01

    to detect test-retest changes and discriminate between performance for different playing standards and positions in elite soccer. Elite (n = 148) and sub-elite male (n = 14) soccer players carried out the Yo-Yo IE2 test on several occasions over consecutive seasons. Test-retest coefficient of variation (CV......) in Yo-Yo IE2 test performance and heart rate after 6 min were 3.9% (n = 37) and 1.4% (n = 32), respectively. Elite male senior and youth U19 players Yo-Yo IE2 performances were better (P ......The aims of this study were to (1) determine the reproducibility of sub-maximal and maximal versions of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2 test), (2) assess the relationship between the Yo-Yo IE2 test and match performance and (3) quantify the sensitivity of the Yo-Yo IE2 test...

  20. Biochemical changes in relation to a maximal exercise test in patients with fibromyalgia

    DEFF Research Database (Denmark)

    Nørregaard, J; Bülow, P M; Mehlsen, J

    1994-01-01

    Patients with fibromyalgia often complain of fatigue and pain during exercise and of worsening of pain days after exercise. The aim of the study described here was to determine if abnormal changes in potassium or lactate could be observed during an exercise test in fibromyalgia. Whether an abnormal...... incline in plasma creatine kinase or myoglobin could be observed days after the test was studied also. Fifteen female fibromyalgia patients and 15 age- and sex-matched controls performed a stepwise incremental maximal bicycle-ergometer test. Blood samples were collected from a catheter in a cubital vein......-1 was reached at a heart rate of 124 min-1 in the patients with fibromyalgia as compared to 140 min-1 in the controls (P = 0.02). In relation to workload, the patients scored higher on a Borg scale for perceived exertion during exercise, but if the Borg score was related to lactate no significant...

  1. Running on a lower-body positive pressure treadmill

    DEFF Research Database (Denmark)

    Raffalt, Peter C; Hovgaard-Hansen, Line; Jensen, Bente Rona

    2013-01-01

    This study investigated maximal oxygen consumption (VO2max) and time to exhaustion while running on a lower-body positive pressure treadmill (LBPPT) at normal body weight (BW) as well as how BW support affects respiratory responses, ground reaction forces, and stride characteristics.......This study investigated maximal oxygen consumption (VO2max) and time to exhaustion while running on a lower-body positive pressure treadmill (LBPPT) at normal body weight (BW) as well as how BW support affects respiratory responses, ground reaction forces, and stride characteristics....

  2. The use of serological tests in combination with the intradermal tuberculin test maximizes the detection of tuberculosis infected goats.

    Science.gov (United States)

    Bezos, Javier; Roy, Álvaro; Infantes-Lorenzo, José Antonio; González, Isabel; Venteo, Ángel; Romero, Beatriz; Grau, Anna; Mínguez, Olga; Domínguez, Lucas; de Juan, Lucía

    2018-05-01

    The diagnosis of tuberculosis (TB) in goats is based mainly on the single and comparative intradermal tuberculin (SIT and CIT) tests and, exceptionally, on the interferon-gamma (IFN-γ) assay, however they are not perfect in terms of sensitivity and specificity. Nevertheless, various serological assays that provide a potential cost-effective approach for the control of TB are also available or under development, and a variety of results have been reported regarding the ability of these tests to detect infected animals, particularly in the early stages of infection. In the present study, SIT/CIT and IFN-γ tests and three different serological assays were evaluated during two consecutive herd testing events in a recently infected caprine herd (n = 447) with a high prevalence of infection in order to evaluate their performance and provide field data with which to improve the TB control programs in this species. The proportion of infected animals that tested positive among all the infected goats (T+/I+ value) in the last herd testing event ranged from 26.2% (IC95%; 19.3-34.5) to 85.7% (IC95%; 78.5-90.7) using cell-based diagnostic tests. The SIT/SCIT tests detected more infected goats than the IFN-γ test, regardless of the interpretation criteria. The T+/I+ value of serology was 83.2 (IC95%; 75.2-89), although it increased significantly (P test (100%, IC95%; 97-100). In general, a parallel interpretation of intradermal tests with serology maximized the detection of infected goats. These results demonstrate that serological tests are valuable diagnostic tools to maximize the detection of TB infected goats, even in recent outbreaks, accelerating the eradication process. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Comparison of the Danish step test and the watt-max test for estimation of maximal oxygen uptake

    DEFF Research Database (Denmark)

    Aadahl, Mette; Zacho, Morten; Linneberg, Allan René

    2013-01-01

    . Altogether, 795 eligible participants (response rate 35.8%) performed the watt max and the Danish step test. Correlation and agreement between the two VO(2max) test results was explored by Pearson's rho, Bland-Altman plots, Kappa(w), and gamma coefficients.Results: The correlation between VO(2max) (ml......Introduction: There is a need for simple and feasible methods for estimation of cardiorespiratory fitness (CRF) in large study populations, as existing methods for valid estimation of maximal oxygen consumption are generally time consuming and relatively expensive to administer. The Danish step...

  4. [Effect of psychotropic drugs on activity of anticonvulsants in maximal electroshock test].

    Science.gov (United States)

    Alikina, N A; Tregubov, A L; Kotegov, V P

    2010-08-01

    The effect ofpsychotropic drugs on the pharmacological properties of anticonvulsants was studied on white mice under maximal electroshock (ME) test conditions. Changes in the anticonvulsant effect of phenobarbital, diphenin, carbamazepine, hexamidine were traced upon their joint administration with psychotropic drugs, including piracetam, aminalon, amitriptyline, imizine, levomepromazine, and lithium oxybutyrate. An important result of research is the fact, that in no one of combinations the basic pharmacological effect of anticonvulsants was decreased. Based on the results of experiments, the most rational combinations of anticonvulsants with psychotropic preparations were revealed as manifested in the ME test. As criterion of rational combination was the increase in the activity of anticonvulsants and reduction of their toxicity in combination or at least invariance of this parameter. Rational combinations include (i) phenobarbital with piracetam, amitriptyline, levomepromazine, and lithium oxybutyrate; (ii) carbamazepine with piracetam; and (iii) hexamidine with amitriptyline, levomepromazine and imizine.

  5. Sperm competition leads to functional adaptations in avian testes to maximize sperm quantity and quality.

    Science.gov (United States)

    Lüpold, Stefan; Wistuba, Joachim; Damm, Oliver S; Rivers, James W; Birkhead, Tim R

    2011-05-01

    The outcome of sperm competition (i.e. competition for fertilization between ejaculates from different males) is primarily determined by the relative number and quality of rival sperm. Therefore, the testes are under strong selection to maximize both sperm number and quality, which are likely to result in trade-offs in the process of spermatogenesis (e.g. between the rate of spermatogenesis and sperm length or sperm energetics). Comparative studies have shown positive associations between the level of sperm competition and both relative testis size and the proportion of seminiferous (sperm-producing) tissue within the testes. However, it is unknown how the seminiferous tissue itself or the process of spermatogenesis might evolve in response to sperm competition. Therefore, we quantified the different germ cell types and Sertoli cells (SC) in testes to assess the efficiency of sperm production and its associations with sperm length and mating system across 10 species of New World Blackbirds (Icteridae) that show marked variation in sperm length and sperm competition level. We found that species under strong sperm competition generate more round spermatids (RS)/spermatogonium and have SC that support a greater number of germ cells, both of which are likely to increase the maximum sperm output. However, fewer of the RS appeared to elongate to mature spermatozoa in these species, which might be the result of selection for discarding spermatids with undesirable characteristics as they develop. Our results suggest that, in addition to overall size and gross morphology, testes have also evolved functional adaptations to maximize sperm quantity and quality.

  6. Comparison of Critical Power and W' Derived From 2 or 3 Maximal Tests.

    Science.gov (United States)

    Simpson, Len Parker; Kordi, Mehdi

    2017-07-01

    Typically, accessing the asymptote (critical power; CP) and curvature constant (W') parameters of the hyperbolic power-duration relationship requires multiple constant-power exhaustive-exercise trials spread over several visits. However, more recently single-visit protocols and personal power meters have been used. This study investigated the practicality of using a 2-trial, single-visit protocol in providing reliable CP and W' estimates. Eight trained cyclists underwent 3- and 12-min maximal-exercise trials in a single session to derive (2-trial) CP and W' estimates. On a separate occasion a 5-min trial was performed, providing a 3rd trial to calculate (3-trial) CP and W'. There were no differences in CP (283 ± 66 vs 282 ± 65 W) or W' (18.72 ± 6.21 vs 18.27 ± 6.29 kJ) obtained from either the 2-trial or 3-trial method, respectively. After 2 familiarization sessions (completing a 3- and a 12-min trial on both occasions), both CP and W' remained reliable over additional separate measurements. The current study demonstrates that after 2 familiarization sessions, reliable CP and W' parameters can be obtained from trained cyclists using only 2 maximal-exercise trials. These results offer practitioners a practical, time-efficient solution for incorporating power-duration testing into applied athlete support.

  7. Acute Changes in Creatine Kinase Serum Levels in Adults Submitted a Static Stretching and Maximal Strength Test

    Directory of Open Access Journals (Sweden)

    M.G. Bara Filho

    2008-01-01

    Full Text Available Strength and flexibility are common components of a training program and their maximal values are obtained through specific tests. However, little information about the damage effect of these training procedures in a skeletal muscle is known. Objective: To verify a serum CK changes 24 h after a sub maximal stretching routine and after the static flexibility and maximal strength tests. Methods: the sample was composed by 14 subjects (man and women, 28 ± 6 yr. physical education students. The volunteers were divided in a control group (CG and experimental group (EG that was submitted in a stretching routine (EG-ST, in a maximal flexibility static test (EG-FLEX and in 1-RM test (EG-1-RM, with one week interval among tests. The anthropometrics characteristics were obtained by digital scale with stadiometer (Filizola, São Paulo, Brasil, 2002. The blood samples were obtained using the IFCC method with reference values 26-155 U/L. The De Lorme and Watkins technique was used to access maximal maximal strength through bench press and leg press. The maximal flexibility test consisted in three 20 seconds sets until the point of maximal discomfort. The stretching was done in normal movement amplitude during 6 secons. Results: The basal and post 24 h CK values in CG and EG (ST; Flex and 1 RM were respectively 195,0 ± 129,5 vs. 202,1 ± 124,2; 213,3 ± 133,2 vs. 174,7 ± 115,8; 213,3 ± 133,2 vs. 226,6 ± 126,7 e 213,3 ± 133,2 vs. 275,9 ± 157,2. It was only observed a significant difference (p = 0,02 in the pre and post values inGE-1RM. Conclusion: only maximal strength dynamic exercise was capable to cause skeletal muscle damage.

  8. Estimation of maximal oxygen uptake via submaximal exercise testing in sports, clinical, and home settings.

    Science.gov (United States)

    Sartor, Francesco; Vernillo, Gianluca; de Morree, Helma M; Bonomi, Alberto G; La Torre, Antonio; Kubis, Hans-Peter; Veicsteinas, Arsenio

    2013-09-01

    Assessment of the functional capacity of the cardiovascular system is essential in sports medicine. For athletes, the maximal oxygen uptake [Formula: see text] provides valuable information about their aerobic power. In the clinical setting, the (VO(2max)) provides important diagnostic and prognostic information in several clinical populations, such as patients with coronary artery disease or heart failure. Likewise, VO(2max) assessment can be very important to evaluate fitness in asymptomatic adults. Although direct determination of [VO(2max) is the most accurate method, it requires a maximal level of exertion, which brings a higher risk of adverse events in individuals with an intermediate to high risk of cardiovascular problems. Estimation of VO(2max) during submaximal exercise testing can offer a precious alternative. Over the past decades, many protocols have been developed for this purpose. The present review gives an overview of these submaximal protocols and aims to facilitate appropriate test selection in sports, clinical, and home settings. Several factors must be considered when selecting a protocol: (i) The population being tested and its specific needs in terms of safety, supervision, and accuracy and repeatability of the VO(2max) estimation. (ii) The parameters upon which the prediction is based (e.g. heart rate, power output, rating of perceived exertion [RPE]), as well as the need for additional clinically relevant parameters (e.g. blood pressure, ECG). (iii) The appropriate test modality that should meet the above-mentioned requirements should also be in line with the functional mobility of the target population, and depends on the available equipment. In the sports setting, high repeatability is crucial to track training-induced seasonal changes. In the clinical setting, special attention must be paid to the test modality, because multiple physiological parameters often need to be measured during test execution. When estimating VO(2max), one has

  9. Sequential Design of Experiments to Maximize Learning from Carbon Capture Pilot Plant Testing

    Energy Technology Data Exchange (ETDEWEB)

    Soepyan, Frits B.; Morgan, Joshua C.; Omell, Benjamin P.; Zamarripa-Perez, Miguel A.; Matuszewski, Michael S.; Miller, David C.

    2018-02-06

    Pilot plant test campaigns can be expensive and time-consuming. Therefore, it is of interest to maximize the amount of learning and the efficiency of the test campaign given the limited number of experiments that can be conducted. This work investigates the use of sequential design of experiments (SDOE) to overcome these challenges by demonstrating its usefulness for a recent solvent-based CO2 capture plant test campaign. Unlike traditional design of experiments methods, SDOE regularly uses information from ongoing experiments to determine the optimum locations in the design space for subsequent runs within the same experiment. However, there are challenges that need to be addressed, including reducing the high computational burden to efficiently update the model, and the need to incorporate the methodology into a computational tool. We address these challenges by applying SDOE in combination with a software tool, the Framework for Optimization, Quantification of Uncertainty and Surrogates (FOQUS) (Miller et al., 2014a, 2016, 2017). The results of applying SDOE on a pilot plant test campaign for CO2 capture suggests that relative to traditional design of experiments methods, SDOE can more effectively reduce the uncertainty of the model, thus decreasing technical risk. Future work includes integrating SDOE into FOQUS and using SDOE to support additional large-scale pilot plant test campaigns.

  10. Usability testing of two e-learning resources: methods to maximize potential for clinician use.

    Science.gov (United States)

    Menon, Anita; Korner-Bitensky, Nicol; Chignell, Mark; Straus, Sharon

    2012-04-01

    Rigorous usability testing of e-learn-ing resources is an important prerequisite to their wide-spread use among clinicians. This study demonstrates the application of an evidence-based approach to usability testing of two stroke-related e-learning resources (StrokEngine). 14 stroke rehabilitation clinicians (occupational therapists and physiotherapists) from Ontario, Canada participated in a 1.5 h in-person testing session. Clinicians navigated StrokEngine in search of information to answer questions on stroke assessment/intervention. Their search patterns were observed and clinicians provided verbal/written feedback about StrokEngine. Content analysis was used to generate themes and categorize them under two broad categories: facilitators and barriers to use. Five key facilitators and three key barriers to Strok-Engine use were identified and related to screen format, layout/organization, ease of navigation, quality of content, likelihood of using StrokEngine in the future, and system dysfunctions. All 14 clinicians were very or extremely satisfied with the layout/organization, quality and clinical relevance of the content, stating that they were likely to use StrokEngine in the future. All identified barriers from this study were addressed with website modifications in order to maximize the usability and navigability of StrokEngine. This rigorous methodology for usability testing can be applied during the design process of any e-learning resource.

  11. Metabolic interpretation of ventilatory parameters during maximal effort test and their applicability to sports

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Barreto Martins

    2007-09-01

    Full Text Available One important tool for producing specifi c and individualized training intensities is to determine ventilatory threshold (VT, respiratory compensation point (RCP and maximal oxygen uptake (VO2max by means of maximum effort testing. However, in order to be able to interpret these data in a wide-ranging manner, it is also important to understand the metabolic responses that occur during the test as the systems transporting and utilizing O2 and producing CO2 adjust. This review article presents an overview of the metabolic responses that take place during a hypothetical maximum effort test, and the applicability of the fi gures thus obtained to the training of athletes. ABSTRACT A determinação das velocidades atingidas no limiar ventilatório (LV, ponto de compensação respiratório (PCR e consumo máximo de O2 (VO2max através de um teste de esforço máximo, é uma ferramenta importante para a aplicação de intensidades de treinamento específicas e individualizadas. Mas para poder interpretar os dados de uma forma abrangente, também é importante o entendimento das respostas metabólicas presentes no ajuste dos sistemas de transporte e utilização de O2 e produção de CO2 durante a realização do teste. Esta revisão apresenta um panorama das respostas metabólicas que acontecem durante a realização de um teste de esforço máximo hipotético, e a aplicabilidade dos valores obtidos no treinamento de atletas.

  12. Positive exercise thallium-201 test responses in patients with less than 50% maximal coronary stenosis: angiographic and clinical predictors

    International Nuclear Information System (INIS)

    Brown, K.A.; Osbakken, M.; Boucher, C.A.; Strauss, H.W.; Pohost, G.M.; Okada, R.D.

    1985-01-01

    The incidence and causes of abnormal thallium-201 (TI-201) myocardial perfusion studies in the absence of significant coronary artery disease were examined. The study group consisted of 100 consecutive patients undergoing exercise TI-201 testing and coronary angiography who were found to have maximal coronary artery diameter narrowing of less than 50%. Maximal coronary stenosis ranged from 0 to 40%. The independent and relative influences of patient clinical, exercise and angiographic data were assessed by logistic regression analysis. Significant predictors of a positive stress TI-201 test result were: (1) percent maximal coronary stenosis (p less than 0.0005), (2) propranolol use (p less than 0.01), (3) interaction of propranolol use and percent maximal stenosis (p less than 0.005), and (4) stress-induced chest pain (p . 0.05). No other patient variable had a significant influence. Positive TI-201 test results were more common in patients with 21 to 40% maximal stenosis (59%) than in patients with 0 to 20% maximal stenosis (27%) (p less than 0.01). Among patients with 21 to 40% stenosis, a positive test response was more common when 85% of maximal predicted heart rate was achieved (75%) than when it was not (40%) (p less than 0.05). Of 16 nonapical perfusion defects seen in patients with 21 to 40% maximal stenosis, 14 were in the territory that corresponded with such a coronary stenosis. Patients taking propranolol were more likely to have a positive TI-201 test result (45%) than patients not taking propranolol (22%) (p less than 0.05)

  13. Oxygen uptake of overweight and obese children at different stages of a progressive treadmill test: Consumo de oxígeno de niños y niñas con sobrepeso y obesos en los diferentes estadios de una prueba progresiva en un tapiz rodante.

    Science.gov (United States)

    Meléndez-Ortega, Agustín; Lucy Davis, Catherine; Barbeau, Paule; Boyle, Colleen Ann

    2010-01-01

    INTRODUCTION: Maximal oxygen uptake (VO2 max) is associated with cardiovascular and metabolic risks but it is difficult to assess in obese children. The objective of this study was to develop an equation to estimate VO2 (mL/kg/min) and to check the % of tests that were maximal according to recommended criteria. METHODS: Stress tests were analyzed of 222 subjects (94 male and 128 female with a BMI above the 85 percentile for age and sex), and repeated 4 months later. Mean age was 9.4 ± 1.1 years and weighed 52.4 ± 13.3 kg. Body fat % (40.5 + 6.2) was determined by DXA (Hologic QDR 4500W). The protocol on the treadmill started with a warm up at 2.5 and 3 mph with a slope of 0% and 2%. The speed was kept at 3 mph for all the stages and the slope was increased 2% every 2 minutes. Statistical analysis (descriptive, t-test and ANOVAS 2×2×2) was done with SPSS 15.0. RESULTS: Only 35% of the tests were maximal. The equation calculates was Y = 2.6x + 22.3 (x = protocol stage). Data pre and post treatment were not statistically different DISCUSSION: Increments in VO2 were consistent despite subject diversity (sex, % body fat, physical fitness, treatment). CONCLUSION: To be able to estimate VO2 at the different stages of the test without complex equipment or specialized staff, will facilitate the performance of stress tests on a daily basis.

  14. Effects of 12-week supervised treadmill training on spatio-temporal gait parameters in patients with claudication.

    Science.gov (United States)

    Konik, Anita; Kuklewicz, Stanisław; Rosłoniec, Ewelina; Zając, Marcin; Spannbauer, Anna; Nowobilski, Roman; Mika, Piotr

    2016-01-01

    The purpose of the study was to evaluate selected temporal and spatial gait parameters in patients with intermittent claudication after completion of 12-week supervised treadmill walking training. The study included 36 patients (26 males and 10 females) aged: mean 64 (SD 7.7) with intermittent claudication. All patients were tested on treadmill (Gait Trainer, Biodex). Before the programme and after its completion, the following gait biomechanical parameters were tested: step length (cm), step cycle (cycle/s), leg support time (%), coefficient of step variation (%) as well as pain-free walking time (PFWT) and maximal walking time (MWT) were measured. Training was conducted in accordance with the current TASC II guidelines. After 12 weeks of training, patients showed significant change in gait biomechanics consisting in decreased frequency of step cycle (p gait was more regular, which was expressed via statistically significant decrease of coefficient of variation (p 0.05). Twelve-week treadmill walking training programme may lead to significant improvement of temporal and spatial gait parameters in patients with intermittent claudication. Twelve-week treadmill walking training programme may lead to significant improvement of pain-free walking time and maximum walking time in patients with intermittent claudication.

  15. A successful capital treadmill

    International Nuclear Information System (INIS)

    Bohun, D.A.

    1995-01-01

    A summary of the operating economics of the Winter Cummings Sand Pool, a horizontal well development project with a sustained rate of development, was presented. A total of 58 horizontal wells have been drilled over a time span of seven years. The production performance of the first pilot wells indicated that development of the pool by horizontal wells could be economically viable. Since its inception the Winter field development was considered to have become a capital treadmill with an incremental rate of return on the incremental investment of 240 percent (a 24 million dollar net operating cash flow for a 10 million dollar investment). Current development status and production forecasts were also discussed. 21 figs

  16. Maximal cardiorespiratory fitness testing in individuals with chronic stroke with cognitive impairment: practice test effects and test-retest reliability.

    Science.gov (United States)

    Olivier, Charles; Doré, Jean; Blanchet, Sophie; Brooks, Dina; Richards, Carol L; Martel, Guy; Robitaille, Nancy-Michelle; Maltais, Désirée B

    2013-11-01

    To evaluate, for individuals with chronic stroke with cognitive impairment, (1) the effects of a practice test on peak cardiorespiratory fitness test results; (2) cardiorespiratory fitness test-retest reliability; and (3) the relationship between individual practice test effects and cognitive impairment. Cross-sectional. Rehabilitation center. A convenience sample of 21 persons (men [n=12] and women [n=9]; age range, 48-81y; 44.9±36.2mo poststroke) with cognitive impairments who had sufficient lower limb function to perform the test. Not applicable. Peak oxygen consumption (Vo(2)peak, ml·kg(-1)·min(-1)). Test-retest reliability of Vo(2)peak was excellent (intraclass correlation coefficient model 2,1 [ICC2,1]=.94; 95% confidence interval [CI], .86-.98). A paired t test showed that there was no significant difference for the group for Vo(2)peak obtained from 2 symptom-limited cardiorespiratory fitness tests performed 1 week apart on a semirecumbent cycle ergometer (test 2-test 1 difference, -.32ml·kg(-1)·min(-1); 95% CI, -.69 to 1.33ml·kg(-1)·min(-1); P=.512). Individual test-retest differences in Vo(2)peak were, however, positively related to general cognitive function as measured by the Mini-Mental State Examination (ρ=.485; Preliably measured in this group without a practice test. General cognitive function, however, may influence the effect of a practice test in that those with lower general cognitive function appear to respond differently to a practice test than those with higher cognitive function. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  17. Treadmill training of infants with Down syndrome: evidence-based developmental outcomes.

    Science.gov (United States)

    Ulrich, D A; Ulrich, B D; Angulo-Kinzler, R M; Yun, J

    2001-11-01

    , parents can use these treadmills in their homes to help their infants with DS learn to walk earlier than they normally would. Current research is aimed at 1) improving the protocol to maximize outcome; 2) determining the impact of treadmill practice on walking gait patterns; 3) testing the application to other populations with a history of delays in walking; and 4) determining the long-term benefits that may accrue from this form of activity. motor development, Down syndrome, early intervention, walking.

  18. Metabolic and clinical comparative analysis of treadmill six-minute walking test and cardiopulmonary exercise testing in obese and eutrophic women Análise clínica e metabólica comparativa entre o teste de caminhada de seis minutos e o teste de exercício cardiopulmonar em mulheres obesas e eutróficas

    Directory of Open Access Journals (Sweden)

    Luciana Di Thommazo-Luporini

    2012-12-01

    Full Text Available BACKGROUND: Impaired exercise tolerance is directly linked to decreased functional capacity as a consequence of obesity. OBJECTIVES: To analyze and compare the cardiopulmonary, metabolic, and perceptual responses during a cardiopulmonary exercise test (CPX and a treadmill six-minute walking test (tread6MWT in obese and eutrophic women. METHOD: Twenty-nine female participants, aged 20-45 years were included. Fourteen were allocated to the obese group and 15 to the eutrophic group. Anthropometric measurements and body composition assessment were performed. RESULTS: In both tests, obese women presented with significantly higher absolute oxygen uptake, minute ventilation, and systolic and diastolic blood pressure; they also presented with lower speed, distance walked, and oxygen uptake corrected by the weight compared to eutrophics. During the maximal exercise test, perceived dyspnea was greater and the respiratory exchange ratio was lower in obese subjects compared to eutrophics. During the submaximal test, carbon dioxide production, tidal volume, and heart rate were higher in obese subjects compared to eutrophic women. When analyzing possible correlations between the CPX and the tread6MWT at peak, there was a strong correlation for the variable heart rate and a moderate correlation for the variable oxygen uptake. The heart rate obtained in the submaximal test was able to predict the one obtained in the maximal test. Bland-Altman plots demonstrated the agreement between both tests to identify metabolic and physiological parameters at peak exercise. CONCLUSIONS: The six-minute walking test induced ventilatory, metabolic, and cardiovascular responses in agreement with the maximal testing. Thus, the six-minute walking test proves to be important for functional evaluation in the physical therapy routine.CONTEXTUALIZAÇÃO: A reduzida tolerância ao exercício está relacionada à diminuída capacidade funcional consequente da obesidade. Objetivos

  19. Metabolic and clinical comparative analysis of treadmill six-minute walking test and cardiopulmonary exercise testing in obese and eutrophic women Análise clínica e metabólica comparativa entre o teste de caminhada de seis minutos e o teste de exercício cardiopulmonar em mulheres obesas e eutróficas

    Directory of Open Access Journals (Sweden)

    Luciana Di Thommazo-Luporini

    2012-01-01

    Full Text Available BACKGROUND: Impaired exercise tolerance is directly linked to decreased functional capacity as a consequence of obesity. OBJECTIVES: To analyze and compare the cardiopulmonary, metabolic, and perceptual responses during a cardiopulmonary exercise test (CPX and a treadmill six-minute walking test (tread6MWT in obese and eutrophic women. METHOD: Twenty-nine female participants, aged 20-45 years were included. Fourteen were allocated to the obese group and 15 to the eutrophic group. Anthropometric measurements and body composition assessment were performed. RESULTS: In both tests, obese women presented with significantly higher absolute oxygen uptake, minute ventilation, and systolic and diastolic blood pressure; they also presented with lower speed, distance walked, and oxygen uptake corrected by the weight compared to eutrophics. During the maximal exercise test, perceived dyspnea was greater and the respiratory exchange ratio was lower in obese subjects compared to eutrophics. During the submaximal test, carbon dioxide production, tidal volume, and heart rate were higher in obese subjects compared to eutrophic women. When analyzing possible correlations between the CPX and the tread6MWT at peak, there was a strong correlation for the variable heart rate and a moderate correlation for the variable oxygen uptake. The heart rate obtained in the submaximal test was able to predict the one obtained in the maximal test. Bland-Altman plots demonstrated the agreement between both tests to identify metabolic and physiological parameters at peak exercise. CONCLUSIONS: The six-minute walking test induced ventilatory, metabolic, and cardiovascular responses in agreement with the maximal testing. Thus, the six-minute walking test proves to be important for functional evaluation in the physical therapy routine.CONTEXTUALIZAÇÃO: A reduzida tolerância ao exercício está relacionada à diminuída capacidade funcional consequente da obesidade. Objetivos

  20. Comparison of dose-responses of contact allergens using the guinea pig maximization test and the local lymph node assay

    NARCIS (Netherlands)

    Och, F.M.M. van; Vandebriel, R.J.; Prinsen, M.K.; Jong, W.H. de; Slob, W.; Loveren, H. van

    2001-01-01

    The guinea pig maximization test (GPMT) has been used as a method for the prediction of skin sensitizing potential for over 30 years. Besides hazard identification, risk assessment of sensitizing chemicals requires the assessment of potency. For the determination of potency based on lowest effective

  1. Estimation of maximal oxygen uptake via submaximal exercise testing in sports, clinical, and home settings

    NARCIS (Netherlands)

    Sartor, F.; Vernillo, G.; de Morree, H.M.; Bonomi, A.G.; La Torre, A.; Kubis, H.P.; Veicsteinas, A.

    2013-01-01

    Assessment of the functional capacity of the cardiovascular system is essential in sports medicine. For athletes, the maximal oxygen uptake (V˙O2max) provides valuable information about their aerobic power. In the clinical setting, the V˙O2max provides important diagnostic and prognostic information

  2. Analysis of elliptically polarized maximally entangled states for bell inequality tests

    Science.gov (United States)

    Martin, A.; Smirr, J.-L.; Kaiser, F.; Diamanti, E.; Issautier, A.; Alibart, O.; Frey, R.; Zaquine, I.; Tanzilli, S.

    2012-06-01

    When elliptically polarized maximally entangled states are considered, i.e., states having a non random phase factor between the two bipartite polarization components, the standard settings used for optimal violation of Bell inequalities are no longer adapted. One way to retrieve the maximal amount of violation is to compensate for this phase while keeping the standard Bell inequality analysis settings. We propose in this paper a general theoretical approach that allows determining and adjusting the phase of elliptically polarized maximally entangled states in order to optimize the violation of Bell inequalities. The formalism is also applied to several suggested experimental phase compensation schemes. In order to emphasize the simplicity and relevance of our approach, we also describe an experimental implementation using a standard Soleil-Babinet phase compensator. This device is employed to correct the phase that appears in the maximally entangled state generated from a type-II nonlinear photon-pair source after the photons are created and distributed over fiber channels.

  3. Test-retest reliability of maximal leg muscle power and functional performance measures in patients with severe osteoarthritis (OA)

    DEFF Research Database (Denmark)

    Villadsen, Allan; Roos, Ewa M.; Overgaard, Søren

    Abstract : Purpose To evaluate the reliability of single-joint and multi-joint maximal leg muscle power and functional performance measures in patients with severe OA. Background Muscle power, taking both strength and velocity into account, is a more functional measure of lower extremity muscle...... and scheduled for unilateral total hip (n=9) or knee (n=11) replacement. Patients underwent a test battery on two occasions separated by approximately one week (range 7 to 11 days). Muscle power was measured using: 1. A linear encoder, unilateral lower limb isolated single-joint dynamic movement, e.g. knee...... flexion 2. A leg extension press, unilateral multi-joint knee and hip extension Functional performance was measured using: 1. 20 m walk usual pace 2. 20 m walk maximal pace 3. 5 times chair stands 4. Maximal number of knee bends/30sec Pain was measured on a VAS prior to and after conducting the entire...

  4. Overspeed HIIT in Lower-Body Positive Pressure Treadmill Improves Running Performance.

    Science.gov (United States)

    Gojanovic, Boris; Shultz, Rebecca; Feihl, Francois; Matheson, Gordon

    2015-12-01

    Optimal high-intensity interval training (HIIT) regimens for running performance are unknown, although most protocols result in some benefit to key performance factors (running economy (RE), anaerobic threshold (AT), or maximal oxygen uptake (VO2max)). Lower-body positive pressure (LBPP) treadmills offer the unique possibility to partially unload runners and reach supramaximal speeds. We studied the use of LBPP to test an overspeed HIIT protocol in trained runners. Eleven trained runners (35 ± 8 yr, VO2max, 55.7 ± 6.4 mL·kg⁻¹·min⁻¹) were randomized to an LBPP (n = 6) or a regular treadmill (CON, n = 5), eight sessions over 4 wk of HIIT program. Four to five intervals were run at 100% of velocity at VO2max (vVO2max) during 60% of time to exhaustion at vVO2max (Tlim) with a 1:1 work:recovery ratio. Performance outcomes were 2-mile track time trial, VO2max, vVO2max, vAT, Tlim, and RE. LBPP sessions were carried out at 90% body weight. Group-time effects were present for vVO2max (CON, 17.5 vs. 18.3, P = 0.03; LBPP, 19.7 vs. 22.3 km·h⁻¹; P HIIT protocol at 100% vVO2max improves field performance, vVO2max, VO2max and submaximal HR in trained runners. Improvements are similar if intervals are run on a regular treadmill or at higher speeds on a LPBB treadmill with 10% body weight reduction. LBPP could provide an alternative for taxing HIIT sessions.

  5. Tissue oxygen partial pressure in the tibialis anterior muscle in patients with claudication before, during and after a two-stage treadmill stress test.

    Science.gov (United States)

    Jung, F; Krüger, A; Pindur, G; Sternitzky, R; Franke, R P; Gori, T

    2014-01-01

    The role of the microcirculation in the pathophysiology and symptoms of peripheral arterial obliterative disease (PAOD) has been progressively emphasized during the past decades. Under resting conditions, already, the tissue oxygen partial pressure in the m. tibialis anterior (pO2im) is reduced to about 50% compared to healthy subjects. In the framework of this study the pO2im of patients with PAOD stage II according to Fontaine (n=16) in the m. tibialis anterior was measured under resting conditions and during walking on a treadmill in comparison to healthy subjects (n=10). Under resting conditions the pO2im only marginally differed between PAOD patients and healthy subjects. But during exercise the pO2im dropped significantly more severely in PAOD patients and a return to baseline values could only be reached when the treadmill was stopped and the patients stood still. The pO2im minima correlated clearly with the clinical symptom of calf pain. The data revealed that the pO2im values were lower in PAOD patients and dropped significantly faster during walking compared to the pO2im values in healthy subjects. The pO2im decrease correlated with the calf pain occurring when the pO2im values approached or fell below 10 mmHg.

  6. Effects of treadmill running on rat gastrocnemius function following botulinum toxin A injection.

    Science.gov (United States)

    Tsai, Sen-Wei; Chen, Chun-Jung; Chen, Hsiao-Lin; Chen, Chuan-Mu; Chang, Yin-Yi

    2012-02-01

    Exercise can improve and maintain neural or muscular function, but the effects of exercise in physiological adaptation to paralysis caused by botulinum toxin A has not been well studied. Twenty-four rats were randomly assigned into control and treadmill groups. The rats assigned to the treadmill group were trained on a treadmill three times per week with the running speed set at 15 m/min. The duration of training was 20 min/session. Muscle strength, nerve conduction study and sciatic functional index (SFI) were used for functional analysis. Treadmill training improved the SFI at 2, 3, and 4 weeks (p = 0.01, 0.004, and 0.01, respectively). The maximal contraction force of the gastrocnemius muscle in the treadmill group was greater than in the control group (p properties of muscle contraction strength, CMAP amplitude, and the recovery of SFI. Copyright © 2011 Orthopaedic Research Society.

  7. The use of Yo-Yo IR1 and Andersen testing for fitness and maximal heart rate assessments of 6-10 yr old school children

    DEFF Research Database (Denmark)

    Ahler, Thomas

    2012-01-01

    ; grade 2, n=16) and six weeks apart by 9-10 year olds (grade 3, n=49). Grade (G) 0-2's also performed an incremental treadmill test (ITT). G2's had a better (pSD) vs 536±218 m) and Andersen test performance (10%; 1050±71 vs 955±56 m) than G0's. For G0-2's YYIR1C......-10 year old children. Additionally, submaximal YYIR1C testing can be used for frequent non-exhaustive fitness assessments....

  8. Effects of Increased Respiratory Resistance on Maximal O2 Uptake and Anaerobic Threshold during Incremental Exercise Tests

    OpenAIRE

    ÖZÇELİK, Oğuz

    2014-01-01

    This study was undertaken to assess whether maximal O2 uptake (VO2max) can be used as an index of measuring aerobic capacity under the condition of increased respiratory resistance. Seven male subjects performed two incremental exercise tests on a cycle ergometer on different days: one control (C) and one breathing through an 8 mm bore diameter respiratory resistance (R). Ventilatory and gas exchange responses were measured with a turbine volume transducer and mass spectrometry, and processed...

  9. Technetium 99m SESTAMIBI myocardial perfusion imaging: Comparison between treadmill, dipyridamole and trans-oesophageal atrial pacing 'stress' tests in normal subjects

    International Nuclear Information System (INIS)

    Primeau, M.; Taillefer, R.; Lambert, R.; Essiambre, R.; Honos, G.

    1991-01-01

    The purpose of this study was to determine the blood clearance, myocardial uptake and heart/lung and heart/liver ratios of technetium 99m methoxyisobutylisonitrile ( 99m Tc-SESTAMIBI) following 3 different types of cardiac stimulation in normal subjects: Treadmill stress (STRESS), intravenous administration of dipyridamole (DIP) and trans-oesophageal atrial pacing (TAP). Ten normal volunteers were submitted to 3 injections of 99m Tc-SESTAMIBI (10 mCi/70 kg, separated by an interval of 7 days) following STRESS (standard Bruce protocol), DIP (0.142 mg/kg.min during 4 min) and TAP procedures. Blood samples were collected from 1 to 60 min after each 99m Tc-SESTAMIBI injection. Planar imaging was performed at 5, 30 and 60 min. Blood retention (percentage of injected dose at 1 min) was 56%±4%, 24%±4% and 38%±6% for STRESS, DIP and TAP, respectively (P 99m Tc-SESTAMIBI. (orig.)

  10. Supra maximal bicycle tests do not detect seasonable progress in groups of elite speed skaters

    NARCIS (Netherlands)

    van Ingen Schenau, G.J.; Bakker, F.C.; de Groot, G.; de Koning, J.J.

    1992-01-01

    Seven female and eight male elite junior skaters performed cycle ergometer tests at four different times during the 1987/1988 season. The tests consisted of a Wingate-type 30-s sprint test and a 2.5-min supramaximal test. The subjects were tested in February, May and September 1987 and in January

  11. Low-cost extrapolation method for maximal LTE radio base station exposure estimation: test and validation.

    Science.gov (United States)

    Verloock, Leen; Joseph, Wout; Gati, Azeddine; Varsier, Nadège; Flach, Björn; Wiart, Joe; Martens, Luc

    2013-06-01

    An experimental validation of a low-cost method for extrapolation and estimation of the maximal electromagnetic-field exposure from long-term evolution (LTE) radio base station installations are presented. No knowledge on downlink band occupation or service characteristics is required for the low-cost method. The method is applicable in situ. It only requires a basic spectrum analyser with appropriate field probes without the need of expensive dedicated LTE decoders. The method is validated both in laboratory and in situ, for a single-input single-output antenna LTE system and a 2×2 multiple-input multiple-output system, with low deviations in comparison with signals measured using dedicated LTE decoders.

  12. Low-cost extrapolation method for maximal lte radio base station exposure estimation: Test and validation

    International Nuclear Information System (INIS)

    Verloock, L.; Joseph, W.; Gati, A.; Varsier, N.; Flach, B.; Wiart, J.; Martens, L.

    2013-01-01

    An experimental validation of a low-cost method for extrapolation and estimation of the maximal electromagnetic-field exposure from long-term evolution (LTE) radio base station installations are presented. No knowledge on down-link band occupation or service characteristics is required for the low-cost method. The method is applicable in situ. It only requires a basic spectrum analyser with appropriate field probes without the need of expensive dedicated LTE decoders. The method is validated both in laboratory and in situ, for a single-input single-output antenna LTE system and a 2x2 multiple-input multiple-output system, with low deviations in comparison with signals measured using dedicated LTE decoders. (authors)

  13. Predição da potência aeróbia (VO2máx de crianças e adolescentes em teste incremental na esteira rolante Prediction of aerobic power (VO2max of children and adolescents during an incremental treadmill test

    Directory of Open Access Journals (Sweden)

    Fabiana Andrade Machado

    2013-03-01

    Full Text Available O consumo máximo de oxigênio (VO2máx é a quantidade máxima de energia que pode ser produzida pelo metabolismo aeróbio em determinada unidade de tempo, podendo ser determinado direta ou indiretamente através de equações preditivas. O objetivo deste trabalho foi elaborar uma equação preditiva específica para determinar o VO2máx de meninos de 10 a 16 anos. Quarenta e dois meninos realizaram teste ergoespirométrico de corrida em esteira rolante com velocidade inicial de 9 km/h até exaustão voluntária. Através da regressão linear múltipla foi possível desenvolver a seguinte equação para a determinação indireta do VO2máx: VO2máx (ml/min = -1574,06 + (141,38 x Vpico + (48,34 * Massa corporal, com erro padrão de estimativa = 191,5 ml/min (4,10 ml/kg/min e o coeficiente de determinação = 0,934. Sugerimos que esta é uma fórmula adequada para predizer o VO2máx para esta população.The maximal oxygen uptake (VO2max is the maximal quantity of energy that can be produced by the aerobic metabolism in certain time unity. It can be determined direct or indirectly by predictive equations. The objective of this study was to make a specific predictive equation to determine the VO2max from boys aged 10-16 years-old. Forty-two boys underwent a treadmill running ergospirometric test, with the initial velocity set at 9 km/h, until voluntary exhaustion. By the multiple linear regression was possible to develop the following equation for the indirect determination of the VO2max: VO2max (ml/min = -1574.06 + (141.38 x Vpeak + (48.34 * Body mass, with standard error of estimate = 191.5 ml/min (4.10 ml/kg/min and coefficient of determination = 0.934. We suggest that this formula is appropriate to predict VO2max for this population.

  14. Mini Treadmill for Musculoskeletal Health

    Science.gov (United States)

    Humphreys, Bradley

    2015-01-01

    Because NASA's approach to space exploration calls for long-term extended missions, there is a pressing need to equip astronauts with effective exercise regimens that will maintain musculoskeletal and cardiovascular health. ZIN Technologies, Inc., has developed an innovative miniature treadmill for use in both zero-gravity and terrestrial environments. The treadmill offers excellent periodic impact exercise to stimulate cardiovascular activity and bone remodeling as well as resistive capability to encourage full-body muscle maintenance. A novel speed-control algorithm allows users to modulate treadmill speed by adjusting stride, and a new subject load device provides a more Earth-like gravity replacement load. This new and compact treadmill offers a unique approach to managing astronaut health while addressing the inherent and stringent challenges of space flight. The innovation also has the potential to offer numerous terrestrial applications, as a real-time daily load stimulus (DLS) measurement feature provides an effective mechanism to combat or manage osteoporosis, a major public health threat for 55 percent of Americans over the age of 50.

  15. Optimum sample size allocation to minimize cost or maximize power for the two-sample trimmed mean test.

    Science.gov (United States)

    Guo, Jiin-Huarng; Luh, Wei-Ming

    2009-05-01

    When planning a study, sample size determination is one of the most important tasks facing the researcher. The size will depend on the purpose of the study, the cost limitations, and the nature of the data. By specifying the standard deviation ratio and/or the sample size ratio, the present study considers the problem of heterogeneous variances and non-normality for Yuen's two-group test and develops sample size formulas to minimize the total cost or maximize the power of the test. For a given power, the sample size allocation ratio can be manipulated so that the proposed formulas can minimize the total cost, the total sample size, or the sum of total sample size and total cost. On the other hand, for a given total cost, the optimum sample size allocation ratio can maximize the statistical power of the test. After the sample size is determined, the present simulation applies Yuen's test to the sample generated, and then the procedure is validated in terms of Type I errors and power. Simulation results show that the proposed formulas can control Type I errors and achieve the desired power under the various conditions specified. Finally, the implications for determining sample sizes in experimental studies and future research are discussed.

  16. Optimal Test Characteristics for Maximal Anaerobic Work on the Bicycle Ergometer

    Science.gov (United States)

    Katch, Victor; And Others

    1977-01-01

    Data from two separate experiments conducted to ascertain the optimum protocol for a maximum anaerobic work output test on the bicycle ergometer indicated that the test duration needs to be approximately forty seconds and the optimal frictional resistance five to six kilograms. (MB)

  17. The Effect of Instructing Impression Management Behaviors on Maximizing Applicants' Performance in the IELTS Speaking Test

    Science.gov (United States)

    Namdar, Sara; Bagheri, Mohammad Sadegh

    2012-01-01

    Speaking proceeds under the constraint of time. While speaking, speakers are under constant pressure to follow the message being received and to formulate rapid responses to their partners. In the IELTS (International English Language Testing System) Speaking Test, the communicative nature of the interview creates an ideal situation for applicants…

  18. Underwater Treadmill Exercise in Adults with Osteoarthritis

    OpenAIRE

    Walker, Kristin; Walker, Cade

    2014-01-01

    The purpose of this study was to quantify the efficacy of a six-week aquatic treadmill exercise program on measures of pain, balance, mobility, and muscle thickness. We received the URCO grant for research. Three participants (age = 64.5 – 10.2) with knee OA completed a six-week exercise training intervention. Outcome measures, collected before (pre) and after (post) the six-week intervention, included visual analog scales for pain, posturography for balance, a 10 m walk test for mobility, an...

  19. Measurement properties of maximal cardiopulmonary exercise tests protocols in persons after stroke: A systematic review.

    Science.gov (United States)

    Wittink, Harriet; Verschuren, Olaf; Terwee, Caroline; de Groot, Janke; Kwakkel, Gert; van de Port, Ingrid

    2017-11-21

    To systematically review and critically appraise the literature on measurement properties of cardiopulmonary exercise test protocols for measuring aerobic capacity, VO2max, in persons after stroke. PubMed, Embase and Cinahl were searched from inception up to 15 June 2016. A total of 9 studies were identified reporting on 9 different cardiopulmonary exercise test protocols. VO2max measured with cardiopulmonary exercise test and open spirometry was the construct of interest. The target population was adult persons after stroke. We included all studies that evaluated reliability, measurement error, criterion validity, content validity, hypothesis testing and/or responsiveness of cardiopulmonary exercise test protocols. Two researchers independently screened the literature, assessed methodological quality using the COnsensus-based Standards for the selection of health Measurement INstruments checklist and extracted data on measurement properties of cardiopulmonary exercise test protocols. Most studies reported on only one measurement property. Best-evidence synthesis was derived taking into account the methodological quality of the studies, the results and the consistency of the results. No judgement could be made on which protocol is "best" for measuring VO2max in persons after stroke due to lack of high-quality studies on the measurement properties of the cardiopulmonary exercise test.

  20. Potential benefits of maximal exercise just prior to return from weightlessness

    Science.gov (United States)

    Convertino, Victor A.

    1987-01-01

    The purpose of this study was to determine whether performance of a single maximal bout of exercise during weightlessness within hours of return to earth would enhance recovery of aerobic fitness and physical work capacities under a 1G environment. Ten healthy men were subjected to a 10-d bedrest period in the 6-deg headdown position. A graded maximal supine cycle ergometer test was performed before and at the end of bedrest to simulate exercise during weightlessness. Following 3 h of resumption of the upright posture, a second maximal exercise test was performed on a treadmill to measure work capacity under conditions of 1G. Compared to before bedrest, peak oxygen consumption, V(O2), decreased by 8.7 percent and peak heart rate (HR) increased by 5.6 percent in the supine cycle test at the end of bedrest. However, there were no significant changes in peak V(O2) and peak HR in the upright treadmill test following bedrest. These data suggest that one bout of maximal leg exercise prior to return from 10 d of weightlessness may be adequate to restore preflight aerobic fitness and physical work capacity.

  1. Evaluation of anaerobic capacity in soccer players using a maximal shuttle run test

    Directory of Open Access Journals (Sweden)

    Alexandre Gomes de Almeida

    2009-01-01

    Full Text Available http://dx.doi.org/10.5007/1980-0037.2009v11n1p88   The aim of this study was to investigate whether a 300-m shuttle run test predicts anaerobic capacity, expressed as mean power output in the Wingate test, in a group of professional soccer players. Twenty-one soccer players (21 ± 2 years; 76.8 ± 7.0 kg; 179.8 ± 6.7 cm from a first division team of the São Paulo Soccer Federation participated in the study. In the first session, the players were submitted to the Wingate test for the determination of relative peak power output, relative mean power output and fatigue index. In the second session, the players underwent a shuttle run test which consisted of a maximum sprint of 20 m at the highest speed possible until completing a distance of 300 m. The total run time and mean velocity over the 20 m (V20m were recorded. Blood samples were collected before and after the 300-m shuttle run test for the determination of lactate concentration ([LAC]. Pearson’s correlation between the Wingate and 300-m shuttle run test variables showed that only relative mean power output was significantly correlated with total run time (r = - 0.75 and V20m (r = 0.72. [LAC] showed a significant increase (p < 0.05 when comparing the values obtained before (2.1 ± 1.0 mM and after (14.3 ± 2.4 mM the shuttle run test. In conclusion, this study demonstrated that the 300-m shuttle run test can predict anaerobic capacity in professional soccer players.

  2. Familiarization, validity and smallest detectable difference of the isometric squat test in evaluating maximal strength.

    Science.gov (United States)

    Drake, David; Kennedy, Rodney; Wallace, Eric

    2018-02-06

    Isometric multi-joint tests are considered reliable and have strong relationships with 1RM performance. However, limited evidence is available for the isometric squat in terms of effects of familiarization and reliability. This study aimed to assess, the effect of familiarization, stability reliability, determine the smallest detectible difference, and the correlation of the isometric squat test with 1RM squat performance. Thirty-six strength-trained participants volunteered to take part in this study. Following three familiarization sessions, test-retest reliability was evaluated with a 48-hour window between each time point. Isometric squat peak, net and relative force were assessed. Results showed three familiarizations were required, isometric squat had a high level of stability reliability and smallest detectible difference of 11% for peak and relative force. Isometric strength at a knee angle of ninety degrees had a strong significant relationship with 1RM squat performance. In conclusion, the isometric squat is a valid test to assess multi-joint strength and can discriminate between strong and weak 1RM squat performance. Changes greater than 11% in peak and relative isometric squat performance should be considered as meaningful in participants who are familiar with the test.

  3. Probabilistic income-maximizing behavior in regional migration: an empirical test.

    Science.gov (United States)

    Weinstein, R I; Evans, R D

    1980-01-01

    "This paper provides an empirical test of the hypothesis that migrants consider income risk in their evaluation of the returns to migration in that higher levels of income risk for a given region reduce the rate of net migration into that region." Theoretical approaches to the incorporation of income risk in migration models are first considered, and alternative approaches are then tested using data on white and nonwhite net migration in the United States between 1960 and 1970. The results indicate support for the hypothesis that the extent of net migration is inversely affected by income risk. excerpt

  4. Performance Validity Testing in Neuropsychology: Methods for Measurement Development and Maximizing Diagnostic Accuracy.

    Science.gov (United States)

    Wodushek, Thomas R; Greher, Michael R

    2017-05-01

    In the first column in this 2-part series, Performance Validity Testing in Neuropsychology: Scientific Basis and Clinical Application-A Brief Review, the authors introduced performance validity tests (PVTs) and their function, provided a justification for why they are necessary, traced their ongoing endorsement by neuropsychological organizations, and described how they are used and interpreted by ever increasing numbers of clinical neuropsychologists. To enhance readers' understanding of these measures, this second column briefly describes common detection strategies used in PVTs as well as the typical methods used to validate new PVTs and determine cut scores for valid/invalid determinations. We provide a discussion of the latest research demonstrating how neuropsychologists can combine multiple PVTs in a single battery to improve sensitivity/specificity to invalid responding. Finally, we discuss future directions for the research and application of PVTs.

  5. A maximal cycle test with good validity and high repeatability in adults of all ages

    DEFF Research Database (Denmark)

    Eriksen, L; Tolstrup, J S; Larsen, Steen

    2014-01-01

    indirectly in both tests and measured directly in one test. Agreement between the direct measurement and the indirect estimate of VO2max and repeatability of the indirect estimates of VO2max were examined by Bland-Altman plots, limits of agreement (LOA) and coefficient of repeatability (CR). The indirect...... method (mean VO2max=3 132 ml · min(-1)) underestimated VO2max as compared to the direct method (mean VO2max=3 190 ml · min(-1)) in men (bias: 58 ml · min(-1) (95% LOA-450 and 565)) and overestimated VO2max in women (mean VO2max=2 328 vs. 2 258 ml · min(-1), bias: - 70 ml · min(-1) (95% LOA-468 and 328...

  6. Maximal exercise test is a useful method for physical capacity and oxygen consumption determination in streptozotocin-diabetic rats

    Directory of Open Access Journals (Sweden)

    Irigoyen Maria-Cláudia

    2007-12-01

    Full Text Available Abstract Background The aim of the present study was to investigate the relationship between speed during maximum exercise test (ET and oxygen consumption (VO2 in control and STZ-diabetic rats, in order to provide a useful method to determine exercise capacity and prescription in researches involving STZ-diabetic rats. Methods Male Wistar rats were divided into two groups: control (CG, n = 10 and diabetic (DG, n = 8. The animals were submitted to ET on treadmill with simultaneous gas analysis through open respirometry system. ET and VO2 were assessed 60 days after diabetes induction (STZ, 50 mg/Kg. Results VO2 maximum was reduced in STZ-diabetic rats (72.5 ± 1 mL/Kg/min-1 compared to CG rats (81.1 ± 1 mL/Kg/min-1. There were positive correlations between ET speed and VO2 (r = 0.87 for CG and r = 0.8 for DG, as well as between ET speed and VO2 reserve (r = 0.77 for CG and r = 0.7 for DG. Positive correlations were also obtained between measured VO2 and VO2 predicted values (r = 0.81 for CG and r = 0.75 for DG by linear regression equations to CG (VO2 = 1.54 * ET speed + 52.34 and DG (VO2 = 1.16 * ET speed + 51.99. Moreover, we observed that 60% of ET speed corresponded to 72 and 75% of VO2 reserve for CG and DG, respectively. The maximum ET speed was also correlated with VO2 maximum for both groups (CG: r = 0.7 and DG: r = 0.7. Conclusion These results suggest that: a VO2 and VO2 reserve can be estimated using linear regression equations obtained from correlations with ET speed for each studied group; b exercise training can be prescribed based on ET in control and diabetic-STZ rats; c physical capacity can be determined by ET. Therefore, ET, which involves a relatively simple methodology and low cost, can be used as an indicator of cardio-respiratory capacity in future studies that investigate the physiological effect of acute or chronic exercise in control and STZ-diabetic male rats.

  7. Maximal exercise test is a useful method for physical capacity and oxygen consumption determination in streptozotocin-diabetic rats

    Science.gov (United States)

    Rodrigues, Bruno; Figueroa, Diego M; Mostarda, Cristiano T; Heeren, Marcelo V; Irigoyen, Maria-Cláudia; De Angelis, Kátia

    2007-01-01

    Background The aim of the present study was to investigate the relationship between speed during maximum exercise test (ET) and oxygen consumption (VO2) in control and STZ-diabetic rats, in order to provide a useful method to determine exercise capacity and prescription in researches involving STZ-diabetic rats. Methods Male Wistar rats were divided into two groups: control (CG, n = 10) and diabetic (DG, n = 8). The animals were submitted to ET on treadmill with simultaneous gas analysis through open respirometry system. ET and VO2 were assessed 60 days after diabetes induction (STZ, 50 mg/Kg). Results VO2 maximum was reduced in STZ-diabetic rats (72.5 ± 1 mL/Kg/min-1) compared to CG rats (81.1 ± 1 mL/Kg/min-1). There were positive correlations between ET speed and VO2 (r = 0.87 for CG and r = 0.8 for DG), as well as between ET speed and VO2 reserve (r = 0.77 for CG and r = 0.7 for DG). Positive correlations were also obtained between measured VO2 and VO2 predicted values (r = 0.81 for CG and r = 0.75 for DG) by linear regression equations to CG (VO2 = 1.54 * ET speed + 52.34) and DG (VO2 = 1.16 * ET speed + 51.99). Moreover, we observed that 60% of ET speed corresponded to 72 and 75% of VO2 reserve for CG and DG, respectively. The maximum ET speed was also correlated with VO2 maximum for both groups (CG: r = 0.7 and DG: r = 0.7). Conclusion These results suggest that: a) VO2 and VO2 reserve can be estimated using linear regression equations obtained from correlations with ET speed for each studied group; b) exercise training can be prescribed based on ET in control and diabetic-STZ rats; c) physical capacity can be determined by ET. Therefore, ET, which involves a relatively simple methodology and low cost, can be used as an indicator of cardio-respiratory capacity in future studies that investigate the physiological effect of acute or chronic exercise in control and STZ-diabetic male rats. PMID:18078520

  8. Peak oxygen uptake in a sprint interval testing protocol vs. maximal oxygen uptake in an incremental testing protocol and their relationship with cross-country mountain biking performance.

    Science.gov (United States)

    Hebisz, Rafał; Hebisz, Paulina; Zatoń, Marek; Michalik, Kamil

    2017-04-01

    In the literature, the exercise capacity of cyclists is typically assessed using incremental and endurance exercise tests. The aim of the present study was to confirm whether peak oxygen uptake (V̇O 2peak ) attained in a sprint interval testing protocol correlates with cycling performance, and whether it corresponds to maximal oxygen uptake (V̇O 2max ) determined by an incremental testing protocol. A sample of 28 trained mountain bike cyclists executed 3 performance tests: (i) incremental testing protocol (ITP) in which the participant cycled to volitional exhaustion, (ii) sprint interval testing protocol (SITP) composed of four 30 s maximal intensity cycling bouts interspersed with 90 s recovery periods, (iii) competition in a simulated mountain biking race. Oxygen uptake, pulmonary ventilation, work, and power output were measured during the ITP and SITP with postexercise blood lactate and hydrogen ion concentrations collected. Race times were recorded. No significant inter-individual differences were observed in regards to any of the ITP-associated variables. However, 9 individuals presented significantly increased oxygen uptake, pulmonary ventilation, and work output in the SITP compared with the remaining cyclists. In addition, in this group of 9 cyclists, oxygen uptake in SITP was significantly higher than in ITP. After the simulated race, this group of 9 cyclists achieved significantly better competition times (99.5 ± 5.2 min) than the other cyclists (110.5 ± 6.7 min). We conclude that mountain bike cyclists who demonstrate higher peak oxygen uptake in a sprint interval testing protocol than maximal oxygen uptake attained in an incremental testing protocol demonstrate superior competitive performance.

  9. Intensive treadmill training in the acute phase after ischemic stroke

    DEFF Research Database (Denmark)

    Strømmen, Anna Maria; Christensen, Thomas; Jensen, Kai

    2016-01-01

    The aim of the study was to (a) assess the feasibility of intensive treadmill training in patients with acute ischemic stroke, (b) test whether physical activity of the legs during training increases with time, and (c) evaluate to what extent training sessions contribute toward the overall physical...... activity of these patients. Twenty hospitalized patients with acute ischemic stroke trained on a treadmill twice daily for 30 min for 5 days and on day 30. Physical activity was measured as activity counts (AC) from accelerometers. A total of 196 of 224 initiated training sessions were completed. Training...... with increasing number of days, with the median AC being 133% higher on day 5 than on day 1. AC in the paretic leg during 60 min of training constituted median 53% of the daytime AC. Early intensive treadmill training in acute ischemic stroke patients is thus feasible and contributes considerably toward...

  10. Entropy maximization

    Indian Academy of Sciences (India)

    Abstract. It is shown that (i) every probability density is the unique maximizer of relative entropy in an appropriate class and (ii) in the class of all pdf f that satisfy. ∫ fhi dμ = λi for i = 1, 2,...,...k the maximizer of entropy is an f0 that is pro- portional to exp(. ∑ ci hi ) for some choice of ci . An extension of this to a continuum of.

  11. Entropy Maximization

    Indian Academy of Sciences (India)

    It is shown that (i) every probability density is the unique maximizer of relative entropy in an appropriate class and (ii) in the class of all pdf that satisfy ∫ f h i d = i for i = 1 , 2 , … , … k the maximizer of entropy is an f 0 that is proportional to exp ⁡ ( ∑ c i h i ) for some choice of c i . An extension of this to a continuum of ...

  12. Investigating the effects of maximal anaerobic fatigue on dynamic postural control using the Y-Balance Test.

    Science.gov (United States)

    Johnston, William; Dolan, Kara; Reid, Niamh; Coughlan, Garrett F; Caulfield, Brian

    2018-01-01

    The Y Balance Test is one of the most commonly used dynamic balance assessments, providing an insight into the integration of the sensorimotor subsystems. In recent times, there has been an increase in interest surrounding it's use in various clinical populations demonstrating alterations in motor function. Therefore, it is important to examine the effect physiological influences such as fatigue play in dynamic postural control, and establish a timeframe for its recovery. Descriptive laboratory study. Twenty male and female (age 23.75±4.79years, height 174.12±8.45cm, mass 69.32±8.76kg) partaking in competitive sport, completed the Y Balance Test protocol at 0, 10 and 20min, prior to a modified 60s Wingate fatiguing protocol. Post-fatigue assessments were then completed at 0, 10 and 20 min post-fatiguing intervention. Intraclass correlation coefficients demonstrated excellent intra-session reliability (0.976-0.982) across the three pre-fatigue YBT tests. Post-hoc paired sample t-tests demonstrated that all three reach directions demonstrated statistically significant differences between pre-fatigue and the first post-fatigue measurement (anterior; p=0.019, posteromedial; p=0.019 & posterolateral; p=0.003). The anterior reach direction returned to pre-fatigue levels within 10min (p=0.632). The posteromedial reach direction returned to pre-fatigue levels within 20min (p=0.236), while the posterolateral direction maintained a statistically significant difference at 20min (p=0.023). Maximal anaerobic fatigue has a negative effect on normalised Y balance test scores in all three directions. Following the fatiguing protocol, dynamic postural control returns to pre-fatigue levels for the anterior (20min). Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  13. Comparison of standardbred trotters exercising on a treadmill and a race track with identical draught resistances.

    Science.gov (United States)

    Gottlieb-Vedi, M; Lindholm, A

    1997-05-17

    The responses in heart rate, plasma lactate and rectal temperature of standardbred trotters to draught loaded interval exercise on a treadmill and a race track were studied. The horses were exercised with incrementally increasing trotting speeds for two-minute intervals with draught loads of 10, 20 and 30 kilopond (kp) in three different tests. Each trotting interval was followed by two-minute periods at a walk without a draught load. Measurements of heart rate and plasma lactate were made at the end of each interval and the rectal temperature was taken at the end of the exercise. The heart rate and plasma lactate levels were significantly lower on the treadmill than on the track in the tests with 10 kp, but no significant differences were found between the treadmill and track exercise tests with the heavier draught resistances. No differences were observed in rectal temperature between treadmill and track conditions. From these findings it was concluded that the workload was significantly greater on the race track compared to the treadmill when the draught resistance was low (10 kp). Although the workload increased on both the race track and the treadmill as draught resistance increased, at the heavier draught resistances track exercise was no longer more demanding than exercise on the treadmill.

