scholarly journals Safety proposals for freediving time limits should consider the metabolic-rate dependence of oxygen stores depletion

2020 ◽  
Vol 50 (4) ◽  
pp. 356-362
Author(s):  
Charlotte Sadler ◽  
◽  
Kaighley Brett ◽  
Aaron Heerboth ◽  
Austin R Swisher ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Ambient Pressure ◽  
Time Limit ◽  
Rate Dependence ◽  
Breath Hold ◽  
Time Limits ◽  
Oxygen Stores ◽  
Hyperbaric Medicine ◽  
Rate Interaction ◽  
Healthy Participants

(Sadler C, Brett K, Heerboth A, Swisher AR, Mehregani N, Touriel R, Cannon DT. Safety proposals for freediving time limits should consider the metabolic-rate dependence of oxygen stores depletion. Diving and Hyperbaric Medicine. 2020 December 20;50(4):356–362. doi: 10.28920/dhm50.4.356-362. PMID: 33325016.) Introduction: There is no required training for breath-hold diving, making dissemination of safety protocols difficult. A recommended breath-hold dive time limit of 60 s was proposed for amateur divers. However, this does not consider the metabolic-rate dependence of oxygen stores depletion. We aimed to measure the effect of apnoea time and metabolic rate on arterial and tissue oxygenation. Methods: Fifty healthy participants (23 (SD 3) y, 22 women) completed four periods of apnoea for 60 s (or to tolerable limit) during rest and cycle ergometry at 20, 40, and 60 W. Apnoea was initiated after hyperventilation to achieve PETCO2 of approximately 25 mmHg. Pulse oximetry, frontal lobe oxygenation, and pulmonary gas exchange were measured throughout. We defined hypoxia as SpO2 < 88%. Results: Static and exercise (20, 40, 60 W) breath-hold break times were 57 (SD 7), 50 (11), 48 (11), and 46 (11) s (F [2.432, 119.2] = 32.0, P < 0.01). The rise in PETCO2 from initiation to breaking of apnoea was dependent on metabolic rate (time × metabolic rate interaction; F [3,147] = 38.6, P < 0.0001). The same was true for the fall in SpO2 (F [3,147] = 2.9, P = 0.03). SpO2 fell to < 88% on 14 occasions in eight participants, all of whom were asymptomatic. Conclusions: Independent of the added complexities of a fall in ambient pressure on ascent, the effect of apnoea time on hypoxia depends on the metabolic rate and is highly variable among individuals. Therefore, we contend that a universally recommended time limit for breath-hold diving or swimming is not useful to guarantee safety.

scholarly journals Perceptual insensitivity to the modulation of interoceptive signals in depression, anxiety, and substance use disorders

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryan Smith ◽  
◽  
Justin S. Feinstein ◽  
Rayus Kuplicki ◽  
Katherine L. Forthman ◽  
...  
Keyword(s):  
Machine Learning ◽  
Substance Use ◽  
Individual Differences ◽  
Substance Use Disorders ◽  
Breath Hold ◽  
Healthy Individuals ◽  
Performance Improvements ◽  
Heartbeat Perception ◽  
Minimal Improvement ◽  
Healthy Participants

AbstractThis study employed a series of heartbeat perception tasks to assess the hypothesis that cardiac interoceptive processing in individuals with depression/anxiety (N = 221), and substance use disorders (N = 136) is less flexible than that of healthy individuals (N = 53) in the context of physiological perturbation. Cardiac interoception was assessed via heartbeat tapping when: (1) guessing was allowed; (2) guessing was not allowed; and (3) experiencing an interoceptive perturbation (inspiratory breath hold) expected to amplify cardiac sensation. Healthy participants showed performance improvements across the three conditions, whereas those with depression/anxiety and/or substance use disorder showed minimal improvement. Machine learning analyses suggested that individual differences in these improvements were negatively related to anxiety sensitivity, but explained relatively little variance in performance. These results reveal a perceptual insensitivity to the modulation of interoceptive signals that was evident across several common psychiatric disorders, suggesting that interoceptive deficits in the realm of psychopathology manifest most prominently during states of homeostatic perturbation.

