Arousal Effects on Cognition: New Strategy Which Isolates Movement and Heart Rate Effects Inherent in Physical Work

1988 ◽  
Vol 32 (17) ◽  
pp. 1140-1144
Author(s):  
Tina Mihaly
Keyword(s):  
Heart Rate ◽  
Physical Work ◽  
The Novel ◽  
Validation Experiment ◽  
Rate Effects ◽  
New Strategy ◽  
Methodological Problems ◽  
Novel Strategy ◽  
Exercise Induced ◽  
Speed Accuracy

Most experiments which have sought to determine the effects of arousal, exercise and/or physical work on psychomotor performance have been tainted by methodological problems. This paper presents a strategy that was developed to overcome one methodological shortcoming inherent in many such studies: the confounding of movement and heart rate. The technique involves administering mental tests during both movement and non-movement intervals, at pre-selected exercise states. Results of a validation experiment, in which 11 subjects performed numerous psychomotor tasks with and without movement at four work intensities (rest, 30% VO2max, 60% VO2max, and post-exercise) on two testing days indicate that this method was sufficiently sensitive to identify previously undetected effects, e.g., movement slows index finger tapping rate and may impair an individual's ability to stabilize speed-accuracy tradeoff strategies in serial choice reaction time tasks. Inverted-U effects were also found, replicating some previous investigations. The novel strategy detailed herein, which isolates the relative effects of movement and elevated heart rate, appears appropriate for use in studies aimed at quantifying the effects of exercise-induced arousal (via cycle ergometry) on mental performance before, during, and after exercise. This work has implications for improving research methodologies and predicting which sorts of everyday speeded mental tasks will be affected when one is simultaneously engaged in physical work.

scholarly journals Frequency Estimation for Grid-Tied Inverters Using Resonant Frequency Estimator

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6513
Author(s):  
Dariusz Zieliński ◽  
Karol Fatyga
Keyword(s):  
Resonant Frequency ◽  
Frequency Estimation ◽  
Short Circuit ◽  
The Novel ◽  
Diesel Generator ◽  
Estimation Algorithms ◽  
New Strategy ◽  
Frequency Changes ◽  
Novel Strategy ◽  
Frequency Estimator

This paper introduces a new strategy of frequency estimation for grid-tied and stand-alone mode AC/DC power converters. Frequency stabilization is required, especially when operating in stand-alone mode with a Droop Control strategy, or in hybrid mode with a Diesel generator. It is also required to reduce or increase power output along with grid frequency changes. The novel strategy utilizes a resonant filter to estimate the frequency of the voltage grid and is referenced as a resonant-frequency-estimator (RFE). A mathematical background is presented for the proposed estimator and its performance is evaluated. It is compared with three common frequency estimation algorithms: SRF-FLL, DDSRF-FLL, and DSOGI-FLL. Results are presented for three cases: frequency swing, harmonics injection, and type B short-circuit. Results are analyzed and the conclusion shows that the proposed novel strategy has comparable parameters to commonly used frequency estimation algorithms while having a loopless structure.

scholarly journals Persistent SARS-CoV-2-positive over 4 months in a COVID-19 patient with CHB

Open Medicine ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 749-753
Author(s):  
Wenyuan Li ◽  
Beibei Huang ◽  
Qiang Shen ◽  
Shouwei Jiang ◽  
Kun Jin ◽  
...  
Keyword(s):  
The Novel ◽  
Chain Reaction ◽  
Health Crisis ◽  
Public Health Crisis ◽  
Oxygen Inhalation ◽  
New Strategy ◽  
Polymerase Chain ◽  
Novel Coronavirus ◽  
Specific Symptoms