  14. Oxygen uptake of overweight and obese children at different stages of a progressive treadmill test. (Consumo de oxígeno de niños y niñas con sobrepeso y obesos en los diferentes estadios de una prueba progresiva en un tapiz rodante.

    Directory of Open Access Journals (Sweden)

    Colleen Ann Boyle

    2010-01-01

    Full Text Available AbstractIntroduction: Maximal oxygen uptake (VO2 max is associated with cardiovascular and metabolic risks but it is difficult to assess in obese children. The objective of this study was to develop an equation to estimate VO2 (mL/kg/min and to check the % of tests that were maximal according to recommended criteria. Methods: Stress tests were analyzed of 222 subjects (94 male and 128 female with a BMI above the 85 percentile for age and sex, and repeated 4 months later. Mean age was 9.4 + 1.1 years and weighed 52.4 + 13.3 kg. Body fat % (40.5 + 6.2 was determined by DXA (Hologic QDR 4500W. The protocol on the treadmill started with a warm up at 2.5 and 3 mph with a slope of 0% and 2%. The speed was kept at 3 mph for all the stages and the slope was increased 2% every 2 minutes. Statistical analysis (descriptive, t-test and ANOVAS 2x2x2 was done with SPSS 15.0. Results: Only 35% of the tests were maximal. The equation calculates was Y = 2.6x + 22.3 (x = protocol stage. Data pre and post treatment were not statistically different. Discussion: Increments in VO2 were consistent despite subject diversity (sex, % body fat, physical fitness, treatment. Conclusion: To be able to estimate VO2 at the different stages of the test without complex equipment or specialized staff, will facilitate the performance of stress tests on a daily basis.ResumenIntroducción: El consumo máximo de oxígeno (VO2 max está asociado con riesgos cardiovasculares y metabólicos pero resulta difícil valorarlo en niños y niñas obesos. El objetivo de este trabajo fue desarrollar una ecuación para estimar su VO2 (mL/kg/min y comprobar el porcentaje de pruebas máximas según los criterios recomendados. Métodos: Se analizaron las pruebas de esfuerzo de 222 sujetos (94 varones y 128 mujeres con un IMC superior al percentil 85 para su edad y sexo, y las repetidas a los 4 meses. Su edad era 9,4 + 1,1 años y pesaban 52,4 + 13,3 kg. El % de grasa corporal (40,5 + 6,2 se

  15. Maximal and anaerobic threshold cardiorespiratory responses during deepwater running

    Directory of Open Access Journals (Sweden)

    Ana Carolina Kanitz

    2014-12-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n1p41   Aquatic exercises provide numerous benefits to the health of their practitioners. To secure these benefits, it is essential to have proper prescriptions to the needs of each individual and, therefore, it is important to study the cardiorespiratory responses of different activities in this environment. Thus, the aim of this study was to compare the cardiorespiratory responses at the anaerobic threshold (AT between maximal deep-water running (DWR and maximal treadmill running (TMR. In addition, two methods of determining the AT (the heart rate deflection point [HRDP] and ventilatory method [VM] are compared in the two evaluated protocols. Twelve young women performed the two maximal protocols. Two-factor ANOVA for repeated measures with a post-hoc Bonferroni test was used (α < 0.05. Significantly higher values of maximal heart rate (TMR: 33.7 ± 3.9; DWR: 22.5 ± 4.1 ml.kg−1.min−1 and maximal oxygen uptake (TMR: 33.7 ± 3.9; DWR: 22.5 ± 4.1 ml.kg−1.min−1 in TMR compared to the DWR were found. Furthermore, no significant differences were found between the methods for determining the AT (TMR: VM: 28.1 ± 5.3, HRDP: 26.6 ± 5.5 ml.kg−1.min−1; DWR: VM: 18.7 ± 4.8, HRDP: 17.8 ± 4.8 ml.kg−1.min−1. The results indicate that a specific maximal test for the trained modality should be conducted and the HRDP can be used as a simple and practical method of determining the AT, based on which the training intensity can be determined

  16. Cerebral Blood Flow Responses to Aquatic Treadmill Exercise.

    Science.gov (United States)

    Parfitt, Rhodri; Hensman, Marianne Y; Lucas, Samuel J E

    2017-07-01

    Aquatic treadmills are used as a rehabilitation method for conditions such as spinal cord injury, osteoarthritis, and stroke, and can facilitate an earlier return to exercise training for athletes. However, their effect on cerebral blood flow (CBF) responses has not been examined. We tested the hypothesis that aquatic treadmill exercise would augment CBF and lower HR compared with land-based treadmill exercise. Eleven participants completed incremental exercise (crossover design) starting from walking pace (4 km·h, immersed to iliac crest [aquatic], 6 km·h [land]) and increasing 1 km·h every 2 min up to 10 km·h for aquatic (maximum belt speed) or 12 km·h for land. After this, participants completed two 2-min bouts of exercise immersed to midthigh and midchest at constant submaximal speed (aquatic), or were ramped to exhaustion (land; increased gradient 2° every min). Middle cerebral artery blood flow velocity (MCAv) and HR were measured throughout, and the initial 10 min of each protocol and responses at each immersion level were compared. Compared with land-based treadmill, MCAvmean increased more from baseline for aquatic exercise (21% vs 12%, P aquatic walking compared with land-based moderate intensity running (~10 cm·s, P = 0.56). Greater water immersion lowered HR (139 vs 178 bpm for midchest vs midthigh), whereas MCAvmean remained constant (P = 0.37). Findings illustrate the potential for aquatic treadmill exercise to enhance exercise-induced elevations in CBF and thus optimize shear stress-mediated adaptation of the cerebrovasculature.

  17. Is CP violation maximal

    International Nuclear Information System (INIS)

    Gronau, M.

    1984-01-01

    Two ambiguities are noted in the definition of the concept of maximal CP violation. The phase convention ambiguity is overcome by introducing a CP violating phase in the quark mixing matrix U which is invariant under rephasing transformations. The second ambiguity, related to the parametrization of U, is resolved by finding a single empirically viable definition of maximal CP violation when assuming that U does not single out one generation. Considerable improvement in the calculation of nonleptonic weak amplitudes is required to test the conjecture of maximal CP violation. 21 references

  18. The effect of caffeine on maximal oxygen uptake and vertical jump performance in male basketball players.

    Science.gov (United States)

    Tucker, Matthew A; Hargreaves, Jill M; Clarke, Jenny C; Dale, Darren L; Blackwell, Gavin J

    2013-02-01

    This study investigated whether performance enhancement from caffeine described by other researchers transfers to male basketball players. The effects of caffeine ingestion were studied in a maximal-effort test on a treadmill that was followed by a vertical-jump test. Five elite-level male basketball players completed a graded treadmill test that measured maximal oxygen uptake, blood lactate profiles, respiratory exchange ratio, and rating of perceived exertion at each 3-minute stage. After a 15-minute warm-down, the subjects performed 10 vertical rebound jumps. Each subject completed the test twice--once with a 3 mg·kg(-1) of body weight dose of caffeine and once with a placebo, with the dosage administered 60 minutes before commencement of exercise. The test was thus administered according to a double-blind protocol. No substantial trends were found between caffeine and control trials, regardless of trial order. The study showed that the specified dosage had negligible effects on the players' power and endurance performance and had no efficacy as an ergogenic aid for male basketball players.

  19. Effect of sonic driving on maximal aerobic performance.

    Science.gov (United States)

    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). 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.

  20. The local lymph node assay compared with the human maximization test as an indicator of allergic potency in humans using patch test clinic populations.

    Science.gov (United States)

    Zaghi, Danny; Maibach, Howard I

    2009-01-01

    The human maximization test (HMT) is a method to evaluate potency in humans, while the local lymph node assay (LLNA) is a test method that allows for the measuring of the allergic potency of a substance in a rodent. It has been proposed that an EC3 value (the value obtained by the LLNA test, ie, the concentration of an allergen leading to a 3-fold increase of baseline proliferation rate) would be a reliable indicator for a compound's allergic potency in humans. This paper compares the correlation between the EC3 value of a compound and its allergic occurrence in the general population with the correlation between the HMT of the compound and its allergic occurrence in the general population, to determine the relationship to potency. The correlation values when outliers were removed from the sample were -0.56 and -0.71 for LLNA and HMT, respectively, suggesting that there is a possible 20% error margin in LLNA's ability to predict potency. The data also suggest that other factors (such as exposure) could play up to a 30% role in the determination of allergic occurrence in the general population. The potency assays might be made more clinically relevant for predicting allergic frequencies by including a frequency factor and other factors in its dermatotoxicological interpretation.

  1. Productivity of transcriptionists using a treadmill desk.

    Science.gov (United States)

    Thompson, Warren G; Levine, James A

    2011-01-01

    Time spent sitting increases all-cause mortality. Sedentary occupations are a major contributor to the obesity epidemic. A treadmill desk offers the potential to increase activity while working; however, it is important to make sure that productivity does not decline. The purpose of this study is to evaluate productivity while using a treadmill desk. Eleven experienced medical transcriptionists participated in the study. Transcriptionists were given 4 hours training in the use of a treadmill desk. They were asked to transcribe tapes for 8 hours both while sitting and while using the treadmill desk. Speed and accuracy of transcription were compared as were the average expended calories per hour. The accuracy of transcription did not differ between sitting and walking transcriptions. The speed of transcription was 16% slower while walking than while sitting (p employee obesity and health care costs. However, more than 4 hours of training will be necessary to prevent a significant drop in employee productivity.

  2. Treadmill Desks at LANL - Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Fellows, Samara Kia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-28

    It is well established that sedentariness is the largest, preventable contributor to premature death, eclipsing smoking in recent years. One approach to reduce sedentariness is by using a treadmill desk to perform office work while walking at a low speed.We found an increased interest level when the treadmill desks were first introduced to LANL, but after a few months interest appeared to drop. It is possible that treadmill desk use was occurring, but subjects did not record their use. The treadmill desks will not be readily available for purchase by employees due to the study outcome. Additionally, conclusive changes in body measurements could not be performed due to lack of follow up by 58% of the participants.

  3. Treadmill desks: A 1-year prospective trial.

    Science.gov (United States)

    Koepp, Gabriel A; Manohar, Chinmay U; McCrady-Spitzer, Shelly K; Ben-Ner, Avner; Hamann, Darla J; Runge, Carlisle F; Levine, James A

    2013-04-01

    Sedentariness is associated with weight gain and obesity. A treadmill desk is the combination of a standing desk and a treadmill that allow employees to work while walking at low speed. The hypothesis was that a 1-year intervention with treadmill desks is associated with an increase in employee daily physical activity (summation of all activity per minute) and a decrease in daily sedentary time (zero activity). Employees (n = 36; 25 women, 11 men) with sedentary jobs (87 ± 27 kg, BMI 29 ± 7 kg/m(2) , n = 10 Lean BMI 30 kg/m(2) ) volunteered to have their traditional desk replaced with a treadmill desk to promote physical activity for 1 year. Daily physical activity (using accelerometers), work performance, body composition, and blood variables were measured at Baseline and 6 and 12 months after the treadmill desk intervention. Subjects who used the treadmill desk increased daily physical activity from baseline 3,353 ± 1,802 activity units (AU)/day to, at 6 months, 4,460 ± 2,376 AU/day (P office workers without affecting work performance. Copyright © 2012 The Obesity Society.

  4. The use of Yo-Yo intermittent recovery level 1 and Andersen testing for fitness and maximal heart rate assessments of 6- to 10-year-old school children

    DEFF Research Database (Denmark)

    Bendiksen, Mads; Ahler, Thomas; Clausen, Helle

    2013-01-01

    ABSTRACT: We evaluated a sub-maximal and maximal version of the Yo-Yo IR1 childrens test (YYIR1C) and the Andersen test for fitness and maximal HR assessments of children aged 6-10. Two repetitions of the YYIR1C and Andersen tests were carried out within one week by 6-7 and 8-9 year olds (grade 0...

  5. The Effects of a Motorized Aquatic Treadmill Exercise Program on Muscle Strength, Cardiorespiratory Fitness, and clinical function in Subacute Stroke Patients -- a Randomized Controlled Pilot Trial.

    Science.gov (United States)

    Lee, So Young; Han, Eun Young; Kim, Bo Ryun; Im, Sang Hee

    2018-03-12

    The aim of this study was to assess the effects of a motorized aquatic treadmill exercise program improve the isometric strength of the knee muscles, cardiorespiratory fitness, arterial stiffness, motor function, balance, functional outcomes and quality of life in subacute stroke patients. Thirty-two patients were randomly assigned to 4-week training sessions of either aquatic therapy(n=19) or land-based aerobic exercise(n=18). Isometric strength was measured using an isokinetic dynamometer. Cardiopulmonary fitness was evaluated using a symptom-limited exercise tolerance test and by measuring brachial ankle pulse wave velocity. Moreover, motor function(Fugl-Meyer Assessment[FMA] and FMA-lower limb[FMA-LL]), balance(Berg Balance Scale[BBS]), Activities of daily living(Korean version of the Modified Barthel Index [K-MBI]), and Quality of life(EQ-5D index) were examined. There were no inter-group differences between demographic and clinical characteristics at baseline(p>0.05). The results shows significant improvements in peak oxygen consumption (p=0.02), maximal isometric strength of the bilateral knee extensors (paquatic therapy group. However, only significant improvements in maximal isometric strength in the knee extensors (p=0.03) and flexors (p=0.04) were found within the aquatic therapy group and control group. Water-based aerobic exercise performed on a motorized aquatic treadmill had beneficial effect on isometric muscle strength in the lower limb.

  6. Effect of beta-alanine supplementation on the onset of blood lactate accumulation (OBLA during treadmill running: Pre/post 2 treatment experimental design

    Directory of Open Access Journals (Sweden)

    Misic Mark

    2010-05-01

    Full Text Available Abstract Background β-Alanine (βA has been shown to improve performance during cycling. This study was the first to examine the effects of βA supplementation on the onset of blood lactate accumulation (OBLA during incremental treadmill running. Methods Seventeen recreationally-active men (mean ± SE 24.9 ± 4.7 yrs, 180.6 ± 8.9 cm, 79.25 ± 9.0 kg participated in this randomized, double-blind, placebo-controlled pre/post test 2-treatment experimental design. Subjects participated in two incremental treadmill tests before and after 28 days of supplementation with either βA (6.0 g·d-1(βA, n = 8 or an equivalent dose of Maltodextrin as the Placebo (PL, n = 9. Heart rate, percent heart rate maximum (%HRmax, %VO2max@OBLA (4.0 mmol.L-1 blood lactate concentration and VO2max (L.min-1 were determined for each treadmill test. Friedman test was used to determine within group differences; and Mann-Whitney was used to determine between group differences for pre and post values (p Results The βA group experienced a significant rightward shift in HR@OBLA beats.min-1 (p 2max@OBLA increased (p 2max (L.min-1 decreased (p Conclusions βA supplementation for 28 days enhanced sub-maximal endurance performance by delaying OBLA. However, βA supplemented individuals had a reduced aerobic capacity as evidenced by the decrease in VO2max values post supplementation.

  7. Cardiovascular response during submaximal underwater treadmill exercise in stroke patients.

    Science.gov (United States)

    Yoo, Jeehyun; Lim, Kil-Byung; Lee, Hong-Jae; Kwon, Yong-Geol

    2014-10-01

    To evaluate the cardiovascular response during head-out water immersion, underwater treadmill gait, and land treadmill gait in stroke patients. Ten stroke patients were recruited for underwater and land treadmill gait sessions. Each session was 40 minutes long; 5 minutes for standing rest on land, 5 minutes for standing rest in water or on treadmill, 20 minutes for treadmill walking in water or on land, 5 minutes for standing rest in water or on treadmill, and 5 minutes for standing rest on land. Blood pressure (BP) and heart rate (HR) were measured during each session. In order to estimate the cardiovascular workload and myocardial oxygen demand, the rate pressure product (RPP) value was calculated by multiplying systolic BP (SBP) by HR. SBP, DBP, mean BP (mBP), and RPP decreased significantly after water immersion, but HR was unchanged. During underwater and land treadmill gait, SBP, mBP, DBP, RPP, and HR increased. However, the mean maximum increases in BP, HR and RPP of underwater treadmill walking were significantly lower than that of land treadmill walking. Stroke patients showed different cardiovascular responses during water immersion and underwater gait as opposed to standing and treadmill-walking on land. Water immersion and aquatic treadmill gait may reduce the workload of the cardiovascular system. This study suggested that underwater treadmill may be a safe and useful option for cardiovascular fitness and early ambulation in stroke rehabilitation.

  8. Optimizing a Treadmill Ramp Protocol to Evaluate Aerobic Capacity of Hemiparetic Poststroke Patients.

    Science.gov (United States)

    Bernardes, Wendell L; Montenegro, Rafael A; Monteiro, Walace D; de Almeida Freire, Raul; Massaferri, Renato; Farinatti, Paulo

    2018-03-01

    Bernardes, WL, Montenegro, RA, Monteiro, WD, de Almeida Freire, R, Massaferri, R, and Farinatti, P. Optimizing a treadmill ramp protocol to evaluate aerobic capacity of hemiparetic poststroke patients. J Strength Cond Res 32(3): 876-884, 2018-A correct assessment of cardiopulmonary capacity is important for aerobic training within motor rehabilitation of poststroke hemiparetic patients (PSHPs). However, specific cardiopulmonary exercise testing (CPET) for these patients are scarce. We proposed adaptations in a protocol originally developed for PSHPs by Ovando et al. (CPET1). We hypothesized that our adapted protocol (CPET2) would improve the original test, by preventing early fatigue and increasing patients' peak performance. Eleven PSHPs (52 ± 14 years, 10 men) performed both protocols. CPET2 integrated changes in final speed (100-120% vs. 140% maximal speed in 10-m walking test), treadmill inclination (final inclination of 5 vs. 10%), and estimated test duration (10 vs. 8 minutes) to smooth the rate of workload increment of CPET1. Peak oxygen uptake (V[Combining Dot Above]O2peak) (20.3 ± 6.1 vs. 18.6 ± 5.0 ml·kg·min; p = 0.04), V[Combining Dot Above]O2 at gas exchange transition (V[Combining Dot Above]O2-GET) (11.5 ± 2.9 vs. 9.8 ± 2.0 ml·kg·min; p = 0.04), and time to exhaustion (10 ± 3 vs. 6 ± 2 minutes; p higher in CPET2 than in CPET1. Slopes and intercepts of regressions describing relationships between V[Combining Dot Above]O2 vs. workload, heart rate vs. workload, and V[Combining Dot Above]O2 vs. heart rate were similar between CPETs. However, standard errors of estimates obtained for regressions between heart rate vs. workload (3.0 ± 1.3 vs. 3.8 ± 1.0 b·min; p = 0.004) and V[Combining Dot Above]O2 vs. heart rate (6.0 ± 2.1 vs. 4.8 ± 2.4 ml·kg·min; p = 0.05) were lower in CPET2 than in CPET1. In conclusion, the present adaptations in Ovando's CPET protocol increased exercise tolerance of PSHPs, eliciting higher V[Combining Dot Above]O2peak

  9. Comparison of the metabolic energy cost of overground and treadmill walking in older adults.

    Science.gov (United States)

    Berryman, Nicolas; Gayda, Mathieu; Nigam, Anil; Juneau, Martin; Bherer, Louis; Bosquet, Laurent

    2012-05-01

    We assessed whether the metabolic energy cost of walking was higher when measured overground or on a treadmill in a population of healthy older adults. We also assessed the association between the two testing modes. Participants (n = 20, 14 men and 6 women aged between 65 and 83 years of age) were randomly divided into two groups. Half of them went through the overground-treadmill sequence while the other half did the opposite order. A familiarization visit was held for each participant prior to the actual testing. For both modes of testing, five walking speeds were experimented (0.67, 0.89, 1.11, 1.33 and 1.67 m s(-1)). Oxygen uptake was monitored for all walking speeds. We found a significant difference between treadmill and track metabolic energy cost of walking, whatever the walking speed. The results show that walking on the treadmill requires more metabolic energy than walking overground for all experimental speeds (P < 0.05). The association between both measures was low to moderate (0.17 < ICC < 0.65), and the standard error of measurement represented 6.9-15.7% of the average value. These data indicate that metabolic energy cost of walking results from a treadmill test does not necessarily apply in daily overground activities. Interventions aiming at reducing the metabolic energy cost of walking should be assessed with the same mode as it was proposed during the intervention. If the treadmill mode is necessary for any purposes, functional overground walking tests should be implemented to obtain a more complete and specific evaluation.

  10. Criterion validity and reliability of a smartphone delivered sub-maximal fitness test for people with type 2 diabetes

    DEFF Research Database (Denmark)

    Brinklov, Cecilie Fau; Thorsen, Ida Kær; Karstoft, Kristian

    2016-01-01

    Background: Prevention of multi-morbidities following non-communicable diseases requires a systematic registration of adverse modifiable risk factors, including low physical fitness. The aim of the study was to establish criterion validity and reliability of a smartphone app (InterWalk) delivered....... The algorithm was validated using leave-one-out cross validation. Test-retest reliability was tested in a subset of participants (N = 10). Results: The overall VO2peak prediction of the algorithm (R2) was 0.60 and 0.45 when the smartphone was placed in the pockets of the pants and jacket, respectively (p ... calorimetry and the acceleration (vector magnitude) from the smartphone was obtained. The vector magnitude was used to predict VO2peak along with the co-variates weight, height and sex. The validity of the algorithm was tested when the smartphone was placed in the right pocket of the pants or jacket...

  11. CATECHOLAMINES AND β2-ADRENOCEPTOR GENE EXPRESSION BEFORE AND AFTER MAXIMAL INCREMENTAL CYCLE TEST IN YOUNG ICE HOCKEY PLAYERS: RELATION TO WORK PERFORMED

    Directory of Open Access Journals (Sweden)

    Urszula Mazurek

    2013-04-01

    Full Text Available The aim of this study was to assess the plasma adrenaline and noradrenaline concentrations as well as whole blood β2-adrenoceptor gene (ADRB2 expression in young ice hockey players before and immediately after exercise in relation to performed work. Nineteen Youth National Team ice hockey players were subjected to the maximal incremental cycloergometer exercise. The test was done in the pre-competitive phase of training. Among many parameters the plasma adrenaline and noradrenaline concentrations and ADRB2 gene expression in peripheral blood mononuclear cells (PBMC were determined before and after exercise. The average performed work was 3261.3 ± 558.3 J · kg-1 and maximal oxygen consumption (VO2max for all players was 53.85 ± 3.91 mL · kg-1 min-1. The geometric mean of the ADRB2 gene expression was statistically significantly different before and after exercise (P ≤ 0.05, while adrenaline and noradrenaline levels in plasma significantly increased after exercise. In the analysed group of athletes we found that initial level of plasma noradrenaline correlated with the performed work (r = - 0.55, P < 0.014 and normalized ADRB2 expression before the exercise correlated with the work done by them (r = 0.48, P<0.039. However, no statistically significant correlations were found between the plasma adrenaline or noradrenaline concentrations and ADRB2 gene expression in peripheral blood of the players. The performed work in the maximal incremental exercise test of regularly training young ice hockey players depends on the initial levels of noradrenaline in plasma and ADRB2 mRNA in PBMC.

  12. Design and Validation of an Instrumented Uneven Terrain Treadmill.

    Science.gov (United States)

    Voloshina, Alexandra S; Ferris, Daniel P

    2018-06-01

    Studying human and animal locomotion on an uneven terrain can be beneficial to basic science and applied studies for clinical and robotic applications. Traditional biomechanical analysis of human locomotion has often been limited to laboratory environments with flat, smooth runways and treadmills. The authors modified a regular exercise treadmill by attaching wooden blocks to the treadmill belt to yield an uneven locomotion surface. To ensure that these treadmill modifications facilitated biomechanical measurements, the authors compared ground reaction force data collected while a subject ran on the modified instrumented treadmill with a smooth surface with data collected using a conventional instrumented treadmill. Comparisons showed only minor differences. These results suggest that adding an uneven surface to a modified treadmill is a viable option for studying human or animal locomotion on an uneven terrain. Other types of surfaces (eg, compliant blocks) could be affixed in a similar manner for studies on other types of locomotion surfaces.

  13. Skin sensitization potency of isoeugenol and its dimers evaluated by a non-radioisotopic modification of the local lymph node assay and guinea pig maximization test.

    Science.gov (United States)

    Takeyoshi, Masahiro; Iida, Kenji; Suzuki, Keiko; Yamazaki, Shunsuke

    2008-05-01

    Allergic contact dermatitis is the serious unwanted effect arising from the use of consumer products such as cosmetics. Isoeugenol is a fragrance chemical with spicy, carnation-like scent, is used in many kinds of cosmetics and is a well-known moderate human sensitizer. It was previously reported that the dimerization of eugenol yielded two types of dimer possessing different sensitization potencies. This study reports the differences in skin sensitization potencies for isoeugenol and two types of dimer, beta-O-4-dilignol and dehydrodiisoeugenol (DIEG), as evaluated by the non-radioisotopic local lymph node assay (non-RI LLNA) and guinea pig maximization test. In the guinea pig maximization test, isoeugenol, beta-O-4-dilignol and DIEG were classified as extreme, weak and moderate sensitizers, respectively. As for the results of non-RI LLNA, the EC3 for isoeugenol, beta-O-4-dilignol and DIEG were calculated as 12.7%, >30% and 9.4%, respectively. The two types of isoeugenol dimer showed different sensitizing activities similar to the case for eugenol dimers. A reduction of sensitization potency achieved by dimerization may lead to developing safer cosmetic ingredients. Isoeugenol dimers are not currently used for fragrance chemicals. However, the dimerization of isoeugenol may yield a promising candidate as a cosmetic ingredient with low sensitization risk. The data may also provide useful information for the structure-activity relationship (SAR) in skin sensitization. Copyright (c) 2007 John Wiley & Sons, Ltd.

  14. Stepping responses to treadmill perturbations vary with severity of motor deficits in human SCI.

    Science.gov (United States)

    Chu, Virginia Way Tong; Hornby, T George; Schmit, Brian D

    2018-04-18

    In this study, we investigated the responses to tread perturbations during human stepping on a treadmill. Our approach was to test the effects of perturbations to a single leg using a split-belt treadmill in healthy participants and in participants with varying severity of spinal cord injury (SCI). We recruited 11 people with incomplete SCI and 5 noninjured participants. As participants walked on an instrumented treadmill, the belt on one side was stopped or accelerated briefly during mid to late stance. A majority of participants initiated an unnecessary swing when the treadmill was stopped in mid stance, although the likelihood of initiating a step was decreased in participants with more severe SCI. Accelerating or decelerating one belt of the treadmill during stance altered the characteristics of swing. We observed delayed swing initiation when the belt was decelerated (i.e. the hip was in a more flexed position at time of swing) and advanced swing initiation with acceleration (i.e. hip extended at swing initiation). Further, the timing and leg posture of heel strike appeared to remain constant, reflected by a sagittal plane hip angle at heel strike that remained the same regardless of the perturbation. In summary, our results supported the current understanding of the role of sensory feedback and central drive in the control of stepping in participants with incomplete SCI and noninjured participants. In particular, the observation of unnecessary swing during a stop perturbation highlights the interdependence of central and sensory drive in walking control.

  15. Using a Split-belt Treadmill to Evaluate Generalization of Human Locomotor Adaptation.

    Science.gov (United States)

    Vasudevan, Erin V L; Hamzey, Rami J; Kirk, Eileen M

    2017-08-23

    Understanding the mechanisms underlying locomotor learning helps researchers and clinicians optimize gait retraining as part of motor rehabilitation. However, studying human locomotor learning can be challenging. During infancy and childhood, the neuromuscular system is quite immature, and it is unlikely that locomotor learning during early stages of development is governed by the same mechanisms as in adulthood. By the time humans reach maturity, they are so proficient at walking that it is difficult to come up with a sufficiently novel task to study de novo locomotor learning. The split-belt treadmill, which has two belts that can drive each leg at a different speed, enables the study of both short- (i.e., immediate) and long-term (i.e., over minutes-days; a form of motor learning) gait modifications in response to a novel change in the walking environment. Individuals can easily be screened for previous exposure to the split-belt treadmill, thus ensuring that all experimental participants have no (or equivalent) prior experience. This paper describes a typical split-belt treadmill adaptation protocol that incorporates testing methods to quantify locomotor learning and generalization of this learning to other walking contexts. A discussion of important considerations for designing split-belt treadmill experiments follows, including factors like treadmill belt speeds, rest breaks, and distractors. Additionally, potential but understudied confounding variables (e.g., arm movements, prior experience) are considered in the discussion.

  16. Treadmill exercise ameliorates social isolation-induced depression through neuronal generation in rat pups.

    Science.gov (United States)

    Cho, Jung-Wan; Jung, Sun-Young; Lee, Sang-Won; Lee, Sam-Jun; Seo, Tae-Beom; Kim, Young-Pyo; Kim, Dae-Young

    2017-12-01

    Social isolation is known to induce emotional and behavioral changes in animals and humans. The effect of treadmill exercise on depression was investigated using social isolated rat pups. The rat pups in the social isolation groups were housed individually. The rat pups in the exercise groups were forced to run on treadmill for 30 min once a day from postnatal day 21 to postnatal day 34. In order to evaluate depression state of rat pups, forced swimming test was performed. Newly generated cells in the hippocampal dentate gyrus were determined by 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry. We examined the expression of 5-hydroxytryptamine (5-HT) and tryptophan hydroxylase (TPH) in the dorsal raphe using immunofluorescence. The expression of brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) was detected by Western blot analysis. The present results demonstrated that social isolation increased resting time and decreased mobility time. Expression of 5-HT and TPH in the dorsal raphe and expression of BDNF and TrkB in the hippocampus were decreased by social isolation. The number of BrdU-positive cells in the hippocampal dentate gyrus was suppressed by social isolation. Treadmill exercise decreased resting time and increased mobility in the social isolated rat pups. Expression of 5-HT, TPH, BDNF, and TrkB was increased by treadmill exercise. The present results suggested that treadmill exercise may ameliorates social isolation-induced depression through increasing neuronal generation.

  17. Residual myocardial ischaemia in first non-Q versus Q wave infarction: maximal exercise testing and ambulatory ST-segment monitoring

    DEFF Research Database (Denmark)

    Mickley, H; Pless, P; Nielsen, J R

    1993-01-01

    the infarction. The prevalence of exercise-induced ischaemic manifestations in the infarct types was similar: chest pain 14% vs 16% and ST-segment depression 54% vs 54%. The ischaemic threshold did not differ either (heart rate at 1 mm of ST-segment depression 120 +/- 27 vs 119 +/- 25 beats.min-1). During early...... in non-Q wave infarction (51%) as compared to Q wave infarction (31%) (P depression on ambulatory recording and exercise testing significantly predicted the development of future angina pectoris, whereas patients at increased risk for subsequent......In a prospective study of 123 consecutive survivors of a first myocardial infarction (43 non-Q wave, 80 Q wave), we determined the total residual ischaemic burden by use of pre-discharge maximal exercise testing and post-discharge 36 h ambulatory ST-segment monitoring initiated 11 +/- 5 days after...

  18. Modular Control of Treadmill vs Overground Running

    Science.gov (United States)

    Farina, Dario; Kersting, Uwe Gustav

    2016-01-01

    Motorized treadmills have been widely used in locomotion studies, although a debate remains concerning the extrapolation of results obtained from treadmill experiments to overground locomotion. Slight differences between treadmill (TRD) and overground running (OVG) kinematics and muscle activity have previously been reported. However, little is known about differences in the modular control of muscle activation in these two conditions. Therefore, we aimed at investigating differences between motor modules extracted from TRD and OVG by factorization of multi-muscle electromyographic (EMG) signals. Twelve healthy men ran on a treadmill and overground at their preferred speed while we recorded tibial acceleration and surface EMG from 11 ipsilateral lower limb muscles. We extracted motor modules representing relative weightings of synergistic muscle activations by non-negative matrix factorization from 20 consecutive gait cycles. Four motor modules were sufficient to accurately reconstruct the EMG signals in both TRD and OVG (average reconstruction quality = 92±3%). Furthermore, a good reconstruction quality (80±7%) was obtained also when muscle weightings of one condition (either OVG or TRD) were used to reconstruct the EMG data from the other condition. The peak amplitudes of activation signals showed a similar timing (pattern) across conditions. The magnitude of peak activation for the module related to initial contact was significantly greater for OVG, whereas peak activation for modules related to leg swing and preparation to landing were greater for TRD. We conclude that TRD and OVG share similar muscle weightings throughout motion. In addition, modular control for TRD and OVG is achieved with minimal temporal adjustments, which were dependent on the phase of the running cycle. PMID:27064978

  19. Treadmill walking with body weight support

    OpenAIRE

    Aaslund, Mona Kristin

    2012-01-01

    Background: Rehabilitating walking in patients post-stroke with safe, task-specific, intensive training of sufficient duration, can be challenging. Body weight supported treadmill training (BWSTT) has been proposed as an effective method to meet these challenges and may therefore have benefits over training overground walking. However, walking characteristics should not be aggravated during BWSTT or require a long familiarisation time compared to overground walking. Objectives: To investi...

  20. The Higher the Insulin Resistance the Lower the Cardiac Output in Men with Type 1 Diabetes During the Maximal Exercise Test.

    Science.gov (United States)

    Niedzwiecki, Pawel; Naskret, Dariusz; Pilacinski, Stanislaw; Pempera, Maciej; Uruska, Aleksandra; Adamska, Anna; Zozulinska-Ziolkiewicz, Dorota

    2017-06-01

    The aim of this study was to assess the hemodynamic parameters analyzed in bioimpedance cardiography during maximal exercise in patients with type 1 diabetes differing in insulin resistance. The study group consisted of 40 men with type 1 diabetes. Tissue sensitivity to insulin was assessed on the basis of the glucose disposal rate (GDR) analyzed during hyperinsulinemic-euglycemic clamp. Patients were divided into groups with GDR insulin sensitivity) and GDR ≥4.5 mg/kg/min (G2 group-higher insulin sensitivity). During the exercise test, the heart rate, systolic volume, cardiac output, cardiac index were measured by the impedance meter (PhysioFlow). Compared with the G2 group, the G1 group had a lower cardiac output (CO): during exercise 8.6 (IQR 7.7-10.0) versus 12.8 (IQR 10.8-13.7) L/min; P insulin resistance is associated with cardiac hemodynamic parameters assessed during and after exercise. The higher the insulin resistance the lower the cardiac output during maximal exercise in men with type 1 diabetes.

  1. Maximal exercise electrocardiography responses and coronary heart disease mortality among men with diabetes mellitus.

    Science.gov (United States)

    Lyerly, G William; Sui, Xuemei; Church, Timothy S; Lavie, Carl J; Hand, Gregory A; Blair, Steven N

    2008-05-27

    An abnormal ECG during maximal exercise testing has been shown to be a powerful predictor of future coronary heart disease (CHD) mortality in asymptomatic men. However, little is known about the relationship between exercise ECG responses and CHD risk in men with diabetes mellitus. We examined the association between exercise ECG responses and mortality in 2854 men with documented diabetes mellitus (mean age 49.5 years) who completed a maximal treadmill exercise test during the period from 1974 to 2001 and who were without a previous cardiovascular disease (CVD) event at baseline. Mortality due to all causes, CHD, and CVD were the main outcome measures across categories of exercise ECG responses, with stratification by cardiorespiratory fitness, quantified as treadmill test duration. During an average follow-up of 16 years, 441 deaths (210 CVD and 133 CHD) were identified. Across normal, equivocal, and abnormal exercise ECG groups, age- and examination year-adjusted CHD mortality rates per 10 000 person-years were 23.0, 48.6, and 69.0, respectively (P(trend)<0.001). After further adjustment for fasting plasma glucose level, smoking, body mass index, hypercholesterolemia, hypertension, family history of CVD or diabetes mellitus, abnormal resting ECG responses, and cardiorespiratory fitness, hazard ratios (95% confidence intervals) were 1.00 (referent), 1.68 (1.01 to 2.77), and 2.21 (1.41 to 3.46; P(trend)<0.001). Similar patterns of associations were noted between exercise ECG testing and both CVD and all-cause mortality risk. Among men with diabetes mellitus, equivocal and abnormal exercise ECG responses were associated with higher risk of all-cause, CVD, and CHD mortality.

  2. Metabolic cost of running is greater on a treadmill with a stiffer running platform.

    Science.gov (United States)

    Smith, James A H; McKerrow, Alexander D; Kohn, Tertius A

    2017-08-01

    Exercise testing on motorised treadmills provides valuable information about running performance and metabolism; however, the impact of treadmill type on these tests has not been investigated. This study compared the energy demand of running on two laboratory treadmills: an HP Cosmos (C) and a Quinton (Q) model, with the latter having a 4.5 times stiffer running platform. Twelve experienced runners ran identical bouts on these treadmills at a range of four submaximal velocities (reported data is for the velocity that approximated 75-81% VO 2max ). The stiffer treadmill elicited higher oxygen consumption (C: 46.7 ± 3.8; Q: 50.1 ± 4.3 ml·kg -1 · min -1 ), energy expenditure (C: 16.0 ± 2.5; Q: 17.7 ± 2.9 kcal · min -1 ), carbohydrate oxidation (C: 9.6 ± 3.1; Q: 13.0 ± 3.9 kcal · min -1 ), heart rate (C: 155 ± 16; Q: 163 ± 16 beats · min -1 ) and rating of perceived exertion (C: 13.8 ± 1.2; Q: 14.7 ± 1.2), but lower fat oxidation (C: 6.4 ± 2.3; Q: 4.6 ± 2.5 kcal · min -1 ) (all analysis of variance treadmill comparisons P running depending on the running platform stiffness.

  3. Profit maximization mitigates competition

    DEFF Research Database (Denmark)

    Dierker, Egbert; Grodal, Birgit

    1996-01-01

    We consider oligopolistic markets in which the notion of shareholders' utility is well-defined and compare the Bertrand-Nash equilibria in case of utility maximization with those under the usual profit maximization hypothesis. Our main result states that profit maximization leads to less price...... competition than utility maximization. Since profit maximization tends to raise prices, it may be regarded as beneficial for the owners as a whole. Moreover, if profit maximization is a good proxy for utility maximization, then there is no need for a general equilibrium analysis that takes the distribution...... of profits among consumers fully into account and partial equilibrium analysis suffices...

  4. Metabolic Rate and Ground Reaction Force During Motorized and Non-Motorized Treadmill Exercise

    Science.gov (United States)

    Everett, Meghan E.; Loehr, James A.; DeWitt, John K.; Laughlin, Mitzi; Lee, Stuart M. C.

    2010-01-01

    PURPOSE: To measure vertical ground reaction force (vGRF) and oxygen consumption (VO2) at several velocities during exercise using a ground-based version of the ISS treadmill in the M and NM modes. METHODS: Subjects (n = 20) walked or ran at 0.89, 1.34, 1.79, 2.24, 2.68, and 3.12 m/s while VO2 and vGRF data were collected. VO2 was measured using open-circuit spirometry (TrueOne 2400, Parvo-Medics). Data were averaged over the last 2 min of each 5-min stage. vGRF was measured in separate 15-s bouts at 125 Hz using custom-fitted pressure-sensing insoles (F-Scan Sport Sensors, Tekscan, Inc). A repeated-measures ANOVA was used to test for differences in VO2 and vGRF between M and NM and across speeds. Significance was set at P < 0.05. RESULTS: Most subjects were unable to exercise for 5 min at treadmill speeds above 1.79 m/s in the NM mode; however, vGRF data were obtained for all subjects at each speed in both modes. VO2 was approx.40% higher during NM than M exercise across treadmill speeds. vGRF increased with treadmill speed but was not different between modes. CONCLUSION: Higher VO2 with no change in vGRF suggests that the additional metabolic cost associated with NM treadmill exercise is accounted for in the horizontal forces required to move the treadmill belt. Although this may limit the exercise duration at faster speeds, high-intensity NM exercise activates the hamstrings and plantarflexors, which are not specifically targeted or well protected by other in-flight countermeasures.

  5. Mini-Treadmill for Musculoskeletal Health, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — ZIN Technologies, Inc. proposes a novel Miniature Treadmill with resistive exercise capability for use in spaceflight exercise countermeasures and broad terrestrial...

  6. Mini-Treadmill for Musculoskeletal Health, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — ZIN Technologies, Inc. is developing a novel Miniature Treadmill with resistive exercise capability for use in spaceflight exercise countermeasures and broad...

  7. Duration-dependence of the effect of treadmill exercise on hyperactivity in attention deficit hyperactivity disorder rats.

    Science.gov (United States)

    Ji, Eun-Sang; Kim, Chang-Ju; Park, Jun Heon; Bahn, Geon Ho

    2014-04-01

    Attention-deficit hyperactivity disorder (ADHD) is a common neurobehavioral disorder, and its symptoms are hyperactivity and deficits in learning and memory. Physical exercise increases dopamine synthesis and neuronal activity in various brain regions. In the present study, we investigate the duration-dependence of the treadmill exercise on hyperactivity in relation with dopamine expression in ADHD. Spontaneously hypertensive rats were used for the ADHD rats and Wistar-Kyoto rats were used for the control rats. The rats in the exercise groups were forced to run on a treadmill for 10 min, 30 min, and 60 min once daily for 28 consecutive days. For this experiment, open field test and immunohistochemistry for tyrosine hydroxylase were conducted. The present results revealed that ADHD rats showed hyperactivity, and tyrosine hydroxylase expression in the striatum and substantia nigra were decreased in ADHD rats. Treadmill exercise alleviated hyperactivity and also increased TH expression in ADHD rats. Treadmill exercise for 30 min per day showed most potent suppressing effect on hyperactivity, and this dose of treadmill exercise also most potently inhibited tyrosine hydroxylase expression. The present study suggests that treadmill exercise for 30 min once a day is the most effective therapeutic intervention for ADHD patients.

  8. Validação de um protocolo para o teste de caminhada de seis minutos em esteira para avaliação de pacientes com hipertensão arterial pulmonar Validation of a treadmill six-minute walk test protocol for the evaluation of patients with pulmonary arterial hypertension

    Directory of Open Access Journals (Sweden)

    Viviane Moreira de Camargo

    2009-05-01

    Full Text Available OBJETIVO: Elaborar e validar um protocolo para teste de caminhada de seis minutos em esteira (TC6est para a avaliação de pacientes com hipertensão arterial pulmonar (HAP. MÉTODOS: A população do estudo foi composta por 73 pacientes com HAP diagnosticados através de cateterismo cardíaco direito, com ou sem inalação de NO. Todos os pacientes realizaram um TC6 em solo e três TC6est baseados em um protocolo de incremento de velocidade pré-determinado e intercalados por um período de repouso. Os pacientes que haviam realizado o teste hemodinâmico com inalação de NO realizaram o terceiro TC6est com a inalação da mesma dose de NO utilizada durante o cateterismo. RESULTADOS: Os resultados mostraram uma correlação da distância caminhada no TC6est com os dados hemodinâmicos, assim como com a classe funcional e com a distância caminhada no solo. Além disso, a distância percorrida no TC6est apresentou uma correlação significativa com a sobrevida, confirmando, portanto, sua correlação com a gravidade da doença. A inalação de NO durante o TC6est levou a variações compatíveis com as variações hemodinâmicas frente à mesma dose de NO, sugerindo que o protocolo em questão pode refletir o efeito de intervenções terapêuticas. CONCLUSÕES: Concluímos que a distância percorrida no TC6est é um marcador funcional e prognóstico na avaliação de rotina de pacientes com HAP.OBJECTIVE: To develop and validate a protocol for the treadmill six-minute walk test (tread6MWT to evaluate patients with pulmonary arterial hypertension (PAH. METHODS:The study population comprised 73 patients with PAH, diagnosed by means of right heart catheterization, with or without NO inhalation. All patients performed a hallway 6MWT and three tread6MWTs based on a pre-determined incremental speed protocol and interposed by a rest period. The patients who had been submitted to hemodynamic testing using NO performed the third tread6MWT while inhaling

  9. Psychophysical and ergogenic effects of synchronous music during treadmill walking.

    Science.gov (United States)

    Karageorghis, Costas I; Mouzourides, Denis A; Priest, David-Lee; Sasso, Tariq A; Morrish, Daley J; Walley, Carolyn J

    2009-02-01

    The present study examined the impact of motivational music and oudeterous (neutral in terms of motivational qualities) music on endurance and a range of psychophysical indices during a treadmill walking task. Experimental participants (N=30; mean age=20.5 years, SD=1.0 years) selected a program of either pop or rock tracks from artists identified in an earlier survey. They walked to exhaustion, starting at 75% maximal heart rate reserve, under conditions of motivational synchronous music, oudeterous synchronous music, and a no-music control. Dependent measures included time to exhaustion, ratings of perceived exertion (RPE), and in-task affect (both recorded at 2-min intervals), and exercise-induced feeling states. A one-way repeated measures ANOVA was used to analyze time to exhaustion data. Two-way repeated measures (Music Condition ? Trial Point) ANOVAs were used to analyze in-task measures, whereas a one-way repeated measures MANOVA was used to analyze the exercise-induced feeling states data. Results indicated that endurance was increased in both music conditions and that motivational music had a greater ergogenic effect than did oudeterous music (pmusic when compared with control throughout the trial (p.05) upon RPE or exercise-induced feeling states, although a moderate effect size was recorded for the latter (etap2=.09). The present results indicate that motivational synchronous music can elicit an ergogenic effect and enhance in-task affect during an exhaustive endurance task.

  10. See Hear: psychological effects of music and music-video during treadmill running

    OpenAIRE

    Hutchinson, Jasmin C.; Karageorghis, Costas I.; Jones, Leighton

    2015-01-01

    Background:\\ud There is a paucity of work addressing the distractive, affect-enhancing, and motivational influences of music and video in combination during exercise.\\ud \\ud Purpose:\\ud We examined the effects of music and music-and-video on a range of psychological and psychophysical variables during treadmill running at intensities above and below ventilatory threshold (VT)\\ud \\ud Methods:\\ud Participants (N = 24) exercised at 10 % of maximal capacity below VT and 10 % above under music-onl...

  11. Treadmill sideways gait training with visual blocking for patients with brain lesions.

    Science.gov (United States)

    Kim, Tea-Woo; Kim, Yong-Wook

    2014-09-01

    [Purpose] The aim of this study was to verify the effect of sideways treadmill training with and without visual blocking on the balance and gait function of patients with brain lesions. [Subjects] Twenty-four stroke and traumatic brain injury subjects participated in this study. They were divided into two groups: an experimental group (12 subjects) and a control group (12 subjects). [Methods] Each group executed a treadmill training session for 20 minutes, three times a week, for 6 weeks. The sideways gait training on the treadmill was performed with visual blocking by the experimental group and with normal vision by the control group. A Biodex Gait Trainer 2 was used to assess the gait function. It was used to measure walking speed, walking distance, step length, and stance time on each foot. The Five-Times-Sit-To-Stand test (FTSST) and Timed Up and Go test (TUG) were used as balance measures. [Results] The sideways gait training with visual blocking group showed significantly improved walking speed, walking distance, step length, and stance time on each foot after training; FTSST and TUG times also significantly improved after training in the experimental group. Compared to the control group, the experimental group showed significant increases in stance time on each foot. [Conclusion] Sideways gait training on a treadmill with visual blocking performed by patients with brain lesions significantly improved their balance and gait function.

  12. Maximally incompatible quantum observables

    Energy Technology Data Exchange (ETDEWEB)

    Heinosaari, Teiko, E-mail: teiko.heinosaari@utu.fi [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Schultz, Jussi, E-mail: jussi.schultz@gmail.com [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Toigo, Alessandro, E-mail: alessandro.toigo@polimi.it [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Ziman, Mario, E-mail: ziman@savba.sk [RCQI, Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 84511 Bratislava (Slovakia); Faculty of Informatics, Masaryk University, Botanická 68a, 60200 Brno (Czech Republic)

    2014-05-01

    The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.

  13. Maximally incompatible quantum observables

    International Nuclear Information System (INIS)

    Heinosaari, Teiko; Schultz, Jussi; Toigo, Alessandro; Ziman, Mario

    2014-01-01

    The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.

  14. Long-term moderate treadmill exercise promotes stress-coping strategies in male and female rats.

    Science.gov (United States)

    Lalanza, Jaume F; Sanchez-Roige, Sandra; Cigarroa, Igor; Gagliano, Humberto; Fuentes, Silvia; Armario, Antonio; Capdevila, Lluís; Escorihuela, Rosa M

    2015-11-05

    Recent evidence has revealed the impact of exercise in alleviating anxiety and mood disorders; however, the exercise protocol that exerts such benefit is far from known. The current study was aimed to assess the effects of long-term moderate exercise on behavioural coping strategies (active vs. passive) and Hypothalamic-Pituitary-Adrenal response in rats. Sprague-Dawley male and female rats were exposed to 32-weeks of treadmill exercise and then tested for two-way active avoidance learning (shuttle-box). Two groups were used as controls: a non-handled sedentary group, receiving no manipulation, and a control group exposed to a stationary treadmill. Female rats displayed shorter escape responses and higher number of avoidance responses, reaching criterion for performance earlier than male rats. In both sexes, exercise shortened escape latencies, increased the total number of avoidances and diminished the number of trials needed to reach criterion for performance. Those effects were greater during acquisition in female rats, but remained over the shuttle-box sessions in treadmill trained male rats. In females, exercise did not change ACTH and corticosterone levels after shuttle-box acquisition. Collectively, treadmill exercise improved active coping strategies in a sex-dependent manner. In a broader context, moderate exercise could serve as a therapeutic intervention for anxiety and mood disorders.

  15. Correlation between plasma endothelin-1 levels and severity of septic liver failure quantified by maximal liver function capacity (LiMAx test. A prospective study.

    Directory of Open Access Journals (Sweden)

    Magnus F Kaffarnik

    Full Text Available To investigate the relationship between the degree of liver dysfunction, quantified by maximal liver function capacity (LiMAx test and endothelin-1, TNF-α and IL-6 in septic surgical patients.28 septic patients (8 female, 20 male, age range 35-80y were prospectively investigated on a surgical intensive care unit. Liver function, defined by LiMAx test, and measurements of plasma levels of endothelin-1, TNF-α and IL-6 were carried out within the first 24 hours after onset of septic symptoms, followed by day 2, 5 and 10. Patients were divided into 2 groups (group A: LiMAx ≥100 μg/kg/h, moderate liver dysfunction; group B: LiMAx <100 μg/kg/h, severe liver dysfunction for analysis and investigated regarding the correlation between endothelin-1 and the severity of liver failure, quantified by LiMAx test.Group B showed significant higher results for endothelin-1 than patients in group A (P = 0.01, d5; 0.02, d10. For TNF-α, group B revealed higher results than group A, with a significant difference on day 10 (P = 0.005. IL-6 showed a non-significant trend to higher results in group B. The Spearman's rank correlation coefficient revealed a significant correlation between LiMAx and endothelin-1 (-0.434; P <0.001, TNF-α (-0.515; P <0.001 and IL-6 (-0.590; P <0.001.Sepsis-related hepatic dysfunction is associated with elevated plasma levels of endothelin-1, TNF-α and IL-6. Low LiMAx results combined with increased endothelin-1 and TNF-α and a favourable correlation between LiMAx and cytokine values support the findings of a crucial role of Endothelin-1 and TNF-α in development of septic liver failure.

  16. Oxygen Consumption of Elite Distance Runners on an Anti-Gravity Treadmill®

    Directory of Open Access Journals (Sweden)

    David K.P. McNeill, John R. Kline, Hendrick D. de Heer, J. Richard Coast

    2015-06-01

    Full Text Available Lower body positive pressure (LBPP, or ‘anti-gravity’ treadmills® have become increasingly popular among elite distance runners. However, to date, few studies have assessed the effect of body weight support (BWS on the metabolic cost of running among elite runners. This study evaluated how BWS influenced the relationship between velocity and metabolic cost among 6 elite male distance runners. Participants ran three- 16 minute tests consisting of 4 stages of 4 minutes at 8, 7, 6 and 5 min·mile−1 pace (3.35, 3.84, 4.47 and 5.36 m·s−1, while maintaining an aerobic effort (Respiratory Exchange Ratio ≤1.00. One test was run on a regular treadmill, one on an anti-gravity treadmill with 40% BWS and one with 20% BWS being provided. Expired gas data were collected and regression equations used to determine and compare slopes. Significant decreases in oxygen uptake (V̇O2 were found with each increase in BWS (p < 0.001. At 20% BWS, the average decrease in net VO2 was greater than proportional (34%, while at 40% BWS, the average net reduction in VO2 was close to proportional (38%. Across velocities, the slope of the relationship between VO2 and velocity (ΔV̇O2/Δv was steeper with less support. The slopes at both the 20% and 40% BWS conditions were similar, especially when compared to the regular treadmill. Variability in VO2 between athletes was much greater on the LBPP treadmill and was greater with increased levels of BWS. In this study we evaluated the effect of body weight support on V̇O2 among elite distance runners. We have shown that oxygen uptake decreased with support, but not in direct proportion to that support. Further, because of the high variability in oxygen uptake between athletes on the LBPP treadmill, prediction equations may not be reliable and other indicators (heart rate, perceived exertion or directly measured oxygen uptake should be used to guide training intensity when training on the LBPP treadmill.

  17. Physiologic Responses to Motorized and Non-Motorized Locomotion Utilizing the International Space Station Treadmill

    Science.gov (United States)

    Smith, Cassie; Lee, Stuart MC; Laughlin, Mitzi; Loehr, James; Norcross, Jason; DeWitt, John; Hagan, R. D.

    2006-01-01

    Treadmill locomotion is used onboard the International Space Station (ISS) as a countermeasure to the effects of prolonged weightlessness. The treadmill operates in two modes: motorized (T-M) and non-motorized (T-NM). Little is known about the potential physiologic differences between modes which may affect countermeasure exercise prescription. PURPOSE: To quantify heart rate (HR), oxygen consumption (VO2), perceived exertion (RPE), and blood lactate (BLa) during T-M and T-NM locomotion at 2 and 4 mph in normal ambulatory subjects. METHODS: Twenty subjects (10 men, 10 women; 31+/-5 yr, 172+/-10 cm, 68+/-13 kg, mean SD) with a treadmill peakVO2 of 45.5+/-5.4 ml/kg/min (mean+/-SD) exercised on the ground-based ISS treadmill. Following a familiarization session in each mode, subjects completed two data collection sessions, T-M and T-NM in random order, at 2 and 4 mph. Subjects attempted to complete 5 min of exercise at each speed; if they could not maintain the speed, the trial was discontinued. At least 5 minutes of rest separated each speed trial, and at least 48 hrs separated each session. VO2 was measured continuously (metabolic gas analysis), while HR (HR monitor) and RPE (Borg Chart, 6-20 scale) were recorded each min. Not all subjects completed 5 min during each condition, therefore the mean of the min 3 and 4 was taken as representative of steady-state. BLa was measured (finger stick) within 2 min post-exercise. Paired t-tests were used to test for differences (p<0.05) between treadmill modes within the same speed. RESULTS: All twenty subjects completed at least 4 min of exercise during all conditions, except T-NM 4 mph when only 11 subjects completed the minimum exercise duration. VO2, HR, RPE and BLa were significantly higher during T-NM locomotion at both speeds.

  18. Treadmill Exercise with Increased Body Loading Enhances Post Flight Functional Performance

    Science.gov (United States)

    Bloomberg, J. J.; Batson, C. D.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Laurie, S.; Lee, S. M. C.; Miller, C. A.; Mulavara, A. P.; Peters, B. T.; hide

    2014-01-01

    The goals of the Functional Task Test (FTT) study were to determine the effects of space flight on functional tests that are representative of high priority exploration mission tasks and to identify the key underlying physiological factors that contribute to decrements in performance. Ultimately this information will be used to assess performance risks and inform the design of countermeasures for exploration class missions. We have previously shown that for Shuttle, ISS and bed rest subjects functional tasks requiring a greater demand for dynamic control of postural equilibrium (i.e. fall recovery, seat egress/obstacle avoidance during walking, object translation, jump down) showed the greatest decrement in performance. Functional tests with reduced requirements for postural stability (i.e. hatch opening, ladder climb, manual manipulation of objects and tool use) showed little reduction in performance. These changes in functional performance were paralleled by similar decrements in sensorimotor tests designed to specifically assess postural equilibrium and dynamic gait control. The bed rest analog allows us to investigate the impact of axial body unloading in isolation on both functional tasks and on the underlying physiological factors that lead to decrements in performance and then compare them with the results obtained in our space flight study. These results indicate that body support unloading experienced during space flight plays a central role in postflight alteration of functional task performance. Given the importance of body-support loading we set out to determine if there is a relationship between the load experienced during inflight treadmill exercise (produced by a harness and bungee system) and postflight functional performance. ISS crewmembers (n=13) were tested using the FTT protocol before and after 6 months in space. Crewmembers were tested three times before flight, and on 1, 6, and 30 days after landing. To determine how differences in body

  19. A maximal incremental effort alters tear osmolarity depending on the fitness level in military helicopter pilots.

    Science.gov (United States)

    Vera, Jesús; Jiménez, Raimundo; Madinabeitia, Iker; Masiulis, Nerijus; Cárdenas, David

    2017-10-01

    Fitness level modulates the physiological responses to exercise for a variety of indices. While intense bouts of exercise have been demonstrated to increase tear osmolarity (Tosm), it is not known if fitness level can affect the Tosm response to acute exercise. This study aims to compare the effect of a maximal incremental test on Tosm between trained and untrained military helicopter pilots. Nineteen military helicopter pilots (ten trained and nine untrained) performed a maximal incremental test on a treadmill. A tear sample was collected before and after physical effort to determine the exercise-induced changes on Tosm. The Bayesian statistical analysis demonstrated that Tosm significantly increased from 303.72 ± 6.76 to 310.56 ± 8.80 mmol/L after performance of a maximal incremental test. However, while the untrained group showed an acute Tosm rise (12.33 mmol/L of increment), the trained group experienced a stable Tosm physical effort (1.45 mmol/L). There was a significant positive linear association between fat indices and Tosm changes (correlation coefficients [r] range: 0.77-0.89), whereas the Tosm changes displayed a negative relationship with the cardiorespiratory capacity (VO2 max; r = -0.75) and performance parameters (r = -0.75 for velocity, and r = -0.67 for time to exhaustion). The findings from this study provide evidence that fitness level is a major determinant of Tosm response to maximal incremental physical effort, showing a fairly linear association with several indices related to fitness level. High fitness level seems to be beneficial to avoid Tosm changes as consequence of intense exercise. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Maximizers versus satisficers

    OpenAIRE

    Andrew M. Parker; Wandi Bruine de Bruin; Baruch Fischhoff

    2007-01-01

    Our previous research suggests that people reporting a stronger desire to maximize obtain worse life outcomes (Bruine de Bruin et al., 2007). Here, we examine whether this finding may be explained by the decision-making styles of self-reported maximizers. Expanding on Schwartz et al. (2002), we find that self-reported maximizers are more likely to show problematic decision-making styles, as evidenced by self-reports of less behavioral coping, greater dependence on others when making decisions...

  1. Maximal combustion temperature estimation

    International Nuclear Information System (INIS)

    Golodova, E; Shchepakina, E

    2006-01-01

    This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models

  2. Differences in Lower Body Kinematics during Forward Treadmill Skating Between Two Different Hockey Skate Designs

    Directory of Open Access Journals (Sweden)

    Mike R. Hellyer

    2016-01-01

    Full Text Available Purpose: The purpose of this study was to investigate the differences in ankle flexibility and skating technique between a traditional hockey skate boot and a hockey skate boot with a flexible rear tendon guard. Skating technique was further investigated at different speeds to give insight on how skating technique alters as skating speed is increased. Methods: Eight elite hockey players were selected for the present study, which was conducted while skating on an Endless Ice Skating Treadmill.  Variables were recorded using a three-camera setup and measured from video records at five selected treadmill speeds using the Dartfish Team Pro v6 software.  Kinematic variables were then compared between the two skate designs with a doubly multivariate repeated measures design.  Statistical significance was set at p<0.05.  Results: Post hoc univariate tests comparing skate designs displayed significant increases in plantar flexion, plantar flexion angular velocity, hip extension, hip extension angular velocity, stride length, and stride velocity while participants were wearing the skates that had a flexible rear tendon guard.  Significant increases were also displayed in plantar flexion, plantar flexion angular velocity, knee extension, knee extension angular velocity, hip extension, hip extension angular velocity, hip abduction range of motion, hip abduction angular velocity, stride width, stride length, and stride velocity as the treadmill speed increased. There was also a significant decrease in the time the skate was in contact with the treadmill as treadmill speed increased. Conclusion: The results suggested that while skating forward, hockey players could improve their hockey skating technique by using hockey skates that have a flexible rear tendon guard.  This flexible tendon guard improved skating technique by increasing the time of force application to the ice by increasing the range of ankle plantar flexion during propulsion of the

  3. Treadmill exercise alleviates stress-induced impairment of social interaction through 5-hydroxytryptamine 1A receptor activation in rats.

    Science.gov (United States)

    Kim, Tae-Woon; Lim, Baek-Vin; Kim, Kijeong; Seo, Jin-Hee; Kim, Chang-Ju

    2015-08-01

    Brain-derived neurotrophic factor (BDNF) and its receptors tyrosine kinase B (trkB), and cyclic adenosine monophosphate response element binding protein (CREB) have been suggested as the neurobiological risk factors causing depressive disorder. Serotonin (5-hydroxytryptamine, 5-HT) plays an important role in the pathogenesis of depression. We in-vestigated the effect of treadmill exercise on social interaction in relation with BDNF and 5-HT expressions following stress in rats. Stress was induced by applying inescapable 0.2 mA electric foot shock to the rats for 7 days. The rats in the exercise groups were forced to run on a motorized treadmill for 30 min once a day for 4 weeks. Social interaction test and western blot for BDNF, TrkB, pCREB, and 5-HT1A in the hippocampus were performed. The results indicate that the spend time with unfamiliar partner was decreased by stress, in contrast, treadmill exercise increased the spending time in the stress-induced rats. Expressions of BDNF, TrkB, and pCREB were decreased by stress, in contrast, treadmill exercise enhanced expressions of BDNF, TrkB, and pCREB in the stress-induced rats. In addition, 5-HT1A receptor expression was de-creased by stress, in contrast, treadmill exercise enhanced 5-HT1A expression in the stress-induced rats. In the present study, treadmill exercise alleviated stress-induced social interaction impairment through enhancing hippocampal plasticity and serotonergic function in the hippocampus. These effects of treadmill exercise are achieved through 5-HT1A receptor activation.

  4. Effects of progressive backward body weight suppoted treadmill training on gait ability in chronic stroke patients: A randomized controlled trial.

