Diving: An activity in which the organism plunges into water. It includes scuba and bell diving. Diving as natural behavior of animals goes here, as well as diving in decompression experiments with humans or animals.Decompression Sickness: A condition occurring as a result of exposure to a rapid fall in ambient pressure. Gases, nitrogen in particular, come out of solution and form bubbles in body fluid and blood. These gas bubbles accumulate in joint spaces and the peripheral circulation impairing tissue oxygenation causing disorientation, severe pain, and potentially death.Seals, Earless: The family Phocidae, suborder PINNIPEDIA, order CARNIVORA, comprising the true seals. They lack external ears and are unable to use their hind flippers to walk. It includes over 18 species including the harp seal, probably the best known seal species in the world.Decompression: Decompression external to the body, most often the slow lessening of external pressure on the whole body (especially in caisson workers, deep sea divers, and persons who ascend to great heights) to prevent DECOMPRESSION SICKNESS. It includes also sudden accidental decompression, but not surgical (local) decompression or decompression applied through body openings.Spheniscidae: The sole family in the order Sphenisciformes, comprised of 17 species of penguins in six genera. They are flightless seabirds of the Southern Hemisphere, highly adapted for marine life.Immersion: The placing of a body or a part thereof into a liquid.Barotrauma: Injury following pressure changes; includes injury to the eustachian tube, ear drum, lung and stomach.Swimming: An activity in which the body is propelled through water by specific movement of the arms and/or the legs. Swimming as propulsion through water by the movement of limbs, tail, or fins of animals is often studied as a form of PHYSICAL EXERTION or endurance.Embolism, Air: Blocking of a blood vessel by air bubbles that enter the circulatory system, usually after TRAUMA; surgical procedures, or changes in atmospheric pressure.Dolphins: Mammals of the families Delphinidae (ocean dolphins), Iniidae, Lipotidae, Pontoporiidae, and Platanistidae (all river dolphins). Among the most well-known species are the BOTTLE-NOSED DOLPHIN and the KILLER WHALE (a dolphin). The common name dolphin is applied to small cetaceans having a beaklike snout and a slender, streamlined body, whereas PORPOISES are small cetaceans with a blunt snout and rather stocky body. (From Walker's Mammals of the World, 5th ed, pp978-9)Birds: Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.Sea Lions: A group comprised of several species of aquatic carnivores in different genera, in the family Otariidae. In comparison to FUR SEALS, they have shorter, less dense hair.Fur Seals: A group comprised of several species of eared seals found in two genera, in the family Otariidae. In comparison to SEA LIONS, they have an especially dense wooly undercoat.Clothing: Fabric or other material used to cover the body.Drug Hypersensitivity Syndrome: Severe drug eruption characterized by high fever, erythematous rash and inflammation of internal organ(s).Inert Gas Narcosis: Progressive mental disturbances and unconsciousness due to breathing mixtures of oxygen and inert gases (argon, helium, xenon, krypton, and atmospheric nitrogen) at high pressure.Drug Eruptions: Adverse cutaneous reactions caused by ingestion, parenteral use, or local application of a drug. These may assume various morphologic patterns and produce various types of lesions.Eosinophilia: Abnormal increase of EOSINOPHILS in the blood, tissues or organs.Breath Holding: An involuntary or voluntary pause in breathing, sometimes accompanied by loss of consciousness.High Pressure Neurological Syndrome: A syndrome related to increased atmospheric pressure and characterized by tremors, nausea, dizziness, decreased motor and mental performance, and SEIZURES. This condition may occur in those who dive deeply (c. 1000 ft) usually while breathing a mixture of oxygen and helium. The condition is associated with a neuroexcitatory effect of helium.Apnea: A transient absence of spontaneous respiration.Mouth Protectors: Devices or pieces of equipment placed in or around the mouth or attached to instruments to protect the external or internal tissues of the mouth and the teeth.Myoglobin: A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Hematocrit: The volume of packed RED BLOOD CELLS in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, ANEMIA shows a low value; POLYCYTHEMIA, a high value.State Government: The level of governmental organization and function below that of the national or country-wide government.United StatesCommitment of Mentally Ill: Legal process required for the institutionalization of a patient with severe mental problems.Drug and Narcotic Control: Control of drug and narcotic use by international agreement, or by institutional systems for handling prescribed drugs. This includes regulations concerned with the manufacturing, dispensing, approval (DRUG APPROVAL), and marketing of drugs.Safety: Freedom from exposure to danger and protection from the occurrence or risk of injury or loss. It suggests optimal precautions in the workplace, on the street, in the home, etc., and includes personal safety as well as the safety of property.China: A country spanning from central Asia to the Pacific Ocean.Track and Field: Sports performed on a track, field, or arena and including running events and other competitions, such as the pole vault, shot put, etc.Golf: A game whose object is to sink a ball into each of 9 or 18 successive holes on a golf course using as few strokes as possible.Gold: A yellow metallic element with the atomic symbol Au, atomic number 79, and atomic weight 197. It is used in jewelry, goldplating of other metals, as currency, and in dental restoration. Many of its clinical applications, such as ANTIRHEUMATIC AGENTS, are in the form of its salts.BooksBook SelectionBook Reviews as Topic: Critical analyses of books or other monographic works.Rare BooksBook PricesSearch Engine: Software used to locate data or information stored in machine-readable form locally or at a distance such as an INTERNET site.Dreams: A series of thoughts, images, or emotions occurring during sleep which are dissociated from the usual stream of consciousness of the waking state.Comprehensive Dental Care: Providing for the full range of dental health services for diagnosis, treatment, follow-up, and rehabilitation of patients.Respiratory Protective Devices: Respirators to protect individuals from breathing air contaminated with harmful dusts, fogs, fumes, mists, gases, smokes, sprays, or vapors.Abbreviations as Topic: Shortened forms of written words or phrases used for brevity.Capital Expenditures: Those funds disbursed for facilities and equipment, particularly those related to the delivery of health care.Industry: Any enterprise centered on the processing, assembly, production, or marketing of a line of products, services, commodities, or merchandise, in a particular field often named after its principal product. Examples include the automobile, fishing, music, publishing, insurance, and textile industries.Equipment and Supplies: Expendable and nonexpendable equipment, supplies, apparatus, and instruments that are used in diagnostic, surgical, therapeutic, scientific, and experimental procedures.Equipment and Supplies, Hospital: Any materials used in providing care specifically in the hospital.