Abstract In recent months, the novel coronavirus disease 2019 (COVID-19) pandemic has become a major public health crisis with takeover more than 1 million lives worldwide. The long-lasting existence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has not yet been reported. Herein, we report a case of SARS-CoV-2 infection with intermittent viral polymerase chain reaction (PCR)-positive for >4 months after clinical rehabilitation. A 35-year-old male was diagnosed with COVID-19 pneumonia with fever but without other specific symptoms. The treatment with lopinavir-ritonavir, oxygen inhalation, and other symptomatic supportive treatment facilitated recovery, and the patient was discharged. However, his viral PCR test was continually positive in oropharyngeal swabs for >4 months after that. At the end of June 2020, he was still under quarantine and observation. The contribution of current antivirus therapy might be limited. The prognosis of COVID-19 patients might be irrelevant to the virus status. Thus, further investigation to evaluate the contagiousness of convalescent patients and the mechanism underlying the persistent existence of SARS-CoV-2 after recovery is essential. A new strategy of disease control, especially extending the follow-up period for recovered COVID-19 patients, is necessary to adapt to the current situation of pandemic.

scholarly journals Delayed improvement local search

2021 ◽  
Author(s):  
Heber F. Amaral ◽  
Sebastián Urrutia ◽  
Lars M. Hvattum
Keyword(s):  
Local Search ◽  
Heuristic Algorithms ◽  
Travelling Salesman Problem ◽  
Computation Time ◽  
The Novel ◽  
Local Optima ◽  
New Strategy ◽  
Max Cut Problem ◽  
Novel Method ◽  
Similar Solutions

AbstractLocal search is a fundamental tool in the development of heuristic algorithms. A neighborhood operator takes a current solution and returns a set of similar solutions, denoted as neighbors. In best improvement local search, the best of the neighboring solutions replaces the current solution in each iteration. On the other hand, in first improvement local search, the neighborhood is only explored until any improving solution is found, which then replaces the current solution. In this work we propose a new strategy for local search that attempts to avoid low-quality local optima by selecting in each iteration the improving neighbor that has the fewest possible attributes in common with local optima. To this end, it uses inequalities previously used as optimality cuts in the context of integer linear programming. The novel method, referred to as delayed improvement local search, is implemented and evaluated using the travelling salesman problem with the 2-opt neighborhood and the max-cut problem with the 1-flip neighborhood as test cases. Computational results show that the new strategy, while slower, obtains better local optima compared to the traditional local search strategies. The comparison is favourable to the new strategy in experiments with fixed computation time or with a fixed target.

Cascade photocaging of diazeniumdiolate: a novel strategy for one and two photon triggered uncaging with real time reporting

2017 ◽  
Vol 53 (68) ◽  
pp. 9470-9473 ◽  
Author(s):  
Krishna Kalyani Behara ◽  
Y. Rajesh ◽  
Yarra Venkatesh ◽  
Bhaskar Rao Pinninti ◽  
Mahitosh Mandal ◽  
...  
Keyword(s):  
Real Time ◽  
Two Photon ◽  
New Strategy ◽  
Novel Strategy

We report a new strategy, viz. cascade photocaging, for protecting diethylamine diazeniumdiolate (O2-position), a light sensitive molecule.

Is there an exercise duration threshold for exercise-induced troponin elevation in healthy recreational athletes? The NEEDED 2014 advanced heart rate monitor substudy

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Bjorkavoll-Bergseth ◽  
B Auestad ◽  
O Kleiven ◽  
O Skadberg ◽  
T Eftestol ◽  
...  
Keyword(s):  
Heart Rate ◽  
Clinical Status ◽  
Exercise Duration ◽  
Strenuous Exercise ◽  
Clinical Consequence ◽  
Funding Source ◽  
Recreational Athletes ◽  
National Budget ◽  
Exercise Induced ◽  
Public Grant

