WorldWideScience

Sample records for understanding fau diving

  1. Children’s Understanding of No Diving Warning Signs: Implications for Preventing Childhood Injury

    Directory of Open Access Journals (Sweden)

    Barbara A. Morrongiello

    2016-07-01

    Full Text Available The current study examined children’s understanding of No Diving warning signs. Normally-developing 7 to 10 year olds were asked questions to assess their understanding of text, images, and main messages on No Diving warning signs. These structured interviews were audio recorded and responses were later coded. Results revealed that children understood the behavior advised against (diving, why it is prohibited (can hit head on the bottom, and what can happen (serious injury including hospitalization. They understood that breaking your neck results in limitations in mobility and can occur from diving, but they did not anticipate that such an injury is likely to occur. There were no gender and few age differences, but diving experience was associated with children significantly downplaying their risk of injury. The findings suggest that having No Diving warning signs explicitly mention a broken neck, may serve to remind children of this potential consequence at the time of decision making. Active adult supervision is particularly important for children who have prior positive diving experiences.

  2. Selective synthesis of FAU-type zeolites

    Science.gov (United States)

    Garcia, Gustavo; Cabrera, Saúl; Hedlund, Jonas; Mouzon, Johanne

    2018-05-01

    In the present work, parameters influencing the selectivity of the synthesis of FAU-zeolites from diatomite were studied. The final products after varying synthesis time were characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and gas adsorption. It was found that high concentrations of NaCl could completely inhibit the formation of zeolite P, which otherwise usually forms as soon as maximum FAU crystallinity is reached. In the presence of NaCl, the FAU crystals were stable for extended time after completed crystallization of FAU before formation of sodalite. It was also found that addition of NaCl barely changed the crystallization kinetics of FAU zeolite and only reduced the final FAU particle size and SiO2/Al2O3 ratio slightly. Other salts containing either Na or Cl were also investigated. Our results suggest that there is a synergistic effect between Na+ and Cl-. This is attributed to the formation of (Na4Cl)3+ clusters that stabilize the sodalite cages. This new finding may be used to increase the selectivity of syntheses leading to FAU-zeolites and avoid the formation of undesirable by-products, especially if impure natural sources of aluminosilica are used.

  3. Understanding scuba diving fatalities: carbon dioxide concentrations in intra-cardiac gas.

    Science.gov (United States)

    Varlet, Vincent; Dominguez, Alejandro; Augsburger, Marc; Lossois, Maisy; Egger, Coraline; Palmiere, Cristian; Vilarino, Raquel; Grabherr, Silke

    2017-06-01

    Important developments in the diagnosis of scuba diving fatalities have been made thanks to forensic imaging tool improvements. Multi-detector computed tomography (MDCT) permits reliable interpretation of the overall gaseous distribution in the cadaver. However, due to post-mortem delay, the radiological interpretation is often doubtful because the distinction between gas related to the dive and post-mortem decomposition artifactual gases becomes less obvious. We present six cases of fatal scuba diving showing gas in the heart and other vasculature. Carbon dioxide (CO₂) in cardiac gas measured by gas chromatography coupled to thermal conductivity detection were employed to distinguish decomposition from embolism based on the detection of decomposition gases (hydrogen, hydrogen sulfide and methane) and to confirm arterial gas embolism (AGE) or post-mortem offgasing diagnoses. A Radiological Alteration Index (RAI) was calculated from the scan. Based on the dive history, the intra-cadaveric gas was diagnosed as deriving from decomposition (one case, minimal RAI of 61), post-mortem decompression artifacts (two cases, intermediate RAI between 60 and 85) and barotrauma/AGE (three cases, maximal RAI between 85 and 100), illustrating a large distribution inside the bodies. MDCT scans should be interpreted simultaneously with compositional analysis of intra-cadaveric gases. Intra-cadaveric gas sampling and analysis may become useful tools for understanding and diagnosing scuba diving fatalities. In cases with short post-mortem delays, the CO₂ concentration of the cardiac gas provides relevant information about the circumstances and cause of death when this parameter is interpreted in combination with the diving profile.

  4. Diving medicine.

    Science.gov (United States)

    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.

  5. Go Deeper, Go Deeper: Understanding submarine command and control during the completion of dived tracking operations.

    Science.gov (United States)

    Roberts, Aaron P J; Stanton, Neville A; Fay, Daniel T

    2018-05-01

    This is a world's first-of-a-kind study providing empirical evidence for understanding submarine control room performance when completing higher and lower demand Dived Tracking (DT) scenarios. A submarine control room simulator was built, using a non-commercial version of Dangerous Waters as the simulation engine. The creation of networked workstations allowed a team of nine operators to perform tasks completed by submarine command teams during DT. The Event Analysis of Systemic Teamwork (EAST) method was used to model the social, task and information networks and describe command team performance. Ten teams were recruited for the study, affording statistical comparisons of how command team roles and level of demand affected performance. Results indicate that command teams can covertly DT a contact differently depending on demand (e.g. volume of contacts). In low demand it was possible to use periscope more often than in high demand, in a 'duck-and-run' fashion. Therefore, the type of information and frequency of particular task completion, was significantly different between the higher and lower demand conditions. This resulted in different operators in the command team experiencing greater demand depending on how the DT mission objective was completed. Potential bottlenecks in the command team were identified and implications are discussed alongside suggestions for future work. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Valorization of vitreous China waste to EMT/FAU, FAU and Na-P zeotype materials.

    Science.gov (United States)

    Maatoug, Nesrine; Delahay, Gérard; Tounsi, Hassib

    2018-04-01

    In this study, Na-X, Na-P, SOD and EMT/FAU zeotype materials have been prepared from vitreous China waste by conventional hydrothermal route and alkaline fusion prior to hydrothermal synthesis. The conventional route has shown its limits in the activation of the waste in the chosen experimental conditions, [NaOH] = 3.5 M and T = 60 °C. The amorphous phase of vitreous China waste plays an important role during the zeolitization process because it easily dissolves into the alkaline solution compared to crystalline phases like quartz and mullite. By the conventional route, Na-X and Na-P1 and SOD zeolites were obtained. The alkaline fusion step using NaOH as mineralizer at 550 °C converted the waste to highly active soluble aluminate and silicate salts. The fused material was mixed with distilled water to have liquid to solid ratio L/S = 5, under vigorous stirring at room temperature for 1 day. The obtained gel with molar composition of 7.0 Na 2 O: 1.0 Al 2 O 3 : 4.8 SiO 2 : 209.4 H 2 O was converted by hydrothermal crystallization at 60 °C to nanosized EMT/FAU zeotype and geopolymeric amorphous aluminosilicate material. With the increase of fusion time, there is a decrease of the amount of EMT-type zeolite. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Ultrasonic Testing of NIF Amplifier FAU Top Plates

    International Nuclear Information System (INIS)

    Chinn, D.J.; Huber, R.D.; Haskins, J.J.; Rodriguez, J.A.; Souza, P.R.; Le, T.V.

    2002-01-01

    A key component in the National Ignition Facility (NIF) laser optic system is the amplifier frame assembly unit (FAU). The cast aluminum top plate that supports the FAU is required to withstand loads that would occur during an earthquake with a recurrence period of 1000 years. The stringent seismic requirements placed on the FAU top plate induced a study of the cast aluminum material used in the top plate. Ultrasonic testing was used to aid in characterizing the aluminum material used in the plates. This report documents the work performed using contact ultrasonic testing to characterize the FAU top plate material. The ultrasonic work reported here had 3 objectives: (1) inspect the plate material before cyclic testing conducted at the Pacific Earthquake Engineering Research Center (PEER); (2) determine the overall quality of individual plates; and (3) detect large defects in critical areas of individual plates. Section III, ''Pre-cyclic test inspection'', describes work performed in support of Objective 1. Section IV, ''Ultrasonic field measurements'', describes work performed in support of Objectives 2 and 3

  8. Phase selection controlled by sodium ions in the synthesis of FAU/LTA composite zeolite

    Directory of Open Access Journals (Sweden)

    Linyan Hu, Sujuan Xie, Qingxia Wang, Shenglin Liu and Longya Xu

    2009-01-01

    Full Text Available Zeolite faujasite (FAU, Linde type A (LTA and FAU/LTA composite have been synthesized using tetramethylammonium cation (TMA + as template, by adjusting only the concentration of Na + ions in the initial solution (1.00 Al2 O3 4.36 SiO2 : 2.39 (TMA2 O : β Na2 O : 249.00H2 O. Na + ions alter the phase composition of the product more than TMA+ or OH− ions. When Na2 O concentration [Na2 O] increases from 0.024 to 0.168, the product gradually changes from pure FAU to pure LTA via the formation of FAU/LTA composite with increasing LTA fraction. Interestingly, the induction periods of FAU and LTA in the FAU/LTA composite zeolite ([Na2 O] is 0.072 are both 13 h, quite different from the induction periods of their individual pure phases—45 h for FAU and 4 h for LTA. During the crystallization, the LTA/(FAU + LTA fraction in the composite zeolite decreases in a nearly linear fashion. Scanning electron microscopy, thermogravimetry and differential thermal analysis indicate some difference between the properties of the FAU/LTA composite zeolite and of the mechanical mixture.

  9. Investigation of Y, FAU-zeolites containing rare earth cations

    International Nuclear Information System (INIS)

    Gardos, G.; De Jonge, A.; Halmos, F.; Kristof, J.; Redey, A.

    1984-01-01

    Polycationic zeolites were made of the H (NHsub(4))-Y, FAU form one. The change of Broensted acid sites was followed as a function of the pretreating temperature by infrared spectroscopy for mixed (La, Ce) form zeolites. It was stated that the 3630 cmsup(-1) absorption band can be related to the acidic OH-groups responsible for the catalytic activity in the alkylating reaction of isobutane with 1-butene, while the band at 3510 cmsup(-1) is characteristic of the non-acidic hydroxyl-groups and has no relation with the catalytic activity. (author)

  10. Preparation of Pd-Loaded Hierarchical FAU Membranes and Testing in Acetophenone Hydrogenation.

    Science.gov (United States)

    Molinari, Raffaele; Lavorato, Cristina; Mastropietro, Teresa F; Argurio, Pietro; Drioli, Enrico; Poerio, Teresa

    2016-03-22

    Pd-loaded hierarchical FAU (Pd-FAU) membranes, containing an intrinsic secondary non-zeolitic (meso)porosity, were prepared and tested in the catalytic transfer hydrogenation of acetophenone (AP) to produce phenylethanol (PE), an industrially relevant product. The best operating conditions were preliminarily identified by testing different solvents and organic hydrogen donors in a batch hydrogenation process where micron-sized FAU seeds were employed as catalyst support. Water as solvent and formic acid as hydrogen source resulted to be the best choice in terms of conversion for the catalytic hydrogenation of AP, providing the basis for the design of a green and sustainable process. The best experimental conditions were selected and applied to the Pd-loaded FAU membrane finding enhanced catalytic performance such as a five-fold higher productivity than with the unsupported Pd-FAU crystals (11.0 vs. 2.2 mgproduct gcat(-1)·h(-1)). The catalytic performance of the membrane on the alumina support was also tested in a tangential flow system obtaining a productivity higher than that of the batch system (22.0 vs. 11.0 mgproduct gcat(-1)·h(-1)).

  11. Preparation of Pd-Loaded Hierarchical FAU Membranes and Testing in Acetophenone Hydrogenation

    Directory of Open Access Journals (Sweden)

    Raffaele Molinari

    2016-03-01

    Full Text Available Pd-loaded hierarchical FAU (Pd-FAU membranes, containing an intrinsic secondary non-zeolitic (mesoporosity, were prepared and tested in the catalytic transfer hydrogenation of acetophenone (AP to produce phenylethanol (PE, an industrially relevant product. The best operating conditions were preliminarily identified by testing different solvents and organic hydrogen donors in a batch hydrogenation process where micron-sized FAU seeds were employed as catalyst support. Water as solvent and formic acid as hydrogen source resulted to be the best choice in terms of conversion for the catalytic hydrogenation of AP, providing the basis for the design of a green and sustainable process. The best experimental conditions were selected and applied to the Pd-loaded FAU membrane finding enhanced catalytic performance such as a five-fold higher productivity than with the unsupported Pd-FAU crystals (11.0 vs. 2.2 mgproduct gcat−1·h−1. The catalytic performance of the membrane on the alumina support was also tested in a tangential flow system obtaining a productivity higher than that of the batch system (22.0 vs. 11.0 mgproduct gcat−1·h−1.

  12. Introduction to Scuba Diving. Diver Education Series.

    Science.gov (United States)

    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…

  13. Bauhaus, Crown Hall, FAU: A Comparative Investigation of the Curriculum Design in Schools of Architecture

    Science.gov (United States)

    Mulrooney, Sarah

    2009-01-01

    One of the central themes addressed by this paper is the design of the curriculum for architectural education using three schools of architecture: the Bauhaus in Dessau, Crown Hall in Chicago and the Faculty of Architecture and Urbanism (FAU) in Sao Paulo. It also reflects on the practices in other schools such as Frank Lloyd Wright's Taliesin…

  14. CERN Scuba Diving Club

    CERN Multimedia

    Club Subaquatique du CERN

    2017-01-01

    Interested in scuba diving? Fancy a fun trial dive? Like every year, the CERN Scuba Diving Club is organizing two free trial dive sessions. Where? Varembé Swimming Pool, Avenue Giuseppe Motta 46, 1202 Genève When? 25th October and 1st November at 19:15 (one session per participant) Price? Trial dives are FREE! Swimming pool entrance 5,40 CHF. What to bring? Swimwear, towel, shower necessities and a padlock – diving equipment will be provided by the CSC. For more information and to subscribe, follow the link below: http://cern.ch/csc-baptemes-2017 Looking forward to meeting you!

  15. O2 store management in diving emperor penguins.

    Science.gov (United States)

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

    2009-01-01

    In order to further define O(2) 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 (P(O(2))) recorder or a blood sampler while they were diving at an isolated dive hole in the sea ice of McMurdo Sound, Antarctica. Arterial P(O(2)) profiles (57 dives) revealed that (a) pre-dive P(O(2)) was greater than that at rest, (b) P(O(2)) transiently increased during descent and (c) post-dive P(O(2)) reached that at rest in 1.92+/-1.89 min (N=53). Venous P(O(2)) profiles (130 dives) revealed that (a) pre-dive venous P(O(2)) was greater than that at rest prior to 61% of dives, (b) in 90% of dives venous P(O(2)) transiently increased with a mean maximum P(O(2)) of 53+/-18 mmHg and a mean increase in P(O(2)) of 11+/-12 mmHg, (c) in 78% of dives, this peak venous P(O(2)) occurred within the first 3 min, and (d) post-dive venous P(O(2)) reached that at rest within 2.23+/-2.64 min (N=84). Arterial and venous P(O(2)) 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 P(N(2)) 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 P(O(2)) and P(N(2)) during dives), muscle ischemia during dives (elevated venous P(O(2)), lack of lactate washout into blood during dives), and arterio-venous shunting of blood both during the surface period (venous P(O(2)) greater than that at rest) and during dives (arterialized venous P(O(2

  16. SCUBA Diving in Pregnancy.

    Science.gov (United States)

    Reid, Robert L; Lorenzo, Melissa

    2018-03-01

    Obstetrical care providers may occasionally encounter women with questions about the safety of Self-Contained Underwater Breathing Apparatus (SCUBA) diving in pregnancy. This article provides an overview of safety issues associated with basic SCUBA diving and offers guidance to practitioners about how to evaluate and counsel pregnant women about the associated maternal and fetal risks. Basic diving physiology is reviewed and the implications of SCUBA diving during pregnancy are discussed. A literature review examined available animal and human data about the potential adverse effects of the physiological changes of pregnancy on divers, the impact of pressure changes during diving, and possible consequences of hyperbaric gas exposure and rapid decompression on mother and fetus. Studies were found by searching the terms "scuba diving," "pregnancy," "fetus," "decompression illness," "hyperbaric medicine," and "animal studies" in the databases Medline, Pubmed, and Embase. Reference lists from existing articles and reports from identified diving magazines were also reviewed. Studies were limited to the English language and included publications until 2016. All relevant human studies were selected. Five retrospective studies and one prospective study assessing the antenatal and postnatal outcomes of women who participated in SCUBA diving while pregnant were reviewed. Published data was limited in both quantity and quality. The authors' experience with SCUBA diving together with a background in obstetrics allowed themes to be explored and recommendations developed. In addition to established risks of SCUBA diving, pregnant women are at increased risk due to changes in body habitus (affecting equipment fitting and balance). Animal data suggest possible adverse fetal effects due to fetal decompression illness (DCI) and hyperbaric oxygen exposure. Human data, though generally reassuring, are of poor quality and thus do not completely exclude adverse outcomes. In general

  17. Diving medicine in clinical practice.

    Science.gov (United States)

    Eichhorn, Lars; Leyk, Dieter

    2015-02-27

    Diving is a popular sport, and some recreational divers have medical risk factors. Their health can be endangered by high extracorporeal (ambient) pressure and its many systemic effects. We review relevant publications on free (breath-hold) diving, scuba diving, medical evaluation for diving, barotrauma, decompression sickness, and diving with medical risk factors, which were retrieved by a selective search of PubMed. Free diving or scuba diving, even at seemingly innocuous depths, puts considerable stress on the cardio - vascular system, ears, and lungs. Unexpected events while diving, diminished functional reserve, and pre-existing medical illnesses increase the risk of a diving accident. An international survey revealed that minor incidents occur in 1.3% of all dives, and decompression accidents in 2 of every 10 000 dives. A properly conducted medical examination to determine diving fitness, followed by appropriate counseling, can make a life-threatening diving accident less likely. To be able to certify diving fitness and give competent medical advice about diving, physicians must be well informed about the physical and physiological changes of diving and the associated risks to health, and they need to know how to perform a medical evaluation of prospective divers. In Germany, any licensed physician may judge a person fit to dive. It is recommended that this be done in adherence to the relevant evaluation standards and recommendations of the medical specialty associations. Randomized controlled trials on the effect of preventive behavior would be desirable, as would a central registry of diving accidents.

  18. Diving and antidepressants.

    Science.gov (United States)

    Querido, Abraham L

    2017-12-01

    Psychoactive drugs pose a risk to both the diver and his or her buddy. Little is known about the safety of diving with antidepressants. Amongst the potential interactions with the diving environment are: somnolence; convulsions; a bleeding tendency (potentially worsening decompression illness, DCI), alterations to glucose metabolism and psychiatric side effects. Fluoxetine may potentially reduce the inflammatory process associated with DCI. This article presents guidelines for recreational diving in combination with antidepressants. These guidelines were endorsed at a meeting of the Dutch Association for Diving Medicine in 2015 and are solely based on 'expert' opinion. Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.

  19. Should children be SCUBA diving?: Cerebral arterial gas embolism in a swimming pool.

    Science.gov (United States)

    Johnson, Valerie; Adkinson, Cheryl; Bowen, Mariya; Ortega, Henry

    2012-04-01

    Cerebral arterial gas embolism (CAGE) is a well-known serious complication of self-contained breathing apparatus (SCUBA) diving. Most serious complications of SCUBA diving occur in adults because most of SCUBA divers are adults. However, young age is an independent risk factor for injury in SCUBA diving and shallow-water SCUBA diving is the riskiest environment for CAGE. We present a case of a 10-year-old boy who developed CAGE while taking SCUBA diving lessons in a university swimming pool. This case illustrates the potential danger of SCUBA diving for children who lack understanding of the physics of diving as well as the often unappreciated risk of shallow-water SCUBA diving. Our intent is to educate providers of primary care to children, so that they may appropriately advise parents about SCUBA diving, and to educate providers of emergency care to children, so that they will recognize this uncommon but serious emergency condition.

  20. SCUBA medicine: a first-responder's guide to diving injuries.

    Science.gov (United States)

    Salahuddin, Moin; James, Laurie A; Bass, Evan Stuart

    2011-01-01

    Self-contained underwater breathing apparatus (SCUBA) diving is an ever-growing sport, and despite a myriad of technological advances to improve safety, it remains dangerous. Providers of medical care for SCUBA divers must have an understanding of diving physiology and potential medical problems that can occur. SCUBA diving also can take participants to remote areas, so being properly prepared for potential emergencies can make a significant difference. The following is a review of diving physiology and the medical problems that can occur in SCUBA divers, along with some suggestions as to how to prepare for a SCUBA excursion.

  1. Sorbate Transport in Carbon Molecular Sieve Membranes and FAU/EMT Intergrowth by Diffusion NMR

    Directory of Open Access Journals (Sweden)

    John J. Low

    2012-02-01

    Full Text Available In this paper we present and discuss selected results of our recent studies of sorbate self-diffusion in microporous materials. The main focus is given to transport properties of carbon molecular sieve (CMS membranes as well as of the intergrowth of FAU-type and EMT-type zeolites. CMS membranes show promise for applications in separations of mixtures of small gas molecules, while FAU/EMT intergrowth can be used as an active and selective cracking catalyst. For both types of applications diffusion of guest molecules in the micropore networks of these materials is expected to play an important role. Diffusion studies were performed by a pulsed field gradient (PFG NMR technique that combines advantages of high field (17.6 T NMR and high magnetic field gradients (up to 30 T/m. This technique has been recently introduced at the University of Florida in collaboration with the National Magnet Lab. In addition to a more conventional proton PFG NMR, also carbon-13 PFG NMR was used.

  2. Methodology scuba diving on tinge

    OpenAIRE

    Vondrášek, David

    2011-01-01

    Title: Methodology of apnea diving Objectives: The main objective of this work is to develop materials that could serve as a learning support students in basic studies of apnea diving. A part of the history of diving equipment and diving physiology of flavor and also methodologies apnea diving. Methods: Study of available sources. Literature available sources. Development of educational material using the material used and its own experience. Results: The result is a learning support for stud...

  3. Socio-economic aspects of the Sodwana Bay SCUBA diving ...

    African Journals Online (AJOL)

    Understanding socio-economic aspects of the diving industry at Sodwana Bay, including data on participant motivation and expenditure, is crucial for the effective management of the St Lucia and Maputaland marine protected areas, South Africa. Between July 2011 and July 2012 a total of 59 553 dives was conducted by ...

  4. Perceptions amongst Tasmanian recreational scuba divers of the value of a diving medical.

    Science.gov (United States)

    Baines, Carol

    2013-12-01

    An online survey was offered to recreational divers in Tasmania to ascertain if they have an understanding of how pressure affects their health and if they considered an annual dive medical necessary. A total of 98 recreational divers completed the survey, five of these had never had a dive medical while 74 felt that if they passed their dive medical they do not have any potential illness. Sixty five saw the dive medical as a comprehensive health check. This project provided an insight to Tasmanian recreational divers' understanding of and attitude towards the value of a dive medical.

  5. 46 CFR 197.430 - SCUBA diving.

    Science.gov (United States)

    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 no...

  6. Yet More Visualized JAMSTEC Cruise and Dive Information

    Science.gov (United States)

    Tomiyama, T.; Hase, H.; Fukuda, K.; Saito, H.; Kayo, M.; Matsuda, S.; Azuma, S.

    2014-12-01

    Every year, JAMSTEC performs about a hundred of research cruises and numerous dive surveys using its research vessels and submersibles. JAMSTEC provides data and samples obtained during these cruises and dives to international users through a series of data sites on the Internet. The "DARWIN (http://www.godac.jamstec.go.jp/darwin/e)" data site disseminates cruise and dive information. On DARWIN, users can search interested cruises and dives with a combination search form or an interactive tree menu, and find lists of observation data as well as links to surrounding databases. Document catalog, physical sample databases, and visual archive of dive surveys (e. g. in http://www.godac.jamstec.go.jp/jmedia/portal/e) are directly accessible from the lists. In 2014, DARWIN experienced an update, which was arranged mainly for enabling on-demand data visualization. Using login users' functions, users can put listed data items into the virtual basket and then trim, plot and download the data. The visualization tools help users to quickly grasp the quality and characteristics of observation data. Meanwhile, JAMSTEC launched a new data site named "JDIVES (http://www.godac.jamstec.go.jp/jdives/e)" to visualize data and sample information obtained by dive surveys. JDIVES shows tracks of dive surveys on the "Google Earth Plugin" and diagrams of deep-sea environmental data such as temperature, salinity, and depth. Submersible camera images and links to associated databases are placed along the dive tracks. The JDVIES interface enables users to perform so-called virtual dive surveys, which can help users to understand local geometries of dive spots and geological settings of associated data and samples. It is not easy for individual researchers to organize a huge amount of information recovered from each cruise and dive. The improved visibility and accessibility of JAMSTEC databases are advantageous not only for second-hand users, but also for on-board researchers themselves.

  7. Otologic Hazards Related to Scuba Diving.

    Science.gov (United States)

    Glazer, Tiffany A; Telian, Steven A

    2016-01-01

    As of 2015, more than 23 million scuba diver certifications have been issued across the globe. Given the popularity of scuba diving, it is incumbent on every physician to know and understand the specific medical hazards and conditions associated with scuba diving. Sources were obtained from PubMed, MEDLINE, and EBSCO databases from 1956 onward and ranged from diverse fields including otologic reviews and wilderness medicine book chapters. Clinical review. Level 5. Otologic hazards can be categorized into barotrauma-related injuries or decompression sickness. When combined with a high index of suspicion, the physician can recognize these disorders and promptly initiate proper treatment of the potentially hazardous and irreversible conditions related to scuba diving.

  8. Exercise before scuba diving ameliorates decompression-induced neutrophil activation.

    Science.gov (United States)

    Madden, Dennis; Thom, Stephen R; Milovanova, Tatyana N; Yang, Ming; Bhopale, Veena M; Ljubkovic, Marko; Dujic, Zeljko

    2014-10-01

    The goals of this study were to investigate the difference in responses between a scuba dive preceded by aerobic exercise (EX) and a nonexercise control dive (CON) and to further evaluate the potential relation between venous gas emboli (VGE) and microparticles (MP). We hypothesized that exercise would alter the quantity and subtype of annexin V-positive MP and VGE. Nineteen divers performed two dives to 18 m seawater for 41 min separated by at least 3 d, one of which was preceded by 60 min of treadmill interval exercise. Blood was obtained before exercise, before diving, and 15 min, 2 h, 4 h, and 24 h after surfacing. Intravascular bubbles were quantified by transthoracic echocardiography at 15, 40, 80, and 120 min. The median VGE remained unchanged between the two dives; however, there was a significant increase in VGE in the exercise dive at 40 and 80 min at rest. MP were significantly elevated by approximately 2 times at all time points after CON compared with those after EX. Markers of neutrophil and platelet activation were elevated by both dives, and these elevations were attenuated in the EX dive. We conclude that some of the differences observed between the EX and CON related to MP and platelet and neutrophil activation provide additional insight into the potential protective benefits of exercise; however, further study is needed to understand the mechanism and true potential of these benefits.

  9. Recent modifications to the investigation of diving related deaths.

    Science.gov (United States)

    Edmonds, Carl; Caruso, James

    2014-03-01

    The investigation of deaths that involve diving using a compressed breathing gas (SCUBA diving) is a specialized area of forensic pathology. Diving related deaths occur more frequently in certain jurisdictions, but any medical examiner or coroner's office may be faced with performing this type of investigation. In order to arrive at the correct conclusion regarding the cause and manner of death, forensic pathologists and investigators need to have a basic understanding of diving physiology, and should also utilize more recently developed technology and ancillary techniques. In the majority of diving related deaths, the cause of death is drowning, but this more often represents a final common pathway due to a water environment. The chain of events leading to the death is just as important to elucidate if similar deaths are to be minimized in the future. Re-enactment of accident scenarios, interrogation of dive computers, postmortem radiographic imaging, and slight alterations in autopsy technique may allow some of these diving related deaths to the better characterized. The amount and location of gas present in the body at the time of autopsy may be very meaningful or may simply represent a postmortem artifact. Medical examiners, coroners, and forensic investigators should consider employing select ancillary techniques to more thoroughly investigate the factors contributing a death associated with SCUBA diving.

  10. Can asthmatic subjects dive?

    Directory of Open Access Journals (Sweden)

    Yochai Adir

    2016-06-01

    Full Text Available 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.

  11. Dive into Scuba

    Science.gov (United States)

    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,…

  12. Human Simulated Diving Experiments.

    Science.gov (United States)

    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)

  13. Physiological constraints and energetic costs of diving behaviour in marine mammals: a review of studies using trained Steller sea lions diving in the open ocean.

    Science.gov (United States)

    Rosen, David A S; Hindle, Allyson G; Gerlinsky, Carling D; Goundie, Elizabeth; Hastie, Gordon D; Volpov, Beth L; Trites, Andrew W

    2017-01-01

    Marine mammals are characterized as having physiological specializations that maximize the use of oxygen stores to prolong time spent under water. However, it has been difficult to undertake the requisite controlled studies to determine the physiological limitations and trade-offs that marine mammals face while diving in the wild under varying environmental and nutritional conditions. For the past decade, Steller sea lions (Eumetopias jubatus) trained to swim and dive in the open ocean away from the physical confines of pools participated in studies that investigated the interactions between diving behaviour, energetic costs, physiological constraints, and prey availability. Many of these studies measured the cost of diving to understand how it varies with behaviour and environmental and physiological conditions. Collectively, these studies show that the type of diving (dive bouts or single dives), the level of underwater activity, the depth and duration of dives, and the nutritional status and physical condition of the animal affect the cost of diving and foraging. They show that dive depth, dive and surface duration, and the type of dive result in physiological adjustments (heart rate, gas exchange) that may be independent of energy expenditure. They also demonstrate that changes in prey abundance and nutritional status cause sea lions to alter the balance between time spent at the surface acquiring oxygen (and offloading CO 2 and other metabolic by-products) and time spent at depth acquiring prey. These new insights into the physiological basis of diving behaviour further our understanding of the potential scope for behavioural responses of marine mammals to environmental changes, the energetic significance of these adjustments, and the consequences of approaching physiological limits.

  14. 46 CFR 197.460 - Diving equipment.

    Science.gov (United States)

    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... in a dive under § 197.346 is inspected before each dive. ...

  15. Provisional Crown Dislodgement during Scuba Diving: A Case of Barotrauma

    OpenAIRE

    Gulve, Meenal Nitin; Gulve, Nitin Dilip

    2013-01-01

    Changes in ambient pressure, for example, during flying, diving, or hyperbaric oxygen therapy, can lead to barotrauma. Although it may seem that this issue was neglected in dental education and research in recent decades, familiarity with and understanding of these facts may be of importance for dental practitioners. We report the case of a patient who experienced barotrauma involving dislodgement of a provisional crown during scuba diving. Patients who are exposed to pressure changes as a pa...

  16. Mesoporous MEL, BEA, and FAU zeolite crystals obtained by in situ formation of carbon template over metal nanoparticles

    DEFF Research Database (Denmark)

    Abildstrøm, Jacob Oskar; Ali, Zahra Nasrudin; Mentzel, Uffe Vie

    2016-01-01

    Here, we report the synthesis and characterization of hierarchical zeolite materials with MEL, BEA and FAU structures. The synthesis is based on the carbon templating method with an in situ-generated carbon template. Through the decomposition of methane and deposition of coke over nickel...... nanoparticles supported on silica, a carbon–silica composite is obtained and exploited as a combined carbon template/silica source for the zeolite synthesis. The mesoporous zeolite materials were all prepared by hydrothermal crystallization in alkaline media followed by removal of the carbon template...

  17. [Oxygen therapy in diving accidents].

    Science.gov (United States)

    Piepho, T; Ehrmann, U; Werner, C; Muth, C M

    2007-01-01

    Diving accidents represent a departure from the routine practice of emergency physicians. The incidence of non-fatal diving accidents is reported as 1-2 per 10,000 dives. Apart from adequate intravenous hydration, oxygen is the only medication with a proven effect in the treatment of diving accidents. After a typical diving accident, administration of oxygen at an inspired concentration (F(I)O(2) 1.0) as high as possible is recommended. Many divers bring along their own oxygen administration systems to the diving sites and these are often better suited for the treatment of diving accidents than the oxygen systems of many emergency responders. Pressure regulators supplying low constant flow oxygen, nasal prongs and inhalation masks are inappropriate. When using artificial ventilation bags with face masks, an oxygen flow of at least 15 l/min should be used. Demand regulators are simple to use and able to deliver a F(I)O2 of 1.0. Their ease of use has earned them high marks in the emergency management of diving accidents and their similarity to standard diving equipment has also aided relatively widespread acceptance. Circulation breathing systems are more technologically complex oxygen delivery systems which permit CO2 absorption and re-breathing at low oxygen flow. In contrast to the demand modules, the likelihood of mistakes during their usage is higher. In diving accidents, the administration of normobaric oxygen, already begun in the field, is the most important therapy and should not be interrupted. Presented with an inadequate supplemental oxygen supply, the inspired oxygen concentration should not be decreased, rather the duration of the oxygen administration should be reduced. Hyperbaric oxygen therapy should be the mainstay of further treatment.

  18. 29 CFR 1910.424 - SCUBA diving.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 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 deeper...

  19. Function of head-bobbing behavior in diving little grebes.

    Science.gov (United States)

    Gunji, Megu; Fujita, Masaki; Higuchi, Hiroyoshi

    2013-08-01

    Most birds show a characteristic head movement that consists of head stabilization and quick displacement. In this movement, which is analogous to saccadic eye movement in mammals, head stabilization plays an important role in stabilizing the retinal image. This head movement, called "head bobbing", is particularly pronounced during walking. Previous studies focusing on anatomical and behavioral features have pointed out that visual information is also important for diving birds, indicating its significance in the head movements of diving birds. In the present study, the kinematic and behavioral features of head bobbing in diving little grebes were described by motion analysis to identify the head movement in diving birds. The results showed that head-bobbing stroke (HBS) consisted of a thrust phase and a hold phase as is typical for head bobbing during walking birds. This suggests that HBS is related to visual stabilization under water. In HBS, grebes tended to dive with longer stroke length and smaller stroke frequency than in non-bobbing stroke. This suggests that the behavior, which is related to vision, affects the kinematic stroke parameters. This clarification of underwater head movement will help in our understanding not only of vision, but also of the kinematic strategy of diving birds.

  20. Analysis of scuba diving indoor training facilities.

    OpenAIRE

    Bažant, Filip

    2009-01-01

    Title: Analysis of scuba diving indoor training facilities. Objective: To describe demands on scuba diving indoor training facilities. Method: The demands were examined by structured answer sheet which were sent to chosen instructors. The information was summarized and evaluated using mathematic techniques. Results: They detail the demands on scuba diving training facilities. Key words: scuba diving indoor training facility, scuba diving, analysis Powered by TCPDF (www.tcpdf.org)

  1. Diving Deep: A Comparative Study of Educator Undergraduate and Graduate Backgrounds and Their Effect on Student Understanding of Engineering and Engineering Careers, Utilizing an Underwater Robotics Program

    Science.gov (United States)

    Scribner, J. Adam

    Numerous studies have demonstrated that educators having degrees in their subjects significantly enhances student achievement, particularly in secondary mathematics and science (Chaney, 1995; Goe, 2007; Rowan, Chiang, & Miller, 1997; Wenglinsky, 2000). Yet, science teachers in states that adopt the Next Generation Science Standards will be facilitating classroom engineering activities despite the fact that few have backgrounds in engineering. This quantitative study analyzed ex-post facto WaterBotics (an innovative underwater robotics curriculum for middle and high school students) data to determine if educators having backgrounds in engineering (i.e., undergraduate and graduate degrees in engineering) positively affected student learning on two engineering outcomes: 1) the engineering design process, and 2) understanding of careers in engineering (who engineers are and what engineers do). The results indicated that educators having backgrounds in engineering did not significantly affect student understanding of the engineering design process or careers in engineering when compared to educators having backgrounds in science, mathematics, technology education, or other disciplines. There were, however, statistically significant differences between the groups of educators. Students of educators with backgrounds in technology education had the highest mean score on assessments pertaining to the engineering design process while students of educators with disciplines outside of STEM had the highest mean scores on instruments that assess for student understanding of careers in engineering. This might be due to the fact that educators who lack degrees in engineering but who teach engineering do a better job of "sticking to the script" of engineering curricula.

  2. Stroke rates and diving air volumes of emperor penguins: implications for dive performance.

    Science.gov (United States)

    Sato, Katsufumi; Shiomi, Kozue; Marshall, Greg; Kooyman, Gerald L; Ponganis, Paul J

    2011-09-01

    Emperor penguins (Aptenodytes forsteri), both at sea and at an experimental dive hole, often have minimal surface periods even after performance of dives far beyond their measured 5.6 min aerobic dive limit (ADL: dive duration associated with the onset of post-dive blood lactate accumulation). Accelerometer-based data loggers were attached to emperor penguins diving in these two different situations to further evaluate the capacity of these birds to perform such dives without any apparent prolonged recovery periods. Minimum surface intervals for dives as long as 10 min were less than 1 min at both sites. Stroke rates for dives at sea were significantly greater than those for dives at the isolated dive hole. Calculated diving air volumes at sea were variable, increased with maximum depth of dive to a depth of 250 m, and decreased for deeper dives. It is hypothesized that lower air volumes for the deepest dives are the result of exhalation of air underwater. Mean maximal air volumes for deep dives at sea were approximately 83% greater than those during shallow (emperor penguins, (b) stroke rate at sea is greater than at the isolated dive hole and, therefore, a reduction in muscle stroke rate does not extend the duration of aerobic metabolism during dives at sea, and (c) a larger diving air volume facilitates performance of deep dives by increasing the total body O(2) store to 68 ml O(2) kg(-1). Although increased O(2) storage and cardiovascular adjustments presumably optimize aerobic metabolism during dives, enhanced anaerobic capacity and hypoxemic tolerance are also essential for longer dives. This was exemplified by a 27.6 min dive, after which the bird required 6 min before it stood up from a prone position, another 20 min before it began to walk, and 8.4 h before it dived again.

  3. Diving and Environmental Simulation Team

    Data.gov (United States)

    Federal Laboratory Consortium — The Diving and Environmental Simulation Team focuses on ways to optimize the performance and safety of Navy divers. Our goal is to increase mission effectiveness by...

  4. Review of the U.S. Department of Energy's "deep dive" effort to understand voltage fade in Li- and Mn-rich cathodes.

    Science.gov (United States)

    Croy, Jason R; Balasubramanian, Mahalingam; Gallagher, Kevin G; Burrell, Anthony K

    2015-11-17

    The commercial introduction of the lithium-ion (Li-ion) battery nearly 25 years ago marked a technological turning point. Portable electronics, dependent on energy storage devices, have permeated our world and profoundly affected our daily lives in a way that cannot be understated. Now, at a time when societies and governments alike are acutely aware of the need for advanced energy solutions, the Li-ion battery may again change the way we do business. With roughly two-thirds of daily oil consumption in the United States allotted for transportation, the possibility of efficient and affordable electric vehicles suggests a way to substantially alleviate the Country's dependence on oil and mitigate the rise of greenhouse gases. Although commercialized Li-ion batteries do not currently meet the stringent demands of a would-be, economically competitive, electrified vehicle fleet, significant efforts are being focused on promising new materials for the next generation of Li-ion batteries. The leading class of materials most suitable for the challenge is the Li- and manganese-rich class of oxides. Denoted as LMR-NMC (Li-manganese-rich, nickel, manganese, cobalt), these materials could significantly improve energy densities, cost, and safety, relative to state-of-the-art Ni- and Co-rich Li-ion cells, if successfully developed.1 The success or failure of such a development relies heavily on understanding two defining characteristics of LMR-NMC cathodes. The first is a mechanism whereby the average voltage of cells continuously decreases with each successive charge and discharge cycle. This phenomenon, known as voltage fade, decreases the energy output of cells to unacceptable levels too early in cycling. The second characteristic is a pronounced hysteresis, or voltage difference, between charge and discharge cycles. The hysteresis represents not only an energy inefficiency (i.e., energy in vs energy out) but may also complicate the state of charge/depth of discharge

  5. Evaluation of LTA-, FAU- and MFI-type zeolites as sorbents of some toxic components of tobacco smoke

    International Nuclear Information System (INIS)

    Iucolano, F.; Caputo, D.; Monetta, T.; Bellucci, F.; Colella, C.

    2008-01-01

    Zeolites 3A, 4A, 13X, H-ZSM-5 were investigated in order to evaluate their possible use in removing toxic compounds from cigarette smoke. Ammonia and acetaldehyde were selected as representative of a wide range of possible sorbates. Adsorption equilibrium data at 313K were collected and analyzed by Langmuir and virial equations to estimate the relevant values of Henry's constant, a useful parameter to estimate the affinity sorbents-sorbates at low pressure. Unlike the Langmuir model, the virial equation provided a good fit for both ammonia and acetaldehyde equilibrium data for all sorbents in the whole range of pressures, especially at low pressure. As already assessed for nitrosamines, FAU- and MFI-type zeolites showed the highest affinity for ammonia and acetaldehyde, allowing these sorbents to be considered an effective potential resource for the removal of some of the main pollutants of tobacco smoke.

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

    Science.gov (United States)

    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.

  7. Potential Benefits of Navy Dive Computer Use in Ships Husbandry Diving: Analysis of Dives Conducted at Puget Sound Naval Shipyard

    National Research Council Canada - National Science Library

    Gault, Keith A

    2008-01-01

    Generation III Air Navy Dive Computers (AIR III) were used to record 315 ships husbandry dives conducted by divers breathing air at the Puget Sound Naval Shipyard from November 2007 to January 2008...

  8. Provisional Crown Dislodgement during Scuba Diving: A Case of Barotrauma.

    Science.gov (United States)

    Gulve, Meenal Nitin; Gulve, Nitin Dilip

    2013-01-01

    Changes in ambient pressure, for example, during flying, diving, or hyperbaric oxygen therapy, can lead to barotrauma. Although it may seem that this issue was neglected in dental education and research in recent decades, familiarity with and understanding of these facts may be of importance for dental practitioners. We report the case of a patient who experienced barotrauma involving dislodgement of a provisional crown during scuba diving. Patients who are exposed to pressure changes as a part of their jobs or hobbies and their dentists should know the causes of barotrauma. In addition, the clinician must be aware of the possible influence of pressure changes on the retention of dental components.

  9. Diving down the reefs? Intensive diving tourism threatens the reefs of the northern Red Sea

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Ott, Jörg A.

    2008-01-01

    Intensive recreational SCUBA diving threatens coral reef ecosystems. The reefs at Dahab, South Sinai, Egypt, are among the world’s most dived (>30,000dives y−1). We compared frequently dived sites to sites with no or little diving. Benthic communities and condition of corals were examined...... to intensive SCUBA diving showed a significantly higher number of broken and damaged corals and significantly lower coral cover. Reef crest coral communities were significantly more affected than those of the reef slope: 95% of the broken colonies were branching ones. No effect of diving on the abundance...... of corallivorous and herbivorous fish was evident. At heavily used dive sites, diver-related sedimentation rates significantly decreased with increasing distance from the entrance, indicating poor buoyancy regulation at the initial phase of the dive. The results show a high negative impact of current SCUBA diving...

  10. Combining Pre- and Post-Nucleation Trajectories for the Synthesis of High FAU-Content Faujasite Nanocrystals from Organic-Free Sols

    Energy Technology Data Exchange (ETDEWEB)

    Khaleel, Maryam; Xu, Wenqian; Lesch, David A.; Tsapatsis, Michael

    2016-06-28

    The effects of synthesis conditions on the FAU/EMT content and the size of nanocrystals, formed from inorganic aluminosilicate sols, were investigated. High resolution transmission electron microscopy imaging and comparison of experimental X-ray diffraction patterns with simulations demonstrated that all materials made starting from synthesis mixtures in the composition range (1.8-33) SiO2: 1 Al2O3: (2.7-33) Na2O: (41-1000) H2O contain FAU/EMT intergrowths. Compositions with low water content increase the FAU fraction up to 0.8 but the crystal size exceeds 100 nm. Extension of the higher FAU purity to nanocrystals was achieved only by first mixing the sol at high water content compositions that favor nanocrystal formation and then - after a certain time - lowering by freeze-drying the water to levels favoring the formation of FAU. Cryogenic transmission electron microscopy and small angle X-ray scattering from representative optically clear and colloidally stable precursor sols (aged and crystallized at ambient temperature) reveal the formation of amorphous aggregates before the detection of crystals, in agreement with earlier findings and an existing model for the aggregative growth of the zeolite MFI. The presence of these amorphous aggregates coincides with the aforementioned state of sol that preserves the original trajectory towards nano-crystals after the pronounced reduction of water content by freeze-drying. If water reduction by freeze-drying is applied earlier (before the detection of amorphous aggregates), the sol follows the low water content trajectory towards larger crystals. Despite this memory effect, the sol at this stage is still agnostic towards FAU or EMT formation, the relative content of which is dominantly determined by the final water content. These findings demonstrate that it is possible to combine the effects of pre-and post-nucleation sol composition to steer crystal size and crystal structure, respectively. They confirm precursor

  11. Beginning Skin and Scuba Diving, Physical Education: 5551.69.

    Science.gov (United States)

    Roberts, Millie

    This course outline is a guide for teaching the principles and basic fundamentals of beginning skin and scuba diving in grades 7-12. The course format includes lectures, skills practice, films, and tests that focus on mastery of skills and understanding correct usage of skin and scuba equipment. Course content includes the following: (a) history,…

  12. Scuba diving death: Always due to drowning? Two forensic cases and a review of the literature.

    Science.gov (United States)

    Aquila, I; Pepe, F; Manno, M; Frati, P; Gratteri, S; Fineschi, V; Ricci, P

    2018-03-01

    Scuba diving is an increasingly common recreational activity. We describe the physiopathology of barotrauma in two cases where death was caused by pulmonary barotrauma while diving. An inspection and autopsy were carried out in both cases. The autopsy data were supported by post-mortem radiological investigation. Histological and toxicological analyses were also carried out, and dive computer and tank manometer analysis performed. In both cases, the cause of death was attributable to arterial gas embolism, resulting from pulmonary barotrauma subsequent to pulmonary over-distension. The dive computer analysis and the tank manometer allowed us to understand what happened underwater. In our opinion, a multidisciplinary approach is crucial in order to clarify the cause of death. Some pathological conditions and risk factors should be considered before diving.

  13. 29 CFR 1926.1084 - SCUBA diving.

    Science.gov (United States)

    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 those...

  14. The epidemiology of injury in scuba diving.

    Science.gov (United States)

    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. Copyright © 2012 S. Karger AG, Basel.

  15. Scuba diving activates vascular antioxidant system.

    Science.gov (United States)

    Sureda, A; Batle, J M; Ferrer, M D; Mestre-Alfaro, A; Tur, J A; Pons, A

    2012-07-01

    The aim was to study the effects of scuba diving immersion on plasma antioxidant defenses, nitric oxide production, endothelin-1 and vascular endothelial growth factor levels. 9 male divers performed an immersion at 50 m depth for a total time of 35 min. Blood samples were obtained before diving at rest, immediately after diving, and 3 h after the diving session. Leukocyte counts, plasma 8oxoHG, malondialdehyde and nitrite levels significantly increased after recovery. Activities of lactate dehydrogenase, creatine kinase, catalase and superoxide significantly increased immediately after diving and these activities remained high after recovery. Plasma myeloperoxidase activity and protein levels and extracellular superoxide dismutase protein levels increased after 3 h. Endothelin-1 concentration significantly decreased after diving and after recovery. Vascular endothelial growth factor concentration significantly increased after diving when compared to pre-diving values, returning to initial values after recovery. Scuba diving at great depth activated the plasma antioxidant system against the oxidative stress induced by elevated pO₂ oxygen associated with hyperbaria. The decrease in endothelin-1 levels and the increase in nitric oxide synthesis could be factors that contribute to post-diving vasodilation. Diving increases vascular endothelial growth factor plasma levels which can contribute to the stimulation of tissue resistance to diving-derived oxidative damage. © Georg Thieme Verlag KG Stuttgart · New York.

  16. Effects of diving and oxygen on autonomic nervous system and cerebral blood flow.

    Science.gov (United States)

    Winklewski, Pawel J; Kot, Jacek; Frydrychowski, Andrzej F; Nuckowska, Magdalena K; Tkachenko, Yurii

    2013-09-01

    Recreational scuba diving is a popular leisure activity with the number of divers reaching several millions worldwide. Scuba diving represents a huge challenge for integrative physiology. In mammalian evolution, physiological reflexes developed to deal with lack of oxygen, rather than with an excess, which makes adaptations to scuba diving more difficult to describe and understand than those associated with breath-hold diving. The underwater environment significantly limits the use of equipment to register the organism's functions, so, in most instances, scientific theories are built on experiments that model real diving to some extent, like hyperbaric exposures, dive reflexes or water immersion. The aim of this review is to summarise the current knowledge related to the influence exerted by physiological conditions specific to diving on the autonomic nervous system and cerebral blood flow. The main factors regulating cerebral blood flow during scuba diving are discussed as follows: 1) increased oxygen partial pressure; 2) immersion-related trigemino-cardiac reflexes and 3) exposure to cold, exercise and stress. Also discussed are the potential mechanisms associated with immersion pulmonary oedema.

  17. Risso's dolphins plan foraging dives.

    Science.gov (United States)

    Arranz, Patricia; Benoit-Bird, Kelly J; Southall, Brandon L; Calambokidis, John; Friedlaender, Ari S; Tyack, Peter L

    2018-02-28

    Humans remember the past and use that information to plan future actions. Lab experiments that test memory for the location of food show that animals have a similar capability to act in anticipation of future needs, but less work has been done on animals foraging in the wild. We hypothesized that planning abilities are critical and common in breath-hold divers who adjust each dive to forage on prey varying in quality, location and predictability within constraints of limited oxygen availability. We equipped Risso's dolphins with sound-and-motion recording tags to reveal where they focus their attention through their externally observable echolocation and how they fine tune search strategies in response to expected and observed prey distribution. The information from the dolphins was integrated with synoptic prey data obtained from echosounders on an underwater vehicle. At the start of the dives, whales adjusted their echolocation inspection ranges in ways that suggest planning to forage at a particular depth. Once entering a productive prey layer, dolphins reduced their search range comparable to the scale of patches within the layer, suggesting that they were using echolocation to select prey within the patch. On ascent, their search range increased, indicating that they decided to stop foraging within that layer and started searching for prey in shallower layers. Information about prey, learned throughout the dive, was used to plan foraging in the next dive. Our results demonstrate that planning for future dives is modulated by spatial memory derived from multi-modal prey sampling (echoic, visual and capture) during earlier dives. © 2018. Published by The Company of Biologists Ltd.

  18. Diving down the reefs? Intensive diving tourism threatens the reefs of the northern Red Sea

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Ott, Jörg A.

    2008-01-01

    Intensive recreational SCUBA diving threatens coral reef ecosystems. The reefs at Dahab, South Sinai, Egypt, are among the world’s most dived (>30,000dives y−1). We compared frequently dived sites to sites with no or little diving. Benthic communities and condition of corals were examined...... to intensive SCUBA diving showed a significantly higher number of broken and damaged corals and significantly lower coral cover. Reef crest coral communities were significantly more affected than those of the reef slope: 95% of the broken colonies were branching ones. No effect of diving on the abundance...... intensities on coral communities and coral condition. Corallivorous and herbivorous fishes are apparently not yet affected, but are endangered if coral cover decline continues. Reducing the number of dives per year, ecologically sustainable dive plans for individual sites, and reinforcing the environmental...

  19. Diving down the reefs? Intensive diving tourism threatens the reefs of the northern Red Sea.

    Science.gov (United States)

    Hasler, Harald; Ott, Jörg A

    2008-10-01

    Intensive recreational SCUBA diving threatens coral reef ecosystems. The reefs at Dahab, South Sinai, Egypt, are among the world's most dived (>30,000 dives y(-1)). We compared frequently dived sites to sites with no or little diving. Benthic communities and condition of corals were examined by the point intercept sampling method in the reef crest zone (3m) and reef slope zone (12 m). Additionally, the abundance of corallivorous and herbivorous fish was estimated based on the visual census method. Sediments traps recorded the sedimentation rates caused by SCUBA divers. Zones subject to intensive SCUBA diving showed a significantly higher number of broken and damaged corals and significantly lower coral cover. Reef crest coral communities were significantly more affected than those of the reef slope: 95% of the broken colonies were branching ones. No effect of diving on the abundance of corallivorous and herbivorous fish was evident. At heavily used dive sites, diver-related sedimentation rates significantly decreased with increasing distance from the entrance, indicating poor buoyancy regulation at the initial phase of the dive. The results show a high negative impact of current SCUBA diving intensities on coral communities and coral condition. Corallivorous and herbivorous fishes are apparently not yet affected, but are endangered if coral cover decline continues. Reducing the number of dives per year, ecologically sustainable dive plans for individual sites, and reinforcing the environmental education of both dive guides and recreational divers are essential to conserve the ecological and the aesthetic qualities of these dive sites.