Transcatheter closure of patent foramen ovale using the Amplatzer septal occluder to prevent recurrence of neurological decompression illness in divers. (1/538)

OBJECTIVE: Large flap valve patent foramens may cause paradoxical thromboembolism and neurological decompression illness in divers. The ability of a self expanding Nitinol wire mesh device (Amplatzer septal occluder) to produce complete closure of the patent foramen ovale was assessed. PATIENTS: Seven adults, aged 18-60 years, who had experienced neurological decompression illness related to diving. Six appeared to have a normal atrial septum on transthoracic echocardiography, while one was found to have an aneurysm of the interatrial septum. METHODS: Right atrial angiography was performed to delineate the morphology of the right to left shunt. The defects were sized bidirectionally with a precalibrated balloon filled with dilute contrast. The largest balloon diameter that could be repeatedly passed across the septum was used to select the occlusion device diameter. Devices were introduced through 7 F long sheaths. All patients underwent transthoracic contrast echocardiography one month after the implant. RESULTS: Device placement was successful in all patients. Device sizes ranged from 9-14 mm. The patient with an aneurysm of the interatrial septum had three defects, which were closed with two devices. Right atrial angiography showed complete immediate closure in all patients. Median (range) fluoroscopy time was 13.7 (6-35) minutes. Follow up contrast echocardiography showed no right to left shunting in six of seven patients and the passage of a few bubbles in one patient. All patients have been allowed to return to diving. CONCLUSION: The Amplatzer septal occluder can close the large flap valve patent foramen ovale in divers who have experienced neurological decompression illness. Interatrial septal aneurysms with multiple defects may require more than one device.  (+info)

