119 research outputs found
Acute and Chronic Effects of a High-Intensity Interval Training Shock Microcycle on Cell-Free DNA: A Randomized Controlled Trial
Abstract Background This study aimed to evaluate acute and chronic exercise-induced changes in cell-free DNA (cfDNA) concentrations during a 7-day high-intensity interval training (HIIT) shock microcycle in trained endurance athletes. Thirty-five participants were randomly assigned to one of three groups: a HIIT-only group (HSM), a HIIT plus low-intensity training group (HSM + LIT), and a control group maintaining regular training. The intervention included 10 HIIT sessions (5 × 4 min at 90–95% maximum heart rate) over 7 days, with HSM + LIT completing an additional 30 min of low-intensity training after each session. Physiological exercise testing (PET) was conducted at baseline, 3-, 7-, and 14-days post-intervention. On days 2 and 7 during the intervention, HIIT sessions were supervised in both morning and afternoon, and venous blood samples were collected at rest, immediately post-exercise, and 30 min post-exercise to measure cfDNA for 90 and 222 bp fragments. Correlations between cfDNA and physiological exercise variables such as peak power output (PPO), running velocity at lactate threshold (LT), and VO₂max were analyzed. Results cfDNA90 (10.4-fold, p < 0.001) and cfDNA222 (12.4-fold, p < 0.001) increased significantly after PET. In addition, cfDNA90 (17.1-fold, p < 0.001) and cfDNA222 (20.2-fold, p < 0.001) increased after HIIT, both remaining significantly elevated 30 min post-HIIT (both p < 0.001). cfDNA90 concentrations were higher in afternoon (22.4-fold) compared to morning HIIT sessions (17.2-fold, p < 0.001). A significant interaction effect was found between group and measurement point for cfDNA90 (p < 0.001) and cfDNA222 (p < 0.001), with higher concentrations in HSM + LIT compared to HSM 30 min post-HIIT. cfDNA90 showed moderate correlations with PPO (r = 0.48, p < 0.001), LT (r = 0.36, p < 0.001) and VO₂max (r = 0.30, p = 0.01). cfDNA222 correlated moderately with VO₂max (r = 0.34, p = 0.001) and slightly with PPO (r = 0.21, p = 0.05). No chronic changes in cfDNA were observed throughout the study period. Conclusions cfDNA is a reliable marker for detecting acute exercise-induced stress. However, the potential of cfDNA for detecting chronic adaptations in short-term, high-intensity interval training settings, such as a HIIT shock cycle, appears limited thus far. Trial registration clinicaltrials.gov, NCT05067426. Registered 05 October 2021—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05067426 . Graphical AbstractKey Points Acute increases in cfDNA concentrations were observed after physiological exercise testing and high-intensity interval training (HIIT). No chronic cfDNA changes were observed during and after a HIIT shock microcycle. Acute increases in cfDNA concentrations correlated with physiological exercise variables e.g. peak power output, running velocity at lactate threshold and VO2max during acute exercise. Higher increases in cfDNA were found after HIIT compared to physiological exercise testing. Higher increases in cfDNA were found after HIIT in the afternoon compared to morning. Higher increases in cfDNA were observed in males compared to females
Selected procedures in teaching biology
by E. Irene Hollenbeck and Elmo Nall Stevenson.This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Includes bibliographical references (pages 54-56).Mode of access: Internet from the Oregon Government Publications Collection.Text in English
Dams, Parks and Politics: Resource Development and Preservation the Truman-Eisenhower Era
This book is a chronicle of the myopia and gamesmanship that dominated Americans’ understanding of their environment on the eve of the nation’s ecology crisis. Based almost entirely on primary sources, Elmo Richardson’s study examines the interplay between the national policies and programs for development and preservation of natural resources in the centralist Truman administration and the localist, enterprise-oriented Eisenhower administration. He shows that the decade examined brought about very little change in the values held by federal policy makers. Although the development of resources was a prominent issue in the elections of 1948, 1952, and 1956, what emerges from Richardson’s account is the shallowness of understanding on the part of the decision makers and the public, and the ease with which policy direction could be deflected. The book demonstrates the persistence of the tradition of development and the nonpartisan character of the movement for preservation, which crossed party lines, regional lines, and economic interest groups.
