A Personal Biography of a Physiological Misnomer: The Anaerobic Threshold

2021 ◽  
Author(s):  
James Hagberg
Keyword(s):  
Anaerobic Threshold ◽  
Anaerobic Metabolism ◽  
Exercise Physiology ◽  
Gas Analysis ◽  
Cardiac Patients ◽  
Substantial Evidence ◽  
New Methods ◽  
Applied Physiology ◽  
Over Time ◽  
Highly Cited

AbstractIn 1973 Wasserman, Whipp, Koyal, and Beaver published a groundbreaking study titled “Anaerobic threshold and respiratory gas analysis during exercise”. At that time, respiratory gas analysis and laboratory computers had evolved such that more advanced respiratory exercise physiology studies were possible. The initial publications from this group on the onset of anaerobic metabolism in cardiac patients, the first breath-by-breath VO2 system, the first description of the anaerobic threshold, and then later new methods to detect the anaerobic threshold have been and continue to be highly cited. In fact, their 1973 anaerobic threshold paper is the sixth and their 1986 paper is the second most cited paper ever published in the Journal of Applied Physiology. The anaerobic threshold concept has also generated>5500 publications with the rates increasing over time. The publication of two papers that help to refute the “anaerobic” explanation for this phenomenon had no effect on the rates of citations of the original anaerobic threshold papers or the number of anaerobic threshold papers published since. Thus, despite now substantial evidence refuting the proposed anaerobic mechanisms underlying this phenomenon, these papers continue to be highly influential in the discipline of exercise physiology and, perhaps even more explicitly, clinical exercise physiology.

scholarly journals Anaerobic metabolism as an indicator of aerobic function during exercise in cardiac patients

1992 ◽  
Vol 20 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Akira Koike ◽  
Michiaki Hiroe ◽  
Hiromasa Adachi ◽  
Takashi Yajima ◽  
Akihiko Nogami ◽  
...  
Keyword(s):  
Anaerobic Metabolism ◽  
Cardiac Patients ◽  
Aerobic Function

A Review of Measurement Equivalence in Organizational Research: What's Old, What's New, What's Next?

2021 ◽  
pp. 109442812110565
Author(s):  
Ajay V. Somaraju ◽  
Christopher D. Nye ◽  
Jeffrey Olenick
Keyword(s):  
Review Paper ◽  
Measurement Equivalence ◽  
Future Directions ◽  
Organizational Research ◽  
Potential Sources ◽  
Organizational Constructs ◽  
Organizational Literature ◽  
Over Time ◽  
Made In ◽  
Highly Cited

The study of measurement equivalence has important implications for organizational research. Nonequivalence across groups or over time can affect the results of a study and the conclusions that are drawn from it. As a result, the review paper by Vandenberg & Lance (2000) has been highly cited and has played an important role in understanding the measurement of organizational constructs. However, that paper is now 20 years old, and a number of advances have been made in the application and interpretation of measurement equivalence (ME) since its publication. Therefore, the goal of the present paper is to provide an updated review of ME techniques that describes recent advances in testing for ME and proposes a taxonomy of potential sources of nonequivalence. Finally, we articulate recommendations for applying these newer methods and consider future directions for measurement equivalence research in the organizational literature.

Classification of Chaotic Behaviors in Jerky Dynamical Systems

2021 ◽  
Vol 30 (1) ◽  
pp. 93-110
Author(s):  
Tianyi Wang ◽  
Keyword(s):  
Machine Learning ◽  
Chaotic Systems ◽  
Chaotic Behavior ◽  
Learning Algorithm ◽  
Model Systems ◽  
Supervised Machine Learning ◽  
Learning Program ◽  
New Methods ◽  
Over Time

Differential equations are widely used to model systems that change over time, some of which exhibit chaotic behaviors. This paper proposes two new methods to classify these behaviors that are utilized by a supervised machine learning algorithm. Dissipative chaotic systems, in contrast to conservative chaotic systems, seem to follow a certain visual pattern. Also, the machine learning program written in the Wolfram Language is utilized to classify chaotic behavior with an accuracy around 99.1±1.1%.