Experiment of nitrox saturation diving with trimix excursion. (2/538)

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.  (+info)

Development of diving capacity in emperor penguins. (3/538)

To compare the diving capacities of juvenile and adult emperor penguins Aptenodytes forsteri, and to determine the physiological variables underlying the diving ability of juveniles, we monitored diving activity in juvenile penguins fitted with satellite-linked time/depth recorders and examined developmental changes in body mass (Mb), hemoglobin concentration, myoglobin (Mb) content and muscle citrate synthase and lactate dehydrogenase activities. Diving depth, diving duration and time-at-depth histograms were obtained from two fledged juveniles during the first 2.5 months after their depature from the Cape Washingon colony in the Ross Sea, Antarctica. During this period, values of all three diving variables increased progressively. After 8-10 weeks at sea, 24-41 % of transmitted maximum diving depths were between 80 and 200 m. Although most dives lasted less than 2 min during the 2 month period, 8-25 % of transmitted dives in the last 2 weeks lasted 2-4 min. These values are lower than those previously recorded in adults during foraging trips. Of the physiological variables examined during chick and juvenile development, only Mb and Mb content did not approach adult values. In both near-fledge chicks and juveniles, Mb was 50-60 % of adult values and Mb content was 24-31 % of adult values. This suggests that the increase in diving capacity of juveniles at sea will be most dependent on changes in these factors.  (+info)

Heart rate and behavior of fur seals: implications for measurement of field energetics. (4/538)

Archival data loggers were used to collect information about depth, swimming speed, and heart rate in 23 free-ranging antarctic fur seals. Deployments averaged 9.6 +/- 5.6 days (SD) and totaled 191 days of recording. Heart rate averaged 108.7 +/- 17.7 beats/min (SD) but varied from 83 to 145 beats/min among animals. Morphometrics explained most variations in heart rate among animals. These interacted with diving activity and swimming speed to produce a complex relationship between heart rate and activity patterns. Heart rate was also correlated with behavior over time lags of several hours. There was significant (P < 0.05) variation among animals in the degree of diving bradycardia. On average, heart rate declined from 100-130 beats/min before the dive to 70-100 beats/min during submersion. On the basis of the relationship between heart rate and rate of oxygen consumption, the overall metabolic rate was 5.46 +/- 1.61 W/kg (SD). Energy expenditure appears to be allocated to different activities within the metabolic scope of individual animals. This highlights the possibility that some activities can be mutually exclusive of one another.  (+info)

Convective oxygen transport and tissue oxygen consumption in Weddell seals during aerobic dives. (5/538)

Unlike their terrestrial counterparts, marine mammals stop breathing and reduce their convective oxygen transport while performing activities (e.g. foraging, courtship, aggressive interactions, predator avoidance and migration) that require sustained power output during submergence. Since most voluntary dives are believed to remain aerobic, the goal of this study was to examine the potential importance of the dive response in optimizing the use of blood and muscle oxygen stores during dives involving different levels of muscular exertion. To accomplish this, we designed a numerical model based on Fick's principle that integrated cardiac output (Vb), regional blood flow, convective oxygen transport (Q(O2)), muscle oxymyoglobin desaturation and regional rates of oxygen consumption (VO2). The model quantified how the optimal matching or mismatching of QO2 to VO2 affected the aerobic dive limit (ADL). We chose an adult Weddell seal Leptonycotes weddellii on which to base our model because of available data on the diving physiology and metabolism of this species. The results show that the use of blood and muscle oxygen stores must be completed at the same time to maximize the ADL for each level of VO2. This is achieved by adjusting Vb (range 19-94 % of resting levels) and muscle QO2 according to the rate of muscle oxygen consumption (VMO2). At higher values of VMO2, Vb and muscle perfusion must increase to maintain an appropriate QO2/VO2 ratio so that available blood and muscle oxygen stores are depleted at the same time. Although the dive response does not sequester blood oxygen exclusively for brain and heart metabolism during aerobic dives, as it does during forced submersion, a reduction in Vb and muscle perfusion below resting levels is necessary to maximize the ADL over the range of diving VO2 (approximately 2-9 ml O2 min-1 kg-1). Despite the reduction in Vb, convective oxygen transport is adequate to maintain aerobic metabolism and normal function in the splanchnic organs, kidneys and other peripheral tissues. As a result, physiological homeostasis is maintained throughout the dive. The model shows that the cardiovascular adjustments known as the dive response enable the diving seal to balance the conflicting metabolic demands of (1) optimizing the distribution and use of blood and muscle oxygen stores to maximize the ADL over the normal range of diving VO2 and (2) ensuring that active muscle receives adequate oxygen as VMO2 increases.  (+info)

