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Sample records for altitude

  1. Athletes at High Altitude.

    Science.gov (United States)

    Khodaee, Morteza; Grothe, Heather L; Seyfert, Jonathan H; VanBaak, Karin

    2016-01-01

    Athletes at different skill levels perform strenuous physical activity at high altitude for a variety of reasons. Multiple team and endurance events are held at high altitude and may place athletes at increased risk for developing acute high altitude illness (AHAI). Training at high altitude has been a routine part of preparation for some of the high level athletes for a long time. There is a general belief that altitude training improves athletic performance for competitive and recreational athletes. A review of relevant publications between 1980 and 2015 was completed using PubMed and Google Scholar. Clinical review. Level 3. AHAI is a relatively uncommon and potentially serious condition among travelers to altitudes above 2500 m. The broad term AHAI includes several syndromes such as acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE). Athletes may be at higher risk for developing AHAI due to faster ascent and more vigorous exertion compared with nonathletes. Evidence regarding the effects of altitude training on athletic performance is weak. The natural live high, train low altitude training strategy may provide the best protocol for enhancing endurance performance in elite and subelite athletes. High altitude sports are generally safe for recreational athletes, but they should be aware of their individual risks. Individualized and appropriate acclimatization is an essential component of injury and illness prevention.

  2. Classical altitude training.

    Science.gov (United States)

    Friedmann-Bette, B

    2008-08-01

    For more than 40 years, the effects of classical altitude training on sea-level performance have been the subject of many scientific investigations in individual endurance sports. To our knowledge, no studies have been performed in team sports like football. Two well-controlled studies showed that living and training at an altitude of >or=1800-2700 m for 3-4 weeks is superior to equivalent training at sea level in well-trained athletes. Most of the controlled studies with elite athletes did not reveal such an effect. However, the results of some uncontrolled studies indicate that sea-level performance might be enhanced after altitude training also in elite athletes. Whether hypoxia provides an additional stimulus for muscular adaptation, when training is performed with equal intensity compared with sea-level training is not known. There is some evidence for an augmentation of total hemoglobin mass after classical altitude training with duration >or=3 weeks at an altitude >or=2000 m due to altitude acclimatization. Considerable individual variation is observed in the erythropoietic response to hypoxia and in the hypoxia-induced reduction of aerobic performance capacity during training at altitude, both of which are thought to contribute to inter-individual variation in the improvement of sea-level performance after altitude training.

  3. HIGH-ALTITUDE ILLNESS

    Directory of Open Access Journals (Sweden)

    Dwitya Elvira

    2015-05-01

    Full Text Available AbstrakHigh-altitude illness (HAI merupakan sekumpulan gejala paru dan otak yang terjadi pada orang yang baru pertama kali mendaki ke ketinggian. HAI terdiri dari acute mountain sickness (AMS, high-altitude cerebral edema (HACE dan high-altitude pulmonary edema (HAPE. Tujuan tinjauan pustaka ini adalah agar dokter dan wisatawan memahami risiko, tanda, gejala, dan pengobatan high-altitude illness. Perhatian banyak diberikan terhadap penyakit ini seiring dengan meningkatnya popularitas olahraga ekstrim (mendaki gunung tinggi, ski dan snowboarding dan adanya kemudahan serta ketersediaan perjalanan sehingga jutaan orang dapat terpapar bahaya HAI. Di Pherice, Nepal (ketinggian 4343 m, 43% pendaki mengalami gejala AMS. Pada studi yang dilakukan pada tempat wisata di resort ski Colorado, Honigman menggambarkan kejadian AMS 22% pada ketinggian 1850 m sampai 2750 m, sementara Dean menunjukkan 42% memiliki gejala pada ketinggian 3000 m. Aklimatisasi merupakan salah satu tindakan pencegahan yang dapat dilakukan sebelum pendakian, selain beberapa pengobatan seperti asetazolamid, dexamethasone, phosopodiestrase inhibitor, dan ginko biloba.Kata kunci: high-altitude illness, acute mountain sickness, edema cerebral, pulmonary edema AbstractHigh-altitude illness (HAI is symptoms of lung and brain that occurs in people who first climb to altitude. HAI includes acute mountain sickness (AMS, high-altitude cerebral edema (HACE and high altitude pulmonary edema (HAPE. The objective of this review was to understand the risks, signs, symptoms, and treatment of high-altitude illness. The attention was given to this disease due to the rising popularity of extreme sports (high mountain climbing, skiing and snowboarding and the ease and availability of the current travelling, almost each year, millions of people could be exposed to the danger of HAI. In Pherice, Nepal (altitude 4343 m, 43% of climbers have symptoms of AMS. Furthermore, in a study conducted at sites in

  4. Altitude-related cough

    Science.gov (United States)

    2013-01-01

    Altitude-related cough is a troublesome condition of uncertain aetiology that affects many visitors to high altitude. The traditionally held belief that it was due solely to the inspiration of cold, dry air was refuted by observations and experiments in long duration hypobaric chamber studies. It is likely that altitude-related cough is a symptom of a number of possible perturbations in the cough reflex arc that may exist independently or together. These include loss of water from the respiratory tract; respiratory tract infections and sub-clinical high altitude pulmonary oedema. The published work on altitude-related cough is reviewed and possible aetiologies for the condition are discussed. PMID:24175933

  5. Endurance training at altitude.

    Science.gov (United States)

    Saunders, Philo U; Pyne, David B; Gore, Christopher J

    2009-01-01

    Since the 1968 Olympic Games when the effects of altitude on endurance performance became evident, moderate altitude training ( approximately 2000 to 3000 m) has become popular to improve competition performance both at altitude and sea level. When endurance athletes are exposed acutely to moderate altitude, a number of physiological responses occur that can comprise performance at altitude; these include increased ventilation, increased heart rate, decreased stroke volume, reduced plasma volume, and lower maximal aerobic power ((.)Vo(2max)) by approximately 15% to 20%. Over a period of several weeks, one primary acclimatization response is an increase in the volume of red blood cells and consequently of (.)Vo(2max). Altitudes > approximately 2000 m for >3 weeks and adequate iron stores are required to elicit these responses. However, the primacy of more red blood cells for superior sea-level performance is not clear-cut since the best endurance athletes in the world, from Ethiopia (approximately 2000 to 3000 m), have only marginally elevated hemoglobin concentrations. The substantial reduction in (.)Vo(2max) of athletes at moderate altitude implies that their training should include adequate short-duration (approximately 1 to 2 min), high-intensity efforts with long recoveries to avoid a reduction in race-specific fitness. At the elite level, athlete performance is not dependent solely on (.)Vo(2max), and the "smallest worthwhile change" in performance for improving race results is as little as 0.5%. Consequently, contemporary statistical approaches that utilize the concept of the smallest worthwhile change are likely to be more appropriate than conventional statistical methods when attempting to understand the potential benefits and mechanisms of altitude training.

  6. Altitude and endurance training.

    Science.gov (United States)

    Rusko, Heikki K; Tikkanen, Heikki O; Peltonen, Juha E

    2004-10-01

    The benefits of living and training at altitude (HiHi) for an improved altitude performance of athletes are clear, but controlled studies for an improved sea-level performance are controversial. The reasons for not having a positive effect of HiHi include: (1) the acclimatization effect may have been insufficient for elite athletes to stimulate an increase in red cell mass/haemoglobin mass because of too low an altitude (altitude training period (training effect at altitude may have been compromised due to insufficient training stimuli for enhancing the function of the neuromuscular and cardiovascular systems; and (3) enhanced stress with possible overtraining symptoms and an increased frequency of infections. Moreover, the effects of hypoxia in the brain may influence both training intensity and physiological responses during training at altitude. Thus, interrupting hypoxic exposure by training in normoxia may be a key factor in avoiding or minimizing the noxious effects that are known to occur in chronic hypoxia. When comparing HiHi and HiLo (living high and training low), it is obvious that both can induce a positive acclimatization effect and increase the oxygen transport capacity of blood, at least in 'responders', if certain prerequisites are met. The minimum dose to attain a haematological acclimatization effect is > 12 h a day for at least 3 weeks at an altitude or simulated altitude of 2100-2500 m. Exposure to hypoxia appears to have some positive transfer effects on subsequent training in normoxia during and after HiLo. The increased oxygen transport capacity of blood allows training at higher intensity during and after HiLo in subsequent normoxia, thereby increasing the potential to improve some neuromuscular and cardiovascular determinants of endurance performance. The effects of hypoxic training and intermittent short-term severe hypoxia at rest are not yet clear and they require further study.

  7. High Altitude and Heart

    Directory of Open Access Journals (Sweden)

    Murat Yalcin

    2011-04-01

    Full Text Available Nowadays, situations associated with high altitude such as mountaineering, aviation increasingly draw the attention of people. Gas pressure decreases and hypoxia is encountered when climbing higher. Physiological and pathological responses of human body to different heights are different. Therefore, physiological and pathological changes that may occur together with height and to know the clinical outcomes of these are important . Acute mountain sickness caused by high altitude and high altitude cerebral edema are preventable diseases with appropriate precautions. Atmospheric oxygen decreasing with height, initiates many adaptive mechanisms. These adaptation mechanisms and acclimatization vary widely among individuals because of reasons such as environmental factors, exercise and cold. High altitude causes different changes in the cardiovascular system with various mechanisms. Although normal individuals easily adapt to these changes, this situation can lead to undesirable results in people with heart disease. For this reason, it should be known the effective evaluation of the people with known heart disease before traveling to high altitude and the complications due to the changes with height and the recommendations can be made to these patients. [TAF Prev Med Bull 2011; 10(2.000: 211-222

  8. Brain Food at High Altitude.

    Science.gov (United States)

    Jain, Vishal

    2016-01-01

    Scenic view at high altitude is a pleasure to the eyes, but it has some shortcoming effects as well. High altitude can be divided into different categories, i.e., high altitude (3000-5000 ft), very high altitude (5000-8000 ft), and extreme altitude (above 8000 ft). Much of the population resides at high altitude, and others go there for tourism. Military personnel are also posted there to defend boundaries. As we ascent to high altitude, partial pressure of oxygen reduces, whereas concentration remains the same; this reduces the availability of oxygen to different body parts. This pathophysiological condition is known as hypobaric hypoxia (HH) which leads to oxidative stress and further causes cognitive dysfunction in some cases. Hypoxia causes neurodegeneration in different brain regions; however, the hippocampus is found to be more prone in comparison to other brain regions. As the hippocampus is affected most, therefore, spatial memory is impaired most during such condition. This chapter will give a brief review of the damaging effect of high altitude on cognition and also throw light on possible herbal interventions at high altitude, which can improve cognitive performance as well as provide protection against the deteriorating effect of hypobaric hypoxia at high altitude.

  9. High altitude organic gold

    DEFF Research Database (Denmark)

    Pouliot, Mariève; Pyakurel, Dipesh; Smith-Hall, Carsten

    2018-01-01

    . Heightened demand in China over the past 15 years, coupled with limited production, has led to a price hike and increased economic importance of harvests to rural households throughout the species’ range. There is, however, limited knowledge on the actors and profit distribution in the O. sinensis production...... by collectors, limited value enhancement, and a high degree of network and territorial embeddedness. Conclusions O. sinensis income is of major economic importance for rural households at the margin of its distribution range in Nepal. Production networks operated by informal actors establishing trust......Ethnopharmacological relevance Ophiocordyceps sinensis (Berk.) G.H.Sung, J.M.Sung, Hywel-Jones & Spatafora, a high altitude Himalayan fungus-caterpillar product found in alpine meadows in China, Bhutan, Nepal, and India, has been used in the Traditional Chinese Medicine system for over 2000 years...

  10. High altitude dermatology

    Directory of Open Access Journals (Sweden)

    G K Singh

    2017-01-01

    Full Text Available Approximately, 140 million people worldwide live permanently at high altitudes (HAs and approximately another 40 million people travel to HA area (HAA every year for reasons of occupation, sports or recreation. In India, whole of Ladakh region, part of Northwest Kashmir, Northern part of Sikkim and Tenga valley of Arunachal are considered inhabited areas of HAA. The low quantity of oxygen, high exposure of ultraviolet (UV light, very low humidity, extreme subzero temperature in winter, high wind velocity, make this region difficult for lowlanders as well as for tourists. Acute mountain sickness, HA pulmonary edema, HA cerebral edema, and thromboembolic conditions are known to occur in HA. However, enough knowledge has not been shared on dermatoses peculiar to this region. Xerosis, UV-related skin disorders (tanning, photomelanosis, acute and chronic sunburn, polymorphic light eruption, chronic actinic dermatitis, actinic cheilitis, etc., cold injuries (frostbite, chilblains, acrocyanosis, erythrocyanosis, etc. nail changes (koilonychias, airborne contact dermatitis, insect bite reaction, and skin carcinoma (basal cell carcinomas, squamous cell carcinomas, and also rarely malignant melanoma are the dermatoses seen in HAAs. Early diagnosis and knowledge of HA dermatoses may prevent serious consequences of disease and improve the quality of life for the visitors as well as for native of the place.

  11. Acute high-altitude sickness

    Directory of Open Access Journals (Sweden)

    Andrew M. Luks

    2017-02-01

    Full Text Available At any point 1–5 days following ascent to altitudes ≥2500 m, individuals are at risk of developing one of three forms of acute altitude illness: acute mountain sickness, a syndrome of nonspecific symptoms including headache, lassitude, dizziness and nausea; high-altitude cerebral oedema, a potentially fatal illness characterised by ataxia, decreased consciousness and characteristic changes on magnetic resonance imaging; and high-altitude pulmonary oedema, a noncardiogenic form of pulmonary oedema resulting from excessive hypoxic pulmonary vasoconstriction which can be fatal if not recognised and treated promptly. This review provides detailed information about each of these important clinical entities. After reviewing the clinical features, epidemiology and current understanding of the pathophysiology of each disorder, we describe the current pharmacological and nonpharmacological approaches to the prevention and treatment of these diseases.

  12. Venus Altitude Cycling Balloon Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The ISTAR Group ( IG) and team mate Thin Red Line Aerospace (TRLA) propose a Venus altitude cycling balloon (Venus ACB), an innovative superpressure balloon...

  13. Altitude training improves glycemic control.

    Science.gov (United States)

    Chen, Shu-Man; Lin, Hsueh-Yi; Kuo, Chia-Hua

    2013-08-31

    Under altitude hypoxia condition, energy reliance on anaerobic glycolysis increases to compensate the shortfall caused by reduced fatty acid oxidation. Short-term moderate altitude exposure plus endurance physical activity has been found to improve glucose tolerance (not fasting glucose) in humans, which is associated with the improvement in the whole-body insulin sensitivity. However, most of people cannot accommodate high altitude exposure above 4500 M due to acute mountain sickness and insulin resistance. There is a wide variation among individuals in response to the altitude challenge. In particular, the improvement in glucose tolerance and insulin sensitivity by prolonged altitude hiking activity was not apparent in those individuals with low baseline dehydroepiandrosterone sulfate (DHEA-S) concentration. In rats, exercise training recovery under prolonged hypoxia exposure (14-15% oxygen, 8 h per day for 6 weeks) can also improve insulin sensitivity, secondary to an effective suppression of adiposity. After prolonged hypoxia training, obese abnormality in upregulated baseline levels of AMP-activated protein kinase (AMPK) and AS160 phosphorylation in skeletal muscle can be reversed. In humans, moderate hypoxia increases postprandial blood distribution towards skeletal muscle during a training recovery. This physiological response plays a role in the redistribution of fuel storage among important energy storage sites and may explain its potent effect on the favorable change in body composition. Altitude training can exert strong impact on our metabolic system, and has the potential to be designed as a non-pharmacological or recreational intervention regimen for correcting metabolic syndromes.

  14. High-altitude pulmonary hypertension

    Directory of Open Access Journals (Sweden)

    X-Q. Xu

    2009-03-01

    Full Text Available High-altitude pulmonary hypertension (HAPH is a specific disease affecting populations that live at high elevations. The prevalence of HAPH among those residing at high altitudes needs to be further defined. Whereas reduction in nitric oxide production may be one mechanism for the development of HAPH, the roles of endothelin-1 and prostaglandin I2 pathways in the pathogenesis of HAPH deserve further study. Although some studies have suggested that genetic factors contribute to the pathogenesis of HAPH, data published to date are insufficient for the identification of a significant number of gene polymorphims in HAPH. The clinical presentation of HAPH is nonspecific. Exertional dyspnoea is the most common symptom and signs related to right heart failure are common in late stages of HAPH. Echocardiography is the most useful screening tool and right heart catheterisation is the gold standard for the diagnosis of HAPH. The ideal management for HAPH is migration to lower altitudes. Phosphodiesterase 5 is an attractive drug target for the treatment of HAPH. In addition, acetazolamide is a promising therapeutic agent for high-altitude pulmonary hypertension. To date, no evidence has confirmed whether endothelin-receptor antagonists have efficacy in the treatment of high-altitude pulmonary hypertension.

  15. Form of breathing at altitude

    OpenAIRE

    Arnáez Lapeyre, Enrique

    2014-01-01

    It is demonstrated by the studies of Professor Monge and colleagues, that the phenomena of cardiac activity in altitude show a predominant vagal influence, which determines paradoxical bradycardic reactions apparently sympathetic origin. Está demostrado, por los estudios del Profesor Monge y colaboradores, que los fenómenos de la actividad cardíaca en la altitud muestran una influencia vagal preponderante, que determina reacciones paradójicas bradicárdicas, al parecer de origen simpático....

  16. Operation Everest II. Altitude Decompression Sickness during Repeated Altitude Exposure,

    Science.gov (United States)

    1986-05-01

    Mayo, D.A. and Bancroft, R.W. Body fat , denitrogeration and decompression sickness in men exercising after abrupt exposure to altitude. Aerospace...Conkin, J., Waligora, J.M., Horrigan Jr., D.J. and Hadley Ill, A.T. Comparison of venous gas emboli and decompression sickness incidence in excercising

  17. ELAHA - ELASTIC AIRCRAFT FOR HIGH ALTITUDES

    OpenAIRE

    Wlach, Sven; Balmer, Georg Robert; Hermann, Milan; Wüsthoff, Tilo

    2017-01-01

    The group Flying Robots at the DLR Institute of Robotics and Mechatronics in Oberpfaffenhofen conducts research on solar powered high altitude aircraft. Due to the high altitude and the almost infinite mission duration, these platforms are also denoted as High Altitude Pseudo-Satellites (HAPS) or High Altitude Platforms (HAP). After the successful flight of HABLEG, which was presented at ESA PAC 2015, work continued with the goal to reach the stratosphere under own power with a reasonable ...

  18. Mood States at 1600 and 4300 Meters High Terrestrial Altitude,

    Science.gov (United States)

    ATTITUDES(PSYCHOLOGY), *STRESS(PSYCHOLOGY), *ALTITUDE SICKNESS, ACCLIMATIZATION, BASE LINES, ARRIVAL, DAY, SCALE, STANDARDIZATION, ASCENT TRAJECTORIES, HIGH ALTITUDE, ALTITUDE, INTERPERSONAL RELATIONS , TIME, BEHAVIOR.

  19. Measuring high-altitude adaptation.

    Science.gov (United States)

    Moore, Lorna G

    2017-11-01

    High altitudes (>8,000 ft or 2,500 m) provide an experiment of nature for measuring adaptation and the physiological processes involved. Studies conducted over the past ~25 years in Andeans, Tibetans, and, less often, Ethiopians show varied but distinct O 2 transport traits from those of acclimatized newcomers, providing indirect evidence for genetic adaptation to high altitude. Short-term (acclimatization, developmental) and long-term (genetic) responses to high altitude exhibit a temporal gradient such that, although all influence O 2 content, the latter also improve O 2 delivery and metabolism. Much has been learned concerning the underlying physiological processes, but additional studies are needed on the regulation of blood flow and O 2 utilization. Direct evidence of genetic adaptation comes from single-nucleotide polymorphism (SNP)-based genome scans and whole genome sequencing studies that have identified gene regions acted upon by natural selection. Efforts have begun to understand the connections between the two with Andean studies on the genetic factors raising uterine blood flow, fetal growth, and susceptibility to Chronic Mountain Sickness and Tibetan studies on genes serving to lower hemoglobin and pulmonary arterial pressure. Critical for future studies will be the selection of phenotypes with demonstrable effects on reproductive success, the calculation of actual fitness costs, and greater inclusion of women among the subjects being studied. The well-characterized nature of the O 2 transport system, the presence of multiple long-resident populations, and relevance for understanding hypoxic disorders in all persons underscore the importance of understanding how evolutionary adaptation to high altitude has occurred. NEW & NOTEWORTHY Variation in O 2 transport characteristics among Andean, Tibetan, and, when available, Ethiopian high-altitude residents supports the existence of genetic adaptations that improve the distribution of blood flow to vital

  20. ALT space shuttle barometric altimeter altitude analysis

    Science.gov (United States)

    Killen, R.

    1978-01-01

    The accuracy was analyzed of the barometric altimeters onboard the space shuttle orbiter. Altitude estimates from the air data systems including the operational instrumentation and the developmental flight instrumentation were obtained for each of the approach and landing test flights. By comparing the barometric altitude estimates to altitudes derived from radar tracking data filtered through a Kalman filter and fully corrected for atmospheric refraction, the errors in the barometric altitudes were shown to be 4 to 5 percent of the Kalman altitudes. By comparing the altitude determined from the true atmosphere derived from weather balloon data to the altitude determined from the U.S. Standard Atmosphere of 1962, it was determined that the assumption of the Standard Atmosphere equations contributes roughly 75 percent of the total error in the baro estimates. After correcting the barometric altitude estimates using an average summer model atmosphere computed for the average latitude of the space shuttle landing sites, the residual error in the altitude estimates was reduced to less than 373 feet. This corresponds to an error of less than 1.5 percent for altitudes above 4000 feet for all flights.

  1. Rocket Engine Altitude Simulation Technologies

    Science.gov (United States)

    Woods, Jody L.; Lansaw, John

    2010-01-01

    John C. Stennis Space Center is embarking on a very ambitious era in its rocket engine propulsion test history. The first new large rocket engine test stand to be built at Stennis Space Center in over 40 years is under construction. The new A3 Test Stand is designed to test very large (294,000 Ibf thrust) cryogenic propellant rocket engines at a simulated altitude of 100,000 feet. A3 Test Stand will have an engine testing chamber where the engine will be fired after the air in the chamber has been evacuated to a pressure at the simulated altitude of less than 0.16 PSIA. This will result in a very unique environment with extremely low pressures inside a very large chamber and ambient pressures outside this chamber. The test chamber is evacuated of air using a 2-stage diffuser / ejector system powered by 5000 lb/sec of steam produced by 27 chemical steam generators. This large amount of power and flow during an engine test will result in a significant acoustic and vibrational environment in and around A3 Test Stand.

  2. Variation in aerodynamic coefficients with altitude

    Directory of Open Access Journals (Sweden)

    Faiza Shahid

    Full Text Available Precise aerodynamics performance prediction plays key role for a flying vehicle to get its mission completed within desired accuracy. Aerodynamic coefficients for same Mach number can be different at different altitude due to difference in Reynolds number. Prediction of these aerodynamics coefficients can be made through experiments, analytical solution or Computational Fluid Dynamics (CFD. Advancements in computational power have generated the concept of using CFD as a virtual Wind Tunnel (WT, hence aerodynamic performance prediction in present study is based upon CFD (numerical test rig. Simulations at different altitudes for a range of Mach numbers with zero angle of attack are performed to predict axial force coefficient behavior with altitude (Reynolds number. Similar simulations for a fixed Mach number ‘3’ and a range of angle of attacks are also carried out to envisage the variation in normal force and pitching moment coefficients with altitude (Reynolds number. Results clearly depict that the axial force coefficient is a function of altitude (Reynolds number and increase as altitude increases, especially for subsonic region. Variation in axial force coefficient with altitude (Reynolds number slightly increases for larger values of angle of attacks. Normal force and pitching moment coefficients do not depend on altitude (Reynolds number at smaller values of angle of attacks but show slight decrease as altitude increases. Present study suggests that variation of normal force and pitching moment coefficients with altitude can be neglected but the variation of axial force coefficient with altitude should be considered for vehicle fly in dense atmosphere. It is recommended to continue this study to more complex configurations for various Mach numbers with side slip and real gas effects. Keywords: Mach number, Reynolds number, Blunt body, Altitude effect, Angle of attacks

  3. Cardiovascular Effects of Altitude on Performance Athletes.

    Science.gov (United States)

    Shah, Ankit B; Coplan, Neil

    Altitude plays an important role in cardiovascular performance and training for athletes. Whether it is mountaineers, skiers, or sea-level athletes trying to gain an edge by training or living at increased altitude, there are many potential benefits and harms of such endeavors. Echocardiographic studies done on athletes at increased altitude have shown evidence for right ventricular dysfunction and pulmonary hypertension, but no change in left ventricular ejection fraction. In addition, 10% of athletes are susceptible to pulmonary hypertension and high-altitude pulmonary edema. Some studies suggest that echocardiography may be able to identify athletes susceptible to high-altitude pulmonary edema prior to competing or training at increased altitudes. Further research is needed on the long-term effects of altitude training, as repeated, transient episodes of pulmonary hypertension and right ventricular dysfunction may have long-term implications. Current literature suggests that performance athletes are not at higher risk for ventricular arrhythmias when training or competing at increased altitudes. For sea-level athletes, the optimal strategy for attaining the benefits while minimizing the harms of altitude training still needs to be clarified, although-for now-the "live high, train low" approach appears to have the most rationale.

  4. Physiological aspects of altitude training and the use of altitude simulators

    OpenAIRE

    Ranković Goran; Radovanović Dragan

    2005-01-01

    Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatization, which improves oxygen transport and/or utilization, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training), live low and train high (training thr...

  5. Variation in aerodynamic coefficients with altitude

    Science.gov (United States)

    Shahid, Faiza; Hussain, Mukkarum; Baig, Mirza Mehmood; Haq, Ihtram ul

    Precise aerodynamics performance prediction plays key role for a flying vehicle to get its mission completed within desired accuracy. Aerodynamic coefficients for same Mach number can be different at different altitude due to difference in Reynolds number. Prediction of these aerodynamics coefficients can be made through experiments, analytical solution or Computational Fluid Dynamics (CFD). Advancements in computational power have generated the concept of using CFD as a virtual Wind Tunnel (WT), hence aerodynamic performance prediction in present study is based upon CFD (numerical test rig). Simulations at different altitudes for a range of Mach numbers with zero angle of attack are performed to predict axial force coefficient behavior with altitude (Reynolds number). Similar simulations for a fixed Mach number '3' and a range of angle of attacks are also carried out to envisage the variation in normal force and pitching moment coefficients with altitude (Reynolds number). Results clearly depict that the axial force coefficient is a function of altitude (Reynolds number) and increase as altitude increases, especially for subsonic region. Variation in axial force coefficient with altitude (Reynolds number) slightly increases for larger values of angle of attacks. Normal force and pitching moment coefficients do not depend on altitude (Reynolds number) at smaller values of angle of attacks but show slight decrease as altitude increases. Present study suggests that variation of normal force and pitching moment coefficients with altitude can be neglected but the variation of axial force coefficient with altitude should be considered for vehicle fly in dense atmosphere. It is recommended to continue this study to more complex configurations for various Mach numbers with side slip and real gas effects.

  6. Multicentric Chemodectomata at High Altitude | Nathanson | South ...

    African Journals Online (AJOL)

    Multicentric chemodectomata in the right glomus intravagale and both carotid bodies were excised from a 74year-old woman. These are rare tumours. The patient was born and lived at an altitude of 1 800 m above sea level. The effects of altitude and chronic hypoxia on the carotid bodies are discussed.

  7. Performance of portable ventilators at altitude.

    Science.gov (United States)

    Blakeman, Thomas; Britton, Tyler; Rodriquez, Dario; Branson, Richard

    2014-09-01

    Aeromedical transport of critically ill patients requires continued, accurate performance of equipment at altitude. Changes in barometric pressure can affect the performance of mechanical ventilators calibrated for operation at sea level. Deploying ventilators that can maintain a consistent tidal volume (VT) delivery at various altitudes is imperative for lung protection when transporting wounded war fighters to each echelon of care. Three ventilators (Impact 731, Hamilton T1, and CareFusion Revel) were tested at pediatric (50 and 100 mL) and adult (250-750 mL) tidal VTs at 0 and 20 cm H₂O positive end expiratory pressure and at inspired oxygen of 0.21 and 1.0. Airway pressure, volume, and flow were measured at sea level as well as at 8,000, 16,000, and 22,000 ft (corresponding to barometric pressures of 760, 564, 412, and 321 mm Hg) using a calibrated pneumotachograph connected to a training test lung in an altitude chamber. Set VT and delivered VT as well as changes in VT at each altitude were compared by t test. The T1 delivered VT within 10% of set VT at 8,000 ft. The mean VT was less than set VT at sea level as a result of circuit compressible volume with the Revel and the 731. Changes in VT varied widely among the devices at sea level and at altitude. Increasing altitudes resulted in larger VT than set for the Revel and the T1. The 731 compensated for changes in altitude delivered VT within 10% at the adult settings at all altitudes. Altitude compensation is an active software algorithm. Only the 731 actively accounts for changes in barometric pressure to maintain the set VT at all tested altitudes.

  8. Measurement of Low-Altitude Infrared Transmission

    National Research Council Canada - National Science Library

    Zeisse, C

    1999-01-01

    Infrared propagation at low altitudes is determined by extinction caused by molecules, aerosol particles, and ray bending by refraction, three effects that control the mean value of the signal (the transmission...

  9. 78 FR 68699 - IFR Altitudes; Miscellaneous Amendments

    Science.gov (United States)

    2013-11-15

    ... routes for which a minimum or maximum en route authorized IFR altitude is prescribed. This regulatory... Federal Airway V70 is Amended to Read in Part U.S./MEXICO BORDER BROWNSVILLE, TX VORTAC.. *5000 *1600...

  10. High Altitude Clear Air Turbulence Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Air Force Flight Dynamics Laboratory conducted the High Altitude Clear Air Turbulence Project in the mid 1960s with the intention of better understanding air...

  11. Introduction to altitude/hypoxic training symposium.

    Science.gov (United States)

    Wilber, Randall L

    2007-09-01

    Altitude/hypoxic training has traditionally been an intriguing and controversial area of research and sport performance. This controversial aspect was evident recently in the form of scholarly debates in highly regarded professional journals, as well as the World Anti-Doping Agency's (WADA) consideration of placing "artificially-induced hypoxic conditions" on the 2007 Prohibited List of Substances/Methods. In light of the ongoing controversy surrounding altitude/hypoxic training, this symposium was organized with the following objectives in mind: 1) to examine the primary physiological responses and underlying mechanisms associated with altitude/hypoxic training, including the influence of genetic predisposition; 2) to present evidence supporting the effect of altitude/hypoxic acclimatization on both hematological and nonhematological markers, including erythrocyte volume, skeletal muscle-buffering capacity, hypoxic ventilatory response, and physiological efficiency/economy; 3) to evaluate the efficacy of several contemporary simulated altitude modalities and training strategies, including hypoxic tents, nitrogen apartments, and intermittent hypoxic exposure (IHE) or training, and to address the legal and ethical issues associated with the use of simulated altitude; and 4) to describe different altitude/hypoxic training strategies used by elite-level athletes, including Olympians and military special forces. In addressing these objectives, papers will be presented on the topics of: 1) effect of hypoxic "dose" on physiological responses and sea-level performance (Drs. Benjamin Levine and James Stray-Gundersen), 2) nonhematological mechanisms of improved performance after hypoxic exposure (Dr. Christopher Gore), 3) application of altitude/hypoxic training by elite athletes (Dr. Randall Wilber), and 4) military applications of hypoxic training (Dr. Stephen Muza).