USING OF SOME HIGH TECHNOLOGIES AGAINST MODERN INTERNATIONAL TERRORISM

2021 ◽  
Author(s):  
Александр Никифорович Валяев
Keyword(s):  
Risk Assessment ◽  
New Technologies ◽  
International Terrorism ◽  
Special Session ◽  
Technology Center ◽  
New Methods ◽  
Wide Scale ◽  
Nuclear Environment ◽  
High Technologies ◽  
Over Time

Сегодня главными угрозами для существования всего человечества являются нарастание интенсивности, в том числе широкомасштабные природные и техногенные катастрофы и международный терроризм (МТ). Согласно прогнозам эта негативная тенденция со временем усилится в 21 веке. И к ним добавился очень опасный вирус COVID-19. Здесь мы представляем результаты наших МТ-исследований по результатам участия в международных тематических мероприятиях, таких как международные научные мероприятия НАТО и Международного научно-технического центра (МНТЦ), в том числе некоторые фрагменты моей работы в качестве члена Международного Научный комитет Международной конференции по моделированию и симуляции хаоса (CHAOS) и руководитель его специальной сессии: «Моделирование оценки рисков для ядерных, экологических и техногенных источников». Особое внимание уделяется организации и проведению подобных мероприятий, направленных на повышение их эффективности и проведения. Предоставляется информация о новых методах борьбы с МТ и предотвращения её возможных действий. Обсуждаются вопросы использования новых технологий, посвященных сегодняшней борьбе с COVID-19 и группировкам МТ Талибан в Афганистане. Today the main great treats for existence of all humanity are intensity increasing and including wide scale natural and manmade catastrophes and international terrorism (IT). According to forecasts, this negative trend will increase over time in the 21st century. And very dangerous COVID-19 was added to them. Here we present the results of our IT researches on the results of participation in international thematic events, such as the international scientific events of NATO and the International Science and Technology Center (ISTC), including some fragments of my work as the member of the International Scientific Committee of Chaotic Modeling and Simulation International Conference (CHAOS) and chief of its Special Session: “Modeling risk assessment for nuclear, environment and manmade sources”. The special attention is paid to the organization and conduct of such events aimed at increasing their effectiveness and implementation. Information is provided on new methods of combating IT and preventing its possible acts. Using of new technologies, devoted to today struggle against COVID-19 and IT Taliban groups in Afghanistan are under discussion.

Cardiopulmonary Exercise Testing

2018 ◽  
pp. 413-436
Author(s):  
Andrew Kao
Keyword(s):  
Exercise Testing ◽  
Exercise Physiology ◽  
Cardiopulmonary Exercise Testing ◽  
Gas Analysis ◽  
Peak Oxygen Consumption ◽  
Normative Values ◽  
Cardiopulmonary Exercise ◽  
Expired Gas Analysis ◽  
Expired Gas

The chapter Cardiopulmonary Exercise Testing focuses on the opportunities provided by cardiopulmonary exercise (CPX) testing. The coordination of 5 organ systems is described in normal exercise physiology to understand abnormal exercise findings. From a few measured expired gas analysis parameters, most of the important exercise variables can be derived, including the peak oxygen consumption (peak VO2). The contribution of both the aerobic and anaerobic phases of exercise to total exercise capacity are described, including the methods for determination of the anaerobic threshold. The calculation of the normative values of peak VO2 are included, and a suggested template of a CPX report is included. The use of CPX testing in the determination of prognosis in heart failure patients is included.

Effect of anemia on intrapulmonary shunt during atelectasis in rabbits

1995 ◽  
Vol 79 (6) ◽  
pp. 1951-1957 ◽  
Author(s):  
S. Deem ◽  
M. J. Bishop ◽  
M. K. Alberts
Keyword(s):  
Hypoxic Pulmonary Vasoconstriction ◽  
Left Lung ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Gas ◽  
Intrapulmonary Shunt ◽  
Fluorescent Microspheres ◽  
Pulmonary Vasoconstriction ◽  
Arterial Po2 ◽  
Over Time

To elucidate the effects of anemia on intrapulmonary shunt, we studied a model of left lung atelectasis in anesthetized rabbits. In 10 rabbits, isovolemic anemia was produced by sequential hemodilution. Seven control rabbits were followed over time, without hemodilution. Intrapulmonary shunt (Qs/QT) was measured by using blood gas analysis and by quantitation of the percentage of blood flow to the collapsed left lung (QLl/QT) using fluorescent microspheres. In control rabbits, Qs/QT and QLl/QT decreased over time, whereas arterial PO2 increased. In hemodiluted rabbits, there was a trend toward increased Qs/QT and QLl/QT. There were significant differences in the behavior of Qs/QT, QLl/QT, and arterial PO2 between control and hemodiluted rabbits. Hemodynamic parameters, including cardiac output and pulmonary artery pressure, were not different between groups. In a third group of rabbits with pharmacologically induced acidosis but no hemodilution, Qs/QT and QLl/QT decreased over time, and arterial PO2 increased. We conclude that acute isovolemic anemia has a deleterious effect on pulmonary gas exchange, possibly through attenuation of hypoxic pulmonary vasoconstriction.

scholarly journals Comparison of maximal lactate steady state with V2, V4, individual anaerobic threshold and lactate minimum speed in horses