Diving and the risk of barotrauma. (6/538)

STUDY OBJECTIVES: Pulmonary barotrauma (PBT) of ascent is a feared complication in compressed air diving. Although certain respiratory conditions are thought to increase the risk of suffering PBT and thus should preclude diving, in most cases of PBT, risk factors are described as not being present. The purpose of our study was to evaluate factors that possibly cause PBT. DESIGN: We analyzed 15 consecutive cases of PBT with respect to dive factors, clinical and radiologic features, and lung function. They were compared with 15 cases of decompression sickness without PBT, which appeared in the same period. RESULTS: Clinical features of PBT were arterial gas embolism (n = 13), mediastinal emphysema (n = 1), and pneumothorax (n = 1). CT of the chest (performed in 12 cases) revealed subpleural emphysematous blebs in 5 cases that were not detected in preinjury and postinjury chest radiographs. A comparison of predive lung function between groups showed significantly lower midexpiratory flow rates at 50% and 25% of vital capacity in PBT patients (p < 0.05 and p < 0.02, respectively). CONCLUSIONS: These results indicate that divers with preexisting small lung cysts and/or end-expiratory flow limitation may be at risk of PBT.  (+info)

High aerobic capacities in the skeletal muscles of pinnipeds: adaptations to diving hypoxia. (7/538)

The objective was to assess the aerobic capacity of skeletal muscles in pinnipeds. Samples of swimming and nonswimming muscles were collected from Steller sea lions (Eumetopias jubatus, n = 27), Northern fur seals (Callorhinus ursinus, n = 5), and harbor seals (Phoca vitulina, n = 37) by using a needle biopsy technique. Samples were either immediately fixed in 2% glutaraldehyde or frozen in liquid nitrogen. The volume density of mitochondria, myoglobin concentration, citrate synthase activity, and beta-hydroxyacyl-CoA dehydrogenase was determined for all samples. The swimming muscles of seals had an average total mitochondrial volume density per volume of fiber of 9.7%. The swimming muscles of sea lions and fur seals had average mitochondrial volume densities of 6.2 and 8.8%, respectively. These values were 1.7- to 2.0-fold greater than in the nonswimming muscles. Myoglobin concentration, citrate synthase activity, and beta-hydroxyacyl-CoA dehydrogenase were 1.1- to 2. 3-fold greater in the swimming vs. nonswimming muscles. The swimming muscles of pinnipeds appear to be adapted for aerobic lipid metabolism under the hypoxic conditions that occur during diving.  (+info)

Functional and high-resolution computed tomographic studies of divers' lungs. (8/538)

