Science.gov

Sample records for 14-d saturation dive

  1. Nutritional Assessment During a 14-d Saturation Dive: the NASA Extreme Environment Mission Operation V Project

    NASA Technical Reports Server (NTRS)

    Smith, S. M.; Davis-Street, J. E.; Fesperman, J. V.; Smith, M. D.; Rice, B. L.; Zwart, S. R.

    2006-01-01

    Ground-based analogs of spaceflight are an important means of studying physiological and nutritional changes associated with space travel, particularly since exploration missions are anticipated, and flight research opportunities are limited. A clinical nutritional assessment of the NASA Extreme Environment Mission Operation V (NEEMO) crew (4 M, 2 F) was conducted before, during, and after the 14-d saturation dive. Blood and urine samples were collected before (D-12 and D-1), during (MD 7 and MD 12), and after (R + 0 and R + 7) the dive. The foods were typical of the spaceflight food system. A number of physiological changes were reported both during the dive and post dive that are also commonly observed during spaceflight. Serum hemoglobin and hematocrit were decreased (P less than 0.05) post dive. Serum ferritin and ceruloplasmin significantly increased during the dive, while transferring receptors tended to go down during the dive and were significantly decreased by the last day (R + 0). Along with significant hematological changes, there was also evidence for increased oxidative damage and stress during the dive. 8-hydroxydeoxyguanosine was elevated (P less than 0.05) during the dive, while glutathione peroxidase and superoxide disrnutase activities were decreased (P less than 0.05) during the dive. Serum C-reactive protein (CRP) concentration also tended to increase during the dive, suggesting the presence of a stress-induced inflammatory response, Decreased leptin during the dive (P less than 0.05) may also be related to the increased stress. Similar to what is observed during spaceflight, subjects had decreased energy intake and weight loss during the dive. Together, these similarities to spaceflight provide a model to further define the physiological effects of spaceflight and investigate potential countermeasures.

  2. Saturation diving; physiology and pathophysiology.

    PubMed

    Brubakk, Alf O; Ross, John A S; Thom, Stephen R

    2014-07-01

    In saturation diving, divers stay under pressure until most of their tissues are saturated with breathing gas. Divers spend a long time in isolation exposed to increased partial pressure of oxygen, potentially toxic gases, bacteria, and bubble formation during decompression combined with shift work and long periods of relative inactivity. Hyperoxia may lead to the production of reactive oxygen species (ROS) that interact with cell structures, causing damage to proteins, lipids, and nucleic acid. Vascular gas-bubble formation and hyperoxia may lead to dysfunction of the endothelium. The antioxidant status of the diver is an important mechanism in the protection against injury and is influenced both by diet and genetic factors. The factors mentioned above may lead to production of heat shock proteins (HSP) that also may have a negative effect on endothelial function. On the other hand, there is a great deal of evidence that HSPs may also have a "conditioning" effect, thus protecting against injury. As people age, their ability to produce antioxidants decreases. We do not currently know the capacity for antioxidant defense, but it is reasonable to assume that it has a limit. Many studies have linked ROS to disease states such as cancer, insulin resistance, diabetes mellitus, cardiovascular diseases, and atherosclerosis as well as to old age. However, ROS are also involved in a number of protective mechanisms, for instance immune defense, antibacterial action, vascular tone, and signal transduction. Low-grade oxidative stress can increase antioxidant production. While under pressure, divers change depth frequently. After such changes and at the end of the dive, divers must follow procedures to decompress safely. Decompression sickness (DCS) used to be one of the major causes of injury in saturation diving. Improved decompression procedures have significantly reduced the number of reported incidents; however, data indicate considerable underreporting of injuries

  3. Nutritional status changes in humans during a 14-day saturation dive: the NASA Extreme Environment Mission Operations V project

    NASA Technical Reports Server (NTRS)

    Smith, Scott M.; Davis-Street, Janis E.; Fesperman, J. Vernell; Smith, Myra D.; Rice, Barbara L.; Zwart, Sara R.

    2004-01-01

    Ground-based analogs of spaceflight are an important means of studying physiologic and nutritional changes associated with space travel, and the NASA Extreme Environment Mission Operations V (NEEMO) is such an analog. To determine whether saturation diving has nutrition-related effects similar to those of spaceflight, we conducted a clinical nutritional assessment of the NEEMO crew (4 men, 2 women) before, during, and after their 14-d saturation dive. Blood and urine samples were collected before, during, and after the dive. The foods consumed by the crew were typical of the spaceflight food system. A number of physiologic changes were observed, during and after the dive, that are also commonly observed during spaceflight. Hemoglobin and hematocrit were lower (P < 0.05) after the dive. Transferrin receptors were significantly lower immediately after the dive. Serum ferritin increased significantly during the dive. There was also evidence indicating that oxidative damage and stress increased during the dive. Glutathione peroxidase and superoxide dismutase decreased during and after the dive (P < 0.05). Decreased leptin during the dive (P < 0.05) may have been related to the increased stress. Subjects had decreased energy intake and weight loss during the dive, similar to what is observed during spaceflight. Together, these similarities to spaceflight provide a model to use in further defining the physiologic effects of spaceflight and investigating potential countermeasures.

  4. Nutritional status changes in humans during a 14-day saturation dive: the NASA Extreme Environment Mission Operations V project.

    PubMed

    Smith, Scott M; Davis-Street, Janis E; Fesperman, J Vernell; Smith, Myra D; Rice, Barbara L; Zwart, Sara R

    2004-07-01

    Ground-based analogs of spaceflight are an important means of studying physiologic and nutritional changes associated with space travel, and the NASA Extreme Environment Mission Operations V (NEEMO) is such an analog. To determine whether saturation diving has nutrition-related effects similar to those of spaceflight, we conducted a clinical nutritional assessment of the NEEMO crew (4 men, 2 women) before, during, and after their 14-d saturation dive. Blood and urine samples were collected before, during, and after the dive. The foods consumed by the crew were typical of the spaceflight food system. A number of physiologic changes were observed, during and after the dive, that are also commonly observed during spaceflight. Hemoglobin and hematocrit were lower (P < 0.05) after the dive. Transferrin receptors were significantly lower immediately after the dive. Serum ferritin increased significantly during the dive. There was also evidence indicating that oxidative damage and stress increased during the dive. Glutathione peroxidase and superoxide dismutase decreased during and after the dive (P < 0.05). Decreased leptin during the dive (P < 0.05) may have been related to the increased stress. Subjects had decreased energy intake and weight loss during the dive, similar to what is observed during spaceflight. Together, these similarities to spaceflight provide a model to use in further defining the physiologic effects of spaceflight and investigating potential countermeasures. PMID:15226467

  5. Pulmonary mechanical function and diffusion capacity after deep saturation dives.

    PubMed Central

    Thorsen, E; Segadal, K; Myrseth, E; Påsche, A; Gulsvik, A

    1990-01-01

    To assess the effects of deep saturation dives on pulmonary function, static and dynamic lung volumes, transfer factor for carbon monoxide (T1CO), delta-N2, and closing volume (CV) were measured before and after eight saturation dives to pressures of 3.1-4.6 MPa. The atmospheres were helium-oxygen mixtures with partial pressures of oxygen of 40-60 kPa. The durations of the dives were 14-30 days. Mean rate of decompression was 10.5-13.5 kPa/hour. A total of 43 divers were examined, six of whom took part in two dives, the others in one only. Dynamic lung volumes did not change significantly but total lung capacity (TLC) increased significantly by 4.3% and residual volume (RV) by 14.8% (p less than 0.05). CV was increased by 16.7% (p less than 0.01). The T1CO was reduced from 13.0 +/- 1.6 to 11.8 +/- 1.7 mmol/min/kPa (p less than 0.01) when corrected to a haemoglobin concentration of 146 g/l. Effective alveolar volume was unchanged. The increase in TLC and decrease in T1CO were correlated (r = -0.574, p less than 0.02). A control examination of 38 of the divers four to six weeks after the dives showed a partial normalisation of the changes. The increase in TLC, RV, and CV, and the decrease in T1CO, could be explained by a loss of pulmonary elastic tissue caused by inflammatory reactions induced by oxygen toxicity or venous gas emboli. PMID:2337532

  6. Experiment of nitrox saturation diving with trimix excursion.

    PubMed

    Shi, Z Y

    1998-11-01

    Depth limitations to diving operation with air as the breathing gas are well known: air density, oxygen toxicity, nitrogen narcosis and requirement for decompression. The main objectives of our experiment were to assess the decompression, counterdiffusion and performance aspect of helium-nitrogen-oxygen excursions from nitrox saturation. The experiment was carried out in a wet diving stimulator with "igloo" attached to a 2-lock living chamber. Four subjects of two teams of 2 divers were saturated at 25 msw simulated depth in a nitrogen oxygen chamber environment for 8 days, during which period they performed 32 divers-excursions to 60 or 80 msw pressure. Excursion gas mix was trimix of 14.6% oxygen, 50% helium and 35.4% nitrogen, which gave a bottom oxygen partial pressure of 1.0 bars at 60 msw and 1.3 at 80 msw. Excursions were for 70 min at 60 msw with three 10-min work periods and 40 min at 80 msw with two 10-min work periods. Work was on a bicycle ergometer at a moderate level. We calculated the excursion decompression with M-Values based on methods of Hamilton (Hamilton et al., 1990). Staged decompression took 70 min for the 60 msw excursion and 98 min for 80 msw, with stops beginning at 34 or 43 msw respectively. After the second dive day bubbles were heard mainly in one diver but in three divers overall, to Spencer Grade III some times. No symptoms were reported. Saturation decompression using the Repex procedures began at 40 msw and was uneventful: Grade II and sometimes III bubbles persisted in 2 of the four divers until 24 hr after surfacing. We conclude that excursions with mixture rich in helium can be performed effectively to as deep as 80 msw using these procedures. PMID:10052222

  7. High-affinity hemoglobin and blood oxygen saturation in diving emperor penguins.

    PubMed

    Meir, Jessica U; Ponganis, Paul J

    2009-10-01

    The emperor penguin (Aptenodytes forsteri) thrives in the Antarctic underwater environment, diving to depths greater than 500 m and for durations longer than 23 min. To examine mechanisms underlying the exceptional diving ability of this species and further describe blood oxygen (O2) transport and depletion while diving, we characterized the O2-hemoglobin (Hb) dissociation curve of the emperor penguin in whole blood. This allowed us to (1) investigate the biochemical adaptation of Hb in this species, and (2) address blood O2 depletion during diving, by applying the dissociation curve to previously collected partial pressure of O2 (PO2) profiles to estimate in vivo Hb saturation (SO2) changes during dives. This investigation revealed enhanced Hb-O2 affinity (P50=28 mmHg, pH 7.5) in the emperor penguin, similar to high-altitude birds and other penguin species. This allows for increased O2 at low blood PO2 levels during diving and more complete depletion of the respiratory O2 store. SO2 profiles during diving demonstrated that arterial SO2 levels are maintained near 100% throughout much of the dive, not decreasing significantly until the final ascent phase. End-of-dive venous SO2 values were widely distributed and optimization of the venous blood O2 store resulted from arterialization and near complete depletion of venous blood O2 during longer dives. The estimated contribution of the blood O2 store to diving metabolic rate was low and highly variable. This pattern is due, in part, to the influx of O2 from the lungs into the blood during diving, and variable rates of tissue O2 uptake. PMID:19801437

  8. Mental abilities and performance efficacy under a simulated 480-m helium–oxygen saturation diving

    PubMed Central

    Hou, Gonglin; Zhang, Youlan; Zhao, Na; Chen, Ruiyong; Xiao, Weibing; Yu, Hao; Wang, Jiachun; Yuan, Ti-Fei

    2015-01-01

    Stress in extreme environment severely disrupts human physiology and mental abilities. The present study investigated the cognition and performance efficacy of four divers during a simulated 480 meters helium–oxygen saturation diving. We analyzed the spatial memory, 2D/3D mental rotation functioning, grip strength, and hand–eye coordination ability in four divers during the 0–480 m compression and decompression processes of the simulated diving. The results showed that except for its mild decrease on grip strength, the high atmosphere pressure condition significantly impaired the hand–eye coordination (especially above 300 m), the reaction time and correct rate of mental rotation, as well as the spatial memory (especially as 410 m), showing high individual variability. We conclude that the human cognition and performance efficacy are significantly affected during deep water saturation diving. PMID:26217291

  9. Mental abilities and performance efficacy under a simulated 480-m helium-oxygen saturation diving.

    PubMed

    Hou, Gonglin; Zhang, Youlan; Zhao, Na; Chen, Ruiyong; Xiao, Weibing; Yu, Hao; Wang, Jiachun; Yuan, Ti-Fei

    2015-01-01

    Stress in extreme environment severely disrupts human physiology and mental abilities. The present study investigated the cognition and performance efficacy of four divers during a simulated 480 meters helium-oxygen saturation diving. We analyzed the spatial memory, 2D/3D mental rotation functioning, grip strength, and hand-eye coordination ability in four divers during the 0-480 m compression and decompression processes of the simulated diving. The results showed that except for its mild decrease on grip strength, the high atmosphere pressure condition significantly impaired the hand-eye coordination (especially above 300 m), the reaction time and correct rate of mental rotation, as well as the spatial memory (especially as 410 m), showing high individual variability. We conclude that the human cognition and performance efficacy are significantly affected during deep water saturation diving. PMID:26217291

  10. Oxygen saturation in free-diving whales: optical sensor development

    NASA Astrophysics Data System (ADS)

    Gutierrez-Herrera, Enoch; Vacas-Jacques, Paulino; Anderson, Rox; Zapol, Warren; Franco, Walfre

    2013-02-01

    Mass stranding of live whales has been explained by proposing many natural or human-related causes. Recent necropsy reports suggest a link between the mass stranding of beaked whales and the use of naval mid-frequency sonar. Surprisingly, whales have experienced symptoms similar to those caused by inert gas bubbles in human divers. Our goal is to develop a compact optical sensor to monitor the consumption of the oxygen stores in the muscle of freely diving whales. To this end we have proposed the use of a near-infrared phase-modulated frequency-domain spectrophotometer, in reflectance mode, to probe tissue oxygenation. Our probe consists of three main components: radiofrequency (RF) modulated light sources, a high-bandwidth avalanche photodiode with transimpedance amplifier, and a RF gain and phase detector. In this work, we concentrate on the design and performance of the light sensor, and its corresponding amplifier unit. We compare three state-of-the-art avalanche photodiodes: one through-hole device and two surface-mount detectors. We demonstrate that the gain due to the avalanche effect differs between sensors. The avalanche gain near maximum bias of the through-hole device exceeds by a factor of 2.5 and 8.3 that of the surface-mount detectors. We present the behavior of our assembled through-hole detector plus high-bandwidth transimpedance amplifier, and compare its performance to that of a commercially available module. The assembled unit enables variable gain, its phase noise is qualitatively lower, and the form factor is significantly smaller. Having a detecting unit that is compact, flexible, and functional is a milestone in the development of our tissue oxygenation tag.

  11. Acute otitis externa in divers working in the North Sea: a microbiological survey of seven saturation dives.

    PubMed Central

    Alcock, S. R.

    1977-01-01

    Saturation diving is an important and widely used technique in the Offshore Oil Industry. During 1974-5 two saturation dives in the North Sea were terminated because of outbreaks of incapacitating otitis externa, and others were disrupted. Pseudomonas aeruginosa was consistently isolated from the ears of affected divers. Because complex work schedules were threatened seven subsequent dives were subjected to microbiological monitoring and control. Colonization of ear canal with P. aeruginosa or with other gram-negative bacilli occurred in 39 (67%) of the 58 divers studied, usually within 7 days of starting the dive. Data obtained by serotyping this isolations of P. aeruginosa suggested that a single infected diver may be the source of organisms which rapidly spread to his colleagues and throughout the living chambers, that the living chambers may constitute a reservoir of infection during and between dives, and that certain serotypes of P. aeruginosa are more likely than others to colonize the ear canal in the conditions of a saturation dive. The control measures used during the dives were only partially effective, but none of the divers suffered severe pain and all the dives were an operational success. PMID:405421

  12. Hormonal and cardiorespiratory changes following simulated saturation dives to 4 and 11 ATA.

    PubMed

    Mateev, G; Djarova, T; Ilkov, A; Sachanska, T; Klissurov, L

    1990-01-01

    Professional divers were compressed with trimix to 4 ATA (2 persons, aged 35 and 26) and to 11 ATA (3 persons, aged 34, 26, and 23) for saturation dives with durations of 48 and 50 h, followed by 33 and 109 h of decompression, respectively. Pre- and postdive cardiorespiratory reactions to a step test--heart rate (HR) and ventilation (VE)--and concentrations of growth hormone, corticotropin, cortisol, insulin, lutotropin, folitropin, triiodothyronine (T3), thyroxine (T4), thyrotropin, and testosterone in serum were studied. All divers developed postdecompression tachycardia (90-108 beats/min), which persisted 24 h after surfacing. Physical fitness assessed by steady state HR and VE during a step test was lowered 24 h after decompression compared with the predive values in 4 divers and enhanced in 1. These data provide evidence for hindered and delayed readaptation of the cardiorespiratory system to a normobaric environment. T3, T4, and testosterone were significantly decreased postdive. Hormonal responses were found to exhibit a very individual pattern from which it was possible to estimate the adaptive reactions after hyperbaric exposure. Professional divers with a lower level of physical fitness showed more pronounced hormonal responses to hyperbaric environments. PMID:2316058

  13. Potential Fifty Percent Reduction in Saturation Diving Decompression Time Using a Combination of Intermittent Recompression and Exercise

    NASA Technical Reports Server (NTRS)

    Gernhardt, Michael I.; Abercromby, Andrew; Conklin, Johnny

    2007-01-01

    Conventional saturation decompression protocols use linear decompression rates that become progressively slower at shallower depths, consistent with free gas phase control vs. dissolved gas elimination kinetics. If decompression is limited by control of free gas phase, linear decompression is an inefficient strategy. The NASA prebreathe reduction program demonstrated that exercise during O2 prebreathe resulted in a 50% reduction (2 h vs. 4 h) in the saturation decompression time from 14.7 to 4.3 psi and a significant reduction in decompression sickness (DCS: 0 vs. 23.7%). Combining exercise with intermittent recompression, which controls gas phase growth and eliminates supersaturation before exercising, may enable more efficient saturation decompression schedules. A tissue bubble dynamics model (TBDM) was used in conjunction with a NASA exercise prebreathe model (NEPM) that relates tissue inert gas exchange rate constants to exercise (ml O2/kg-min), to develop a schedule for decompression from helium saturation at 400 fsw. The models provide significant prediction (p < 0.001) and goodness of fit with 430 cases of DCS in 6437 laboratory dives for TBDM (p = 0.77) and with 22 cases of DCS in 159 altitude exposures for NEPM (p = 0.70). The models have also been used operationally in over 25,000 dives (TBDM) and 40 spacewalks (NEPM). The standard U.S. Navy (USN) linear saturation decompression schedule from saturation at 400 fsw required 114.5 h with a maximum Bubble Growth Index (BGI(sub max)) of 17.5. Decompression using intermittent recompression combined with two 10 min exercise periods (75% VO2 (sub peak)) per day required 54.25 h (BGI(sub max): 14.7). Combined intermittent recompression and exercise resulted in a theoretical 53% (2.5 day) reduction in decompression time and theoretically lower DCS risk compared to the standard USN decompression schedule. These results warrant future decompression trials to evaluate the efficacy of this approach.

  14. [Fatigue and performance of divers during a simulated, non-saturated oxygen-helium dive to 180 meters].

    PubMed

    Mohri, M

    1990-06-01

    A non-saturated mixed-gas dive to 180 meters depth was carried out at JAMSTEC, using diving simulator (hyperbaric chamber) facilities. Compression started at 10:00 h with helium and oxygen and was carried out at a rate of 12 m/min. Decompression started at 11:15 h using the Comex Helox 180 Diving Manual. Decompression to 1 ATA required 49.2 h. A survey of subjective symptoms, sleep feelings and ball-bearing tests were performed. All night electrophysiological recording of subjects' sleep was performed and polygraphic analysis of nocturnal sleep was done with visual scoring. The results were as follows: Arriving at 180 meters, the complaint rate was 39.2% and fatigue was greater. The type of fatigue that was based on the composition + ratio of symptoms was that of mental fatigue. During the decompression it was recovery. The performance in the ball-bearing test decreased about 20% at a depth of 180 meters because of tremors and disturbance of attention as well as other factors showing symptoms of high-pressure nervous syndrome. The sleep feelings were different in experienced persons and non-experienced persons. The non-experienced persons had markedly decreased REM stages and slept badly all night. Based on these results, fatigue and the performance of divers were discussed. PMID:2214291

  15. Doppler ultrasound surveillance in deep tunneling compressed-air work with Trimix breathing: bounce dive technique compared to saturation-excursion technique.

    PubMed

    Vellinga, T P van Rees; Sterk, W; de Boer, A G E M; van der Beek, A J; Verhoeven, A C; van Dijk, F J H

    2008-01-01

    The Western Scheldt Tunneling Project in The Netherlands provided a unique opportunity to evaluate two deep-diving techniques with Doppler ultrasound surveillance. Divers used the bounce diving techniques for repair and maintenance of the TBM. The tunnel boring machine jammed at its deepest depth. As a result the work time was not sufficient. The saturation diving technique was developed and permitted longer work time at great depth. Thirty-one divers were involved in this project. Twenty-three divers were examined using Doppler ultrasound. Data analysis addressed 52 exposures to Trimix at 4.6-4.8 bar gauge using the bounce technique and 354 exposures to Trimix at 4.0-6.9 bar gauge on saturation excursions. No decompression incidents occurred with either technique during the described phase of the project. Doppler ultrasound revealed that the bubble loads assessed in both techniques were generally low. We find out, that despite longer working hours, shorter decompression times and larger physical workloads, the saturation-excursion technique was associated with significant lower bubble grades than in the bounce technique using Doppler Ultrasound. We conclude that the saturation-excursion technique with Trimix is a good option for deep and long exposures in caisson work. The Doppler technique proved valuable, and it should be incorporated in future compressed-air work. PMID:19175196

  16. Saturation diving with heliox to 350 meters. Observation on hearing threshold, brainstem evoked response and acoustic impedance.