  20. Drift dives and prolonged surfacing periods in Baikal seals: resting strategies in open waters?

    Science.gov (United States)

    Watanabe, Yuuki Y; Baranov, Eugene A; Miyazaki, Nobuyuki

    2015-09-01

    Many pinnipeds frequently rest on land or ice, but some species remain in open waters for weeks or months, raising the question of how they rest. A unique type of dive, called drift dives, has been reported for several pinnipeds with suggested functions of rest, food processing and predator avoidance. Prolonged surfacing periods have also been observed in captive seals and are thought to aid food processing. However, information from other species in a different environment would be required to better understand the nature and function of this behavior. In this study, we attached multi-sensor tags to Baikal seals Pusa sibirica, a rare, freshwater species that has no aquatic predators and few resting grounds during the ice-free season. The seals exhibited repeated drift dives (mean depth, 116 m; duration, 10.1 min) in the daytime and prolonged periods at the surface (mean duration, 1.3 h) mainly around dawn. Drift dives and prolonged surfacing periods were temporally associated and observed between a series of foraging dives, suggesting a similar function, i.e. a combination of resting and food processing. The maximum durations of both drift and foraging dives were 15.4 min, close to the aerobic dive limit of this species; therefore, metabolic rates might not be significantly depressed during drift dives, further supporting the function of food processing rather than purely resting. Our results also show that drift diving can occur in a predator-free environment, and thus predator avoidance is not a general explanation of drift dives in pinnipeds. © 2015. Published by The Company of Biologists Ltd.

  1. Medical Management and Risk Reduction of the Cardiovascular Effects of Underwater Diving.

    Science.gov (United States)

    Whayne, Thomas F

    2017-06-20

    Undersea diving is a sport and commercial industry. Knowledge of potential problems began with Caisson disease or "the bends", first identified with compressed air in the construction of tunnels under rivers in the 19th century. Subsequently, there was the commercially used old-fashioned diving helmet attached to a suit, with compressed air pumped down from the surface. Breathhold diving, with no supplementary source of air or other breathing mixture, is also a sport as well as a commercial fishing tool in some parts of the world. There has been an evolution to self-contained underwater breathing apparatus (SCUBA) diving with major involvement as a recreational sport but also of major commercial importance. Knowledge of the physiology and cardiovascular plus other medical problems associated with the various forms of diving have evolved extensively. The major medical catastrophes of SCUBA diving are air embolism and decompression sickness (DCS). Understanding of the essential referral to a hyperbaric recompression chamber for these problems is critical, as well as immediate measures until that recompression is achieved. These include the administration of 100% oxygen and rehydration with intravenous normal saline. Undersea diving continues to expand, especially as a sport, and a basic understanding of the associated preventive and emergency medicine will decrease complications and save lives. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Moderator and Mediator Effects of Scuba Diving Specialization on Marine-Based Environmental Knowledge-Behavior Contingency

    Science.gov (United States)

    Thapa, Brijesh; Graefe, Alan R.; Meyer, Louisa A.

    2005-01-01

    Given the growth in scuba diving activities and the importance of environmental education programs to alleviate the potential impacts on coral reef ecosystems, there is a need to better understand the diving community, its environmental knowledge, and subsequent behavioral actions. The purpose of this study was to explore the role or influence of…

  3. Development of diving capacity in emperor penguins.

    Science.gov (United States)

    Ponganis, P J; Starke, L N; Horning, M; Kooyman, G L

    1999-04-01

    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.

  4. How Elephant Seals (Mirounga leonina Adjust Their Fine Scale Horizontal Movement and Diving Behaviour in Relation to Prey Encounter Rate.

    Directory of Open Access Journals (Sweden)

    Yves Le Bras

    Full Text Available Understanding the diving behaviour of diving predators in relation to concomitant prey distribution could have major practical applications in conservation biology by allowing the assessment of how changes in fine scale prey distribution impact foraging efficiency and ultimately population dynamics. The southern elephant seal (Mirounga leonina, hereafter SES, the largest phocid, is a major predator of the southern ocean feeding on myctophids and cephalopods. Because of its large size it can carry bio-loggers with minimal disturbance. Moreover, it has great diving abilities and a wide foraging habitat. Thus, the SES is a well suited model species to study predator diving behaviour and the distribution of ecologically important prey species in the Southern Ocean. In this study, we examined how SESs adjust their diving behaviour and horizontal movements in response to fine scale prey encounter densities using high resolution accelerometers, magnetometers, pressure sensors and GPS loggers. When high prey encounter rates were encountered, animals responded by (1 diving and returning to the surface with steeper angles, reducing the duration of transit dive phases (thus improving dive efficiency, and (2 exhibiting more horizontally and vertically sinuous bottom phases. In these cases, the distance travelled horizontally at the surface was reduced. This behaviour is likely to counteract horizontal displacement from water currents, as they try to remain within favourable prey patches. The prey encounter rate at the bottom of dives decreased with increasing diving depth, suggesting a combined effect of decreased accessibility and prey density with increasing depth. Prey encounter rate also decreased when the bottom phases of dives were spread across larger vertical extents of the water column. This result suggests that the vertical aggregation of prey can regulate prey density, and as a consequence impact the foraging success of SESs. To our knowledge

  5. Blood temperature profiles of diving elephant seals.

    Science.gov (United States)

    Meir, Jessica U; Ponganis, Paul J

    2010-01-01

    Hypothermia-induced reductions in metabolic rate have been proposed to suppress metabolism and prolong the duration of aerobic metabolism during dives of marine mammals and birds. To determine whether core hypothermia might contribute to the repetitive long-duration dives of the northern elephant seal Mirounga angustirostris, blood temperature profiles were obtained in translocated juvenile elephant seals equipped with a thermistor and backpack recorder. Representative temperature (the y-intercept of the mean temperature vs. dive duration relationship) was 37.2 degrees C +/- 0.6 degrees C (n=3 seals) in the extradural vein, 38.1 degrees C +/- 0.7 degrees C (n = 4 seals) in the hepatic sinus, and 38.8 degrees +/- 1.6 degrees C (n = 6 deals) in the aorta. Mean temperature was significantly though weakly negatively related to dive duration in all but one seal. Mean venous temperatures of all dives of individual seals ranged between 36 degrees and 38 degrees C, while mean arterial temperatures ranged between 35 degrees and 39 degrees C. Transient decreases in venous and arterial temperatures to as low as 30 degrees -33 degrees C occurred in some dives >30 min (0.1% of dives in the study). The lack of significant core hypothermia during routine dives (10-30 min) and only a weak negative correlation of mean temperature with dive duration do not support the hypothesis that a cold-induced Q(10) effect contributes to metabolic suppression of central tissues during dives. The wide range of arterial temperatures while diving and the transient declines in temperature during long dives suggest that alterations in blood flow patterns and peripheral heat loss contribute to thermoregulation during diving.

  6. Animal Models for Investigating the Central Control of the Mammalian Diving Response

    Science.gov (United States)

    McCulloch, Paul Frederick

    2012-01-01

    Pioneering studies by Per Scholander indicated that the diving response consists of reflexly induced apnea, bradycardia and an alteration of blood flow that maintains perfusion of the heart and brain. More recently field physiological studies have shown that many marine animals can adjust cardiorespiratory aspects of their diving response depending upon the behavioral situation. This could suggest that the very labile heart rate during diving is under direct cortical control. However, the final control of autonomic nervous system functioning resides within the brainstem and not the cortex. Many physiologists regard the brain as a “black box” where important neuronal functioning occurs, but the complexity of such functioning leaves systematic investigation a daunting task. As a consequence the central control of the diving response has been under-investigated. Thus, to further advance the field of diving physiology by understanding its central neuronal control, it would be first necessary to understand the reflex circuitry that exists within the brainstem of diving animals. To do this will require an appropriate animal model. In this review, two animals, the muskrat and rat, will be offered as animal models to investigate the central aspects of the diving response. Firstly, although these rodents are not marine animals, natural histories indicate that both animals can and do exploit aquatic environments. Secondly, physiological recordings during natural and simulated diving indicate that both animals possess the same basic physiological responses to underwater submersion that occur in marine animals. Thirdly, the size and ease of housing of both animals makes them attractive laboratory research animals. Finally, the enormous amount of scientific literature regarding rodent brainstem autonomic control mechanisms, and the availability of brain atlases, makes these animals ideal choices to study the central control of the mammalian diving response. PMID:22661956

  7. Animal models for investigating the central control of the mammalian diving response

    Directory of Open Access Journals (Sweden)

    Paul eMcculloch

    2012-05-01

    Full Text Available Pioneering studies by Per Scholander indicated that the diving response consists of reflexly induced apnea, bradycardia and an alteration of blood flow that maintains perfusion of the heart and brain. More recently field physiological studies have shown that many marine animals can adjust cardiorespiratory aspects of their diving response depending upon the behavioral situation. This could suggest that the very labile heart rate during diving is under direct cortical control. However, the final control of ANS functioning resides within the brainstem and not the cortex. Many physiologists regard the brain as a black box where important neuronal functioning occurs, but the complexity of such functioning leaves systematic investigation a daunting task. As a consequence the central control of the diving response has been under-investigated. Thus, to further advance the field of diving physiology by understanding its central neuronal control, it would be first necessary to understand the reflex circuitry that exists within the brainstem of diving animals. To do this will require an appropriate animal model. In this review, two animals, the muskrat and rat, will be offered as animal models to investigate the central aspects of the diving response. Firstly, although these rodents are not marine animals, natural histories indicate that both animals can and do exploit aquatic environments. Secondly, physiological recordings during natural and simulated diving indicate that both animals possess the same basic physiological responses to underwater submersion that occur in marine animals. Thirdly, the size and ease of housing of both animals makes them attractive laboratory research animals. Finally, the enormous amount of scientific literature regarding rodent brainstem autonomic control mechanisms, and the availability of brain atlases, makes these animals ideal choices to study the central control of the mammalian diving response.

  8. Effect of Shallow and Deep SCUBA Dives on Heart Rate Variability

    Science.gov (United States)

    Noh, Yeonsik; Posada-Quintero, Hugo F.; Bai, Yan; White, Joseph; Florian, John P.; Brink, Peter R.; Chon, Ki H.

    2018-01-01

    Prolonged and high pressure diving may lead to various physiological changes including significant alterations of autonomic nervous system (ANS) activity that may be associated with altered physical performance, decompression sickness, or central nervous system oxygen toxicity. Ideally, researchers could elucidate ANS function before, during, and after dives that are most associated with altered function and adverse outcomes. However, we have a limited understanding of the activities of the ANS especially during deeper prolonged SCUBA diving because there has never been a convenient way to collect physiological data during deep dives. This work is one of the first studies which was able to collect electrocardiogram (ECG) data from SCUBA divers at various depths (33, 66, 99, 150, and 200 ftsw; equivalent to 10.05, 20.10, 30.17, 45.72, and 60.96 m of salt water, respectively) breathing different gas mixtures (air, nitrox and trimix). The aim of this study was to shed light on cardiac ANS behavior during dives, including deep dives. With the aid of dry suits, a Holter monitor that could handle the pressure of a 200 ft. dive, and a novel algorithm that can provide a useful assessment of the ANS from the ECG signal, we investigated the effects of SCUBA dives with different time durations, depths and gas mixtures on the ANS. Principal dynamic mode (PDM) analysis of the ECG, which has been shown to provide accurate separation of the sympathetic and parasympathetic dynamics, was employed to assess the difference of ANS behavior between baseline and diving conditions of varying depths and gas mixtures consisting of air, nitrox and trimix. For all depths and gas mixtures, we found consistent dominance in the parasympathetic activity and a concomitant increase of the parasympathetic dynamics with increasing diving duration and depth. For 33 and 66 ft. dives, we consistently found significant decreases in heart rates (HR) and concomitant increases in parasympathetic activities

  9. Effect of Shallow and Deep SCUBA Dives on Heart Rate Variability

    Directory of Open Access Journals (Sweden)

    Yeonsik Noh

    2018-02-01

    Full Text Available Prolonged and high pressure diving may lead to various physiological changes including significant alterations of autonomic nervous system (ANS activity that may be associated with altered physical performance, decompression sickness, or central nervous system oxygen toxicity. Ideally, researchers could elucidate ANS function before, during, and after dives that are most associated with altered function and adverse outcomes. However, we have a limited understanding of the activities of the ANS especially during deeper prolonged SCUBA diving because there has never been a convenient way to collect physiological data during deep dives. This work is one of the first studies which was able to collect electrocardiogram (ECG data from SCUBA divers at various depths (33, 66, 99, 150, and 200 ftsw; equivalent to 10.05, 20.10, 30.17, 45.72, and 60.96 m of salt water, respectively breathing different gas mixtures (air, nitrox and trimix. The aim of this study was to shed light on cardiac ANS behavior during dives, including deep dives. With the aid of dry suits, a Holter monitor that could handle the pressure of a 200 ft. dive, and a novel algorithm that can provide a useful assessment of the ANS from the ECG signal, we investigated the effects of SCUBA dives with different time durations, depths and gas mixtures on the ANS. Principal dynamic mode (PDM analysis of the ECG, which has been shown to provide accurate separation of the sympathetic and parasympathetic dynamics, was employed to assess the difference of ANS behavior between baseline and diving conditions of varying depths and gas mixtures consisting of air, nitrox and trimix. For all depths and gas mixtures, we found consistent dominance in the parasympathetic activity and a concomitant increase of the parasympathetic dynamics with increasing diving duration and depth. For 33 and 66 ft. dives, we consistently found significant decreases in heart rates (HR and concomitant increases in

  10. High diving metabolism results in a short aerobic dive limit for Steller sea lions (Eumetopias jubatus).

    Science.gov (United States)

    Gerlinsky, Carling D; Rosen, David A S; Trites, Andrew W

    2013-07-01

    The diving capacity of marine mammals is typically defined by the aerobic dive limit (ADL) which, in lieu of direct measurements, can be calculated (cADL) from total body oxygen stores (TBO) and diving metabolic rate (DMR). To estimate cADL, we measured blood oxygen stores, and combined this with diving oxygen consumption rates (VO2) recorded from 4 trained Steller sea lions diving in the open ocean to depths of 10 or 40 m. We also examined the effect of diving exercise on O2 stores by comparing blood O2 stores of our diving animals to non-diving individuals at an aquarium. Mass-specific blood volume of the non-diving individuals was higher in the winter than in summer, but there was no overall difference in blood O2 stores between the diving and non-diving groups. Estimated TBO (35.9 ml O2 kg(-1)) was slightly lower than previously reported for Steller sea lions and other Otariids. Calculated ADL was 3.0 min (based on an average DMR of 2.24 L O2 min(-1)) and was significantly shorter than the average 4.4 min dives our study animals performed when making single long dives-but was similar to the times recorded during diving bouts (a series of 4 dives followed by a recovery period on the surface), as well as the dive times of wild animals. Our study is the first to estimate cADL based on direct measures of VO2 and blood oxygen stores for an Otariid and indicates they have a much shorter ADL than previously thought.

  11. Massive pneumoperitoneum after scuba diving.

    Science.gov (United States)

    Oh, Seung-Tak; Kim, Wook; Jeon, Hae-Myung; Kim, Jeong-Soo; Kim, Kee-Whan; Yoo, Seung-Jin; Kim, Eung-Kuk

    2003-01-01

    Pneumoperitoneum usually indicates rupture of a hollow viscus and considered a surgical emergency. But air may also enter the peritoneum from the lung or the genital organs in female without visceral perforation. While scuba diving, the rapid ascent is usually controlled by placing in a decompression chamber and the excess gas volume is exhaled. Failure to allow this excess gas to escape will result in overdistension of air passage, which may rupture resulting in pulmonary interstitial emphysema or, if air enters the circulation, air embolus can occur. Pneumo-peritoneum is a rare complication of diving accidents. While the majority of cases are not related to an intraabdominal catastrophy, more than 20% have been the result of gastric rupture. We report a 42-yr-old male patient with massive pneumoperitoneum after scuba diving, who presented himself with dyspnea and abdominal distension. Knowledge of this rare condition and its benign course may allow the emergency physician and surgeon to order appropriate studies to help avoid unnecessary surgical treatment. It is important to determine promptly whether the air emanated from a ruptured viscus or was introduced from an extraperitoneal source. Free air in the abdomen does not always indicate a ruptured intra-abdominal viscus. PMID:12692430

  12. Shallow Water Diving - The NASA Experience

    Science.gov (United States)

    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.

  13. Saturation diving; physiology and pathophysiology.

    Science.gov (United States)

    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

  14. Persistent (patent) foramen ovale (PFO): implications for safe diving.

    Science.gov (United States)

    Germonpré, Peter

    2015-06-01

    Diving medicine is a peculiar specialty. There are physicians and scientists from a wide variety of disciplines with an interest in diving and who all practice 'diving medicine': the study of the complex whole-body physiological changes and interactions upon immersion and emersion. To understand these, the science of physics and molecular gas and fluid movements comes into play. The ultimate goal of practicing diving medicine is to preserve the diver's health, both during and after the dive. Good medicine starts with prevention. For most divers, underwater excursions are not a professional necessity but a hobby; avoidance of risk is generally a much better option than risk mitigation or cure. However, prevention of diving illnesses seems to be even more difficult than treating those illnesses. The papers contained in this issue of DHM are a nice mix of various aspects of PFO that divers are interested in, all of them written by specialist doctors who are avid divers themselves. However, diving medicine should also take advantage of research from the "non-diving" medicine community, and PFO is a prime example. Cardiology and neurology have studied PFO for as long, or even longer than divers have been the subjects of PFO research, and with much greater numbers and resources. Unexplained stroke has been associated with PFO, as has severe migraine with aura. As the association seems to be strong, investigating the effect of PFO closure was a logical step. Devices have been developed and perfected, allowing now for a relatively low-risk procedure to 'solve the PFO problem'. However, as with many things in science, the results have not been as spectacular as hoped for: patients still get recurrences of stroke, still have migraine attacks. The risk-benefit ratio of PFO closure for these non-diving diseases is still debated. For diving, we now face a similar problem. Let there be no doubt that PFO is a pathway through which venous gas emboli (VGE) can arterialize, given

  15. What triggers the aerobic dive limit? Patterns of muscle oxygen depletion during dives of emperor penguins.

    Science.gov (United States)

    Williams, Cassondra L; Meir, Jessica U; Ponganis, Paul J

    2011-06-01

    The physiological basis of the aerobic dive limit (ADL), the dive duration associated with the onset of post-dive blood lactate elevation, is hypothesized to be depletion of the muscle oxygen (O(2)) store. A dual wavelength near-infrared spectrophotometer was developed and used to measure myoglobin (Mb) O(2) saturation levels in the locomotory muscle during dives of emperor penguins (Aptenodytes forsteri). Two distinct patterns of muscle O(2) depletion were observed. Type A dives had a monotonic decline, and, in dives near the ADL, the muscle O(2) store was almost completely depleted. This pattern of Mb desaturation was consistent with lack of muscle blood flow and supports the hypothesis that the onset of post-dive blood lactate accumulation is secondary to muscle O(2) depletion during dives. The mean type A Mb desaturation rate allowed for calculation of a mean muscle O(2) consumption of 12.4 ml O(2) kg(-1) muscle min(-1), based on a Mb concentration of 6.4 g 100 g(-1) muscle. Type B desaturation patterns demonstrated a more gradual decline, often reaching a mid-dive plateau in Mb desaturation. This mid-dive plateau suggests maintenance of some muscle perfusion during these dives. At the end of type B dives, Mb desaturation rate increased and, in dives beyond the ADL, Mb saturation often reached near 0%. Thus, although different physiological strategies may be used during emperor penguin diving, both Mb desaturation patterns support the hypothesis that the onset of post-dive lactate accumulation is secondary to muscle O(2) store depletion.

  16. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... doctor to give you an accurate prognosis. Understanding the Difference Between Cure and Remission Cure means that ... about her colorectal cancer prognosis. Diving Out of the Dark View this video on YouTube. Andrew wants ...

  17. Cation Movements during Dehydration and NO2 Desorption in a Ba-Y,FAU zeolite: an in situ Time-resolved X-ray Diffraction Study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianqin; Hanson, Jonathan C.; Kwak, Ja Hun; Szanyi, Janos; Peden, Charles HF

    2013-02-28

    Synchrotron-based in situ time-resolved X-ray diffraction and Rietveld analysis were used to probe the interactions between BaY, FAU zeolite frameworks and H2O or NO2 molecules. These results provided information about the migration of the Ba2+ cations in the zeolite framework during dehydration and during NO2 adsorption/desorption processes in a water free zeolite. In the hydrated structure water molecules form four double rings of hexagonal ice-like clusters [(H2O)6] in the 12-ring openings of the super-cage. These water rings interacted with the cations and the zeolite framework through four cation/water clusters centered over the four 6-membered rings of the super-cage (site II). Interpenetrating tetrahedral water clusters [(H2O)4] and tetrahedral Ba+2 cation clusters were observed in the sodalite cage. Consistent with the reported FT-IR results, three different ionic NOx species (NO+, NO+-NO2, and NO3-) were observed following NO2 adsorption by the dehydrated Ba-Y,FAU zeolite. The structure of the water and the NOx species were correlated with the interactions between the adsorbates, the cations, and the framework. The population of Ba2+ ions at different cationic positions strongly depended on the amount of bound water or NOx species. Both dehydration and NO2 adsorption/desorption resulted in facile migration of Ba2+ ions among the different cationic positions. Data obtained in this work have provided direct evidence for the Ba2+ cation migration to accommodate the binding of gas molecules. This important feature may play a pivotal role in the strong binding of NO2 to Ba-Y,FAU zeolite, a prerequisite for high catalytic activity in lean NOx reduction catalysis.

  18. Otorhinolaryngology and Diving-Part 2: Otorhinolaryngological Fitness for Compressed Gas Scuba Diving: A Review.

    Science.gov (United States)

    Lechner, Matt; Sutton, Liam; Fishman, Jonathan M; Kaylie, David M; Moon, Richard E; Masterson, Liam; Klingmann, Christoph; Birchall, Martin A; Lund, Valerie J; Rubin, John S

    2018-03-01

    Self-contained underwater breathing apparatus (scuba) diving has become increasingly popular with millions of people diving each year. Otorhinolaryngologists are often consulted either by patients or diving physicians regarding fitness to dive, and at present, the guidelines do not provide comprehensive information regarding the evaluation of this patient cohort. The aim of this review is to provide a comprehensive overview of existing otorhinolaryngological guidelines for fitness to dive recreationally. There is a paucity of guidelines for assessing otorhinolaryngological fitness to dive in the recreational diver. Comprehensive guidelines exist from US, European, and UK regulatory bodies regarding fitness for commercial diving; however, not all of these can be directly extrapolated to the recreational diver. There are also a variety of conditions that are not covered either by the existing fitness for recreational diving guidelines or the commercial regulatory bodies. With the paucity of recreational fitness to dive guidelines we must draw on information from the commercial diving regulatory bodies. We have provided our own recommendations on the conditions that are not covered by either of the above, to provide otorhinolaryngologists with the information they require to assess fitness for recreational diving.

  19. Flying after diving: in-flight echocardiography after a scuba diving week.

    Science.gov (United States)

    Cialoni, Danilo; Pieri, Massimo; Balestra, Costantino; Marroni, Alessandro

    2014-10-01

    Flying after diving may increase decompression sickness risk (DCS), but strong evidence indicating minimum preflight surface intervals (PFSI) is missing. On return flights after a diving week on a live-aboard, 32 divers were examined by in-flight echocardiography with the following protocol: 1) outgoing flight, no previous dive; 2) during the diving week; 3) before the return flight after a 24-h PFSI; and 4) during the return flight. All divers completed similar multiple repetitive dives during the diving week. All dives were equivalent as to inert gas load and gradient factor upon surfacing. No bubbles in the right heart were found in any diver during the outgoing flight or at the preflight control after a 24-h PFSI following the diving week. A significant increase in the number and grade of bubbles was observed during the return flight. However, bubbles were only observed in 6 of the 32 divers. These six divers were the same ones who developed bubbles after every dive. Having observed a 24-h preflight interval, the majority of divers did not develop bubbles during altitude exposure; however, it is intriguing to note that the same subjects who developed significant amounts of bubbles after every dive showed equally significant bubble grades during in-flight echocardiography notwithstanding a correct PFSI. This indicates a possible higher susceptibility to bubble formation in certain individuals, who may need longer PFSI before altitude exposure after scuba diving.

  20. Otorhinolaryngology and Diving-Part 1: Otorhinolaryngological Hazards Related to Compressed Gas Scuba Diving: A Review.

    Science.gov (United States)

    Lechner, Matt; Sutton, Liam; Fishman, Jonathan M; Kaylie, David M; Moon, Richard E; Masterson, Liam; Klingmann, Christoph; Birchall, Martin A; Lund, Valerie J; Rubin, John S

    2018-03-01

    Scuba diving is becoming increasingly popular. However, scuba diving is associated with specific risks; 80% of adults and 85% of juvenile divers (aged 6-17 years) have been reputed to have an ear, nose, or throat complaint related to diving at some point during their diving career. Divers frequently seek advice from primary care physicians, diving physicians, and otorhinolaryngologists, not only in the acute setting, but also related to the long-term effects of diving. The principles underpinning diving-related injuries that may present to the otorhinolaryngologist rely on gas volume and gas saturation laws, and the prevention of these injuries requires both that the diver is skilled and that their anatomy allows for pressure equalization between the various anatomical compartments. The overlapping symptoms of middle ear barotrauma, inner ear barotrauma, and inner ear decompression sickness can cause a diagnostic conundrum, and a thorough history of both the diver's symptoms and the dive itself are required to elucidate the diagnosis. Correct diagnosis and appropriate treatment result in a more timely return to safe diving. The aim of this review is to provide a comprehensive overview of otorhinolaryngological complications during diving. With the increasing popularity of diving and the frequency of ear, nose, or throat-related injuries, it could be expected that these injuries will become more common and this review provides a resource for otorhinolaryngologists to diagnose and treat these conditions.

  1. 46 CFR 197.410 - Dive procedures.

    Science.gov (United States)

    2010-10-01

    ... treatment; and (iii) A dive team member, other than the diver, is trained and available to operate the... past performance of the decompression table used; and (C) Individual susceptibility; and (iii) The... shall ensure that the working interval of a dive is terminated when he so directs or when— (1) A diver...

  2. Teaching Persons with Disabilities to SCUBA Diving.

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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.

  4. The effect of using a pre-dive checklist on the incidence of diving mishaps in recreational scuba diving: a cluster-randomized trial.

    Science.gov (United States)

    Ranapurwala, Shabbar I; Denoble, Petar J; Poole, Charles; Kucera, Kristen L; Marshall, Stephen W; Wing, Steve

    2016-02-01

    Scuba diving mishaps, caused by equipment problems or human errors, increase the occurrence of injuries and fatalities while diving. Pre-dive checklists may mitigate mishaps. This study evaluated the effect of using a pre-dive checklist on the incidence of diving mishaps in recreational divers. A multi-location cluster-randomized trial with parallel groups and allocation concealment was conducted between 1 June and 17 August 2012. The participants had to be at least 18 years of age, permitted to dive by the dive operator and planning to dive on the day of participation. They were recruited at the pier and dive boats at four locations. The intervention group received a pre-dive checklist and post-dive log. The control group received a post-dive log only. The outcomes, self-reported major and minor mishaps, were prompted by a post-dive questionnaire. Mishap rates per 100 dives were compared using Poisson regression with generalized estimating equations. Intent-to-treat, per-protocol and marginal structural model analyses were conducted. A total of 1043 divers (intervention = 617; control = 426) made 2041 dives, on 70 location-days (intervention = 40; control = 30) at four locations. Compared with the control group, the incidence of major mishaps decreased in the intervention group by 36%, minor mishaps by 26% and all mishaps by 32%. On average, there was one fewer mishap in every 25 intervention dives. In this trial, pre-dive checklist use prevented mishaps which could lead to injuries and fatalities. Pre-dive checklists can increase diving safety and their use should be promoted. Trial Registration: ClinicalTrials.gov ID NCT01960738. Published by Oxford University Press on behalf of the International Epidemiological Association 2015. This work is written by US Government employees and is in the public domain in the US.

  5. Provisional Crown Dislodgement during Scuba Diving: A Case of Barotrauma

    Directory of Open Access Journals (Sweden)

    Meenal Nitin Gulve

    2013-01-01

    Full Text Available Changes in ambient pressure, for example, during flying, diving, or hyperbaric oxygen therapy, can lead to barotrauma. Although it may seem that this issue was neglected in dental education and research in recent decades, familiarity with and understanding of these facts may be of importance for dental practitioners. We report the case of a patient who experienced barotrauma involving dislodgement of a provisional crown during scuba diving. Patients who are exposed to pressure changes as a part of their jobs or hobbies and their dentists should know the causes of barotrauma. In addition, the clinician must be aware of the possible influence of pressure changes on the retention of dental components.

  6. The death of buddy diving?

    Science.gov (United States)

    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

  7. A importância do trabalho de Miranda Magnoli nas experiências de pesquisa sobre arquitetura da paisagem na FAU-UFRJ

    Directory of Open Access Journals (Sweden)

    Vera Regina Tângari

    2006-06-01

    Full Text Available O objetivo deste artigo é relacionar a importância dos conceitos emanados do trabalho da professora Miranda Martinelli Magnoli para a formação de um corpo de pesquisa sobre arquitetura da paisagem, a partir de 2000, no Programa de Pós-Graduação em Arquitetura da FAU-UFRJ. Utilizando como referência as dissertações de mestrado e teses de doutorado produzidas e em produção pelo ProArq, pretende-se salientar o peso da reflexão crítica, profunda e sistemática que a professora Magnoli impõe ao seu trabalho, como professora e pesquisadora da pós-graduação da FAUUSP, na qual a autora desenvolveu sua tese de doutorado e seus principais reflexos nas atividades didáticas na graduação e na pós-graduação da FAU-UFRJ.

  8. A no-decompression air dive and ultrasound lung comets.

    Science.gov (United States)

    Dujic, Zeljko; Marinovic, Jasna; Obad, Ante; Ivancev, Vladimir; Breskovic, Toni; Jovovic, Pavle; Ljubkovic, Marko

    2011-01-01

    Increased accumulation of extravascular lung water after repetitive deep trimix dives was recently reported. This effect was evident 40 min post-dive, but in subsequent studies most signs of this lung congestion were not evident 2-3 h post-dive, indicating no major negative effects on respiratory gas exchange following deep dives. Whether this response is unique for trimix dives or also occurs in more frequent air dives is presently unknown. A single no-decompression field dive to 33 m with 20 min bottom time was performed by 12 male divers. Multiple ultrasound lung comets (ULC), bubble grade (BG), and single-breath lung diffusing capacity (DLCO) measurements were made before and up to 120 min after the dive. Median BG was rather high with maximal values observed at 40 min post-dive [median 4 (4-4)]. Arterialization of bubbles from the venous side was observed only in one diver lasting up to 60 min post-dive. Despite high BG, no DCS symptoms were noted. DLCO and ULC were unchanged after the dive at any time point (DLCO(corr) was 33.6 +/- 1.9 ml x min(-1) mmHg(-1) pre-dive, 32.7 +/- 3.8 ml x min(-1) x mmHg(-1) at 60 min post-dive, and 33.2 +/- 5.3 ml x min(-1) x mmHg(-1) at 120 min post-dive; ULC count was 4.1 +/- 1.9 pre-dive, 4.9 +/- 3.3 at 20 min post-dive, and 3.3 +/- 1.9 at 60 min post-dive. These preliminary findings show no evidence of increased accumulation of extravascular lung water in male divers after a single no-decompression air dive at the limits of accepted Norwegian diving tables.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  11. DeepDive: Declarative Knowledge Base Construction.

    Science.gov (United States)

    De Sa, Christopher; Ratner, Alex; Ré, Christopher; Shin, Jaeho; Wang, Feiran; Wu, Sen; Zhang, Ce

    2016-03-01

    The dark data extraction or knowledge base construction (KBC) problem is to populate a SQL database with information from unstructured data sources including emails, webpages, and pdf reports. KBC is a long-standing problem in industry and research that encompasses problems of data extraction, cleaning, and integration. We describe DeepDive, a system that combines database and machine learning ideas to help develop KBC systems. The key idea in DeepDive is that statistical inference and machine learning are key tools to attack classical data problems in extraction, cleaning, and integration in a unified and more effective manner. DeepDive programs are declarative in that one cannot write probabilistic inference algorithms; instead, one interacts by defining features or rules about the domain. A key reason for this design choice is to enable domain experts to build their own KBC systems. We present the applications, abstractions, and techniques of DeepDive employed to accelerate construction of KBC systems.

  12. Onboard Acoustic Recording from Diving Elephant Seals

    National Research Council Canada - National Science Library

    Fletcher, Stacia

    1996-01-01

    The aim of this project was to record sounds impinging on free-ranging northern elephant seals, Mirounga angustirostris, a first step in determining the importance of LFS to these animals as they dive...

  13. Field Management of Accidental Hypothermia during Diving

    Science.gov (United States)

    1990-01-01

    Hypothermia Diuresis continues due to anti- diuretic hormone (ADH) suppression, atrial natriuretic factor (ANF) secretion (26), and reduced renal tubular...temperature pills. Although difficult to accomplish, rectal temperature has been used to monitor body core temperature in the field. Mercury low...concentrations, leading to toxic reactions. B. PREVENTION OF HYPOTHERMIA DURING DIVING Poor dive planning, obligating a cold diver to remain at rest during

  14. Impacts of Artificial Reefs and Diving Tourism

    Directory of Open Access Journals (Sweden)

    Sandra Jakšić

    2013-10-01

    Full Text Available Coral reefs are currently endangered throughout the world. One of the main activities responsible for this is scuba-diving. Scuba-diving on coral reefs was not problematic in the begging, but due to popularization of the new sport, more and more tourists desired to participate in the activity. Mass tourism, direct contact of the tourists with the coral reefs and unprofessional behavior underwater has a negative effect on the coral reefs. The conflict between nature preservation and economy benefits related to scuba-diving tourism resulted in the creation of artificial reefs, used both to promote marine life and as tourists attractions, thereby taking the pressure off the natural coral reefs. Ships, vehicles and other large structures can be found on the coastal sea floor in North America, Australia, Japan and Europe. The concept of artificial reefs as a scuba-diving attraction was developed in Florida. The main goal was to promote aquaculture, with the popularization of scuba-diving attractions being a secondary effect. The aim of this paper is to determine the effects of artificial reefs on scuba-diving tourism, while taking into account the questionnaire carried out among 18 divers

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

    Science.gov (United States)

    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.

  16. Venous gas embolism after an open-water air dive and identical repetitive dive

    NARCIS (Netherlands)

    Schellart, N. A. M.; Sterk, W.

    2012-01-01

    Decompression tables indicate that a repetitive dive to the same depth as a first dive should be shortened to obtain the same probability of occurrence of decompression sickness (pDCS). Repetition protocols are based on small numbers, a reason for re-examination. Since venous gas embolism (VGE) and

  17. Experimental studies and dynamics modeling analysis of the swimming and diving of whirligig beetles (Coleoptera: Gyrinidae.

    Directory of Open Access Journals (Sweden)

    Zhonghua Xu

    Full Text Available Whirligig beetles (Coleoptera, Gyrinidae can fly through the air, swiftly swim on the surface of water, and quickly dive across the air-water interface. The propulsive efficiency of the species is believed to be one of the highest measured for a thrust generating apparatus within the animal kingdom. The goals of this research were to understand the distinctive biological mechanisms that allow the beetles to swim and dive, while searching for potential bio-inspired robotics applications. Through static and dynamic measurements obtained using a combination of microscopy and high-speed imaging, parameters associated with the morphology and beating kinematics of the whirligig beetle's legs in swimming and diving were obtained. Using data obtained from these experiments, dynamics models of both swimming and diving were developed. Through analysis of simulations conducted using these models it was possible to determine several key principles associated with the swimming and diving processes. First, we determined that curved swimming trajectories were more energy efficient than linear trajectories, which explains why they are more often observed in nature. Second, we concluded that the hind legs were able to propel the beetle farther than the middle legs, and also that the hind legs were able to generate a larger angular velocity than the middle legs. However, analysis of circular swimming trajectories showed that the middle legs were important in maintaining stable trajectories, and thus were necessary for steering. Finally, we discovered that in order for the beetle to transition from swimming to diving, the legs must change the plane in which they beat, which provides the force required to alter the tilt angle of the body necessary to break the surface tension of water. We have further examined how the principles learned from this study may be applied to the design of bio-inspired swimming/diving robots.

  18. Experimental studies and dynamics modeling analysis of the swimming and diving of whirligig beetles (Coleoptera: Gyrinidae).

    Science.gov (United States)

    Xu, Zhonghua; Lenaghan, Scott C; Reese, Benjamin E; Jia, Xinghua; Zhang, Mingjun

    2012-01-01

    Whirligig beetles (Coleoptera, Gyrinidae) can fly through the air, swiftly swim on the surface of water, and quickly dive across the air-water interface. The propulsive efficiency of the species is believed to be one of the highest measured for a thrust generating apparatus within the animal kingdom. The goals of this research were to understand the distinctive biological mechanisms that allow the beetles to swim and dive, while searching for potential bio-inspired robotics applications. Through static and dynamic measurements obtained using a combination of microscopy and high-speed imaging, parameters associated with the morphology and beating kinematics of the whirligig beetle's legs in swimming and diving were obtained. Using data obtained from these experiments, dynamics models of both swimming and diving were developed. Through analysis of simulations conducted using these models it was possible to determine several key principles associated with the swimming and diving processes. First, we determined that curved swimming trajectories were more energy efficient than linear trajectories, which explains why they are more often observed in nature. Second, we concluded that the hind legs were able to propel the beetle farther than the middle legs, and also that the hind legs were able to generate a larger angular velocity than the middle legs. However, analysis of circular swimming trajectories showed that the middle legs were important in maintaining stable trajectories, and thus were necessary for steering. Finally, we discovered that in order for the beetle to transition from swimming to diving, the legs must change the plane in which they beat, which provides the force required to alter the tilt angle of the body necessary to break the surface tension of water. We have further examined how the principles learned from this study may be applied to the design of bio-inspired swimming/diving robots.

  19. Stroke frequencies of emperor penguins diving under sea ice.

    Science.gov (United States)

    van Dam, R P; Ponganis, P J; Ponganis, K V; Levenson, D H; Marshall, G

    2002-12-01

    During diving, intermittent swim stroke patterns, ranging from burst/coast locomotion to prolonged gliding, represent potential energy conservation mechanisms that could extend the duration of aerobic metabolism and, hence, increase the aerobic dive limit (ADL, dive duration associated with onset of lactate accumulation). A 5.6 min ADL for emperor penguins had been previously determined with lactate measurements after dives of ADL(M), mean stroke frequency during travel segments was significantly less than that in dives Emperor penguins did not exhibit any significant (>10 s) periods of prolonged gliding during these shallow (1.6 s, and with lower stroke frequency associated with increased dive duration.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    McCulloch, Paul F

    2014-11-12

    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

  2. Environmental Physiology and Diving Medicine

    Directory of Open Access Journals (Sweden)

    Gerardo Bosco

    2018-02-01

    Full Text Available Man’s experience and exploration of the underwater environment has been recorded from ancient times and today encompasses large sections of the population for sport enjoyment, recreational and commercial purpose, as well as military strategic goals. Knowledge, respect and maintenance of the underwater world is an essential development for our future and the knowledge acquired over the last few dozen years will change rapidly in the near future with plans to establish secure habitats with specific long-term goals of exploration, maintenance and survival. This summary will illustrate briefly the physiological changes induced by immersion, swimming, breath-hold diving and exploring while using special equipment in the water. Cardiac, circulatory and pulmonary vascular adaptation and the pathophysiology of novel syndromes have been demonstrated, which will allow selection of individual characteristics in order to succeed in various environments. Training and treatment for these new microenvironments will be suggested with description of successful pioneers in this field. This is a summary of the physiology and the present status of pathology and therapy for the field.

  3. Environmental Physiology and Diving Medicine

    Science.gov (United States)

    Bosco, Gerardo; Rizzato, Alex; Moon, Richard E.; Camporesi, Enrico M.

    2018-01-01

    Man’s experience and exploration of the underwater environment has been recorded from ancient times and today encompasses large sections of the population for sport enjoyment, recreational and commercial purpose, as well as military strategic goals. Knowledge, respect and maintenance of the underwater world is an essential development for our future and the knowledge acquired over the last few dozen years will change rapidly in the near future with plans to establish secure habitats with specific long-term goals of exploration, maintenance and survival. This summary will illustrate briefly the physiological changes induced by immersion, swimming, breath-hold diving and exploring while using special equipment in the water. Cardiac, circulatory and pulmonary vascular adaptation and the pathophysiology of novel syndromes have been demonstrated, which will allow selection of individual characteristics in order to succeed in various environments. Training and treatment for these new microenvironments will be suggested with description of successful pioneers in this field. This is a summary of the physiology and the present status of pathology and therapy for the field. PMID:29456518

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

    Directory of Open Access Journals (Sweden)

    Jessica U Meir

    Full Text Available 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

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

    Science.gov (United States)

    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

  6. The effect of pre-dive ingestion of dark chocolate on endothelial function after a scuba dive.

    Science.gov (United States)

    Theunissen, Sigrid; Balestra, Costantino; Boutros, Antoine; De Bels, David; Guerrero, François; Germonpré, Peter

    2015-03-01

    The aim of the study was to observe the effects of dark chocolate on endothelial function after scuba diving. Forty-two male scuba divers were divided into two groups: a control (n=21) and a chocolate group (n=21). They performed a 33-metres deep scuba-air dive for 20 minutes in a diving pool (Nemo 33, Brussels). Water temperature was 33⁰C. The chocolate group ingested 30 g of dark chocolate (86% cocoa) 90 minutes before the dive. Flow-mediated dilatation (FMD), digital photoplethysmography and nitric oxide (NO) and peroxynitrites (ONOO-) levels were measured before and after the scuba dive in both groups. A significant decrease in FMD was observed in the control group after the dive (91±7% (mean±95% confidence interval) of pre-dive values; Pdive values; Pdives. No variation of circulating NO level was observed in the control group whereas an increase was shown in the chocolate group (154±73% of pre-dive values; P=0.04). A significant reduction in ONOO- was observed in the control group (84±12% of pre-dive values; P=0.003) whereas no variation was shown after the dive with chocolate intake (100±28% of pre-dive values; ns). Ingestion of 30 g of dark chocolate 90 minutes before scuba diving prevented post-dive endothelial dysfunction, as the antioxidants contained in dark chocolate probably scavenge free radicals.

  7. Socio-economic aspects of the tiger shark diving industry within the ...

    African Journals Online (AJOL)

    Understanding socio-economic aspects of the tiger shark Galeocerdo cuvier diving industry, including information on participant expectations, experiences and expenditure, is necessary for the effective management of the Aliwal Shoal Marine Protected Area on the east coast of South Africa. Between January and ...

  8. Underwater laboratory: Teaching physics through diving practice

    International Nuclear Information System (INIS)

    Favale, F.

    2013-01-01

    Diving education and diving science and technology may be a useful tool in teaching physics in non–physics-oriented High School courses. In this paper we present an activity which combines some simple theoretical aspects of fluid statics, fluid dynamics and gas behavior under pressure with diving experience, where the swimming pool and the sea are used as a laboratory. This topic had previously been approached in a pure experimental way in school laboratory, but some particular experiments became much more attractive and meaningful to the students when they could use their bodies to perform them directly in water. The activity was carried out with groups of students from Italian High School classes in different situations.

  9. Effects of scuba diving on vascular repair mechanisms.

    Science.gov (United States)

    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.

  10. 46 CFR 197.210 - Designation of diving supervisor.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Designation of diving supervisor. 197.210 Section 197.210 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations General § 197.210 Designation of diving...

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

    Science.gov (United States)

    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... space; and (f) The surface-supplied air diver has the equipment required by § 197.346 (b) or (d). ...

  12. Diving and Aerospace Data System International Decompression Data Bank.

    Science.gov (United States)

    1981-10-01

    exchange. PENNDEC Dive Recording Cards Input Penndec Coded Data .] Output dive profiles IDDBO2 Reads Penndec Program Cards MERMAID Converts coded dive to...run time for user Interaction. Very little CPU time is used 0-0all match during these interactions. Five of the programs , non. mtch also require a

  13. Nitrogen Solubility in Adipose Tissues of Diving Animals: Implications for Human Divers and for Modeling Diving Physiology

    Science.gov (United States)

    2016-11-01

    Implications for Human Divers and for Modeling Diving Physiology ," Dr. Heather Kooprrian, lead Principal Investigator. We thank Office ofNaval Research for...Adipose Tissues of Diving An imals: Impl ications for Human Divers and for Modeling Diving 5b. GRANT NUMBER Physiology N00014-12-1-0442 5c. PROGRAM...adipose of marine mammals, seabirds, and turtles, and in mammals used as models for diving physiology , as well as human tissue , in conjunction with

  14. Chain of events analysis for a scuba diving fatality.

    Science.gov (United States)

    Lippmann, John; Stevenson, Christopher; McD Taylor, David; Williams, Jo; Mohebbi, Mohammadreza

    2017-09-01

    A scuba diving fatality usually involves a series of related events culminating in death. Several studies have utilised a chain of events-type analysis (CEA) to isolate and better understand the accident sequence in order to facilitate the creation of relevant countermeasures. The aim of this research was to further develop and better define a process for performing a CEA to reduce potential subjectivity and increase consistency between analysts. To develop more comprehensive and better-defined criteria, existing criteria were modified and a template was created and tested using a CEA. Modifications comprised addition of a category for pre-disposing factors, expansion of criteria for the triggers and disabling agents present during the incident, and more specific inclusion criteria to better encompass a dataset of 56 fatalities. Four investigators (raters) used both the previous criteria and this template, in randomly assigned order, to examine a sample of 13 scuba diver deaths. Individual results were scored against the group consensus for the CEA. Raters' agreement consistency was compared using the Index of Concordance and intra-class correlation coefficients (ICC). The template is presented. The index of concordance between the raters increased from 62% (194⁄312) using the previous criteria to 82% (257⁄312) with use of this template indicating a substantially higher inter-rater agreement when allocating criteria. The agreement in scoring with and without template use was also quantified by ICC which were generally graded as low, illustrating a substantial change in consistency of scoring before and after template use. The template for a CEA for a scuba diving fatality improves consistency of interpretation between users and may improve comparability of diving fatality reports.

  15. A Navy Diving Supervisor's Guide to the Nontechnical Skills Required for Safe and Productive Diving Operations

    National Research Council Canada - National Science Library

    O'Connor, Paul E

    2005-01-01

    Although the diving community is proficient in identifying and mitigating technical problems, it is not as adept in recognizing and reducing the nontechnical human factors errors that cause accidents...

  16. Seasonal movements, aggregations and diving behavior of Atlantic bluefin tuna (Thunnus thynnus revealed with archival tags.

    Directory of Open Access Journals (Sweden)

    Andreas Walli

    2009-07-01

    Full Text Available Electronic tags were used to examine the seasonal movements, aggregations and diving behaviors of Atlantic bluefin tuna (Thunnus thynnus to better understand their migration ecology and oceanic habitat utilization. Implantable archival tags (n = 561 were deployed in bluefin tuna from 1996 to 2005 and 106 tags were recovered. Movement paths of the fish were reconstructed using light level and sea-surface-temperature-based geolocation estimates. To quantify habitat utilization we employed a weighted kernel estimation technique that removed the biases of deployment location and track length. Throughout the North Atlantic, high residence times (167+/-33 days were identified in four spatially confined regions on a seasonal scale. Within each region, bluefin tuna experienced distinct temperature regimes and displayed different diving behaviors. The mean diving depths within the high-use areas were significantly shallower and the dive frequency and the variance in internal temperature significantly higher than during transit movements between the high-use areas. Residence time in the more northern latitude high-use areas was significantly correlated with levels of primary productivity. The regions of aggregation are associated with areas of abundant prey and potentially represent critical foraging habitats that have seasonally abundant prey. Throughout the North Atlantic mean diving depth was significantly correlated with the depth of the thermocline, and dive behavior changed in relation to the stratification of the water column. In this study, with numerous multi-year tracks, there appear to be repeatable patterns of clear aggregation areas that potentially are changing with environmental conditions. The high concentrations of bluefin tuna in predictable locations indicate that Atlantic bluefin tuna are vulnerable to concentrated fishing efforts in the regions of foraging aggregations.

  17. Seasonal movements, aggregations and diving behavior of Atlantic bluefin tuna (Thunnus thynnus) revealed with archival tags.

    Science.gov (United States)

    Walli, Andreas; Teo, Steven L H; Boustany, Andre; Farwell, Charles J; Williams, Tom; Dewar, Heidi; Prince, Eric; Block, Barbara A

    2009-07-07

    Electronic tags were used to examine the seasonal movements, aggregations and diving behaviors of Atlantic bluefin tuna (Thunnus thynnus) to better understand their migration ecology and oceanic habitat utilization. Implantable archival tags (n = 561) were deployed in bluefin tuna from 1996 to 2005 and 106 tags were recovered. Movement paths of the fish were reconstructed using light level and sea-surface-temperature-based geolocation estimates. To quantify habitat utilization we employed a weighted kernel estimation technique that removed the biases of deployment location and track length. Throughout the North Atlantic, high residence times (167+/-33 days) were identified in four spatially confined regions on a seasonal scale. Within each region, bluefin tuna experienced distinct temperature regimes and displayed different diving behaviors. The mean diving depths within the high-use areas were significantly shallower and the dive frequency and the variance in internal temperature significantly higher than during transit movements between the high-use areas. Residence time in the more northern latitude high-use areas was significantly correlated with levels of primary productivity. The regions of aggregation are associated with areas of abundant prey and potentially represent critical foraging habitats that have seasonally abundant prey. Throughout the North Atlantic mean diving depth was significantly correlated with the depth of the thermocline, and dive behavior changed in relation to the stratification of the water column. In this study, with numerous multi-year tracks, there appear to be repeatable patterns of clear aggregation areas that potentially are changing with environmental conditions. The high concentrations of bluefin tuna in predictable locations indicate that Atlantic bluefin tuna are vulnerable to concentrated fishing efforts in the regions of foraging aggregations.

  18. Negative neurofunctional effects of frequency, depth and environment in recreational scuba diving: the Geneva "memory dive" study

    Science.gov (United States)

    Slosman, D; de Ribaupierre, S; Chicherio, C; Ludwig, C; Montandon, M; Allaoua, M; Genton, L; Pichard, C; Grousset, A; Mayer, E; Annoni, J; de Ribaupierre, A

    2004-01-01

    Objectives: To explore relationships between scuba diving activity, brain, and behaviour, and more specifically between global cerebral blood flow (CBF) or cognitive performance and total, annual, or last 6 months' frequencies, for standard dives or dives performed below 40 m, in cold water or warm sea geographical environments. Methods: A prospective cohort study was used to examine divers from diving clubs around Lac Léman and Geneva University Hospital. The subjects were 215 healthy recreational divers (diving with self-contained underwater breathing apparatus). Main outcome measures were: measurement of global CBF by 133Xe SPECT (single photon emission computed tomography); psychometric and neuropsychological tests to assess perceptual-motor abilities, spatial discrimination, attentional resources, executive functioning, and memory; evaluation of scuba diving activity by questionnaire focusing on number and maximum depth of dives and geographical site of the diving activity (cold water v warm water); and body composition analyses (BMI). Results: (1) A negative influence of depth of dives on CBF and its combined effect with BMI and age was found. (2) A specific diving environment (more than 80% of dives in lakes) had a negative effect on CBF. (3) Depth and number of dives had a negative influence on cognitive performance (speed, flexibility and inhibition processing in attentional tasks). (4) A negative effect of a specific diving environment on cognitive performance (flexibility and inhibition components) was found. Conclusions: Scuba diving may have long-term negative neurofunctional effects when performed in extreme conditions, namely cold water, with more than 100 dives per year, and maximal depth below 40 m. PMID:15039241

  19. Serum levels of S-100B after recreational scuba diving.

    Science.gov (United States)

    Stavrinou, L C; Kalamatianos, T; Stavrinou, P; Papasilekas, T; Psachoulia, C; Tzavara, C; Stranjalis, G

    2011-12-01

    Recreational scuba diving is a sport of increasing popularity. Previous studies indicating subtle brain injury in asymptomatic divers imply a cumulative effect of minor neural insults in association with diving for professional and/or recreational purposes, over the long-term. This is the first study to investigate putative neural tissue burden during recreational scuba diving by measuring circulating levels of S-100B, a sensitive biomarker of brain injury. 5 male divers performed 3 consecutive dives under conservative recreational diving settings (maximum depth 15 m, duration of dive 56 min, ascend rate 1.15 m/min) with an interval of 12 h between each session. Although a small increase in serum S-100B levels after each dive was apparent, this increase did not quite reach statistical significance (p=0.057). Moreover, no abnormal S-100B values were recorded (mean baseline: 0.06 μg/L, mean post-dive: 0.086 μg/L) and no effect of the 3 consecutive dives on changes in S-100B levels was detected. These results suggest that under the experimental conditions tested, diving does not seem to have a discernible and/or cumulative impact on central nervous system integrity. The extent to which variable diving settings and practices as well as individual susceptibility factors underlie putative neural tissue burden in asymptomatic divers, remains to be established. © Georg Thieme Verlag KG Stuttgart · New York.

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

    Science.gov (United States)

    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 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.