OBJECTIVES: Several cross-sectional studies have described a decrease in the expiratory flow rates of divers. The objective of this study was to determine whether the combined application of high-resolution computed tomography (HRCT) and lung function testing supports the reported development of small airway obstruction in divers. METHODS: Thirty-two navy divers, 27 commercial divers, and 48 referents matched for age and smoking history underwent pulmonary function testing and HRCT of the lungs supplemented by a limited number of expiratory scans. The commercial divers were older and dived longer than the navy divers. Multivariate regression analysis was used to assess the relevant correlations of age, height, pack-years of cigarette smoking, and indices of diving exposure with lung function parameters. RESULTS: The inspiratory vital capacity and forced vital capacity (FVC) were greater, while the FEV% [(100 x FEV10)FVC] and maximum expiratory flow (MEF) at 25% (MEF25) of the FVC were lower for the navy divers than for the referents. The lung volumes and expiratory airflow pattern did not differ between the commercial divers and the corresponding referents. The forced expiratory volume in 1 second (FEV10), FEV%, MEF75, and MEF25 correlated negatively with the years of diving experience. This association was independent of age, height, and pack-years of cigarette smoking. For the majority of the divers and referents the expiratory HRCT revealed minor lobular air trapping without any difference between the groups. The HRCT did not show relevant morphologic abnormalities of small or large airways. CONCLUSIONS: The data confirm that diving may affect pulmonary function. However, there is no radiologic evidence for the development of small airway disease in these 2 subgroups of divers.  (+info)