    PubMed

    Wang, L; Jiang, W; Gong, J H; Zheng, X Y

    1994-12-01

    Four divers were compressed to 350 m to observe changes in hearing threshold, brainstem evoked response and acoustic impedance. The divers experienced no tinnitus, impairment of hearing, earache during compression. Examination showed that the threshold of lower frequency range of hearing was elevated because of the masking effect of the noise in the hyperbaric chamber. Changes in waveform and latency of brainstem evoked response were due to changes in sound wave transmission affected by the chamber pressure and a poor ratio of signal to noise in the hyperbaric environment with heliox. All these changes were transient. After leaving the chamber, the hearing threshold and brainstem evoked response returned to normal. Besides, there were no changes in tympanogram, acoustic compliance and stapedius reflex before and after diving. This indicated the designed speed of compression and decompression in the experiment caused no damage to the divers' acoustic system, and the functions of their Eustachain tubes, middle and inner ears were normal during the diving test. PMID:7882734

  17. Diving emergencies.

    PubMed

    DeGorordo, Antonio; Vallejo-Manzur, Federico; Chanin, Katia; Varon, Joseph

    2003-11-01

    Self-Contained Underwater Breathing Apparatus (SCUBA) diving popularity is increasing tremendously, reaching a total of 9 million people in the US during 2001, and 50,000 in the UK in 1985. Over the past 10 years, new advances, equipment improvements, and improved diver education have made SCUBA diving safer and more enjoyable. Most diving injuries are related to the behaviour of the gases and pressure changes during descent and ascent. The four main pathologies in diving medicine include: barotrauma (sinus, otic, and pulmonary); decompression illness (DCI); pulmonary edema and pharmacological; and toxic effects of increased partial pressures of gases. The clinical manifestations of a diving injury may be seen during a dive or up to 24 h after it. Physicians living far away from diving places are not excluded from the possibility of encountering diver-injured patients and therefore need to be aware of these injuries. This article reviews some of the principles of diving and pathophysiology of diving injuries as well as the acute treatment, and further management of these patients. PMID:14625107

  18. Diving medicine.

    PubMed

    Bove, Alfred A

    2014-06-15

    Exposure to the undersea environment has unique effects on normal physiology and can result in unique disorders that require an understanding of the effects of pressure and inert gas supersaturation on organ function and knowledge of the appropriate therapies, which can include recompression in a hyperbaric chamber. The effects of Boyle's law result in changes in volume of gas-containing spaces when exposed to the increased pressure underwater. These effects can cause middle ear and sinus injury and lung barotrauma due to lung overexpansion during ascent from depth. Disorders related to diving have unique presentations, and an understanding of the high-pressure environment is needed to properly diagnose and manage these disorders. Breathing compressed air underwater results in increased dissolved inert gas in tissues and organs. On ascent after a diving exposure, the dissolved gas can achieve a supersaturated state and can form gas bubbles in blood and tissues, with resulting tissue and organ damage. Decompression sickness can involve the musculoskeletal system, skin, inner ear, brain, and spinal cord, with characteristic signs and symptoms. Usual therapy is recompression in a hyperbaric chamber following well-established protocols. Many recreational diving candidates seek medical clearance for diving, and healthcare providers must be knowledgeable of the environmental exposure and its effects on physiologic function to properly assess individuals for fitness to dive. This review provides a basis for understanding the diving environment and its accompanying disorders and provides a basis for assessment of fitness for diving. PMID:24869752

  19. Diving birds

    NASA Astrophysics Data System (ADS)

    Clanet, Christophe; Masson, Lucien; McKinley, Gareth; Cohen, Robert; Ecole polytechnique Collaboration; MIT Collaboration

    2015-11-01

    Many seabirds (gannets, pelicans, gulls, albatrosses) dive into water at high speeds (25 m/s) in order to capture underwater preys. Diving depths of 20 body lengths are reported in the literature. This value is much larger than the one achieved by men, which is of the order of 5. We study this difference by comparing the impact of slender vs bluff bodies. We show that, contrary to bluff bodies, the penetration depth of slender bodies presents a maximum value for a specific impact velocity that we connect to the velocity of diving birds.

  20. Diving Medicine: Frequently Asked Questions

    MedlinePlus

    ... re-evaluating your fitness to dive. Thyroid Conditions Fitness to Dive Asthma and Scuba Diving Bone Considerations ... Healthy, But Overweight DAN Discusses the Issue of Fitness and Diving By Joel Dovenbarger, Vice President, DAN ...

  1. Neurological long term consequences of deep diving.

    PubMed Central

    Todnem, K; Nyland, H; Skeidsvoll, H; Svihus, R; Rinck, P; Kambestad, B K; Riise, T; Aarli, J A

    1991-01-01

    Forty commercial saturation divers, mean age 34.9 (range 24-49) years, were examined one to seven years after their last deep dive (190-500 metres of seawater). Four had by then lost their divers' licence because of neurological problems. Twenty seven (68%) had been selected by neurological examination and electroencephalography before the deep dives. The control group consisted of 100 men, mean age 34.0 (range 22-48) years. The divers reported significantly more symptoms from the nervous system. Concentration difficulties and paraesthesia in feet and hands were common. They had more abnormal neurological findings by neurological examination compatible with dysfunction in the lumbar spinal cord or roots. They also had a larger proportion of abnormal electroencephalograms than the controls. The neurological symptoms and findings were highly significantly correlated with exposure to deep diving (depth included), but even more significantly correlated to air and saturation diving and prevalence of decompression sickness. Visual evoked potentials, brainstem auditory evoked potentials, and magnetic resonance imaging of the brain did not show more abnormal findings in the divers. Four (10%) divers had had episodes of cerebral dysfunction during or after the dives; two had had seizures, one had had transitory cerebral ischaemia and one had had transitory global amnesia. It is concluded that deep diving may have a long term effect on the nervous system of the divers. PMID:2025592

  2. Travelers' Health: Scuba Diving

    MedlinePlus

    ... no-decompression limits of their dive tables or computers. Risk factors for DCI are primarily dive depth, ... 12]. Available from: http://www.diversalertnetwork.org/research/projects/fad/workshop/FADWorkshopProceedings.pdf . Chapter 2 - Environmental Hazards ...

  3. 17 CFR 240.14d-101 - Schedule 14D-9.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Schedule 14D-9. 240.14d-101 Section 240.14d-101 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) GENERAL RULES AND REGULATIONS, SECURITIES EXCHANGE ACT OF 1934 Rules and Regulations Under the Securities Exchange Act of 1934 Regulation 14d...

  4. Fatal diving accidents in western Norway 1983-2007.

    PubMed

    Ramnefjell, M P; Morild, I; Mørk, S J; Lilleng, P K

    2012-11-30

    Despite efforts to reduce their number, fatal diving accidents still occur. The circumstances and post-mortem findings in 40 fatal diving accidents in western Norway from 1983 through 2007 were investigated. Diving experience, medical history and toxicology reports were retrieved. The material consisted of recreational divers, professional saturation divers and professional divers without experience with saturation. In 33 cases the diving equipment was examined as part of the forensic investigation. In 27 cases defects in the diving equipment were found. For six divers such defects were responsible for the fatal accidents. Eighteen divers died on the surface or less than 10 m below surface. Five divers reached below 100 msw, and two of them died at this depth. The fatalities were not season-dependent. However, wave-height and strength of currents were influential factors in some cases. Twelve divers were diving alone. Twenty divers had one buddy, 9 of these divers were alone at the time of death. The cause of death was drowning in 31 out of 40 divers; one of them had a high blood-ethanol concentration, in two other divers ethanol was found in the urine, indicating previous ethanol consumption. Nine divers died from sudden decompression, pulmonary barotraumas, underwater trauma and natural causes. The study shows that most of the fatal diving accidents could be avoided if adequate diving safety procedures had been followed. PMID:22981212

  5. [Lungs et diving].

    PubMed

    Héritier, F; Avanzi, P; Nicod, L

    2014-11-19

    Whilst underwater, the body is submitted to significant variations of the surrounding pressure according to the depth. These conditions modify the hemodynamic and the ventilatory mechanics considerably. Some repercussions, like pulmonary barotrauma, are related to simple physical phenomena. Others, like decompression sickness, are due to more com- plex processes. Breath-hold diving disrupts haematosis and can be complicated by alveolar haemorrhage and loss of consciousness. Acute pulmonary oedema during scuba-diving, breath-hold diving and swimming has been reported more recently. In case of pulmonary disorders scuba-diving is contraindicated most of the time. It is therefore highly recommended to seek medical advice to prevent problems. PMID:25603564

  6. Deep-diving dinosaurs

    NASA Astrophysics Data System (ADS)

    Hayman, John

    2012-08-01

    Dysbaric bone necrosis demonstrated in ichthyosaurs may be the result of prolonged deep diving rather than rapid ascent to escape predators. The bone lesions show structural and anatomical similarity to those that may occur in human divers and in the deep diving sperm whale, Physeter macrocephalus.

  7. Deep-diving dinosaurs.

    PubMed

    Hayman, John

    2012-08-01

    Dysbaric bone necrosis demonstrated in ichthyosaurs may be the result of prolonged deep diving rather than rapid ascent to escape predators. The bone lesions show structural and anatomical similarity to those that may occur in human divers and in the deep diving sperm whale, Physeter macrocephalus. PMID:22824942

  8. Diving and hyperbaric ophthalmology.

    PubMed

    Butler, F K

    1995-01-01

    Exposure of the human body to ambient pressures greater than that at sea level may result in various disorders, some of which have ocular manifestations. Additionally, some eye disorders and postoperative states may be adversely affected by the underwater environment or other hyperbaric exposures. The prevalence of recreational, military, and commercial diving, as well as the medical use of hyperbaric oxygen therapy, requires that ophthalmologists be familiar with the effects of the hyperbaric environment on the normal and diseased eye. The ophthalmology and diving medical literatures were surveyed for publications relating to the ophthalmic aspects of diving and hyperbaric exposures. Underwater optics, underwater refractive correction, and ophthalmic aspects of a fitness-to-dive evaluation are summarized. The evaluation and management of ocular manifestations of decompression sickness and arterial gas embolism are reviewed and guidelines for diving after ocular surgery are proposed. PMID:7604359

  9. 17 CFR 240.14d-102 - Schedule 14D-1F. Tender offer statement pursuant to rule 14d-1(b) under the Securities Exchange...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Schedule 14D-1F. Tender offer statement pursuant to rule 14d-1(b) under the Securities Exchange Act of 1934. 240.14d-102 Section 240.14d-102 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) GENERAL...

  10. 17 CFR 240.14d-102 - Schedule 14D-1F. Tender offer statement pursuant to rule 14d-1(b) under the Securities Exchange...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Schedule 14D-1F. Tender offer statement pursuant to rule 14d-1(b) under the Securities Exchange Act of 1934. 240.14d-102 Section 240.14d-102 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) GENERAL...

  11. 17 CFR 240.14d-103 - Schedule 14D-9F. Solicitation/recommendation statement pursuant to section 14(d)(4) of the...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Schedule 14D-9F. Solicitation/recommendation statement pursuant to section 14(d)(4) of the Securities Exchange Act of 1934 and rules 14d-1(b) and 14e-2(c) thereunder. 240.14d-103 Section 240.14d-103 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION...

  12. Diving dynamics of seabirds

    NASA Astrophysics Data System (ADS)

    Jung, Sunghwan; Chang, Brian; Croson, Matt; Straker, Lorian; Dove, Carla

    2015-03-01

    Diving is the activity of falling from air into water, which is somewhat dangerous due to the impact. Humans dive for entertainments less than 20 meters high, however seabirds dive as a hunting mechanism from more than 20 meters high. Moreover, most birds including seabirds have a slender and long neck compared to many other animals, which can potentially be the weakest part of the body upon axial impact compression. Motivated by the diving dynamics, we investigate the effect of surface and geometric configurations on structures consisting of a beak-like cone and a neck-like elastic beam. A transition from non-buckling to buckling is characterized and understood through physical experiments and an analytical model.

  13. Diving fatality investigations: recent changes.

    PubMed

    Edmonds, Carl; Caruso, James

    2014-06-01

    Modifications to the investigation procedures in diving fatalities have been incorporated into the data acquisition by diving accident investigators. The most germane proposal for investigators assessing diving fatalities is to delay the drawing of conclusions until all relevant diving information is known. This includes: the accumulation and integration of the pathological data; the access to dive computer information; re-enactments of diving incidents; post-mortem CT scans and the interpretation of intravascular and tissue gas detected. These are all discussed, with reference to the established literature and recent publications. PMID:24986727

  14. [Case report: fatal diving-accident. Or: accident while diving?].

    PubMed

    Böttcher, F; Jüttner, B; Krause, A; Rocha, M; Koppert, W

    2012-02-01

    This example of a fatal diving accident shows how challenging such cases can be in pre-hospital and clinical care. There is no common mechanism in diving fatalities and more than one group of disorders coming along with decompression sickness. Diving medicine is not an element of medical education, which results in insecurity and hampers adequate therapy of diving incidents. This is aggravated by an insufficient availability of hyperbaric chambers in Germany. PMID:22354401

  15. 46 CFR 197.460 - Diving equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Diving equipment. 197.460 Section 197.460 Shipping COAST... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.460 Diving equipment. The diving supervisor shall insure that the diving equipment designated for...

  16. 46 CFR 197.460 - Diving equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Diving equipment. 197.460 Section 197.460 Shipping COAST... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.460 Diving equipment. The diving supervisor shall insure that the diving equipment designated for...

  17. 46 CFR 197.460 - Diving equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Diving equipment. 197.460 Section 197.460 Shipping COAST... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.460 Diving equipment. The diving supervisor shall insure that the diving equipment designated for...

  18. 46 CFR 197.410 - Dive procedures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Operations § 197.410 Dive procedures. (a) The diving supervisor shall insure that— (1) Before commencing diving operations, dive team members are briefed on— (i... safety of the diving operation; and (iii) Any modifications to the operations manual or...

  19. 46 CFR 197.460 - Diving equipment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Diving equipment. 197.460 Section 197.460 Shipping COAST... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.460 Diving equipment. The diving supervisor shall insure that the diving equipment designated for...

  20. 46 CFR 197.430 - SCUBA diving.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false SCUBA diving. 197.430 Section 197.430 Shipping COAST... GENERAL PROVISIONS Commercial Diving Operations Specific Diving Mode Procedures § 197.430 SCUBA diving. The diving supervisor shall insure that— (a) SCUBA diving is not conducted— (1) Outside the...

  1. 46 CFR 197.460 - Diving equipment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Diving equipment. 197.460 Section 197.460 Shipping COAST... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.460 Diving equipment. The diving supervisor shall insure that the diving equipment designated for...

  2. 46 CFR 197.430 - SCUBA diving.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false SCUBA diving. 197.430 Section 197.430 Shipping COAST... GENERAL PROVISIONS Commercial Diving Operations Specific Diving Mode Procedures § 197.430 SCUBA diving. The diving supervisor shall insure that— (a) SCUBA diving is not conducted— (1) Outside the...

  3. 46 CFR 197.430 - SCUBA diving.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false SCUBA diving. 197.430 Section 197.430 Shipping COAST... GENERAL PROVISIONS Commercial Diving Operations Specific Diving Mode Procedures § 197.430 SCUBA diving. The diving supervisor shall insure that— (a) SCUBA diving is not conducted— (1) Outside the...

  4. 46 CFR 197.430 - SCUBA diving.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false SCUBA diving. 197.430 Section 197.430 Shipping COAST... GENERAL PROVISIONS Commercial Diving Operations Specific Diving Mode Procedures § 197.430 SCUBA diving. The diving supervisor shall insure that— (a) SCUBA diving is not conducted— (1) Outside the...

  5. 46 CFR 197.430 - SCUBA diving.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false SCUBA diving. 197.430 Section 197.430 Shipping COAST... GENERAL PROVISIONS Commercial Diving Operations Specific Diving Mode Procedures § 197.430 SCUBA diving. The diving supervisor shall insure that— (a) SCUBA diving is not conducted— (1) Outside the...

  6. Diving behaviour, dive cycles and aerobic dive limit in the platypus Ornithorhynchus anatinus.

    PubMed

    Bethge, Philip; Munks, Sarah; Otley, Helen; Nicol, Stewart

    2003-12-01

    We investigated the diving behaviour, the time allocation of the dive cycle and the behavioural aerobic dive limit (ADL) of platypuses (Ornithorhynchus anatinus) living at a sub-alpine Tasmanian lake. Individual platypuses were equipped with combined data logger-transmitter packages measuring dive depth. Mean dive duration was 31.3 s with 72% of all dives lasting between 18 and 40 s. Mean surface duration was 10.1 s. Mean dive depth was 1.28 m with a maximum of 8.77 m. Platypuses performed up to 1600 dives per foraging trip with a mean of 75 dives per hour. ADL was estimated by consideration of post-dive surface intervals vs. dive durations. Only 15% of all dives were found to exceed the estimated ADL of 40 s, indicating mainly aerobic diving in the species. Foraging platypuses followed a model of optimised recovery time, the optimal breathing theory. Total bottom duration or total foraging duration per day is proposed as a useful indicator of foraging efficiency and hence habitat quality in the species. PMID:14667845

  7. The Physics of Diving

    NASA Astrophysics Data System (ADS)

    Katzgraber, Helmut

    2007-10-01

    The underwater world, and in particular our oceans, represent a final frontier of exploration. In the past, studying the underwater fauna and flora used to be a dangerous undertaking reserved to professional divers. Technological advances over the last 50 years have given sports divers the opportunity to explore this fascinating world using self-contained underwater breathing apparatuses (SCUBA). Despite these technological advances humans have to cope with an unusual environment: perception is different underwater and there is always a risk of decompression illness due to the ambient pressure. After a brief overview of SCUBA diving, some physical phenomena particular to diving will be presented.

  8. Can asthmatic subjects dive?

    PubMed

    Adir, Yochai; Bove, Alfred A

    2016-06-01

    Recreational diving with self-contained underwater breathing apparatus (scuba) has grown in popularity. Asthma is a common disease with a similar prevalence in divers as in the general population. Due to theoretical concern about an increased risk for pulmonary barotrauma and decompression sickness in asthmatic divers, in the past the approach to asthmatic diver candidates was very conservative, with scuba disallowed. However, experience in the field and data in the current literature do not support this dogmatic approach. In this review the theoretical risk factors of diving with asthma, the epidemiological data and the recommended approach to the asthmatic diver candidate will be described. PMID:27246598

  9. Neurological effects of deep diving.

    PubMed

    Grønning, Marit; Aarli, Johan A

    2011-05-15

    Deep diving is defined as diving to depths more than 50 m of seawater (msw), and is mainly used for occupational and military purposes. A deep dive is characterized by the compression phase, the bottom time and the decompression phase. Neurological and neurophysiologic effects are demonstrated in divers during the compression phase and the bottom time. Immediate and transient neurological effects after deep dives have been shown in some divers. However, the results from the epidemiological studies regarding long term neurological effects from deep diving are conflicting and still not conclusive. Prospective clinical studies with sufficient power and sensitivity are needed to solve this very important issue. PMID:21377169

  10. Lung collapse in the diving sea lion: hold the nitrogen and save the oxygen

    PubMed Central

    McDonald, Birgitte I.; Ponganis, Paul J.

    2012-01-01

    Lung collapse is considered the primary mechanism that limits nitrogen absorption and decreases the risk of decompression sickness in deep-diving marine mammals. Continuous arterial partial pressure of oxygen profiles in a free-diving female California sea lion (Zalophus californianus) revealed that (i) depth of lung collapse was near 225 m as evidenced by abrupt changes in during descent and ascent, (ii) depth of lung collapse was positively related to maximum dive depth, suggesting that the sea lion increased inhaled air volume in deeper dives and (iii) lung collapse at depth preserved a pulmonary oxygen reservoir that supplemented blood oxygen during ascent so that mean end-of-dive arterial was 74 ± 17 mmHg (greater than 85% haemoglobin saturation). Such information is critical to the understanding and the modelling of both nitrogen and oxygen transport in diving marine mammals. PMID:22993241

  11. Diving into Oceans.

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1992-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Diving Into Oceans." Contents are organized into the following sections: (1)…

  12. Dive into Scuba

    ERIC Educational Resources Information Center

    Coelho, Jeffrey; Fielitz, Lynn R.

    2006-01-01

    Scuba is a unique physical education activity that middle school and high school students can experience in physical education to provide them with the basic skills needed to enjoy the sport for many years to come. This article describes the basic scuba diving equipment, proper training and certification for instructors and students, facilities,…

  13. Human Simulated Diving Experiments.

    ERIC Educational Resources Information Center

    Bruce, David S.; Speck, Dexter F.

    1979-01-01

    This report details several simulated divinq experiments on the human. These are suitable for undergraduate or graduate laboratories in human or environmental physiology. The experiment demonstrates that a diving reflex is precipitated by both facial cooling and apnea. (Author/RE)

  14. Toppling Techniques in Diving

    ERIC Educational Resources Information Center

    Wilson, Barry D.