  1. Estimating the risk of a scuba diving fatality in Australia.

    Science.gov (United States)

    Lippmann, John; Stevenson, Christopher; McD Taylor, David; Williams, Jo

    2016-12-01

    There are few data available on which to estimate the risk of death for Australian divers. This report estimates the risk of a scuba diving fatality for Australian residents, international tourists diving in Queensland, and clients of a large Victorian dive operator. Numerators for the estimates were obtained from the Divers Alert Network Asia-Pacific dive fatality database. Denominators were derived from three sources: Participation in Exercise, Recreation and Sport Surveys, 2001-2010 (Australian resident diving activity data); Tourism Research Australia surveys of international visitors to Queensland 2006-2014 and a dive operator in Victoria 2007-2014. Annual fatality rates (AFR) and 95% confidence intervals (95% CI) were calculated using an exact binomial test. Estimated AFRs were: 0.48 (0.37-0.59) deaths per 100,000 dives, or 8.73 (6.85-10.96) deaths per 100,000 divers for Australian residents; 0.12 (0.05-0.25) deaths per 100,000 dives, or 0.46 (0.20-0.91) deaths per 100,000 divers for international visitors to Queensland; and 1.64 (0.20-5.93) deaths per 100,000 dives for the dive operator in Victoria. On a per diver basis, Australian residents are estimated to be almost twenty times more likely to die whilst scuba diving than are international visitors to Queensland, or to lower than fourfold on a per dive basis. On a per dive basis, divers in Victoria are fourteen times more likely to die than are Queensland international tourists. Although some of the estimates are based on potentially unreliable denominator data extrapolated from surveys, the diving fatality rates in Australia appear to vary by State, being considerably lower in Queensland than in Victoria. These estimates are similar to or lower than comparable overseas estimates, although reliability of all such measurements varies with study size and accuracy of the data available.

  2. Characterization of CPs/Ca-exchanged FAU- and LTA-type zeolite nanocomposites and their selectivity for CO2 and N2 adsorption

    Science.gov (United States)

    Salehi, Samira; Anbia, Mansoor

    2017-11-01

    The objective of this study was to investigate the adsorption capacity and selectivity of CPs/Ca-exchanged FAU- and LTA-type zeolite composites for carbon dioxide (CO2), and nitrogen (N2). The adsorption isotherms of CO2 and N2 on the adsorbents were measured at 298, 323, and 348 K and with a pressure range of 0-5 bar by means of the volumetric adsorption method. Modification of zeolite using cation exchange technique was used to determine the effect of different cation on gas adsorption characteristics. Sodium cations originally present in NaX, NaY and NaA are exchanged with calcium cations. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX), X-Ray Diffraction (XRD) and N2 adsorption/desorption isotherms were used to characterize the structure of the prepared zeolites. The addition of conducting polymers (CPs), polythiophene (PTh) and polypyrrole (PPy), to Ca-exchanged zeolites can improve the adsorption capacities of the material and at the same time increase the selectivity of the composite. CPs/Ca-zeolite nanocomposites were prepared by adding CPs to the CaX, CaY and CaA with different weight percentages p% (p = 5, 10 and 15%). CaX/PTh-15 can be used to separate CO2 from N2 due to its high adsorption selectivity for CO2 over N2.

  3. Sickle cell trait and diving: review and recommendations.

    Science.gov (United States)

    Vigilante, John A; DiGeorge, Nicholas W

    2014-01-01

    Sickle cell trait, once thought to be a benign condition, has been associated with complications which may be of concern to the diver, such as splenic infarction and exercise-related sudden death. Medical clearance to dive for those with this common hemoglobinopathy has been a source of debate, with differing recommendations for both civilian and military candidates. To assess this disparity, a review was conducted of published findings and opinions regarding sickle cell trait and fitness to dive. Literature search was conducted using PubMed/Medline. Keywords included sickle cell trait, hemoglobinopathy, exercise-related sudden death, decompression sickness, diving, special operations, military. Results that included cases of sickle cell trait were included. Further, current guidelines were ascertained from public institutions, prominent diving texts, and the U.S. Military. Review of the literature reveals that complications of sickle cell trait are rare, with no reports of corresponding dive-related injury. Analysis of the physiology of diving as it pertains to the condition, as well as the absence of reported cases, suggest there is minimal increased risk in sport and technical civilian diving. Opinion for military fitness to dive is varied. As specific circumstances thought to predispose to sickle cell trait complication may be unavoidable in the completion of military duties, diving is not recommended for these individuals. However, recreational and commercial diving using typical precautions seems reasonable.

  4. Exercise intensity inferred from air consumption during recreational scuba diving.

    Science.gov (United States)

    Buzzacott, Peter; Pollock, Neal W; Rosenberg, Michael

    2014-06-01

    Episodic exercise is a risk factor for acute cardiac events and cardiac complications are increasingly recognized in fatalities during recreational scuba diving. What is not known is the exercise intensity involved in typical recreational diving. This study used pre- to post-dive gas cylinder pressure drop to estimate air consumption and, from that, exercise intensity during recreational dives. Dive profiles were captured electronically and divers self-reported cylinder pressure changes, perceived workload, thermal status and any problems during dives. Mean surface air consumption (SAC) rate per kg body weight and mean exercise intensity (reported in metabolic equivalents, MET multiples of assumed resting metabolic rate of 3.5 mL·kg⁻¹·min⁻¹) were then estimated. Data are reported as mean ± standard deviation. A total of 959 recreational air dives (20 ± 9 metres' sea water maximum depth; 50 ± 12 min underwater time) by 139 divers (42 ± 10 y age; 11 ± 10 y of diving; 12% smokers; 73% male) were monitored. Problems were reported with 129/959 dives: buoyancy (45%), equalization (38%), rapid ascent (10%), vertigo (5%) and other (2%). Assuming a 10% overestimate due to cylinder cooling and uncontrolled gas loss, the estimated exercise intensity associated with monitored dives was 5 ± 1 MET. Mean ± 2SD, or 7 MET, captures the effort associated with the vast majority of dives monitored. Our estimates suggest that uncomplicated recreational dives require moderate-intensity energy expenditure to complete, with a 7-MET capacity generally adequate. Higher levels of aerobic fitness are still strongly recommended to ensure ample reserves. Further research is needed to quantify energetic demands of recreational diving during both typical and emergent events in both experienced and less experienced divers.

  5. Diving physiology of seabirds and marine mammals: Relevance, challenges and some solutions for field studies.

    Science.gov (United States)

    Andrews, Russel D; Enstipp, Manfred R

    2016-12-01

    To fully understand how diving seabirds and marine mammals balance the potentially conflicting demands of holding their breath while living their lives underwater (and maintaining physiological homeostasis during exercise, feeding, growth, and reproduction), physiological studies must be conducted with animals in their natural environments. The purpose of this article is to review the importance of making physiological measurements on diving animals in field settings, while acknowledging the challenges and highlighting some solutions. The most extreme divers are great candidates for study, especially in a comparative and mechanistic context. However, physiological data are also required of a wide range of species for problems relating to other disciplines, in particular ecology and conservation biology. Physiological data help with understanding and predicting the outcomes of environmental change, and the direct impacts of anthropogenic activities. Methodological approaches that have facilitated the development of field-based diving physiology include the isolated diving hole protocol and the translocation paradigm, and while there are many techniques for remote observation, animal-borne biotelemetry, or "biologging", has been critical. We discuss issues related to the attachment of instruments, the retrieval of data and sensing of physiological variables, while also considering negative impacts of tagging. This is illustrated with examples from a variety of species, and an in-depth look at one of the best studied and most extreme divers, the emperor penguin (Aptenodytes forsteri). With a variety of approaches and high demand for data on the physiology of diving seabirds and marine mammals, the future of field studies is bright. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    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. © 2011 Australian Dental Association.

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

    Science.gov (United States)

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

    Science.gov (United States)

    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.

  9. [Decompression problems in diving in mountain lakes].

    Science.gov (United States)

    Bühlmann, A A

    1989-08-01

    The relationship between tolerated high-pressure tissue nitrogen and ambient pressure is practically linear. The tolerated nitrogen high pressure decreases at altitude, as the ambient pressure is lower. Additionally, tissues with short nitrogen half-times have a higher tolerance than tissues which retain nitrogen for longer duration. For the purpose of determining safe decompression routines, the human body can be regarded as consisting of 16 compartments with half-times from 4 to 635 minutes for nitrogen. The coefficients for calculation of the tolerated nitrogen-high pressure in the tissues can be deduced directly from the half-times for nitrogen. We show as application the results of 573 simulated air dives in the pressure-chamber and 544 real dives in mountain lakes in Switzerland (1400-2600 m above sea level) and in Lake Titicaca (3800 m above sea level). They are in accordance with the computed limits of tolerance.

  10. Temporomandibular dysfunction syndrome associated with scuba diving mouthpieces.

    Science.gov (United States)

    Hobson, R S

    1991-01-01

    As previous reports have highlighted that temporomandibular joint dysfunction syndrome can occur during scuba diving due to the use of a diving mouthpiece, 74 divers of varied experience (62 male, 12 female) were asked to evaluate the efficiency of the mouthpiece for the ease of grip, insertion into the mouth, clearing of water, air sharing, comfort and overall efficiency. They also recorded the level of muscle and joint discomfort experienced during diving and non-diving activities. The results indicate that temporomandibular joint problems unrelated to diving are compounded by the use of a diving mouthpiece. The diver's assessment of muscle tension and comfort while using the mouthpiece was found to be a good predictor of whether temporomandibular dysfunction would occur and the assessment scores have been used in a formula to aid selection of a mouthpiece. PMID:1913032

  11. Physiology of safety deep stops and their importance during diving

    OpenAIRE

    Moravcová, Petra

    2008-01-01

    Title: Physiology ofdeep safety stops and their importance during diving Objective: Explanation of physiology of deep safety stops and their importance during diving. Presentation of the physiologically optima! method of accomplishing the deep stops. Methods: Summary of the available information concerning the physiology of deep safety stops and also the physic and physiology of diving connected with the subject. Follow-up clearing the importance ofthese stops for divers. Results: Inclusion o...

  12. Diving costs as a component of daily energy budgets of aquatic birds and mammals : Generalizing the inclusion of dive-recovery costs demonstrated in tufted ducks

    NARCIS (Netherlands)

    deLeeuw, JJ

    1996-01-01

    Metabolic studies on freely diving birds and mammals are reviewed and allometric relations of diving costs are presented. A distinction can be made between three different types of diving costs: (1) metabolic rate during submergence, relevant in estimating aerobic dive limits, (2) average metabolic

  13. [Scuba diving in children: Physiology, risks and recommendations].

    Science.gov (United States)

    Cilveti, R; Osona, B; Peña, J A; Moreno, L; Asensio, O

    2015-12-01

    The increase in recreational scuba diving in recent years, including children, involves risks and the possibility of accidents. While legislation, conditions and risks of scuba diving are well documented in adults, scientific evidence in scuba diving by children and adolescents is sparse and isolated. Furthermore, existing guidelines and recommendations for adults cannot be transferred directly to children. These circumstances have led to the Group on Techniques of the Spanish Society of Pediatric Pulmonology (SENP) to perform a literature search to review and update the knowledge about scuba diving in children. Physiological adaptations of the body are examined during the dive, as well as the anatomical and physiological characteristics of children that should be taken into account in scuba diving. The most common types of accidents and its causes, as well as the risks of scuba diving practice in children with previous diseases are discussed, along with details of the medical and psychological requirements for scuba diving to be considered in the assessment of child and adolescent. A list of recommendations for scuba diving with compressed air in children is presented by a group of experts. Copyright © 2015 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

  14. Gait switches in deep-diving beaked whales: biomechanical strategies for long-duration dives.

    Science.gov (United States)

    Martín López, Lucía Martina; Miller, Patrick J O; Aguilar de Soto, Natacha; Johnson, Mark

    2015-05-01

    Diving animals modulate their swimming gaits to promote locomotor efficiency and so enable longer, more productive dives. Beaked whales perform extremely long and deep foraging dives that probably exceed aerobic capacities for some species. Here, we use biomechanical data from suction-cup tags attached to three species of beaked whales (Mesoplodon densirostris, N=10; Ziphius cavirostris, N=9; and Hyperoodon ampullatus, N=2) to characterize their swimming gaits. In addition to continuous stroking and stroke-and-glide gaits described for other diving mammals, all whales produced occasional fluke-strokes with distinctly larger dorso-ventral acceleration, which we termed 'type-B' strokes. These high-power strokes occurred almost exclusively during deep dive ascents as part of a novel mixed gait. To quantify body rotations and specific acceleration generated during strokes we adapted a kinematic method combining data from two sensors in the tag. Body rotations estimated with high-rate magnetometer data were subtracted from accelerometer data to estimate the resulting surge and heave accelerations. Using this method, we show that stroke duration, rotation angle and acceleration were bi-modal for these species, with B-strokes having 76% of the duration, 52% larger body rotation and four times more surge than normal strokes. The additional acceleration of B-strokes did not lead to faster ascents, but rather enabled brief glides, which may improve the overall efficiency of this gait. Their occurrence towards the end of long dives leads us to propose that B-strokes may recruit fast-twitch fibres that comprise ∼80% of swimming muscles in Blainville's beaked whales, thus prolonging foraging time at depth. © 2015. Published by The Company of Biologists Ltd.

  15. Exercise before and after SCUBA diving and the role of cellular microparticles in decompression stress.

    Science.gov (United States)

    Madden, Dennis; Thom, Stephen R; Dujic, Zeljko

    2016-01-01

    Risk in SCUBA diving is often associated with the presence of gas bubbles in the venous circulation formed during decompression. Although it has been demonstrated time-after-time that, while venous gas emboli (VGE) often accompany decompression sickness (DCS), they are also frequently observed in high quantities in asymptomatic divers following even mild recreational dive profiles. Despite this VGE are commonly utilized as a quantifiable marker of the potential for an individual to develop DCS. Certain interventions such as exercise, antioxidant supplements, vibration, and hydration appear to impact VGE production and the decompression process. However promising these procedures may seem, the data are not yet conclusive enough to warrant changes in decompression procedure, possibly suggesting a component of individual response. We hypothesize that the impact of exercise varies widely in individuals and once tested, recommendations can be made that will reduce individual decompression stress and possibly the incidence of DCS. The understanding of physiological adaptations to diving stress can be applied in different diseases that include endothelial dysfunction and microparticle (MP) production. Exercise before diving is viewed by some as a protective form of preconditioning because some studies have shown that it reduces VGE quantity. We propose that MP production and clearance might be a part of this mechanism. Exercise after diving appears to impact the risk of adverse events as well. Research suggests that the arterialization of VGE presents a greater risk for DCS than when emboli are eliminated by the pulmonary circuit before they have a chance to crossover. Laboratory studies have demonstrated that exercise increases the incidence of crossover likely through extra-cardiac mechanisms such as intrapulmonary arterial-venous anastomoses (IPAVAs). This effect of exercise has been repeated in the field with divers demonstrating a direct relationship between exercise

  16. Energetic costs of surface swimming and diving of birds.

    Science.gov (United States)

    Butler, P J

    2000-01-01

    The energetic costs of swimming at the surface (swimming) and swimming underwater (diving) are compared in tufted ducks (Aythya fuligula) and three species of penguins, the gentoo (Pygoscelis papua), the king (Aptenodytes patagonicus), and the emperor (Aythya forsteri). Ducks swim on the surface and use their webbed feet as paddles, whereas penguins tend to swim just below the surface and use their flippers as hydrofoils, the latter being much more efficient. Penguins are more streamlined in shape. Thus, the amount of energy required to transport a given mass of bird a given distance (known as the cost of transport) is some two to three times greater in ducks than in penguins. Ducks are also very buoyant, and overcoming the force of buoyancy accounts for 60% and 85% of the cost of descent and remaining on the bottom, respectively, in these birds. The energy cost of a tufted duck diving to about 1.7 m is similar to that when it is swimming at its maximum sustainable speed at the surface (i.e., approximately 3.5 times the value when resting on water). Nonetheless, because of the relatively short duration of its dives, the tufted duck dives well within its calculated aerobic dive limit (cADL, usable O(2) stores per rate of O(2) usage when underwater). However, these three species of penguins have maximum dive durations ranging from 5 min to almost 16 min and maximum dive depths from 155 to 530 m. When these birds dive, they have to metabolise at no more than when resting in water in order for cADL to encompass the duration of most of their natural dives. In gentoo and king penguins, there is a fall in abdominal temperature during bouts of diving; this may reduce the oxygen requirements in the abdominal region, thus enabling dive duration to be extended further than would otherwise be the case.

  17. Diving through the thermal window: implications for a warming world.

    Science.gov (United States)

    Campbell, Hamish A; Dwyer, Ross G; Gordos, Matthew; Franklin, Craig E

    2010-12-22

    Population decline and a shift in the geographical distribution of some ectothermic animals have been attributed to climatic warming. Here, we show that rises in water temperature of a few degrees, while within the thermal window for locomotor performance, may be detrimental to diving behaviour in air-breathing ectotherms (turtles, crocodilians, marine iguanas, amphibians, snakes and lizards). Submergence times and internal and external body temperature were remotely recorded from freshwater crocodiles (Crocodylus johnstoni) while they free-ranged throughout their natural habitat in summer and winter. During summer, the crocodiles' mean body temperature was 5.2±0.1°C higher than in winter and the largest proportion of total dive time was composed of dive durations approximately 15 min less than in winter. Diving beyond 40 min during summer required the crocodiles to exponentially increase the time they spent on the surface after the dive, presumably to clear anaerobic debt. The relationship was not as significant in winter, even though a greater proportion of dives were of a longer duration, suggesting that diving lactate threshold (DLT) was reduced in summer compared with winter. Additional evidence for a reduced DLT in summer was derived from the stronger influence body mass exerted upon dive duration, compared to winter. The results demonstrate that the higher summer body temperature increased oxygen demand during the dive, implying that thermal acclimatization of the diving metabolic rate was inadequate. If the study findings are common among air-breathing diving ectotherms, then long-term warming of the aquatic environment may be detrimental to behavioural function and survivorship.

  18. To dive or not to dive with bleomycin: a practical algorithm

    NARCIS (Netherlands)

    van Hulst, Robert A.; Rietbroek, Ronald C.; Gaastra, Menno T. W.; Schlösser, Noel J. J.

    2011-01-01

    Bleomycin is used in the treatment of different cancers, but possible side effects of interstitial pneumonitis and fibrosis are associated with increased concentrations of oxygen. Therefore, clinicians are reluctant to declare young people fit for scuba diving after bleomycin treatment, because

  19. The risk of developing a contact allergy to materials present in diving suits and diving equipment

    Directory of Open Access Journals (Sweden)

    Gadomski Krzysztof

    2017-06-01

    Full Text Available Allergic contact eczema is the most common occupational skin disease caused by allergens. Thus far, no research has been conducted in Poland in relation to the development of contact allergies amongst divers resulting from particular diving suit components. A group of 86 divers were examined using allergy patch tests. Standard products of contact allergy diagnostics were used containing 40 allergens.

  20. The risk of developing a contact allergy to materials present in diving suits and diving equipment

    OpenAIRE

    Gadomski Krzysztof; Siermontowski Piotr; Dąbrowiecki Zbigniew; Olszaski Romuald

    2017-01-01

    Allergic contact eczema is the most common occupational skin disease caused by allergens. Thus far, no research has been conducted in Poland in relation to the development of contact allergies amongst divers resulting from particular diving suit components. A group of 86 divers were examined using allergy patch tests. Standard products of contact allergy diagnostics were used containing 40 allergens.

  1. Danish diving-related fatalities 1999-2012

    DEFF Research Database (Denmark)

    Vinkel, Julie; Bak, Peter; Hyldegaard, Ole

    2016-01-01

    AIM: The purpose was to explore causative tendencies among diving fatalities to prevent similar injuries in the future. METHODS: We report 33 fatal diving injuries that occurred among Danish divers during the period 1999-2012 in Scandinavian waters. The study was performed as a retrospective...

  2. Scuba Diving and Kinesiology: Development of an Academic Program

    Science.gov (United States)

    Kovacs, Christopher R.; Walter, Daniel

    2015-01-01

    The use of scuba diving as a recreational activity within traditional university instructional programs has been well established. Departments focusing on kinesiology, physical education, or exercise science have often provided scuba diving lessons as part of their activity-based course offerings. However, few departments have developed an…

  3. Are the Risks of Sport Scuba Diving Being Underestimated?

    Science.gov (United States)

    Roos, Robert

    1989-01-01

    A lawsuit has challenged the safety of the tables widely used in scuba diving. Other concerns also have emerged: A condition known as patent foramen ovale may increase the risk of decompression sickness, and studies are raising questions about the long-term effects of diving. (Author/JD)

  4. Scuba diving is possible and safe for patients with haemophilia.

    Science.gov (United States)

    Schved, J F; De Haro, M; Drapeau, M; Schved, M

    2012-01-01

    For a long time, physical activities have been contraindicated in haemophiliacs or were restricted to few activities. Sports are nowadays advocated for haemophiliacs. Although various lists of physical activities have been proposed, scuba diving is never mentioned. Thus, with a group of haemophilic volunteers, a study was launched on whether, with strict medical follow-up, scuba diving could be allowed for patients with haemophilia. All the participants followed a training program including theory and assessment. In 6 years, a total of 517 dives were performed by 20 patients with congenital bleeding disorders. Nine were under prophylaxis for haemophilia, and nine received on-demand treatment. Two patients had type I von Willebrand's disease. Among the 20 patients, 12 made 12-153 dives, whereas six made eight dives each. No incident was noted during or after the dives. Thus, scuba diving can be authorized for PWH, if they have none of the specific medical contraindications for diving and if they have received medical training allowing them to manage their disease themselves. © 2011 Blackwell Publishing Ltd.

  5. 29 CFR 1926.1076 - Qualifications of dive team.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Qualifications of dive team. 1926.1076 Section 1926.1076 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... § 1926.1076 Qualifications of dive team. Note: The requirements applicable to construction work under...

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

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Responsibilities of the diving supervisor. 197.404 Section 197.404 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Operations § 197.404...

  7. Non-barotraumatic tooth fracture during scuba diving.

    Science.gov (United States)

    Gunepin, Mathieu; Zadik, Yehuda; Derache, Florence; Dychter, Leon

    2013-06-01

    When dental pain or tooth fracture occurs during diving, variations in atmospheric pressure are usually considered as etiology. We present a case of a military diver referred for dental pain which appeared during diving. Diagnoses suggested by the diving medical specialist were barodontalgia and dental barotrauma. The dental exam, however, highlighted a tooth fracture due to the in-diving use of an inappropriate mouth regulator which yielded excessive occlusal pressure on a tooth with pre-existing extensive dental restoration. This case highlights the importance of the use of an adapted mouthpiece by divers, and the need for awareness of physicians and dentists who treat divers of the implications of scuba diving on dental and oral medicine.

  8. Novel locomotor muscle design in extreme deep-diving whales.

    Science.gov (United States)

    Velten, B P; Dillaman, R M; Kinsey, S T; McLellan, W A; Pabst, D A

    2013-05-15

    Most marine mammals are hypothesized to routinely dive within their aerobic dive limit (ADL). Mammals that regularly perform deep, long-duration dives have locomotor muscles with elevated myoglobin concentrations that are composed of predominantly large, slow-twitch (Type I) fibers with low mitochondrial volume densities (V(mt)). These features contribute to extending ADL by increasing oxygen stores and decreasing metabolic rate. Recent tagging studies, however, have challenged the view that two groups of extreme deep-diving cetaceans dive within their ADLs. Beaked whales (including Ziphius cavirostris and Mesoplodon densirostris) routinely perform the deepest and longest average dives of any air-breathing vertebrate, and short-finned pilot whales (Globicephala macrorhynchus) perform high-speed sprints at depth. We investigated the locomotor muscle morphology and estimated total body oxygen stores of several species within these two groups of cetaceans to determine whether they (1) shared muscle design features with other deep divers and (2) performed dives within their calculated ADLs. Muscle of both cetaceans displayed high myoglobin concentrations and large fibers, as predicted, but novel fiber profiles for diving mammals. Beaked whales possessed a sprinter's fiber-type profile, composed of ~80% fast-twitch (Type II) fibers with low V(mt). Approximately one-third of the muscle fibers of short-finned pilot whales were slow-twitch, oxidative, glycolytic fibers, a rare fiber type for any mammal. The muscle morphology of beaked whales likely decreases the energetic cost of diving, while that of short-finned pilot whales supports high activity events. Calculated ADLs indicate that, at low metabolic rates, both beaked and short-finned pilot whales carry sufficient onboard oxygen to aerobically support their dives.

  9. 46 CFR 197.434 - Surface-supplied mixed-gas diving.

    Science.gov (United States)

    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... diving is conducted, a decompression chamber or a closed bell meeting the requirements of § 197.332 is...

  10. Sports-related lung injury during breath-hold diving

    Directory of Open Access Journals (Sweden)

    Tanja Mijacika

    2016-12-01

    Full Text Available The number of people practising recreational breath-hold diving is constantly growing, thereby increasing the need for knowledge of the acute and chronic effects such a sport could have on the health of participants. Breath-hold diving is potentially dangerous, mainly because of associated extreme environmental factors such as increased hydrostatic pressure, hypoxia, hypercapnia, hypothermia and strenuous exercise. In this article we focus on the effects of breath-hold diving on pulmonary function. Respiratory symptoms have been reported in almost 25% of breath-hold divers after repetitive diving sessions. Acutely, repetitive breath-hold diving may result in increased transpulmonary capillary pressure, leading to noncardiogenic oedema and/or alveolar haemorrhage. Furthermore, during a breath-hold dive, the chest and lungs are compressed by the increasing pressure of water. Rapid changes in lung air volume during descent or ascent can result in a lung injury known as pulmonary barotrauma. Factors that may influence individual susceptibility to breath-hold diving-induced lung injury range from underlying pulmonary or cardiac dysfunction to genetic predisposition. According to the available data, breath-holding does not result in chronic lung injury. However, studies of large populations of breath-hold divers are necessary to firmly exclude long-term lung damage.

  11. The impact of predive exercise on repetitive SCUBA diving.

    Science.gov (United States)

    Madden, Dennis; Barak, Otto; Thom, Stephen R; Yang, Ming; Bhopale, Veena M; Ljubkovic, Marko; Dujic, Zeljko

    2016-05-01

    SCUBA diving frequently involves repetitive exposures. The goal of this study was to see how exercise impacts microparticles (MPs), endothelial function and venous gas emboli (VGE) throughout multiple dives. Sixteen divers in two groups (G1 and G2) each completed six dives, three preceded by exercise (EX) and three as controls (CON). Blood for MP analysis was collected before and after each dive. VGE were monitored via transthoracic echocardiography 30, 60 and 90 min after surfacing. Exercise before diving consisted of 60-min running including eight, 3-min intervals at 90% VO2max. Exercise did not have a significant impact on VGE. There was no significant difference in MP counts between EX and CON. Both groups experienced a significant decrease in MP counts in the last three dives compared to the first three (G1 P = 0·0008, G2 P = 0001). Other indices of neutrophil/platelet interaction (dual-positive CD63/41 and CD62/41) show a significant increase (P = 0·004 and 0·0001) in G2. Both groups experienced a significant decrease in MPs at all measurements in the second series of dives compared to the first, regardless of the placement of exercise. Whether this is related to an effect of suppression of MPs or exercise timing is not clear. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  12. Cardiovascular changes during SCUBA diving: an underwater Doppler echocardiographic study.

    Science.gov (United States)

    Marabotti, C; Scalzini, A; Menicucci, D; Passera, M; Bedini, R; L'Abbate, A

    2013-09-01

    Body immersion induces blood redistribution (from peripheral to intrathoracic vessels) and is a powerful autonomic stimulus (activating both parasympathetic and sympathetic systems). For these reasons, concerns have been raised about the safety of diving for subjects with previous heart disease. The aim of this study was to evaluate cardiovascular changes occurring during recreational SCUBA diving, as assessed by underwater Doppler echocardiography. Eighteen healthy experienced divers underwent a 2D Doppler echocardiography basally, during two 15' steps of still SCUBA diving at different depths (10 m followed by 5 m) and shortly after the end of immersion. During dive, left ventricular (LV) diastolic volume and early left ventricular filling significantly increased (5 m vs. basal: P dive vs. basal: P dive). This study documents that shallow-depth SCUBA diving induces LV enlargement and diastolic dysfunction. Direct underwater evaluation by Doppler echocardiography could be an appropriate tool for unmasking subjects at risk for underwater-related accidents. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  13. Early diving behaviour in juvenile penguins: improvement or selection processes.

    Science.gov (United States)

    Orgeret, Florian; Weimerskirch, Henri; Bost, Charles-André

    2016-08-01

    The early life stage of long-lived species is critical to the viability of population, but is poorly understood. Longitudinal studies are needed to test whether juveniles are less efficient foragers than adults as has been hypothesized. We measured changes in the diving behaviour of 17 one-year-old king penguins Aptenodytes patagonicus at Crozet Islands (subantartic archipelago) during their first months at sea, using miniaturized tags that transmitted diving activity in real time. We also equipped five non-breeder adults with the same tags for comparison. The data on foraging performance revealed two groups of juveniles. The first group made shallower and shorter dives that may be indicative of early mortality while the second group progressively increased their diving depths and durations, and survived the first months at sea. This surviving group of juveniles required the same recovery durations as adults, but typically performed shallower and shorter dives. There is thereby a relationship between improved diving behaviour and survival in young penguins. This long period of improving diving performance in the juvenile life stage is potentially a critical period for the survival of deep avian divers and may have implications for their ability to adapt to environmental change. © 2016 The Authors.

  14. [Medical certification for high altitude travel and scuba diving].

    Science.gov (United States)

    Wuillemin, Timothée; Dos Santos Bragança, Angel; Ziltener, Jean-Luc; Berney, Jean-Yves; Lanier, Cédric

    2014-09-24

    People are more and more looking for adventures and discovery of unusual locations. Journeys to high altitude and scuba diving are part of these activities and their access has become easier for a lot of people not necessarily experienced with their dangers. The general practitioner will have to be able to deliver some advices and recommendations to his patients about the risks related to these activities and their ability to practice them. He will also have to deliver some certificates of medical fitness to dive. This paper proposes a brief review of the most important medical aspects to know about high altitude and scuba diving.

  15. Alveolar hemorrhage after scuba diving: a case report.

    Science.gov (United States)

    Tsai, Ming-Ju; Tsai, Mee-Sun; Tsai, Ying-Ming; Lien, Chi-Tun; Hwang, Jhi-Jhu; Huang, Ming-Shyan

    2010-07-01

    Self-contained underwater breathing apparatus (scuba) diving is increasingly popular in Taiwan. There are few references in the literature regarding pulmonary hemorrhage as the sole manifestation of pulmonary barotrauma in scuba divers, and no study from Taiwan was found in the literature. We present the case of a 25-year-old man who suffered alveolar hemorrhage related to pulmonary barotrauma as a complication of scuba diving. To our knowledge, this is the first case report describing a Taiwanese subject suffering from non-fatal pulmonary hemorrhage after scuba diving. Copyright 2010 Elsevier. Published by Elsevier B.V. All rights reserved.

  16. Alveolar Hemorrhage After Scuba Diving: A Case Report

    Directory of Open Access Journals (Sweden)

    Ming-Ju Tsai

    2010-07-01

    Full Text Available Self-contained underwater breathing apparatus (scuba diving is increasingly popular in Taiwan. There are few references in the literature regarding pulmonary hemorrhage as the sole manifestation of pulmonary barotrauma in scuba divers, and no study from Taiwan was found in the literature. We present the case of a 25-year-old man who suffered alveolar hemorrhage related to pulmonary barotrauma as a complication of scuba diving. To our knowledge, this is the first case report describing a Taiwanese subject suffering from non-fatal pulmonary hemorrhage after scuba diving.

  17. Influences of spatial and temporal variability of sound scattering layers on deep diving odontocete behavior

    Science.gov (United States)

    Copeland, Adrienne Marie

    Patchiness of prey can influence the behavior of a predator, as predicted by the optimal foraging theory which states that an animal will maximize the energy gain while minimizing energy loss. While this relationship has been studied and is relatively well understood in some terrestrial systems, the same is far from true in marine systems. It is as important to investigate this in the marine realm in order to better understand predator distribution and behavior. Micronekton, organisms from 2-20 cm, might be a key component in understanding this as it is potentially an essential link in the food web between primary producers and higher trophic levels, including cephalopods which are primary prey items of deep diving odontocetes (toothed whales). My dissertation assesses the spatial and temporal variability of micronekton in the Northwestern Hawaiian Islands (NWHI), the Main Hawaiian Islands' (MHI) Island of Hawaii, and the Gulf of Mexico (GOM). Additionally it focuses on understanding the relationship between the spatial distribution of micronekton and environmental and geographic factors, and how the spatial and temporal variability of this micronekton relates to deep diving odontocete foraging. I used both an active Simrad EK60 echosounder system to collect water column micronekton backscatter and a passive acoustic system to detect the presence of echolocation clicks from deep diving beaked, sperm, and short-finned pilot whales. My results provide insight into what might be contributing to hotspots of micronekton which formed discrete layers in all locations, a shallow scattering layer (SSL) from the surface to about 200 m and a deep scattering layer (DSL) starting at about 350 m. In both the GOM and the NWHI, the bathymetry and proximity to shore influenced the amount of micronekton backscatter with locations closer to shore and at shallower depths having higher backscatter. We found in all three locations that some species of deep diving odontocetes were

  18. Dive Risk Factors, Gas Bubble Formation, and Decompression Illness in Recreational SCUBA Diving: Analysis of DAN Europe DSL Data Base.

    Science.gov (United States)

    Cialoni, Danilo; Pieri, Massimo; Balestra, Costantino; Marroni, Alessandro

    2017-01-01

    Introduction: The popularity of SCUBA diving is steadily increasing together with the number of dives and correlated diseases per year. The rules that govern correct decompression procedures are considered well known even if the majority of Decompression Sickness (DCS) cases are considered unexpected confirming a bias in the "mathematical ability" to predict DCS by the current algorithms. Furthermore, little is still known about diving risk factors and any individual predisposition to DCS. This study provides an in-depth epidemiological analysis of the diving community, to include additional risk factors correlated with the development of circulating bubbles and DCS. Materials and Methods: An originally developed database (DAN DB) including specific questionnaires for data collection allowed the statistical analysis of 39,099 electronically recorded open circuit dives made by 2,629 European divers (2,189 males 83.3%, 440 females 16.7%) over 5 years. The same dive parameters and risk factors were investigated also in 970 out of the 39,099 collected dives investigated for bubble formation, by 1-min precordial Doppler, and in 320 sea-level dives followed by DCS symptoms. Results: Mean depth and GF high of all the recorded dives were 27.1 m, and 0.66, respectively; the average ascent speed was lower than the currently recommended "safe" one (9-10 m/min). We found statistically significant relationships between higher bubble grades and BMI, fat mass, age, and diving exposure. Regarding incidence of DCS, we identified additional non-bubble related risk factors, which appear significantly related to a higher DCS incidence, namely: gender, strong current, heavy exercise, and workload during diving. We found that the majority of the recorded DCS cases were not predicted by the adopted decompression algorithm and would have therefore been defined as "undeserved." Conclusion: The DAN DB analysis shows that most dives were made in a "safe zone," even if data show an evident

  19. Dive Risk Factors, Gas Bubble Formation, and Decompression Illness in Recreational SCUBA Diving: Analysis of DAN Europe DSL Data Base

    Science.gov (United States)

    Cialoni, Danilo; Pieri, Massimo; Balestra, Costantino; Marroni, Alessandro

    2017-01-01

    Introduction: The popularity of SCUBA diving is steadily increasing together with the number of dives and correlated diseases per year. The rules that govern correct decompression procedures are considered well known even if the majority of Decompression Sickness (DCS) cases are considered unexpected confirming a bias in the “mathematical ability” to predict DCS by the current algorithms. Furthermore, little is still known about diving risk factors and any individual predisposition to DCS. This study provides an in-depth epidemiological analysis of the diving community, to include additional risk factors correlated with the development of circulating bubbles and DCS. Materials and Methods: An originally developed database (DAN DB) including specific questionnaires for data collection allowed the statistical analysis of 39,099 electronically recorded open circuit dives made by 2,629 European divers (2,189 males 83.3%, 440 females 16.7%) over 5 years. The same dive parameters and risk factors were investigated also in 970 out of the 39,099 collected dives investigated for bubble formation, by 1-min precordial Doppler, and in 320 sea-level dives followed by DCS symptoms. Results: Mean depth and GF high of all the recorded dives were 27.1 m, and 0.66, respectively; the average ascent speed was lower than the currently recommended “safe” one (9–10 m/min). We found statistically significant relationships between higher bubble grades and BMI, fat mass, age, and diving exposure. Regarding incidence of DCS, we identified additional non-bubble related risk factors, which appear significantly related to a higher DCS incidence, namely: gender, strong current, heavy exercise, and workload during diving. We found that the majority of the recorded DCS cases were not predicted by the adopted decompression algorithm and would have therefore been defined as “undeserved.” Conclusion: The DAN DB analysis shows that most dives were made in a “safe zone,” even if data

  20. Dive Risk Factors, Gas Bubble Formation, and Decompression Illness in Recreational SCUBA Diving: Analysis of DAN Europe DSL Data Base

    Directory of Open Access Journals (Sweden)

    Danilo Cialoni

    2017-09-01

    Full Text Available Introduction: The popularity of SCUBA diving is steadily increasing together with the number of dives and correlated diseases per year. The rules that govern correct decompression procedures are considered well known even if the majority of Decompression Sickness (DCS cases are considered unexpected confirming a bias in the “mathematical ability” to predict DCS by the current algorithms. Furthermore, little is still known about diving risk factors and any individual predisposition to DCS. This study provides an in-depth epidemiological analysis of the diving community, to include additional risk factors correlated with the development of circulating bubbles and DCS.Materials and Methods: An originally developed database (DAN DB including specific questionnaires for data collection allowed the statistical analysis of 39,099 electronically recorded open circuit dives made by 2,629 European divers (2,189 males 83.3%, 440 females 16.7% over 5 years. The same dive parameters and risk factors were investigated also in 970 out of the 39,099 collected dives investigated for bubble formation, by 1-min precordial Doppler, and in 320 sea-level dives followed by DCS symptoms.Results: Mean depth and GF high of all the recorded dives were 27.1 m, and 0.66, respectively; the average ascent speed was lower than the currently recommended “safe” one (9–10 m/min. We found statistically significant relationships between higher bubble grades and BMI, fat mass, age, and diving exposure. Regarding incidence of DCS, we identified additional non-bubble related risk factors, which appear significantly related to a higher DCS incidence, namely: gender, strong current, heavy exercise, and workload during diving. We found that the majority of the recorded DCS cases were not predicted by the adopted decompression algorithm and would have therefore been defined as “undeserved.”Conclusion: The DAN DB analysis shows that most dives were made in a “safe zone

  1. Decompression from He-N2-O2 (TRIMIX) Bounce Dives Is Not More Efficient Than From He-O2 (HELIOX) Bounce Dives

    Science.gov (United States)

    2015-05-28

    Deep Sea He- O2 rig” (a few dives used band masks ) with switching to 100% oxygen for decompression stops at 50 fsw and shallower. There are 98 constant...N2- O2 (TRIMIX) BOUNCE DIVES IS NOT MORE EFFICIENT THAN FROM He- O2 (HELIOX) BOUNCE DIVES Authors: Distribution...DATES COVERED (From - To) Feb 2013 – Jan 2015 4. TITLE AND SUBTITLE Decompression from He-N2- O2 (trimix) bounce dives is not more efficient than

  2. 29 CFR 1910.422 - Procedures during dive.

    Science.gov (United States)

    2010-07-01

    ... or burning on closed compartments, structures or pipes, which contain a flammable vapor or in which a... from a dive team member; (3) Communications are lost and can not be quickly re-established between the...

  3. Dives from missions of the NOAA ship Okeanos Explorer.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Dataset shows dives made by a Remotely Operated Vehicle (ROV) or an Autonomous Underwater Vehicle (AUV) from the NOAA ship Okeanos Explorer during expeditions from...

  4. SCUBA Diving for Blind and Visually Impaired People.

    Science.gov (United States)

    Candela, Anthony R.

    1982-01-01

    The author, a trained scuba (self-contained underwater breathing apparatus) diver who is severely visually impaired provides an orientation to scuba diving as a leisure and career activity. (Author/SB)

  5. The risks of scuba diving: a focus on Decompression Illness.

    Science.gov (United States)

    Hall, Jennifer

    2014-11-01

    Decompression Illness includes both Decompression Sickness (DCS) and Pulmonary Overinflation Syndrome (POIS), subsets of diving-related injury related to scuba diving. DCS is a condition in which gas bubbles that form while diving do not have adequate time to be resorbed or "off-gassed," resulting in entrapment in specific regions of the body. POIS is due to an overly rapid ascent to the surface resulting in the rupture of alveoli and subsequent extravasation of air bubbles into tissue planes or even the cerebral circulation. Divers must always be cognizant of dive time and depth, and be trained in the management of decompression. A slow and controlled ascent, plus proper control of buoyancy can reduce the dangerous consequences of pulmonary barotrauma. The incidence of adverse effects can be diminished with safe practices, allowing for the full enjoyment of this adventurous aquatic sport.

  6. Underwater and Dive Station Work-Site Noise Surveys

    National Research Council Canada - National Science Library

    Wolgemuth, Keith S; Cudahy, Edward A; Schwaller, Derek W

    2008-01-01

    Previous work performed by the Naval Submarine Medical Research Laboratory (NSMRL) had developed in-water permissible continuous noise exposure guidance Work performed by the Navy Experimental Diving Unit...

  7. Diving decompression models and bubble metrics: modern computer syntheses.

    Science.gov (United States)

    Wienke, B R

    2009-04-01

    A quantitative summary of computer models in diving applications is presented, underscoring dual phase dynamics and quantifying metrics in tissue and blood. Algorithms covered include the multitissue, diffusion, split phase gradient, linear-exponential, asymmetric tissue, thermodynamic, varying permeability, reduced gradient bubble, tissue bubble diffusion, and linear-exponential phase models. Defining relationships are listed, and diver staging regimens are underscored. Implementations, diving sectors, and correlations are indicated for models with a history of widespread acceptance, utilization, and safe application across recreational, scientific, military, research, and technical communities. Presently, all models are incomplete, but many (included above) are useful, having resulted in diving tables, underwater meters, and dive planning software. Those herein employ varying degrees of calibration and data tuning. We discuss bubble metrics in tissue and blood as a backdrop against computer models. The past 15 years, or so, have witnessed changes and additions to diving protocols and table procedures, such as shorter nonstop time limits, slower ascent rates, shallow safety stops, ascending repetitive profiles, deep decompression stops, helium based breathing mixtures, permissible reverse profiles, multilevel techniques, both faster and slower controlling repetitive tissue halftimes, smaller critical tensions, longer flying-after-diving surface intervals, and others. Stimulated by Doppler and imaging technology, table and decompression meter development, theory, statistics, chamber and animal testing, or safer diving consensus, these modifications affect a gamut of activity, spanning bounce to decompression, single to multiday, and air to mixed gas diving. As it turns out, there is growing support for many protocols on operational, experimental, and theoretical grounds, with bubble models addressing many concerns on plausible bases, but with further testing or

  8. B-type natriuretic peptide secretion following scuba diving

    DEFF Research Database (Denmark)

    Passino, Claudio; Franzino, Enrico; Giannoni, Alberto

    2011-01-01

    To examine the neurohormonal effects of a scuba dive, focusing on the acute changes in the plasma concentrations of the different peptide fragments from the B-type natriuretic peptide (BNP) precursor.......To examine the neurohormonal effects of a scuba dive, focusing on the acute changes in the plasma concentrations of the different peptide fragments from the B-type natriuretic peptide (BNP) precursor....

  9. The Mammalian Diving Response: An Enigmatic Reflex to Preserve Life?

    Science.gov (United States)

    2013-01-01

    The mammalian diving response is a remarkable behavior that overrides basic homeostatic reflexes. It is most studied in large aquatic mammals but is seen in all vertebrates. Pelagic mammals have developed several physiological adaptations to conserve intrinsic oxygen stores, but the apnea, bradycardia, and vasoconstriction is shared with those terrestrial and is neurally mediated. The adaptations of aquatic mammals are reviewed here as well as the neural control of cardiorespiratory physiology during diving in rodents. PMID:23997188

  10. Separation of BSA through FAU-type zeolite ceramic composite membrane formed on tubular ceramic support: Optimization of process parameters by hybrid response surface methodology and biobjective genetic algorithm.

    Science.gov (United States)

    Vinoth Kumar, R; Ganesh Moorthy, I; Pugazhenthi, G

    2017-08-09

    In this study, Faujasite (FAU) zeolite was coated on low-cost tubular ceramic support as a separating layer through hydrothermal route. The mixture of silicate and aluminate solutions was used to create a zeolitic separation layer on the support. The prepared zeolite ceramic composite membrane was characterized using X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), particle size distribution (PSD), field emission scanning electron microscopy (FESEM), and zeta potential measurements. The porosity of ceramic support (53%) was reduced by the deposition of FAU (43%) zeolite layer. The pore size and water permeability of the membrane were evaluated as 0.179 µm and 1.62 × 10 -7  m 3 /m 2  s kPa, respectively, which are lower than that of the support (pore size of 0.309 µm and water permeability of 5.93 × 10 -7  m 3 /m 2  s kPa). The permeate flux and rejection potential of the prepared membrane were evaluated by microfiltration of bovine serum albumin (BSA). To study the influences of three independent variables such as operating pressure (68.94-275.79 kPa), concentration of BSA (100-500 ppm), and solution pH (2-4) on permeate flux and percentage of rejection, the response surface methodology (RSM) was used. The predicted models for permeate flux and rejection were further subjected to biobjective genetic algorithm (GA). The hybrid RSM-GA approach resulted in a maximum permeate flux of 2.66 × 10 -5  m 3 /m 2  s and BSA rejection of 88.02%, at which the optimum conditions were attained as 100 ppm BSA concentration, 2 pH solution, and 275.79 kPa applied pressure. In addition, the separation efficiency was compared with other membranes applied for BSA separation to know the potential of the fabricated FAU zeolite ceramic composite membrane.

  11. Extracting Databases from Dark Data with DeepDive.

    Science.gov (United States)

    Zhang, Ce; Shin, Jaeho; Ré, Christopher; Cafarella, Michael; Niu, Feng

    2016-01-01

    DeepDive is a system for extracting relational databases from dark data : the mass of text, tables, and images that are widely collected and stored but which cannot be exploited by standard relational tools. If the information in dark data - scientific papers, Web classified ads, customer service notes, and so on - were instead in a relational database, it would give analysts a massive and valuable new set of "big data." DeepDive is distinctive when compared to previous information extraction systems in its ability to obtain very high precision and recall at reasonable engineering cost; in a number of applications, we have used DeepDive to create databases with accuracy that meets that of human annotators. To date we have successfully deployed DeepDive to create data-centric applications for insurance, materials science, genomics, paleontologists, law enforcement, and others. The data unlocked by DeepDive represents a massive opportunity for industry, government, and scientific researchers. DeepDive is enabled by an unusual design that combines large-scale probabilistic inference with a novel developer interaction cycle. This design is enabled by several core innovations around probabilistic training and inference.

  12. Activation of Brainstem Neurons by Underwater Diving in the Rat

    Science.gov (United States)

    Panneton, W. Michael; Gan, Qi; Le, Jason; Livergood, Robert S.; Clerc, Philip; Juric, Rajko

    2012-01-01

    The mammalian diving response is a powerful autonomic adjustment to underwater submersion greatly affecting heart rate, arterial blood pressure, and ventilation. The bradycardia is mediated by the parasympathetic nervous system, arterial blood pressure is mediated via the sympathetic system and still other circuits mediate the respiratory changes. In the present study we investigate the cardiorespiratory responses and the brainstem neurons activated by voluntary diving of trained rats, and, compare them to control and swimming animals which did not dive. We show that the bradycardia and increase in arterial blood pressure induced by diving were significantly different than that induced by swimming. Neuronal activation was calculated after immunohistochemical processing of brainstem sections for Fos protein. Labeled neurons were counted in the caudal pressor area, the medullary dorsal horn, subnuclei of the nucleus tractus solitarii (NTS), the nucleus raphe pallidus (RPa), the rostroventrolateral medulla, the A5 area, the nucleus locus coeruleus, the Kölliker–Fuse area, and the external lateral and superior lateral subnuclei of the parabrachial nucleus. All these areas showed significant increases in Fos labeling when data from voluntary diving rats were compared to control rats and all but the commissural subnucleus of the NTS, A5 area, and RPa were significantly different from swimming rats. These data provide a substrate for more precise experiments to determine the role of these nuclei in the reflex circuits driving the diving response. PMID:22563319

  13. Activation of brainstem neurons by underwater diving in the rat

    Directory of Open Access Journals (Sweden)

    W Michael ePanneton

    2012-05-01

    Full Text Available The mammalian diving response is a powerful autonomic adjustment to underwater submersion greatly affecting heart rate, arterial blood pressure and ventilation. The bradycardia is known to be mediated by the parasympathetic nervous system, arterial blood pressure is mediated via the sympathetic system and still other circuits mediate the respiratory changes. In the present study we investigate the cardiorespiratory responses and the brainstem neurons activated by voluntary diving of trained rats, and, compare them to control and swimming animals which did not dive. We show that the bradycardia and increase in arterial blood pressure induced by diving were significantly different that induced by swimming. Neuronal activation was calculated after immunohistochemical processing of brainstem sections for Fos protein. Labeled neurons were counted in the caudal pressor area, the medullary dorsal horn, subnuclei of the nucleus tractus solitarii, the nucleus raphe pallidus, the rostroventrolateral medulla, the A5 area, the nucleus locus coeruleus, the Kölliker-Fuse area and the external lateral and superior lateral subnuclei of the parabrachial nucleus. All these areas showed significant increases in Fos labeling when data from voluntary diving rats were compared to control rats and all but the commissural subnucleus of the nucleus tractus solitarii, A5 area, and raphe pallidus were different from swimming rats. These data provide a substrate for more precise experiments to determine the role of these nuclei in the reflex circuits driving the diving response.

  14. Poor flight performance in deep-diving cormorants.

    Science.gov (United States)

    Watanabe, Yuuki Y; Takahashi, Akinori; Sato, Katsufumi; Viviant, Morgane; Bost, Charles-André

    2011-02-01

    Aerial flight and breath-hold diving present conflicting morphological and physiological demands, and hence diving seabirds capable of flight are expected to face evolutionary trade-offs regarding locomotory performances. We tested whether Kerguelen shags Phalacrocorax verrucosus, which are remarkable divers, have poor flight capability using newly developed tags that recorded their flight air speed (the first direct measurement for wild birds) with propeller sensors, flight duration, GPS position and depth during foraging trips. Flight air speed (mean 12.7 m s(-1)) was close to the speed that minimizes power requirement, rather than energy expenditure per distance, when existing aerodynamic models were applied. Flights were short (mean 92 s), with a mean summed duration of only 24 min day(-1). Shags sometimes stayed at the sea surface without diving between flights, even on the way back to the colony, and surface durations increased with the preceding flight durations; these observations suggest that shags rested after flights. Our results indicate that their flight performance is physiologically limited, presumably compromised by their great diving capability (max. depth 94 m, duration 306 s) through their morphological adaptations for diving, including large body mass (enabling a large oxygen store), small flight muscles (to allow for large leg muscles for underwater propulsion) and short wings (to decrease air volume in the feathers and hence buoyancy). The compromise between flight and diving, as well as the local bathymetry, shape the three-dimensional foraging range (<26 km horizontally, <94 m vertically) in this bottom-feeding cormorant.

  15. Regional heterothermy and conservation of core temperature in emperor penguins diving under sea ice.

    Science.gov (United States)

    Ponganis, P J; Van Dam, R P; Levenson, D H; Knower, T; Ponganis, K V; Marshall, G

    2003-07-01

    Temperatures were recorded at several body sites in emperor penguins (Aptenodytes forsteri) diving at an isolated dive hole in order to document temperature profiles during diving and to evaluate the role of hypothermia in this well-studied model of penguin diving physiology. Grand mean temperatures (+/-S.E.) in central body sites during dives were: stomach: 37.1+/-0.2 degrees C (n=101 dives in five birds), pectoral muscle: 37.8+/-0.1 degrees C (n=71 dives in three birds) and axillary/brachial veins: 37.9+/-0.1 degrees C (n=97 dives in three birds). Mean diving temperature and duration correlated negatively at only one site in one bird (femoral vein, r=-0.59, Pemperors. Although prey ingestion can result in cooling in the stomach, these findings and the lack of negative correlations between internal temperatures and diving duration do not support a role for hypothermia-induced metabolic suppression of the abdominal organs as a mechanism of extension of aerobic dive time in emperor penguins diving at the isolated dive hole. Such high temperatures within the body and the observed decreases in limb, anterior abdomen, subcutaneous and sub-feather temperatures are consistent with preservation of core temperature and cooling of an outer body shell secondary to peripheral vasoconstriction, decreased insulation of the feather layer, and conductive/convective heat loss to the water environment during the diving of these emperor penguins.

  16. Determinants of arterial gas embolism after scuba diving.

    Science.gov (United States)

    Ljubkovic, Marko; Zanchi, Jaksa; Breskovic, Toni; Marinovic, Jasna; Lojpur, Mihajlo; Dujic, Zeljko

    2012-01-01

    Scuba diving is associated with breathing gas at increased pressure, which often leads to tissue gas supersaturation during ascent and the formation of venous gas emboli (VGE). VGE crossover to systemic arteries (arterialization), mostly through the patent foramen ovale, has been implicated in various diving-related pathologies. Since recent research has shown that arterializations frequently occur in the absence of cardiac septal defects, our aim was to investigate the mechanisms responsible for these events. Divers who tested negative for patent foramen ovale were subjected to laboratory testing where agitated saline contrast bubbles were injected in the cubital vein at rest and exercise. The individual propensity for transpulmonary bubble passage was evaluated echocardiographically. The same subjects performed a standard air dive followed by an echosonographic assessment of VGE generation (graded on a scale of 0-5) and distribution. Twenty-three of thirty-four subjects allowed the transpulmonary passage of saline contrast bubbles in the laboratory at rest or after a mild/moderate exercise, and nine of them arterialized after a field dive. All subjects with postdive arterialization had bubble loads reaching or exceeding grade 4B in the right heart. In individuals without transpulmonary passage of saline contrast bubbles, injected either at rest or after an exercise bout, no postdive arterialization was detected. Therefore, postdive VGE arterialization occurs in subjects that meet two criteria: 1) transpulmonary shunting of contrast bubbles at rest or at mild/moderate exercise and 2) VGE generation after a dive reaches the threshold grade. These findings may represent a novel concept in approach to diving, where diving routines will be tailored individually.