Elmo Richardson is the author of The Politics of Conservation: Crusades and Controversies, 1897-1913, and several articles dealing with federal resource programs during the 1930s.https://uknowledge.uky.edu/upk_environmental_policy/1000/thumbnail.jp
Relativistic mean proportion
The so called modern physics is at present included in the curricula of high school. Therefore, we often organize in-depth lessons on quantum mechanics and on the special theory of relativity (SR). In the following sections, we want to show a lesson given by the first author of this paper. He proposes to students a proportion to deduce relativistic time dilation and length contraction without knowing the Lorentz transformations
Extracting location context from transcripts: a comparison of ELMo and TF-IDF
Using transcripts of the TV-series FRIENDS, this paper explores the problem of predicting the location in which a sentence was said. The research focuses on using feature extraction on the sentences, and training a logistic regression model on those features. Specifically looking at the differences in performance between using ELMo and TF-IDF for this feature extraction, achieving an accuracy rate of 58\% and 67\% respectively on a binary classification. The paper also explores the effect of several data cleaning techniques on the results. Git repository containing the source code used in the paper - https://github.com/David-Happel/scene-location-NLPCSE3000 Research ProjectComputer Science and Engineerin
Distance measures in cosmology: a simple approach
The aim of this paper is to analyze the concept of cosmological distance with a simple didactic approach that is not easy to find in textbooks. In this way, we hope to help facilitate student learning about this issue.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Investigation of the Sympathetic Regulation in Delayed Onset Muscle Soreness: Results of an RCT.
Sports-related pain and injury is directly linked to tissue inflammation, thus involving the autonomic nervous system (ANS). In the present experimental study, we disable the sympathetic part of the ANS by applying a stellate ganglion block (SGB) in an experimental model of delayed onset muscle soreness (DOMS) of the biceps muscle. We included 45 healthy participants (female 11, male 34, age 24.16 ± 6.67 years [range 18-53], BMI 23.22 ± 2.09 kg/m2) who were equally randomized to receive either (i) an SGB prior to exercise-induced DOMS (preventive), (ii) sham intervention in addition to DOMS (control/sham), or (iii) SGB after the induction of DOMS (rehabilitative). The aim of the study was to determine whether and to what extent sympathetically maintained pain (SMP) is involved in DOMS processing. Focusing on the muscular area with the greatest eccentric load (biceps distal fifth), a significant time × group interaction on the pressure pain threshold was observed between preventive SGB and sham (p = 0.034). There was a significant effect on pain at motion (p = 0.048), with post hoc statistical difference at 48 h (preventive SGB Δ1.09 ± 0.82 cm VAS vs. sham Δ2.05 ± 1.51 cm VAS; p = 0.04). DOMS mediated an increase in venous cfDNA -as a potential molecular/inflammatory marker of DOMS- within the first 24 h after eccentric exercise (time effect p = 0.018), with a peak at 20 and 60 min. After 60 min, cfDNA levels were significantly decreased comparing preventive SGB to sham (unpaired t-test p = 0.008). At both times, 20 and 60 min, cfDNA significantly correlated with observed changes in PPT. The 20-min increase was more sensitive, as it tended toward significance at 48 h (r = 0.44; p = 0.1) and predicted the early decrease of PPT following preventive stellate blocks at 24 h (r = 0.53; p = 0.04). Our study reveals the broad impact of the ANS on DOMS and exercise-induced pain. For the first time, we have obtained insights into the sympathetic regulation of pain and inflammation following exercise overload. As this study is of a translational pilot character, further research is encouraged to confirm and specify our observations
Tell me how long it takes for light to travel and I will tell you how fast you go
The Italian Government's Ministry of Public Education has introduced the special theory of relativity for students in their last year of high school. For this reason, we often organize in-depth lessons on modern physics, in general, and on relativity theory in particular. Often, even simple new comers of physics participate. For example, we would like to show, in a subsequence lesson in the classroom, a relation proposed by the first author of this paper, a distinguished jurist and lover of general science. This relation allows us to deduce the Lorentz factor without knowing the relative velocity between the reference frames
Multimodal Web-Based Telerehabilitation for Patients With Post–COVID-19 Condition: Protocol for a Randomized Controlled Trial
BackgroundPatients with post–COVID-19 condition (PCC) experience persistent, long-term health consequences following SARS-CoV-2 infection, including fatigue, hyperventilation, cognitive impairment, and limitations in daily activities. There is emerging evidence suggesting that exercise and respiratory therapy–based telerehabilitation is safe and could potentially improve physical capacity while reducing health care costs.