  • Public safety divers differ from recreational, scientific and commercial divers who can generally plan the date, time, and location of a dive, and dive only if the conditions are conducive to the task. (wikipedia.org)
  • Public safety divers respond to emergencies 24 hours a day, 7 days a week, and may be required to dive in the middle of the night, during inclement weather, in zero visibility "black water," or in waters polluted by chemicals and biohazards. (wikipedia.org)
  • In addition to basic diving skills training , public safety divers require specialized training for recognizing hazards , conducting risk assessments , search procedures , diving in zero visibility, using full-face masks with communication systems, and recovering evidence that is admissible in court. (wikipedia.org)
  • Federal legislation applies where there is no relevant state legislation and the divers are employees diving as part of their occupation. (wikipedia.org)
  • On January 25, 1998, Tom and Eileen Lonergan, 2 American divers left Port Douglas Australia for a dive tour on the Great Barrier. (mapquest.com)
  • In May of 2008, Neely and Dalton who were both experienced divers were on the second day of a dive tour near Hayman Island. (mapquest.com)
  • In October 2011, deep sea divers Paul Kilne and Fernando Garcia Puerta were on a chartered dive tour in Biscane Bay near Miami Florida. (mapquest.com)
  • Most divers can not dive at their home towns, or the available sites are severely limited, and must travel at least a short distance to reach suitable dive sites. (wikitravel.org)
  • Dedicated divers plan entire dive holidays to areas offering sites of particular interest, and others may want to include some dive sites in their itineraries. (wikitravel.org)
  • Recreational scuba diving has become a popular sport in the United States, with almost 9 million certified divers. (aafp.org)
  • 1 Although divers are concentrated along coastal regions, many others dive in inland lakes, streams, quarries and reservoirs, or fly to distant dive sites. (aafp.org)
  • Each year, between 900 and 1,000 divers are treated with recompression therapy for severe dive-related complications. (aafp.org)
  • All divers must be able to think clearly, make sound decisions, and effectively manage events occurring around and during diving activities. (divermag.com)
  • For divers, these fears can include being denied a medical fitness certificate or being rejected by a dive buddy or group. (divermag.com)
  • Scuba Diving for qualified divers (Certified) OR No-experience necessary 'Resort Scuba Diving' for beginners - one or two scuba dives available. (reeftrips.com.au)
  • Global Scuba Diving Equipment Product Overview, Applications, End-Users, Consumer & Demand Analysis From 2020-2026" is presented in this report. (eshcarmel.org)
  • British tourists Louise Woodger and Gordon Pratley spent a terrifying 6 hours drifting on Australia's Great Barrier Reef after strong currents caused them to become separated from their dive group while out on a dive in September 2005. (mapquest.com)
  • Other diving-related neurologic complications include headache and oxygen toxicity. (aafp.org)
  • It's a beautiful calm clear day as you embark on a majestic scuba diving tour that takes you down through clear turquoise waters to explore the vibrant colors of the aqua life below. (mapquest.com)
  • Firefighters will find the diving equipment has similarities to the full face masks and breathing apparatus worn in smoke filled environments. (wikipedia.org)
  • Weddell seals can hold their breath for extended periods (20 minutes to an hour) and can dive to depths of 500 meters. (vernier.com)
  • Wetsuits are cheap simple diving suits that are typically used when diving in water between 10 and 25 C (50 to 80 F). (apparelsearch.com)
  • Wetsuits are also commonly worn for water sport activities other than diving, such as wind surfing and triathlon. (apparelsearch.com)
  • The exemption was written to include the ability to deviate from safe diving practices under limited conditions where compliance would be impracticable due to time constraints or the possible consequences of failing to perform the task overwhelm the risks taken using available facilities. (wikipedia.org)
  • When breathing with the face submerged, the diving response increases proportionally to decreasing water temperature. (wikipedia.org)
  • Some of the water they are required to dive in is contaminated , and they may be required to wear vulcanized drysuits , with diving helmets sealed to the suit, and utilize surface supplied air . (wikipedia.org)
  • At times, the decontamination process that takes place out of the water can be longer than the dive time. (wikipedia.org)
  • Suffering from hypothermia, dehydration and hallucinations due to their long time in the water, The Allens were thankfully found and rescued by two teenagers who were attending a boat while their father was diving below. (mapquest.com)
  • Drysuits are used typically when diving in water temperatures between 0 and 15 C (32 to 60 F). (apparelsearch.com)
  • The sea here is beautiful and diving is one of the most popular water sports for both tourists and locals. (jamaicantreasures.com)
  • Related topics include snorkeling, which generally refers to swimming on the surface while breathing through a snorkel, free diving, which involves breath hold underwater swimming, and SNUBA , which provides a surface source of pressurised breathing air, supplied to the diver through a limited length of hose and a mouthpiece. (wikitravel.org)
  • 5 Physicians need to be aware of the broad spectrum of neurologic injuries that can occur during dive accidents to ensure early recognition, accurate diagnosis and appropriate therapy. (aafp.org)
  • You can learn to dive far more quickly than you can learn snow sports, for example, and a high level of fitness and strength is not always necessary. (wikitravel.org)
  • Knowledge of the physiology and cardiovascular plus other medical problems associated with the various forms of diving have evolved extensively. (eurekaselect.com)
  • Thomas F. Whayne*, "Medical Management and Risk Reduction of the Cardiovascular Effects of Underwater Diving", Current Vascular Pharmacology (2018) 16: 344. (eurekaselect.com)
  • Once you've had your fill of the watery and tropical world of Jamaica diving , be sure to make some time on the itinerary for above and below-ground adventures that are sure to be just as pleasing. (jamaicantreasures.com)
  • During each dive, heart rate and cardiac output decrease dramatically as blood is shunted away from the extremities and directed to the vital organs. (vernier.com)
  • Scuba diving is an excellent way to see some very beautiful sites: Tropical coral diving sites with their colourful sea life are the most famous but other scuba diving attractions include tropical and temperate rocky reefs, shipwrecks, caverns and caves. (wikitravel.org)
  • The lack of suitable dive sites in large parts of the world also makes diver training a significant travel activity. (wikitravel.org)
  • Last week I sent a friend a text for tips on French fine diving, to help write this article about the best France scuba dive sites. (awe365.com)
  • Barotrauma to the middle or inner ear can occur during the descent or ascent phases of the dive and may cause vertigo and other neurologic symptoms. (aafp.org)
  • The pair embarked on a dive at St. Crispin's reef with their group and their tour boat did the unthinkable and left the dive site without them. (mapquest.com)