  17. Acoustic measurements of post-dive cardiac responses in southern elephant seals (Mirounga leonina) during surfacing at sea.

    Science.gov (United States)

    Day, Louise; Jouma'a, Joffrey; Bonnel, Julien; Guinet, Christophe

    2017-05-01

    Measuring physiological data in free-ranging marine mammals remains challenging, owing to their far-ranging foraging habitat. Yet, it is important to understand how these divers recover from effort expended underwater, as marine mammals can perform deep and recurrent dives. Among them, southern elephant seals ( Mirounga leonina ) are one of the most extreme divers, diving continuously at great depth and for long duration while travelling over large distances within the Southern Ocean. To determine how they manage post-dive recovery, we deployed hydrophones on four post-breeding female southern elephant seals. Cardiac data were extracted from sound recordings when the animal was at the surface, breathing. Mean heart rate at the surface was 102.4±4.9 beats min -1 and seals spent on average 121±20 s breathing. During these surface intervals, the instantaneous heart rate increased with time. Elephant seals are assumed to drastically slow their heart rate (bradycardia) while they are deep underwater, and increase it (tachycardia) during the ascent towards the surface. Our finding suggests that tachycardia continues while the animal stays breathing at the surface. Also, the measured mean heart rate at the surface was unrelated to the duration and swimming effort of the dive prior to the surface interval. Recovery (at the surface) after physical effort (underwater) appears to be related to the overall number of heart beats performed at the surface, and therefore total surface duration. Southern elephant seals recover from dives by adjusting the time spent at the surface rather than their heart rate. © 2017. Published by The Company of Biologists Ltd.

  18. Air sac PO2 and oxygen depletion during dives of emperor penguins.

    Science.gov (United States)

    Knower Stockard, T; Heil, J; Meir, J U; Sato, K; Ponganis, K V; Ponganis, P J

    2005-08-01

    In order to determine the rate and magnitude of respiratory O2 depletion during dives of emperor penguins (Aptenodytes forsteri), air sac O2 partial pressure (PO2) was recorded in 73 dives of four birds at an isolated dive hole. These results were evaluated with respect to hypoxic tolerance, the aerobic dive limit (ADL; dive duration beyond which there is post-dive lactate accumulation) and previously measured field metabolic rates (FMRs). 55% of dives were greater in duration than the previously measured 5.6-min ADL. PO2 and depth profiles revealed compression hyperoxia and gradual O2 depletion during dives. 42% of final PO2s during the dives (recorded during the last 15 s of ascent) were emperors. In dives of durations greater than the ADL, the calculated end-of-dive air sac O2 fraction was <4%. The respiratory O2 store depletion rate of an entire dive, based on the change in O2 fraction during a dive and previously measured diving respiratory volume, ranged from 1 to 5 ml O2 kg(-1) min(-1) and decreased exponentially with diving duration. The mean value, 2.1+/-0.8 ml O2 kg(-1) min(-1), was (1) 19-42% of previously measured respiratory O(2) depletion rates during forced submersions and simulated dives, (2) approximately one-third of the predicted total body resting metabolic rate and (3) approximately 10% of the measured FMR. These findings are consistent with a low total body metabolic rate during the dive.

  19. Bilateral sectioning of the anterior ethmoidal nerves does not eliminate the diving response in voluntarily diving rats

    Science.gov (United States)

    Chotiyanonta, Jill S; DiNovo, Karyn M; McCulloch, Paul F

    2013-01-01

    The diving response is characterized by bradycardia, apnea, and increased peripheral resistance. This reflex response is initiated by immersing the nose in water. Because the anterior ethmoidal nerve (AEN) innervates the nose, our hypothesis was that intact AENs are essential for initiating the diving response in voluntarily diving rats. Heart rate (HR) and arterial blood pressure (BPa) were monitored using implanted biotransmitters. Sprague-Dawley rats were trained to voluntarily swim 5 m underwater. During diving, HR decreased from 480 ± 15 to 99 ± 5 bpm and BPa increased from 136 ± 2 to 187 ± 3 mmHg. Experimental rats (N = 9) then received bilateral AEN sectioning, while Sham rats (N = 8) did not. During diving in Experimental rats 7 days after AEN surgery, HR decreased from 478 ± 13 to 76 ± 4 bpm and BPa increased from 134 ± 3 to 186 ± 4 mmHg. Responses were similar in Sham rats. Then, during nasal stimulation with ammonia vapors in urethane-anesthetized Experimental rats, HR decreased from 368 ± 7 to 83 ± 4 bpm, and BPa increased from 126 ± 7 to 175 ± 4 mmHg. Responses were similar in Sham rats. Thus, 1 week after being sectioned the AENs are not essential for initiating a full cardiorespiratory response during both voluntary diving and nasal stimulation. We conclude that other nerve(s) innervating the nose are able to provide an afferent signal sufficient to initiate the diving response, although neuronal plasticity within the medullary dorsal horn may be necessary for this to occur. PMID:24400143

  20. The Use of Artificial Reefs for Recreational Diving

    Directory of Open Access Journals (Sweden)

    Tuğçe ŞENSURAT GENÇ

    2017-11-01

    Full Text Available Scuba diving has become a burgeoning branch of the tourism service. Various activities of recreational diving do not especially necessitate natural reefs-any varied vehicle such as ship, plane and other large structures may be adequately attractive. Coastal groups are turning to these structures by the way of supplying new locations for scuba diving tourists. Despite the lack of a global database, our literature review indicated extensive use of artificial reefs for recreation in the United States, currently viewed as the pioneering puissance and professional in the field. Moreover, the Canadian and Australian governments have both promoted several “ships to reef” programs focused on recreation. However, the used of three-dimensional structures (ships, planes etc. as artificial reefs in sensitive ecosystems such as the Mediterranean and Red Sea is not a common practice. Although scuba divers are interested in such type of structures, ships to reef is a matter of debate especially in the Mediterranean region. In Turkey, a National Artificial Reef Program was drafted in 2008, however there is no regulation at present about intentionally sinking a ship for the creation of recreational diving destinations. The aim of this review was to investigate the use of man-made structures as artificial reefs for recreational diving around the world.

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

    Directory of Open Access Journals (Sweden)

    Stephen J Trumble

    2012-06-01

    Full Text Available 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 stochiometric level, the metabolism of PUFAs (polyunsaturated fatty acids utilizes less oxygen than metabolizing either MUFAs (monounsaturated fatty acids or SFAs (saturated fatty acids 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.

  2. Recreational Diving Practice for Stress Management: An Exploratory Trial

    Directory of Open Access Journals (Sweden)

    Frédéric Beneton

    2017-12-01

    Full Text Available Background: Within the components of Scuba diving there are similarities with meditation and mindfulness techniques by training divers to be in a state of open monitoring associated with slow and ample breathing. Perceived stress is known to be diminished during meditation practice. This study evaluates the benefits of scuba diving on perceived stress and mindful functioning.Method: A recreational diving group (RDG; n = 37 was compared with a multisport control group (MCG; n = 30 on perceived stress, mood, well-being and mindfulness by answering auto-questionnaires before and after a 1-week long UCPA course. For the diving group, stability of the effects was evaluated 1 month later using similar auto-questionnaires.Results: Perceived stress did not decrease after the course for the MCG [ The divers showed a significant reduction on the perceived stress score (p < 0.05 with a sustainable effect (p = 0.01]. An improvement in mood scale was observed in both groups. This was associated to an increase in mindfulness abilities.Conclusions: The practice of a recreational sport improves the mood of subjects reporting the thymic benefits of a physical activity performed during a vacation period. The health benefits of recreational diving appear to be greater than the practice of other sports in reducing stress and improving well-being.

  3. Desmopression Prevents Immersion Diuresis and Improves Physical Performance After Long Duration Dives

    National Research Council Canada - National Science Library

    Nyquist, P. A; Schrot, J; Thomas, J. R; Hyde, D; Taylor, W. R

    2005-01-01

    .... Before the experimental dive, subjects received 40 microg of Desmopressin intranasally. Before and after each dive blood samples were taken, performance assessments were performed, and urine, electrolyte and hematologic values were determined...

  4. A Biomedical Assessment of a One-Atmosphere Diving System: JIM-4.

    Science.gov (United States)

    1981-12-01

    diving dress ................................. A7 Fig. 9. Galeazzi diving suit ................................. A8 Fig. 10. Peress’s diving system, the...joints, one in each shoulder and two in each leg. Around the time that Neufeldt and Kuhnke were developing their system, an Italian developer Galeazzi ...produced an atmospheric diving system (Davis, 1969). A photograph in Davis’s book shows a 1930’s Galeazzi suit that is virtually identical to a recent

  5. Permanent mechanical deformation of an intrathecal baclofen pump secondary to scuba diving: a case report.

    Science.gov (United States)

    Draulans, N; Roels, E; Kiekens, C; Nuttin, B; Peers, K

    2013-11-01

    Case report. To describe the case of a spinal cord injury patient that went scuba diving resulting in a mechanical deformation of his intrathecal baclofen pump. University Hospitals Leuven, Belgium. Case report. Diving below 10 meters of depth can result in irreversible mechanical damage of the drug reservoir of an intrathecal baclofen pump. Patients with an intrathecal baclofen pump should be warned for the risks associated with scuba diving and should not dive more than 10 meters below sea level.

  6. Risk of Central Nervous System Decompression Sickness in Air Diving to No-Stop Limits

    Science.gov (United States)

    2009-01-01

    cause underestimation of the decompression stresses of the dives and slightly conservative estimates of PCNSDCS by a model fit to data that includes...NSW III for air scuba diving . However, since the NSW III assumes air breathing shallower than 78 fsw and constant 0.7 atm P02 in nitrogen otherwise...signifying its use for air diving ) of the NSW III is already available. RECOMMENDATIONS The AIR III should be adopted for air scuba diving . The

  7. Incremental Knowledge Base Construction Using DeepDive.

    Science.gov (United States)

    Shin, Jaeho; Wu, Sen; Wang, Feiran; De Sa, Christopher; Zhang, Ce; Ré, Christopher

    2015-07-01

    Populating a database with unstructured information is a long-standing problem in industry and research that encompasses problems of extraction, cleaning, and integration. Recent names used for this problem include dealing with dark data and knowledge base construction (KBC). In this work, we describe DeepDive, a system that combines database and machine learning ideas to help develop KBC systems, and we present techniques to make the KBC process more efficient. We observe that the KBC process is iterative, and we develop techniques to incrementally produce inference results for KBC systems. We propose two methods for incremental inference, based respectively on sampling and variational techniques. We also study the tradeoff space of these methods and develop a simple rule-based optimizer. DeepDive includes all of these contributions, and we evaluate Deep-Dive on five KBC systems, showing that it can speed up KBC inference tasks by up to two orders of magnitude with negligible impact on quality.

  8. Edmund Goodwyn and the first description of diving bradycardia.

    Science.gov (United States)

    Vega, Jose L

    2017-08-01

    Diving bradycardia is a primordial oxygen-conserving reflex by which the heart rate of air-breathing vertebrates, including humans, slows down in response to water immersion. Its discovery is attributed to Paul Bert, whose seminal observation was published in 1870 as part of a series of experiments that examined physiological adaptations to asphyxia in ducks and other animals. However, Edmund Goodwyn, a British physician who studied medicine at the University of Edinburgh, had already described this reflex in his doctoral thesis, which was originally published in Latin in 1786 and again in English in 1788. Ironically, even though Goodwyn's work has yet to be recognized in the diving physiology literature, it was referenced in the very publication that contains Bert's original observation. Thus this article brings Goodwyn's work and its historical context to light and argues that he should be credited with the first description of diving bradycardia. Copyright © 2017 the American Physiological Society.

  9. The cardiovascular and endocrine responses to voluntary and forced diving in trained and untrained rats

    Science.gov (United States)

    DiNovo, Karyn. M.; Connolly, Tiffanny M.

    2010-01-01

    The mammalian diving response, consisting of apnea, bradycardia, and increased total peripheral resistance, can be modified by conscious awareness, fear, and anticipation. We wondered whether swim and dive training in rats would 1) affect the magnitude of the cardiovascular responses during voluntary and forced diving, and 2) whether this training would reduce or eliminate any stress due to diving. Results indicate Sprague-Dawley rats have a substantial diving response. Immediately upon submersion, heart rate (HR) decreased by 78%, from 453 ± 12 to 101 ± 8 beats per minute (bpm), and mean arterial pressure (MAP) decreased 25%, from 143 ± 1 to 107 ± 5 mmHg. Approximately 4.5 s after submergence, MAP had increased to a maximum 174 ± 3 mmHg. Blood corticosterone levels indicate trained rats find diving no more stressful than being held by a human, while untrained rats find swimming and diving very stressful. Forced diving is stressful to both trained and untrained rats. The magnitude of bradycardia was similar during both voluntary and forced diving, while the increase in MAP was greater during forced diving. The diving response of laboratory rats, therefore, appears to be dissimilar from that of other animals, as most birds and mammals show intensification of diving bradycardia during forced diving compared with voluntary diving. Rats may exhibit an accentuated antagonism between the parasympathetic and sympathetic branches of the autonomic nervous system, such that in the autonomic control of HR, parasympathetic activity overpowers sympathetic activity. Additionally, laboratory rats may lack the ability to modify the degree of parasympathetic outflow to the heart during an intense cardiorespiratory response (i.e., the diving response). PMID:19923359

  10. Effect of repetitive SCUBA diving on humoral markers of endothelial and central nervous system integrity.

    Science.gov (United States)

    Bilopavlovic, Nada; Marinovic, Jasna; Ljubkovic, Marko; Obad, Ante; Zanchi, Jaksa; Pollock, Neal W; Denoble, Petar; Dujic, Zeljko

    2013-07-01

    During SCUBA diving decompression, there is a significant gas bubble production in systemic veins, with rather frequent bubble crossover to arterial side even in asymptomatic divers. The aim of the current study was to investigate potential changes in humoral markers of endothelial and brain damage (endothelin-1, neuron-specific enolase and S-100β) after repetitive SCUBA diving with concomitant assessment of venous gas bubble production and subsequent arterialization. Sixteen male divers performed four open-water no-decompression dives to 18 msw (meters of sea water) lasting 49 min in consecutive days during which they performed moderate-level exercise. Before and after dives 1 and 4 blood was drawn, and bubble production and potential arterialization were echocardiographically evaluated. In addition, a control dive to 5 msw was performed with same duration, water temperature and exercise load. SCUBA diving to 18 msw caused significant bubble production with arterializations in six divers after dive 1 and in four divers after dive 4. Blood levels of endothelin-1 and neuron-specific enolase did not change after diving, but levels of S-100β were significantly elevated after both dives to 18 msw and a control dive. Creatine kinase activity following a control dive was also significantly increased. Although serum S-100β levels were increased after diving, concomitant increase of creatine kinase during control, almost bubble-free, dive suggests the extracranial release of S-100β, most likely from skeletal muscles. Therefore, despite the significant bubble production and sporadic arterialization after open-water dives to 18 msw, the current study found no signs of damage to neurons or the blood-brain barrier.

  11. Mishaps and unsafe conditions in recreational scuba diving and pre-dive checklist use: a prospective cohort study.

    Science.gov (United States)

    Ranapurwala, Shabbar I; Wing, Steve; Poole, Charles; Kucera, Kristen L; Marshall, Stephen W; Denoble, Petar J

    2017-12-01

    Recreational scuba diving involves the use of complex instruments and specialized skills in an unforgiving environment. Errors in dive preparation in such an environment may lead to unsafe conditions, mishaps, injuries and fatalities. Diving mishaps can be major and minor based on their potential to cause injury and the severity of the resulting injury. The objective of this study is to assess the incidence of diving mishaps and unsafe conditions, and their associations with the participants' routine use of their own checklists. Between June and August 2012, 426 divers participated in the control group of a randomized trial to evaluate the effectiveness of an intervention pre-dive checklist. The current nested analysis prospectively follows the control participants, who did not receive the intervention checklist. Poisson regression models with generalized estimating equations were used to estimate rate ratios comparing written checklist use with memorized and no checklist use. The overall incidence of major mishaps and minor mishaps was 11.2 and 18.2 per 100 dives, respectively. Only 8% participants reported written checklist use, 71% reported using memorized checklists, and 21% did not use any checklist. The rate ratio for written checklist use as compared to using a memorized or no checklist was 0.47 (95%CI: 0.27, 0.83) for all mishaps (major and minor combined), and 0.31 (95% CI: 0.10, 0.93) for major mishaps. The rate of mishaps among memorized checklist users was similar to no checklist users. This study reinforces the utility of written checklists to prevent mishaps and, potentially, injuries and fatalities.

  12. A red orange extract modulates the vascular response to a recreational dive: a pilot study on the effect of anthocyanins on the physiological consequences of scuba diving.

    Science.gov (United States)

    Balestra, C; Cimino, F; Theunissen, S; Snoeck, T; Provyn, S; Canali, R; Bonina, A; Virgili, F

    2016-09-01

    Nutritional antioxidants have been proposed as an expedient strategy to counter the potentially deleterious effects of scuba diving on endothelial function, flow-mediated dilation (FMD) and heart function. Sixteen volunteers performing a single standard dive (20 min at 33 m) according to US Navy diving procedures were randomly assigned to two groups: one was administered with two doses of 200 mg of an anthocyanins (AC)-rich extract from red oranges, 12 and 4 h before diving. Anthocyanins supplementation significantly modulated the effects of diving on haematocrit, body water distribution and FMD. AC administration significantly reduces the potentially harmful endothelial effects of a recreational single dive. The lack of any significant effect on the most common markers of plasma antioxidant capacity suggests that the mechanism underlying this protective activity is independent of the putative antioxidant effect of AC and possibly involves cellular signalling modulation of the response to high oxygen.

  13. Diving deeper into individual foraging specializations of a large marine predator, the southern sea lion.

    Science.gov (United States)

    Baylis, A M M; Orben, R A; Arnould, J P Y; Peters, K; Knox, T; Costa, D P; Staniland, I J

    2015-12-01

    Despite global declines in the abundance of marine predators, knowledge of foraging ecology, necessary to predict the ecological consequences of large changes in marine predator abundance, remains enigmatic for many species. Given that populations suffering severe declines are of conservation concern, we examined the foraging ecology of southern sea lions (SSL) (Otaria flavescens)-one of the least studied otariids (fur seal and sea lions)-which have declined by over 90% at the Falkland Islands since the 1930s. Using a combination of biologging devices and stable isotope analysis of vibrissae, we redress major gaps in the knowledge of SSL ecology and quantify patterns of individual specialization. Specifically, we revealed two discrete foraging strategies, these being inshore (coastal) and offshore (outer Patagonian Shelf). The majority of adult female SSL (72% or n = 21 of 29 SSL) foraged offshore. Adult female SSL that foraged offshore travelled further (92 ± 20 vs. 10 ± 4 km) and dived deeper (75 ± 23 vs. 21 ± 8 m) when compared to those that foraged inshore. Stable isotope analysis revealed long-term fidelity (years) to these discrete foraging habitats. In addition, we found further specialization within the offshore group, with adult female SSL separated into two clusters on the basis of benthic or mixed (benthic and pelagic) dive behavior (benthic dive proportion was 76 ± 9 vs. 51 ± 8%, respectively). We suggest that foraging specialization in depleted populations such as SSL breeding at the Falkland Islands, are influenced by foraging site fidelity, and could be independent of intraspecific competition. Finally, the behavioral differences we describe are crucial to understanding population-level dynamics, impediments to population recovery, and threats to population persistence.

  14. Aerobic dive limit. What is it and is it always used appropriately?

    Science.gov (United States)

    Butler, Patrick J

    2006-09-01

    The original definition of aerobic dive limit (ADL) was the dive duration after which there is an increase in post-dive concentration of lactate in the blood of Weddell seals freely diving in the field. The only other species in which such measurements have been made is the emperor penguin. For all other species, aerobic dive limit has been calculated (cADL) by dividing usable oxygen stores with an estimation of the rate of oxygen consumption during diving. Unfortunately, cADL is often referred to as the aerobic dive limit, implying that it is equivalent to that determined from the measurement of post-dive blood lactate concentration. However, this is not so, as at cADL all of the usable oxygen would have been consumed, whereas Weddell seals and emperor penguins can dive for at least 2-3 times longer than their ADL. Thus, at ADL, there is still some usable oxygen remaining in the stores. It is suggested that to avoid continued confusion between these two terms, the former is called diving lactate threshold (DLT), as it is somewhat analogous to the lactate threshold in exercising terrestrial vertebrates. Possible explanations of how some species routinely dive beyond their cADL are also discussed.

  15. Cerebral damage in diving: Taking the cue from sports concussion ...

    African Journals Online (AJOL)

    Taking the cue from sports concussion medicine, it is proposed that there is an urgent need to incorporate neurocognitive baseline and follow-up screening as a core component in the medical management of those involved in intensive commercial and recreational compressed air diving activities. The objective would be to ...

  16. Carbon Dioxide Changes in Hyperventilation and Breath-hold Diving

    African Journals Online (AJOL)

    1974-01-05

    Jan 5, 1974 ... South Africa. S. Afr. Med. l., 48, 18 (1974). Under conditions of normal atmospheric pressure, breath- holding results in important changes in the mechanism whereby the CO, is transported ... haemoglobin in the face of falling CO, output to the ... Hong,' in a field study of Korean diving women, noted that they ...

  17. Danish diving-related fatalities 1999-2012

    DEFF Research Database (Denmark)

    Vinkel, Julie; Bak, Peter; Hyldegaard, Ole

    2016-01-01

    overview. The empiric data consists of police reports, forensic autopsy reports and examination of the diving equipment. Data were assembled and analyzed using Pivot and Excel. Frequencies and means (± SD) were used to describe categorical and continuous variables respectively. RESULTS: The mean age was 38...

  18. 46 CFR 197.334 - Open diving bells.

    Science.gov (United States)

    2010-10-01

    ... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS... occupied open bell to the dive location; (c) Have an umbilical; and (d) Be—(1) Made of corrosion-resisting material; or (2) Protected against and maintained free from injurious corrosion. ...

  19. A Measurement of "g" Using Alexander's Diving Bell

    Science.gov (United States)

    Quiroga, M.; Martinez, S.; Otranto, S.

    2010-01-01

    This paper describes a very simple exercise using an inverted test tube pushed straight down into a column of water to determine the free-fall acceleration "g". The exercise employs the ideal gas law and only involves the measurement of the displacement of the bottom of the "diving bell" and the water level inside the tube with respect to the…

  20. Doppler Bubble Grades After Diving and Relevance of Body Fat

    NARCIS (Netherlands)

    Schellart, Nico A. M.; Vellinga, Tjeerd P. van Rees; Van Dijk, Frank J.; Sterk, Wouter

    2012-01-01

    SCHELLART NAM, VAN REES VELLINGA TP, VAN DIJK FJ, STERK W. Doppler bubble grades after diving and relevance of body fat. Aviat Space Environ Med 2012; 83:951-7. Background: From the literature on venous gas embolism (VGE) and decompression sickness (DCS), it remains unclear whether body fat is a

  1. Diving for dope” : Controlling underwater drug trafficking

    NARCIS (Netherlands)

    Eski, Y.

    2017-01-01

    This paper will offer an ethnographic account of the everyday reality of controlling illegal underwater drug trafficking in the global Port of Rotterdam (PoR). In so doing, it will explore what it means for customs diving officers to do drug inspections under challenging circumstances in order to

  2. 29 CFR 1910.410 - Qualifications of dive team.

    Science.gov (United States)

    2010-07-01

    ... employee's experience or training, except that limited additional tasks may be assigned to an employee... experience or training necessary to perform assigned tasks in a safe and healthful manner. (2) Each dive team member shall have experience or training in the following: (i) The use of tools, equipment and systems...

  3. Oxygen Toxicity and Special Operations Forces Diving: Hidden and Dangerous

    NARCIS (Netherlands)

    Wingelaar, Thijs T.; van Ooij, Pieter-Jan A. M.; van Hulst, Rob A.

    2017-01-01

    In Special Operations Forces (SOF) closed-circuit rebreathers with 100% oxygen are commonly utilized for covert diving operations. Exposure to high partial pressures of oxygen (PO2) could cause damage to the central nervous system (CNS) and pulmonary system. Longer exposure time and higher PO2 leads

  4. Diving behaviour of African penguins: do they differ from other ...

    African Journals Online (AJOL)

    African penguins Spheniscus demersus closely resemble Magellanic S. magellanicus and Humboldt S. humboldti penguins and have similar breeding and feeding ecologies. Adults feed on pelagic schooling fish in continental shelf waters, but African penguins have been reported to have shallower dive angles and remain ...

  5. Scuba diving injuries among Divers Alert Network members 2010-2011.

    Science.gov (United States)

    Ranapurwala, Shabbar I; Bird, Nicholas; Vaithiyanathan, Pachabi; Denoble, Petar J

    2014-06-01

    Scuba diving injuries vary greatly in severity and prognosis. While decompression sickness (DCS) and arterial gas embolism can be tracked easily, other forms of diving injury remain unaccounted for. The purpose of this paper is to assess rates of overall self-reported scuba-diving-related injuries, self-reported DCS-like symptoms, and treated DCS and their association with diver certification level, diving experience and demographic factors. We analyzed self-reported data from a Divers Alert Network membership health survey conducted during the summer of 2011. Poisson regression models with scaled deviance were used to model the relative rates of reported injuries. Models were adjusted for sex, age, body mass index (BMI) and average annual dives, based on the bias-variance tradeoff. The overall rate of diving-related injury was 3.02 per 100 dives, self-reported DCS symptoms was 1.55 per 1,000 dives and treated DCS was 5.72 per 100,000 dives. Diving-related injury and self-reported DCS symptom rates decreased for higher diver certification levels, increasing age, increasing number of average annual dives and for men; they increased for increasing BMI. Diving injury rates may be higher than previously thought, indicating a greater burden on the diving community. Self-reported DCS-like symptoms are a small fraction of all dive-related injuries and those receiving treatment for DCS are an even smaller fraction. The small number of divers seeking treatment may suggest the mild nature and a tendency towards natural resolution for most injuries.

  6. Sensitivity to hypercapnia and elimination of CO2 following diving in Steller sea lions (Eumetopias jubatus).

    Science.gov (United States)

    Gerlinsky, Carling D; Rosen, David A S; Trites, Andrew W

    2014-05-01

    The diving ability of marine mammals is a function of how they use and store oxygen and the physiological control of ventilation, which is in turn dependent on the accumulation of CO2. To assess the influence of CO2 on physiological control of dive behaviour, we tested how increasing levels of inspired CO2 (hypercarbia) and decreasing inspired O2 (hypoxia) affected the diving metabolic rate, submergence times, and dive recovery times (time to replenish O2 stores and eliminate CO2) of freely diving Steller sea lions. We also measured changes in breathing frequency of diving and non-diving individuals. Our findings show that hypercarbia increased breathing frequency (as low as 2 % CO2), but did not affect metabolic rate, or the duration of dives or surface intervals (up to 3 % CO2). Changes in breathing rates indicated respiratory drive was altered by hypercarbia at rest, but blood CO2 levels remained below the threshold that would alter normal dive behaviour. It took the sea lions longer to remove accumulated CO2 than it did for them to replenish their O2 stores following dives (whether breathing ambient air, hypercarbia, or hypoxia). This difference between O2 and CO2 recovery times grew with increasing dive durations, increasing hypercarbia, and was greater for bout dives, suggesting there could be a build-up of CO2 load with repeated dives. Although we saw no evidence of CO2 limiting dive behaviour, the longer time required to remove CO2 may eventually exhibit control over the overall time they can spend in apnoea and overall foraging duration.

  7. Diving-flight aerodynamics of a peregrine falcon (Falco peregrinus.

    Directory of Open Access Journals (Sweden)

    Benjamin Ponitz

    Full Text Available This study investigates the aerodynamics of the falcon Falco peregrinus while diving. During a dive peregrines can reach velocities of more than 320 km h⁻¹. Unfortunately, in freely roaming falcons, these high velocities prohibit a precise determination of flight parameters such as velocity and acceleration as well as body shape and wing contour. Therefore, individual F. peregrinus were trained to dive in front of a vertical dam with a height of 60 m. The presence of a well-defined background allowed us to reconstruct the flight path and the body shape of the falcon during certain flight phases. Flight trajectories were obtained with a stereo high-speed camera system. In addition, body images of the falcon were taken from two perspectives with a high-resolution digital camera. The dam allowed us to match the high-resolution images obtained from the digital camera with the corresponding images taken with the high-speed cameras. Using these data we built a life-size model of F. peregrinus and used it to measure the drag and lift forces in a wind-tunnel. We compared these forces acting on the model with the data obtained from the 3-D flight path trajectory of the diving F. peregrinus. Visualizations of the flow in the wind-tunnel uncovered details of the flow structure around the falcon's body, which suggests local regions with separation of flow. High-resolution pictures of the diving peregrine indicate that feathers pop-up in the equivalent regions, where flow separation in the model falcon occurred.

  8. Diving-flight aerodynamics of a peregrine falcon (Falco peregrinus).

    Science.gov (United States)

    Ponitz, Benjamin; Schmitz, Anke; Fischer, Dominik; Bleckmann, Horst; Brücker, Christoph

    2014-01-01

    This study investigates the aerodynamics of the falcon Falco peregrinus while diving. During a dive peregrines can reach velocities of more than 320 km h⁻¹. Unfortunately, in freely roaming falcons, these high velocities prohibit a precise determination of flight parameters such as velocity and acceleration as well as body shape and wing contour. Therefore, individual F. peregrinus were trained to dive in front of a vertical dam with a height of 60 m. The presence of a well-defined background allowed us to reconstruct the flight path and the body shape of the falcon during certain flight phases. Flight trajectories were obtained with a stereo high-speed camera system. In addition, body images of the falcon were taken from two perspectives with a high-resolution digital camera. The dam allowed us to match the high-resolution images obtained from the digital camera with the corresponding images taken with the high-speed cameras. Using these data we built a life-size model of F. peregrinus and used it to measure the drag and lift forces in a wind-tunnel. We compared these forces acting on the model with the data obtained from the 3-D flight path trajectory of the diving F. peregrinus. Visualizations of the flow in the wind-tunnel uncovered details of the flow structure around the falcon's body, which suggests local regions with separation of flow. High-resolution pictures of the diving peregrine indicate that feathers pop-up in the equivalent regions, where flow separation in the model falcon occurred.

  9. Recursive filtering for zero offset correction of diving depth time series with GNU R package diveMove.

    Directory of Open Access Journals (Sweden)

    Sebastián P Luque

    Full Text Available Zero offset correction of diving depth measured by time-depth recorders is required to remove artifacts arising from temporal changes in accuracy of pressure transducers. Currently used methods for this procedure are in the proprietary software domain, where researchers cannot study it in sufficient detail, so they have little or no control over how their data were changed. GNU R package diveMove implements a procedure in the Free Software domain that consists of recursively smoothing and filtering the input time series using moving quantiles. This paper describes, demonstrates, and evaluates the proposed method by using a "perfect" data set, which is subsequently corrupted to provide input for the proposed procedure. The method is evaluated by comparing the corrected time series to the original, uncorrupted, data set from an Antarctic fur seal (Arctocephalus gazella Peters, 1875. The Root Mean Square Error of the corrected data set, relative to the "perfect" data set, was nearly identical to the magnitude of noise introduced into the latter. The method, thus, provides a flexible, reliable, and efficient mechanism to perform zero offset correction for analyses of diving behaviour. We illustrate applications of the method to data sets from four species with large differences in diving behaviour, measured using different sampling protocols and instrument characteristics.

  10. Swimming: An Introduction to Swimming, Diving, and SCUBA Diving for Blind and Physically Handicapped Individuals. Leisure Pursuit Series.

    Science.gov (United States)

    Cylke, Frank Kurt, Ed.

    The annotated guide lists information sources available from the National Library Service for the Blind and Physically Handicapped in print, disc, cassette, and braille formats concerning swimming and diving with special reference to blind swimmers. The guide begins with a brief sketch of a champion swimmer who is also legally blind and an…

  11. Thermal substitution and aerobic efficiency: measuring and predicting effects of heat balance on endotherm diving energetics.

    Science.gov (United States)

    Lovvorn, J R

    2007-11-29

    For diving endotherms, modelling costs of locomotion as a function of prey dispersion requires estimates of the costs of diving to different depths. One approach is to estimate the physical costs of locomotion (Pmech) with biomechanical models and to convert those estimates to chemical energy needs by an aerobic efficiency (eta=Pmech/Vo2) based on oxygen consumption (Vo2) in captive animals. Variations in eta with temperature depend partly on thermal substitution, whereby heat from the inefficiency of exercising muscles or the heat increment of feeding (HIF) can substitute for thermogenesis. However, measurements of substitution have ranged from lack of detection to nearly complete use of exercise heat or HIF. This inconsistency may reflect (i) problems in methods of calculating substitution, (ii) confounding mechanisms of thermoregulatory control, or (iii) varying conditions that affect heat balance and allow substitution to be expressed. At present, understanding of how heat generation is regulated, and how heat is transported among tissues during exercise, digestion, thermal challenge and breath holding, is inadequate for predicting substitution and aerobic efficiencies without direct measurements for conditions of interest. Confirming that work rates during exercise are generally conserved, and identifying temperatures at those work rates below which shivering begins, may allow better prediction of aerobic efficiencies for ecological models.

  12. When sustainability of a tourism destination is a requirement: Does the consumer perceive sacrifices in diving experiences?

    Directory of Open Access Journals (Sweden)

    Polyanna de Lourdes Saraiva do Nascimento

    2017-06-01

    Full Text Available Consumer behaviour refers to some subjective characteristics of individuals, their cultural principles and living experiences throughout their lives, aspects that awaken the individual’s desire to consume certain products and services and sometimes the tendency to give up some personal and discretionary resources to concretize this consumption, in other words, to make sacrifices. In this present study, the emphasis focuses on the understanding of the way Dutch and Brazilian consumers carry out the sacrifice in diving experiences, while the practice of sustainability is required. Therefore, the aspects that motivated this study are related to the need to explore the sacrifice theme in consumer relations, mainly when associated with products and services where the hedonic experience is felt, as it is through diving. The research is interpretative, considering that it captures objective results from the studied phenomenon, by using semi-structured interviews collected with divers, totalling twenty-three interviews in Brazil and Netherlands. The collected data was analysed according to content analysis. The results pointed out the relationship between sacrifices and sustainability, in diving experiences associated with the abdication of resources such as: recreation, time, comfort and money. Moreover, the predisposition to sacrifice something is directly related to living experiences during the practice of the activity, considering that it awakens positive feelings and generates a strong individual affective commitment. These aspects emphasize the provision of the individuals to follow the rules for sustainability determined by tourist destinations for diving, as well as the desire to explore without destroying, aiming to keep practicing that activity are that location.

  13. Managing dive tourism for the sustainable use of coral reefs: validating diver perceptions of attractive site features.

    Science.gov (United States)

    Uyarra, Maria C; Watkinson, Andrew R; Côté, Isabelle M

    2009-01-01

    It has been argued that strategies to manage natural areas important for tourism and recreation should integrate an understanding of tourist preferences for specific natural features. However, the accuracy of tourist recalled perceptions of environmental attributes, which are usually derived from post hoc surveys and used to establish management priorities, is currently unmeasured. We tested the validity of the relationship between tourist-stated preferences and actual condition of coral reefs around the Caribbean island of Bonaire. Using standardized questionnaires, we asked 200 divers to select their most and least favorite dive sites and the attributes that contributed to that selection. We also carried out ecological surveys at 76 of the 81 dives sites around the island to assess the actual conditions of the attributes indicated as important for site selection. Fish- and coral-related attributes were key features affecting dive enjoyment. In general, divers appeared to be able to perceive differences between sites in the true condition of biological attributes such as fish species richness, total number of fish schools, live coral cover, coral species richness, and reef structural complexity, although men and women divers differed in their ability to perceive/recall some of the attributes. Perceived differences in environmental attributes, such as surface conditions, underwater current, and the likelihood of encountering rare fish and sea turtles, were not empirically validated. The fact that divers perceive correctly differences in the condition of some of the key biological attributes that affect dive enjoyment reinforces the need to maintain overall reef condition at satisfactory levels. However, variation in accuracy of perceptions owing to demographic factors and attribute type suggests the need for caution when using public perceptions to develop environmental management strategies, particularly for coral reefs.

  14. Muscle energy stores and stroke rates of emperor penguins: implications for muscle metabolism and dive performance.

    Science.gov (United States)

    Williams, Cassondra L; Sato, Katsufumi; Shiomi, Kozue; Ponganis, Paul J

    2012-01-01

    In diving birds and mammals, bradycardia and peripheral vasoconstriction potentially isolate muscle from the circulation. During complete ischemia, ATP production is dependent on the size of the myoglobin oxygen (O(2)) store and the concentrations of phosphocreatine (PCr) and glycogen (Gly). Therefore, we measured PCr and Gly concentrations in the primary underwater locomotory muscle of emperor penguin and modeled the depletion of muscle O(2) and those energy stores under conditions of complete ischemia and a previously determined muscle metabolic rate. We also analyzed stroke rate to assess muscle workload variation during dives and evaluate potential limitations on the model. Measured PCr and Gly concentrations, 20.8 and 54.6 mmol kg(-1), respectively, were similar to published values for nondiving animals. The model demonstrated that PCr and Gly provide a large anaerobic energy store, even for dives longer than 20 min. Stroke rate varied throughout the dive profile, indicating muscle workload was not constant during dives as was assumed in the model. The stroke rate during the first 30 s of dives increased with increased dive depth. In extremely long dives, lower overall stroke rates were observed. Although O(2) consumption and energy store depletion may vary during dives, the model demonstrated that PCr and Gly, even at concentrations typical of terrestrial birds and mammals, are a significant anaerobic energy store and can play an important role in the emperor penguin's ability to perform long dives.

  15. Post-dive blood lactate concentrations in emperor penguins, Aptenodytes forsteri.

    Science.gov (United States)

    Ponganis, P J; Kooyman, G L; Starke, L N; Kooyman, C A; Kooyman, T G

    1997-06-01

    In order to determine an aerobic diving limit (ADL) in emperor penguins (Aptenodytes forsteri), post-dive blood lactate concentrations were measured in penguins foraging at an isolated sea ice hole. Resting lactate concentrations were 1.2-2.7 mmol l-1. Serial samples revealed that lactate level usually peaked within 5 min after dives and that 7-12 min was required for lactate concentrations to decrease from 5-8 mmol l-1 to less than 2.5 mmol l-1. Post-dive lactate level was not elevated above 3 mmol l-1 for dives shorter than 5 min. Two-phase regression analysis revealed a transaction at 5.6 min in the post-dive lactate level versus diving duration relationship. All dives longer than 7 min were associated with lactate concentrations greater than 5 mmol l-1. We conclude that the ADL in emperor penguins ranges between 5 and 7 min. These are the first determinations of post-dive lactate concentrations in any free-diving bird and are currently the only physiological assessment of an ADL in an avian species.

  16. Short- and long-term effects of diving on pulmonary function

    Directory of Open Access Journals (Sweden)

    Kay Tetzlaff

    2017-03-01

    Full Text Available The diving environment provides a challenge to the lung, including exposure to high ambient pressure, altered gas characteristics and cardiovascular effects on the pulmonary circulation. Several factors associated with diving affect pulmonary function acutely and can potentially cause prolonged effects that may accumulate gradually with repeated diving exposure. Evidence from experimental deep dives and longitudinal studies suggests long-term adverse effects of diving on the lungs in commercial deep divers, such as the development of small airways disease and accelerated loss of lung function. In addition, there is an accumulating body of evidence that diving with self-contained underwater breathing apparatus (scuba may not be associated with deleterious effects on pulmonary function. Although changes in pulmonary function after single scuba dives have been found to be associated with immersion, ambient cold temperatures and decompression stress, changes in lung function were small and suggest a low likelihood of clinical significance. Recent evidence points to no accelerated loss of lung function in military or recreational scuba divers over time. Thus, the impact of diving on pulmonary function largely depends on factors associated with the individual diving exposure. However, in susceptible subjects clinically relevant worsening of lung function may occur even after single shallow-water scuba dives.

  17. The genetic component of the forced diving bradycardia response in mammals

    Directory of Open Access Journals (Sweden)

    Andreas eFahlman

    2011-09-01

    Full Text Available We contrasted the forced diving bradycardia between two genetically similar (inbred rat strains (Fischer and Buffalo, compared to that of outbred rats (Wistar. The animals were habituated to forced diving for 4 weeks. Each animal was then tested during one 40-sec dive on each of 3 days. The heart rate (fH was measured before, during, and after each dive. Fischer and Buffalo exhibited marked difference in dive bradycardia (Fischer: 120.9 ± 14.0 beats • min-1 vs. Buffalo: 92.8 ± 12.8 beats • min-1, P < 0.05. Outbred rats showed an intermediate response (103.0 ± 30.9 beats • min-1 but their between-animal variability in mean dive fH and pre-diving resting fH were higher than the inbred strains (P < 0.05, which showed no difference (P > 0.05. The decreased variability in fH in inbred rats as compared with the outbred group indicates that reduced genetic variability minimizes variability of the diving bradycardia between individuals. Heritability within strains was assessed by the repeatability (R index and was 0.93 ± 0.05 for the outbred, 0.84 ± 0.16 for Buffalo, and 0.80 ± 0.12 for Fischer rats for fH during diving. Our results suggest that a portion of the mammalian diving bradycardia may be a heritable trait.

  18. Turkish recreational divers: a comparative study of their demographics, diving habits, health and attitudes towards safety.

    Science.gov (United States)

    Mirasoglu, Bengusu; Aktas, Samil

    2017-09-01

    In Turkey, scuba diving has become more popular and accessible in the past decade and there has been a commensurate rise in the number of certified divers. This new generation of recreational divers has not been described in detail previously. The aim of this study was to profile this group, while investigating any gender differences and making comparisons with the global diving community. Turkish dive club members and diving forum⁄blog readers were invited to complete an online questionnaire investigating their demography, medical issues and diving history and habits. The questionnaire was completed by 303 female and 363 male divers. Significant differences were found between the sexes in terms of demographics, diving experience and attitudes toward safety. Previous or ongoing medical conditions were reported by 100 female divers and 141 males. Only 29% of females and 22% of males had been examined by a physician trained to conduct assessments of fitness to dive. Female divers did not report problems while diving during menstruation or while taking oral contraceptives. There was no significant difference in the occurrence of decompression sickness (DCS) and DCS-like symptoms between the sexes. This is the largest study to date conducted on recreational divers in Turkey and so carries some value. It profiles their physical and behavioral attributes as well as differences in diving practices between the sexes in Turkey. Our findings should have implications for medical screening and dive training standards.

  19. Argon used as dry suit insulation gas for cold-water diving.

    Science.gov (United States)

    Vrijdag, Xavier Ce; van Ooij, Pieter-Jan Am; van Hulst, Robert A

    2013-06-03

    Cold-water diving requires good thermal insulation because hypothermia is a serious risk. Water conducts heat more efficiently compared to air. To stay warm during a dive, the choice of thermal protection should be based on physical activity, the temperature of the water, and the duration of exposure. A dry suit, a diving suit filled with gas, is the most common diving suit in cold water. Air is the traditional dry suit inflation gas, whereas the thermal conductivity of argon is approximately 32% lower compared to that of air. This study evaluates the benefits of argon, compared to air, as a thermal insulation gas for a dry suit during a 1-h cold-water dive by divers of the Royal Netherlands Navy. Seven male Special Forces divers made (in total) 19 dives in a diving basin with water at 13 degrees C at a depth of 3 m for 1 h in upright position. A rubber dry suit and woollen undergarment were used with either argon (n = 13) or air (n = 6) (blinded to the divers) as suit inflation gas. Core temperature was measured with a radio pill during the dive. Before, halfway, and after the dive, subjective thermal comfort was recorded using a thermal comfort score. No diver had to abort the test due to cold. No differences in core temperature and thermal comfort score were found between the two groups. Core temperature remained unchanged during the dives. Thermal comfort score showed a significant decrease in both groups after a 60-min dive compared to baseline. In these tests the combination of the dry suit and undergarment was sufficient to maintain core temperature and thermal comfort for a dive of 1h in water at 13 degrees C. The use of argon as a suit inflation gas had no added value for thermal insulation compared to air for these dives.

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

    Science.gov (United States)

    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.

  1. Argon used as dry suit insulation gas for cold-water diving

    Science.gov (United States)

    2013-01-01

    Background Cold-water diving requires good thermal insulation because hypothermia is a serious risk. Water conducts heat more efficiently compared to air. To stay warm during a dive, the choice of thermal protection should be based on physical activity, the temperature of the water, and the duration of exposure. A dry suit, a diving suit filled with gas, is the most common diving suit in cold water. Air is the traditional dry suit inflation gas, whereas the thermal conductivity of argon is approximately 32% lower compared to that of air. This study evaluates the benefits of argon, compared to air, as a thermal insulation gas for a dry suit during a 1-h cold-water dive by divers of the Royal Netherlands Navy. Methods Seven male Special Forces divers made (in total) 19 dives in a diving basin with water at 13°C at a depth of 3 m for 1 h in upright position. A rubber dry suit and woollen undergarment were used with either argon (n = 13) or air (n = 6) (blinded to the divers) as suit inflation gas. Core temperature was measured with a radio pill during the dive. Before, halfway, and after the dive, subjective thermal comfort was recorded using a thermal comfort score. Results No diver had to abort the test due to cold. No differences in core temperature and thermal comfort score were found between the two groups. Core temperature remained unchanged during the dives. Thermal comfort score showed a significant decrease in both groups after a 60-min dive compared to baseline. Conclusions In these tests the combination of the dry suit and undergarment was sufficient to maintain core temperature and thermal comfort for a dive of 1 h in water at 13°C. The use of argon as a suit inflation gas had no added value for thermal insulation compared to air for these dives. PMID:24438580

  2. Competitive apnea diving sessions induces an adaptative antioxidant response in mononucleated blood cells.

    Science.gov (United States)

    Sureda, A; Batle, J M; Tur, J A; Pons, A

    2015-09-01

    The aim was evaluating the effects of hypoxia/reoxygenation repetitive episodes during 5 days of apnea diving (3-day training/2-day competition) on peripheral blood mononuclear cells (PBMCs) antioxidant defenses, oxidative damage, and plasma xanthine oxidase activity. Blood samples, from seven professional apnea divers, were taken under basal conditions the previous morning to the first training session (pre-diving basal), 4 h after ending the competition (4 h post-diving) and the following morning (15 h after last dive) in basal conditions (post-diving basal). Glucose levels significantly decreased whereas triglycerides increased at 4 h post-diving, both returning to basal values at post-diving basal. Glutathione reductase and catalase activity significantly increased after 4 h post-diving remaining elevated at post-diving basal. Glutathione peroxidase and superoxide dismutase activities and catalase protein levels progressively increased after diving with significant differences respect to initial values at post-diving basal. No significant differences were observed in circulating PBMCs and oxidative damage markers. Plasma xanthine oxidase activity and nitrite levels, but not the inducible nitric oxide synthetase, significantly increased 4 h post-diving, returning to the basal values after 15 h. In conclusion, chronic and repetitive episodes of diving apnea during five consecutive days increased plasma xanthine oxidase activity and nitric oxide production which could enhance the signalling role of reactive oxygen and nitrogen species for PBMCs antioxidant adaptation against hypoxia/reoxygenation.

  3. High intensity cycling before SCUBA diving reduces post-decompression microparticle production and neutrophil activation.

    Science.gov (United States)

    Madden, Dennis; Thom, Stephen R; Yang, Ming; Bhopale, Veena M; Ljubkovic, Marko; Dujic, Zeljko

    2014-09-01

    Venous gas emboli (VGE) have traditionally served as a marker for decompression stress after SCUBA diving and a reduction in bubble loads is a target for precondition procedures. However, VGE can be observed in large quantities with no negative clinical consequences. The effect of exercise before diving on VGE has been evaluated with mixed results. Microparticle (MP) counts and sub-type expression serve as indicators of vascular inflammation and DCS in mice. The goal of the present study is to evaluate the effect of anaerobic cycling (AC) on VGE and MP following SCUBA diving. Ten male divers performed two dives to 18 m for 41 min, one dive (AC) was preceded by a repeated-Wingate cycling protocol; a control dive (CON) was completed without exercise. VGE were analyzed at 15, 40, 80, and 120 min post-diving. Blood for MP analysis was collected before exercise (AC only), before diving, 15 and 120 min after surfacing. VGE were significantly lower 15 min post-diving in the AC group, with no difference in the remaining measurements. MPs were elevated by exercise and diving, however, post-diving elevations were attenuated in the AC dive. Some markers of neutrophil elevation (CD18, CD41) were increased in the CON compared to the AC dive. The repeated-Wingate protocol resulted in an attenuation of MP counts and sub-types that have been related to vascular injury and DCS-like symptoms in mice. Further studies are needed to determine if MPs represent a risk factor or marker for DCS in humans.

  4. Investigating annual diving behaviour by hooded seals (Cystophora cristata) within the Northwest Atlantic Ocean.

    Science.gov (United States)

    Andersen, Julie M; Skern-Mauritzen, Mette; Boehme, Lars; Wiersma, Yolanda F; Rosing-Asvid, Aqqalu; Hammill, Mike O; Stenson, Garry B

    2013-01-01

    With the exception of relatively brief periods when they reproduce and moult, hooded seals, Cystophora cristata, spend most of the year in the open ocean where they undergo feeding migrations to either recover or prepare for the next fasting period. Valuable insights into habitat use and diving behaviour during these periods have been obtained by attaching Satellite Relay Data Loggers (SRDLs) to 51 Northwest (NW) Atlantic hooded seals (33 females and 18 males) during ice-bound fasting periods (2004-2008). Using General Additive Models (GAMs) we describe habitat use in terms of First Passage Time (FPT) and analyse how bathymetry, seasonality and FPT influence the hooded seals' diving behaviour described by maximum dive depth, dive duration and surface duration. Adult NW Atlantic hooded seals exhibit a change in diving activity in areas where they spend >20 h by increasing maximum dive depth, dive duration and surface duration, indicating a restricted search behaviour. We found that male and female hooded seals are spatially segregated and that diving behaviour varies between sexes in relation to habitat properties and seasonality. Migration periods are described by increased dive duration for both sexes with a peak in May, October and January. Males demonstrated an increase in dive depth and dive duration towards May (post-breeding/pre-moult) and August-October (post-moult/pre-breeding) but did not show any pronounced increase in surface duration. Females dived deepest and had the highest surface duration between December and January (post-moult/pre-breeding). Our results suggest that the smaller females may have a greater need to recover from dives than that of the larger males. Horizontal segregation could have evolved as a result of a resource partitioning strategy to avoid sexual competition or that the energy requirements of males and females are different due to different energy expenditure during fasting periods.

  5. Individual dietary specialization and dive behaviour in the California sea otter: Using archival time-depth data to detect alternative foraging strategies

    Science.gov (United States)

    Tinker, M.T.; Costa, D.P.; Estes, J.A.; Wieringa, N.

    2007-01-01

    The existence of individual prey specializations has been reported for an ever-growing number of taxa, and has important ramifications for our understanding of predator-prey dynamics. We use the California sea otter population as a case study to validate the use of archival time-depth data to detect and measure differences in foraging behaviour and diet. We collected observational foraging data from radio-tagged sea otters that had been equipped with Mk9 time depth recorders (TDRs, Wildlife Computers, Redmond, WA). After recapturing the study animals and retrieving the TDRs it was possible to compare the two data types, by matching individual dives from the TDR record with observational data and thus examining behavioural correlates of capture success and prey species. Individuals varied with respect to prey selection, aggregating into one of three distinct dietary specializations. A number of TDR-derived parameters, particularly dive depth and post-dive surface interval, differed predictably between specialist types. A combination of six dive parameters was particularly useful for discriminating between specialist types, and when incorporated into a multivariate cluster analysis, these six parameters resulted in classification of 13 adult female sea otters into three clusters that corresponded almost perfectly to the diet-based classification (1 out of 13 animals was misclassified). Thus based solely on quantifiable traits of time-depth data that have been collected over an appropriate period (in this case 1 year per animal), it was possible to assign female sea otters to diet type with >90% accuracy. TDR data can thus be used as a tool to measure the degree of individual specialization in sea otter populations, a conclusion that will likely apply to other diving marine vertebrates as well. Our ultimate goals must be both to understand the causes of individual specialization, and to incorporate such variation into models of population- and community-level food web

  6. Development of a Simulation Model for Swimming with Diving Fins

    Directory of Open Access Journals (Sweden)

    Motomu Nakashima

    2018-02-01

    Full Text Available The simulation model to assess the performance of diving fin was developed by extending the swimming human simulation model SWUM. A diving fin was modeled as a series of five rigid plates and connected to the human model by springs and dampers. These plates were connected to each other by virtual springs and dampers, and fin’s bending property was represented by springs and dampers as well. An actual diver’s swimming motion with fins was acquired by a motion capture experiment. In order to determine the bending property of the fin, two bending tests on land were conducted. In addition, an experiment was conducted in order to determine the fluid force coefficients in the fluid force model for the fin. Finally, using all measured and identified information, a simulation, in which the experimental situation was reproduced, was carried out. It was confirmed that the diver in the simulation propelled forward in the water successfully.