  12. Child health and living at high altitude.

    Science.gov (United States)

    Niermeyer, S; Andrade Mollinedo, P; Huicho, L

    2009-10-01

    The health of children born and living at high altitude is shaped not only by the low-oxygen environment, but also by population ancestry and sociocultural determinants. High altitude and the corresponding reduction in oxygen delivery during pregnancy result in lower birth weight with higher elevation. Children living at high elevations are at special risk for hypoxaemia during infancy and during acute lower respiratory infection, symptomatic high-altitude pulmonary hypertension, persistence of fetal vascular connections, and re-entry high-altitude pulmonary oedema. However, child health varies from one population group to another due to genetic adaptation as well as factors such as nutrition, intercurrent infection, exposure to pollutants and toxins, socioeconomic status, and access to medical care. Awareness of the risks uniquely associated with living at high altitude and monitoring of key health indicators can help protect the health of children at high altitude. These considerations should be incorporated into the scaling-up of effective interventions for improving global child health and survival.

  13. [Physiological aspects of altitude training and the use of altitude simulators].

    Science.gov (United States)

    Ranković, Goran; Radovanović, Dragan

    2005-01-01

    Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatisation, which improves oxygen transport and/or utilisation, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training), live low and train high (training through hypoxia), and live high and train low (the new trend). In an effort to reduce the financial and logistical challenges of travelling to high-altitude training sites, scientists and manufactures have developed artificial high-altitude environments, which simulate the hypoxic conditions of moderate altitude (2000-3000 meters). Endurance athletes from many sports have recently started using nitrogen environments, or hypoxic rooms and tents as part of their altitude training programmes. The results of controlled studies on these modalities of high-altitude training, their practical approach, and ethics are summarised.

  14. Physiological aspects of altitude training and the use of altitude simulators

    Directory of Open Access Journals (Sweden)

    Ranković Goran

    2005-01-01

    Full Text Available Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatization, which improves oxygen transport and/or utilization, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training, live low and train high (training through hypoxia, and live high and train low (the new trend. In an effort to reduce the financial and logistical challenges of traveling to high-altitude training sites, scientists and manufactures have developed artificial high-altitude environments, which simulate the hypoxic conditions of moderate altitude (2000-3000 meters. Endurance athletes from many sports have recently started using nitrogen environments, or hypoxic rooms and tents as part of their altitude training programmes. The results of controlled studies on these modalities of high-altitude training, their practical approach, and ethics are summarized.

  15. Acute high-altitude illness | Hofmeyr | South African Medical Journal

    African Journals Online (AJOL)

    A substantial proportion of South Africa (SA)'s population lives at high altitude (>1 500 m), and many travel to very high altitudes (>3 500 m) for tourism, business, recreation or religious pilgrimages every year. Despite this, knowledge of acute altitude illnesses is poor among SA doctors. At altitude, the decreasing ambient ...

  16. Altitude Registration of Limb-Scattered Radiation

    Science.gov (United States)

    Moy, Leslie; Bhartia, Pawan K.; Jaross, Glen; Loughman, Robert; Kramarova, Natalya; Chen, Zhong; Taha, Ghassan; Chen, Grace; Xu, Philippe

    2017-01-01

    One of the largest constraints to the retrieval of accurate ozone profiles from UV backscatter limb sounding sensors is altitude registration. Two methods, the Rayleigh scattering attitude sensing (RSAS) and absolute radiance residual method (ARRM), are able to determine altitude registration to the accuracy necessary for long-term ozone monitoring. The methods compare model calculations of radiances to measured radiances and are independent of onboard tracking devices. RSAS determines absolute altitude errors, but, because the method is susceptible to aerosol interference, it is limited to latitudes and time periods with minimal aerosol contamination. ARRM, a new technique introduced in this paper, can be applied across all seasons and altitudes. However, it is only appropriate for relative altitude error estimates. The application of RSAS to Limb Profiler (LP) measurements from the Ozone Mapping and Profiler Suite (OMPS) on board the Suomi NPP (SNPP) satellite indicates tangent height (TH) errors greater than 1 km with an absolute accuracy of +/-200 m. Results using ARRM indicate a approx. 300 to 400m intra-orbital TH change varying seasonally +/-100 m, likely due to either errors in the spacecraft pointing or in the geopotential height (GPH) data that we use in our analysis. ARRM shows a change of approx. 200m over 5 years with a relative accuracy (a long-term accuracy) of 100m outside the polar regions.

  17. Sprite initiation altitude measured by triangulation

    Science.gov (United States)

    Stenbaek-Nielsen, H. C.; Haaland, R.; McHarg, M. G.; Hensley, B. A.; Kanmae, T.

    2010-03-01

    High time resolution (10,000 frames per second) images of sprites combined with multistation concurrent video recordings have provided data for triangulation of the altitude of the initial sprite onset. The high-speed images were obtained from the Langmuir Laboratory, New Mexico, during summer campaigns in 2007 and 2008 with video observations from sites at Portales, New Mexico, and Las Vegas, New Mexico. Sprites start with one or more downward-propagating streamer heads. The triangulated onset altitudes of this initial downward streamer vary between 66 and 89 km. In some sprites the downward streamers are followed a little later by upward-propagating streamers. The upward streamers start from a lower altitude and existing luminous sprite structures and their triangulated altitudes vary from 64 to 78 km. The downward streamers create C sprite characteristics, while the upward streamers form the broad diffuse tops of carrot sprites. In the sprites analyzed the higher onset altitudes for the downward-propagating initial streamers were associated with C sprites and the lower with carrot sprites, but our larger data set indicates that this is not generally the case. It appears that the dominant sprite types vary from year to year, indicating that some longer-lasting environmental parameter, such as mesospheric conductivity and composition or thunderstorm cloud dynamics, may play an important role in determining the types of sprites observed.

  18. Altitude, gun ownership, rural areas, and suicide.

    Science.gov (United States)

    Kim, Namkug; Mickelson, Jennie B; Brenner, Barry E; Haws, Charlotte A; Yurgelun-Todd, Deborah A; Renshaw, Perry F

    2011-01-01

    The authors recently observed a correlation between state altitude and suicide rate in the United States, which could be explained by higher rates of gun ownership and lower population density in the intermountain West. The present study evaluated the relationship between mean county and state altitude in the United States and total age-adjusted suicide rates, firearm-related suicide rates, and non-firearm-related suicide rates. The authors hypothesized that altitude would be significantly associated with suicide rate. Elevation data were calculated with an approximate spatial resolution of 0.5 km, using zonal statistics on data sets compiled from the National Geospatial-Intelligence Agency and the National Aeronautics and Space Administration. Suicide and population density data were obtained through the Centers for Disease Control and Prevention (CDC) WONDER database. Gun ownership data were obtained through the CDC's Behavioral Risk Factor Surveillance System. A significant positive correlation was observed between age-adjusted suicide rate and county elevation (r=0.51). Firearm (r=0.41) and non-firearm suicide rates (r=0.32) were also positively correlated with mean county elevation. When altitude, gun ownership, and population density are considered as predictor variables for suicide rates on a state basis, altitude appears to be a significant independent risk factor. This association may be related to the effects of metabolic stress associated with mild hypoxia in individuals with mood disorders.

  19. Altitude retinopathy on Mount Everest, 1989.

    Science.gov (United States)

    Butler, F K; Harris, D J; Reynolds, R D

    1992-05-01

    The authors studied prospectively the incidence of and risk factors for high altitude retinal hemorrhages among 14 members of the 1989 American Everest Expedition. All subjects had comprehensive eye examinations and fundus photography performed at sea level before the expedition and again at the Mt. Everest Base Camp after 6 weeks of exposure to altitudes between 5300 and 8200 meters. Asymptomatic intraretinal hemorrhages were found in five eyes of four climbers. An additional eye of one of these climbers had a central retinal vein occlusion with vitreous hemorrhage, which reduced visual acuity to counting fingers. Higher baseline intraocular pressure and use of nonsteroidal anti-inflammatory drugs were found to be significant risk factors for development of altitude retinopathy.

  20. Paschen Considerations for High Altitude Airships

    Science.gov (United States)

    Ferguson, D. C.; Hillard, G. B.

    2004-01-01

    Recently, there have been several proposals submitted to funding agencies for long-lived high altitude (about 70,000 feet) airships for communications, surveillance, etc. In order for these airships to remain at altitude, high power, high efficiency, lightweight solar arrays must be used, and high efficiency power management and distribution systems must be employed. The needs for high power and high efficiency imply high voltage systems. However, the air pressure at these extreme altitudes is such that electrical power systems will be near the Paschen discharge minimum over a wide range of electrode separations. In this paper, preliminary calculations are made for acceptable high voltage design practices under ambient, hydrogen and helium gas atmospheres.

  1. Atmospheric electron flux at airplane altitude

    International Nuclear Information System (INIS)

    Enomoto, R.; Chiba, J.; Ogawa, K.; Sumiyoshi, T.; Takasaki, F.; Kifune, T.; Matsubara, Y.; Nishimura, J.

    1991-01-01

    We have developed a new detector to systematically measure the cosmic-ray electron flux at airplane altitudes. We loaded a lead-glass-based electron telescope onto a commercial cargo airplane. The first experiment was carried out using the air route between Narita (Japan) and Sydney (Australia); during this flight we measured the electron flux at various altitudes and latitudes. The thresholds of the electron energies were 1, 2, and 4 GeV. The results agree with a simple estimation using one-dimensional shower theory. A comparison with a Monte Carlo calculation was made

  2. High-Altitude Cirrus Clouds and Climate

    Indian Academy of Sciences (India)

    2002-12-03

    Dec 3, 2002 ... High-Altitude Cirrus Clouds and Climate. S Veerabuthiran. Introduction. Clouds are aesthetically appealing. Without them, there would be no rain or snow, thunder or lightning, rainbows or halos. A cloud is a visible aggregate of tiny water droplets or ice crystals suspended in the air. Most clouds result from ...

  3. Menstrual history in altitude chamber trainees.

    Science.gov (United States)

    Schirmer, J U; Workman, W T

    1992-07-01

    Previous studies have determined a higher rate of altitude-induced decompression sickness (DCS) in women than in men. Women are reportedly at higher risk for developing DCS during menses. A study of menstrual history in women completing altitude chamber training without developing DCS has never been accomplished. The purpose of this study was to collect and analyze menstrual history in these women. Thirteen U.S. Air Force Aerospace Physiology Units participated in a USAF-approved survey for 1 year. After completing altitude chamber flights, data on age, day of menstrual cycle (DMC), birth control pill use (BCP), and mean durations of menstrual cycle and menses were collected. There were 508 responses analyzed. There was no differences between mean duration of menstrual cycle and menses in the Yes (Y) and No (N) BCP groups. Y and N BCP groups were equally distributed across the menstrual cycle. Women completing altitude chamber training without developing DCS appear to be evenly distributed across their menstrual cycle, with use of BCPs not affecting their susceptibility to DCS.

  4. Dietary Recommendations for Cyclists during Altitude Training.

    Science.gov (United States)

    Michalczyk, Małgorzata; Czuba, Miłosz; Zydek, Grzegorz; Zając, Adam; Langfort, Józef

    2016-06-18

    The concept of altitude or hypoxic training is a common practice in cycling. However, several strategies for training regimens have been proposed, like "live high, train high" (LH-TH), "live high, train low" (LH-TL) or "intermittent hypoxic training" (IHT). Each of them combines the effect of acclimatization and different training protocols that require specific nutrition. An appropriate nutrition strategy and adequate hydration can help athletes achieve their fitness and performance goals in this unfriendly environment. In this review, the physiological stress of altitude exposure and training will be discussed, with specific nutrition recommendations for athletes training under such conditions. However, there is little research about the nutrition demands of athletes who train at moderate altitude. Our review considers energetic demands and body mass or body composition changes due to altitude training, including respiratory and urinary water loss under these conditions. Carbohydrate intake recommendations and hydration status are discussed in detail, while iron storage and metabolism is also considered. Last, but not least the risk of increased oxidative stress under hypoxic conditions and antioxidant supplementation suggestions are presented.

  5. Dietary Recommendations for Cyclists during Altitude Training

    Directory of Open Access Journals (Sweden)

    Małgorzata Michalczyk

    2016-06-01

    Full Text Available The concept of altitude or hypoxic training is a common practice in cycling. However, several strategies for training regimens have been proposed, like “live high, train high” (LH-TH, “live high, train low” (LH-TL or “intermittent hypoxic training” (IHT. Each of them combines the effect of acclimatization and different training protocols that require specific nutrition. An appropriate nutrition strategy and adequate hydration can help athletes achieve their fitness and performance goals in this unfriendly environment. In this review, the physiological stress of altitude exposure and training will be discussed, with specific nutrition recommendations for athletes training under such conditions. However, there is little research about the nutrition demands of athletes who train at moderate altitude. Our review considers energetic demands and body mass or body composition changes due to altitude training, including respiratory and urinary water loss under these conditions. Carbohydrate intake recommendations and hydration status are discussed in detail, while iron storage and metabolism is also considered. Last, but not least the risk of increased oxidative stress under hypoxic conditions and antioxidant supplementation suggestions are presented.

  6. Physiology of High-Altitude Acclimatization

    Indian Academy of Sciences (India)

    IAS Admin

    alkalosis due to HVR is offset by increased excretion of sodium and bicarbonate ions in the urine and retention of hydrogen ions. (shifting towards acidosis). Hormonal responses play very important regulatory functions during high altitude exposure. Under this, the role of renin– angiotensin–aldosterone axis as an important ...

  7. Ocular morbidity among porters at high altitudes.

    Science.gov (United States)

    Gnyawali, Subodh; Shrestha, Gauri Shankar; Khanal, Safal; Dennis, Talisa; Spencer, John C

    2017-01-01

    High altitude, often characterized by settings over 2400m, can be detrimental to the human body and pose a significant risk to ocular health. Reports concerning various ocular morbidities occurring as a consequence of high altitude are limited in the current literature. This study was aimed at evaluating the ocular health of porters working at high altitudesof Himalayas in Nepal. A mobile eye clinic was set up in Ghat and patient data were collected from its out- patient unit by a team of seven optometrists which was run for five days. Ghat is a small village in north-eastern Nepal, located at 2860 m altitude. Travellers walking through the trekking route were invited to get their eyes checked at the clinic. Comprehensive ocular examinations were performed, including visual acuities, objective and subjective refraction, anterior and posterior segment evaluations, and intraocular pressure measurements; blood pressure and blood glucose levels were also measured as required. Ocular therapeutics, prescription glasses, sunglasses and ocular health referrals were provided free of cost as necessary. A total of 1890 people visited the eye clinic, among which 57.4% (n=1084) were porters. Almost half of the porters had an ocular morbidity. Correctable refractive error was most prevalent, with other ocular health-related complications, including dry eye disease, infectious disorders, glaucoma and cataract. Proper provision of regular and effective eye care services should be made more available for those residing at these high altitudes in Nepal. © NEPjOPH.

  8. Mesenteric ischemia, high altitude and Hill's criteria

    African Journals Online (AJOL)

    Acute occlusive mesenteric ischemia in high altitude of southwestern region of Saudi Arabia. Ann Afr Med 2012;11: 5-10. Source of Support: Nil, Conflict of Interest: None declared. .... Relocation of residence to sea level, which in most cases in this area involves a distance of less than 50 km such as from Abha to. Ad Darb or ...

  9. High altitude pulmonary edema among "Amarnath Yatris"

    Directory of Open Access Journals (Sweden)

    Parvaiz A Koul

    2013-01-01

    Full Text Available Background: Annual pilgrimage (Yatra to the cave shrine of Shri Amarnath Ji′ is a holy ritual among the Hindu devotees of Lord Shiva. Located in the Himalayan Mountain Range (altitude 13,000 ft in south Kashmir, the shrine is visited by thousands of devotees and altitude sickness is reportedly common. Materials and Methods: More than 600,000 pilgrims visited the cave shrine in 2011 and 2012 with 239 recorded deaths. Thirty one patients with suspected altitude sickness were referred from medical centers en-route the cave to Sher-i-Kashmir Institute of Medical Sciences, a tertiary-care center in capital Srinagar (5,000 ft. The clinical features and the response to treatment were recorded. Results: Thirty-one patients (all lowlanders, 19 male; age 18-60 years, median 41 had presented with acute onset breathlessness of 1-4 days (median 1.9 d starting within 12-24 h of a rapid ascent; accompanied by cough (68%, headache (8%, dizziness and nausea (65%. Sixteen patients had associated encephalopathy. Clinical features on admission included tachypnea ( n = 31, tachycardia ( n = 23, bilateral chest rales ( n = 29, cyanosis ( n = 22 and grade 2-4 encephalopathy. Hypoxemia was demonstrable in 24 cases and bilateral infiltrates on radiologic imaging in 29. Ten patients had evidence of high-altitude cerebral edema. All patients were managed with oxygen, steroids, nifedipine, sildenafil and other supportive measures including invasive ventilation ( n = 3. Three patients died due to multiorgan dysfunction. Conclusions: Altitude sickness is common among Amaranath Yatris from the plains and appropriate educational strategies should be invoked for prevention and prompt treatment.

  10. CAMEX-4 ER-2 HIGH ALTITUDE DROPSONDE V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The CAMEX-4 ER-2 High Altitude Dropsonde dataset was collected by the ER-2 High Altitude Dropsonde System (EHAD), which used dropwinsondes fitted with Global...

  11. GRIP HIGH-ALTITUDE MMIC SOUNDING RADIOMETER (HAMSR) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP High-Altitude MMIC Sounding Radiometer (HAMSR) dataset was collectd by the High Altitude monolithic microwave integrated Circuit (MMIC) Sounding Radiometer...

  12. The High Altitude Gamma Ray Observatory, HAWC

    Science.gov (United States)

    González, M. M.

    2011-10-01

    The Volcano Sierra Negra in Puebla, Mexico was selected to host HAWC (High Altitude Water Cherenkov), a unique obervatory of wide field of view (2π sr) capable of observing the sky continously at energies from 0.5 TeV to 100 TeV. HAWC is an array of 300 large water tanks (7.3 m diameter × 5 m depth) at an altitude of 4100 m. a. s. l. Each tank is instrumented with three upward-looking photomultipliers tubes. The full array will be capable of observing the most energetic gamma rays from the most violent events in the universe. HAWC will be 15 times more sensitive than its predecesor, Milagro. We present HAWC, the scientific case and capabilities.

  13. The yak genome and adaptation to life at high altitude

    DEFF Research Database (Denmark)

    Qiu, Qiang; Zhang, Guojie; Ma, Tao

    2012-01-01

    Domestic yaks (Bos grunniens) provide meat and other necessities for Tibetans living at high altitude on the Qinghai-Tibetan Plateau and in adjacent regions. Comparison between yak and the closely related low-altitude cattle (Bos taurus) is informative in studying animal adaptation to high altitude...

  14. Spatial and temporal distribution of ionospheric currents-4: altitude ...

    African Journals Online (AJOL)

    (a) The continuous distribution of current density model reproduces the altitude distribution parameters of EEJ current density very well, (b) the altitude distribution parameters of EEJ current density in India and Peru are not significantly different and (c) The altitude distribution parameters of EEJ current density from rockets ...

  15. The effect of altitude hypoxia on glucose homeostasis in men

    DEFF Research Database (Denmark)

    Larsen, J J; Hansen, J M; Olsen, Niels Vidiendal

    1997-01-01

    1. Exposure to altitude hypoxia elicits changes in glucose homeostasis with increases in glucose and insulin concentrations within the first few days at altitude. Both increased and unchanged hepatic glucose production (HGP) have previously been reported in response to acute altitude hypoxia...

  16. The effect of altitude hypoxia on glucose homeostasis in men

    DEFF Research Database (Denmark)

    Larsen, J J; Hansen, J M; Olsen, Niels Vidiendal

    1997-01-01

    1. Exposure to altitude hypoxia elicits changes in glucose homeostasis with increases in glucose and insulin concentrations within the first few days at altitude. Both increased and unchanged hepatic glucose production (HGP) have previously been reported in response to acute altitude hypoxia. Ins...

  17. Magion-4 High-Altitude Cusp Study

    Czech Academy of Sciences Publication Activity Database

    Merka, J.; Šafránková, J.; Němeček, Z.; Šimůnek, Jiří

    2005-01-01

    Roč. 26, č. 1-3 (2005), s. 57-69 ISSN 0169-3298 R&D Projects: GA ČR(CZ) GA205/02/0947 Institutional research plan: CEZ:AV0Z30420517 Keywords : cusp-like plasma * dipole tilt angle * high-altitude cusp * magnetopause * magnetopause * reconnection Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.975, year: 2005

  18. HIGH ALTITUDES EFFECTS ON HEMATOLOGIC BLOOD PARAMETERS

    Directory of Open Access Journals (Sweden)

    Hasim Rushiti

    2015-05-01

    Full Text Available The approach and the objective of this experiment are consistent with the determination of changes of blood parameters after the stay of the students at an altitude of 1800-2300 meters, for a ten-day long ski course. In this paper are included a total of 64 students of the Faculty of Sport Sciences in Prishtina, of the age group of 19-25 (the average age is 21. All students previously have undergone a medical check for TA, arterial pulse and respiratory rate. In particular, the health situation is of subjects was examined, then, all students, at the same time, gave blood for analysis. In this experiment, three main hematologic parameters were taken in consideration: such as hemoglobin, hematocrit and red blood cells. The same analyses were carried out after the 10-day stay at a high altitude. The results of the experiment have shown significant changes after the ten-day stay at high altitude, despite the previous results that show changes only after the twenty-day stay in such elevations.

  19. Drag derived altitude aided navigation method

    Directory of Open Access Journals (Sweden)

    Hua SONG

    2017-10-01

    Full Text Available The navigation problem of the lifting reentry vehicles has attracted much research interest in the past decade. This paper researches the navigation in the blackout zone during the reentry phase of the aircraft, when the communication signals are attenuated and even interrupted by the blackout zone. However, when calculating altitude, a pure classic inertial navigation algorithm appears imprecise and divergent. In order to obtain a more precise aircraft altitude, this paper applies an integrated navigation method based on inertial navigation algorithms, which uses drag derived altitude to aid the inertial navigation during the blackout zone. This method can overcome the shortcomings of the inertial navigation system and improve the navigation accuracy. To further improve the navigation accuracy, the applicable condition and the main error factors, such as the atmospheric coefficient error and drag coefficient error are analyzed in detail. Then the damping circuit design of the navigation control system and the damping coefficients determination is introduced. The feasibility of the method is verified by the typical reentry trajectory simulation, and the influence of the iterative times on the accuracy is analyzed. Simulation results show that iterative three times achieves the best effect.

  20. Altitude variation of cosmic-ray neutrons

    International Nuclear Information System (INIS)

    Nakamura, T.; Uwamino, Y.; Ohkubo, T.; Hara, A.

    1987-01-01

    The altitude variation of the cosmic-ray neutron energy spectrum and the dose equivalent rate was measured at an average geomagnetic latitude of 24 degrees N by using the high-efficiency multi-sphere neutron spectrometer and neutron dose-equivalent counter developed by the authors. The data were obtained from a 2-h flight over Japan on 27 February 1985. The neutron energy spectra measured at sea level and at altitudes of 4880 m and at 11,280 m were compared with the calculated spectra of O'Brien and with other experimental spectra, and they are in moderately good agreement with them. The dose equivalent rate increases according to a quadratic curve up to about 6000 m and then increases linearly between 6000 m and 11,280 m. The dependence of dose equivalent rates at sea level and at an altitude of 12,500 m on geomagnetic latitude also is given by referring to other experimental results

  1. Trajectory Control For High Altitude Balloons

    Science.gov (United States)

    Aaron, K.; Nock, K.; Heun, M.; Wyszkowski, C.

    We will discuss the continuing development of the StratoSailTM Balloon Trajectory Control System presented at the 33rd COSPAR in 2000. A vertical wing suspended on a 15-km tether from a high altitude balloon uses the difference in wind velocity between the altitude of the balloon and the altitude of the wing to create an aerodynamic sideforce. This sideforce, transmitted to the balloon gondola via the tether, causes the balloon to move laterally. Although the balloon's resultant drift velocity is quite small (a few meters per second), the effect becomes significant over long periods of time (hours to days). Recently, a full-scale wing, rudder and boom assembly has been fabricated, a winch system testbed has been completed, and a lightweight tether with reduced susceptibility to ultraviolet damage has been developed. The development effort for this invention, with pending international patents, has been funded by the NASA/SBIR program in support of the Ultra Long Duration Balloon (ULDB) program.

  2. High-Altitude Illnesses: Physiology, Risk Factors, Prevention, and Treatment

    Directory of Open Access Journals (Sweden)

    Andrew T. Taylor

    2011-01-01

    Full Text Available High-altitude illnesses encompass the pulmonary and cerebral syndromes that occur in non-acclimatized individuals after rapid ascent to high altitude. The most common syndrome is acute mountain sickness (AMS which usually begins within a few hours of ascent and typically consists of headache variably accompanied by loss of appetite, nausea, vomiting, disturbed sleep, fatigue, and dizziness. With millions of travelers journeying to high altitudes every year and sleeping above 2,500 m, acute mountain sickness is a wide-spread clinical condition. Risk factors include home elevation, maximum altitude, sleeping altitude, rate of ascent, latitude, age, gender, physical condition, intensity of exercise, pre-acclimatization, genetic make-up, and pre-existing diseases. At higher altitudes, sleep disturbances may become more profound, mental performance is impaired, and weight loss may occur. If ascent is rapid, acetazolamide can reduce the risk of developing AMS, although a number of high-altitude travelers taking acetazolamide will still develop symptoms. Ibuprofen can be effective for headache. Symptoms can be rapidly relieved by descent, and descent is mandatory, if at all possible, for the management of the potentially fatal syndromes of high-altitude pulmonary and cerebral edema. The purpose of this review is to combine a discussion of specific risk factors, prevention, and treatment options with a summary of the basic physiologic responses to the hypoxia of altitude to provide a context for managing high-altitude illnesses and advising the non-acclimatized high-altitude traveler.

  3. Dose-response of altitude training: how much altitude is enough?

    Science.gov (United States)

    Levine, Benjamin D; Stray-Gundersen, James

    2006-01-01

    Altitude training continues to be a key adjunctive aid for the training of competitive athletes throughout the world. Over the past decade, evidence has accumulated from many groups of investigators that the "living high--training low" approach to altitude training provides the most robust and reliable performance enhancements. The success of this strategy depends on two key features: 1) living high enough, for enough hours per day, for a long enough period of time, to initiate and sustain an erythropoietic effect of high altitude; and 2) training low enough to allow maximal quality of high intensity workouts, requiring high rates of sustained oxidative flux. Because of the relatively limited access to environments where such a strategy can be practically applied, numerous devices have been developed to "bring the mountain to the athlete," which has raised the key issue of the appropriate "dose" of altitude required to stimulate an acclimatization response and performance enhancement. These include devices using molecular sieve technology to provide a normobaric hypoxic living or sleeping environment, approaches using very high altitudes (5,500m) for shorter periods of time during the day, and "intermittent hypoxic training" involving breathing very hypoxic gas mixtures for alternating 5 minutes periods over the course of 60-90 minutes. Unfortunately, objective testing of the strategies employing short term (less than 4 hours) normobaric or hypobaric hypoxia has failed to demonstrate an advantage of these techniques. Moreover individual variability of the response to even the best of living high--training low strategies has been great, and the mechanisms behind this variability remain obscure. Future research efforts will need to focus on defining the optimal dosing strategy for these devices, and determining the underlying mechanisms of the individual variability so as to enable the individualized "prescription" of altitude exposure to optimize the performance of

  4. A vitivinicultura de altitude em Santa Catarina

    OpenAIRE

    Losso, Flavia Baratieri

    2016-01-01

    Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em Geografia, Florianópolis, 2016. O presente estudo analisou as relações entre a formação sócio-espacial, a produção e o consumo de vinhos finos de altitude em Santa Catarina como indutores do desenvolvimento do Enoturismo no Estado mediante o entendimento de que este tipo de turismo poderá intervir na economia do vinho, agregando valor e influenciando o consumo des...

  5. Random Deviations from Cruise Altitudes of a Turbojet Transport at Altitudes of a Turbojet Transport at Altitudes between 20,000 and 41,000 Feet

    Science.gov (United States)

    Gracey, William; Shipp, Jo Ann

    1961-01-01

    An evaluation has been made of the random deviations from the cruise altitudes (called flight technical error) of a large turbojet transport on scheduled, passenger-carrying operations over the Eastern United States, the Atlantic Ocean, and Western Europe. Data were collected from l9O flights through an altitude range of 20,000 to 41,000 feet and for a time period from January to August 1959. The results of the investigation, based on an evaluation of the altitude recordings of an NASA VGH recorder, showed that for a high percentage of the total cruise time (99.0 percent) the airplane operated within 100 feet of its stabilized cruise altitude. On occasion, however, the excursions of the airplane from the cruise altitude reached large values (in excess of 1,000 feet in the worst case).

  6. The FAA altitude chamber training flight profile : a survey of altitude reactions, 1965-1989.

    Science.gov (United States)

    1990-09-01

    Reactions from 1,161 trainees out of 12,759 trainees subjected to the FAA altitude chamber training flights from 1965-1989 are annotated in this survey. Although there were some mild and expected reactions, these training profiles appear to provide a...

  7. Simulated altitude exposure assessment by hyperspectral imaging

    Science.gov (United States)

    Calin, Mihaela Antonina; Macovei, Adrian; Miclos, Sorin; Parasca, Sorin Viorel; Savastru, Roxana; Hristea, Razvan

    2017-05-01

    Testing the human body's reaction to hypoxia (including the one generated by high altitude) is important in aeronautic medicine. This paper presents a method of monitoring blood oxygenation during experimental hypoxia using hyperspectral imaging (HSI) and a spectral unmixing model based on a modified Beer-Lambert law. A total of 20 healthy volunteers (males) aged 25 to 60 years were included in this study. A line-scan HSI system was used to acquire images of the faces of the subjects. The method generated oxyhemoglobin and deoxyhemoglobin distribution maps from the foreheads of the subjects at 5 and 10 min of hypoxia and after recovery in a high oxygen breathing mixture. The method also generated oxygen saturation maps that were validated using pulse oximetry. An interesting pattern of desaturation on the forehead was discovered during the study, showing one of the advantages of using HSI for skin oxygenation monitoring in hypoxic conditions. This could bring new insight into the physiological response to high altitude and may become a step forward in air crew testing.

  8. Altitude variations of ionospheric currents at auroral latitudes

    International Nuclear Information System (INIS)

    Kamide, Y.; Brekke, A.