    1977-01-01

    This paper demonstrates that in a toppling dive (1) a 1:1 ratio exists between the rotational speed of the diver immediately before and after the take-off and (2) the take-off angle as defined by Page is approximately 50 percent. (Author)

  15. Treatment of diving emergencies.

    PubMed

    Moon, R E

    1999-04-01

    Recognition of condition attributable to the environmental changes experienced by divers will facilitate appropriate treatment. The diagnosis of these conditions rarely requires sophisticated imaging or electrophysiologic testing. Divers who have suspected DCI, in addition to general supportive measures, should be administered fluids and oxygen and transported to a recompression chamber. For diving-related conditions, on-line consultation is available from the Divers Alert Network, Durham, NC (919-684-8111). PMID:10331136

  16. Neurology and diving.

    PubMed

    Massey, E Wayne; Moon, Richard E

    2014-01-01

    Diving exposes a person to the combined effects of increased ambient pressure and immersion. The reduction in pressure when surfacing can precipitate decompression sickness (DCS), caused by bubble formation within tissues due to inert gas supersaturation. Arterial gas embolism (AGE) can also occur due to pulmonary barotrauma as a result of breath holding during ascent or gas trapping due to disease, causing lung hyperexpansion, rupture and direct entry of alveolar gas into the blood. Bubble disease due to either DCS or AGE is collectively known as decompression illness. Tissue and intravascular bubbles can induce a cascade of events resulting in CNS injury. Manifestations of decompression illness can vary in severity, from mild (paresthesias, joint pains, fatigue) to severe (vertigo, hearing loss, paraplegia, quadriplegia). Particularly as these conditions are uncommon, early recognition is essential to provide appropriate management, consisting of first aid oxygen, targeted fluid resuscitation and hyperbaric oxygen, which is the definitive treatment. Less common neurologic conditions that do not require hyperbaric oxygen include rupture of a labyrinthine window due to inadequate equalization of middle ear pressure during descent, which can precipitate vertigo and hearing loss. Sinus and middle ear overpressurization during ascent can compress the trigeminal and facial nerves respectively, causing temporary facial hypesthesia and lower motor neuron facial weakness. Some conditions preclude safe diving, such as seizure disorders, since a convulsion underwater is likely to be fatal. Preventive measures to reduce neurologic complications of diving include exclusion of individuals with specific medical conditions and safe diving procedures, particularly related to descent and ascent. PMID:24365363

  17. Medical aspects of sport diving.

    PubMed

    Bove, A A

    1996-05-01

    Medical issues in sport diving include illnesses that are caused by diving, and medical disorders that compromise safety. Cerebral air embolism and decompression sickness of the brain and spinal cord can result from diving. Sport divers may manifest a spectrum of symptoms from air embolism, which can range from unconsciousness to minimal symptoms, which include fatigue, personality change, poor concentration, irritability, and changes in vision. The physician must search for these minor symptoms in divers who are suspected of pulmonary barotrauma. Medical disorders of concern in diving include diseases of the lungs, the heart, the brain, and the endocrine system, particularly diabetes. Other factors involved in diving safety are exercise capacity and training. Clinical practice standards usually prohibit diving by individuals who have a seizure disorder that requires continuous medication. In the United States, we will not approve diving for individuals who have insulin-dependent diabetes or severe asthma. Some divers can return to diving after myocardial infarction or bypass surgery if they demonstrate good exercise tolerance and no ischemia on a graded exercise test, which simulates the physical activity needed for safe diving. PMID:9148089

  18. Electrocardiographic aspects of deep dives in elite breath-hold divers.

    PubMed

    Lemaître, F; Lafay, V; Taylor, M; Costalat, G; Gardette, B

    2013-01-01

    The cardiac diving response, 12-lead electrocardiogram (ECG) and the prevalence, time of onset, and possible associations of cardiac arrhythmias were examined during deep breath-hold (BH) dives. Nine elite BH divers (33.2 +/- 3.6 years; mean +/- SD) performed one constant-weight dive of at least 75% of their best personal performance (70 +/- 7 meters for 141 +/- 22 seconds) wearing a 12-lead ECG Holter monitor. Diving parameters (depth and time), oxygen saturation (SaO2), blood lactate concentration and ventilatory parameters were also recorded. Bradycardia during these dives was pronounced (52.2 +/- 12.2%), with heart rates dropping to 46 +/- 10 beats/minute. The diving reflex was strong, overriding the stimulus of muscular exercise during the ascent phase of the dive for all divers. Classical arrhythmias occurred, mainly after surfacing, and some conduction alterations were detected at the bottom of the dives. The BH divers did not show any right shift of the QRS electrical axis during their dives. PMID:23682546

  19. Surface pauses in relation to dive duration in imperial cormorants; how much time for a breather?

    PubMed

    Wilson, Rory P; Quintana, Flavio

    2004-05-01

    Air-breathing animals diving to forage can optimize time underwater by diving with just enough oxygen for the projected performance underwater. By so doing they surface with minimal body oxygen levels, which leads to maximal rates of oxygen uptake. We examined whether imperial cormorants Phalacrocorax atriceps adhere to this by examining dive:pause ratios in birds diving for extended, continuous periods to constant depths, assuming that the oxygen used underwater was exactly replenished by the periods at the surface. Examination of the cumulative time spent in surface pauses relative to the cumulative time spent in diving showed that surface pauses increase according to a power curve function of time spent in the dive or water depth. In a simplistic model we considered the rate at which birds expended energy underwater to be constant and that the rate of oxygen replenishment during the surface pause was directly proportional to the oxygen deficit. We then worked out values for the rate constant for the surface pause before using this constant to examine bird body oxygen levels immediately pre- and post dive. The model predicted that imperial cormorants do not submerge with just enough oxygen to cover their projected dive performance but rather dive with substantial reserves, although these reserves decrease with increasing dive depth/duration. We speculate that these oxygen reserves may be used to enhance bird survival when rare events, such as the appearance of predators or discovery of large prey requiring extended handling time, occur. The form of the oxygen saturation curve over time at the surface means that the time costs for maintaining constant oxygen reserves become particularly onerous for long, deep dives, so the observed decrease in reserves with increasing dive duration is expected in animals benefiting by optimizing for time. PMID:15107434

  20. Fatty Acid use in Diving Mammals: More than Merely Fuel

    PubMed Central

    Trumble, Stephen J.; Kanatous, Shane B.

    2012-01-01

    Diving mammals, are under extreme pressure to conserve oxygen as well as produce adequate energy through aerobic pathways during breath-hold diving. Typically a major source of energy, lipids participate in structural and regulatory roles and have an important influence on the physiological functions of an organism. At the stoichiometric level, the metabolism of polyunsaturated fatty acids (PUFAs) utilizes less oxygen than metabolizing either monounsaturated fatty acids or saturated fatty acids (SFAs) and yields fewer ATP per same length fatty acid. However, there is evidence that indicates the cellular metabolic rate is directly correlated to the lipid composition of the membranes such that the greater the PUFA concentration in the membranes the greater the metabolic rate. These findings appear to be incompatible with diving mammals that ingest and metabolize high levels of unsaturated fatty acids while relying on stored oxygen. Growing evidence from birds to mammals including recent evidence in Weddell seals also indicates that at the whole animal level the utilization of PUFAs to fuel their metabolism actually conserves oxygen. In this paper, we make an initial attempt to ascertain the beneficial adaptations or limitations of lipids constituents and potential trade-offs in diving mammals. We discuss how changes in Antarctic climate are predicted to have numerous different environmental effects; such potential shifts in the availability of certain prey species or even changes in the lipid composition (increased SFA) of numerous fish species with increasing water temperatures and how this may impact the diving ability of Weddell seals. PMID:22707938

  1. 43 CFR 15.8 - Skin diving.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Skin diving. 15.8 Section 15.8 Public Lands: Interior Office of the Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.8 Skin diving. Diving with camera, or diving for observation and pleasure is permitted and encouraged within...

  2. 43 CFR 15.8 - Skin diving.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Skin diving. 15.8 Section 15.8 Public Lands: Interior Office of the Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.8 Skin diving. Diving with camera, or diving for observation and pleasure is permitted and encouraged within...

  3. 43 CFR 15.8 - Skin diving.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Skin diving. 15.8 Section 15.8 Public Lands: Interior Office of the Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.8 Skin diving. Diving with camera, or diving for observation and pleasure is permitted and encouraged within...

  4. 43 CFR 15.8 - Skin diving.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Skin diving. 15.8 Section 15.8 Public Lands: Interior Office of the Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.8 Skin diving. Diving with camera, or diving for observation and pleasure is permitted and encouraged within the Preserve....

  5. 43 CFR 15.8 - Skin diving.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Skin diving. 15.8 Section 15.8 Public Lands: Interior Office of the Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.8 Skin diving. Diving with camera, or diving for observation and pleasure is permitted and encouraged within...

  6. 29 CFR 1910.424 - SCUBA diving.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false SCUBA diving. 1910.424 Section 1910.424 Labor Regulations... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations Specific Operations Procedures § 1910.424 SCUBA diving. (a) General. Employers engaged in SCUBA diving shall comply with the...

  7. 29 CFR 1910.424 - SCUBA diving.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false SCUBA diving. 1910.424 Section 1910.424 Labor Regulations... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations Specific Operations Procedures § 1910.424 SCUBA diving. (a) General. Employers engaged in SCUBA diving shall comply with the...

  8. 29 CFR 1910.424 - SCUBA diving.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false SCUBA diving. 1910.424 Section 1910.424 Labor Regulations... SCUBA diving. (a) General. Employers engaged in SCUBA diving shall comply with the following requirements, unless otherwise specified. (b) Limits. SCUBA diving shall not be conducted: (1) At depths...

  9. 29 CFR 1910.424 - SCUBA diving.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 5 2014-07-01 2014-07-01 false SCUBA diving. 1910.424 Section 1910.424 Labor Regulations... SCUBA diving. (a) General. Employers engaged in SCUBA diving shall comply with the following requirements, unless otherwise specified. (b) Limits. SCUBA diving shall not be conducted: (1) At depths...

  10. 29 CFR 1910.424 - SCUBA diving.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false SCUBA diving. 1910.424 Section 1910.424 Labor Regulations... SCUBA diving. (a) General. Employers engaged in SCUBA diving shall comply with the following requirements, unless otherwise specified. (b) Limits. SCUBA diving shall not be conducted: (1) At depths...

  11. [The heart and underwater diving].

    PubMed

    Lafay, V

    2006-11-01

    Cardiovascular examination of a certain number of candidates for underwater diving raises justifiable questions of aptitude. An indicative list of contraindications has been proposed by the French Federation of Underwater Studies and Sports but a physiopathological basis gives a better understanding of what is involved. During diving, the haemodynamic changes due not only to the exercise but also to cold immersion, hyperoxaemia and decompression impose the absence of any symptomatic cardiac disease. Moreover, the vasoconstriction caused by the cold and hyperoxaemia should incite great caution in both coronary and hypertensive patients. The contraindication related to betablocker therapy is controversial and the debate has not been settled in France. The danger of drowning makes underwater diving hazardous in all pathologies carrying a risk of syncope. Pacemaker patients should be carefully assessed and the depth of diving limited. Finally, the presence of right-to-left intracardiac shunts increases the risk of complications during decompressionand contraindicates underwater diving. Patent foramen ovale is a special case but no special investigation is required for its detection. The cardiologist examining candidates for underwater diving should take all these factors into consideration because, although underwater diving is a sport associated with an increased risk, each year there are more and more people, with differing degrees of aptitude, who wish to practice it. PMID:17181043

  12. Medical Aspects of Scuba Diving

    PubMed Central

    Suke, Ralph

    1985-01-01

    Scuba divers may encounter dangerous levels of stress, due to increased ambient pressures and hostile environments. Divers therefore require a high level of mental and cardiorespiratory fitness. They must be informed of specific contraindications to diving. Family physicians with a basic knowledge of the medical aspects of scuba diving are in a very good position to examine and advise sports divers. Screening mainly involves an assessment of emotional stability and cardiorespiratory fitness, and an ear, nose and throat examination. Common problems suffered by scuba divers are discussed, as are temporary and permanent contraindications to diving. PMID:21274131

  13. 17 CFR 240.14d-11 - Subsequent offering period.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Subsequent offering period... Securities Exchange Act of 1934 Regulation 14d § 240.14d-11 Subsequent offering period. A bidder may elect to provide a subsequent offering period of at least three business days during which tenders will be...

  14. [Asthma and scuba diving: can asthmatic patients dive?].

    PubMed

    Sade, Kobi; Wiesel, Ory; Kivity, Shmuel; Levo, Yoram

    2007-04-01

    Self-contained underwater breathing apparatus (scuba) diving has grown in popularity, with millions of divers enjoying the sport worldwide. This activity presents unique physical and physiological challenges to the respiratory system, raising numerous concerns about individuals with asthma who choose to dive. Asthma had traditionally been a contraindication to recreational diving, although this caveat has been ignored by large numbers of such patients. Herein we review the currently available literature to provide evidence-based evaluation of the risks associated with diving that are posed to asthmatics. Although there is some indication that asthmatics may be at an increased risk of pulmonary barotrauma, the risk seems to be small. Thus, under the right circumstances, patients with asthma can safely participate in recreational diving without any apparent increased risk of an asthma-related event. Decisions on whether or not diving is hazardous must be made on an individual basis and be founded upon an informed decision shared by both patient and physician. PMID:17476937

  15. Neurologic complications of scuba diving.

    PubMed

    Newton, H B

    2001-06-01

    Recreational scuba diving has become a popular sport in the United States, with almost 9 million certified divers. When severe diving injury occurs, the nervous system is frequently involved. In dive-related barotrauma, compressed or expanding gas within the ears, sinuses and lungs causes various forms of neurologic injury. Otic barotrauma often induces pain, vertigo and hearing loss. In pulmonary barotrauma of ascent, lung damage can precipitate arterial gas embolism, causing blockage of cerebral blood vessels and alterations of consciousness, seizures and focal neurologic deficits. In patients with decompression sickness, the vestibular system, spinal cord and brain are affected by the formation of nitrogen bubbles. Common signs and symptoms include vertigo, thoracic myelopathy with leg weakness, confusion, headache and hemiparesis. Other diving-related neurologic complications include headache and oxygen toxicity. PMID:11417773

  16. Neurological complications of underwater diving.

    PubMed

    Rosińska, Justyna; Łukasik, Maria; Kozubski, Wojciech

    2015-01-01

    The diver's nervous system is extremely sensitive to high ambient pressure, which is the sum of atmospheric and hydrostatic pressure. Neurological complications associated with diving are a difficult diagnostic and therapeutic challenge. They occur in both commercial and recreational diving and are connected with increasing interest in the sport of diving. Hence it is very important to know the possible complications associated with this kind of sport. Complications of the nervous system may result from decompression sickness, pulmonary barotrauma associated with cerebral arterial air embolism (AGE), otic and sinus barotrauma, high pressure neurological syndrome (HPNS) and undesirable effect of gases used for breathing. The purpose of this review is to discuss the range of neurological symptoms that can occur during diving accidents and also the role of patent foramen ovale (PFO) and internal carotid artery (ICA) dissection in pathogenesis of stroke in divers. PMID:25666773

  17. Pulmonary dysanapsis and diving assessments.

    PubMed

    Ong, Lin Min; Bennett, Michael H; Thomas, Paul S

    2009-01-01

    Airway obstruction is a relative contraindication to diving. Dive candidates are assessed clinically, and lung function tests evaluate variables such as forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and the FEV1/FVC ratio. A small number of individuals have a normal FEV1, but a disproportionately large lung capacity, or pulmonary dysanapsis. These individuals have a decreased FEV1/FVC ratio, suggesting airway obstruction, which may affect their dive medical assessments. Three cases of pulmonary dysanapsis presented for fitness-to-dive assessment. Case 1, a 29-year-old male had an FEV1: 3.52 L (85% predicted), FVC: 5.31 L (108.5% predicted), giving a FEV1/FVC of 66%. Case 2, a 25-year-old male with an FEV1: 4.55 L (95% predicted), FVC: 7.0 L (121% predicted) and a FEV1/FVC of 66%. Albuterol produced an FEV1 increase of 11%, but his hypertonic saline challenge was negative. Case 3, a 61-year-old man had an FEV1: 3.49 L (126% predicted), FVC: 7.06 L (216% predicted), and a FEV1/FVC of 49%. This report highlights pulmonary dysanapsis which may be confused with obstructive airway disease and applicants deemed unfit to dive. While pulmonary dysanapsis may increase the risk of airway hyperresponsiveness, there is no evidence of an association with diving-related pulmonary barotrauma. PMID:20112528

  18. EPO modulation in a 14-days undersea scuba dive.

    PubMed

    Revelli, L; Vagnoni, S; D'Amore, A; Di Stasio, E; Lombardi, C P; Storti, G; Proietti, R; Balestra, C; Ricerca, B M

    2013-10-01

    Erythropoiesis is affected during deep saturation dives. The mechanism should be related to a downregulation of serum Erythropoietin (s-EPO) concentration or to a toxic effect of the hyperbaric hyperoxia. We evaluated s-EPO and other haematological parameters in 6 scuba divers before, during and after a 14-days guinness saturation dive (8-10 m). Athletes were breathing air at 1.8-2 ATA, under the control of a team of physicians. Serum parameters were measured before diving (T0) and: 7 days (T1), 14 days (T2) after the beginning of the dive and 2 h (T3) and 24 h (T4) after resurfacing. Hgb, and many other haematological parameters did not change whereas Ht, s-EPO, the ratio between s-EPO predicted and that observed and reticulocytes (absolute, percent) declined progressively from T0 to T3. At T4 a significant rise in s-EPO was observed. Hgb did not vary but erythropoiesis seemed to be affected as s-EPO and reticulocyte counts showed. All these changes were statistically significant. The experiment, conducted in realistic conditions of dive length, oxygen concentration and pressure, allows us to formulate some hypotheses about the role of prolonged hyperbarism on erythropoiesis. The s-EPO rise, 24 h after resurfacing, is clearly documented and related to the "Normobaric Oxygen Paradox". This evidence suggests interesting hypotheses for new clinical applications such as modulation of s-EPO production and Hgb content triggered by appropriate O₂ administration in pre-surgical patients or in some anemic disease. PMID:23670359

  19. Control of ventilation in diving birds.

    PubMed

    Butler, Patrick J; Halsey, Lewis G

    2008-01-01

    Studies on diving ducks indicate that the carotid bodies affect dive duration when the birds are hypoxic before a dive but not when they are hypercapnic. When close to their critical concentrations (beyond which the ducks will not dive), both oxygen and carbon dioxide reduce dive duration but hypercapnia has a much larger influence than hypoxia on surface duration. Also, excessive removal of carbon dioxide before a dive may be as important a factor in preparing for that dive as the replacement of the oxygen used during the previous dive. This observation is compatible with a physiological model of the control of diving behaviour in the Weddell seal which emphasises the significance of the level of carbon dioxide in the blood perfusing the brain. PMID:18085287

  20. Concentration of circulating autoantibodies against HSP 60 is lowered through diving when compared to non-diving rats

    PubMed Central

    Havnes, Marianne B.; Ahlén, Catrine; Brubakk, Alf O.; Iversen, Ole-Jan

    2012-01-01

    Objective Skin and ear infections, primarily caused by Pseudomonas aeruginosa (P. aeruginosa), are recurrent problems for saturation divers, whereas infections caused by P. aeruginosa are seldom observed in healthy people outside saturation chambers. Cystic fibrosis (CF) patients suffer from pulmonary infections by P. aeruginosa, and it has been demonstrated that CF patients have high levels of autoantibodies against Heat shock protein 60 (HSP60) compared to controls, probably due to cross-reacting antibodies induced by P. aeruginosa. The present study investigated whether rats immunised with P. aeruginosa produced autoantibodies against their own HSP60 and whether diving influenced the level of circulating anti-HSP60 antibodies. Methods A total of 24 rats were randomly assigned to one of three groups (‘immunised’, ‘dived’ and ‘immunised and dived’). The rats in group 1 and 3 were immunised with the bacteria P. aeruginosa, every other week. Groups 2 and 3 were exposed to simulated air dives to 400 kPa (4 ata) with 45 min bottom time, every week for 7 weeks. Immediately after surfacing, the rats were anaesthetised and blood was collected from the saphenous vein. The amount of anti-HSP60 rat antibodies in the serum was analysed by enzyme linked immunosorbent assay. Results The immunised rats (group 1) showed a significant increase in the level of autoantibodies against HSP60, whereas no autoantibodies were detected in the dived rats (group 2). The rats both immunised and dived (group 3) show no significant increase in circulating autoantibodies against HSP60. A possible explanation may be that HSP60 is expressed during diving and that cross-reacting antibodies are bound. PMID:23990832

  1. Free and forced diving in ducks: habituation of the initial dive response.

    PubMed

    Gabrielsen, G W

    1985-01-01

    Response habituation in pekin ducks was observed during a study of the early phase of the dive response. This is interpreted as the orienting response and strongly suggests higher CNS influence in the initial phase of the forced immersion heart rate response. Repeated forced dives (20-30 s) of restrained ducks were performed with 40 s recovery period between dives. During the first dives, the ducks' heart rates fell 69% (272 +/- 8 to 83 +/- 32 beats X min-1, means +/- SE) of pre-dive values. The extent of this bradycardia decreased progressively as the dives were repeated. After 60 dives, the heart rates dropped by only 29% (248 +/- 3 to 177 +/- 25 beats X min-1 for pre-dive value). Voluntary diving of the ducks, lasting 5-20 s, caused no diving bradycardia. They showed breathing tachycardia which caused a 25% increase in heart rates above diving level (160 +/- 5 to 200 +/- 12 beats X min-1). PMID:3969834

  2. [Diving accidents. Emergency treatment of serious diving accidents].