ObjectiveThis study aims to evaluate the superiority of a multimodal, symptom-titrated telerehabilitation program over standard care in patients with PCC who are severely affected, using the highest oxygen uptake rate (VO2peak [mL/min/kg]) achieved during the cardiopulmonary exercise test (CPET) and minute ventilation/carbon dioxide production slope (VE/VCO2 [full slope]) as primary outcomes. In addition, this study seeks to provide novel insights into the clinical and physiological adaptations associated with PCC, informing future rehabilitation strategies.
MethodsThis prospective, randomized, waitlist-controlled trial was approved by the Rhineland-Palatinate Medical Association ethics committee. All procedures comply with the Declaration of Helsinki. This study comprises 3 examination time points, which include patient-reported outcomes, clinical assessments, and a CPET. It is structured into an 8-week intervention phase followed by an 8-week follow-up phase. Following baseline assessment, patients will be randomly assigned to either the intervention group (IG) or the control group (CG). During the intervention phase, IG participants will receive a web-based, multimodal, symptom-titrated telerehabilitation program consisting of sports medicine consultations, weekly teleconsultations, a structured pacing approach, and exercise and respiratory therapy. In contrast, CG participants will receive treatment as usual, which includes a single sports medicine consultation on healthy habits and a self-directed pacing approach for managing symptoms and daily activities. During the follow-up phase, IG participants will continue training independently without teleconsultations, whereas CG participants will undergo the same telerehabilitation intervention as the IG. A follow-up assessment will be conducted for both groups to evaluate long-term effects. This study adheres to the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) guidelines and follows the Consensus on Exercise Reporting Template.
ResultsRecruitment began in August 2023 and was extended until March 2025. As of March 2025, 80 participants have been recruited, and data analysis is ongoing. Final results are expected by December 2025, with a cross-sectional analysis of baseline data anticipated by July 2025.
ConclusionsThis study is the first randomized controlled trial investigating the effectiveness of multimodal and symptom-titrated telerehabilitation in patients with PCC who are severely affected. The integration of various objective diagnostic systems will provide valuable insights into emerging postviral fatigue syndromes, supporting the development of CPET-based diagnostics, personalized rehabilitation strategies, and future research on long-term telerehabilitation effectiveness. The findings will be disseminated through peer-reviewed publications, professional networks, and patient advocacy groups to ensure scientific, clinical, and public impact.
Trial RegistrationGerman Clinical Trials Register (DRKS) DRKS00032394; https://drks.de/search/de/trial/DRKS00032394
International Registered Report Identifier (IRRID)DERR1-10.2196/6504
Platelets, endothelial cells and leukocytes contribute to the exercise-triggered release of extracellular vesicles into the circulation
Physical activity initiates a wide range of multi-systemic adaptations that promote mental and physical health. Recent work demonstrated that exercise triggers the release of extracellular vesicles (EVs) into the circulation, possibly contributing to exercise-associated adaptive systemic signalling. Circulating EVs comprise a heterogeneous collection of different EV-subclasses released from various cell types. So far, a comprehensive picture of the parental and target cell types, EV-subpopulation diversity and functional properties of EVs released during exercise (ExerVs) is lacking. Here, we performed a detailed EV-phenotyping analysis to explore the cellular origin and potential subtypes of ExerVs.Healthy male athletes were subjected to an incremental cycling test until exhaustion and blood was drawn before, during, and immediately after the test. Analysis of total blood plasma by EV Array suggested endothelial and leukocyte characteristics of ExerVs. We further purified ExerVs from plasma by size exclusion chromatography as well as CD9-, CD63- or CD81-immunobead isolation to examine ExerV-subclass dynamics. EV-marker analysis demonstrated increasing EV-levels during cycling exercise, with highest levels at peak exercise in all EV-subclasses analysed. Phenotyping of ExerVs using a multiplexed flow-cytometry platform revealed a pattern of cell surface markers associated with ExerVs and identified lymphocytes (CD4, CD8), monocytes (CD14), platelets (CD41, CD42, CD62P), endothelial cells (CD105, CD146) and antigen presenting cells (MHC-II) as ExerV-parental cells. We conclude that multiple cell types associated with the circulatory system contribute to a pool of heterogeneous ExerVs, which may be involved in exercise-related signalling mechanisms and tissue crosstalk
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