Abstract Background/Introduction Following prolonged strenuous exercise there is an exercise-induced troponin (cTn) elevation in healthy individuals. The precise mechanisms and clinical consequence of this cTn elevation remain to be determined. It has recently been demonstrated that exercise intensity, exceeding a heart rate (HR) of 150 bpm, is correlated with exercise-induced cTn elevation. Purpose The present work aims to determine if there is a threshold for exercise duration with a HR exceeding 150 bpm associated with an excessive exercise-induced cTn elevation. Methods A total of 177 healthy subjects were included in the present analysis of HR data obtained from sport watches used during a 91-km recreational mountain bike cycle race. Clinical status, cTnI, ECGs, blood pressure and demographics were obtained 24 h prior to- and at 3 h and 24 h after the race. Results are reported as median and 25th and 75th percentile. We used Tree regression to determine the association between elevated cTnI and exercise duration exceeding a HR of 150 bpm. Results Subjects were 82% (n=146) males, 44 (39–51) years, with a race time of 3.5 (3.1–3.9) h. Baseline cTnI was 1.9 (1.6–3.3) ng/L. There was a cTnI elevation in all study participants at 3 h, cTnI: 60.0 (36.0–99.3) ng/L, with a significant (p<0.001) reduction at 24 hours following exercise, cTnI: 10.9 (6.1–22.4) ng/L. Tree regression identified 168 min of exercise, with a HR exceeding 150 bpm, to be associated with an excessive increase in cTnI both at 3 h, and at 24 h following the race (figure). The median cTn values above and below the threshold are presented in the Table. Conclusion The present analysis suggests that exceeding a specific duration of high intensity exercise may be associated with excessive cTn elevation in susceptible individuals. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Western Norway Health authoritites.

Relation between heart rate and QT interval in exercise-induced myocardial ischemia

1985 ◽  
Vol 56 (13) ◽  
pp. 861-862 ◽  
Author(s):  
Massimo Romano ◽  
Teresa Di Maro ◽  
Giovanni Carella ◽  
Maria Rosaria Cotecchia ◽  
Giuseppe Ferro ◽  
...  
Keyword(s):  
Heart Rate ◽  
Myocardial Ischemia ◽  
Qt Interval ◽  
Exercise Induced

scholarly journals New Strategy for Analog Circuit Performance Evaluation under Disturbance and Fault Value

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Aihua Zhang ◽  
Yongchao Wang ◽  
Chen Chen ◽  
Hamid Reza Karimi
Keyword(s):  
Performance Evaluation ◽  
Support Vector Regression ◽  
Analog Circuit ◽  
Support Vector ◽  
Training Set ◽  
Circuit Performance ◽  
New Strategy ◽  
Indirect Evaluation ◽  
Novel Strategy ◽  
Fuzzy Learning

Focus on this issue of disturbance and fault value is inevitable in data collection about analog circuit. A novel strategy is developed for analog circuit online performance evaluation based on fuzzy learning and double weighted support vector machine (DWMK-FSVM). First, the double weighted support vector regression machine is employed to be the indirect evaluation means, relied on the college analog electronic technology experiment to evaluate analog circuit. Second, the superiority of fuzzy learning also is addressed to realize active suppression to the fault values and disturbance parameters. Moreover, the multikernel RBF is employed by support vector regression machine to realize more flexibility online such as the bandwidths tuning. Numerical results, supported by the college analog circuit experiments, adopted OTL performance eight indexes, which were obtained via precision instrument evaluation in two years to construct training set and are then to be evaluated online based on DWMK-FSVM. Simulation results presented not only highlight precision of the evaluation strategy derived here but also illustrate its great robustness.

scholarly journals Lower extremity muscle size and strength and aerobic capacity decrease with caloric restriction but not with exercise-induced weight loss

2007 ◽  
Vol 102 (2) ◽  
pp. 634-640 ◽  
Author(s):  
Edward P. Weiss ◽  
Susan B. Racette ◽  
Dennis T. Villareal ◽  
Luigi Fontana ◽  
Karen Steger-May ◽  
...  
Keyword(s):  
Weight Loss ◽  
Caloric Restriction ◽  
Aerobic Capacity ◽  
Lean Mass ◽  
Muscle Volume ◽  
Muscle Size ◽  
Thigh Muscle ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Exercise Induced