    1993-01-01

    On the basis of updated EISCAT experiments, the first full derivation of the ionospheric current density of the auroral electrojets at six different altitudes are presented. It is found that current vectors at different altitudes are quite different, although the eastward and westward currents prevail in the evening and morning sectors, respectively, once the currents are integrated over altitude. The eastward electrojet becomes almost northward whilst the westward electrojet becomes almost southward, at the highest altitude, 125 km, in this study. The physical implications of these characteristics are discussed

  9. Aspirated Compressors for High Altitude Engines, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Aurora Flight Sciences proposes to incorporate aspirated compressor technology into a high altitude, long endurance (HALE) concept engine. Aspiration has been proven...

  10. Does 'altitude training' increase exercise performance in elite athletes?

    Science.gov (United States)

    Lundby, Carsten; Robach, Paul

    2016-07-01

    What is the topic of this review? The aim is to evaluate the effectiveness of various altitude training strategies as investigated within the last few years. What advances does it highlight? Based on the available literature, the foundation to recommend altitude training to athletes is weak. Athletes may use one of the various altitude training strategies to improve exercise performance. The scientific support for such strategies is, however, not as sound as one would perhaps imagine. The question addressed in this review is whether altitude training should be recommended to elite athletes or not. © 2016 The Authors. Experimental Physiology © 2016 The Physiological Society.

  11. GRIP HIGH-ALTITUDE MMIC SOUNDING RADIOMETER (HAMSR) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Altitude monolithic microwave integrated Circuit (MMIC) Sounding Radiometer (HAMSR) is a microwave atmospheric sounder developed by JPL under the NASA...

  12. Anticoagulation Considerations for Travel to High Altitude.

    Science.gov (United States)

    DeLoughery, Thomas G

    2015-09-01

    DeLoughery, Thomas G. Anticoagulation considerations for travel to high altitude. High Alt Med Biol 16:181-185, 2015.-An increasing percentage of the population are on anticoagulation medicine for clinical reasons ranging from stroke prevention in atrial fibrillation to long term prevention of deep venous thrombosis. In recent years, several new direct oral anticoagulants have entered the market. The key questions that should be kept in mind when approaching a potential traveler on anticoagulation are: 1) why is the patient on anticoagulation? 2) do they need to stay on anticoagulation? 3) what are the choices for their anticoagulation? 4) will there be any drug interactions with medications needed for travel? and 5) how will they monitor their anticoagulation while traveling? Knowing the answers to these questions then can allow for proper counseling and planning for the anticoagulated traveler's trip.

  13. HAWC: The high altitude water Cherenkov observatory

    Science.gov (United States)

    Goodman, Jordan A.

    2013-02-01

    The High Altitude Water Cherenkov Observatory (HAWC) is currently being deployed at 4100m above sea level on the Vulcan Sierra Negra near Puebla, Mexico. The HAWC observatory will consist of 250-300 Water Cherenkov Detectors totaling approximately 22,000 m2 of instrumented area. The water Cherenkov technique allows HAWC to have a nearly 100% duty cycle and large field of view, making the HAWC observatory an ideal instrument for the study of transient phenomena. With its large effective area, excellent angular and energy resolutions, and efficient gamma-hadron separation, HAWC will survey the TeV gamma-ray sky, measure spectra of galactic sources from 1 TeV to beyond 100 TeV, and map galactic diffuse gamma ray emission. The science goals, instrument performance and status of the HAWC observatory will be presented.

  14. Effects of altitude to blood parameters

    Directory of Open Access Journals (Sweden)

    Đelkapić Milosava

    2012-01-01

    Full Text Available Reducing of partial pressure of oxygen in the air leads to a reduced arterial oxygen saturation and increases secretion of erythropoietin, wich stimulates erythropoiesis. Study included 63 healthy children aged 7 years, devided into 3 groups. I group consists of 21 children from suburb of altitude of 370 m, II group of 22 children from the village on 822 m, III group of 21 children from the town on 411 m. Complete blood count was determined on a Hematology analyzer HmX ( Beckman Coulter. Statistical analysis of data showed that children from II group have a higher average values of erythrocytes than children from the I (p0.05. Results show that stay in the village is useful for stimulation of erythropoiesis.

  15. Power Budget Analysis for High Altitude Airships

    Science.gov (United States)

    Choi, Sang H.; Elliott, James R.; King, Glen C.

    2006-01-01

    The High Altitude Airship (HAA) has various potential applications and mission scenarios that require onboard energy harvesting and power distribution systems. The energy source considered for the HAA s power budget is solar photon energy that allows the use of either photovoltaic (PV) cells or advanced thermoelectric (ATE) converters. Both PV cells and an ATE system utilizing high performance thermoelectric materials were briefly compared to identify the advantages of ATE for HAA applications in this study. The ATE can generate a higher quantity of harvested energy than PV cells by utilizing the cascaded efficiency of a three-staged ATE in a tandem mode configuration. Assuming that each stage of ATE material has the figure of merit of 5, the cascaded efficiency of a three-staged ATE system approaches the overall conversion efficiency greater than 60%. Based on this estimated efficiency, the configuration of a HAA and the power utility modules are defined.

  16. The Impact of Altitude on Sleep-Disordered Breathing in Children Dwelling at High Altitude: A Crossover Study.

    Science.gov (United States)

    Hughes, Benjamin H; Brinton, John T; Ingram, David G; Halbower, Ann C

    2017-09-01

    Sleep-disordered breathing (SDB) is prevalent among children and is associated with adverse health outcomes. Worldwide, approximately 250 million individuals reside at altitudes higher than 2000 meters above sea level (masl). The effect of chronic high-altitude exposure on children with SDB is unknown. This study aims to determine the impact of altitude on sleep study outcomes in children with SDB dwelling at high altitude. A single-center crossover study was performed to compare results of high-altitude home polysomnography (H-PSG) with lower altitude laboratory polysomnography (L-PSG) in school-age children dwelling at high altitude with symptoms consistent with SDB. The primary outcome was apnea-hypopnea index (AHI), with secondary outcomes including obstructive AHI; central AHI; and measures of oxygenation, sleep quality, and pulse rate. Twelve participants were enrolled, with 10 included in the final analysis. Median altitude was 1644 masl on L-PSG and 2531 masl on H-PSG. Median AHI was 2.40 on L-PSG and 10.95 on H-PSG. Both obstructive and central respiratory events accounted for the difference in AHI. Oxygenation and sleep fragmentation were worse and pulse rate higher on H-PSG compared to L-PSG. These findings reveal a clinically substantial impact of altitude on respiratory, sleep, and cardiovascular outcomes in children with SDB who dwell at high altitude. Within this population, L-PSG underestimates obstructive sleep apnea and central sleep apnea compared to H-PSG. Given the shortage of high-altitude pediatric sleep laboratories, these results suggest a role for home sleep apnea testing for children residing at high altitude. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  17. Effects of ascent to high altitude on human antimycobacterial immunity.

    Directory of Open Access Journals (Sweden)

    Sarah Eisen

    Full Text Available Tuberculosis infection, disease and mortality are all less common at high than low altitude and ascent to high altitude was historically recommended for treatment. The immunological and mycobacterial mechanisms underlying the association between altitude and tuberculosis are unclear. We studied the effects of altitude on mycobacteria and antimycobacterial immunity.Antimycobacterial immunity was assayed in 15 healthy adults residing at low altitude before and after they ascended to 3400 meters; and in 47 long-term high-altitude residents. Antimycobacterial immunity was assessed as the extent to which participants' whole blood supported or restricted growth of genetically modified luminescent Bacille Calmette-Guérin (BCG mycobacteria during 96 hours incubation. We developed a simplified whole blood assay that could be used by a technician in a low-technology setting. We used this to compare mycobacterial growth in participants' whole blood versus positive-control culture broth and versus negative-control plasma.Measurements of mycobacterial luminescence predicted the number of mycobacterial colonies cultured six weeks later. At low altitude, mycobacteria grew in blood at similar rates to positive-control culture broth whereas ascent to high altitude was associated with restriction (p ≤ 0.002 of mycobacterial growth to be 4-times less than in culture broth. At low altitude, mycobacteria grew in blood 25-times more than negative-control plasma whereas ascent to high altitude was associated with restriction (p ≤ 0.01 of mycobacterial growth to be only 6-times more than in plasma. There was no evidence of differences in antimycobacterial immunity at high altitude between people who had recently ascended to high altitude versus long-term high-altitude residents.An assay of luminescent mycobacterial growth in whole blood was adapted and found to be feasible in low-resource settings. This demonstrated that ascent to or residence at high altitude was

  18. Accuracy of Handheld Blood Glucose Meters at High Altitude

    NARCIS (Netherlands)

    de Mol, Pieter; Krabbe, Hans G.; de Vries, Suzanna T.; Fokkert, Marion J.; Dikkeschei, Bert D.; Rienks, Rienk; Bilo, Karin M.; Bilo, Henk J. G.

    2010-01-01

    Background: Due to increasing numbers of people with diabetes taking part in extreme sports (e. g., high-altitude trekking), reliable handheld blood glucose meters (BGMs) are necessary. Accurate blood glucose measurement under extreme conditions is paramount for safe recreation at altitude. Prior

  19. Cognition and metacognition at extreme altitudes on Mount Everest.

    Science.gov (United States)

    Nelson, T O; Dunlosky, J; White, D M; Steinberg, J; Townes, B D; Anderson, D

    1990-12-01

    The FACTRETRIEVAL2 test battery, which assesses both retrieval of general information from memory and metacognition about that retrieval, was administered to people before and after a recent expedition to Mount Everest and at extreme altitudes above 6,400 m (higher than any mountain in North America or Europe). The major findings were as follows: First, the same extreme altitudes already known to impair learning did not affect either accuracy or latency of retrieval, and this robustness of retrieval occurred for both recall and forced-choice recognition. Second, extreme altitude did affect metacognition: The climbers showed a decline in their feeling of knowing both while at extreme altitude and after returning to Kathmandu (i.e., both an effect and an aftereffect of extreme altitude). Third, extreme altitude had different effects than alcohol intoxication (previously assessed by Nelson. McSpadden, Fromme, & Marlatt, 1986). Alcohol intoxication affected retrieval without affecting metacognition, whereas extreme altitude affected metacognition without affecting retrieval; this different pattern for extreme altitude versus alcohol intoxication implies that (a) hypoxia does not always yield the same outcome as alcohol intoxication and (b) neither retrieval nor metacognition is strictly more sensitive than the other for detecting changes in independent variables.

  20. Improving estimation of flight altitude in wildlife telemetry studies

    Science.gov (United States)

    Poessel, Sharon; Duerr, Adam E.; Hall, Jonathan C.; Braham, Melissa A.; Katzner, Todd

    2018-01-01

    Altitude measurements from wildlife tracking devices, combined with elevation data, are commonly used to estimate the flight altitude of volant animals. However, these data often include measurement error. Understanding this error may improve estimation of flight altitude and benefit applied ecology.There are a number of different approaches that have been used to address this measurement error. These include filtering based on GPS data, filtering based on behaviour of the study species, and use of state-space models to correct measurement error. The effectiveness of these approaches is highly variable.Recent studies have based inference of flight altitude on misunderstandings about avian natural history and technical or analytical tools. In this Commentary, we discuss these misunderstandings and suggest alternative strategies both to resolve some of these issues and to improve estimation of flight altitude. These strategies also can be applied to other measures derived from telemetry data.Synthesis and applications. Our Commentary is intended to clarify and improve upon some of the assumptions made when estimating flight altitude and, more broadly, when using GPS telemetry data. We also suggest best practices for identifying flight behaviour, addressing GPS error, and using flight altitudes to estimate collision risk with anthropogenic structures. Addressing the issues we describe would help improve estimates of flight altitude and advance understanding of the treatment of error in wildlife telemetry studies.

  1. Effect of high altitude cosmic irradiation upon cell generation time

    International Nuclear Information System (INIS)

    Soleilhavoup, J.P.; Croute, F.; Tixador, R.; Blanquet, Y.; Planel, H.

    1975-01-01

    Paramecia cultures placed at 3800 meter altitude show a proliferating activity acceleration compared to control cultures placed at low altitude under the same environment conditions. These results confirm the cosmic irradiation influence upon the activating effect produced by the natural ionizing radiations on living organisms [fr

  2. Respiratory Muscle Training and Exercise Endurance at Altitude.

    Science.gov (United States)

    Helfer, Samuel; Quackenbush, Joseph; Fletcher, Michael; Pendergast, David R

    2016-08-01

    Climbing and trekking at altitude are common recreational and military activities. Physiological effects of altitude are hypoxia and hyperventilation. The hyperventilatory response to altitude may cause respiratory muscle fatigue and reduce sustained submaximal exercise. Voluntary isocapnic hyperpnea respiratory muscle training (VIHT) improves exercise endurance at sea level and at depth. The purpose of this study was to test the hypothesis that VIHT would improve exercise time at altitude [3600 m (11,811 ft)] compared to control and placebo groups. Subjects pedaled an ergometer until exhaustion at simulated altitude in a hypobaric chamber while noninvasive arterial saturation (Sao2), ventilation (VE), and oxygen consumption (Vo2) were measured. As expected, Sao2 decreased to 88 ± 4% saturation at rest and to 81 ± 2% during exercise, and was not affected by VIHT. VIHT resulted in a 40% increase in maximal training VE compared to pre-VIHT. Exercise endurance significantly increased 44% after VIHT (P = altitude post-VIHT increased more (49%) for longer (21 min) and decreased less (11% at 25.4 ± 6.7 min). VIHT improved exercise time at altitude and sustained VE. This suggests that VIHT reduced respiratory muscle fatigue and would be useful to trekkers and military personnel working at altitude. Helfer S, Quackenbush J, Fletcher M, Pendergast DR. Respiratory muscle training and exercise endurance at altitutde. Aerosp Med Hum Perform. 2016; 87(8):704-711.

  3. Exercise and Training at Altitudes: Physiological Effects and Protocols

    Directory of Open Access Journals (Sweden)

    Olga Cecilia Vargas Pinilla

    2014-01-01

    Full Text Available An increase in altitude leads to a proportional fall in the barometric pressure, and a decrease in atmospheric oxygen pressure, producing hypobaric hypoxia that affects, in different degrees, all body organs, systems and functions. The chronically reduced partial pressure of oxygen causes that individuals adapt and adjust to physiological stress. These adaptations are modulated by many factors, including the degree of hypoxia related to altitude, time of exposure, exercise intensity and individual conditions. It has been established that exposure to high altitude is an environmental stressor that elicits a response that contributes to many adjustments and adaptations that influence exercise capacity and endurance performance. These adaptations include in crease in hemoglobin concentration, ventilation, capillary density and tissue myoglobin concentration. However, a negative effect in strength and power is related to a decrease in muscle fiber size and body mass due to the decrease in the training intensity. Many researches aim at establishing how training or living at high altitudes affects performance in athletes. Training methods, such as living in high altitudes training low, and training high-living in low altitudes have been used to research the changes in the physical condition in athletes and how the physiological adaptations to hypoxia can enhanceperformance at sea level. This review analyzes the literature related to altitude training focused on how physiological adaptations to hypoxic environments influence performance, and which protocols are most frequently used to train in high altitudes.

  4. [Hemoglobin and testosterone: importance on high altitude acclimatization and adaptation].

    Science.gov (United States)

    Gonzales, Gustavo F

    2011-03-01

    The different types of response mechanisms that the organism uses when exposed to hypoxia include accommodation, acclimatization and adaptation. Accommodation is the initial response to acute exposure to high altitude hypoxia and is characterized by an increase in ventilation and heart rate. Acclimatization is observed in individuals temporarily exposed to high altitude, and to some extent, it enables them to tolerate the high altitudes. In this phase, erythropoiesis is increased, resulting in higher hemoglobin and hematocrit levels to improve oxygen delivery capacity. Adaptation is the process of natural acclimatization where genetical variations and acclimatization play a role in allowing subjects to live without any difficulties at high altitudes. Testosterone is a hormone that regulates erythropoiesis and ventilation and could be associated to the processes of acclimatization and adaptation to high altitude. Excessive erythrocytosis, which leads to chronic mountain sickness, is caused by low arterial oxygen saturation, ventilatory inefficiency and reduced ventilatory response to hypoxia. Testosterone increases during acute exposure to high altitude and also in natives at high altitude with excessive erythrocytosis. Results of current research allow us to conclude that increase in serum testosterone and hemoglobin is adequate for acclimatization, as they improve oxygen transport, but not for high altitude adaptation, since high serum testosterone levels are associated to excessive erythrocytosis.

  5. Cold induced peripheral vasodilation at high altitudes- a field study

    NARCIS (Netherlands)

    Daanen, H.A.M.; Ruiten, H.J.A. van

    2000-01-01

    A significant reduction in cold-induced vasodilation (CIVD) is observed at high altitudes. No agreement is found in the literature about acclimatization effects on CIVD. Two studies were performed to investigate the effect of altitude acclimatization on CIVD. In the first study 13 male subjects

  6. Short communication: Effect of altitude on erosive characteristics of ...

    African Journals Online (AJOL)

    High-resolution rainfall data from two stations in the northern KwaZulu-Natal Drakensberg provide insight into the effect of altitude on individual rainfall event characteristics. The effect of altitude on the duration and erosivity (rainfall intensity and kinetic energy) of concurrent rainfall on the escarpment and in the foothills is ...

  7. AltitudeOmics: Resetting of cerebrovascular CO2 reactivity following acclimatization to high altitude

    Directory of Open Access Journals (Sweden)

    Jui-Lin eFan

    2016-01-01

    Full Text Available Previous studies reported enhanced cerebrovascular CO2 reactivity upon ascent to high altitude using linear models. However, there is evidence that this response may be sigmoidal in nature. Moreover, it was speculated that these changes at high altitude are mediated by alterations in acid-base buffering. Accordingly, we reanalyzed previously published data to assess middle cerebral blood flow velocity (MCAv responses to modified rebreathing at sea level (SL, upon ascent (ALT1 and following 16 days of acclimatization (ALT16 to 5,260 m in 21 lowlanders. Using sigmoid curve fitting of the MCAv responses to CO2, we found the amplitude (95% vs. 129%, SL vs. ALT1, 95% confidence intervals (CI [77, 112], [111, 145], respectively, P=0.024 and the slope of the sigmoid response (4.5 vs. 7.5 %/mmHg, SL vs. ALT1, 95% CIs [3.1, 5.9], [6.0, 9.0], respectively, P=0.026 to be enhanced at ALT1, which persisted with acclimatization at ALT16 (amplitude: 177%, 95% CI [139, 215], P<0.001; slope: 10.3 %/mmHg, 95% CI [8.2, 12.5], P=0.003 compared to SL. Meanwhile, the sigmoidal response midpoint was unchanged at ALT1 (SL: 36.5 mmHg; ALT1: 35.4 mmHg, 95% CIs [34.0, 39.0], [33.1, 37.7], respectively, P=0.982, while it was reduced by ~7 mmHg at ALT16 (28.6 mmHg, 95% CI [26.4, 30.8], P=0.001 vs. SL, indicating leftward shift of the cerebrovascular CO2 response to a lower arterial partial pressure of CO2 (PaCO2 following acclimatization to altitude. Sigmoid fitting revealed a leftward shift in the midpoint of the cerebrovascular response curve which could not be observed with linear fitting. These findings demonstrate that there is resetting of the cerebrovascular CO2 reactivity operating point to a lower PaCO2 following acclimatization to high altitude. This cerebrovascular resetting is likely the result of an altered acid-base buffer status resulting from prolonged exposure to the severe hypocapnia associated with ventilatory acclimatization to high altitude.

  8. Low-Altitude Operation of Unmanned Rotorcraft

    Science.gov (United States)

    Scherer, Sebastian

    Currently deployed unmanned rotorcraft rely on preplanned missions or teleoperation and do not actively incorporate information about obstacles, landing sites, wind, position uncertainty, and other aerial vehicles during online motion planning. Prior work has successfully addressed some tasks such as obstacle avoidance at slow speeds, or landing at known to be good locations. However, to enable autonomous missions in cluttered environments, the vehicle has to react quickly to previously unknown obstacles, respond to changing environmental conditions, and find unknown landing sites. We consider the problem of enabling autonomous operation at low-altitude with contributions to four problems. First we address the problem of fast obstacle avoidance for a small aerial vehicle and present results from over a 1000 rims at speeds up to 10 m/s. Fast response is achieved through a reactive algorithm whose response is learned based on observing a pilot. Second, we show an algorithm to update the obstacle cost expansion for path planning quickly and demonstrate it on a micro aerial vehicle, and an autonomous helicopter avoiding obstacles. Next, we examine the mission of finding a place to land near a ground goal. Good landing sites need to be detected and found and the final touch down goal is unknown. To detect the landing sites we convey a model based algorithm for landing sites that incorporates many helicopter relevant constraints such as landing sites, approach, abort, and ground paths in 3D range data. The landing site evaluation algorithm uses a patch-based coarse evaluation for slope and roughness, and a fine evaluation that fits a 3D model of the helicopter and landing gear to calculate a goodness measure. The data are evaluated in real-time to enable the helicopter to decide on a place to land. We show results from urban, vegetated, and desert environments, and demonstrate the first autonomous helicopter that selects its own landing sites. We present a generalized

  9. Accuracy of handheld blood glucose meters at high altitude.

    Directory of Open Access Journals (Sweden)

    Pieter de Mol

    Full Text Available BACKGROUND: Due to increasing numbers of people with diabetes taking part in extreme sports (e.g., high-altitude trekking, reliable handheld blood glucose meters (BGMs are necessary. Accurate blood glucose measurement under extreme conditions is paramount for safe recreation at altitude. Prior studies reported bias in blood glucose measurements using different BGMs at high altitude. We hypothesized that glucose-oxidase based BGMs are more influenced by the lower atmospheric oxygen pressure at altitude than glucose dehydrogenase based BGMs. METHODOLOGY/PRINCIPAL FINDINGS: Glucose measurements at simulated altitude of nine BGMs (six glucose dehydrogenase and three glucose oxidase BGMs were compared to glucose measurement on a similar BGM at sea level and to a laboratory glucose reference method. Venous blood samples of four different glucose levels were used. Moreover, two glucose oxidase and two glucose dehydrogenase based BGMs were evaluated at different altitudes on Mount Kilimanjaro. Accuracy criteria were set at a bias 6.5 mmol/L and <1 mmol/L from reference glucose (when <6.5 mmol/L. No significant difference was observed between measurements at simulated altitude and sea level for either glucose oxidase based BGMs or glucose dehydrogenase based BGMs as a group phenomenon. Two GDH based BGMs did not meet set performance criteria. Most BGMs are generally overestimating true glucose concentration at high altitude. CONCLUSION: At simulated high altitude all tested BGMs, including glucose oxidase based BGMs, did not show influence of low atmospheric oxygen pressure. All BGMs, except for two GDH based BGMs, performed within predefined criteria. At true high altitude one GDH based BGM had best precision and accuracy.

  10. Intriguing radiation signatures at aviation altitudes

    Science.gov (United States)

    Tobiska, W. K.

    2017-12-01

    The Automated Radiation Measurements for Aerospace Safety (ARMAS) project captures absorbed dose in Si with a fleet of 6 instruments on research aircraft. These dose rates are then converted to an effective dose rate. Over 325 flights since 2013 have captured global radiation at nearly all altitudes and latitudes. The radiation is predominantly caused by atmospheric neutrons and protons from galactic cosmic rays (GCRs). We have not yet obtained dose from solar energetic particle (SEP) events, which are rather rare. On 13 flights we have also measured dose rates that are up to twice the GCR background for approximately a half an hour per event while flying at higher magnetic latitudes near 60 degrees. The timing of the radiation appears to be coincident with periods of mild geomagnetic disturbances while flying above 10 km at L-shells of 3 to 6. The radiation source is best modeled as secondary gamma-ray photons caused by precipitating ultra-relativistic electrons from the outer Van Allen radiation belt originating as loss cone electrons scattered by electromagnetic ion cyclotron (EMIC) waves. We describe the observations and the lines of evidence for this intriguing new radiation source relevant to aviation crew and frequent flyers.

  11. The high-altitude water Cherenkov Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Mostafa, Miguel A., E-mail: miguel@psu.edu [Department of Physics, Colorado State University, Ft Collins, CO (United States)

    2014-07-01

    The High-Altitude Water Cherenkov (HAWC) observatory is a large field of view, continuously operated, TeV γ -ray experiment under construction at 4,100ma.s.l. in Mexico. The HAWC observatory will have an order of magnitude better sensitivity, angular resolution, and background rejection than its predecessor, the Milagro experiment. The improved performance will allow to detect both the transient and steady emissions, to study the Galactic diffuse emission at TeV energies, and to measure or constrain the TeV spectra of GeV γ -ray sources. In addition, HAWC will be the only ground-based instrument capable of detecting prompt emission from γ -ray bursts above 50 GeV. The HAWC observatory will consist of an array of 300 water Cherenkov detectors (WCDs), each with four photomultiplier tubes. This array is currently under construction on the flanks of the Sierra Negra volcano near the city of Puebla, Mexico. The first 30 WCDs (forming an array approximately the size of Milagro) were deployed in Summer 2012, and 100 WCDs will be taking data by May, 2013. We present in this paper the motivation for constructing the HAWC observatory, the status of the deployment, and the first results from the constantly growing array. (author)

  12. The high-altitude water Cherenkov Observatory

    International Nuclear Information System (INIS)

    Mostafa, Miguel A.

    2014-01-01

    The High-Altitude Water Cherenkov (HAWC) observatory is a large field of view, continuously operated, TeV γ -ray experiment under construction at 4,100ma.s.l. in Mexico. The HAWC observatory will have an order of magnitude better sensitivity, angular resolution, and background rejection than its predecessor, the Milagro experiment. The improved performance will allow to detect both the transient and steady emissions, to study the Galactic diffuse emission at TeV energies, and to measure or constrain the TeV spectra of GeV γ -ray sources. In addition, HAWC will be the only ground-based instrument capable of detecting prompt emission from γ -ray bursts above 50 GeV. The HAWC observatory will consist of an array of 300 water Cherenkov detectors (WCDs), each with four photomultiplier tubes. This array is currently under construction on the flanks of the Sierra Negra volcano near the city of Puebla, Mexico. The first 30 WCDs (forming an array approximately the size of Milagro) were deployed in Summer 2012, and 100 WCDs will be taking data by May, 2013. We present in this paper the motivation for constructing the HAWC observatory, the status of the deployment, and the first results from the constantly growing array. (author)

  13. The High-Altitude Water Cherenkov Observatory

    Science.gov (United States)

    Mostafá, Miguel A.

    2014-10-01

    The High-Altitude Water Cherenkov (HAWC) observatory is a large field of view, continuously operated, TeV γ-ray experiment under construction at 4,100 m a.s.l. in Mexico. The HAWC observatory will have an order of magnitude better sensitivity, angular resolution, and background rejection than its predecessor, the Milagro experiment. The improved performance will allow us to detect both the transient and steady emissions, to study the Galactic diffuse emission at TeV energies, and to measure or constrain the TeV spectra of GeV γ-ray sources. In addition, HAWC will be the only ground-based instrument capable of detecting prompt emission from γ-ray bursts above 50 GeV. The HAWC observatory will consist of an array of 300 water Cherenkov detectors (WCDs), each with four photomultiplier tubes. This array is currently under construction on the flanks of the Sierra Negra volcano near the city of Puebla, Mexico. The first 30 WCDs (forming an array approximately the size of Milagro) were deployed in Summer 2012, and 100 WCDs will be taking data by May, 2013. We present in this paper the motivation for constructing the HAWC observatory, the status of the deployment, and the first results from the constantly growing array.

  14. The High Altitude Water Cherenkov (HAWC) Observatory

    Science.gov (United States)

    Springer, Wayne

    2014-06-01

    The High Altitude Water Cherenkov (HAWC) observatory is a continuously operated, wide field of view detector based upon a water Cherenkov technology developed by the Milagro experiment. HAWC observes, at an elevation of 4100 m on Sierra Negra Mountain in Mexico, extensive air showers initiated by gamma and cosmic rays. The completed detector will consist of 300 closely spaced water tanks each instrumented with four photomultiplier tubes that provide timing and charge information used to reconstruct energy and arrival direction. HAWC has been optimized to observe transient and steady emission from point as well as diffuse sources of gamma rays in the energy range from several hundred GeV to several hundred TeV. Studies in solar physics as well as the properties of cosmic rays will also be performed. HAWC has been making observations at various stages of deployment since completion of 10% of the array in summer 2012. A discussion of the detector design, science capabilities, current construction/commissioning status, and first results will be presented...

  15. DLR HABLEG- High Altitude Balloon Launched Experimental Glider

    Science.gov (United States)

    Wlach, S.; Schwarzbauch, M.; Laiacker, M.

    2015-09-01

    The group Flying Robots at the DLR Institute of Robotics and Mechatronics in Oberpfaffenhofen conducts research on solar powered high altitude aircrafts. Due to the high altitude and the almost infinite mission duration, these platforms are also denoted as High Altitude Pseudo-Satellites (HAPS). This paper highlights some aspects of the design, building, integration and testing of a flying experimental platform for high altitudes. This unmanned aircraft, with a wingspan of 3 m and a mass of less than 10 kg, is meant to be launched as a glider from a high altitude balloon in 20 km altitude and shall investigate technologies for future large HAPS platforms. The aerodynamic requirements for high altitude flight included the development of a launch method allowing for a safe transition to horizontal flight from free-fall with low control authority. Due to the harsh environmental conditions in the stratosphere, the integration of electronic components in the airframe is a major effort. For regulatory reasons a reliable and situation dependent flight termination system had to be implemented. In May 2015 a flight campaign was conducted. The mission was a full success demonstrating that stratospheric research flights are feasible with rather small aircrafts.

  16. Respiratory Muscle Training and Cognitive Function Exercising at Altitude.

    Science.gov (United States)

    Quackenbush, Joseph; Duquin, Aubrey; Helfer, Samuel; Pendergast, David R

    2016-01-01

    Hiking and trekking often occur at altitudes up to 12,000 ft altitude. The hypoxia-induced hyperventilation at altitude paradoxically reduces arterial CO2 (Paco2). A reduction in Paco2 results in vasoconstriction of the blood vessels of the brain and thus in local hypoxia. The local hypoxia likely affects cognitive function, which may result in reduced performance and altitude accidents. Recent publications have demonstrated that voluntary isocapnic hyperventilatory training of the respiratory muscles (VIHT) can markedly enhance exercise endurance as it is associated with reduced ventilation and its energy cost. VIHT may be useful in blunting the altitude-induced hyperventilation leading to higher Paco2 and improved cognitive function. This study examined the effects of VIHT, compared to control (C) and placebo (PVIHT) groups, on selected measures of executive functioning, including working memory and processing speed (i.e., Stroop Test, Symbol Digit Modalities Test, and Digit Span Forward) at simulated altitude up to 12,000 ft. Associated physiological parameters were also measured. The Digit Span Forward Test did not show improvements after VIHT in any group. The VIHT group, but not C or PVIHT groups, improved significantly (17-30%) on the Stroop Test. Similarly the VIHT group, but not the C and PVIHT groups, improved correct responses (26%) and number of attempts (24%) on the Symbol Digit Modalities Test. In addition, reaction time was also improved (16%). VIHT improved processing speed and working memory during exercise at altitude.