    Science.gov (United States)

    Kim, Kyung Hun; Lee, Kyoung Bo; Bae, Young-Hyeon; Fong, Shirley S M; Lee, Suk Min

    2017-10-23

    A stroke patient with hemiplegic gait is generally described as being slow and asymmetric. Body weight-supported treadmill training and backward gait training are recent additions to therapeutic gait trainings that may help improve gait in stroke patient with hemiplegic gait. Therefore, we examined the effect of progressive backward body weight-supported treadmill training on gait in chronic stroke patients with hemiplegic gait. Thirty subjects were divided to the experimental and control groups. The experimental group consisted of 15 patients and underwent progressive backward body weight-supported treadmill training. The control group consisted of 15 patients and underwent general treadmill gait training five times per week, for a total of four weeks. The OptoGait was used to analyze gait kinematics, and the dynamic gait index (DGI) and results of the 6-minute walk test were used as the clinical evaluation indicators. A follow-up test was carried out four weeks later to examine persistence of exercise effects. The experimental group showed statistically significant results in all dependent variables week four compared to the control group. However, until the eighth week, only the dependent variables, of affected step length (ASL), stride length (SL), and DGI differed significantly between the two groups. This study verified that progressive bodyweight-supported treadmill training had a positive influence on the temporospatial characteristics of gait and clinical gait evaluation index in chronic stroke patients.

  5. Acute and chronic effects of aquatic treadmill training on land treadmill running kinematics: A cross-over and single-subject design approach.

    Science.gov (United States)

    Bressel, Eadric; Louder, Talin J; Hoover, James P; Roberts, Luke C; Dolny, Dennis G

    2017-11-01

    The aim of this study was to determine if selected kinematic measures (foot strike index [SI], knee contact angle and overstride angle) were different between aquatic treadmill (ATM) and land treadmill (LTM) running, and to determine if these measures were altered during LTM running as a result of 6 weeks of ATM training. Acute effects were tested using 15 competitive distance runners who completed 1 session of running on each treadmill type at 5 different running speeds. Subsequently, three recreational runners completed 6 weeks of ATM training following a single-subject baseline, intervention and withdrawal experiment. Kinematic measures were quantified from digitisation of video. Regardless of speed, SI values during ATM running (61.3 ± 17%) were significantly greater (P = 0.002) than LTM running (42.7 ± 23%). Training on the ATM did not change (pre/post) the SI (26 ± 3.2/27 ± 3.1), knee contact angle (165 ± 0.3/164 ± 0.8) or overstride angle (89 ± 0.4/89 ± 0.1) during LTM running. Although SI values were different between acute ATM and LTM running, 6 weeks of ATM training did not appear to alter LTM running kinematics as evidenced by no change in kinematic values from baseline to post intervention assessments.

  6. Maximally multipartite entangled states

    Science.gov (United States)

    Facchi, Paolo; Florio, Giuseppe; Parisi, Giorgio; Pascazio, Saverio

    2008-06-01

    We introduce the notion of maximally multipartite entangled states of n qubits as a generalization of the bipartite case. These pure states have a bipartite entanglement that does not depend on the bipartition and is maximal for all possible bipartitions. They are solutions of a minimization problem. Examples for small n are investigated, both analytically and numerically.

  7. Maximizers versus satisficers

    Directory of Open Access Journals (Sweden)

    Andrew M. Parker

    2007-12-01

    Full Text Available Our previous research suggests that people reporting a stronger desire to maximize obtain worse life outcomes (Bruine de Bruin et al., 2007. Here, we examine whether this finding may be explained by the decision-making styles of self-reported maximizers. Expanding on Schwartz et al. (2002, we find that self-reported maximizers are more likely to show problematic decision-making styles, as evidenced by self-reports of less behavioral coping, greater dependence on others when making decisions, more avoidance of decision making, and greater tendency to experience regret. Contrary to predictions, self-reported maximizers were more likely to report spontaneous decision making. However, the relationship between self-reported maximizing and worse life outcomes is largely unaffected by controls for measures of other decision-making styles, decision-making competence, and demographic variables.

  8. Metabolic responses to prolonged work during treadmill and water immersion running.

    Science.gov (United States)

    Frangolias, D D; Rhodes, E C; Taunton, J E; Belcastro, A N; Coutts, K D

    2000-12-01

    The primary aim of this study was to compare the physiological responses to prolonged treadmill (TM) and water immersion to the neck (WI) running at threshold intensity. Ten endurance runners performed TM and WI running VO2max tests. Subjects completed submaximal performance tests at ventilatory threshold (Tvent) intensities under TM and WI conditions and responses at 15 and 42 minutes examined. VO2 was lower in WI (p<0.05) at maximal effort and Tvent. The Tvent VO2 intensities interpolated from the TM and WI VO2max tests were performed in both TM (i.e., TM@TM(tvent),TM@WI(tvent), corresponding to 77.6 and 71.3% respectively of TM VO2max) and WI conditions (i.e., WI@TM(tvent), WI@WI(tvent), corresponding to 85.5% and 78.2% respectively of WI VO2max). Each of the dependent variables was analyzed using a 3-way repeated measures ANOVA (2 conditions X 2 exercise intensities X 7 time points during exercise). VO2max values were significantly lower in the WI (52.4(5.1) ml.kg(-1) min(-1)) versus TM (59.7(6.5) ml.kg(-1) min(-1)) condition. VO2 during submaximal tests were similar during the TM and WI conditions. HR and [BLa] responses to exercise at and above WI(tvent) were similar during short-term exercise, but values tended to be lower during prolonged exercise in the WI condition. There were no statistical differences in VE responses in the 2 conditions, however as with HR and [BLa] an upward trend was noted with TM exercise over the 42 minute duration of the tests. RPE at WI(tvent) was similar for TM and WI exercise sessions, however, RPE at TM(tvent) was higher during WI compared to TM running. Cardiovascular drift was observed during prolonged TM but not WI running. Results suggest differences in metabolic responses to prolonged submaximal exercise in WI, however it can be used effectively for cross training.

  9. Physiological responses of young thoroughbred horses to intermittent high-intensity treadmill training.

    Science.gov (United States)

    Ohmura, Hajime; Matsui, Akira; Hada, Tetsuro; Jones, James H

    2013-08-17

    Training of young Thoroughbred horses must balance development of cardiopulmonary function and aerobic capacity with loading of the musculoskeletal system that can potentially cause structural damage and/or lameness. High-speed equine treadmills are sometimes used to supplement exercise on a track in the training of young Thoroughbreds because the horse can run at high speeds but without the added weight of a rider. We tested the hypothesis that intermittent high-intensity exercise on a treadmill of young Thoroughbred horses entering training can enhance development of aerobic capacity (VO2max) and running performance more than conventional training under saddle, and do so without causing lameness. Twelve yearling Thoroughbreds trained for 8 months with conventional riding (C) only, conventional riding plus a short (2 month, S) interval of once-per-week high-intensity treadmill exercise, or a long (8 month, L) interval of once-per-week high-intensity treadmill exercise. Three treadmill exercise tests evaluated VO2max, oxygen transport and running performance variables in June of the yearling year (only for L), October of the yearling year and April of the 2-year-old year. No horses experienced lameness during the study. Aerobic capacity increased in all groups after training. In both October and April, VO2max in L was higher than in C, but did not differ between L and S or S and C. Running speeds eliciting VO2max also increased in all groups after training, with S (809±3 m/s) and L (804±9 m/s) higher than C (764±27 m/s). Maximum heart rate decreased for all groups after training. Hematocrit and hemoglobin concentration increased for L throughout training. Young Thoroughbred horses can increase aerobic capacity and running performance more than by strictly using track training under saddle with the addition of intermittent high-intensity treadmill exercise, and they can do so without experiencing lameness. This finding suggests that young racehorses might be able

  10. Treadmill training with partial body weight support after stroke.

    Science.gov (United States)

    Hesse, Stefan; Werner, Cordula; von Frankenberg, Sophie; Bardeleben, Anita

    2003-02-01

    Treadmill therapy with partial BWS is a promising new approach to improve gait ability after stroke. This task-specific approach enables nonambulatory patients the repetitive practice of complex gait cycles instead of single-limb gait-preparatory maneuvers. Patients walk more symmetrically with less spasticity and better cardiovascular efficiency on the treadmill than with floor walking. Several controlled, clinical studies have shown the potential of treadmill training as a therapeutic intervention for nonambulatory patients with chronic stroke-related hemiplegia. Furthermore, controlled trials in acute stroke survivors have shown that treadmill training is as effective as other physiotherapy approaches that stress the repetitive practice of gait. Controlled multicenter trials comparing locomotor training with conventional therapy will be forthcoming. An electromechanical gait trainer that relieves the strenuous effort of the therapists and provides control of the trunk in a phase-dependent manner is a new technical alternative for gait training in severely impaired stroke patients.

  11. Treadmill walking exercise modulates bone mineral status and ...

    African Journals Online (AJOL)

    Treadmill walking exercise modulates bone mineral status and inflammatory cytokines in obese asthmatic patients with long term intake of corticosteroids. Shehab M. Abd El-Kader, Osama H. Al-Jiffri, Eman M. Ashmawy, Riziq Allah M. Gaowgzeh ...

  12. Treadmills: a preventable source of pediatric friction burn injuries.

    Science.gov (United States)

    Maguiña, Pirko; Palmieri, Tina L; Greenhalgh, David G

    2004-01-01

    Treadmills are a burn risk for children. A child's hand can get trapped in the conveyor belt, causing friction burns to the underlying tissue. The purpose of this retrospective study was to review the characteristics and treatment of treadmill-related burns in children from 1998 to 2002. Ten patients, at a mean age of 3.4 years, sustained injuries associated with treadmill use. Trapping of the hand between the conveyor belt and the base was the most frequent injury mechanism. Burn location was predominantly on fingers and palms. Four patients required operative intervention. All patients required specialized wound care as well as scar management and occupational therapy. Treadmills pose a danger to children. Current safety devices are ineffective for preventing serious hand injuries in children. New design modifications and public awareness are needed to improve child safety.

  13. Arctigenin Efficiently Enhanced Sedentary Mice Treadmill Endurance

    Science.gov (United States)

    Chen, Jing; Yu, Liang; Hu, Lihong; Jiang, Hualiang; Shen, Xu

    2011-01-01

    Physical inactivity is considered as one of the potential risk factors for the development of type 2 diabetes and other metabolic diseases, while endurance exercise training could enhance fat oxidation that is associated with insulin sensitivity improvement in obesity. AMP-activated protein kinase (AMPK) as an energy sensor plays pivotal roles in the regulation of energy homeostasis, and its activation could improve glucose uptake, promote mitochondrial biogenesis and increase glycolysis. Recent research has even suggested that AMPK activation contributed to endurance enhancement without exercise. Here we report that the natural product arctigenin from the traditional herb Arctium lappa L. (Compositae) strongly increased AMPK phosphorylation and subsequently up-regulated its downstream pathway in both H9C2 and C2C12 cells. It was discovered that arctigenin phosphorylated AMPK via calmodulin-dependent protein kinase kinase (CaMKK) and serine/threonine kinase 11(LKB1)-dependent pathways. Mice treadmill based in vivo assay further indicated that administration of arctigenin improved efficiently mice endurance as reflected by the increased fatigue time and distance, and potently enhanced mitochondrial biogenesis and fatty acid oxidation (FAO) related genes expression in muscle tissues. Our results thus suggested that arctigenin might be used as a potential lead compound for the discovery of the agents with mimic exercise training effects to treat metabolic diseases. PMID:21887385

  14. Arctigenin efficiently enhanced sedentary mice treadmill endurance.

    Directory of Open Access Journals (Sweden)

    Xuan Tang

    Full Text Available Physical inactivity is considered as one of the potential risk factors for the development of type 2 diabetes and other metabolic diseases, while endurance exercise training could enhance fat oxidation that is associated with insulin sensitivity improvement in obesity. AMP-activated protein kinase (AMPK as an energy sensor plays pivotal roles in the regulation of energy homeostasis, and its activation could improve glucose uptake, promote mitochondrial biogenesis and increase glycolysis. Recent research has even suggested that AMPK activation contributed to endurance enhancement without exercise. Here we report that the natural product arctigenin from the traditional herb Arctium lappa L. (Compositae strongly increased AMPK phosphorylation and subsequently up-regulated its downstream pathway in both H9C2 and C2C12 cells. It was discovered that arctigenin phosphorylated AMPK via calmodulin-dependent protein kinase kinase (CaMKK and serine/threonine kinase 11(LKB1-dependent pathways. Mice treadmill based in vivo assay further indicated that administration of arctigenin improved efficiently mice endurance as reflected by the increased fatigue time and distance, and potently enhanced mitochondrial biogenesis and fatty acid oxidation (FAO related genes expression in muscle tissues. Our results thus suggested that arctigenin might be used as a potential lead compound for the discovery of the agents with mimic exercise training effects to treat metabolic diseases.

  15. The slope of the oxygen pulse curve does not depend on the maximal heart rate in elite soccer players

    Directory of Open Access Journals (Sweden)

    Raphael Rodrigues Perim

    2011-01-01

    Full Text Available INTRODUCTION: It is unknown whether an extremely high heart rate can affect oxygen pulse profile during progressive maximal exercise in healthy subjects. OBJECTIVE: Our aim was to compare relative oxygen pulse (adjusted for body weight curves in athletes at their maximal heart rate during treadmill cardiopulmonary exercise testing. METHODS: A total of 180 elite soccer players were categorized in quartiles according to their maximum heart rate values (n = 45. Oxygen consumption, maximum heart rate and relative oxygen pulse curves in the extreme quartiles, Q1 and Q4, were compared at intervals corresponding to 10% of the total duration of a cardiopulmonary exercise testing. RESULTS: Oxygen consumption was similar among all subjects during cardiopulmonary exercise testing; however subjects in Q1 started to exhibit lower maximum heart rate values when 20% of the test was complete. Conversely, the relative oxygen pulse was higher in this group when cardiopulmonary exercise testing was 40% complete (p<.01. Although the slopes of the lines were similar (p = .25, the regression intercepts differed (p<.01 between Q1 and Q4. During the last two minutes of testing, a flat or decreasing oxygen pulse was identified in 20% of the soccer players, and this trend was similar between subjects in Q1 and Q4. CONCLUSION: Relative oxygen pulse curve slopes, which serve as an indirect and non-invasive surrogate for stroke volume, suggest that the stroke volume is similar in young and aerobically fit subjects regardless of the maximum heart rate reached.

  16. The Effects of Combined Treadmill Training and Pharmacological Treatment on Management of Multiple Sclerosis Female Patients

    Directory of Open Access Journals (Sweden)

    Ali Asghar Arastoo

    2013-04-01

    Full Text Available Objectives: To compare the effectiveness of two treatment methods of ‘combination pharmacological treatment and treadmill training’ and ‘pharmacological treatment’ on management of multiple sclerosis (MS female patients. Methods: In this quasi experimental and interventional study a sample of 20 MS patients (mean age: 36.75 years with Expanded Disability Status Scale scores (EDSS 1.0 to 4.0 were randomly assigned to a ‘pharmacologic treatment’ (Ph group and a combination group of ‘pharmacologic treatment& treadmill training’ (PhTT. All these individuals used the drugs of choice ‘Rebif’ and ‘Avonex’. The intervention consisted of 8-weeks (24 sessions of treadmill training (30 minutes each, at 40-75% of age-predicted maximum heart rate for the PhTT group. The Ph group followed their own routine treatment program. Balance, speed and endurance of walking, quality of life and fatigue were measured by Berg Balance Score, 10 meter timed walk test, 2 minute walk test, and Fatigue Severity Scale (FFS. Data were analyzed by paired t test and one way ANOVA. Results: Comparison of results indicated that pre and post intervention led to significant improvements in the balance score (P=0.001, 10m walk time (P=0.001, walking endurance (P=0.007, and FFS (P=0.04 in the PhTT group. In contrast, no significant changes were observed in the Ph group’s balance score, 10m timed walk and fatigue, while there was a significant decrease in the 2min walking distance (P=0.015 in this group. Discussion: These results suggest that treadmill training in combination with pharmacological treatment improve balance and walking capacity and level of fatigue in women with mild to moderate MS.

  17. Angiographic and functional comparison of patients with silent and symptomatic treadmill ischemia early after myocardial infarction

    International Nuclear Information System (INIS)

    Ouyang, P.; Shapiro, E.P.; Chandra, N.C.; Gottlieb, S.H.; Chew, P.H.; Gottlieb, S.O.

    1987-01-01

    Sixty consecutive patients were studied who had positive responses to Naughton exercise treadmill testing (at least 1.5 mm of ST-segment shift in at least 2 leads or thallium reperfusion abnormalities) with or without symptoms of angina 11 +/- 1 days after acute myocardial infarction (AMI). All patients had undergone coronary angiography 24 +/- 4 days after infarction. Thirty-eight patients (63%) had no treadmill angina (silent ischemia, group I) and 22 patients had typical treadmill angina (symptomatic ischemia, group II). Use of beta-blocking drugs, calcium antagonists and nitrates at the time of exercise testing did not differ in the 2 groups. All 9 patients with diabetes mellitus were in the asymptomatic group (p less than 0.40) and group I had a greater proportion of inferior wall AMI (30 of 38) than group II (11 of 22, p = 0.02). Total exercise treadmill test duration (group I 422 +/- 31 seconds, group II 400 +/- 46 seconds) and rate-pressure product were not different in the 2 groups. The number of patients unable to exercise 5 minutes (12 in group I and 7 in group II), the number with diffuse electrocardiographic changes (9 in group I and 7 in group II), and the number with inadequate blood pressure response (8 in group I and 4 in group II) were also similar. At coronary arteriography the mean number of arteries with at least 70% diameter stenosis was 2.0 +/- 0.2 in group I and 2.2 +/- 0.2 in group II (difference not significant)

  18. Cardiovascular responses to treadmill exercise in Nigerian ...

    African Journals Online (AJOL)

    The systolic blood pressure (SBP) and pressure rate product (PRP) during maximal exercise were also increased in hypertensives with LVH and hypertensive without LVH when compared to normotensive controls. The hypertensives with LVH and hypertensives without LVH also showed significant limitation to heart rate ...

  19. Efficacy of Aquatic Treadmill Training on Gait Symmetry and Balance in Subacute Stroke Patients.

    Science.gov (United States)

    Lee, Mi Eun; Jo, Geun Yeol; Do, Hwan Kwon; Choi, Hee Eun; Kim, Woo Jin

    2017-06-01

    To determine the efficacy of aquatic treadmill training (ATT) as a new modality for stroke rehabilitation, by assessing changes in gait symmetry, balance function, and subjective balance confidence for the paretic and non-paretic leg in stroke patients. Twenty-one subacute stroke patients participated in 15 intervention sessions of aquatic treadmill training. The Comfortable 10-Meter Walk Test (CWT), spatiotemporal gait parameters, Berg Balance Scale (BBS), and Activities-specific Balance Confidence scale (ABC) were assessed pre- and post-interventions. From pre- to post-intervention, statistically significant improvements were observed in the CWT (0.471±0.21 to 0.558±0.23, pstroke therapy, with other modalities.

  20. Effect of the treadmill training factors on the locomotor ability after space flight

    Science.gov (United States)

    Lysova, Nataliya; Fomina, Elena

    Training on the treadmill constitutes the central component of the Russian system of countermeasures against the negative effects of microgravity. Effectiveness of the treadmill training is influenced by three main factors. Namely, these are intensity (velocity and regularity), axial loading with the use of elastic bungee cords and percentage of time for training on the non-motorized treadmill within the overall training program. Previously we have demonstrated the significance of each factor separately: intensity (Kozlovskaya I.B. et al., 2011), passive mode (Fomina E.V. et al., 2012) and axial loading (Fomina E.V. et al., 2013). The Russian system of in-flight countermeasures gives preference to interval training sessions in which walking alternates with short episodes of intensive running. Locomotion on the non-motorized treadmill should make approx. 30% of the total time of locomotor training. The ISS RS treadmill can be utilized with the motor in motion (active mode) or out of motion so that the cosmonaut has to push the belt with his feet (passive mode). Axial loading of the cosmonaut must be 60-70% of his body weight. However, there is a huge variety of strategies cosmonauts choose of when they exercise on the treadmill in the course of long-duration ISS missions. Purpose of the investigation was comparative analysis of different locomotion training regimens from the standpoint of their effectiveness in microgravity. Criteria of effectiveness evaluation were the results of the locomotion test that includes walking along the fixed support at the preset rate of 90 steps/min. Peak amplitude on the m. soleus electromyogram was analyzed. The experiment was performed with participation of 18 Russian members of extended ISS missions. Each locomotion training factors was rated using the score scale from 0 to 10: Intensity (0 to 10), Percentage of passive mode training (recommended 30% was taken as 10 and could go down to 0 if the passive mode was not applied) and

  1. Modelos para predição da carga máxima no teste clínico de esforço cardiopulmonar Maximal workload prediction models in the clinical cardio-pulmonary effort test

    Directory of Open Access Journals (Sweden)

    Fernando dos Santos Nogueira

    2006-08-01

    Full Text Available OBJETIVO: Este estudo buscou derivar equações generalizadas para predição da carga máxima para homens e mulheres jovens. MÉTODOS: O método da ergoespirometria direta (Aerosport® TEEM 100, Estados Unidos da América do Norte foi empregado para determinar o VO2máx e a carga máxima (Wmáx, no cicloergômetro (Monark®, Brasil, de 30 homens (25 ± 5 anos, 75,0 ± 10,7 kg; 48,4 ± 8,8 mL . kg -1 . min -1 e 243 ± 51 Watts e 30 mulheres (26 ± 5 anos, 56,7 ± 5,9 kg, 39,8 ± 7,6 mL . kg -1 . min -1 e 172 ± 37 Watts. A idade e a massa corporal foram empregadas como variáveis independentes. Para todos os testes estatísticos aceitou-se o nível de significância de p OBJECTIVE: This study sought to derive generalized equations for predicting maximal workload for young men and women. METHODS: Direct ergospirometry (Aerosport® TEEM 100, USA was used to determine VO2máx and the maximal work load (Wmax on the cycle ergometer test (Monark®, Brazil of thirty men (25 ± 5 years, 75.0 ± 10.7 kg; 48.4 ± 8.8 mL . kg -1 . min -1 and 243 ± 51 Watts and thirty women (26 ± 5 years, 56.7 ± 5.9 kg, 39.8 ± 7.6 mL . kg -1 . min -1 and 172 ± 37 Watts. Age and body mass were used as independent variables. For all statistic tests, a p < 0.05 significance level was adopted. RESULTS: In the multiple linear adjustment, the maximal workload was explained by age and body mass as 54% (r = 0.73 for men, and as 76% (r = 0.87 for women, with standard errors of 0.66 W . kg -1 and 25 Watts. The proposed equations were cross-validated using another sample with similar age and VO2máx characteristics comprised of fifteen men and fifteen women. The intraclass correlation between the predicted Wmax values and those measures by ergospirometry were 0.70 and 0.69, with standard errors of 28.4 and 15.8 Watts, respectively, for men and women. CONCLUSIONS: This study exhibits valid generalized equations for determining the maximal cycle ergonometer workload for men and

  2. Oxygen consumption of elite distance runners on an anti-gravity treadmill®.

    Science.gov (United States)

    McNeill, David K P; Kline, John R; de Heer, Hendrick D; Coast, J Richard

    2015-06-01

    Lower body positive pressure (LBPP), or 'anti-gravity' treadmills® have become increasingly popular among elite distance runners. However, to date, few studies have assessed the effect of body weight support (BWS) on the metabolic cost of running among elite runners. This study evaluated how BWS influenced the relationship between velocity and metabolic cost among 6 elite male distance runners. Participants ran three- 16 minute tests consisting of 4 stages of 4 minutes at 8, 7, 6 and 5 min·mile(-1) pace (3.35, 3.84, 4.47 and 5.36 m·s(-1)), while maintaining an aerobic effort (Respiratory Exchange Ratio ≤1.00). One test was run on a regular treadmill, one on an anti-gravity treadmill with 40% BWS and one with 20% BWS being provided. Expired gas data were collected and regression equations used to determine and compare slopes. Significant decreases in oxygen uptake (V̇O2) were found with each increase in BWS (p rate, perceived exertion or directly measured oxygen uptake) should be used to guide training intensity when training on the LBPP treadmill. Key pointsWith increasing amounts of body weight-support (BWS), the slope of the relationship between velocity and oxygen consumption (ΔVO2/Δv) decreases significantly. This means the change in oxygen consumption (VO2) is significantly smaller over a given change in velocity at higher amounts of BWS.There is a non-linear decrease in VO2 with increasing BWS. As such, with each increment in the amount of BWS provided, the reduction in VO2 becomes increasingly smaller.This paper provides first of its kind data on the effects of BWS on the cost of running among highly trained, elite runners. The outcomes of this study are in line with previous findings among non-elite runners.

  3. Does mental exertion alter maximal muscle activation?

    Directory of Open Access Journals (Sweden)

    Vianney eRozand

    2014-09-01

    Full Text Available Mental exertion is known to impair endurance performance, but its effects on neuromuscular function remain unclear. The purpose of this study was to test the hypothesis that mental exertion reduces torque and muscle activation during intermittent maximal voluntary contractions of the knee extensors. Ten subjects performed in a randomized order three separate mental exertion conditions lasting 27 minutes each: i high mental exertion (incongruent Stroop task, ii moderate mental exertion (congruent Stroop task, iii low mental exertion (watching a movie. In each condition, mental exertion was combined with ten intermittent maximal voluntary contractions of the knee extensor muscles (one maximal voluntary contraction every 3 minutes. Neuromuscular function was assessed using electrical nerve stimulation. Maximal voluntary torque, maximal muscle activation and other neuromuscular parameters were similar across mental exertion conditions and did not change over time. These findings suggest that mental exertion does not affect neuromuscular function during intermittent maximal voluntary contractions of the knee extensors.

  4. Understanding Violations of Gricean Maxims in Preschoolers and Adults

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    Mako eOkanda

    2015-07-01

    Full Text Available This study used a revised Conversational Violations Test to examine Gricean maxim violations in 4- to 6-year-old Japanese children and adults. Participants’ understanding of the following maxims was assessed: be informative (first maxim of quantity, avoid redundancy (second maxim of quantity, be truthful (maxim of quality, be relevant (maxim of relation, avoid ambiguity (second maxim of manner, and be polite (maxim of politeness. Sensitivity to violations of Gricean maxims increased with age: 4-year-olds’ understanding of maxims was near chance, 5-year-olds understood some maxims (first maxim of quantity and maxims of quality, relation, and manner, and 6-year-olds and adults understood all maxims. Preschoolers acquired the maxim of relation first and had the greatest difficulty understanding the second maxim of quantity. Children and adults differed in their comprehension of the maxim of politeness. The development of the pragmatic understanding of Gricean maxims and implications for the construction of developmental tasks from early childhood to adulthood are discussed.

  5. Attention demanding tasks during treadmill walking reduce step width variability in young adults

    Directory of Open Access Journals (Sweden)

    Troy Karen L

    2005-08-01

    Full Text Available Abstract Background The variability of step time and step width is associated with falls by older adults. Further, step time is significantly influenced when performing attention demanding tasks while walking. Without exception, step time variability has been reported to increase in normal and pathologically aging older adults. Because of the role of step width in managing frontal plane dynamic stability, documenting the influence of attention-demanding tasks on step width variability may provide insight to events that can disturb dynamic stability during locomotion and increase fall risk. Preliminary evidence suggests performance of an attention demanding task significantly decreases step width variability of young adults walking on a treadmill. The purpose of the present study was to confirm or refute this finding by characterizing the extent and direction of the effects of a widely used attention demanding task (Stroop test on the step width variability of young adults walking on a motorized treadmill. Methods Fifteen healthy young adults walked on a motorized treadmill at a self-selected velocity for 10 minutes under two conditions; without performing an attention demanding task and while performing the Stroop test. Step width of continuous and consecutive steps during the collection was derived from the data recorded using a motion capture system. Step width variability was computed as the standard deviation of all recorded steps. Results Step width decreased four percent during performance of the Stroop test but the effect was not significant (p = 0.10. In contrast, the 16 percent decrease in step width variability during the Stroop test condition was significant (p = 0.029. Conclusion The results support those of our previous work in which a different attention demanding task also decreased step width variability of young subjects while walking on a treadmill. The decreased step width variability observed while performing an attention

  6. Thermoregulatory responses to skin wetting during prolonged treadmill running.

    Science.gov (United States)

    Bassett, D R; Nagle, F J; Mookerjee, S; Darr, K C; Ng, A V; Voss, S G; Napp, J P

    1987-02-01

    We examined the physiological responses to skin wetting during a 120-min level treadmill run to assess whether skin wetting would reduce the dehydration and the increase in core temperature associated with prolonged exercise. Testing was conducted in an environmental chamber (T = 29.5 degrees C, wind velocity = 3 m X sec-1) under two different humidity conditions (33 or 66% relative humidity). Ten male subjects performed two runs in each humidity condition; one served as a control run. The other included spraying the body with 50 ml of water (T = 29.5 degrees C) every 10 min. Spraying had no effect on rectal temperature (Tre), heart rate, oxygen consumption, perceived exertion, sweat loss, or percent change in plasma volume in both the humid and the dry conditions. Spraying produced a significant reduction in mean skin temperature (Tsk), which increased the (Tre - Tsk) gradient. At the same time, overall skin conductance (K) was decreased, presumably as a result of cutaneous vasoconstriction due to the low Tsk. Since heat transfer from the body's core to the skin is expressed by the equation: heat transfer = K X (Tre - Tsk) the spraying had no effect on heat transfer away from the core, and Tre remained unchanged.

  7. The influence of water depth on kinematic and spatiotemporal gait parameters during aquatic treadmill walking.

    Science.gov (United States)

    Jung, Taeyou; Kim, Yumi; Lim, Hyosok; Vrongistinos, Konstantinos

    2018-01-16

    The purpose of this study was to investigate kinematic and spatiotemporal variables of aquatic treadmill walking at three different water depths. A total of 15 healthy individuals completed three two-minute walking trials at three different water depths. The aquatic treadmill walking was conducted at waist-depth, chest-depth and neck-depth, while a customised 3-D underwater motion analysis system captured their walking. Each participant's self-selected walking speed at the waist level was used as a reference speed, which was applied to the remaining two test conditions. A repeated measures ANOVA showed statistically significant differences among the three walking conditions in stride length, cadence, peak hip extension, hip range of motion (ROM), peak ankle plantar flexion and ankle ROM (All p values hip ROM as the water depth rose from waist and chest to the neck level. However, our study found no significant difference between waist and chest level water in all variables. Hydrodynamics, such as buoyancy and drag force, in response to changes in water depths, can affect gait patterns during aquatic treadmill walking.

  8. A physiological and biomechanical comparison of over-ground, treadmill and ergometer wheelchair propulsion.

    Science.gov (United States)

    Mason, Barry; Lenton, John; Leicht, Christof; Goosey-Tolfrey, Victoria

    2014-01-01

    The purpose of the study was to determine which laboratory-based modality provides the most valid physiological and biomechanical representation of over-ground sports wheelchair propulsion. Fifteen able-bodied participants with previous experience of wheelchair propulsion performed a 3-minute exercise trial at three speeds (4, 6 and 8 km ∙ h(-1)) in three testing modalities over separate sessions: (i) over-ground propulsion on a wooden sprung surface; (ii) wheelchair ergometer propulsion; (iii) treadmill propulsion at four different gradients (0%, 0.7%, 1.0% and 1,3%). A 0.7% treadmill gradient was shown to best reflect the oxygen uptake (7.3 to 9.1% coefficient of variation (CV)) and heart rate responses (4.9 to 6.4% CV) of over-ground propulsion at 4 and 6 km ∙ h(-1). A 1.0% treadmill gradient provided a more valid representation of oxygen uptake during over-ground propulsion at 8 km ∙ h(-1) (8.6% CV). Physiological demand was significantly underestimated in the 0% gradient and overestimated in the 1.3% gradient and wheelchair ergometer trials compared to over-ground trials (Ppropulsion at lower speeds (4 and 6 km ∙ h(-1)) whereas a 1.0% gradient may be more suitable at 8 km ∙ h(-1).

  9. On the maximal superalgebras of supersymmetric backgrounds

    International Nuclear Information System (INIS)

    Figueroa-O'Farrill, Jose; Hackett-Jones, Emily; Moutsopoulos, George; Simon, Joan

    2009-01-01

    In this paper we give a precise definition of the notion of a maximal superalgebra of certain types of supersymmetric supergravity backgrounds, including the Freund-Rubin backgrounds, and propose a geometric construction extending the well-known construction of its Killing superalgebra. We determine the structure of maximal Lie superalgebras and show that there is a finite number of isomorphism classes, all related via contractions from an orthosymplectic Lie superalgebra. We use the structure theory to show that maximally supersymmetric waves do not possess such a maximal superalgebra, but that the maximally supersymmetric Freund-Rubin backgrounds do. We perform the explicit geometric construction of the maximal superalgebra of AdS 4 X S 7 and find that it is isomorphic to osp(1|32). We propose an algebraic construction of the maximal superalgebra of any background asymptotic to AdS 4 X S 7 and we test this proposal by computing the maximal superalgebra of the M2-brane in its two maximally supersymmetric limits, finding agreement.

  10. Comparing handrim biomechanics for treadmill and overground wheelchair propulsion

    Science.gov (United States)

    Kwarciak, Andrew M.; Turner, Jeffrey T.; Guo, Liyun; Richter, W. Mark

    2010-01-01

    Study design Cross-sectional study. Objectives To compare handrim biomechanics recorded during overground propulsion to those recorded during propulsion on a motor-driven treadmill. Setting Biomechanics laboratory. Methods Twenty-eight manual wheelchair users propelled their own wheelchairs, at a self-selected speed, on a low-pile carpet and on a wheelchair accessible treadmill. Handrim biomechanics were recorded with an OptiPush instrumented wheelchair wheel. Results Across the two conditions, all handrim biomechanics were found to be similar and highly correlated (r > 0.85). Contact angle, peak force, average force, and peak axle moment differed by 1.6% or less across the two conditions. While not significant, power output and cadence tended to be slightly higher for the treadmill condition (3.5% and 3.6%, respectively), due to limitations in adjusting the treadmill grade. Conclusion Based on the results of this study, a motor-driven treadmill can serve as a valid surrogate for overground studies of wheelchair propulsion. PMID:21042332

  11. The effects of arm crank ergometry, cycle ergometry and treadmill walking on postural sway in healthy older females.

    Science.gov (United States)

    Hill, M W; Oxford, S W; Duncan, M J; Price, M J

    2015-01-01

    Older adults are increasingly being encouraged to exercise but this may lead to muscle fatigue, which can adversely affect postural stability. Few studies have investigated the effects of upper body exercise on postural sway in groups at risk of falling, such as the elderly. The purpose of this study was to compare the effects arm crank ergometry (ACE), cycle ergometry (CE) and treadmill walking (TM) on postural sway in healthy older females. In addition, this study sought to determine the time necessary to recover postural control after exercise. A total of nine healthy older females participated in this study. Participants stood on a force platform to assess postural sway which was measured by displacement of the centre of pressure before and after six separate exercise trials. Each participant completed three incremental exercise tests to 85% of individual's theoretical maximal heart rate (HRMAX) for ACE, CE and TM. Subsequent tests involved 20-min of ACE, CE and TM exercise at a relative workload corresponding to 50% of each individual's predetermined heart rate reserve (HRE). Post fatigue effects and postural control recovery were measured at different times after exercise (1, 3, 5, 10, 15 and 30-min). None of the participants exhibited impaired postural stability after ACE. In contrast, CE and TM elicited significant post exercise balance impairments, which lasted for ∼ 10 min post exercise. We provide evidence of an exercise mode which does not elicit post exercise balance impairments. Older adults should exercise caution immediately following exercise engaging the lower limbs to avoid fall risk. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Evaluation of Cooper 12-minute walk/run test as a marker of cardiorespiratory fitness in young urban children with persistent asthma.

    Science.gov (United States)

    Weisgerber, Michael; Danduran, Michael; Meurer, John; Hartmann, Kathryn; Berger, Stuart; Flores, Glenn

    2009-07-01

    To evaluate Cooper 12-minute run/walk test (CT12) as a one-time estimate of cardiorespiratory fitness and marker of fitness change compared with treadmill fitness testing in young children with persistent asthma. A cohort of urban children with asthma participated in the asthma and exercise program and a subset completed pre- and postintervention fitness testing. Treadmill fitness testing was conducted by an exercise physiologist in the fitness laboratory at an academic children's hospital. CT12 was conducted in a college recreation center gymnasium. Forty-five urban children with persistent asthma aged 7 to 14 years participated in exercise interventions. A subset of 19 children completed pre- and postintervention exercise testing. Participants completed a 9-week exercise program where they participated in either swimming or golf 3 days a week for 1 hour. A subset of participants completed fitness testing by 2 methods before and after program completion. CT12 results (meters), maximal oxygen consumption ((.)Vo2max) (mL x kg(-1) x min(-1)), and treadmill exercise time (minutes). CT12 and maximal oxygen consumption were moderately correlated (preintervention: 0.55, P = 0.003; postintervention: 0.48, P = 0.04) as one-time measures of fitness. Correlations of the tests as markers of change over time were poor and nonsignificant. In children with asthma, CT12 is a reasonable one-time estimate of fitness but a poor marker of fitness change over time.

  13. Tri-maximal vs. bi-maximal neutrino mixing

    International Nuclear Information System (INIS)

    Scott, W.G

    2000-01-01

    It is argued that data from atmospheric and solar neutrino experiments point strongly to tri-maximal or bi-maximal lepton mixing. While ('optimised') bi-maximal mixing gives an excellent a posteriori fit to the data, tri-maximal mixing is an a priori hypothesis, which is not excluded, taking account of terrestrial matter effects

  14. Implementation and adherence issues in a workplace treadmill desk intervention.

    Science.gov (United States)

    Tudor-Locke, Catrine; Hendrick, Chelsea A; Duet, Megan T; Swift, Damon L; Schuna, John M; Martin, Corby K; Johnson, William D; Church, Timothy S

    2014-10-01

    We report experiences, observations, and general lessons learned, specifically with regards to participant recruitment and adherence, while implementing a 6-month randomized controlled treadmill desk intervention (the WorkStation Pilot Study) in a real-world office-based health insurance workplace. Despite support from the company's upper administration, relatively few employees responded to the company-generated e-mail to participate in the study. Ultimately only 41 overweight/obese participants were deemed eligible and enrolled from a recruitment pool of 728 workers. Participants allocated to the Treadmill Desk Group found the treadmill desk difficult to use for 45 min twice a day as scheduled. Overall attendance averaged 45%-50% of all possible scheduled sessions. The most frequently reported reasons for missing sessions included work conflict (35%), out of office (30%), and illness/injury/drop-out (20%). Although focus groups indicated consistently positive comments about treadmill desks, an apparent challenge was fitting a rigid schedule of shared use to an equally rigid and demanding work schedule punctuated with numerous tasks and obligations that could not easily be interrupted. Regardless, we documented that sedentary office workers average ∼43 min of light-intensity (∼2 METs) treadmill walking daily in response to a scheduled, facilitated, and shared access workplace intervention. Workstation alternatives that combine computer-based work with light-intensity physical activity are a potential solution to health problems associated with excessive sedentary behavior; however, there are numerous administrative, capital, and human resource challenges confronting employers considering providing treadmill desks to workers in a cost-effective and equitable manner.

  15. An innovative training program based on virtual reality and treadmill: effects on gait of persons with multiple sclerosis.

    Science.gov (United States)

    Peruzzi, Agnese; Zarbo, Ignazio Roberto; Cereatti, Andrea; Della Croce, Ugo; Mirelman, Anat

    2017-07-01

    In this single blind randomized controlled trial, we examined the effect of a virtual reality-based training on gait of people with multiple sclerosis. Twenty-five individuals with multiple sclerosis with mild to moderate disability were randomly assigned to either the control group (n = 11) or the experimental group (n = 14). The subjects in the control group received treadmill training. Subjects in the experimental group received virtual reality based treadmill training. Clinical measures and gait parameters were evaluated. Subjects in both the groups significantly improved the walking endurance and speed, cadence and stride length, lower limb joint ranges of motion and powers, during single and dual task gait. Moreover, subjects in the experimental group also improved balance, as indicated by the results of the clinical motor tests (p virtual reality to improve gait measures in individuals with multiple sclerosis. Implication of rehabilitation Gait deficits are common in multiple sclerosis (85%) and worsen during dual task activities. Intensive and progressive treadmill training, with and without virtual reality, is effective on dual task gait in persons with multiple sclerosis. Virtual reality-based treadmill training requiring obstacle negotiation increases the range of motion and the power generated at the hip, consequently allowing longer stride length and, consequently, higher gait speed.

  16. Effects of body-weight supported treadmill training on kinetic symmetry in persons with chronic stroke.

    Science.gov (United States)

    Combs, Stephanie A; Dugan, Eric L; Ozimek, Elicia N; Curtis, Amy B

    2012-11-01

    The purpose was to examine changes in kinetic symmetry in persons with chronic stroke immediately and 6-months after body-weight supported treadmill training. Fifteen participants at least six-months post stroke and able to ambulate between 0.4 and 0.8m/s and 20 participants without neurological conditions completed all phases of the study and were included in the analysis. The non-disabled group served as a comparison for describing changes in kinetic symmetry. The stroke group completed 24 sessions of body-weight supported treadmill training over 8-weeks with 20 minutes of total walking per session. Bilateral 3-dimensional motion analysis and gait speed were assessed 1-week before training (pre-test), 1-week after training (post-test) and 6-months after training (retention) in a repeated measures design. Relative propulsion of the paretic leg and relative positive work of the hip, knee and ankle joints of both legs were calculated to evaluate symmetry of kinetic forces. Statistically significant differences in relative propulsion and positive joint work within the paretic and non-paretic legs were not found over time. The stroke group significantly improved gait speed from pre- to post-test (p=.001) and pre-test to retention (p=.008). In comparison to the non-disabled group, forces produced by the stroke group were asymmetrical demonstrating compensatory adaptation. Although the participants with chronic stroke walked faster after body-weight supported treadmill training, the relative percentages of propulsion and positive work remained unchanged. These findings suggest that the increase in speed was likely due to strengthening existing compensatory strategies rather than through recovery of normal kinetic symmetry. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Sponsorship for the Sustainability of Historical-Architectural Heritage: Application of a Model’s Original Test Finalized to Maximize the Profitability of Private Investors

    Directory of Open Access Journals (Sweden)

    Luigi Dolores

    2017-09-01

    Full Text Available This paper deals with private sponsorship as a tool for the redevelopment of Italy’s vast wealth of historical-architectural public heritage sites. Italian law provides for the stipulation of sponsorship agreements by and between public sector agencies or entities (which need financial resources to restore or re-qualify property and private sector investors (which guarantee the capital sought by the public sector in exchange for significant returns on their investments raising various economic issues, particularly in connection with the profitability thresholds for private sector investors in return for the public sector’s use of their financial resources. In this paper, the authors focus on how private sector investors determine how much of their businesses turnover constitutes the optimal percentage level of overall income that may be invested in sponsorships to maximize business profitability. For this purpose, a model based on past works on the subject (Bucci et al., 2003 has been chosen by the authors. Such model gives a solution for verifying a sponsorship’s profitability. This model is static and is applicable to single-product companies that invest in sponsorships, under the theories of monopolistic competition and of Cobb-Douglas production function. Our objectives are to present this model, explaining in detail the mathematical steps, simplifying the model where possible in order to reduce the levels of complexity in its application, and finally to apply it to real case scenarios of cultural sponsorships.

  18. Discordance of exercise thallium testing with coronary arteriography in patients with atypical presentations

    International Nuclear Information System (INIS)

    Bungo, M.W.; Leland, O.S. Jr.

    1983-01-01

    Eighty-one patients with diagnostically difficult clinical presentations suggesting coronary disease underwent symptom-limited maximal-exercise treadmill testing (ETT) and exercise radionuclide scanning with 201 Tl. Results of these tests were in agreement in only 47 percent of the cases. Either exercise thallium or ETT was positive in 94 percent of patients with disease. Among a population with a disease prevalence of 67 percent, agreement between exercise thallium an ETT predicted disease in 92 percent of instances or excluded disease in 82 percent of instances. Frequent discordance between these two tests in 53 percent of the cases unfortunately limits this usefulness

  19. Treadmilling of actin filaments via Brownian dynamics simulations

    DEFF Research Database (Denmark)

    Guo, Kunkun; Shillcock, Julian C.; Lipowsky, Reinhard

    2010-01-01

    . For concentrations close to the critical concentration CT = CT,cr, the filaments undergo treadmilling, i.e., they grow at the barbed and shrink at the pointed end, which leads to directed translational motion of the whole filament. The corresponding nonequilibrium states are characterized by several global fluxes...

  20. Ghost crabs on a treadmill: Oxygen Uptake and Haemocyanin ...

    African Journals Online (AJOL)

    Ghost crabs Ocypode ceratophthalmus were exercised on a specially constructed treadmill. At a running speed of 13,3 cm s-1, most crabs ran for 2 h before getting fatigued. At this speed the oxygen consumption rate (MO2) was measured in time intervals for a total of 52 min. For exercised crabs the MO2 values are about ...

  1. Integrated effect of treadmill training combined with dynamic ankle ...

    African Journals Online (AJOL)

    Abd El Aziz Ali Sherief

    2015-01-13

    Jan 13, 2015 ... of this study was to determine the combined effects of treadmill and dynamic ankle foot ... electrical stimulation, constrained induced therapy and ortho- ... restricted plantar flexion. .... older). (2) The child performs the item according to the criteria ... applied and intended to control position and motion of the.

  2. Gait Coordination After Stroke: Benefits of Acoustically Paced Treadmill Walking

    NARCIS (Netherlands)

    Roerdink, M.; Lamoth, C.J.C.; Kwakkel, G.; van Wieringen, P.C.W.; Beek, P.J.

    2007-01-01

    Background and Purpose: Gait coordination often is compromised after stroke. The purpose of this study was to evaluate the efficacy of acoustically paced treadmill walking as a method for improving gait coordination in people after stroke. Participants: Ten people after stroke volunteered for the

  3. Gait coordination after stroke: benefits of acoustically paced treadmill walking.

    NARCIS (Netherlands)

    Roerdink, M.; Lamoth, C.J.; Kwakkel, G.; Wieringen, P.C. van; Beek, P.J.

    2007-01-01

    BACKGROUND AND PURPOSE: Gait coordination often is compromised after stroke. The purpose of this study was to evaluate the efficacy of acoustically paced treadmill walking as a method for improving gait coordination in people after stroke. PARTICIPANTS: Ten people after stroke volunteered for the

  4. Biomechanical Analysis of Treadmill Locomotion on the International Space Station

    Science.gov (United States)

    De Witt, J. K.; Fincke, R. S.; Guilliams, M. E.; Ploutz-Snyder, L. L.

    2011-01-01

    Treadmill locomotion exercise is an important aspect of ISS exercise countermeasures. It is widely believed that an optimized treadmill exercise protocol could offer benefits to cardiovascular and bone health. If training heart rate is high enough, treadmill exercise is expected to lead to improvements in aerobic fitness. If impact or bone loading forces are high enough, treadmill exercise may be expected to contribute to improved bone outcomes. Ground-based research suggests that joint loads increase with increased running speed. However, it is unknown if increases in locomotion speed results in similar increases in joint loads in microgravity. Although data exist regarding the biomechanics of running and walking in microgravity, a majority were collected during parabolic flight or during investigations utilizing a microgravity analog. The Second Generation Treadmill (T2) has been in use on the International Space Station (ISS) and records the ground reaction forces (GRF) produced by crewmembers during exercise. Biomechanical analyses will aid in understanding potential differences in typical gait motion and allow for modeling of the human body to determine joint and muscle forces during exercise. By understanding these mechanisms, more appropriate exercise prescriptions can be developed that address deficiencies. The objective of this evaluation is to collect biomechanical data from crewmembers during treadmill exercise prior to and during flight. The goal is to determine if locomotive biomechanics differ between normal and microgravity environments and to determine how combinations of subject load and speed influence joint loading during in-flight treadmill exercise. Further, the data will be used to characterize any differences in specific bone and muscle loading during locomotion in these two gravitational conditions. This project maps to the HRP Integrated Research Plan risks including Risk of Bone Fracture (Gap B15), Risk of Early Onset Osteoporosis Due to

  5. Effects of robotic treadmill training on functional mobility, walking capacity, motor symptoms and quality of life in ambulatory patients with Parkinson's disease: a preliminary prospective longitudinal study.

    Science.gov (United States)

    Paker, Nurdan; Bugdayci, Derya; Goksenoglu, Goksen; Sen, Aysu; Kesiktas, Nur

    2013-01-01

    Decreased mobility and walking capacity occur frequently in Parkinson's disease (PD). Robotic treadmill training is a novel method to improve the walking capacity in rehabilitation. The primary aim of this study was to investigate the effects of robotic treadmill training on functional mobility and walking capacity in PD. Secondly, we aimed to assess the effects of the robotic treadmill training the motor symptoms and quality of life in patients with PD. Seventy patients with idiopathic Parkinson's disease who admitted to the outpatient clinic of the rehabilitation hospital were screened and 12 ambulatory volenteers who met the study criteria were included in this study. Patients were evaluated by Hoehn Yahr (HY) scale clinically. Two sessions robotic treadmill training per week during 5 weeks was planned for every patient. Patients were evaluated by the Timed Up and Go (TUG) test, 10 meter walking test (10 MWT), Unified Parkinson's Disease Rating Scale (UPDRS) motor section and Parkinson's Disease Questionnaire-39 (PDQ-39) at the baseline, at the 5 and 12 weeks. Cognitive and emotional states of the patients were assessed by Mini Mental State Examination (MMSE) test and Hospital Anxiety and Depression Scale (HADS) at the baseline. All patients were under medical treatment for the PD in this study and drug treatment was not changed during the study. Ten patients completed the study. The mean age was 65.6 ± 6.6 years. Five patients (50%) were women. Disease severity was between the HY stage 1-3. Two patients did not continue the robotic treadmill training after 7 sessions. They also did not want to come for control visits. TUG test, 10 MWT and UPDRS motor subscale scores showed statistically significant improvement after robotic treadmill training (p = 0.02, p = 0.001, p = 0.016). PDQ-39 scores improved significantly after robotic treadmill training (p = 0.03), however, the scores turned back to the baseline level at the 12. week control. As a result of this

  6. MAXIM: The Blackhole Imager

    Science.gov (United States)

    Gendreau, Keith; Cash, Webster; Gorenstein, Paul; Windt, David; Kaaret, Phil; Reynolds, Chris

    2004-01-01

    The Beyond Einstein Program in NASA's Office of Space Science Structure and Evolution of the Universe theme spells out the top level scientific requirements for a Black Hole Imager in its strategic plan. The MAXIM mission will provide better than one tenth of a microarcsecond imaging in the X-ray band in order to satisfy these requirements. We will overview the driving requirements to achieve these goals and ultimately resolve the event horizon of a supermassive black hole. We will present the current status of this effort that includes a study of a baseline design as well as two alternative approaches.

  7. Social group utility maximization

    CERN Document Server

    Gong, Xiaowen; Yang, Lei; Zhang, Junshan

    2014-01-01

    This SpringerBrief explains how to leverage mobile users' social relationships to improve the interactions of mobile devices in mobile networks. It develops a social group utility maximization (SGUM) framework that captures diverse social ties of mobile users and diverse physical coupling of mobile devices. Key topics include random access control, power control, spectrum access, and location privacy.This brief also investigates SGUM-based power control game and random access control game, for which it establishes the socially-aware Nash equilibrium (SNE). It then examines the critical SGUM-b

  8. Treadmill exercise ameliorates Alzheimer disease-associated memory loss through the Wnt signaling pathway in the streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Kim, Dae-Young; Jung, Sun-Young; Kim, Kijeong; Kim, Chang-Ju

    2016-08-01

    Diabetes mellitus is considered as a risk factor for Alzheimer disease. The aim of the present study was to evaluate the possibility whether treadmill exercise ameliorates Alzheimer disease-associated memory loss in the diabetes mellitus. For this study, the effects of treadmill exercise on short-term memory and spatial learning ability in relation with Wnt signaling pathway were evaluated using the streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by intraperitoneal injection of STZ. Step-down avoidance task and 8-arm radial maze test were performed for the memory function. Immunohistochemistry for 5-bro-mo-2'-deoxyridine (BrdU) and doublecortin (DCX) and Western blot for Wnt3 and glycogen synthase kinase-3β (GSK-3β) were conducted. The rats in the exercise groups were made to run on the treadmill for 30 min per one day, 5 times a week, during 12 weeks. In the present results, short-term memory and spatial learning ability were deteriorated by induction of diabetes. Treadmill exercise improved short-term memory and spatial learning ability in the diabetic rats. The numbers of BrdU-positive and DCX-positive cells in the hippocampal dentate gyrus were decreased by induction of diabetes. Treadmill exercise increased these numbers in the diabetic rats. Wnt3 expression in the hippocampus was decreased and GSK-3β expression in the hippocampus was increased by induction of diabetes. Treadmill exercise increased Wnt3 expression and suppressed GSK-3β expression in the diabetic rats. The present study suggests that treadmill exercise alleviates Alzheimer disease-associated memory loss by increasing neurogenesis through activating Wnt signaling pathway in the diabetic rats.

  9. Effectiveness of treadmill training on balance control in elderly people: a randomized controlled clinical trial.

    Science.gov (United States)

    Pirouzi, Soraya; Motealleh, Ali Reza; Fallahzadeh, Fatemeh; Fallahzadeh, Mohammad Amin

    2014-11-01

    Physical exercise would improve postural stability, which is an essential factor in preventing accidental fall among the elderly population. The aim of this study is to examine the effectiveness of treadmill walking on balance improvement among the elderly people. A total of 30 community dwelling older adults with a Berg Balance Scale score of 36-48 and the ability to walk without aid were considered and divided into control (n=15) and experimental (n=15) groups. Individuals in the experimental group participated in 30 minutes of forward and backward treadmill training based on three times a week interval for a period of four weeks. Individuals in the control group were instructed to continue with their daily routine activity. Before and after training, gait speed was measured by six-minute walk test and balance ability was evaluated by Fullerton Advanced Balance Scale (FABS) and Berg Balance Scale (BBS) tests. Postural sway items such as the Center of Pressure (COP), average displacement and velocity were evaluated by using a force platform system. Data were collected in quiet standing, tandem position and standing on foam pads before and after intervention. After intervention, balance variables in the experimental group indicated a significant improvement in quiet standing on firm and foam surfaces, but no considerable improvement was shown in tandem position. A between-group comparison showed a significant reduction in COP velocity in the sagittal plane (P=0.030) during quiet standing and in the frontal plane (P=0.001) during standing on foam, whereas no significant reduction in COP parameters during tandem position was found. It is recommended that twelve sessions of forward and backward treadmill walk are effective in balance improvement in elderly people. IRCT201209199440N2.

  10. Effects of treadmill exercise intensity on spatial working memory and long-term memory in rats.

    Science.gov (United States)

    Wang, Xiao-Qin; Wang, Gong-Wu

    2016-03-15

    Moderate exercise promotes learning and memory. Most studies mainly focused on memory exercise effects of in the ageing and patients. There is lack of quantitative research about effect of regular exercise intensity on different memory types in normal subjects. Present study investigated the effects of different intensities of treadmill exercise on working memory and long-term memory. Fifty female Wistar rats were trained by T-maze delayed spatial alternation (DSA) task with 3 delays (10s, 60s and 300s). Then they got a 30min treadmill exercise for 30days in 4 intensities (control, 0m/min; lower, 15m/min; middle, 20m/min, and higher, 30m/min). Then animals were tested in DSA, passive avoidance and Morris water maze tasks. 1. Exercise increased the neuronal density of hippocampal subregions (CA1, CA3 and dentate gyrus) vs. naïve/control. 2. In DSA task, all groups have similar baseline, lower intensity improved 10s delay accuracy vs. baseline/control; middle and higher intensities improved 300s delay accuracy vs. baseline/control. 3. In water maze learning, all groups successfully found the platform, but middle intensity improved platform field crossing times vs. control in test phase. Present results suggested that treadmill exercise can improve long-term spatial memory and working memory; lower intensity benefits to short-term delayed working memory, and middle or higher intensity benefits to long-term delayed working memory. There was an inverted U dose-effect relationship between exercise intensity and memory performance, but exercise -working memory effect was impacted by delay duration. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Effectiveness of Treadmill Training on Balance Control in Elderly People: A Randomized Controlled Clinical Trial

    Directory of Open Access Journals (Sweden)

    Soraya Pirouzi

    2014-11-01

    Full Text Available Physical exercise would improve postural stability, which is an essential factor in preventing accidental fall among the elderly population. The aim of this study is to examine the effectiveness of treadmill walking on balance improvement among the elderly people. A total of 30 community dwelling older adults with a Berg Balance Scale score of 36-48 and the ability to walk without aid were considered and divided into control (n=15 and experimental (n=15 groups. Individuals in the experimental group participated in 30 minutes of forward and backward treadmill training based on three times a week interval for a period of four weeks. Individuals in the control group were instructed to continue with their daily routine activity. Before and after training, gait speed was measured by six-minute walk test and balance ability was evaluated by Fullerton Advanced Balance Scale (FABS and Berg Balance Scale (BBS tests. Postural sway items such as the Center of Pressure (COP, average displacement and velocity were evaluated by using a force platform system. Data were collected in quiet standing, tandem position and standing on foam pads before and after intervention. After intervention, balance variables in the experimental group indicated a significant improvement in quiet standing on firm and foam surfaces, but no considerable improvement was shown in tandem position. A between-group comparison showed a significant reduction in COP velocity in the sagittal plane (P=0.030 during quiet standing and in the frontal plane (P=0.001 during standing on foam, whereas no significant reduction in COP parameters during tandem position was found. It is recommended that twelve sessions of forward and backward treadmill walk are effective in balance improvement in elderly people. Trial Registration Number: IRCT201209199440N2

  12. Long term treadmill exercise performed to chronic social isolated rats regulate anxiety behavior without improving learning.

    Science.gov (United States)

    Cevik, Ozge Selin; Sahin, Leyla; Tamer, Lulufer

    2018-05-01

    The type and duration of exposure to stress is an important influence on emotional and cognitive functions. Learning is the adaptive response of the central nervous system that occurs in hippocampus which affects from environmental factors like exercise. In this study, we investigated effects of long term treadmill exercise on learning and behavior on chronic social isolated rat. Male Wistar rats (n = 32) randomly assigned into four groups: control, exercised, social isolation, social isolation + exercise during postnatal days (PNDs) 21-34. Social isolation protocol was applied during 14 days by placing rat in a cage one by one. Rats were exercised during 5 days, days were chosen randomly for overall 4 weeks (20, 30, 50, 60 min respectively). Finally, learning performance was evaluated by Morris water maze (MWM). Anxiety behavior was evaluated by Open field and elevated plus maze test. At the end of learning and behavior tests, the rats were decapitated to collect blood samples via intracardiac puncture and corticosterone analysis was performed with ELISA method. Animal weights and water consumption did not change significantly but food intake differed among groups. Corticosterone level did not change between groups. The frequency of entering to the target quadrant increased in exercised rat significantly. However, there was no difference in learning and memory in rats. Treadmill exercise reduced anxiety behavior significantly. Taken together these findings may point out that, long term treadmill exercise did not change learning and memory but reduced anxiety level of rat without changing corticosterone level. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Long-term treadmill exercise-induced neuroplasticity and associated memory recovery of streptozotocin-induced diabetic rats: an experimenter blind, randomized controlled study.

    Science.gov (United States)

    You, Joshua Sung H; Kim, Chung-Ju; Kim, Mee Young; Byun, Yong Gwon; Ha, So Young; Han, Bong Suk; Yoon, Bum Chul

    2009-01-01

    We investigated a long-term exercise-induced neuroplasticity and spatial memory recovery in 15 rats in a treadmill as follows: normal control rats (NC), streptozotocin (STZ)-induced diabetic control rats (DC), and STZ-induced diabetic rats exercising in a treadmill (DE). As per the DE group, the running exercise in a treadmill was administered for 30 minutes a day for 6 weeks. Neuronal immediate-early gene (IEG) expression (c-Fos) in the hippocampus and radial arm maze (RAM) tests were measured and revealed that the c-Fos levels in DE were significantly higher than those in NC and DC (p memory performance scores, obtained from the RAM test, were significantly different among the three groups (p memory scores of NC and DE were higher than those of DC (p memory. This is the first experimental evidence in literature that supports the efficacy of exercise-induced neuroplasticity and spatial motor memory in diabetes care.

  14. Comparison of the skin sensitizing potential of unsaturated compounds as assessed by the murine local lymph node assay (LLNA) and the guinea pig maximization test (GPMT).

    Science.gov (United States)

    Kreiling, R; Hollnagel, H M; Hareng, L; Eigler, D; Lee, M S; Griem, P; Dreessen, B; Kleber, M; Albrecht, A; Garcia, C; Wendel, A

    2008-06-01

    The skin sensitization potential of eight unsaturated and one saturated lipid (bio)chemicals was tested in both the LLNA and the GPMT to address the hypothesis that chemicals with unsaturated carbon-carbon double bonds may result in a higher number of unspecific (false positive) results in the LLNA compared to the GPMT. Seven substances (oleic acid, linoleic acid, linolenic acid, undecylenic acid, maleic acid, squalene and octinol) gave clear positive results in the LLNA (stimulation index (SI)> or = 3) and thus would require labelling as skin sensitizer. Fumaric acid and succinic acid gave clearly negative results. In the GPMT, besides some sporadic skin reactions, reproducible skin reactions indicating an allergic response were found in a few animals for four test substances. Based on the GPMT results, only undecylenic acid would have to be classified and labelled as a skin sensitizer according to the European Dangerous Substance Directive (67/548/EEC) (results for linoleic acid were inconclusive), while the other seven test substances would not require labelling. Possible mechanisms for unspecific skin cell stimulation and lymph node responses are discussed. In conclusion, the suitability of the LLNA for unsaturated compounds bearing structural similarity to the tested substances should be carefully considered and the GPMT should remain available as an accepted test method for skin sensitization hazard identification.

  15. Crossfit-based high-intensity power training improves maximal aerobic fitness and body composition.

    Science.gov (United States)

    Smith, Michael M; Sommer, Allan J; Starkoff, Brooke E; Devor, Steven T

    2013-11-01

    The purpose of this study was to examine the effects of a crossfit-based high-intensity power training (HIPT) program on aerobic fitness and body composition. Healthy subjects of both genders (23 men, 20 women) spanning all levels of aerobic fitness and body composition completed 10 weeks of HIPT consisting of lifts such as the squat, deadlift, clean, snatch, and overhead press performed as quickly as possible. Additionally, this crossfit-based HIPT program included skill work for the improvement of traditional Olympic lifts and selected gymnastic exercises. Body fat percentage was estimated using whole-body plethysmography, and maximal aerobic capacity (VO2max) was measured by analyzing expired gasses during a Bruce protocol maximal graded treadmill test. These variables were measured again after 10 weeks of training and compared for significant changes using a paired t-test. Results showed significant (p < 0.05) improvements of VO2max in men (43.10 ± 1.40 to 48.96 ± 1.42 ml · kg · min) and women (35.98 ± 1.60 to 40.22 ± 1.62 ml · kg · min) and decreased body fat percentage in men (22.2 ± 1.3 to 18.0 ± 1.3) and women (26.6 ± 2.0 to 23.2 ± 2.0). These improvements were significant across all levels of initial fitness. Significant correlations between absolute oxygen consumption and oxygen consumption relative to body weight was found in both men (r = 0.83, p < 0.001) and women (r = 0.94, p < 0.001), indicating that HIPT improved VO2max scaled to body weight independent of changes to body composition. Our data show that HIPT significantly improves VO2max and body composition in subjects of both genders across all levels of fitness.