2014 ◽  
Vol 66 (1) ◽  
pp. 39-46 ◽  
Author(s):  
O.A.B. Soares ◽  
G.C. Ferraz ◽  
C.B. Martins ◽  
D.P.M. Dias ◽  
J.C. Lacerda-Neto ◽  
...  
Keyword(s):  
Steady State ◽  
Anaerobic Threshold ◽  
Exercise Physiology ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Maximal Lactate Steady State ◽  
Exercise Load ◽  
Individual Anaerobic Threshold ◽  
Minimum Speed ◽  
Lactate Minimum

The anaerobic threshold is a physiologic event studied in various species. There are various methods for its assessment, recognized in the human and equine exercise physiology literature, several of these involving the relationship between blood lactate concentration (LAC) and exercise load, measured in a standardized exercise test. The aim of this study was to compare four of these methods: V2, V4, individual anaerobic threshold (IAT) and lactate minimum speed (LMS) with the method recognized as the gold standard for the assessment of anaerobic threshold, maximal lactate steady-state (MLSS). The five tests were carried out in thirteen trained Arabian horses, in which velocities and associated LAC could be measured. The mean velocities and the LAC associated with the anaerobic threshold for the five methods were respectively: V2 = 9.67±0.54; V4 = 10.98±0.47; V IAT = 9.81±0.72; V LMS = 7.50±0.57 and V MLSS = 6.14±0.45m.s-1 and LAC IAT = 2.17±0.93; LAC LMS = 1.17±0.62 and LAC MLSS = 0.84±0.21mmol.L-1. None of the velocities were statistically equivalent to V MLSS (P<0.05). V2, V4 and V LMS showed a good correlation with V MLSS , respectively: r = 0.74; r = 0.78 and r = 0.83, and V IAT did not significantly correlate with V MLSS. Concordance between the protocols was relatively poor, i.e., 3.28±1.00, 4.84±0.30 and 1.43±0.32m.s-1 in terms of bias and 95% agreement limits for V2, V4 and LMS methods when compared to MLSS. Only LAC LMS did not differ statistically from LAC MLSS. Various authors have reported the possibility of the assessment of anaerobic threshold using rapid protocols such as V4 and LMS for humans and horses. This study corroborates the use of these tests, but reveals that adjustments in the protocols are necessary to obtain a better concordance between the tests and the MLSS.

The mineral world

2020 ◽  
pp. 164-194
Author(s):  
Elizabeth Bloxam
Keyword(s):  
Eastern Desert ◽  
Cross Cultural ◽  
New Methods ◽  
Cultural Transformations ◽  
Cultural Methods ◽  
Level Data ◽  
The Social ◽  
Micro Level ◽  
Over Time

This chapter considers past and current research of procurement landscapes (quarries and mines) and the extent to which landscape archaeologies, together with comparative and cross-cultural methods in practice and theory have impacted on this field of study. Two case studies are presented in which these new methods of survey and characterization of procurement landscape have been deployed, along the Aswan West Bank and in the central Wadi Hammamat (Eastern Desert). The chapter goes on to address the ways in which holistic ‘bottom up’ approaches to interpreting micro-level data offers us fresh insights into understanding the social organization of procurement within broader aspects of social and cultural transformations over time.

scholarly journals Response to Cardiac Resynchronization Therapy: The Muscular Metabolic Pathway

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Jérémie Jaussaud ◽  
Pierre Blanc ◽  
Pierre Bordachar ◽  
Raymond Roudaut ◽  
Hervé Douard
Keyword(s):  
Anaerobic Threshold ◽  
Anaerobic Metabolism ◽  
Left Ventricular ◽  
Cardiac Resynchronization ◽  
Left Ventricular Ejection ◽  
Ventricular Ejection Fraction ◽  
Peripheral Muscle ◽  
Echocardiographic Evaluation ◽  
Exchange Measurement ◽  
Circulatory Power

Background. Changes in peripheral muscle in heart failure lead to a shift from aerobic to early anaerobic metabolism during exercise leading to ergoreflex overactivation and exaggerated hyperventilation evaluated by the VE/VCO2slope.Methods. 50 patients (38 males, years) performed cardio-pulmonary exercise test with gaz exchange measurement and echocardiographic evaluation before and 6 months after CRT.Results. The peak respiratory exchange (VCO2/ VO2) ratio was significantly reduced from to () and the time to the anaerobic threshold was increased from to seconds (). Peak VO2, VE/VCO2, peak circulatory power and NYHA were improved after CRT ( to ml/kg/min (), to (), to  mmHg.ml/kg/min () and to ()). In addition, left ventricular ejection fraction and end-systolic volumes were improved from to % () and from to ml ().Conclusion. We suggest that CRT leads to an increase in oxidative muscular metabolism and postponed anaerobic threshold reducing exaggerated hyperventilation during exercise.

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