  7. Oxygen Toxicity and Special Operations Forces Diving: Hidden and Dangerous

    Directory of Open Access Journals (Sweden)

    Thijs T. Wingelaar

    2017-07-01

    Full Text Available In Special Operations Forces (SOF closed-circuit rebreathers with 100% oxygen are commonly utilized for covert diving operations. Exposure to high partial pressures of oxygen (PO2 could cause damage to the central nervous system (CNS and pulmonary system. Longer exposure time and higher PO2 leads to faster development of more serious pathology. Exposure to a PO2 above 1.4 ATA can cause CNS toxicity, leading to a wide range of neurologic complaints including convulsions. Pulmonary oxygen toxicity develops over time when exposed to a PO2 above 0.5 ATA and can lead to inflammation and fibrosis of lung tissue. Oxygen can also be toxic for the ocular system and may have systemic effects on the inflammatory system. Moreover, some of the effects of oxygen toxicity are irreversible. This paper describes the pathophysiology, epidemiology, signs and symptoms, risk factors and prediction models of oxygen toxicity, and their limitations on SOF diving.

  8. Biosonar, dive and foraging activity of satellite tracked harbour porpoises (Phocoena phocoena)

    DEFF Research Database (Denmark)

    Linnenschmidt, Meike; Teilmann, Jonas; Akamatsu, Tomonari

    2013-01-01

    , and a satellite transmitter. The units were programmed to release after 24 or 72 h. Possible foraging occurred mostly near the surface or at the bottom of a dive. The porpoises showed individual diversity in biosonar activity (50,000 clicks per hour) and in dive frequency (6–179 dives per hour). We...... confirm that wild harbor porpoises use more intense clicks than captive animals. A positive tendency between number of dives and clicks per hour was found for a subadult male, which stayed near shore. It showed a distinct day-night cycle with low echolocation rates during the day, but five times higher...... rates and higher dive activity at night. A female traveling in open waters showed no diel rhythm, but its sonar activity was three times higher compared to the males’. Considerable individual differences in dive and echolocation activity could have been influenced by biological and physical factors...

  9. A Review of SCUBA Diving Impacts and Implication for Coral Reefs Conservation and Tourism Management

    Directory of Open Access Journals (Sweden)

    Zainal Abidin Siti Zulaiha

    2014-01-01

    Full Text Available Dive tourism has become important in term of magnitude and significantly contributes to regional economies. Nevertheless, in the absence of proper controls and enforcement, unplanned tourism growth has caused environmental degradation which undermines the long-term sustainability of the tourism industry. The purpose of this paper is to explore factors that contribute to the SCUBA diving impacts on coral and fish communities. This paper explains the causes of a certain event, validating the problem of impacts, defining the core issues and identifies possible causes leading to an effect. The phenomenon of diving impacts on coral reefs is a result of intensive use of dive site over the long-term. The divers can reduce their impacts towards coral reefs through responsible diving behaviors. The causes of cumulative diver’s contacts are more complicated than it seems. In response, this paper proposes the best mitigation strategies that need to be considered for future dive tourism management.

  10. Energetic cost of foraging in free-diving emperor penguins.

    Science.gov (United States)

    Nagy, K A; Kooyman, G L; Ponganis, P J

    2001-01-01

    Hypothesizing that emperor penguins (Aptenodytes forsteri) would have higher daily energy expenditures when foraging for their food than when being hand-fed and that the increased expenditure could represent their foraging cost, we measured field metabolic rates (FMR; using doubly labeled water) over 4-d periods when 10 penguins either foraged under sea ice or were not allowed to dive but were fed fish by hand. Surprisingly, penguins did not have higher rates of energy expenditure when they dove and captured their own food than when they did not forage but were given food. Analysis of time-activity and energy budgets indicated that FMR was about 1.7 x BMR (basal metabolic rate) during the 12 h d(-1) that penguins were lying on sea ice. During the remaining 12 h d(-1), which we termed their "foraging period" of the day, the birds were alert and active (standing, preening, walking, and either free diving or being hand-fed), and their FMR was about 4.1 x BMR. This is the lowest cost of foraging estimated to date among the eight penguin species studied. The calculated aerobic diving limit (ADL(C)), determined with the foraging period metabolic rate of 4.1 x BMR and known O(2) stores, was only 2.6 min, which is far less than the 6-min ADL previously measured with postdive lactate analyses in emperors diving under similar conditions. This indicates that calculating ADL(C) from an at-sea or foraging-period metabolic rate in penguins is not appropriate. The relatively low foraging cost for emperor penguins contributes to their relatively low total daily FMR (2.9 x BMR). The allometric relationship for FMR in eight penguin species, including the smallest and largest living representatives, is kJ d(-1)=1,185 kg(0.705).

  11. Behavioral Ecology of Deep Diving Odontocetes in The Bahamas

    Science.gov (United States)

    2015-10-19

    female and sub-adult male sperm whales in the Gulf of Mexico , Western Atlantic Ocean, and Mediterranean Sea (i.e., similar to the demographic mixture...entire unit. Variation across species in their vertical foraging habitat suggests diet differences while the diving capacity of beaked whales enabled...SUBJECT TERMS Behavioral ecology, odontocete, social structure, residency patterns, reproductive biology, diet , foraging ecology, habitat use, population

  12. Ultrasound lung "comets" increase after breath-hold diving.

    Science.gov (United States)

    Lambrechts, Kate; Germonpré, Peter; Charbel, Brian; Cialoni, Danilo; Musimu, Patrick; Sponsiello, Nicola; Marroni, Alessandro; Pastouret, Frédéric; Balestra, Costantino

    2011-04-01

    The purpose of the study was to analyze the ultrasound lung comets (ULCs) variation, which are a sign of extra-vascular lung water. Forty-two healthy individuals performed breath-hold diving in different conditions: dynamic surface apnea; deep variable-weight apnea and shallow, face immersed without effort (static maximal and non-maximal). The number of ULCs was evaluated by means of an ultrasound scan of the chest, before and after breath-hold diving sessions. The ULC score increased significantly from baseline after dynamic surface apnea (p = 0.0068), after deep breath-hold sessions (p = 0.0018), and after static maximal apnea (p = 0.031). There was no statistically significant difference between the average increase of ULC scores after dynamic surface apnea and deep breath-hold diving. We, therefore, postulate that extravascular lung water accumulation may be due to other factors than (deep) immersion alone, because it occurs during dynamic surface apnea as well. Three mechanisms may be responsible for this. First, the immersion-induced hydrostatic pressure gradient applied on the body causes a shift of peripheral venous blood towards the thorax. Second, the blood pooling effect found during the diving response Redistributes blood to the pulmonary vascular bed. Third, it is possible that the intense involuntary diaphragmatic contractions occurring during the "struggle phase" of the breath-hold can also produce a blood shift from the pulmonary capillaries to the pulmonary alveoli. A combination of these factors may explain the observed increase in ULC scores in deep, shallow maximal and shallow dynamic apneas, whereas shallow non-maximal apneas seem to be not "ULC provoking".

  13. Parasympathetic preganglionic cardiac motoneurons labeled after voluntary diving

    Directory of Open Access Journals (Sweden)

    W Michael ePanneton

    2014-01-01

    Full Text Available A dramatic bradycardia is induced by underwater submersion in vertebrates. The location of parasympathetic preganglionic cardiac motor neurons driving this aspect of the diving response was investigated using cFos immunohistochemistry combined with retrograde transport of cholera toxin subunit B (CTB to double-label neurons. After pericardial injections of CTB, trained rats voluntarily dove underwater, and their heart rates dropped immediately to 95±2bpm, an 80% reduction. After immunohistochemical processing, the vast majority of CTB labeled neurons were located in the reticular formation from the rostral cervical spinal cord to the facial motor nucleus, confirming previous studies. Labeled neurons caudal to the rostral ventrolateral medulla were usually spindle-shaped aligned along an oblique line running from the dorsal vagal nucleus to the ventrolateral reticular formation, while those more rostrally were multipolar with extended dendrites. Nine percent of retrogradely-labeled neurons were positive for both cFos and CTB after diving and 74% of these were found rostral to the obex. CTB also was transported transganglionically in primary afferent fibers, resulting in large granular deposits in dorsolateral, ventrolateral, and commissural subnuclei of the nucleus tractus solitarii and finer deposits in lamina I and IV-V of the trigeminocervical complex. The overlap of parasympathetic preganglionic cardiac motor neurons activated by diving with those activated by baro- and chemoreceptors in the rostral ventrolateral medulla is discussed. Thus the profound bradycardia seen with underwater submersion reinforces the notion that the mammalian diving response is the most powerful autonomic reflex known.

  14. Beaked Whale Group Deep Dive Behavior from Passive Acoustic Monitoring

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Beaked Whale Group Deep Dive Behavior from Passive...described explicitly, beaked whales are one of the cetacean taxa more sensitive to use of Navy sonar (Moretti et al., 2014; Tyack et al., 2011). Despite...their vulnerability, Blainville’s beaked whale , Mesoplodon densirostris (Md), are routinely detected year-round on the AUTEC range, coincident with

  15. Decompression tables and dive-outcome data: graphical analysis.

    Science.gov (United States)

    Van Liew, H D; Flynn, E T

    2005-01-01

    We compare outcomes of experimental air dives with prescriptions for ascent given by various air decompression tables. Among experimental dives compiled in the U.S. Navy Decompression Database, many profiles that resulted in decompression sickness (DCS) have longer total decompression times (TDTs, defined as times spent at decompression stops plus time to travel from depth to the surface) than profiles prescribed by the U.S. Navy table; thus, the divers developed DCS despite spending more time at stops than the table requires. The same is true to a lesser extent for the table used by the Canadian forces. A few DCS cases occurred in profiles having longer TDTs than those of the VVal-18 table and a table prepared at the University of Pennsylvania. The TDTs for 2.2% risk according to the probabilistic NMRI'98 Model are often far longer than TDTs of experimental dives that resulted in DCS. This analysis dramatizes the large differences among alternative decompression instructions and illustrates how the U.S. Navy table provides too little time at stops when bottom times are long.

  16. Intrapulmonary shunt and SCUBA diving: another risk factor?

    Science.gov (United States)

    Madden, Dennis; Ljubkovic, Marko; Dujic, Zeljko

    2015-02-01

    Laboratory and field investigations have demonstrated that intrapulmonary arteriovenous anastomoses (IPAVA) may provide an additional means for venous gas emboli (VGE) to cross over to the arterial circulation due to their larger diameter compared to pulmonary microcirculation. Once thought to be the primary cause of decompression sickness (DCS), it has been demonstrated that, even in large quantities, their presence does not always result in injury. Normally, VGE are trapped in the site of gas exchange in the lungs and eliminated via diffusion. When VGE crossover takes place in arterial circulation, they have the potential to cause more harm as they are redistributed to the brain, spinal column, and other sensitive tissues. The patent foramen ovale (PFO) was once thought to be the only risk factor for an increase in arterialization; however, IPAVAs represent another pathway for this crossover to occur. The opening of IPAVAs is associated with exercise and hypoxic gas mixtures, both of which divers may encounter. The goal of this review is to describe how IPAVAs may impact diving physiology, specifically during decompression, and what this means for the individual diver as well as the future of commercial and recreational diving. Future research must continue on the relationship between IPAVAs and the environmental and physiological circumstances that lead to their opening and closing, as well as how they may contribute to diving injuries such as DCS. © 2015, Wiley Periodicals, Inc.

  17. A comparison of auditory brainstem responses across diving bird species

    Science.gov (United States)

    Crowell, Sara E.; Berlin, Alicia; Carr, Catherine E.; Olsen, Glenn H.; Therrien, Ronald E.; Yannuzzi, Sally E.; Ketten, Darlene R.

    2015-01-01

    There is little biological data available for diving birds because many live in hard-to-study, remote habitats. Only one species of diving bird, the black-footed penguin (Spheniscus demersus), has been studied in respect to auditory capabilities (Wever et al., Proc Natl Acad Sci USA 63:676–680, 1969). We, therefore, measured in-air auditory threshold in ten species of diving birds, using the auditory brainstem response (ABR). The average audiogram obtained for each species followed the U-shape typical of birds and many other animals. All species tested shared a common region of the greatest sensitivity, from 1000 to 3000 Hz, although audiograms differed significantly across species. Thresholds of all duck species tested were more similar to each other than to the two non-duck species tested. The red-throated loon (Gavia stellata) and northern gannet (Morus bassanus) exhibited the highest thresholds while the lowest thresholds belonged to the duck species, specifically the lesser scaup (Aythya affinis) and ruddy duck (Oxyura jamaicensis). Vocalization parameters were also measured for each species, and showed that with the exception of the common eider (Somateria mollisima), the peak frequency, i.e., frequency at the greatest intensity, of all species' vocalizations measured here fell between 1000 and 3000 Hz, matching the bandwidth of the most sensitive hearing range.

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

    Science.gov (United States)

    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.

  19. Reactive Oxygen Species, Mitochondria, and Endothelial Cell Death during In Vitro Simulated Dives.

    Science.gov (United States)

    Wang, Qiong; Guerrero, François; Mazur, Aleksandra; Lambrechts, Kate; Buzzacott, Peter; Belhomme, Marac; Theron, Michaël

    2015-07-01

    Excessive reactive oxygen species (ROS) is considered a consequence of hyperoxia and a major contributor to diving-derived vascular endothelial damage and decompression sickness. The aims of this work were: 1) to directly observe endothelial ROS production during simulated air dives as well as its relation with both mitochondrial activity and cell survival; and 2) to determine which ambient factor during air diving (hydrostatic pressure or oxygen and/or nitrogen partial pressure) is responsible for the observed modifications. In vitro diving simulation was performed with bovine arterial endothelial cells under real-time observation. The effects of air diving, hydrostatic, oxygen and nitrogen pressures, and N-acetylcysteine (NAC) treatment on mitochondrial ROS generation, mitochondrial membrane potential and cellular survival during simulation were investigated. Vascular endothelial cells performing air diving simulation suffered excessive mitochondrial ROS, mitochondrial depolarization, and cell death. These effects were prevented by NAC: after NAC treatment, the cells presented no difference in damage from nondiving cells. Oxygen diving showed a higher effect on ROS generation but lower impacts on mitochondrial depolarization and cell death than hydrostatic or nitrogen diving. Nitrogen diving had no effect on the inductions of ROS, mito-depolarization, or cell death. This study is the first direct observation of mitochondrial ROS production, mitochondrial membrane potential and cell survival during diving. Simulated air SCUBA diving induces excessive ROS production, which leads to mitochondrial depolarization and endothelial cell death. Oxygen partial pressure plays a crucial role in the production of ROS. Deleterious effects of hyperoxia-induced ROS are potentiated by hydrostatic pressure. These findings hold new implications for the pathogenesis of diving-derived endothelial dysfunction.

  20. The diving physiology of bottlenose dolphins (Tursiops truncatus). II. Biomechanics and changes in buoyancy at depth.

    Science.gov (United States)

    Skrovan, R C; Williams, T M; Berry, P S; Moore, P W; Davis, R W

    1999-10-01

    During diving, marine mammals must balance the conservation of limited oxygen reserves with the metabolic costs of swimming exercise. As a result, energetically efficient modes of locomotion provide an advantage during periods of submergence and will presumably increase in importance as the animals perform progressively longer dives. To determine the effect of a limited oxygen supply on locomotor performance, we compared the kinematics and behavior of swimming and diving bottlenose dolphins. Adult bottlenose dolphins (Tursiops truncatus) were trained to swim horizontally near the water surface or submerged at 5 m and to dive to depths ranging from 12 to 112 m. Swimming kinematics (preferred swimming mode, stroke frequency and duration of glides) were monitored using submersible video cameras (Sony Hi-8) held by SCUBA divers or attached to a pack on the dorsal fin of the animal. Drag and buoyant forces were calculated from patterns of deceleration for horizontally swimming and vertically diving animals. The results showed that dolphins used a variety of swimming gaits that correlated with acceleration. The percentage of time spent gliding during the descent phase of dives increased with depth. Glide distances ranged from 7.1+/-1.9 m for 16 m dives to 43.6+/-7.0 m (means +/- s.e.m.) for 100 m dives. These gliding patterns were attributed to changes in buoyancy associated with lung compression at depth. By incorporating prolonged glide periods, the bottlenose dolphin realized a theoretical 10-21 % energetic savings in the cost of a 100 m dive in comparison with dives based on neutral buoyancy models. Thus, modifying locomotor patterns to account for physical changes with depth appears to be one mechanism that enables diving mammals with limited oxygen stores to extend the duration of a dive.

  1. Risk of Neurological Insult in Competitive Deep Breath-Hold Diving.

    Science.gov (United States)

    Tetzlaff, Kay; Schöppenthau, Holger; Schipke, Jochen D

    2017-02-01

    It has been widely believed that tissue nitrogen uptake from the lungs during breath-hold diving would be insufficient to cause decompression stress in humans. With competitive free diving, however, diving depths have been ever increasing over the past decades. A case is presented of a competitive free-diving athlete who suffered stroke-like symptoms after surfacing from his last dive of a series of 3 deep breath-hold dives. A literature and Web search was performed to screen for similar cases of subjects with serious neurological symptoms after deep breath-hold dives. A previously healthy 31-y-old athlete experienced right-sided motor weakness and difficulty speaking immediately after surfacing from a breathhold dive to a depth of 100 m. He had performed 2 preceding breath-hold dives to that depth with surface intervals of only 15 min. The presentation of symptoms and neuroimaging findings supported a clinical diagnosis of stroke. Three more cases of neurological insults were retrieved by literature and Web search; in all cases the athletes presented with stroke-like symptoms after single breath-hold dives of depths exceeding 100 m. Two of these cases only had a short delay to recompression treatment and completely recovered from the insult. This report highlights the possibility of neurological insult, eg, stroke, due to cerebral arterial gas embolism as a consequence of decompression stress after deep breath-hold dives. Thus, stroke as a clinical presentation of cerebral arterial gas embolism should be considered another risk of extreme breath-hold diving.

  2. Ontogeny of diving behaviour in the Australian sea lion: trials of adolescence in a late bloomer.

    Science.gov (United States)

    Fowler, Shannon L; Costa, Daniel P; Arnould, John P Y; Gales, Nicholas J; Kuhn, Carey E

    2006-03-01

    1. Foraging behaviours of the Australian sea lion (Neophoca cinerea) reflect an animal working hard to exploit benthic habitats. Lactating females demonstrate almost continuous diving, maximize bottom time, exhibit elevated field metabolism and frequently exceed their calculated aerobic dive limit. Given that larger animals have disproportionately greater diving capabilities, we wanted to examine how pups and juveniles forage successfully. 2. Time/depth recorders were deployed on pups, juveniles and adult females at Seal Bay Conservation Park, Kangaroo Island, South Australia. Ten different mother/pup pairs were equipped at three stages of development (6, 15 and 23 months) to record the diving behaviours of 51 (nine instruments failed) animals. 3. Dive depth and duration increased with age. However, development was slow. At 6 months, pups demonstrated minimal diving activity and the mean depth for 23-month-old juveniles was only 44 +/- 4 m, or 62% of adult mean depth. 4. Although pups and juveniles did not reach adult depths or durations, dive records for young sea lions indicate benthic diving with mean bottom times (2.0 +/- 0.2 min) similar to those of females (2.1 +/- 0.2 min). This was accomplished by spending higher proportions of each dive and total time at sea on or near the bottom than adults. Immature sea lions also spent a higher percentage of time at sea diving. 5. Juveniles may have to work harder because they are weaned before reaching full diving capability. For benthic foragers, reduced diving ability limits available foraging habitat. Furthermore, as juveniles appear to operate close to their physiological maximum, they would have a difficult time increasing foraging effort in response to reductions in prey. Although benthic prey are less influenced by seasonal fluctuations and oceanographic perturbations than epipelagic prey, demersal fishery trawls may impact juvenile survival by disrupting habitat and removing larger size classes of prey. These

  3. Argon used as dry suit insulation gas for cold-water diving

    OpenAIRE

    Vrijdag, Xavier CE; van Ooij, Pieter-Jan AM; van Hulst, Robert A

    2013-01-01

    Background Cold-water diving requires good thermal insulation because hypothermia is a serious risk. Water conducts heat more efficiently compared to air. To stay warm during a dive, the choice of thermal protection should be based on physical activity, the temperature of the water, and the duration of exposure. A dry suit, a diving suit filled with gas, is the most common diving suit in cold water. Air is the traditional dry suit inflation gas, whereas the thermal conductivity of argon is ap...

  4. [A CASE OF NATTOU (FERMENTED-SOYBEAN)-INDUCED LATE-ONSET ANAPHYLAXIS FOLLOWING SCUBA DIVING].

    Science.gov (United States)

    Nagakura, Toshikazu; Tanaka, Katsuichirou; Horikawa, Satoshi

    2015-06-01

    We here report a 34-years old male who had nattou-(fermented-soybean) induced late-onset anaphylaxis following SCUBA diving to about 20 m in the ocean off a small remote Japanese island (Kuroshima, Okinawa). He had eaten nattou for breakfast at 7:30 am. He traveled by boat to the dive site, dove twice and then ate lunch at 12:30 on the diving boat (no nattou at lunch). After lunch at 14:30 he dove again (third dive of the day) during which time itchiness started. Back on the diving boat, urticarial was noticed. At 15:30, while washing his diving gear at the diving shop near the harbor, he fainted. A physician arrived on the scene at 15:45. Chest sound was clear and SpO2 was 98%, and blood pressure was 60/- mmHg. Intra-venous hydrocortisone was given, however, his recovery was not satisfactory. Then he was transferred to the Yaeyama Hospital by helicopter at 17:45. The examination of diving computer analysis reveals no sign of increased residual nitrogen, denying the possibility of decompression syndrome. Prick to prick test shows a strongly positive response to nattou. Nattou-induced late-onset anaphylaxis following SCUBA diving was suspected.

  5. The Effect of 20 Minutes Scuba Diving on Cognitive Function of Professional Scuba Divers.

    Science.gov (United States)

    Pourhashemi, Seyedeh Faezeh; Sahraei, Hedayat; Meftahi, Gholam Hossein; Hatef, Boshra; Gholipour, Bahareh

    2016-09-01

    Physical activity increases the performance of the nervous system by stimulating the body's metabolism and improving the efficiency of the ATP production system. In the present study, the effect of twenty minutes scuba diving in high depth (10m) on cognitive function and stress system activity was investigated. Twelve professional scuba divers with a mean age of 23 ± 1 year, weight of 80 ± 2.5 kg and height of 1.79 ± 3.5 cm resident in the city of Mashhad participated in the test. Their cognitive functions were measured 60 min before and 20 min after diving and the data were evaluated using the PASAT software. In the present study, parameters such as general mental health, sustained attention, average response speed, and mental fatigue were measured. Moreover, in order to determine the activity of the stress system, their salivary cortisol was collected before and after diving. Results revealed that, the general mental health of these scuba divers was normal and it did not undergo a remarkable change after diving. Their average response speed and sustained attention had a significant decrease after scuba diving. Mental fatigue after diving increased. Also, salivary cortisol level significantly increased after diving. According to our data, it seems that scuba diving as stress stimulant increases cortisol level and therefore reduces cognitive performance after diving.

  6. The effect of scuba diving on airflow obstruction in divers with asthma.

    Science.gov (United States)

    Lawrence, Christopher H D; Chen, Isobel Y D

    2016-03-01

    People with asthma are an under-represented group amongst scuba divers. Many may avoid or are advised against diving due to the potential risks, including bronchoconstriction, pulmonary barotrauma and arterial gas embolism. The aim of this study was to establish whether divers with asthma were more likely to experience reversible airways obstruction following typical scuba diving than divers without asthma. All divers with a history of asthma attending Operation Wallacea in Honduras were identified and peak expiratory flow rates (PEF) were measured pre and immediately post dive. All dives were boat dives in tropical sea water. Scuba dives were defined as those lasting between 40 and 55 minutes to a depth of between 10 and 18 metres. Of the 356 divers attending, 22 were identified as having asthma, of whom 19 were suitable for testing. They were classified by treatment regimen: five on no treatment, 11 on salbutamol only and three on regular preventative treatment. Twenty-four divers without a history of asthma acted as a control group. Open-water scuba diving caused a small decrease in PEF in all populations (median decrease 4.4%, P scuba diving. Differences to previous studies are likely due to environmental conditions, including dive depth.

  7. Epilepsy, scuba diving and risk assessment. Near misses and the need for ongoing vigilance.

    Science.gov (United States)

    Smart, David; Lippmann, John

    2013-03-01

    There is ongoing debate about the safety of scuba diving for individuals with a history of epilepsy. An in-water seizure is highly likely to be fatal. Recommendations for fitness to dive vary with some regarding epilepsy as an absolute contraindication to diving (South Pacific Underwater Medicine Society) and others permitting diving under strict criteria (United Kingdom Sport Diving Medical Committee) with diving to be postponed for a period of three to five years without seizures. Long-term follow up of people with epilepsy shows that at least one-third will have a recurrence and that the risk remains elevated for many years. We present three cases where individuals with a history of epilepsy (or likely epilepsy) almost fell through the cracks of health risk assessment, two with near-fatal consequences. These cases inform the on-going debate about fitness to dive for those with current or past epilepsy, and highlight the importance of education for doctors, dive professionals and divers about the risks associated with epilepsy and diving.

  8. Decompression syndrome and the evolution of deep diving physiology in the Cetacea

    Science.gov (United States)

    Beatty, Brian Lee; Rothschild, Bruce M.

    2008-09-01

    Whales repetitively dive deep to feed and should be susceptible to decompression syndrome, though they are not known to suffer the associated pathologies. Avascular osteonecrosis has been recognized as an indicator of diving habits of extinct marine amniotes. Vertebrae of 331 individual modern and 996 fossil whales were subjected to macroscopic and radiographic examination. Avascular osteonecrosis was found in the Oligocene basal odontocetes (Xenorophoidea) and in geologically younger mysticetes, such as Aglaocetus [a sister taxon to Balaenopteridae + (Balaenidae + Eschrichtiidae) clade]. These are considered as early “experiments” in repetitive deep diving, indicating that they independently converged on their similar specialized diving physiologies.

  9. Constraint lines and performance envelopes in behavioral physiology: the case of the aerobic dive limit.

    Directory of Open Access Journals (Sweden)

    Markus eHorning

    2012-09-01

    Full Text Available Constraint lines - the boundaries that delimit point clouds in bivariate scattergrams - have been applied in macro-ecology to quantify the effects of limiting factors on response variables, but have not been applied to the behavioral performance and physiological ecology of individual vertebrates. I propose that behavioral scattergrams of air-breathing, diving vertebrates contain informative edges that convey insights into physiological constraints that shape the performance envelopes of divers. In the classic example of repeated cycles of apnea and eupnea in diving, airbreathing vertebrates, the need to balance oxygen consumption and intake should differentially constrain recovery for dives within or exceeding the aerobic dive limit. However, the bulk of variance observed in recovery versus dive duration scattergrams originates from undetermined behavioral variables, and deviations from overall stasis may become increasingly apparent at progressively smaller scales of observation. As shown on dive records from 79 Galápagos fur seals, the selection of appropriate time scales of integration yields two distinct recovery boundaries for dive series within and beyond the estimated aerobic dive limit. An analysis of the corresponding constraint lines is independent of central tendencies in data and avoids violating parametric assumptions for large data sets where variables of interest account for only a small portion of observed variance. I hypothesize that the intercept between these constraint lines represents the effective aerobic dive limit, and present physiological and ecological considerations to support this hypothesis.

  10. Environmental System Science Data Infrastructure for a Virtual Ecosystem (ESS-DIVE) - A New U.S. DOE Data Archive

    Science.gov (United States)

    Agarwal, D.; Varadharajan, C.; Cholia, S.; Snavely, C.; Hendrix, V.; Gunter, D.; Riley, W. J.; Jones, M.; Budden, A. E.; Vieglais, D.

    2017-12-01

    The ESS-DIVE archive is a new U.S. Department of Energy (DOE) data archive designed to provide long-term stewardship and use of data from observational, experimental, and modeling activities in the earth and environmental sciences. The ESS-DIVE infrastructure is constructed with the long-term vision of enabling broad access to and usage of the DOE sponsored data stored in the archive. It is designed as a scalable framework that incentivizes data providers to contribute well-structured, high-quality data to the archive and that enables the user community to easily build data processing, synthesis, and analysis capabilities using those data. The key innovations in our design include: (1) application of user-experience research methods to understand the needs of users and data contributors; (2) support for early data archiving during project data QA/QC and before public release; (3) focus on implementation of data standards in collaboration with the community; (4) support for community built tools for data search, interpretation, analysis, and visualization tools; (5) data fusion database to support search of the data extracted from packages submitted and data available in partner data systems such as the Earth System Grid Federation (ESGF) and DataONE; and (6) support for archiving of data packages that are not to be released to the public. ESS-DIVE data contributors will be able to archive and version their data and metadata, obtain data DOIs, search for and access ESS data and metadata via web and programmatic portals, and provide data and metadata in standardized forms. The ESS-DIVE archive and catalog will be federated with other existing catalogs, allowing cross-catalog metadata search and data exchange with existing systems, including DataONE's Metacat search. ESS-DIVE is operated by a multidisciplinary team from Berkeley Lab, the National Center for Ecological Analysis and Synthesis (NCEAS), and DataONE. The primarily data copies are hosted at DOE's NERSC

  11. Creativity in the Research Process. Accompanying Aristotle on a scuba diving excursion in the Red Sea

    Directory of Open Access Journals (Sweden)

    Åke Nilsén

    2013-06-01

    Full Text Available The paper investigates creativity as an attitude on demand from the researcher in a special situation in the research process. The situation occurs when the collected data does not coinside with the antecipated result. Hans Joas understanding of creative action is abolished for the adaptation of the Aristotelian concept of practical wisdom (phronesis as the foundation for the attitude. The data has to be analysed with the unique and particular in focus in order for new connections and relations to be revealed. An attitude concentrated on revealing the particular in the data is necessary. From there a new attitude takes over that focuses the general on behalf of the particular. The research process is exposed in a parallell text on Scuba diving.

  12. Estimating trans-seasonal variability in water column biomass for a highly migratory, deep diving predator.

    Directory of Open Access Journals (Sweden)

    Malcolm D O'Toole

    Full Text Available The deployment of animal-borne electronic tags is revolutionizing our understanding of how pelagic species respond to their environment by providing in situ oceanographic information such as temperature, salinity, and light measurements. These tags, deployed on pelagic animals, provide data that can be used to study the ecological context of their foraging behaviour and surrounding environment. Satellite-derived measures of ocean colour reveal temporal and spatial variability of surface chlorophyll-a (a useful proxy for phytoplankton distribution. However, this information can be patchy in space and time resulting in poor correspondence with marine animal behaviour. Alternatively, light data collected by animal-borne tag sensors can be used to estimate chlorophyll-a distribution. Here, we use light level and depth data to generate a phytoplankton index that matches daily seal movements. Time-depth-light recorders (TDLRs were deployed on 89 southern elephant seals (Mirounga leonina over a period of 6 years (1999-2005. TDLR data were used to calculate integrated light attenuation of the top 250 m of the water column (LA(250, which provided an index of phytoplankton density at the daily scale that was concurrent with the movement and behaviour of seals throughout their entire foraging trip. These index values were consistent with typical seasonal chl-a patterns as measured from 8-daySea-viewing Wide Field-of-view Sensor (SeaWiFs images. The availability of data recorded by the TDLRs was far greater than concurrent remotely sensed chl-a at higher latitudes and during winter months. Improving the spatial and temporal availability of phytoplankton information concurrent with animal behaviour has ecological implications for understanding the movement of deep diving predators in relation to lower trophic levels in the Southern Ocean. Light attenuation profiles recorded by animal-borne electronic tags can be used more broadly and routinely to estimate

  13. Changes in dive behaviour during naval sonar exposure in killer whales, long-finned pilot whales and sperm whales

    Directory of Open Access Journals (Sweden)

    Lise Doksæter Sivle

    2012-10-01

    Full Text Available Anthropogenic underwater sound in the environment might potentially affect the behavior of marine mammals enough to have an impact on their reproduction and survival. Diving behavior of 5 killer whales (Orcinus orca, 7 long-finned pilot whales (Globicephala melas and 4 sperm whales (Physeter macrocephalus were studied during controlled exposures to naval sonar (LFAS: 1-2 kHz and MFAS: 6-7 kHz during three field seasons (2006-2009. Diving behavior was monitored before, during and after sonar exposure using an archival tag placed on the animal with suction cups. The tag recorded the animal’s vertical movement, and additional data on horizontal movement and vocalizations were used to determine behavioral modes. Killer whales that were conducting deep dives at sonar onset changed abruptly to shallow diving during LFAS, while killer whales conducting deep dives at the onset of MFAS did not alter dive mode. When in shallow diving mode at sonar onset, killer whales did not change their diving behavior. Pilot and sperm whales performed normal deep dives during MFAS exposure. During LFAS exposures, long-finned pilot whales mostly performed fewer deep dives and some sperm whales performed shallower and shorter dives. Acoustic recording data presented previously indicates that deep diving is associated with feeding. Therefore, the observed changes in dive behavior of the three species could potentially reduce the foraging efficiency of the affected animals.

  14. How man-made interference might cause gas bubble emboli in deep diving whales

    Directory of Open Access Journals (Sweden)

    Andreas eFahlman

    2014-01-01

    Full Text Available Recent cetacean mass strandings in close temporal and spatial association with sonar activity has raised the concern that anthropogenic sound may harm breath-hold diving marine mammals. Necropsy results of the stranded whales have shown evidence of bubbles in the tissues, similar to those in human divers suffering from decompression sickness (DCS. It has been proposed that changes in behavior or physiological responses during diving could increase tissue and blood N2 levels, thereby increasing DCS risk. Dive data recorded from sperm, killer, long-finned pilot, Blainville’s beaked and Cuvier’s beaked whales before and during exposure to low- (1-2 kHz and mid- (2-7 kHz frequency active sonar were used to estimate the changes in blood and tissue N2 tension (PN2. Our objectives were to determine if differences in 1 dive behavior or 2 physiological responses to sonar are plausible risk factors for bubble formation. The theoretical estimates indicate that all species may experience high N2 levels. However, unexpectedly, deep diving generally result in higher end-dive PN2 as compared with shallow diving. In this focused review we focus on three possible explanations: 1 We revisit an old hypothesis that CO2, because of its much higher diffusivity, form bubble precursors that continue to grow in N2 supersaturated tissues. Such a mechanism would be less dependent on the alveolar collapse depth but affected by elevated levels of CO2 following a burst of activity during sonar exposure. 2 During deep dives, a greater duration of time might be spent at depths where gas exchange continues as compared with shallow dives. The resulting elevated levels of N2 in deep diving whales might also make them more susceptible to anthropogenic disturbances. 3 Extended duration of dives even at depths beyond where the alveoli collapse could result in slow continuous accumulation of N2 in the adipose tissues that eventually becomes a liability.

  15. Does recreational scuba diving have clinically significant effect on routine haematological parameters?

    Science.gov (United States)

    Perovic, Antonija; Nikolac, Nora; Braticevic, Marina Njire; Milcic, Ana; Sobocanec, Sandra; Balog, Tihomir; Dabelic, Sanja; Dumic, Jerka

    2017-06-15

    Scuba diving represents a combination of exercise and changes in environmental conditions. This study aimed to evaluate changes in haematological parameters after recreational scuba diving in order to identify clinically significant changes. The study included males, 17 recreational divers, median age (range) 41 (30-52) years. Blood samples were taken before diving, immediately after diving to 30 meters for 30 minutes, 3 hours and 6 hours after diving. Complete blood counts were analyzed on the Cell Dyn Ruby haematology analyzer. Statistical significance between successive measurements was tested using Friedman test. The difference between the two measurements was judged against desirable bias (DSB) derived from biological variation and calculated reference change values (RCV). The difference higher than RCV was considered clinically significant. A statistically significant increase and difference judging against DSB was observed: for neutrophils immediately, 3 and 6 hours after diving (18%, 34% and 36%, respectively), for white blood cells (WBCs) 3 and 6 hours after diving (20% and 25%, respectively), for lymphocytes (20%) and monocytes (23%) 6 hours after diving. A statistically significant decrease and difference judging against DSB was found: immediately after diving for monocytes (- 15%), 3 and 6 hours after diving for red blood cells (RBCs) (- 2.6% and -2.9%, respectively), haemoglobin (- 2.1% and - 2.8%, respectively) and haematocrit (- 2.4% and - 3.2%, respectively). A clinically significant change was not found for any of the test parameters when compared to RCV. Observed statistically significant changes after recreational scuba diving; WBCs, neutrophils, lymphocytes, monocytes increase and RBCs, haemoglobin, haematocrit decrease, probably will not affect clinical decision.

  16. Epidemiology of morbidity and mortality in US and Canadian recreational scuba diving.

    Science.gov (United States)

    Buzzacott, P; Schiller, D; Crain, J; Denoble, P J

    2018-02-01

    This study investigates morbidity and mortality suffered by divers in the USA and Canada. Prospectively recruited probability-weighted sample for estimating the national burden of injury and a weighted retrospective survey for estimating exposure. The National Electronic Surveillance System and Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) were searched for scuba diving injuries. The Divers Alert Network diving fatality database was searched for deaths, and Sports and Fitness Industry Association estimates for diving were obtained from annual surveys. In the USA, there were an estimated 1394 emergency department (ED) presentations annually for scuba-related injuries. The majority (80%) were treated and/or released. There were an estimated 306 million dives made by the US residents 2006-2015 and concurrently 563 recreational diving deaths, a fatality rate of 0.18 per 10 5 dives and 1.8 per 10 5 diver-years. There were 658 diving deaths in the US 2006-2015 and 13,943 ED presentations for scuba injuries, giving a ratio of 47 diving deaths in the USA for every 1000 ED presentations. There were 98 cases of scuba-related injuries identified in the CHIRPP data. The prevalence of scuba-related injuries for patients aged 3-17 years was 1.5 per 10 5 cases, and the prevalence of scuba-related injuries to patients 18-62 years was 16.5 per 10 5 cases. In Canada and the USA, only one out of every 10,000 ED presentations is due to a scuba-related injury. That there are 47 deaths for every 1000 ED presentations for scuba injuries speaks to the relatively unforgiving environment in which scuba diving takes place. For 1.8 deaths per million recreational dives, mortality in scuba diving is nonetheless relatively low. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  17. Acute and potentially persistent effects of scuba diving on the blood transcriptome of experienced divers.

    Science.gov (United States)

    Eftedal, Ingrid; Ljubkovic, Marko; Flatberg, Arnar; Jørgensen, Arve; Brubakk, Alf O; Dujic, Zeljko

    2013-10-16

    During scuba diving, the circulatory system is stressed by an elevated partial pressure of oxygen while the diver is submerged and by decompression-induced gas bubbles on ascent to the surface. This diving-induced stress may trigger decompression illness, but the majority of dives are asymptomatic. In this study we have mapped divers' blood transcriptomes with the aim of identifying genes, biological pathways, and cell types perturbed by the physiological stress in asymptomatic scuba diving. Ten experienced divers abstained from diving for >2 wk before performing a 3-day series of daily dives to 18 m depth for 47 min while breathing compressed air. Blood for microarray analysis was collected before and immediately after the first and last dives, and 10 matched nondivers provided controls for predive stationary transcriptomes. MetaCore GeneGo analysis of the predive samples identified stationary upregulation of genes associated with apoptosis, inflammation, and innate immune responses in the divers, most significantly involving genes in the TNFR1 pathway of caspase-dependent apoptosis, HSP60/HSP70 signaling via TLR4, and NF-κB-mediated transcription. Diving caused pronounced shifts in transcription patterns characteristic of specific leukocytes, with downregulation of genes expressed by CD8+ T lymphocytes and NK cells and upregulation of genes expressed by neutrophils, monocytes, and macrophages. Antioxidant genes were upregulated. Similar transient responses were observed after the first and last dive. The results indicate that sublethal oxidative stress elicits the myeloid innate immune system in scuba diving and that extensive diving may cause persistent change in pathways controlling apoptosis, inflammation, and innate immune responses.

  18. The effects of experimentally induced hyperthyroidism on the diving physiology of harbor seals (Phoca vitulina

    Directory of Open Access Journals (Sweden)

    Gundula M Weingartner

    2012-09-01

    Full Text Available Many phocid seals are expert divers that remain submerged longer than expected based on estimates of oxygen storage and utilization. This discrepancy is most likely due to an overestimation of diving metabolic rate. During diving, a selective redistribution of blood flow occurs, which may result in reduced metabolism in the hypoperfused tissues and a possible decline in whole-body metabolism to below the resting level (hypometabolism. Thyroid hormones are crucial in regulation of energy metabolism in vertebrates and therefore their control might be an important part of achieving a hypometabolic state during diving. To investigate the effect of thyroid hormones on diving physiology of phocid seals, we measured oxygen consumption, heart rate, and post-dive lactate concentrations in five harbor seals (Phoca vitulina conducting 5 min dives on command, in both euthyroid and experimentally induced hyperthyroid states. Oxygen consumption during diving was significantly reduced (by 25 % in both euthyroid and hyperthyroid states, confirming that metabolic rate during diving falls below resting levels. Hyperthyroidism increased oxygen consumption (by 7-8 % when resting in water and during diving, compared with the euthyroid state, illustrating the marked effect of thyroid hormones on metabolic rate. Consequently, post-dive lactate concentrations were significantly increased in the hyperthyroid state, suggesting that the greater oxygen consumption rates forced seals to make increased use of anaerobic metabolic pathways. During diving, hyperthyroid seals also exhibited a more profound decline in heart rate than seals in the euthyroid state, indicating that these seals were pushed towards their aerobic limit and required a more pronounced cardiovascular response. Our results demonstrate the powerful role of thyroid hormones in metabolic regulation and support the hypothesis that thyroid hormones play a role in modulating the at-sea metabolism of phocid seals.

  19. The effects of experimentally induced hyperthyroidism on the diving physiology of harbor seals (Phoca vitulina)

    Science.gov (United States)

    Weingartner, Gundula M.; Thornton, Sheila J.; Andrews, Russel D.; Enstipp, Manfred R.; Barts, Agnieszka D.; Hochachka, Peter W.

    2012-01-01

    Many phocid seals are expert divers that remain submerged longer than expected based on estimates of oxygen storage and utilization. This discrepancy is most likely due to an overestimation of diving metabolic rate. During diving, a selective redistribution of blood flow occurs, which may result in reduced metabolism in the hypoperfused tissues and a possible decline in whole-body metabolism to below the resting level (hypometabolism). Thyroid hormones are crucial in regulation of energy metabolism in vertebrates and therefore their control might be an important part of achieving a hypometabolic state during diving. To investigate the effect of thyroid hormones on diving physiology of phocid seals, we measured oxygen consumption, heart rate, and post-dive lactate concentrations in five harbor seals (Phoca vitulina) conducting 5 min dives on command, in both euthyroid and experimentally induced hyperthyroid states. Oxygen consumption during diving was significantly reduced (by 25%) in both euthyroid and hyperthyroid states, confirming that metabolic rate during diving falls below resting levels. Hyperthyroidism increased oxygen consumption (by 7–8%) when resting in water and during diving, compared with the euthyroid state, illustrating the marked effect of thyroid hormones on metabolic rate. Consequently, post-dive lactate concentrations were significantly increased in the hyperthyroid state, suggesting that the greater oxygen consumption rates forced seals to make increased use of anaerobic metabolic pathways. During diving, hyperthyroid seals also exhibited a more profound decline in heart rate than seals in the euthyroid state, indicating that these seals were pushed toward their aerobic limit and required a more pronounced cardiovascular response. Our results demonstrate the powerful role of thyroid hormones in metabolic regulation and support the hypothesis that thyroid hormones play a role in modulating the at-sea metabolism of phocid seals. PMID:23060807

  20. How man-made interference might cause gas bubble emboli in deep diving whales.

    Science.gov (United States)

    Fahlman, Andreas; Tyack, Peter L; Miller, Patrick J O; Kvadsheim, Petter H

    2014-01-01

    Recent cetacean mass strandings in close temporal and spatial association with sonar activity has raised the concern that anthropogenic sound may harm breath-hold diving marine mammals. Necropsy results of the stranded whales have shown evidence of bubbles in the tissues, similar to those in human divers suffering from decompression sickness (DCS). It has been proposed that changes in behavior or physiological responses during diving could increase tissue and blood N2 levels, thereby increasing DCS risk. Dive data recorded from sperm, killer, long-finned pilot, Blainville's beaked and Cuvier's beaked whales before and during exposure to low- (1-2 kHz) and mid- (2-7 kHz) frequency active sonar were used to estimate the changes in blood and tissue N2 tension (PN2 ). Our objectives were to determine if differences in (1) dive behavior or (2) physiological responses to sonar are plausible risk factors for bubble formation. The theoretical estimates indicate that all species may experience high N2 levels. However, unexpectedly, deep diving generally result in higher end-dive PN2 as compared with shallow diving. In this focused review we focus on three possible explanations: (1) We revisit an old hypothesis that CO2, because of its much higher diffusivity, forms bubble precursors that continue to grow in N2 supersaturated tissues. Such a mechanism would be less dependent on the alveolar collapse depth but affected by elevated levels of CO2 following a burst of activity during sonar exposure. (2) During deep dives, a greater duration of time might be spent at depths where gas exchange continues as compared with shallow dives. The resulting elevated levels of N2 in deep diving whales might also make them more susceptible to anthropogenic disturbances. (3) Extended duration of dives even at depths beyond where the alveoli collapse could result in slow continuous accumulation of N2 in the adipose tissues that eventually becomes a liability.

  1. Diving behavior in a free-living, semi-aquatic herbivore, the Eurasian beaverCastor fiber.

    Science.gov (United States)

    Graf, Patricia Maria; Wilson, Rory Paul; Sanchez, Lea Cohen; Hacklӓnder, Klaus; Rosell, Frank

    2018-01-01

    Semi-aquatic mammals have secondarily returned to the aquatic environment, although they spend a major part of their life operating in air. Moving both on land, as well as in, and under water is challenging because such species are considered to be imperfectly adapted to both environments. We deployed accelerometers combined with a depth sensor to study the diving behavior of 12 free-living Eurasian beavers Castor fiber in southeast Norway between 2009 and 2011 to examine the extent to which beavers conformed with mass-dependent dive capacities, expecting them to be poorer than wholly aquatic species. Dives were generally shallow (<1 m) and of short duration (<30 s), suggesting that the majority of dives were aerobic. Dive parameters such as maximum diving depth, dive duration, and bottom phase duration were related to the effort during different dive phases and the maximum depth reached. During the descent, mean vectorial dynamic body acceleration (VeDBA-a proxy for movement power) was highest near the surface, probably due to increased upthrust linked to fur- and lung-associated air. Inconsistently though, mean VeDBA underwater was highest during the ascent when this air would be expected to help drive the animals back to the surface. Higher movement costs during ascents may arise from transporting materials up, the air bubbling out of the fur, and/or the animals' exhaling during the bottom phase of the dive. In a manner similar to other homeotherms, beavers extended both dive and bottom phase durations with diving depth. Deeper dives tended to have a longer bottom phase, although its duration was shortened with increased VeDBA during the bottom phase. Water temperature did not affect diving behavior. Overall, the beavers' dive profile (depth, duration) was similar to other semi-aquatic freshwater divers. However, beavers dived for only 2.8% of their active time, presumably because they do not rely on diving for food acquisition.

  2. Diving of great shearwaters (Puffinus gravis in cold and warm water regions of the South Atlantic Ocean.

    Directory of Open Access Journals (Sweden)

    Robert A Ronconi

    Full Text Available BACKGROUND: Among the most widespread seabirds in the world, shearwaters of the genus Puffinus are also some of the deepest diving members of the Procellariiformes. Maximum diving depths are known for several Puffinus species, but dive depths or diving behaviour have never been recorded for great shearwaters (P. gravis, the largest member of this genus. This study reports the first high sampling rate (2 s of depth and diving behaviour for Puffinus shearwaters. METHODOLOGY/PRINCIPAL FINDINGS: Time-depth recorders (TDRs were deployed on two female great shearwaters nesting on Inaccessible Island in the South Atlantic Ocean, recording 10 consecutive days of diving activity. Remote sensing imagery and movement patterns of 8 males tracked by satellite telemetry over the same period were used to identify probable foraging areas used by TDR-equipped females. The deepest and longest dive was to 18.9 m and lasted 40 s, but most (>50% dives were <2 m deep. Diving was most frequent near dawn and dusk, with <0.5% of dives occurring at night. The two individuals foraged in contrasting oceanographic conditions, one in cold (8 to 10°C water of the Sub-Antarctic Front, likely 1000 km south of the breeding colony, and the other in warmer (10 to 16°C water of the Sub-tropical Frontal Zone, at the same latitude as the colony, possibly on the Patagonian Shelf, 4000 km away. The cold water bird spent fewer days commuting, conducted four times as many dives as the warm water bird, dived deeper on average, and had a greater proportion of bottom time during dives. CONCLUSIONS/SIGNIFICANCE: General patterns of diving activity were consistent with those of other shearwaters foraging in cold and warm water habitats. Great shearwaters are likely adapted to forage in a wide range of oceanographic conditions, foraging mostly with shallow dives but capable of deep diving.

  3. Using Stimulation of the Diving Reflex in Humans to Teach Integrative Physiology

    Science.gov (United States)

    Choate, Julia K.; Denton, Kate M.; Evans, Roger G.; Hodgson, Yvonne

    2014-01-01

    During underwater submersion, the body responds by conserving O[subscript 2] and prioritizing blood flow to the brain and heart. These physiological adjustments, which involve the nervous, cardiovascular, and respiratory systems, are known as the diving response and provide an ideal example of integrative physiology. The diving reflex can be…

  4. Argon used as dry suit insulation gas for cold-water diving

    NARCIS (Netherlands)

    Vrijdag, Xavier C. E.; van Ooij, Pieter-Jan A. M.; van Hulst, Robert A.

    2013-01-01

    Cold-water diving requires good thermal insulation because hypothermia is a serious risk. Water conducts heat more efficiently compared to air. To stay warm during a dive, the choice of thermal protection should be based on physical activity, the temperature of the water, and the duration of

  5. [Underwater dive in fresh water complicated by a cardiorespiratory arrest on obstructive shock].

    Science.gov (United States)

    Bourmanne, E; Jacobs, D; Caldow, M; El Kaissi, M

    2015-01-01

    We present the case of a french patient who dived in fresh water in Lac de l'Eau d'Heure on 8 December 2014. The 35 meters deep diving was complicated by an obstructive shock resulting from lung overpressure and decompression illness.

  6. 36 CFR 3.18 - May I snorkel or underwater dive in park waters?

    Science.gov (United States)

    2010-07-01

    ... dive in park waters? 3.18 Section 3.18 Parks, Forests, and Public Property NATIONAL PARK SERVICE... waters? (a) Snorkeling and underwater diving is allowed in park waters, subject to closures or restrictions designated by the superintendent in accordance with §§ 1.5 and 1.7 of this chapter. (b) In waters...

  7. Deep-Diving California Sea Lions: Are They Pushing Their Physiological Limit

    Science.gov (United States)

    2015-09-30

    Time into dive (s) aorta posterior vena cava stroke rate Stroke rate data have been analyzed and are in preparation for publication. As illustrated...posterior vena caval hemoglobin saturation and arterial saturation during deep dives demonstate the complexity of the relationship between these

  8. Deep-Diving California Sea Lions: Are They Pushing Their Physiological Limit?

    Science.gov (United States)

    2014-09-30

    in -1 ) Time into dive (s) aorta posterior vena cava stroke rate Stroke rate data have been analyzed and are in preparation for publication. As...Profiles of heart rate, stroke rate, posterior vena caval hemoglobin saturation and arterial saturation during deep dives demonstate the complexity

  9. Resistance Training for Rescue Divers in the Sport Scuba Diving Industry.

    Science.gov (United States)

    Mier, Constance M.; Kegeles, Sharon

    2002-01-01

    Asserts that the need for certified rescue divers increases as the diving industry grows. Rescue divers must be physically prepared to perform several dives in one day and to carry equipment on and off the boat. Physical recovery is also important, as they must be alert at all times to potential emergency situations. This require high levels of…

  10. Increase of pulmonary arterial pressure in subjects with venous gas emboli after uncomplicated recreational SCUBA diving.

    Science.gov (United States)

    Marabotti, Claudio; Scalzini, Alessandro; Chiesa, Ferruccio

    2013-04-01

    The presence of circulating gas bubbles has been repeatedly reported after uncomplicated SCUBA dives. The clinical and pathophysiological relevance of this phenomenon is still under debate but some experimental data suggest that silent bubbles may have a damaging potential on pulmonary endothelial cells. The aim of the present study was to evaluate the possible hemodynamic effect on pulmonary circulation of post-dive circulating gas bubbles. To this aim, 16 experienced divers were studied by Doppler-echocardiography in basal conditions and 2.0 ± 0.15 h after an uncomplicated, unrestricted recreational SCUBA dive. At the post-dive examination, circulating bubbles were present in 10/16 subjects (62.5%). Divers with circulating bubbles showed a significant post-dive increase of pulmonary systolic arterial pressure (evaluated by the maximal velocity of the physiological tricuspid regurgitation; P dive decrease of transmitral E/A ratio (index of left ventricular diastolic function: subjects with bubbles P dive diastolic function changes, observed in both groups, may be explained by a preload reduction due to immersion natriuresis. The results of the present study add some evidence that post-dive circulating bubbles, although symptomless, have an easily detectable pathogenetic potential, inducing unfavorable hemodynamic changes in the lesser circulation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Constructing safety through “contrast” during training in scuba diving ...