  16. Allergenicity evaluation of p-chloro-m-cresol and p-chloro-m-xylenol by non-radioactive murine local lymph-node assay and multiple-dose guinea pig maximization test

    International Nuclear Information System (INIS)

    Yamano, Tetsuo; Shimizu, Mitsuru; Noda, Tsutomu

    2003-01-01

    p-Chloro-m-cresol (PCMC) and p-chloro-m-xylenol (PCMX) are known to cause allergic contact dermatitis. For risk assessment of skin sensitizers, information on dose-response profiles in the induction and elicitation phases and cross-reactivity with analogous chemicals are important. In the non-radioactive local lymph-node assay (LLNA) using 5-bromo-2'-deoxyuridine instead of 3 H-methyl thymidine, significant effect on lymph node cell proliferation was detected at 10% PCMC and 25% PCMX, while in the multiple-dose guinea pig maximization test (GPMT) at least one animal tested in the group was sensitized at a 5 ppm induction dose of either chemical. When mean skin reaction score in an animal group maximally sensitized with each allergen with the GPMT was plotted against log challenge concentration, linear regression lines with high correlations were obtained in both cases. The calculated elicitation threshold was lower for PCMC than PCMX. The area under the linear regression line between the threshold point and 1% of the elicitation concentration, another index of relative elicitation potency, was also greater for PCMC. Bidirectional cross-reactivity between PCMX and PCMC was detected in the GPMT. PCMC was thus identified in both LLNA and GPMT as a stronger sensitizer than PCMX in both the induction and elicitation phases. These results suggest that the non-radioactive LLNA is a simple and useful method for evaluating allergenicity in the induction phase, while the GPMT using a maximally sensitized animal group is more suitable for assessing the dose-response profile and cross-reactivity in the elicitation phase

  17. Insulin resistance and maximal oxygen uptake

    DEFF Research Database (Denmark)

    Seibaek, Marie; Vestergaard, Henrik; Burchardt, Hans

    2003-01-01

    BACKGROUND: Type 2 diabetes, coronary atherosclerosis, and physical fitness all correlate with insulin resistance, but the relative importance of each component is unknown. HYPOTHESIS: This study was undertaken to determine the relationship between insulin resistance, maximal oxygen uptake......, and the presence of either diabetes or ischemic heart disease. METHODS: The study population comprised 33 patients with and without diabetes and ischemic heart disease. Insulin resistance was measured by a hyperinsulinemic euglycemic clamp; maximal oxygen uptake was measured during a bicycle exercise test. RESULTS......: There was a strong correlation between maximal oxygen uptake and insulin-stimulated glucose uptake (r = 0.7, p = 0.001), and maximal oxygen uptake was the only factor of importance for determining insulin sensitivity in a model, which also included the presence of diabetes and ischemic heart disease. CONCLUSION...

  18. Effects of treadmill exercise on cortical bone in the third metacarpus of young horses

    International Nuclear Information System (INIS)

    McCarthy, R.N.; Jeffcott, L.B.

    1992-01-01

    The effects of exercise and relative inactivity on cortical bone were compared in young horses. Two groups were used; one was given a 14-week programme of exercise (n = 6) and the other kept as unexercised controls (n = 6). The first nine weeks of exercise involved trotting and cantering (2 to 4 km d-1 at speeds up to 12 m s-1) on a treadmill set at an incline of 3 degrees. Over the next five weeks the horses were trained at near maximal speeds (that is, up to 14.5 m s-1) with no incline of the treadmill. At the end of the programme marked differences in cortical porosity and distribution of subperiosteal osteogenesis at the mid-shaft of the third metacarpal bone were found between the groups. Histomorphometrical examination of the dorsal cortex showed minimal bone remodelling in the exercised horses, but extensive modelling as evidenced by the large amount of subperiosteal bone formation. In contrast, the unexercised horses had significantly more bone remodelling and less formation of subperiosteal bone. The histomorphometric and microradiographic findings provided an explanation for changes in the non-invasive bone measurements that occurred during training. Bone mineral content of the mid-metacarpus was found to increase more in the exercised than the unexercised horses despite a lower overall growth in bodyweight. In those horses that completed the full training programme, ultrasound speed increased significantly by the end of the training programme. It remained unchanged in the horse that did not complete the full exercise programme and decreased slightly in the unexercised horses. The difference in ultrasound speed between the groups was considered to reflect differences in intracortical bone porosity, endosteal bone formation and alterations in skin thickness. The stiffness of cortical bone increased significantly in the exercised horses but remained unaltered in the unexercised horses

  19. Step-to-step variability in treadmill walking: influence of rhythmic auditory cueing.

    Directory of Open Access Journals (Sweden)

    Philippe Terrier

    Full Text Available While walking, human beings continuously adjust step length (SpL, step time (SpT, step speed (SpS = SpL/SpT and step width (SpW by integrating both feedforward and feedback mechanisms. These motor control processes result in correlations of gait parameters between consecutive strides (statistical persistence. Constraining gait with a speed cue (treadmill and/or a rhythmic auditory cue (metronome, modifies the statistical persistence to anti-persistence. The objective was to analyze whether the combined effect of treadmill and rhythmic auditory cueing (RAC modified not only statistical persistence, but also fluctuation magnitude (standard deviation, SD, and stationarity of SpL, SpT, SpS and SpW. Twenty healthy subjects performed 6 × 5 min. walking tests at various imposed speeds on a treadmill instrumented with foot-pressure sensors. Freely-chosen walking cadences were assessed during the first three trials, and then imposed accordingly in the last trials with a metronome. Fluctuation magnitude (SD of SpT, SpL, SpS and SpW was assessed, as well as NonStationarity Index (NSI, which estimates the dispersion of local means in the times series (SD of 20 local means over 10 steps. No effect of RAC on fluctuation magnitude (SD was observed. SpW was not modified by RAC, what is likely the evidence that lateral foot placement is separately regulated. Stationarity (NSI was modified by RAC in the same manner as persistent pattern: Treadmill induced low NSI in the time series of SpS, and high NSI in SpT and SpL. On the contrary, SpT, SpL and SpS exhibited low NSI under RAC condition. We used relatively short sample of consecutive strides (100 as compared to the usual number of strides required to analyze fluctuation dynamics (200 to 1000 strides. Therefore, the responsiveness of stationarity measure (NSI to cued walking opens the perspective to perform short walking tests that would be adapted to patients with a reduced gait perimeter.

  20. Effects of Progressive Body Weight Support Treadmill Forward and Backward Walking Training on Stroke Patients' Affected Side Lower Extremity's Walking Ability.

    Science.gov (United States)

    Kim, Kyunghoon; Lee, Sukmin; Lee, Kyoungbo

    2014-12-01

    [Purpose] The purpose of the present study was to examine the effects of progressive body weight supported treadmill forward and backward walking training (PBWSTFBWT), progressive body weight supported treadmill forward walking training (PBWSTFWT), progressive body weight supported treadmill backward walking training (PBWSTBWT), on stroke patients' affected side lower extremity's walking ability. [Subjects and Methods] A total of 36 chronic stroke patients were divided into three groups with 12 subjects in each group. Each of the groups performed one of the progressive body weight supported treadmill training methods for 30 minute, six times per week for three weeks, and then received general physical therapy without any other intervention until the follow-up tests. For the assessment of the affected side lower extremity's walking ability, step length of the affected side, stance phase of the affected side, swing phase of the affected side, single support of the affected side, and step time of the affected side were measured using optogait and the symmetry index. [Results] In the within group comparisons, all the three groups showed significant differences between before and after the intervention and in the comparison of the three groups, the PBWSTFBWT group showed more significant differences in all of the assessed items than the other two groups. [Conclusion] In the present study progressive body weight supported treadmill training was performed in an environment in which the subjects were actually walked, and PBWSTFBWT was more effective at efficiently training stroke patients' affected side lower extremity's walking ability.

  1. Treadmill Exercise Improves Motor Dysfunction and Hyperactivity of the Corticostriatal Glutamatergic Pathway in Rats with 6-OHDA-Induced Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2017-01-01

    Full Text Available Hyperactivity in the corticostriatal glutamatergic pathway (CGP induces basal ganglia dysfunction, contributing to parkinsonian syndrome (PS. Physical exercise can improve PS. However, the effect of exercise on the CGP, and whether this pathway is involved in the improvement of PS, remains unclear. Parkinson’s disease (PD was induced in rats by 6-hydroxydopamine injection into the right medial forebrain bundle. Motor function was assessed using the cylinder test. Striatal neuron (SN spontaneous and evoked firing activity was recorded, and the expression levels of Cav1.3 and CaMKII in the striatum were measured after 4 weeks of treadmill exercise. The motor function in PD rats was improved by treadmill exercise. SN showed significantly enhanced excitability, and treadmill exercise reduced SN excitability in PD rats. In addition, firing activity was evoked in SNs by stimulation of the primary motor cortex, and SNs exhibited significantly decreased stimulus threshold, increased firing rates, and reduced latency. The expression of Cav1.3 and p-CaMKII (Thr286 in the striatum were enhanced in PD rats. However, these effects were reversed by treadmill exercise. These findings suggest that treadmill exercise inhibits CGP hyperactivity in PD rats, which may be related to improvement of PS.

  2. DETERMINATION OF MAXIMAL OXYGEN CONSUMPTION OF COSTA RICAN FIRST DIVISION FOOTBALL PLAYERS DURING 2008 PRESEASON

    Directory of Open Access Journals (Sweden)

    Jorge Salas-Cabrera

    2009-12-01

    Full Text Available The objective of this study was to assess the cardiorespiratory profile (VO2max of Costa Rican first division football players during preseason and compare VO2max by players’ positions. Methodology: A total of 9 Costa Rican first division football teams were evaluated in this study for a total sample of 219 professional players ages 20-36 with an average age of 24.64 ± 4.35 years, average body weight of 73.34 kg ± 7.34, and a fat percentage of 9.78 % ± 3.64. In order to evaluate the VO2max of players, the treadmill protocol was used as recommended by Wilmore and Costill (2007. This was a maximal test. Results: an average VO2max of 57.71 ml/kg/min ± 8.8 was found; however, no statistically significant differences were found (p = .752 between positions. Conclusion: there were no differences in VO2max by positions.

  3. Walking on an Oscillating Treadmill: Two Paths to Functional Adaptation

    Science.gov (United States)

    Brady, Rachel A.; Peters, Brian T.; Bloomberg, Jacob J.

    2010-01-01

    We mounted a treadmill on top of a six degree-of-freedom motion base platform to investigate and characterize locomotor responses produced by healthy adults when introduced to a novel walking condition. Subjects were classified into two groups according to how their stride times were affected by the perturbation. Our data suggest that a person's choice of adaptation strategy is influenced by the relationship between his unique, natural stride frequency and the external frequency imposed by the motion base. Our data suggest that a person's stride time response while walking on a laterally oscillating treadmill is influenced by the relationship between his unique, natural stride frequency and the imposed external frequency of the motion base. This relationship may be useful for checking the efficacy of gait training and rehabilitation programs. Preselecting and manipulating a person's EST could be one way to draw him out of his preferred "entrainment well" during therapy or training.

  4. Burning more than calories: treadmill friction injuries in children.

    LENUS (Irish Health Repository)

    Davidson, C C

    2012-02-01

    Treadmill injuries in young children are a serious but little documented problem. Friction burns occur when the hands come into contact with the moving belt resulting in deep burns that often require hospital admission and surgery. The aim of this study was to assess the nature and prevalence of injuries sustained and to highlight treadmill friction burns as a public health issue previously undocumented in Ireland. A retrospective chart review from January 2006 until March 2008 was performed and functional outcome was assessed by the modified Michigan Hand Outcomes Questionnaire. Eight girls and four boys from one year and seven months to seven years and five months were treated. Eight children required admission to hospital and to date three have required surgery for their injuries. This is a new and increasing problem in Ireland which must be highlighted.

  5. Addition of a non-immersive virtual reality component to treadmill training to reduce fall risk in older adults (V-TIME): a randomised controlled trial.

    Science.gov (United States)

    Mirelman, Anat; Rochester, Lynn; Maidan, Inbal; Del Din, Silvia; Alcock, Lisa; Nieuwhof, Freek; Rikkert, Marcel Olde; Bloem, Bastiaan R; Pelosin, Elisa; Avanzino, Laura; Abbruzzese, Giovanni; Dockx, Kim; Bekkers, Esther; Giladi, Nir; Nieuwboer, Alice; Hausdorff, Jeffrey M

    2016-09-17

    Age-associated motor and cognitive deficits increase the risk of falls, a major cause of morbidity and mortality. Because of the significant ramifications of falls, many interventions have been proposed, but few have aimed to prevent falls via an integrated approach targeting both motor and cognitive function. We aimed to test the hypothesis that an intervention combining treadmill training with non-immersive virtual reality (VR) to target both cognitive aspects of safe ambulation and mobility would lead to fewer falls than would treadmill training alone. We carried out this randomised controlled trial at five clinical centres across five countries (Belgium, Israel, Italy, the Netherlands, and the UK). Adults aged 60-90 years with a high risk of falls based on a history of two or more falls in the 6 months before the study and with varied motor and cognitive deficits were randomly assigned by use of computer-based allocation to receive 6 weeks of either treadmill training plus VR or treadmill training alone. Randomisation was stratified by subgroups of patients (those with a history of idiopathic falls, those with mild cognitive impairment, and those with Parkinson's disease) and sex, with stratification per clinical site. Group allocation was done by a third party not involved in onsite study procedures. Both groups aimed to train three times per week for 6 weeks, with each session lasting about 45 min and structured training progression individualised to the participant's level of performance. The VR system consisted of a motion-capture camera and a computer-generated simulation projected on to a large screen, which was specifically designed to reduce fall risk in older adults by including real-life challenges such as obstacles, multiple pathways, and distracters that required continual adjustment of steps. The primary outcome was the incident rate of falls during the 6 months after the end of training, which was assessed in a modified intention

  6. Negligible motion artifacts in scalp electroencephalography (EEG during treadmill walking

    Directory of Open Access Journals (Sweden)

    Kevin eNathan

    2016-01-01

    Full Text Available Recent Mobile Brain/Body Imaging (MoBI techniques based on active electrode scalp electroencephalogram (EEG allow the acquisition and real-time analysis of brain dynamics during active unrestrained motor behavior involving whole body movements such as treadmill walking, over-ground walking and other locomotive and non-locomotive tasks. Unfortunately, MoBI protocols are prone to physiological and non-physiological artifacts, including motion artifacts that may contaminate the EEG recordings. A few attempts have been made to quantify these artifacts during locomotion tasks but with inconclusive results due in part to methodological pitfalls. In this paper, we investigate the potential contributions of motion artifacts in scalp EEG during treadmill walking at three different speeds (1.5, 3.0, and 4.5 km/h using a wireless 64 channel active EEG system and a wireless inertial sensor attached to the subject’s head. The experimental setup was designed according to good measurement practices using state-of-the-art commercially-available instruments, and the measurements were analyzed using Fourier analysis and wavelet coherence approaches. Contrary to prior claims, the subjects’ motion did not significantly affect their EEG during treadmill walking although precaution should be taken when gait speeds approach 4.5 km/h. Overall, these findings suggest how MoBI methods may be safely deployed in neural, cognitive, and rehabilitation engineering applications.

  7. Anaerobic digestion in combination with 2nd generation ethanol production for maximizing biofuels yield from lignocellulosic biomass – testing in an integrated pilot-scale biorefinery plant

    DEFF Research Database (Denmark)

    Uellendahl, Hinrich; Ahring, Birgitte Kiær

    An integrated biorefinery concept for 2nd generation bioethanol production together with biogas production from the fermentation effluent was tested in pilot-scale. The pilot plant comprised pretreatment, enzymatic hydrolysis, hexose and pentose fermentation into ethanol and anaerobic digestion......-VS/(m3•d) a methane yield of 340 L/kg-VS was achieved for thermophilic operation while 270 L/kg-VS was obtained under mesophilic conditions. Thermophilic operation was, however, less robust towards further increase of the loading rate and for loading rates higher than 5 kg-VS/(m3•d) the yield was higher...... for mesophilic than for thermophilic operation. The effluent from the ethanol fermentation showed no signs of toxicity to the anaerobic microorganisms. Implementation of the biogas production from the fermentation effluent accounted for about 30% higher biofuels yield in the biorefinery compared to a system...

  8. A pilot clinical trial on a Variable Automated Speed and Sensing Treadmill (VASST) for hemiparetic gait rehabilitation in stroke patients.

    Science.gov (United States)

    Chua, Karen S G; Chee, Johnny; Wong, Chin J; Lim, Pang H; Lim, Wei S; Hoo, Chuan M; Ong, Wai S; Shen, Mira L; Yu, Wei S

    2015-01-01

    Impairments in walking speed and capacity are common problems after stroke which may benefit from treadmill training. However, standard treadmills, are unable to adapt to the slower walking speeds of stroke survivors and are unable to automate training progression. This study tests a Variable Automated Speed and Sensing Treadmill (VASST) using a standard clinical protocol. VASST is a semi-automated treadmill with multiple sensors and micro controllers, including wireless control to reposition a fall-prevention harness, variable pre-programmed exercise parameters and laser beam foot sensors positioned on the belt to detect subject's foot positions. An open-label study with assessor blinding was conducted in 10 community-dwelling chronic hemiplegic patients who could ambulate at least 0.1 m/s. Interventions included physiotherapist-supervised training on VASST for 60 min three times per week for 4 weeks (total 12 h). Outcome measures of gait speed, quantity, balance, and adverse events were assessed at baseline, 2, 4, and 8 weeks. Ten subjects (8 males, mean age 55.5 years, 2.1 years post stroke) completed VASST training. Mean 10-m walk test speed was 0.69 m/s (SD = 0.29) and mean 6-min walk test distance was 178.3 m (84.0). After 4 weeks of training, 70% had significant positive gains in gait speed (0.06 m/s, SD = 0.08 m/s, P = 0.037); and 90% improved in walking distance. (54.3 m, SD = 30.9 m, P = 0.005). There were no adverse events. This preliminary study demonstrates the initial feasibility and short-term efficacy of VASST for walking speed and distance for people with chronic post-stroke hemiplegia.

  9. Maximal Bell's inequality violation for non-maximal entanglement

    International Nuclear Information System (INIS)

    Kobayashi, M.; Khanna, F.; Mann, A.; Revzen, M.; Santana, A.

    2004-01-01

    Bell's inequality violation (BIQV) for correlations of polarization is studied for a product state of two two-mode squeezed vacuum (TMSV) states. The violation allowed is shown to attain its maximal limit for all values of the squeezing parameter, ζ. We show via an explicit example that a state whose entanglement is not maximal allow maximal BIQV. The Wigner function of the state is non-negative and the average value of either polarization is nil

  10. A Dual Track Treadmill in a Virtual Reality Environment as a Countermeasure for Neurovestibular Adaptations in Microgravity

    Science.gov (United States)

    DAndrea, Susan E.; Kahelin, Michael W.; Horowitz, Jay G.; OConnor, Philip A.

    2004-01-01

    While the neurovestibular system is capable of adapting to altered environments such as microgravity, the adaptive state achieved in space in inadequate for 1G. This leads to gait and postural instabilities when returning to a gravity environment and may create serious problems in future missions to Mars. New methods are needed to improve the understanding of the adaptive capabilities of the human neurovestibular system and to develop more effective countermeasures. The concept behind the current study is that by challenging the neurovestibular system while walking or running, a treadmill can help to readjust the relationship between the visual, vestibular and proprioceptive signals that are altered in a microgravity environment. As a countermeasure, this device could also benefit the musculoskeletal and cardiovascular systems and at the same time decrease the overall time spent exercising. The overall goal of this research is to design, develop, build and test a dual track treadmill, which utilizes virtual reality,

  11. Physiological effects of bioceramic material: harvard step, resting metabolic rate and treadmill running assessments.

    Science.gov (United States)

    Leung, Ting-Kai; Kuo, Chia-Hua; Lee, Chi-Ming; Kan, Nai-Wen; Hou, Chien-Wen

    2013-12-31

    Previous biomolecular and animal studies have shown that a room-temperature far-infrared-rayemitting ceramic material (bioceramic) demonstrates physical-biological effects, including the normalization of psychologically induced stress-conditioned elevated heart rate in animals. In this clinical study, the Harvard step test, the resting metabolic rate (RMR) assessment and the treadmill running test were conducted to evaluate possible physiological effects of the bioceramic material in human patients. The analysis of heart rate variability (HRV) during the Harvard step test indicated that the bioceramic material significantly increased the high-frequency (HF) power spectrum. In addition, the results of RMR analysis suggest that the bioceramic material reduced oxygen consumption (VO2). Our results demonstrate that the bioceramic material has the tendency to stimulate parasympathetic responses, which may reduce resting energy expenditure and improve cardiorespiratory recovery following exercise.

  12. Effects of Gait Training With Body Weight Support on a Treadmill Versus Overground in Individuals With Stroke.

    Science.gov (United States)

    Gama, Gabriela L; Celestino, Melissa L; Barela, José A; Forrester, Larry; Whitall, Jill; Barela, Ana M

    2017-04-01

    To investigate the effects of gait training with body weight support (BWS) on a treadmill versus overground in individuals with chronic stroke. Randomized controlled trial. University research laboratory. Individuals (N=28) with chronic stroke (>6mo from the stroke event). Participants were randomly assigned to receive gait training with BWS on a treadmill (n=14) or overground (n=14) 3 times a week for 6 weeks. Gait speed measured using the 10-meter walk test, endurance measured using the 6-minute walk test, functional independence measured using the motor domain of the FIM, lower limb recovery measured using the lower extremity domain of the Fugl-Meyer assessment, step length, step length symmetry ratio, and single-limb support duration. Measurements were obtained at baseline, immediately after the training session, and 6 weeks after the training session. At 1 week after the last training session, both groups improved in all outcome measures except paretic step length and step length symmetry ratio, which were improved only in the overground group (P=.01 and P=.01, respectively). At 6 weeks after the last training session, all improvements remained and the treadmill group also improved paretic step length (P.05). Individuals with chronic stroke equally improve gait speed and other gait parameters after 18 sessions of BWS gait training on either a treadmill or overground. Only the overground group improved step length symmetry ratio, suggesting a role of integrating overground walking into BWS interventions poststroke. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  13. Preventive and therapeutic effect of treadmill running on chronic stress-induced memory deficit in rats.

    Science.gov (United States)

    Radahmadi, Maryam; Alaei, Hojjatallah; Sharifi, Mohammad Reza; Hosseini, Nasrin

    2015-04-01

    Previous results indicated that stress impairs learning and memory. In this research, the effects of preventive, therapeutic and regular continually running activity on chronic stress-induced memory deficit in rats were investigated. 70 male rats were randomly divided into seven groups as follows: Control, Sham, Stress-Rest, Rest-Stress, Stress-Exercise, Exercise-Stress and Exercise-Stress & Exercise groups. Chronic restraint stress was applied 6 h/day for 21days and treadmill running 1 h/day. Memory function was evaluated by the passive avoidance test. The results revealed that running activities had therapeutic effect on mid and long-term memory deficit and preventive effects on short and mid-term memory deficit in stressed rats. Regular continually running activity improved mid and long-term memory compared to Exercise-Stress group. The beneficial effects of exercise were time-dependent in stress conditions. Finally, data corresponded to the possibility that treadmill running had a more important role on treatment rather than on prevention on memory impairment induced by stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Energy expenditure and physiological responses during walking on a treadmill and moving on the Torqway vehicle.

    Science.gov (United States)

    Maciejczyk, Marcin; Wiecek, Magdalena; Szymura, Jadwiga; Szygula, Zbigniew

    2016-01-01

    One of the new products which can be used to increase physical activity and energy expenditure is the Torqway vehicle, powered by the upper limbs. The aim of this study was to (1) assess the usefulness and repeatability of the Torqway vehicle for physical exercise, (2) compare energy expenditure and physiological responses during walking on a treadmill and during physical effort while moving on the Torqway at a constant speed. The participants (11 men, aged 20.2 ± 1.3) performed the incremental test and submaximal exercises (walking on the treadmill and moving on the Torqway vehicle at the same speed). Energy expenditure during the exercise on the Torqway was significantly higher (p = 0.001) than during the walking performed at the same speed. The intensity of the exercise performed on the Torqway expressed as %VO2max and %HRmax was significantly ( p walking (respectively: 35.0 ± 6.0 vs. 29.4 ± 7.4 %VO2max and 65.1 ± 7.3 vs. 47.2 ± 7.4 %HRmax). Exercise on the Torqway vehicle allows for the intensification of the exercise at a low movement speed, comparable to walking. Moving on the Torqway vehicle could be an effective alternative activity for physical fitness and exercise rehabilitation programs.

  15. Moderate treadmill running exercise prior to tendon injury enhances wound healing in aging rats.

    Science.gov (United States)

    Zhang, Jianying; Yuan, Ting; Wang, James H-C

    2016-02-23

    The effect of exercise on wound healing in aging tendon was tested using a rat moderate treadmill running (MTR) model. The rats were divided into an MTR group that ran on a treadmill for 4 weeks and a control group that remained in cages. After MTR, a window defect was created in the patellar tendons of all rats and wound healing was analyzed. We found that MTR accelerated wound healing by promoting quicker closure of wounds, improving the organization of collagen fibers, and decreasing senescent cells in the wounded tendons when compared to the cage control. MTR also lowered vascularization, increased the numbers of tendon stem/progenitor cells (TSCs) and TSC proliferation than the control. Besides, MTR significantly increased the expression of stem cell markers, OCT-4 and Nanog, and tenocyte genes, Collagen I, Collagen III and tenomodulin, and down-regulated PPAR-γ, Collagen II and Runx-2 (non-tenocyte genes). These findings indicated that moderate exercise enhances healing of injuries in aging tendons through TSC based mechanisms, through which exercise regulates beneficial effects in tendons. This study reveals that appropriate exercise may be used in clinics to enhance tendon healing in aging patients.

  16. Maximally Symmetric Composite Higgs Models.

    Science.gov (United States)

    Csáki, Csaba; Ma, Teng; Shu, Jing

    2017-09-29

    Maximal symmetry is a novel tool for composite pseudo Goldstone boson Higgs models: it is a remnant of an enhanced global symmetry of the composite fermion sector involving a twisting with the Higgs field. Maximal symmetry has far-reaching consequences: it ensures that the Higgs potential is finite and fully calculable, and also minimizes the tuning. We present a detailed analysis of the maximally symmetric SO(5)/SO(4) model and comment on its observational consequences.

  17. Principles of maximally classical and maximally realistic quantum ...

    Indian Academy of Sciences (India)

    Principles of maximally classical and maximally realistic quantum mechanics. S M ROY. Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India. Abstract. Recently Auberson, Mahoux, Roy and Singh have proved a long standing conjecture of Roy and Singh: In 2N-dimensional phase space, ...

  18. Effect of treadmill versus overground running on the structure of variability of stride timing.

    Science.gov (United States)

    Lindsay, Timothy R; Noakes, Timothy D; McGregor, Stephen J

    2014-04-01

    Gait timing dynamics of treadmill and overground running were compared. Nine trained runners ran treadmill and track trials at 80, 100, and 120% of preferred pace for 8 min. each. Stride time series were generated for each trial. To each series, detrended fluctuation analysis (DFA), power spectral density (PSD), and multiscale entropy (MSE) analysis were applied to infer the regime of control along the randomness-regularity axis. Compared to overground running, treadmill running exhibited a higher DFA and PSD scaling exponent, as well as lower entropy at non-preferred speeds. This indicates a more ordered control for treadmill running, especially at non-preferred speeds. The results suggest that the treadmill itself brings about greater constraints and requires increased voluntary control. Thus, the quantification of treadmill running gait dynamics does not necessarily reflect movement in overground settings.

  19. A LABORATORY TEST FOR THE EXAMINATION OF ALACTIC RUNNING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Armin Kibele

    2005-12-01

    Full Text Available A new testing procedure is introduced to evaluate the alactic running performance in a 10s sprint task with near-maximal movement velocity. The test is performed on a motor-equipped treadmill with inverted polarity that increases mechanical resistance instead of driving the treadmill belt. As a result, a horizontal force has to be exerted against the treadmill surface in order to overcome the resistant force of the engine and to move the surface in a backward direction. For this task, subjects lean with their hands towards the front safety barrier of the treadmill railing with a slightly inclined body posture. The required skill resembles the pushing movement of bobsleigh pilots at the start of a race. Subjects are asked to overcome this mechanical resistance and to cover as much distance as possible within a time period of 10 seconds. Fifteen male students (age: 27.7 ± 4.1 years, body height: 1.82 ± 0.46 m, body mass: 78.3 ± 6.7 kg participated in a study. As the resistance force was set to 134 N, subjects ran 35.4 ± 2.6 m on the average corresponding to a mean running velocity of 3.52 ± 0.25 m·s-1. The validity of the new test was examined by statistical inference with various measures related to alactic performance including a metabolic equivalent to estimate alactic capacity (2892 ± 525 mL O2, an estimate for the oxygen debt (2662 ± 315 ml, the step test by Margaria to estimate alactic energy flow (1691 ± 171 W, and a test to measure the maximal strength in the leg extensor muscles (2304 ± 351 N. The statistical evaluation showed that the new test is in good agreement with the theoretical assumptions for alactic performance. Significant correlation coefficients were found between the test criteria and the measures for alactic capacity (r = 0.79, p < 0.01 as well as alactic power (r = 0.77, p < 0.01. The testing procedure is easy to administer and it is best suited to evaluate the alactic capacity for bobsleigh pilots as well as for

  20. Mechanical alterations during interval-training treadmill runs in high-level male team-sport players.

    Science.gov (United States)

    Girard, Olivier; Brocherie, Franck; Morin, Jean-Benoit; Millet, Grégoire P

    2017-01-01

    To examine mechanical alterations during interval-training treadmill runs in high-level team-sport players. Within-participants repeated measures. Twenty high-level male field-hockey players performed six 30-s runs at 5.53±0.19ms -1 corresponding to 115% of their velocity associated with maximal oxygen uptake (vVO 2max ) with 30-s passive recovery on an instrumented treadmill. Continuous measurement of running kinetics/kinematics and spring-mass characteristics were performed and values were subsequently averaged over 20s (8th-28ths) for comparison. Contact time (+1.1±4.3%; p=0.044), aerial time (+4.1±5.3%; p=0.001), step length (+2.4±2.2%; pteam-sport players modified their mechanical behaviour towards lower vertical stiffness while preserving a constant leg stiffness. Maintenance of running velocity induced longer step lengths and decreased step frequencies that were also accompanied by increased impact loading rates. These mechanical alterations occurred early during the set. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Inflight Treadmill Exercise Can Serve as Multi-Disciplinary Countermeasure System

    Science.gov (United States)

    Bloomberg, J. J.; Batson, C. D.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Laurie, S.; Lee, S. M. C.; Miller, C. A.; Mulavara, A. P.; Peters, B. T.; hide

    2014-01-01

    The goals of the Functional Task Test (FTT) study were to determine the effects of space flight on functional tests that are representative of high priority exploration mission tasks and to identify the key underlying physiological factors that contribute to decrements in performance. Ultimately this information will be used to assess performance risks and inform the design of countermeasures for exploration class missions. We have previously shown that for Shuttle, ISS and bed rest subjects, functional tasks requiring a greater demand for dynamic control of postural equilibrium (i.e. fall recovery, seat egress/obstacle avoidance during walking, object translation, jump down) showed the greatest decrement in performance. Functional tests with reduced requirements for postural stability (i.e. hatch opening, ladder climb, manual manipulation of objects and tool use) showed little reduction in performance. These changes in functional performance were paralleled by similar decrements in sensorimotor tests designed to specifically assess postural equilibrium and dynamic gait control. The bed rest analog allows us to investigate the impact of axial body unloading in isolation on both functional tasks and on the underlying physiological factors that lead to decrements in performance and then compare them with the results obtained in our space flight study. These results indicate that body support unloading experienced during space flight plays a central role in postflight alteration of functional task performance. These data also support the concept that space flight may cause central adaptation of converging body-load somatosensory and vestibular input during gravitational transitions [1]. Therefore, we conclude that providing significant body-support loading during inflight treadmill along with balance training is necessary to mitigate decrements in critical mission tasks that require dynamic postural stability and mobility. Data obtained from space flight and bed rest

  2. Forced treadmill exercise can induce stress and increase neuronal damage in a mouse model of global cerebral ischemia

    Directory of Open Access Journals (Sweden)

    Martina Svensson

    2016-12-01

    Full Text Available Physical exercise is known to be a beneficial factor by increasing the cellular stress tolerance. In ischemic stroke, physical exercise is suggested to both limit the brain injury and facilitate behavioral recovery. In this study we investigated the effect of physical exercise on brain damage following global cerebral ischemia in mice. We aimed to study the effects of 4.5 weeks of forced treadmill running prior to ischemia on neuronal damage, neuroinflammation and its effect on general stress by measuring corticosterone in feces. We subjected C57bl/6 mice (n = 63 to either treadmill running or a sedentary program prior to induction of global ischemia. Anxious, depressive, and cognitive behaviors were analyzed. Stress levels were analyzed using a corticosterone ELISA. Inflammatory and neurological outcomes were analyzed using immunohistochemistry, multiplex electrochemoluminescence ELISA and Western blot. To our surprise, we found that forced treadmill running induced a stress response, with increased anxiety in the Open Field test and increased levels of corticosterone. In accordance, mice subjected to forced exercise prior to ischemia developed larger neuronal damage in the hippocampus and showed higher cytokine levels in the brain and blood compared to non-exercised mice. The extent of neuronal damage correlated with increased corticosterone levels. To compare forced treadmill with voluntary wheel running, we used a different set of mice that exercised freely on running wheels. These mice did not show any anxiety or increased corticosterone levels. Altogether, our results indicate that exercise pre-conditioning may not be beneficial if the animals are forced to run as it can induce a detrimental stress response.

  3. V̇O2 and Muscle Deoxygenation Kinetics During Skating: Comparison Between Slide Board and Treadmill Skating.

    Science.gov (United States)

    Piucco, Tatiane; Soares, Rogério; Diefenthaeler, Fernando; Millet, Guillaume; Murias, Juan

    2017-11-15

    this study aimed to compare the oxygen uptake (V̇O 2 ) kinetics during skating on a treadmill and skating on a slide board and discuss potential mechanisms that might control the V̇O 2 kinetics responses during skating. breath-by-breath pulmonary V̇O 2 and near-infrared spectroscopy-derived muscle deoxygenation ([HHbMb]) were monitored continuously in 12 well-trained young long track speed skaters. On-transient V̇O 2 and [HHbMb] responses to skating on a treadmill and skating on a slide board at 80% of the estimated gas exchange threshold were fitted as mono-exponential function. The signals were time aligned, and the individual [HHbMb]-to-V̇O 2 ratio was calculated as the average value from 20-120 s after exercise starts. the time constants for the adjustment of phase II V̇O 2 (τ V̇O 2 ) and [HHbMb] (τ[HHbMb]) were low and similar between slide board vs. treadmill skating (18.1 ± 3.4 vs. 18.9 ± 3.6 for τ V̇O 2 and 12.6 ± 4.0 vs. 12.4 ± 4.0 s for τ[HHbMb]). The [HHbMb]/V̇O 2 ratio was not different from 1.0 (p > 0.05) in both conditions. the fast V̇O 2 kinetics during skating suggest that chronical adaptation to skating might overcome any possible restriction in leg blood flow during low intensity exercise. The [HHbMb]/V̇O 2 ratio values also suggest a good matching of O 2 delivery to O 2 utilization in trained speed skaters. The similar τ V̇O 2 and τ [HHbMb] values between slide board and treadmill further reinforce the validity of using a slide board for skating testing and training purposes.

  4. Characterization of in vivo Achilles tendon forces in rabbits during treadmill locomotion at varying speeds and inclinations.

    Science.gov (United States)

    West, John R; Juncosa, Natalia; Galloway, Marc T; Boivin, Gregory P; Butler, David L

    2004-11-01

    The objective of this study was to test the hypothesis that increasing the speed and inclination of the treadmill increases the peak Achilles tendon forces and their rates of rise and fall in force. Implantable force transducers (IFT) were inserted in the confluence of the medial and lateral heads of the left gastrocnemius tendon in 11 rabbits. IFT voltages were successfully recorded in 8 animals as the animals hopped on a treadmill at each of two speeds (0.1 and 0.3 mph) and inclinations (0 degrees and 12 degrees). Instrumented tendons were isolated shortly after sacrifice and calibrated. Contralateral unoperated tendons were failed in uniaxial tension to determine maximum or failure force, from which safety factor (ratio of maximum force to peak in vivo force) was calculated for each activity. Peak force and the rates of rise and fall in force significantly increased with increasing treadmill inclination (prabbit Achilles tendon and other tendon repairs. Force patterns can also serve as input data for mechanical stimulation of tissue-engineered constructs in culture. Such approaches are expected to help accelerate tendon repair after injury.

  5. Treadmill training with partial body-weight support after anterior cruciate ligament reconstruction: a randomized controlled trial.

    Science.gov (United States)

    Luo, Yuan; Shen, Weizhong; Jiang, Zhong; Sha, Jiao

    2016-12-01

    [Purpose] To compare the effects of treadmill training with partial body weight support (TTPBWS) and conventional physical therapy (PT) on subjects with anterior cruciate ligament reconstructions. [Subjects and Methods] A total of 40 subjects were randomly allocated to either a treatment group or a control group. Subjects received either treadmill training with partial body weight support (treatment group) or conventional physical therapy (control group). The circumferences of the lower extremities, Holden classifications, 10-meter walking times and the International Knee Documentation Committee (IKDC) scores were compared at 12 and 24 weeks post-operation. The knee joint stability was tested at 24 weeks post-operation using a KT-1000. [Results] Significant differences were found between the two groups at the 12 weeks post-operation. For most of the measures, there was no significant difference between the groups at 24 weeks post-operation. Interestingly, for most of the measures, there was no significant difference between their values in the treatment group at 12 weeks and their values in the control group at 24 weeks post-operation. [Conclusion] The function of a subject's lower extremities can be improved and the improvement was clearly accelerated by the intervention of treadmill training with partial body weight support, without compromising the stability of the knee joints in a given follow-up period.

  6. Treadmill training improves overground walking economy in Parkinson’s disease: A randomized, controlled pilot study

    Directory of Open Access Journals (Sweden)

    Miguel eFERNANDEZ-DEL-OLMO

    2014-09-01

    Full Text Available Gait disturbances are one of the principal and most incapacitating symptoms of Parkinson’s disease (PD. In addition, walking economy is impaired in PD patients and could contribute to excess fatigue in this population. An important number of studies have shown that treadmill training can improve kinematic parameters in PD patients. However, the effects of treadmill and overground walking on the walking economy remain unknown. The goal of this study was to explore the walking economy changes in response to a treadmill and an overground training program, as well as the differences in the walking economy during treadmill and overground walking. 22 mild PD patients were randomly assigned to a treadmill or overground training group. The training program consisted of 5 weeks (3 sessions/week. We evaluated the energy expenditure of overground walking, before and after each of the training programs. The energy expenditure of treadmill walking (before the program was also evaluated. The treadmill, but not the overground training program, lead to an improvement in the walking economy (the rate of oxygen consumed per distance, during overground walking at a preferred speed in PD patients. In addition, walking on a treadmill required more energy expenditure compared with overground walking at the same speed. This study provides evidence that in mild PD patients, treadmill training is more beneficial compared with that of walking overground, leading to a greater improvement in the walking economy. This finding is of clinical importance for the therapeutic administration of exercise in Parkinson’s disease.

  7. Rhythm perturbations in acoustically paced treadmill walking after stroke.

    Science.gov (United States)

    Roerdink, Melvyn; Lamoth, Claudine J C; van Kordelaar, Joost; Elich, Peter; Konijnenbelt, Manin; Kwakkel, Gert; Beek, Peter J

    2009-09-01

    In rehabilitation, acoustic rhythms are often used to improve gait after stroke. Acoustic cueing may enhance gait coordination by creating a stable coupling between heel strikes and metronome beats and provide a means to train the adaptability of gait coordination to environmental changes, as required in everyday life ambulation. To examine the stability and adaptability of auditory-motor synchronization in acoustically paced treadmill walking in stroke patients. Eleven stroke patients and 10 healthy controls walked on a treadmill at preferred speed and cadence under no metronome, single-metronome (pacing only paretic or nonparetic steps), and double-metronome (pacing both footfalls) conditions. The stability of auditory-motor synchronization was quantified by the variability of the phase relation between footfalls and beats. In a separate session, the acoustic rhythms were perturbed and adaptations to restore auditory-motor synchronization were quantified. For both groups, auditory-motor synchronization was more stable for double-metronome than single-metronome conditions, with stroke patients exhibiting an overall weaker coupling of footfalls to metronome beats than controls. The recovery characteristics following rhythm perturbations corroborated the stability findings and further revealed that stroke patients had difficulty in accelerating their steps and instead preferred a slower-step response to restore synchronization. In gait rehabilitation practice, the use of acoustic rhythms may be more effective when both footfalls are paced. In addition, rhythm perturbations during acoustically paced treadmill walking may not only be employed to evaluate the stability of auditory-motor synchronization but also have promising implications for evaluation and training of gait adaptations in neurorehabilitation practice.

  8. Treadmill training and body weight support for walking after stroke.

    Science.gov (United States)

    Mehrholz, Jan; Thomas, Simone; Elsner, Bernhard

    2017-08-17

    Treadmill training, with or without body weight support using a harness, is used in rehabilitation and might help to improve walking after stroke. This is an update of the Cochrane review first published in 2003 and updated in 2005 and 2014. To determine if treadmill training and body weight support, individually or in combination, improve walking ability, quality of life, activities of daily living, dependency or death, and institutionalisation or death, compared with other physiotherapy gait-training interventions after stroke. The secondary objective was to determine the safety and acceptability of this method of gait training. We searched the Cochrane Stroke Group Trials Register (last searched 14 February 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) and the Database of Reviews of Effects (DARE) (the Cochrane Library 2017, Issue 2), MEDLINE (1966 to 14 February 2017), Embase (1980 to 14 February 2017), CINAHL (1982 to 14 February 2017), AMED (1985 to 14 February 2017) and SPORTDiscus (1949 to 14 February 2017). We also handsearched relevant conference proceedings and ongoing trials and research registers, screened reference lists, and contacted trialists to identify further trials. Randomised or quasi-randomised controlled and cross-over trials of treadmill training and body weight support, individually or in combination, for the treatment of walking after stroke. Two review authors independently selected trials, extracted data, and assessed risk of bias and methodological quality. The primary outcomes investigated were walking speed, endurance, and dependency. We included 56 trials with 3105 participants in this updated review. The average age of the participants was 60 years, and the studies were carried out in both inpatient and outpatient settings. All participants had at least some walking difficulties and many could not walk without assistance. Overall, the use of treadmill training did not increase the chances of walking

  9. Cardiorespiratory Coordination in Repeated Maximal Exercise

    Directory of Open Access Journals (Sweden)

    Sergi Garcia-Retortillo

    2017-06-01

    Full Text Available Increases in cardiorespiratory coordination (CRC after training with no differences in performance and physiological variables have recently been reported using a principal component analysis approach. However, no research has yet evaluated the short-term effects of exercise on CRC. The aim of this study was to delineate the behavior of CRC under different physiological initial conditions produced by repeated maximal exercises. Fifteen participants performed 2 consecutive graded and maximal cycling tests. Test 1 was performed without any previous exercise, and Test 2 6 min after Test 1. Both tests started at 0 W and the workload was increased by 25 W/min in males and 20 W/min in females, until they were not able to maintain the prescribed cycling frequency of 70 rpm for more than 5 consecutive seconds. A principal component (PC analysis of selected cardiovascular and cardiorespiratory variables (expired fraction of O2, expired fraction of CO2, ventilation, systolic blood pressure, diastolic blood pressure, and heart rate was performed to evaluate the CRC defined by the number of PCs in both tests. In order to quantify the degree of coordination, the information entropy was calculated and the eigenvalues of the first PC (PC1 were compared between tests. Although no significant differences were found between the tests with respect to the performed maximal workload (Wmax, maximal oxygen consumption (VO2 max, or ventilatory threshold (VT, an increase in the number of PCs and/or a decrease of eigenvalues of PC1 (t = 2.95; p = 0.01; d = 1.08 was found in Test 2 compared to Test 1. Moreover, entropy was significantly higher (Z = 2.33; p = 0.02; d = 1.43 in the last test. In conclusion, despite the fact that no significant differences were observed in the conventionally explored maximal performance and physiological variables (Wmax, VO2 max, and VT between tests, a reduction of CRC was observed in Test 2. These results emphasize the interest of CRC

  10. Hemodynamic mechanisms of the attenuated blood pressure response to mental stress after a single bout of maximal dynamic exercise in healthy subjects

    Directory of Open Access Journals (Sweden)

    F.J. Neves

    2012-07-01

    Full Text Available To determine the hemodynamic mechanisms responsible for the attenuated blood pressure response to mental stress after exercise, 26 healthy sedentary individuals (age 29 ± 8 years underwent the Stroop color-word test before and 60 min after a bout of maximal dynamic exercise on a treadmill. A subgroup (N = 11 underwent a time-control experiment without exercise. Blood pressure was continuously and noninvasively recorded by infrared finger photoplethysmography. Stroke volume was derived from pressure signals, and cardiac output and peripheral vascular resistance were calculated. Perceived mental stress scores were comparable between mental stress tests both in the exercise (P = 0.96 and control (P = 0.24 experiments. After exercise, the blood pressure response to mental stress was attenuated (pre: 10 ± 13 vs post: 6 ± 7 mmHg; P 0.05. In conclusion, a single bout of maximal dynamic exercise attenuates the blood pressure response to mental stress in healthy subjects, along with lower stroke volume and cardiac output, denoting an acute modulatory action of exercise on the central hemodynamic response to mental stress.

  11. See hear: psychological effects of music and music-video during treadmill running.

    Science.gov (United States)

    Hutchinson, Jasmin C; Karageorghis, Costas I; Jones, Leighton

    2015-04-01

    There is a paucity of work addressing the distractive, affect-enhancing, and motivational influences of music and video in combination during exercise. We examined the effects of music and music-and-video on a range of psychological and psychophysical variables during treadmill running at intensities above and below ventilatory threshold (VT). Participants (N = 24) exercised at 10 % of maximal capacity below VT and 10 % above under music-only, music-and-video, and control conditions. There was a condition × intensity × time interaction for perceived activation and state motivation, and an intensity × time interaction for state attention, perceived exertion (RPE), and affective valence. The music-and-video condition elicited the highest levels of dissociation, lowest RPE, and most positive affective responses regardless of exercise intensity. Attentional manipulations influence psychological and psychophysical variables at exercise intensities above and below VT, and this effect is enhanced by the combined presentation of auditory and visual stimuli.

  12. Maximizing and customer loyalty: Are maximizers less loyal?

    Directory of Open Access Journals (Sweden)

    Linda Lai

    2011-06-01

    Full Text Available Despite their efforts to choose the best of all available solutions, maximizers seem to be more inclined than satisficers to regret their choices and to experience post-decisional dissonance. Maximizers may therefore be expected to change their decisions more frequently and hence exhibit lower customer loyalty to providers of products and services compared to satisficers. Findings from the study reported here (N = 1978 support this prediction. Maximizers reported significantly higher intentions to switch to another service provider (television provider than satisficers. Maximizers' intentions to switch appear to be intensified and mediated by higher proneness to regret, increased desire to discuss relevant choices with others, higher levels of perceived knowledge of alternatives, and higher ego involvement in the end product, compared to satisficers. Opportunities for future research are suggested.

  13. Implications of maximal Jarlskog invariant and maximal CP violation

    International Nuclear Information System (INIS)

    Rodriguez-Jauregui, E.; Universidad Nacional Autonoma de Mexico

    2001-04-01

    We argue here why CP violating phase Φ in the quark mixing matrix is maximal, that is, Φ=90 . In the Standard Model CP violation is related to the Jarlskog invariant J, which can be obtained from non commuting Hermitian mass matrices. In this article we derive the conditions to have Hermitian mass matrices which give maximal Jarlskog invariant J and maximal CP violating phase Φ. We find that all squared moduli of the quark mixing elements have a singular point when the CP violation phase Φ takes the value Φ=90 . This special feature of the Jarlskog invariant J and the quark mixing matrix is a clear and precise indication that CP violating Phase Φ is maximal in order to let nature treat democratically all of the quark mixing matrix moduli. (orig.)

  14. Age-Predicted Maximal Heart Rate in Recreational Marathon Runners: A Cross-Sectional Study on Fox's and Tanaka's Equations

    Science.gov (United States)

    Nikolaidis, Pantelis T.; Rosemann, Thomas; Knechtle, Beat

    2018-01-01

    Age-based prediction equations of maximal heart rate (HRmax), such as the popular formulas Fox's 220-age, or Tanaka's 208-0.7 × age, have been widely used in various populations. Surprisingly, so far these equations have not been validated in marathon runners, despite the importance of the role of HRmax for training purposes in endurance running. The aim of the present study was to examine the validity of Fox and Tanaka equations in a large sample of women and men recreational marathon runners. Participants (n = 180, age 43.2 ± 8.5 years, VO2max 46.8 mL/min/kg, finishers in at least one marathon during the last year) performed a graded exercise test on a treadmill, where HRmax was measured. Measured HRmax correlated largely with age in the total sample (r = −0.50, p marathon runners. In addition, exercise physiologists and sport scientists should consider the observed differences among various assessment methods when performing exercise testing or prescribing training program relying on HR. PMID:29599724

  15. Age-Predicted Maximal Heart Rate in Recreational Marathon Runners: A Cross-Sectional Study on Fox's and Tanaka's Equations.

    Science.gov (United States)

    Nikolaidis, Pantelis T; Rosemann, Thomas; Knechtle, Beat

    2018-01-01

    Age-based prediction equations of maximal heart rate (HR max ), such as the popular formulas Fox's 220-age, or Tanaka's 208-0.7 × age, have been widely used in various populations. Surprisingly, so far these equations have not been validated in marathon runners, despite the importance of the role of HR max for training purposes in endurance running. The aim of the present study was to examine the validity of Fox and Tanaka equations in a large sample of women and men recreational marathon runners. Participants ( n = 180, age 43.2 ± 8.5 years, VO 2max 46.8 mL/min/kg, finishers in at least one marathon during the last year) performed a graded exercise test on a treadmill, where HR max was measured. Measured HR max correlated largely with age in the total sample ( r = -0.50, p marathon runners. In addition, exercise physiologists and sport scientists should consider the observed differences among various assessment methods when performing exercise testing or prescribing training program relying on HR.

  16. Biomechanics of the Treadmill Locomotion on the International Space Station

    Science.gov (United States)

    DeWitt, John; Cromwell, R. L.; Ploutz-Snyder, L. L.

    2014-01-01

    Exercise prescriptions completed by International Space Station (ISS) crewmembers are typically based upon evidence obtained during ground-based investigations, with the assumption that the results of long-term training in weightlessness will be similar to that attained in normal gravity. Coupled with this supposition are the assumptions that exercise motions and external loading are also similar between gravitational environments. Normal control of locomotion is dependent upon learning patterns of muscular activation and requires continual monitoring of internal and external sensory input [1]. Internal sensory input includes signals that may be dependent on or independent of gravity. Bernstein hypothesized that movement strategy planning and execution must include the consideration of segmental weights and inertia [2]. Studies of arm movements in microgravity showed that individuals tend to make errors but that compensation strategies result in adaptations, suggesting that control mechanisms must include peripheral information [3-5]. To date, however, there have been no studies examining a gross motor activity such as running in weightlessness other than using microgravity analogs [6-8]. The objective of this evaluation was to collect biomechanical data from crewmembers during treadmill exercise before and during flight. The goal was to determine locomotive biomechanics similarities and differences between normal and weightless environments. The data will be used to optimize future exercise prescriptions. This project addresses the Critical Path Roadmap risks 1 (Accelerated Bone Loss and Fracture Risk) and 11 (Reduced Muscle Mass, Strength, and Endurance). Data were collected from 7 crewmembers before flight and during their ISS missions. Before launch, crewmembers performed a single data collection session at the NASA Johnson Space Center. Three-dimensional motion capture data were collected for 30 s at speeds ranging from 1.5 to 9.5 mph in 0.5 mph increments

  17. Phenomenology of maximal and near-maximal lepton mixing

    International Nuclear Information System (INIS)

    Gonzalez-Garcia, M. C.; Pena-Garay, Carlos; Nir, Yosef; Smirnov, Alexei Yu.

    2001-01-01

    The possible existence of maximal or near-maximal lepton mixing constitutes an intriguing challenge for fundamental theories of flavor. We study the phenomenological consequences of maximal and near-maximal mixing of the electron neutrino with other (x=tau and/or muon) neutrinos. We describe the deviations from maximal mixing in terms of a parameter ε(equivalent to)1-2sin 2 θ ex and quantify the present experimental status for |ε| e mixing comes from solar neutrino experiments. We find that the global analysis of solar neutrino data allows maximal mixing with confidence level better than 99% for 10 -8 eV 2 ∼ 2 ∼ -7 eV 2 . In the mass ranges Δm 2 ∼>1.5x10 -5 eV 2 and 4x10 -10 eV 2 ∼ 2 ∼ -7 eV 2 the full interval |ε| e mixing in atmospheric neutrinos, supernova neutrinos, and neutrinoless double beta decay

  18. Maximal quantum Fisher information matrix

    International Nuclear Information System (INIS)

    Chen, Yu; Yuan, Haidong

    2017-01-01

    We study the existence of the maximal quantum Fisher information matrix in the multi-parameter quantum estimation, which bounds the ultimate precision limit. We show that when the maximal quantum Fisher information matrix exists, it can be directly obtained from the underlying dynamics. Examples are then provided to demonstrate the usefulness of the maximal quantum Fisher information matrix by deriving various trade-off relations in multi-parameter quantum estimation and obtaining the bounds for the scalings of the precision limit. (paper)

  19. Partial Body Weight-Supported Treadmill Training in Spinocerebellar Ataxia.

    Science.gov (United States)

    de Oliveira, Laura Alice Santos; Martins, Camilla Polonini; Horsczaruk, Carlos Henrique Ramos; da Silva, Débora Cristina Lima; Vasconcellos, Luiz Felipe; Lopes, Agnaldo José; Meira Mainenti, Míriam Raquel; Rodrigues, Erika de Carvalho

    2018-01-01

    The motor impairments related to gait and balance have a huge impact on the life of individuals with spinocerebellar ataxia (SCA). Here, the aim was to assess the possibility of retraining gait, improving cardiopulmonary capacity, and challenging balance during gait in SCA using a partial body weight support (BWS) and a treadmill. Also, the effects of this training over functionality and quality of life were investigated. Eight SCA patients were engaged in the first stage of the study that focused on gait training and cardiovascular conditioning. From those, five took part in a second stage of the study centered on dynamic balance training during gait. The first and second stages lasted 8 and 10 weeks, respectively, both comprising sessions of 50 min (2 times per week). The results showed that gait training using partial BWS significantly increased gait performance, treadmill inclination, duration of exercise, and cardiopulmonary capacity in individuals with SCA. After the second stage, balance improvements were also found. Combining gait training and challenging tasks to the postural control system in SCA individuals is viable, well tolerated by patients with SCA, and resulted in changes in capacity for walking and balance.

  20. Skin sensitization potency and cross-reactivity of p-phenylenediamine and its derivatives evaluated by non-radioactive murine local lymph node assay and guinea-pig maximization test.

    Science.gov (United States)

    Yamano, Tetsuo; Shimizu, Mitsuru

    2009-04-01

    p-Phenylenediamine (PPD)-related chemicals have been used as antioxidants in rubber products, and many cases of contact dermatitis caused by these chemicals have been reported. The aim of this study was to investigate relative sensitizing potency and cross-reactivity among PPD derivatives. Five PPD derivatives, p-aminodiphenylamine (PADPA), N,N'-diphenyl-p-phenylenediamine (DPPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (DMBPPD), N-(1-methylheptyl)-N'-phenyl-p-phenylenediamine (MHPPD), and the core chemical PPD were evaluated for their sensitizing potency and cross-reactivity using the non-radioactive murine local lymph node assay (LLNA) and the guinea-pig maximization test (GPMT). PPD and all the derivatives were identified as primary sensitizers in both tests. The order of potency in the LLNA was as follows: IPPD and PADPA > PPD > DMBPPD and MHPPD > DPPD. In the GPMT, all six groups of animals sensitized with one of these chemicals cross-reacted to four other derivatives. Specifically, the five groups that have a common basic PADPA structure, that is PADPA, DPPD, IPPD, DMBPPD, and MHPPD, all reacted to each other at almost the same scores, while none of them reacted to PPD. The cross-reactivity profile found in the study was to some extent different from that in previous human data, where distinction between cross-reaction and concomitant primary sensitization is not always clear.

  1. Transcranial Direct Current Stimulation combined with treadmill training in the subacute phase following stroke: case series

    DEFF Research Database (Denmark)

    Figlewski, Krystian; Nielsen, Jørgen Feldbæk; Blicher, Jakob

    such as transcranial Direct Current Stimulation (tDCS). In neurophysiologic studies an imbalance of interhemispheric interactions has been demonstrated which is believed to interfere with the recovery process. This imbalance can be ameliorated by upregulation of the excitability in the lesioned hemisphere applying...... anodal tDCS. Aims: to evaluate the feasibility of anodal tDCS with body weight support treadmill training (BWSTT) in the subacute stroke patients. Methods Four subjects (Table 1.) participated in BWSTT coupled with anodal tDCS thrice per week for 4 weeks. Subjects were included within 14 days from stroke...... onset. Anodal tDCS was delivered to excite the cortical leg motor area using 35 cm2 saline soaked electrodes. During BWSTT a 2 mA current was applied for 20 minutes. Evaluations conducted at baseline and after the intervention included 10-meters walking test (10 MWT), isokinetic muscle strength of knee...

  2. Maximize x(a - x)

    Science.gov (United States)

    Lange, L. H.

    1974-01-01

    Five different methods for determining the maximizing condition for x(a - x) are presented. Included is the ancient Greek version and a method attributed to Fermat. None of the proofs use calculus. (LS)

  3. Finding Maximal Quasiperiodicities in Strings

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Pedersen, Christian N. S.

    2000-01-01

    of length n in time O(n log n) and space O(n). Our algorithm uses the suffix tree as the fundamental data structure combined with efficient methods for merging and performing multiple searches in search trees. Besides finding all maximal quasiperiodic substrings, our algorithm also marks the nodes......Apostolico and Ehrenfeucht defined the notion of a maximal quasiperiodic substring and gave an algorithm that finds all maximal quasiperiodic substrings in a string of length n in time O(n log2 n). In this paper we give an algorithm that finds all maximal quasiperiodic substrings in a string...... in the suffix tree that have a superprimitive path-label....

  4. On the maximal diphoton width

    CERN Document Server

    Salvio, Alberto; Strumia, Alessandro; Urbano, Alfredo

    2016-01-01

    Motivated by the 750 GeV diphoton excess found at LHC, we compute the maximal width into $\\gamma\\gamma$ that a neutral scalar can acquire through a loop of charged fermions or scalars as function of the maximal scale at which the theory holds, taking into account vacuum (meta)stability bounds. We show how an extra gauge symmetry can qualitatively weaken such bounds, and explore collider probes and connections with Dark Matter.

  5. Trp64Arg polymorphism of the ADRB3 gene associated with maximal fat oxidation and LDL-C levels in non-obese adolescents.

    Science.gov (United States)

    Jesus, Íncare Correa de; Alle, Lupe Furtado; Munhoz, Eva Cantalejo; Silva, Larissa Rosa da; Lopes, Wendell Arthur; Tureck, Luciane Viater; Purim, Katia Sheylla Malta; Titski, Ana Claudia Kapp; Leite, Neiva

    2017-09-21

    To analyze the association between the Trp64Arg polymorphism of the ADRB3 gene, maximal fat oxidation rates and the lipid profile levels in non-obese adolescents. 72 schoolchildren, of both genders, aged between 11 and 17 years, participated in the study. The anthropometric and body composition variables, in addition to total cholesterol, HDL-c, LDL-c, triglycerides, insulin, and basal glycemia, were evaluated. The sample was divided into two groups according to the presence or absence of the polymorphism: non-carriers of the Arg64 allele, i.e., homozygous (Trp64Trp: n=54), and carriers of the Arg64 allele (Trp64Arg+Arg64Arg: n=18), in which the frequency of the Arg64 allele was 15.2%. The maximal oxygen uptake and peak of oxygen uptake during exercise were obtained through the symptom-limited, submaximal treadmill test. Maximal fat oxidation was determined according to the ventilatory ratio proposed in Lusk's table. Adolescents carrying the less frequent allele (Trp64Arg and Arg64Arg) had higher LDL-c levels (p=0.031) and lower maximal fat oxidation rates (p=0.038) when compared with non-carriers (Trp64Trp). Although the physiological processes related to lipolysis and lipid metabolism are complex, the presence of the Arg 64 allele was associated with lower rates of FATMAX during aerobic exercise, as well as with higher levels of LDL-c in adolescents. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  6. Increasing physical activity in office workers ? the Inphact Treadmill study; a study protocol for a 13-month randomized controlled trial of treadmill workstations

    OpenAIRE

    Bergman, Frida; Boraxbekk, Carl-Johan; Wennberg, Patrik; S?rlin, Ann; Olsson, Tommy

    2015-01-01

    Background Sedentary behaviour is an independent risk factor for mortality and morbidity, especially for type 2 diabetes. Since office work is related to long periods that are largely sedentary, it is of major importance to find ways for office workers to engage in light intensity physical activity (LPA). The Inphact Treadmill study aims to investigate the effects of installing treadmill workstations in offices compared to conventional workstations. Methods/Design A two-arm, 13-month, randomi...

  7. Compliance of Children with Moderate to Severe Intellectual Disability to Treadmill Walking: A Pilot Study

    Science.gov (United States)

    Vashdi, E.; Hutzler, Y.; Roth, D.

    2008-01-01

    Background: Individuals with Intellectual Disability (ID) exhibit reduced levels of compliance to exercise, including treadmill walking. The purpose of this study was to measure the effects of several training conditions on compliance to participation in treadmill walking of children with moderate to severe ID. Method: Criteria for compliance were…

  8. Comparison between treadmill training with rhythmic auditory stimulation and ground walking with rhythmic auditory stimulation on gait ability in chronic stroke patients: A pilot study.