Caloric restriction (CR) results in fat loss; however, it may also result in loss of muscle and thereby reduce strength and aerobic capacity (V̇o2 max). These effects may not occur with exercise-induced weight loss (EX) because of the anabolic effects of exercise on heart and skeletal muscle. We tested the hypothesis that CR reduces muscle size and strength and V̇o2 max, whereas EX preserves or improves these parameters. Healthy 50- to 60-yr-old men and women (body mass index of 23.5–29.9 kg/m2) were studied before and after 12 mo of weight loss by CR ( n = 18) or EX ( n = 16). Lean mass was assessed by dual-energy X-ray absorptiometry, thigh muscle volume by MRI, isometric and isokinetic knee flexor strength by dynamometry, and treadmill V̇o2 max by indirect calorimetry. Both interventions caused significant decreases in body weight (CR: −10.7 ± 1.4%, EX: −9.5 ± 1.5%) and lean mass (CR: −3.5 ± 0.7%, EX: −2.2 ± 0.8%), with no significant differences between groups. Significant decreases in thigh muscle volume (−6.9 ± 0.8%) and composite knee flexion strength (−7.2 ± 3%) occurred in the CR group only. Absolute V̇o2 max decreased significantly in the CR group (−6.8 ± 2.3%), whereas the EX group had significant increases in both absolute (+15.5 ± 2.4%) and relative (+28.3 ± 3.0%) V̇o2 max. These data provide evidence that muscle mass and absolute physical work capacity decrease in response to 12 mo of CR but not in response to a similar weight loss induced by exercise. These findings suggest that, during EX, the body adapts to maintain or even enhance physical performance capacity.

scholarly journals Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers

1996 ◽  
Vol 81 (5) ◽  
pp. 1901-1907 ◽  
Author(s):  
Roland Favier ◽  
Esperanza Caceres ◽  
Laurent Guillon ◽  
Brigitte Sempore ◽  
Michel Sauvain ◽  
...  
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Metabolic Responses ◽  
Physiological Data ◽  
Respiratory Gas Exchange ◽  
Gum Chewing ◽  
Arterial Blood ◽  
Before And After ◽  
Exercise Induced

Favier, Roland, Esperanza Caceres, Laurent Guillon, Brigitte Sempore, Michel Sauvain, Harry Koubi, and Hilde Spielvogel. Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers. J. Appl. Physiol. 81(5): 1901–1907, 1996.—To determine the effects of acute coca use on the hormonal and metabolic responses to exercise, 12 healthy nonhabitual coca users were submitted twice to steady-state exercise (∼75% maximal O2 uptake). On one occasion, they were asked to chew 15 g of coca leaves 1 h before exercise, whereas on the other occasion, exercise was performed after 1 h of chewing a sugar-free chewing gum. Plasma epinephrine, norepinephrine, insulin, glucagon, and metabolites (glucose, lactate, glycerol, and free fatty acids) were determined at rest before and after coca chewing and during the 5th, 15th, 30th, and 60th min of exercise. Simultaneously to these determinations, cardiorespiratory variables (heart rate, mean arterial blood pressure, oxygen uptake, and respiratory gas exchange ratio) were also measured. At rest, coca chewing had no effect on plasma hormonal and metabolic levels except for a significantly reduced insulin concentration. During exercise, the oxygen uptake, heart rate, and respiratory gas exchange ratio were significantly increased in the coca-chewing trial compared with the control (gum-chewing) test. The exercise-induced drop in plasma glucose and insulin was prevented by prior coca chewing. These results contrast with previous data obtained in chronic coca users who display during prolonged submaximal exercise an exaggerated plasma sympathetic response, an enhanced availability and utilization of fat (R. Favier, E. Caceres, H. Koubi, B. Sempore, M. Sauvain, and H. Spielvogel. J. Appl. Physiol. 80: 650–655, 1996). We conclude that, whereas coca chewing might affect glucose homeostasis during exercise, none of the physiological data provided by this study would suggest that acute coca chewing in nonhabitual users could enhance tolerance to exercise.

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