  17. Application of altitude/hypoxic training by elite athletes.

    Science.gov (United States)

    Wilber, Randall L

    2007-09-01

    At the Olympic level, differences in performance are typically less than 0.5%. This helps explain why many contemporary elite endurance athletes in summer and winter sport incorporate some form of altitude/hypoxic training within their year-round training plan, believing that it will provide the "competitive edge" to succeed at the Olympic level. The purpose of this paper is to describe the practical application of altitude/hypoxic training as used by elite athletes. Within the general framework of the paper, both anecdotal and scientific evidence will be presented relative to the efficacy of several contemporary altitude/hypoxic training models and devices currently used by Olympic-level athletes for the purpose of legally enhancing performance. These include the three primary altitude/hypoxic training models: 1) live high+train high (LH+TH), 2) live high+train low (LH+TL), and 3) live low+train high (LL+TH). The LH+TL model will be examined in detail and will include its various modifications: natural/terrestrial altitude, simulated altitude via nitrogen dilution or oxygen filtration, and hypobaric normoxia via supplemental oxygen. A somewhat opposite approach to LH+TL is the altitude/hypoxic training strategy of LL+TH, and data regarding its efficacy will be presented. Recently, several of these altitude/hypoxic training strategies and devices underwent critical review by the World Anti-Doping Agency (WADA) for the purpose of potentially banning them as illegal performance-enhancing substances/methods. This paper will conclude with an update on the most recent statement from WADA regarding the use of simulated altitude devices.

  18. Mitochondrial DNA response to high altitude: a new perspective on high-altitude adaptation.

    Science.gov (United States)

    Luo, Yongjun; Yang, Xiaohong; Gao, Yuqi

    2013-08-01

    Mitochondria are the energy metabolism centers of the cell. More than 95% of cellular energy is produced by mitochondrial oxidative phosphorylation. Hypoxia affects a wide range of energy generation and consumption processes in animals. The most important mechanisms limiting ATP consumption increase the efficiency of ATP production and accommodate the reduced production of ATP by the body. All of these mechanisms relate to changes in mitochondrial function. Mitochondrial function can be affected by variations in mitochondrial DNA, including polymorphisms, content changes, and deletions. These variations play an important role in acclimatization or adaptation to hypoxia. In this paper, the association between mitochondrial genome sequences and high-altitude adaptation is reviewed.

  19. Altitude Training in Elite Swimmers for Sea Level Performance (Altitude Project).

    Science.gov (United States)

    Rodríguez, Ferran A; Iglesias, Xavier; Feriche, Belén; Calderón-Soto, Carmen; Chaverri, Diego; Wachsmuth, Nadine B; Schmidt, Walter; Levine, Benjamin D

    2015-09-01

    This controlled, nonrandomized, parallel-groups trial investigated the effects on performance, V˙O2 and hemoglobin mass (tHbmass) of four preparatory in-season training interventions: living and training at moderate altitude for 3 and 4 wk (Hi-Hi3, Hi-Hi), living high and training high and low (Hi-HiLo, 4 wk), and living and training at sea level (SL) (Lo-Lo, 4 wk). From 61 elite swimmers, 54 met all inclusion criteria and completed time trials over 50- and 400-m crawl (TT50, TT400), and 100 (sprinters) or 200 m (nonsprinters) at best stroke (TT100/TT200). Maximal oxygen uptake (V˙O2max) and HR were measured with an incremental 4 × 200 m test. Training load was estimated using cumulative training impulse method and session RPE. Initial measures (PRE) were repeated immediately (POST) and once weekly on return to SL (PostW1 to PostW4). tHbmass was measured in duplicate at PRE and once weekly during the camp with CO rebreathing. Effects were analyzed using mixed linear modeling. TT100 or TT200 was worse or unchanged immediately at POST, but improved by approximately 3.5% regardless of living or training at SL or altitude after at least 1 wk of SL recovery. Hi-HiLo achieved greater improvement 2 (5.3%) and 4 wk (6.3%) after the camp. Hi-HiLo also improved more in TT400 and TT50 2 (4.2% and 5.2%, respectively) and 4 wk (4.7% and 5.5%) from return. This performance improvement was not linked linearly to changes in V˙O2max or tHbmass. A well-implemented 3- or 4-wk training camp may impair performance immediately but clearly improves performance even in elite swimmers after a period of SL recovery. Hi-HiLo for 4 wk improves performance in swimming above and beyond altitude and SL controls through complex mechanisms involving altitude living and SL training effects.

  20. Ferrum metabolism after permanence at extreme altitude on Mount Everest.

    Science.gov (United States)

    Martínez-Ballarín, E; Arregui, R

    1994-05-01

    High altitude has always intrigued physiologists because of the remarkable ability of man to adapt to the hostile environment. Despite numerous studies examining the physiological alterations occurring during exercise after exposure to hypoxia and the adaptative effects of sustained residence at altitude, several issues remain unresolved. The aim of investigation of the Spanish Medical Research Expedition to Mount Everest in 1992 was an extensive study on the physiological adaptations to the hypobaric environment at extreme altitude. We are presenting advance results the gasometry, acid-base parameters and ferrum metabolism.

  1. Altitude training considerations for the winter sport athlete.

    Science.gov (United States)

    Chapman, Robert F; Stickford, Jonathon L; Levine, Benjamin D

    2010-03-01

    Winter sports events routinely take place at low to moderate altitudes, and nearly all Winter Olympic Games have had at least one venue at an altitude >1000 m. The acute and chronic effects of altitude can have a substantial effect on performance outcomes. Acutely, the decline in oxygen delivery to working muscle decreases maximal oxygen uptake, negatively affecting performance in endurance events, such as cross-country skiing and biathlon. The reduction in air resistance at altitude can dramatically affect sports involving high velocities and technical skill components, such as ski jumping, speed skating, figure skating and ice hockey. Dissociation between velocity and sensations usually associated with work intensity (ventilation, metabolic signals in skeletal muscle and heart rate) may impair pacing strategy and make it difficult to determine optimal race pace. For competitions taking place at altitude, a number of strategies may be useful, depending on the altitude of residence of the athlete and ultimate competition altitude, as follows. First, allow extra time and practice (how much is yet undetermined) for athletes to adjust to the changes in projectile motion; hockey, shooting, figure skating and ski jumping may be particularly affected. These considerations apply equally in the reverse direction; that is, for athletes practising at altitude but competing at sea level. Second, allow time for acclimatization for endurance sports: 3-5 days if possible, especially for low altitude (500-2000 m); 1-2 weeks for moderate altitude (2000-3000 m); and at least 2 weeks if possible for high altitude (>3000 m). Third, increase exercise-recovery ratios as much as possible, with 1:3 ratio probably optimal, and consider more frequent substitutions for sports where this is allowed, such as ice hockey. Fourth, consider the use of supplemental O(2) on the sideline (ice hockey) or in between heats (skating and Alpine skiing) to facilitate recovery. For competitions at sea

  2. General introduction to altitude adaptation and mountain sickness

    DEFF Research Database (Denmark)

    Bartsch, P.; Saltin, B.

    2008-01-01

    . The alteration at the muscle level at altitude is minor and so is the effect on the metabolism, although it is debated whether a possible reduction in blood lactate accumulation occurs during exercise at altitude. Transient acute mountain sickness (headache, anorexia, and nausea) is present in 10-30% of subjects...... ascent (average ascent rate 300 m/day above 2000 m a.s.l.), primarily in order to sleep and feel well, and minimize the risk of mountain sickness. A new classification of altitude levels based on the effects on performance and well-being is proposed and an overview given over the various modalities using...

  3. Productivity of Permanent Pastures Located at Different Altitudes

    Directory of Open Access Journals (Sweden)

    Dorin Rechiţean

    2010-10-01

    Full Text Available This work studies the yielding and grazing capacity of some permanent pastures located in Banat’s Mountains, at 236 – 1300 m altitude. The mean results achieved showed that the yield difference between the minimal altitude level (236 m and the maximal one (1300 m is 0.93 t/ha DM. This difference leads to the conclusion that the yield of the permanent pastures located in the studied area decreases with 0.87 kg/ha DM (about 0.5 t/ha fresh mass for each 100 m of altitude.

  4. Oxidative stress and the high altitude environment

    Directory of Open Access Journals (Sweden)

    Jakub Krzeszowiak

    2013-03-01

    Full Text Available In the recent years there has been considerable interest in mountain sports, including mountaineering, owing to the general availability of climbing clothing and equipment as well trainings and professional literature. This raised a new question for the environmental and mountain medicine: Is mountaineering harmful to health? Potential hazards include the conditions existing in the alpine environment, i.e. lower atmospheric pressure leading to the development of hypobaric hypoxia, extreme physical effort, increased UV radiation, lack of access to fresh food, and mental stress. A reasonable measure of harmfulness of these factors is to determine the increase in the level of oxidative stress. Alpine environment can stimulate the antioxidant enzyme system but under specific circumstances it may exceed its capabilities with simultaneous consumption of low-molecular antioxidants resulting in increased generation of reactive oxygen species (ROS. This situation is referred to as oxidative stress. Rapid and uncontrolled proliferation of reactive oxygen species leads to a number of adverse changes, resulting in the above-average damage to the lipid structures of cell membranes (peroxidation, proteins (denaturation, and nucleic acids. Such situation within the human body cannot take place without resultant systemic consequences. This explains the malaise of people returning from high altitude and a marked decrease in their physical fitness. In addition, a theory is put forward that the increase in the level of oxidative stress is one of the factors responsible for the onset of acute mountain sickness (AMS. However, such statement requires further investigation because the currently available literature is inconclusive. This article presents the causes and effects of development of oxidative stress in the high mountains.

  5. Evaluation of an Oxygen Concentrator for Use at High Altitude

    National Research Council Canada - National Science Library

    Forte, Vincent

    1999-01-01

    Supplying medical oxygen at high altitude sites is a major logistical problem. Oxygen concentrators based on molecular sieve technology provide an almost inexhaustible source of medical grade oxygen at a relatively low cost...

  6. Altitude Compensating Nozzle Transonic Performance Flight Demonstration, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Altitude compensating nozzles continue to be of interest for use on future launch vehicle boosters and upper stages because of their higher mission average Isp and...

  7. The radiation protection problems of high altitude and space flight

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1993-01-01

    This paper considers the radiation environment in aircraft at high altitudes and spacecraft in low earth orbit and in deep space and the factors that influence the dose equivalents. Altitude, latitude and solar cycle are the major influences for flights below the radiation belts. In deep space, solar cycle and the occurrence of solar particle events are the factors of influence. The major radiation effects of concern are cancer and infertility in males. In high altitude aircraft the radiation consists mainly of protons and neutrons, with neutrons contributing about half the equivalent dose. The average dose rate at altitudes of transcontinental flights that approach the polar regions are greater by a factor of about 2.5 than on routes at low latitudes. Current estimates of does to air crews suggest they are well within the ICRP (1990) recommended dose limits for radiation workers

  8. Physiology and pathophysiology at high altitude: considerations for the anesthesiologist.

    Science.gov (United States)

    Leissner, Kay B; Mahmood, Feroze U

    2009-01-01

    Millions of people live in, work in, and travel to areas of high altitude (HA). Skiers, trekkers, and mountaineers reach altitudes of 2500 m to more than 8000 m for recreation, and sudden ascents to high altitude without the benefits of acclimatization are increasingly common. HA significantly affects the human body, especially the cardiovascular and pulmonary systems, because of oxygen deprivation due to decreased ambient barometric pressure. Rapid ascents may lead to high-altitude diseases that sometimes have fatal consequences. Other factors, such as severe cold, dehydration, high winds, and intense solar radiation, increase the morbidity of patients at HA. Anesthesiologists working in or visiting areas of higher elevations should become familiar with the human physiology, altered pharmacology, and disease pattern of HA.

  9. The radiation protection problems of high altitude and space flight

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1993-04-01

    This paper considers the radiation environment in aircraft at high altitudes and spacecraft in low earth orbit and in deep space and the factors that influence the dose equivalents. Altitude, latitude and solar cycle are the major influences for flights below the radiation belts. In deep space, solar cycle and the occurrence of solar particle events are the factors of influence. The major radiation effects of concern are cancer and infertility in males. In high altitude aircraft the radiation consists mainly of protons and neutrons, with neutrons contributing about half the equivalent dose. The average dose rate at altitudes of transcontinental flights that approach the polar regions are greater by a factor of about 2.5 than on routes at low latitudes. Current estimates of does to air crews suggest they are well within the ICRP (1990) recommended dose limits for radiation workers.

  10. The radiation protection problems of high altitude and space flight

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1993-01-01

    This paper considers the radiation environment in aircraft at high altitudes and spacecraft in low earth orbit and in deep space and the factors that influence the dose equivalents. Altitude, latitude and solar cycle are the major influences for flights below the radiation belts. In deep space, solar cycle and the occurrence of solar particle events are the factors of influence. The major radiation effects of concern are cancer and infertility in males. In high altitude aircraft the radiation consists mainly of protons and neutrons, with neutrons contributing about half the equivalent dose. The average dose rate at altitudes of transcontinental flights that approach the polar regions are greater by a factor of about 2.5 than on routes at low latitudes. Current estimates of does to air crews suggest they are well within the ICRP (1990) recommended dose limits for radiation workers.

  11. Obesity as a Conditioning Factor for High-Altitude Diseases

    Directory of Open Access Journals (Sweden)

    Rocío San Martin

    2017-08-01

    Full Text Available Obesity, a worldwide epidemic, has become a major health burden because it is usually accompanied by an increased risk for insulin resistance, diabetes, hypertension, cardiovascular diseases, and even some kinds of cancer. It also results in associated increases in healthcare expenditures and labor and economic consequences. There are also other fields of medicine and biology where obesity or being overweight play a major role, such as high-altitude illnesses (acute mountain sickness, hypoxic pulmonary hypertension, and chronic mountain sickness, where an increasing relationship among these two morbid statuses has been demonstrated. This association could be rooted in the interactions between obesity-related metabolic alterations and critical ventilation impairments due to obesity, which would aggravate hypobaric hypoxia at high altitudes, leading to hypoxemia, which is a trigger for developing high-altitude diseases. This review examines the current literature to support the idea that obesity or overweight could be major conditioning factors at high altitude.

  12. NAMMA HIGH ALTITUDE MMIC SOUNDING RADIOMETER (HAMSR) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA High Altitude MMIC Sounding Radiometer (HAMSR) dataset consists of data collected by HAMSR, which is a 25-channel microwave atmospheric sounder operating...

  13. Plants at high altitude exhibit higher component of alternative respiration.

    Science.gov (United States)

    Kumar, Narinder; Vyas, Dhiraj; Kumar, Sanjay

    2007-01-01

    Total respiration, capacities of cytochrome (CytR) and alternative respiration (AR) were studied in two varieties of barley (Horedum vulgare) and wheat (Triticum aestivum) each and one variety of pea (Pisum sativum) at low (Palampur; 1300 m) and high altitudes (Kibber; 4200 m). Similar studies were carried out in naturally growing Rumex nepalensis and Trifoilum repenses at Palampur, Palchan (2250 m) and Marhi (3250 m). All the plants species exhibited lower CytR but significantly higher AR capacity at high altitude (HA) (72-1117% higher) as compared to those at low altitude (LA). Glycolytic product, pyruvate and tricarboxylic acid cycle intermediate, citrate increased with increase in altitude. While the role of these metabolites in relation to HA biology is discussed, significantly higher AR at HA is proposed to be an adaptive mechanism against the metabolic perturbations wherein it might act to lower reactive oxygen species and also provides metabolic homeostasis to plants under the environment of HA.

  14. Ben Macdhui High Altitude Trace Gas and Aerosol Transport Experiment

    CSIR Research Space (South Africa)

    Piketh, SJ

    1999-01-01

    Full Text Available The Ben Macdhui High Altitude Aerosol and Trace Gas Transport Experiment (BHATTEX) was started to characterize the nature and magnitude of atmospheric, aerosol and trace gas transport paths recirculation over and exiting from southern Africa...

  15. Enhancing team-sport athlete performance: is altitude training relevant?

    Science.gov (United States)

    Billaut, François; Gore, Christopher J; Aughey, Robert J

    2012-09-01

    Field-based team sport matches are composed of short, high-intensity efforts, interspersed with intervals of rest or submaximal exercise, repeated over a period of 60-120 minutes. Matches may also be played at moderate altitude where the lower oxygen partial pressure exerts a detrimental effect on performance. To enhance run-based performance, team-sport athletes use varied training strategies focusing on different aspects of team-sport physiology, including aerobic, sprint, repeated-sprint and resistance training. Interestingly, 'altitude' training (i.e. living and/or training in O(2)-reduced environments) has only been empirically employed by athletes and coaches to improve the basic characteristics of speed and endurance necessary to excel in team sports. Hypoxia, as an additional stimulus to training, is typically used by endurance athletes to enhance performance at sea level and to prepare for competition at altitude. Several approaches have evolved in the last few decades, which are known to enhance aerobic power and, thus, endurance performance. Altitude training can also promote an increased anaerobic fitness, and may enhance sprint capacity. Therefore, altitude training may confer potentially-beneficial adaptations to team-sport athletes, which have been overlooked in contemporary sport physiology research. Here, we review the current knowledge on the established benefits of altitude training on physiological systems relevant to team-sport performance, and conclude that current evidence supports implementation of altitude training modalities to enhance match physical performances at both sea level and altitude. We hope that this will guide the practice of many athletes and stimulate future research to better refine training programmes.

  16. Altitude training for elite endurance performance: a 2012 update.

    Science.gov (United States)

    Fudge, Barry W; Pringle, Jamie S M; Maxwell, Neil S; Turner, Gareth; Ingham, Stephen A; Jones, Andrew M

    2012-01-01

    Altitude training is commonly used by endurance athletes and coaches in pursuit of enhancement of performance on return to sea level. The purpose of the current review article was to update and evaluate recent literature relevant to the practical application of altitude training for endurance athletes. Consequently, the literature can be considered in either of two categories: performance-led investigations or mechanistic advancements/insights. Each section discusses the relevant literature and proposes future directions where appropriate.

  17. Impact of Altitude on Power Output during Cycling Stage Racing.

    Science.gov (United States)

    Garvican-Lewis, Laura A; Clark, Bradley; Martin, David T; Schumacher, Yorck Olaf; McDonald, Warren; Stephens, Brian; Ma, Fuhai; Thompson, Kevin G; Gore, Christopher J; Menaspà, Paolo

    2015-01-01

    The purpose of this study was to quantify the effects of moderate-high altitude on power output, cadence, speed and heart rate during a multi-day cycling tour. Power output, heart rate, speed and cadence were collected from elite male road cyclists during maximal efforts of 5, 15, 30, 60, 240 and 600 s. The efforts were completed in a laboratory power-profile assessment, and spontaneously during a cycling race simulation near sea-level and an international cycling race at moderate-high altitude. Matched data from the laboratory power-profile and the highest maximal mean power output (MMP) and corresponding speed and heart rate recorded during the cycling race simulation and cycling race at moderate-high altitude were compared using paired t-tests. Additionally, all MMP and corresponding speeds and heart rates were binned per 1000 m (3000 m) according to the average altitude of each ride. Mixed linear modelling was used to compare cycling performance data from each altitude bin. Power output was similar between the laboratory power-profile and the race simulation, however MMPs for 5-600 s and 15, 60, 240 and 600 s were lower (p ≤ 0.005) during the race at altitude compared with the laboratory power-profile and race simulation, respectively. Furthermore, peak power output and all MMPs were lower (≥ 11.7%, p ≤ 0.001) while racing >3000 m compared with rides completed near sea-level. However, speed associated with MMP 60 and 240 s was greater (p cycling power output during competition. Decrement in cycling power output at altitude does not seem to affect speed which tended to be greater at higher altitudes.

  18. Evolutionary adaptation to high altitude: a view from in utero

    Science.gov (United States)

    Julian, Colleen Glyde; Wilson, Megan J.; Moore, Lorna G.

    2010-01-01

    A primary focus within biological anthropology has been to elucidate the processes of evolutionary adaptation. A. Roberto Frisancho helped move anthropology towards more mechanistic explanations of human adaptation by drawing attention to the importance of the functional relevance of human variation. Using the natural laboratory of high altitude, he and others asked whether the unique physiology of indigenous high-altitude residents was the result of acclimatization, developmental plasticity and/or genetic adaptation in response to the high-altitude environment. We approach the question of human adaptation to high altitude from a somewhat unique vantage point; namely, by examining physiological characteristics – pregnancy and pregnancy outcome -- that are most closely associated with reproductive fitness. Here we review the potent example of high-altitude native population’s resistance to hypoxia-associated reductions in birth weight, which is often associated with higher infant morbidity and mortality at high altitude. With the exception of two recent publications, these comparative birth weight studies have utilized surnames, self-identification and/or linguistic characteristics to assess ancestry, and none have linked ‘advantageous’ phenotypes to specific genetic variations. Recent advancements in genetic and statistical tools have enabled us to assess individual ancestry with higher resolution, identify the genetic basis of complex phenotypes and to infer the effect of natural selection on specific gene regions. Using these technologies our studies are now directed to determine the genetic variations that underlie the mechanisms by which high-altitude ancestry protects fetal growth and, in turn, to further our understanding of evolutionary processes involved in human adaptation to high altitude. PMID:19367578

  19. Can people with Raynaud's phenomenon travel to high altitude?

    Science.gov (United States)

    Luks, Andrew M; Grissom, Colin K; Jean, Dominique; Swenson, Erik R

    2009-01-01

    To determine whether high altitude travel adversely affects mountain enthusiasts with Raynaud's phenomenon. Volunteers with Raynaud's phenomenon were recruited using announcements disseminated by organizations dedicated to climbing or wilderness travel and Internet discussion boards dedicated to mountain activities to complete an online, anonymous survey. Survey questions addressed demographic variables, aspects of their Raynaud's phenomenon, and features of their mountain activities. Respondents compared experiences with Raynaud's phenomenon between high (>2440 m; 8000 feet) and low elevations and rated agreement with statements concerning their disease and the effects of high altitude. One hundred forty-two people, 98% of whom had primary Raynaud's phenomenon, completed the questionnaire. Respondents spent 5 to 7 days per month at elevations above 2440 m and engaged in 5.4 +/- 2.0 different activities. Eighty-nine percent of respondents engaged in winter sports and only 22% reported changing their mountain activities because of Raynaud's phenomenon. Respondents reported a variety of tactics to prevent and treat Raynaud's attacks, but only 12% used prophylactic medications. Fifteen percent of respondents reported an episode of frostbite following a Raynaud's phenomenon attack at high altitude. There was considerable heterogeneity in participants' perceptions of the frequency, duration, and severity of attacks at high altitude compared to their home elevation. Motivated individuals with primary Raynaud's phenomenon, employing various prevention and treatment strategies, can engage in different activities, including winter sports, at altitudes above 2440 m. Frostbite may be common in this population at high altitude, and care must be taken to prevent its occurrence.

  20. Reentry High Altitude Pulmonary Edema in the Himalayas.

    Science.gov (United States)

    Baniya, Santosh; Holden, Christopher; Basnyat, Buddha

    2017-12-01

    Baniya, Santosh, Christopher Holden, and Buddha Basnyat. Reentry high altitude pulmonary edema in the Himalayas. High Alt Med Biol. 18:425-427, 2017.-Reentry high altitude pulmonary edema (HAPE), a subset of HAPE, is a well recognized, life-threatening illness documented almost exclusively in the North and South Americans, who live at high altitude (>2500 m) and return to their homes after a brief sojourn of days to months at lower altitude. This phenomenon has not been reported in Sherpas or other people of Tibetan origin in Nepal or India. And it has rarely been reported from Tibet. In this study we document a case of reentry HAPE in Manang region (3500 m) of Nepal in a 7-year-old Nepali boy of Tibetan ancestry who fell ill when he ascended to his village (Manang, 3500 m) from Besisahar (760 m) in 1 day in a motor vehicle after spending the winter (December to March) at Besisahar with his family. With more motorable road access to high altitude settlements in the Himalayas, reentry HAPE may need to be strongly considered by healthcare professionals in local residents of high altitude; otherwise life-threatening complications may ensue as in our case report.

  1. Evaluation of Intensive Care Unit Ventilators at Altitude.

    Science.gov (United States)

    Blakeman, Thomas; Rodriquez, Dario; Petro, Michael; Branson, Richard

    Devices may forgo US military air worthiness and safety testing in an attempt to expedite the availability of critical assets such as mechanical ventilators with a waiver for one-time use in extenuating circumstances. We evaluated two Intensive Care Unit (ICU) level ventilators: Drager Evita XL and Puritan Bennett (PB) 840 in an altitude chamber at sea level and altitudes of 8,000 and 16,000 feet. Altitude affected delivered tidal volumes (VTs) in volume control mode (VCV) and Pressure Regulated Volume Controlled (PRVC) mode at altitude with the Evita XL but the differences were not considered clinically important with the PB 840. Sixty-seven percent of the V T s were outside the ASTM standard of ± 10% of set V T with the Evita XL at altitude. The PB 840 did not deliver V T s that were larger than the ASTM standard up to an altitude of 16,000 feet while the majority of the delivered V T s with the Därger XL were greater than the ASTM standard. This could present a patient safety issue. Caregivers must be aware of the capabilities and limitations of ICU ventilators when utilized in a hypobaric environment in order to provide safe care. Copyright © 2017 Air Medical Journal Associates. All rights reserved.

  2. The Study of a Super Low Altitude Satellite

    Science.gov (United States)

    Noda, Atsushi; Homma, Masanori; Utashima, Masayoshi

    This paper reports the result of a study for super low altitude satellite. The altitude of this satellite's orbit is lower than ever. The altitude of a conventional earth observing satellite is generally around from 600km to 900km. The lowest altitude of earth observing satellite launched in Japan was 350km; the Tropical Rainfall Measuring Mission (TRMM). By comparison, the satellite reported in this paper is much lower than that and it is planned to orbit below 200km. Furthermore, the duration of the flight planned is more than two years. Any satellite in the world has not achieved to keep such a low altitude that long term. The satellite in such a low orbit drops quickly because of the strong air drag. Our satellite will cancel the air drag effect by ion engine thrust. To realize this idea, a drag-free system will be applied. This usually leads a complicated and expensive satellite system. We, however, succeeded in finding a robust control law for a simple system even under the unpredictable change of air drag. When the altitude of the satellite is lowered successfully, the spatial resolution of an optical sensor can be highly improved. If a SAR is equipped with the satellite, it enables the drastic reduction of electric power consumption and the fabulous spatial resolution improvement at the same time.

  3. Analysis of high-altitude de-acclimatization syndrome after exposure to high altitudes: a cluster-randomized controlled trial.

    Science.gov (United States)

    He, Binfeng; Wang, Jianchun; Qian, Guisheng; Hu, Mingdong; Qu, Xinming; Wei, Zhenghua; Li, Jin; Chen, Yan; Chen, Huaping; Zhou, Qiquan; Wang, Guansong

    2013-01-01

    The syndrome of high-altitude de-acclimatization commonly takes place after long-term exposure to high altitudes upon return to low altitudes. The syndrome severely affects the returnee's quality of life. However, little attention has been paid to careful characterization of the syndrome and their underlying mechanisms. Male subjects from Chongqing (n = 67, 180 m) and Kunming (n = 70, 1800 m) visited a high-altitude area (3650 m) about 6 months and then returned to low-altitude. After they came back, all subjects were evaluated for high-altitude de-acclimatization syndrome on the 3(rd), 50(th), and 100(th). Symptom scores, routine blood and blood gas tests, and myocardial zymograms assay were used for observation their syndrome. The results showed that the incidence and severity of symptoms had decreased markedly on the 50(th) and 100(th) days, compared with the 3(rd) day. The symptom scores and incidence of different symptoms were lower among subjects returning to Kunming than among those returning to Chongqing. On the 3(rd) day, RBC, Hb, Hct, CK, CK-MB, and LDH values were significantly lower than values recorded at high altitudes, but they were higher than baseline values. On the 50(th) day, these values were not different from baseline values, but LDH levels did not return to baseline until the 100(th) day. These data show that, subjects who suffered high-altitude de-acclimatization syndrome, the recovery fully processes takes a long time (≥ 100(th) days). The appearance of the syndrome is found to be related to the changes in RBC, Hb, Hct, CK, CK-MB, and LDH levels, which should be caused by reoxygenation after hypoxia.

  4. When should oxygen be given to children at high altitude? A systematic review to define altitude-specific hypoxaemia.

    Science.gov (United States)

    Subhi, Rami; Smith, Katherine; Duke, Trevor

    2009-01-01

    Acute respiratory infections (ARI) cause 3 million deaths in children worldwide each year. Most of these deaths occur from pneumonia in developing countries, and hypoxaemia is the most common fatal complication. Simple and adaptable indications for oxygen therapy are important in the management of ARI. The current WHO definition of hypoxaemia as any arterial oxygen saturation (SpO(2)) oxygen saturation with altitude. This study aimed to define normal oxygen saturation and to estimate the threshold of hypoxaemia for children permanently living at different altitudes. We carried out a systematic review of the literature addressing normal values of oxygen saturation in children aged 1 week to 12 years. Hypoxaemia was defined as any SpO(2) at or below the 2.5th centile for a population of healthy children at a given altitude. Meta-regression analysis was performed to estimate the change in mean SpO(2) and the hypoxaemia threshold with increasing altitude. 14 studies were reviewed and analysed to produce prediction equations for estimating the expected mean SpO(2) in normal children, and the threshold SpO(2) indicating hypoxaemia at various altitudes. An SpO(2) of 90% is the 2.5th centile for a population of healthy children living at an altitude of approximately 2500 m above sea level. This decreases to 85% at an altitude of approximately 3200 m. For health facilities at very high altitudes, giving oxygen to all children with an SpO(2) oxygen supplies are limited. In such settings, Spo(2) children most in need of oxygen supplementation.

  5. Kajian Teknologi High Altitude Platform (HAP [Study of High Altitude Platform (HAP Technology

    Directory of Open Access Journals (Sweden)

    Amry Daulat Gultom

    2016-07-01

    Full Text Available High Altitude Platform (HAP merupakan solusi alternatif untuk mengatasi keterbatasan infrastruktur terestrial maupun satelit. HAP merupakan pesawat ataupun balon udara yang ditempatkan pada ketinggian 20-50 km di atas permukaan bumi. Kelebihan yang utama dari HAP adalah kemudahan dalam penempatan, fleksibilitas, biaya operasionalnya rendah, delay  propagasi rendah, sudut elevasi lebar, cakupan yang luas. Penelitian ini dilakukan untuk mengetahui potensi HAP untuk komunikasi pita lebar dan perkembangannya di Indonesia. Analisis dilakukan secara deskriptif dengan mengolah data literatur yang didapat. Hasil penelitian menunjukkan bahwa di Indonesia terdapat potensi teknologi HAP untuk komunikasi pita lebar dengan lebar pita 2x300 MHz di band 27,9-28,2 GHz dan 31-31,3 GHz. Namun, belum ada peraturan yang mengatur alokasi frekuensi untuk HAP secara khusus di Indonesia.*****High Altitude Platform (HAP has been developed as an alternative solution in order to overcome limitation of terrestrial and satellite communication system. HAP is an aircraft or balloon situated on 20-50 km above the earth. Main advantages of HAP are flexibility in deployment, low propagation delay, wide elevation angle and broad coverage. The research is conducted to gather HAP potential for broadband communication and its development in Indonesia. Analysis is conducted by descriptive analysis from literature study gather. The research result shows that in Indonesia, there is potential of HAP technology for broadband communication with 2x300 MHz bandwidth within 27,9-28,2 GHz and 31-31,3 GHz. Yet, there are no specific regulations managing frequency allocation for HAP in Indonesia.