    Science.gov (United States)

    Park, Jin; Park, So-yeon; Kim, Yong-wook; Woo, Youngkeun

    2015-01-01

    Generally, treadmill training is very effective intervention, and rhythmic auditory stimulation is designed to feedback during gait training in stroke patients. The purpose of this study was to compare the gait abilities in chronic stroke patients following either treadmill walking training with rhythmic auditory stimulation (TRAS) or over ground walking training with rhythmic auditory stimulation (ORAS). Nineteen subjects were divided into two groups: a TRAS group (9 subjects) and an ORAS group (10 subjects). Temporal and spatial gait parameters and motor recovery ability were measured before and after the training period. Gait ability was measured by the Biodex Gait trainer treadmill system, Timed up and go test (TUG), 6 meter walking distance (6MWD) and Functional gait assessment (FGA). After the training periods, the TRAS group showed a significant improvement in walking speed, step cycle, step length of the unaffected limb, coefficient of variation, 6MWD, and, FGA when compared to the ORAS group (p <  0.05). Treadmill walking training during the rhythmic auditory stimulation may be useful for rehabilitation of patients with chronic stroke.

  9. A user-driven treadmill control scheme for simulating overground locomotion.

    Science.gov (United States)

    Kim, Jonghyun; Stanley, Christopher J; Curatalo, Lindsey A; Park, Hyung-Soon

    2012-01-01

    Treadmill-based locomotor training should simulate overground walking as closely as possible for optimal skill transfer. The constant speed of a standard treadmill encourages automaticity rather than engagement and fails to simulate the variable speeds encountered during real-world walking. To address this limitation, this paper proposes a user-driven treadmill velocity control scheme that allows the user to experience natural fluctuations in walking velocity with minimal unwanted inertial force due to acceleration/deceleration of the treadmill belt. A smart estimation limiter in the scheme effectively attenuates the inertial force during velocity changes. The proposed scheme requires measurement of pelvic and swing foot motions, and is developed for a treadmill of typical belt length (1.5 m). The proposed scheme is quantitatively evaluated here with four healthy subjects by comparing it with the most advanced control scheme identified in the literature.

  10. Treadmill workstations: the effects of walking while working on physical activity and work performance.

    Science.gov (United States)

    Ben-Ner, Avner; Hamann, Darla J; Koepp, Gabriel; Manohar, Chimnay U; Levine, James

    2014-01-01

    We conducted a 12-month-long experiment in a financial services company to study how the availability of treadmill workstations affects employees' physical activity and work performance. We enlisted sedentary volunteers, half of whom received treadmill workstations during the first two months of the study and the rest in the seventh month of the study. Participants could operate the treadmills at speeds of 0-2 mph and could use a standard chair-desk arrangement at will. (a) Weekly online performance surveys were administered to participants and their supervisors, as well as to all other sedentary employees and their supervisors. Using within-person statistical analyses, we find that overall work performance, quality and quantity of performance, and interactions with coworkers improved as a result of adoption of treadmill workstations. (b) Participants were outfitted with accelerometers at the start of the study. We find that daily total physical activity increased as a result of the adoption of treadmill workstations.

  11. Assessing gait adaptability in people with a unilateral amputation on an instrumented treadmill with a projected visual context.

    Science.gov (United States)

    Houdijk, Han; van Ooijen, Mariëlle W; Kraal, Jos J; Wiggerts, Henri O; Polomski, Wojtek; Janssen, Thomas W J; Roerdink, Melvyn

    2012-11-01

    Gait adaptability, including the ability to avoid obstacles and to take visually guided steps, is essential for safe movement through a cluttered world. This aspect of walking ability is important for regaining independent mobility but is difficult to assess in clinical practice. The objective of this study was to investigate the validity of an instrumented treadmill with obstacles and stepping targets projected on the belt's surface for assessing prosthetic gait adaptability. This was an observational study. A control group of people who were able bodied (n=12) and groups of people with transtibial (n=12) and transfemoral (n=12) amputations participated. Participants walked at a self-selected speed on an instrumented treadmill with projected visual obstacles and stepping targets. Gait adaptability was evaluated in terms of anticipatory and reactive obstacle avoidance performance (for obstacles presented 4 steps and 1 step ahead, respectively) and accuracy of stepping on regular and irregular patterns of stepping targets. In addition, several clinical tests were administered, including timed walking tests and reports of incidence of falls and fear of falling. Obstacle avoidance performance and stepping accuracy were significantly lower in the groups with amputations than in the control group. Anticipatory obstacle avoidance performance was moderately correlated with timed walking test scores. Reactive obstacle avoidance performance and stepping accuracy performance were not related to timed walking tests. Gait adaptability scores did not differ in groups stratified by incidence of falls or fear of falling. Because gait adaptability was affected by walking speed, differences in self-selected walking speed may have diminished differences in gait adaptability between groups. Gait adaptability can be validly assessed by use of an instrumented treadmill with a projected visual context. When walking speed is taken into account, this assessment provides unique

  12. Effect of body-weight suspension training versus treadmill training on gross motor abilities of children with spastic diplegic cerebral palsy.

    Science.gov (United States)

    Emara, Hatem A; El-Gohary, Tarek M; Al-Johany, Ahmed A

    2016-06-01

    Suspension training and treadmill training are commonly used for promoting functional gross motor skills in children with cerebral palsy. The aim of this study was to compare the effect of body-weight suspension training versus treadmill training on gross motor functional skills. Assessor-blinded, randomized, controlled intervention study. Outpatient rehabilitation facility. Twenty children with spastic diplegia (7 boys and 13 girls) in the age ranged from 6 to 8 years old were randomly allocated into two equal groups. All children were assessed at baseline, after 18-session and after 36-session. During the twelve-week outpatient rehabilitation program, both groups received traditional therapeutic exercises. Additionally, one group received locomotor training using the treadmill while the other group received locomotor training using body-weight suspension through the dynamic spider cage. Assessment included dimensions "D" standing and "E" walking of the gross motor function measure, in addition to the 10-m Walking Test and the five times sit to stand test. Training was applied three times per week for twelve consecutive weeks. No significant difference was found in standing or walking ability for measurements taken at baseline or after 18-session of therapy. Measurements taken at 36-session showed that suspension training achieved significantly (Ptraining for dimension D as well as for dimension E. No significant difference was found between suspension training and treadmill training regarding walking speed or sit to stand transitional skills. Body-weight suspension training is effective in improving walking and locomotor capabilities in children with spastic diplegia. After three month suspension training was superior to treadmill training. Body-weight suspension training promotes adequate postural stability, good balance control, and less exertion which facilitates efficient and safe gait.

  13. Utilidad de los puntajes clínicos para mejorar la predicción de enfermedad coronaria significativa después de una prueba de esfuerzo convencional Usefulness of clinical scores to improve prediction of significant coronary heart disease after conventional treadmill exercise testing

    Directory of Open Access Journals (Sweden)

    Fernando A Guerrero

    2008-10-01

    mejoren aún más dicho desempeño.Background: in the last AHA/ACC expert consensus document, clinical scores to improve sensitivity (68% and specificity (77% of the exercise testing, diagnostic method considered a first line diagnostic method for coronary heart disease treatment (one of the main causes of mortality in Colombia and worldwide, are recommended. Nevertheless, few institutions in our country use them and they are difficult to apply in populations different to the ones for which they were developed. For this reason, a study to assess its performance in our environment, is needed. Materials and Methods: Morise and Duke treadmill scores were chosen to assess the reason for its validation in several populations, and were mentioned in the AHA/ACC consensus. The Morise and Duke scores classified patients in at low, middle and high risk for coronary heart disease. Primary objectives: validate the prediction scales for coronary heart disease and determine the best cutoff value for each score in a one year follow-up. Secondary objectives: determine the composite endpoint for acute myocardial infarction, cardiac death, angina requiring hospitalization, coronary obstruction >50% and/or angioplasty and stent implantation. Determine the best cutoff point through the ROC curves. Inclusion Criteria: patients >18 years old with suspected coronary heart disease. Exclusion Criteria: pregnant women with documented coronary heart disease, uninterpretable EKG, incapacity or contraindication for performing exercise stress test for any reason, ST depression 27,5: 18% (45 and diabetes mellitus: 16% (19. Morise score classified 36% (43 patients at low risk, 52% (61 at intermediate risk and 12% (14 at high risk. According to Duke the results were 53% (63, 41% (48 and 6% (7 respectively. When interpreting an isolated exercise testing, cardiologists classified patients: 81% (95 negative, 8% (10 suggestive and 11% (14 positive. The composite endpoint appeared in 11% (14 patients. When

  14. [Kinetics of heifers and cows walking on an instrumented treadmill].

    Science.gov (United States)

    Nuss, K; Waldern, N M; Weishaupt, M A; Wiestner, T

    2015-01-01

    Kinetic data of stride characteristics and ground reaction forces of cattle become increasingly important as automated lameness detection may be installed in dairy cow housing systems in the future. Therefore, sound heifers and cows were measured on an instrumented treadmill to collect such basic data. Nine heifers and 10 cows were trained to walk on an instrumented treadmill. Vertical ground reaction forces as well as step and stride timing and length variables were measured for all limbs simultaneously. On average, 16 stride cycles in cows and 24 strides in heifers were analysed in each case. The cows walked on the treadmill at an average speed of 1.2 ± 0.05 m/s (mean ± standard deviation), with a stride rate of 43.0 ± 1.9/min and a stride length of 1.68 ± 0.1 m. The heifers had average values of 1.3 ± 0.04 m/s, 53.7 ± 2.2/min and 1.49 ± 0.05 m, respectively. The stance duration relative to stride duration (the duty factor) was for the cows significantly longer in the forelimbs (67%) than in the hind limbs (64%). Force-time-curves of all limbs showed two peaks, one after landing (FP1) and another during push off (FP2). Vertical ground reaction force was highest for FP1 in the hind limbs, but for FP2 in the forelimbs. At all limbs, force minimum between the peaks occurred shortly before midstance. The vertical impulse carried by both forelimbs amounted to 53.7% of the total stride impulse in cows and to 55.0% in heifers. The location of the centre of body mass varied during the stride cycle but was always located more towards the front limbs. Cows and heifers showed a symmetrical walk with minimal intra-individual variations. Relative stride impulse of the front limbs was higher than that of the hind limbs. Peak vertical force in the hind limbs was highest at landing and in the forelimbs at push off. The present study offers kinetic data of sound cows and heifers which might be helpful as guidelines for automated systems for lameness detection in cattle.

  15. Quantitative comparison of the results obtained by the multiple-dose guinea pig maximization test and the non-radioactive murine local lymph-node assay for various biocides.

    Science.gov (United States)

    Yamano, Tetsuo; Shimizu, Mitsuru; Noda, Tsutomu

    2005-07-01

    We compared the results of the multiple-dose guinea pig maximization test (GPMT) and the non-radioactive murine local lymph-node assay (LLNA) for various biocides. Thirteen out of 17 positive biocides in the GPMT gave positive results in the LLNA. In the GPMT, the minimum first induction doses ranged over four orders (0.00005-0.5%), while elicitation-threshold doses, which were evaluated using an optimally sensitized group of animals in the multiple-dose studies, ranged over five orders (0.00006-2.8%). In the LLNA, minimum induction doses ranged over more than three orders (0.01-30%). With respect to 13 biocides that were positive in both the GPMT and the LLNA, results were quantitatively compared. When compared after conversion to corresponding area doses (microg/cm), the minimum doses required to elicit skin reaction in guinea pigs were always lower than that for induction in mice with all biocides. Correlation between minimum induction doses from the GPMT and the LLNA seemed poor (r=0.57), while that between minimum induction doses in the LLNA and elicitation-threshold doses in the GPMT was relatively good (r=0.73). The results suggest the possibility to estimate human elicitation-threshold doses, which are definitely lacking in the process of risk assessment for skin-sensitizers, from the data of the LLNA.

  16. Quantitative comparison of the results obtained by the multiple-dose guinea pig maximization test and the non-radioactive murine local lymph-node assay for various biocides

    International Nuclear Information System (INIS)

    Yamano, Tetsuo; Shimizu, Mitsuru; Noda, Tsutomu

    2005-01-01

    We compared the results of the multiple-dose guinea pig maximization test (GPMT) and the non-radioactive murine local lymph-node assay (LLNA) for various biocides. Thirteen out of 17 positive biocides in the GPMT gave positive results in the LLNA. In the GPMT, the minimum first induction doses ranged over four orders (0.00005-0.5%), while elicitation-threshold doses, which were evaluated using an optimally sensitized group of animals in the multiple-dose studies, ranged over five orders (0.00006-2.8%). In the LLNA, minimum induction doses ranged over more than three orders (0.01-30%). With respect to 13 biocides that were positive in both the GPMT and the LLNA, results were quantitatively compared. When compared after conversion to corresponding area doses (μg/cm), the minimum doses required to elicit skin reaction in guinea pigs were always lower than that for induction in mice with all biocides. Correlation between minimum induction doses from the GPMT and the LLNA seemed poor (r = 0.57), while that between minimum induction doses in the LLNA and elicitation-threshold doses in the GPMT was relatively good (r = 0.73). The results suggest the possibility to estimate human elicitation-threshold doses, which are definitely lacking in the process of risk assessment for skin-sensitizers, from the data of the LLNA

  17. Prognostic value of exercise echocardiography: validation of a new risk index combining echocardiographic, treadmill, and exercise electrocardiographic parameters.

    Science.gov (United States)

    Mazur, Wojciech; Rivera, Jose M; Khoury, Alexander F; Basu, Abhijeet G; Perez-Verdia, Alejandro; Marks, Gary F; Chang, Su Min; Olmos, Leopoldo; Quiñones, Miguel A; Zoghbi, William A

    2003-04-01

    Exercise (Ex) echocardiography has been shown to have significant prognostic power, independent of other known predictors of risk from an Ex stress test. The purpose of this study was to evaluate a risk index, incorporating echocardiographic and conventional Ex variables, for a more comprehensive risk stratification and identification of a very low-risk group. Two consecutive, mutually exclusive populations referred for treadmill Ex echocardiography with the Bruce protocol were investigated: hypothesis-generating (388 patients; 268 males; age 55 +/- 13 years) and hypothesis-testing (105 patients; 61 males age: 54 +/- 14 years).Cardiac events included cardiac death, myocardial infarction, late revascularization (>90 days), hospital admission for unstable angina, and admission for heart failure. Mean follow-up in the hypothesis-generating population was 3.1 years. There were 38 cardiac events. Independent predictors of events by multivariate analysis were: Ex wall motion score index (odds ratio [OR] = 2.77/Unit; P or = 1 mm (OR = 2.84; P =.002); and treadmill time (OR = 0.87/min; P =.037). A risk index was generated on the basis of the multivariate Cox regression model as: risk index = 1.02 (Ex wall motion score index) + 1.04 (S-T change) - 0.14 (treadmill time). The validity of this index was tested in the hypothesis-testing population. Event rates at 3 years were lowest (0%) in the lower quartile of risk index (-1.22 to -0.47), highest (29.6%) in the upper quartile (+0.66 to +2.02), and intermediate (19.2% to 15.3%) in the intermediate quartiles. The OR of the risk index for predicting cardiac events was 2.94/Unit ([95% confidence interval: 1.4 to 6.2]; P =.0043). Echocardiographic and Ex parameters are independent powerful predictors of cardiac events after treadmill stress testing. A risk index can be derived with these parameters for a more comprehensive risk stratification with Ex echocardiography.

  18. Maximization

    Directory of Open Access Journals (Sweden)

    A. Garmroodi Asil

    2017-09-01

    To further reduce the sulfur dioxide emission of the entire refining process, two scenarios of acid gas or air preheats are investigated when either of them is used simultaneously with the third enrichment scheme. The maximum overall sulfur recovery efficiency and highest combustion chamber temperature is slightly higher for acid gas preheats but air preheat is more favorable because it is more benign. To the best of our knowledge, optimization of the entire GTU + enrichment section and SRU processes has not been addressed previously.

  19. Simultaneous low level treadmill exercise and intravenous dipyridamole stress thallium imaging

    International Nuclear Information System (INIS)

    Casale, P.N.; Guiney, T.E.; Strauss, H.W.; Boucher, C.A.

    1988-01-01

    Intravenous dipyridamole-thallium imaging unmasks ischemia in patients unable to exercise adequately. However, some of these patients can perform limited exercise, which, if added, may provide useful information. Treadmill exercise combined with dipyridamole-thallium imaging was performed in 100 patients and results compared with those of 100 other blindly age- and sex-matched patients who received dipyridamole alone. Exercise began after completion of the dipyridamole infusion. Mean +/- 1 standard deviation peak heart rate (109 +/- 19 vs 83 +/- 12 beats/min, p less than 0.0001) and peak systolic and diastolic blood pressure (146 +/- 28/77 +/- 14 vs 125 +/- 24/68 +/- 11 mm Hg, p less than 0.0001) were higher in the exercise group compared with the nonexercise group. There was no difference in the occurrence of chest pain, but more patients in the exercise group developed ST-segment depression (26 vs 12%, p less than 0.0001). The exercise group had fewer noncardiac side effects (4 vs 12%, p less than 0.01) and a higher target (heart) to background (liver) count ratio (2.1 +/- 0.7 vs 1.2 +/- 0.3; p less than 0.01), due to fewer liver counts. There were no deaths, myocardial infarctions or sustained arrhythmias in either group. Combined treadmill exercise and dipyridamole testing is safe, associated with fewer noncardiac side effects, a higher target to background ratio and a higher incidence of clinical electrocardiographic ischemia than dipyridamole alone. Therefore, it is recommended whenever possible

  20. Treadmill walking with load carriage increases aortic pressure wave reflection.

    Science.gov (United States)

    Ribeiro, Fernando; Oliveira, Nórton L; Pires, Joana; Alves, Alberto J; Oliveira, José

    2014-01-01

    The study examined the effects of treadmill walking with load carriage on derived measures of central pressure and augmentation index in young healthy subjects. Fourteen male subjects (age 31.0 ± 1.0 years) volunteered in this study. Subjects walked 10 minutes on a treadmill at a speed of 5 km/h carrying no load during one session and a load of 10% of their body weight on both upper limbs in two water carboys with handle during the other session. Pulse wave analysis was performed at rest and immediately after exercise in the radial artery of the right upper limb by applanation tonometry. The main result indicates that walking with load carriage sharply increased augmentation index at 75 bpm (-5.5 ± 2.2 to -1.4 ± 2.2% vs. -5.2 ± 2.8 to -5.5 ± 2.1%, p<0.05), and also induced twice as high increments in central pulse pressure (7.4 ± 1.5 vs. 3.1 ± 1.4 mmHg, p<0.05) and peripheral (20.5 ± 2.7 vs. 10.3 ± 2.5 mmHg, p<0.05) and central systolic pressure (14.7 ± 2.1 vs. 7.4 ± 2.0 mmHg, p<0.05). Walking with additional load of 10% of their body weight (aerobic exercise accompanied by upper limb isometric contraction) increases derived measures of central pressure and augmentation index, an index of wave reflection and arterial stiffness. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  1. Acute Exercise and Oxidative Stress: CrossFit™ vs. Treadmill Bout

    Science.gov (United States)

    Kliszczewicz, Brian; Quindry, C. John; Blessing, L. Daniel; Oliver, D. Gretchen; Esco, R. Michael; Taylor, J. Kyle

    2015-01-01

    CrossFit™, a popular high-intensity training modality, has been the subject of scrutiny, with concerns of elevated risk of injury and health. Despite these concerns empirical evidence regarding physiologic stresses including acute oxidative stress is lacking. Therefore, the purpose of this investigation was to examine the acute redox response to a CrossFit™ bout. Furthermore, these findings were compared to a high-intensity treadmill bout as a point of reference. Ten males 26.4 ± 2.7 yrs having three or more months of CrossFit™ experience participated in the present study. Blood plasma was collected at four time points: Pre-exercise (PRE), immediately-post-exercise (IPE), 1 hr-post (1-HP) and 2 hr-post (2-HP), to examine oxidative damage and antioxidant capacity. Regarding plasma oxidative damage, CrossFit™ and Treadmill elicited a time-dependent increase of lipid peroxides 1-HP (CrossFit™=+143%, Treadmill=+115%) and 2-HP (CrossFit™=+256%, Treadmill+167%). Protein Carbonyls were increased IPE in CF only (+5%), while a time-dependent decrease occurred 1-HP (CrossFit™=−16%, Treadmill=−8%) and 2-HP (CF=−16%, TM=−1%) compared to IPE. Regarding antioxidant capacity, Ferric Reducing Antioxidant Power also demonstrated a time-dependent increase within CrossFit™ and Treadmill: IPE (CrossFit™=+25%, Treadmill=+17%), 1-HP (CrossFit™=+26%, Treadmill=+4.8%), 2-HP (CrossFit™=+20%, Treadmill=+12%). Total Enzymatic Antioxidant Capacity showed a time-dependent decrease in IPE (CrossFit™=−10%, Treadmill=−12%), 1-HP (CrossFit™=−12%, Treadmill=−6%), 2-HP (CrossFit™=−7%, Treadmill=−11%). No trial-dependent differences were observed in any biomarker of oxidative stress. The CrossFit™ bout elicited an acute blood oxidative stress response comparable to a traditional bout of high-intensity treadmill running. Results also confirm that exercise intensity and the time course of exercise recovery influence oxidative responses. PMID:26557192

  2. Acute Exercise and Oxidative Stress: CrossFit(™) vs. Treadmill Bout.

    Science.gov (United States)

    Kliszczewicz, Brian; Quindry, C John; Blessing, L Daniel; Oliver, D Gretchen; Esco, R Michael; Taylor, J Kyle

    2015-09-29

    CrossFit(™), a popular high-intensity training modality, has been the subject of scrutiny, with concerns of elevated risk of injury and health. Despite these concerns empirical evidence regarding physiologic stresses including acute oxidative stress is lacking. Therefore, the purpose of this investigation was to examine the acute redox response to a CrossFit(™) bout. Furthermore, these findings were compared to a high-intensity treadmill bout as a point of reference. Ten males 26.4 ± 2.7 yrs having three or more months of CrossFit(™) experience participated in the present study. Blood plasma was collected at four time points: Pre-exercise (PRE), immediately-post-exercise (IPE), 1 hr-post (1-HP) and 2 hr-post (2-HP), to examine oxidative damage and antioxidant capacity. Regarding plasma oxidative damage, CrossFit(™) and Treadmill elicited a time-dependent increase of lipid peroxides 1-HP (CrossFit(™)=+143%, Treadmill=+115%) and 2-HP (CrossFit(™)=+256%, Treadmill+167%). Protein Carbonyls were increased IPE in CF only (+5%), while a time-dependent decrease occurred 1-HP (CrossFit(™)=-16%, Treadmill=-8%) and 2-HP (CF=-16%, TM=-1%) compared to IPE. Regarding antioxidant capacity, Ferric Reducing Antioxidant Power also demonstrated a time-dependent increase within CrossFit(™) and Treadmill: IPE (CrossFit(™)=+25%, Treadmill=+17%), 1-HP (CrossFit(™)=+26%, Treadmill=+4.8%), 2-HP (CrossFit(™)=+20%, Treadmill=+12%). Total Enzymatic Antioxidant Capacity showed a time-dependent decrease in IPE (CrossFit(™)=-10%, Treadmill=-12%), 1-HP (CrossFit(™)=-12%, Treadmill=-6%), 2-HP (CrossFit(™)=-7%, Treadmill=-11%). No trial-dependent differences were observed in any biomarker of oxidative stress. The CrossFit(™) bout elicited an acute blood oxidative stress response comparable to a traditional bout of high-intensity treadmill running. Results also confirm that exercise intensity and the time course of exercise recovery influence oxidative responses.

  3. Acute Exercise and Oxidative Stress: CrossFit™ vs. Treadmill Bout

    Directory of Open Access Journals (Sweden)

    Kliszczewicz Brian

    2015-09-01

    Full Text Available CrossFit™, a popular high-intensity training modality, has been the subject of scrutiny, with concerns of elevated risk of injury and health. Despite these concerns empirical evidence regarding physiologic stresses including acute oxidative stress is lacking. Therefore, the purpose of this investigation was to examine the acute redox response to a CrossFit™ bout. Furthermore, these findings were compared to a high-intensity treadmill bout as a point of reference. Ten males 26.4 ± 2.7 yrs having three or more months of CrossFit™ experience participated in the present study. Blood plasma was collected at four time points: Pre-exercise (PRE, immediately-post-exercise (IPE, 1 hr-post (1-HP and 2 hr-post (2-HP, to examine oxidative damage and antioxidant capacity. Regarding plasma oxidative damage, CrossFit™ and Treadmill elicited a time-dependent increase of lipid peroxides 1-HP (CrossFit™=+143%,Treadmill=+115% and 2-HP (CrossFit™=+256%,Treadmill+167%. Protein Carbonyls were increased IPE in CF only (+5%, while a time-dependent decrease occurred 1-HP (CrossFit™=−16%,Treadmill=−8% and 2-HP (CF=−16%,TM=−1% compared to IPE. Regarding antioxidant capacity, Ferric Reducing Antioxidant Power also demonstrated a time-dependent increase within CrossFit™ and Treadmill: IPE (CrossFit™=+25%,Treadmill=+17%, 1-HP (CrossFit™=+26%,Treadmill=+4.8%, 2-HP (CrossFit™=+20%,Treadmill=+12%. Total Enzymatic Antioxidant Capacity showed a time-dependent decrease in IPE (CrossFit™= −10%,Treadmill=−12%, 1-HP (CrossFit™= −12%,Treadmill=−6%, 2-HP (CrossFit™= −7%,Treadmill=−11%. No trial-dependent differences were observed in any biomarker of oxidative stress. The CrossFit™ bout elicited an acute blood oxidative stress response comparable to a traditional bout of high-intensity treadmill running. Results also confirm that exercise intensity and the time course of exercise recovery influence oxidative responses.

  4. Effects of a high-intensity interval training program versus a moderate-intensity continuous training program on maximal oxygen uptake and blood pressure in healthy adults: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Arboleda Serna, Víctor Hugo; Arango Vélez, Elkin Fernando; Gómez Arias, Rubén Darío; Feito, Yuri

    2016-08-18

    Participation in aerobic exercise generates increased cardiorespiratory fitness, which results in a protective factor for cardiovascular disease and all-cause mortality. High-intensity interval training might cause higher increases in cardiorespiratory fitness in comparison with moderate-intensity continuous training; nevertheless, current evidence is not conclusive. To our knowledge, this is the first study to test the effect of high-intensity interval training with total load duration of 7.5 min per session. A randomized controlled trial will be performed on two groups of healthy, sedentary male volunteers (n = 44). The study protocol will include 24 exercise sessions, three times a week, including aerobic training on a treadmill and strength training exercises. The intervention group will perform 15 bouts of 30 s, each at an intensity between 90 % and 95 % of maximal heart rate. The control group will complete 40 min of continuous exercise, ranging between 65 % and 75 % of maximal heart rate. The primary outcome measure to be evaluated will be maximal oxygen uptake (VO2max), and systolic and diastolic blood pressure will be evaluated as secondary outcome measures. Waist circumference, body mass index, and body composition will also be evaluated. Epidemiological evidence shows the link between VO2max and its association with chronic conditions that trigger CVD. Therefore, finding ways to improve VO2max and reduce blood pressure it is of vital importance to public health. NCT02288403 . Registered on 4 November 2014.

  5. Maximizing Entropy over Markov Processes

    DEFF Research Database (Denmark)

    Biondi, Fabrizio; Legay, Axel; Nielsen, Bo Friis

    2013-01-01

    The channel capacity of a deterministic system with confidential data is an upper bound on the amount of bits of data an attacker can learn from the system. We encode all possible attacks to a system using a probabilistic specification, an Interval Markov Chain. Then the channel capacity...... as a reward function, a polynomial algorithm to verify the existence of an system maximizing entropy among those respecting a specification, a procedure for the maximization of reward functions over Interval Markov Chains and its application to synthesize an implementation maximizing entropy. We show how...... to use Interval Markov Chains to model abstractions of deterministic systems with confidential data, and use the above results to compute their channel capacity. These results are a foundation for ongoing work on computing channel capacity for abstractions of programs derived from code....

  6. Maximizing entropy over Markov processes

    DEFF Research Database (Denmark)

    Biondi, Fabrizio; Legay, Axel; Nielsen, Bo Friis

    2014-01-01

    The channel capacity of a deterministic system with confidential data is an upper bound on the amount of bits of data an attacker can learn from the system. We encode all possible attacks to a system using a probabilistic specification, an Interval Markov Chain. Then the channel capacity...... as a reward function, a polynomial algorithm to verify the existence of a system maximizing entropy among those respecting a specification, a procedure for the maximization of reward functions over Interval Markov Chains and its application to synthesize an implementation maximizing entropy. We show how...... to use Interval Markov Chains to model abstractions of deterministic systems with confidential data, and use the above results to compute their channel capacity. These results are a foundation for ongoing work on computing channel capacity for abstractions of programs derived from code. © 2014 Elsevier...

  7. Reliability of maximal isometric knee strength testing with modified hand-held dynamometry in patients awaiting total knee arthroplasty: useful in research and individual patient settings? A reliability study

    Directory of Open Access Journals (Sweden)

    Koblbauer Ian FH

    2011-10-01

    Full Text Available Abstract Background Patients undergoing total knee arthroplasty (TKA often experience strength deficits both pre- and post-operatively. As these deficits may have a direct impact on functional recovery, strength assessment should be performed in this patient population. For these assessments, reliable measurements should be used. This study aimed to determine the inter- and intrarater reliability of hand-held dynamometry (HHD in measuring isometric knee strength in patients awaiting TKA. Methods To determine interrater reliability, 32 patients (81.3% female were assessed by two examiners. Patients were assessed consecutively by both examiners on the same individual test dates. To determine intrarater reliability, a subgroup (n = 13 was again assessed by the examiners within four weeks of the initial testing procedure. Maximal isometric knee flexor and extensor strength were tested using a modified Citec hand-held dynamometer. Both the affected and unaffected knee were tested. Reliability was assessed using the Intraclass Correlation Coefficient (ICC. In addition, the Standard Error of Measurement (SEM and the Smallest Detectable Difference (SDD were used to determine reliability. Results In both the affected and unaffected knee, the inter- and intrarater reliability were good for knee flexors (ICC range 0.76-0.94 and excellent for knee extensors (ICC range 0.92-0.97. However, measurement error was high, displaying SDD ranges between 21.7% and 36.2% for interrater reliability and between 19.0% and 57.5% for intrarater reliability. Overall, measurement error was higher for the knee flexors than for the knee extensors. Conclusions Modified HHD appears to be a reliable strength measure, producing good to excellent ICC values for both inter- and intrarater reliability in a group of TKA patients. High SEM and SDD values, however, indicate high measurement error for individual measures. This study demonstrates that a modified HHD is appropriate to

  8. Effects of exercise-induced fatigue on postural balance: a comparison of treadmill versus cycle fatiguing protocols.

    Science.gov (United States)

    Wright, Katherine E; Lyons, Thomas S; Navalta, James W

    2013-05-01

    The authors of this study examined the effects of muscle fatigue on balance indices and recovery time in recreationally trained individuals after incremental tests on a treadmill and a cycle ergometer. Sixteen participants (male N = 11, female N = 5) (mean age = 21.2 ± 2 years) completed this study. Balance measures were performed on a Biodex Balance System via the Dynamic Balance Test. Balance was measured pre-exercise, immediately post-exercise, and at 3-, 6-, 9-, 12-, 15-, 18-, and 21-min post-exercise. Immediately following the fatiguing treadmill test, balance increased significantly in the overall stability index (SI) (from 4.38 ± 2.48 to 6.09 ± 1.80) and the anterior/posterior index (API) (from 3.49 ± 2.18 to 5.28 ± 1.81) (p balance was not altered significantly in SI or API. Balance was not altered significantly for the medial/lateral index for either exercise test at any time point. Additionally, there were no significant differences in time to recovery. At 12-min post-exercise, all indices were below pre-exercise values, indicating that fatiguing exercise has a positive effect on balance over time. These results are consistent with previous research, suggesting that any effects of fatigue on balance are seen immediately and are diminished as time after exercise increases.

  9. Quantifying cardiorespiratory responses resulting from speed and slope increments during motorized treadmill propulsion among manual wheelchair users.

    Science.gov (United States)

    Gauthier, Cindy; Grangeon, Murielle; Ananos, Ludivine; Brosseau, Rachel; Gagnon, Dany H

    2017-09-01

    Cardiorespiratory fitness assessment and training among manual wheelchair (MW) users are predominantly done with an arm-crank ergometer. However, arm-crank ergometer biomechanics differ substantially from MW propulsion biomechanics. This study aimed to quantify cardiorespiratory responses resulting from speed and slope increments during MW propulsion on a motorized treadmill and to calculate a predictive equation based on speed and slope for estimating peak oxygen uptake (VO 2peak ) in MW users. In total, 17 long-term MW users completed 12 MW propulsion periods (PP), each lasting 2min, on a motorized treadmill, in a random order. Each PP was separated by a 2-min rest. PPs were characterized by a combination of 3 speeds (0.6, 0.8 and 1.0m/s) and 4 slopes (0°, 2.7°, 3.6° and 4.8°). Six key cardiorespiratory outcome measures (VO 2 , heart rate, respiratory rate, minute ventilation and tidal volume) were recorded by using a gas-exchange analysis system. Rate of perceived exertion (RPE) was measured by using the modified 10-point Borg scale after each PP. For the 14 participants who completed the test, cardiorespiratory responses increased in response to speed and/or slope increments, except those recorded between the 3.6 o and 4.8 o slope, for which most outcome measures were comparable. The RPE was positively associated with cardiorespiratory response (r s ≥0.85). A VO 2 predictive equation (R 2 =99.7%) based on speed and slope for each PP was computed. This equation informed the development of a future testing protocol to linearly increase VO 2 via 1-min stages during treadmill MW propulsion. Increasing speed and slope while propelling a MW on a motorized treadmill increases cardiorespiratory response along with RPE. RPE can be used to easily and accurately monitor cardiorespiratory responses during MW exercise. The VO 2 can be predicted to some extent by speed and slope during MW propulsion. A testing protocol is proposed to assess cardiorespiratory fitness

  10. A Reactive Balance Rating Method that Correlates with Kinematics after Trip-Like Perturbations on a Treadmill and Fall Risk Among Residents of Older Adult Congregate Housing.

    Science.gov (United States)

    Madigan, Michael L; Aviles, Jessica; Allin, Leigh J; Nussbaum, Maury A; Alexander, Neil B

    2018-04-16

    A growing number of studies are using modified treadmills to train reactive balance after trip-like perturbations that require multiple steps to recover balance. The goal of this study was thus to develop and validate a low-tech reactive balance rating method in the context of trip-like treadmill perturbations to facilitate the implementation of this training outside the research setting. Thirty-five residents of five senior congregate housing facilities participated in the study. Subjects completed a series of reactive balance tests on a modified treadmill from which the reactive balance rating was determined, along with a battery of standard clinical balance and mobility tests that predict fall risk. We investigated the strength of correlation between the reactive balance rating and reactive balance kinematics. We compared the strength of correlation between the reactive balance rating and clinical tests predictive of fall risk, with the strength of correlation between reactive balance kinematics and the same clinical tests. We also compared the reactive balance rating between subjects predicted to be at a high or low risk of falling. The reactive balance rating was correlated with reactive balance kinematics (Spearman's rho squared = .04 - .30), exhibited stronger correlations with clinical tests than most kinematic measures (Spearman's rho squared = .00 - .23), and was 42-60% lower among subjects predicted to be at a high risk for falling. The reactive balance rating method may provide a low-tech, valid measure of reactive balance kinematics, and an indicator of fall risk, after trip-like postural perturbations.

  11. Complexity, fractal dynamics and determinism in treadmill ambulation: Implications for clinical biomechanists.

    Science.gov (United States)

    Hollman, John H; Watkins, Molly K; Imhoff, Angela C; Braun, Carly E; Akervik, Kristen A; Ness, Debra K

    2016-08-01

    Reduced inter-stride complexity during ambulation may represent a pathologic state. Evidence is emerging that treadmill training for rehabilitative purposes may constrain the locomotor system and alter gait dynamics in a way that mimics pathological states. The purpose of this study was to examine the dynamical system components of gait complexity, fractal dynamics and determinism during treadmill ambulation. Twenty healthy participants aged 23.8 (1.2) years walked at preferred walking speeds for 6min on a motorized treadmill and overground while wearing APDM 6 Opal inertial monitors. Stride times, stride lengths and peak sagittal plane trunk velocities were measured. Mean values and estimates of complexity, fractal dynamics and determinism were calculated for each parameter. Data were compared between overground and treadmill walking conditions. Mean values for each gait parameter were statistically equivalent between overground and treadmill ambulation (P>0.05). Through nonlinear analyses, however, we found that complexity in stride time signals (P<0.001), and long-range correlations in stride time and stride length signals (P=0.005 and P=0.024, respectively), were reduced on the treadmill. Treadmill ambulation induces more predictable inter-stride time dynamics and constrains fluctuations in stride times and stride lengths, which may alter feedback from destabilizing perturbations normally experienced by the locomotor control system during overground ambulation. Treadmill ambulation, therefore, may provide less opportunity for experiencing the adaptability necessary to successfully ambulate overground. Investigators and clinicians should be aware that treadmill ambulation will alter dynamic gait characteristics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Maximal frustration as an immunological principle.

    Science.gov (United States)

    de Abreu, F Vistulo; Mostardinha, P

    2009-03-06

    A fundamental problem in immunology is that of understanding how the immune system selects promptly which cells to kill without harming the body. This problem poses an apparent paradox. Strong reactivity against pathogens seems incompatible with perfect tolerance towards self. We propose a different view on cellular reactivity to overcome this paradox: effector functions should be seen as the outcome of cellular decisions which can be in conflict with other cells' decisions. We argue that if cellular systems are frustrated, then extensive cross-reactivity among the elements in the system can decrease the reactivity of the system as a whole and induce perfect tolerance. Using numerical and mathematical analyses, we discuss two simple models that perform optimal pathogenic detection with no autoimmunity if cells are maximally frustrated. This study strongly suggests that a principle of maximal frustration could be used to build artificial immune systems. It would be interesting to test this principle in the real adaptive immune system.

  13. Chamaebatiaria millefolium (Torr.) Maxim.: fernbush

    Science.gov (United States)

    Nancy L. Shaw; Emerenciana G. Hurd

    2008-01-01

    Fernbush - Chamaebatiaria millefolium (Torr.) Maxim. - the only species in its genus, is endemic to the Great Basin, Colorado Plateau, and adjacent areas of the western United States. It is an upright, generally multistemmed, sweetly aromatic shrub 0.3 to 2 m tall. Bark of young branches is brown and becomes smooth and gray with age. Leaves are leathery, alternate,...

  14. Comportamento cardiorrespiratório em crianças saudáveis durante o exercício progressivo máximo Comportamiento cardiorrespiratorio en niños saludables durante el ejercicio progresivo máximo Cardiorespiratory responses during progressive maximal exercise test in healthy children

    Directory of Open Access Journals (Sweden)

    Danilo Marcelo Leite do Prado

    2010-04-01

    sugieren que los niños tienen menor eficiencia cardiovascular y respiratoria. Con todo, los niños presentaron mayor eficiencia metabólica durante la prueba de esfuerzo. En resumen, a pesar de las diferencias observadas, los niños mostraron niveles similares de capacidad de esfuerzo, al compararlos con los adultos.BACKGROUND: Little is known about cardiorespiratory and metabolic response in healthy children during progressive maximal exercise test. OBJECTIVE: To test the hypothesis that children show different responses in cardiorespiratory and metabolic parameters during progressive maximal exercise test when compared with adults. METHODS: Twenty-five healthy children (gender, 15M/10F; age, 10.2 ± 0.2 and 20 healthy adults (gender, 11M/9F; age, 27.5 ± 0.4 underwent a progressive treadmill cardiopulmonary test until exhaustion to determine the maximal aerobic capacity and ventilatory anaerobic threshold (VAT. RESULTS: The peak workload (5.9±0.1 vs 5.6±0.1 mph, respectively; p>0.05, exercise time (9.8±0.4 vs 10.2±0.4 min, respectively; p>0.05, and relative aerobic fitness (VO2peak, 39.4±2.1 vs 39.1±2.0 ml.kg-1.min-1, respectively; p>0.05 were similar in children and adults. At ventilatory anaerobic threshold, the heart rate, VO2 ml.kg-1.min-1, respiratory rate (RR, functional estimate of dead space (VD/VT, ventilatory equivalent for oxygen (VE/VO2 and end-tidal pressure for oxygen (PETO2 were higher in children, while tidal volume (VT, O2 pulse and end-tidal pressure for carbon dioxide (PETCO2 were lower. At peak of exercise, children showed higher RR and VD/VT. However, O2 pulse, VT, pulmonary ventilation, PETCO2 and respiratory exchange ratio were lower in children than adults. CONCLUSION: Cardiorespiratory and metabolic responses during progressive exercise test are different in children as compared to adults. Specifically, these differences suggest that children have lower cardiovascular and ventilatory efficiency. However, children showed higher metabolic

  15. Improving balance skills in patients who had stroke through virtual reality treadmill training.

    Science.gov (United States)

    Yang, Saiwei; Hwang, Wei-Hsung; Tsai, Yi-Ching; Liu, Fu-Kang; Hsieh, Lin-Fen; Chern, Jen-Suh

    2011-12-01

    The aim of this study was to evaluate the effects of virtual reality (VR) treadmill training on the balance skills of patients who have had a stroke. A total of 14 patients with strokes were recruited and randomly assigned to receive VR treadmill or traditional treadmill training. The outcome measures that were included for the study were center of pressure (COP) sway excursion, COP maximum sway in anterior-posterior direction, COP maximum sway in medial-lateral direction, COP sway area, bilateral limb-loading symmetric index, the sway excursion values for the paretic foot (sway excursion/P), paretic limb stance time (stance time/P), number of steps of the paretic limb (number of steps/P), and contact area of the paretic foot (contact A/P) during quiet stance, sit-to-stand transfer, and level walking. There were no significant improvements in COP-related measures and symmetric index during the quiet stance, either in the VR treadmill or traditional treadmill training group (P > 0.05). However, the difference between groups after training in COP maximum sway in medial-lateral direction during the quiet stance was significant (P = 0.038). Traditional treadmill training failed to improve sit-to-stand performance, whereas VR treadmill training improved symmetric index (P = 0.028) and sway excursion (P = 0.046) significantly during sit-to-stand transfer. The changes of symmetric index between groups were markedly different (P = 0.045). Finally, both groups improved significantly in stance time/P, but only VR treadmill training increased contact A/P (P = 0.034) after training during level walking. The difference between groups during level walking was not significant. Neither traditional treadmill nor VR treadmill training had any effect on balance skill during quiet stance, but VR treadmill training improved balance skill in the medial-lateral direction better than traditional training did. VR treadmill training also improved balance skill during sit-to-stand transfers

  16. É possível determinar a economia de corrida através do teste progressivo até a exaustão? Is possible to predict running economy using maximal incremental exercise test?

    Directory of Open Access Journals (Sweden)

    Rômulo Cássio de Moraes Bertuzzi

    2010-09-01

    Full Text Available O objetivo do presente estudo foi verificar a possibilidade de se estimar a economia de corrida (EC a partir do coeficiente angular gerado pela relação VO2 vs. intensidade de testes progressivos até a exaustão (EC INCLINA. Para tanto, 16 corredores de provas de longa duração (idade 32 ± 7 anos, massa corporal 70,0 ± 6,7 kg, estatura 173,3 ± 5,0 cm, O2máx 57,9 ± 5,8 ml·kg-1·min-1 foram submetidos a um teste incremental e a dois testes de cargas constantes (12 km·h-1 e a intensidade de 90% do segundo limiar ventilatório para a mensuração da EC. Foram detectadas correlações fracas entre o EC INCLINA e a EC estabelecida a 12 km·h-1 (r = 0,49; p = 0,054 e na intensidade de 90% do segundo limiar ventilatório (r = 0,55; p = 0,027. Além disso, o EC INCLINA também estava negativamente correlacionado com a concentração sanguínea de lactato (r = -0,75; p = 0,001 e a razão de troca respiratória (r = -0,80; p The purpose of the present study was to investigate the association between running economy (RE and the slope of the regression line obtained as the individual relationship between oxygen uptake and the corresponding intensity in the incremental test (EC INCLINA. Sixteen recreational long-distance runners (age 32 ± 7 years, body mass 70,0 ± 6.7 kg, height 173.3 ± 5.0 cm, VO2max 57.9 ± 5.8 ml·kg-1·min-1 performed a progressive incremental test and two submaximal workload tests (at 12 km·h-1 and 90% second ventilatory threshold to determine the RE. There was significant correlation between EC INCLINA and RE measured at 12 km·h-1 (r = 0.49; p = 0.054 and at 90% second ventilatory threshold (r = 0.55; p = 0.027. In addition, EC INCLINA also was negatively correlated with peak blood lactate (r = -0.75; p = 0.001 and peak respiratory exchange rate (r = -0.80; p < 0.001. These findings suggest that EC INCLINA would be an alternative parameter employed to determine the endurance performance in recreational long

  17. Kinetic Sprint Asymmetries on a non-motorised Treadmill in Rugby Union Athletes.

    Science.gov (United States)

    Brown, Scott R; Cross, Matt R; Girard, Olivier; Brocherie, Franck; Samozino, Pierre; Morin, Jean-Benoît

    2017-11-01

    The purpose of this study was to present a potential link between sprint kinetic (vertical [F V ] and horizontal force [F H ]) asymmetries and athletic performance during acceleration and maximal velocity (v max ) sprinting. Thirty un-injured male rugby athletes performed 8-s sprints on a non-motorised treadmill. Kinetic data were divided into 'strong' and 'weak' legs based on individually averaged peak values observed during sprinting and were analysed to evaluate asymmetry. Large differences were found between the strong and weak legs in F H during acceleration (4.3 vs. 3.5 N·kg -1 ) and v max (3.7 vs. 2.8 N·kg -1 ) sprinting (both ES=1.2), but not in F V (21.8 vs. 20.8 N·kg -1 , ES=- 0.6 for acceleration; 23.9 vs. 22.8 N·kg -1 , ES=- 0.5 for v max , respectively). Group mean asymmetry was lower in F V compared to F H during acceleration (1.6 vs. 6.8%) and v max (1.6 vs. 8.2%). The range of asymmetry was much lower in F V (0.03-4.3%) compared to F H (0.2-28%). In un-injured rugby athletes, the magnitude and range of asymmetry scores in F H , occurring during acceleration and v max phases, where much greater than those found in F V . These findings highlight the potential for some un-injured athletes to possess kinetic asymmetries known as crucial components for acceleration performance in sprinting. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Treadmill Training with HAL Exoskeleton—A Novel Approach for Symptomatic Therapy in Patients with Limb-Girdle Muscular Dystrophy—Preliminary Study

    Science.gov (United States)

    Sczesny-Kaiser, Matthias; Kowalewski, Rebecca; Schildhauer, Thomas A.; Aach, Mirko; Jansen, Oliver; Grasmücke, Dennis; Güttsches, Anne-Katrin; Vorgerd, Matthias; Tegenthoff, Martin

    2017-01-01

    Purpose: Exoskeletons have been developed for rehabilitation of patients with walking impairment due to neurological disorders. Recent studies have shown that the voluntary-driven exoskeleton HAL® (hybrid assistive limb) can improve walking functions in spinal cord injury and stroke. The aim of this study was to assess safety and effects on walking function of HAL® supported treadmill therapy in patients with limb-girdle muscular dystrophy (LGMD). Materials and Methods: Three LGMD patients received 8 weeks of treadmill training with HAL® 3 times a week. Outcome parameters were 10-meter walk test (10 MWT), 6-minute walk test, and timed-up-and-go test (TUG). Parameters were assessed pre and post training and 6 weeks later (follow-up). Results: All patients completed the therapy without adverse reactions and reported about improvement in endurance. Improvements in outcome parameters after 8 weeks could be demonstrated. Persisting effects were observed after 6 weeks for the 10 MWT and TUG test (follow-up). Conclusions: HAL® treadmill training in LGMD patients can be performed safely and enables an intensive highly repetitive locomotor training. All patients benefitted from this innovative method. Upcoming controlled studies with larger cohorts should prove its effects in different types of LGMD and other myopathies. PMID:28848377

  19. Treadmill Training with HAL Exoskeleton-A Novel Approach for Symptomatic Therapy in Patients with Limb-Girdle Muscular Dystrophy-Preliminary Study.

    Science.gov (United States)

    Sczesny-Kaiser, Matthias; Kowalewski, Rebecca; Schildhauer, Thomas A; Aach, Mirko; Jansen, Oliver; Grasmücke, Dennis; Güttsches, Anne-Katrin; Vorgerd, Matthias; Tegenthoff, Martin

    2017-01-01

    Purpose: Exoskeletons have been developed for rehabilitation of patients with walking impairment due to neurological disorders. Recent studies have shown that the voluntary-driven exoskeleton HAL® (hybrid assistive limb) can improve walking functions in spinal cord injury and stroke. The aim of this study was to assess safety and effects on walking function of HAL® supported treadmill therapy in patients with limb-girdle muscular dystrophy (LGMD). Materials and Methods: Three LGMD patients received 8 weeks of treadmill training with HAL® 3 times a week. Outcome parameters were 10-meter walk test (10 MWT), 6-minute walk test, and timed-up-and-go test (TUG). Parameters were assessed pre and post training and 6 weeks later (follow-up). Results: All patients completed the therapy without adverse reactions and reported about improvement in endurance. Improvements in outcome parameters after 8 weeks could be demonstrated. Persisting effects were observed after 6 weeks for the 10 MWT and TUG test (follow-up). Conclusions: HAL® treadmill training in LGMD patients can be performed safely and enables an intensive highly repetitive locomotor training. All patients benefitted from this innovative method. Upcoming controlled studies with larger cohorts should prove its effects in different types of LGMD and other myopathies.

  20. Treadmill Training with HAL Exoskeleton—A Novel Approach for Symptomatic Therapy in Patients with Limb-Girdle Muscular Dystrophy—Preliminary Study

    Directory of Open Access Journals (Sweden)

    Matthias Sczesny-Kaiser

    2017-08-01

    Full Text Available Purpose: Exoskeletons have been developed for rehabilitation of patients with walking impairment due to neurological disorders. Recent studies have shown that the voluntary-driven exoskeleton HAL® (hybrid assistive limb can improve walking functions in spinal cord injury and stroke. The aim of this study was to assess safety and effects on walking function of HAL® supported treadmill therapy in patients with limb-girdle muscular dystrophy (LGMD.Materials and Methods: Three LGMD patients received 8 weeks of treadmill training with HAL® 3 times a week. Outcome parameters were 10-meter walk test (10 MWT, 6-minute walk test, and timed-up-and-go test (TUG. Parameters were assessed pre and post training and 6 weeks later (follow-up.Results: All patients completed the therapy without adverse reactions and reported about improvement in endurance. Improvements in outcome parameters after 8 weeks could be demonstrated. Persisting effects were observed after 6 weeks for the 10 MWT and TUG test (follow-up.Conclusions: HAL® treadmill training in LGMD patients can be performed safely and enables an intensive highly repetitive locomotor training. All patients benefitted from this innovative method. Upcoming controlled studies with larger cohorts should prove its effects in different types of LGMD and other myopathies.

  1. Effects of an attention demanding task on dynamic stability during treadmill walking

    Directory of Open Access Journals (Sweden)

    Troy Karen L

    2008-04-01

    Full Text Available Abstract Background People exhibit increased difficulty balancing when they perform secondary attention-distracting tasks while walking. However, a previous study by Grabiner and Troy (J. Neuroengineering Rehabil., 2005 found that young healthy subjects performing a concurrent Stroop task while walking on a motorized treadmill exhibited decreased step width variability. However, measures of variability do not directly quantify how a system responds to perturbations. This study re-analyzed data from Grabiner and Troy 2005 to determine if performing the concurrent Stroop task directly affected the dynamic stability of walking in these same subjects. Methods Thirteen healthy volunteers walked on a motorized treadmill at their self-selected constant speed for 10 minutes both while performing the Stroop test and during undisturbed walking. This Stroop test consisted of projecting images of the name of one color, printed in text of a different color, onto a wall and asking subjects to verbally identify the color of the text. Three-dimensional motions of a marker attached to the base of the neck (C5/T1 were recorded. Marker velocities were calculated over 3 equal intervals of 200 sec each in each direction. Mean variability was calculated for each time series as the average standard deviation across all strides. Both "local" and "orbital" dynamic stability were quantified for each time series using previously established methods. These measures directly quantify how quickly small perturbations grow or decay, either continuously in real time (local or discretely from one cycle to the next (orbital. Differences between Stroop and Control trials were evaluated using a 2-factor repeated measures ANOVA. Results Mean variability of trunk movements was significantly reduced during the Stroop tests compared to normal walking. Conversely, local and orbital stability results were mixed: some measures showed slight increases, while others showed slight decreases

  2. Body-weight-supported treadmill rehabilitation after stroke.

    Science.gov (United States)

    Duncan, Pamela W; Sullivan, Katherine J; Behrman, Andrea L; Azen, Stanley P; Wu, Samuel S; Nadeau, Stephen E; Dobkin, Bruce H; Rose, Dorian K; Tilson, Julie K; Cen, Steven; Hayden, Sarah K

    2011-05-26

    Locomotor training, including the use of body-weight support in treadmill stepping, is a physical therapy intervention used to improve recovery of the ability to walk after stroke. The effectiveness and appropriate timing of this intervention have not been established. We stratified 408 participants who had had a stroke 2 months earlier according to the extent of walking impairment--moderate (able to walk 0.4 to stroke had occurred (early locomotor training), the second group received this training 6 months after the stroke had occurred (late locomotor training), and the third group participated in an exercise program at home managed by a physical therapist 2 months after the stroke (home-exercise program). Each intervention included 36 sessions of 90 minutes each for 12 to 16 weeks. The primary outcome was the proportion of participants in each group who had an improvement in functional walking ability 1 year after the stroke. At 1 year, 52.0% of all participants had increased functional walking ability. No significant differences in improvement were found between early locomotor training and home exercise (adjusted odds ratio for the primary outcome, 0.83; 95% confidence interval [CI], 0.50 to 1.39) or between late locomotor training and home exercise (adjusted odds ratio, 1.19; 95% CI, 0.72 to 1.99). All groups had similar improvements in walking speed, motor recovery, balance, functional status, and quality of life. Neither the delay in initiating the late locomotor training nor the severity of the initial impairment affected the outcome at 1 year. Ten related serious adverse events were reported (occurring in 2.2% of participants undergoing early locomotor training, 3.5% of those undergoing late locomotor training, and 1.6% of those engaging in home exercise). As compared with the home-exercise group, each of the groups receiving locomotor training had a higher frequency of dizziness or faintness during treatment (P=0.008). Among patients with severe walking

  3. Treadmill vs. overground walking: different response to physical interaction.

    Science.gov (United States)

    Ochoa, Julieth; Sternad, Dagmar; Hogan, Neville

    2017-10-01

    Rehabilitation of human motor function is an issue of growing significance, and human-interactive robots offer promising potential to meet the need. For the lower extremity, however, robot-aided therapy has proven challenging. To inform effective approaches to robotic gait therapy, it is important to better understand unimpaired locomotor control: its sensitivity to different mechanical contexts and its response to perturbations. The present study evaluated the behavior of 14 healthy subjects who walked on a motorized treadmill and overground while wearing an exoskeletal ankle robot. Their response to a periodic series of ankle plantar flexion torque pulses, delivered at periods different from, but sufficiently close to, their preferred stride cadence, was assessed to determine whether gait entrainment occurred, how it differed across conditions, and if the adapted motor behavior persisted after perturbation. Certain aspects of locomotor control were exquisitely sensitive to walking context, while others were not. Gaits entrained more often and more rapidly during overground walking, yet, in all cases, entrained gaits synchronized the torque pulses with ankle push-off, where they provided assistance with propulsion. Furthermore, subjects entrained to perturbation periods that required an adaption toward slower cadence, even though the pulses acted to accelerate gait, indicating a neural adaptation of locomotor control. Lastly, during 15 post-perturbation strides, the entrained gait period was observed to persist more frequently during overground walking. This persistence was correlated with the number of strides walked at the entrained gait period (i.e., longer exposure), which also indicated a neural adaptation. NEW & NOTEWORTHY We show that the response of human locomotion to physical interaction differs between treadmill and overground walking. Subjects entrained to a periodic series of ankle plantar flexion torque pulses that shifted their gait cadence

  4. IMNN: Information Maximizing Neural Networks

    Science.gov (United States)

    Charnock, Tom; Lavaux, Guilhem; Wandelt, Benjamin D.

    2018-04-01

    This software trains artificial neural networks to find non-linear functionals of data that maximize Fisher information: information maximizing neural networks (IMNNs). As compressing large data sets vastly simplifies both frequentist and Bayesian inference, important information may be inadvertently missed. Likelihood-free inference based on automatically derived IMNN summaries produces summaries that are good approximations to sufficient statistics. IMNNs are robustly capable of automatically finding optimal, non-linear summaries of the data even in cases where linear compression fails: inferring the variance of Gaussian signal in the presence of noise, inferring cosmological parameters from mock simulations of the Lyman-α forest in quasar spectra, and inferring frequency-domain parameters from LISA-like detections of gravitational waveforms. In this final case, the IMNN summary outperforms linear data compression by avoiding the introduction of spurious likelihood maxima.

  5. Is the β phase maximal?

    International Nuclear Information System (INIS)

    Ferrandis, Javier

    2005-01-01

    The current experimental determination of the absolute values of the CKM elements indicates that 2 vertical bar V ub /V cb V us vertical bar =(1-z), with z given by z=0.19+/-0.14. This fact implies that irrespective of the form of the quark Yukawa matrices, the measured value of the SM CP phase β is approximately the maximum allowed by the measured absolute values of the CKM elements. This is β=(π/6-z/3) for γ=(π/3+z/3), which implies α=π/2. Alternatively, assuming that β is exactly maximal and using the experimental measurement sin(2β)=0.726+/-0.037, the phase γ is predicted to be γ=(π/2-β)=66.3 o +/-1.7 o . The maximality of β, if confirmed by near-future experiments, may give us some clues as to the origin of CP violation

  6. Body weight supported treadmill training versus traditional training in patients dependent on walking assistance after stroke: a randomized controlled trial.

    Science.gov (United States)

    Høyer, Ellen; Jahnsen, Reidun; Stanghelle, Johan Kvalvik; Strand, Liv Inger

    2012-01-01

    Treadmill training with body weight support (TTBWS) for relearning walking ability after brain damage is an approach under current investigation. Efficiency of this method beyond traditional training is lacking evidence, especially in patients needing walking assistance after stroke. The objective of this study was to investigate change in walking and transfer abilities, comparing TTBWS with traditional walking training. A single-blinded, randomized controlled trial was conducted. Sixty patients referred for multi-disciplinary primary rehabilitation were assigned into one of two intervention groups, one received 30 sessions of TTBWS plus traditional training, the other traditional training alone. Daily training was 1 hr. Outcome measures were Functional Ambulation Categories (FAC), Walking, Functional Independence Measure (FIM); shorter transfer and stairs, 10 m and 6-min walk tests. Substantial improvements in walking and transfer were shown within both groups after 5 and 11 weeks of intervention. Overall no statistical significant differences were found between the groups, but 12 of 17 physical measures tended to show improvements in favour of the treadmill approach. Both training strategies provided significant improvements in the tested activities, suggesting that similar outcomes can be obtained in the two modalities by systematic, intensive and goal directed training.

  7. Indicação de cintilografia de perfusão do miocárdio para a detecção de doença arterial coronariana, baseada em evidências ergométricas e clínico-epidemiológicas Indication of myocardial perfusion scintigraphy for coronary artery disease detection based on clinical-epidemiological and treadmill test evidences

    Directory of Open Access Journals (Sweden)

    Paulo Schiavom Duarte

    2006-10-01

    Full Text Available OBJETIVO: Avaliar quando se devem realizar exames de cintilografia de perfusão do miocárdio (CPM, baseando-se em informações objetivas obtidas do teste ergométrico e da análise dos fatores clínico-epidemiológicos para doença arterial coronária (DAC. MÉTODOS: Foram submetidos a CPM 2.100 pacientes que foram classificados segundo o resultado da cintilografia, do escore de Duke e de escore clínico-epidemiológico, baseado em Framingham. Os pacientes com cintilografia positiva foram acompanhados a fim de definir se os resultados eram verdadeiros positivos. Foram utilizadas receiver operating characteristic (ROC curvas para definir a eficiência e os melhores pontos de corte dos escores de Duke e clínico-epidemiológico, na seleção dos pacientes que deveriam ser submetidos a cintilografia. RESULTADOS: Observou-se que, restringindo a solicitação da cintilografia a pacientes com escore de Duke abaixo de 7,5 e/ou escore clínico-epidemiológico acima de 4, deixaríamos de realizar cerca de 50% dos exames com riscos mínimos de perda de diagnóstico. CONCLUSÃO: A utilização do escore de Duke e de escore clínico-epidemiológico para orientar a solicitação da CPM pode diminuir expressivamente o número de exames desnecessários.OBJECTIVE: To establish when the myocardial perfusion scintigraphy (MPS should be performed based on well-defined information obtained from treadmill test results and clinical-epidemiological parameters for coronary artery disease (CAD. METHODS: 2,100 patients who underwent MPS were classified according to the results of scintigraphy, the Duke score and a clinical-epidemiological score based on Framingham study. The patients with positive results on MPS were followed to define whether the results were true positives. Receiver operating characteristic (ROC curves were used to establish the efficiency and the best Duke and clinical-epidemiological scores to define patients that should be submitted to

  8. Strategy to maximize maintenance operation

    OpenAIRE

    Espinoza, Michael

    2005-01-01

    This project presents a strategic analysis to maximize maintenance operations in Alcan Kitimat Works in British Columbia. The project studies the role of maintenance in improving its overall maintenance performance. It provides strategic alternatives and specific recommendations addressing Kitimat Works key strategic issues and problems. A comprehensive industry and competitive analysis identifies the industry structure and its competitive forces. In the mature aluminium industry, the bargain...

  9. Scalable Nonlinear AUC Maximization Methods

    OpenAIRE

    Khalid, Majdi; Ray, Indrakshi; Chitsaz, Hamidreza

    2017-01-01

    The area under the ROC curve (AUC) is a measure of interest in various machine learning and data mining applications. It has been widely used to evaluate classification performance on heavily imbalanced data. The kernelized AUC maximization machines have established a superior generalization ability compared to linear AUC machines because of their capability in modeling the complex nonlinear structure underlying most real world-data. However, the high training complexity renders the kernelize...

