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In my December 2014 EUBS... more
In my December 2014 EUBS President's column, entitled "Hydrophobicity: the link between bubbles, bubblers and autoimmunity?" (Diving Hyperb Med. 2014;44:185), the text in the first two paragraphs under the subheading "Surfactants act against proteins and cause autoimmune diseases" should have been attributed to: Arieli R. Was the appearance of surfactants in air breathing vertebrates ultimately the cause of decompression sickness and autoimmune disease? Resp Physiol Neurobiol. 2015;206:15-18. This paper was available on-line from November 2014. Dr Arieli accepts that this omission was unintentional on my part and that the promulgation of his theories was done from the best of motives.
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Les redacteurs et les auteurs de ce livre sont un groupe de scientifiques et de medecins possedant une vaste experience et des connaissances approfondies de la physiologie de la plongee et de la theorie de la decompression. Comme... more
Les redacteurs et les auteurs de ce livre sont un groupe de scientifiques et de medecins possedant une vaste experience et des connaissances approfondies de la physiologie de la plongee et de la theorie de la decompression. Comme c'est souvent le cas, il faut un effort collectif pour reussir a faire progresser les connaissances pratiques. Le familier "le tout est plus grand que la somme de ses parties" est souvent vrai et le Groupe de recherche PHYPODE incarne ce concept. En regroupant logiquement les differents elements de la science et de la medecine de la plongee avec des sections provocantes et " matiere a reflexion ", le texte offre des lecons precieuses a ceux qui s'interessent a l'etat actuel de la plongee. Malgre pres de 170 ans de recherche, la nature fondamentale du stress de decompression demeure insaisissable. Comme il est bien decrit dans ce livre, de grands progres ont ete realises en ce qui concerne les elements pratiques permettant de plonger en toute securite. Ce travail est une traduction realisee avec l'intelligence artificielle.
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info:eu-repo/semantics/published
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Doctorat en kinésithérapie et réadaptationinfo:eu-repo/semantics/nonPublishe
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Exposure to acute normobaric hypoxia (NH) elicits reactive oxygen species (ROS) accumulation, whose production kinetics and oxidative damage were here investigated. Nine subjects were monitored while breathing an NH mixture (0.125 FIO2 in... more
Exposure to acute normobaric hypoxia (NH) elicits reactive oxygen species (ROS) accumulation, whose production kinetics and oxidative damage were here investigated. Nine subjects were monitored while breathing an NH mixture (0.125 FIO2 in air, about 4100 m) and during recovery with room air. ROS production was assessed by Electron Paramagnetic Resonance in capillary blood. Total antioxidant capacity, lipid peroxidation (TBARS and 8-iso-PFG2α), protein oxidation (PC) and DNA oxidation (8-OH-dG) were measured in plasma and/or urine. The ROS production rate (μmol·min−1) was monitored (5, 15, 30, 60, 120, 240 and 300 min). A production peak (+50%) was reached at 4 h. The on-transient kinetics, exponentially fitted (t1/2 = 30 min r2 = 0.995), were ascribable to the low O2 tension transition and the mirror-like related SpO2 decrease: 15 min: −12%; 60 min: −18%. The exposure did not seem to affect the prooxidant/antioxidant balance. Significant increases in PC (+88%) and 8-OH-dG (+67%) at ...
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ObjectiveWe aimed to evaluate the feasibility of an online High-Intensity Interval Training (HIIT) program on clinical psychological symptoms in higher education students in the context of the COVID-19 pandemic lockdown.Materials and... more
ObjectiveWe aimed to evaluate the feasibility of an online High-Intensity Interval Training (HIIT) program on clinical psychological symptoms in higher education students in the context of the COVID-19 pandemic lockdown.Materials and MethodsDuring the lockdown, 30 students aged 18–25 years, who had been screened previously with a cut-off score ≥5 in the Generalized Anxiety Disorder-7 (GAD-7) questionnaire, were randomly assigned to either the 4-week HIIT program with three sessions per week conducted through online videos, or a no-intervention control group. The primary outcome was the feasibility assessment. The secondary outcome was a psychological self-report with the 21-items Depression, Anxiety, and Stress Scale (DASS-21). Assessment and intervention were performed in compliance with social distancing rules.ResultsTwo participants in the HIIT were lost to follow-up, leaving 13 participants vs. 15 in the control group. We observed high adherence (87%) and complete safety for men...
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Introduction: Scuba diving represents stressful event for cardiovascular system. Breathing with compressed air, hyperbaric environment and microbubbles formation are the main factors are the most influencing factors for pulmonary... more
Introduction: Scuba diving represents stressful event for cardiovascular system. Breathing with compressed air, hyperbaric environment and microbubbles formation are the main factors are the most influencing factors for pulmonary circulation. Hypothesis: The aim of the study was to evaluate the change in morphology and function of the right heart after scuba dive with compressed air. Methods: Ten healthy sport divers (2 woman, 8 men, average age 42.1 ± 4.1 yrs., 21-52yrs) performed one scuba dive with compressed air (the depth was 20 meters, bottom tine 20 minutes, one safety stop at 3 m, water temperature 15°C). Echocardiography was performed just before and immediately after the dive, and every 60 minutes after surfacing with the aim to evaluate the presence of microbubbles (iVivid, GE). Results: After the dive, left atrium, right ventricle and inferior vena cava diameters significantly decreased (LA: 30.4±2.1 vs. 27.1±1.2 mm, p<0.05; RV: 27.8±2.1 vs. 25.2±1.1mm, p<0.05; IVC: 19.3±1.1 vs. 17.6±0.9 mm, p...