    PubMed

    Schröder, S; Lier, H; Wiese, S

    2004-11-01

    Decompression injuries are potentially life-threatening incidents mainly due to a rapid decline in ambient pressure. Decompression illness (DCI) results from the presence of gas bubbles in the blood and tissue. DCI may be classified as decompression sickness (DCS) generated from the liberation of gas bubbles following an oversaturation of tissues with inert gas and arterial gas embolism (AGE) mainly due to pulmonary barotrauma. People working under hyperbaric pressure, e.g. in a caisson for general construction under water, and scuba divers are exposed to certain risks. Diving accidents can be fatal and are often characterized by organ dysfunction, especially neurological deficits. They have become comparatively rare among professional divers and workers. However, since recreational scuba diving is gaining more and more popularity there is an increasing likelihood of severe diving accidents. Thus, emergency staff working close to areas with a high scuba diving activity, e.g. lakes or rivers, may be called more frequently to a scuba diving accident. The correct and professional emergency treatment on site, especially the immediate and continuous administration of normobaric oxygen, is decisive for the outcome of the accident victim. The definitive treatment includes rapid recompression with hyperbaric oxygen. The value of adjunctive medication, however, remains controversial. PMID:15565421

  3. 46 CFR 197.432 - Surface-supplied air diving.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Surface-supplied air diving. 197.432 Section 197.432... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Specific Diving Mode Procedures § 197.432 Surface-supplied air diving. The diving supervisor shall insure that— (a) Surface-supplied air diving is...

  4. 46 CFR 197.432 - Surface-supplied air diving.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Surface-supplied air diving. 197.432 Section 197.432... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Specific Diving Mode Procedures § 197.432 Surface-supplied air diving. The diving supervisor shall insure that— (a) Surface-supplied air diving is...

  5. Diving seabirds: the stability of a diving elastic beam

    NASA Astrophysics Data System (ADS)

    Chang, Brian; Croson, Matthew; Jung, Sunghwan

    2015-11-01

    In this study, we examine the buckling stability of a beam attached to a cone plunge diving into a bath of water, which is inspired by diving birds. This beam-cone system initially experiences an impact force before the cone is completely submerged, followed by a hydrodynamic drag force. Using high speed imaging techniques, it was observed that the soft elastic beam exhibits either buckling (unstable) or non-buckling (stable) behaviors upon impact and submergence. Large cone angles, long beams, and high impact velocities likely cause buckling in the beam. By varying geometric factors of the beam-cone system and changing the impact velocity, a transition from non-buckling to buckling is characterized through physical experiments and is verified by an analytical model. This study elucidates under which conditions diving birds may possibly get injured.

  6. Diving at altitude: from definition to practice.

    PubMed

    Egi, S Murat; Pieri, Massimo; Marroni, Alessandro

    2014-01-01

    Diving above sea level has different motivations for recreational, military, commercial and scientific activities. Despite the apparently wide practice of inland diving, there are three major discrepancies about diving at altitude: threshold elevation that requires changes in sea level procedures; upper altitude limit of the applicability of these modifications; and independent validation of altitude adaptation methods of decompression algorithms. The first problem is solved by converting the normal fluctuation in barometric pressure to an altitude equivalent. Based on the barometric variations recorded from a meteorological center, it is possible to suggest 600 meters as a threshold for classifying a dive as an "altitude" dive. The second problem is solved by proposing the threshold altitude of aviation (2,400 meters) to classify "high" altitude dives. The DAN (Divers Alert Network) Europe diving database (DB) is analyzed to solve the third problem. The database consists of 65,050 dives collected from different dive computers. A total of 1,467 dives were found to be classified as altitude dives. However, by checking the elevation according to the logged geographical coordinates, 1,284 dives were disqualified because the altitude setting had been used as a conservative setting by the dive computer despite the fact that the dive was made at sea level. Furthermore, according to the description put forward in this manuscript, 72 dives were disqualified because the surface level elevation is lower than 600 meters. The number of field data (111 dives) is still very low to use for the validation of any particular method of altitude adaptation concerning decompression algorithms. PMID:25562941

  7. Upper respiratory tract and aural flora of saturation divers.

    PubMed Central

    Jones, D M; Davis, P

    1978-01-01

    The conditions of helium saturation diving promote the proliferation of Gram-negative bacterial species in the external auditory meatus of divers. These changes in flora occurred in the absence of operational diving, that is, no contact with water. The colonising bacteria were autogenous in origin and cross-colonisation was observed between divers. On return to normal atmospheric conditions the aural flora became predominantly Gram-positive again within 48 hours. PMID:690235

  8. 33 CFR 146.40 - Diving casualties.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CONTINENTAL SHELF ACTIVITIES OPERATIONS OCS Facilities § 146.40 Diving casualties. Diving related casualties are reported in accordance with 46 CFR 197.484 and 197.486. ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Diving casualties. 146.40...

  9. 33 CFR 146.40 - Diving casualties.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CONTINENTAL SHELF ACTIVITIES OPERATIONS OCS Facilities § 146.40 Diving casualties. Diving related casualties are reported in accordance with 46 CFR 197.484 and 197.486. ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Diving casualties. 146.40...

  10. 33 CFR 146.40 - Diving casualties.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CONTINENTAL SHELF ACTIVITIES OPERATIONS OCS Facilities § 146.40 Diving casualties. Diving related casualties are reported in accordance with 46 CFR 197.484 and 197.486. ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Diving casualties. 146.40...

  11. 29 CFR 1926.1084 - SCUBA diving.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false SCUBA diving. 1926.1084 Section 1926.1084 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1084 SCUBA diving. Note: The requirements applicable to construction work under this section are identical to...

  12. 29 CFR 1926.1084 - SCUBA diving.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false SCUBA diving. 1926.1084 Section 1926.1084 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1084 SCUBA diving. Note: The requirements applicable to construction work under this section are identical to...

  13. 33 CFR 146.40 - Diving casualties.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CONTINENTAL SHELF ACTIVITIES OPERATIONS OCS Facilities § 146.40 Diving casualties. Diving related casualties are reported in accordance with 46 CFR 197.484 and 197.486. ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Diving casualties. 146.40...

  14. 33 CFR 146.40 - Diving casualties.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CONTINENTAL SHELF ACTIVITIES OPERATIONS OCS Facilities § 146.40 Diving casualties. Diving related casualties are reported in accordance with 46 CFR 197.484 and 197.486. ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Diving casualties. 146.40...

  15. A review of asthma and scuba diving.

    PubMed

    Tetzlaff, Kay; Muth, Claus M; Waldhauser, Lisa K

    2002-10-01

    An increasing number of asthmatics participate in recreational scuba diving. This activity presents unique physical and physiological challenges to the respiratory system. This review addresses the susceptibility of divers with asthma to diving accidents, acute asthmatic attacks, and long-term exacerbation of their disease. Recommendations on fitness to dive with asthma and airway hyperresponsiveness are provided. PMID:12442945

  16. The epidemiology of injury in scuba diving.

    PubMed

    Buzzacott, Peter L

    2012-01-01

    The epidemiology of injury associated with recreational scuba diving is reviewed. A search of electronic databases and reference lists identified pertinent research. Barotrauma, decompression sickness and drowning-related injuries were the most common morbidities associated with recreational scuba diving. The prevalence of incidents ranged from 7 to 35 injuries per 10,000 divers and from 5 to 152 injuries per 100,000 dives. Recreational scuba diving fatalities account for 0.013% of all-cause mortality aged ≥ 15 years. Drowning was the most common cause of death. Among treated injuries, recovery was complete in the majority of cases. Dive injuries were associated with diver-specific factors such as insufficient training and preexisting medical conditions. Environmental factors included air temperature and flying after diving. Dive-specific factors included loss of buoyancy control, rapid ascent and repetitive deep diving. The most common event to precede drowning was running out of gas (compressed air). Though diving injuries are relatively rare prospective, longitudinal studies are needed to quantify the effects of known risk factors and, indeed, asymptomatic injuries (e.g. brain lesions). Dive injury health economics data also remains wanting. Meanwhile, health promotion initiatives should continue to reinforce adherence to established safe diving practices such as observing depth/time limits, safety stops and conservative ascent rates. However, there is an obvious lack of evaluated diving safety interventions. PMID:22824839

  17. Basic medical implications of scuba diving.

    PubMed

    Crook, R A

    1977-12-01

    The rapid growth of scuba diving as a sport and the vast expansion of underwater exploration for energy has made it necessary for all physicians to become familiar with diving emergencies. The basic principles of scuba diving and related clinical implications are outlined to provide a more meaningful understanding of problems which may affect a diver. PMID:604521

  18. 29 CFR 1926.1084 - SCUBA diving.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false SCUBA diving. 1926.1084 Section 1926.1084 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1084 SCUBA diving. Note: The requirements applicable to construction work under this section are identical to...

  19. 29 CFR 1926.1084 - SCUBA diving.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false SCUBA diving. 1926.1084 Section 1926.1084 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1084 SCUBA diving. Note: The requirements applicable to construction work under this section are identical to...

  20. 29 CFR 1926.1084 - SCUBA diving.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false SCUBA diving. 1926.1084 Section 1926.1084 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1084 SCUBA diving. Note: The requirements applicable to construction work under this section are identical to...

  1. 17 CFR 240.14d-100 - Schedule TO. Tender offer statement under section 14(d)(1) or 13(e)(1) of the Securities Exchange...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 3 2012-04-01 2012-04-01 false Schedule TO. Tender offer... Exchange Act of 1934 Regulation 14d § 240.14d-100 Schedule TO. Tender offer statement under section 14(d)(1....C. 20549 Schedule TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the...

  2. 17 CFR 240.14d-100 - Schedule TO. Tender offer statement under section 14(d)(1) or 13(e)(1) of the Securities Exchange...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Schedule TO. Tender offer... Exchange Act of 1934 Regulation 14d § 240.14d-100 Schedule TO. Tender offer statement under section 14(d)(1....C. 20549 Schedule TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the...

  3. 17 CFR 240.14d-100 - Schedule TO. Tender offer statement under section 14(d)(1) or 13(e)(1) of the Securities Exchange...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Schedule TO. Tender offer... Exchange Act of 1934 Regulation 14d § 240.14d-100 Schedule TO. Tender offer statement under section 14(d)(1....C. 20549 Schedule TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the...

  4. Recreational technical diving part 2: decompression from deep technical dives.

    PubMed

    Doolette, David J; Mitchell, Simon J

    2013-06-01

    Technical divers perform deep, mixed-gas 'bounce' dives, which are inherently inefficient because even a short duration at the target depth results in lengthy decompression. Technical divers use decompression schedules generated from modified versions of decompression algorithms originally developed for other types of diving. Many modifications ostensibly produce shorter and/or safer decompression, but have generally been driven by anecdote. Scientific evidence relevant to many of these modifications exists, but is often difficult to locate. This review assembles and examines scientific evidence relevant to technical diving decompression practice. There is a widespread belief that bubble algorithms, which redistribute decompression in favour of deeper decompression stops, are more efficient than traditional, shallow-stop, gas-content algorithms, but recent laboratory data support the opposite view. It seems unlikely that switches from helium- to nitrogen-based breathing gases during ascent will accelerate decompression from typical technical bounce dives. However, there is evidence for a higher prevalence of neurological decompression sickness (DCS) after dives conducted breathing only helium-oxygen than those with nitrogen-oxygen. There is also weak evidence suggesting less neurological DCS occurs if helium-oxygen breathing gas is switched to air during decompression than if no switch is made. On the other hand, helium-to-nitrogen breathing gas switches are implicated in the development of inner-ear DCS arising during decompression. Inner-ear DCS is difficult to predict, but strategies to minimize the risk include adequate initial decompression, delaying helium-to-nitrogen switches until relatively shallow, and the use of the maximum safe fraction of inspired oxygen during decompression. PMID:23813463

  5. Diving and marine medicine review part II: diving diseases.

    PubMed

    Spira, A

    1999-09-01

    Diving is a high-risk sport. There are approximately between 1 to 3 million recreational scuba divers in the USA (with over a quarter-million learning scuba annually); there are about 1 million in Europe and over 50,000 in the United Kingdom. In this population 3-9 deaths/100,000 occur annually in the US alone, and those surviving diving injuries far exceeds this. Diving morbidity can be from near-drowning, from gas bubbles, from barotrauma or from environmental hazards. In reality, the most common cause of death in divers is drowning (60%), followed by pulmonary-related illnesses. The mean number of annual diving fatalities in the USA from 1970 to 1993 was 103.5 (sd 24.0) and the median was 106. This article will focus primarily upon pressure effects on the health of a diver. There are two principle ways pressure can affect us: by direct mechanical effects and by changing the partial pressures of inspired gases. Dysbarism is a general term used to describe pathology from altered environmental pressure, and has two main forms: barotrauma from the uncontrolled expansion of gas within gas-filled body compartments and decompression sickness from too rapid a return to atmospheric pressure after breathing air under increased pressures. Greater than 90% of the human body is either water or bone, which is incompressible; the areas directly affected by pressure changes thus are those that are filled with air or gas. These sites include the middle ear, the eustachian tube, the sinuses, the thorax, and the gastrointestinal tract. Air in these cavities is compressed when the ambient pressure rises because the pressure of inhaled air must equilibrate with the ambient pressure. PMID:10467155

  6. DIVE Into Metadata With MMI

    NASA Astrophysics Data System (ADS)

    Neiswender, C.; Bermudez, L.; Galbraith, N. R.; Graybeal, J.

    2007-12-01

    Within research environments, good, usable data is paramount to scientific success. However, extremely diverse data is often distributed across many institutions, collected in a variety of ways, and stored in dissimilar systems. Standards-based interoperability is the key to harnessing this variety into a strategic set of usable data. As a community collaboration, the Marine Metadata Interoperability project (MMI) exists to promote the exchange, integration and use of marine data through enhanced data publishing, discovery, documentation and accessibility. To accomplish these goals, MMI has established a collaborative web environment (http://marinemetadata.org), informative guides, workshops on current topics, vocabulary working groups, and interoperable projects (OOSTethys and the OGC Oceans Interoperability Experiment, http://www.oostethys.org/). In January 2008, MMI will launch a new initiative: the DIVE Strike Force. Called DIVE for Discover, Interrogate, Validate and Educate. The MMI strike force initiative will facilitate concentrated research into a specific area needed by the marine science community. Each focused team of scientists, technologists and data managers will work to comprehensively review and explain existing capabilities and best practices, comparing existing solutions for the community. For this first DIVE Strike Force, team efforts will be focused on metadata tools. The Tools Strike Force will: * Discover available tools for the creation and publication of metadata and metadata vocabularies; * Interrogate the community about each tool, assessing criteria to be agreed upon, for example the capabilities of each, strengths and weaknesses, level of adoption, and where each tool would best be used; * Validate the best and most applicable tools objectively; * Educate the wider marine metadata community using the MMI webpage, and other resources as appropriate. Participants in each DIVE will be solicited from throughout the community, and

  7. 46 CFR 197.210 - Designation of diving supervisor.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Designation of diving supervisor. 197.210 Section 197... HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations General § 197.210 Designation of diving supervisor. The name of the diving supervisor for each commercial diving operation shall be— (a)...

  8. 46 CFR 197.210 - Designation of diving supervisor.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Designation of diving supervisor. 197.210 Section 197... HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations General § 197.210 Designation of diving supervisor. The name of the diving supervisor for each commercial diving operation shall be— (a)...

  9. 46 CFR 197.210 - Designation of diving supervisor.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Designation of diving supervisor. 197.210 Section 197... HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations General § 197.210 Designation of diving supervisor. The name of the diving supervisor for each commercial diving operation shall be— (a)...

  10. 46 CFR 197.210 - Designation of diving supervisor.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Designation of diving supervisor. 197.210 Section 197... HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations General § 197.210 Designation of diving supervisor. The name of the diving supervisor for each commercial diving operation shall be— (a)...

  11. 46 CFR 197.210 - Designation of diving supervisor.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Designation of diving supervisor. 197.210 Section 197... HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations General § 197.210 Designation of diving supervisor. The name of the diving supervisor for each commercial diving operation shall be— (a)...

  12. Advanced instrumentation for research in diving and hyperbaric medicine.

    PubMed

    Sieber, Arne; L'Abbate, Antonio; Kuch, Benjamin; Wagner, Matthias; Benassi, Antonio; Passera, Mirko; Bedini, Remo

    2010-01-01

    Improving the safety of diving and increasing knowledge about the adaptation of the human body to underwater and hyperbaric environment require specifically developed underwater instrumentation for physiological measurements. In fact, none of the routine clinical devices for health control is suitable for in-water and/or under-pressure operation. The present paper addresses novel technological acquisitions and the development of three dedicated devices: * an underwater data logger for recording O2 saturation (reflective pulsoxymetry), two-channel ECG, depth and temperature; * an underwater blood pressure meter based on the oscillometric method; and * an underwater echography system. Moreover, examples of recordings are presented and discussed. PMID:20929183

  13. Diving medicine: a review of current evidence.

    PubMed

    Lynch, James H; Bove, Alfred A

    2009-01-01

    Recreational scuba diving is a growing sport worldwide, with an estimated 4 million sport divers in the United States alone. Because divers may seek medical care for a disorder acquired in a remote location, physicians everywhere should be familiar with the physiology, injury patterns, and treatment of injuries and illnesses unique to the underwater environment. Failure to properly recognize, diagnose, and appropriately treat some diving injuries can have catastrophic results. In addition, recreational dive certification organizations require physical examinations for medical clearance to dive. This article will review both common and potentially life-threatening conditions associated with diving and will review current evidence behind fitness to dive considerations for elderly divers and those with common medical conditions. PMID:19587254

  14. Diving medicine: a review of current evidence.

    PubMed

    Lynch, James H; Bove, Alfred A

    2009-01-01

    Recreational scuba diving is a growing sport worldwide, with an estimated 4 million sport divers in the United States alone. Because divers may seek medical care for a disorder acquired in a remote location, physicians everywhere should be familiar with the physiology, injury patterns, and treatment of injuries and illnesses unique to the underwater environment. Failure to properly recognize, diagnose, and appropriately treat some diving injuries can have catastrophic results. In addition, recreational dive certification organizations require physical examinations for medical clearance to dive. This article will review both common and potentially life-threatening conditions associated with diving and will review current evidence behind fitness to dive considerations for elderly divers and those with common medical conditions. PMID:20112651

  15. Oral and maxillofacial aspects of diving medicine.

    PubMed

    Brandt, Matthew T

    2004-02-01

    Sport diving has witnessed explosive growth in the past decade, as 8.5 million people are certified in the United States alone. Even though scuba diving is a relatively safe sport, there are serious risks that all divers must consider. Beyond the better-known sequelae such as decompression sickness, middle ear dysfunction, and potential central nervous system effects, scuba diving also carries inherent risk to the maxillofacial region. Atypical facial pain, temporomandibular joint dysfunction, sinus barotraumas, and barodontalgia have all been reported by dentists and physicians treating military, commercial, and sport divers. Additionally, clinicians must address anatomic concerns for would-be divers, including cleft lip and palate, edentulism, or patients with pre-existing temporomandibular dysfunction, midfacial trauma, or craniomaxillofacial surgery. Health care professionals should have a thorough understanding of the implications of scuba diving for consultation and recommendation regarding diving fitness and the treatment of adverse effects of scuba diving to the maxillofacial region. PMID:15040636

  16. Saturation meter

    DOEpatents

    Gregurech, S.

    1984-08-01

    A saturation meter for use in a pressurized water reactor plant comprising a differential pressure transducer having a first and second pressure sensing means and an alarm. The alarm is connected to the transducer and is preset to activate at a level of saturation prior to the formation of a steam void in the reactor vessel.

  17. Shallow Water Diving - The NASA Experience

    NASA Technical Reports Server (NTRS)

    Fitzpatrick, Daniel; Kelsey-Seybold

    2010-01-01

    This slide presentation reviews some of the problems and solutions that personnel have experienced during sessions in the Neutral Bu0yancy Lab (NBL). It reviews the standard dive that occurs at the NBL, Boyles and Henry's laws as they relate to the effects of diving. It then reviews in depth some of the major adverse physiologic events that happen during a diving session: Ear and Sinus Barotrauma, Decompression Sickness, (DCS), Pulmonary Barotrauma (i.e., Arterial Gas Embolism (AGE). Mediastinal Emphysema, Subcutaneous Emphysema, and Pneumothorax) Oxygen Toxicity and Hypothermia. It includes information about the pulmonary function in NBL divers. Also included is recommendations about flying after diving.

  18. Can diving-induced tissue nitrogen supersaturation increase the chance of acoustically driven bubble growth in marine mammals?