  10. Evaluation of respiratory dynamics by volumetric capnography during submaximal exercise protocol of six minutes on treadmill in cystic fibrosis patients.

    Science.gov (United States)

    Parazzi, Paloma L F; Marson, Fernando A L; Ribeiro, Maria A G O; Schivinski, Camila I S; Ribeiro, José D

    2017-11-29

    Volumetric capnography provides the standard CO 2 elimination by the volume expired per respiratory cycle and is a measure to assess pulmonary involvement. Thus, the objective of this study was to evaluate the respiratory dynamics of healthy control subjects and those with cystic fibrosis in a submaximal exercise protocol for six minutes on the treadmill, using volumetric capnography parameters (slope 3 [Slp3], Slp3/tidal volume [Slp3/TV], and slope 2 [Slp2]). This was a cross-sectional study with 128 subjects (cystic fibrosis, 64 subjects; controls, 64 subjects]. Participants underwent volumetric capnography before, during, and after six minutes on the treadmill. Statistical analysis was performed using the Friedman, Mann-Whitney, and Kruskal-Wallis tests, considering age and sex. An alpha=0.05 was considered. Six minutes on the treadmill evaluation: in cystic fibrosis, volumetric capnography parameters were different before, during, and after six minutes on the treadmill; the same was observed for the controls, except for Slp2. Regarding age, an Slp3 difference was observed in cystic fibrosis patients regardless of age, at all moments, and in controls for age≥12 years; a difference in Slp3/TV was observed in cystic fibrosis and controls, regardless of age; and an Slp2 difference in the cystic fibrosis, regardless of age. Regarding sex, Slp3 and Slp3/TV differences were observed in cystic fibrosis regardless of sex, and in controls in male participants; an Slp2 difference was observed in the cystic fibrosis and female participants. The analysis between groups (cystic fibrosis and controls) indicated that Slp3 and Slp3/TV has identified the CF, regardless of age and sex, while the Slp2 showed the CF considering age. Cystic fibrosis showed greater values of the parameters before, during, and after exercise, even when stratified by age and sex, which may indicate ventilation inhomogeneity in the peripheral pathways in the cystic fibrosis. Copyright © 2017

  11. Improved kinect-based spatiotemporal and kinematic treadmill gait assessment.

    Science.gov (United States)

    Eltoukhy, Moataz; Oh, Jeonghoon; Kuenze, Christopher; Signorile, Joseph

    2017-01-01

    A cost-effective, clinician friendly gait assessment tool that can automatically track patients' anatomical landmarks can provide practitioners with important information that is useful in prescribing rehabilitative and preventive therapies. This study investigated the validity and reliability of the Microsoft Kinect v2 as a potential inexpensive gait analysis tool. Ten healthy subjects walked on a treadmill at 1.3 and 1.6m·s -1 , as spatiotemporal parameters and kinematics were extracted concurrently using the Kinect and three-dimensional motion analysis. Spatiotemporal measures included step length and width, step and stride times, vertical and mediolateral pelvis motion, and foot swing velocity. Kinematic outcomes included hip, knee, and ankle joint angles in the sagittal plane. The absolute agreement and relative consistency between the two systems were assessed using interclass correlations coefficients (ICC2,1), while reproducibility between systems was established using Lin's Concordance Correlation Coefficient (rc). Comparison of ensemble curves and associated 90% confidence intervals (CI90) of the hip, knee, and ankle joint angles were performed to investigate if the Kinect sensor could consistently and accurately assess lower extremity joint motion throughout the gait cycle. Results showed that the Kinect v2 sensor has the potential to be an effective clinical assessment tool for sagittal plane knee and hip joint kinematics, as well as some spatiotemporal temporal variables including pelvis displacement and step characteristics during the gait cycle. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Multi-segment foot kinematics and plantar fascia strain during treadmill and overground running

    OpenAIRE

    Sinclair, Jonathan Kenneth; Taylor, Paul John; Vincent, Hayley

    2014-01-01

    Although physiologically beneficial, running is known to be associated with a high incidence of chronic injuries. Excessive coronal and transverse plane motions of the foot segments and strain experienced by the plantar fascia are linked to the development of a number of chronic injuries. This study examined differences in multi-segment foot kinematics and plantar fascia strain during treadmill and overground running. Twelve male recreational runners ran at 4.0 m.s-1 in both treadmill and ove...

  13. Design of a heart rate controller for treadmill exercise using a recurrent fuzzy neural network.

    Science.gov (United States)

    Lu, Chun-Hao; Wang, Wei-Cheng; Tai, Cheng-Chi; Chen, Tien-Chi

    2016-05-01

    In this study, we developed a computer controlled treadmill system using a recurrent fuzzy neural network heart rate controller (RFNNHRC). Treadmill speeds and inclines were controlled by corresponding control servo motors. The RFNNHRC was used to generate the control signals to automatically control treadmill speed and incline to minimize the user heart rate deviations from a preset profile. The RFNNHRC combines a fuzzy reasoning capability to accommodate uncertain information and an artificial recurrent neural network learning process that corrects for treadmill system nonlinearities and uncertainties. Treadmill speeds and inclines are controlled by the RFNNHRC to achieve minimal heart rate deviation from a pre-set profile using adjustable parameters and an on-line learning algorithm that provides robust performance against parameter variations. The on-line learning algorithm of RFNNHRC was developed and implemented using a dsPIC 30F4011 DSP. Application of the proposed control scheme to heart rate responses of runners resulted in smaller fluctuations than those produced by using proportional integra control, and treadmill speeds and inclines were smoother. The present experiments demonstrate improved heart rate tracking performance with the proposed control scheme. The RFNNHRC scheme with adjustable parameters and an on-line learning algorithm was applied to a computer controlled treadmill system with heart rate control during treadmill exercise. Novel RFNNHRC structure and controller stability analyses were introduced. The RFNNHRC were tuned using a Lyapunov function to ensure system stability. The superior heart rate control with the proposed RFNNHRC scheme was demonstrated with various pre-set heart rates. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. FLOUTING MAXIMS IN INDONESIA LAWAK KLUB CONVERSATION

    Directory of Open Access Journals (Sweden)

    Rahmawati Sukmaningrum

    2017-04-01

    Full Text Available This study aims to identify the types of maxims flouted in the conversation in famous comedy show, Indonesia Lawak Club. Likewise, it also tries to reveal the speakers‘ intention of flouting the maxim in the conversation during the show. The writers use descriptive qualitative method in conducting this research. The data is taken from the dialogue of Indonesia Lawak club and then analyzed based on Grice‘s cooperative principles. The researchers read the dialogue‘s transcripts, identify the maxims, and interpret the data to find the speakers‘ intention for flouting the maxims in the communication. The results show that there are four types of maxims flouted in the dialogue. Those are maxim of quality (23%, maxim of quantity (11%, maxim of manner (31%, and maxim of relevance (35. Flouting the maxims in the conversations is intended to make the speakers feel uncomfortable with the conversation, show arrogances, show disagreement or agreement, and ridicule other speakers.

  15. Implications of treadmilling for the stability and polarity of actin and tubulin polymers in vivo.

    Science.gov (United States)

    Kirschner, M W

    1980-07-01

    In this report, we examine how the cell can selectively stabilize anchored filaments and suppress spontaneous filament assembly. Because microtubules and actin filaments have an organized distribution in cells, the cell must have a mechanism for suppressing spontaneous and random polymerization. Though the mechanism for suppressing spontaneous polymerization is unknown, an unusual property of these filaments has been demonstrated recently, i.e., under steady-stae conditions, in vitro actin filaments and microtubules can exhibit a flux of subunits through the polymers called "treadmilling." In vivo, however, most, if not all, of these polymers are attached at one end to specific structures and treadmilling should not occur. The function of treadmilling in vivo is, therefore, unclear at present. However, as shown here, the same physicochemical property of coupling assembly to ATP or GTP hydrolysis that leads to treadmilling in vitro can act to selectively stabilize anchored polymers in vivo. I show here that the theory of treadmilling implies that the concentration of subunits necessary for assembly of the nonanchored polymer will in general be higher than the concentration necessary for the assembly of polymers anchored with a specific polarity. This disparity in the monomer concentrations required for assembly can lead to a selective stabilization of anchored polymers and complete suppression of spontaneous polymerization at apparent equilibrium in vivo. It is possible, therefore, that the phenomenon of treadmilling is an in vitro manifestation of a mechanism designed to use ATP or GTP hydrolysis to control the spatial organization of filaments in the cell.

  16. A systematic review of standing and treadmill desks in the workplace.

    Science.gov (United States)

    MacEwen, Brittany T; MacDonald, Dany J; Burr, Jamie F

    2015-01-01

    Standing and treadmill desks are intended to reduce the amount of time spent sitting in today's otherwise sedentary office. Proponents of these desks suggest that health benefits may be acquired as standing desk use discourages long periods of sitting, which has been identified as an independent health risk factor. Our objectives were thus to analyze the evidence for standing and treadmill desk use in relation to physiological (chronic disease prevention and management) and psychological (worker productivity, well-being) outcomes. A computer-assisted systematic search of Medline, PubMed, PsycINFO, SPORTDiscus, CINAHL, CENTRAL, and EMBASE databases was employed to identify all relevant articles related to standing and treadmill desk use. Treadmill desks led to the greatest improvement in physiological outcomes including postprandial glucose, HDL cholesterol, and anthropometrics, while standing desk use was associated with few physiological changes. Standing and treadmill desks both showed mixed results for improving psychological well-being with little impact on work performance. Standing and treadmill desks show some utility for breaking up sitting time and potentially improving select components of health. At present; however, there exist substantial evidence gaps to comprehensively evaluate the utility of each type of desk to enhance health benefits by reducing sedentary time. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Fall-related gait characteristics on the treadmill and in daily life.

    Science.gov (United States)

    Rispens, Sietse M; Van Dieën, Jaap H; Van Schooten, Kimberley S; Cofré Lizama, L Eduardo; Daffertshofer, Andreas; Beek, Peter J; Pijnappels, Mirjam

    2016-02-02

    Body-worn sensors allow assessment of gait characteristics that are predictive of fall risk, both when measured during treadmill walking and in daily life. The present study aimed to assess differences as well as associations between fall-related gait characteristics measured on a treadmill and in daily life. In a cross-sectional study, trunk accelerations of 18 older adults (72.3 ± 4.5 years) were recorded during walking on a treadmill (Dynaport Hybrid sensor) and during daily life (Dynaport MoveMonitor). A comprehensive set of 32 fall-risk-related gait characteristics was estimated and compared between both settings. For 25 gait characteristics, a systematic difference between treadmill and daily-life measurements was found. Gait was more variable, less symmetric, and less stable during daily life. Fourteen characteristics showed a significant correlation between treadmill and daily-life measurements, including stride time and regularity (0.48  0.25). Gait characteristics revealed less stable, less symmetric, and more variable gait during daily life than on a treadmill, yet about half of the characteristics were significantly correlated between conditions. These results suggest that daily-life gait analysis is sensitive to static personal factors (i.e., physical and cognitive capacity) as well as dynamic situational factors (i.e., behavior and environment), which may both represent determinants of fall risk.

  18. Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners.

    Science.gov (United States)

    Mikkola, Jussi; Vesterinen, Ville; Taipale, Ritva; Capostagno, Benoit; Häkkinen, Keijo; Nummela, Ari

    2011-10-01

    The purpose of this study was to assess the effects of heavy resistance, explosive resistance, and muscle endurance training on neuromuscular, endurance, and high-intensity running performance in recreational endurance runners. Twenty-seven male runners were divided into one of three groups: heavy resistance, explosive resistance or muscle endurance training. After 6 weeks of preparatory training, the groups underwent an 8-week resistance training programme as a supplement to endurance training. Before and after the 8-week training period, maximal strength (one-repetition maximum), electromyographic activity of the leg extensors, countermovement jump height, maximal speed in the maximal anaerobic running test, maximal endurance performance, maximal oxygen uptake ([V·]O(₂max)), and running economy were assessed. Maximal strength improved in the heavy (P = 0.034, effect size ES = 0.38) and explosive resistance training groups (P = 0.003, ES = 0.67) with increases in leg muscle activation (heavy: P = 0.032, ES = 0.38; explosive: P = 0.002, ES = 0.77). Only the heavy resistance training group improved maximal running speed in the maximal anaerobic running test (P = 0.012, ES = 0.52) and jump height (P = 0.006, ES = 0.59). Maximal endurance running performance was improved in all groups (heavy: P = 0.005, ES = 0.56; explosive: P = 0.034, ES = 0.39; muscle endurance: P = 0.001, ES = 0.94), with small though not statistically significant improvements in [V·]O(₂max) (heavy: ES = 0.08; explosive: ES = 0.29; muscle endurance: ES = 0.65) and running economy (ES in all groups running endurance performance. However, both heavy and explosive strength training were beneficial in improving neuromuscular characteristics, and heavy resistance training in particular contributed to improvements in high-intensity running characteristics. Thus, endurance runners should include heavy resistance training in their training programmes to enhance endurance performance, such as

  19. Effects of endurance training and competition on exercise tests in relatively untrained people.

    Science.gov (United States)

    Verstappen, F T; Janssen, G M; Does, R J

    1989-10-01

    One hundred fourteen subjects (34 +/- 8 years) without any competition background took part in an endurance training study to be completed after 1.5 years with running a marathon. Ultimately, 60 males and 18 females achieved that goal. The training program, carefully supervised, was divided into three phases with a maximum of 45, 70, and 110 km/week training volume and concluded with a performance race of 15, 25, and 42.195 km, respectively. Three days before and 3 and 5 days after each race, 35 subjects were selected to perform a progressive treadmill test and the remaining subjects participated in performing field tests of running 400 and 1000 m. The maximal velocity achieved in the treadmill test was 4.75 +/- 0.36 m.s-1 for males and 4.18 +/- 0.28 m.s-1 for females; it remained constant throughout the study. However, the running velocity at 4 mmol.1(-1) plasma lactate concentration increased about 10% from phase 1 to 3. In the females this rise already appeared to be completed in phase 2. Heart rate showed a tendency to increase at both submaximal and maximal exercise from training phase 1 to 2 and 3, whereas plasma lactate concentration showed a decreasing tendency. Three days after the 25 km and the marathon race the maximal running velocity in the exercise test was 2%-4% lower compared with the pre-race test (P less than 0.05). Five days after the race this difference again faded away. This small decline in running performance was not reflected in changes of physiologic responses such as heart rate or plasma lactate concentration.

  20. Maximizing policy learning in international committees

    DEFF Research Database (Denmark)

    Nedergaard, Peter

    2007-01-01

    , this article demonstrates that valuable lessons can be learned about policy learning, in practice and theoretically, by analysing the cooperation in the OMC committees. Using the Advocacy Coalition Framework as the starting point of analysis, 15 hypotheses on policy learning are tested. Among other things......, it is concluded that in order to maximize policy learning in international committees, empirical data should be made available to committees and provided by sources close to the participants (i.e. the Commission). In addition, the work in the committees should be made prestigious in order to attract well...

  1. Can monkeys make investments based on maximized pay-off?

    Directory of Open Access Journals (Sweden)

    Sophie Steelandt

    2011-03-01

    Full Text Available Animals can maximize benefits but it is not known if they adjust their investment according to expected pay-offs. We investigated whether monkeys can use different investment strategies in an exchange task. We tested eight capuchin monkeys (Cebus apella and thirteen macaques (Macaca fascicularis, Macaca tonkeana in an experiment where they could adapt their investment to the food amounts proposed by two different experimenters. One, the doubling partner, returned a reward that was twice the amount given by the subject, whereas the other, the fixed partner, always returned a constant amount regardless of the amount given. To maximize pay-offs, subjects should invest a maximal amount with the first partner and a minimal amount with the second. When tested with the fixed partner only, one third of monkeys learned to remove a maximal amount of food for immediate consumption before investing a minimal one. With both partners, most subjects failed to maximize pay-offs by using different decision rules with each partner' quality. A single Tonkean macaque succeeded in investing a maximal amount to one experimenter and a minimal amount to the other. The fact that only one of over 21 subjects learned to maximize benefits in adapting investment according to experimenters' quality indicates that such a task is difficult for monkeys, albeit not impossible.

  2. Human-Robot Interaction: Does Robotic Guidance Force Affect Gait-Related Brain Dynamics during Robot-Assisted Treadmill Walking?

    Directory of Open Access Journals (Sweden)

    Kristel Knaepen

    Full Text Available In order to determine optimal training parameters for robot-assisted treadmill walking, it is essential to understand how a robotic device interacts with its wearer, and thus, how parameter settings of the device affect locomotor control. The aim of this study was to assess the effect of different levels of guidance force during robot-assisted treadmill walking on cortical activity. Eighteen healthy subjects walked at 2 km.h-1 on a treadmill with and without assistance of the Lokomat robotic gait orthosis. Event-related spectral perturbations and changes in power spectral density were investigated during unassisted treadmill walking as well as during robot-assisted treadmill walking at 30%, 60% and 100% guidance force (with 0% body weight support. Clustering of independent components revealed three clusters of activity in the sensorimotor cortex during treadmill walking and robot-assisted treadmill walking in healthy subjects. These clusters demonstrated gait-related spectral modulations in the mu, beta and low gamma bands over the sensorimotor cortex related to specific phases of the gait cycle. Moreover, mu and beta rhythms were suppressed in the right primary sensory cortex during treadmill walking compared to robot-assisted treadmill walking with 100% guidance force, indicating significantly larger involvement of the sensorimotor area during treadmill walking compared to robot-assisted treadmill walking. Only marginal differences in the spectral power of the mu, beta and low gamma bands could be identified between robot-assisted treadmill walking with different levels of guidance force. From these results it can be concluded that a high level of guidance force (i.e., 100% guidance force and thus a less active participation during locomotion should be avoided during robot-assisted treadmill walking. This will optimize the involvement of the sensorimotor cortex which is known to be crucial for motor learning.

  3. Human-Robot Interaction: Does Robotic Guidance Force Affect Gait-Related Brain Dynamics during Robot-Assisted Treadmill Walking?

    Science.gov (United States)

    Knaepen, Kristel; Mierau, Andreas; Swinnen, Eva; Fernandez Tellez, Helio; Michielsen, Marc; Kerckhofs, Eric; Lefeber, Dirk; Meeusen, Romain

    2015-01-01

    In order to determine optimal training parameters for robot-assisted treadmill walking, it is essential to understand how a robotic device interacts with its wearer, and thus, how parameter settings of the device affect locomotor control. The aim of this study was to assess the effect of different levels of guidance force during robot-assisted treadmill walking on cortical activity. Eighteen healthy subjects walked at 2 km.h-1 on a treadmill with and without assistance of the Lokomat robotic gait orthosis. Event-related spectral perturbations and changes in power spectral density were investigated during unassisted treadmill walking as well as during robot-assisted treadmill walking at 30%, 60% and 100% guidance force (with 0% body weight support). Clustering of independent components revealed three clusters of activity in the sensorimotor cortex during treadmill walking and robot-assisted treadmill walking in healthy subjects. These clusters demonstrated gait-related spectral modulations in the mu, beta and low gamma bands over the sensorimotor cortex related to specific phases of the gait cycle. Moreover, mu and beta rhythms were suppressed in the right primary sensory cortex during treadmill walking compared to robot-assisted treadmill walking with 100% guidance force, indicating significantly larger involvement of the sensorimotor area during treadmill walking compared to robot-assisted treadmill walking. Only marginal differences in the spectral power of the mu, beta and low gamma bands could be identified between robot-assisted treadmill walking with different levels of guidance force. From these results it can be concluded that a high level of guidance force (i.e., 100% guidance force) and thus a less active participation during locomotion should be avoided during robot-assisted treadmill walking. This will optimize the involvement of the sensorimotor cortex which is known to be crucial for motor learning.

  4. Mindfulness and Affective Responses to Treadmill Walking in Individuals with Low Intrinsic Motivation to Exercise

    Science.gov (United States)

    COX, ANNE E.; ROBERTS, MADELINE A.; CATES, HAILEY L.; MCMAHON, AMANDA K.

    2018-01-01

    An aversion to the sensations of physical exertion can deter engagement in physical activity. This is due in part to an associative focus in which individuals are attending to uncomfortable interoceptive cues. The purpose of this study was to test the effect of mindfulness on affective valence, ratings of perceived exertion (RPE), and enjoyment during treadmill walking. Participants (N=23; Mage=19.26, SD = 1.14) were only included in the study if they engaged in no more than moderate levels of physical activity and reported low levels of intrinsic motivation. They completed three testing sessions including a habituation session to determine the grade needed to achieve 65% of heart rate reserve (HRR); a control condition in which they walked at 65% of HRR for 10 minutes and an experimental condition during which they listened to a mindfulness track that directed them to attend to the physical sensations of their body in a nonjudgmental manner during the 10-minute walk. ANOVA results showed that in the mindfulness condition, affective valence was significantly more positive (p = .02, ηp2 = .22), enjoyment and mindfulness of the body were higher (p mindfulness of the body was moderately associated with higher enjoyment (p mindfulness but not the control condition. Results suggest that mindfulness during exercise is associated with more positive affective responses. PMID:29541336

  5. Treadmill exercise attenuates the severity of physical dependence, anxiety, depressive-like behavior and voluntary morphine consumption in morphine withdrawn rats receiving methadone maintenance treatment.

    Science.gov (United States)

    Alizadeh, Maryam; Zahedi-Khorasani, Mahdi; Miladi-Gorji, Hossein

    2018-05-30

    This study was designed to examine whether treadmill exercise would attenuate the severity of physical dependence, methadone-induced anxiety, depression and voluntary morphine consumption in morphine withdrawn rats receiving methadone maintenance treatment (MMT). The rats were chronically treated with bi-daily doses (10 mg/kg, at 12 h intervals) of morphine for 14 days. The exercising rats receiving MMT were forced to run on a motorized treadmill for 30 days during morphine withdrawal. Then, rats were tested for the severity of morphine dependence, the elevated plus-maze (EPM), sucrose preference test (SPT) and voluntary morphine consumption using a two-bottle choice (TBC) paradigm. The results showed that naloxone- precipitated opioid withdrawal signs were decreased in exercising morphine-dependent rats receiving MMT than sedentary rats. Also, the exercising morphine-dependent rats receiving MMT exhibited an increased time on open arms, preference for sucrose and a lower morphine preference ratio than sedentary rats. We conclude that treadmill exercise decreased the severity of physical dependence, anxiety/depressive-like behaviors and also the voluntary morphine consumption in morphine withdrawn rats receiving MMT. Thus, exercise may benefit in the treatment of addicts during MMT. Copyright © 2018. Published by Elsevier B.V.

  6. Comparison of Aerobic Performance Testing Protocols in Elite Male Wheelchair Basketball Players

    Directory of Open Access Journals (Sweden)

    Molik Bartosz

    2017-12-01

    Full Text Available In wheelchair sports, aerobic performance is commonly assessed with the use of an arm crank ergometer (ACE, a wheelchair ergometer (WCE or a wheelchair treadmill (WCT. There are different protocols to identify peak oxygen uptake in wheelchair sports; however, only a few protocols have been applied to evaluate these conditions in wheelchair basketball players. The purpose of this study was to compare physiological responses during maximal exercise testing with the use of ACE and WCT in wheelchair basketball players. Twelve elite male wheelchair basketball players participated in this study. The research was performed during a training camp of the Polish National Wheelchair Basketball Team. The study participants were divided into two functional categories: A (players with class 1.0 - 2.5 and B (players with class 3.0 - 4.5. Two main maximal exercise tests, i.e. wheelchair treadmill stress test (WCT test and arm crank ergometer stress test (ACE test were used to evaluate aerobic performance of the players. There were no statistically significant differences in aerobic tests between the players from both groups. The comparison of results achieved in two aerobic tests performed on WCT and ACE did not reveal any significant differences between the analyzed variables (peak heart rate (HRpeak, peak oxygen uptake (VO2peak, minute ventilation (VE, anaerobic threshold (AT, lactate concentration (LApeak, and a drop in lactate concentration (%LA. Strong correlations between results achieved in WCT and ACE tests were found for VO2peak, VE and LApeak. The main conclusion of the study is that both WCT and ACE tests may be useful when determining aerobic capacity of wheelchair basketball players. Moreover, both protocols can be used by athletes regardless of their functional capabilities and types of impairment.

  7. Efficacy of Feedback-Controlled Robotics-Assisted Treadmill Exercise to Improve Cardiovascular Fitness Early After Stroke: A Randomized Controlled Pilot Trial.

    Science.gov (United States)

    Stoller, Oliver; de Bruin, Eling D; Schindelholz, Matthias; Schuster-Amft, Corina; de Bie, Rob A; Hunt, Kenneth J

    2015-07-01

    Cardiovascular fitness is greatly reduced after stroke. Although individuals with mild to moderate impairments benefit from conventional cardiovascular exercise interventions, there is a lack of effective approaches for persons with severely impaired physical function. This randomized controlled pilot trial investigated efficacy and feasibility of feedback-controlled robotics-assisted treadmill exercise (FC-RATE) for cardiovascular rehabilitation in persons with severe impairments early after stroke. Twenty individuals (age 61 ± 11 years; 52 ± 31 days poststroke) with severe motor limitations (Functional Ambulation Classification 0-2) were recruited for FC-RATE or conventional robotics-assisted treadmill exercise (RATE) (4 weeks, 3 × 30-minute sessions/wk). Outcome measures focused on peak cardiopulmonary performance parameters, training intensity, and feasibility, with examiners blinded to allocation. All 14 allocated participants (70% of recruited) completed the intervention (7/group, withdrawals unrelated to intervention), without serious adverse events occurring. Cardiovascular fitness increased significantly in both groups, with peak oxygen uptake increasing from 14.6 to 17.7 mL · kg · min (+17.8%) after 4 weeks (45.8%-55.7% of predicted maximal aerobic capacity; time effect P = 0.01; no group-time interaction). Training intensity (% heart rate reserve) was significantly higher for FC-RATE (40% ± 3%) than for conventional RATE (14% ± 2%) (P = 0.001). Substantive overall increases in the main cardiopulmonary performance parameters were observed, but there were no significant between-group differences when comparing FC-RATE and conventional RATE. Feedback-controlled robotics-assisted treadmill exercise significantly increased exercise intensity, but recommended intensity levels for cardiovascular training were not consistently achieved. Future research should focus on appropriate algorithms within advanced robotic systems to promote optimal cardiovascular

  8. Treadmill exercise induced functional recovery after peripheral nerve repair is associated with increased levels of neurotrophic factors.

    Directory of Open Access Journals (Sweden)

    Jae-Sung Park

    Full Text Available Benefits of exercise on nerve regeneration and functional recovery have been reported in both central and peripheral nervous system disease models. However, underlying molecular mechanisms of enhanced regeneration and improved functional outcomes are less understood. We used a peripheral nerve regeneration model that has a good correlation between functional outcomes and number of motor axons that regenerate to evaluate the impact of treadmill exercise. In this model, the median nerve was transected and repaired while the ulnar nerve was transected and prevented from regeneration. Daily treadmill exercise resulted in faster recovery of the forelimb grip function as evaluated by grip power and inverted holding test. Daily exercise also resulted in better regeneration as evaluated by recovery of compound motor action potentials, higher number of axons in the median nerve and larger myofiber size in target muscles. Furthermore, these observations correlated with higher levels of neurotrophic factors, glial derived neurotrophic factor (GDNF, brain derived neurotrophic factor (BDNF and insulin-like growth factor-1 (IGF-1, in serum, nerve and muscle suggesting that increase in muscle derived neurotrophic factors may be responsible for improved regeneration.

  9. Partial Body Weight-Supported Treadmill Training in Patients With Parkinson Disease: Impact on Gait and Clinical Manifestation.

    Science.gov (United States)

    Ganesan, Mohan; Sathyaprabha, Talakad N; Pal, Pramod Kumar; Gupta, Anupam

    2015-09-01

    To evaluate the effect of conventional gait training (CGT) and partial weight-supported treadmill training (PWSTT) on gait and clinical manifestation. Prospective experimental research design. Hospital. Patients with idiopathic Parkinson disease (PD) (N=60; mean age, 58.15±8.7y) on stable dosage of dopaminomimetic drugs were randomly assigned into the 3 following groups (20 patients in each group): (1) nonexercising PD group, (2) CGT group, and (3) PWSTT group. The interventions included in the study were CGT and PWSTT. The sessions of the CGT and PWSTT groups were given in patient's self-reported best on status after regular medications. The interventions were given for 30min/d, 4d/wk, for 4 weeks (16 sessions). Clinical severity was measured by the Unified Parkinson Disease Rating Scale (UPDRS) and its subscores. Gait was measured by 2 minutes of treadmill walking and the 10-m walk test. Outcome measures were evaluated in their best on status at baseline and after the second and fourth weeks. Four weeks of CGT and PWSTT gait training showed significant improvements of UPDRS scores, its subscores, and gait performance measures. Moreover, the effects of PWSTT were significantly better than CGT on most measures. PWSTT is a promising intervention tool to improve the clinical and gait outcome measures in patients with PD. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  10. Effects of synchronous music on treadmill running among elite triathletes.

    Science.gov (United States)

    Terry, Peter C; Karageorghis, Costas I; Saha, Alessandra Mecozzi; D'Auria, Shaun

    2012-01-01

    Music can provide ergogenic, psychological, and psychophysical benefits during physical activity, especially when movements are performed synchronously with music. The present study developed the train of research on synchronous music and extended it to elite athletes. Repeated-measures laboratory experiment. Elite triathletes (n=11) ran in time to self-selected motivational music, a neutral equivalent and a no-music control during submaximal and exhaustive treadmill running. Measured variables were time-to-exhaustion, mood responses, feeling states, RPE, blood lactate concentration, oxygen consumption and running economy. Time-to-exhaustion was 18.1% and 19.7% longer, respectively, when running in time to motivational and neutral music, compared to no music. Mood responses and feeling states were more positive with motivational music compared to either neutral music or no music. RPE was lowest for neutral music and highest for the no-music control. Blood lactate concentrations were lowest for motivational music. Oxygen consumption was lower with music by 1.0%-.7%. Both music conditions were associated with better running economy than the no-music control. Although neutral music did not produce the same level of psychological benefits as motivational music, it proved equally beneficial in terms of time-to-exhaustion and oxygen consumption. In functional terms, the motivational qualities of music may be less important than the prominence of its beat and the degree to which participants are able to synchronise their movements to its tempo. Music provided ergogenic, psychological and physiological benefits in a laboratory study and its judicious use during triathlon training should be considered. Copyright © 2011 Sports Medicine Australia. All rights reserved.

  11. Pharmacokinetics of detomidine administered to horses at rest and after maximal exercise.

    Science.gov (United States)

    Hubbell, J A E; Sams, R A; Schmall, L M; Robertson, J T; Hinchcliff, K W; Muir, W W

    2009-05-01

    Increased doses of detomidine are required to produce sedation in horses after maximal exercise compared to calm or resting horses. To determine if the pharmacokinetics of detomidine in Thoroughbred horses are different when the drug is given during recuperation from a brief period of maximal exercise compared to administration at rest. Six Thoroughbred horses were preconditioned by exercising them on a treadmill. Each horse ran a simulated race at a treadmill speed that caused it to exercise at 120% of its maximal oxygen consumption. One minute after the end of exercise, horses were treated with detomidine. Each horse was treated with the same dose of detomidine on a second occasion a minimum of 14 days later while standing in a stocks. Samples of heparinised blood were obtained at various time points on both occasions. Plasma detomidine concentrations were determined by liquid chromatography-mass spectrometry. The plasma concentration vs. time data were analysed by nonlinear regression analysis. Median back-extrapolated time zero plasma concentration was significantly lower and median plasma half-life and median mean residence time were significantly longer when detomidine was administered after exercise compared to administration at rest. Median volume of distribution was significantly higher after exercise but median plasma clearance was not different between the 2 administrations. Detomidine i.v. is more widely distributed when administered to horses immediately after exercise compared to administration at rest resulting in lower peak plasma concentrations and a slower rate of elimination. The dose requirement to produce an equivalent effect may be higher in horses after exercise than in resting horses and less frequent subsequent doses may be required to produce a sustained effect.

  12. Maximal Abelian sets of roots

    CERN Document Server

    Lawther, R

    2018-01-01

    In this work the author lets \\Phi be an irreducible root system, with Coxeter group W. He considers subsets of \\Phi which are abelian, meaning that no two roots in the set have sum in \\Phi \\cup \\{ 0 \\}. He classifies all maximal abelian sets (i.e., abelian sets properly contained in no other) up to the action of W: for each W-orbit of maximal abelian sets we provide an explicit representative X, identify the (setwise) stabilizer W_X of X in W, and decompose X into W_X-orbits. Abelian sets of roots are closely related to abelian unipotent subgroups of simple algebraic groups, and thus to abelian p-subgroups of finite groups of Lie type over fields of characteristic p. Parts of the work presented here have been used to confirm the p-rank of E_8(p^n), and (somewhat unexpectedly) to obtain for the first time the 2-ranks of the Monster and Baby Monster sporadic groups, together with the double cover of the latter. Root systems of classical type are dealt with quickly here; the vast majority of the present work con...

  13. Discordance of exercise thallium testing with coronary arteriography in patients with atypical presentations

    International Nuclear Information System (INIS)

    Bungo, M.W.; Leland, O.S. Jr.

    1983-01-01

    Eighty-one patients with diagnostically difficult clinical presentations suggesting coronary artery disease underwent symptom-limited maximal-exercise treadmill testing (ETT) and exercise radionuclide scanning with thallium-201 followed by coronary angiography. Results showed that in nearly half of the patients (47%) these tests were in agreement, while either exercise thallium or ETT was positive in 94% of patients with coronary artery disease. It was found that agreement between exercise thallium and ETT tests predicted disease in 92% of the instances or excluded disease in 82% of the instances. It is concluded that despite frequent discord between these two tests in 53% of the cases, a significant gain in exclusive diagnostic capability is realized when applied to a patient population anticipated to have a disease prevalence equal to the 67% encountered in this study

  14. Blood lactate clearance after maximal exercise depends on active recovery intensity.

    Science.gov (United States)

    Devlin, J; Paton, B; Poole, L; Sun, W; Ferguson, C; Wilson, J; Kemi, O J

    2014-06-01

    High-intensity exercise is time-limited by onset of fatigue, marked by accumulation of blood lactate. This is accentuated at maximal, all-out exercise that rapidly accumulates high blood lactate. The optimal active recovery intensity for clearing lactate after such maximal, all-out exercise remains unknown. Thus, we studied the intensity-dependence of lactate clearance during active recovery after maximal exercise. We constructed a standardized maximal, all-out treadmill exercise protocol that predictably lead to voluntary exhaustion and blood lactate concentration>10 mM. Next, subjects ran series of all-out bouts that increased blood lactate concentration to 11.5±0.2 mM, followed by recovery exercises ranging 0% (passive)-100% of the lactate threshold. Repeated measurements showed faster lactate clearance during active versus passive recovery (P40%>passive recovery, Pexercise clears accumulated blood lactate faster than passive recovery in an intensity-dependent manner, with maximum clearance occurring at active recovery of 80% of lactate threshold.

  15. Effects of adding a virtual reality environment to different modes of treadmill walking.

    Science.gov (United States)

    Sloot, L H; van der Krogt, M M; Harlaar, J

    2014-03-01

    Differences in gait between overground and treadmill walking are suggested to result from imposed treadmill speed and lack of visual flow. To counteract this effect, feedback-controlled treadmills that allow the subject to control the belt speed along with an immersive virtual reality (VR) have recently been developed. We studied the effect of adding a VR during both fixed speed (FS) and self-paced (SP) treadmill walking. Nineteen subjects walked on a dual-belt instrumented treadmill with a simple endless road projected on a 180° circular screen. A main effect of VR was found for hip flexion offset, peak hip extension, peak knee extension moment, knee flexion moment gain and ankle power during push off. A consistent interaction effect between VR and treadmill mode was found for 12 out of 30 parameters, although the differences were small and did not exceed 50% of the within subject stride variance. At FS, the VR seemed to slightly improve the walking pattern towards overground walking, with for example a 6.5mm increase in stride length. At SP, gait became slightly more cautious by adding a VR, with a 9.1mm decrease in stride length. Irrespective of treadmill mode, subjects rated walking with the VR as more similar to overground walking. In the context of clinical gait analysis, the effects of VR are too small to be relevant and are outweighed by the gains of adding a VR, such as a more stimulating experience and possibility of augmenting it by real-time feedback. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Specific smartphone usage and cognitive performance affect gait characteristics during free-living and treadmill walking.

    Science.gov (United States)

    Niederer, Daniel; Bumann, Anke; Mühlhauser, Yvonne; Schmitt, Mareike; Wess, Katja; Engeroff, Tobias; Wilke, Jan; Vogt, Lutz; Banzer, Winfried

    2018-04-06

    Mobile phone tasks like texting, typing, and dialling during walking are known to impact gait characteristics. Beyond that, the effects of performing smartphone-typical actions like researching and taking self-portraits (selfie) on gait have not been investigated yet. We aimed to investigate the effects of smartphone usage on relevant gait characteristics and to reveal potential association of basic cognitive and walking plus smartphone dual-task abilities. Our cross-sectional, cross-over study on physically active, healthy participants was performed on two days, interrupted by a 24-h washout in between. Assessments were: 1) Cognitive testing battery consisting of the trail making test (TMT A and B) and the Stroop test 2) Treadmill walking under five smartphone usage conditions: no use (control condition), reading, dialling, internet searching and taking a selfie in randomized order. Kinematic and kinetic gait characteristics were assessed to estimate conditions influence. In our sample of 36 adults (24.6 ± 1 years, 23 female, 13 male), ANCOVAs followed by post-hoc t-tests revealed that smartphone usage impaired all tested gait characteristics: gait speed (decrease, all conditions): F = 54.7, p smartphone usage was systematically associated with the TMT B time regarding cadence and double stride length for reading (r = -0.37), dialling (r = -0.35) and taking a selfie (r = -0.34). Smartphone usage substantially impacts walking characteristics in most situations. Changes of gait patterns indicate higher cognitive loads and lower awareness. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Post-exercise hypotensive responses following an acute bout of aquatic and overground treadmill walking in people post-stroke: a pilot study.

    Science.gov (United States)

    Lai, Byron; Jeng, Brenda; Vrongistinos, Konstantinos; Jung, Taeyou

    2015-06-01

    The purpose of this study is to investigate the effects of a single-bout of aquatic treadmill walking (ATW) and overground treadmill walking (OTW) on the magnitude and duration of post-exercise ambulatory blood pressure (BP) in people post-stroke. Seven people post-stroke participated in a cross-sectional comparative study. BP was monitored for up to 9 hours after a 15-minute bout of ATW and OTW at approximately 70% of maximal oxygen consumption (VO2max), performed on separate days. Mean systolic and diastolic BP values were compared between both exercise conditions and a day without exercise (control). Three hours after OTW, mean SBP increased by 9% from pre-exercise baseline compared to a 3% decrease during the control day (P stroke can sustain sufficient walking intensities necessary to reduce BP following cardiovascular exercise. Also, these data suggest that ATW can elicit clinically meaningful reductions in DBP and night-time SBP. Thus, it is recommended for clinicians to consider ATW as a non-pharmaceutical means to regulate DBP and promote nighttime dipping of SBP in people post-stroke. However, caution is advised during the immediate hours after exercise, a period of possible BP inflation.

  18. The Effects of Hypobaric Hypoxia on Erythropoiesis, Maximal Oxygen Uptake and Energy Cost of Exercise Under Normoxia in Elite Biathletes

    Directory of Open Access Journals (Sweden)

    Milosz Czuba

    2014-12-01

    Full Text Available The aim of the present study was to evaluate the effects of 3 weeks altitude training according to the HiHiLo (live high-base train high-interval train low procedure as described by Chapman et al. (1998, on erythropoiesis, maximal oxygen uptake and energy cost of exercise under normoxia in elite biathletes. Fifteen male elite biathletes randomly divided into an experimental (H group (n = 7; age 27.1 ± 4.6 years; maximal oxygen uptake (VO2max 66.9 ± 3.3 ml·kg–1·min–1; body height (BH 1.81 ± 0.06 m; body mass (BM 73.1 ± 5.4kg, and a control (C group (n = 8; age 23.2 ± 0.9 years; VO2max 68.2 ± 4.1 ml·kg–1·min–1; BH 1.75 ± 0.03 m; BM 63.1 ± 1.5 kg took part in the study. The H group stayed for 3 weeks at an altitude of 2015 m and performed endurance training on skis four times per week at 3000 m. Additionally, the training protocol included three high-intensity interval sessions at an altitude of 1000 m. The C group followed the same training protocol with skirollers in normoxia at an altitude of 600 m. The HiHiLo protocol applied in our study did not change VO2max or maximal workload (WRmax significantly during the incremental treadmill test in group H. However, the energy cost for selected submaximal workloads in group H was significantly (p < 0.01 reduced compared to group C (-5.7%, -4.4%, -6% vs. -3.5%, -2.1%, -2.4%. Also a significant (p < 0.001 increase in serum EPO levels during the first two weeks of HiHiLo training at 2015 m was observed, associated with a significant (p < 0.05 increase in hemoglobin mass, number of erythrocytes, hematocrit value and percent of reticulocytes compared with initial values (by 6.4%, 5%, 4.6% and 16,6%, respectively. In group C, changes in these variables were not observed. These positive changes observed in our study led to a conclusion that the HiHiLo training method could improve endurance in normoxia, since most of the biathlon competitions are performed at submaximal intensities.

  19. Maximal exercise electrocardiographic responses and coronary heart disease mortality among men with metabolic syndrome.

    Science.gov (United States)

    Lyerly, G William; Sui, Xuemei; Church, Timothy S; Lavie, Carl J; Hand, Gregory A; Blair, Steven N

    2010-03-01

    To examine the association between abnormal exercise electrocardiographic (E-ECG) test results and mortality (all-cause and that resulting from coronary heart disease [CHD] or cardiovascular disease [CVD]) in a large population of asymptomatic men with metabolic syndrome (MetS). A total of 9191 men (mean age, 46.9 years) met the criteria of having MetS. All completed a maximal E-ECG treadmill test (May 14, 1979, through April 9, 2001) and were without a previous CVD event or diabetes at baseline. Main outcomes were all-cause mortality, mortality due to CHD, and mortality due to CVD. Cox regression analysis was used to quantify the mortality risk according to E-ECG responses. During a follow-up of 14 years, 633 deaths (242 CVD and 150 CHD) were identified. Mortality rates and hazard ratios (HRs) across E-ECG responses were the following: for all-cause mortality: HR, 1.36; 95% confidence interval (CI), 1.09-1.70 for equivocal responses and HR, 1.41; 95% CI, 1.12-1.77 for abnormal responses (P(trend)<.001); for mortality due to CVD: HR, 1.29; 95% CI, 0.88-1.88 for equivocal responses and HR, 2.04; 95% CI, 1.46-2.84 for abnormal responses (P(trend)<.001); and for mortality due to CHD: HR, 1.62; 95% CI, 1.02-2.56 for equivocal responses and HR, 2.45; 95% CI, 1.62-3.69 for abnormal responses (P(trend)<.001). A positive gradient for CHD, CVD, and all-cause mortality rates across E-ECG categories within 3, 4, or 5 MetS components was observed (P<.001 for all). Among men with MetS, an abnormal E-ECG response was associated with higher risk of all-cause, CVD, and CHD mortality. These findings underscore the importance of E-ECG tests to identify men with MetS who are at risk of dying.

  20. Plasma homocysteine level in cardiac syndrome X and its relation with duke treadmill score

    International Nuclear Information System (INIS)

    Timurkaynak, T.; Balcioglu, S.; Arslan, U.; Kocaman, Sinan A.; Cengel, A.

    2008-01-01

    Objective was to investigate the plasma homocysteine level and relationship between plasma homocysteine level and duke treadmill score (DTS) in cardiac syndrome X (CSX) patients. Seventy-nine patients (36 male, 43 female, mean age: 50+-8.8 years) admitted to Gazi University Hospital, Ankara, Turkey with typical effort angina, positive stress test and angiographically normal coronary arteries between January and September 2006 were included in this prospective and controlled study. Thirty asymptomatic patients (11 male, 19 female, mean age: 47.6+-8.3 years) with two cardiovascular risk factors were chosen as a control group. Plasma homocysteine level was measured in both groups and DTS was calculated in the CSX group. Plasma homocysteine was measured with AxSYM homocysteine immunoassay method in both groups. Plasma homocysteine level was higher in the CSx group compared to the control group 16.5+-4.9 umol/L, n=79, versus 12.4+-4.1 umol/L, n=30, p<0.001). The DTS was -2.7+-5.3 in the CSX group. There was a negative correlation between the DTS and homocysteine levels in the CSX group. (r=-0.506, p<0.001). Plasma homocysteine level, which is known to cause endothelial dysfunction and microvascular ischemia were higher in CSX patients. Also, this increase in homocysteine level correlated with the DTS, which represents the magnitude of ischemia. (author)

  1. Fractional flow reserve in patients with intermediate values of Duke Treadmill Score and borderline coronary lesions

    Directory of Open Access Journals (Sweden)

    Simić I.

    2013-01-01

    Full Text Available Despite the wide usage of exercise ECG tests and Duke Treadmill Score (DTS in clinical practice, no comparison between this scoring system and Fractional Flow Reserve (FFR has yet been made, particularly in cases of angiographically verified borderline lesions. Thirty patients with single coronary lesions and angiographically assessed borderline stenosis (between 30-70% and previously calculated intermediate values of DTS between -10 to +4 were examined using FFR. Adequate specificity and sensitivity (0.769 and 0.556, respectively were in a more narrow range of -0.5 to -10. Sex and age did not have an influence on the DTS values. There was a correlation between the values of FFR and age (r=0.395, p=0.031 and between angiographic assessment of stenosis and quantitative coronary angiography (QCA (r=0.648, p<0.0001. In the study population, a decision on revascularization could not be based solely on angiographic or QCA assessment of the artery or on the values of DTS.

  2. The correlation between running economy and maximal oxygen uptake: cross-sectional and longitudinal relationships in highly trained distance runners.

    Science.gov (United States)

    Shaw, Andrew J; Ingham, Stephen A; Atkinson, Greg; Folland, Jonathan P

    2015-01-01

    A positive relationship between running economy and maximal oxygen uptake (V̇O2max) has been postulated in trained athletes, but previous evidence is equivocal and could have been confounded by statistical artefacts. Whether this relationship is preserved in response to running training (changes in running economy and V̇O2max) has yet to be explored. This study examined the relationships of (i) running economy and V̇O2max between runners, and (ii) the changes in running economy and V̇O2max that occur within runners in response to habitual training. 168 trained distance runners (males, n = 98, V̇O2max 73.0 ± 6.3 mL∙kg-1∙min-1; females, n = 70, V̇O2max 65.2 ± 5.9 mL kg-1∙min-1) performed a discontinuous submaximal running test to determine running economy (kcal∙km-1). A continuous incremental treadmill running test to volitional exhaustion was used to determine V̇O2max 54 participants (males, n = 27; females, n = 27) also completed at least one follow up assessment. Partial correlation analysis revealed small positive relationships between running economy and V̇O2max (males r = 0.26, females r = 0.25; Peconomy and V̇O2max in response to habitual training (r = 0.35; Peconomy and V̇O2max in highly trained distance runners. With >85% of the variance in these parameters unexplained by this relationship, these findings reaffirm that running economy and V̇O2max are primarily determined independently.

  3. Postnatal Treadmill Exercise Alleviates Prenatal Stress-Induced Anxiety in Offspring Rats by Enhancing Cell Proliferation Through 5-Hydroxytryptamine 1A Receptor Activation

    Directory of Open Access Journals (Sweden)

    Sam Jun Lee

    2016-05-01

    Full Text Available Purpose: Stress during pregnancy is a risk factor for the development of anxiety-related disorders in offspring later in life. The effects of treadmill exercise on anxiety-like behaviors and hippocampal cell proliferation were investigated using rats exposed to prenatal stress. Methods: Exposure of pregnant rats to a hunting dog in an enclosed room was used to induce stress. Anxiety-like behaviors of offspring were evaluated using the elevated plus maze test. Immunohistochemistry for the detection of 5-bromo-2ʹ- deoxyuridine and doublecortin (DCX in the hippocampal dentate gyrus and 5-hydroxytryptamine 1A receptors (5-HT1A in the dorsal raphe was conducted. Brain-derived neurotrophic factor (BDNF and tyrosine kinase B (TrkB levels in the hippocampus were evaluated by western blot analysis. Results: Offspring of maternal rats exposed to stress during pregnancy showed anxiety-like behaviors. Offspring also showed reduced expression of BDNF, TrkB, and DCX in the dentate gyrus, decreased cell proliferation in the hippocampus, and reduced 5-HT1A expression in the dorsal raphe. Postnatal treadmill exercise by offspring, but not maternal exercise during pregnancy, enhanced cell proliferation and expression of these proteins. Conclusions: Postnatal treadmill exercise ameliorated anxiety-like behaviors in offspring of stressed pregnant rats, and the alleviating effect of exercise on these behaviors is hypothesized to result from enhancement of cell proliferation through 5-HT1A activation in offspring rats.

  4. Treadmill Running Ameliorates Destruction of Articular Cartilage and Subchondral Bone, Not Only Synovitis, in a Rheumatoid Arthritis Rat Model

    Directory of Open Access Journals (Sweden)

    Seiji Shimomura

    2018-06-01

    Full Text Available We analyzed the influence of treadmill running on rheumatoid arthritis (RA joints using a collagen-induced arthritis (CIA rat model. Eight-week-old male Dark Agouti rats were randomly divided into four groups: The control group, treadmill group (30 min/day for 4 weeks from 10-weeks-old, CIA group (induced CIA at 8-weeks-old, and CIA + treadmill group. Destruction of the ankle joint was evaluated by histological analyses. Morphological changes of subchondral bone were analyzed by μ-CT. CIA treatment-induced synovial membrane invasion, articular cartilage destruction, and bone erosion. Treadmill running improved these changes. The synovial membrane in CIA rats produced a large amount of tumor necrosis factor-α and Connexin 43; production was significantly suppressed by treadmill running. On μ-CT of the talus, bone volume fraction (BV/TV was significantly decreased in the CIA group. Marrow star volume (MSV, an index of bone loss, was significantly increased. These changes were significantly improved by treadmill running. Bone destruction in the talus was significantly increased with CIA and was suppressed by treadmill running. On tartrate-resistant acid phosphate and alkaline phosphatase (TRAP/ALP staining, the number of osteoclasts around the pannus was decreased by treadmill running. These findings indicate that treadmill running in CIA rats inhibited synovial hyperplasia and joint destruction.

  5. Maximizing benefits from resource development

    International Nuclear Information System (INIS)

    Skjelbred, B.

    2002-01-01

    The main objectives of Norwegian petroleum policy are to maximize the value creation for the country, develop a national oil and gas industry, and to be at the environmental forefront of long term resource management and coexistence with other industries. The paper presents a graph depicting production and net export of crude oil for countries around the world for 2002. Norway produced 3.41 mill b/d and exported 3.22 mill b/d. Norwegian petroleum policy measures include effective regulation and government ownership, research and technology development, and internationalisation. Research and development has been in five priority areas, including enhanced recovery, environmental protection, deep water recovery, small fields, and the gas value chain. The benefits of internationalisation includes capitalizing on Norwegian competency, exploiting emerging markets and the assurance of long-term value creation and employment. 5 figs

  6. Maximizing synchronizability of duplex networks

    Science.gov (United States)

    Wei, Xiang; Emenheiser, Jeffrey; Wu, Xiaoqun; Lu, Jun-an; D'Souza, Raissa M.

    2018-01-01

    We study the synchronizability of duplex networks formed by two randomly generated network layers with different patterns of interlayer node connections. According to the master stability function, we use the smallest nonzero eigenvalue and the eigenratio between the largest and the second smallest eigenvalues of supra-Laplacian matrices to characterize synchronizability on various duplexes. We find that the interlayer linking weight and linking fraction have a profound impact on synchronizability of duplex networks. The increasingly large inter-layer coupling weight is found to cause either decreasing or constant synchronizability for different classes of network dynamics. In addition, negative node degree correlation across interlayer links outperforms positive degree correlation when most interlayer links are present. The reverse is true when a few interlayer links are present. The numerical results and understanding based on these representative duplex networks are illustrative and instructive for building insights into maximizing synchronizability of more realistic multiplex networks.

  7. Treadmill exercise alleviates short-term memory impairment in 6-hydroxydopamine-induced Parkinson's rats.

    Science.gov (United States)

    Cho, Han-Sam; Shin, Mal-Soon; Song, Wook; Jun, Tae-Won; Lim, Baek-Vin; Kim, Young-Pyo; Kim, Chang-Ju

    2013-01-01

    Progressive loss of dopaminergic neurons in substantia nigra is a key pathogenesis of Parkinson's disease. In the present study, we investigated the effects of treadmill exercise on short-term memory, apoptotic dopaminergic neuronal cell death and fiber loss in the nigrostriatum, and cell proliferation in the hippocampal dentate gyrus of Parkinson's rats. Parkinson's rats were made by injection of 6-hydroxydopamine (6-OHDA) into the striatum using stereotaxic instrument. Four weeks after 6-OHDA injection, the rats in the 6-OHDA-injection group exhibited significant rotational asymmetry following apomorphine challenge. The rats in the exercise groups were put on the treadmill to run for 30 min once a day for 14 consecutive days starting 4 weeks after 6-OHDA injection. In the present results, extensive degeneration of the dopaminergic neurons in the substantia nigra with loss of dopaminergic fibers in the striatum were produced in the rats without treadmill running, which resulted in short-term memory impairment. However, the rats performing treadmill running for 2 weeks alleviated nigrostriatal dopaminergic cell loss and alleviated short-term memory impairment with increasing cell proliferation in the hippocampal dentate gyrus of Parkinson's rats. The present results show that treadmill exercise may provide therapeutic value for the Parkinson's disease.

  8. Human H-reflexes are smaller in difficult beam walking than in normal treadmill walking.

    Science.gov (United States)

    Llewellyn, M; Yang, J F; Prochazka, A

    1990-01-01

    Hoffman (H) reflexes were elicited from the soleus (SOL) muscle while subjects walked on a treadmill and on a narrow beam (3.5 cm wide, raised 34 cm from the floor). The speed of walking on the treadmill was selected for each subject to match the background activation level of their SOL muscle during beam walking. The normal reciprocal activation pattern of the tibialis anterior and SOL muscles in treadmill walking was replaced by a pattern dominated by co-contraction on the beam. In addition, the step cycle duration was more variable and the time spent in the swing phase was reduced on the beam. The H-reflexes were highly modulated in both tasks, the amplitude being high in the stance phase and low in the swing phase. The H-reflex amplitude was on average 40% lower during beam walking than treadmill walking. The relationship between the H-reflex amplitude and the SOL EMG level was quantified by a regression line relating the two variables. The slope of this line was on average 41% lower in beam walking than treadmill walking. The lower H-reflex gain observed in this study and the high level of fusimotor drive observed in cats performing similar tasks suggest that the two mechanisms which control the excitability of this reflex pathway (i.e. fusimotor action and control of transmission at the muscle spindle to moto-neuron synapse) may be controlled independently.

  9. Treadmill workstations: the effects of walking while working on physical activity and work performance.

    Directory of Open Access Journals (Sweden)

    Avner Ben-Ner

    Full Text Available We conducted a 12-month-long experiment in a financial services company to study how the availability of treadmill workstations affects employees' physical activity and work performance. We enlisted sedentary volunteers, half of whom received treadmill workstations during the first two months of the study and the rest in the seventh month of the study. Participants could operate the treadmills at speeds of 0-2 mph and could use a standard chair-desk arrangement at will. (a Weekly online performance surveys were administered to participants and their supervisors, as well as to all other sedentary employees and their supervisors. Using within-person statistical analyses, we find that overall work performance, quality and quantity of performance, and interactions with coworkers improved as a result of adoption of treadmill workstations. (b Participants were outfitted with accelerometers at the start of the study. We find that daily total physical activity increased as a result of the adoption of treadmill workstations.

  10. Mechanical Alterations Associated with Repeated Treadmill Sprinting under Heat Stress.

    Directory of Open Access Journals (Sweden)

    Olivier Girard

    Full Text Available Examine the mechanical alterations associated with repeated treadmill sprinting performed in HOT (38°C and CON (25°C conditions.Eleven recreationally active males performed a 30-min warm-up followed by three sets of five 5-s sprints with 25-s recovery and 3-min between sets in each environment. Constant-velocity running for 1-min at 10 and 20 km.h-1 was also performed prior to and following sprinting.Mean skin (37.2±0.7 vs. 32.7±0.8°C; P<0.001 and core (38.9±0.2 vs. 38.8±0.3°C; P<0.05 temperatures, together with thermal comfort (P<0.001 were higher following repeated sprinting in HOT vs. CON. Step frequency and vertical stiffness were lower (-2.6±1.6% and -5.5±5.5%; both P<0.001 and contact time (+3.2±2.4%; P<0.01 higher in HOT for the mean of sets 1-3 compared to CON. Running distance per sprint decreased from set 1 to 3 (-7.0±6.4%; P<0.001, with a tendency for shorter distance covered in HOT vs. CON (-2.7±3.4%; P = 0.06. Mean vertical (-2.6±5.5%; P<0.01, horizontal (-9.1±4.4%; P<0.001 and resultant ground reaction forces (-3.0±2.8%; P<0.01 along with vertical stiffness (-12.9±2.3%; P<0.001 and leg stiffness (-8.4±2.7%; P<0.01 decreased from set 1 to 3, independently of conditions. Propulsive power decreased from set 1 to 3 (-16.9±2.4%; P<0.001, with lower propulsive power values in set 2 (-6.6%; P<0.05 in HOT vs. CON. No changes in constant-velocity running patterns occurred between conditions, or from pre-to-post repeated-sprint exercise.Thermal strain alters step frequency and vertical stiffness during repeated sprinting; however without exacerbating mechanical alterations. The absence of changes in constant-velocity running patterns suggests a strong link between fatigue-induced velocity decrements during sprinting and mechanical alterations.

  11. Mechanical Alterations Associated with Repeated Treadmill Sprinting under Heat Stress

    Science.gov (United States)

    Brocherie, Franck; Morin, Jean-Benoit; Racinais, Sébastien; Millet, Grégoire P.; Périard, Julien D.

    2017-01-01

    Purpose Examine the mechanical alterations associated with repeated treadmill sprinting performed in HOT (38°C) and CON (25°C) conditions. Methods Eleven recreationally active males performed a 30-min warm-up followed by three sets of five 5-s sprints with 25-s recovery and 3-min between sets in each environment. Constant-velocity running for 1-min at 10 and 20 km.h-1 was also performed prior to and following sprinting. Results Mean skin (37.2±0.7 vs. 32.7±0.8°C; P<0.001) and core (38.9±0.2 vs. 38.8±0.3°C; P<0.05) temperatures, together with thermal comfort (P<0.001) were higher following repeated sprinting in HOT vs. CON. Step frequency and vertical stiffness were lower (-2.6±1.6% and -5.5±5.5%; both P<0.001) and contact time (+3.2±2.4%; P<0.01) higher in HOT for the mean of sets 1–3 compared to CON. Running distance per sprint decreased from set 1 to 3 (-7.0±6.4%; P<0.001), with a tendency for shorter distance covered in HOT vs. CON (-2.7±3.4%; P = 0.06). Mean vertical (-2.6±5.5%; P<0.01), horizontal (-9.1±4.4%; P<0.001) and resultant ground reaction forces (-3.0±2.8%; P<0.01) along with vertical stiffness (-12.9±2.3%; P<0.001) and leg stiffness (-8.4±2.7%; P<0.01) decreased from set 1 to 3, independently of conditions. Propulsive power decreased from set 1 to 3 (-16.9±2.4%; P<0.001), with lower propulsive power values in set 2 (-6.6%; P<0.05) in HOT vs. CON. No changes in constant-velocity running patterns occurred between conditions, or from pre-to-post repeated-sprint exercise. Conclusions Thermal strain alters step frequency and vertical stiffness during repeated sprinting; however without exacerbating mechanical alterations. The absence of changes in constant-velocity running patterns suggests a strong link between fatigue-induced velocity decrements during sprinting and mechanical alterations. PMID:28146582

  12. VIOLATION OF CONVERSATION MAXIM ON TV ADVERTISEMENTS

    Directory of Open Access Journals (Sweden)

    Desak Putu Eka Pratiwi

    2015-07-01

    Full Text Available Maxim is a principle that must be obeyed by all participants textually and interpersonally in order to have a smooth communication process. Conversation maxim is divided into four namely maxim of quality, maxim of quantity, maxim of relevance, and maxim of manner of speaking. Violation of the maxim may occur in a conversation in which the information the speaker has is not delivered well to his speaking partner. Violation of the maxim in a conversation will result in an awkward impression. The example of violation is the given information that is redundant, untrue, irrelevant, or convoluted. Advertisers often deliberately violate the maxim to create unique and controversial advertisements. This study aims to examine the violation of maxims in conversations of TV ads. The source of data in this research is food advertisements aired on TV media. Documentation and observation methods are applied to obtain qualitative data. The theory used in this study is a maxim theory proposed by Grice (1975. The results of the data analysis are presented with informal method. The results of this study show an interesting fact that the violation of maxim in a conversation found in the advertisement exactly makes the advertisements very attractive and have a high value.

  13. Treadmill training with an incline reduces ankle joint stiffness and improves active range of movement during gait in adults with cerebral palsy

    DEFF Research Database (Denmark)

    Lorentzen, Jakob; Kirk, Henrik; Fernandez-Lago, Helena

    2017-01-01

    of gait were obtained before and after the intervention/control period. Intervention subjects trained 31.4 SD 10.1 days for 29.0 SD 2.3 min (total) 15.2 h. RESULTS: Passive ankle joint stiffness was reduced (F = 5.1; p = 0.031), maximal gait speed increased (F = 42.8, p ...PURPOSE: We investigated if 30 min of daily treadmill training with an incline for 6 weeks would reduce ankle joint stiffness and improve active range of movement in adults with cerebral palsy (CP). METHODS: The study was designed as a randomized controlled clinical trial including 32 adults...... prior to heel strike increased (F = 5.3, p reduces ankle joint stiffness and increases active ROM during...