  6. Fit for high altitude: are hypoxic challenge tests useful?

    Directory of Open Access Journals (Sweden)

    Matthys Heinrich

    2011-02-01

    Full Text Available Abstract Altitude travel results in acute variations of barometric pressure, which induce different degrees of hypoxia, changing the gas contents in body tissues and cavities. Non ventilated air containing cavities may induce barotraumas of the lung (pneumothorax, sinuses and middle ear, with pain, vertigo and hearing loss. Commercial air planes keep their cabin pressure at an equivalent altitude of about 2,500 m. This leads to an increased respiratory drive which may also result in symptoms of emotional hyperventilation. In patients with preexisting respiratory pathology due to lung, cardiovascular, pleural, thoracic neuromuscular or obesity-related diseases (i.e. obstructive sleep apnea an additional hypoxic stress may induce respiratory pump and/or heart failure. Clinical pre-altitude assessment must be disease-specific and it includes spirometry, pulsoximetry, ECG, pulmonary and systemic hypertension assessment. In patients with abnormal values we need, in addition, measurements of hemoglobin, pH, base excess, PaO2, and PaCO2 to evaluate whether O2- and CO2-transport is sufficient. Instead of the hypoxia altitude simulation test (HAST, which is not without danger for patients with respiratory insufficiency, we prefer primarily a hyperoxic challenge. The supplementation of normobaric O2 gives us information on the acute reversibility of the arterial hypoxemia and the reduction of ventilation and pulmonary hypertension, as well as about the efficiency of the additional O2-flow needed during altitude exposure. For difficult judgements the performance of the test in a hypobaric chamber with and without supplemental O2-breathing remains the gold standard. The increasing numbers of drugs to treat acute pulmonary hypertension due to altitude exposure (acetazolamide, dexamethasone, nifedipine, sildenafil or to other etiologies (anticoagulants, prostanoids, phosphodiesterase-5-inhibitors, endothelin receptor antagonists including mechanical aids to

  7. Effect of oxygen supplementation in a hatchery at high altitude and ...

    African Journals Online (AJOL)

    The objective of this study was to investigate the effect of oxygen supplementation on broiler eggs in a hatchery at high altitude on the growth performance and ascites syndrome of broilers reared at low altitude. The treatment groups were low altitude with no oxygen supplemented in the hatchery (LA-NOX); high altitude with ...

  8. Effect of altitude on physiological performance: a statistical analysis using results of international football games.

    Science.gov (United States)

    McSharry, Patrick E

    2007-12-22

    To assess the effect of altitude on match results and physiological performance of a large and diverse population of professional athletes. Statistical analysis of international football (soccer) scores and results. FIFA extensive database of 1460 football matches in 10 countries spanning over 100 years. Altitude had a significant (Pnegative impact on physiological performance as revealed through the overall underperformance of low altitude teams when playing against high altitude teams in South America. High altitude teams score more and concede fewer goals with increasing altitude difference. Each additional 1000 m of altitude difference increases the goal difference by about half of a goal. The probability of the home team winning for two teams from the same altitude is 0.537, whereas this rises to 0.825 for a home team with an altitude difference of 3695 m (such as Bolivia v Brazil) and falls to 0.213 when the altitude difference is -3695 m (such as Brazil v Bolivia). Altitude provides a significant advantage for high altitude teams when playing international football games at both low and high altitudes. Lowland teams are unable to acclimatise to high altitude, reducing physiological performance. As physiological performance does not protect against the effect of altitude, better predictors of individual susceptibility to altitude illness would facilitate team selection.

  9. Transcriptome and network changes in climbers at extreme altitudes.

    Directory of Open Access Journals (Sweden)

    Fang Chen

    Full Text Available Extreme altitude can induce a range of cellular and systemic responses. Although it is known that hypoxia underlies the major changes and that the physiological responses include hemodynamic changes and erythropoiesis, the molecular mechanisms and signaling pathways mediating such changes are largely unknown. To obtain a more complete picture of the transcriptional regulatory landscape and networks involved in extreme altitude response, we followed four climbers on an expedition up Mount Xixiabangma (8,012 m, and collected blood samples at four stages during the climb for mRNA and miRNA expression assays. By analyzing dynamic changes of gene networks in response to extreme altitudes, we uncovered a highly modular network with 7 modules of various functions that changed in response to extreme altitudes. The erythrocyte differentiation module is the most prominently up-regulated, reflecting increased erythrocyte differentiation from hematopoietic stem cells, probably at the expense of differentiation into other cell lineages. These changes are accompanied by coordinated down-regulation of general translation. Network topology and flow analyses also uncovered regulators known to modulate hypoxia responses and erythrocyte development, as well as unknown regulators, such as the OCT4 gene, an important regulator in stem cells and assumed to only function in stem cells. We predicted computationally and validated experimentally that increased OCT4 expression at extreme altitude can directly elevate the expression of hemoglobin genes. Our approach established a new framework for analyzing the transcriptional regulatory network from a very limited number of samples.

  10. Gender not a factor for altitude decompression sickness risk

    Science.gov (United States)

    Webb, James T.; Kannan, Nandini; Pilmanis, Andrew A.

    2003-01-01

    INTRODUCTION: Early, retrospective reports of the incidence of altitude decompression sickness (DCS) during altitude chamber training exposures indicated that women were more susceptible than men. We hypothesized that a controlled, prospective study would show no significant difference. METHODS: We conducted 25 altitude chamber decompression exposure profiles. A total of 291 human subjects, 197 men and 94 women, underwent 961 exposures to simulated altitude for up to 8 h, using zero to 4 h of preoxygenation. Throughout the exposures, subjects breathed 100% oxygen, rested or performed mild or strenuous exercise, and were monitored for precordial venous gas emboli (VGE) and DCS symptoms. RESULTS: No significant differences in DCS incidence were observed between men (49.5%) and women (45.3%). However, VGE occurred at significantly higher rates among men than women under the same exposure conditions, 69.3% and 55.0% respectively. Women using hormonal contraception showed significantly greater susceptibility to DCS than those not using hormonal contraception during the latter two weeks of the menstrual cycle. Significantly higher DCS incidence was observed in the heaviest men, in women with the highest body fat, and in subjects with the highest body mass indices and lowest levels of fitness. CONCLUSION: No differences in altitude DCS incidence were observed between the sexes under our test conditions, although men developed VGE more often than women. Age and height showed no significant influence on DCS incidence, but persons of either sex with higher body mass index and lower physical fitness developed DCS more frequently.

  11. Andean and Tibetan patterns of adaptation to high altitude.

    Science.gov (United States)

    Bigham, Abigail W; Wilson, Megan J; Julian, Colleen G; Kiyamu, Melisa; Vargas, Enrique; Leon-Velarde, Fabiola; Rivera-Chira, Maria; Rodriquez, Carmelo; Browne, Vaughn A; Parra, Esteban; Brutsaert, Tom D; Moore, Lorna G; Shriver, Mark D

    2013-01-01

    High-altitude hypoxia, or decreased oxygen levels caused by low barometric pressure, challenges the ability of humans to live and reproduce. Despite these challenges, human populations have lived on the Andean Altiplano and the Tibetan Plateau for millennia and exhibit unique circulatory, respiratory, and hematological adaptations to life at high altitude. We and others have identified natural selection candidate genes and gene regions for these adaptations using dense genome scan data. One gene previously known to be important in cellular oxygen sensing, egl nine homolog 1 (EGLN1), shows evidence of positive selection in both Tibetans and Andeans. Interestingly, the pattern of variation for this gene differs between the two populations. Continued research among Tibetan populations has identified statistical associations between hemoglobin concentration and single nucleotide polymorphism (SNP) genotype at EGLN1 and a second gene, endothelial PAS domain protein 1 (EPAS1). To measure for the effects of EGLN1 and EPAS1 altitude genotypes on hemoglobin concentration among Andean highlanders, we performed a multiple linear regression analysis of 10 candidate SNPs in or near these two genes. Our analysis did not identify significant associations between EPAS1 or EGLN1 SNP genotypes and hemoglobin concentration in Andeans. These results contribute to our understanding of the unique set of adaptations developed in different highland groups to the hypoxia of high altitude. Overall, the results provide key insights into the patterns of genetic adaptation to high altitude in Andean and Tibetan populations. Copyright © 2013 Wiley Periodicals, Inc.

  12. [Relationship between baroreflex function and training effects on altitude training].

    Science.gov (United States)

    Yanagida, Ryo; Ogawa, Yojiro; Mizuochi, Fumio; Suzuki, Tsukasa; Takahashi, Masanori; Iwasaki, Kenichi

    2012-05-01

    Altitude training is frequently used for athletes requiring competitive endurance in an attempt to improve their sea-level performance. However, there has been no study in which the mechanisms by which spontaneous arterial-cardiac baroreflex function changes was examined in responders or nonresponders of altitude training. The purpose of this study was to clarify the different effects of altitude training on baroreflex function between responders and nonresponders. Twelve university student cross-country skiers (6 men, 6 women; age, 19±1 years) participated in the altitude training in a camp for 3 weeks, which was carried out in accordance with the method of Living High-Training Low. Baroreflex function was estimated by transfer function analysis before and after the training. The responders of the training were 3 men and 2 women, and the nonresponders were 3 men and 4 women. In the responders, the transfer function gain in the high-frequency range significantly increased after the training (28.9→46.5 ms/mmHg p=0.021). On the other hand, no significant change in this index was observed in the nonresponders (25.9→21.2 ms/mmHg p=0.405). As indicated by the results of transfer function gain in the high-frequency range, the baroreflex function in the responders increased significantly after the altitude training, whereas no significant change was observed in the nonresponders.

  13. Arterial thrombosis at high altitude resulting in loss of limb.

    Science.gov (United States)

    Fagenholz, Peter J; Gutman, Jonathan A; Murray, Alice F; Noble, Vicki E; Wu, Anette; Zeimer, Gerhard; Harris, N Stuart

    2007-01-01

    Vascular thrombosis is an uncommon but recognized peril of high altitude travel. Traditionally, this has been associated with prolonged exposure to extreme altitudes where dehydration, hemoconcentration, cold, use of constrictive clothing, and enforced stasis due to severe weather have been named as contributing factors. It is widely hypothesized that hypoxia itself alters the coagulation cascade to create a prothrombotic milieu, though evidence thus far is limited and frequently conflicting. Case reports have described venous thrombosis, pulmonary embolism, cerebrovascular accidents, transient ischemic attacks, and thromboses of the portal circulation at altitude. We report a unique case of aortic thrombosis presenting with critical lower extremity ischemia in a previously healthy individual after a brief exposure to altitudes up to 4620 m. None of the frequently invoked risk factors of dehydration, cold, enforced use of constrictive clothing, weather-imposed inactivity, or extreme altitude were present, and no medical predisposition to thrombosis was identified, suggesting hypoxia as the most likely prothrombotic stimulus. We discuss the treatment of this problem and the application of Doppler ultrasonography in a wilderness setting.

  14. High-altitude headache and acute mountain sickness.

    Science.gov (United States)

    Carod-Artal, F J

    2014-01-01

    Headache is the most common complication associated with exposure to high altitude, and can appear as an isolated high-altitude headache (HAH) or in conjunction with acute mountain sickness (AMS). The purpose of this article is to review several aspects related to diagnosis and treatment of HAH. HAH occurs in 80% of all individuals at altitudes higher than 3000 meters. The second edition of ICHD-II includes HAH in the chapter entitled "Headaches attributed to disorder of homeostasis". Hypoxia elicits a neurohumoral and haemodynamic response that may provoke increased capillary pressure and oedema. Hypoxia-induced cerebral vasodilation is a probable cause of HAH. The main symptom of AMS is headache, frequently accompanied by sleep disorders, fatigue, dizziness and instability, nausea and anorexia. Some degree of individual susceptibility and considerable inter-individual variability seem to be present in AMS. High-altitude cerebral oedema is the most severe form of AMS, and may occur above 2500 meters. Brain MRI studies have found variable degrees of oedema in subcortical white matter and the splenium of the corpus callosum. HAH can be treated with paracetamol or ibuprofen. Pharmacological treatment of AMS is intended to increase ventilatory drive with drugs such as acetazolamide, and reduce inflammation and cytokine release by means of steroids. Symptom escalation seems to be present along the continuum containing HAH, AMS, and high-altitude cerebral oedema. Copyright © 2012 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  15. An Undergraduate-Built Prototype Altitude Determination System (PADS) for High Altitude Research Balloons.

    Science.gov (United States)

    Verner, E.; Bruhweiler, F. C.; Abot, J.; Casarotto, V.; Dichoso, J.; Doody, E.; Esteves, F.; Morsch Filho, E.; Gonteski, D.; Lamos, M.; Leo, A.; Mulder, N.; Matubara, F.; Schramm, P.; Silva, R.; Quisberth, J.; Uritsky, G.; Kogut, A.; Lowe, L.; Mirel, P.; Lazear, J.

    2014-12-01

    In this project a multi-disciplinary undergraduate team from CUA, comprising majors in Physics, Mechanical Engineering, Electrical Engineering, and Biology, design, build, test, fly, and analyze the data from a prototype attitude determination system (PADS). The goal of the experiment is to determine if an inexpensive attitude determination system could be built for high altitude research balloons using MEMS gyros. PADS is a NASA funded project, built by students with the cooperation of CUA faculty, Verner, Bruhweiler, and Abot, along with the contributed expertise of researchers and engineers at NASA/GSFC, Kogut, Lowe, Mirel, and Lazear. The project was initiated through a course taught in CUA's School of Engineering, which was followed by a devoted effort by students during the summer of 2014. The project is an experiment to use 18 MEMS gyros, similar to those used in many smartphones, to produce an averaged positional error signal that could be compared with the motion of the fixed optical system as recorded through a string of optical images of stellar fields to be stored on a hard drive flown with the experiment. The optical system, camera microprocessor, and hard drive are enclosed in a pressure vessel, which maintains approximately atmospheric pressure throughout the balloon flight. The experiment uses multiple microprocessors to control the camera exposures, record gyro data, and provide thermal control. CUA students also participated in NASA-led design reviews. Four students traveled to NASA's Columbia Scientific Balloon Facility in Palestine, Texas to integrate PADS into a large balloon gondola containing other experiments, before being shipped, then launched in mid-August at Ft. Sumner, New Mexico. The payload is to fly at a float altitude of 40-45,000 m, and the flight last approximately 15 hours. The payload is to return to earth by parachute and the retrieved data are to be analyzed by CUA undergraduates. A description of the instrument is presented

  16. Reduced oxygen at high altitude limits maximum size.

    Science.gov (United States)

    Peck, L S; Chapelle, G

    2003-11-07

    The trend towards large size in marine animals with latitude, and the existence of giant marine species in polar regions have long been recognized, but remained enigmatic until a recent study showed it to be an effect of increased oxygen availability in sea water of a low temperature. The effect was apparent in data from 12 sites worldwide because of variations in water oxygen content controlled by differences in temperature and salinity. Another major physical factor affecting oxygen content in aquatic environments is reduced pressure at high altitude. Suitable data from high-altitude sites are very scarce. However, an exceptionally rich crustacean collection, which remains largely undescribed, was obtained by the British 1937 expedition from Lake Titicaca on the border between Peru and Bolivia in the Andes at an altitude of 3809 m. We show that in Lake Titicaca the maximum length of amphipods is 2-4 times smaller than other low-salinity sites (Caspian Sea and Lake Baikal).

  17. Conductivity and electric field variations with altitude in the stratosphere

    Science.gov (United States)

    Holzworth, Robert H.

    1991-01-01

    Data regarding electric field, derived current density, and conductivity are presented for two balloons from the Electrodynamics of the Middle Atmosphere experiment which underwent the longest period of daily altitude variation. The magnetic L values range from 4.3 to 9.5 for the 18 days of Southern Hemisphere statistics, and the average conductivity and vertical electric fields are given. Simultaneous measurements of the average conductivity scale height and the vertical electric-field scale height indicate that vertical current density does not vary with altitude in the 10-28-km range. The measured conductivity varies significantly at a given altitude on a particular day, and some conductivity data sets are similar to other measurements between 10 and 30 km. Comparisons of the measured data to predictions from models of stratospheric conductivity demonstrate significant discrepancies.

  18. High-Altitude, Long-Endurance Airships for Coastal Surveillance

    Science.gov (United States)

    Dolce, James L.; Collozza, Anthony

    2005-01-01

    A high altitude solar powered airship provides the ability to carry large payloads to high altitudes and remain on station for extended periods of time. This study examines applications and background of this type of concept vehicle, reviews the history of high altitude flight and provides a point design analysis. The capabilities and limitations of the airship are demonstrated and possible solutions are proposed. Factors such as time of year, latitude, wind speeds, and payload are considered in establishing the capabilities of the airship. East and west coast operation is evaluated. The key aspect to success of this type of airship is the design and operation of the propulsion and power system. A preliminary propulsion/power system design was produced based on a regenerative fuel cell energy storage system and solar photovoltaic array for energy production. Results on power system requirements for year long operation is presented.

  19. Wilderness medicine at high altitude: recent developments in the field

    Directory of Open Access Journals (Sweden)

    Shah NM

    2015-09-01

    Full Text Available Neeraj M Shah,1 Sidra Hussain,2 Mark Cooke,3 John P O’Hara,3 Adrian Mellor3,4 1Division of Asthma, Allergy and Lung Biology, King’s College London, UK; 2School of Medicine, University College London, London, UK; 3Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK; 4Academic Department of Military Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, UK Abstract: Travel to high altitude is increasingly popular. With this comes an increased incidence of high-altitude illness and therefore an increased need to improve our strategies to prevent and accurately diagnose these. In this review, we provide a summary of recent advances of relevance to practitioners who may be advising travelers to altitude. Although the Lake Louise Score is now widely used as a diagnostic tool for acute mountain sickness (AMS, increasing evidence questions the validity of doing so, and of considering AMS as a single condition. Biomarkers, such as brain natriuretic peptide, are likely correlating with pulmonary artery systolic pressure, thus potential markers of the development of altitude illness. Established drug treatments include acetazolamide, nifedipine, and dexamethasone. Drugs with a potential to reduce the risk of developing AMS include nitrate supplements, propagators of nitric oxide, and supplemental iron. The role of exercise in the development of altitude illness remains hotly debated, and it appears that the intensity of exercise is more important than the exercise itself. Finally, despite copious studies demonstrating the value of preacclimatization in reducing the risk of altitude illness and improving performance, an optimal protocol to preacclimatize an individual remains elusive. Keywords: hypoxia, acute mountain sickness, acclimatization, biomarkers, preacclimatization

  20. Convergent Evolution of Rumen Microbiomes in High-Altitude Mammals.

    Science.gov (United States)

    Zhang, Zhigang; Xu, Dongming; Wang, Li; Hao, Junjun; Wang, Jinfeng; Zhou, Xin; Wang, Weiwei; Qiu, Qiang; Huang, Xiaodan; Zhou, Jianwei; Long, Ruijun; Zhao, Fangqing; Shi, Peng

    2016-07-25

    Studies of genetic adaptation, a central focus of evolutionary biology, most often focus on the host's genome and only rarely on its co-evolved microbiome. The Qinghai-Tibetan Plateau (QTP) offers one of the most extreme environments for the survival of human and other mammalian species. Yaks (Bos grunniens) and Tibetan sheep (T-sheep) (Ovis aries) have adaptations for living in this harsh high-altitude environment, where nomadic Tibetan people keep them primarily for food and livelihood [1]. Adaptive evolution affects energy-metabolism-related genes in a way that helps these ruminants live at high altitude [2, 3]. Herein, we report convergent evolution of rumen microbiomes for energy harvesting persistence in two typical high-altitude ruminants, yaks and T-sheep. Both ruminants yield significantly lower levels of methane and higher yields of volatile fatty acids (VFAs) than their low-altitude relatives, cattle (Bos taurus) and ordinary sheep (Ovis aries). Ultra-deep metagenomic sequencing reveals significant enrichment in VFA-yielding pathways of rumen microbial genes in high-altitude ruminants, whereas methanogenesis pathways show enrichment in the cattle metagenome. Analyses of RNA transcriptomes reveal significant upregulation in 36 genes associated with VFA transport and absorption in the ruminal epithelium of high-altitude ruminants. Our study provides novel insights into the contributions of microbiomes to adaptive evolution in mammals and sheds light on the biological control of greenhouse gas emissions from livestock enteric fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Are macroinvertebrates in high altitude streams affected by oxygen deficiency?

    DEFF Research Database (Denmark)

    Jacobsen, Dean; Rostgaard, S.; Vásconez, J. J.

    2003-01-01

    1. The solubility of oxygen in water increases with decreasing temperature. This has led to a general perception of cold, high mountain streams as more oxygen rich than warmer lowland streams, and that macroinvertebrates inhabiting high altitude streams have had no need to adapt to critical oxygen...... conditions. However, this fails to take into account that oxygen solubility declines with decreasing atmospheric pressure, which may be of importance at high altitudes. 2. Based on samples of macroinvertebrate benthos and in situ measurements of respiratory oxygen demand of macroinvertebrates in small...

  2. Viticultura tropical a gran altitud. Condiciones y expresiones del terroir

    OpenAIRE

    Marco Quijano Rico

    2009-01-01

    Nuestro proyecto se inició en 1982 en la Loma de Puntalarga, entre 2500 y2600 metros de altitud, a 5,78 ºN y 72,98 ºW, en la cordillera oriental de los Andes. Las variedades más utilizadas actualmente son Pinot noir, Riesling y cruzamientos de Riesling x Silvaner. Desde 1984 se realizan trabajos de investigación sobre temas pertinentes. La baja latitud, la elevada altitud, el volumen de precipitación relativamente modesto y la transparencia del cielo, determinan el flujo de radiación solar in...

  3. Description of SHARC: The Strategic High-Altitude Radiance Code

    Science.gov (United States)

    Sharma, R. D.; Ratkowski, A. J.; Sundberg, R. L.; Duff, J. W.; Bernstein, L. S.

    1989-08-01

    The Strategic High-Altitude Radiance Code (SHARC) is a new computer code that calculates atmospheric radiation and transmittance for paths from 60 to 300 km altitude in the 2 to 40 microns spectral region. It models radiation due to NLTE (Non-Local Thermodynamic Equilibrium) molecular emissions. This initial version of SHARC includes the five strongest IR radiators, NO, CO, H2, O3, and CO2. This report describes the code and models used to calculate the NLTE molecular populations and the resulting atmospheric radiance. The SHARC Manual is reproduced in the appendix.

  4. Ischemic Preconditioning Improves Time Trial Performance at Moderate Altitude.

    Science.gov (United States)

    Paradis-Deschênes, Pénélope; Joanisse, Denis R; Billaut, François

    2018-03-01

    Endurance athletes often compete and train at altitude where exercise capacity is reduced. Investigating acclimation strategies is therefore critical. Ischemic preconditioning (IPC) can improve endurance performance at sea level through improved O2 delivery and utilization, which could also prove beneficial at altitude. However, data are scarce, and there is no study at altitudes commonly visited by endurance athletes. In a randomized, crossover study, we investigated performance and physiological responses in 13 male endurance cyclists during four 5-km cycling time trials (TT), preceded by either IPC (3 × 5 min ischemia/5-min reperfusion cycles at 220 mm Hg) or SHAM (20 mm Hg) administered to both thighs, at simulated low (FIO2 0.180, ~1200 m) and moderate (FIO2 0.154, ~2400 m) altitudes. Time to completion, power output, cardiac output (Q˙), arterial O2 saturation (SpO2), quadriceps tissue saturation index (TSI) and RPE were recorded throughout the TT. Differences between IPC and SHAM were analyzed at every altitude using Cohen effect size (ES) and compared with the smallest worthwhile change. At low altitude, IPC possibly improved time to complete the TT (-5.2 s, -1.1%; Cohen ES ± 90% confidence limits -0.22, -0.44; 0.01), power output (2.7%; ES 0.21, 0.08; 0.51), and Q˙ (5.0%; ES 0.27, 0.00; 0.54), but did not alter SpO2, muscle TSI, and RPE. At moderate altitude, IPC likely enhanced completion time (-7.3 s; -1.5%; ES -0.38, -0.55; -0.20), and power output in the second half of the TT (4.6%; ES 0.28, -0.15; 0.72), increased SpO2 (1.0%; ES 0.38, -0.05; 0.81), and decreased TSI (-6.5%; ES -0.27, -0.73; 0.20) and RPE (-5.4%, ES -0.27, -0.48; -0.06). Ischemic preconditioning may provide an immediate and effective strategy to defend SpO2 and enhance high-intensity endurance performance at moderate altitude.

  5. Bell's palsy at high altitude -- an unsuspected finding.

    Science.gov (United States)

    Kumar, K V S Hari; Shijith, K P; Ahmad, F M H

    2016-01-01

    Bell's palsy is a common condition seen in clinical practice. The aetiology of this condition is not clearly defined and neuroimaging is essential to exclude intracranial causes of infra-nuclear facial palsy. We report a young soldier, who presented with Bell's palsy and neuroimaging revealed an unsuspected finding of multiple intracranial calcifications. Detailed evaluation revealed the additional diagnosis of vitamin D deficiency and secondary hyperparathyroidism due to lack of sun exposure at high altitude area. The health care practitioners, looking after the soldiers at high altitude areas should be aware of the measures to prevent vitamin D deficiency. Intracranial calcifications are uncommon in hyperparathyroidism and Bell's palsy.

  6. [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.

  7. Rare Particle Searches with the high altitude SLIM experiment

    CERN Document Server

    Balestra, S; Fabbri, F; Giacomelli, G; Giacomelli, R; Giorgini, M; Kumar, A; Manzoor, S; McDonald, J; Margiotta, A; Medinaceli, E; Nogales, J; Patrizii, L; Popa, V; Quereshi, I; Saavedra, O; Sher, G; Shahzad, M; Spurio, M; Ticona, R; Togo, V; Velarde, A; Zanini, A

    2005-01-01

    The search for rare particles in the cosmic radiation remains one of the main aims of non-accelerator particle astrophysics. Experiments at high altitude allow lower mass thresholds with respect to detectors at sea level or underground. The SLIM experiment is a large array of nuclear track detectors located at the Chacaltaya High Altitude Laboratory (5290 m a.s.l.). The preliminary results from the analysis of a part of the first 236 sq.m exposed for more than 3.6 y are here reported. The detector is sensitive to Intermediate Mass Magnetic Monopoles and to SQM nuggets and Q-balls, which are possible Dark Matter candidates.

  8. Variation of the gravity acceleration with the latitude and altitude

    Directory of Open Access Journals (Sweden)

    Wilson Lopes

    2009-01-01

    Full Text Available The propose of this work is an equation for the module of the acceleration vector of the gravity, varying with the latitude and altitude. For this purpose, the following values of the gravity acceleration were used, at the sea level: in the equator, g0 = 9,7803 m/s2, and in the latitude of 450, gP = 9,8062 m/s2. The terrestrial profile were assumed as being a revolution ellipsoid, flattened in the poles, and the acceleration of the gravity varying with the altitude, at sea level, was considered dependent of the latitude too.

  9. Iron Supplementation and Altitude: Decision Making Using a Regression Tree

    Directory of Open Access Journals (Sweden)

    Laura A. Garvican-Lewis, Andrew D. Govus, Peter Peeling, Chris R. Abbiss, Christopher J. Gore

    2016-03-01

    Full Text Available Altitude exposure increases the body’s need for iron (Gassmann and Muckenthaler, 2015, primarily to support accelerated erythropoiesis, yet clear supplementation guidelines do not exist. Athletes are typically recommended to ingest a daily oral iron supplement to facilitate altitude adaptations, and to help maintain iron balance. However, there is some debate as to whether athletes with otherwise healthy iron stores should be supplemented, due in part to concerns of iron overload. Excess iron in vital organs is associated with an increased risk of a number of conditions including cancer, liver disease and heart failure. Therefore clear guidelines are warranted and athletes should be discouraged from ‘self-prescribing” supplementation without medical advice. In the absence of prospective-controlled studies, decision tree analysis can be used to describe a data set, with the resultant regression tree serving as guide for clinical decision making. Here, we present a regression tree in the context of iron supplementation during altitude exposure, to examine the association between pre-altitude ferritin (Ferritin-Pre and the haemoglobin mass (Hbmass response, based on daily iron supplement dose. De-identified ferritin and Hbmass data from 178 athletes engaged in altitude training were extracted from the Australian Institute of Sport (AIS database. Altitude exposure was predominantly achieved via normobaric Live high: Train low (n = 147 at a simulated altitude of 3000 m for 2 to 4 weeks. The remaining athletes engaged in natural altitude training at venues ranging from 1350 to 2800 m for 3-4 weeks. Thus, the “hypoxic dose” ranged from ~890 km.h to ~1400 km.h. Ethical approval was granted by the AIS Human Ethics Committee, and athletes provided written informed consent. An in depth description and traditional analysis of the complete data set is presented elsewhere (Govus et al., 2015. Iron supplementation was prescribed by a sports physician

  10. Pathophysiology of acute mountain sickness and high altitude pulmonary oedema

    DEFF Research Database (Denmark)

    Sutton, J R; Lassen, N

    1979-01-01

    We review the evidence that acute mountain sickness (AMS) and high altitude pulmonary oedema (HAPO) occur together more often than is realized. We hypothesize that AMS and HAPO have a common pathophysiological basis: both are due to increased pressure and flow in the microcirculation, causing...... oedema in the brain and oedema in the lungs....

  11. Low-Altitude Distribution of Radiation Belt Electrons

    National Research Council Canada - National Science Library

    Selesnick, R. S; Looper, M. D; Albert, J. M

    2004-01-01

    A numerical simulation of the low-altitude electron radiation belt is described. It includes dependences on the electron's bounce and drift phases, equatorial pitch angle, and kinetic energy in the range of 1 to several MeV at L = 3.5...

  12. Organics, Meteoritic Material, and other Elements in High Altitude Aerosols

    Science.gov (United States)

    Mahoney, M.; Murphy, D. M.; Thomson, D. S.

    1998-01-01

    Recent in situ measurements of the chemical composition of single aerosol particles at altitudes up to 19 km have revealed a number of surprising features about ambient particles. Upper tropospheric aerosols in the study region often contained more organic material than sulfate.