    PubMed

    Houser, D S; Howard, R; Ridgway, S

    2001-11-21

    The potential for acoustically mediated causes of stranding in cetaceans (whales and dolphins) is of increasing concern given recent stranding events associated with anthropogenic acoustic activity. We examine a potentially debilitating non-auditory mechanism called rectified diffusion. Rectified diffusion causes gas bubble growth, which in an insonified animal may produce emboli, tissue separation and high, localized pressure in nervous tissue. Using the results of a dolphin dive study and a model of rectified diffusion for low-frequency exposure, we demonstrate that the diving behavior of cetaceans prior to an intense acoustic exposure may increase the chance of rectified diffusion. Specifically, deep diving and slow ascent/descent speed contributes to increased gas-tissue saturation, a condition that amplifies the likelihood of rectified diffusion. The depth of lung collapse limits nitrogen uptake per dive and the surface interval duration influences the amount of nitrogen washout from tissues between dives. Model results suggest that low-frequency rectified diffusion models need to be advanced, that the diving behavior of marine mammals of concern needs to be investigated to identify at-risk animals, and that more intensive studies of gas dynamics within diving marine mammals should be undertaken. PMID:11894990

  19. Ultrasonic evidence of acute interstitial lung edema after SCUBA diving is resolved within 2-3h.

    PubMed

    Ljubkovic, Marko; Gaustad, Svein Erik; Marinovic, Jasna; Obad, Ante; Ivancev, Vladimir; Bilopavlovic, Nada; Breskovic, Toni; Wisloff, Ulrik; Brubakk, Alf; Dujic, Zeljko

    2010-04-30

    Recently, an increase in extravascular lung water (EVLW) accumulation with diminished left ventricular contractility within 60 min after SCUBA diving was reported. We have observed previously that diving was associated with reduced diffusing lung capacity for carbon monoxide (DLCO) and arterial oxygen pressure for up to 60-80 min postdive. Here we investigated whether increased EVLW persists 2-3h after successive deep dives in a group of seven male divers. The echocardiographic indices of pulmonary water accumulation (ultrasound lung comets (ULC)) and left ventricular function, respiratory functional measurements and arterial oxygen saturation (SaO(2)) were assessed 2-3h post diving, while venous gas bubbles (VGB) and the blood levels of NT-proBNP and proANP were analyzed 40 min after surfacing. Spirometry values, flow-volume, DLCO, SaO(2) and ULC were unchanged after each dive, except for significant increase in ULC after the second dive. Left ventricular function was reduced, while NT-proBNP and proANP levels were significantly elevated after majority of dives, suggesting a cardiac strain. PMID:20188217

  20. The Physics of Breath-Hold Diving.

    ERIC Educational Resources Information Center

    Aguilella, Vicente; Aguilella-Arzo, Marcelo

    1996-01-01

    Analyzes physical features of breath-hold diving. Considers the diver's descent and the initial surface dive and presents examples that show the diver's buoyancy equilibrium varying with depth, the driving force supplied by finning, and the effect of friction between the water and the diver. (Author/JRH)

  1. Introduction to Scuba Diving. Diver Education Series.

    ERIC Educational Resources Information Center

    Somers, Lee H.

    Scuba diving is often referred to as a "recreational sport." However, the term "sport" sometimes implies erroneous connotations and limits understanding. Scuba diving can be an avocation or a vocation. It is a pastime, a pursuit, or even a lifestyle, that can be as limited or extensive as one makes it. A persons level of commitment, degree of…

  2. Rotation, Translation, and Trajectory in Diving

    ERIC Educational Resources Information Center

    Stroup, Francis; Bushnell, David L.

    1969-01-01

    The fundamental techniques of diving such as the approach, arm swing, hurdle, lift, body positions, and entrance form are relatively stable and can be reduced largely to habit. However, after a diver has mastered them, there remains the problem of partitioning the energy exerted in a dive between translation and rotation. (CK)

  3. Orbital fracture deterioration after scuba diving.

    PubMed

    Nakatani, Hiroko; Yoshioka, Nobutaka

    2009-07-01

    Sinus barotrauma is a common disease in divers. However, it is not familiar to maxillofacial surgeon. We presented orbital fracture deterioration by sinus barotrauma in scuba diving and a review of literatures. We also discussed the clinical features, the prevention, and the possible mechanism of orbital fracture deterioration after scuba diving. PMID:19625851

  4. Teaching Persons with Disabilities to SCUBA Diving.

    ERIC Educational Resources Information Center

    Jankowski, Louis W.

    This booklet is designed to sensitize and inform the scuba diving instructor on appropriate attitudes and successful methods for teaching scuba diving to persons with physical disability. It addresses misconceptions about people with disabilities and the importance of effective two-way communication and mutual respect between instructors and…

  5. Predicting performance in competitive apnea diving. Part III: deep diving.

    PubMed

    Schagatay, Erika

    2011-12-01

    The first of these reviews described the physiological factors defining the limits of static apnea, while the second examined performance in apneic distance swimming. This paper reviews the factors determining performance in depth disciplines, where hydrostatic pressure is added to the stressors associated with apnea duration and physical work. Apneic duration is essential for performance in all disciplines, and is prolonged by any means that increases gas storage or tolerance to asphyxia or reduces metabolic rate. For underwater distance swimming, the main challenge is to restrict metabolism despite the work of swimming, and to redirect blood flow to allow the most vital functions. Here, work economy, local tissue energy and oxygen stores, anaerobic capacity of the muscles, and possibly technical improvements will be essential for further development. In the depth disciplines, direct pressure effects causing barotrauma, the narcotic effects of gases, decompression sickness (DCS) and possibly air embolism during ascent need to be taken into account, as does the risk of hypoxia when the dive cannot be rapidly interrupted before the surface is reached again. While in most deep divers apneic duration is not the main limitation thus far, greater depths may call for exceptionally long apneas and slower ascents to avoid DCS. Narcotic effects may also affect the ultimate depth limit, which the divers currently performing 'constant weight with fins' dives predict to be around 156 metres' sea water. To reach these depths, serious physiological challenges have to be met, technical developments needed and safety procedures developed concomitantly. PMID:22183699

  6. Advanced deep sea diving equipment

    NASA Technical Reports Server (NTRS)

    Danesi, W. A.

    1972-01-01

    Design requirements are generated for a deep sea heavy duty diving system to equip salvage divers with equipment and tools that permit work of the same quality and in times approaching that done on the surface. The system consists of a helmet, a recirculator for removing carbon dioxide, and the diver's dress. The diver controls the inlet flow by the recirculatory control valve and is able to change closed cycle operation to open cycle if malfunction occurs. Proper function of the scrubber in the recirculator minimizes temperature and humidity effects as it filters the returning air.

  7. Validation of diving decompression tables.

    PubMed

    Kłos, Ryszard; Nishi, Ron; Olszański, Roman

    2002-01-01

    Research on the validation of decompression tables is one of the common subject areas of the co-operation undertaken between the Defence and Civil Institute of Environmental Medicine, Toronto, Canada, and The Naval Academy of Gdynia, Poland. For several years now, a systematic survey of diving technologies has been conducted among the target projects financed by the Polish State Committee for Scientific Research and the Polish Navy. Among the most important problems discussed have been various aspects of decompression safety. The present paper shows a study to standardise and unify validation procedures for decompression in the Polish Navy. PMID:12608591

  8. The cardiovascular system and diving risk.

    PubMed

    Bove, Alfred A

    2011-01-01

    Recreational scuba diving is a sport that requires a certain physical capacity, in addition to consideration of the environmental stresses produced by increased pressure, low temperature and inert gas kinetics in tissues of the body. Factors that may influence ability to dive safely include age, physical conditioning, tolerance of cold, ability to compensate for central fluid shifts induced by water immersion, and ability to manage exercise demands when heart disease might compromise exercise capacity. Patients with coronary heart disease, valvular heart disease, congenital heart disease and cardiac arrhythmias are capable of diving, but consideration must be given to the environmental factors that might interact with the cardiac disorder. Understanding of the interaction of the diving environment with various cardiac disorders is essential to providing a safe diving environment to individual divers with known heart disease. PMID:21877555

  9. Cormorants dive through the Polar night.

    PubMed

    Grémillet, David; Kuntz, Grégoire; Gilbert, Caroline; Woakes, Antony J; Butler, Patrick J; le Maho, Yvon

    2005-12-22

    Most seabirds are visual hunters and are thus strongly affected by light levels. Dependence on vision should be problematic for species wintering at high latitudes, as they face very low light levels for extended periods during the Polar night. We examined the foraging rhythms of male great cormorants (Phalacrocorax carbo) wintering north of the Polar circle in West Greenland, conducting the first year-round recordings of the diving activity in a seabird wintering at high latitudes. Dive depth data revealed that birds dived every day during the Arctic winter and did not adjust their foraging rhythms to varying day length. Therefore, a significant proportion of the dive bouts were conducted in the dark (less than 1 lux) during the Polar night. Our study underlines the stunning adaptability of great cormorants and raises questions about the capacity of diving birds to use non-visual cues to target fish. PMID:17148235

  10. [Medical aspects of diving in the tropics].

    PubMed

    Muth, C M; Müller, P; Kemmer, A

    2005-07-01

    Scuba diving vacations in tropical surroundings belong to the repertoire of most divers. In addition to carefully making travel plans and taking care of the necessary vaccinations and appropriate malaria prophylaxis, the following points also must be observed. The flight itself affects diving safety. In particular, a too short time interval between diving and the return flight can lead to decompression problems. Because most of the diving areas are reached by ship, many divers need a prophylaxis against motion sickness. Moreover, external otitis occurs more frequently while diving in the tropics. Finally, there is potential danger from the sea inhabitants, primarily from scorpion fishes, Portuguese Man-of-Wars, box jellyfishes as well as cone snails. PMID:16041936

  11. The death of buddy diving?

    PubMed

    Cooper, P David

    2011-12-01

    Dear Editor, By focussing on the details of the Watson case, I believe Bryan Walpole has missed the thrust of my earlier letter. I agree this was a complex case, which is why I deliberately avoided the murky specifics in order to consider the 'big-picture' ramifications of the judgement. My concerns relate to the potential consequences of the unintended interplay between unrelated developments in the medical and legal arenas. Taken together, I believe these developments threaten the very institution of buddy diving. I have been unable to verify Dr Walpole's claim that the statute under which Mr Watson was convicted has not been used previously in a criminal trial. I must, however, refute his assertion that this legislation is some sort of idiosyncratic historical hangover or legal curiosity unique to Queensland. Although the original legislation pre-dates Australian federation, this statute has survived intact through 110 years of reviews and amendments to the Queensland Criminal Code. The application of this 19th century law to the Watson case now provides a direct, post-federation, 21st century relevance. Nor is Queensland alone in having such a statute on its books. Section 151 of the Criminal Code Act in Dr Walpole's home state of Tasmania states "When a person undertakes to do any act, the omission to do which is or may be dangerous to human life or health, it is his duty to do that act." Similar statutes can also be found in the legislation of other Australian states and as far afield as New Zealand and Canada. The phrasing of the relevant sections is, in many cases, almost identical to Queensland's, reflecting the common judicial heritage of these places. Even if this ruling's reach extended no further than the Queensland border its ramifications would be immense. Tourism statistics reveal that over 1.2 million visitors perform nearly 3.5 million dives/snorkels in Queensland each year. An estimated 93% of international divers visiting Australia stopover in

  12. [Health aspects of diving in ENT medicine. Part II: Diving fitness].

    PubMed

    Klingmann, C; Wallner, F

    2004-09-01

    Diving has become increasingly popular. With the growing number of patients who want to dive, there is an increasing number of divers who require their regular medical examination. As ENT problems are the most common disorders in divers, otorhinolaryngologists regularly have to assess the diver's fitness. It should be noted that an ENT examination does not certify complete fitness to dive! Diving can be resumed 3 months after middle ear surgery, especially after tympanoplastic type I, II and III with insertion of a PORP, when there is regular middle ear ventilation without atrophic scars of the tympanic membrane. Even after stapes surgery, diving can be resumed when there are no signs of vestibular irritation during a provocation test. By 3 months after sinus surgery, the diver should perform a test dive under supervision before fitness to dive can be certified. After inner ear barotrauma, the diver remains fit to dive depending on his hearing ability in the involved ear. After inner ear decompression illness, one should look for a vascular right-to-left shunt before diving can be resumed. These and many more aspects are discussed in this article on how to determine whether a diver with ENT problems is fit to dive. PMID:15221086

  13. Hematological response and diving response during apnea and apnea with face immersion.

    PubMed

    Schagatay, Erika; Andersson, Johan P A; Nielsen, Bodil

    2007-09-01

    Increased hematocrit (Hct) attributable to splenic contraction accompanies human apneic diving or apnea with face immersion. Apnea also causes heart rate reduction and peripheral vasoconstriction, i.e., a cardiovascular diving response, which is augmented by face immersion. The aim was to study the role of apnea and facial immersion in the initiation of the hematological response and to relate this to the cardiovascular diving response and its oxygen conservation during repeated apneas. Seven male volunteers performed two series of five apneas of fixed near-maximal duration: one series in air (A) and the other with facial immersion in 10 degrees C water (FIA). Apneas were spaced by 2 min and series by 20 min of rest. Venous blood samples, taken before and after each apnea, were analysed for Hct, hemoglobin concentration (Hb), lactic acid, blood gases and pH. Heart rate, skin capillary blood flow and arterial oxygen saturation were continuously measured non-invasively. A transient increase of Hct and Hb by approximately 4% developed progressively across both series. As no increase of the response resulted with face immersion, we concluded that the apnea, or its consequences, is the major stimulus evoking splenic contraction. An augmented cardiovascular diving response occurred during FIA compared to A. Arterial oxygen saturation remained higher, venous oxygen stores were more depleted and lactic acid accumulation was higher across the FIA series, indicating oxygen conservation with the more powerful diving response. This study shows that the hematological response is not involved in causing the difference in oxygen saturation between apnea and apnea with face immersion. PMID:17541787

  14. 46 CFR 197.404 - Responsibilities of the diving supervisor.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Responsibilities of the diving supervisor. 197.404... SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Operations § 197.404 Responsibilities of the diving supervisor. (a) The diving supervisor shall— (1) Be fully cognizant of...

  15. 29 CFR 1910.410 - Qualifications of dive team.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations Personnel... relevant to assigned tasks; (ii) Techniques of the assigned diving mode: and (iii) Diving operations and... control the exposure of others to hyperbaric conditions shall be trained in diving-related physics...

  16. 46 CFR 197.404 - Responsibilities of the diving supervisor.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Responsibilities of the diving supervisor. 197.404... SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Operations § 197.404 Responsibilities of the diving supervisor. (a) The diving supervisor shall— (1) Be fully cognizant of...

  17. 29 CFR 1910.410 - Qualifications of dive team.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations Personnel... relevant to assigned tasks; (ii) Techniques of the assigned diving mode: and (iii) Diving operations and... control the exposure of others to hyperbaric conditions shall be trained in diving-related physics...

  18. 29 CFR 1910.410 - Qualifications of dive team.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations Personnel... relevant to assigned tasks; (ii) Techniques of the assigned diving mode: and (iii) Diving operations and... control the exposure of others to hyperbaric conditions shall be trained in diving-related physics...

  19. 46 CFR 197.404 - Responsibilities of the diving supervisor.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Responsibilities of the diving supervisor. 197.404... SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Operations § 197.404 Responsibilities of the diving supervisor. (a) The diving supervisor shall— (1) Be fully cognizant of...

  20. 29 CFR 1910.410 - Qualifications of dive team.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations Personnel... relevant to assigned tasks; (ii) Techniques of the assigned diving mode: and (iii) Diving operations and... control the exposure of others to hyperbaric conditions shall be trained in diving-related physics...

  1. 29 CFR 1910.410 - Qualifications of dive team.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations Personnel... relevant to assigned tasks; (ii) Techniques of the assigned diving mode: and (iii) Diving operations and... control the exposure of others to hyperbaric conditions shall be trained in diving-related physics...

  2. 46 CFR 197.320 - Diving ladder and stage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Diving ladder and stage. 197.320 Section 197.320... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.320 Diving ladder and stage. (a) Each diving ladder must— (1) Be capable of supporting the weight of at least two divers; (2) Extend...

  3. 29 CFR 1910.426 - Mixed-gas diving.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Mixed-gas diving. 1910.426 Section 1910.426 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations Specific Operations Procedures § 1910.426 Mixed-gas diving. (a) General. Employers engaged in mixed-gas diving shall comply with the...

  4. 46 CFR 197.404 - Responsibilities of the diving supervisor.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Responsibilities of the diving supervisor. 197.404... SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Operations § 197.404 Responsibilities of the diving supervisor. (a) The diving supervisor shall— (1) Be fully cognizant of...

  5. 46 CFR 197.320 - Diving ladder and stage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Diving ladder and stage. 197.320 Section 197.320... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.320 Diving ladder and stage. (a) Each diving ladder must— (1) Be capable of supporting the weight of at least two divers; (2) Extend...

  6. 46 CFR 197.404 - Responsibilities of the diving supervisor.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Responsibilities of the diving supervisor. 197.404... SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Operations § 197.404 Responsibilities of the diving supervisor. (a) The diving supervisor shall— (1) Be fully cognizant of...

  7. 29 CFR 1910.426 - Mixed-gas diving.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Mixed-gas diving. 1910.426 Section 1910.426 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations Specific Operations Procedures § 1910.426 Mixed-gas diving. (a) General. Employers engaged in mixed-gas diving shall comply with the...

  8. 46 CFR 197.432 - Surface-supplied air diving.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Surface-supplied air diving. 197.432 Section 197.432...-supplied air diving. The diving supervisor shall insure that— (a) Surface-supplied air diving is conducted... space; and (f) The surface-supplied air diver has the equipment required by § 197.346 (b) or (d)....

  9. 29 CFR 1910.425 - Surface-supplied air diving.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Surface-supplied air diving. 1910.425 Section 1910.425... Procedures § 1910.425 Surface-supplied air diving. (a) General. Employers engaged in surface-supplied air...-supplied air diving shall not be conducted at depths deeper than 190 fsw, except that dives with...

  10. 29 CFR 1910.425 - Surface-supplied air diving.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false Surface-supplied air diving. 1910.425 Section 1910.425... Procedures § 1910.425 Surface-supplied air diving. (a) General. Employers engaged in surface-supplied air...-supplied air diving shall not be conducted at depths deeper than 190 fsw, except that dives with...

  11. 46 CFR 197.432 - Surface-supplied air diving.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Surface-supplied air diving. 197.432 Section 197.432...-supplied air diving. The diving supervisor shall insure that— (a) Surface-supplied air diving is conducted... space; and (f) The surface-supplied air diver has the equipment required by § 197.346 (b) or (d)....

  12. Adrenal gland denervation and diving in ducks.

    PubMed

    Mangalam, H J; Jones, D R; Lacombe, A M

    1987-06-01

    The extreme elevation in plasma levels of free norepinephrine (NE) and free epinephrine (EP), which occurs during forced diving of ducks (Anas platyrhynchos), was studied before and after denervation of the adrenal glands. In intact animals both NE and EP concentration increased by up to two orders of magnitude in a 4-min dive but by a significantly lesser amount if the duck breathed O2 before the dive. Denervating the adrenal glands reduced the amounts of both catecholamines (CA) released during dives, plasma EP decreased to 10%, and NE to 50% of values obtained before denervation. Breathing O2 before a dive virtually eliminated CA release in denervates, indicating that hypoxia was the important non-neural releasing agent. Hypoxia was also the most important neural releasing agent compared with hypercapnia, acidosis, or hypoglycemia. Adrenal denervation did not cause significant changes in heart rate, blood pressure, arterial blood gas tensions, pH, or plasma glucose during dives, although denervation caused increased variation in some of these variables. In ducks CA release in dives is largely due to decreasing arterial O2 partial pressure, and full expression of the response is dependent on intact innervation of the adrenal gland. PMID:3591985

  13. Rapid brain cooling in diving ducks.

    PubMed

    Caputa, M; Folkow, L; Blix, A S

    1998-08-01

    Hypothermia may limit asphyxic damages to the brain, and many small homeotherms have been shown to use anapyrexic strategies when exposed to asphyxic conditions. Larger homeotherms do not seem to use the same strategy, but could save oxygen and prevent hypoxic brain damage by employing selective brain cooling (SBC) in connection with asphyxia. To test the hypothesis that selective brain cooling may take place in connection with asphyxia, we have recorded brain [hypothalamic (THyp)] and body [colonic (TC)] temperatures and heart rates in four Pekin ducks during 5-min simulated (head submersion) diving in cold water (10 degrees C). Diving resulted in a drop in THyp (3.1 +/- 1.4 degrees C) that continued into the recovery period (P < 0.001). Restricting heat loss from the buccal cavity and eyes during diving compromised brain cooling in an additive manner. TC was not influenced by diving. Control cooling of the head with crushed ice during a 5-min period of undisturbed breathing had no effect on THyp. Warm water (35 degrees C) markedly reduced brain cooling, and dive capacity was reduced by approximately 14% (P < 0.05) compared with diving in water at 10 degrees C. The data suggest that SBC is used in ducks during diving, and we propose that this mechanism may enable the bird to save oxygen for prolonged aerobic submergence and to protect the brain from asphyxic damages. PMID:9688670

  14. [Fitness to dive in the otorhinolaryngological field].

    PubMed

    Klingmann, C; Praetorius, M; Böhm, F; Tetzlaff, K; Plinkert, P K

    2008-05-01

    In line with the rising number of recreational divers, the otorhinolaryngologist has to deal with growing numbers of diving-associated disorders of the ear, nose and throat (ENT). Nevertheless, the majority of divers present to their ENT doctor for assessment of their fitness to dive. On the basis of long-term follow-up examinations and increasing experience in diving medicine, even divers with a history of ENT problems can be considered fit to dive. Therefore, diving is possible after tympanoplasty, surgery to improve hearing including stapesplasty, after implantation of middle ear amplifiers or cochlear implants, after sinus or scull base surgery and even after canal wall down mastoidectomy, provided that certain requirements are fulfilled. Assessing fitness to dive after inner ear barotrauma as well as after inner ear decompression illness requires meticulous consideration of residual damage and possible underlying conditions like vascular right-to-left shunts. This article is based on the new recommendations of the German Undersea and Hyperbaric Medical Society for the assessment of fitness to dive in the otorhinolaryngological field. PMID:18415065

  15. Dive and discover: Expeditions to the seafloor

    NASA Astrophysics Data System (ADS)

    Ayers Lawrence, Lisa

    The Dive and Discover Web site is a virtual treasure chest of deep sea science and classroom resources. The goals of Dive and Discover are to engage students, teachers, and the general public in the excitement of ocean disco very through an interactive educational Web site. You can follow scientists on oceanographic research cruises by reading their daily cruise logs, viewing photos and video clips of the discoveries, and even e-mailing questions to the scientists and crew. WHOI has also included an "Educator's Companion" section with teaching strategies, activities, and assessments, making Dive and Discover an excellent resource for the classroom.