Efectele pandemiei SARS-CoV-2 asupra activității și procedurii în fața Curții Europene a Drepturilor Omului

2021 ◽  
Vol 2021 (2021) ◽  
pp. 147-163
Author(s):  
Corneliu-Liviu POPESCU ◽  
Keyword(s):  
Human Rights ◽  
Time Limit ◽  
European Convention ◽  
Time Limits ◽  
European Court ◽  
Procedural Time

At the beginning of the SARS-CoV-2 pandemic, the European Court of Human Rights ruled and then extended the decision to suspend part of its activity, as well as certain procedural time-limits, including time-limit for referral to the Court through the means of a state or an individual application. These measures do not comply with the European Convention on Human Rights, nor with the Rules of the Court. The control of the regularity of these measures may be exercised by the judicial formations of the Court, acting in the specific cases.

A Note on Metabolic Rate Dependence on Body Size in Plants and Animals

2003 ◽  
Vol 221 (2) ◽  
pp. 301-307 ◽  
Author(s):  
ANASTASSIA M. MAKARIEVA ◽  
VICTOR G. GORSHKOV ◽  
BAI-LIAN LI
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Rate Dependence

Arterial blood gas tensions during breath-hold diving in the Korean ama

1993 ◽  
Vol 75 (1) ◽  
pp. 285-293 ◽  
Author(s):  
J. Qvist ◽  
W. E. Hurford ◽  
Y. S. Park ◽  
P. Radermacher ◽  
K. J. Falke ◽  
...  
Keyword(s):  
Radial Artery ◽  
Breath Hold ◽  
Blood Gas ◽  
Arterial Pco2 ◽  
Blood Samples ◽  
Arterial Blood Gas ◽  
Time Limits ◽  
Arterial Blood ◽  
Normal Ranges ◽  
Arterial Po2

Korean female unassisted divers (cachido ama) breath-hold dive > 100 times to depths of 3–7 m during a work day. We sought to determine the extent of arterial hypoxemia during normal working dives and reasonable time limits for breath-hold diving by measuring radial artery blood gas tensions and pH in five cachido ama who dove to a fixed depth of 4–5 m and then continued to breath hold for various times after their return to the surface. Eighty-two blood samples were withdrawn from indwelling radial artery catheters during 37 ocean dives. We measured compression hyperoxia [arterial PO2 = 141 +/- 24 (SD) Torr] and hypercapnia (arterial PCO2 = 46.6 +/- 2.4 Torr) at depth. Mean arterial PO2 near the end of breath-hold dives lasting 32–95 s (62 +/- 14 s) was decreased (62.6 +/- 13.5 Torr). Mean arterial PCO2 reached 49.9 +/- 5.4 Torr. Complete return of these values to their baseline did not occur until 15–20 s after breathing was resumed. In dives of usual working duration (< 30 s), blood gas tensions remained within normal ranges. Detailed analysis of hemoglobin components and intrinsic oxygenation properties revealed no evidence for adaptive changes that could increase the tolerance of the ama to hypoxic or hypothermic conditions associated with repetitive diving.

International Court of Justice

1962 ◽  
Vol 16 (1) ◽  
pp. 217-217 ◽  
Keyword(s):  
United Kingdom ◽  
Time Limit ◽  
International Court Of Justice ◽  
Time Limits ◽  
The United Kingdom ◽  
Court Of Justice ◽  
International Court ◽  
The Republic ◽  
The Government

Case concerning the Northern Cameroons (Cameroun v. United Kingdom): In an order of July 6, 1961, the International Court of Justice fixed the time limits for the filing of pleadings in the case concerning the Northern Cameroons as follows: for the memorial of the Republic of Cameroun, November 1, 1961; and for the countermemorial of the United Kingdom, March 1, 1962. Subsequently, in an order of November 2, 1961, the Court, in accordance with a request from the agent of the government of the Republic of Cameroun, extended to January 3, 1962, the time limit for the filing of the memorial of the Republic of Cameroun and to May 2, 1962, the time limit for the filing of the countermemorial of the United Kingdom.

scholarly journals THE SMALL AND LARGE TIME IMPLIED VOLATILITIES IN THE MINIMAL MARKET MODEL