    African Journals Online (AJOL)

    Safety is a very important aspect in scuba diving, as not complying with safety regulations can lead to serious injury or even death. In this article the researchers focused on the discursive construction of safety during training in scuba diving. The research position fell within the field of discursive psychology. The researcher ...

  12. Life under water: physiological adaptations to diving and living at sea.

    Science.gov (United States)

    Castellini, Michael

    2012-07-01

    This review covers the field of diving physiology by following a chronological approach and focusing heavily on marine mammals. Because the study of modern diving physiology can be traced almost entirely to the work of Laurence Irving in the 1930s, this particular field of physiology is different than most in that it did not derive from multiple laboratories working at many locations or on different aspects of a similar problem. Because most of the physiology principles still used today were first formulated by Irving, it is important to the study of this field that the sequence of thought is examined as a progression of theory. The review covers the field in roughly decadal blocks and traces ideas as they were first suggested, tested, modified and in some cases, abandoned. Because diving physiology has also been extremely dependent on new technologies used in the development of diving recorders, a chronological approach fits well with advances in electronics and mechanical innovation. There are many species that dive underwater as part of their natural behavior, but it is mainly the marine mammals (seals, sea lions, and whales) that demonstrate both long duration and dives to great depth. There have been many studies on other diving species including birds, snakes, small aquatic mammals, and humans. This work examines these other diving species as appropriate and a listing of reviews and relevant literature on these groups is included at the end. © 2012 American Physiological Society. Compr Physiol 2:1853-1872, 2012.

  13. Arterial stress hormones during scuba diving with different breathing gases.

    Science.gov (United States)

    Weist, Frank; Strobel, Günther; Hölzl, Mathias; Böning, Dieter

    2012-07-01

    The purpose of the study was to determine whether the conditions during scuba diving without exercise (e.g., submersion, restricted breathing) stimulate the activities of the sympathoadrenergic system and the hypothalamic-pituitary-adrenal axis. This might facilitate panic reactions in dangerous situations. Fifteen experienced rescue divers participated in three experiments with two submersions each in a diving tower where ambient pressure could be varied. During submersion (duration = 15 min), they were breathing either pure oxygen (ambient pressure = 1.1 bar) or air (1.1 and 5.3 bar) or Heliox21 (21% O(2) and 79% He, 1.1 and 5.3 bar). The subjects stayed upright immediately below the water surface holding one hand with a cannulated radial artery out in the air. Noradrenaline, adrenaline, and dopamine concentrations in arterial blood and heart rate (HR) variability as indicators of sympathoadrenergic activity and cortisol and adrenocorticotropic hormone concentrations as strain indicators were measured. [Noradrenaline] and [adrenaline] (initial values (mean ± SE) = 1616 ± 93 and 426 ± 38 pmol·L(-1)) decreased significantly by up to 30% and 50%, respectively, after 11 min of submersion, independent of pressure and inspired gas. HR variability showed roughly corresponding changes and also indications for parasympathetic stimulation, but artifacts by interference among HR monitors reduced the number of usable measurements. The other hormone concentrations did not change significantly. There was no increase of stress hormone concentrations in experienced subjects. The reduction of [noradrenaline] and [adrenaline] during scuba diving seems to be a reaction to orthostatic relief caused by external hydrostatic pressure on peripheral vasculature. The activity of the vegetative nervous system might be estimated from HR variability if interference among pulse watches can be avoided.

  14. Sebastian Pinnacles, Oculina Banks Clelia Dive 619 Narrative 2001 - Videotape and Visual Observations from Submersible Dives to the Oculina Banks Deep Sea Coral Reefs (NODC Accession 0047190)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are from one of fourteen 2001 submersible "Clelia" dives. Narratives including habitat descriptions and estimates of megafaunal species abundance were...

  15. Jeff's Reef Oculina Banks Clelia Dive 607 Narrative 2001 - Videotape and Visual Observations from Submersible Dives to the Oculina Banks Deep Sea Coral Reefs (NODC Accession 0047190)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These are data from one of fourteen 2001 submersible "Clelia" dives. Narratives including habitat descriptions and estimates of megafaunal species abundance were...

  16. Sebastian Pinnacles, Oculina Banks Clelia Dive 618 Narrative 2001 - Videotape and Visual Observations from Submersible Dives to the Oculina Banks Deep Sea Coral Reefs (NODC Accession 0047190)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are from one of fourteen 2001 submersible "Clelia" dives. Narratives including habitat descriptions and estimates of megafaunal species abundance were...

  17. Sebastian Pinnacles, Oculina Banks Clelia Dive 615 Narrative 2001 - Videotape and Visual Observations from Submersible Dives to the Oculina Banks Deep Sea Coral Reefs (NODC Accession 0047190)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are from one of fourteen 2001 submersible "Clelia" dives. Narratives including habitat descriptions and estimates of megafaunal species abundance were...

  18. Sebastian Pinnacles, Oculina Banks Clelia Dive 614 Narrative 2001 - Videotape and Visual Observations from Submersible Dives to the Oculina Banks Deep Sea Coral Reefs (NODC Accession 0047190)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are from one of fourteen 2001 submersible "Clelia" dives. Narratives including habitat descriptions and estimates of megafaunal species abundance were...

  19. Cocoa Beach, Oculina Banks Clelia Dive 617 Narrative 2001 - Videotape and Visual Observations from Submersible Dives to the Oculina Banks Deep Sea Coral Reefs (NODC Accession 0047190)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are from one of from fourteen 2001 submersible "Clelia" dives. Narratives including habitat descriptions and estimates of megafaunal species abundance...

  20. PNW cetacean muscle biochemistry - Muscle Myoglobin Content and Acid Buffering Capacity of Cetaceans from the Pacific Northwest to Assess Dive Capacity and the Development of Diving Capabilities

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project assesses the development of two important skeletal muscle adaptations for diving (enhanced myoglobin content and acid buffering capacities) in a range...

  1. Jeff's Reef, Oculina Banks Clelia Dive 606 Narrative 2001 - Videotape and Visual Observations from Submersible Dives to the Oculina Banks Deep Sea Coral Reefs (NODC Accession 0047190)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These are data from one of fourteen 2001 submersible "Clelia" dives. Narratives including habitat descriptions and estimates of megafaunal species abundance were...

  2. 76 FR 9817 - Standard on Commercial Diving Operations; Extension of the Office of Management and Budget's (OMB...

    Science.gov (United States)

    2011-02-22

    ...] Standard on Commercial Diving Operations; Extension of the Office of Management and Budget's (OMB) Approval... Commercial Diving Operations Standard (29 CFR part 1910, subpart T). DATES: Comments must be submitted... obtaining information (29 U.S.C. 657). Subpart T applies to diving and related support operations conducted...

  3. 76 FR 67480 - Standard on Commercial Diving Operations; Extension of the Office of Management and Budget's (OMB...

    Science.gov (United States)

    2011-11-01

    ...] Standard on Commercial Diving Operations; Extension of the Office of Management and Budget's (OMB) Approval... Commercial Diving Operations Standard (29 CFR part 1910, subpart T). DATES: Comments must be submitted... existing Standard on Commercial Diving Operations (29 CFR part 1910, Subpart [[Page 67481

  4. Changes in dive behavior during naval sonar exposure in killer whales, long-finned pilot whales, and sperm whales.

    Science.gov (United States)

    Sivle, L D; Kvadsheim, P H; Fahlman, A; Lam, F P A; Tyack, P L; Miller, P J O

    2012-01-01

    Anthropogenic underwater sound in the environment might potentially affect the behavior of marine mammals enough to have an impact on their reproduction and survival. Diving behavior of four killer whales (Orcinus orca), seven long-finned pilot whales (Globicephala melas), and four sperm whales (Physeter macrocephalus) was studied during controlled exposures to naval sonar [low frequency active sonar (LFAS): 1-2 kHz and mid frequency active sonar (MFAS): 6-7 kHz] during three field seasons (2006-2009). Diving behavior was monitored before, during and after sonar exposure using an archival tag placed on the animal with suction cups. The tag recorded the animal's vertical movement, and additional data on horizontal movement and vocalizations were used to determine behavioral modes. Killer whales that were conducting deep dives at sonar onset changed abruptly to shallow diving (ShD) during LFAS, while killer whales conducting deep dives at the onset of MFAS did not alter dive mode. When in ShD mode at sonar onset, killer whales did not change their diving behavior. Pilot and sperm whales performed normal deep dives (NDD) during MFAS exposure. During LFAS exposures, long-finned pilot whales mostly performed fewer deep dives and some sperm whales performed shallower and shorter dives. Acoustic recording data presented previously indicates that deep diving (DD) is associated with feeding. Therefore, the observed changes in dive behavior of the three species could potentially reduce the foraging efficiency of the affected animals.

  5. Tag-based Heart Rate Measurements of Harbor Porpoises During Normal and Noise-exposed Dives to Study Stress Responses

    Science.gov (United States)

    2015-09-30

    potential plasticity of their diving physiology , and their physiological responses to stress. The typical mammalian startle or stress response to an...2) study the dive heart rate, activity and ventilation rate of wild porpoises and opportunistically examine the physiological and behavioral... physiological systems in cetaceans in the wild. APPROACH Objective one: Physiological and behavioral response to acoustic stressors Dive heart rate

  6. On the adiabatic theorem when eigenvalues dive into the continuum

    DEFF Research Database (Denmark)

    Cornean, Decebal Horia; Jensen, Arne; Knörr, Hans Konrad

    For a Wigner-Weisskopf model of an atom consisting of a quantum dot coupled to an energy reservoir described by a three-dimensional Laplacian we study the survival probability of a bound state when the dot energy varies smoothly and adiabatically in time. The initial state corresponds to a discrete...... eigenvalue which dives into the continuous spectrum and re-emerges from it as the dot energy is varied in time and finally returns to its initial value. Our main result is that for a large class of couplings, the survival probability of this bound state vanishes in the adiabatic limit....

  7. Suitability Analysis For Scuba Diving To Develop Marine Tourism At Saebus Island, East Java, Indonesia

    Science.gov (United States)

    Wijaya, Putranto; Putra, Tri; Hidayat, Fatra; Levraeni, Chandra; Rizmaadi, Mada; Ambariyanto, Ambariyanto

    2018-02-01

    Indonesian government currently has policies to improve the performance of the tourism sector, including marine tourism. One of the attractions of marine tourism is the coral ecosystem especially through scuba diving activities. The purpose of this study was to determine the suitability of the coral ecosystem on Saebus Island, East Java, to find appropriate locations for scuba diving activities. Purposive samplings were done around the island to determine four stations which will be assessed through suitability analysis. Tourism Suitability Index was used to assess all stations for scuba diving activities. The result showed that all four stations were categorized as very suitable with the score: 85%, 85%, 85% and 83%, respectively. Several aspects that need to be improved and anticipated for diving at all stations are coral coverage and water current. These results suggest that there are several spots around Saebus Island that are suitable for diving site, and can be promoted as marine tourism destination.

  8. Gastro-esophageal barotrauma in diving: similarities with Mallory-Weiss syndrome.

    Science.gov (United States)

    Novomeský, F

    1999-01-01

    Mallory-Weiss syndrome (MWS) is a well-defined entity in clinical medicine. However, the development of such a syndrome as a result of overpressure barotrauma of the stomach after repeated shallow-water scuba dives is rare. Also rare is the delayed onset of the MWS, approximately 20 hours after the dives. The causes of development of MWS in connection with scuba diving are discussed. The main causes seem to be the repeated changes of gas volume in the stomach with subsequent pressure forces toward the cardia in the course of repeated dives. The possibility of serious diving accident due to overpressure barotrauma of gastro-intestinal system is also pointed out.

  9. Suitability Analysis For Scuba Diving To Develop Marine Tourism At Saebus Island, East Java, Indonesia

    Directory of Open Access Journals (Sweden)

    Wijaya Putranto

    2018-01-01

    Full Text Available Indonesian government currently has policies to improve the performance of the tourism sector, including marine tourism. One of the attractions of marine tourism is the coral ecosystem especially through scuba diving activities. The purpose of this study was to determine the suitability of the coral ecosystem on Saebus Island, East Java, to find appropriate locations for scuba diving activities. Purposive samplings were done around the island to determine four stations which will be assessed through suitability analysis. Tourism Suitability Index was used to assess all stations for scuba diving activities. The result showed that all four stations were categorized as very suitable with the score: 85%, 85%, 85% and 83%, respectively. Several aspects that need to be improved and anticipated for diving at all stations are coral coverage and water current. These results suggest that there are several spots around Saebus Island that are suitable for diving site, and can be promoted as marine tourism destination.

  10. Acute ischemic colitis during scuba diving: Report of a unique case

    Science.gov (United States)

    Goumas, Konstantinos; Poulou, Androniki; Tyrmpas, Ioannis; Dandakis, Dimitrios; Bartzokis, Stavros; Tsamouri, Magdalini; Barbati, Kalipso; Soutos, Dimitrios

    2008-01-01

    The presentation of clinical symptoms due to decompression during diving, varies significantly, as mainly minor disturbances for the gastrointestinal tract in particular have been reported. The following case debates whether diving can cause severe symptoms from the gastrointestinal system. We describe a clinical case of ischemic colitis presented in a 27-year-old male, who manifested abdominal pain while in the process of scuba diving 20 meters undersea, followed by bloody diarrhoea as soon as he ascended to sea level. Taking into account his past medical history, the thorough, impeccable clinical and laboratory examinations and presence of no other factors predisposing to ischemia of the colon, we assume that a possible relationship between diving conditions and the pathogenesis of ischemic colitis may exist. This unusual case might represent a hematologic manifestation of decompression sickness, due to increased coagulability and/or transient air emboli, occurring during a routine scuba diving ascent to sea level. PMID:18506937

  11. Modelling foraging movements of diving predators: a theoretical study exploring the effect of heterogeneous landscapes on foraging efficiency.

    Science.gov (United States)

    Chimienti, Marianna; Bartoń, Kamil A; Scott, Beth E; Travis, Justin M J

    2014-01-01

    Foraging in the marine environment presents particular challenges for air-breathing predators. Information about prey capture rates, the strategies that diving predators use to maximise prey encounter rates and foraging success are still largely unknown and difficult to observe. As well, with the growing awareness of potential climate change impacts and the increasing interest in the development of renewable sources it is unknown how the foraging activity of diving predators such as seabirds will respond to both the presence of underwater structures and the potential corresponding changes in prey distributions. Motivated by this issue we developed a theoretical model to gain general understanding of how the foraging efficiency of diving predators may vary according to landscape structure and foraging strategy. Our theoretical model highlights that animal movements, intervals between prey capture and foraging efficiency are likely to critically depend on the distribution of the prey resource and the size and distribution of introduced underwater structures. For multiple prey loaders, changes in prey distribution affected the searching time necessary to catch a set amount of prey which in turn affected the foraging efficiency. The spatial aggregation of prey around small devices (∼ 9 × 9 m) created a valuable habitat for a successful foraging activity resulting in shorter intervals between prey captures and higher foraging efficiency. The presence of large devices (∼ 24 × 24 m) however represented an obstacle for predator movement, thus increasing the intervals between prey captures. In contrast, for single prey loaders the introduction of spatial aggregation of the resources did not represent an advantage suggesting that their foraging efficiency is more strongly affected by other factors such as the timing to find the first prey item which was found to occur faster in the presence of large devices. The development of this theoretical model represents a useful

  12. Diving behavior and movements of juvenile hawksbill turtles Eretmochelys imbricata on a Caribbean coral reef

    Science.gov (United States)

    Blumenthal, J. M.; Austin, T. J.; Bothwell, J. B.; Broderick, A. C.; Ebanks-Petrie, G.; Olynik, J. R.; Orr, M. F.; Solomon, J. L.; Witt, M. J.; Godley, B. J.

    2009-03-01

    As historically abundant spongivores, hawksbill turtles Eretmochelys imbricata likely played a key ecological role on coral reefs. However, coral reefs are now experiencing global declines and many hawksbill populations are critically reduced. For endangered species, tracking movement has been recognized as fundamental to management. Since movements in marine vertebrates encompass three dimensions, evaluation of diving behavior and range is required to characterize marine turtle habitat. In this study, habitat use of hawksbill turtles on a Caribbean coral reef was elucidated by quantifying diel depth utilization and movements in relation to the boundaries of marine protected areas. Time depth recorders (TDRs) and ultrasonic tags were deployed on 21 Cayman Islands hawksbills, ranging in size from 26.4 to 58.4 cm straight carapace length. Study animals displayed pronounced diel patterns of diurnal activity and nocturnal resting, where diurnal dives were significantly shorter, deeper, and more active. Mean diurnal dive depth (±SD) was 8 ± 5 m, range 2-20 m, mean nocturnal dive depth was 5 ± 5 m, range 1-14 m, and maximum diurnal dive depth was 43 ± 27 m, range 7-91 m. Larger individuals performed significantly longer dives. Body mass was significantly correlated with mean dive depth for nocturnal but not diurnal dives. However, maximum diurnal dive depth was significantly correlated with body mass, suggesting partitioning of vertical habitat by size. Thus, variable dive capacity may reduce intraspecific competition and provide resistance to degradation in shallow habitats. Larger hawksbills may also represent important predators on deep reefs, creating a broad ecological footprint over a range of depths.

  13. Effect of immersion, submersion, and scuba diving on heart rate variability

    Science.gov (United States)

    Schipke, J; Pelzer, M

    2001-01-01

    Background—Heart rate variability (HRV) describes the cyclic variations in heart rate and offers a non-invasive tool for investigating the modulatory effects of neural mechanisms elicited by the autonomic nervous system on intrinsic heart rate. Objective—To introduce the HRV concept to healthy volunteers under control conditions and during scuba diving. In contrast with more established manoeuvres, diving probably activates both the sympathetic and parasympathetic nervous system through various stimuli—for example, through cardiac stretch receptors, respiration pattern, psychological stress, and diving reflex. A further aim of the study was to introduce a measure for determining a candidate's ability to scuba dive by providing (a) standard values for HRV measures (three from the time domain and three from the frequency domain) and (b) physiological responses to a strenuous manoeuvre such as scuba diving. Methods—Twenty five trained scuba divers were investigated while diving under pool conditions (27°C) after the effects of head out immersion and submersion on HRV had been studied. Results and conclusions—(a) Immersion under pool conditions is a powerful stimulus for both the sympathetic and parasympathetic nervous system. (b) As neither the heart rate nor the HRV changed on going from immersion to submersion, the parasympathetic activation was probably due to haemodynamic alterations. (c) All HRV measures showed an increase in the parasympathetic activity. (d) If a physiological HRV is a mechanism for providing adaptability and flexibility, diving should not provoke circulatory problems in healthy subjects. (e) Either a lower than normal HRV under control conditions or a reduction in HRV induced by diving would be unphysiological, and a scuba diving candidate showing such characteristics should be further investigated. Key Words: immersion; submersion; scuba diving; autonomous nervous system; heart rate variability PMID:11375876

  14. The rat: a laboratory model for studies of the diving response

    Science.gov (United States)

    Gan, Qi; Juric, Rajko

    2010-01-01

    Underwater submersion in mammals induces apnea, parasympathetically mediated bradycardia, and sympathetically mediated peripheral vasoconstriction. These effects are collectively termed the diving response, potentially the most powerful autonomic reflex known. Although these physiological responses are directed by neurons in the brain, study of neural control of the diving response has been hampered since 1) it is difficult to study the brains of animals while they are underwater, 2) feral marine mammals are usually large and have brains of variable size, and 3) there are but few references on the brains of naturally diving species. Similar responses are elicited in anesthetized rodents after stimulation of their nasal mucosa, but this nasopharyngeal reflex has not been compared directly with natural diving behavior in the rat. In the present study, we compared hemodynamic responses elicited in awake rats during volitional underwater submersion with those of rats swimming on the water's surface, rats involuntarily submerged, and rats either anesthetized or decerebrate and stimulated nasally with ammonia vapors. We show that the hemodynamic changes to voluntary diving in the rat are similar to those of naturally diving marine mammals. We also show that the responses of voluntary diving rats are 1) significantly different from those seen during swimming, 2) generally similar to those elicited in trained rats involuntarily “dunked” underwater, and 3) generally different from those seen from dunking naive rats underwater. Nasal stimulation of anesthetized rats differed most from the hemodynamic variables of rats trained to dive voluntarily. We propose that the rat trained to dive underwater is an excellent laboratory model to study neural control of the mammalian diving response, and also suggest that some investigations may be done with nasal stimulation of decerebrate preparations to decipher such control. PMID:20093670

  15. Potential Synergies between Nature-Based Tourism and Sustainable Use of Marine Resources: Insights from Dive Tourism in Territorial User Rights for Fisheries in Chile.

    Science.gov (United States)

    Biggs, Duan; Amar, Francisca; Valdebenito, Abel; Gelcich, Stefan

    2016-01-01

    Novel solutions to conserve biodiversity whilst allowing for resource harvesting are urgently needed. In marine systems, Territorial User Rights for Fisheries (TURFs) are promoted to enable sustainable use of resources. We investigate the potential for synergies between nature-based tourism and TURFs on Chile's central coast. Of 135 recreational divers surveyed, 77% indicated that the fish species they preferred sighting were declining and 80% indicated that they would dive more often in TURFs, which have higher abundance of favoured species. Regression analysis shows that respondents that perceive that TURFs fulfil a conservation function are more willing to pay to dive in a TURF. However, respondents who understand the bureaucratic functioning of a TURF are less willing to pay, and there is diversity in how divers feel payments should be made. A participatory approach is required to navigate these complexities to achieve synergies between nature-based tourism and resource harvesting in TURFs.

  16. Niche overlap, threshold food densities, and limits to prey depletion for a diving duck assemblage in an estuarine bay

    Science.gov (United States)

    Lovvorn, James R.; De La Cruz, Susan; Takekawa, John Y.; Shaskey, Laura E.; Richman, Samantha E.

    2013-01-01

    Planning for marine conservation often requires estimates of the amount of habitat needed to support assemblages of interacting species. During winter in subtidal San Pablo Bay, California, the 3 main diving duck species are lesser scaup Aythya affinis (LESC), greater scaup A. marila (GRSC), and surf scoter Melanitta perspicillata (SUSC), which all feed almost entirely on the bivalve Corbula amurensis. Decreased body mass and fat, increased foraging effort, and major departures of these birds appeared to result from food limitation. Broad overlap in prey size, water depth, and location suggested that the 3 species responded similarly to availability of the same prey. However, an energetics model that accounts for differing body size, locomotor mode, and dive behavior indicated that each species will become limited at different stages of prey depletion in the order SUSC, then GRSC, then LESC. Depending on year, 35 to 66% of the energy in Corbula standing stocks was below estimated threshold densities for profitable foraging. Ectothermic predators, especially flounders and sturgeons, could reduce excess carrying capacity for different duck species by 4 to 10%. A substantial quantity of prey above profitability thresholds was not exploited before most ducks left San Pablo Bay. Such pre-depletion departure has been attributed in other taxa to foraging aggression. However, in these diving ducks that showed no overt aggression, this pattern may result from high costs of locating all adequate prey patches, resulting reliance on existing flocks to find food, and propensity to stay near dense flocks to avoid avian predation. For interacting species assemblages, modeling profitability thresholds can indicate the species most vulnerable to food declines. However, estimates of total habitat needed require better understanding of factors affecting the amount of prey above thresholds that is not depleted before the predators move elsewhere.

  17. Dumpster diving: Mezi etikou a zákonem

    Directory of Open Access Journals (Sweden)

    Jana Kliková

    2017-06-01

    Full Text Available The aim of this paper is to reflect on the ethical dilemma of researchers who encounter illegal activity during their research, or of researchers who are particularly interested in this kind of activity. The inspiration comes from research that we are currently conducting on dumpster diving as a source of creativity. We interview people in the Pilsen Region who pursue this activity, or who used to do so. Although dumpster diving is becoming more popular, it is not legal. Waste remains tangible property and therefore always belongs to someone. For this reason, its appropriation is not in agreement with the law. According to the codes of ethics of various anthropological associations, the researcher should always be mindful of respecting the privacy and safety of the people the researcher is scientifically interested in. This could be a significant problem in cases where the anthropologist witnesses an illegal activity. Since the law is formally superior to an ethical code, the researcher should notify the police, especially if the activity in question is subject to the duty to report a crime. The question is how to cope with this “ethically important moment in research” (Guillemin and Gillam 2004, 262.

  18. Superior canal dehiscence syndrome associated with scuba diving.

    Science.gov (United States)

    Kitajima, Naoharu; Sugita-Kitajima, Akemi; Kitajima, Seiji

    2017-06-01

    A 28-year-old female diver presented with dizziness and difficulty clearing her left ear whilst scuba diving. Her pure-tone audiometry and tympanometry were normal. Testing of Eustachian tube function revealed tubal stenosis. Video-oculography revealed a predominantly torsional nystagmus while the patient was in the lordotic position. Fistula signs were positive. High-resolution computed tomography (HRCT) of the temporal bone revealed a diagnosis of bilateral superior semicircular canal dehiscence (SCDS). Cervical vestibular-evoked myogenic potential (cVEMP) testing showed that the amplitude of the cVEMP measured from her left ear was larger than that from the right. In electronystagmography (ENG), nose-pinched Valsalva manoeuvres caused eye movements to be mainly directed counterclockwise with a vertical component. Tullio phenomenon was also positive for both ears. SCDS patients tend to be misdiagnosed and misunderstood; common misdiagnoses in these cases are alternobaric vertigo (AV), inner ear barotrauma, and inner-ear decompression sickness. It is difficult to diagnose vertigo attacks after scuba diving as SCDS; however, when the patient develops sound- and/or pressure-induced vertical-torsional nystagmus, HRCT should be conducted to confirm a diagnosis of SCDS.

  19. Inner ear decompression sickness in compressed-air diving.

    Science.gov (United States)

    Klingmann, Christoph

    2012-01-01

    Inner ear decompression sickness (IEDCS) has become more frequently reported in recreational diving. We examined 34 divers after IEDCS and analyzed their dive profiles, pattern of symptoms, time of symptom onset and the association with a right-to left shunt (r/l shunt). Four divers used mixed gas and were excluded from the analysis. Of the remaining 30 divers, 25 presented with isolated IEDCS alone, while five divers had additional skin and neurological symptoms. All divers presented with vertigo (100%), and 12 divers reported additional hearing loss (40%). All symptoms occurred within 120 minutes (median 30 minutes) of ascent. Twenty-two of 30 divers (73.3%) showed a r/l shunt. A possible explanation for the frequent association of a r/l shunt and the dominance of vestibular rather than cochlear symptoms could be attributed to the different blood supply of the inner ear structures and the different size of the labyrinthine compartments. The cochlea has a blood supply up to four times higher than the vestibular part of the inner ear, whereas the vestibular fluid space is 30% larger. The higher prevalence of symptoms referrable to the less well-perfused vestibular organ provides further evidence that persistent local inert gas supersaturation may cause growth of incoming arterial bubbles and may therefore be an important pathophysiological factor in IEDCS.

  20. Dive and Explore: An Interactive Exhibit That Simulates Making an ROV Dive to a Submarine Volcano, Hatfield Marine Science Visitor Center, Newport, Oregon

    Science.gov (United States)

    Weiland, C.; Chadwick, W. W.; Hanshumaker, W.; Osis, V.; Hamilton, C.

    2002-12-01

    We have created a new interactive exhibit in which the user can sit down and simulate that they are making a dive to the seafloor with the remotely operated vehicle (ROV) named ROPOS. The exhibit immerses the user in an interactive experience that is naturally fun but also educational. This new public display is located at the Hatfield Marine Science Visitor Center in Newport, Oregon. The exhibit is designed to look like the real ROPOS control console and includes three video monitors, a PC, a DVD player, an overhead speaker, graphic panels, buttons, lights, dials, and a seat in front of a joystick. The dives are based on real seafloor settings at Axial seamount, an active submarine volcano on the Juan de Fuca Ridge (NE Pacific) that is also the location of a seafloor observatory called NeMO. The user can choose between 1 of 3 different dives sites in the caldera of Axial Volcano. Once a dive is chosen, then the user watches ROPOS being deployed and then arrives into a 3-D computer-generated seafloor environment that is based on the real world but is easier to visualize and navigate. Once on the bottom, the user is placed within a 360 degree panorama and can look in all directions by manipulating the joystick. By clicking on markers embedded in the scene, the user can then either move to other panorama locations via movies that travel through the 3-D virtual environment, or they can play video clips from actual ROPOS dives specifically related to that scene. Audio accompanying the video clips informs the user where they are going or what they are looking at. After the user is finished exploring the dive site they end the dive by leaving the bottom and watching the ROV being recovered onto the ship at the surface. The user can then choose a different dive or make the same dive again. Within the three simulated dives there are a total of 6 arrival and departure movies, 7 seafloor panoramas, 12 travel movies, and 23 ROPOS video clips. The exhibit software was created

  1. Repetitive Diving in Trained Rats Still Increases Fos Production in Brainstem Neurons after Bilateral Sectioning of the Anterior Ethmoidal Nerve.

    Science.gov (United States)

    McCulloch, Paul F; Warren, Erik A; DiNovo, Karyn M

    2016-01-01

    This research was designed to investigate the role of the anterior ethmoidal nerve (AEN) during repetitive trained diving in rats, with specific attention to activation of afferent and efferent brainstem nuclei that are part of this reflexive response. The AEN innervates the nose and nasal passages and is thought to be an important component of the afferent limb of the diving response. Male Sprague-Dawley rats (N = 24) were trained to swim and dive through a 5 m underwater maze. Some rats (N = 12) had bilateral sectioning of the AEN, others a Sham surgery (N = 12). Twelve rats (6 AEN cut and 6 Sham) had 24 post-surgical dive trials over 2 h to activate brainstem neurons to produce Fos, a neuronal activation marker. Remaining rats were non-diving controls. Diving animals had significantly more Fos-positive neurons than non-diving animals in the caudal pressor area, ventral medullary dorsal horn, ventral paratrigeminal nucleus, nucleus tractus solitarius, rostral ventrolateral medulla, Raphe nuclei, A5, Locus Coeruleus, and Kölliker-Fuse area. There were no significant differences in brainstem Fos labeling in rats diving with and without intact AENs. Thus, the AENs are not required for initiation of the diving response. Other nerve(s) that innervate the nose and nasal passages, and/or suprabulbar activation of brainstem neurons, may be responsible for the pattern of neuronal activation observed during repetitive trained diving in rats. These results help define the central neuronal circuitry of the mammalian diving response.

  2. Repetitive Diving in Trained Rats Still Increases Fos Production in Brainstem Neurons after Bilateral Sectioning of the Anterior Ethmoidal Nerve

    Science.gov (United States)

    McCulloch, Paul F.; Warren, Erik A.; DiNovo, Karyn M.

    2016-01-01

    This research was designed to investigate the role of the anterior ethmoidal nerve (AEN) during repetitive trained diving in rats, with specific attention to activation of afferent and efferent brainstem nuclei that are part of this reflexive response. The AEN innervates the nose and nasal passages and is thought to be an important component of the afferent limb of the diving response. Male Sprague-Dawley rats (N = 24) were trained to swim and dive through a 5 m underwater maze. Some rats (N = 12) had bilateral sectioning of the AEN, others a Sham surgery (N = 12). Twelve rats (6 AEN cut and 6 Sham) had 24 post-surgical dive trials over 2 h to activate brainstem neurons to produce Fos, a neuronal activation marker. Remaining rats were non-diving controls. Diving animals had significantly more Fos-positive neurons than non-diving animals in the caudal pressor area, ventral medullary dorsal horn, ventral paratrigeminal nucleus, nucleus tractus solitarius, rostral ventrolateral medulla, Raphe nuclei, A5, Locus Coeruleus, and Kölliker-Fuse area. There were no significant differences in brainstem Fos labeling in rats diving with and without intact AENs. Thus, the AENs are not required for initiation of the diving response. Other nerve(s) that innervate the nose and nasal passages, and/or suprabulbar activation of brainstem neurons, may be responsible for the pattern of neuronal activation observed during repetitive trained diving in rats. These results help define the central neuronal circuitry of the mammalian diving response. PMID:27148082

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

    Science.gov (United States)

    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 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 dive (P 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. Scuba diving does not affect bone mineral density or bone mineral content.

    Science.gov (United States)

    Wesolowska, Katarzyna; Czarkowska-Paczek, Bozena; Przedlacki, Jerzy; Przybylski, Jacek

    2011-12-01

    Scuba diving is a very specialized, physically demanding activity. The bones of divers are subjected to stress from water pressure, from the forces generated when their muscles resist water pressure, and from weightlessness. Notably, few studies have addressed the effects of diving on bone mineral density (BMD) and bone mineral content (BMC), and the results have been controversial. The goal of the study was to assess BMD and BMC in a group of professional scuba divers. The study group (diving group [D]) included 16 male professional scuba divers who also worked as firemen. The control group included 14 firemen who did not scuba dive (non-diving group [ND]). The groups were matched by age, weight, and height. The BMD and BMC of the whole skeleton, L1-L4, total hip, and femoral neck were assessed by dual-energy X-ray absorptiometry. There were no differences in BMD or in BMC in the two groups, and the BMD and BMC values were within one standard deviation in terms of Z- and T-scores. There was no correlation between total diving time (hours) and BMD in the D group. Scuba diving does not negatively influence bone turnover. Copyright © 2011 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

  5. Recreational scuba diving: negative or positive effects of oxidative and cardiovascular stress?

    Science.gov (United States)

    Perovic, Antonija; Unic, Adriana; Dumic, Jerka

    2014-01-01

    Environmental conditions and increased physical activity during scuba diving are followed by increased production of free radicals and disturbed redox balance. Redox balance disorder is associated with damage of cellular components, changes of cellular signaling pathways and alterations of gene expression. Oxidative stress leads to increased expression of sirtuins (SIRTs), molecules which play an important role in the antioxidant defense, due to their sensitivity to the changes in the redox status and their ability to regulate redox homeostasis. These facts make SIRTs interesting to be considered as molecules affected by scuba diving and in that sense, as potential biomarkers of oxidative status or possible drug targets in reduction of reactive oxygen species (ROS) accumulation. In addition, SIRTs effects through currently known targets make them intriguing molecules which can act positively on health in general and whose expression can be induced by scuba diving.A demanding physical activity, as well as other circumstances present in scuba diving, has the greatest load on the cardiovascular function (CV). The mechanisms of CV response during scuba diving are still unclear, but diving-induced oxidative stress and the increase in SIRTs expression could be an important factor in CV adaptation. This review summarizes current knowledge on scuba diving-induced oxidative and CV stress and describes the important roles of SIRTs in the (patho)physiological processes caused by the redox balance disorder.

  6. 12-lead Holter monitoring in diving and water sports: a preliminary investigation.

    Science.gov (United States)

    Bosco, Gerardo; De Marzi, Elena; Michieli, Pierantonio; Omar, Hesham R; Camporesi, Enrico M; Padulo, Johnny; Paoli, Antonio; Mangar, Devanand; Schiavon, Maurizio

    2014-12-01

    To demonstrate the utility of 12-lead Holter monitoring underwater. A Holter monitor, recording a 12-lead electrocardiogram (ECG) underwater, was applied to 16 pre-trained volunteer scuba divers (13 males and three females). Dive computers were synchronized with the Holter recorder to correlate the ECG tracings with diving events. Our main objective was to demonstrate the utility of recording over a period of time a good quality 12-lead ECG underwater. The ECGs were analyzed for heart rate (HR), arrhythmias, conduction abnormalities and ischaemic events in relation to various stages of diving as follows: baseline, pre diving, diving, and post diving. The ECG tracings were of good quality with minimal artefacts. Analysis of variance (ANOVA) demonstrated a significant difference in HR during the various diving stages (P < 0.0001). Other recorded ECG abnormalities included supraventricular ectopic beats (four cases), ventricular ectopic beats (eight cases) and ventricular couplets (two cases). Conduction abnormalities included rate-dependent right and left bundle branch block; however, these findings were previously known in these divers. No evidence of ischaemia was seen. Continuous 12-lead Holter monitoring underwater can produce good quality tracings. Further studies are necessary to assess its usefulness in divers at risk for or with known coronary artery disease, and its comparison with other forms of cardiac stress tests.

  7. Exercise at depth alters bradycardia and incidence of cardiac anomalies in deep-diving marine mammals.

    Science.gov (United States)

    Williams, Terrie M; Fuiman, Lee A; Kendall, Traci; Berry, Patrick; Richter, Beau; Noren, Shawn R; Thometz, Nicole; Shattock, Michael J; Farrell, Edward; Stamper, Andy M; Davis, Randall W

    2015-01-16

    Unlike their terrestrial ancestors, marine mammals routinely confront extreme physiological and physical challenges while breath-holding and pursuing prey at depth. To determine how cetaceans and pinnipeds accomplish deep-sea chases, we deployed animal-borne instruments that recorded high-resolution electrocardiograms, behaviour and flipper accelerations of bottlenose dolphins (Tursiops truncatus) and Weddell seals (Leptonychotes weddellii) diving from the surface to >200 m. Here we report that both exercise and depth alter the bradycardia associated with the dive response, with the greatest impacts at depths inducing lung collapse. Unexpectedly, cardiac arrhythmias occurred in >73% of deep, aerobic dives, which we attribute to the interplay between sympathetic and parasympathetic drivers for exercise and diving, respectively. Such marked cardiac variability alters the common view of a stereotypic 'dive reflex' in diving mammals. It also suggests the persistence of ancestral terrestrial traits in cardiac function that may help explain the unique sensitivity of some deep-diving marine mammals to anthropogenic disturbances.

  8. Deep-diving by narwhals Monodon monoceros: differences in foraging behavior between wintering areas?

    DEFF Research Database (Denmark)

    Laidre, K. L.; Heide-Jørgensen, M. P.; Dietz, R.

    2003-01-01

    between summer and winter. Clear differences were observed between 2 wintering grounds. Whales occupying one wintering ground spent most of their time diving to between 200 and 400 m (25 dives per day, SE 3), confirmed by both depth and temperature recording tags. In contrast, narwhals in a separate...... wintering ground spent less time at shallow depths and most of their time diving to at least 800 m (13 to 26 dives per day, SE 1 to 3). A model of occupancy time at depth showed that whales making multiple daily deep dives spent over 3 h at >800 m (SD 0.6) and traveled 13 min (SD 1) per round trip to reach...... this depth. Whales diving to between 200 and 400 m spent approximately 2.5 h (SD 0.4) at this depth, traveling 5 min per round trip. The observed differences in time allocation and dive behavior indicate local variation between the 2 wintering grounds in the Baffin Bay ecosystem....

  9. A new method to quantify within dive foraging behaviour in marine predators.

    Directory of Open Access Journals (Sweden)

    Karine Heerah

    Full Text Available Studies on diving behaviour classically divide a dive into three phases: the descent, bottom and ascent phases, with foraging assumed to occur during the bottom phase. The greater complexity of dive revealed through modern, high resolution data highlights the need to re-assess this approach and to consider a larger number of phases within individual dives. Two southern elephant seals (SES were fitted with a head mounted Time Depth Recorder (TDR and an accelerometer from which prey capture attempts were estimated. A Weddell seal was also fitted with a TDR. TDRs for both species recorded depth once per second. We quantified the within dive behaviour using an automated broken stick algorithm identifying the optimal number of segments within each dive. The vertical sinuosity of the segments was used to infer two types of behaviours, with highly sinuous segments indicating "hunting" and less sinuous segments indicating "transiting". Using the broken stick method the seals alternated between "hunting" and "transit" modes with an average of 6±2 and 7±0.02 behavioural phases within each dive for the Weddell seal and SES, respectively. In SES, 77% of prey capture attempts (identified from the acceleration data occurred in highly sinuous phases ("hunting" as defined by our new approach. SES spent more time in transit mode within a dive, and hunting mostly occurred during the bottom phase. Conversely the Weddell seal spent more time in hunting mode which also occurred during bottom phase but occurred mostly at shallower depths. Such differences probably reflect different foraging tactics and habitat use. For both species, hunting time differs significantly from bottom time previously used as a proxy for the time spent foraging in a dive. The hunting time defined by our method therefore provides a more accurate fine-scale description of the seals' foraging behaviour.

  10. Continuous real-time monitoring and recording of glycemia during scuba diving: pilot study.

    Science.gov (United States)

    Pieri, Massimo; Cialoni, Danilo; Marroni, Alessandro

    2016-01-01

    Insulin-dependent diabetes has been considered a scuba diving contraindication. This is currently being reconsidered for well-controlled diabetes. We developed a real-time continuous glucose monitor (CGM) to check glycemia, or blood glucose (BG), during diving, both for prospective studies and to increase diabetic diver safety, allowing for real-time control of glycemia and hypoglycemia prevention. To ensure CGM measurement accuracy we tested the method under hyperbaric conditions. Two experienced diabetic divers were studied during a one-week diving cruise. BG was monitored every five minutes on every dive, by a dedicated CGM, and values were visible to the divers throughout their dives. The mean of relative difference (MRD) between CGM and capillary blood glucose was calculated. Measurement accuracy was assessed according to ISO guideline 15197 and by Clarke Error Grid (CEG) analysis. Both divers showed gradual BG decrease during diving. Hyperbaric chamber accuracy tests showed two of 26 MRD values (7.7%) slightly exceeding the ISO-15197 allowed difference (5%). However, our data suggest that this discrepancy may have been an artefact. Our data (even limited to two subjects only) agree with the current literature showing that also in our investigated subjects diving does not imply significant risks of hypoglycemia. The use of a real-time CGM by diabetic divers during their dives can provide immediate information on BG values and trends, thus significantly improving diving safety. The accuracy tests comparing continuous glucose monitoring (CGM) and capillary blood glucose measurement (CBM) data recorded under hyperbaric conditions showed that data recorded under pressure are very close to the ISO-15197 and CEG acceptable limits.

  11. Dive characteristics can predict foraging success in Australian fur seals (Arctocephalus pusillus doriferus as validated by animal-borne video

    Directory of Open Access Journals (Sweden)

    Beth L. Volpov

    2016-03-01

    Full Text Available Dive characteristics and dive shape are often used to infer foraging success in pinnipeds. However, these inferences have not been directly validated in the field with video, and it remains unclear if this method can be applied to benthic foraging animals. This study assessed the ability of dive characteristics from time-depth recorders (TDR to predict attempted prey capture events (APC that were directly observed on animal-borne video in Australian fur seals (Arctocephalus pusillus doriferus, n=11. The most parsimonious model predicting the probability of a dive with ≥1 APC on video included only descent rate as a predictor variable. The majority (94% of the 389 total APC were successful, and the majority of the dives (68% contained at least one successful APC. The best model predicting these successful dives included descent rate as a predictor. Comparisons of the TDR model predictions to video yielded a maximum accuracy of 77.5% in classifying dives as either APC or non-APC or 77.1% in classifying dives as successful verses unsuccessful. Foraging intensity, measured as either total APC per dive or total successful APC per dive, was best predicted by bottom duration and ascent rate. The accuracy in predicting total APC per dive varied based on the number of APC per dive with maximum accuracy occurring at 1 APC for both total (54% and only successful APC (52%. Results from this study linking verified foraging dives to dive characteristics potentially opens the door to decades of historical TDR datasets across several otariid species.

  12. Returning on empty: extreme blood O2 depletion underlies dive capacity of emperor penguins.

    Science.gov (United States)

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

    2007-12-01

    Blood gas analyses from emperor penguins (Aptenodytes forsteri) at rest, and intravascular P(O(2)) profiles from free-diving birds were obtained in order to examine hypoxemic tolerance and utilization of the blood O(2) store during dives. Analysis of blood samples from penguins at rest revealed arterial P(O(2))s and O(2) contents of 68+/-7 mmHg (1 mmHg= 133.3 Pa) and 22.5+/-1.3 ml O(2) dl(-1) (N=3) and venous values of 41+/-10 mmHg and 17.4+/-2.9 ml O(2) dl(-1) (N=9). Corresponding arterial and venous Hb saturations for a hemoglobin (Hb) concentration of 18 g dl(-1) were >91% and 70%, respectively. Analysis of P(O(2)) profiles obtained from birds equipped with intravascular P(O(2)) electrodes and backpack recorders during dives revealed that (1) the decline of the final blood P(O(2)) of a dive in relation to dive duration was variable, (2) final venous P(O(2)) values spanned a 40-mmHg range at the previously measured aerobic dive limit (ADL; dive duration associated with onset of post-dive blood lactate accumulation), (3) final arterial, venous and previously measured air sac P(O(2)) values were indistinguishable in longer dives, and (4) final venous P(O(2)) values of longer dives were as low as 1-6 mmHg during dives. Although blood O(2) is not depleted at the ADL, nearly complete depletion of the blood O(2) store occurs in longer dives. This extreme hypoxemic tolerance, which would be catastrophic in many birds and mammals, necessitates biochemical and molecular adaptations, including a shift in the O(2)-Hb dissociation curve of the emperor penguin in comparison to those of most birds. A relatively higher-affinity Hb is consistent with blood P(O(2)) values and O(2) contents of penguins at rest.

  13. DIVE: a graph-based visual-analytics framework for big data.

    Science.gov (United States)

    Rysavy, Steven J; Bromley, Dennis; Daggett, Valerie

    2014-01-01

    The need for data-centric scientific tools is growing; domains such as biology, chemistry, and physics are increasingly adopting computational approaches. So, scientists must deal with the challenges of big data. To address these challenges, researchers built a visual-analytics platform named DIVE (Data Intensive Visualization Engine). DIVE is a data-agnostic, ontologically expressive software framework that can stream large datasets at interactive speeds. In particular, DIVE makes novel contributions to structured-data-model manipulation and high-throughput streaming of large, structured datasets.

  14. Insulin-dependent diabetes mellitus and recreational scuba diving in Australia.

    Science.gov (United States)

    Johnson, Rebecca

    2016-09-01

    Dive medicine bodies worldwide recognise that, with comprehensive screening and careful management, people with insulin-dependent diabetes (IDDM) can dive safely. Despite this, people with IDDM in Australia are generally denied access to dive training, an out-dated status quo that is not acceptable to the Australian diabetes community. This paper reflects upon the important advocacy work that has been done to progress this issue, and what is still required to open up access and bring Australia into line with more flexible and supportive international standards.

  15. Clinical Application of Newly Developed Custom-made Mouthpiece for Scuba Diving.

    Science.gov (United States)

    Hirose, Toshiaki; Gonda, Tomoya; Maeda, Yoshinobu

    To describe a method for customizing scuba diving mouthpieces, to examine their usability, and to assess divers' satisfaction with their use. A rational method for fabricating custom-made mouthpieces for scuba diving was developed. Twenty scuba divers agreed to use a custom-made mouthpiece for at least 4 weeks. After mouthpiece use, participants completed an 11-item questionnaire. Custom-made mouthpieces had significantly lower scores for all items on the questionnaire except uncomfortable sensation, indicating that they were more comfortable than ready-made mouthpieces. It can be concluded that these novel custom-made mouthpieces for scuba diving offer greater comfort than ready-made mouthpieces.

  16. Aerobic dive limits of seals with mutant myoglobin using combined thermochemical and physiological data

    DEFF Research Database (Denmark)

    Dasmeh, Pouria; Davis, Randall W.; Kepp, Kasper Planeta

    2013-01-01

    are nearly neutral in terms of ADL and the inferred fitness. We also find that the cardiac system, the muscle O2-store, animal behavior (i.e. pre-dive ventilation), and the oxygen binding affinity of Mb, KO2, have co-evolved to optimize dive duration at routine aerobic diving conditions, suggesting...... that such conditions are mostly selected upon in seals. The model is capable of roughly quantifying the physiological impact of single-protein mutations and thus bridges an important gap between animal physiology and molecular (protein) evolution....

  17. Assessing the congruence of thermal niche estimations derived from distribution and physiological data. A test using diving beetles.

    Directory of Open Access Journals (Sweden)

    David Sánchez-Fernández

    Full Text Available A basic aim of ecology is to understand the determinants of organismal distribution, the niche concept and species distribution models providing key frameworks to approach the problem. As temperature is one of the most important factors affecting species distribution, the estimation of thermal limits is crucially important for inferring range constraints. It is expectable that thermal physiology data derived from laboratory experiments and species' occurrences may express different aspects of the species' niche. However, there is no study systematically testing this prediction in a given taxonomic group while controlling by potential phylogenetic inertia. We estimate the thermal niches of twelve Palaearctic diving beetles species using physiological data derived from experimental analyses in order to examine the extent to which these coincided with those estimated from distribution models based on observed occurrences. We found that thermal niche estimates derived from both approaches lack general congruence, and these results were similar before and after controlling by phylogeny. The congruence between potential distributions obtained from the two different procedures was also explored, and we found again that the percentage of agreement were not very high (~60%. We confirm that both thermal niche estimates derived from geographical and physiological data are likely to misrepresent the true range of climatic variation that these diving beetles are able to tolerate, and so these procedures could be considered as incomplete but complementary estimations of an inaccessible reality.

  18. The extracranial venous system in the heads of beaked whales, with implications on diving physiology and pathogenesis.

    Science.gov (United States)

    Costidis, Alexander M; Rommel, Sentiel A

    2016-01-01

    Beaked whales are a poorly known but diverse group of whales that have received considerable attention due to strandings that have been temporally and spatially associated with naval sonar deployment. Postmortem studies on stranded carcasses have revealed lesions consistent with decompression sickness, including intravascular gas and fat emboli. These findings have been supported by analyses of intravascular gas emboli showing composition dominated by nitrogen gas. To increase our understanding of the pathophysiology of nitrogen bubble formation and intravascular embolization, we examined the gross and microscopic anatomy of the venous system in the head of beaked whales. Since the potential sources of intravascular fat and gas emboli were of greatest interest, focus was placed on the acoustic fat bodies and pneumatic accessory sinus system. Herein, we describe intimate arteriovenous associations with specialized adipose depots and air sinuses in beaked whales. These vascular structures comprise an extensive network of thin-walled vessels with a large surface area, which is likely to facilitate exchange of nitrogen gas and may, therefore, form anatomic regions that may be important in physiological management of diving gases. These structures may also be vulnerable to pathologic introduction of emboli into the vascular system. Expansive, thin-walled venous lakes are found within the pterygoid region, which suggest the potential for nitrogen exchange as well as for compensation of middle-ear pressures during descent on a dive. These findings warrant further research into the structure and function of this morphology as it relates to normal and pathologic physiology. © 2015 Wiley Periodicals, Inc.

  19. On the adiabatic theorem when eigenvalues dive into the continuum

    DEFF Research Database (Denmark)

    Cornean, Decebal Horia; Jensen, Arne; Knörr, Hans Konrad

    2018-01-01

    We consider a reduced two-channel model of an atom consisting of a quantum dot coupled to an open scattering channel described by a three-dimensional Laplacian. We are interested in the survival probability of a bound state when the dot energy varies smoothly and adiabatically in time. The initia...... in the adiabatic limit. At the end of the paper, we present a short outlook on how our method may be extended to cover other classes of Hamiltonians; details will be given elsewhere....... state corresponds to a discrete eigenvalue which dives into the continuous spectrum and re-emerges from it as the dot energy is varied in time and finally returns to its initial value. Our main result is that for a large class of couplings, the survival probability of this bound state vanishes...

  20. Airway efficiency during the use of SCUBA diving mouthpieces.

    Science.gov (United States)

    Hobson, R S

    1996-01-01

    OBJECTIVE: To investigate the effect of varying interdental bite platform thickness of the scuba mouthpiece on airway efficiency. METHODS: 10 male divers had their mean peak flow measured for free breathing, maximum flow with diving mouthpiece, teeth in occlusion, and for five experimental mouthpieces with different thickness of interdental bite platform (1 mm, 2 mm, 3 mm, 4 mm, and 5 mm). RESULTS: The connecting airway between the demand valve and mouthpiece was found to be a major limiting factor in airway efficiency. An interdental bite platform of 4 mm resulted in the greatest air flow with a further increase in thickness resulting in air flow restriction. CONCLUSIONS: The use of an interdental bite platform of 4 mm placed between the premolar and molar teeth ensures the greatest airway efficiency and also results in a design which provides the least temporomandibular joint discomfort for the diver. Images Figure 1 Figure 2 PMID:8799600

  1. Course Outline for a SCUBA Diving Speciality "UNDERWATER Survey DIVER"

    Science.gov (United States)

    Papadimitriou, K.

    2015-04-01

    The purpose of this paper is to outline a course for the training of divers with a special interest in underwater surveying (e.g. surveyors, archaeologists, biologists, geologists, photographers/videographers). This outline presents: i) the Courses' Standards ii) the Learning Objectives for the related Knowledge Development, iii) the Skills that have to be conducted, iv) the Performance Requirements for the students and v) the Open Water Considerations for the Training Dives. It is expected that the resulting course outline will be used as a reference for the training of certified divers who want to become underwater surveyors, providing them basic knowledge and skills to survey adequate data for the detailed documentation of submerged features. Moreover the combination of knowledge (what) and the skills (how) that are presented during the proposed course attempt to define a protocol for the recording of underwater features in favor of mapping and 3D modeling.