  16. Dive and discover: Expeditions to the seafloor

    NASA Astrophysics Data System (ADS)

    Lawrence, Lisa Ayers

    The Dive and Discover Web site is a virtual treasure chest of deep sea science and classroom resources. The goals of Dive and Discover are to engage students, teachers, and the general public in the excitement of ocean disco very through an interactive educational Web site. You can follow scientists on oceanographic research cruises by reading their daily cruise logs, viewing photos and video clips of the discoveries, and even e-mailing questions to the scientists and crew. WHOI has also included an “Educator's Companion” section with teaching strategies, activities, and assessments, making Dive and Discover an excellent resource for the classroom.

  17. A case of bilateral ophthalmoplegia while diving.

    PubMed

    Lee, Blair C; Young, Colin R

    2015-01-01

    This case report presents a military diver who became dysphoric and lost consciousness during a routine surface-supplied dive. The patient regained consciousness spontaneously, but the physical exam was notable for bilateral ophthalmoplegia. Full eye movement was regained during hyperbaric oxygen (HBO2) therapy, and the patient subsequently made a full recovery. Equipment and dive profile analysis led to the conclusion of hypercapnia and arterial gas embolism as the probable causes of the diver's symptoms. This is a unique case of isolated bilateral ophthalmoplegia presenting in a diving injury. PMID:26403021

  18. Heart rate regulation and extreme bradycardia in diving emperor penguins.

    PubMed

    Meir, Jessica U; Stockard, Torre K; Williams, Cassondra L; Ponganis, Katherine V; Ponganis, Paul J

    2008-04-01

    To investigate the diving heart rate (f(H)) response of the emperor penguin (Aptenodytes forsteri), the consummate avian diver, birds diving at an isolated dive hole in McMurdo Sound, Antarctica were outfitted with digital electrocardiogram recorders, two-axis accelerometers and time depth recorders (TDRs). In contrast to any other freely diving bird, a true bradycardia (f(H) significantly diving [dive f(H) (total beats/duration)=57+/-2 beats min(-1), f(H) at rest=73+/-2 beats min(-1) (mean +/- s.e.m.)]. For dives less than the aerobic dive limit (ADL; duration beyond which [blood lactate] increases above resting levels), dive f(H)=85+/-3 beats min(-1), whereas f(H) in dives greater than the ADL was significantly lower (41+/-1 beats min(-1)). In dives greater than the ADL, f(H) reached extremely low values: f(H) during the last 5 mins of an 18 min dive was 6 beats min(-1). Dive f(H) and minimum instantaneous f(H) during dives declined significantly with increasing dive duration. Dive f(H) was independent of swim stroke frequency. This suggests that progressive bradycardia and peripheral vasoconstriction (including isolation of muscle) are primary determinants of blood oxygen depletion in diving emperor penguins. Maximum instantaneous surface interval f(H) in this study is the highest ever recorded for emperor penguins (256 beats min(-1)), equivalent to f(H) at V(O(2)) max., presumably facilitating oxygen loading and post-dive metabolism. The classic Scholander-Irving dive response in these emperor penguins contrasts with the absence of true bradycardia in diving ducks, cormorants, and other penguin species. PMID:18375841

  19. 17 CFR 240.14d-8 - Exemption from statutory pro rata requirements.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... rata requirements. 240.14d-8 Section 240.14d-8 Commodity and Securities Exchanges SECURITIES AND... rata requirements. Notwithstanding the pro rata provisions of section 14(d)(6) of the Act, if any... taken up and paid for as nearly as may be pro rata, disregarding fractions, according to the number...

  20. 17 CFR 240.14d-8 - Exemption from statutory pro rata requirements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Exemption from statutory pro... Regulations Under the Securities Exchange Act of 1934 Regulation 14d § 240.14d-8 Exemption from statutory pro rata requirements. Notwithstanding the pro rata provisions of section 14(d)(6) of the Act, if...

  1. 17 CFR 240.14d-2 - Commencement of a tender offer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 3 2012-04-01 2012-04-01 false Commencement of a tender offer... Securities Exchange Act of 1934 Regulation 14d § 240.14d-2 Commencement of a tender offer. (a) Date of commencement. A bidder will have commenced its tender offer for purposes of section 14(d) of the Act (15...

  2. 17 CFR 240.14d-2 - Commencement of a tender offer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Commencement of a tender offer... Securities Exchange Act of 1934 Regulation 14d § 240.14d-2 Commencement of a tender offer. (a) Date of commencement. A bidder will have commenced its tender offer for purposes of section 14(d) of the Act (15...

  3. 17 CFR 240.14d-2 - Commencement of a tender offer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Commencement of a tender offer... Securities Exchange Act of 1934 Regulation 14d § 240.14d-2 Commencement of a tender offer. (a) Date of commencement. A bidder will have commenced its tender offer for purposes of section 14(d) of the Act (15...

  4. BacDive--the Bacterial Diversity Metadatabase.

    PubMed

    Söhngen, Carola; Bunk, Boyke; Podstawka, Adam; Gleim, Dorothea; Overmann, Jörg

    2014-01-01

    BacDive-the Bacterial Diversity Metadatabase (http://bacdive.dsmz.de) merges detailed strain-linked information on the different aspects of bacterial and archaeal biodiversity. Currently (release 9/2013), BacDive contains entries for 23 458 strains and provides information on their taxonomy, morphology, physiology, sampling and concomitant environmental conditions as well as molecular biology. Where available, links to access the respective biological resources are given. The majority of the BacDive data is manually annotated and curated. The BacDive portal offers an easy-to-use simple search and in addition powerful advanced search functionalities allowing to combine more than 30 search fields for text and numerical data. The user can compile individual sets of strains to a download selection that can easily be imported into nearly all spreadsheet applications. PMID:24214959

  5. P-47 Thunderbolt with dive recovery flaps

    NASA Technical Reports Server (NTRS)

    1946-01-01

    Caption: 'The dive recovery flaps on this P-47 Thunderbolt are barely visible underneath the wings. Photograph and caption published in Winds of Change, 75th Anniversary NASA publication (pages 52-53 and 130), by James Schultz.

  6. Recreational Diving Impacts on Coral Reefs and the Adoption of Environmentally Responsible Practices within the SCUBA Diving Industry

    NASA Astrophysics Data System (ADS)

    Roche, Ronan C.; Harvey, Chloe V.; Harvey, James J.; Kavanagh, Alan P.; McDonald, Meaghan; Stein-Rostaing, Vivienne R.; Turner, John R.

    2016-07-01

    Recreational diving on coral reefs is an activity that has experienced rapidly growing levels of popularity and participation. Despite providing economic activity for many developing coastal communities, the potential role of dive impacts in contributing to coral reef damage is a concern at heavily dived locations. Management measures to address this issue increasingly include the introduction of programmes designed to encourage environmentally responsible practices within the dive industry. We examined diver behaviour at several important coral reef dive locations within the Philippines and assessed how diver characteristics and dive operator compliance with an environmentally responsible diving programme, known as the Green Fins approach, affected reef contacts. The role of dive supervision was assessed by recording dive guide interventions underwater, and how this was affected by dive group size. Of the 100 recreational divers followed, 88 % made contact with the reef at least once per dive, with a mean (±SE) contact rate of 0.12 ± 0.01 per min. We found evidence that the ability of dive guides to intervene and correct diver behaviour in the event of a reef contact decreases with larger diver group sizes. Divers from operators with high levels of compliance with the Green Fins programme exhibited significantly lower reef contact rates than those from dive operators with low levels of compliance. The successful implementation of environmentally responsible diving programmes, which focus on influencing dive industry operations, can contribute to the management of human impacts on coral reefs.

  7. Recreational Diving Impacts on Coral Reefs and the Adoption of Environmentally Responsible Practices within the SCUBA Diving Industry.

    PubMed

    Roche, Ronan C; Harvey, Chloe V; Harvey, James J; Kavanagh, Alan P; McDonald, Meaghan; Stein-Rostaing, Vivienne R; Turner, John R

    2016-07-01

    Recreational diving on coral reefs is an activity that has experienced rapidly growing levels of popularity and participation. Despite providing economic activity for many developing coastal communities, the potential role of dive impacts in contributing to coral reef damage is a concern at heavily dived locations. Management measures to address this issue increasingly include the introduction of programmes designed to encourage environmentally responsible practices within the dive industry. We examined diver behaviour at several important coral reef dive locations within the Philippines and assessed how diver characteristics and dive operator compliance with an environmentally responsible diving programme, known as the Green Fins approach, affected reef contacts. The role of dive supervision was assessed by recording dive guide interventions underwater, and how this was affected by dive group size. Of the 100 recreational divers followed, 88 % made contact with the reef at least once per dive, with a mean (±SE) contact rate of 0.12 ± 0.01 per min. We found evidence that the ability of dive guides to intervene and correct diver behaviour in the event of a reef contact decreases with larger diver group sizes. Divers from operators with high levels of compliance with the Green Fins programme exhibited significantly lower reef contact rates than those from dive operators with low levels of compliance. The successful implementation of environmentally responsible diving programmes, which focus on influencing dive industry operations, can contribute to the management of human impacts on coral reefs. PMID:27055531

  8. Decompression sickness following breath-hold diving.

    PubMed

    Schipke, J D; Gams, E; Kallweit, Oliver

    2006-01-01

    Despite convincing evidence of a relationship between breath-hold diving and decompression sickness (DCS), the causal connection is only slowly being accepted. Only the more recent textbooks have acknowledged the risks of repetitive breath-hold diving. We compare four groups of breath-hold divers: (1) Japanese and Korean amas and other divers from the Pacific area, (2) instructors at naval training facilities, (3) spear fishers, and (4) free-dive athletes. While the number of amas is likely decreasing, and Scandinavian Navy training facilities recorded only a few accidents, the number of spear fishers suffering accidents is on the rise, in particular during championships or using scooters. Finally, national and international associations (e.g., International Association of Free Drives [IAFD] or Association Internationale pour Le Developpment De L'Apnee [AIDA]) promote free-diving championships including deep diving categories such as constant weight, variable weight, and no limit. A number of free-diving athletes, training for or participating in competitions, are increasingly accident prone as the world record is presently set at a depth of 171 m. This review presents data found after searching Medline and ISI Web of Science and using appropriate Internet search engines (e.g., Google). We report some 90 cases in which DCS occurred after repetitive breath-hold dives. Even today, the risk of suffering from DCS after repetitive breath-hold diving is often not acknowledged. We strongly suggest that breath-hold divers and their advisors and physicians be made aware of the possibility of DCS and of the appropriate therapeutic measures to be taken when DCS is suspected. Because the risk of suffering from DCS increases depending on depth, bottom time, rate of ascent, and duration of surface intervals, some approaches to assess the risks are presented. Regrettably, none of these approaches is widely accepted. We propose therefore the development of easily manageable

  9. SCUBA Diving and Asthma: Clinical Recommendations and Safety.

    PubMed

    Coop, Christopher A; Adams, Karla E; Webb, Charles N

    2016-02-01

    The objective of this article is to review the available studies regarding asthma and SCUBA (self-contained underwater breathing apparatus) diving. A literature search was conducted in MEDLINE to identify peer-reviewed articles related to asthma and SCUBA diving using the following keywords: asthma, allergy, and SCUBA diving. SCUBA diving is a popular sport with more than 9 million divers in the USA. SCUBA diving can be a dangerous sport. Bronchospasm can develop in asthmatic patients and cause airway obstruction. Airway obstruction may be localized to the distal airway which prevents gas elimination. Uncontrolled expansion of the distal airway may result in pulmonary barotrauma. There is also the risk of a gas embolism. Asthmatic divers can also aspirate seawater which may induce bronchospasm. Pollen contamination of their oxygen tank may exacerbate atopic asthma in patients. Diving may be hazardous to the lung function of patients with asthma. Despite the risks of SCUBA diving, many asthmatic individuals can dive without serious diving events. Diving evaluations for asthmatic patients have focused on a thorough patient history, spirometry, allergy testing, and bronchial challenges. For patients that wish to dive, their asthma should be well controlled without current chest symptoms. Patients should have a normal spirometry. Some diving societies recommend that an asthmatic patient should successfully pass a bronchial provocation challenge. Recommendations also state that exercise-, emotion-, and cold-induced asthmatics should not dive. Asthmatic patients requiring rescue medication within 48 h should not dive. PMID:25666876

  10. Distributed Saturation

    NASA Technical Reports Server (NTRS)

    Chung, Ming-Ying; Ciardo, Gianfranco; Siminiceanu, Radu I.

    2007-01-01

    The Saturation algorithm for symbolic state-space generation, has been a recent break-through in the exhaustive veri cation of complex systems, in particular globally-asyn- chronous/locally-synchronous systems. The algorithm uses a very compact Multiway Decision Diagram (MDD) encoding for states and the fastest symbolic exploration algo- rithm to date. The distributed version of Saturation uses the overall memory available on a network of workstations (NOW) to efficiently spread the memory load during the highly irregular exploration. A crucial factor in limiting the memory consumption during the symbolic state-space generation is the ability to perform garbage collection to free up the memory occupied by dead nodes. However, garbage collection over a NOW requires a nontrivial communication overhead. In addition, operation cache policies become critical while analyzing large-scale systems using the symbolic approach. In this technical report, we develop a garbage collection scheme and several operation cache policies to help on solving extremely complex systems. Experiments show that our schemes improve the performance of the original distributed implementation, SmArTNow, in terms of time and memory efficiency.

  11. Training rats to voluntarily dive underwater: investigations of the mammalian diving response.

    PubMed

    McCulloch, Paul F

    2014-01-01

    Underwater submergence produces autonomic changes that are observed in virtually all diving animals. This reflexly-induced response consists of apnea, a parasympathetically-induced bradycardia and a sympathetically-induced alteration of vascular resistance that maintains blood flow to the heart, brain and exercising muscles. While many of the metabolic and cardiorespiratory aspects of the diving response have been studied in marine animals, investigations of the central integrative aspects of this brainstem reflex have been relatively lacking. Because the physiology and neuroanatomy of the rat are well characterized, the rat can be used to help ascertain the central pathways of the mammalian diving response. Detailed instructions are provided on how to train rats to swim and voluntarily dive underwater through a 5 m long Plexiglas maze. Considerations regarding tank design and procedure room requirements are also given. The behavioral training is conducted in such a way as to reduce the stressfulness that could otherwise be associated with forced underwater submergence, thus minimizing activation of central stress pathways. The training procedures are not technically difficult, but they can be time-consuming. Since behavioral training of animals can only provide a model to be used with other experimental techniques, examples of how voluntarily diving rats have been used in conjunction with other physiological and neuroanatomical research techniques, and how the basic training procedures may need to be modified to accommodate these techniques, are also provided. These experiments show that voluntarily diving rats exhibit the same cardiorespiratory changes typically seen in other diving animals. The ease with which rats can be trained to voluntarily dive underwater, and the already available data from rats collected in other neurophysiological studies, makes voluntarily diving rats a good behavioral model to be used in studies investigating the central aspects of the

  12. Physiology of diving of birds and mammals.

    PubMed

    Butler, P J; Jones, D R

    1997-07-01

    This review concentrates on the physiological responses, and their control, in freely diving birds and mammals that enable them to remain submerged and sometimes quite active for extended periods of time. Recent developments in technology have provided much detailed information on the behavior of these fascinating animals. Unfortunately, the advances in technology have been insufficient to enable physiologists to obtain anything like the same level of detail on the metabolic rate and physiological adjustments that occur during natural diving. This has led to much speculation and calculations based on many assumptions concerning usable oxygen stores and metabolic rate during diving, in an attempt to explain the observed behavior. Despite their shortcomings, these calculations have provided useful insights into the degree of adaptations of various species of aquatic birds and mammals. Many of them, e.g., ducks, smaller penguins, fur seals, and Weddell seals, seem able to metabolize aerobically, when diving, at approximately the same (if not greater) rate as they do at the surface. Their enhanced oxygen stores are able to support aerobic metabolism, at what would not be considered unusually low levels, for the duration of the dives, although there are probably circulatory readjustments to ensure that the oxygen stores are managed judiciously. For other species, such as the larger penguins, South Georgian shag, and female elephant seals, there is a general consensus that they must either be reducing their aerobic metabolic rate when diving, possibly by way of regional hypothermia, and/or producing ATP, at least partly, by anaerobiosis and metabolizing the lactic acid when at the surface (although this is hardly likely in the case of the female elephant seals). Circulation is the proximate regulator of metabolism during aerobic diving, and heart rate is the best single indicator of circulatory adjustment. During voluntary dives, heart rates range from extreme

  13. Metabolic regulation in diving birds and mammals.

    PubMed

    Butler, Patrick J

    2004-08-12

    Ducks, fur seals, Weddell seals and probably most cetaceans seem to be able to dive and remain aerobic for durations that are consistent with their elevated stores of usable oxygen and their metabolic rate while diving being similar to that when they are resting at the surface of the water. Ducks, in fact, have a high metabolic rate while diving, mainly because of their large positive buoyancy, but other species have relatively low buoyancy, are better streamlined and use lift-based rather than drag-based propulsion. However, species such as the larger penguins, grey seals and elephant seals seem to achieve the impossible by performing a substantial proportion of their dives for periods longer than would be expected on the above assumptions, and yet remaining aerobic. The logical conclusion is that during such dives these species reduce their metabolic rate below the resting level (hypometabolism) and, in some of them, there is a regional reduction in body temperature (hypothermia) which may contribute to the reduction in metabolic rate. PMID:15288601

  14. Blood Oxygen Depletion Is Independent of Dive Function in a Deep Diving Vertebrate, the Northern Elephant Seal

    PubMed Central

    Meir, Jessica U.; Robinson, Patrick W.; Vilchis, L. Ignacio; Kooyman, Gerald L.; Costa, Daniel P.; Ponganis, Paul J.

    2013-01-01

    Although energetics is fundamental to animal ecology, traditional methods of determining metabolic rate are neither direct nor instantaneous. Recently, continuous blood oxygen (O2) measurements were used to assess energy expenditure in diving elephant seals (Mirounga angustirostris), demonstrating that an exceptional hypoxemic tolerance and exquisite management of blood O2 stores underlie the extraordinary diving capability of this consummate diver. As the detailed relationship of energy expenditure and dive behavior remains unknown, we integrated behavior, ecology, and physiology to characterize the costs of different types of dives of elephant seals. Elephant seal dive profiles were analyzed and O2 utilization was classified according to dive type (overall function of dive: transit, foraging, food processing/rest). This is the first account linking behavior at this level with in vivo blood O2 measurements in an animal freely diving at sea, allowing us to assess patterns of O2 utilization and energy expenditure between various behaviors and activities in an animal in the wild. In routine dives of elephant seals, the blood O2 store was significantly depleted to a similar range irrespective of dive function, suggesting that all dive types have equal costs in terms of blood O2 depletion. Here, we present the first physiological evidence that all dive types have similarly high blood O2 demands, supporting an energy balance strategy achieved by devoting one major task to a given dive, thereby separating dive functions into distinct dive types. This strategy may optimize O2 store utilization and recovery, consequently maximizing time underwater and allowing these animals to take full advantage of their underwater resources. This approach may be important to optimizing energy expenditure throughout a dive bout or at-sea foraging trip and is well suited to the lifestyle of an elephant seal, which spends > 90% of its time at sea submerged making diving its most

  15. Blood oxygen depletion is independent of dive function in a deep diving vertebrate, the northern elephant seal.

    PubMed

    Meir, Jessica U; Robinson, Patrick W; Vilchis, L Ignacio; Kooyman, Gerald L; Costa, Daniel P; Ponganis, Paul J

    2013-01-01

    Although energetics is fundamental to animal ecology, traditional methods of determining metabolic rate are neither direct nor instantaneous. Recently, continuous blood oxygen (O2) measurements were used to assess energy expenditure in diving elephant seals (Mirounga angustirostris), demonstrating that an exceptional hypoxemic tolerance and exquisite management of blood O2 stores underlie the extraordinary diving capability of this consummate diver. As the detailed relationship of energy expenditure and dive behavior remains unknown, we integrated behavior, ecology, and physiology to characterize the costs of different types of dives of elephant seals. Elephant seal dive profiles were analyzed and O2 utilization was classified according to dive type (overall function of dive: transit, foraging, food processing/rest). This is the first account linking behavior at this level with in vivo blood O2 measurements in an animal freely diving at sea, allowing us to assess patterns of O2 utilization and energy expenditure between various behaviors and activities in an animal in the wild. In routine dives of elephant seals, the blood O2 store was significantly depleted to a similar range irrespective of dive function, suggesting that all dive types have equal costs in terms of blood O2 depletion. Here, we present the first physiological evidence that all dive types have similarly high blood O2 demands, supporting an energy balance strategy achieved by devoting one major task to a given dive, thereby separating dive functions into distinct dive types. This strategy may optimize O2 store utilization and recovery, consequently maximizing time underwater and allowing these animals to take full advantage of their underwater resources. This approach may be important to optimizing energy expenditure throughout a dive bout or at-sea foraging trip and is well suited to the lifestyle of an elephant seal, which spends > 90% of its time at sea submerged making diving its most "natural

  16. 29 CFR 1910.422 - Procedures during dive.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations General Operations Procedures § 1910.422... applicable to each diving operation unless otherwise specified. (b) Water entry and exit. (1) A means...

  17. 29 CFR 1910.422 - Procedures during dive.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations General Operations Procedures § 1910.422... applicable to each diving operation unless otherwise specified. (b) Water entry and exit. (1) A means...

  18. Use of a mobile diving support vessel, Offshore California

    SciTech Connect

    Carroll, J.P.

    1983-03-01

    The Blue Dolphin is a converted workboat with a one-atmosphere manipulator bell diving system. It provides diving support for Chevron's offshore drilling program. This support includes underwater inspection, repair and salvage.

  19. 29 CFR 1910.422 - Procedures during dive.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations General Operations Procedures § 1910.422... applicable to each diving operation unless otherwise specified. (b) Water entry and exit. (1) A means...