2012 ◽  
Vol 15 (08) ◽  
pp. 1250057
Author(s):  
ZHI JUN GUO ◽  
ECKHARD PLATEN
Keyword(s):  
Interest Rates ◽  
Implied Volatility ◽  
Large Time ◽  
Time Limit ◽  
Market Model ◽  
Explicit Formulas ◽  
Time Limits ◽  
Long Run ◽  
Minimal Market Model ◽  
Short Time

This paper derives explicit formulas for both the small and the large time limits of the implied volatility in the minimal market model. It is shown that interest rates do impact on the implied volatility in the long run, even though they are negligible in the short time limit.

Intrapulmonary distribution of alveolar gas exchange during breath-hold diving in humans

1995 ◽  
Vol 78 (2) ◽  
pp. 410-416 ◽  
Author(s):  
M. H. Liner ◽  
D. Linnarsson
Keyword(s):  
Atmospheric Pressure ◽  
Impedance Cardiography ◽  
Ambient Pressure ◽  
Co2 Exchange ◽  
Phase Iii ◽  
Breath Hold ◽  
Pulmonary Perfusion ◽  
Normal Atmospheric Pressure ◽  
Wet Surface ◽  
Alveolar Gas Exchange

Expirograms for CO2 and O2 obtained immediately after 75-s breath holds (BHs) in thermoneutral conditions were studied in 10 subjects. BHs were performed at normal atmospheric pressure in dry condition (dry surface BH), at normal atmospheric pressure submerged (wet surface BH), and during a transient increase of ambient pressure to 3 atmospheres absolute submerged (wet BH dive). Cardiac index was estimated by means of impedance cardiography. Phase III (alveolar plateau) slopes for CO2 expirograms were lowest after wet surface BH. The greater slope observed after dry surface BH was attributed mainly to intrapulmonary perfusion heterogeneity and the greater slope seen after wet BH dive to continuing alveolar CO2 exchange during expiration. Cardiogenic oscillations in phase III (evaluated by spectral analysis) were largest after dry surface BH, much reduced by wet surface BH, and further reduced by wet BH dive. This was attributed to more even distribution of pulmonary perfusion during submersion and compression. Terminal changes of the expirograms (phase IV) revealed a less even interregional pulmonary distribution of CO2 and a more even distribution of O2 after wet BH dive compared with wet surface BH. This difference was attributed to improved apical pulmonary perfusion at depth during the wet BH dives.

V. CASES BEFORE THE COURT

2004 ◽  
Vol 53 (3) ◽  
pp. 762-767
Keyword(s):  
Bosnia And Herzegovina ◽  
Time Limit ◽  
Genocide Convention ◽  
Serbia And Montenegro ◽  
Time Limits ◽  
The Republic ◽  
Made In

1. Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v Serbia and Montenegro).The Republic of Bosnia and Herzegovina instituted proceedings against Yugoslavia on 20 March 1993 alleging violations of the 1949 Genocide Convention and requesting an indication of provisional measures which was made in an order of 8 April 1993.1 This was reaffirmed in an order of 13 September 1993,2 following a second request for provisional measures made by Bosnia and Herzegovina on 27 July 1993 and a request made by Yugoslavia on 10 August 1993.3 By an order of 16 April 19934 the following time limits were set for the filing of the written pleadings: Bosnia and Herzegovina, memorial, 15 October 1993; Yugoslavia, counter-memorial, 15 April 1994. By an order of 7 October 19935 these were extended to: Bosnia and Herzegovina, memorial, 15 April 1994; Yugoslavia, counter-memorial, 15 April 1995 and, by order of 21 March 1995,6 the date for the submission of the Yugoslavian counter-memorial was again extended to 30 June 1995. On 26 June 1995 Yugoslavia submitted preliminary objections which were rejected by the Court in its order of 11 July 1996.7 By an order of 23 July 19968 the time limit for filing the Yugoslav counter-memorial was fixed as 23 July 1997. The counter-memorial was filed on 22 July 1997 and contained counterclaims against Bosnia and Herzegovina and, in an order of 17 December 1997,9 the Court held them to be admissible and that they formed a part of the current proceedings. These counter-claims were subsequently withdrawn at the request of Bosnia and Herzegovina, this being noted by the Court in its order of 10 September 2001.10 The order of 17 December 199711 set the following time limits for the written pleadings on the merits: Bosnia and Herzegovina, reply, 23 January,1998; Yugoslavia, rejoinder, 23 July 1998. By an order of 22 January 199812 these were extended to: Bosnia and Herzegovina, reply, 23 April 1998; Yugoslavia, rejoinder, 22 January 1999. By an order of 11 December 199813 the time limit for the submission of the Yugoslav rejoinder was further extended, to 22 February 1999.