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info:eu-repo/semantics/published
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Previous studies suggest that altered gravity levels during parabolic flight maneuvers affect spatial updating. Little is known about the impact of the experimental setting and psychological stressors associated with parabolic flight... more
Previous studies suggest that altered gravity levels during parabolic flight maneuvers affect spatial updating. Little is known about the impact of the experimental setting and psychological stressors associated with parabolic flight experiments on attentional processes. To address this gap, we investigated the level of alertness, selective and sustained attention in 1 and 0 g using a Go/No-Go Continuous Performance Task. We also identified several parameters associated with the experimental set-up of a parabolic flight that could be expected to affect attentional processing. These included the use of scopolamine, sleep quality prior to the flight day, participant’s stress level as well as mood and anxiety state before and after the parabolic flight. We observed a deterioration in attentional processing prior to the first parabola that was further aggravated in weightlessness and returned to baseline after the last parabola.Reaction Time,HitandFalse Alarm Ratewere moderately correla...
Research Interests: Psychology, Cognition, Attention, Medicine, Anxiety, and 10 moreHuman, Mood, Microgravity, DDC, ANXIETY, Alertness, Scopolamine, Parabola, Education Physique, and Adverse effects
We report Blood Oxygen Level Dependent (BOLD) signal changes recorded in the brain of an elite breath-hold diver during voluntary dry long breath-hold by means of fMRI. An independent component analysis (ICA) method was applied to extract... more
We report Blood Oxygen Level Dependent (BOLD) signal changes recorded in the brain of an elite breath-hold diver during voluntary dry long breath-hold by means of fMRI. An independent component analysis (ICA) method was applied to extract brain areas that are putatively involved in the apnea process network. We discuss the hypothesis that these BOLD signal variations express the functional adaptive diving response under long apnea at rest. This is a preliminary report, which results are promising for large series investigations.
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Research Interests: Physiology, Environmental Science, Medicine, Diving, Humans, and 6 moreNitrogen, Helium, Oxygen, Breathing, Education Physique, and Heliox
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Introduction: The SARS-CoV2 pandemic has led to an worldwide shortage of Personal Protection Devices (PPD) for medical and paramedical personnel. Adaptation of commercially available snorkel masks to serve as full face masks has been... more
Introduction: The SARS-CoV2 pandemic has led to an worldwide shortage of Personal Protection Devices (PPD) for medical and paramedical personnel. Adaptation of commercially available snorkel masks to serve as full face masks has been proposed. Even not formally approved as PPD, they are publicized on social media as suitable for this use. Concerns about actual protection levels and risk of carbon dioxide (CO2) accumulation while wearing them for extended periods made us perform a systematic testing of various brands, in order to verify whether they are as safe and effective as claimed. Methods: A “fit” test was performed, analogous to gas mask testing. Respiratory safety was evaluated by measuring end-tidal CO2 and oxygen saturation while wearing the masks in rest and during physical exercise. Masks were tested with 3D adaptors to mount regular bacterial-viral ventilator filters when available, or with snorkel openings covered with N95/FFP2 cloth. Results: Modified masks performed r...
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Research Interests: Cognition, Medicine, Diving, Humans, Air, and 7 moreNitrogen, Respiration, Oxygen, Adult, Breathing, Task Performance and Analysis, and Decompression
info:eu-repo/semantics/publishe
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Research Interests: Psychology, Medicine, Hypergravity, Microgravity, Arousal, and 3 moreAlertness, G, and Education Physique
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Divers Alert Network Europe has created a database with a large amount of dive-related data that has been collected since 1993 within the scope of the Diving Safety Laboratory citizen science project. The main objectives of this study are... more
Divers Alert Network Europe has created a database with a large amount of dive-related data that has been collected since 1993 within the scope of the Diving Safety Laboratory citizen science project. The main objectives of this study are the grouping divers by their health information and revealing significant differences in diving parameters using data mining techniques. Due to the methodology of the project, data cleaning was performed before applying clustering methods in order to eliminate potential mistakes resulting from inaccuracies and missing information. Despite the fact that 63% of the data were lost during the cleaning phase, the remaining 1,169 “clean” diver data enabled meaningful clustering using the “two-step” method. Experienced male divers without any health problems are in Cluster 1. Male and female divers with health problems and high rates of cigarette smoking are in Cluster 2; healthy, overweight divers are in Cluster 3. There are significant differences in te...
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Venous gas emboli (VGE) are often quantified as a marker of decompression stress on echocardiograms. Bubblecounting has been proposed as an easy to learn method, but remains time-consuming, rendering large dataset analysis impractical.... more
Venous gas emboli (VGE) are often quantified as a marker of decompression stress on echocardiograms. Bubblecounting has been proposed as an easy to learn method, but remains time-consuming, rendering large dataset analysis impractical. Computer automation of VGE counting following this method has therefore been suggested as a means to eliminate rater bias and save time. A necessary step for this automation relies on the selection of a frame during late ventricular diastole (LVD) for each cardiac cycle of the recording. Since electrocardiograms (ECG) are not always recorded in field experiments, here we propose a fully automated method for LVD frame selection based on regional intensity minimization. The algorithm is tested on 20 previously acquired echocardiography recordings (from the original bubble-counting publication), half of which were acquired at rest (Rest) and the other half after leg flexions (Flex). From the 7,140 frames analyzed, sensitivity was found to be 0.913 [95% C...