  20. 29 CFR 1910.422 - Procedures during dive.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations General Operations Procedures § 1910.422... applicable to each diving operation unless otherwise specified. (b) Water entry and exit. (1) A means...

  1. Barotrauma of the ears and sinuses after scuba diving.

    PubMed

    Becker, G D; Parell, G J

    2001-05-01

    The pathophysiology, differential diagnosis, and currently available management of barotrauma affecting the ears and sinuses after scuba diving are reviewed, along with medical standards for resuming scuba diving after barotrauma has resolved. PMID:11407445

  2. Habituation of the cardiac response to involuntary diving in diving and dabbling ducks.

    PubMed

    Gabbott, G R; Jones, D R

    1987-09-01

    1. Bradycardia in response to forced submergence was habituated in dabbling (Anas platyrhynchos, Linnaeus) and diving (Aythya americana, Eyton) ducks by repetitively submerging the animals, each day for several days, for periods of 40 and 20 s, respectively. The onset of pronounced bradycardia was delayed with each successive trial, until little or no bradycardia occurred during submergence. Diving bradycardia is driven by chemoreceptors in the dabbler and caused by stimulation of narial receptors in the diver. 2. Mean arterial blood pressure in dives was unchanged from pre-dive levels in both naive and trained dabbling ducks. PaO2, PaCO2 and pHa at the end of a dive were similar before and after habituation training. 3. Bradycardia occurred in dives by habituated dabbling ducks if the animal breathed 15% O2 before submergence. The ventilatory responses to breathing high and low levels of oxygen were unaffected by habituation training. 4. The changes in blood gases during dives by naive and habituated dabbling ducks were the same: therefore, in the absence of a demonstrated decrement in receptor chemosensitivity or efferent potency, the locus of habituation must reside in the central nervous system. PMID:3694117

  3. Recreational technical diving part 1: an introduction to technical diving methods and activities.

    PubMed

    Mitchell, Simon J; Doolette, David J

    2013-06-01

    Technical divers use gases other than air and advanced equipment configurations to conduct dives that are deeper and/or longer than typical recreational air dives. The use of oxygen-nitrogen (nitrox) mixes with oxygen fractions higher than air results in longer no-decompression limits for shallow diving, and faster decompression from deeper dives. For depths beyond the air-diving range, technical divers mix helium, a light non-narcotic gas, with nitrogen and oxygen to produce 'trimix'. These blends are tailored to the depth of intended use with a fraction of oxygen calculated to produce an inspired oxygen partial pressure unlikely to cause cerebral oxygen toxicity and a nitrogen fraction calculated to produce a tolerable degree of nitrogen narcosis. A typical deep technical dive will involve the use of trimix at the target depth with changes to gases containing more oxygen and less inert gas during the decompression. Open-circuit scuba may be used to carry and utilise such gases, but this is very wasteful of expensive helium. There is increasing use of closed-circuit 'rebreather' devices. These recycle expired gas and potentially limit gas consumption to a small amount of inert gas to maintain the volume of the breathing circuit during descent and the amount of oxygen metabolised by the diver. This paper reviews the basic approach to planning and execution of dives using these methods to better inform physicians of the physical demands and risks. PMID:23813462

  4. Summer diving behavior of male walruses in Bristol Bay, Alaska

    USGS Publications Warehouse

    Jay, C.V.; Farley, Sean D.; Garner, G.W.

    2001-01-01

    Pacific walruses (Odobenus rosmarus divergens) make trips from ice or land haul-out sites to forage for benthic prey. We describe dive and trip characteristics from time-depth-recorder data collected over a one-month period during summer from four male Pacific walruses in Bristol Bay, Alaska. Dives were classified into four types. Shallow (4 m), short (2.7 min), square-shaped dives accounted for 11% of trip time, and many were probably associated with traveling. Shallow (2 m) and very short (0.5 min) dives composed only 1% of trip time. Deep (41 m), long (7.2 min), square-shaped dives accounted for 46% of trip time and were undoubtedly associated with benthic foraging. V-shaped dives ranged widely in depth, were of moderate duration (4.7 min), and composed 3% of trip time. These dives may have been associated with navigation or exploration of the seafloor for potential prey habitat. Surface intervals between dives were similar among dive types, and generally lasted 1-2 min. Total foraging time was strongly correlated with trip duration and there was no apparent diel pattern of diving in any dive type among animals. We found no correlation between dive duration and postdive surface interval within dive types, suggesting that diving occurred within aerobic dive limits. Trip duration varied considerably within and among walruses (0.3-9.4 d), and there was evidence that some of the very short trips were unrelated to foraging. Overall, walruses were in the water for 76.6% of the time, of which 60.3% was spent diving.

  5. [Complex profile of the reflex diving response].

    PubMed

    Wierzba, Tomasz H; Ropiak, Arkadiusz

    2011-01-01

    Breath-holding coupled with face cooling triggers a set of the reflex cardiovascular responses, defined as a diving reflex. The major reflex responses include a decrease in heart rate and peripheral vasoconstriction with an increase of arterial pressure to evoke central blood pooling with preferential provision of the brain and heart perfusion. Due to high individual variability and situational dependence the individual course of the reflex response is hardly predictable. Heart rhythm disturbances are the major, sometimes fatal complications of the response. This review is an outline of causing factors, circumstances, mechanisms and the effects of the diving reflex and their practical implications, including risk factors of the critical arrhythmias occurred in diving. PMID:22125213

  6. 29 CFR 1926.1086 - Mixed-gas diving.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Mixed-gas diving. 1926.1086 Section 1926.1086 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1086 Mixed-gas diving. Note: The requirements applicable to construction work under this section...

  7. 46 CFR 56.50-110 - Diving support systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Diving support systems. 56.50-110 Section 56.50-110... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-110 Diving support systems. (a) In addition to the requirements of this part, piping for diving installations which is permanently...

  8. 29 CFR 1915.6 - Commerical diving operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Commerical diving operations. 1915.6 Section 1915.6 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Commerical diving operations. Commerical diving operations shall be subject to subpart T of part...

  9. 29 CFR 1926.1086 - Mixed-gas diving.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Mixed-gas diving. 1926.1086 Section 1926.1086 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1086 Mixed-gas diving. Note: The requirements applicable to construction work under this section...

  10. 46 CFR 56.50-110 - Diving support systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Diving support systems. 56.50-110 Section 56.50-110... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-110 Diving support systems. (a) In addition to the requirements of this part, piping for diving installations which is permanently...

  11. 29 CFR 1915.6 - Commerical diving operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Commerical diving operations. 1915.6 Section 1915.6 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Commerical diving operations. Commerical diving operations shall be subject to subpart T of part...

  12. 29 CFR 1926.1085 - Surface-supplied air diving.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Surface-supplied air diving. 1926.1085 Section 1926.1085..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1085 Surface-supplied air diving. Note: The requirements applicable to construction...

  13. 46 CFR 56.50-110 - Diving support systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Diving support systems. 56.50-110 Section 56.50-110... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-110 Diving support systems. (a) In addition to the requirements of this part, piping for diving installations which is permanently...

  14. 29 CFR 1926.1086 - Mixed-gas diving.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Mixed-gas diving. 1926.1086 Section 1926.1086 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1086 Mixed-gas diving. Note: The requirements applicable to construction work under this section...

  15. 29 CFR 1915.6 - Commerical diving operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Commerical diving operations. 1915.6 Section 1915.6 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Commerical diving operations. Commerical diving operations shall be subject to subpart T of part...

  16. 46 CFR 197.432 - Surface-supplied air diving.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... at depths less than 190 fsw, except that dives with bottom times of 30 minutes or less may be conducted to depths of 220 fsw; (b) Each diving operation has a primary breathing gas supply; (c) Each diver... deeper than 130 fsw or outside the no-decompression limits— (1) Each diving operation has a...

  17. 29 CFR 1910.425 - Surface-supplied air diving.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-supplied air diving shall not be conducted at depths deeper than 190 fsw, except that dives with bottom times of 30 minutes or less may be conducted to depths of 220 fsw. (2) A decompression chamber shall be... fsw. (3) A bell shall be used for dives with an inwater decompression time greater than 120...

  18. 29 CFR 1910.426 - Mixed-gas diving.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... fsw or when the dive involves inwater decompression time of greater than 120 minutes, except when... depths greater than 300 fsw, except when diving is conducted in physically confining spaces. (c... for dives deeper than 100 fsw or outside the no-decompression limits. (8) When a closed bell is...

  19. 29 CFR 1910.426 - Mixed-gas diving.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... fsw or when the dive involves inwater decompression time of greater than 120 minutes, except when... depths greater than 300 fsw, except when diving is conducted in physically confining spaces. (c... for dives deeper than 100 fsw or outside the no-decompression limits. (8) When a closed bell is...

  20. 29 CFR 1910.426 - Mixed-gas diving.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... fsw or when the dive involves inwater decompression time of greater than 120 minutes, except when... depths greater than 300 fsw, except when diving is conducted in physically confining spaces. (c... for dives deeper than 100 fsw or outside the no-decompression limits. (8) When a closed bell is...

  1. 29 CFR 1926.1086 - Mixed-gas diving.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Mixed-gas diving. 1926.1086 Section 1926.1086 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1086 Mixed-gas diving. Note: The requirements applicable to construction work under this section...

  2. 29 CFR 1910.425 - Surface-supplied air diving.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Surface-supplied air diving. 1910.425 Section 1910.425..., DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations Specific Operations Procedures § 1910.425 Surface-supplied air diving. (a) General. Employers engaged in surface-supplied...

  3. 46 CFR 197.334 - Open diving bells.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Open diving bells. 197.334 Section 197.334 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.334 Open diving bells. Each open...

  4. 29 CFR 1926.1085 - Surface-supplied air diving.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Surface-supplied air diving. 1926.1085 Section 1926.1085..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1085 Surface-supplied air diving. Note: The requirements applicable to construction...

  5. 29 CFR 1915.6 - Commerical diving operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Commerical diving operations. 1915.6 Section 1915.6 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Commerical diving operations. Commerical diving operations shall be subject to subpart T of part...

  6. 29 CFR 1926.1086 - Mixed-gas diving.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Mixed-gas diving. 1926.1086 Section 1926.1086 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1086 Mixed-gas diving. Note: The requirements applicable to construction work under this section...

  7. 29 CFR 1926.1085 - Surface-supplied air diving.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Surface-supplied air diving. 1926.1085 Section 1926.1085..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Diving Specific Operations Procedures § 1926.1085 Surface-supplied air diving. Note: The requirements applicable to construction...

  8. 46 CFR 56.50-110 - Diving support systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Diving support systems. 56.50-110 Section 56.50-110... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-110 Diving support systems. (a) In addition to the requirements of this part, piping for diving installations which is permanently...

  9. 29 CFR 1910.425 - Surface-supplied air diving.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Surface-supplied air diving. 1910.425 Section 1910.425..., DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations Specific Operations Procedures § 1910.425 Surface-supplied air diving. (a) General. Employers engaged in surface-supplied...

  10. 46 CFR 56.50-110 - Diving support systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Diving support systems. 56.50-110 Section 56.50-110... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-110 Diving support systems. (a) In addition to the requirements of this part, piping for diving installations which is permanently...

  11. 46 CFR 197.334 - Open diving bells.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Open diving bells. 197.334 Section 197.334 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.334 Open diving bells. Each open...

  12. 29 CFR 1915.6 - Commerical diving operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Commerical diving operations. 1915.6 Section 1915.6 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Commerical diving operations. Commerical diving operations shall be subject to subpart T of part...

  13. 29 CFR 1910.422 - Procedures during dive.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Procedures during dive. 1910.422 Section 1910.422 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations General Operations Procedures § 1910.422 Procedures during dive....

  14. 29 CFR 1910.421 - Pre-dive procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Pre-dive procedures. 1910.421 Section 1910.421 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations General Operations Procedures § 1910.421 Pre-dive procedures. (a)...

  15. 29 CFR 1910.421 - Pre-dive procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Pre-dive procedures. 1910.421 Section 1910.421 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations General Operations Procedures § 1910.421 Pre-dive procedures. (a)...

  16. 29 CFR 1910.421 - Pre-dive procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Pre-dive procedures. 1910.421 Section 1910.421 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Commercial Diving Operations General Operations Procedures § 1910.421 Pre-dive procedures. (a)...

  17. Effects of scuba diving on vascular repair mechanisms.

    PubMed

    Culic, Vedrana Cikes; Van Craenenbroeck, Emeline; Muzinic, Nikolina Rezic; Ljubkovic, Marko; Marinovic, Jasna; Conraads, Viviane; Dujic, Zeljko

    2014-01-01

    A single air dive causes transient endothelial dysfunction. Endothelial progenitor cells (EPCs) and circulating angiogenic cells (CAC) contribute synergistically to endothelial repair. In this study (1) the acute effects of diving on EPC numbers and CAC migration and (2) the influence of the gas mixture (air/nitrox-36) was investigated. Ten divers performed two dives to 18 meters on Day (D) 1 and D3, using air. After 15 days, dives were repeated with nitrox-36. Blood sampling took place before and immediately after diving. Circulating EPCs were quantified by flow cytometry, CAC migration of culture was assessed on D7. When diving on air, a trend for reduced EPC numbers is observed post-dive, which is persistent on D1 and D3. CAC migration tends to improve acutely following diving. These effects are more pronounced with nitrox-36 dives. Diving acutely affects EPC numbers and CAC function, and to a larger extent when diving with nitrox-36. The diving-induced oxidative stress may influence recruitment or survival of EPC. The functional improvement of CAC could be a compensatory mechanism to maintain endothelial homeostasis. PMID:24851546

  18. Saturated fat (image)

    MedlinePlus

    ... saturated fats. Vegetable sources of saturated fat include coconut and palm oils. When looking at a food ... saturated fats. Vegetable sources of saturated fat include coconut and palm oils. When looking at a food ...

  19. Physiological and clinical aspects of apnea diving.

    PubMed

    Muth, Claus-Martin; Ehrmann, Ulrich; Radermacher, Peter

    2005-09-01

    Apnea diving is a fascinating example of applied physiology. The record for apnea diving as an extreme sport is 171 meters, 8:58 minutes. The short time beneath the surface induces profound cardiovascular and respiratory effects. Variations of blood-gas tensions result from the interaction of metabolism and the rapid sequence of compression and decompression. Decompression sickness is possible. Apnea divers can reach depths beyond the theoretic physiologic limit by using the lung-packing maneuver. Apnea divers exhibit a fall in heart rate, which can be trained and is an oxygen-conserving effect, but increases the incidence of ventricular arrhythmia. PMID:16140133

  20. Diving into the Ice Bucket Challenge

    PubMed Central

    McKee, Kathleen; Batra, Ayush; Klein, Joshua P.; Henderson, Galen V.

    2015-01-01

    Triggered by facial exposure to cold water and apnea, the mammalian diving reflex consists of bradycardia and peripheral arteriolar vasoconstriction leading to an increase in central arterial pressure. It has been previously associated with ischemic stroke but not definitively with intracerebral hemorrhage. We present a case of intracerebral hemorrhage occurring in a woman with poorly controlled hypertension following her participation in the amyotrophic lateral sclerosis fund-raising “Ice Bucket Challenge,” in which ice-cold water was poured on her head. We suspect that facial exposure to ice-cold water triggered the diving reflex, causing a hypertensive surge and ultimately the intracerebral hemorrhage. PMID:26288676

  1. O2 store management in diving emperor penguins

    PubMed Central

    Ponganis, P. J.; Stockard, T. K.; Meir, J. U.; Williams, C. L.; Ponganis, K. V.; Howard, R.

    2009-01-01

    Summary In order to further define O2 store utilization during dives and understand the physiological basis of the aerobic dive limit (ADL, dive duration associated with the onset of post-dive blood lactate accumulation), emperor penguins (Aptenodytes forsteri) were equipped with either a blood partial pressure of oxygen (PO2) recorder or a blood sampler while they were diving at an isolated dive hole in the sea ice of McMurdo Sound, Antarctica. Arterial PO2 profiles (57 dives) revealed that (a) pre-dive PO2 was greater than that at rest, (b) PO2 transiently increased during descent and (c) post-dive PO2 reached that at rest in 1.92±1.89 min (N=53). Venous PO2 profiles (130 dives) revealed that (a) pre-dive venous PO2 was greater than that at rest prior to 61% of dives, (b) in 90% of dives venous PO2 transiently increased with a mean maximum PO2 of 53±18 mmHg and a mean increase in PO2 of 11±12 mmHg, (c) in 78% of dives, this peak venous PO2 occurred within the first 3 min, and (d) post-dive venous PO2 reached that at rest within 2.23±2.64 min (N=84). Arterial and venous PO2 values in blood samples collected 1–3 min into dives were greater than or near to the respective values at rest. Blood lactate concentration was less than 2 mmol l–1 as far as 10.5 min into dives, well beyond the known ADL of 5.6 min. Mean arterial and venous PN2 of samples collected at 20–37 m depth were 2.5 times those at the surface, both being 2.1±0.7 atmospheres absolute (ATA; N=3 each), and were not significantly different. These findings are consistent with the maintenance of gas exchange during dives (elevated arterial and venous PO2 and PN2 during dives), muscle ischemia during dives (elevated venous PO2, lack of lactate washout into blood during dives), and arterio-venous shunting of blood both during the surface period (venous PO2 greater than that at rest) and during dives (arterialized venous PO2 values during descent, equivalent arterial and venous PN2 values during

  2. [Scuba diving and the heart. Cardiac aspects of sport scuba diving].

    PubMed

    Muth, Claus-Martin; Tetzlaff, Kay

    2004-06-01

    Diving with self-contained underwater breathing apparatus (scuba) has become a popular recreational sports activity throughout the world. A high prevalence of cardiovascular disorders among the population makes it therefore likely that subjects suffering from cardiovascular problems may want to start scuba diving. Although scuba diving is not a competitive sport requiring athletic health conditions, a certain medical fitness is recommended because of the physical peculiarities of the underwater environment. Immersion alone will increase cardiac preload by central blood pooling with a rise in both cardiac output and blood pressure, counteracted by increased diuresis. Exposure to cold and increased oxygen partial pressure during scuba diving will additionally increase afterload by vasoconstrictive effects and may exert bradyarryhthmias in combination with breath-holds. Volumes of gas-filled body cavities will be affected by changing pressure (Figure 1), and inert gas components of the breathing gas mixture such as nitrogen in case of air breathing will dissolve in body tissues and venous blood with increasing alveolar inert gas pressure. During decompression a free gas phase may form in supersaturated tissues, resulting in the generation of inert gas microbubbles that are eliminated by the venous return to the lungs under normal circumstances. Certain cardiovascular conditions may have an impact on these physiological changes and pose the subject at risk of suffering adverse events from scuba diving. Arterial hypertension may be aggravated by underwater exercise and immersion. Symptomatic coronary artery disease and symptomatic heart rhythm disorders preclude diving. The occurrence of ventricular extrasystoles according to Lown classes I and II, and the presence of atrial fibrillation are considered relative contraindications in the absence of an aggravation following exercise. Asymptomatic subjects with Wolff-Parkinson-White syndrome may be allowed to dive, but in

  3. [Health aspects of diving in ENT medicine. Part I: Diving associated diseases].

    PubMed

    Klingmann, C; Wallner, F

    2004-08-01

    There has been a steady increase in the number of recreational scuba divers in the last years, with a growing number of diving associated diseases involving ENT medicine. Disorders of the ears, sinuses and pharynx are those most common in divers. In particular, external otitis and barotrauma of the middle ear are commonly treated by every ENT specialist. They usually do not lead to any permanent complaints. Incidents involving the cochleovestibular system are less common, but can result in deafness, vertigo and tinnitus, and therefore have to be treated appropriately. To treat diving medical disorders, the physician has to have some basic understanding of the physical laws that lead to diving incidents. This article will inform the reader of the forces that are encountered by divers, and then give details of the treatment of acute ENT diseases which result from diving incidents. PMID:15221085

  4. The dive response redefined: underwater behavior influences cardiac variability in freely diving dolphins.

    PubMed

    Noren, Shawn R; Kendall, Traci; Cuccurullo, Veronica; Williams, Terrie M

    2012-08-15

    A hallmark of the dive response, bradycardia, promotes the conservation of onboard oxygen stores and enables marine mammals to submerge for prolonged periods. A paradox exists when marine mammals are foraging underwater because activity should promote an elevation in heart rate (f(H)) to support increased metabolic demands. To assess the effect of the interaction between the diving response and underwater activity on f(H), we integrated interbeat f(H) with behavioral observations of adult bottlenose dolphins diving and swimming along the coast of the Bahamas. As expected for the dive response, f(H) while resting during submergence (40±6 beats min(-1)) was significantly lower than f(H) while resting at the water surface (105±8 beats min(-1)). The maximum recorded f(H) (f(H,max)) was 128±7 beats min(-1), and occurred during post-dive surface intervals. During submergence, the level of bradycardia was modified by activity. Behaviors such as simple head bobbing at depth increased f(H) by 40% from submerged resting levels. Higher heart rates were observed for horizontal swimming at depth. Indeed, the dolphins operated at 37-58% of their f(H,max) while active at depth and approached 57-79% of their f(H,max) during anticipatory tachycardia as the animals glided to the surface. f(H) was significantly correlated with stroke frequency (range=0-2.5 strokes s(-1), r=0.88, N=25 dives) and calculated swim speed (range=0-5.4 m s(-1), r=0.88, N=25 dives). We find that rather than a static reflex, the dive response is modulated by behavior and exercise in a predictable manner. PMID:22837445

  5. 17 CFR 240.14d-9 - Recommendation or solicitation by the subject company and others.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Recommendation or solicitation by the subject company and others. 240.14d-9 Section 240.14d-9 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) GENERAL RULES AND REGULATIONS, SECURITIES EXCHANGE ACT OF 1934 Rules and Regulations Under...