Breath-hold black-blood T1rho mapping improves liver T1rho quantification in healthy volunteers

2017 ◽  
Vol 59 (3) ◽  
pp. 257-265 ◽  
Author(s):  
Yì Xiáng J Wáng ◽  
Min Deng ◽  
Gladys G Lo ◽  
Dong Liang ◽  
Jing Yuan ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Intraclass Correlation ◽  
Breath Hold ◽  
Black Blood ◽  
Single Shot ◽  
Spin Lock ◽  
Single Breath ◽  
Single Breath Hold ◽  
Healthy Participants ◽  
Bright Blood

Background Recent researches suggest that T1rho may be a non-invasive and quantitative technique for detecting and grading liver fibrosis. Purpose To compare a multi-breath-hold bright-blood fast gradient echo (GRE) imaging and a single breath-hold single-shot fast spin echo (FSE) imaging with black-blood effect for liver parenchyma T1rho measurement and to study liver physiological T1rho value in healthy volunteers. Material and Methods The institutional Ethics Committee approved this study. 28 healthy participants (18 men, 10 women; age = 29.6 ± 5.1 years) underwent GRE liver T1rho imaging, and 20 healthy participants (10 men, 10 women; age = 36.9 ± 10.3 years) underwent novel black-blood FSE liver T1rho imaging, both at 3T with spin-lock frequency of 500 Hz. The FSE technique allows simultaneous acquisition of four spin lock times (TSLs; 1 ms, 10 ms, 30 ms, 50msec) in 10 s. Results For FSE technique the intra-scan repeatability intraclass correlation coefficient (ICC) was 0.98; while the inter-scan reproducibility ICC was 0.82 which is better than GRE technique’s 0.76. Liver T1rho value in women tended to have a higher value than T1rho values in men (FSE: 42.28 ± 4.06 ms for women and 39.13 ± 2.12 ms for men; GRE: 44.44 ± 1.62 ms for women and 42.36 ± 2.00 ms for men) and FSE technique showed liver T1rho value decreased slightly as age increased. Conclusion Single breath-hold black-blood FSE sequence has better scan–rescan reproducibility than multi-breath-hold bright-blood GRE sequence. Gender and age dependence of liver T1rho in healthy participants is observed, with young women tending to have a higher T1rho measurement.

Down to the wire: The cultural clock of physicists and the discourse of consensus

1997 ◽  
Vol 26 (4) ◽  
pp. 479-505 ◽  
Author(s):  
Elinor Ochs ◽  
Sally Jacoby
Keyword(s):  
Experimental Data ◽  
Scientific Discourse ◽  
Time Limit ◽  
Temporal Organization ◽  
Time Limits ◽  
Working Through ◽  
Physical Universe ◽  
The Wire ◽  
University Laboratory

ABSTRACTThis study examines how deadlines and time limits for conference talks organize the discourse of consensus among collaborating experimental and theoretical physicists in a university laboratory Six months of videotaped observations, including two cycles of conference talk preparation, indicate that, as the date of an upcoming conference nears, several things happen (a)Co-authoring physicists usually have not achieved agreement on all aspects of the findings (b)They nevertheless direct their energies to constructing a hybrid presentation rhetoric that satisfies the co-authors and fits the talk to the official conference talk time limit (c) In the process of working through matters of rhetoric – what to say, what to display visually, what to leave out, and in what order the information should be presented – the physicists construct a working consensus on matters of physics theory and experimental data explaining the properties and dynamics of the physical universe (Scientific discourse, consensus, temporal organization, rhetoric )

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