  13. Hypoxic Hypoxia at Moderate Altitudes: State of the Science

    Science.gov (United States)

    2011-05-01

    arrhythmias resulting in cardiac arrest . Respiratory compensation in acute hypoxia Ascent to altitude occurs with a non-linear decrease in ambient...generation of respiratory rhythm are able to maintain cardiorespiratory functions during hypoxic episodes (Peña, Parkis, Tryba, & Ramirez, 2004). In

  14. Bats aloft: Variation in echolocation call structure at high altitudes

    Science.gov (United States)

    Bats alter their echolocation calls in response to changes in ecological and behavioral conditions, but little is known about how they adjust their call structure in response to changes in altitude. This study examines altitudinal variation in the echolocation calls of Brazilian free-tailed bats, T...

  15. Transcriptome and network changes in climbers at extreme altitudes

    DEFF Research Database (Denmark)

    Chen, Fang; Zhang, Wei; Liang, Yu

    2012-01-01

    Extreme altitude can induce a range of cellular and systemic responses. Although it is known that hypoxia underlies the major changes and that the physiological responses include hemodynamic changes and erythropoiesis, the molecular mechanisms and signaling pathways mediating such changes are lar...

  16. Complication Rates in Altitude Restricted Patients Following Aeromedical Evacuation

    Science.gov (United States)

    2016-04-01

    Infection Soh Tissue Infection Empyema Resuscitative Anemia/Blood Loss Hypovolemia Shock (traumatic) Blood Transfusion Reaction Postoperative...Major Arrhythmia Miscellaneous Other Adverse Drug Reaction Total Complications 354 AEROSPACE MEDICINE AND HUMAN PERFORMANCE Vol. 87, No.4 April...whole blood.27 In patients with massive transfusions , bubbles already in tile circulation will grow with altitude and may well serve CAR & POSTFLIGHT

  17. [Soil microbial functional diversity of different altitude Pinus koraiensis forests].

    Science.gov (United States)

    Han, Dong-xue; Wang, Ning; Wang, Nan-nan; Sun, Xue; Feng, Fu-juan

    2015-12-01

    In order to comprehensively understand the soil microbial carbon utilization characteristics of Pinus koraiensis forests, we took the topsoil (0-5 cm and 5-10 cm) along the 700-1100 m altitude in Changbai Mountains and analyzed the vertical distributed characteristics and variation of microbial functional diversity along the elevation gradient by Biolog microplate method. The results showed that there were significant differences in functional diversity of microbial communities at different elevations. AWCD increased with the extension of incubation time and AWCD at the same soil depth gradually decreased along with increasing altitude; Shannon, Simpson and McIntosh diversity index also showed the same trend with AWCD and three different diversity indices were significantly different along the elevation gradient; Species diversity and functional diversity showed the same variation. The utilization intensities of six categories carbon sources had differences while amino acids were constantly the most dominant carbon source. Principal component analysis (PCA) identified that soil microbial carbon utilization at different altitudes had obvious spatial differentiation, as reflected in the use of carbohydrates, amino acids and carboxylic acids. In addition, the cluster of the microbial diversity indexes and AWCD values of different altitudes showed that the composition of vegetation had a significant impact on soil microbial composition and functional activity.

  18. Limb skeletal muscle adaptation in athletes after training at altitude

    DEFF Research Database (Denmark)

    Mizuno, M; Juel, C; Bro-Rasmussen, Thomas

    1990-01-01

    increase in buffer capacity of GAS and short-term running time (P less than 0.05). Thus the present study indicates no effect of 2 wk of altitude training on VO2 max but provides evidence to suggest an improvement in short-term exercise performance, which may be the result of an increase in muscle buffer...

  19. PHYSICAL ADAPTATION OF CHILDREN TO LIFE AT HIGH-ALTITUDE

    NARCIS (Netherlands)

    DEMEER, K; HEYMANS, HSA; ZIJLSTRA, WG

    Children permanently exposed to hypoxia at altitudes of > 3000 m above sea level show a phenotypical form of adaptation. Under these environmental conditions, oxygen uptake in the lungs is enhanced by increases in ventilation, lung compliance, and pulmonary diffusion. Lung and thorax volumes in

  20. Commentary: Mesenteric ischemia, high altitude and Hill's criteria ...

    African Journals Online (AJOL)

    Commentary: Mesenteric ischemia, high altitude and Hill's criteria. R Sanda. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's ...

  1. Effect of altitude on fatty acid composition in Turkish hazelnut ...

    African Journals Online (AJOL)

    The objective of this study was to evaluate the change of fatty acid composition in Delisava, Yomra, Sivri and Karayaglı Turkish hazelnut varieties with altitude. Fatty acid composition were determined by gas chromatography (GC) equiped with flame ionisation detector (FID) after obtained fatty acid methyl esters from crude ...

  2. Civilian Training in High-Altitude Flight Physiology

    Science.gov (United States)

    1991-08-01

    A survey was conducted to determine if training in high-altitude physiology should : be required for civilian pilots; what the current status of such training was; and, : if required, what should be included in an ideal curriculum. The survey include...

  3. Limnology and cyanobacterial diversity of high altitude lakes of ...

    Indian Academy of Sciences (India)

    Limnological data of four high altitude lakes from the cold desert region of Himachal Pradesh, India, has been correlated with cyanobacterial diversity. Physico-chemical characteristics and nutrient contents of the studied lakes revealed that Sissu Lake is mesotrophic while Chandra Tal, Suraj Tal and Deepak Tal are ...

  4. Acute occlusive mesenteric ischemia in high altitude of ...

    African Journals Online (AJOL)

    Background and Objectives: Mesenteric ischemia which can be acute or chronic depending on the rapidity of compromised blood flow produces bowel ischemia, infarction, bacterial transmigration, endotoxemia, multisystem organ failure and death. High altitude can precipitate thrombosis because of hypobaric hypoxia and ...

  5. Variation in the isotopic content of precipitation with altitude

    International Nuclear Information System (INIS)

    Stowhas, L.; Silva, C.; Moser, H.; Stichler, W.

    1975-03-01

    Monthly precipitation and single storms have been collected during three years at 12 stations along a W-E profile in Chile, going from Juan Fernandez Islands to Valparaiso, Santiago and Infiernillo in the Andes, and analysed for their deuterium content. The deltaD values are correlated with the altitude of the station, the mean temperature - which also largely depends on the altitude - and the distance from the sea. The correlation parameters show however important variations from year to year and even more from month to month. For instance, in the stretch Santiago (520 m a.s.l.) - La Parva (2680 m) the mean isotopic gradient with altitude were: -1.84 deltaD per mil/100 m in 1970, -1.09 in 1971 and -2.0 in 1972. The low value observed in 1971 could be a consequence of the peculiar weather characteristics of this unusually dry year. In the stretch from the coast to Santiago the trend of the isotopic composition of precipitation is more complicated, because the so-called continental effect is superimposed to the altitude effect. The deuterium content variations have been also determined in snowpack profiles at La Parva station. The results show that snow melting occurs slowly at the bottom during the whole winter, at the expenses of the heat stored during summer in the soil. The melting of the surface snow layers only starts at the end of the winter and then proceeds very fast

  6. The genetic architecture of adaptations to high altitude in Ethiopia.

    Science.gov (United States)

    Alkorta-Aranburu, Gorka; Beall, Cynthia M; Witonsky, David B; Gebremedhin, Amha; Pritchard, Jonathan K; Di Rienzo, Anna

    2012-01-01

    Although hypoxia is a major stress on physiological processes, several human populations have survived for millennia at high altitudes, suggesting that they have adapted to hypoxic conditions. This hypothesis was recently corroborated by studies of Tibetan highlanders, which showed that polymorphisms in candidate genes show signatures of natural selection as well as well-replicated association signals for variation in hemoglobin levels. We extended genomic analysis to two Ethiopian ethnic groups: Amhara and Oromo. For each ethnic group, we sampled low and high altitude residents, thus allowing genetic and phenotypic comparisons across altitudes and across ethnic groups. Genome-wide SNP genotype data were collected in these samples by using Illumina arrays. We find that variants associated with hemoglobin variation among Tibetans or other variants at the same loci do not influence the trait in Ethiopians. However, in the Amhara, SNP rs10803083 is associated with hemoglobin levels at genome-wide levels of significance. No significant genotype association was observed for oxygen saturation levels in either ethnic group. Approaches based on allele frequency divergence did not detect outliers in candidate hypoxia genes, but the most differentiated variants between high- and lowlanders have a clear role in pathogen defense. Interestingly, a significant excess of allele frequency divergence was consistently detected for genes involved in cell cycle control and DNA damage and repair, thus pointing to new pathways for high altitude adaptations. Finally, a comparison of CpG methylation levels between high- and lowlanders found several significant signals at individual genes in the Oromo.

  7. Effect of altitude on the protein metabolism of Bolivian children

    International Nuclear Information System (INIS)

    San Miguel Simron, J.L.; Berger, J.; Spielvogel, H.; Tellez Castellon, W.; Lujan Medina, C.; Caceres, E.

    1996-01-01

    The malnutrition is prevalent and is a major problem among Bolivian children. It is caused by several interacting factors: (1) inadequate protein energy intake due to low socio-economic status; (ii) exposure to acute, repeated and chronic bacterial infections; (iii) exposure to multiple and chronic parasitic infections; (iv) high altitude of the capital, La Paz, 3600 m, with a numerous populations compared to the rest of the country. The research objectives in the first phase are: (i) determination of protein utilization with a non-invasive method using stable isotope tracer among children living at high and low altitude; (ii) determination of protein metabolism among eutrophic children without parasitic or acute bacterial infections at both altitudes; (iii) determination of protein requirement among these children. Two groups of 10 pubertal children, matched for age and sex, of same socio-economic status, eutrophic, without malnutrition, infections or intestinal parasites will be studied; the different status being arrived by anthropometric, nutritional intake, biochemical and pediatrical evaluation. For the metabolic study, stable isotopes L-[1-13C] leucine labelled casein will be used and 13 CO 2 excreted will be measured. All the basic nutritional assessment and VCO 2 measurements will be performed in Bolivia, while the samples of expired gas will be stored in Vacutainers for further analysis by isotope radio mass spectrometer (IRMS), in Clermont-Ferrand, France. The plans for future work is based on the study of the effects of the different variables and their interactions. The following will be evaluated: (i) the socio-economic status; (ii) the bacterial infections: (iii) the parasitic infections; (iv) the altitude. As published by Obert, et al., the socio-economic variable is more connected with the nutritional status than with the altitude. 12 refs, 1 fig., 1 tab

  8. Women at Altitude: Effects of Menstrual Cycle Phase and Alpha-Adrenergic Blockade on High Altitude Acclimatization

    Science.gov (United States)

    1999-10-01

    and venous tone. Alpha 1-adrenergic blockade with prazosin attenuated the rise in SNS activity at 4,300 m and prevented the increase in PNS activity in...Physiol 1991;70(3):1129-36. 4. Zamudio S., S.K. Palmer, T.E. Dahms, et al. Blood volume expansion, preeclampsia , and infant birth weight at high altitude

  9. Why Are High Altitude Natives So Strong at High Altitude? Nature vs. Nurture: Genetic Factors vs. Growth and Development.

    Science.gov (United States)

    Brutsaert, Tom

    Among high-altitude natives there is evidence of a general hypoxia tolerance leading to enhanced performance and/or increased capacity in several important domains. These domains likely include an enhanced physical work capacity, an enhanced reproductive capacity, and an ability to resist several common pathologies of chronic high-altitude exposure. The "strength" of the high-altitude native in this regard may have both a developmental and a genetic basis, although there is better evidence for the former (developmental effects) than for the latter. For example, early-life hypoxia exposure clearly results in lung growth and remodeling leading to an increased O2 diffusing capacity in adulthood. Genetic research has yet to reveal a population genetic basis for enhanced capacity in high-altitude natives, but several traits are clearly under genetic control in Andean and Tibetan populations e.g., resting and exercise arterial O2 saturation (SaO2). This chapter reviews the effects of nature and nurture on traits that are relevant to the process of gas exchange, including pulmonary volumes and diffusion capacity, the maximal oxygen consumption (VO2max), the SaO2, and the alveolar-arterial oxygen partial pressure difference (A-aDO2) during exercise.

  10. Control of respiration in flight muscle from the high-altitude bar-headed goose and low-altitude birds.

    Science.gov (United States)

    Scott, Graham R; Richards, Jeffrey G; Milsom, William K

    2009-10-01

    Bar-headed geese fly at altitudes of up to 9,000 m on their biannual migration over the Himalayas. To determine whether the flight muscle of this species has evolved to facilitate exercise at high altitude, we compared the respiratory properties of permeabilized muscle fibers from bar-headed geese and several low-altitude waterfowl species. Respiratory capacities were assessed for maximal ADP stimulation (with single or multiple inputs to the electron transport system) and cytochrome oxidase excess capacity (with an exogenous electron donor) and were generally 20-40% higher in bar-headed geese when creatine was present. When respiration rates were extrapolated to the entire pectoral muscle mass, bar-headed geese had a higher mass-specific aerobic capacity. This may represent a surplus capacity that counteracts the depressive effects of hypoxia on mitochondrial respiration. However, there were no differences in activity for mitochondrial or glycolytic enzymes measured in homogenized muscle. The [ADP] leading to half-maximal stimulation (K(m)) was approximately twofold higher in bar-headed geese (10 vs. 4-6 microM), and, while creatine reduced K(m) by 30% in this species, it had no effect on K(m) in low-altitude birds. Mitochondrial creatine kinase may therefore contribute to the regulation of oxidative phosphorylation in flight muscle of bar-headed geese, which could promote efficient coupling of ATP supply and demand. However, this was not based on differences in creatine kinase activity in isolated mitochondria or homogenized muscle. The unique differences in bar-headed geese existed without prior exercise or hypoxia exposure and were not a result of phylogenetic history, and may, therefore, be important evolutionary specializations for high-altitude flight.

  11. Schistosomiasis transmission at high altitude crater lakes in western Uganda.

    Science.gov (United States)

    John, Rubaihayo; Ezekiel, Moghusu; Philbert, Clouds; Andrew, Abaasa

    2008-08-11

    Contrary to previous reports which indicated no transmission of schistosomiasis at altitude >1,400 m above sea level in Uganda, in this study it has been established that schistosomiasis transmission can take place at an altitude range of 1487-1682 m above sea level in western Uganda. An epidemiological survey of intestinal schistosomiasis was carried out in school children staying around 13 high altitude crater lakes in Western Uganda. Stool samples were collected and then processed with the Kato-Katz technique using 42 mg templates. Thereafter schistosome eggs were counted under a microscope and eggs per gram (epg) of stool calculated. A semi-structured questionnaire was used to obtain demographic data and information on risk factors. 36.7% of the pupils studied used crater lakes as the main source of domestic water and the crater lakes studied were at altitude ranging from 1487-1682 m above sea level. 84.6% of the crater lakes studied were infective with over 50% of the users infected. The overall prevalence of Schistosoma mansoni infection was 27.8% (103/370) with stool egg load ranging from 24-6048 per gram of stool. 84.3%( 312) had light infections (400 egg/gm of stool). Prevalence was highest in the age group 12-14 years (49.5%) and geometric mean intensity was highest in the age group 9-11 years (238 epg). The prevalence and geometric mean intensity of infection among girls was lower (26%; 290 epg) compared to that of boys (29.6%; 463 epg) (t = 4.383, p model, altitude and water source (crater lakes) were significantly associated with infection. The altitudinal threshold for S. mansoni transmission in Uganda has changed and use of crater water at an altitude higher than 1,400 m above sea level poses a risk of acquiring S. mansoni infection in western Uganda. However, further research is required to establish whether the observed altitudinal threshold change is as a result of climate change or other factors. It is also necessary to establish the impact this

  12. Strength and Cycle Time of Ventilatory Oscillations in Unacclimatized Humans at High Altitude,

    Science.gov (United States)

    1983-03-04

    altitude chamber at simulated high altitudes of 8,000, 9,000, 11,000 and 14,000 feet. Periodic breathing which was strong enough to include apnea at the time...feet. Periodic breathing which was strong enough to include apnea at the time of minimum ventilation was seen in all subjects at high altitude. The cycle...respiration, is brought about by various conditions of stress, specifically heart disorders, neurological disord- ers, premature birth and high altitude (3

  13. First year results of the High Altitude Water Cherenkov observatory

    International Nuclear Information System (INIS)

    Carramiñana, Alberto

    2016-01-01

    The High Altitude Water Cherenkov (HAWC) γ-ray observatory is a wide field of view (1.8 Sr) and high duty cycle (> 95% up-time) detector of unique capabilities for the study of TeV gamma-ray sources. Installed at an altitude of 4100m in the Northern slope of Volcan Sierra Negra, Puebla, by a collaboration of about thirty institutions of Mexico and the United States, HAWC has been in full operations since March 2015, surveying 2/3 of the sky every sidereal day, monitoring active galaxies and mapping sources in the Galactic Plane to a detection level of 1 Crab per day. This contribution summarizes the main results of the first year of observations of the HAWC γ-ray observatory. (paper)

  14. First year results of the High Altitude Water Cherenkov observatory

    Science.gov (United States)

    Carramiñana, Alberto

    2016-10-01

    The High Altitude Water Cherenkov (HAWC) γ-ray observatory is a wide field of view (1.8 Sr) and high duty cycle (> 95% up-time) detector of unique capabilities for the study of TeV gamma-ray sources. Installed at an altitude of 4100m in the Northern slope of Volcan Sierra Negra, Puebla, by a collaboration of about thirty institutions of Mexico and the United States, HAWC has been in full operations since March 2015, surveying 2/3 of the sky every sidereal day, monitoring active galaxies and mapping sources in the Galactic Plane to a detection level of 1 Crab per day. This contribution summarizes the main results of the first year of observations of the HAWC γ-ray observatory.

  15. Investigating the auroral electrojets with low altitude polar orbiting satellites

    DEFF Research Database (Denmark)

    Moretto, T.; Olsen, Nils; Ritter, P.

    2002-01-01

    Three geomagnetic satellite missions currently provide high precision magnetic field measurements from low altitude polar orbiting spacecraft. We demonstrate how these data can be used to determine the intensity and location of the horizontal currents that flow in the ionosphere, predominantly...... in the auroral electrojets. First, we examine the results during a recent geomagnetic storm. The currents derived from two satellites at different altitudes are in very good agreement, which verifies good stability of the method. Further, a very high degree of correlation (correlation coefficients of 0.......8-0.9) is observed between the amplitudes of the derived currents and the commonly used auroral electro-jet indices based on magnetic measurements at ground. This points to the potential of defining an auroral activity index based on the satellite observations, which could be useful for space weather monitoring...

  16. Low-altitude trapped protons at the geomagnetic equator

    Science.gov (United States)

    Guzik, T. G.; Miah, M. A.; Mitchell, J. M.; Wefel, J. P.

    1989-01-01

    Geomagnetically trapped protons in the 0.6- to 9-MeV energy range were measured at latitudes near the geomagnetic equator by the Phoenix 1 experiment on board the S81-1 mission from May to November 1982. The protons show a distribution in latitude along the line of minimum magnetic field strength with a full width at half maximum of about 10 deg but with no appreciable longitudinal variation. Between 170 and 290 Km the peak proton flux shows a fifth-power altitude dependence, in contrast to previous measurements at higher altitudes, possibly demonstrating source attenuation. The efficiency of the telescope is calculated as a function of particle pitch angle and used to investigate the time dependence (1969-1982) of the intensity.

  17. Low-altitude trapped protons at the geomagnetic equator

    International Nuclear Information System (INIS)

    Guzik, T.G.; Miah, M.A.; Mitchell, J.W.; Wefel, J.P.

    1989-01-01

    Geomagnetically trapped protons in the 0.6- to 9-MeV energy range were measured at latitudes near the geomagnetic equator by the Phoenix 1 experiment on board the S81-1 mission from May to November 1982. The protons show a distribution in latitude along the line of minimum magnetic field strength with a full width at half maximum of ∼10 0 but with no appreciable longitudinal variation. Between 170 and 290 km the peak proton flux shows a fifth-power altitude dependence, in contrast to previous measurements at higher altitudes, possibly demonstrating source attenuation. The efficiency of the telescope is calculated as a function of particle pitch angle and used to investigate the time dependence (1969--1982) of the intensity. copyright American Geophysical Union 1989

  18. Cosmic microwave background science at commercial airline altitudes

    Science.gov (United States)

    Feeney, Stephen M.; Gudmundsson, Jon E.; Peiris, Hiranya V.; Verde, Licia; Errard, Josquin

    2017-07-01

    Obtaining high-sensitivity measurements of degree-scale cosmic microwave background (CMB) polarization is the most direct path to detecting primordial gravitational waves. Robustly recovering any primordial signal from the dominant foreground emission will require high-fidelity observations at multiple frequencies, with excellent control of systematics. We explore the potential for a new platform for CMB observations, the Airlander 10 hybrid air vehicle, to perform this task. We show that the Airlander 10 platform, operating at commercial airline altitudes, is well suited to mapping frequencies above 220 GHz, which are critical for cleaning CMB maps of dust emission. Optimizing the distribution of detectors across frequencies, we forecast the ability of Airlander 10 to clean foregrounds of varying complexity as a function of altitude, demonstrating its complementarity with both existing (Planck) and ongoing (C-BASS) foreground observations. This novel platform could play a key role in defining our ultimate view of the polarized microwave sky.

  19. A new method for aerodynamic test of high altitude propellers

    Directory of Open Access Journals (Sweden)

    Xiying Gong

    Full Text Available A ground test system is designed for aerodynamic performance tests of high altitude propellers. The system is consisted of stable power supply, servo motors, two-component balance constructed by tension-compression sensors, ultrasonic anemometer, data acquisition module. It is loaded on a truck to simulate propellers’ wind-tunnel test for different wind velocities at low density circumstance. The graphical programming language LABVIEW for developing virtual instrument is used to realize the test system control and data acquisition. Aerodynamic performance test of a propeller with 6.8 m diameter was completed by using this system. The results verify the feasibility of the ground test method. Keywords: High altitude propeller, Ground test, Virtual instrument control system

  20. Breathlessness at High Altitude: First Episode of Bronchoconstriction in an Otherwise Healthy Sojourner.

    Science.gov (United States)

    Bhandari, Sanjeeb Sudarshan; Koirala, Pranawa; Lohani, Sadichhya; Phuyal, Pratibha; Basnyat, Buddha

    2017-06-01

    Bhandari, Sanjeeb Sudarshan, Pranawa Koirala, Sadichhya Lohani, Pratibha Phuyal, and Buddha Basnyat. Breathlessness at high altitude: first episode of bronchoconstriction in an otherwise healthy sojourner. High Alt Med Biol.. 18:179-181, 2017-High-altitude illness is a collective term for less severe acute mountain sickness and more severe high-altitude pulmonary edema (HAPE) and high-altitude cerebral edema, which we can experience while traveling to high altitude. These get better when we get down to the lower altitudes. People with many comorbidities also have been traveling to high altitudes from the dawn of civilization. Obstructive airway diseases can be confused with HAPE at high altitude. Asthma is one of those obstructive pulmonary diseases, but it is shown to get better with travel to the altitudes higher than the residing altitude. We present a case of 55-year-old nonsmoker, athletic, female, a lowland resident who developed difficulty breathing for the first time at high altitude. She did not get better with the descent to lower altitude and timely intake of acetazolamide. Her pulmonary function test showed obstructive airway pattern, which got better with salbutamol/ipratropium nebulization and oxygen.

  1. Altitude acclimatization and blood volume: effects of exogenous erythrocyte volume expansion

    DEFF Research Database (Denmark)

    Sawka, M N; Young, Jette Feveile; Rock, P B

    1996-01-01

    We studied sea-level residents during 13 days of altitude acclimatization to determine 1) altitude acclimatization effects on erythrocyte volume and plasma volume, 2) if exogenous erythrocyte volume expansion alters subsequent erythrocyte volume and plasma volume adaptations, 3) if an increased b......, and mean arterial pressure elevation. These findings better define human blood volume responses during altitude acclimatization....

  2. Anti-Fatigue Effects of Methazolamide in High- Altitude Hypoxic Mice ...

    African Journals Online (AJOL)

    altitude anoxic mice. Methods: Mice fatigued by high-altitude hypoxia were housed in a hypobaric chamber (equivalent to a low pressure chamber of 5000 m altitude) for 10 consecutive days. The anti-fatigue property of MTZ was evaluated by ...

  3. Decompression tables for inside chamber attendants working at altitude.

    Science.gov (United States)

    Bell, James; Thombs, Paul A; Davison, William J; Weaver, Lindell K

    2014-01-01

    Hyperbaric oxygen (HBO2) multiplace chamber inside attendants (IAs) are at risk for decompression sickness (DCS). Standard decompression tables are formulated for sea-level use, not for use at altitude. At Presbyterian/St. Luke's Medical Center (Denver, Colorado, 5,924 feet above sea level) and Intermountain Medical Center (Murray, Utah, 4,500 feet), the decompression obligation for IAs is managed with U.S. Navy Standard Air Tables corrected for altitude, Bühlmann Tables, and the Nobendem© calculator. IAs also breathe supplemental oxygen while compressed. Presbyterian/St. Luke's (0.83 atmospheres absolute/atm abs) uses gauge pressure, uncorrected for altitude, at 45 feet of sea water (fsw) (2.2 atm abs) for routine wound care HBO2 and 66 fsw (2.8 atm abs) for carbon monoxide/cyanide poisoning. Presbyterian/St. Luke's provides oxygen breathing for the IAs at 2.2 atm abs. At Intermountain (0.86 atm abs), HBO2 is provided at 2.0 atm abs for routine treatments and 3.0 atm abs for carbon monoxide poisoning. Intermountain IAs breathe intermittent 50% nitrogen/50% oxygen at 3.0 atm abs and 100% oxygen at 2.0 atm abs. The chamber profiles include a safety stop. From 1990-2013, Presbyterian/St. Luke's had 26,900 total IA exposures: 25,991 at 45 fsw (2.2 atm abs) and 646 at 66 fsw (2.8 atm abs); there have been four cases of IA DCS. From 2008-2013, Intermountain had 1,847 IA exposures: 1,832 at 2 atm abs and 15 at 3 atm abs, with one case of IA DCS. At both facilities, DCS incidents occurred soon after the chambers were placed into service. Based on these results, chamber inside attendant risk for DCS at increased altitude is low when the inside attendants breathe supplemental oxygen.

  4. Wilderness medicine at high altitude: recent developments in the field

    OpenAIRE

    Shah, Neeraj M; Hussain, Sidra; Cooke, Mark; O’Hara, John P; Mellor, Adrian

    2015-01-01

    Neeraj M Shah,1 Sidra Hussain,2 Mark Cooke,3 John P O’Hara,3 Adrian Mellor3,4 1Division of Asthma, Allergy and Lung Biology, King’s College London, UK; 2School of Medicine, University College London, London, UK; 3Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK; 4Academic Department of Military Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, UK Abstract: Travel to high altitude is increasingly p...

  5. High energy astrophysics and high-altitude laboratories

    International Nuclear Information System (INIS)

    Lipari, P.; University La Sapienza, Rome

    2001-01-01

    These are some summary remarks given at the Chacaltaya meeting on cosmic ray physics, held in La Paz (Bolivia), July 23-27, 2000. The meeting covered a wide range of topics in cosmic ray physics and high energy astrophysics. This contribution briefly touches on some of the highlights of the meeting, and discusses the important role that high-altitude laboratories can have in the future of these fundamental fields

  6. Civilian Training in High-Altitude Flight Physiology

    Science.gov (United States)

    1991-08-01

    wequote the following. and above. This concern is escalated by the follow- ing quote from an article entitled "HYPOXIA: the Bioastronautics Data Book NASA ...decrementwhen Air Force or Navy Base or NASA facility. In the altitude is combined with stress, age, sleep dep- event the chamber training is not possible...required fordifferent A-8 situations in flight. A familia ;zation with 3. Aging: regulators and masks, equipment checks, and other general rules is

  7. Training-dependent cognitive advantage is suppressed at high altitude.

    Science.gov (United States)

    Li, Peng; Zhang, Gang; You, Hai-Yan; Zheng, Ran; Gao, Yu-Qi

    2012-06-25

    Ascent to high altitude is associated with decreases in cognitive function and work performance as a result of hypoxia. Some workers with special jobs typically undergo intensive mental training because they are expected to be agile, stable and error-free in their job performance. The purpose of this study was to determine the risk to cognitive function acquired from training following hypoxic exposure. The results of WHO neurobehavioral core tests battery (WHO-NCTB) and Raven's standard progressive matrices (RSPM) tests of a group of 54 highly trained military operators were compared with those of 51 non-trained ordinary people and were investigated at sea level and on the fifth day after arrival at high altitudes (3900m). Meanwhile, the plasma levels of brain-derived neurotrophic factor (BDNF), interleukin 1β (IL-1β) and vascular endothelial growth factor (VEGF) were examined. The result showed that at sea level, the trained group exhibited significantly better performance on neurobehavioral and RSPM tests. At high altitude, both groups had decreased accuracy in most cognitive tests and took longer to finish them. More importantly, the highly trained subjects showed more substantial declines than the non-trained subjects in visual reaction accuracy, auditory reaction speed, digit symbol scores, ability to report correct dots in a pursuit aiming test and total RSPM scores. This means that the training-dependent cognitive advantages in these areas were suppressed at high altitudes. The above phenomenon maybe associated with decreased BDNF and elevated inflammatory factor during hypoxia, and other mechanisms could not be excluded. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. DEVELOPMENT OF A HIGH ALTITUDE LOW OPENING HUMANITARIAN AIRDROP SYSTEM

    Science.gov (United States)

    2017-07-12

    design of a delivery system (airdrop and helicopter sling load), and development of both an analytical model to characterize deployed aid item...easier rigging. The cargo net system has shown that delivering humanitarian aid from the cargo hook of a helicopter is a viable solution. 41 4...ALTITUDE LOW OPENING HUMANITARIAN AIRDROP SYSTEM by Marc N. Tardiff July 2017 Final Report October 2010 – July

  9. The University of Alberta High Altitude Balloon Program

    Science.gov (United States)

    Johnson, W.; Buttenschoen, A.; Farr, Q.; Hodgson, C.; Mann, I. R.; Mazzino, L.; Rae, J.; University of Alberta High Altitude Balloon Team

    2011-12-01

    The University of Alberta High Altitude Balloon (UA-HAB) program is a one and half year program sponsored by the Canadian Space Agency (CSA) that offers hands on experience for undergraduate and graduate students in the design, build, test and flight of an experimental payload on a high altitude balloon platform. Utilising low cost weather balloon platforms, and through utilisation of the CSA David Florida Laboratory for thermal-vacuum tests , in advance of the final flight of the payload on a NASA high altitude balloon platform. Collectively the program provided unique opportunities for students to experience mission phases which parallel those of a space satellite mission. The program has facilitated several weather balloon missions, which additionally provide educational opportunities for university students and staff, as well as outreach opportunities among junior and senior high school students. Weather balloon missions provide a cheap and quick alternative to suborbital missions; they can be used to test components for more expensive missions, as well as to host student based projects from different disciplines such as Earth and Atmospheric Sciences (EAS), Physics, and Engineering. In addition to extensive skills development, the program aims to promote recruitment of graduate and undergraduate students into careers in space science and engineering. Results from the UA-HAB program and the flight of the UA-HAB shielded Gieger counter payload for cosmic ray and space radiation studies will be presented. Lessons learned from developing and maintaining a weather balloon program will also be discussed. This project is undertaken in partnership with the High Altitude Student Platform, organized by Louisiana State University and the Louisiana Space Consortium (LaSpace), and sponsored by NASA, with the financial support of the Canadian Space Agency.