  2. A case of deep burns, while diving The Lusitania.

    LENUS (Irish Health Repository)

    Curran, John N

    2010-07-01

    We present the first documented case of severe burns, sustained by a diver as a result of auto-ignition of air-activated heat packs at high partial pressure of oxygen and high ambient pressure. Our patient was diving the shipwreck of The Lusitania off the south coast of Ireland. This is a significant wreck, lying 90 metres down on the seabed. Torpedoed by a German U-boat in 1915, its loss prompted American involvement in WW1. Several unlikely events combined in this case to bring about serious and life threatening injuries. Herein we discuss the case and explore some of the physical and chemical processes that lead to these injuries.

  3. Regional variability in diving physiology and behavior in a widely distributed air-breathing marine predator, the South American sea lion (Otaria byronia).

    Science.gov (United States)

    Hückstädt, Luis A; Tift, Michael S; Riet-Sapriza, Federico; Franco-Trecu, Valentina; Baylis, Alastair M M; Orben, Rachael A; Arnould, John P Y; Sepulveda, Maritza; Santos-Carvallo, Macarena; Burns, Jennifer M; Costa, Daniel P

    2016-08-01

    Our understanding of how air-breathing marine predators cope with environmental variability is limited by our inadequate knowledge of their ecological and physiological parameters. Because of their wide distribution along both coasts of the sub-continent, South American sea lions (Otaria byronia) provide a valuable opportunity to study the behavioral and physiological plasticity of a marine predator in different environments. We measured the oxygen stores and diving behavior of South American sea lions throughout most of its range, allowing us to demonstrate that diving ability and behavior vary across its range. We found no significant differences in mass-specific blood volumes of sea lions among field sites and a negative relationship between mass-specific oxygen storage and size, which suggests that exposure to different habitats and geographical locations better explains oxygen storage capacities and diving capability in South American sea lions than body size alone. The largest animals in our study (individuals from Uruguay) were the shallowest and shortest duration divers, and had the lowest mass-specific total body oxygen stores, while the deepest and longest duration divers (individuals from southern Chile) had significantly larger mass-specific oxygen stores, despite being much smaller animals. Our study suggests that the physiology of air-breathing diving predators is not fixed, but that it can be adjusted, to a certain extent, depending on the ecological setting and or habitat. These adjustments can be thought of as a 'training effect': as the animal continues to push its physiological capacity through greater hypoxic exposure, its breath-holding capacity increases. © 2016. Published by The Company of Biologists Ltd.

  4. Dive Activities for Bioluminescence 2009 - Office of Ocean Exploration and Research

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Information about dive activities were recorded by personnel during the "Bioluminescence 2009" expedition, July 20 through 31, 2009. Additional information was...

  5. EX1504L4 Dive03 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  6. EX1504L3 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  7. Personality and behavioural outcomes in diving: current status and recommendations for future research.

    Science.gov (United States)

    van Wijk, Charles H

    2017-12-01

    This paper provides a brief overview of the shift from studies describing the personality profiles of divers to studies exploring associations between personality variables and diving performance in terms of behavioural outcomes. The personality associations that were investigated include performance during training, panic proneness, diving injuries, susceptibility to inert gas narcosis, and the behaviour of tourist divers. The paper concludes with a number of suggested directions for further research on personality and diving that may provide tangible benefits in terms of both enhanced safety and improved performance underwater. Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.

  8. EX1605L3 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  9. EX1606 Dive03 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  10. EX1504L4 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  11. EX1606 Dive01 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  12. EX1606 Dive09 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  13. EX1605L3 Dive01 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  14. EX1606 Dive14 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  15. EX1504L3 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  16. EX1605L3 Dive20 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  17. EX1504L2 Dive14 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  18. EX1606 Dive10 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  19. EX1504L4 Dive12 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  20. EX1504L3 Dive03 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  1. EX1605L3 Dive15 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  2. EX1605L3 Dive09 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  3. EX1605L3 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  4. EX1504L2 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  5. EX1605L3 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  6. EX1606 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  7. EX1504L4 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  8. EX1504L2 Dive18 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  9. EX1606 Dive11 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  10. EX1605L3 Dive08 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  11. EX1504L2 Dive16 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  12. EX1605L3 Dive10 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  13. EX1605L3 Dive16 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  14. EX1606 Dive08 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  15. EX1605L3 Dive22 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  16. EX1605L3 Dive17 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  17. EX1606 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  18. EX1504L4 Dive10 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  19. EX1605L3 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  20. EX1605L3 Dive12 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  1. EX1504L3 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  2. EX1606 Dive12 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  3. EX1605L3 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  4. EX1605L3 Dive21 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  5. EX1606 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  6. EX1605L3 Dive19 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  7. EX1605L3 Dive14 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  8. EX1504L2 Dive12 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  9. EX1605L3 Dive11 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  10. EX1605L3 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  11. EX1504L2 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  12. EX1606 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  13. EX1606 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  14. Non-Dive Activities for Operation Deep Scope 2005 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Information about non-dive activities were recorded into the Cruise Information Management System (CIMS) by the NOAA Office of Ocean Exploration's data manager...

  15. EX1606 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  16. Bermuda Deep Water Caves 2011: Dives of Discovery between 20110607 and 20110627

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During the three week NOAA Ocean Exploration project, Bermuda Deep Water Caves 2011: Dives of Discovery, our four member deep team, aided by numerous assistants,...

  17. Submersible Data (Dive Trackpoints) for Life on the Edge 2004 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data and information collected by the submersible Johnson Sea-Link I along its track during twenty-five dives of the 2004 "Life on the Edge" expedition sponsored by...

  18. Pulmonary Effects of Eight-Hour MK 16 MOD 1 Dives

    National Research Council Canada - National Science Library

    Shykoff, B

    2007-01-01

    ...) to those previously attained at 12 to 14 feet. Seventeen U.S. Navy divers dove underwater in the ascent tower at Navy Diving and Salvage Training Center with the MK 16 MOD 1 underwater breathing apparatus...

  19. Dive Activities for Expedition to the Deep Slope 2006 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Information about dive activities were recorded by personnel during the "Expedition to the Deep Slope 2006" expedition, May 7 through June 2, 2006. Additional...

  20. Dive Activities for Expedition to the Deep Slope 2007 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Information about dive activities were recorded by personnel during the "Expedition to the Deep Slope 2007" expedition, June 4 through July 6, 2007. Additional...

  1. EX1504L2 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  2. EX1504L2 Dive01 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  3. Submersible Data (Dive Trackpoints) for Davidson Seamount 2006 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data and information collected by the Remotely Operated Vehicle Tiburon along its track during thirteen dives of the "Davidson Seamount 2006" expedition sponsored by...

  4. EX1504L3 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  5. EX1504L2 Dive17 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  6. EX1504L2 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  7. EX1504L3 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  8. EX1504L4 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  9. EX1504L2 Dive08 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  10. EX1504L2 Dive10 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  11. EX1504L2 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  12. Facial baroparesis: a critical differential diagnosis for scuba diving accidents--case report.

    Science.gov (United States)

    Iakovlev, E V; Iakovlev, V V

    2014-01-01

    Facial nerve baroparesis is a rare and potentially under-reported complication of scuba diving. A diver, after surfacing from a shallow dive, developed isolated left-sided facial palsy accompanied by pain and decreased hearing in the left ear. No other signs or symptoms attributable to a scuba diving accident were detected. Forty minutes later, he heard a "pop" in the affected ear, after which all symptoms quickly resolved. Repeat neurological and ear examinations were normal. He showed no residual or new symptoms 24 hours later. The differential diagnosis of facial neurological deficit after diving includes decompression sickness, cerebral air embolism due to pulmonary barotrauma, facial nerve barotrauma and common conditions such as stroke and Bell's palsy. It is important to recognize the condition since recompression treatment can further damage the facial nerve.

  13. Growing Evidence about the Relationship between Vessel Dissection and Scuba Diving

    Directory of Open Access Journals (Sweden)

    Simona Brajkovic

    2013-09-01

    Full Text Available Carotid and vertebral artery dissection are relatively frequent and risky conditions. In the last decade, different patients with extracranial (and in 1 case also intracranial dissections associated with the practice of scuba diving were reported. The connection between the two conditions has not been fully explained so far. In the present article, we report the case of a patient presenting with Claude Bernard-Horner syndrome and homolateral XII cranial nerve palsy, manifesting a few days after diving in the cold water of a lake. The patient ended up having internal carotid artery dissection associated with the formation of a pseudoaneurysm. Here, we offer a summary of all cases reported in the literature about scuba diving and arterial dissection, and provide a critical discussion about which scuba diving-related factors can trigger the dissection of cervical vessels.

  14. Growing Evidence about the Relationship between Vessel Dissection and Scuba Diving.

    Science.gov (United States)

    Brajkovic, Simona; Riboldi, Giulietta; Govoni, Alessandra; Corti, Stefania; Bresolin, Nereo; Comi, Giacomo Pietro

    2013-01-01

    Carotid and vertebral artery dissection are relatively frequent and risky conditions. In the last decade, different patients with extracranial (and in 1 case also intracranial) dissections associated with the practice of scuba diving were reported. The connection between the two conditions has not been fully explained so far. In the present article, we report the case of a patient presenting with Claude Bernard-Horner syndrome and homolateral XII cranial nerve palsy, manifesting a few days after diving in the cold water of a lake. The patient ended up having internal carotid artery dissection associated with the formation of a pseudoaneurysm. Here, we offer a summary of all cases reported in the literature about scuba diving and arterial dissection, and provide a critical discussion about which scuba diving-related factors can trigger the dissection of cervical vessels.

  15. Recreational scuba diving in Caribbean marine protected areas: do the users pay?

    Science.gov (United States)

    Green, Edmund; Donnelly, Rachel

    2003-03-01

    There are more than 200 marine protected areas (MPAs) in the Caribbean and Central America that contain coral reefs and are therefore theoretically attractive to scuba divers. One fifth of dive operators in 30 countries were surveyed for their use of MPAs: the majority are located within 20 km of at least one MPA and 46% conduct at least 80% of their diving within a MPA. An estimated 15 million dives take place outside of Florida each year, half of these occurring inside MPAs. Only 25% of MPAs containing coral reefs charge divers an entry or user fee, which is most usually USD 2-3 levied per dive or per diver. The revenue generated by these fees is estimated at USD 1-2 million annually, but the potential for generating income has not been fully realized. A significant contribution to the cost of regional conservation could be achieved if higher fees were applied more widely than at present.

  16. Non-Dive Activities for Life on the Edge 2004 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Information about non-dive activities were recorded into the Cruise Information Management System (CIMS) by the NOAA Office of Ocean Exploration's data manager...

  17. Submersible Data (Dive Waypoints) for Investigating the Charleston Bump 2003 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data and information collected by the submersible Johnson Sea-Link II at waypoints along its track during fourteen dives of the 2003 "Investigating the Charleston...

  18. Submersible Data (Dive Trackpoints) for Expedition to the Deep Slope 2007 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data and information collected by the ROV Jason along its track during sixteen dives of the 2007 "Expedition to the Deep Slope" expedition sponsored by the National...

  19. Four-Hour Dives with Exercise While Breathing Oxygen Partial Pressure of 1.3 ATM

    National Research Council Canada - National Science Library

    Shykoff, B

    2006-01-01

    ...) or less but does not address the possible accumulation of effects over multiple days. We have conducted experimental four-hour dives with oxygen partial pressure (Po2) of approximately 1.4 atmospheres (atm...

  20. Three-Hour Dives with Exercise While Breathing Oxygen Partial Pressure of 1.3 ATM

    National Research Council Canada - National Science Library

    Shykoff, B

    2007-01-01

    ...) or less but does not address the possible accumulation of effects over multiple days. When we conducted experimental four-hour dives with oxygen partial pressure (Po2) of approximately 1.4 atmospheres (atm...

  1. EX1504L4 Dive01 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  2. EX1504L4 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  3. EX1504L2 Dive11 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  4. EX1504L4 Dive09 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  5. EX1504L4 Dive11 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  6. EX1504L2 Dive09 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  7. EX1504L4 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  8. EX1504L4 Dive08 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  9. EX1504L2 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  10. Buoyancy Regulation and the Energetics of Diving in Dolphins Seals, Sea Lions and Sea Otters

    National Research Council Canada - National Science Library

    Costa, Daniel

    1998-01-01

    We examined swim speed and ascent descent rates in sea lions and elephant seals in order to make comparisons in their diving strategies and how these may be effected by different strategies of buoyancy regulation...

  11. EX1504L4 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  12. EX1504L2 Dive15 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  13. Winter and spring diving behavior of bowhead whales relative to prey

    KAUST Repository

    Heide-Jørgensen, Mads

    2013-10-23

    Background Little is known about bowhead whale (Balaena mysticetus) foraging behavior and what concentrations of prey are required to balance the energetic trade-offs of feeding. We used satellite telemetry, archival depth recorders, and water column echo sounding data to study bowhead whale diving behavior relative to prey depth and concentration in Disko Bay, West Greenland. Results Between March and May 2008 to 2011, nine bowhead whales were tagged in Disko Bay, West Greenland with instruments that collected data on location and diving over a period of 1 to 33 days. The frequency of U-dives (presumed to be foraging dives) was low during winter months but more than doubled in spring concurrent with a decrease in diving depth. The mean speed of the horizontal bottom phase of the U-dives was 0.9 ms-1 and on average, whales spent 37% of their time at the bottom phase of the dive. In March, bowhead whales presumably fed on copepods (Calanus spp.) close to the seabed (between 100 and 400 m). In April and May, after the copepods ascended to shallower depths, bowhead whales also dove to shallower depths (approximately 30 m) more often. However, echo sounding surveys in the vicinity of feeding whales in early May indicated that patches of copepods could still be found close to the seabed. Conclusions There was a marked change in diving behavior from winter through spring and this was likely in response to the changes in sea ice conditions, primary production and potential copepod abundance in the upper part of the water column. Depth and duration of dives changed significantly during this period; however, other dive parameters (for example the proportion of time spent feeding on the bottom of U-dives) remained fairly constant indicating a constant feeding effort. Bowhead whales target copepods at or close to the seabed in winter months in Disko Bay and continue feeding on copepods when they migrate to the surface. However, bowhead whales leave West Greenland before peak

  14. Design of an adaptive controller for dive-plane control of a torpedo-shaped AUV

    Science.gov (United States)

    Cao, Jian; Su, Yumin; Zhao, Jinxin

    2011-09-01

    Underwater vehicles operating in complex ocean conditions present difficulties in determining accurate dynamic models. To guarantee robustness against parameter uncertainty, an adaptive controller for dive-plane control, based on Lyapunov theory and back-stepping techniques, was proposed. In the closed-loop system, asymptotic tracking of the reference depth and pitch angle trajectories was accomplished. Simulation results were presented which show effective dive-plane control in spite of the uncertainties in the system parameters.

  15. The political economy of dive tourism: precarity at the periphery in Malaysia

    OpenAIRE

    Hampton, Mark P.; Jeyacheya, Julia; Lee, Donna

    2017-01-01

    Using a critical political economy approach and the concept of labour precarity, the international dive tourism industry in Sabah, Malaysia and its workers’ vulnerabilities are interrogated. Fieldwork data highlights dive tourism’s socio-economic impacts and the precarity of labour within the international tourism sector and also critiques it as a development strategy for a peripheral region. The paper challenges the optimistic views of labour precarity found in the existing political economy...

  16. DIVE: A Graph-based Visual Analytics Framework for Big Data

    OpenAIRE

    Rysavy, Steven J.; Bromley, Dennis; Daggett, Valerie

    2014-01-01

    The need for data-centric scientific tools is growing; domains like biology, chemistry, and physics are increasingly adopting computational approaches. As a result, scientists must now deal with the challenges of big data. To address these challenges, we built a visual analytics platform named DIVE: Data Intensive Visualization Engine. DIVE is a data-agnostic, ontologically-expressive software framework capable of streaming large datasets at interactive speeds. Here we present the technical d...

  17. A Review of SCUBA Diving Impacts and Implication for Coral Reefs Conservation and Tourism Management

    OpenAIRE

    Zainal Abidin Siti Zulaiha; Mohamed Badaruddin

    2014-01-01

    Dive tourism has become important in term of magnitude and significantly contributes to regional economies. Nevertheless, in the absence of proper controls and enforcement, unplanned tourism growth has caused environmental degradation which undermines the long-term sustainability of the tourism industry. The purpose of this paper is to explore factors that contribute to the SCUBA diving impacts on coral and fish communities. This paper explains the causes of a certain event, validating the pr...

  18. Dive Tourism and the Entrepreneurial Process in the Perhentian Islands, Malaysia

    OpenAIRE

    Jeyacheya, Julia; Hampton, Mark P.

    2016-01-01

    Dive tourism is a high growth, niche sector for island and coastal developing nations and is propelled predominantly by local tourism entrepreneurs and small businesses. This chapter examines dive tourism in peninsula Malaysia and particularly the factors influencing the entrepreneurial process. Much research on tourism entrepreneurs is derived from analysing business in the developed world, and has focused on the individual, not the process. Significantly less research exists for middle inco...

  19. Can foraging ecology drive the evolution of body size in a diving endotherm?

    Directory of Open Access Journals (Sweden)

    Timothée R Cook

    Full Text Available Within a single animal species, different morphs can allow for differential exploitation of foraging niches between populations, while sexual size dimorphism can provide each sex with access to different resources. Despite being potentially important agents of evolution, resource polymorphisms, and the way they operate in wild populations, remain poorly understood. In this study, we examine how trophic factors can select for different body sizes between populations and sexes in a diving endotherm. Dive depth and duration are positively related to body size in diving birds and mammals, a relationship explained by a lower mass-specific metabolic rate and greater oxygen stores in larger individuals. Based on this allometry, we predict that selection for exploiting resources situated at different depths can drive the evolution of body size in species of diving endotherms at the population and sexual level. To test this prediction, we studied the foraging ecology of Blue-eyed Shags, a group of cormorants with male-biased sexual size dimorphism from across the Southern Ocean. We found that mean body mass and relative difference in body mass between sexes varied by up to 77% and 107% between neighbouring colonies, respectively. Birds from colonies with larger individuals dived deeper than birds from colonies with smaller individuals, when accounting for sex. In parallel, males dived further offshore and deeper than females and the sexual difference in dive depth reflected the level of sexual size dimorphism at each colony. We argue that body size in this group of birds is under intense selection for diving to depths of profitable benthic prey patches and that, locally, sexual niche divergence selection can exaggerate the sexual size dimorphism of Blue-eyed Shags initially set up by sexual selection. Our findings suggest that trophic resources can select for important geographic micro-variability in body size between populations and sexes.

  20. Pulmonary Function in a Diving Population Aged Over 40 Years Old: A Cross-Sectional Study

    Science.gov (United States)

    2000-08-01

    1992. Universidad de Murcia. Br.J.Ind.Med. 1987; 44:467-469. 14. MELERO MORENO C. Enfermedad 3. CALI-CORLEO R. Special medical pulmonar obstructiva...DE Respiratory mechanics in men following a LA ESPIROMETRIA FORZADA. Grupo deep air dive. J. Appl. Physiol. 1986; 61: de trabajo de la SEPAR, para la...diving experience to pulmonary function REQUENA JM. CARRERAS CASTELLET among U.S. Navy Divers.Undersea JM. Enfermedad pulmonar obstructiva Bimedical

  1. Crystal structure of an ethylene sorption complex of fully vacuum-dehydrated fully Ag+-exchanged zeolite X (FAU). Silver atoms have reduced ethylene to give CH2 2- carbanions at framework oxide vacancies.

    Science.gov (United States)

    Lee, Young Mi; Choi, Seo Jung; Kim, Yang; Seff, Karl

    2005-11-03

    The crystal structure of an ethylene sorption complex of fully vacuum-dehydrated fully Ag(+)-exchanged zeolite X (FAU), a = 24.865(2) A, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd at 21 degrees C. It is very different from the ethylene complex of Ag(92)-X that had been dehydrated at 400 degrees C in flowing oxygen, as were the two dehydrated structures. The crystal was prepared by ion exchange in a flowing stream of aqueous 0.05 M AgNO(3) for 3 days, followed by dehydration at 400 degrees C and 2 x 10(-6) Torr for 2 days, followed by exposure to 300 Torr of zeolitically dry ethylene gas for 2 h at 21 degrees C. The structure was determined in this atmosphere and was refined using all data to the final error indices (based upon the 534 reflections for which F(o) > 4sigma(F(o))) R(1) = 0.062 and wR(2) = 0.135. In this structure, per unit cell, 14 Ag(+) ions were found at the octahedral site I (Ag-O = 2.611(9) A), and 32 partially reduced Ag(+) ions fill two different site I' positions deep in the sodalite cavities (Ag-O = 2.601(13) and 2.618(12) A). The sodalite cavities host two different cationic silver clusters. In about 47% of sodalite units, eight silver atoms form interpenetrating tetrahedra, Ag(8)(n+) (n = 4 is suggested), with T(d)() symmetry. The other 53% of the sodalite units host cyclo-Ag(4)(m+) (m = 2 is suggested) cations with near S(4) symmetry. These clusters are very similar to those in vacuum-dehydrated Ag(92)-X. Thirty-two Ag(+) ions fill the single 6-rings, 15 at site II' (Ag-O = 2.492(10) A), and 17 at site II (Ag-O = 2.460(9) A). The latter 17 lie in supercages where each forms a lateral pi-complex with an ethylene molecule. In turn, each C(2)H(4) molecule forms two cis electrostatic hydrogen bonds to framework oxygens. The remaining 14 Ag+ ions occupy three different II' sites. Vacuum dehydration had caused substantial decomposition: per unit cell, 30 of the 92 Ag(+) ions were reduced and 15

  2. Diving behaviour of Cuvier's beaked whales exposed to two types of military sonar.

    Science.gov (United States)

    Falcone, Erin A; Schorr, Gregory S; Watwood, Stephanie L; DeRuiter, Stacy L; Zerbini, Alexandre N; Andrews, Russel D; Morrissey, Ronald P; Moretti, David J

    2017-08-01

    Cuvier's beaked whales ( Ziphius cavirostris ) have stranded in association with mid-frequency active sonar (MFAS) use, and though the causative mechanism linking these events remains unclear, it is believed to be behaviourally mediated. To determine whether MFAS use was associated with behavioural changes in this species, satellite tags were used to record the diving and movements of 16 Cuvier's beaked whales for up to 88 days in a region of frequent MFAS training off the coast of Southern California. Tag data were combined with summarized records of concurrent bouts of high-power, surface-ship and mid-power, helicopter-deployed MFAS use, along with other potential covariates, in generalized additive mixed-effects models. Deep dives, shallow dives and surface intervals tended to become longer during MFAS use, with some variation associated with the total amount of overlapping MFAS during the behaviour. These changes in dives and surface intervals contributed to a longer interval between deep dives, a proxy for foraging disruption in this species. Most responses intensified with proximity and were more pronounced during mid-power than high-power MFAS use at comparable distances within approximately 50 km, despite the significantly lower source level of mid-power MFAS. However, distance-mediated responses to high-power MFAS, and increased deep dive intervals during mid-power MFAS, were evident up to approximately 100 km away.

  3. Using stimulation of the diving reflex in humans to teach integrative physiology.

    Science.gov (United States)

    Choate, Julia K; Denton, Kate M; Evans, Roger G; Hodgson, Yvonne

    2014-12-01

    During underwater submersion, the body responds by conserving O2 and prioritizing blood flow to the brain and heart. These physiological adjustments, which involve the nervous, cardiovascular, and respiratory systems, are known as the diving response and provide an ideal example of integrative physiology. The diving reflex can be stimulated in the practical laboratory setting using breath holding and facial immersion in water. Our undergraduate physiology students complete a laboratory class in which they investigate the effects of stimulating the diving reflex on cardiovascular variables, which are recorded and calculated with a Finapres finger cuff. These variables include heart rate, cardiac output, stroke volume, total peripheral resistance, and arterial pressures (mean, diastolic, and systolic). Components of the diving reflex are stimulated by 1) facial immersion in cold water (15°C), 2) breathing with a snorkel in cold water (15°C), 3) facial immersion in warm water (30°C), and 4) breath holding in air. Statistical analysis of the data generated for each of these four maneuvers allows the students to consider the factors that contribute to the diving response, such as the temperature of the water and the location of the sensory receptors that initiate the response. In addition to providing specific details about the equipment, protocols, and learning outcomes, this report describes how we assess this practical exercise and summarizes some common student misunderstandings of the essential physiological concepts underlying the diving response. Copyright © 2014 The American Physiological Society.

  4. Temporomandibular disorders in scuba divers-an increased risk during diving certification training.

    Science.gov (United States)

    Oztürk, Ozmen; Tek, Mustafa; Seven, Hüseyin

    2012-11-01

    The design of a diving regulator's mouthpiece increases the risk of a temporomandibular disorder (TMD) in scuba divers. The total weight of a diving regulator is reflected directly on the temporomandibular joint, causing articular and periarticular disorders. In the current study, the prevalence of TMD in scuba divers triggered during diving certification training is investigated. We also aimed to determine the factors that lead to TMD during diving training and clarify the observation that there is an increased incidence of TMD in inexperienced divers. The study was held between 2006 and 2011. Ninety-seven divers were referred with the complaint of pain around temporomandibular area. The divers were classified according to their diving experience. Symptoms and signs of TMD were graded. Fourteen divers were diagnosed with TMD. Temporomandibular disorder was seen more frequently in inexperienced divers than in experienced divers (P = 0.0434). The most prevalent symptom was an increased effort for mouthpiece gripping. Temporomandibular joint tenderness and trigger point activation were the mostly seen physical signs. Thirteen divers had an improvement with therapy. The increased effort for stabilizing the mouthpiece is a recognized factor in TMD development. Attention must be paid to an association of scuba diving with TMDs, especially in inexperienced divers having a scuba certification training.

  5. Ecological carrying capacity assessment of diving site: A case study of Mabul Island, Malaysia.

    Science.gov (United States)

    Zhang, Li-Ye; Chung, Shan-Shan; Qiu, Jian-Wen

    2016-12-01

    Despite considered a non-consumptive use of the marine environment, diving-related activities can cause damages to coral reefs. It is imminent to assess the maximum numbers of divers that can be accommodated by a diving site before it is subject to irreversible deterioration. This study aimed to assess the ecological carrying capacity of a diving site in Mabul Island, Malaysia. Photo-quadrat line transect method was used in the benthic survey. The ecological carrying capacity was assessed based on the relationship between the number of divers and the proportion of diver damaged hard corals in Mabul Island. The results indicated that the proportion of diver damaged hard corals occurred exponentially with increasing use. The ecological carrying capacity of Mabul Island is 15,600-16,800 divers per diving site per year at current levels of diver education and training with a quarterly threshold of 3900-4200 per site. Our calculation shows that management intervention (e.g. limiting diving) is justified at 8-14% of hard coral damage. In addition, the use of coral reef dominated diving sites should be managed according to their sensitivity to diver damage and the depth of the reefs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Sponge divers of the Aegean and medical consequences of risky compressed-air dive profiles.

    Science.gov (United States)

    Toklu, Akin Savas; Cimsit, Maide

    2009-04-01

    Historically, Turkey once had a substantial number of professional sponge divers, a population known for a relatively high incidence of diving-related conditions such as decompression sickness (DCS) and dysbaric osteonecrosis (DON). Sponge diving ended in the mid-1980s when nearly all of the sponges in the Aegean and Mediterranean Seas contracted a bacterial disease and the occupation became unprofitable. We reviewed the records of Turkish sponge divers for information on their level of knowledge, diving equipment, dive profiles, and occupational health problems. Information was collected by: 1) interviewing former sponge divers near Bodrum, where most of them had settled; 2) reviewing the relevant literature; and 3) examining the medical records of sponge divers who underwent recompression treatment. These divers used three types of surface-supplied equipment, including hard helmets, Fernez apparatus, and hookahs; the latter were preferred because they allowed divers the greatest freedom of movement while harvesting sponges underwater. These divers used profiles that we now know involved a high risk for DCS and DON. We were able to access the records of 58 divers who had received recompression treatment. All of the cases involved severe DCS and delays from dive to recompression that averaged 72 h. Complete resolution of symptoms occurred in only 11 cases (19%). Thus, we were able to document the several factors that contributed to the risks in this occupational group, including unsafe dive profiles, resistance to seeking treatment, long delays before recompression, and the fact that recompression treatment used air rather than oxygen.

  7. Gliding flight: speed and acceleration of ideal falcons during diving and pull out.

    Science.gov (United States)

    Tucker

    1998-01-14

    Some falcons, such as peregrines (Falco peregrinus), attack their prey in the air at the end of high-speed dives and are thought to be the fastest of animals. Estimates of their top speed in a dive range up to 157 m s-1, although speeds this high have never been accurately measured. This study investigates the aerodynamic and gravitational forces on 'ideal falcons' and uses a mathematical model to calculate speed and acceleration during diving. Ideal falcons have body masses of 0.5-2.0 kg and morphological and aerodynamic properties based on those measured for real falcons. The top speeds reached during a dive depend on the mass of the bird and the angle and duration of the dive. Given enough time, ideal falcons can reach top speeds of 89-112 m s-1 in a vertical dive, the higher speed for the heaviest bird, when the parasite drag coefficient has a value of 0.18. This value was measured for low-speed flight, and it could plausibly decline to 0.07 at high speeds. Top speeds then would be 138-174 m s-1. An ideal falcon diving at angles between 15 and 90 degrees with a mass of 1 kg reaches 95 % of top speed after travelling approximately 1200 m. The time and altitude loss to reach 95 % of top speed range from 38 s and 322 m at 15 degrees to 16 s and 1140 m at 90 degrees, respectively. During pull out at top speed from a vertical dive, the 1 kg ideal falcon can generate a lift force 18 times its own weight by reducing its wing span, compared with a lift force of 1.7 times its weight at full wing span. The falcon loses 60 m of altitude while pulling out of the dive, and lift and loss of altitude both decrease as the angle of the dive decreases. The 1 kg falcon can slow down in a dive by increasing its parasite drag and the angle of attack of its wings. Both lift and drag increase with angle of attack, but the falcon can cancel the increased lift by holding its wings in a cupped position so that part of the lift is directed laterally. The increased drag of wings producing

  8. Effects of oxygen-enriched air on cognitive performance during SCUBA-diving - an open-water study.

    Science.gov (United States)

    Brebeck, Anne-Kathrin; Deussen, Andreas; Schmitz-Peiffer, Henning; Range, Ursula; Balestra, Costantino; Cleveland, Sinclair; Schipke, Jochen D

    2017-01-01

    Backround: Nitrogen narcosis impairs cognitive function, a fact relevant during SCUBA-diving. Oxygen-enriched air (nitrox) became popular in recreational diving, while evidence of its advantages over air is limited. Compare effects of nitrox28 and air on two psychometric tests. In this prospective, double-blind, open-water study, 108 advanced divers (38 females) were randomized to an air or a nitrox-group for a 60-min dive to 24 m salt water. Breathing gas effects on cognitive performance were assessed during the dive using a short- and long-term memory test and a number connection test. Nitrox28 divers made fewer mistakes only on the long-term memory test (p = 0.038). Female divers remembered more items than male divers (p dive, beneficial nitrox28 effects to diver performance were moderate but could contribute to diving safety.

  9. Hardware and Procedures for Using the Diveair2 Monitor to Test Diving Air Quality in the Field

    Science.gov (United States)

    2011-09-01

    sampling hardware, consisting of a. four high-pressure (HP) adaptors to attach to various Navy sources of diving air — scuba , the Lightweight...Compressors and air banks. 2) Scuba bottles that have already been charged. 3) The Navy’s Lightweight Dive System (LWDS), both during and following...of ~150 mL/min. 7. Skip down to DIVING AIR MONITORING (section F). E. TESTING SCUBA BOTTLES (previously charged) or TESTING LWDS AND FADS

  10. Comparative analysis of free and scuba diving for benthopelagic and cryptic fish species associated with rocky reefs

    OpenAIRE

    Giordano,Rodolfo Gutterres; Santos,Luciano Neves dos

    2014-01-01

    This work aimed to assess, through experimental comparisons between free and scuba diving performed in Arraial do Cabo city, RJ, Brazil, the abundances of Scartella cristata e Chaetodon striatus -two reef fish species of contrasting behaviors- in different depth layers of sheltered and exposed rocky reefs. C. striatus was homogeneously distributed through all the depth strata (0-10 m) and scuba diving should be preferred over free diving to assess the abundance of this species at exposed rock...

  11. Physiological, morphological, and ecological tradeoffs influence vertical habitat use of deep-diving toothed-whales in the Bahamas

    Science.gov (United States)

    Durban, John W.; Claridge, Diane E.; Dunn, Charlotte A.; Fearnbach, Holly; Parsons, Kim M.; Andrews, Russel D.; Ballance, Lisa T.

    2017-01-01

    Dive capacity among toothed whales (suborder: Odontoceti) has been shown to generally increase with body mass in a relationship closely linked to the allometric scaling of metabolic rates. However, two odontocete species tagged in this study, the Blainville’s beaked whale Mesoplodon densirostris and the Cuvier’s beaked whale Ziphius cavirostris, confounded expectations of a simple allometric relationship, with exceptionally long (mean: 46.1 min & 65.4 min) and deep dives (mean: 1129 m & 1179 m), and comparatively small body masses (med.: 842.9 kg & 1556.7 kg). These two species also exhibited exceptionally long recovery periods between successive deep dives, or inter-deep-dive intervals (M. densirostris: med. 62 min; Z. cavirostris: med. 68 min). We examined competing hypotheses to explain observed patterns of vertical habitat use based on body mass, oxygen binding protein concentrations, and inter-deep-dive intervals in an assemblage of five sympatric toothed whales species in the Bahamas. Hypotheses were evaluated using dive data from satellite tags attached to the two beaked whales (M. densirostris, n = 12; Z. cavirostris, n = 7), as well as melon-headed whales Peponocephala electra (n = 13), short-finned pilot whales Globicephala macrorhynchus (n = 15), and sperm whales Physeter macrocephalus (n = 27). Body mass and myoglobin concentration together explained only 36% of the variance in maximum dive durations. The inclusion of inter-deep-dive intervals, substantially improved model fits (R2 = 0.92). This finding supported a hypothesis that beaked whales extend foraging dives by exceeding aerobic dive limits, with the extension of inter-deep-dive intervals corresponding to metabolism of accumulated lactic acid. This inference points to intriguing tradeoffs between body size, access to prey in different depth strata, and time allocation within dive cycles. These tradeoffs and resulting differences in habitat use have important implications for spatial

  12. Multi-stakeholder Values on the Sustainability of Dive Tourism: Case Studies of Sipadan and Perhentian Islands, Malaysia

    OpenAIRE

    Haddock-Fraser, Janet; Hampton, Mark P.

    2012-01-01

    The impact on the marine environment of the rapidly growing dive tourism industry in less developed countries is increasingly understood, but little research currently exists on its impact on overall sustainability at host sites. This article applies Social Exchange Theory to assess multistakeholders’ perspectives of dive tourism for two Malaysian islands: the Perhentians and Sipadan. We argue that multiple interest groups exist within the sites, with heterogeneous attitudes relating to dive ...

  13. Deep Dive Topic: State of understanding of capsule modeling in context of high-foot

    Energy Technology Data Exchange (ETDEWEB)

    Hurricane, O. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Clark, D. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-14

    The work is summarized from several perspectives: 1D simulation perspective: Post-shot models agree with yield data to within a factor of ~2 at low implosion velocities, but the models diverge from the data as the velocity and convergence ratio increase. 2D simulation perspective: Integrated hohlraum-capsule post-shot models agree with primary data for most implosions, but overpredict yield and DSR for a few of the highest velocity implosions. High-resolution 3D post-shot capsule-only modeling captures much of the delivered performance of the one shot currently simulated.

  14. Dissection of the internal carotid artery after SCUBA-diving: a case report and review of the literature.

    Science.gov (United States)

    Hafner, Franz; Gary, Thomas; Harald, Froehlich; Pilger, Ernst; Groell, Reinhard; Brodmann, Marianne

    2011-03-01

    Dissections of the internal carotid arteries are a well known complication of cervical trauma. Neurologic symptoms in patients after SCUBA-diving are often associated with gas embolism or decompression illness. This report presents a rare case of carotid artery dissection immediately after SCUBA-diving in a 37-year-old woman, with left-side facial paresthesias and left-cervical pain as the first symptoms after SCUBA-diving without rapid ascent to the water-surface. A review of the literature focuses on symptoms, morphologic aspects, and therapeutic options in reported cases of cervical artery dissection after SCUBA-diving.

  15. A BRIEF NOTE ON THE RELATIONSHIP BETWEEN ANXIETY AND PERFORMANCE IN SCUBA DIVING IN ADOLESCENTS: A FIELD STUDY.

    Science.gov (United States)

    Steinberg, Fabian; Doppelmayr, Michael

    2015-06-01

    This study explored the relationship between anxiety and scuba diving performance of young individuals (N = 44; 16.9 yr., SD = 1.2) participating in an introductory scuba diving activity. The question was whether the well-known negative correlation between anxiety and scuba diving performance found for experienced and middle-aged scuba divers will be observed in young participants in their first dive experience. Diving instructors rated standardized scuba diving skills that were correlated with individual state and trait anxiety. There was no relationship between anxiety and scuba diving performance, neither for state nor for trait anxiety. This non-significant correlation between anxiety and performance was in contrast to recent findings observed for experienced divers or those who participated at a scuba diving training program. Considering the differences in methodological design between this study and recent investigations, further research is needed to reveal possible relations between anxiety, scuba diving performance, and panic behavior in beginner-level youth or adults.

  16. Diving, Jumping and Drinking: instabilities during water entry and exit

    Science.gov (United States)

    Jung, Sunghwan

    2017-11-01

    All organisms interact with fluids in one way or another, and some have presumably adapted their behaviors or features in response to fluid-mechanical forces. Particularly, fluid forces are of great importance when organisms or their body parts move in and out of water. In this talk, I will discuss three problems in which fluid mechanics principles affect form and function of animals. The first problem is how several seabirds (e.g. Gannets and Boobies) dive into water at up to 24 m/s without any injuries. This study examines the effects of their beak shape and dense feathers during water entry to reduce or spread the impact force on the body. The second problem is how animals jump out of water, from plankton to whales. Some aquatic animals generate enough force to exit the water surface as an effective method of capturing prey or escaping from predators. Finally, I will discuss about lapping animals (e.g. dog and cat) as a combined water entry and exit. During the tongue-lapping, associated fluid forces and pinch-off instability will be discussed.

  17. Evolutionary Genetics of Hypoxia Tolerance in Cetaceans during Diving

    Science.gov (United States)

    Tian, Ran; Wang, Zhengfei; Niu, Xu; Zhou, Kaiya; Xu, Shixia; Yang, Guang

    2016-01-01

    Hypoxia was a major challenge faced by cetaceans during the course of secondary aquatic adaptation. Although physiological traits of hypoxia tolerance in cetaceans have been well characterized, the underlying molecular mechanisms remain unknown. We investigated the sequences of 17 hypoxia-tolerance-related genes in representative cetaceans to provide a comprehensive insight into the genetic basis of hypoxia tolerance in these animals. Genes involved in carrying and transporting oxygen in the blood and muscle (hemoglobin-α and β, myoglobin), and genes involved in the regulation of vasoconstriction (endothelin-1, -2, and -3; endothelin receptor type A and B; adrenergic receptor α-1D; and arginine vasopressin) appear to have undergone adaptive evolution, evidence for positive selection on their particular sites, and radical physiochemical property changes of selected condons. Interestingly, “long-diving” cetaceans had relatively higher ω (dN/dS) values than “short-diving” cetaceans for the hemoglobin β gene, indicating divergent selective pressure presented in cetacean lineages with different diving abilities. Additionally, parallel positive selection or amino acid changes (ADRA1D: P50A, A53G, AVPR1B: I/V270T) among animals exposed to different hypoxia habitats reflect functional convergence or similar genetic mechanisms of hypoxia tolerance. In summary, positive selection, divergent selective pressures, and parallel evolution at the molecular level provided some new insights into the genetic adaptation of hypoxia tolerance. PMID:26912402

  18. Repetitive Diving in Trained Rats Still Increases Fos Production in Brainstem Neurons after Bilateral Sectioning of the Anterior Ethmoidal Nerve

    Directory of Open Access Journals (Sweden)

    Paul F Mcculloch

    2016-04-01

    Full Text Available This research was designed to investigate the role of the anterior ethmoidal nerve (AEN during repetitive trained diving in rats, with specific attention to activation of afferent and efferent brainstem nuclei that are part of this reflexive response. The AEN innervates the nose and nasal passages and is thought to be an important component of the afferent limb of the diving response. Male Sprague-Dawley rats (N=24 were trained to swim and dive through a 5 m underwater maze. Some rats (N=12 had bilateral sectioning of the AEN, others a Sham surgery (N=12. Twelve rats (6 AEN cut and 6 Sham had 24 post-surgical dive trials over 2 hrs to activate brainstem neurons to produce Fos, a neuronal activation marker. Remaining rats were non-diving controls. Diving animals had significantly more Fos-positive neurons than non-diving animals in the caudal pressor area, ventral medullary dorsal horn, ventral paratrigeminal nucleus, nucleus tractus solitarius, rostral ventrolateral medulla, Raphe nuclei, A5, Locus Coeruleus, and Kölliker-Fuse area. There were no significant differences in brainstem Fos labeling in rats diving with and without intact AENs. Thus the AENs are not required for initiation of the diving response. Other nerve(s that innervate the nose and nasal passages, and/or suprabulbar activation of brainstem neurons, may be responsible for the pattern of neuronal activation observed during repetitive trained diving in rats. These results help define the central neuronal circuitry of the mammalian diving response.

  19. Common metabolic constraints on dive duration in endothermic and ectothermic vertebrates

    Directory of Open Access Journals (Sweden)

    April Hayward

    2016-10-01

    Full Text Available Dive duration in air-breathing vertebrates is thought to be constrained by the volume of oxygen stored in the body and the rate at which it is consumed (i.e., “oxygen store/usage hypothesis”. The body mass-dependence of dive duration among endothermic vertebrates is largely supportive of this model, but previous analyses of ectothermic vertebrates show no such body mass-dependence. Here we show that dive duration in both endotherms and ectotherms largely support the oxygen store/usage hypothesis after accounting for the well-established effects of temperature on oxygen consumption rates. Analyses of the body mass and temperature dependence of dive duration in 181 species of endothermic vertebrates and 29 species of ectothermic vertebrates show that dive duration increases as a power law with body mass, and decreases exponentially with increasing temperature. Thus, in the case of ectothermic vertebrates, changes in environmental temperature will likely impact the foraging ecology of divers.

  20. Measurement of flying and diving metabolic rate in wild animals: Review and recommendations.

    Science.gov (United States)

    Elliott, Kyle H

    2016-12-01

    Animals' abilities to fly long distances and dive to profound depths fascinate earthbound researchers. Due to the difficulty of making direct measurements during flying and diving, many researchers resort to modeling so as to estimate metabolic rate during each of those activities in the wild, but those models can be inaccurate. Fortunately, the miniaturization, customization and commercialization of biologgers has allowed researchers to increasingly follow animals on their journeys, unravel some of their mysteries and test the accuracy of biomechanical models. I provide a review of the measurement of flying and diving metabolic rate in the wild, paying particular attention to mass loss, doubly-labelled water, heart rate and accelerometry. Biologgers can impact animal behavior and influence the very measurements they are designed to make, and I provide seven guidelines for the ethical use of biologgers. If biologgers are properly applied, quantification of metabolic rate across a range of species could produce robust allometric relationships that could then be generally applied. As measuring flying and diving metabolic rate in captivity is difficult, and often not directly translatable to field conditions, I suggest that applying multiple techniques in the field to reinforce one another may be a viable alternative. The coupling of multi-sensor biologgers with biomechanical modeling promises to improve precision in the measurement of flying and diving metabolic rate in wild animals. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Mobility, expansion and management of a multi-species scuba diving fishery in East Africa.

    Science.gov (United States)

    Eriksson, Hampus; de la Torre-Castro, Maricela; Olsson, Per

    2012-01-01

    Scuba diving fishing, predominantly targeting sea cucumbers, has been documented to occur in an uncontrolled manner in the Western Indian Ocean and in other tropical regions. Although this type of fishing generally indicates a destructive activity, little attention has been directed towards this category of fishery, a major knowledge gap and barrier to management. With the aim to capture geographic scales, fishing processes and social aspects the scuba diving fishery that operate out of Zanzibar was studied using interviews, discussions, participant observations and catch monitoring. The diving fishery was resilient to resource declines and had expanded to new species, new depths and new fishing grounds, sometimes operating approximately 250 km away from Zanzibar at depths down to 50 meters, as a result of depleted easy-access stock. The diving operations were embedded in a regional and global trade network, and its actors operated in a roving manner on multiple spatial levels, taking advantage of unfair patron-client relationships and of the insufficient management in Zanzibar. This study illustrates that roving dynamics in fisheries, which have been predominantly addressed on a global scale, also take place at a considerably smaller spatial scale. Importantly, while proposed management of the sea cucumber fishery is often generic to a simplified fishery situation, this study illustrates a multifaceted fishery with diverse management requirements. The documented spatial scales and processes in the scuba diving fishery emphasize the need for increased regional governance partnerships to implement management that fit the spatial scales and processes of the operation.

  2. Hypercapnia in diving: a review of CO₂ retention in submersed exercise at depth.

    Science.gov (United States)

    Dunworth, Sophia A; Natoli, Michael J; Cooter, Mary; Cherry, Anne D; Peacher, Dionne F; Potter, Jennifer F; Wester, Tracy E; Freiberger, John J; Moon, Richard E

    2017-01-01

    Carbon dioxide (CO₂) retention, or hypercapnia, is a known risk of diving that can cause mental and physical impairments leading to life-threatening accidents. Often, such accidents occur due to elevated inspired carbon dioxide. For instance, in cases of CO₂ elimination system failures during rebreather dives, elevated inspired partial pressure of carbon dioxide (PCO₂) can rapidly lead to dangerous levels of hypercapnia. Elevations in PaCO₂ (arterial pressure of PCO₂) can also occur in divers without a change in inspired PCO₂. In such cases, hypercapnia occurs due to alveolar hypoventilation. Several factors of the dive environment contribute to this effect through changes in minute ventilation and dead space. Predominantly, minute ventilation is reduced in diving due to changes in respiratory load and associated changes in respiratory control. Minute ventilation is further reduced by hyperoxic attenuation of chemosensitivity. Physiologic dead space is also increased due to elevated breathing gas density and to hyperoxia. The Haldane effect, a reduction in CO₂ solubility in blood due to hyperoxia, may contribute indirectly to hypercapnia through an increase in mixed venous PCO₂. In some individuals, low ventilatory response to hypercapnia may also contribute to carbon dioxide retention. This review outlines what is currently known about hypercapnia in diving, including its measurement, cause, mental and physical effects, and areas for future study. Copyright© Undersea and Hyperbaric Medical Society.

  3. Analytical approximations of diving-wave imaging in constant-gradient medium

    KAUST Repository

    Stovas, Alexey

    2014-06-24

    Full-waveform inversion (FWI) in practical applications is currently used to invert the direct arrivals (diving waves, no reflections) using relatively long offsets. This is driven mainly by the high nonlinearity introduced to the inversion problem when reflection data are included, which in some cases require extremely low frequency for convergence. However, analytical insights into diving waves have lagged behind this sudden interest. We use analytical formulas that describe the diving wave’s behavior and traveltime in a constant-gradient medium to develop insights into the traveltime moveout of diving waves and the image (model) point dispersal (residual) when the wrong velocity is used. The explicit formulations that describe these phenomena reveal the high dependence of diving-wave imaging on the gradient and the initial velocity. The analytical image point residual equation can be further used to scan for the best-fit linear velocity model, which is now becoming a common sight as an initial velocity model for FWI. We determined the accuracy and versatility of these analytical formulas through numerical tests.

  4. Teaching Teaching & Understanding Understanding

    DEFF Research Database (Denmark)

    2006-01-01

    "Teaching Teaching & Understanding Understanding" is a 19-minute award-winning short-film about teaching at university and higher-level educational institutions. It is based on the "Constructive Alignment" theory developed by Prof. John Biggs. The film delivers a foundation for understanding what...

  5. 75 FR 81224 - Availability of Recreational Diving, Oil and Gas Operations and Commercial Fishing Seats for the...

    Science.gov (United States)

    2010-12-27

    ... Recreational Diving, Oil and Gas Operations and Commercial Fishing Seats for the Flower Garden Banks National... Service (NOS), National Oceanic and Atmospheric Administration (NOAA), Department of Commerce DOC). ACTION... seats on the Flower Garden Banks National Marine Sanctuary Advisory Council: Recreational Diving, Oil...

  6. Endothelial function and cardiovascular stress markers after a single dive in aging rats (ApoE knockout rats)

    DEFF Research Database (Denmark)

    Berenji Ardestani, Simin; Pedersen, Michael

    Diving exposes body to a variety of stressors during the dive itself, and gas bubbles that develop during the decompression (ascent) phase. The compressed gas breath augments partial pressure of oxygen (PO2) causing the oxygen concentration of the blood to increase above normal (hyperoxia) likely...

  7. Scuba diving and otology: a systematic review with recommendations on diagnosis, treatment and post-operative care.

    Science.gov (United States)

    Livingstone, Devon M; Smith, Kristine A; Lange, Beth

    2017-06-01

    Scuba diving is a popular recreational and professional activity with inherent risks. Complications related to barotrauma and decompression illness can pose significant morbidity to a diver's hearing and balance systems. The majority of dive-related injuries affect the head and neck, particularly the outer, middle and inner ear. Given the high incidence of otologic complications from diving, an evidence-based approach to the diagnosis and treatment of otic pathology is a necessity. We performed a systematic and comprehensive literature review including the pathophysiology, diagnosis, and treatment of otologic pathology related to diving. This included inner, middle, and outer ear anatomic subsites, as well as facial nerve complications, mal de debarquement syndrome, sea sickness and fitness to dive recommendations following otologic surgery. Sixty-two papers on diving and otologic pathology were included in the final analysis. We created a set of succinct evidence-based recommendations on each topic that should inform clinical decisions by otolaryngologists, dive medicine specialists and primary care providers when faced with diving-related patient pathology.

  8. 75 FR 36062 - Availability of Conservation Seat and Diving Operations Seat for the Flower Garden Banks National...

    Science.gov (United States)

    2010-06-24

    ... Conservation Seat and Diving Operations Seat for the Flower Garden Banks National Marine Sanctuary Advisory... Flower Garden Banks National Marine Sanctuary Advisory Council: Conservation and Diving Operations... Jennifer Morgan, NOAA--Flower Garden Banks National Marine Sanctuary, 4700 Avenue U, Bldg. 216, Galveston...

  9. Heart rates and swim speeds of emperor penguins diving under sea ice.

    Science.gov (United States)

    Kooyman, G L; Ponganis, P J; Castellini, M A; Ponganis, E P; Ponganis, K V; Thorson, P H; Eckert, S A; LeMaho, Y

    1992-04-01

    Heart rate during overnight rest and while diving were recorded from five emperor penguins with a microprocessor-controlled submersible recorder. Heart rate, cardiac output and stroke volume were also measured in two resting emperor penguins using standard electrocardiography and thermodilution measurements. Swim velocities from eight birds were obtained with the submersible recorder. The resting average of the mean heart rates was 72 beats min-1. Diving heart rates were about 15% lower than resting rates. Cardiac outputs of 1.9-2.9 ml kg-1 s-1 and stroke volumes of 1.6-2.7 ml kg-1 were similar to values recorded from mammals of the same body mass. Swim velocities averaged 3 m s-1. The swim speeds and heart rates suggest that muscle O2 depletion must occur frequently: therefore, many dives require a significant energy contribution from anaerobic glycolysis.

  10. Assessing the Social Carrying Capacity of Diving Sites in Mabul Island, Malaysia

    Science.gov (United States)

    Zhang, Liye; Chung, ShanShan

    2015-12-01

    This study has explored social carrying capacity of an underwater environment based on divers' perceived crowding. Two dimensions were assessed, the number of divers seen and the proximity of diver. Data were obtained from a survey of 132 divers dived in Mabul Island, Malaysia during 2013-2014. Photographs depicting four levels of diver number and four levels of diver proximity in different combinations were shown to the respondents for assessing their acceptability. Between the two variables, the "number of divers" was the most influential factor for divers' perceived crowding. Divers would start to feel unacceptably crowded if 8-9 divers were visible to them at one time. Based on this, it is likely that the use level of diving sites in Mabul Island has already exceeded its social carrying capacity. Implications for future research and diving tourism management for Mabul Island are also discussed in the paper.

  11. Suicidal nitrogen inhalation by use of scuba full-face diving mask.

    Science.gov (United States)

    Straka, Lubomir; Novomesky, Frantisek; Gavel, Anton; Mlynar, Juraj; Hejna, Petr

    2013-09-01

    A 29-year-old man was found dead lying on the bed in a hotel room in a famous Slovak mountain resort. He had a full-face diving mask on his face, connected through a diving breath regulator to a valve of an industrial (nondiving) high-pressure tank containing pure 100% nitrogen. The breath regulator (open-circuit type) used allowed inhalation of nitrogen without addition of open air, and the full-face diving mask assured aspiration of the gas even during the time of unconsciousness. At autopsy, we found the typical signs of suffocation. Toxicological analysis revealed 94.7% content of nitrogen in alveolar air. Following the completion of the police investigation, the manner of death was classified as a suicide. Within the medico-legal literature, there has been only one similar case of suicidal nitrogen inhalation described. © 2013 American Academy of Forensic Sciences.