  6. 17 CFR 240.14d-3 - Filing and transmission of tender offer statement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... tender offer statement. 240.14d-3 Section 240.14d-3 Commodity and Securities Exchanges SECURITIES AND... tender offer statement. (a) Filing and transmittal. No bidder shall make a tender offer if, after... subject company's securities for which the tender offer is made, unless as soon as practicable on the...

  7. 17 CFR 240.14d-6 - Disclosure of tender offer information to security holders.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Disclosure of tender offer... Regulations Under the Securities Exchange Act of 1934 Regulation 14d § 240.14d-6 Disclosure of tender offer.... If a tender offer is published, sent or given to security holders on the date of commencement...

  8. Sphenoid sinus barotrauma after free diving.

    PubMed

    Bourolias, Constantinos; Gkotsis, Antonios

    2011-01-01

    We report 2 cases of a 29- and a 37-year-old male patient both having sphenoid sinus barotrauma associated with free diving at about 12-m depth. A unilateral occupation of the sphenoid sinus was revealed in both cases by computed tomography and magnetic resonance imaging examination of the paranasal sinuses. PMID:20022669

  9. [Injuries caused by pressure differences while diving].

    PubMed

    Kemmer, A; Welslau, W; Muth, C M

    2005-07-01

    Barotraumas are caused by pressure differences. As described by Boyle's Law, barotraumas develop during the descent phase of diving (and much more rarely during the ascent). The most frequently affected are the ears and paranasal sinuses, in addition to the facial skin and eyes. The most important preventive measure is performing pressure compensation in the affected body cavities. Barotrauma is treated symptomatically. PMID:16041937

  10. 46 CFR 197.410 - Dive procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... of decompression sickness prior to each dive; (4) A depth, bottom time profile, including any... sickness or gas embolism; (iii) The diver is advised of the location of an operational decompression... decompression chamber; and (9) When decompression sickness or gas embolism is suspected or symptoms are...

  11. 46 CFR 197.410 - Dive procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of decompression sickness prior to each dive; (4) A depth, bottom time profile, including any... sickness or gas embolism; (iii) The diver is advised of the location of an operational decompression... decompression chamber; and (9) When decompression sickness or gas embolism is suspected or symptoms are...

  12. 46 CFR 197.410 - Dive procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of decompression sickness prior to each dive; (4) A depth, bottom time profile, including any... sickness or gas embolism; (iii) The diver is advised of the location of an operational decompression... decompression chamber; and (9) When decompression sickness or gas embolism is suspected or symptoms are...

  13. 46 CFR 197.410 - Dive procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... of decompression sickness prior to each dive; (4) A depth, bottom time profile, including any... sickness or gas embolism; (iii) The diver is advised of the location of an operational decompression... decompression chamber; and (9) When decompression sickness or gas embolism is suspected or symptoms are...

  14. [Case Report - Really a diving accident?].

    PubMed

    Fichtner, Andreas

    2015-10-01

    A 17 y old male SCUBA diver presents himself for hospital admission after a suspected diving accident. All clinical signs are favouring the initial diagnosis: loss of leg motor function, paresthesia, disturbed vision and headache. What are your further diagnostic and therapeutic steps? Can you proof the initial diagnosis? What differential diagnoses are relevant or even mimicked? PMID:26510103

  15. Pulmonary function in children after open water SCUBA dives.

    PubMed

    Winkler, B E; Tetzlaff, K; Muth, C-M; Hebestreit, H

    2010-10-01

    An increasing number of children and adolescents is diving with Self-Contained Underwater Breathing Apparatus (SCUBA). SCUBA diving is associated with health risks such as pulmonary barotrauma, especially in children and in individuals with airflow limitation. As no data has been published on the effects of open-water diving on pulmonary function in children, the objective of this study was to evaluate the effects of SCUBA dives on airflow in children. 16 healthy children aged 10-13 years underwent spirometry and a cycle-exercise challenge while breathing cold air. They subsequently performed dives to 1-m and 8-m depth in random order. Pulmonary function was measured before and after the exercise challenge and the dives. There were statistically significant decreases in FEV1, FVC, FEV1/FVC, MEF25 and MEF50 after the cold-air exercise challenge and the dives. Changes in lung function following the exercise challenge did not predict the responses to SCUBA diving. In 3 children the post-dive decrements in FEV1 exceeded 10%. These children had a lower body weight and BMI percentile. SCUBA diving in healthy children may be associated with relevant airflow limitation. A low body mass might contribute to diving-associated bronchoconstriction. In the majority of subjects, no clinically relevant airway obstruction could be observed. PMID:20677123

  16. Diving behaviour and heart rate in tufted ducks (Aythya fuligula).

    PubMed

    Stephenson, R; Butler, P J; Woakes, A J

    1986-11-01

    Diving behaviour and heart rate were monitored in tufted ducks diving under circumstances which simulated various environmental conditions such as feeding under ice in winter. When distance to food was increased on a covered outdoor pond, dive duration increased proportionately, but it was calculated that time available for feeding was reduced during the longer-distance 'extended' dives. There was a gradual reduction in heart rate to 77.3 +/- 13.8 beats min-1, which is significantly lower than the resting value of 121.1 +/- 14.1 beats min-1, during the course of extended dives, suggesting that the ducks could gradually switch over to a 'classical' oxygen-conserving response during these prolonged voluntary dives. The duration of the pre-dive preparatory period was positively correlated with dive distance. When the ducks were briefly unable to resurface during an otherwise normal feeding dive in an indoor tank, a situation which may occur if they become disoriented under ice, there was an immediate switch to a full bradycardia. Reduction in heart rate during these 'enclosed' dives occurred only when the ducks were apparently aware of the situation and the rate of onset of bradycardia was very similar to that previously observed during involuntary submersion of tufted ducks. Minimum heart rate was the same at 46 beats min-1 after 15 s of enclosed dives and after 30 s of involuntary submersions, despite the differences in levels of activity in the two situations. PMID:3805996

  17. Effects of Long-term Diving Training on Cortical Gyrification

    PubMed Central

    Zhang, Yuanchao; Zhao, Lu; Bi, Wenwei; Wang, Yue; Wei, Gaoxia; Evans, Alan; Jiang, Tianzi

    2016-01-01

    During human brain development, cortical gyrification, which is believed to facilitate compact wiring of neural circuits, has been shown to follow an inverted U-shaped curve, coinciding with the two-stage neurodevelopmental process of initial synaptic overproduction with subsequent pruning. This trajectory allows postnatal experiences to refine the wiring, which may manifest as endophenotypic changes in cortical gyrification. Diving experts, typical elite athletes who commence intensive motor training at a very young age in their early childhood, serve ideal models for examining the gyrification changes related to long-term intensive diving training. Using local gyrification index (LGI), we compared the cortical gyrification between 12 diving experts and 12 controls. Compared with controls, diving experts showed widespread LGI reductions in regions relevant to diving performance. Negative correlations between LGIs and years of diving training were also observed in diving experts. Further exploratory network efficiency analysis of structural cortical networks, inferred from interregional correlation of LGIs, revealed comparable global and local efficiency in diving experts relative to controls. These findings suggest that gyrification reductions in diving experts may be the result of long-term diving training which could refine the neural circuitry (via synaptic pruning) and might be the anatomical substrate underlying their extraordinary diving performance. PMID:27320849

  18. The marine mammal dive response is exercise modulated to maximize aerobic dive duration.

    PubMed

    Davis, Randall W; Williams, Terrie M

    2012-08-01

    When aquatically adapted mammals and birds swim submerged, they exhibit a dive response in which breathing ceases, heart rate slows, and blood flow to peripheral tissues and organs is reduced. The most intense dive response occurs during forced submersion which conserves blood oxygen for the brain and heart, thereby preventing asphyxiation. In free-diving animals, the dive response is less profound, and energy metabolism remains aerobic. However, even this relatively moderate bradycardia seems diametrically opposed to the normal cardiovascular response (i.e., tachycardia and peripheral vasodilation) during physical exertion. As a result, there has been a long-standing paradox regarding how aquatic mammals and birds exercise while submerged. We hypothesized based on cardiovascular modeling that heart rate must increase to ensure adequate oxygen delivery to active muscles. Here, we show that heart rate (HR) does indeed increase with flipper or fluke stroke frequency (SF) during voluntary, aerobic dives in Weddell seals (HR = 1.48SF - 8.87) and bottlenose dolphins (HR = 0.99SF + 2.46), respectively, two marine mammal species with different evolutionary lineages. These results support our hypothesis that marine mammals maintain aerobic muscle metabolism while swimming submerged by combining elements of both dive and exercise responses, with one or the other predominating depending on the level of exertion. PMID:22585422

  19. Oxygen uptake during post dive recovery in a diving bird Aythya fuligula: implications for optimal foraging models.

    PubMed

    Parkes, Roland; Halsey, Lewis G; Woakes, Anthony J; Holder, Roger L; Butler, Patrick J

    2002-12-01

    The rate of oxygen uptake at the surface between dives was measured for four tufted ducks, Aythya fuligula, during bouts of foraging dives to a depth of 1.8 m. The ducks surfaced into a respirometer box after each dive so that the rate of oxygen uptake ((O(2))) could be measured. (O(2)) decreased over time at the surface and there was a particularly rapid phase of oxygen uptake for approximately the first 3s. The specific shape of the oxygen uptake curve is dependent upon the duration of the preceding dive. The uptake curve after longer dives was significantly steeper during the first 3s at the surface than after shorter dives, although (O(2)) after the first 3s was not significantly different between these two dive duration bins. Thus, the mean total oxygen uptake (V(O(2))) was higher after surface periods following longer dives. Due to the high (O(2)) during the initial part of the surface period, the curve associated with longer dives was statistically biphasic, with the point of inflection at 3.3s. The curve for shorter dives was not statistically biphasic. The birds may increase their respiratory frequency during the first 3s after longer dives, producing the increased (O(2)), which would enable the birds to resaturate their oxygen stores more rapidly in response to the increased oxygen depletion of the longer submergence time. PMID:12432016

  20. [Hyperbaric therapy and diving medicine - diving medicine - present state and prospects].

    PubMed

    Winkler, Bernd; Muth, Claus-Martin; Piepho, Tim

    2015-10-01

    The diving accident (decompression incident, DCI) occurs in the decompression phase of dives. The DCI can either be caused by an arterial gas embolism (AGE) subsequent to a pulmonary barotrauma or by the formation of inert gas bubbles subsequent to a reduction of ambient pressure during the ascent from depth. In contrast to the traditional assumption that decompression incidents only occur if decompression rules are neglected, recent data indicate that a vast amount of diving accidents occur even though divers adhered to the rules. Hence, there is a large inter- and intraindividual variability in the predisposition for diving accidents. Within the past few years, the molecular understanding of the pathophysiology of diving accidents has improved considerably. It is now well accepted that pro-inflammatory and pro-coagulatory mechanisms play a central role. Moreover, microparticles are increasingly discussed in the pathogenesis of diving accidents. These new molecular findings have not yet resulted in new therapeutic approaches. However, new approaches of preconditioning before the dive have been developed which are intended to reduce the risk of diving accidents. The symptoms of a diving accident show a large variability and range. They reach from pruritus over tension in the female breast, marbled skin and pain in the joints to severe neurological disability like paraplegia or hemiplegia. Furthermore, pulmonary symptoms can be a result of a pulmonary gas embolism and/or a tension pneumothorax. Extreme cases can also manifest as generalized, difficult-to-treat seizures, loss of consciousness or even death. The evidence-based therapy of diving accidents consists of an immediate application of 100% inspiratory O2. This can be performed via a demand valve, face mask with reservoir bag or ventilation bag connected to a reservoir bag. Fluid substitution is performed by i. v. infusion of 500-1000ml/h of cristalloids. If consciousness is not impaired, the diver is

  1. Respiratory and cardiovascular control during diving in birds and mammals.

    PubMed

    Butler, P J

    1982-10-01

    Recent studies on freely diving birds and mammals indicate that, contrary to the classical hypothesis, the majority of dives are aerobic with minimal cardiovascular adjustments (i.e. bradycardia and selective vasoconstriction). It is postulated that during these aerobic dives the cardiovascular adjustments result from the opposing influences of exercise and the classical diving response, with the bias towards the exercise response. It is envisaged that the active muscles, as well as the brain and heart, are adequately supplied with blood to enable them to metabolize aerobically. Intense mental activity, particularly in carnivores seeking their prey, may also attenuate the classical response. Aerobic dives are usually terminated well before the oxygen stores are depleted, and another dive follows once they have been replenished. In this way a series of dives is performed. Prolonged dives are endured as a result of a shift towards the classical response of bradycardia, presumably more intense vasoconstriction, and anaerobiosis. This may be a form of alarm response, particularly in small animals such as ducks and coypus, or it may be a means of allowing the marine birds and mammals that dive deeply for their food to engage in unusually long hunting expeditions. For those that dive under ice, it may also allow long periods of underwater exploration as well as being a safety mechanism should the animal become disoriented. PMID:6757368

  2. Hormonal regulatory adjustments during voluntary diving in Weddell seals.

    PubMed

    Hochachka, P W; Liggins, G C; Guyton, G P; Schneider, R C; Stanek, K S; Hurford, W E; Creasy, R K; Zapol, D G; Zapol, W M

    1995-10-01

    Subadult male Weddell seals were instrumented with microcomputer-based backpacks and were then monitored during voluntary diving and recovery periods in McMurdo Sound, Antarctica. Depth and duration of diving, swim speed, and dive pattern were routinely monitored. An indwelling venous catheter was used to collect plasma samples at various time periods before and following diving episodes, so that changes in plasma concentrations of hormones and of metabolites could be measured. Adrenergic and nitroxidergic regulatory effects were assessed indirectly by measuring concentration changes in catecholamine and cyclic guanosine monophosphate (cGMP), respectively. The studies found that (i), except for dives of less than several minutes, epinephrine and norepinephrine both increased as a function of diving duration, then rapidly decreased during recovery (with a half time of about 10 min), (ii) that the changes in catecholamine concentrations correlated with splenic contraction and an increase in circulating red blood cell mass (hematocrit), (iii) that the changes in catecholamines, especially [epinephrine], were inversely related to insulin/glucagon ratios, which mediated a postdiving hyperglycemia, and (iv) that in long dives (but not short ones) the changes in catecholamines correlated with increasing reliance on anaerobic metabolism, indicated by increased plasma lactate concentrations. These diving-catecholamine relationships during voluntary diving at sea were similar to those observed during enforced submergence (simulated diving) under controlled laboratory conditions. At the end of diving, even while catecholamine concentrations were still high, many of the above effects were rapidly reversed and the reversal appeared to correlate with accelerated nitric oxide production, indirectly indicated by increased plasma cGMP concentrations. Taken together, the data led to the hypothesis of important adrenergic regulation of the diving response in seals, with rapid

  3. 46 CFR 197.434 - Surface-supplied mixed-gas diving.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Surface-supplied mixed-gas diving. 197.434 Section 197... HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Specific Diving Mode Procedures § 197.434 Surface-supplied mixed-gas diving. The diving supervisor shall insure that— (a) When...

  4. 46 CFR 197.434 - Surface-supplied mixed-gas diving.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Surface-supplied mixed-gas diving. 197.434 Section 197... HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Specific Diving Mode Procedures § 197.434 Surface-supplied mixed-gas diving. The diving supervisor shall insure that— (a) When...

  5. Saturated fat (image)

    MedlinePlus

    Saturated fat can raise blood cholesterol and can put you at risk for heart disease and stroke. You should ... limit any foods that are high in saturated fat. Sources of saturated fat include whole-milk dairy ...

  6. A forensic diving medicine examination of a highly publicised scuba diving fatality.

    PubMed

    Edmonds, Carl

    2012-12-01

    A high-profile diving death occurred in 2003 at the site of the wreck of the SS Yongala off the Queensland coast. The victim's buddy, her husband, was accused of her murder and found guilty of manslaughter in an Australian court. A detailed analysis of all the evidence concerning this fatality suggests alternative medical reasons for her death. The value of decompression computers in determining the diving details and of CT scans in clarifying autopsy findings is demonstrated. The victim was medically, physically and psychologically unfit to undertake the fatal dive. She was inexperienced and inadequately supervised. She was over-weighted and exposed for the first time to difficult currents. The analysis of the dive demonstrates how important it is to consider the interaction of all factors and to not make deductions from individual items of information. It also highlights the importance of early liaison between expert divers, technicians, diving clinicians and pathologists, if inappropriate conclusions are to be avoided. PMID:23258459

  7. Deadly diving? Physiological and behavioural management of decompression stress in diving mammals

    PubMed Central

    Hooker, S. K.; Fahlman, A.; Moore, M. J.; Aguilar de Soto, N.; Bernaldo de Quirós, Y.; Brubakk, A. O.; Costa, D. P.; Costidis, A. M.; Dennison, S.; Falke, K. J.; Fernandez, A.; Ferrigno, M.; Fitz-Clarke, J. R.; Garner, M. M.; Houser, D. S.; Jepson, P. D.; Ketten, D. R.; Kvadsheim, P. H.; Madsen, P. T.; Pollock, N. W.; Rotstein, D. S.; Rowles, T. K.; Simmons, S. E.; Van Bonn, W.; Weathersby, P. K.; Weise, M. J.; Williams, T. M.; Tyack, P. L.

    2012-01-01

    Decompression sickness (DCS; ‘the bends’) is a disease associated with gas uptake at pressure. The basic pathology and cause are relatively well known to human divers. Breath-hold diving marine mammals were thought to be relatively immune to DCS owing to multiple anatomical, physiological and behavioural adaptations that reduce nitrogen gas (N2) loading during dives. However, recent observations have shown that gas bubbles may form and tissue injury may occur in marine mammals under certain circumstances. Gas kinetic models based on measured time-depth profiles further suggest the potential occurrence of high blood and tissue N2 tensions. We review evidence for gas-bubble incidence in marine mammal tissues and discuss the theory behind gas loading and bubble formation. We suggest that diving mammals vary their physiological responses according to multiple stressors, and that the perspective on marine mammal diving physiology should change from simply minimizing N2 loading to management of the N2 load. This suggests several avenues for further study, ranging from the effects of gas bubbles at molecular, cellular and organ function levels, to comparative studies relating the presence/absence of gas bubbles to diving behaviour. Technological advances in imaging and remote instrumentation are likely to advance this field in coming years. PMID:22189402

  8. Diving dentistry: a review of the dental implications of scuba diving.

    PubMed

    Zadik, Y; Drucker, S

    2011-09-01

    In light of the overwhelming popularity of self-contained underwater breathing apparatus (SCUBA) diving, general dental practitioners should be prepared to address complications arising as a result of diving and to provide patients with accurate information. The aim of this article was to introduce the concepts of diving medicine and dentistry to the dentist, and to supply the dental practitioner with some diagnostic tools as well as treatment guidelines. The literature was reviewed to address diving barotrauma (pressure-induced injury related to an air space) to the head, face and oral regions, as well as scuba mouthpiece-related oral conditions. The relevant conditions for dentists who treat divers include diving-associated headache (migraine, tension-type headache), barosinusitis and barotitis-media (sinus and middle ear barotrauma, respectively), neuropathy, trigeminal (CN V) or facial (CN VII) nerve baroparesis (pressure-induced palsy), dental barotrauma (barometric-related tooth injury), barodontalgia (barometric-related dental pain), mouthpiece-associated herpes infection, pharyngeal gag reflex and temporomandibular joint disorder (dysfunction). For each condition, a theoretical description is followed by practical recommendations for the dental practitioner for the prevention and management of the condition. PMID:21884141

  9. The silent witness: using dive computer records in diving fatality investigations.

    PubMed

    Sayer, Martin D J; Azzopardi, Elaine

    2014-09-01

    Downloaded data from diving computers can offer invaluable insights into diving incidents resulting in fatalities. Such data form an essential part of subsequent investigations or in legal actions related to the diving incident. It is often tempting to accept the information being displayed from a computer download without question. However, there is a large variability between the makes and models of dive computer in how the data are recorded, stored and re-displayed and caution must be employed in the interpretation of the evidence. In reporting on downloaded data, investigators should be fully aware of the limitations in the data retrieved. They should also know exactly how to interpret parameters such as: the accuracy of the dive profile; the effects of different mode settings; the precision of displayed water temperatures; the potential for misrepresenting breathing rates where there are data from integrated monitoring systems, and be able to challenge some forms of displayed information either through re-modelling based on the pressure/time profiles or by testing the computers in standardised conditions. PMID:25311326

  10. Influence of occupational diving upon the nervous system: an epidemiological study.

    PubMed Central

    Todnem, K; Nyland, H; Kambestad, B K; Aarli, J A

    1990-01-01

    Neurological signs and symptoms were recorded from 156 air and saturation divers and 100 controls. Fifty one (33%) of the divers had had symptoms from the central nervous system during decompression. Also, 22 (14%) had been unconscious while diving. In total 79 (51%) had had decompression sickness (DCS). Twelve (8%) of the divers and no controls had had specific neurological symptoms (vision disturbances, vertigo, reduced skin sensitivity) in non-diving situations, and six (4%) of the divers (no controls) had had episodes of cerebral dysfunction (seizures, transient cerebral ischaemia, transient amnesia). The divers had significantly more general symptoms from the nervous system and more abnormal neurological findings than the controls. The most prominent symptoms were difficulties in concentration and problems with long and short term memory. The most prominent abnormal findings in the divers were compatible with dysfunction in the distal spinal cord or nerve roots, and polyneuropathy. The general neurological symptoms and findings were independently significantly correlated with diving exposure, prevalence of DCS, and age. PMID:2171631