  10. Wind Compensation by Radiometer Arrays in High Altitude Propulsion

    Science.gov (United States)

    2012-05-01

    échauffés execent sur les autres à des distances sensibles. Annales de Chimie et de Physique 29:57-62 2. Crookes W (1874) On attraction and repulsion...For both altitudes, the computational domain is approximately 40 mean free paths in the radial direction. Since radial coordinate of the radiometer...is assumed to be 10 K and 30 K for 60 and 80 km, respectively. Comparison of the flow velocity profiles along the radial coordinate , obtained by

  11. The sleep of elite athletes at sea level and high altitude: a comparison of sea-level natives and high-altitude natives (ISA3600)

    Science.gov (United States)

    Roach, Gregory D; Schmidt, Walter F; Aughey, Robert J; Bourdon, Pitre C; Soria, Rudy; Claros, Jesus C Jimenez; Garvican-Lewis, Laura A; Buchheit, Martin; Simpson, Ben M; Hammond, Kristal; Kley, Marlen; Wachsmuth, Nadine; Gore, Christopher J; Sargent, Charli

    2013-01-01

    Background Altitude exposure causes acute sleep disruption in non-athletes, but little is known about its effects in elite athletes. The aim of this study was to examine the effects of altitude on two groups of elite athletes, that is, sea-level natives and high-altitude natives. Methods Sea-level natives were members of the Australian under-17 soccer team (n=14). High-altitude natives were members of a Bolivian under-20 club team (n=12). Teams participated in an 18-day (19 nights) training camp in Bolivia, with 6 nights at near sea level in Santa Cruz (430 m) and 13 nights at high altitude in La Paz (3600 m). Sleep was assessed on every day/night using activity monitors. Results The Australians’ sleep was shorter, and of poorer quality, on the first night at altitude compared with sea level. Sleep quality returned to normal by the end of the first week at altitude, but sleep quantity had still not stabilised at its normal level after 2 weeks. The quantity and quality of sleep obtained by the Bolivians was similar, or greater, on all nights at altitude compared with sea level. The Australians tended to obtain more sleep than the Bolivians at sea level and altitude, but the quality of the Bolivians’ sleep tended to be better than that of the Australians at altitude. Conclusions Exposure to high altitude causes acute and chronic disruption to the sleep of elite athletes who are sea-level natives, but it does not affect the sleep of elite athletes who are high-altitude natives. PMID:24282197

  12. The sleep of elite athletes at sea level and high altitude: a comparison of sea-level natives and high-altitude natives (ISA3600).

    Science.gov (United States)

    Roach, Gregory D; Schmidt, Walter F; Aughey, Robert J; Bourdon, Pitre C; Soria, Rudy; Claros, Jesus C Jimenez; Garvican-Lewis, Laura A; Buchheit, Martin; Simpson, Ben M; Hammond, Kristal; Kley, Marlen; Wachsmuth, Nadine; Gore, Christopher J; Sargent, Charli

    2013-12-01

    Altitude exposure causes acute sleep disruption in non-athletes, but little is known about its effects in elite athletes. The aim of this study was to examine the effects of altitude on two groups of elite athletes, that is, sea-level natives and high-altitude natives. Sea-level natives were members of the Australian under-17 soccer team (n=14). High-altitude natives were members of a Bolivian under-20 club team (n=12). Teams participated in an 18-day (19 nights) training camp in Bolivia, with 6 nights at near sea level in Santa Cruz (430 m) and 13 nights at high altitude in La Paz (3600 m). Sleep was assessed on every day/night using activity monitors. The Australians' sleep was shorter, and of poorer quality, on the first night at altitude compared with sea level. Sleep quality returned to normal by the end of the first week at altitude, but sleep quantity had still not stabilised at its normal level after 2 weeks. The quantity and quality of sleep obtained by the Bolivians was similar, or greater, on all nights at altitude compared with sea level. The Australians tended to obtain more sleep than the Bolivians at sea level and altitude, but the quality of the Bolivians' sleep tended to be better than that of the Australians at altitude. Exposure to high altitude causes acute and chronic disruption to the sleep of elite athletes who are sea-level natives, but it does not affect the sleep of elite athletes who are high-altitude natives.

  13. S-40: Acute Phase Protein Increse in High Altitude Mountaineers

    Directory of Open Access Journals (Sweden)

    Tolga Saka

    2017-03-01

    Full Text Available “Erciyes Tigers” are an elite group of high altitude climbers. They have been climbing ErciyesMountain (3500 m, in Kayseri, Turkey once a week at least for ten years. When they climb Erciyes in winter, they also take a snow bath. This study investigated the effects of regular high altitude climbing on the metabolic and hematological responses of mountaineers. Venous blood samples were taken to investigate hematological, biochemical parameters and some hormone values from 21 mountaineers and 16 healthy age-matched sedentary volunteers at resting condition. The neutrophil/lymphocyte (N/L ratio was calculated. The N/L was associated with an increased risk of long-term mortality and it could provide a good measure of exercise stress and subsequent recovery. Most of the hematological and biochemical parameters i.e., erythrocyte, leukocyte, hemoglobin and hematocrit values did not change significantly. The neutrophil to lymphocyte (N/L ratio was significantly (p<0.04 decreased in the mountaineer compared with the sedentary group. Total protein (p<0.000 and albumin (0.001 were lower, while ferritin (p<0.04, creatine (p<0.03 and creatine phosphokinase levels (p<0.01 were higher in mountaineers. Our results show that regular high altitude climbing increased serum levels of some acute-phase proteins and these increments were not transient.

  14. Red cell function at extreme altitude on Mount Everest.

    Science.gov (United States)

    Winslow, R M; Samaja, M; West, J B

    1984-01-01

    As part of the American Medical Research Expedition to Everest in 1981, we measured hemoglobin concentration, red cell 2,3-diphosphoglycerate (2,3-DPG), Po2 at which hemoglobin is 50% saturated (P50), and acid-base status in expedition members at various altitudes. All measurements were made in expedition laboratories and, with the exception of samples from the South Col of Mt. Everest (8,050 m), within 2 h of blood collection. In vivo conditions were estimated from direct measurements of arterial blood gases and pH or inferred from base excess and alveolar PCO2. As expected, increased 2,3-DPG was associated with slightly increased P50, when expressed at pH 7.4. Because of respiratory alkalosis, however, the subjects' in vivo P50 at 6,300 m (27.6 Torr) was slightly less than at sea level (28.1 Torr). The estimated in vivo P50 was progressively lower at 8,050 m (24.9 Torr) and on the summit at 8,848 m (19.4 Torr in one subject). Our data suggest that, at extreme altitude, the blood O2 equilibrium curve shifts progressively leftward because of respiratory alkalosis. This left shift protects arterial O2 saturation at extreme altitude.

  15. APPLICATION OF UAV SYSTEM FOR LOW ALTITUDE PHOTOGRAMMETRY IN SHANXI

    Directory of Open Access Journals (Sweden)

    C. Junqing

    2012-07-01

    Full Text Available Recent years, as the urgent demands of the state and society for high-resolution aerial images and large-scale DLG (Digital Line Graphic, UAV borne low-altitude Photogrammetry system are used more and more widely. Combining the application of UAV system in Shanxi for collecting the 1:1000 scale DLG, in this paper, the main steps and key technologies of UAV system for lower altitude aerial photogrammetry are introduced. In this passage, we took an area of Shanxi as the survey area, acquired 1024 aerial images of the survey area. After the calculation of aerial triangulation, we get the plane accuracy of the encrypted points is 0.21 m and the height accuracy of encrypted points is 0.35 m, could meet the accuracy of 1:1000 scale mapping. It can be seen that the UAV system for low altitude photogrammetry has its own advantages in acquiring high resolution aerial images and large scale DLG, and UAV system has a great development prospects.

  16. Differentiation of pulmonary embolism from high altitude pulmonary edema

    International Nuclear Information System (INIS)

    Khan, D.A.; Hashim, R.; Mirza, T.M.; Matloob-ur-Rehman, M.

    2003-01-01

    Objective: To differentiate the high altitude pulmonary edema (HAPE) from pulmonary embolism (PE) by clinical probability model of PE, lactate dehydrogenase (LDH), aspartate transaminase (AST) and D-dimer assays at high altitude. Subjects and Methods: Consecutive 40 patients evacuated from height > 3000 meters with symptoms of PE or HAPE were included. Clinical pretest probabilities scores of PE, Minutex D-dimer assay (Biopool international) and cardiac enzymes estimation by IFCC approved methods, were used for diagnosis. Mann-Whitney U test was applied by using SPSS and level of significance was taken at (p 500 ng/ml. Plasma D-dimer of 500 ng/ml was considered as cut-off value; 6(66.7%) patients of PE could be diagnosed and 30 (96.7%) cases of HAPE excluded indicating very good negative predictive value. Serum LDH, AST and CK were raised above the reference ranges in 8 (89%), 7 (78%) and 3 (33%) patients of PE as compared to 11 (35%), 6 (19%) and 9 (29%) of HAPE respectively. Conclusion: Clinical assessment in combination with D-dimer assay, LDH and AST can be used for timely differentiation of PE from HAPE at high altitude where diagnostic imaging procedures are not available. (author)

  17. Measurement and Characterization of Helicopter Noise at Different Altitudes

    Science.gov (United States)

    Watts, Michael E.; Greenwood, Eric; Stephenson, James

    2016-01-01

    This paper presents an overview of a flight test campaign performed at different test sites whose altitudes ranged from 0 to 7000 feet above mean sea level (AMSL) between September 2014 and February 2015. The purposes of this campaign were to: investigate the effects of altitude variation on noise generation, investigate the effects of gross weight variation on noise generation, establish the statistical variability in acoustic flight testing of helicopters, and characterize the effects of transient maneuvers on radiated noise for a medium-lift utility helicopter. In addition to describing the test campaign, results of the acoustic effects of altitude variation for the AS350 SD1 and EH-60L aircraft are presented. Large changes in acoustic amplitudes were observed in response to changes in ambient conditions when the helicopter was flown at constant indicated airspeed and gross weight at the three test sites. However, acoustic amplitudes were found to scale with ambient pressure when flight conditions were defined in terms of the non-dimensional parameters, such as the weight coefficient and effective hover tip Mach number.

  18. The individual response to training and competition at altitude.

    Science.gov (United States)

    Chapman, Robert F

    2013-12-01

    Performance in athletic activities that include a significant aerobic component at mild or moderate altitudes shows a large individual variation. Physiologically, a large portion of the negative effect of altitude on exercise performance can be traced to limitations of oxygen diffusion, either at the level of the alveoli or the muscle microvasculature. In the lung, the ability to maintain arterial oxyhaemoglobin saturation (SaO₂) appears to be a primary factor, ultimately influencing oxygen delivery to the periphery. SaO₂ in hypoxia can be defended by increasing ventilatory drive; however, during heavy exercise, many athletes demonstrate limitations to expiratory flow and are unable to increase ventilation in hypoxia. Additionally, increasing ventilatory work in hypoxia may actually be negative for performance, if dyspnoea increases or muscle blood flow is reduced secondary to an increased sympathetic outflow (eg, the muscle metaboreflex response). Taken together, some athletes are clearly more negatively affected during exercise in hypoxia than other athletes. With careful screening, it may be possible to develop a protocol for determining which athletes may be the most negatively affected during competition and/or training at altitude.

  19. The sleep of elite athletes at sea level and high altitude: a comparison of sea-level natives and high-altitude natives (ISA3600)

    OpenAIRE

    Roach, Gregory D; Schmidt, Walter F; Aughey, Robert J; Bourdon, Pitre C; Soria, Rudy; Claros, Jesus C Jimenez; Garvican-Lewis, Laura A; Buchheit, Martin; Simpson, Ben M; Hammond, Kristal; Kley, Marlen; Wachsmuth, Nadine; Gore, Christopher J; Sargent, Charli

    2013-01-01

    Background Altitude exposure causes acute sleep disruption in non-athletes, but little is known about its effects in elite athletes. The aim of this study was to examine the effects of altitude on two groups of elite athletes, that is, sea-level natives and high-altitude natives. Methods Sea-level natives were members of the Australian under-17 soccer team (n=14). High-altitude natives were members of a Bolivian under-20 club team (n=12). Teams participated in an 18-day (19 nights) training c...

  20. Lightweight Liquid Helium Dewar for High-Altitude Balloon Payloads

    Science.gov (United States)

    Kogut, Alan; James, Bryan; Fixsen, Dale

    2013-01-01

    Astrophysical observations at millimeter wavelengths require large (2-to-5- meter diameter) telescopes carried to altitudes above 35 km by scientific research balloons. The scientific performance is greatly enhanced if the telescope is cooled to temperatures below 10 K with no emissive windows between the telescope and the sky. Standard liquid helium bucket dewars can contain a suitable telescope for telescope diameter less than two meters. However, the mass of a dewar large enough to hold a 3-to-5-meter diameter telescope would exceed the balloon lift capacity. The solution is to separate the functions of cryogen storage and in-flight thermal isolation, utilizing the unique physical conditions at balloon altitudes. Conventional dewars are launched cold: the vacuum walls necessary for thermal isolation must also withstand the pressure gradient at sea level and are correspondingly thick and heavy. The pressure at 40 km is less than 0.3% of sea level: a dewar designed for use only at 40 km can use ultra thin walls to achieve significant reductions in mass. This innovation concerns new construction and operational techniques to produce a lightweight liquid helium bucket dewar. The dewar is intended for use on high-altitude balloon payloads. The mass is low enough to allow a large (3-to-5-meter) diameter dewar to fly at altitudes above 35 km on conventional scientific research balloons without exceeding the lift capability of the balloon. The lightweight dewar has thin (250- micron) stainless steel walls. The walls are too thin to support the pressure gradient at sea level: the dewar launches warm with the vacuum space vented continuously during ascent to eliminate any pressure gradient across the walls. A commercial 500-liter storage dewar maintains a reservoir of liquid helium within a minimal (hence low mass) volume. Once a 40-km altitude is reached, the valve venting the vacuum space of the bucket dewar is closed to seal the vacuum space. A vacuum pump then

  1. Inverse association between altitude and obesity: A prevalence study among Andean and low-altitude adult individuals of Peru

    Science.gov (United States)

    Woolcott, Orison O.; Gutierrez, Cesar; Castillo, Oscar A.; Elashoff, Robert M.; Stefanovski, Darko; Bergman, Richard N.

    2015-01-01

    Objective To determine the association between altitude and obesity in a nationally representative sample of the Peruvian adult population. Design and Methods This is a cross-sectional analysis of publicly available data from the Food and Nutrition National Center (CENAN, Peru), period 2009-2010. Prevalence ratio of obesity and abdominal obesity was determined as a measure of association. Obesity and abdominal obesity were diagnosed based on direct anthropometric measurements. Results The final dataset consisted of 31,549 individuals ≥20 years old. The prevalence ratio of obesity was as follows: 1.00 between 0–499 m (reference category), 1.00 (95% confidence interval 0.87-1.16) between 500–1,499 m, 0.74 (0.63-0.86) between 1,500–2,999, and 0.54 (0.45-0.64) at ≥3,000 m, adjusting for age, sex, self-reported physical activity, out-migration rate, urbanization, poverty, education, and geographical latitude and longitude. In the same order, the adjusted prevalence ratio of abdominal obesity was 1.00, 1.01 (0.94-1.07), 0.93 (0.87-0.99), and 0.89 (0.82-0.95), respectively. We found an interaction between altitude and sex and between altitude and age (Pobesity and abdominal obesity. Conclusions Among Peruvian adult individuals, we found an inverse association between altitude and obesity, adjusting for multiple covariates. This adjusted association varied by sex and age. PMID:26935008

  2. High altitude pulmonary edema, down syndrome, and obstructive sleep apneas.

    Science.gov (United States)

    Richalet, Jean-Paul; Chenivesse, Cécile; Larmignat, Philippe; Meille, Laurent

    2008-01-01

    A 24-year-old adult with a Down syndrome was admitted in December 2006 at the Moutiers hospital in the French Alps for an acute inaugural episode of high altitude pulmonary edema (HAPE) that occurred in the early morning of day 3 after his arrival to La Plagne (2000 m). This patient presented an interventricular septal defect operated on at the age of 7, a hypothyroidism controlled by 50 microg levothyrox, a state of obesity (BMI 37.8 kg/m(2)), and obstructive sleep apneas with a mean of 42 obstructive apneas or hypopneas per hour, treated with continuous positive airway pressure (CPAP). The patient refused to use his CPAP during his stay in La Plagne. At echocardiography, resting parameters were normal, with a left ventricular, ejection fraction of 60%, a normokinetic right ventricle, and an estimated systolic pulmonary artery pressure (sPAP) of 30 mmHg. At exercise, sPAP rose to 45 mmHg and the right ventricle was still normokinetic and not dilated. An exercise hypoxic tolerance test performed at 60 W and at the equivalent altitude of 3300 m revealed a severe drop in arterial oxygen saturation down to 60%, with an abnormal low ventilatory response to hypoxia, suggesting a defect in peripheral chemosensitivity to hypoxia. In conclusion, patients with Down syndrome, including adults with no cardiac dysfunction and regular physical activity, are at risk of HAPE even at moderate altitude when they suffer from obstructive sleep apneas associated with obesity and low chemoresponsiveness. This observation might be of importance since an increasing number of young adults with Down syndrome participate in recreational or sport activities, including skiing and mountaineering.

  3. High Altitude Venus Operations Concept Trajectory Design, Modeling and Simulation

    Science.gov (United States)

    Lugo, Rafael A.; Ozoroski, Thomas A.; Van Norman, John W.; Arney, Dale C.; Dec, John A.; Jones, Christopher A.; Zumwalt, Carlie H.

    2015-01-01

    A trajectory design and analysis that describes aerocapture, entry, descent, and inflation of manned and unmanned High Altitude Venus Operation Concept (HAVOC) lighter-than-air missions is presented. Mission motivation, concept of operations, and notional entry vehicle designs are presented. The initial trajectory design space is analyzed and discussed before investigating specific trajectories that are deemed representative of a feasible Venus mission. Under the project assumptions, while the high-mass crewed mission will require further research into aerodynamic decelerator technology, it was determined that the unmanned robotic mission is feasible using current technology.

  4. Computations of ideal and real gas high altitude plume flows

    Science.gov (United States)

    Feiereisen, William J.; Venkatapathy, Ethiraj

    1988-01-01

    In the present work, complete flow fields around generic space vehicles in supersonic and hypersonic flight regimes are studied numerically. Numerical simulation is performed with a flux-split, time asymptotic viscous flow solver that incorporates a generalized equilibrium chemistry model. Solutions to generic problems at various altitude and flight conditions show the complexity of the flow, the equilibrium chemical dissociation and its effect on the overall flow field. Viscous ideal gas solutions are compared against equilibrium gas solutions to illustrate the effect of equilibrium chemistry. Improved solution accuracy is achieved through adaptive grid refinement.

  5. Snow chemistry of high altitude glaciers in the French Alps

    OpenAIRE

    MAUPETIT, FRANÇOIS; DELMAS, ROBERT J.

    2011-01-01

    Snow samples were collected as snowcores in the accumulation zone of four high altitude glaciers (2980–3540 m.a.s.l.) from each of the 4 highest mountain areas of the French Alps, during 3 consecutive years: 1989, 1990 and 1991. Sampling was performed in spring (∼ May), before the onset of late spring–summer percolation. The accumulated snow therefore reflects winter and spring conditions. A complementary sampling of fresh-snow was performed on an event basis, on one of the studied glaciers, ...

  6. Perseus High Altitude Remotely Piloted Aircraft on Ramp

    Science.gov (United States)

    1991-01-01

    The Perseus proof-of-concept vehicle waits on Rogers Dry Lake in the pre-dawn darkness before a test flight at the Dryden Flight Research Center, Edwards, California. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus design, which began with the Perseus Proof-Of-Concept aircraft. Perseus was initially developed as part of NASA's Small High-Altitude Science Aircraft (SHASA) program, which later evolved into the

  7. Sequencing of 50 human exomes reveals adaptation to high altitude

    DEFF Research Database (Denmark)

    Yi, Xin; Liang, Yu; Huerta-Sanchez, Emilia

    2010-01-01

    Residents of the Tibetan Plateau show heritable adaptations to extreme altitude. We sequenced 50 exomes of ethnic Tibetans, encompassing coding sequences of 92% of human genes, with an average coverage of 18x per individual. Genes showing population-specific allele frequency changes, which...... difference between Tibetan and Han samples, representing the fastest allele frequency change observed at any human gene to date. This SNP's association with erythrocyte abundance supports the role of EPAS1 in adaptation to hypoxia. Thus, a population genomic survey has revealed a functionally important locus...

  8. Electromagnetic coupling of high-altitude, nuclear electromagnetic pulses

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    We have used scale models to measure the predicted coupling of electromagnetic fields simulating the effects of high-altitude nuclear electromagnetic pulses (HEMP) on the interior surfaces of electronic components. Predictive tools for exterior coupling are adequate. For interior coupling, however, such tools are in their infancy. Our methodological approach combines analytical, computational, and laboratory techniques in a complementary way to take advantage of their separate strengths. Computer models are a promising tool, as they can be used to treat complex objects with arbitrary shapes, dielectrics, and cables, and multiple apertures. Laboratory tests can expand the domain of investigation even further

  9. Effect of altitude on protein metabolism in Bolivian children

    International Nuclear Information System (INIS)

    Beaufrere, B.; Gachon, P.; Boirie, Y.; San Miguel, J.L.; Maubois, J.L.; Coudert, J.

    1994-01-01

    Protein utilization during feeding is difficult to assess by classical tracer methodology, particularly under field conditions. We propose a new approach using the measurement of tracer recovery (expired 13 CO 2 ) after the ingestion of a single oral dose of a 13 C-leucine labelled milk protein. Protein will be obtained by infusing a cow with 13 C-leucine. The difference between the amounts of tracer given and recovered should be an index of protein utilization. Since altitude might influence protein absorption, this non-invasive method will be used in Bolivian children, living either at 3600 m (La Paz) or at sea level. (author). 14 refs

  10. High-altitude electromagnetic pulse environment over the lossy ground

    International Nuclear Information System (INIS)

    Xie Yanzhao; Wang Zanji

    2003-01-01

    The electromagnetic field above ground produced by an incident high-altitude electromagnetic pulse plane wave striking the ground plane was described in this paper in terms of the Fresnel reflection coefficients and the numerical FFT. The pulse reflected from the ground plane always cancel the incident field for the horizontal field component, but the reflected field adds to the incident for the vertical field component. The results of several cases for variations in the observation height, angle of incidence and lossy ground electrical parameters were also presented showing different e-field components above the earth

  11. WCDMA Uplink Interference Assessment from Multiple High Altitude Platform Configurations

    Directory of Open Access Journals (Sweden)

    A. Mohammed

    2008-06-01

    Full Text Available We investigate the possibility of multiple high altitude platform (HAP coverage of a common cell area using a wideband code division multiple access (WCDMA system. In particular, we study the uplink system performance of the system. The results show that depending on the traffic demand and the type of service used, there is a possibility of deploying 3–6 HAPs covering the same cell area. The results also show the effect of cell radius on performance and the position of the multiple HAP base stations which give the worst performance.

  12. Attempt to measure the cosmic background radiation at high altitude

    International Nuclear Information System (INIS)

    Labeyrie, Jacques; Le Boiteux, Henri

    1959-01-01

    Results are given of the measurement by G.M. tubes of hard component of cosmic background between o and 60 km of altitude, at 43 deg. N latitude, on january 27, 1959 (17 h. GMT). The counting rate starts at 0.3 pulses per second (sea level) reaches a maximum value of 15.6 (18 km) and remains constant at 5.7 above 40 km. Reprint of a paper published in Le Journal de Physique et le Radium, t. 20, p. 573, may 1959

  13. Cosmic radiation doses at flight level altitudes of airliners

    International Nuclear Information System (INIS)

    Viragh, E.; Petr, I.

    1985-01-01

    Changes are discussed in flux density of cosmic radiation particles with time as are the origin of cosmic radiation, the level of cosmic radiation near the Earth's surface, and the determination of cosmic radiation doses in airliners. Doses and dose rates are given measured on different flight routes. In spite of the fact that the flight duration at an altitude of about 10 km makes for about 80% of the total flight time, the overall radiation burden of the crews at 1000 flight hours a year is roughly double that of the rest of the population. (J.C.)

  14. Source of the low-altitude hiss in the ionosphere

    Czech Academy of Sciences Publication Activity Database

    Chen, L.; Santolík, Ondřej; Hájoš, Mychajlo; Zheng, L.; Zhima, Z.; Heelis, R.; Hanzelka, Miroslav; Horne, R. B.; Parrot, M.

    2017-01-01

    Roč. 44, č. 5 (2017), s. 2060-2069 ISSN 0094-8276 R&D Projects: GA ČR(CZ) GA17-07027S; GA MŠk(CZ) LH15304 Grant - others:AV ČR(CZ) AP1401 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378289 Keywords : ionospheric hiss * low-altitude hiss * plasmaspheric hiss * ray tracing Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 4.253, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2016GL072181/full

  15. Defining the "dose" of altitude training: how high to live for optimal sea level performance enhancement.

    Science.gov (United States)

    Chapman, Robert F; Karlsen, Trine; Resaland, Geir K; Ge, R-L; Harber, Matthew P; Witkowski, Sarah; Stray-Gundersen, James; Levine, Benjamin D

    2014-03-15

    Chronic living at altitudes of ∼2,500 m causes consistent hematological acclimatization in most, but not all, groups of athletes; however, responses of erythropoietin (EPO) and red cell mass to a given altitude show substantial individual variability. We hypothesized that athletes living at higher altitudes would experience greater improvements in sea level performance, secondary to greater hematological acclimatization, compared with athletes living at lower altitudes. After 4 wk of group sea level training and testing, 48 collegiate distance runners (32 men, 16 women) were randomly assigned to one of four living altitudes (1,780, 2,085, 2,454, or 2,800 m). All athletes trained together daily at a common altitude from 1,250-3,000 m following a modified live high-train low model. Subjects completed hematological, metabolic, and performance measures at sea level, before and after altitude training; EPO was assessed at various time points while at altitude. On return from altitude, 3,000-m time trial performance was significantly improved in groups living at the middle two altitudes (2,085 and 2,454 m), but not in groups living at 1,780 and 2,800 m. EPO was significantly higher in all groups at 24 and 48 h, but returned to sea level baseline after 72 h in the 1,780-m group. Erythrocyte volume was significantly higher within all groups after return from altitude and was not different between groups. These data suggest that, when completing a 4-wk altitude camp following the live high-train low model, there is a target altitude between 2,000 and 2,500 m that produces an optimal acclimatization response for sea level performance.

  16. Influence of altitude training modality on performance and total haemoglobin mass in elite swimmers.

    Science.gov (United States)

    Gough, Clare E; Saunders, Philo U; Fowlie, John; Savage, Bernard; Pyne, David B; Anson, Judith M; Wachsmuth, Nadine; Prommer, Nicole; Gore, Christopher J

    2012-09-01

    We compared changes in performance and total haemoglobin mass (tHb) of elite swimmers in the weeks following either Classic or Live High:Train Low (LHTL) altitude training. Twenty-six elite swimmers (15 male, 11 female, 21.4 ± 2.7 years; mean ± SD) were divided into two groups for 3 weeks of either Classic or LHTL altitude training. Swimming performances over 100 or 200 m were assessed before altitude, then 1, 7, 14 and 28 days after returning to sea-level. Total haemoglobin mass was measured twice before altitude, then 1 and 14 days after return to sea-level. Changes in swimming performance in the first week after Classic and LHTL were compared against those of Race Control (n = 11), a group of elite swimmers who did not complete altitude training. In addition, a season-long comparison of swimming performance between altitude and non-altitude groups was undertaken to compare the progression of performances over the course of a competitive season. Regardless of altitude training modality, swimming performances were substantially slower 1 day (Classic 1.4 ± 1.3% and LHTL 1.6 ± 1.6%; mean ± 90% confidence limits) and 7 days (0.9 ± 1.0% and 1.9 ± 1.1%) after altitude compared to Race Control. In both groups, performances 14 and 28 days after altitude were not different from pre-altitude. The season-long comparison indicated that no clear advantage was obtained by swimmers who completed altitude training. Both Classic and LHTL elicited ~4% increases in tHb. Although altitude training induced erythropoeisis, this physiological adaptation did not transfer directly into improved competitive performance in elite swimmers.

  17. Women at Altitude: Effects of Menstrual Cycle Phase and Alpha-Adrenergic Blockade on High Altitude Acclimatization.

    Science.gov (United States)

    1996-10-01

    Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, vA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction...Palmer SK, Dahms TE, et al. Blood volume expansion, preeclampsia , and infant birth weight at high altitude. J Appl Physiol 1993;74:1566- 73. Contract...is Ms. Virginia Miller at DSN 343-7327 or by email at virginia.miller@det.amedd.army.mil. FOR THE COMMANDER: PHYL IM. RINEHART Deputy Chief of, Staff for Information Management

  18. ARMAS and NAIRAS Comparisons of Radiation at Aviation Altitudes

    Science.gov (United States)

    Bell, L. D.

    2015-12-01

    Space Environment Technologies and the Space Weather Center (SWC) at Utah State University are deploying and obtaining effective dose rate radiation data from dosimeters flown on research aircraft. This project is called Automated Radiation Measurements for Aerospace Safety (ARMAS). Through several dozen flights since 2013 the ARMAS project has successfully demonstrated the operation of a micro-dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from galactic cosmic rays (GCR's) and solar energetic particles (SEP's). Space weather effects upon the near Earth environment are to dynamic changes in the energy transfer process from the Sun's photons, particles, and fields. The coupling between the solar and galactic high-energy particles, and atmospheric regions can significantly affect human tissue and the aircrafts technology as a result of radiation exposure. We describe and compare the types of radiation we have been measuring with the NAIRAS global climatological model as it relates to human tissue susceptibility and as a source at different altitude regions.