  12. Phylogeny of diving beetles reveals a coevolutionary arms race between the sexes.

    Directory of Open Access Journals (Sweden)

    Johannes Bergsten

    Full Text Available BACKGROUND: Darwin illustrated his sexual selection theory with male and female morphology of diving beetles, but maintained a cooperative view of their interaction. Present theory suggests that instead sexual conflict should be a widespread evolutionary force driving both intersexual coevolutionary arms races and speciation. METHODOLOGY/PRINCIPAL FINDINGS: We combined Bayesian phylogenetics, complete taxon sampling and a multi-gene approach to test the arms race scenario on a robust diving beetle phylogeny. As predicted, suction cups in males and modified dorsal surfaces in females showed a pronounced coevolutionary pattern. The female dorsal modifications impair the attachment ability of male suction cups, but each antagonistic novelty in females corresponds to counter-differentiation of suction cups in males. CONCLUSIONS: A recently diverged sibling species pair in Japan is possibly one consequence of this arms race and we suggest that future studies on hypoxia might reveal the key to the extraordinary selection for female counter-adaptations in diving beetles.

  13. A case of anterior cerebral artery dissection caused by scuba diving.

    Science.gov (United States)

    Fukuoka, Takuya; Kato, Yuji; Ohe, Yasuko; Deguchi, Ichiro; Maruyama, Hajime; Hayashi, Takeshi; Tanahashi, Norio

    2014-08-01

    A 51-year-old man was admitted with right hemiparesis during scuba diving, without headache. Brain magnetic resonance (MR) imaging depicted high-intensity areas in the left superior frontal and cingulate gyri on diffusion-weighted imaging. Dissection of the anterior cerebral artery (ACA) was detected using axial MR angiography and 3-dimensional MR cisternography. Dissection of the ACA during and after scuba diving has not been reported before. Dissection of the arteries should be included in the differential diagnosis when neurologic symptoms occur both during and after scuba diving, even if the patient does not experience headache. Furthermore, the combination of MR cisternography and MR angiography is useful to detect ACA dissection. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  14. Mental abilities and performance efficacy under a simulated 480 meters helium-oxygen saturation diving

    Directory of Open Access Journals (Sweden)

    gonglin ehou

    2015-07-01

    Full Text Available 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 meters 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 at 300 meters, the reaction time and correct rate of mental rotation, as well as the spatial memory (especially as 410 meters, showing high individual variability. We conclude that the human cognition and performance efficacy are significantly affected during deep water saturation diving.

  15. A comparison of blood nitric oxide metabolites and hemoglobin functional properties among diving mammals

    DEFF Research Database (Denmark)

    Fago, Angela; Parraga, Daniel Garcia; Petersen, Elin E.

    2017-01-01

    in regulating blood flow, we measured concentration of nitrite and S-nitrosothiols (SNO), two metabolites of the vasodilator nitric oxide (NO), in the blood of 5 species of marine mammals differing in their dive duration: bottlenose dolphin, South American sea lion, harbor seal, walrus and beluga whale. We also...... examined oxygen affinity, sensitivity to 2,3-diphosphoglycerate (DPG) and nitrite reductase activity of the hemoglobin (Hb) to search for possible adaptive variations in these functional properties. We found levels of plasma and red blood cells nitrite similar to those reported for terrestrial mammals...... in blood oxygen affinity among diving mammals likely derive from phenotypic variations in red blood cell DPG levels. The nitrite reductase activities of the Hbs were overall slightly higher than that of human Hb, with the Hb of beluga whale, capable of longest dives, having the highest activity. Taken...

  16. Cerebral magnetic resonance imaging of compressed air divers in diving accidents.

    Science.gov (United States)

    Gao, G K; Wu, D; Yang, Y; Yu, T; Xue, J; Wang, X; Jiang, Y P

    2009-01-01

    To investigate the characteristics of the cerebral magnetic resonance imaging (MRI) of compressed air divers in diving accidents, we conducted an observational case series study. MRI of brain were examined and analysed on seven cases compressed air divers complicated with cerebral arterial gas embolism CAGE. There were some characteristics of cerebral injury: (1) Multiple lesions; (2) larger size; (3) Susceptible to parietal and frontal lobe; (4) Both cortical grey matter and subcortical white matter can be affected; (5) Cerebellum is also the target of air embolism. The MRI of brain is an sensitive method for detecting cerebral lesions in compressed air divers in diving accidents. The MRI should be finished on divers in diving accidents within 5 days.

  17. Relevance of postmortem radiology to the diagnosis of fatal cerebral gas embolism from compressed air diving.

    Science.gov (United States)

    Cole, A J; Griffiths, D; Lavender, S; Summers, P; Rich, K

    2006-05-01

    To test the hypothesis that artefact caused by postmortem off-gassing is at least partly responsible for the presence of gas within the vascular system and tissues of the cadaver following death associated with compressed air diving. Controlled experiment sacrificing sheep after a period of simulated diving in a hyperbaric chamber and carrying out sequential postmortem computed tomography (CT) on the cadavers. All the subject sheep developed significant quantities of gas in the vascular system within 24 hours, as demonstrated by CT and necropsy, while the control animals did not. The presence of gas in the vascular system of human cadavers following diving associated fatalities is to be expected, and is not necessarily connected with gas embolism following pulmonary barotrauma, as has previously been claimed.

  18. SCUBA divers as oceanographic samplers: The potential of dive computers to augment aquatic temperature monitoring

    Science.gov (United States)

    Wright, Serena; Hull, Tom; Sivyer, David B.; Pearce, David; Pinnegar, John K.; Sayer, Martin D. J.; Mogg, Andrew O. M.; Azzopardi, Elaine; Gontarek, Steve; Hyder, Kieran

    2016-01-01

    Monitoring temperature of aquatic waters is of great importance, with modelled, satellite and in-situ data providing invaluable insights into long-term environmental change. However, there is often a lack of depth-resolved temperature measurements. Recreational dive computers routinely record temperature and depth, so could provide an alternate and highly novel source of oceanographic information to fill this data gap. In this study, a citizen science approach was used to obtain over 7,000 scuba diver temperature profiles. The accuracy, offset and lag of temperature records was assessed by comparing dive computers with scientific conductivity-temperature-depth instruments and existing surface temperature data. Our results show that, with processing, dive computers can provide a useful and novel tool with which to augment existing monitoring systems all over the globe, but especially in under-sampled or highly changeable coastal environments. PMID:27445104

  19. Regulation of stroke pattern and swim speed across a range of current velocities: Diving by common eiders wintering in polynyas in the Canadian Arctic

    NARCIS (Netherlands)

    Heath, J.P.; Gilchrist, H.G.; Ydenberg, R.C.

    2006-01-01

    Swim speed during diving has important energetic consequences. Not only do costs increase as drag rises non-linearly with increasing speed, but speed also affects travel time to foraging patches and therefore time and energy budgets over the entire dive cycle. However, diving behaviour has rarely

  20. Rapid maturation of the muscle biochemistry that supports diving in Pacific walruses (Odobenus rosmarus divergens)

    Science.gov (United States)

    Norem, Shawn R.; Jay, Chadwick V.; Burns, Jennifer M.; Fischbach, Anthony S.

    2015-01-01

    Physiological constraints dictate animals’ ability to exploit habitats. For marine mammals, it is important to quantify physiological limits that influence diving and their ability to alter foraging behaviors. We characterized age-specific dive limits of walruses by measuring anaerobic (acid-buffering capacity) and aerobic (myoglobin content) capacities of the muscles that power hind (longissimus dorsi) and fore (supraspinatus) flipper propulsion. Mean buffering capacities were similar across muscles and age classes (a fetus, five neonatal calves, a 3 month old and 20 adults), ranging from 41.31 to 54.14 slykes and 42.00 to 46.93 slykes in the longissimus and supraspinatus, respectively. Mean myoglobin in the fetus and neonatal calves fell within a narrow range (longissimus: 0.92–1.68 g 100 g−1 wet muscle mass; supraspinatus: 0.88–1.64 g 100 g−1 wet muscle mass). By 3 months post-partum, myoglobin in the longissimus increased by 79%, but levels in the supraspinatus remained unaltered. From 3 months post-partum to adulthood, myoglobin increased by an additional 26% in the longissimus and increased by 126% in the supraspinatus; myoglobin remained greater in the longissimus compared with the supraspinatus. Walruses are unique among marine mammals because they are born with a mature muscle acid-buffering capacity and attain mature myoglobin content early in life. Despite rapid physiological development, small body size limits the diving capacity of immature walruses and extreme sexual dimorphism reduces the diving capacity of adult females compared with adult males. Thus, free-ranging immature walruses likely exhibit the shortest foraging dives while adult males are capable of the longest foraging dives.

  1. Ascorbic acid supplementation diminishes microparticle elevations and neutrophil activation following SCUBA diving.

    Science.gov (United States)

    Yang, Ming; Barak, Otto F; Dujic, Zeljko; Madden, Dennis; Bhopale, Veena M; Bhullar, Jasjeet; Thom, Stephen R

    2015-08-15

    Predicated on evidence that diving-related microparticle generation is an oxidative stress response, this study investigated the role that oxygen plays in augmenting production of annexin V-positive microparticles associated with open-water SCUBA diving and whether elevations can be abrogated by ascorbic acid. Following a cross-over study design, 14 male subjects ingested placebo and 2-3 wk later ascorbic acid (2 g) daily for 6 days prior to performing either a 47-min dive to 18 m of sea water while breathing air (∼222 kPa N2/59 kPa O2) or breathing a mixture of 60% O2/balance N2 from a tight-fitting face mask at atmospheric pressure for 47 min (∼40 kPa N2/59 kPa O2). Within 30 min after the 18-m dive in the placebo group, neutrophil activation, and platelet-neutrophil interactions occurred, and the total number of microparticles, as well as subgroups bearing CD66b, CD41, CD31, CD142 proteins or nitrotyrosine, increased approximately twofold. No significant elevations occurred among divers after ingesting ascorbic acid, nor were elevations identified in either group after breathing 60% O2. Ascorbic acid had no significant effect on post-dive intravascular bubble production quantified by transthoracic echocardiography. We conclude that high-pressure nitrogen plays a key role in neutrophil and microparticle-associated changes with diving and that responses can be abrogated by dietary ascorbic acid supplementation. Copyright © 2015 the American Physiological Society.

  2. Body density and diving gas volume of the northern bottlenose whale (Hyperoodon ampullatus).

    Science.gov (United States)

    Miller, Patrick; Narazaki, Tomoko; Isojunno, Saana; Aoki, Kagari; Smout, Sophie; Sato, Katsufumi

    2016-08-15

    Diving lung volume and tissue density, reflecting lipid store volume, are important physiological parameters that have only been estimated for a few breath-hold diving species. We fitted 12 northern bottlenose whales with data loggers that recorded depth, 3-axis acceleration and speed either with a fly-wheel or from change of depth corrected by pitch angle. We fitted measured values of the change in speed during 5 s descent and ascent glides to a hydrodynamic model of drag and buoyancy forces using a Bayesian estimation framework. The resulting estimate of diving gas volume was 27.4±4.2 (95% credible interval, CI) ml kg(-1), closely matching the measured lung capacity of the species. Dive-by-dive variation in gas volume did not correlate with dive depth or duration. Estimated body densities of individuals ranged from 1028.4 to 1033.9 kg m(-3) at the sea surface, indicating overall negative tissue buoyancy of this species in seawater. Body density estimates were highly precise with ±95% CI ranging from 0.1 to 0.4 kg m(-3), which would equate to a precision of <0.5% of lipid content based upon extrapolation from the elephant seal. Six whales tagged near Jan Mayen (Norway, 71°N) had lower body density and were closer to neutral buoyancy than six whales tagged in the Gully (Nova Scotia, Canada, 44°N), a difference that was consistent with the amount of gliding observed during ascent versus descent phases in these animals. Implementation of this approach using longer-duration tags could be used to track longitudinal changes in body density and lipid store body condition of free-ranging cetaceans. © 2016. Published by The Company of Biologists Ltd.

  3. Bubble formation and endothelial function before and after 3 months of dive training.

    Science.gov (United States)

    Pontier, Jean-Michel; Guerrero, François; Castagna, Olivier

    2009-01-01

    It has been suggested that repeated compression-decompression cycles reduce diver susceptibility to decompression sickness (DCS). This study examined whether intensive scuba dive training would reduce bubble formation and modulate endothelial function as shown by skin circulation. There were 22 military divers who were studied before and after a 90-d program of physical training and open-sea air diving (mean 67 dives total). Skin blood flow in the forearm was measured at rest (baseline), during post-occlusive hyperemia (endothelium-dependent vasodilatation), and with local heating to 42 degrees C (maximal vasodilatation). Subjects were also examined by pulsed Doppler for venous bubbles 30, 60, and 90 min after surfacing from a hyperbaric exposure to 400 kPa (30 msw) for 30 min in a dry chamber. None of the divers experienced DCS during the training period. There was no change in weight, body mass index, maximal oxygen uptake, or endothelial function. Bubble grades by the Kisman Integrated Severity Score were significantly decreased immediately after the diving training period (3.6 +/- 9.2 vs. 16.4 +/- 14.3) and increased 3 mo after this period (10.3 +/- 13.9 vs. 3.6 +/- 9.2). The results highlight that repeated scuba dives and regular physical exercise activity reduce bubble formation and probably have a protective effect against DCS risk. Although this phenomenon has been observed for decades, the mechanism remains complex and the results cannot elucidate the effects of physical exercise and NO production. Bubble formation could activate the stress response which could be the basis for diving acclimatization.

  4. Middle ear barotrauma causing transient facial nerve paralysis after scuba diving.

    Science.gov (United States)

    Carmichael, Matthew Lee; Boyev, K Paul

    2016-12-01

    Middle ear barotrauma is a well known entity with typical injury occurring when diving or ascending in a commercial jetliner. Patients often present with symptoms of acute onset otalgia, hearing loss and sometimes haemotympanum (with or without tympanic membrane perforation). On rare occasions, facial nerve paralysis can occur when the tympanic segment of the facial nerve is dehiscent within the middle ear. We present a case of spontaneously resolving facial nerve palsy associated with middle ear barotrauma following a brief, shallow dive. Prompt and astute diagnosis leads to proper management with simple myringotomy and can prevent unnecessary testing and other misguided treatments.

  5. Influence of repetitive diving in freshwater on pressure equalization and Eustachian tube function in recreational scuba divers.

    Science.gov (United States)

    Jansen, Stefanie; Boor, Manuela; Meyer, Moritz F; Pracht, Eberhard D; Volland, Ruth; Klünter, Heinz D; Hüttenbrink, Karl-Bernd; Beutner, Dirk; Grosheva, Maria

    2017-12-01

    We investigated the effect of repetitive pressure exposure during freshwater dives on Eustachian tube function and the middle ear, assessed by the Eustachian tube function test (ETFT). This prospective observational cohort study included 23 divers over three consecutive days of diving in freshwater lakes in Nordhausen, Germany. Participants underwent otoscopy and ETFT before the first dive, between each dive and after the last dive. ETFT included regular tympanometry (R-tymp), tympanometry after Valsalva (V-tymp) and after swallowing (S-tymp). The peak pressure difference between the R-tymp and the V-tymp (R-V dP ) defined effectiveness of pressure equalization after Valsalva manoeuvres. We evaluated the change in compliance and peak pressure and correlated the results to the otoscopic findings and diving experience. Twenty-three divers performed 144 dives. Middle ear barotrauma was assessed using the Edmonds modification of the TEED scoring system. In the ETFT, the R-tymp peak pressure displayed a negative shift from day one to three (P = 0.001) and differed significantly between the experience groups (P = 0.01). R-V dP did not change significantly on any of the three days of diving (all P > 0.05). Participants without MEBt showed significantly lower R-tymp values than did those with barotrauma (P = 0.019). Repetitive pressure exposure during three consecutive days of freshwater diving led to a negative shift of the peak pressure in the middle ear. Less experienced divers showed significantly higher middle ear peak pressure and higher pressure differences after equalization manoeuvres. Higher middle ear peak pressure was also associated with a higher prevalence of barotrauma. Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.

  6. Influence of repetitive diving in saltwater on pressure equalization and Eustachian tube function in recreational scuba divers.

    Science.gov (United States)

    Meyer, Moritz F; Boor, Manuela; Jansen, Stefanie; Pracht, Eberhard D; Felsch, Moritz; Klünter, Heinz D; Hüttenbrink, Karl-Bernd; Beutner, Dirk; Grosheva, Maria

    2017-12-01

    We investigated in a prospective, observational trial the feasibility of using the Eustachian tube function test (ETFT) to measure the effect of repetitive pressure exposure during open seawater dives on Eustachian tube function. The study included 28 adult divers during six consecutive days of diving in the Red Sea. Participants underwent otoscopy and ETFT before the first dive, between each dive and after the last dive. ETFT included regular tympanometry (R-tymp), tympanometry after Valsalva (V-tymp) and after swallowing (S-tymp). The R-tymp was obtained as 'baseline' peak pressure. After a Valsalva, the peak pressure should shift (positively), revealing a positive shift of the tympanic membrane. This pressure shift is defined here as R-V dP . The changes in compliance and peak pressure were recorded and correlated with otoscopic findings and diving experience. Middle ear barotrauma was scored using the Edmonds modified TEED scale. The 28 participants performed 437 dives. Positive shift of pressure in the middle ear was evident with significant changes from day one to day three (P Diving experience significantly correlated with R-tymp peak pressure and prevalence of middle ear barotrauma. Significant changes in middle ear pressure and pressure equalization from repeated pressure exposure in saltwater were seen using ETFT. Repetitive, multi-day diving led to significantly decreased compliance and increased R-tymp peak pressure (overpressure) in the middle ear. Most profound changes were observed in less and intermediate experienced divers. Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.

  7. Scuba diving induces nitric oxide synthesis and the expression of inflammatory and regulatory genes of the immune response in neutrophils.

    Science.gov (United States)

    Sureda, Antoni; Batle, Juan M; Capó, Xavier; Martorell, Miquel; Córdova, Alfredo; Tur, Josep A; Pons, Antoni

    2014-09-01

    Scuba diving, characterized by hyperoxia and hyperbaria, could increase reactive oxygen species production which acts as signaling molecules to induce adaptation against oxidative stress. The aim was to study the effects of scuba diving immersion on neutrophil inflammatory response, the induction of oxidative damage, and the NO synthesis. Nine male divers performed a dive at 50 m depth for a total time of 35 min. Blood samples were obtained at rest before the dive, after the dive, and 3 h after the diving session. Markers of oxidative and nitrosative damage, nitrite, and the gene expression of genes related with the synthesis of nitric oxide and lipid mediators, cytokine synthesis, and inflammation were determined in neutrophils. The mRNA levels of genes related with the inflammatory and immune response of neutrophils, except TNF-α, myeloperoxidase, and toll-like receptor (TLR) 2, significantly increased after the recovery period respect to predive and postdive levels. NF-κB, IL-6, and TLR4 gene expression reported significant differences immediately after diving respect to the predive values. Protein nitrotyrosine levels significantly rose after diving and remained high during recovery, whereas no significant differences were reported in malondialdehyde. Neutrophil nitrite levels as indicative of inducible nitric oxide synthase (iNOS) activity progressively increased after diving and recovery. The iNOS protein levels maintained the basal values in all situations. Scuba diving which combines hyperoxia, hyperbaria, and acute exercise induces nitrosative damage with increased nitrotyrosine levels and an inflammatory response in neutrophils. Copyright © 2014 the American Physiological Society.

  8. Dive-related fatalities among tourist and local divers in the northern Croatian littoral (1980-2010).

    Science.gov (United States)

    Stemberga, Valter; Petaros, Anja; Rasic, Veronika; Azman, Josip; Sosa, Ivan; Coklo, Miran; Uhac, Ivone; Bosnar, Alan

    2013-01-01

    The aim of the study was to retrospectively analyze diving fatalities occurring in Primorje-Gorski Kotar County (northern Croatian littoral), Croatia between 1980 and 2010 in order to identify differences between fatally injured tourist and resident divers, as well as temporal changes in the frequency of diver deaths. Medico-legal and police reports of 47 consecutive fatal diving cases were reviewed to determine the frequency of death among divers in relation to year and month of death, age, sex, nationality, organization of diving, diving type, and health condition. The majority of victims were foreign citizens (59.6%) most of whom fell victim to scuba diving (70.4%). It was found that 79% of resident divers succumbed during free-diving. The number of diving fatalities increased significantly in the last three decades, especially among free-divers. Of the victims, 93% were males, usually belonging to younger age groups with tourist divers being significantly older than local divers. And 31.9% of divers, mostly tourists, showed signs of acute, chronic, or congenital pathological conditions. Fatally injured foreign divers differ from resident diver fatalities in diving method and age. Tourists are the group most at risk while scuba diving according to the Croatian sample. Occupational scuba divers and free-divers are the group most at risk among resident divers. This study is an important tool in uncovering the most common victims of diving and the related risk factors. It also highlights the problems present in the legal and medical monitoring of recreational divers and discusses possible pre-event, event, and post-event preventive actions that could lead to reduced mortality rates in divers. © 2013 International Society of Travel Medicine.

  9. Point of no return in diving emperor penguins: is the timing of the decision to return limited by the number of strokes?

    Science.gov (United States)

    Shiomi, Kozue; Sato, Katsufumi; Ponganis, Paul J

    2012-01-01

    At some point in a dive, breath-hold divers must decide to return to the surface to breathe. The issue of when to end a dive has been discussed intensively in terms of foraging ecology and behavioral physiology, using dive duration as a temporal parameter. Inevitably, however, a time lag exists between the decision of animals to start returning to the surface and the end of the dive, especially in deep dives. In the present study, we examined the decision time in emperor penguins under two different conditions: during foraging trips at sea and during dives at an artificial isolated dive hole. It was found that there was an upper limit for the decision-to-return time irrespective of dive depth in birds diving at sea. However, in a large proportion of dives at the isolated dive hole, the decision-to-return time exceeded the upper limit at sea. This difference between the decision times in dives at sea versus the isolated dive hole was accounted for by a difference in stroke rate. The stroke rates were much lower in dives at the isolated hole and were inversely correlated with the upper limit of decision times in individual birds. Unlike the decision time to start returning, the cumulative number of strokes at the decision time fell within a similar range in the two experiments. This finding suggests that the number of strokes, but not elapsed time, constrained the decision of emperor penguins to return to the surface. While the decision to return and to end a dive may be determined by a variety of ecological, behavioral and physiological factors, the upper limit to that decision time may be related to cumulative muscle workload.

  10. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Cancer Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer Leukemia Liver Cancer Lung ... need for different kinds of information about her colorectal cancer prognosis. Diving Out of the Dark View this ...

  11. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Treatment Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer Leukemia Liver Cancer Lung ... need for different kinds of information about her colorectal cancer prognosis. Diving Out of the Dark View this ...

  12. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Health Professional Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer Leukemia Liver Cancer Lung ... need for different kinds of information about her colorectal cancer prognosis. Diving Out of the Dark View this ...

  13. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Professional Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer Leukemia Liver Cancer Lung ... need for different kinds of information about her colorectal cancer prognosis. Diving Out of the Dark View this ...

  14. A CATALOG OF GROUND WATER FLOW SOLUTIONS FOR PLUME DIVING CALCULATIONS

    Science.gov (United States)

    This report focuses on the problem of diving plumes, a term which generally refers to plumes that go deeper into aquifers with distances from their sources. This document presents the mathematical basis of software for real-time development and refinement of site conceptual model...

  15. Calling under pressure: Short-finned pilot whales make social calls during deep foraging dives

    DEFF Research Database (Denmark)

    Jensen, Frants Havmand; Marrero Perez, Jacobo; Johnson, Mark

    2011-01-01

    that the energy content of calls is lower at depths where lungs are collapsed and where the air volume available for sound generation is limited by ambient pressure. Frequency content was unaffected, providing a possible cue for group or species identification of diving whales. Social calls may be important...... to maintain social ties for foraging animals, but may be impacted adversely by vessel noise....

  16. Diving behavior of the reef manta ray links coral reefs with adjacent deep pelagic habitats

    KAUST Repository

    Braun, Camrin D.

    2014-02-06

    Recent successful efforts to increase protection for manta rays has highlighted the lack of basic ecological information, including vertical and horizontal movement patterns, available for these species. We deployed pop-up satellite archival transmitting tags on nine reef manta rays, Manta alfredi, to determine diving behaviors and vertical habitat use. Transmitted and archived data were obtained from seven tagged mantas over deployment periods of 102-188 days, including three recovered tags containing 2.6 million depth, temperature, and light level data points collected every 10 or 15 seconds. Mantas frequented the upper 10 m during daylight hours and tended to occupy deeper water throughout the night. Six of the seven individuals performed a cumulative 76 deep dives (>150 m) with one individual reaching 432 m, extending the known depth range of this coastal, reef-oriented species and confirming its role as an ecological link between epipelagic and mesopelagic habitats. Mean vertical velocities calculated from high-resolution dive data (62 dives >150 m) from three individuals suggested that mantas may use gliding behavior during travel and that this behavior may prove more efficient than continuous horizontal swimming. The behaviors in this study indicate manta rays provide a previously unknown link between the epi- and mesopelagic layers of an extremely oligotrophic marine environment and provide evidence of a third marine species that utilizes gliding to maximize movement efficiency. © 2014 Braun et al.

  17. 76 FR 31454 - Special Conditions: Gulfstream Model GVI Airplane; Automatic Speed Protection for Design Dive Speed

    Science.gov (United States)

    2011-06-01

    ... 611 of Public Law 92-574, the ``Noise Control Act of 1972.'' The FAA issues special conditions, as... the GVI flight control laws. The GVI is equipped with a high speed protection system that limits nose... the dive from non-symmetric attitudes, unless the airplane is protected by the flight control laws...

  18. 76 FR 8917 - Special Conditions: Gulfstream Model GVI Airplane; Automatic Speed Protection for Design Dive Speed

    Science.gov (United States)

    2011-02-16

    ...; Automatic Speed Protection for Design Dive Speed AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... design features include a high speed protection system. These proposed special conditions contain the... Design Features The GVI is equipped with a high speed protection system that limits nose down pilot...

  19. Correction for adiabatic effects in lethe calculated instantaneous gas consumption of scuba dives

    NARCIS (Netherlands)

    Schellart, Nico A. M.; Le Péchon, Jean-Claude

    2015-01-01

    Introduction: In scuba-diving practice, instantaneous gas consumption is generally calculated from the fall in cylinder pressure without considering the effects of water temperature (heat transfer) and adiabatic processes. We aimed to develop a simple but precise method for calculating the

  20. 75 FR 14493 - Safety Zone; Dive Platform, Pago Pago Harbor, American Samoa

    Science.gov (United States)

    2010-03-26

    .... Coast Guard performed dive operations on the CHEHALIS wreck to determine the wreck's potential pollution... wreck's potential pollution threat with pre-staging vessels beginning March 25, 2010 and conducting... of the water to the ocean floor. These coordinates are based upon the National Oceanic and...

  1. Twee nieuwe citroenzweefvliegen voor Nederland: Xanthogramma dives en X. stackelbergi (Diptera: Syrphidae)

    NARCIS (Netherlands)

    Steenis, van W.; Bot, S.; Barendregt, A.

    2014-01-01

    De gewone citroenzweefvlieg Xanthogramma pedissequum is een eenvoudig te herkennen zweefvlieg. Tenminste, dat dachten we tot voor kort. Nu blijkt dat de bijna identieke X. dives en X. stackelbergi ook in Nederland rondvliegen. Gelukkig zijn er enkele kenmerken waarmee deze drie soorten

  2. Biosonar, diving and movements of two tagged white-beaked dolphin in Icelandic waters

    DEFF Research Database (Denmark)

    Rasmussen, Marianne H.; Akamatsu, Tomonari; Teilmann, Jonas

    2013-01-01

    For the first time bio-logging tags were attached to free-ranging white-beaked dolphins, Lagenorhynchus albirostris. A satellite tag was attached to one animal while an acoustic A-tag, a time-depth recorder and a VHF transmitter complex was attached to a second dolphin with a suction cup....... The satellite tag transmitted for 201 days, during which time the dolphin stayed in the coastal waters of western Iceland. The acoustic tag complex was on the second animal for 13 hours and 40 minutes and provided the first insight in echolocation behaviour of a free-ranging white-beaked dolphin. The tag...... registered 162 dives. The dolphin dove to a maximum depth of 45 m, which is about the depth of the bay in which the dolphin was swimming. Two basic types of dives were identified; U-shaped and V-shaped dives. The dolphin used more time in U-shaped dives, more clicks and sonar signals with shorter click...

  3. Co-discoverer of evidence for quarks killed in diving accident

    CERN Multimedia

    Nadis, S

    1999-01-01

    Henry Kendall died last week while scuba diving in a Florida lake. He was awarded the Nobel prize in 1990 along with Friedman and Taylor, for their work in the late 1960s that provided the first direct evidence for quarks (1 page).

  4. Construction of Tests in the Cognitive and Psychomotor Domains for Skin and Scuba Diving.

    Science.gov (United States)

    McCarthy, Jean

    The fundamental purposes of this study were to develop mastery tests in the cognitive and psychomotor domains for skin and scuba diving and to establish validity and reliability for the tests. A table of specifications was developed for each domain, and a pilot study refined the initial test batteries into their final form. In the main study,…

  5. Safety of antimalarial medications for use while scuba diving in malaria Endemic Regions.

    Science.gov (United States)

    Petersen, Kyle; Regis, David P

    2016-01-01

    Recreational diving occurs annually in areas of the world where malaria is endemic. The safety and efficacy of antimalarials for travelers in a hyperbaric environment is unknown. Of particular concern would be medications with adverse effects that could either mimic diving related illnesses such as barotrauma, decompression sickness (DCS) and gas toxicities, or increase the risk for such illnesses. We conducted a review of PubMed and Cochrane databases to determine rates of neurologic adverse effects or other effects from antimalarials that may be a problem in the diving environment. One case report was found on diving and mefloquine. Multiple case reports and clinical trials were found describing neurologic adverse effects of the major chemoprophylactic medications atovaquone/proguanil, chloroquine, doxycycline, mefloquine, and primaquine. Of the available literature, atovaquone/proguanil and doxycycline are most likely the safest agents and should be preferred; atovaquone/proguanil is superior due to reduced rates of sunburn in the marine environment. Primaquine also appears to be safe, but has reduced efficacy against P. falciparum ; mefloquine possesses the highest rate of neurologic side effects and therefore these agents should be limited to extreme cases of patients intolerant to other agents. Chloroquine appears unsafe in the hyperbaric environment and should be avoided. More studies are required to include database reviews of returned divers traveling to malaria endemic areas and randomized controlled trials in the hyperbaric environments.

  6. Calling under pressure: short-finned pilot whales make social calls during deep foraging dives.

    Science.gov (United States)

    Jensen, Frants H; Perez, Jacobo Marrero; Johnson, Mark; Soto, Natacha Aguilar; Madsen, Peter T

    2011-10-22

    Toothed whales rely on sound to echolocate prey and communicate with conspecifics, but little is known about how extreme pressure affects pneumatic sound production in deep-diving species with a limited air supply. The short-finned pilot whale (Globicephala macrorhynchus) is a highly social species among the deep-diving toothed whales, in which individuals socialize at the surface but leave their social group in pursuit of prey at depths of up to 1000 m. To investigate if these animals communicate acoustically at depth and test whether hydrostatic pressure affects communication signals, acoustic DTAGs logging sound, depth and orientation were attached to 12 pilot whales. Tagged whales produced tonal calls during deep foraging dives at depths of up to 800 m. Mean call output and duration decreased with depth despite the increased distance to conspecifics at the surface. This shows that the energy content of calls is lower at depths where lungs are collapsed and where the air volume available for sound generation is limited by ambient pressure. Frequency content was unaffected, providing a possible cue for group or species identification of diving whales. Social calls may be important to maintain social ties for foraging animals, but may be impacted adversely by vessel noise.

  7. Exercise after SCUBA diving increases the incidence of arterial gas embolism.

    Science.gov (United States)

    Madden, Dennis; Lozo, Mislav; Dujic, Zeljko; Ljubkovic, Marko

    2013-09-01

    Arterialization of gas bubbles after decompression from scuba diving has traditionally been associated with pulmonary barotraumas or cardiac defects, such as the patent foramen ovale. Recent studies have demonstrated the right-to-left passage of bubbles through intrapulmonary arterial-venous anastamoses (IPAVA) that allow blood to bypass the pulmonary microcirculation. These passages open up during exercise, and the aim of this study is to see if exercise in a postdiving period increases the incidence of arterialization. After completing a dive to 18 m for 47 min, patent foramen ovale-negative subjects were monitored via transthoracic echocardiography, within 10 min after surfacing, for bubble score at rest. Subjects then completed an incremental cycle ergometry test to exhaustion under continuous transthoracic echocardiography observation. Exercise was suspended if arterialization was observed and resumed when the arterialization cleared. If arterialization was observed a second time, exercise was terminated, and oxygen was administered. Out of 23 subjects, 3 arterialized at rest, 12 arterialized with exercise, and 8 did not arterialize at all even during maximal exercise. The time for arterialization to clear with oxygen was significantly shorter than without. Exercise after diving increased the incidence of arterialization from 13% at rest to 52%. This study shows that individuals are capable of arterializing through IPAVA, and that the intensity at which these open varies by individual. Basic activities associated with SCUBA diving, such as surface swimming or walking with heavy equipment, may be enough to allow the passage of venous gas emboli through IPAVA.

  8. Three-Hour Dives with Exercise While Breathing Oxygen Partial Pressure of 1.3 ATM

    Science.gov (United States)

    2007-10-01

    good health. Table 1. Subject characteristics n = 16 Median (range) Age (Yr) 37 (26-47) Height (in) 71.5 (68-72) Weight (Ib) 195 (165-285) Smokers ...NEDU TR 05-20, Navy Experimental Diving Unit, Oct 2005. 8. American Thoracic Society, "Standardization of Spirometry 1994 Update," American Journal

  9. Marine foraging ecology influences mercury bioaccumulation in deep-diving northern elephant seals.

    Science.gov (United States)

    Peterson, Sarah H; Ackerman, Joshua T; Costa, Daniel P

    2015-07-07

    Mercury contamination of oceans is prevalent worldwide and methylmercury concentrations in the mesopelagic zone (200-1000 m) are increasing more rapidly than in surface waters. Yet mercury bioaccumulation in mesopelagic predators has been understudied. Northern elephant seals (Mirounga angustirostris) biannually travel thousands of kilometres to forage within coastal and open-ocean regions of the northeast Pacific Ocean. We coupled satellite telemetry, diving behaviour and stable isotopes (carbon and nitrogen) from 77 adult females, and showed that variability among individuals in foraging location, diving depth and δ(13)C values were correlated with mercury concentrations in blood and muscle. We identified three clusters of foraging strategies, and these resulted in substantially different mercury concentrations: (i) deeper-diving and offshore-foraging seals had the greatest mercury concentrations, (ii) shallower-diving and offshore-foraging seals had intermediate levels, and (iii) coastal and more northerly foraging seals had the lowest mercury concentrations. Additionally, mercury concentrations were lower at the end of the seven-month-long foraging trip (n = 31) than after the two-month- long post-breeding trip (n = 46). Our results indicate that foraging behaviour influences mercury exposure and mesopelagic predators foraging in the northeast Pacific Ocean may be at high risk for mercury bioaccumulation. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  10. Diving response after a one-week diet and overnight fasting.

    Science.gov (United States)

    Ghiani, Giovanna; Marongiu, Elisabetta; Olla, Sergio; Pinna, Marco; Pusceddu, Matteo; Palazzolo, Girolamo; Sanna, Irene; Roberto, Silvana; Crisafulli, Antonio; Tocco, Filippo

    2016-01-01

    We hypothesized that overnight fasting after a short dietary period, especially with carbohydrates, could allow performing breath-hold diving with no restraint for diaphragm excursion and blood shift and without any increase of metabolism, and in turn improve the diving response. During two separate sessions, 8 divers carried out two trials: (A) a 30-m depth dive, three hours after a normal breakfast and (B) a dive to the same depth, but after following a diet and fasting overnight. Each test consisted of 3 apnea phases: descent, static and ascent whose durations were measured by a standard chronometer. An impedance cardiograph, housed in an underwater torch, provided data on trans-thoracic fluid index (TFI), stroke volume (SV), heart rate (HR) and cardiac output (CO). Mean blood pressure (MBP), arterial O2 saturation (SaO2), blood glucose (Glu) and blood lactate (BLa) were also collected. In condition B, duration of the static phase of the dive was longer than A (37.8 ± 7.4 vs. 27.3 ± 8.4 s respectively, P fasting was lower than breakfast one (-2.6 ± 5.1 vs. 5.7 ± 7.6 ml, P fasting was lower than the same phase after breakfast (-0.4 ± 0.5 vs. 0.4 ± 0.5 L · min(-1) respectively, P fasting, SaO2 was higher than A (92.0 ± 2.7 vs. 89.4 ± 2.9 % respectively, P < 0.05) and BLa was lower in the same comparison (4.2 ± 0.7 vs. 5.3 ± 1.1 mmol∙L(-1), P < 0.05). An adequate balance between metabolic and splancnic status may improve the diving response during a dive at a depth of 30 m, in safe conditions for the athlete's health.

  11. Judging complex movement performances for excellence: a principal components analysis-based technique applied to competitive diving.

    Science.gov (United States)

    Young, Cole; Reinkensmeyer, David J

    2014-08-01

    Athletes rely on subjective assessment of complex movements from coaches and judges to improve their motor skills. In some sports, such as diving, snowboard half pipe, gymnastics, and figure skating, subjective scoring forms the basis for competition. It is currently unclear whether this scoring process can be mathematically modeled; doing so could provide insight into what motor skill is. Principal components analysis has been proposed as a motion analysis method for identifying fundamental units of coordination. We used PCA to analyze movement quality of dives taken from USA Diving's 2009 World Team Selection Camp, first identifying eigenpostures associated with dives, and then using the eigenpostures and their temporal weighting coefficients, as well as elements commonly assumed to affect scoring - gross body path, splash area, and board tip motion - to identify eigendives. Within this eigendive space we predicted actual judges' scores using linear regression. This technique rated dives with accuracy comparable to the human judges. The temporal weighting of the eigenpostures, body center path, splash area, and board tip motion affected the score, but not the eigenpostures themselves. These results illustrate that (1) subjective scoring in a competitive diving event can be mathematically modeled; (2) the elements commonly assumed to affect dive scoring actually do affect scoring (3) skill in elite diving is more associated with the gross body path and the effect of the movement on the board and water than the units of coordination that PCA extracts, which might reflect the high level of technique these divers had achieved. We also illustrate how eigendives can be used to produce dive animations that an observer can distort continuously from poor to excellent, which is a novel approach to performance visualization. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Buoyancy under control: underwater locomotor performance in a deep diving seabird suggests respiratory strategies for reducing foraging effort.

    Directory of Open Access Journals (Sweden)

    Timothée R Cook

    Full Text Available BACKGROUND: Because they have air stored in many body compartments, diving seabirds are expected to exhibit efficient behavioural strategies for reducing costs related to buoyancy control. We study the underwater locomotor activity of a deep-diving species from the Cormorant family (Kerguelen shag and report locomotor adjustments to the change of buoyancy with depth. METHODOLOGY/PRINCIPAL FINDINGS: Using accelerometers, we show that during both the descent and ascent phases of dives, shags modelled their acceleration and stroking activity on the natural variation of buoyancy with depth. For example, during the descent phase, birds increased swim speed with depth. But in parallel, and with a decay constant similar to the one in the equation explaining the decrease of buoyancy with depth, they decreased foot-stroke frequency exponentially, a behaviour that enables birds to reduce oxygen consumption. During ascent, birds also reduced locomotor cost by ascending passively. We considered the depth at which they started gliding as a proxy to their depth of neutral buoyancy. This depth increased with maximum dive depth. As an explanation for this, we propose that shags adjust their buoyancy to depth by varying the amount of respiratory air they dive with. CONCLUSIONS/SIGNIFICANCE: Calculations based on known values of stored body oxygen volumes and on deep-diving metabolic rates in avian divers suggest that the variations of volume of respiratory oxygen associated with a respiration mediated buoyancy control only influence aerobic dive duration moderately. Therefore, we propose that an advantage in cormorants--as in other families of diving seabirds--of respiratory air volume adjustment upon diving could be related less to increasing time of submergence, through an increased volume of body oxygen stores, than to reducing the locomotor costs of buoyancy control.

  13. Pressure Induced Changes in Adaptive Immune Function in Belugas (Delphinapterus leucas; implications for dive physiology and health

    Directory of Open Access Journals (Sweden)

    Laura A Thompson

    2016-09-01

    Full Text Available Increased pressure, associated with diving, can alter cell function through several mechanisms and has been shown to impact immune functions performed by peripheral blood mononuclear cells (PBMC in humans. While marine mammals possess specific adaptations which protect them from dive related injury, it is unknown how their immune system is adapted to the challenges associated with diving. The purpose of this study was to measure PBMC activation (IL2R expression and Concanavalin A induced lymphocyte proliferation (BrdU incorporation in belugas following in vitro pressure exposures during baseline, Out of Water Examination (OWE and capture/release conditions. Beluga blood samples (n=4 were obtained from animals at the Mystic Aquarium and from free ranging animals in Alaska (n=9. Human blood samples (n=4 (Biological Specialty Corporation were run for comparison. In vivo catecholamines and cortisol were measured in belugas to characterize the neuroendocrine response. Comparison of cellular responses between controls and pressure exposed cells, between conditions in belugas, between belugas and humans as well as between dive profiles, were run using mixed generalized linear models (α=0.05. Cortisol was significantly higher in wild belugas and OWE samples as compared with baseline for aquarium animals. Both IL2R expression and proliferation displayed significant pressure induced changes, and these responses varied between conditions in belugas. Both belugas and humans displayed increased IL2R expression, while lymphocyte proliferation decreased for aquarium animals and increased for humans and wild belugas. Results suggest beluga PBMC function is altered during diving and changes may represent dive adaptation as the response differs from humans, a non-dive adapted mammal. In addition, characteristics of a dive (i.e., duration, depth as well as neuroendocrine activity can alter the response of beluga cells, potentially impacting the ability of animals

  14. Effect of scuba diving on the oxidant/antioxidant status, SIRT1 and SIRT3 expression in recreational divers after a winter nondive period.

    Science.gov (United States)

    Perović, Antonija; Sobočanec, Sandra; Dabelić, Sanja; Balog, Tihomir; Dumić, Jerka

    2018-02-01

    The aim of this study was to examine the effects of scuba diving on oxidative damage markers in erythrocytes and plasma, antioxidant system in peripheral blood mononuclear cells (PBMCs), as well as sirtuin 1 (SIRT1) and sirtuin 3 (SIRT3) gene expressions in recreational divers after a winter nondive period (at least 5 months). For that purpose, 17 male recreational divers performed an immersion at a depth of 30 m for 30 min. Blood samples were collected immediately before and after diving, 3 and 6 h after diving. Erythrocyte lipid peroxidation measured by thiobarbituric-reactive substances (TBARS) method was significantly increased immediately after diving, but returned to the baseline 6 h after diving, while no significant change was found for plasma TBARS and protein carbonyl derivates in both plasma and erythrocytes. Diving-induced catalase (CAT), superoxide dismutase 2 (SOD2), and consequently total superoxide dismutase (SOD) activities in the PBMC samples (significantly increased immediately after diving, reached the maximum activities 3 h after diving, while 6 h after diving only CAT activity remained significantly increased). No significant change was observed for SOD1 activity and gene expression, as well as SOD2 expression, while CAT and SIRT1 expressions were slightly decreased immediately after diving and 3 h after diving. Interestingly, SIRT3 expression was significantly increased 6 h after diving. In conclusion, after the first dive to 30 m after a nondive season, activation of antioxidant defence was not sufficient to prevent oxidative damage, while SIRT3 upregulation could be a step towards an adaptive response to the diving.

  15. Pre-dive whole-body vibration better reduces decompression-induced Vascular Gas Emboli than oxygenation or a combination of both.

    Directory of Open Access Journals (Sweden)

    Costantino Balestra

    2016-11-01

    Full Text Available Purpose: Since non-provocative dive profiles are no guarantor of protection against decompression sickness, novel means including pre-dive preconditioning interventions, are proposed for its prevention. This study investigated and compared the effect of pre-dive oxygenation, pre-dive whole body vibration or a combination of both on post-dive bubble formation. Methods: 6 healthy volunteers performed 6 no-decompression dives each, to a depth of 33 mfw for 20 minutes (3 control dives without preconditioning and 1 of each preconditioning protocol with a minimum interval of 1 week between each dive. Post-dive bubbles were counted in the precordium by two-dimensional echocardiography, 30 and 90 minutes after the dive, with and without knee flexing. Each diver served as his own control.Results: Vascular gas emboli (VGE were systematically observed before and after knee flexing at each post-dive measurement. Compared to the control dives, we observed a decrease in VGE count of 23.8±7.4% after oxygen breathing (p<0.05, 84.1±5.6% after vibration (p<0.001, and 55.1±9.6% after vibration combined with oxygen (p<0.001. The difference between all preconditioning methods was statistically significant.Conclusions: The precise mechanism that induces the decrease in post-dive VGE and thus makes the diver more resistant to decompression stress is still not known. However, it seems that a pre-dive mechanical reduction of existing gas nuclei might best explain the beneficial effects of this strategy. The apparent non-synergic effect of oxygen and vibration has probably to be understood because of different mechanisms involved.

  16. CFD based investigation on the impact acceleration when a gannet impacts with water during plunge diving.

    Science.gov (United States)

    Wang, T M; Yang, X B; Liang, J H; Yao, G C; Zhao, W D

    2013-09-01

    Plunge diving is the most commonly used feeding method of a gannet, which can make the gannet transit from air to water rapidly and successfully. A large impact acceleration can be generated due to the air-to-water transition. However, the impact acceleration experienced by the gannet during plunge diving has not been studied. In this paper, this issue is investigated by using the CFD method. The effect of the dropping height and the water-entry inclination angle on the impact acceleration is considered. The results reveal that the impact acceleration along the longitudinal body axis increases with either of the two parameters. The peak time decreases with the dropping height. A quadratic relation is found between the peak impact acceleration and the initial water-entry velocity. According to the computation, when the dropping height is 30 m (most of gannets plunge from about this height), the peak impact acceleration can reach about 23 times the gravitational acceleration, which will exert a considerable force on the gannet body. Furthermore, the pressure distribution of different water-entry inclination angles indicates that the large pressure asymmetry caused by a small oblique angle may lead to a large impact acceleration in the direction perpendicular to the longitudinal body axis and cause damage to the neck of the gannet, which partly explains the reason why a gannet performing a high plunge diving in nature enters water with a large oblique angle from the perspective of impact mechanics. The investigation on the plunge-diving behavior in this paper will inspire and promote the development of a biomimetic amphibious robot that transits from air to water with the plunge-diving mode.

  17. Grey Nurse Shark ( Carcharias taurus) Diving Tourism: Tourist Compliance and Shark Behaviour at Fish Rock, Australia

    Science.gov (United States)

    Smith, Kirby; Scarr, Mark; Scarpaci, Carol

    2010-11-01

    Humans can dive with critically endangered grey nurse sharks ( Carcharias taurus) along the east coast of Australia. This study investigated both compliance of tourist divers to a code of conduct and legislation and the behaviour of grey nurse sharks in the presence of divers. A total of 25 data collection dives were conducted from December 2008 to January 2009. Grey nurse shark and diver behaviour were documented using 2-min scan samples and continuous observation. The proportion of time spent observing human-shark interactions was 9.4% of total field time and mean human-shark interaction time was 15.0 min. Results were used to gauge the effectiveness of current management practices for the grey nurse shark dive industry at Fish Rock in New South Wales, Australia. Grey nurse shark dive tourists were compliant to stipulations in the code of conduct and legislation (compliance ranged from 88 to 100%). The research detailed factors that may promote compliance in wildlife tourism operations such as the clarity of the stipulations, locality of the target species and diver perceptions of sharks. Results indicated that grey nurse sharks spent the majority of their time milling (85%) followed by active swimming (15%). Milling behaviour significantly decreased in the presence of more than six divers. Distance between sharks and divers, interaction time and number of sharks were not significantly correlated with grey nurse shark school behaviour. Jaw gaping, rapid withdrawal and stiff or jerky movement were the specific behaviours of grey nurse sharks that occurred most frequently and were associated with distance between divers and sharks and the presence of six or more divers. Revision of the number of divers allowed per interaction with a school of grey nurse sharks and further research on the potential impacts that shark-diving tourism may pose to grey nurse sharks is recommended.

  18. Mobility, Expansion and Management of a Multi-Species Scuba Diving Fishery in East Africa

    Science.gov (United States)

    Eriksson, Hampus; de la Torre-Castro, Maricela; Olsson, Per

    2012-01-01

    Background Scuba diving fishing, predominantly targeting sea cucumbers, has been documented to occur in an uncontrolled manner in the Western Indian Ocean and in other tropical regions. Although this type of fishing generally indicates a destructive activity, little attention has been directed towards this category of fishery, a major knowledge gap and barrier to management. Methodology and Principal Findings With the aim to capture geographic scales, fishing processes and social aspects the scuba diving fishery that operate out of Zanzibar was studied using interviews, discussions, participant observations and catch monitoring. The diving fishery was resilient to resource declines and had expanded to new species, new depths and new fishing grounds, sometimes operating approximately 250 km away from Zanzibar at depths down to 50 meters, as a result of depleted easy-access stock. The diving operations were embedded in a regional and global trade network, and its actors operated in a roving manner on multiple spatial levels, taking advantage of unfair patron-client relationships and of the insufficient management in Zanzibar. Conclusions and Significance This study illustrates that roving dynamics in fisheries, which have been predominantly addressed on a global scale, also take place at a considerably smaller spatial scale. Importantly, while proposed management of the sea cucumber fishery is often generic to a simplified fishery situation, this study illustrates a multifaceted fishery with diverse management requirements. The documented spatial scales and processes in the scuba diving fishery emphasize the need for increased regional governance partnerships to implement management that fit the spatial scales and processes of the operation. PMID:22530034

  19. Grey nurse shark (Carcharias taurus) diving tourism: Tourist compliance and shark behaviour at Fish Rock, Australia.

    Science.gov (United States)

    Smith, Kirby; Scarr, Mark; Scarpaci, Carol

    2010-11-01

    Humans can dive with critically endangered grey nurse sharks (Carcharias taurus) along the east coast of Australia. This study investigated both compliance of tourist divers to a code of conduct and legislation and the behaviour of grey nurse sharks in the presence of divers. A total of 25 data collection dives were conducted from December 2008 to January 2009. Grey nurse shark and diver behaviour were documented using 2-min scan samples and continuous observation. The proportion of time spent observing human-shark interactions was 9.4% of total field time and mean human-shark interaction time was 15.0 min. Results were used to gauge the effectiveness of current management practices for the grey nurse shark dive industry at Fish Rock in New South Wales, Australia. Grey nurse shark dive tourists were compliant to stipulations in the code of conduct and legislation (compliance ranged from 88 to 100%). The research detailed factors that may promote compliance in wildlife tourism operations such as the clarity of the stipulations, locality of the target species and diver perceptions of sharks. Results indicated that grey nurse sharks spent the majority of their time milling (85%) followed by active swimming (15%). Milling behaviour significantly decreased in the presence of more than six divers. Distance between sharks and divers, interaction time and number of sharks were not significantly correlated with grey nurse shark school behaviour. Jaw gaping, rapid withdrawal and stiff or jerky movement were the specific behaviours of grey nurse sharks that occurred most frequently and were associated with distance between divers and sharks and the presence of six or more divers. Revision of the number of divers allowed per interaction with a school of grey nurse sharks and further research on the potential impacts that shark-diving tourism may pose to grey nurse sharks is recommended.

  20. Mobility, expansion and management of a multi-species scuba diving fishery in East Africa.

    Directory of Open Access Journals (Sweden)

    Hampus Eriksson

    Full Text Available BACKGROUND: Scuba diving fishing, predominantly targeting sea cucumbers, has been documented to occur in an uncontrolled manner in the Western Indian Ocean and in other tropical regions. Although this type of fishing generally indicates a destructive activity, little attention has been directed towards this category of fishery, a major knowledge gap and barrier to management. METHODOLOGY AND PRINCIPAL FINDINGS: With the aim to capture geographic scales, fishing processes and social aspects the scuba diving fishery that operate out of Zanzibar was studied using interviews, discussions, participant observations and catch monitoring. The diving fishery was resilient to resource declines and had expanded to new species, new depths and new fishing grounds, sometimes operating approximately 250 km away from Zanzibar at depths down to 50 meters, as a result of depleted easy-access stock. The diving operations were embedded in a regional and global trade network, and its actors operated in a roving manner on multiple spatial levels, taking advantage of unfair patron-client relationships and of the insufficient management in Zanzibar. CONCLUSIONS AND SIGNIFICANCE: This study illustrates that roving dynamics in fisheries, which have been predominantly addressed on a global scale, also take place at a considerably smaller spatial scale. Importantly, while proposed management of the sea cucumber fishery is often generic to a simplified fishery situation, this study illustrates a multifaceted fishery with diverse management requirements. The documented spatial scales and processes in the scuba diving fishery emphasize the need for increased regional governance partnerships to implement management that fit the spatial scales and processes of the operation.