  14. Seasonal variations in body composition, maximal oxygen uptake, and gas exchange threshold in cross-country skiers.

    Science.gov (United States)

    Polat, Metin; Korkmaz Eryılmaz, Selcen; Aydoğan, Sami

    2018-01-01

    In order to ensure that athletes achieve their highest performance levels during competitive seasons, monitoring their long-term performance data is crucial for understanding the impact of ongoing training programs and evaluating training strategies. The present study was thus designed to investigate the variations in body composition, maximal oxygen uptake (VO 2max ), and gas exchange threshold values of cross-country skiers across training phases throughout a season. In total, 15 athletes who participate in international cross-country ski competitions voluntarily took part in this study. The athletes underwent incremental treadmill running tests at 3 different time points over a period of 1 year. The first measurements were obtained in July, during the first preparation period; the second measurements were obtained in October, during the second preparation period; and the third measurements were obtained in February, during the competition period. Body weight, body mass index (BMI), body fat (%), as well as VO 2max values and gas exchange threshold, measured using V-slope method during the incremental running tests, were assessed at all 3 time points. The collected data were analyzed using SPSS 20 package software. Significant differences between the measurements were assessed using Friedman's twoway variance analysis with a post hoc option. The athletes' body weights and BMI measurements at the third point were significantly lower compared with the results of the second measurement ( p exchange threshold, running speed at the gas exchange threshold, VO 2max , amount of oxygen consumed at gas exchange threshold level (VO 2GET ), maximal heart rate (HR max ), and heart rate at gas exchange threshold level (HR GET ) values did not significantly differ between the measurement time points ( p >0.05). VO 2max and gas exchange threshold values recorded during the third measurements, the timing of which coincided with the competitive season of the cross-country skiers

  15. Iodophenylpentadecanoic acid-myocardial blood flow relationship during maximal exercise with coronary occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, J.H.; Martin, G.V.; Link, J.M.; Krohn, K.A.; Bassingthwaighte, J.B. (Seattle VA Medical Center, WA (USA))

    1990-01-01

    Imaging {sup 123}I-labeled iodophenylpentadecanoic acid (IPPA) uptake and clearance from the myocardium following exercise has been advocated as a means of detecting myocardial ischemia because fatty acid deposition is enhanced and clearance prolonged in regions of low flow. However, normal regional myocardial blood flows are markedly heterogeneous, and it is not known how this heterogeneity affects regional metabolism or substrate uptake and thus image interpretation. In five instrumented dogs running at near maximal workload on a treadmill, {sup 131}I-labeled IPPA and 15-micron 46Sc microspheres were injected into the left atrium after 30 sec of circumflex coronary artery occlusion. Microsphere and IPPA activity were determined in 250 mapped pieces of myocardium of approximately 400 mg. Myocardial blood flows (from microspheres) ranged from 0.05 to 7.6 ml/min/g. Deposition of IPPA was proportional to regional flows (r = 0.83) with an average retention of 25%. The mean endocardial-epicardial ratio for IPPA (0.90 {plus minus} 0.43) was similar to that for microspheres (0.94 {plus minus} 0.47; p = 0.08). Thus, initial IPPA deposition during treadmill exercise increases in proportion to regional myocardial blood flow over a range of flows from very low to five times normal.

  16. Iodophenylpentadecanoic acid-myocardial blood flow relationship during maximal exercise with coronary occlusion

    International Nuclear Information System (INIS)

    Caldwell, J.H.; Martin, G.V.; Link, J.M.; Krohn, K.A.; Bassingthwaighte, J.B.

    1990-01-01

    Imaging 123 I-labeled iodophenylpentadecanoic acid (IPPA) uptake and clearance from the myocardium following exercise has been advocated as a means of detecting myocardial ischemia because fatty acid deposition is enhanced and clearance prolonged in regions of low flow. However, normal regional myocardial blood flows are markedly heterogeneous, and it is not known how this heterogeneity affects regional metabolism or substrate uptake and thus image interpretation. In five instrumented dogs running at near maximal workload on a treadmill, 131 I-labeled IPPA and 15-micron 46Sc microspheres were injected into the left atrium after 30 sec of circumflex coronary artery occlusion. Microsphere and IPPA activity were determined in 250 mapped pieces of myocardium of approximately 400 mg. Myocardial blood flows (from microspheres) ranged from 0.05 to 7.6 ml/min/g. Deposition of IPPA was proportional to regional flows (r = 0.83) with an average retention of 25%. The mean endocardial-epicardial ratio for IPPA (0.90 ± 0.43) was similar to that for microspheres (0.94 ± 0.47; p = 0.08). Thus, initial IPPA deposition during treadmill exercise increases in proportion to regional myocardial blood flow over a range of flows from very low to five times normal

  17. Iodophenylpentadecanoic acid-myocardial blood flow relationship during maximal exercise with coronary occlusion.

    Science.gov (United States)

    Caldwell, J H; Martin, G V; Link, J M; Krohn, K A; Bassingthwaighte, J B

    1990-01-01

    Imaging 123I-labeled iodophenylpentadecanoic acid (IPPA) uptake and clearance from the myocardium following exercise has been advocated as a means of detecting myocardial ischemia because fatty acid deposition is enhanced and clearance prolonged in regions of low flow. However, normal regional myocardial blood flows are markedly heterogeneous, and it is not known how this heterogeneity affects regional metabolism or substrate uptake and thus image interpretation. In five instrumented dogs running at near maximal workload on a treadmill, 131I-labeled IPPA and 15-micron 46Sc microspheres were injected into the left atrium after 30 sec of circumflex coronary artery occlusion. Microsphere and IPPA activity were determined in 250 mapped pieces of myocardium of approximately 400 mg. Myocardial blood flows (from microspheres) ranged from 0.05 to 7.6 ml/min/g. Deposition of IPPA was proportional to regional flows (r = 0.83) with an average retention of 25%. The mean endocardial-epicardial ratio for IPPA (0.90 +/- 0.43) was similar to that for microspheres (0.94 +/- 0.47; p = 0.08). Thus, initial IPPA deposition during treadmill exercise increases in proportion to regional myocardial blood flow over a range of flows from very low to five times normal.

  18. Conjugated linoleic acid supplementation does not maximize motor performance and abdominal and trunk fat loss induced by aerobic training in overweight women

    Directory of Open Access Journals (Sweden)

    Fábio Luiz Cheche PINA

    Full Text Available ABSTRACT Objective: To analyze the effect of eight weeks of conjugated linoleic acid supplementation on physical performance, and trunk and abdominal fat in overweight women submitted to an aerobic training program. Methods: Twenty-eight overweight women (body mass index ³25 kg/m2 were divided randomly and double-blindly to receive conjugated linoleic acid or placebo, both associated with an aerobic exercise program (frequency = three times a week, duration=30 min/session, intensity=80% of maximum heart rate. Conjugated linoleic acid (3.2 g and placebo (4.0 g supplements were consumed daily (four capsules for eight weeks. Maximum speed and time to exhaustion were determined in incremental treadmill test. Trunk fat was estimated by dual-energy X-Ray absorptiometry. Waist circumference was used as indicator of abdominal fat. Results: Main effect of time (p0.05. Similarly, significant reductions (p0.05. Conclusion: The results of this study suggest that conjugated linoleic acid supplementation does not maximize motor performance, and loss of body and abdominal fat induced by aerobic training in overweight women.

  19. Bilateral coordination and gait symmetry after body-weight supported treadmill training for persons with chronic stroke.

    Science.gov (United States)

    Combs, Stephanie A; Dugan, Eric L; Ozimek, Elicia N; Curtis, Amy B

    2013-04-01

    Locomotor interventions are commonly assessed using functional outcomes, but these outcomes provide limited information about changes toward recovery or compensatory mechanisms. The study purposes were to examine changes in gait symmetry and bilateral coordination following body-weight supported treadmill training in individuals with chronic hemiparesis due to stroke and to compare findings to participants without disability. Nineteen participants with stroke (>6 months) who ambulated between 0.4 and 0.8 m/s and 22 participants without disability were enrolled in this repeated-measures study. The stroke group completed 24 intervention sessions over 8 weeks with 20 minutes of walking/session. The non-disabled group served as a comparison for describing changes in symmetry and coordination. Bilateral 3-dimensional motion analysis and gait speed were assessed across 3 time points (pre-test, immediate post-test, and 6-month retention). Continuous relative phase was used to evaluate bilateral coordination (thigh-thigh, shank-shank, foot-foot) and gait symmetry was assessed with spatiotemporal ratios (step length, swing time, stance time). Significant improvements in continuous relative phase (shank-shank and foot-foot couplings) were found at post-test and retention for the stroke group. Significant differences in spatiotemporal symmetry ratios were not found over time. Compared to the non-disabled group, changes in bilateral coordination moved in the direction of normal recovery. Most measures of continuous relative phase were more responsive to change after training than the spatiotemporal ratios. After body-weight supported treadmill training, the stroke group made improvements toward recovery of normal bilateral coordination. Bilateral coordination and gait symmetry measures may assess different aspects of gait. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. A Comparison of Locomotor Therapy Interventions: Partial-Body Weight-Supported Treadmill, Lokomat, and G-EO Training in People With Traumatic Brain Injury.

    Science.gov (United States)

    Esquenazi, Alberto; Lee, Stella; Wikoff, Amanda; Packel, Andrew; Toczylowski, Theresa; Feeley, John

    2017-09-01

    Literature in the application of gait training techniques in persons with traumatic brain injury (TBI) is limited. Current techniques require multiple staff and are physically demanding. The use of a robotic locomotor training may provide improved training capacity for this population. To examine the impact of 3 different modes of locomotor therapy on gait velocity and spatiotemporal symmetry using an end effector robot (G-EO); a robotic exoskeleton (Lokomat), and manual assisted partial-body weight-supported treadmill training (PBWSTT) in participants with traumatic brain injury. Randomized, prospective study. Tertiary rehabilitation hospital. A total of 22 individuals with ≥12 months chronic TBI with hemiparetic pattern able to walk overground without assistance at velocities between 0.2 and 0.6 m/s. Eighteen sessions of 45 minutes of assigned locomotor training. Overground walking self-selected velocity (SSV), maximal velocity (MV), spatiotemporal asymmetry ratio, 6-Minute Walk Test (6MWT), and mobility domain of Stroke Impact Scale (MSIS). Severity in walking dysfunction was similar across groups as determined by walking velocity data. At baseline, participants in the Lokomat group had a baseline velocity that was slightly slower compared with the other groups. Training elicited a statistically significant median increase in SSV for all groups compared with pretraining (Lokomat, P = .04; G-EO, P = .03; and PBWSTT, P = .02) and MV excluding the G-EO group (Lokomat, P = .04; PBWSTT, P = .03 and G-EO, P = .15). There were no pre-post significant differences in swing time, stance time, and step length asymmetry ratios at SSV or MV for any of the interventions. Mean rank in the change of SSV and MV was not statistically significantly different between groups. Participants in the G-EO and PBWSTT groups significantly improved their 6MWT posttraining (P = .04 and .03, respectively). The MSIS significantly improved only for the Lokomat group (P = .04 and .03). The

  1. Water depth effects on impact loading, kinematic and physiological variables during water treadmill running.

    Science.gov (United States)

    Macdermid, Paul W; Wharton, Josh; Schill, Carina; Fink, Philip W

    2017-07-01

    The purpose of this study was to compare impact loading, kinematic and physiological responses to three different immersion depths (mid-shin, mid-thigh, and xiphoid process) while running at the same speed on a water based treadmill. Participants (N=8) ran on a water treadmill at three depths for 3min. Tri-axial accelerometers were used to identify running dynamics plus measures associated with impact loading rates, while heart rate data were logged to indicate physiological demand. Participants had greater peak impact accelerations (prunning immersed to the xiphoid process. Physiological effort determined by heart rate was also significantly less (prunning immersed to the xiphoid process. Water immersed treadmill running above the waistline alters kinematics of gait, reduces variables associated with impact, while decreasing physiological demand compared to depths below the waistline. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Impact of enhanced sensory input on treadmill step frequency: infants born with myelomeningocele.

    Science.gov (United States)

    Pantall, Annette; Teulier, Caroline; Smith, Beth A; Moerchen, Victoria; Ulrich, Beverly D

    2011-01-01

    To determine the effect of enhanced sensory input on the step frequency of infants with myelomeningocele (MMC) when supported on a motorized treadmill. Twenty-seven infants aged 2 to 10 months with MMC lesions at, or caudal to, L1 participated. We supported infants upright on the treadmill for 2 sets of 6 trials, each 30 seconds long. Enhanced sensory inputs within each set were presented in random order and included baseline, visual flow, unloading, weights, Velcro, and friction. Overall friction and visual flow significantly increased step rate, particularly for the older subjects. Friction and Velcro increased stance-phase duration. Enhanced sensory input had minimal effect on leg activity when infants were not stepping. : Increased friction via Dycem and enhancing visual flow via a checkerboard pattern on the treadmill belt appear to be more effective than the traditional smooth black belt surface for eliciting stepping patterns in infants with MMC.

  3. The Rise of the Food Risk Society and the Changing Nature of the Technological Treadmill

    Directory of Open Access Journals (Sweden)

    Lioudmila Chatalova

    2016-06-01

    Full Text Available Economic development of transition and developed countries is associated with increasingly unhealthy dietary habits among low-income population segments. Drawing on Ulrich Beck’s sociological theory of risk society, the present research note calls attention to the positive relation between national economic development and food risks that result in the rise of food-related diseases and healthcare costs. On this basis, we argue that the knowledge-intensive agribusiness may translate Cochrane’s technological treadmill into Beck’s risk treadmill that shifts a growing share of food-related healthcare costs from producers toward consumers, state, and the healthcare system. This argument motivates a novel research program dealing with the “food risk treadmill” that emerges in response to modern farming and agribusiness practices. Awareness of the food risk treadmill may help to streamline the development of agricultural science and to prevent it from being excessively dominated by the agricultural and food industry.

  4. Maximizing ROI (return on information)

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, B.

    2000-05-01

    The role and importance of managing information are discussed, underscoring the importance by quoting from the report of the International Data Corporation, according to which Fortune 500 companies lost $ 12 billion in 1999 due to inefficiencies resulting from intellectual re-work, substandard performance , and inability to find knowledge resources. The report predicts that this figure will rise to $ 31.5 billion by 2003. Key impediments to implementing knowledge management systems are identified as : the cost and human resources requirement of deployment; inflexibility of historical systems to adapt to change; and the difficulty of achieving corporate acceptance of inflexible software products that require changes in 'normal' ways of doing business. The author recommends the use of model, document and rule-independent systems with a document centered interface (DCI), employing rapid application development (RAD) and object technologies and visual model development, which eliminate these problems, making it possible for companies to maximize their return on information (ROI), and achieve substantial savings in implementation costs.

  5. Maximizing the optical network capacity.

    Science.gov (United States)

    Bayvel, Polina; Maher, Robert; Xu, Tianhua; Liga, Gabriele; Shevchenko, Nikita A; Lavery, Domaniç; Alvarado, Alex; Killey, Robert I

    2016-03-06

    Most of the digital data transmitted are carried by optical fibres, forming the great part of the national and international communication infrastructure. The information-carrying capacity of these networks has increased vastly over the past decades through the introduction of wavelength division multiplexing, advanced modulation formats, digital signal processing and improved optical fibre and amplifier technology. These developments sparked the communication revolution and the growth of the Internet, and have created an illusion of infinite capacity being available. But as the volume of data continues to increase, is there a limit to the capacity of an optical fibre communication channel? The optical fibre channel is nonlinear, and the intensity-dependent Kerr nonlinearity limit has been suggested as a fundamental limit to optical fibre capacity. Current research is focused on whether this is the case, and on linear and nonlinear techniques, both optical and electronic, to understand, unlock and maximize the capacity of optical communications in the nonlinear regime. This paper describes some of them and discusses future prospects for success in the quest for capacity. © 2016 The Authors.

  6. Effect of maturation on hemodynamic and autonomic control recovery following maximal running exercise in highly-trained young soccer players

    Directory of Open Access Journals (Sweden)

    Martin eBuchheit

    2011-10-01

    Full Text Available The purpose of this study was to examine the effect of maturation on post-exercise hemodynamic and autonomic responses. Fifty-five highly-trained young male soccer players (12-18 yr classified as pre-, circum- or post-peak height velocity (PHV performed a graded running test to exhaustion on a treadmill. Before (Pre and after (5th-10th min, Post exercise, heart rate (HR, stroke volume (SV, cardiac ouput (CO, arterial pressure (AP and total peripheral resistance (TPR were monitored. Parasympathetic (high-frequency [HFRR] of HR variability (HRV and baroreflex sensitivity [Ln BRS] and sympathetic activity (low-frequency [LFSAP] of systolic AP variability were estimated. Post-exercise blood lactate [La]b, the HR recovery (HRR time constant and parasympathetic reactivation (time varying HRV analysis were assessed. In all three groups, exercise resulted in increased HR, CO, AP and LFSAP (P<0.001, decreased SV, HFRR and Ln BRS (all P<0.001, and no change in TPRI (P=0.98. There was no ‘maturation x time’ interaction for any of the hemodynamic or autonomic variables (all P>0.22. After exercise, pre-PHV players displayed lower SV, CO and [La]b, faster HRR and greater parasympathetic reactivation compared with circum- and post-PHV players. Multiple regression analysis showed that lean muscle mass, [La]b and Pre parasympathetic activity were the strongest predictors of HRR (r2=0.62, P<0.001. While pre-PHV players displayed a faster HRR and greater post-exercise parasympathetic reactivation, maturation had little influence on the hemodynamic and autonomic responses following maximal running exercise. HRR relates to lean muscle mass, blood acidosis and intrinsic parasympathetic function, with less evident impact of post-exercise autonomic function.

  7. Maximizing policy learning in international committees

    DEFF Research Database (Denmark)

    Nedergaard, Peter

    2007-01-01

    , this article demonstrates that valuable lessons can be learned about policy learning, in practice and theoretically, by analysing the cooperation in the OMC committees. Using the Advocacy Coalition Framework as the starting point of analysis, 15 hypotheses on policy learning are tested. Among other things......In the voluminous literature on the European Union's open method of coordination (OMC), no one has hitherto analysed on the basis of scholarly examination the question of what contributes to the learning processes in the OMC committees. On the basis of a questionnaire sent to all participants......, it is concluded that in order to maximize policy learning in international committees, empirical data should be made available to committees and provided by sources close to the participants (i.e. the Commission). In addition, the work in the committees should be made prestigious in order to attract well...

  8. MAXIMIZING THE BENEFITS OF ERP SYSTEMS

    Directory of Open Access Journals (Sweden)

    Paulo André da Conceição Menezes

    2010-04-01

    Full Text Available The ERP (Enterprise Resource Planning systems have been consolidated in companies with different sizes and sectors, allowing their real benefits to be definitively evaluated. In this study, several interactions have been studied in different phases, such as the strategic priorities and strategic planning defined as ERP Strategy; business processes review and the ERP selection in the pre-implementation phase, the project management and ERP adaptation in the implementation phase, as well as the ERP revision and integration efforts in the post-implementation phase. Through rigorous use of case study methodology, this research led to developing and to testing a framework for maximizing the benefits of the ERP systems, and seeks to contribute for the generation of ERP initiatives to optimize their performance.

  9. Gait Complexity and Regularity Are Differently Modulated by Treadmill Walking in Parkinson's Disease and Healthy Population

    Directory of Open Access Journals (Sweden)

    Thibault Warlop

    2018-02-01

    Full Text Available Variability raises considerable interest as a promising and sensitive marker of dysfunction in physiology, in particular in neurosciences. Both internally (e.g., pathology and/or externally (e.g., environment generated perturbations and the neuro-mechanical responses to them contribute to the fluctuating dynamics of locomotion. Defective internal gait control in Parkinson's disease (PD, resulting in typical timing gait disorders, is characterized by the breakdown of the temporal organization of stride duration variability. Influence of external cue on gait pattern could be detrimental or advantageous depending on situations (healthy or pathological gait pattern, respectively. As well as being an interesting rehabilitative approach in PD, treadmills are usually implemented in laboratory settings to perform instrumented gait analysis including gait variability assessment. However, possibly acting as an external pacemaker, treadmill could modulate the temporal organization of gait variability of PD patients which could invalidate any gait variability assessment. This study aimed to investigate the immediate influence of treadmill walking (TW on the temporal organization of stride duration variability in PD and healthy population. Here, we analyzed the gait pattern of 20 PD patients and 15 healthy age-matched subjects walking on overground and on a motorized-treadmill (randomized order at a self-selected speed. The temporal organization and regularity of time series of walking were assessed on 512 consecutive strides and assessed by the application of non-linear mathematical methods (i.e., the detrended fluctuation analysis and power spectral density; and sample entropy, for the temporal organization and regularity of gait variability, respectively. A more temporally organized and regular gait pattern seems to emerge from TW in PD while no influence was observed on healthy gait pattern. Treadmill could afford the necessary framework to regulate gait

  10. Functional effects of treadmill-based gait training at faster speeds in stroke survivors: a prospective, single-group study.

    Science.gov (United States)

    Mohammadi, Roghayeh; Ershad, Navid; Rezayinejad, Marziyeh; Fatemi, Elham; Phadke, Chetan P

    2017-09-01

    To examine the functional effects of walking retraining at faster than self-selected speed (SSS). Ten individuals with chronic stroke participated in a 4-week training over a treadmill at walking speeds 40% faster than SSS, three times per week, 30 min/session. Outcome measures assessed before, after, and 2 months after the end of intervention were the Timed Up and Go, the 6-Minute Walk, the 10-Meter Walk test, the Modified Ashworth Scale, SSS, and fastest comfortable speed. After 4 weeks of training, all outcome measures showed clinically meaningful and statistically significant improvements (Ptraining. The results showed that a strategy of training at a speed 40% faster than SSS can improve functional activity in individuals with chronic stroke, with effects lasting up to 2 months after the intervention.

  11. Prognostic value of myocardial perfusion SPECT images in combination with the maximal heart rate at exercise testing in Japanese patients with suspected ischemic heart disease. A sub-analysis of J-ACCESS

    International Nuclear Information System (INIS)

    Ueshima, Kenji; Usami, Satoru; Yasuno, Shinji; Nakao, Kazuwa; Yamashina, Akira; Nishiyama, Osamu; Yamazaki, Takuya; Nishimura, Tsunehiko

    2009-01-01

    We assessed whether a combination of summed stress scores (SSS) using exercise myocardial perfusion single photon emission computed tomography (SPECT) (Ex-SPECT) and maximal heart rate accurately predicts cardiac events through a sub-analysis of J-ACCESS (Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT) which was conducted to evaluate the prognosis of Japanese patients with suspected ischemic heart disease. In J-ACCESS, 2,373 patients with suspected coronary artery disease not receiving beta-blocker treatment underwent Ex-SPECT. These patients were categorized into the following four groups: Group A [achieved target heart rate (THR) and SSS<4: n=631], B (did not achieve THR and SSS<4: n=612), C (achieved THR and SSS≥4: n=570), and D (did not achieve THR and SSS≥4: n=560). We evaluated the incidence rate of cardiac events including cardiac death, myocardial infarction, and heart failure requiring hospital admission during a 3-year period. In Group A, B, C, and D, 9 of 631 (1.4%), 15 of 612 (2.4%), 23 of 570 (4.0%) and 30 of 560 (5.4%) patients experienced cardiac events, respectively. Although the hazard ratio of the SSS≥4 was 2.45 (p<0.001) and that of the attained THR was 0.69 (p=0.10) in the multiple Cox regression analysis, Kaplan-Meier curves showed that the cardiac events rate was lower in the order of A, B, C, and D (p<0.001). The combination of SSS using Ex-SPECT and the maximal heart rate is a useful predictor of cardiac events in patients with suspected coronary artery disease. (author)

  12. Cardiovascular rehabilitation soon after stroke using feedback-controlled robotics-assisted treadmill exercise: study protocol of a randomised controlled pilot trial.

    Science.gov (United States)

    Stoller, Oliver; de Bruin, Eling D; Schuster-Amft, Corina; Schindelholz, Matthias; de Bie, Rob A; Hunt, Kenneth J

    2013-09-22

    After experiencing a stroke, most individuals also suffer from cardiac disease, are immobile and thus have low endurance for exercise. Aerobic capacity is seriously reduced in these individuals and does not reach reasonable levels after conventional rehabilitation programmes. Cardiovascular exercise is beneficial for improvement of aerobic capacity in mild to moderate stroke. However, less is known about its impact on aerobic capacity, motor recovery, and quality-of-life in severely impaired individuals. The aim of this pilot study is to explore the clinical efficacy and feasibility of cardiovascular exercise with regard to aerobic capacity, motor recovery, and quality-of-life using feedback-controlled robotics-assisted treadmill exercise in non-ambulatory individuals soon after experiencing a stroke. This will be a single-centred single blind, randomised control trial with a pre-post intervention design. Subjects will be recruited early after their first stroke (≤20 weeks) at a neurological rehabilitation clinic and will be randomly allocated to an inpatient cardiovascular exercise programme that uses feedback-controlled robotics-assisted treadmill exercise (experimental) or to conventional robotics-assisted treadmill exercise (control). Intervention duration depends on the duration of each subject's inpatient rehabilitation period. Aerobic capacity, as the primary outcome measure, will be assessed using feedback-controlled robotics-assisted treadmill-based cardiopulmonary exercise testing. Secondary outcome measures will include gait speed, walking endurance, standing function, and quality-of-life. Outcome assessment will be conducted at baseline, after each 4-week intervention period, and before clinical discharge. Ethical approval has been obtained. Whether cardiovascular exercise in non-ambulatory individuals early after stroke has an impact on aerobic capacity, motor recovery, and quality-of-life is not yet known. Feedback-controlled robotics

  13. Effects of treadmill inclination on electromyographic activity and hind limb kinematics in healthy hounds at a walk.

    Science.gov (United States)

    Lauer, Susanne K; Hillman, Robert B; Li, Li; Hosgood, Giselle L

    2009-05-01

    To evaluate the effect of treadmill incline on muscle activity and joint range of motion (ROM) in hind limbs of dogs. 8 purpose-bred healthy adult hounds. Activities of the hamstring (semimembranosus, semitendinosus, and biceps femoris muscles), gluteal (superficial, middle, and deep gluteal muscles), and quadriceps (femoris, vastus lateralis, vastus intermedius, and vastus medialis muscles) muscle groups and hip and stifle joint ROM were measured with surface electrogoniometric and myographic sensors in hounds walking on a treadmill at 0.54 m/s at inclines of 5%, 0%, and -5% in random order. Mean electromyographic activities and mean ROMs at each inclination were compared for swing and stance phases. Treadmill inclination did not affect duration of the stance and swing phases or the whole stride. When treadmill inclination was increased from -5% to 5%, hip joint ROM increased and the degree of stifle joint extension decreased significantly. In the beginning of the stance phase, activity of the hamstring muscle group was significantly increased when walking at a 5% incline versus a 5% decline. In the end of the stance phase, that activity was significantly increased when walking at a 5% incline versus at a 5% decline or on a flat surface. Activity of the gluteal and quadriceps muscle groups was not affected when treadmill inclination changed. Treadmill inclination affected joint kinematics only slightly. Walking on a treadmill at a 5% incline had more potential to strengthen the hamstring muscle group than walking on a treadmill with a flat or declined surface.

  14. Effects of treadmill training with the eyes closed on gait and balance ability of chronic stroke patients.

    Science.gov (United States)

    Kim, Yong-Wook; Moon, Sung-Jun

    2015-09-01

    [Purpose] The purpose of this study was to compare the effect of treadmill walking with the eyes closed and open on the gait and balance abilities of chronic stroke patients. [Subjects and Methods] Thirty patients with chronic stroke participated in this study. The treadmill gait training for each group lasted 40 minutes, and sessions were held 3 times a week for 4 weeks. Gait ability was measured using a Biodex Gait Trainer Treadmill System. Balance ability was measured using a Biodex Balance System. [Results] After the treadmill training' the treadmill training with eyes closed (TEC) group showed significant improvements in walking distance' step length' coefficient of variation' and limit of stability (overall' lateral affected' forward lateral unaffected) compared to the treadmill training with eyes open (TEO) group. [Conclusion] The walking and balance abilities of the TEC participants showed more improvement after the treadmill walking sessions than those of the TEO participants. Therefore' treadmill walking with visual deprivation may be useful for the rehabilitation of patients with chronic stroke.

  15. Effects of a 6-Week Aquatic Treadmill Exercise Program on Cardiorespiratory Fitness and Walking Endurance in Subacute Stroke Patients: A PILOT TRIAL.

    Science.gov (United States)

    Han, Eun Young; Im, Sang Hee

    2017-03-15

    To assess the feasibility and safety of a 6-week course of water walking performed using a motorized aquatic treadmill in individuals with subacute stroke for cardiorespiratory fitness, walking endurance, and activities of daily living. Twenty subacute stroke patents were randomly assigned to aquatic treadmill exercise (ATE) or land-based exercise (LBE). The ATE group (n = 10) performed water-based aerobic exercise on a motorized aquatic treadmill, and the LBE group (n = 10) performed land-based aerobic exercise on a cycle ergometer. Both groups performed aerobic exercise for 30 minutes, 5 times per week for 6 weeks. Primary outcome measures were 6-minute walk test for walking endurance and cardiopulmonary fitness parameters of a symptom-limited exercise tolerance test, and secondary measures were Korean version of the Modified Barthel Index (K-MBI) for activities of daily living. All variables were assessed at baseline and at the end of the intervention. The ATE group showed significant improvements in 6-minute walk test (P = .005), peak oxygen uptake (V·o2peak; P = .005), peak heart rate (P = .007), exercise tolerance test duration (P = .005), and K-MBI (P = .008). The LBE group showed a significant improvement only in K-MBI (P = .012). In addition, improvement in V·o2peak was greater in the ATE than in the LBE group. This preliminary study showed that a 6-week ATE program improved peak aerobic capacity and walking endurance in patients with subacute stroke. The improvement in V·o2peak after an ATE exercise program was greater than that observed after an LBE program. Therefore, ATE effectively improves cardiopulmonary fitness in patients with subacute stroke.

  16. Combination of robot-assisted and conventional body-weight-supported treadmill training improves gait in persons with multiple sclerosis: a pilot study.

    Science.gov (United States)

    Ruiz, Jennifer; Labas, Michele P; Triche, Elizabeth W; Lo, Albert C

    2013-12-01

    The majority of persons with multiple sclerosis (MS) experience problems with gait, which they characterize as highly disabling impairments that adversely impact their quality of life. Thus, it is crucial to develop effective therapies to improve mobility for these individuals. The purpose of this study was to determine whether combination gait training, using robot-assisted treadmill training followed by conventional body-weight-supported treadmill training within the same session, improved gait and balance in individuals with MS. This study tested combination gait training in 7 persons with MS. The participants were randomized into the immediate therapy group (IT group) or the delayed therapy group (DT group). In phase I of the trial, the IT group received treatment while the DT group served as a concurrent comparison group. In phase II of the trial, the DT group received treatment identical to the treatment received by the IT group in phase I. Outcome measures included the 6-Minute Walk Test (6MWT), the Timed 25-Foot Walk Test, velocity, cadence, and the Functional Reach Test (FRT). Nonparametric statistical techniques were used for analysis. Combination gait training resulted in significantly greater improvements in the 6MWT for the IT group (median change = +59 m) compared with Phase I DT group (median change = -8 m) (P = 0.08) and FRT (median change = +3.3 cm in IT vs -0.8 cm in the DT group phase I; P = 0.03). Significant overall pre-post improvements following combination gait training were found in 6MWT (+32 m; P = 0.02) and FRT (+3.3 cm; P = 0.06) for IT and Phase II DT groups combined. Combination of robot with body-weight-supported treadmill training gait training is feasible and improved 6MWT and FRT distances in persons with MS.Video Abstract available (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A62) for more insights from the authors.

  17. Effects of home-based locomotor treadmill training on gross motor function in young children with cerebral palsy: a quasi-randomized controlled trial.

    Science.gov (United States)

    Mattern-Baxter, Katrin; McNeil, Stefani; Mansoor, Jim K

    2013-11-01

    To examine the effects of an intensive home-based program of treadmill training on motor skills related to walking in preambulatory children with cerebral palsy (CP). Quasi-randomized controlled trial. Homes of the participants. Children with CP (N=12) with Gross Motor Function Classification System levels I and II were assigned to the intervention group (n=6; mean age ± SD, 21.76±6.50mo) and control group (n=6; 21.25±6.07mo). All children were tested preintervention, postintervention, at a 1-month follow-up, and at a 4-month follow-up. All children received their weekly scheduled physical therapy sessions at their homes. In addition, children in the intervention group walked on a portable treadmill in their homes 6 times per week, twice daily for 10- to 20-minute sessions, for 6 weeks. The intervention was carried out by the children's parents with weekly supervision by a physical therapist. Gross Motor Function Measure-66 Dimensions D/E, Peabody Developmental Motor Scales-2 (PDMS-2), Pediatric Evaluation of Disability Inventory (PEDI), timed 10-m walk test (10MWT), and Functional Mobility Scale (FMS). The Friedman test and Mann-Whitney U test were conducted for within-group and between-group differences, respectively. There was a significant between-group treatment effect for the PDMS-2 at posttest (P=.01) and 1-month postintervention follow-up (P=.09), as well as for the PEDI at posttest (P=.01), the 1-month postintervention follow-up (P=.009), and the 4-month postintervention follow-up (P=.04). The FMS was significant at the posttest (P=.04). Home-based treadmill training accelerates the attainment of walking skills and decreases the amount of support used for walking in young children with CP. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  18. AUC-Maximizing Ensembles through Metalearning.

    Science.gov (United States)

    LeDell, Erin; van der Laan, Mark J; Petersen, Maya

    2016-05-01

    Area Under the ROC Curve (AUC) is often used to measure the performance of an estimator in binary classification problems. An AUC-maximizing classifier can have significant advantages in cases where ranking correctness is valued or if the outcome is rare. In a Super Learner ensemble, maximization of the AUC can be achieved by the use of an AUC-maximining metalearning algorithm. We discuss an implementation of an AUC-maximization technique that is formulated as a nonlinear optimization problem. We also evaluate the effectiveness of a large number of different nonlinear optimization algorithms to maximize the cross-validated AUC of the ensemble fit. The results provide evidence that AUC-maximizing metalearners can, and often do, out-perform non-AUC-maximizing metalearning methods, with respect to ensemble AUC. The results also demonstrate that as the level of imbalance in the training data increases, the Super Learner ensemble outperforms the top base algorithm by a larger degree.

  19. Balance and gait performance after maximal and submaximal endurance exercise in seniors: is there a higher fall-risk?

    Science.gov (United States)

    Donath, Lars; Zahner, Lukas; Roth, Ralf; Fricker, Livia; Cordes, Mareike; Hanssen, Henner; Schmidt-Trucksäss, Arno; Faude, Oliver

    2013-03-01

    Impaired balance and gait performance increase fall-risk in seniors. Acute effects of different exercise bouts on gait and balance were not yet addressed. Therefore, 19 healthy seniors (10 women, 9 men, age: 64.6 ± 3.2 years) were examined on 3 days. After exhaustive treadmill testing, participants randomly completed a 2-km treadmill walking test (76 ± 8 % VO(2max)) and a resting control condition. Standing balance performance (SBALP) was assessed by single limb-eyes opened (SLEO) and double limb-eyes closed (DLEC) stance. Gait parameters were collected at comfortable walking velocity. A condition × time interaction of center of pressure path length (COP(path)) was observed for both balance tasks (p fall-risk in seniors. Balance changes upon 2-km testing might be of minor relevance. Gait is not affected during single task walking at given velocities.

  20. On maximal massive 3D supergravity

    OpenAIRE

    Bergshoeff , Eric A; Hohm , Olaf; Rosseel , Jan; Townsend , Paul K

    2010-01-01

    ABSTRACT We construct, at the linearized level, the three-dimensional (3D) N = 4 supersymmetric " general massive supergravity " and the maximally supersymmetric N = 8 " new massive supergravity ". We also construct the maximally supersymmetric linearized N = 7 topologically massive supergravity, although we expect N = 6 to be maximal at the non-linear level. (Bergshoeff, Eric A) (Hohm, Olaf) (Rosseel, Jan) P.K.Townsend@da...

  1. Inclusive Fitness Maximization:An Axiomatic Approach

    OpenAIRE

    Okasha, Samir; Weymark, John; Bossert, Walter

    2014-01-01

    Kin selection theorists argue that evolution in social contexts will lead organisms to behave as if maximizing their inclusive, as opposed to personal, fitness. The inclusive fitness concept allows biologists to treat organisms as akin to rational agents seeking to maximize a utility function. Here we develop this idea and place it on a firm footing by employing a standard decision-theoretic methodology. We show how the principle of inclusive fitness maximization and a related principle of qu...

  2. Activity versus outcome maximization in time management.

    Science.gov (United States)

    Malkoc, Selin A; Tonietto, Gabriela N

    2018-04-30

    Feeling time-pressed has become ubiquitous. Time management strategies have emerged to help individuals fit in more of their desired and necessary activities. We provide a review of these strategies. In doing so, we distinguish between two, often competing, motives people have in managing their time: activity maximization and outcome maximization. The emerging literature points to an important dilemma: a given strategy that maximizes the number of activities might be detrimental to outcome maximization. We discuss such factors that might hinder performance in work tasks and enjoyment in leisure tasks. Finally, we provide theoretically grounded recommendations that can help balance these two important goals in time management. Published by Elsevier Ltd.

  3. Task-oriented maximally entangled states

    International Nuclear Information System (INIS)

    Agrawal, Pankaj; Pradhan, B

    2010-01-01

    We introduce the notion of a task-oriented maximally entangled state (TMES). This notion depends on the task for which a quantum state is used as the resource. TMESs are the states that can be used to carry out the task maximally. This concept may be more useful than that of a general maximally entangled state in the case of a multipartite system. We illustrate this idea by giving an operational definition of maximally entangled states on the basis of communication tasks of teleportation and superdense coding. We also give examples and a procedure to obtain such TMESs for n-qubit systems.

  4. Beyond the Hedonic Treadmill: Revising the Adaptation Theory of Well-Being

    Science.gov (United States)

    Diener, Ed; Lucas, Richard E.; Napa, Christine

    2006-01-01

    According to the hedonic treadmill model, good and bad events temporarily affect happiness, but people quickly adapt back to hedonic neutrality. The theory, which has gained widespread acceptance in recent years, implies that individual and societal efforts to increase happiness are doomed to failure. The recent empirical work outlined here…

  5. Treadmill exercise does not change gene expression of adrenal catecholamine biosynthetic enzymes in chronically stressed rats

    Directory of Open Access Journals (Sweden)

    LJUBICA GAVRILOVIC

    2013-09-01

    Full Text Available ABSTRACT Chronic isolation of adult animals represents a form of psychological stress that produces sympatho-adrenomedullar activation. Exercise training acts as an important modulator of sympatho-adrenomedullary system. This study aimed to investigate physical exercise-related changes in gene expression of catecholamine biosynthetic enzymes (tyrosine hydroxylase, dopamine-ß-hydroxylase and phenylethanolamine N-methyltransferase and cyclic adenosine monophosphate response element-binding (CREB in the adrenal medulla, concentrations of catecholamines and corticosterone (CORT in the plasma and the weight of adrenal glands of chronically psychosocially stressed adult rats exposed daily to 20 min treadmill running for 12 weeks. Also, we examined how additional acute immobilization stress changes the mentioned parameters. Treadmill running did not result in modulation of gene expression of catecholamine synthesizing enzymes and it decreased the level of CREB mRNA in the adrenal medulla of chronically psychosocially stressed adult rats. The potentially negative physiological adaptations after treadmill running were recorded as increased concentrations of catecholamines and decreased morning CORT concentration in the plasma, as well as the adrenal gland hypertrophy of chronically psychosocially stressed rats. The additional acute immobilization stress increases gene expression of catecholamine biosynthetic enzymes in the adrenal medulla, as well as catecholamines and CORT levels in the plasma. Treadmill exercise does not change the activity of sympatho-adrenomedullary system of chronically psychosocially stressed rats.

  6. Quantifying Gait Impairment Using an Instrumented Treadmill in People with Multiple Sclerosis

    Science.gov (United States)

    Kalron, Alon; Dvir, Zeevi; Frid, Lior; Achiron, Anat

    2013-01-01

    Background and Objective. Treadmill gait analysis has been proposed as an attractive alternative for overground walking measuring systems. The purpose of this study was twofold: first to determine spatiotemporal parameters of treadmill gait in patients with multiple sclerosis (MS) and second to examine whether these parameters are associated with specific functional impairments in this cohort. Method. Eighty-seven relapsing-remitting patients diagnosed with MS, 50 women and 37 men, aged 40.9 ± 11.9 with an expanded disability status scale (EDSS) score of 2.7 ± 1.6, participated in this study. Twenty-five apparently healthy subjects, 14 women and 11 men, aged 38.5 ± 9.4, served as controls. Spatiotemporal gait parameters were obtained using the Zebris FDM-T Treadmill (Zebris Medical GmbH, Germany). People with MS demonstrated significantly shorter steps, extended stride time, wider base of support, longer step time, reduced single support phase, and a prolonged double support phase compared to the healthy controls. The EDSS score was significantly correlated with all spatiotemporal gait parameters. Conclusion. The instrumented treadmill may be an effective tool in assessing ambulation capabilities of people with MS. PMID:23878746

  7. Use of an antigravity treadmill for rehabilitation of a pelvic stress injury.

    Science.gov (United States)

    Tenforde, Adam S; Watanabe, Laine M; Moreno, Tamara J; Fredericson, Michael

    2012-08-01

    Pelvic stress injuries are a relatively uncommon form of injury that require high index of clinician suspicion and usually MRI for definitive diagnosis. We present a case report of a 21-year-old female elite runner who was diagnosed with pelvic stress injury and used an antigravity treadmill during rehabilitation. She was able to return to pain-free ground running at 8 weeks after running at 95% body weight on the antigravity treadmill. Ten weeks from time of diagnosis, she competed at her conference championships and advanced to the NCAA Championships in the 10,000-meters. She competed in both races without residual pain. To our knowledge, this is the first published case report on use of an antigravity treadmill in rehabilitation of bone-related injuries. Our findings suggest that use of an antigravity treadmill for rehabilitation of a pelvic stress injury may result in appropriate bone loading and healing during progression to ground running and faster return to competition. Future research may identify appropriate protocols for recovery from overuse lower extremity injuries and other uses for this technology, including neuromuscular recovery and injury prevention. Copyright © 2012 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  8. Exercise capacity in Dutch children : New reference values for the Bruce treadmill protocol

    NARCIS (Netherlands)

    M.H.M. van der Cammen-van Zijp (Monique); H.J.G. van den Berg-Emons (Rita); S.P. Willemsen (Sten); H.J. Stam (Henk); D. Tibboel (Dick); H. IJsselstijn (Hanneke)

    2010-01-01

    textabstractThe Bruce treadmill protocol is suitable for children 4 years of age and older. Dutch reference values were established in 1987. We considered that children's exercise capacity has deteriorated due to changes in physical activity patterns and eating habits. We determined new reference

  9. Analysis of gait using a treadmill and a Time-of-flight camera

    DEFF Research Database (Denmark)

    Jensen, Rasmus Ramsbøl; Paulsen, Rasmus Reinhold; Larsen, Rasmus

    2009-01-01

    We present a system that analyzes human gait using a treadmill and a Time-of-flight camera. The camera provides spatial data with local intensity measures of the scene, and data are collected over several gait cycles. These data are then used to model and analyze the gait. For each frame...

  10. Effect of Constraint Loading on the Lower Limb Muscle Forces in Weightless Treadmill Exercise

    Directory of Open Access Journals (Sweden)

    Ning Guo

    2018-01-01

    Full Text Available Long exposure to the microgravity will lead to muscle atrophy and bone loss. Treadmill exercise could mitigate the musculoskeletal decline. But muscle atrophy remains inevitable. The constraint loading applied on astronauts could affect the muscle force and its atrophy severity. However, the quantitative correlation between constraint loading mode and muscle forces remains unclear. This study aimed to characterize the influence of constraint loading mode on the lower limb muscle forces in weightless treadmill exercise. The muscle forces in the full gait cycle were calculated with the inverse dynamic model of human musculoskeletal system. The calculated muscle forces at gravity were validated with the EMG data. Muscle forces increased at weightlessness compared with those at the earth’s gravity. The increasing percentage from high to low is as follows: biceps femoris, gastrocnemius, soleus, vastus, and rectus femoris, which was in agreement with the muscle atrophy observed in astronauts. The constraint loading mode had an impact on the muscle forces in treadmill exercise and thus could be manipulated to enhance the effect of the muscle training in spaceflight. The findings could provide biomechanical basis for the optimization of treadmill constraint system and training program and improve the countermeasure efficiency in spaceflight.

  11. Treadmill Training with Partial Body-Weight Support in Children with Cerebral Palsy: A Systematic Review

    Science.gov (United States)

    Mutlu, Akmer; Krosschell, Kristin; Spira, Deborah Gaebler

    2009-01-01

    OKAim: The aim of this systematic review was to examine the literature on the effects of partial body-weight support treadmill training (PBWSTT) in children with cerebral palsy (CP) on functional outcomes and attainment of ambulation. Method: We searched the relevant literature from 1950 to July 2007. We found eight studies on the use of PWSBTT on…

  12. A public dataset of overground and treadmill walking kinematics and kinetics in healthy individuals

    Directory of Open Access Journals (Sweden)

    Claudiane A. Fukuchi

    2018-04-01

    Full Text Available In a typical clinical gait analysis, the gait patterns of pathological individuals are commonly compared with the typically faster, comfortable pace of healthy subjects. However, due to potential bias related to gait speed, this comparison may not be valid. Publicly available gait datasets have failed to address this issue. Therefore, the goal of this study was to present a publicly available dataset of 42 healthy volunteers (24 young adults and 18 older adults who walked both overground and on a treadmill at a range of gait speeds. Their lower-extremity and pelvis kinematics were measured using a three-dimensional (3D motion-capture system. The external forces during both overground and treadmill walking were collected using force plates and an instrumented treadmill, respectively. The results include both raw and processed kinematic and kinetic data in different file formats: c3d and ASCII files. In addition, a metadata file is provided that contain demographic and anthropometric data and data related to each file in the dataset. All data are available at Figshare (DOI: 10.6084/m9.figshare.5722711. We foresee several applications of this public dataset, including to examine the influences of speed, age, and environment (overground vs. treadmill on gait biomechanics, to meet educational needs, and, with the inclusion of additional participants, to use as a normative dataset.

  13. Comparison of vertical ground reaction forces during overground and treadmill running. A validation study

    NARCIS (Netherlands)

    Kluitenberg, Bas; Bredeweg, Steef W.; Zijlstra, Sjouke; Zijlstra, Wiebren; Buist, Ida

    2012-01-01

    Background: One major drawback in measuring ground-reaction forces during running is that it is time consuming to get representative ground-reaction force (GRF) values with a traditional force platform. An instrumented force measuring treadmill can overcome the shortcomings inherent to overground

  14. Pre-exercise carbohydrate and fluid ingestion: influence of glycemic response on 10-km treadmill running performance in the heat.

    Science.gov (United States)

    Mitchell, J B; Braun, W A; Pizza, F X; Forrest, M

    2000-03-01

    The purpose of this study was to determine the influence of ingesting solutions containing mixtures of carbohydrate (CHO) types on pre-exercise glycemic response, exercise-induced hypoglycemia, metabolic responses, and 10-km treadmill running performance in a warm environment. Ten trained runners completed 6, self-paced 10-km treadmill runs one hour after ingesting 900 ml of one of the following test solutions: a water placebo (WP), an 8 g 100 ml-1 high fructose corn syrup solution (HFG; 72 g CHO), a 6 g 100 ml-1 glucose solution (GLU; 54 g CHO), a 6 g.100 ml-1 sucrose/glucose mixture (SUG; 54 g CHO), or banana with water to equal 900 ml (BAN; approx. 54 g CHO). The sixth condition was 675 ml of an 8 g.100 ml-1 HFCS solution (LFG; 54 g CHO). Blood samples were taken prior to ingestion and every 15 min during rest and at 15 and 30 min, and at the end of the 10-km run. Blood was analyzed for glucose (BG) insulin (IN), glycerol, lactate, and percent change in plasma volume. Urine volume during the 1 hour of rest and change in body mass during exercise were also determined. A significant (p glucose was related to the PEGR; however, the decline in BG did not affect 10-km running performance. In addition, there were no differences in the metabolic responses during exercise between the different CHO types, nor did the type of CHO influence running performance. Finally, the presence of CHO and/or electrolytes in the hydration solutions produced a better fluid retention during the 60-min pre-exercise rest period compared to water. The results confirmed that if a competitive athlete consumed a breakfast prior to ingesting a CHO-electrolyte beverage, a practice that is common, the glycemic responses may be different.

  15. A novel walking speed estimation scheme and its application to treadmill control for gait rehabilitation.

    Science.gov (United States)

    Yoon, Jungwon; Park, Hyung-Soon; Damiano, Diane Louise

    2012-08-28

    Virtual reality (VR) technology along with treadmill training (TT) can effectively provide goal-oriented practice and promote improved motor learning in patients with neurological disorders. Moreover, the VR + TT scheme may enhance cognitive engagement for more effective gait rehabilitation and greater transfer to over ground walking. For this purpose, we developed an individualized treadmill controller with a novel speed estimation scheme using swing foot velocity, which can enable user-driven treadmill walking (UDW) to more closely simulate over ground walking (OGW) during treadmill training. OGW involves a cyclic acceleration-deceleration profile of pelvic velocity that contrasts with typical treadmill-driven walking (TDW), which constrains a person to walk at a preset constant speed. In this study, we investigated the effects of the proposed speed adaptation controller by analyzing the gait kinematics of UDW and TDW, which were compared to those of OGW at three pre-determined velocities. Ten healthy subjects were asked to walk in each mode (TDW, UDW, and OGW) at three pre-determined speeds (0.5 m/s, 1.0 m/s, and 1.5 m/s) with real time feedback provided through visual displays. Temporal-spatial gait data and 3D pelvic kinematics were analyzed and comparisons were made between UDW on a treadmill, TDW, and OGW. The observed step length, cadence, and walk ratio defined as the ratio of stride length to cadence were not significantly different between UDW and TDW. Additionally, the average magnitude of pelvic acceleration peak values along the anterior-posterior direction for each step and the associated standard deviations (variability) were not significantly different between the two modalities. The differences between OGW and UDW and TDW were mainly in swing time and cadence, as have been reported previously. Also, step lengths between OGW and TDW were different for 0.5 m/s and 1.5 m/s gait velocities, and walk ratio between OGS and UDW was

  16. A novel walking speed estimation scheme and its application to treadmill control for gait rehabilitation

    Directory of Open Access Journals (Sweden)

    Yoon Jungwon

    2012-08-01

    Full Text Available Abstract Background Virtual reality (VR technology along with treadmill training (TT can effectively provide goal-oriented practice and promote improved motor learning in patients with neurological disorders. Moreover, the VR + TT scheme may enhance cognitive engagement for more effective gait rehabilitation and greater transfer to over ground walking. For this purpose, we developed an individualized treadmill controller with a novel speed estimation scheme using swing foot velocity, which can enable user-driven treadmill walking (UDW to more closely simulate over ground walking (OGW during treadmill training. OGW involves a cyclic acceleration-deceleration profile of pelvic velocity that contrasts with typical treadmill-driven walking (TDW, which constrains a person to walk at a preset constant speed. In this study, we investigated the effects of the proposed speed adaptation controller by analyzing the gait kinematics of UDW and TDW, which were compared to those of OGW at three pre-determined velocities. Methods Ten healthy subjects were asked to walk in each mode (TDW, UDW, and OGW at three pre-determined speeds (0.5 m/s, 1.0 m/s, and 1.5 m/s with real time feedback provided through visual displays. Temporal-spatial gait data and 3D pelvic kinematics were analyzed and comparisons were made between UDW on a treadmill, TDW, and OGW. Results The observed step length, cadence, and walk ratio defined as the ratio of stride length to cadence were not significantly different between UDW and TDW. Additionally, the average magnitude of pelvic acceleration peak values along the anterior-posterior direction for each step and the associated standard deviations (variability were not significantly different between the two modalities. The differences between OGW and UDW and TDW were mainly in swing time and cadence, as have been reported previously. Also, step lengths between OGW and TDW were different for 0.5 m/s and 1.5 m/s gait velocities

  17. Evaluating the sensitization potential of surfactants: integrating data from the local lymph node assay, guinea pig maximization test, and in vitro methods in a weight-of-evidence approach.

    Science.gov (United States)

    Ball, Nicholas; Cagen, Stuart; Carrillo, Juan-Carlos; Certa, Hans; Eigler, Dorothea; Emter, Roger; Faulhammer, Frank; Garcia, Christine; Graham, Cynthia; Haux, Carl; Kolle, Susanne N; Kreiling, Reinhard; Natsch, Andreas; Mehling, Annette

    2011-08-01

    An integral part of hazard and safety assessments is the estimation of a chemical's potential to cause skin sensitization. Currently, only animal tests (OECD 406 and 429) are accepted in a regulatory context. Nonanimal test methods are being developed and formally validated. In order to gain more insight into the responses induced by eight exemplary surfactants, a battery of in vivo and in vitro tests were conducted using the same batch of chemicals. In general, the surfactants were negative in the GPMT, KeratinoSens and hCLAT assays and none formed covalent adducts with test peptides. In contrast, all but one was positive in the LLNA. Most were rated as being irritants by the EpiSkin assay with the additional endpoint, IL1-alpha. The weight of evidence based on this comprehensive testing indicates that, with one exception, they are non-sensitizing skin irritants, confirming that the LLNA tends to overestimate the sensitization potential of surfactants. As results obtained from LLNAs are considered as the gold standard for the development of new nonanimal alternative test methods, results such as these highlight the necessity to carefully evaluate the applicability domains of test methods in order to develop reliable nonanimal alternative testing strategies for sensitization testing. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. [Potential analysis for research on physiotherapy-led treadmill training in Parkinson's disease].

    Science.gov (United States)

    Lohkamp, Monika; Braun, Cordula; Wasner, Mieke; Voigt-Radloff, Sebastian

    2014-01-01

    Parkinson's disease is one of the major neurodegenerative disorders with prevalence rates between 0.1 and 0.2 % in the global population and 1.8 % in people aged 64 years and over. Future incidence rates are estimated to increase within aging societies. The progressive course of Parkinson's disease is clinically characterised by bradykinesia, rigidity and tremor. These limitations in motor functioning reduce the capacity to work, social participation and the clients' quality of life. Parkinson's disease causes incapacity to work and a large number of days off from work. The benefits clients expect from physiotherapy-led treatment include an improvement of gait, a better speed of motion and the decrease of fatigue and rigidity. A recent Cochrane review (Mehrholz et al., 2010) analysed seven randomised comparisons with 153 participants and found that treadmill training compared with no treatment improved gait speed (SMD 0.50; 95 % confidence interval [0.17 to 0.84]). A lack of evidence exists on how to reduce fatigue and rigidity. There is also need to evaluate long-term effects and cost-effectiveness. Furthermore, an updated meta-analysis should include eleven new randomised trials on treadmill training after 2009. Physiotherapy-led treadmill training can easily be transferred into the German healthcare context since the environmental and educational preconditions are met by German physiotherapeutic care. Within the German context, there is need to prepare a randomised clinical trial evaluating the impact of physiotherapy-led treadmill training on motor functioning, quality of life, costs, adverse events und long-term effects. Prior to this, a feasibility study should explore the acceptance and intensity of treadmill training as well as the access of private physiotherapy practices to people suffering from early- to mid-stage Parkinson's disease. Copyright © 2014. Published by Elsevier GmbH.

  19. Comparison of energy expenditure between aquatic and overground treadmill walking in people post-stroke.

    Science.gov (United States)

    Jung, Taeyou; Ozaki, Yoshi; Lai, Byron; Vrongistinos, Konstantinos

    2014-03-01

    This study aimed to compare the cardiorespiratory responses between aquatic treadmill walking (ATW) and overground treadmill walking (OTW) in people with hemiparesis post-stroke. Eight participants post-stroke aged 58.5 ± 11.4 years and eight healthy adult controls aged 56.1 ± 8.6 years participated in a cross-sectional comparative study. Participants completed three 8-minute walking sessions separated by at least 72-hour rest. On the first visit, participants identified their comfortable walking speed on an aquatic and overground treadmill. The second and third visit consisted of either ATW or OTW at a matched speed. Oxygen consumption (VO2), carbon dioxide production (VCO2 ), minute ventilation (VE) and energy expenditure (EE) were measured at rest and during walking in both exercise modes. Mean steady-state cardiorespiratory responses during ATW showed a significant decrease compared with OTW at a matched speed. During ATW, mean VO2 values decreased by 39% in the stroke group and 21% in the control group, mean VCO2 values decreased by 42% in the stroke group and 30% in the control group, and mean EE decreased by 40% in the stroke group and 25% in the control group. Mean steady-state VE values and resting cardiorespiratory response values showed no significant change between the two conditions. This study demonstrated a decreased metabolic cost when ATW at matched speeds to that of OTW. Reduced metabolic cost during ATW may allow for longer durations of treadmill-induced gait training compared with OTW for improved outcomes. This knowledge may aid clinicians when prescribing aquatic treadmill exercise for people post-stroke with goals of improving gait and functional mobility. However, decreased metabolic cost during ATW suggests that to improve cardiovascular fitness, ATW may not be a time-efficient method of cardiovascular exercise for healthy adults and people post-stroke. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Maximally Entangled Multipartite States: A Brief Survey

    International Nuclear Information System (INIS)

    Enríquez, M; Wintrowicz, I; Życzkowski, K

    2016-01-01

    The problem of identifying maximally entangled quantum states of a composite quantum systems is analyzed. We review some states of multipartite systems distinguished with respect to certain measures of quantum entanglement. Numerical results obtained for 4-qubit pure states illustrate the fact that the notion of maximally entangled state depends on the measure used. (paper)

  1. Utility maximization and mode of payment

    NARCIS (Netherlands)

    Koning, R.H.; Ridder, G.; Heijmans, R.D.H.; Pollock, D.S.G.; Satorra, A.

    2000-01-01

    The implications of stochastic utility maximization in a model of choice of payment are examined. Three types of compatibility with utility maximization are distinguished: global compatibility, local compatibility on an interval, and local compatibility on a finite set of points. Keywords:

  2. Corporate Social Responsibility and Profit Maximizing Behaviour

    OpenAIRE

    Becchetti, Leonardo; Giallonardo, Luisa; Tessitore, Maria Elisabetta

    2005-01-01

    We examine the behavior of a profit maximizing monopolist in a horizontal differentiation model in which consumers differ in their degree of social responsibility (SR) and consumers SR is dynamically influenced by habit persistence. The model outlines parametric conditions under which (consumer driven) corporate social responsibility is an optimal choice compatible with profit maximizing behavior.

  3. Inclusive fitness maximization: An axiomatic approach.

    Science.gov (United States)

    Okasha, Samir; Weymark, John A; Bossert, Walter

    2014-06-07

    Kin selection theorists argue that evolution in social contexts will lead organisms to behave as if maximizing their inclusive, as opposed to personal, fitness. The inclusive fitness concept allows biologists to treat organisms as akin to rational agents seeking to maximize a utility function. Here we develop this idea and place it on a firm footing by employing a standard decision-theoretic methodology. We show how the principle of inclusive fitness maximization and a related principle of quasi-inclusive fitness maximization can be derived from axioms on an individual׳s 'as if preferences' (binary choices) for the case in which phenotypic effects are additive. Our results help integrate evolutionary theory and rational choice theory, help draw out the behavioural implications of inclusive fitness maximization, and point to a possible way in which evolution could lead organisms to implement it. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Maximal Entanglement in High Energy Physics

    Directory of Open Access Journals (Sweden)

    Alba Cervera-Lierta, José I. Latorre, Juan Rojo, Luca Rottoli

    2017-11-01

    Full Text Available We analyze how maximal entanglement is generated at the fundamental level in QED by studying correlations between helicity states in tree-level scattering processes at high energy. We demonstrate that two mechanisms for the generation of maximal entanglement are at work: i $s$-channel processes where the virtual photon carries equal overlaps of the helicities of the final state particles, and ii the indistinguishable superposition between $t$- and $u$-channels. We then study whether requiring maximal entanglement constrains the coupling structure of QED and the weak interactions. In the case of photon-electron interactions unconstrained by gauge symmetry, we show how this requirement allows reproducing QED. For $Z$-mediated weak scattering, the maximal entanglement principle leads to non-trivial predictions for the value of the weak mixing angle $\\theta_W$. Our results are a first step towards understanding the connections between maximal entanglement and the fundamental symmetries of high-energy physics.

  5. The effect of shoe type on static and dynamic balance during treadmill walking in young healthy women.

    Science.gov (United States)

    Kim, Mi-Kyoung; Kong, Byung-Sun; Yoo, Kyung-Tae

    2017-09-01

    [Purpose] The purpose of this study was to analyze the effect of various shoes on the static and dynamic balance of young women in their 20s. [Subjects and Methods] The subjects of the study were 15 healthy young women and repeated measured design. The subjects walked on the treadmill at a speed of 4 km/h for 30 minutes wearing three types of shoes: sneaker, rain boots, and combat boots. Balance was measured by a Romberg test and a limits of stability test. One-way ANOVA was used for statistical analysis. [Results] As the results of the Romberg test, the main effect of time was shown in the EO-COG area, EO-COG length, and EO-COG velocity. As the results of the limits of stability test, the main effects of time in LT, RT, FW, and total. There were significant differences in the LT in the sneaker group, the rain boots group, and the LT and RT in the combat boots group between the pre- and post-test. [Conclusion] The characteristics of shoes such as the materials, hardness, and thickness of the soles, the coefficient of friction of the outsoles, and the collar height affected the static and dynamic balance.

  6. Joint kinematics and kinetics of overground accelerated running versus running on an accelerated treadmill.

    Science.gov (United States)

    Caekenberghe, Ine Van; Segers, Veerle; Aerts, Peter; Willems, Patrick; De Clercq, Dirk

    2013-07-06

    Literature shows that running on an accelerated motorized treadmill is mechanically different from accelerated running overground. Overground, the subject has to enlarge the net anterior-posterior force impulse proportional to acceleration in order to overcome linear whole body inertia, whereas on a treadmill, this force impulse remains zero, regardless of belt acceleration. Therefore, it can be expected that changes in kinematics and joint kinetics of the human body also are proportional to acceleration overground, whereas no changes according to belt acceleration are expected on a treadmill. This study documents kinematics and joint kinetics of accelerated running overground and running on an accelerated motorized treadmill belt for 10 young healthy subjects. When accelerating overground, ground reaction forces are characterized by less braking and more propulsion, generating a more forward-oriented ground reaction force vector and a more forwardly inclined body compared with steady-state running. This change in body orientation as such is partly responsible for the changed force direction. Besides this, more pronounced hip and knee flexion at initial contact, a larger hip extension velocity, smaller knee flexion velocity and smaller initial plantarflexion velocity are associated with less braking. A larger knee extension and plantarflexion velocity result in larger propulsion. Altogether, during stance, joint moments are not significantly influenced by acceleration overground. Therefore, we suggest that the overall behaviour of the musculoskeletal system (in terms of kinematics and joint moments) during acceleration at a certain speed remains essentially identical to steady-state running at the same speed, yet acting in a different orientation. However, because acceleration implies extra mechanical work to increase the running speed, muscular effort done (in terms of power output) must be larger. This is confirmed by larger joint power generation at the level of

  7. Joint kinematics and kinetics of overground accelerated running versus running on an accelerated treadmill

    Science.gov (United States)

    Van Caekenberghe, Ine; Segers, Veerle; Aerts, Peter; Willems, Patrick; De Clercq, Dirk

    2013-01-01

    Literature shows that running on an accelerated motorized treadmill is mechanically different from accelerated running overground. Overground, the subject has to enlarge the net anterior–posterior force impulse proportional to acceleration in order to overcome linear whole body inertia, whereas on a treadmill, this force impulse remains zero, regardless of belt acceleration. Therefore, it can be expected that changes in kinematics and joint kinetics of the human body also are proportional to acceleration overground, whereas no changes according to belt acceleration are expected on a treadmill. This study documents kinematics and joint kinetics of accelerated running overground and running on an accelerated motorized treadmill belt for 10 young healthy subjects. When accelerating overground, ground reaction forces are characterized by less braking and more propulsion, generating a more forward-oriented ground reaction force vector and a more forwardly inclined body compared with steady-state running. This change in body orientation as such is partly responsible for the changed force direction. Besides this, more pronounced hip and knee flexion at initial contact, a larger hip extension velocity, smaller knee flexion velocity and smaller initial plantarflexion velocity are associated with less braking. A larger knee extension and plantarflexion velocity result in larger propulsion. Altogether, during stance, joint moments are not significantly influenced by acceleration overground. Therefore, we suggest that the overall behaviour of the musculoskeletal system (in terms of kinematics and joint moments) during acceleration at a certain speed remains essentially identical to steady-state running at the same speed, yet acting in a different orientation. However, because acceleration implies extra mechanical work to increase the running speed, muscular effort done (in terms of power output) must be larger. This is confirmed by larger joint power generation at the level

  8. Comparison of arbutamine stress and treadmill exercise thallium-201 SPECT: Hemodynamics, safety profile and diagnostic accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Kiat, H.; Berman, D.S. [Cedars-Sinai Medical Centre, Los Angeles, California, LA (United States)

    1998-02-01

    Full text: Arbutamine (ARB), a new pharmacologic stress agent with enhanced chronotropic property compared to dobutamine, was compared with treadmill (TM) exercise testing (Ex) in a multicenter study using thallium-201 (Tl) SPECT. Of the total of 184 patients who underwent ARB, 69 also had TM stress and quantitative coronary angiography. Fifty-eight patients with a low pretest likelihood of CAD also underwent ARB study for evaluation of test specificity (normalcy rate). Tl scans were scored by a central laboratory using a 20 segment (seg)/scan visual analysis (5 point system: 0=normal, 4-absent uptake). Maximum heart rate (HR) by ARB and Ex was 122 vs 141 bpm (p<0.05). Mean %HR change from baseline was similar (79% vs 82%, respectively, p=ns). Maximum systolic BP for ARB and Ex was 173 vs 175 mmHg, and mean % change from baseline was 24% vs 28% (p=ns). Sensitivity for detecting CAD (270% stenosis) by ARB Tl was 94% and 97% by Ex Tl (p=ns). Stress Tl SPECT segmental agreement for presence of defect between ARB and Ex was 92% (kappa=0.8, p<0.001). Exact segmental stress Tl score (0-4 grading) agreement was 83 % (kappa=0.7, p<0.001). Among 346 segs with stress defects by both ARB and Ex defect reversibility agreement was 86% (kappa=0.7, p<0.001). The normalcy rate for ARB TI-SPECT among patients with a low likelihood of CAD was 90%. Adverse events were mostly mild (tremor: 23%, flushing: 10%, headache: 10%, paraesthesia: 8%, dizziness: 8%, hot flushes: 4%). Arrhythimia of clinical concern occurred in 8% (10/122) of ARB patients who had cardiac catheterisation and in 1.4% (1/69) of patients who had stress Tl. Of all 184 patients with ARB stress, ARB was discontinued due to arrhythmia in 7(5%) and 1 patient had IV Metoprolol for frequent ventricular couplets. Sustained arrhythmias were not observed

  9. Comparison of arbutamine stress and treadmill exercise thallium-201 SPECT: Hemodynamics, safety profile and diagnostic accuracy

    International Nuclear Information System (INIS)

    Kiat, H.; Berman, D.S.

    1998-01-01

    Full text: Arbutamine (ARB), a new pharmacologic stress agent with enhanced chronotropic property compared to dobutamine, was compared with treadmill (TM) exercise testing (Ex) in a multicenter study using thallium-201 (Tl) SPECT. Of the total of 184 patients who underwent ARB, 69 also had TM stress and quantitative coronary angiography. Fifty-eight patients with a low pretest likelihood of CAD also underwent ARB study for evaluation of test specificity (normalcy rate). Tl scans were scored by a central laboratory using a 20 segment (seg)/scan visual analysis (5 point system: 0=normal, 4-absent uptake). Maximum heart rate (HR) by ARB and Ex was 122 vs 141 bpm (p<0.05. Mean %HR change from baseline was similar (79% vs 82%, respectively, p=ns). Maximum systolic BP for ARB and Ex was 173 vs 175 mmHg, and mean % change from baseline was 24% vs 28% (p=ns). Sensitivity for detecting CAD (270% stenosis) by ARB Tl was 94% and 97% by Ex Tl (p=ns). Stress Tl SPECT segmental agreement for presence of defect between ARB and Ex was 92% (kappa=0.8, p<0.001). Exact segmental stress Tl score (0-4 grading) agreement was 83 % (kappa=0.7, p<0.001). Among 346 segs with stress defects by both ARB and Ex defect reversibility agreement was 86% (kappa=0.7, p<0.001). The normalcy rate for ARB TI-SPECT among patients with a low likelihood of CAD was 90%. Adverse events were mostly mild (tremor: 23%, flushing: 10%, headache: 10%, paraesthesia: 8%, dizziness: 8%, hot flushes: 4%). Arrhythimia of clinical concern occurred in 8% (10/122) of ARB patients who had cardiac catheterisation and in 1.4% (1/69) of patients who had stress Tl. Of all 184 patients with ARB stress, ARB was discontinued due to arrhythmia in 7(5%) and 1 patient had IV Metoprolol for frequent ventricular couplets. Sustained arrhythmias were not observed

  10. Maximizing your return on people.

    Science.gov (United States)

    Bassi, Laurie; McMurrer, Daniel

    2007-03-01

    Though most traditional HR performance metrics don't predict organizational performance, alternatives simply have not existed--until now. During the past ten years, researchers Laurie Bassi and Daniel McMurrer have worked to develop a system that allows executives to assess human capital management (HCM) and to use those metrics both to predict organizational performance and to guide organizations' investments in people. The new framework is based on a core set of HCM drivers that fall into five major categories: leadership practices, employee engagement, knowledge accessibility, workforce optimization, and organizational learning capacity. By employing rigorously designed surveys to score a company on the range of HCM practices across the five categories, it's possible to benchmark organizational HCM capabilities, identify HCM strengths and weaknesses, and link improvements or back-sliding in specific HCM practices with improvements or shortcomings in organizational performance. The process requires determining a "maturity" score for each practice, based on a scale of 1 (low) to 5 (high). Over time, evolving maturity scores from multiple surveys can reveal progress in each of the HCM practices and help a company decide where to focus improvement efforts that will have a direct impact on performance. The authors draw from their work with American Standard, South Carolina's Beaufort County School District, and a bevy of financial firms to show how improving HCM scores led to increased sales, safety, academic test scores, and stock returns. Bassi and McMurrer urge HR departments to move beyond the usual metrics and begin using HCM measurement tools to gauge how well people are managed and developed throughout the organization. In this new role, according to the authors, HR can take on strategic responsibility and ensure that superior human capital management becomes central to the organization's culture.

  11. Analysis Spectrum of ECG Signal and QRS Detection during Running on Treadmill

    Science.gov (United States)

    Agung Suhendra, M.; Ilham R., M.; Simbolon, Artha I.; Faizal A., M.; Munandar, A.

    2018-03-01

    The heart is an important organ in our metabolism in which it controls circulatory and oxygen. The heart exercise is needed one of them using the treadmill to prevent health. To analysis, it using electrocardiograph (ECG) to investigating and diagnosing anomalies of the heart. In this paper, we would like to analysis ECG signals during running on the treadmill with kinds of speeds. There are two analysis ECG signals i.e. QRS detection and power spectrum density (PSD). The result of PSD showed that subject 3 has highly for all subject and the result of QRS detection using pan Tomkins algorithm that a percentage of failed detection is an approaching to 0 % for all subject.

  12. Treadmill training as an augmentation treatment for Alzheimer?s disease: a pilot randomized controlled study

    Directory of Open Access Journals (Sweden)

    Cynthia Arcoverde

    2014-03-01

    Full Text Available Objective To assess the effect of aerobic exercise on the cognition and functional capacity in Alzheimer’s disease (AD patients. Method Elderly (n=20 with mild dementia (NINCDS-ADRDA/CDR1 were randomly assigned to an exercise group (EG on a treadmill (30 minutes, twice a week and moderate intensity of 60% VO2max and control group (GC 10 patients. The primary outcome measure was the cognitive function using Cambridge Cognitive Examination (CAMCOG. Specifics instruments were also applied to evaluate executive function, memory, attention and concentration, cognitive flexibility, inhibitory control and functional capacity. Results After 16 weeks, the EG showed improvement in cognition CAMCOG whereas the CG declined. Compared to the CG, the EG presented significant improvement on the functional capacity. The analysis of the effect size has shown a favorable response to the physical exercise in all dependent variables. Conclusion Walking on treadmill may be recommended as an augmentation treatment for patients with AD.

  13. Bipartite Bell Inequality and Maximal Violation

    International Nuclear Information System (INIS)

    Li Ming; Fei Shaoming; Li-Jost Xian-Qing

    2011-01-01

    We present new bell inequalities for arbitrary dimensional bipartite quantum systems. The maximal violation of the inequalities is computed. The Bell inequality is capable of detecting quantum entanglement of both pure and mixed quantum states more effectively. (general)

  14. HEALTH INSURANCE: CONTRIBUTIONS AND REIMBURSEMENT MAXIMAL

    CERN Document Server

    HR Division

    2000-01-01

    Affected by both the salary adjustment index on 1.1.2000 and the evolution of the staff members and fellows population, the average reference salary, which is used as an index for fixed contributions and reimbursement maximal, has changed significantly. An adjustment of the amounts of the reimbursement maximal and the fixed contributions is therefore necessary, as from 1 January 2000.Reimbursement maximalThe revised reimbursement maximal will appear on the leaflet summarising the benefits for the year 2000, which will soon be available from the divisional secretariats and from the AUSTRIA office at CERN.Fixed contributionsThe fixed contributions, applicable to some categories of voluntarily insured persons, are set as follows (amounts in CHF for monthly contributions):voluntarily insured member of the personnel, with complete coverage:815,- (was 803,- in 1999)voluntarily insured member of the personnel, with reduced coverage:407,- (was 402,- in 1999)voluntarily insured no longer dependent child:326,- (was 321...

  15. Maximal Inequalities for Dependent Random Variables

    DEFF Research Database (Denmark)

    Hoffmann-Jorgensen, Jorgen

    2016-01-01

    Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X-k. Then a......Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X......-k. Then a maximal inequality gives conditions ensuring that the maximal partial sum M-n = max(1) (...

  16. Maximizing Function through Intelligent Robot Actuator Control

    Data.gov (United States)

    National Aeronautics and Space Administration — Maximizing Function through Intelligent Robot Actuator Control Successful missions to Mars and beyond will only be possible with the support of high-performance...

  17. An ethical justification of profit maximization

    DEFF Research Database (Denmark)

    Koch, Carsten Allan

    2010-01-01

    In much of the literature on business ethics and corporate social responsibility, it is more or less taken for granted that attempts to maximize profits are inherently unethical. The purpose of this paper is to investigate whether an ethical argument can be given in support of profit maximizing...... behaviour. It is argued that some form of consequential ethics must be applied, and that both profit seeking and profit maximization can be defended from a rule-consequential point of view. It is noted, however, that the result does not apply unconditionally, but requires that certain form of profit (and...... utility) maximizing actions are ruled out, e.g., by behavioural norms or formal institutions....

  18. A definition of maximal CP-violation

    International Nuclear Information System (INIS)

    Roos, M.

    1985-01-01

    The unitary matrix of quark flavour mixing is parametrized in a general way, permitting a mathematically natural definition of maximal CP violation. Present data turn out to violate this definition by 2-3 standard deviations. (orig.)

  19. A cosmological problem for maximally symmetric supergravity

    International Nuclear Information System (INIS)

    German, G.; Ross, G.G.

    1986-01-01

    Under very general considerations it is shown that inflationary models of the universe based on maximally symmetric supergravity with flat potentials are unable to resolve the cosmological energy density (Polonyi) problem. (orig.)

  20. Maximal supergravities and the E10 model

    International Nuclear Information System (INIS)

    Kleinschmidt, Axel; Nicolai, Hermann

    2006-01-01

    The maximal rank hyperbolic Kac-Moody algebra e 10 has been conjectured to play a prominent role in the unification of duality symmetries in string and M theory. We review some recent developments supporting this conjecture

  1. Evaluation of a Treadmill with Vibration Isolation and Stabilization (TVIS) for Use on the International Space Station

    Science.gov (United States)

    McCrory, Jean L.; Lemmon, David R.; Sommer, H. Joseph; Prout, Brian; Smith, Damon; Korth, Deborah W.; Lucero, Javier; Greenisen, Michael; Moore, Jim

    1999-01-01

    A treadmill with vibration isolation and stabilization designed for the International Space Station (ISS) was evaluated during Shuttle mission STS-81. Three crew members ran and walked on the device, which floats freely in zero gravity. For the majority of the more than 2 hours of locomotion studied, the treadmill showed peak to peak linear and angular displacements of less than 2.5 cm and 2.5 deg, respectively. Vibration transmitted to the vehicle was within the microgravity allocation limits that are defined for the ISS. Refinements to the treadmill and harness system are discussed. This approach to treadmill design offers the possibility of generating 1G-like loads on the lower extremities while preserving the microgravity environment of the ISS for structural safety and vibration free experimental conditions.

  2. Optimal spectral tracking - with application to speed dependent neural modulation of tibialis anterior during human treadmill walking

    DEFF Research Database (Denmark)

    Brittain, John-Stuart; Catton, Celia; Conway, Bernard A.

    2009-01-01

    ) during healthy treadmill locomotion. The approach adopts adaptive filter theory while retaining a spectral focus, thus remaining compatible with much of the current literature. Spectral tracking procedures are evaluated using both surrogate and neurophysiological time-series. Confidence intervals...

  3. Role of adenosine in the regulation of coronary blood flow in swine at rest and during treadmill exercise

    NARCIS (Netherlands)

    D.J.G.M. Duncker (Dirk); R. Stubenitsky (René); P.D. Verdouw (Pieter)

    1998-01-01

    textabstractA pivotal role for adenosine in the regulation of coronary blood flow is still controversial. Consequently, we investigated its role in the regulation of coronary vasomotor tone in swine at rest and during graded treadmill exercise. During exercise,

  4. Heart rate recovery after maximal exercise is blunted in hypertensive seniors

    Science.gov (United States)

    Best, Stuart A.; Bivens, Tiffany B.; Dean Palmer, M.; Boyd, Kara N.; Melyn Galbreath, M.; Okada, Yoshiyuki; Carrick-Ranson, Graeme; Shibata, Shigeki; Hastings, Jeffrey L.; Spencer, Matthew D.; Tarumi, Takashi; Levine, Benjamin D.; Fu, Qi

    2014-01-01

    Abnormal heart rate recovery (HRR) after maximal exercise may indicate autonomic dysfunction and is a predictor for cardiovascular mortality. HRR is attenuated with aging and in middle-age hypertensive patients, but it is unknown whether HRR is attenuated in older-age adults with hypertension. This study compared HRR among 16 unmedicated stage 1 hypertensive (HTN) participants [nine men/seven women; 68 ± 5 (SD) yr; awake ambulatory blood pressure (BP) 149 ± 10/87 ± 7 mmHg] and 16 normotensive [control (CON)] participants (nine men/seven women; 67 ± 5 yr; 122 ± 4/72 ± 5 mmHg). HR, BP, oxygen uptake (V̇o2), cardiac output (Qc), and stroke volume (SV) were measured at rest, at two steady-state work rates, and graded exercise to peak during maximal treadmill exercise. During 6 min of seated recovery, the change in HR (ΔHR) was obtained every minute and BP every 2 min. In addition, HRR and R-R interval (RRI) recovery kinetics were analyzed using a monoexponential function, and the indexes (HRRI and RRII) were calculated. Maximum V̇o2, HR, Qc, and SV responses during exercise were not different between groups. ΔHR was significantly different (P age adults, HRR is attenuated further with the presence of hypertension, which may be attributable to an impairment of autonomic function. PMID:25301897

  5. Short-term step-to-step correlation in plantar pressure distributions during treadmill walking, and implications for footprint trail analysis.

    Science.gov (United States)

    Pataky, Todd C; Savage, Russell; Bates, Karl T; Sellers, William I; Crompton, Robin H

    2013-09-01

    The gait cycle is continuous, but for practical reasons one is often forced to analyze one or only a few adjacent cycles, for example in non-treadmill laboratory investigations and in fossilized footprint analysis. The nature of variability in long-term gait cycle dynamics has been well-investigated, but short-term variability, and specifically correlation, which are highly relevant to short gait bouts, have not. We presently tested for step-to-step autocorrelation in a total of 5243 plantar pressure (PP) distributions from ten subjects who walked at 1.1m/s on an instrumented treadmill. Following spatial foot alignment, data were analyzed both from three points of interest (POI): heel, central metatarsals, and hallux, and for the foot surface as a whole, in a mass-univariate manner. POI results revealed low average step-to-step autocorrelation coefficients (r=0.327±0.094; mean±st. dev.). Formal statistical testing of the whole-foot r distributions reached significance over an average of only 0.42±0.52% of the foot's surface, even for a highly conservative uncorrected threshold of p<0.05. The common assumption, that short gait bouts consist of independent cycles, is therefore not refuted by the present PP results. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Robot-Applied Resistance Augments the Effects of Body Weight-Supported Treadmill Training on Stepping and Synaptic Plasticity in a Rodent Model of Spinal Cord Injury.

    Science.gov (United States)

    Hinahon, Erika; Estrada, Christina; Tong, Lin; Won, Deborah S; de Leon, Ray D

    2017-08-01

    The application of resistive forces has been used during body weight-supported treadmill training (BWSTT) to improve walking function after spinal cord injury (SCI). Whether this form of training actually augments the effects of BWSTT is not yet known. To determine if robotic-applied resistance augments the effects of BWSTT using a controlled experimental design in a rodent model of SCI. Spinally contused rats were treadmill trained using robotic resistance against horizontal (n = 9) or vertical (n = 8) hind limb movements. Hind limb stepping was tested before and after 6 weeks of training. Two control groups, one receiving standard training (ie, without resistance; n = 9) and one untrained (n = 8), were also tested. At the terminal experiment, the spinal cords were prepared for immunohistochemical analysis of synaptophysin. Six weeks of training with horizontal resistance increased step length, whereas training with vertical resistance enhanced step height and movement velocity. None of these changes occurred in the group that received standard (ie, no resistance) training or in the untrained group. Only standard training increased the number of step cycles and shortened cycle period toward normal values. Synaptophysin expression in the ventral horn was highest in rats trained with horizontal resistance and in untrained rats and was positively correlated with step length. Adding robotic-applied resistance to BWSTT produced gains in locomotor function over BWSTT alone. The impact of resistive forces on spinal connections may depend on the nature of the resistive forces and the synaptic milieu that is present after SCI.

  7. Gaussian maximally multipartite-entangled states

    Science.gov (United States)

    Facchi, Paolo; Florio, Giuseppe; Lupo, Cosmo; Mancini, Stefano; Pascazio, Saverio

    2009-12-01

    We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of these states and their frustration for n≤7 .

  8. Gaussian maximally multipartite-entangled states

    International Nuclear Information System (INIS)

    Facchi, Paolo; Florio, Giuseppe; Pascazio, Saverio; Lupo, Cosmo; Mancini, Stefano

    2009-01-01

    We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of these states and their frustration for n≤7.

  9. Neutrino mass textures with maximal CP violation

    International Nuclear Information System (INIS)

    Aizawa, Ichiro; Kitabayashi, Teruyuki; Yasue, Masaki

    2005-01-01

    We show three types of neutrino mass textures, which give maximal CP violation as well as maximal atmospheric neutrino mixing. These textures are described by six real mass parameters: one specified by two complex flavor neutrino masses and two constrained ones and the others specified by three complex flavor neutrino masses. In each texture, we calculate mixing angles and masses, which are consistent with observed data, as well as Majorana CP phases

  10. Why firms should not always maximize profits

    OpenAIRE

    Kolstad, Ivar

    2006-01-01

    Though corporate social responsibility (CSR) is on the agenda of most major corporations, corporate executives still largely support the view that corporations should maximize the returns to their owners. There are two lines of defence for this position. One is the Friedmanian view that maximizing owner returns is the corporate social responsibility of corporations. The other is a position voiced by many executives, that CSR and profits go together. This paper argues that the first position i...

  11. Maximally Informative Observables and Categorical Perception

    OpenAIRE

    Tsiang, Elaine

    2012-01-01

    We formulate the problem of perception in the framework of information theory, and prove that categorical perception is equivalent to the existence of an observable that has the maximum possible information on the target of perception. We call such an observable maximally informative. Regardless whether categorical perception is real, maximally informative observables can form the basis of a theory of perception. We conclude with the implications of such a theory for the problem of speech per...

  12. Fractal fluctuations in spatiotemporal variables when walking on a self-paced treadmill.

    Science.gov (United States)

    Choi, Jin-Seung; Kang, Dong-Won; Seo, Jeong-Woo; Tack, Gye-Rae

    2017-12-08

    This study investigated the fractal dynamic properties of stride time (ST), stride length (SL) and stride speed (SS) during walking on a self-paced treadmill (STM) in which the belt speed is automatically controlled by the walking speed. Twelve healthy young subjects participated in the study. The subjects walked at their preferred walking speed under four conditions: STM, STM with a metronome (STM+met), fixed-speed (conventional) treadmill (FTM), and FTM with a metronome (FTM+met). To compare the fractal dynamics between conditions, the mean, variability, and fractal dynamics of ST, SL, and SS were compared. Moreover, the relationship among the variables was examined under each walking condition using three types of surrogates. The mean values of all variables did not differ between the two treadmills, and the variability of all variables was generally larger for STM than for FTM. The use of a metronome resulted in a decrease in variability in ST and SS for all conditions. The fractal dynamic characteristics of SS were maintained with STM, in contrast to FTM, and only the fractal dynamic characteristics of ST disappeared when using a metronome. In addition, the fractal dynamic patterns of the cross-correlated surrogate results were identical to those of all variables for the two treadmills. In terms of the fractal dynamic properties, STM walking was generally closer to overground walking than FTM walking. Although further research is needed, the present results will be useful in research on gait fractal dynamics and rehabilitation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Peptidoglycan synthesis drives an FtsZ-treadmilling-independent step of cytokinesis.

    Science.gov (United States)

    Monteiro, João M; Pereira, Ana R; Reichmann, Nathalie T; Saraiva, Bruno M; Fernandes, Pedro B; Veiga, Helena; Tavares, Andreia C; Santos, Margarida; Ferreira, Maria T; Macário, Vânia; VanNieuwenhze, Michael S; Filipe, Sérgio R; Pinho, Mariana G

    2018-02-22

    Peptidoglycan is the main component of the bacterial wall and protects cells from the mechanical stress that results from high intracellular turgor. Peptidoglycan biosynthesis is very similar in all bacteria; bacterial shapes are therefore mainly determined by the spatial and temporal regulation of peptidoglycan synthesis rather than by the chemical composition of peptidoglycan. The form of rod-shaped bacteria, such as Bacillus subtilis or Escherichia coli, is generated by the action of two peptidoglycan synthesis machineries that act at the septum and at the lateral wall in processes coordinated by the cytoskeletal proteins FtsZ and MreB, respectively. The tubulin homologue FtsZ is the first protein recruited to the division site, where it assembles in filaments-forming the Z ring-that undergo treadmilling and recruit later divisome proteins. The rate of treadmilling in B. subtilis controls the rates of both peptidoglycan synthesis and cell division. The actin homologue MreB forms discrete patches that move circumferentially around the cell in tracks perpendicular to the long axis of the cell, and organize the insertion of new cell wall during elongation. Cocci such as Staphylococcus aureus possess only one type of peptidoglycan synthesis machinery, which is diverted from the cell periphery to the septum in preparation for division. The molecular cue that coordinates this transition has remained elusive. Here we investigate the localization of S. aureus peptidoglycan biosynthesis proteins and show that the recruitment of the putative lipid II flippase MurJ to the septum, by the DivIB-DivIC-FtsL complex, drives peptidoglycan incorporation to the midcell. MurJ recruitment corresponds to a turning point in cytokinesis, which is slow and dependent on FtsZ treadmilling before MurJ arrival but becomes faster and independent of FtsZ treadmilling after peptidoglycan synthesis activity is directed to the septum, where it provides additional force for cell envelope

  14. Treadmill Exercise Attenuates Retinal Oxidative Stress in Naturally-Aged Mice: An Immunohistochemical Study

    Directory of Open Access Journals (Sweden)

    Chan-Sik Kim

    2015-09-01

    Full Text Available In the retina, a number of degenerative diseases, including glaucoma, diabetic retinopathy, and age-related macular degeneration, may occur as a result of aging. Oxidative damage is believed to contribute to the pathogenesis of aging as well as to age-related retinal disease. Although physiological exercise has been shown to reduce oxidative stress in rats and mice, it is not known whether it has a similar effect in retinal tissues. The aim of this study was to evaluate retinal oxidative stress in naturally-aged mice. In addition, we evaluated the effects of aerobic training on retinal oxidative stress by immunohistochemically evaluating oxidative stress markers. A group of twelve-week-old male mice were not exercised (young control. Two groups of twenty-two-month-old male mice were created: an old control group and a treadmill exercise group. The old control group mice were not exercised. The treadmill exercise group mice ran on a treadmill (5 to 12 m/min, 30 to 60 min/day, 3 days/week for 12 weeks. The retinal thickness and number of cells in the ganglion cell layer of the naturally-aged mice were reduced compared to those in the young control mice. However, treadmill exercise reversed these morphological changes in the retinas. We evaluated retinal expression of carboxymethyllysine (CML, 8-hydroxy-2′-deoxyguanosine (8-OHdG and nitrotyrosine. The retinas from the aged mice showed increased CML, 8-OHdG, and nitrotyrosine immunostaining intensities compared to young control mice. The exercise group exhibited significantly lower CML levels and nitro-oxidative stress than the old control group. These results suggest that regular exercise can reduce retinal oxidative stress and that physiological exercise may be distinctly advantageous in reducing retinal oxidative stress.

  15. Changes in muscle activation patterns in response to enhanced sensory input during treadmill stepping in infants born with myelomeningocele

    OpenAIRE

    Pantall, Annette; Teulier, Caroline; Ulrich, Beverly D.

    2012-01-01

    Infants with myelomeningocele (MMC) increase step frequency in response to modifications to the treadmill surface. The aim was to investigate how these modifications impacted the electromyographic (EMG) patterns. We analyzed EMG from 19 infants aged 2–10 months, with MMC at the lumbosacral level. We supported infants upright on the treadmill for 12 trials, each 30 seconds long. Modifications included visual flow, unloading, weights, Velcro and lcriction. Surface electrodes recorded EMG from t...

  16. External Mechanical Work and Pendular Energy Transduction of Overground and Treadmill Walking in Adolescents with Unilateral Cerebral Palsy

    OpenAIRE

    Zollinger, Marie; Degache, Francis; Currat, Gabriel; Pochon, Ludmila; Peyrot, Nicolas; Newman, Christopher J.; Malatesta, Davide

    2016-01-01

    PURPOSE: Motor impairments affect functional abilities and gait in children and adolescents with cerebral palsy (CP). Improving their walking is an essential objective of treatment, and the use of a treadmill for gait analysis and training could offer several advantages in adolescents with CP. However, there is a controversy regarding the similarity between treadmill and overground walking both for gait analysis and training in children and adolescents. The aim of this study was to compare th...

  17. Loading Configurations and Ground Reaction Forces During Treadmill Running in Weightlessness

    Science.gov (United States)

    DeWitt, John; Schaffner, Grant; Blazine, Kristi; Bentley, Jason; Laughlin, Mitzi; Loehr, James; Hagan, Donald

    2003-01-01

    Studies have shown losses in bone mineral density of 1-2% per month in critical weight bearing areas such as the proximal femur during long-term space flight (Grigoriev, 1998). The astronauts currently onboard the International Space Station (ISS) use a treadmill as an exercise countermeasure to bone loss that occurs as a result of prolonged exposure to weightlessness. A crewmember exercising on the treadmill is attached by a harness and loading device. Ground reaction forces are obtained through the loading device that pulls the crewn1ember towards the treadmill surface during locomotion. McCrory et al. (2002) found that the magnitude of the peak ground reaction force (pGRF) during horizontal suspension running, or simulated weightlessness, was directly related to the load applied to the subject. It is thought that strain magnitude and strain rate affects osteogenesis, and is a function of the magnitude and rate of change of the ground reaction force. While it is not known if a minimum stimulus exists for osteogenesis, it has been hypothesized that in order to replicate the bone formation occurring in normal gravity (1 G), the exercise in weightlessness should mimic the forces that occur on earth. Specifically, the pGRF obtained in weightlessness should be comparable to that achieved in 1 G.

  18. Antigravity treadmill training during the early rehabilitation phase following unicompartmental knee arthroplasty: A case series.

    Science.gov (United States)

    Huang, Chun-Hao; Schroeder, E Todd; Powers, Christopher

    2018-02-26

    Patients who have undergone unicompartmental knee arthroplasty (UKA) have been reported to exhibit altered gait 19-25 months post-surgery. The most common gait impairment in this population is inadequate knee flexion and a corresponding decrease in the knee extensor moment during loading response (i.e., quadriceps avoidance). The purpose of this case series was to determine whether incorporation of antigravity treadmill training into a standard physical therapy program can eliminate quadriceps avoidance gait during the early rehabilitation phase following UKA. Four females who underwent UKA were recruited for this study. Participants completed antigravity treadmill training three times per week for 12 weeks in addition to their standard physical therapy program. Instrumented gait analysis was performed at baseline (pre-intervention), week 6 (mid-intervention), and week 12 (post-intervention). We found that peak knee flexion and the peak knee extensor moment during the weight acceptance phase of gait increased to normal values following the 12-week intervention period (14.1 ± 6.5° to 20.6 ± 1.5° and 0.4 ± 0.3 to 0.7 ± 0.2 Nm/kg respectively). The findings of this case series suggest that a standard physical therapy program that incorporates early gait training using an antigravity treadmill may be beneficial in eliminating "quadriceps avoidance" during the early rehabilitation phase following UKA.

  19. Influence of treadmill acceleration on actual walk-to-run transition.

    Science.gov (United States)

    Van Caekenberghe, I; Segers, V; De Smet, K; Aerts, P; De Clercq, D

    2010-01-01

    When accelerating continuously, humans spontaneously change from a walking to a running pattern by means of a walk-to-run transition (WRT). Results of previous studies indicate that when higher treadmill accelerations are imposed, higher WRT-speeds can be expected. By studying the kinematics of the WRT at different accelerations, the underlying mechanisms can be unravelled. 19 young, healthy female subjects performed walk-to-run transitions on a constantly accelerating treadmill (0.1, 0.2 and 0.5 m s(-2)). A higher acceleration induced a higher WRT-speed, by effecting the preparation of transition, as well as the actual transition step. Increasing the acceleration caused a higher WRT-speed as a result of a greater step length during the transition step, which was mainly a consequence of a prolonged airborne phase. Besides this effect on the transition step, the direct preparation phase of transition (i.e. the last walking step before transition) appeared to fulfil specific constraints required to execute the transition regardless of the acceleration imposed. This highlights an important role for this step in the debate regarding possible determinants of WRT. In addition spatiotemporal and kinematical data confirmed that WRT remains a discontinuous change of gait pattern in all accelerations imposed. It is concluded that the walk-to-run transition is a discontinuous switch from walking to running which depends on the magnitude of treadmill belt acceleration. Copyright 2009 Elsevier B.V. All rights reserved.

  20. Different Intensities of Treadmill Running Exercise do Not Alter Melatonin Levels in Rats

    Directory of Open Access Journals (Sweden)

    Ionara Rodrigues Siqueira

    2011-04-01

    Full Text Available Background: Regular and moderate exercise has been considered an interesting neuroprotective strategy. Our research group demonstrated that a protocol of moderate exercise on a treadmill reduced, while a protocol of high-intensity exercise increased in vitro ischemic cell damage in Wistar rats. The molecular mechanisms by which physical exercise exerts neuroprotective effects remain unclear. Accumulating evidence suggests that exercise may have short- and long-term effects on melatonin secretion in humans. Melatonin, the main product of the pineal gland, has been shown to have neuroprotective effects in models of brain and spinal cord injury and cerebral ischemia. A dual modulation of melatonin secretion by physical activity has also been demonstrated. This study aimed to investigate the effect of different exercise intensities, moderate- and high-intensity exercise, on serum melatonin levels in rats. Methods: Thirty-five adult male Wistar rats were divided into non-exercised (sedentary and exercised (20- or 60-min sessions groups. The exercise protocols consisted of two weeks of daily treadmill training. Blood samples were collected approximately 16 hours after the last training session (8:00-10:00 and melatonin levels were assayed by ELISA. Results: The exercise protocols, two weeks of 20 min/day or 60 min/day of treadmill running, did not affect serum melatonin levels. Conclusion: Our data demonstrated that melatonin levels may not be directly involved in the exercise-induced, intensity-dependent dual effect on in vitro ischemia.

  1. Matching optical flow to motor speed in virtual reality while running on a treadmill

    Science.gov (United States)

    Lafortuna, Claudio L.; Mugellini, Elena; Abou Khaled, Omar

    2018-01-01

    We investigated how visual and kinaesthetic/efferent information is integrated for speed perception in running. Twelve moderately trained to trained subjects ran on a treadmill at three different speeds (8, 10, 12 km/h) in front of a moving virtual scene. They were asked to match the visual speed of the scene to their running speed–i.e., treadmill’s speed. For each trial, participants indicated whether the scene was moving slower or faster than they were running. Visual speed was adjusted according to their response using a staircase until the Point of Subjective Equality (PSE) was reached, i.e., until visual and running speed were perceived as equivalent. For all three running speeds, participants systematically underestimated the visual speed relative to their actual running speed. Indeed, the speed of the visual scene had to exceed the actual running speed in order to be perceived as equivalent to the treadmill speed. The underestimation of visual speed was speed-dependent, and percentage of underestimation relative to running speed ranged from 15% at 8km/h to 31% at 12km/h. We suggest that this fact should be taken into consideration to improve the design of attractive treadmill-mediated virtual environments enhancing engagement into physical activity for healthier lifestyles and disease prevention and care. PMID:29641564

  2. Evaluation of a workplace treadmill desk intervention: a randomized controlled trial.

    Science.gov (United States)

    Schuna, John M; Swift, Damon L; Hendrick, Chelsea A; Duet, Megan T; Johnson, William D; Martin, Corby K; Church, Timothy S; Tudor-Locke, Catrine

    2014-12-01

    To evaluate the effectiveness of a 3-month treadmill desk intervention in eliciting changes in physical activity and sedentary behavior among overweight/obese office workers. A randomized controlled trial was conducted among overweight/obese office workers (n = 41; mean age = 40.1 ± 10.1 years) at a private workplace. Participants were randomly assigned to a shared-treadmill desk intervention (n = 21) or a usual working condition control group (n = 20). Accelerometer-determined physical activity and sedentary behavior were measured before and after the intervention. Compared with the control group, the intervention group increased daily steps (1622 steps/day; P = 0.013) and light physical activity (1.6 minutes/hour; P = 0.008), and decreased sedentary time (-3.6 minutes/hour; P = 0.047) during working hours. Shared-treadmill desks in the workplace can be effective at promoting favorable changes in light physical activity (specifically 40 to 99 steps/minute) and sedentary behavior among overweight/obese office workers.

  3. Habituation of 10-year-old hockey players to treadmill skating.

    Science.gov (United States)

    Lockwood, Kelly L; Frost, Gail

    2007-05-01

    This study assessed changes in selected physiological and kinematic variables over 6 weeks of treadmill skating in an effort to understand the process of habituation to this novel training modality. Seven male, Atom-A hockey players who were injury-free and had no previous treadmill skating experience participated in the study. Players performed four 1-min skating bouts at progressively increasing speeds, each week, for 6 weeks. One speed (10.5 km/h) was repeated weekly to allow for assessment of the habituation process. Our criteria for habituation were: a decrease in stride rate, heart rate and rating of perceived exertion, and an increase in stride length, trunk angle and vertical movement of the centre of mass, leading to a plateau, over the course of the 6-week study. Significant decreases were seen in stride rate, heart rate and ratings of perceived exertion, and significant increases were found in stride length. Some of these changes were evident after only one week of training and all were present by week 4. After 6 weeks (24 min) of exposure to treadmill skating, all participants displayed a visibly more efficient skating style.

  4. A synergy perspective on gait – over-ground vs. treadmill walking

    DEFF Research Database (Denmark)

    Læssøe, Uffe; Madeleine, Pascal

    on movements has proposed that elemental and performance variables may represent good and bad components of variability [2]. We suggest that the gait pattern can be regarded as a movement synergy in which medio-lateral deviation in one stride can be corrected during the next stride (the elemental variables......). Such corrections ensure a straight gait path (the performance variable). AIM: The aim of this study was to apply a synergy approach to gait analysis by comparing over-ground and treadmill walking. The treadmill was hypothesized to demand a less variable walking path resulting in a larger good/bad variability ratio...... of the strides, and bad variance with respect to a similar line with a negative slope. The good/bad variance ratio was calculated and the difference between treadmill and over-ground walking was finally evaluated. RESULTS: The good/bad variance ratio for over-ground walking was 1.7 (CI95%: 1.5-2.0). When walking...

  5. Generalization of improved step length symmetry from treadmill to overground walking in persons with stroke and hemiparesis†

    Science.gov (United States)

    Savin, Douglas N.; Morton, Susanne M.; Whitall, Jill

    2013-01-01

    Objectives Determine whether adaptation to a swing phase perturbation during gait transferred from treadmill to overground walking, the rate of overground deadaptation, and whether overground aftereffects improved step length asymmetry in persons with hemiparetic stroke and gait asymmetry. Methods Ten participants with stroke and hemiparesis and 10 controls walked overground on an instrumented gait mat, adapted gait to a swing phase perturbation on a treadmill, then walked overground on the gait mat again. Outcome measures, primary: overground step length symmetry, rates of treadmill step length symmetry adaptation and overground step length symmetry deadaptation; secondary: overground gait velocity, stride length, and stride cycle duration. Results Step length symmetry aftereffects generalized to overground walking and adapted at a similar rate on the treadmill in both groups. Aftereffects decayed at a slower rate overground in participants with stroke and temporarily improved overground step length asymmetry. Both groups’ overground gait velocity increased post adaptation due to increased stride length and decreased stride duration. Conclusions Stroke and hemiparesis do not impair generalization of step length symmetry changes from adapted treadmill to overground walking, but prolong overground aftereffects. Significance Motor adaptation during treadmill walking may be an effective treatment for improving overground gait asymmetries post-stroke. PMID:24286858

  6. Pre-Ischemic Treadmill Training for Prevention of Ischemic Brain Injury via Regulation of Glutamate and Its Transporter GLT-1

    Directory of Open Access Journals (Sweden)

    Jingchun Guo

    2012-07-01

    Full Text Available Pre-ischemic treadmill training exerts cerebral protection in the prevention of cerebral ischemia by alleviating neurotoxicity induced by excessive glutamate release following ischemic stroke. However, the underlying mechanism of this process remains unclear. Cerebral ischemia-reperfusion injury was observed in a rat model after 2 weeks of pre-ischemic treadmill training. Cerebrospinal fluid was collected using the microdialysis sampling method, and the concentration of glutamate was determined every 40 min from the beginning of ischemia to 4 h after reperfusion with high-performance liquid chromatography (HPLC-fluorescence detection. At 3, 12, 24, and 48 h after ischemia, the expression of the glutamate transporter-1 (GLT-1 protein in brain tissues was determined by Western blot respectively. The effect of pre-ischemic treadmill training on glutamate concentration and GLT-1 expression after cerebral ischemia in rats along with changes in neurobehavioral score and cerebral infarct volume after 24 h ischemia yields critical information necessary to understand the protection mechanism exhibited by pre-ischemic treadmill training. The results demonstrated that pre-ischemic treadmill training up-regulates GLT-1 expression, decreases extracellular glutamate concentration, reduces cerebral infarct volume, and improves neurobehavioral score. Pre-ischemic treadmill training is likely to induce neuroprotection after cerebral ischemia by regulating GLT-1 expression, which results in re-uptake of excessive glutamate.

  7. Recovery of heart rate variability after treadmill exercise analyzed by lagged Poincaré plot and spectral characteristics.

    Science.gov (United States)

    Shi, Ping; Hu, Sijung; Yu, Hongliu

    2018-02-01

    The aim of this study was to analyze the recovery of heart rate variability (HRV) after treadmill exercise and to investigate the autonomic nervous system response after exercise. Frequency domain indices, i.e., LF(ms 2 ), HF(ms 2 ), LF(n.u.), HF(n.u.) and LF/HF, and lagged Poincaré plot width (SD1 m ) and length (SD2 m ) were introduced for comparison between the baseline period (Pre-E) before treadmill running and two periods after treadmill running (Post-E1 and Post-E2). The correlations between lagged Poincaré plot indices and frequency domain indices were applied to reveal the long-range correlation between linear and nonlinear indices during the recovery of HRV. The results suggested entirely attenuated autonomic nervous activity to the heart following the treadmill exercise. After the treadmill running, the sympathetic nerves achieved dominance and the parasympathetic activity was suppressed, which lasted for more than 4 min. The correlation coefficients between lagged Poincaré plot indices and spectral power indices could separate not only Pre-E and two sessions after the treadmill running, but also the two sessions in recovery periods, i.e., Post-E1 and Post-E2. Lagged Poincaré plot as an innovative nonlinear method showed a better performance over linear frequency domain analysis and conventional nonlinear Poincaré plot.

  8. Shareholder, stakeholder-owner or broad stakeholder maximization

    OpenAIRE

    Mygind, Niels

    2004-01-01

    With reference to the discussion about shareholder versus stakeholder maximization it is argued that the normal type of maximization is in fact stakeholder-owner maxi-mization. This means maximization of the sum of the value of the shares and stake-holder benefits belonging to the dominating stakeholder-owner. Maximization of shareholder value is a special case of owner-maximization, and only under quite re-strictive assumptions shareholder maximization is larger or equal to stakeholder-owner...

  9. FAMILIARISATION AND RELIABILITY OF SPRINT TEST INDICES DURING LABORATORY AND FIELD ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Andrew Galbraith

    2009-12-01

    Full Text Available The aim of the study was to assess the reliability of sprint performance in both field and laboratory conditions. Twenty-one male (mean ± s: 19 ± 1 years, 1.79 ± 0.07 m, 77.6 ± 7.1 kg and seventeen female team sport players (mean ± s: 21 ± 4 years, 1.68 ± 0. 07 m, 62.7 ± 4.7 kg performed a maximal 20-metre sprint running test on eight separate occasions. Four trials were conducted on a non-motorised treadmill in the laboratory; the other four were conducted outdoors on a hard-court training surface with time recorded by single-beam photocells. Trials were conducted in random order with no familiarisation prior to testing. There was a significant difference between times recorded during outdoor field trials (OFT and indoor laboratory trials (ILT using a non-motorised treadmill (3.47 ± 0.53 vs. 6.06 ±1.17s; p < 0.001. The coefficient of variation (CV for time was 2.55-4.22% for OFT and 5.1-7.2% for ILT. During ILT peak force (420.9 ± 87.7N, mean force (147.2 ± 24.7N, peak power (1376.8 ± 451.9W and mean power (514.8 ± 164.4W, and were measured. The CV for all ILT variables was highest during trial 1-2 comparison. The CV (95% confidence interval for the trial 3-4 comparison yielded: 9.4% (7.7-12. 1%, 7.9% (6.4-10.2%, 10.1% (8.2-13.1% and 6.2% (5.1-8.0% for PF, MF, PP and MP and respectively. The results indicate that reliable data can be derived for single maximal sprint measures, using fixed distance protocols. However, significant differences in time/speed over 20-m exist between field and laboratory conditions. This is primarily due to the frictional resistance in the non- motorised treadmill. Measures of force and power during ILT require at least 3 familiarisations to reduce variability in test scores

  10. A home-based body weight supported treadmill training program for children with cerebral palsy: A case series.

    Science.gov (United States)

    Kenyon, Lisa K; Westman, Marci; Hefferan, Ashley; McCrary, Peter; Baker, Barbara J

    2017-07-01

    Contemporary approaches to the treatment of cerebral palsy (CP) advocate a task-specific approach that emphasizes repetition and practice of specific tasks. Recent studies suggest that body-weight-supported treadmill training (BWSTT) programs may be beneficial in clinical settings. The purposes of this case series were to explore the outcomes and feasibility of a home-based BWSTT program for three children with CP. Three children with CP at Gross Motor Function Classification System (GMFCS) Levels III or IV participated in this case series. Examination included the Functional Assessment Questionnaire (FAQ), the 10-meter walk test, the Gross Motor Function Measure (GMFM-66), and the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test (PEDI-CAT). A harness system was used to conduct the BWSTT program over an 8-12 week period. All of the families reported enjoying the BWSTT program and found the harness easy to use. Participant 2 increased from a 2 to a 4 on the FAQ, while Participant 3 increased from a 6 to a 7. Two of the participants demonstrated post-intervention improvements in functional mobility. In addition to mobility outcomes, future research should explore the potential health benefits of a home-based BWSTT program.

  11. Effect of Maximal Versus Supra-Maximal Exhausting Race on Lipid Peroxidation, Antioxidant Activity and Muscle-Damage Biomarkers in Long-Distance and Middle-Distance Runners.

    Science.gov (United States)

    Mohamed, Said; Lamya, Ncir; Hamda, Mansour

    2016-03-01

    Exhausting physical exercise increases lipid peroxidation and causes important muscle damages. The human body tries to mitigate these adverse effects by mobilizing its antioxidant defenses. This study aims to investigate the effect of a maximal versus supra-maximal race sustained until exhaustion on lipid peroxidation, antioxidant activity and muscle-damage biomarkers in trained (i.e. long-distance and middle-distance runners) and sedentary subjects. The study has been carried out on 8 middle-distance runners (MDR), 9 long-distance runners (LDR), and 8 sedentary subjects (SS). Each subject has undergone two exhaustive running tests, the first one is an incremental event (VAMEVAL test), the second one is a constant supra-maximal intensity test (limited-time test). Blood samples were collected at rest and immediately after each test. A significant increase in malondialdehyde (MDA) concentrations was observed in SS and MDR after the VAMEVAL test and in LDR after the Limited-Time test. A significant difference was also observed between LDR and the other two groups after the VAMEVAL test, and between LDR and MDR after the Limited-Time test. Significant modifications, notably, in myoglobin, CK, LDH, IL-6, TNF-α, and TAS were likewise noted but depending on the race-type and the sportive specialty. Maximal and supra-maximal races induce a significant increase in lipid peroxidation and cause non-negligible inflammation and muscle damage. These effects were relatively related to the physical exercise type and the sportive specialty.

  12. Several submaximal exercise tests are reliable, valid and acceptable in people with chronic pain, fibromyalgia or chronic fatigue: a systematic review.

    Science.gov (United States)

    Ratter, Julia; Radlinger, Lorenz; Lucas, Cees

    2014-09-01

    Are submaximal and maximal exercise tests reliable, valid and acceptable in people with chronic pain, fibromyalgia and fatigue disorders? Systematic review of studies of the psychometric properties of exercise tests. People older than 18 years with chronic pain, fibromyalgia and chronic fatigue disorders. Studies of the measurement properties of tests of physical capacity in people with chronic pain, fibromyalgia or chronic fatigue disorders were included. Studies were required to report: reliability coefficients (intraclass correlation coefficient, alpha reliability coefficient, limits of agreements and Bland-Altman plots); validity coefficients (intraclass correlation coefficient, Spearman's correlation, Kendal T coefficient, Pearson's correlation); or dropout rates. Fourteen studies were eligible: none had low risk of bias, 10 had unclear risk of bias and four had high risk of bias. The included studies evaluated: Åstrand test; modified Åstrand test; Lean body mass-based Åstrand test; submaximal bicycle ergometer test following another protocol other than Åstrand test; 2-km walk test; 5-minute, 6-minute and 10-minute walk tests; shuttle walk test; and modified symptom-limited Bruce treadmill test. None of the studies assessed maximal exercise tests. Where they had been tested, reliability and validity were generally high. Dropout rates were generally acceptable. The 2-km walk test was not recommended in fibromyalgia. Moderate evidence was found for reliability, validity and acceptability of submaximal exercise tests in patients with chronic pain, fibromyalgia or chronic fatigue. There is no evidence about maximal exercise tests in patients with chronic pain, fibromyalgia and chronic fatigue. Copyright © 2014. Published by Elsevier B.V.

  13. Age-Predicted Maximal Heart Rate in Recreational Marathon Runners: A Cross-Sectional Study on Fox's and Tanaka's Equations

    Directory of Open Access Journals (Sweden)

    Pantelis T. Nikolaidis

    2018-03-01

    Full Text Available Age-based prediction equations of maximal heart rate (HRmax, such as the popular formulas Fox's 220-age, or Tanaka's 208-0.7 × age, have been widely used in various populations. Surprisingly, so far these equations have not been validated in marathon runners, despite the importance of the role of HRmax for training purposes in endurance running. The aim of the present study was to examine the validity of Fox and Tanaka equations in a large sample of women and men recreational marathon runners. Participants (n = 180, age 43.2 ± 8.5 years, VO2max 46.8 mL/min/kg, finishers in at least one marathon during the last year performed a graded exercise test on a treadmill, where HRmax was measured. Measured HRmax correlated largely with age in the total sample (r = −0.50, p < 0.001, women (r = −0.60, p < 0.001 and men (r = −0.53, p < 0.001. In women, a large main effect of method on HRmax (p = 0.001, η2 = 0.294 was shown with measured HRmax lower than Fox-HRmax (−4.8 bpm; −8.4, −1.3 and Tanaka-HRmax (−4.9 bpm; −8.1, −1.8. In men, a moderate effect of assessment method on HRmax was found (p = 0.001, η2 = 0.066 with measured HRmax higher than Fox-HRmax (+2.8; 1.0, 4.6, Tanaka-HRmax higher than Fox-HRmax (+1.2; 0.7, 1.7. Based on these findings, it was concluded that Fox and Tanaka' formulas overestimated HRmax by ~5 bpm in women, whereas Fox underestimated HRmax in men by ~3 bpm. Thus, we recommend the further use of Tanaka's formula in men marathon runners. In addition, exercise physiologists and sport scientists should consider the observed differences among various assessment methods when performing exercise testing or prescribing training program relying on HR.

  14. Vacua of maximal gauged D=3 supergravities

    International Nuclear Information System (INIS)

    Fischbacher, T; Nicolai, H; Samtleben, H

    2002-01-01

    We analyse the scalar potentials of maximal gauged three-dimensional supergravities which reveal a surprisingly rich structure. In contrast to maximal supergravities in dimensions D≥4, all these theories possess a maximally supersymmetric (N=16) ground state with negative cosmological constant Λ 2 gauged theory, whose maximally supersymmetric groundstate has Λ = 0. We compute the mass spectra of bosonic and fermionic fluctuations around these vacua and identify the unitary irreducible representations of the relevant background (super)isometry groups to which they belong. In addition, we find several stationary points which are not maximally supersymmetric, and determine their complete mass spectra as well. In particular, we show that there are analogues of all stationary points found in higher dimensions, among them are de Sitter (dS) vacua in the theories with noncompact gauge groups SO(5, 3) 2 and SO(4, 4) 2 , as well as anti-de Sitter (AdS) vacua in the compact gauged theory preserving 1/4 and 1/8 of the supersymmetries. All the dS vacua have tachyonic instabilities, whereas there do exist nonsupersymmetric AdS vacua which are stable, again in contrast to the D≥4 theories

  15. Treadmill running prevents age-related memory deficit and alters neurotrophic factors and oxidative damage in the hippocampus of Wistar rats.

    Science.gov (United States)

    Vanzella, Cláudia; Neves, Juliana Dalibor; Vizuete, Adriana Fernanda; Aristimunha, Dirceu; Kolling, Janaína; Longoni, Aline; Gonçalves, Carlos Alberto Saraiva; Wyse, Angela T S; Netto, Carlos Alexandre

    2017-09-15

    Clinical and pre-clinical studies indicate that exercise is beneficial to many aspects of brain function especially during aging. The present study investigated the effects of a treadmill running protocol in young (3month-old) and aged (22month-old) male Wistar rats, on: I) cognitive function, as assessed by spatial reference memory in the Morris water maze; II) oxidative stress parameters and the expression of neurotrophic factors BDNF, NT-3, IGF-1 and VEGF in the hippocampus. Animals of both ages were assigned to sedentary (non-exercised) and exercised (20min of daily running sessions, 3 times per week for 4weeks) groups. Cognition was assessed by a reference memory task run in the Morris water maze; twenty four hours after last session of behavioral testing hippocampi were collected for biochemical analysis. Results demonstrate that the moderate treadmill running exercise: I) prevented age-related deficits in reference memory in the Morris water maze; II) prevented the age-related increase of reactive oxygen species levels and lipid peroxidation in the hippocampus; III) caused an increase of BDNF, NT-3 and IGF-1 expression in the hippocampus of aged rats. Taken together, results suggest that both exercise molecular effects, namely the reduction of oxidative stress and the increase of neurotrophic factors expression in the hippocampus, might be related to its positive effect on memory performance in aged rats. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Use of an Anti-Gravity Treadmill for Early Postoperative Rehabilitation After Total Knee Replacement: A Pilot Study to Determine Safety and Feasibility.

    Science.gov (United States)

    Bugbee, William D; Pulido, Pamela A; Goldberg, Timothy; D'Lima, Darryl D

    2016-01-01

    The objective was to determine the safety, feasibility, and effects of anti-gravity gait training on functional outcomes (Knee Injury and Osteoarthritis Outcome Score [KOOS], the Timed Up and Go test [TUG], Numerical Rating Scale [NRS] for pain) with the AlterG® Anti-Gravity Treadmill® device for total knee arthroplasty (TKA) rehabilitation. Subjects (N = 30) were randomized to land-based vs anti-gravity gait training over 4 weeks of physical therapy after TKA. Adverse events, complications, and therapist satisfaction were recorded. All patients completed rehabilitation protocols without adverse events. KOOS, TUG, and NRS scores improved in both groups with no significant differences between groups. For the AlterG group, Sports/Recreation and Quality of Life subscales of the KOOS had the most improvement. At the end of physical therapy, TUG and NRS pain scores improved from 14 seconds to 8 seconds and from 2.8 to 1.1, respectively. Subjectively, therapists reported 100% satisfaction with the AlterG. This initial pilot study demonstrated that the AlterG Anti-Gravity Treadmill device was safe and feasible. While functional outcomes improved over time with use of the anti-gravity gait training, further studies are needed to define the role of this device as an alternative or adjunct to established rehabilitation protocols.

  17. Physiological and biomechanical responses to walking underwater on a non-motorised treadmill: effects of different exercise intensities and depths in middle-aged healthy women.

    Science.gov (United States)

    Benelli, Piero; Colasanti, Franca; Ditroilo, Massimiliano; Cuesta-Vargas, Antonio; Gatta, Giorgio; Giacomini, Francesco; Lucertini, Francesco

    2014-01-01

    Non-motorised underwater treadmills are commonly used in fitness activities. However, no studies have examined physiological and biomechanical responses of walking on non-motorised treadmills at different intensities and depths. Fifteen middle-aged healthy women underwent two underwater walking tests at two different depths, immersed either up to the xiphoid process (deep water) or the iliac crest (shallow water), at 100, 110, 120, 130 step-per-minute (spm). Oxygen consumption (VO2), heart rate (HR), blood lactate concentration, perceived exertion and step length were determined. Compared to deep water, walking in shallow water exhibited, at all intensities, significantly higher VO2 (+13.5%, on average) and HR (+8.1%, on average) responses. Water depth did not influence lactate concentration, whereas perceived exertion was higher in shallow compared to deep water, solely at 120 (+40%) and 130 (+39.4%) spm. Average step length was reduced as the intensity increased (from 100 to 130 spm), irrespective of water depth. Expressed as a percentage of maximum, average VO2 and HR were: 64-76% of peak VO2 and 71-90% of maximum HR, respectively at both water depths. Accordingly, this form of exercise can be included in the "vigorous" range of exercise intensity, at any of the step frequencies used in this study.

  18. What Did We Learn from the Animal Studies of Body Weight-Supported Treadmill Training and Where Do We Go from Here?

    Science.gov (United States)

    de Leon, Ray D; Dy, Christine J

    2017-05-01

    Body weight-supported treadmill training (BWSTT) developed from animal studies of spinal cord injury (SCI). Evidence that spinal cats (i.e., cats that have a complete surgical transection of the cord) could regain the ability to step on a moving treadmill indicated a vast potential for spinal circuits to generate walking without the brain. BWSTT represented a means to unlock that potential. As the technique was adapted as a rehabilitation intervention for humans with SCI, shortcomings in the translation to walking in the real world were exposed. Evidence that BWSTT has not been as successful for humans with SCI leads us to revisit key animal studies. In this short review, we describe the task-specific nature of BWSTT and discuss how this specificity may pose limits on the recovery of overground walking. Also discussed are more recent studies that have introduced new strategies and tools that adapt BWSTT ideas to more functionally-relevant tasks. We introduce a new device for weight-supported overground walking in rats called Circular BART (Body weight supported Ambulatory Rat Trainer) and demonstrate that it is relatively easy and inexpensive to produce. Future animal studies will benefit from the development of simple tools that facilitate training and testing of overground walking.

  19. What Did We Learn from the Animal Studies of Body Weight–Supported Treadmill Training and Where Do We Go from Here?

    Science.gov (United States)

    Dy, Christine J.

    2017-01-01

    Abstract Body weight–supported treadmill training (BWSTT) developed from animal studies of spinal cord injury (SCI). Evidence that spinal cats (i.e., cats that have a complete surgical transection of the cord) could regain the ability to step on a moving treadmill indicated a vast potential for spinal circuits to generate walking without the brain. BWSTT represented a means to unlock that potential. As the technique was adapted as a rehabilitation intervention for humans with SCI, shortcomings in the translation to walking in the real world were exposed. Evidence that BWSTT has not been as successful for humans with SCI leads us to revisit key animal studies. In this short review, we describe the task-specific nature of BWSTT and discuss how this specificity may pose limits on the recovery of overground walking. Also discussed are more recent studies that have introduced new strategies and tools that adapt BWSTT ideas to more functionally-relevant tasks. We introduce a new device for weight-supported overground walking in rats called Circular BART (Body weight supported Ambulatory Rat Trainer) and demonstrate that it is relatively easy and inexpensive to produce. Future animal studies will benefit from the development of simple tools that facilitate training and testing of overground walking. PMID:27863455

  20. A quantification of the treadmill 6-min walk test using the MyWellness Key™ accelerometer

    Directory of Open Access Journals (Sweden)

    S. Andy Sparks

    2015-06-01

    Conclusion: Estimated energy expenditure provided by the MWK was strongly correlated to 6MWW; however, MWK underestimated energy expenditure as measured by gas analysis. The MWK may provide outcome data that supplement those currently provided by the 6MWD for functional capacity assessment during the t-6MWT.

  1. An information maximization model of eye movements

    Science.gov (United States)

    Renninger, Laura Walker; Coughlan, James; Verghese, Preeti; Malik, Jitendra

    2005-01-01

    We propose a sequential information maximization model as a general strategy for programming eye movements. The model reconstructs high-resolution visual information from a sequence of fixations, taking into account the fall-off in resolution from the fovea to the periphery. From this framework we get a simple rule for predicting fixation sequences: after each fixation, fixate next at the location that minimizes uncertainty (maximizes information) about the stimulus. By comparing our model performance to human eye movement data and to predictions from a saliency and random model, we demonstrate that our model is best at predicting fixation locations. Modeling additional biological constraints will improve the prediction of fixation sequences. Our results suggest that information maximization is a useful principle for programming eye movements.

  2. Utility Maximization in Nonconvex Wireless Systems

    CERN Document Server

    Brehmer, Johannes

    2012-01-01

    This monograph formulates a framework for modeling and solving utility maximization problems in nonconvex wireless systems. First, a model for utility optimization in wireless systems is defined. The model is general enough to encompass a wide array of system configurations and performance objectives. Based on the general model, a set of methods for solving utility maximization problems is developed. The development is based on a careful examination of the properties that are required for the application of each method. The focus is on problems whose initial formulation does not allow for a solution by standard convex methods. Solution approaches that take into account the nonconvexities inherent to wireless systems are discussed in detail. The monograph concludes with two case studies that demonstrate the application of the proposed framework to utility maximization in multi-antenna broadcast channels.

  3. LOAD THAT MAXIMIZES POWER OUTPUT IN COUNTERMOVEMENT JUMP

    Directory of Open Access Journals (Sweden)

    Pedro Jimenez-Reyes

    2016-02-01

    Full Text Available ABSTRACT Introduction: One of the main problems faced by strength and conditioning coaches is the issue of how to objectively quantify and monitor the actual training load undertaken by athletes in order to maximize performance. It is well known that performance of explosive sports activities is largely determined by mechanical power. Objective: This study analysed the height at which maximal power output is generated and the corresponding load with which is achieved in a group of male-trained track and field athletes in the test of countermovement jump (CMJ with extra loads (CMJEL. Methods: Fifty national level male athletes in sprinting and jumping performed a CMJ test with increasing loads up to a height of 16 cm. The relative load that maximized the mechanical power output (Pmax was determined using a force platform and lineal encoder synchronization and estimating the power by peak power, average power and flight time in CMJ. Results: The load at which the power output no longer existed was at a height of 19.9 ± 2.35, referring to a 99.1 ± 1% of the maximum power output. The load that maximizes power output in all cases has been the load with which an athlete jump a height of approximately 20 cm. Conclusion: These results highlight the importance of considering the height achieved in CMJ with extra load instead of power because maximum power is always attained with the same height. We advise for the preferential use of the height achieved in CMJEL test, since it seems to be a valid indicative of an individual's actual neuromuscular potential providing a valid information for coaches and trainers when assessing the performance status of our athletes and to quantify and monitor training loads, measuring only the height of the jump in the exercise of CMJEL.

  4. Maximizing band gaps in plate structures

    DEFF Research Database (Denmark)

    Halkjær, Søren; Sigmund, Ole; Jensen, Jakob Søndergaard

    20