  19. Scientific verification of High Altitude Water Cherenkov observatory

    International Nuclear Information System (INIS)

    Marinelli, Antonio; Sparks, Kathryne; Alfaro, Ruben; González, María Magdalena; Patricelli, Barbara; Fraija, Nissim

    2014-01-01

    The High Altitude Water Cherenkov (HAWC) observatory is a TeV gamma-ray and cosmic-ray detector currently under construction at an altitude of 4100 m close to volcano Sierra Negra in the state of Puebla, Mexico. The HAWC [1] observatory is an extensive air-shower array composed of 300 optically isolated water Cherenkov detectors (WCDs). Each WCD contains ∼200,000 l of filtered water and four upward-facing photomultiplier tubes. In Fall 2014, when the HAWC observatory will reach an area of 22,000 m 2 , the sensitivity will be 15 times higher than its predecessor Milagro [2]. Since September 2012, more than 30 WCDs have been instrumented and taking data. This first commissioning phase has been crucial for the verification of the data acquisition and event reconstruction algorithms. Moreover, with the increasing number of instrumented WCDs, it is important to verify the data taken with different configuration geometries. In this work we present a comparison between Monte Carlo simulation and data recorded by the experiment during 24 h of live time between 14 and 15 April of 2013 when 29 WCDs were active

  20. Scientific verification of High Altitude Water Cherenkov observatory

    Science.gov (United States)

    Marinelli, Antonio; Sparks, Kathryne; Alfaro, Ruben; González, María Magdalena; Patricelli, Barbara; Fraija, Nissim

    2014-04-01

    The High Altitude Water Cherenkov (HAWC) observatory is a TeV gamma-ray and cosmic-ray detector currently under construction at an altitude of 4100 m close to volcano Sierra Negra in the state of Puebla, Mexico. The HAWC [1] observatory is an extensive air-shower array composed of 300 optically isolated water Cherenkov detectors (WCDs). Each WCD contains ~200,000 l of filtered water and four upward-facing photomultiplier tubes. In Fall 2014, when the HAWC observatory will reach an area of 22,000 m2, the sensitivity will be 15 times higher than its predecessor Milagro [2]. Since September 2012, more than 30 WCDs have been instrumented and taking data. This first commissioning phase has been crucial for the verification of the data acquisition and event reconstruction algorithms. Moreover, with the increasing number of instrumented WCDs, it is important to verify the data taken with different configuration geometries. In this work we present a comparison between Monte Carlo simulation and data recorded by the experiment during 24 h of live time between 14 and 15 April of 2013 when 29 WCDs were active.

  1. Scientific verification of High Altitude Water Cherenkov observatory

    Energy Technology Data Exchange (ETDEWEB)

    Marinelli, Antonio, E-mail: antonio.marinelli@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, Mexico D.F. (Mexico); Sparks, Kathryne [Department of Physics, Pennsylvania State University, University Park, PA (United States); Alfaro, Ruben [Instituto de Física, Universidad Nacional Autónoma de México, Mexico D.F. (Mexico); González, María Magdalena; Patricelli, Barbara; Fraija, Nissim [Instituto de Astronomia, Universidad Nacional Autónoma de México, Mexico D.F. (Mexico)

    2014-04-01

    The High Altitude Water Cherenkov (HAWC) observatory is a TeV gamma-ray and cosmic-ray detector currently under construction at an altitude of 4100 m close to volcano Sierra Negra in the state of Puebla, Mexico. The HAWC [1] observatory is an extensive air-shower array composed of 300 optically isolated water Cherenkov detectors (WCDs). Each WCD contains ∼200,000 l of filtered water and four upward-facing photomultiplier tubes. In Fall 2014, when the HAWC observatory will reach an area of 22,000 m{sup 2}, the sensitivity will be 15 times higher than its predecessor Milagro [2]. Since September 2012, more than 30 WCDs have been instrumented and taking data. This first commissioning phase has been crucial for the verification of the data acquisition and event reconstruction algorithms. Moreover, with the increasing number of instrumented WCDs, it is important to verify the data taken with different configuration geometries. In this work we present a comparison between Monte Carlo simulation and data recorded by the experiment during 24 h of live time between 14 and 15 April of 2013 when 29 WCDs were active.

  2. Terminal altitude maximization for Mars entry considering uncertainties

    Science.gov (United States)

    Cui, Pingyuan; Zhao, Zeduan; Yu, Zhengshi; Dai, Juan

    2018-04-01

    Uncertainties present in the Mars atmospheric entry process may cause state deviations from the nominal designed values, which will lead to unexpected performance degradation if the trajectory is designed merely based on the deterministic dynamic model. In this paper, a linear covariance based entry trajectory optimization method is proposed considering the uncertainties presenting in the initial states and parameters. By extending the elements of the state covariance matrix as augmented states, the statistical behavior of the trajectory is captured to reformulate the performance metrics and path constraints. The optimization problem is solved by the GPOPS-II toolbox in MATLAB environment. Monte Carlo simulations are also conducted to demonstrate the capability of the proposed method. Primary trading performances between the nominal deployment altitude and its dispersion can be observed by modulating the weights on the dispersion penalty, and a compromised result referring to maximizing the 3σ lower bound of the terminal altitude is achieved. The resulting path constraints also show better satisfaction in a disturbed environment compared with the nominal situation.

  3. Semianalytic Integration of High-Altitude Orbits under Lunisolar Effects

    Directory of Open Access Journals (Sweden)

    Martin Lara

    2012-01-01

    Full Text Available The long-term effect of lunisolar perturbations on high-altitude orbits is studied after a double averaging procedure that removes both the mean anomaly of the satellite and that of the moon. Lunisolar effects acting on high-altitude orbits are comparable in magnitude to the Earth’s oblateness perturbation. Hence, their accurate modeling does not allow for the usual truncation of the expansion of the third-body disturbing function up to the second degree. Using canonical perturbation theory, the averaging is carried out up to the order where second-order terms in the Earth oblateness coefficient are apparent. This truncation order forces to take into account up to the fifth degree in the expansion of the lunar disturbing function. The small values of the moon’s orbital eccentricity and inclination with respect to the ecliptic allow for some simplification. Nevertheless, as far as the averaging is carried out in closed form of the satellite’s orbit eccentricity, it is not restricted to low-eccentricity orbits.

  4. Change in turbopause altitude at 52 and 70° N

    Directory of Open Access Journals (Sweden)

    C. M. Hall

    2016-02-01

    Full Text Available The turbopause is the demarcation between atmospheric mixing by turbulence (below and molecular diffusion (above. When studying concentrations of trace species in the atmosphere, and particularly long-term change, it may be important to understand processes present, together with their temporal evolution that may be responsible for redistribution of atmospheric constituents. The general region of transition between turbulent and molecular mixing coincides with the base of the ionosphere, the lower region in which molecular oxygen is dissociated, and, at high latitude in summer, the coldest part of the whole atmosphere. This study updates previous reports of turbopause altitude, extending the time series by half a decade, and thus shedding new light on the nature of change over solar-cycle timescales. Assuming there is no trend in temperature, at 70° N there is evidence for a summer trend of  ∼  1.6 km decade−1, but for winter and at 52° N there is no significant evidence for change at all. If the temperature at 90 km is estimated using meteor trail data, it is possible to estimate a cooling rate, which, if applied to the turbopause altitude estimation, fails to alter the trend significantly irrespective of season. The observed increase in turbopause height supports a hypothesis of corresponding negative trends in atomic oxygen density, [O]. This supports independent studies of atomic oxygen density, [O], using mid-latitude time series dating from 1975, which show negative trends since 2002.

  5. Reduction of Altitude Diffuser Jet Noise Using Water Injection

    Science.gov (United States)

    Allgood, Daniel C.; Saunders, Grady P.; Langford, Lester A.

    2011-01-01

    A feasibility study on the effects of injecting water into the exhaust plume of an altitude rocket diffuser for the purpose of reducing the far-field acoustic noise has been performed. Water injection design parameters such as axial placement, angle of injection, diameter of injectors, and mass flow rate of water have been systematically varied during the operation of a subscale altitude test facility. The changes in acoustic far-field noise were measured with an array of free-field microphones in order to quantify the effects of the water injection on overall sound pressure level spectra and directivity. The results showed significant reductions in noise levels were possible with optimum conditions corresponding to water injection at or just upstream of the exit plane of the diffuser. Increasing the angle and mass flow rate of water injection also showed improvements in noise reduction. However, a limit on the maximum water flow rate existed as too large of flow rate could result in un-starting the supersonic diffuser.

  6. Radiation Safety Issues in High Altitude Commercial Aircraft

    Science.gov (United States)

    Wilson, John W.; Cucinotta, Francis A.; Shinn, Judy L.

    1995-01-01

    The development of a global economy makes the outlook for high speed commercial intercontinental flight feasible, and the development of various configurations operating from 20 to 30 km have been proposed. In addition to the still unresolved issues relating to current commercial operations (12-16 km), the higher dose rates associated with the higher operating altitudes makes il imperative that the uncertainties in the atmospheric radiation environment and the associated health risks be re-examined. Atmospheric radiation associated with the galactic cosmic rays forms a background level which may, under some circumstances, exceed newly recommended allowable exposure limits proposed on the basis of recent evaluations of the A -bomb survivor data (due to increased risk coefficients). These larger risk coefficients, within the context of the methodology for estimating exposure limits, are resulting in exceedingly low estimated allowable exposure limits which may impact even present day flight operations and was the reason for the CEC workshop in Luxembourg (1990). At higher operating altitudes, solar particles events can produce exposures many orders of magnitude above background levels and pose significant health risks to the most sensitive individuals (such as during pregnancy). In this case the appropriate quality factors are undefined, and some evidence exists which indicates that the quality factor for stochastic effects is a substantial underestimate.

  7. Three plasma metabolite signatures for diagnosing high altitude pulmonary edema

    Science.gov (United States)

    Guo, Li; Tan, Guangguo; Liu, Ping; Li, Huijie; Tang, Lulu; Huang, Lan; Ren, Qian

    2015-10-01

    High-altitude pulmonary edema (HAPE) is a potentially fatal condition, occurring at altitudes greater than 3,000 m and affecting rapidly ascending, non-acclimatized healthy individuals. However, the lack of biomarkers for this disease still constitutes a bottleneck in the clinical diagnosis. Here, ultra-high performance liquid chromatography coupled with Q-TOF mass spectrometry was applied to study plasma metabolite profiling from 57 HAPE and 57 control subjects. 14 differential plasma metabolites responsible for the discrimination between the two groups from discovery set (35 HAPE subjects and 35 healthy controls) were identified. Furthermore, 3 of the 14 metabolites (C8-ceramide, sphingosine and glutamine) were selected as candidate diagnostic biomarkers for HAPE using metabolic pathway impact analysis. The feasibility of using the combination of these three biomarkers for HAPE was evaluated, where the area under the receiver operating characteristic curve (AUC) was 0.981 and 0.942 in the discovery set and the validation set (22 HAPE subjects and 22 healthy controls), respectively. Taken together, these results suggested that this composite plasma metabolite signature may be used in HAPE diagnosis, especially after further investigation and verification with larger samples.

  8. Living High and Feeling Low: Altitude, Suicide, and Depression.

    Science.gov (United States)

    Kious, Brent M; Kondo, Douglas G; Renshaw, Perry F

    After participating in this activity, learners should be better able to:• Assess epidemiologic evidence that increased altitude of residence is linked to increased risk of depression and suicide• Evaluate strategies to address hypoxia-related depression and suicidal ideation ABSTRACT: Suicide and major depressive disorder (MDD) are complex conditions that almost certainly arise from the influences of many interrelated factors. There are significant regional variations in the rates of MDD and suicide in the United States, suggesting that sociodemographic and environmental conditions contribute. Here, we review epidemiological evidence that increases in the altitude of residence are linked to the increased risk of depression and suicide. We consider the possibility that chronic hypobaric hypoxia (low blood oxygen related to low atmospheric pressure) contributes to suicide and depression, which is suggested by animal models, short-term studies in humans, and the effects of hypoxic medical conditions on suicide and depression. We argue that hypobaric hypoxia could promote suicide and depression by altering serotonin metabolism and brain bioenergetics; both of these pathways are implicated in depression, and both are affected by hypoxia. Finally, we briefly examine treatment strategies to address hypoxia-related depression and suicidal ideation that are suggested by these findings, including creatine monohydrate and the serotonin precursors tryptophan and 5-hydroxytryptophan.

  9. Os empreendedores de vinhos de altitude do planalto catarinense

    Directory of Open Access Journals (Sweden)

    Nubia Alves de Carvalho Ferreira

    2011-09-01

    Full Text Available O objetivo desse estudo é analisar e classificar os empreendedores de vinhos de altitude do Planalto Catarinense, por meio da utilização da tipologia de Westhead e Wright (1998. Esses autores apontam três tipos - o noviço/iniciante, o serial e o de portfólio. Para tanto, analisa quais são as características empreendedoras utilizadas. Verifica ainda se o fato de possuírem experiência em outros setores colabora para a consolidação dessa nova atividade. Trata-se de uma abordagem qualitativa, sendo a pesquisa do tipo exploratória que se configura como um estudo de caso. Os dados foram coletados por meio de pesquisa a sites, revistas, documentos e pessoas envolvidas no processo de formação e gestão dos empreendimentos em vinhos de altitude e, sobretudo, por meio de entrevistas semiestruturadas com os empreendedores. Os resultados obtidos demonstram a tipologia portfólio, evidenciam as habilidades como a característica preponderante desses empreendedores e confirmam outros trabalhos e cases pesquisados e apresentados na literatura. Ressalva-se a necessidade de novas pesquisas, em maior profundidade e número de entrevistados.

  10. ER-2 High Altitude Solar Cell Calibration Flights

    Science.gov (United States)

    Myers, Matthew; Wolford, David; Snyder, David; Piszczor, Michael

    2015-01-01

    Evaluation of space photovoltaics using ground-based simulators requires primary standard cells which have been characterized in a space or near-space environment. Due to the high cost inherent in testing cells in space, most primary standards are tested on high altitude fixed wing aircraft or balloons. The ER-2 test platform is the latest system developed by the Glenn Research Center (GRC) for near-space photovoltaic characterization. This system offers several improvements over GRC's current Learjet platform including higher altitude, larger testing area, onboard spectrometers, and longer flight season. The ER-2 system was developed by GRC in cooperation with NASA's Armstrong Flight Research Center (AFRC) as well as partners at the Naval Research Laboratory and Air Force Research Laboratory. The system was designed and built between June and September of 2014, with the integration and first flights taking place at AFRC's Palmdale facility in October of 2014. Three flights were made testing cells from GRC as well as commercial industry partners. Cell performance data was successfully collected on all three flights as well as solar spectra. The data was processed using a Langley extrapolation method, and performance results showed a less than half a percent variation between flights, and less than a percent variation from GRC's current Learjet test platform.

  11. Physical condition among middle altitude trekkers in an aging society.

    Science.gov (United States)

    Saito, Shigeru; Tobe, Ken; Harada, Naomi; Aso, Chizu; Nishihara, Fumio; Shimada, Hitoshi

    2002-07-01

    The number of alpine accidents has markedly increased among elderly trekkers in an aging society, Japan. We evaluated the physical condition of 176 trekkers by interview and physical examination on a popular middle altitude mountain. Heart rate, noninvasive blood pressure and arterial oxygen saturation (SpO2) were measured using a portable life monitor. It was revealed that more than 70% of the trekkers were over 50. Seventy-five percent of trekkers over 70 had some pre-existing medical problems. Systolic and diastolic blood pressure before the start of trekking, increased with age. However, such age-dependent differences were not apparent at the summit hut. SpO2 values decreased slightly but significantly with age. In conclusion, many elderly people enjoy nonchallenging middle altitude trekking in an aging society. Alpine accidents caused by health problems tend to arise more frequently in this population. Alpine rescue teams should be well-prepared for the alpine accidents of elderly trekkers. Copyright 2002, Elsevier Science (USA). All rights reserved.)

  12. High altitude and pre-eclampsia: Adaptation or protection.

    Science.gov (United States)

    Ahmed, Sarah I Y; Ibrahim, Muntaser E; Khalil, Eltahir A G

    2017-07-01

    Adaptive genes of high altitude can also be protective in diseases like preeclampsia, hypertension, and diabetes mellitus, Alzheimer, Parkinson Disease and Cancer, which may result from deregulation of hypoxia pathway. The example of pre-eclampsia and normal pregnancy were studied to see if the hypoxia-induced disorders can be dragged towards adaptation. Here, we analyse the genetic variants that are known to be associated with adaptation to high altitude hypoxia. Our results demonstrated that the genetic variants of EPAS1, ADAM9, and EGLN1 increased approximately three-fold in the cases of preeclampsia compared to normal pregnancy. This may suggest the ability of the hypoxic cells of preeclampsia to respond to the high selective pressure of hypoxia with a higher degree of genetic variability, which can lead to adaptation. Signs of "acclimatisation" were seen both in cases and controls but with higher frequencies in controls. This can be a new approach that follows patients' genetic selection and susceptibility of individuals for adaptability, which could be enhanced by drug development. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Limb skeletal muscle adaptation in athletes after training at altitude

    DEFF Research Database (Denmark)

    Mizuno, M; Juel, C; Bro-Rasmussen, Thomas

    1990-01-01

    Morphological and biochemical characteristics of biopsies obtained from gastrocnemius (GAS) and triceps brachii muscle (TRI), as well as maximal O2 uptake (VO2 max) and O2 deficit, were determined in 10 well-trained cross-country skiers before and after a 2-wk stay (2,100 m above sea level......) and training (2,700 m above sea level) at altitude. On return to sea level, VO2 max was the same as the prealtitude value, whereas an increase in O2 deficit (29%) and in short-term running performance (17%) was observed (P less than 0.05). GAS showed maintained capillary supply but a 10% decrease...... increase in buffer capacity of GAS and short-term running time (P less than 0.05). Thus the present study indicates no effect of 2 wk of altitude training on VO2 max but provides evidence to suggest an improvement in short-term exercise performance, which may be the result of an increase in muscle buffer...

  14. Autophagy Is a Promoter for Aerobic Exercise Performance during High Altitude Training

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    2018-01-01

    Full Text Available High altitude training is one of the effective strategies for improving aerobic exercise performance at sea level via altitude acclimatization, thereby improving oxygen transport and/or utilization. But its underlying molecular mechanisms on physiological functions and exercise performance of athletes are still vague. More recent evidence suggests that the recycling of cellular components by autophagy is an important process of the body involved in the adaptive responses to exercise. Whether high altitude training can activate autophagy or whether high altitude training can improve exercise performance through exercise-induced autophagy is still unclear. In this narrative review article, we will summarize current research advances in the improvement of exercise performance through high altitude training and its reasonable molecular mechanisms associated with autophagy, which will provide a new field to explore the molecular mechanisms of adaptive response to high altitude training.

  15. Health and Work at High Altitude - a Study of the Mauna-Kea Observatories

    Science.gov (United States)

    Forster, P. J. G.

    1984-06-01

    The low oxygen environment of high altitude decreases the efficiency and poses risks to the health of personnel manning telescopes at high altitudes. In a study at the Mauna Kea observatories (4200 m) in Hawaii, symptoms of acute mountain sickness were prevalent amongst telescope staff. Memory and psychomotor ability deteriorated on initial exposure to high altitude. Altitude-sickness symptoms abated and performance improved after several days on the mountain. Individual workers reacted to the stress of hypoxia in a reproducible manner on each ascent. Episodes of potentially fatal altitude sickness (pulmonary and cerebral edema) were unexpectedly rare. Provision for immediate descent and awareness of the hazards of hypoxia are the most effective precautions to ensure safe working at high-altitude-based observatories.

  16. Risk Stratification for Athletes and Adventurers in High-Altitude Environments: Recommendations for Preparticipation Evaluation.

    Science.gov (United States)

    Campbell, Aaron D; McIntosh, Scott E; Nyberg, Andy; Powell, Amy P; Schoene, Robert B; Hackett, Peter

    2015-12-01

    High-altitude athletes and adventurers face a number of environmental and medical risks. Clinicians often advise participants or guiding agencies before or during these experiences. Preparticipation evaluation (PPE) has the potential to reduce risk of high-altitude illnesses in athletes and adventurers. Specific conditions susceptible to high-altitude exacerbation also important to evaluate include cardiovascular and lung diseases. Recommendations by which to counsel individuals before participation in altitude sports and adventures are few and of limited focus. We reviewed the literature, collected expert opinion, and augmented principles of a traditional sport PPE to accommodate the high-altitude wilderness athlete/adventurer. We present our findings with specific recommendations on risk stratification during a PPE for the high-altitude athlete/adventurer. Copyright © 2015. Published by Elsevier Inc.

  17. Study of the Army Helicopter Design Hover Criterion Using Temperature and Pressure Altitude

    Science.gov (United States)

    2017-09-01

    Words) Ambient temperature and altitude are used to determine design points for helicopters. In this paper, pressure altitude is used to...Ground Effect; Pressure Altitude, Design Points, ACMES: Advanced Climate Modeling and Environmental Simulations 1. Abstract Ambient temperature and...of ambient air. Both compressibility and air density determine the amount of work that a rotor has to accomplish in order to propel a rotorcraft

  18. Cerebrovascular responses to hypoxia and hypocapnia in Ethiopian high altitude dwellers.

    Science.gov (United States)

    Claydon, Victoria E; Gulli, Giosué; Slessarev, Marat; Appenzeller, Otto; Zenebe, Guta; Gebremedhin, Amha; Hainsworth, Roger

    2008-02-01

    Cerebrovascular responses to hypoxia and hypocapnia in Peruvian altitude dwellers are impaired. This could contribute to the high incidence of altitude-related illness in Andeans. Ethiopian high altitude dwellers may show a different pattern of adaptation to high altitude. We aimed to examine cerebral reactivity to hypoxia and hypocapnia in healthy Ethiopian high altitude dwellers. Responses were compared with our previous data from Peruvians. We studied 9 Ethiopian men at their permanent residence of 3622 m, and one day after descent to 794 m. We continuously recorded cerebral blood flow velocity (CBFV; transcranial Doppler). End-tidal oxygen (P(ET)o(2)) was decreased from 100 mm Hg to 50 mm Hg with end-tidal carbon dioxide (P(ET)co(2)) clamped at the subject's resting level. P(ET)co(2) was then manipulated by voluntary hyper- and hypoventilation, with P(ET)o(2) clamped at 100 mm Hg (normoxia) and 50 mm Hg (hypoxia). During spontaneous breathing, P(ET)co(2) increased after descent, from 38.2+/-1.0 mm Hg to 49.8+/-0.6 mm Hg (Phypoxia at either high (-0.19+/-3.1%) or low (1.1+/-2.9%) altitudes. Cerebrovascular reactivity to normoxic hypocapnia at high and low altitudes was 3.92+/-0.5%.mm Hg(-1) and 3.09+/-0.4%.mm Hg(-1); reactivity to hypoxic hypocapnia was 4.83+/-0.7%.mm Hg(-1) and 2.82+/-0.5%.mm Hg(-1). Responses to hypoxic hypocapnia were significantly smaller at low altitude. The cerebral circulation of Ethiopian high altitude dwellers is insensitive to hypoxia, unlike Peruvian high altitude dwellers. Cerebrovascular responses to P(ET)co(2) were greater in Ethiopians than Peruvians, particularly at high altitude. This, coupled with their high P(ET)co(2) levels, would lead to high cerebral blood flows, and may be advantageous for altitude living.

  19. Design study for remotely piloted, high-altitude airplanes powered by microwave energy

    Science.gov (United States)

    Morris, C. E. K., Jr.

    1983-01-01

    A design study has been conducted for unmanned, microwave-powered airplanes that must fly with long endurance at high altitude. They are proposed to conduct communications-relay, observation, or various scientific missions above approximately 55,000 feet altitude. The special characteristics of the microwave-power system and high-altitude, low-speed vehicle are reviewed. Examples of both sizing and performance analysis are used to suggest design procedure guidelines.

  20. Altitude-Related Change in Endotracheal Tube Cuff Pressures in Helicopter EMS.

    Science.gov (United States)

    Weisberg, Stacy N; McCall, Jonathan C; Tennyson, Joseph

    2017-06-01

    Over-inflation of endotracheal tube (ETT) cuffs has the potential to lead to scarring and stenosis of the trachea.1, 2,3, 4 The air inside an ETT cuff is subject to expansion as atmospheric pressure decreases, as happens with an increase in altitude. Emergency medical services helicopters are not pressurized, thereby providing a good environment for studying the effects of altitude changes ETT cuff pressures. This study aims to explore the relationship between altitude and ETT cuff pressures in a helicopter air-medical transport program. ETT cuffs were initially inflated in a nonstandardized manner and then adjusted to a pressure of 25 cmH 2 O. The pressure was again measured when the helicopter reached maximum altitude. A final pressure was recorded when the helicopter landed at the receiving facility. We enrolled 60 subjects in the study. The mean for initial tube cuff pressures was 70 cmH 2 O. Maximum altitude for the program ranged from 1,000-3,000 feet above sea level, with a change in altitude from 800-2,480 feet. Mean cuff pressure at altitude was 36.52 ± 8.56 cmH 2 O. Despite the significant change in cuff pressure at maximum altitude, there was no relationship found between the maximum altitude and the cuff pressures measured. Our study failed to demonstrate the expected linear relationship between ETT cuff pressures and the maximum altitude achieved during typical air-medical transportation in our system. At altitudes less than 3,000 feet above sea level, the effect of altitude change on ETT pressure is minimal and does not require a change in practice to saline-filled cuffs.

  1. Altitude training: an up-to-date approach and implementation in practice

    OpenAIRE

    Issurin, Vladimir

    2007-01-01

    This article overviews current comprehension of altitude training, which is quite contradictory: many sources declare that altitude training provides no benefits to sea level performances compared to appropriate conventional training while others consider altitude training to be an efficacious and proven tool to enhance high-performance preparation. This contradiction can be partly explained by the variety of individual training responses, i.e., individual predispositions among some athletes ...

  2. Altitude-Related Change in Endotracheal Tube Cuff Pressures in Helicopter EMS

    Directory of Open Access Journals (Sweden)

    Stacy N. Weisberg

    2017-05-01

    Full Text Available Introduction: Over-inflation of endotracheal tube (ETT cuffs has the potential to lead to scarring and stenosis of the trachea. 1, 2, 3, 4 The air inside an ETT cuff is subject to expansion as atmospheric pressure decreases, as happens with an increase in altitude. Emergency medical services helicopters are not pressurized, thereby providing a good environment for studying the effects of altitude changes ETT cuff pressures. This study aims to explore the relationship between altitude and ETT cuff pressures in a helicopter air-medical transport program. Methods: ETT cuffs were initially inflated in a nonstandardized manner and then adjusted to a pressure of 25 cmH 2O. The pressure was again measured when the helicopter reached maximum altitude. A final pressure was recorded when the helicopter landed at the receiving facility. Results: We enrolled 60 subjects in the study. The mean for initial tube cuff pressures was 70 cmH 2O. Maximum altitude for the program ranged from 1,000–3,000 feet above sea level, with a change in altitude from 800–2,480 feet. Mean cuff pressure at altitude was 36.52 ± 8.56 cmH 2O. Despite the significant change in cuff pressure at maximum altitude, there was no relationship found between the maximum altitude and the cuff pressures measured. Conclusion: Our study failed to demonstrate the expected linear relationship between ETT cuff pressures and the maximum altitude achieved during typical air-medical transportation in our system. At altitudes less than 3,000 feet above sea level, the effect of altitude change on ETT pressure is minimal and does not require a change in practice to saline-filled cuffs.

  3. How do diurnal long-distance migrants select flight altitude in relation to wind?

    OpenAIRE

    María Mateos-Rodríguez; Felix Liechti

    2012-01-01

    To save energy and time, migratory birds are expected to select time periods and flight altitudes with favorable wind conditions. In spring 2006, we studied diurnal migration using tracking radar at the Strait of Messina. A total of 1530 radar tracks were analyzed with respect to flight altitude and wind conditions. The tracks included Honey Buzzards, Marsh, Montagu's, and Pallid Harriers, Black Kites, falcons, swallows, swifts, and herons. Maximum flight altitude recorded was 2495 m above gr...

  4. Nutritional Strategies for the Preservation of Fat Free Mass at High Altitude

    Directory of Open Access Journals (Sweden)

    Stacie L. Wing-Gaia

    2014-02-01

    Full Text Available Exposure to extreme altitude presents many physiological challenges. In addition to impaired physical and cognitive function, energy imbalance invariably occurs resulting in weight loss and body composition changes. Weight loss, and in particular, loss of fat free mass, combined with the inherent risks associated with extreme environments presents potential performance, safety, and health risks for those working, recreating, or conducting military operations at extreme altitude. In this review, contributors to muscle wasting at altitude are highlighted with special emphasis on protein turnover. The article will conclude with nutritional strategies that may potentially attenuate loss of fat free mass during high altitude exposure.

  5. The body weight loss during acute exposure to high-altitude hypoxia in sea level residents.

    Science.gov (United States)

    Ge, Ri-Li; Wood, Helen; Yang, Hui-Huang; Liu, Yi-Ning; Wang, Xiu-Juan; Babb, Tony

    2010-12-25

    Weight loss is frequently observed after acute exposure to high altitude. However, the magnitude and rate of weight loss during acute exposure to high altitude has not been clarified in a controlled prospective study. The present study was performed to evaluate weight loss at high altitude. A group of 120 male subjects [aged (32±6) years] who worked on the construction of the Golmud-Lhasa Railway at Kunlun Mountain (altitude of 4 678 m) served as volunteer subjects for this study. Eighty-five workers normally resided at sea level (sea level group) and 35 normally resided at an altitude of 2 200 m (moderate altitude group). Body weight, body mass index (BMI), and waist circumference were measured in all subjects after a 7-day stay at Golmud (altitude of 2 800 m, baseline measurements). Measurements were repeated after 33-day working on Kunlun Mountain. In order to examine the daily rate of weight loss at high altitude, body weight was measured in 20 subjects from the sea level group (sea level subset group) each morning before breakfast for 33 d at Kunlun Mountain. According to guidelines established by the Lake Louise acute mountain sickness (AMS) consensus report, each subject completed an AMS self-report questionnaire two days after arriving at Kunlun Mountain. After 33-day stay at an altitude of 4 678 m, the average weight loss for the sea level group was 10.4% (range 6.5% to 29%), while the average for the moderate altitude group was 2.2% (-2% to 9.1%). The degree of weight loss (Δ weight loss) after a 33-day stay at an altitude of 4 678 m was significantly correlated with baseline body weight in the sea level group (r=0.677, P0.05). In the sea level subset group, a significant weight loss was observed within 20 d, but the weight remained stable thereafter. AMS-score at high altitude was significantly higher in the sea level group (4.69±2.48) than that in the moderate altitude group (2.97±1.38), and was significantly correlated with baseline body weight

  6. Special problems and capabilities of high altitude lighter than air vehicles

    Science.gov (United States)

    Wessel, P. R.; Petrone, F. J.

    1975-01-01

    Powered LTA vehicles have historically been limited to operations at low altitudes. Conditions exist which may enable a remotely piloted unit to be operated at an altitude near 70,000 feet. Such systems will be launched like high altitude balloons, operate like nonrigid airships, and have mission capabilities comparable to a low altitude stationary satellite. The limited lift available and the stratospheric environment impose special requirements on power systems, hull materials and payloads. Potential nonmilitary uses of the vehicle include communications relay, environmental monitoring and ship traffic control.

  7. Sleep disturbance at simulated altitude indicated by stratified respiratory disturbance index but not hypoxic ventilatory response.

    Science.gov (United States)

    Kinsman, Tahnee A; Townsend, Nathan E; Gore, Christopher J; Hahn, Allan G; Clark, Sally A; Aughey, Robert J; McKenna, Michael J; Hawley, John A; Chow, Chin-Moi

    2005-08-01

    At high altitudes, the clinically defined respiratory disturbance index (RDI) and high hypoxic ventilatory response (HVR) have been associated with diminished sleep quality. Increased RDI has also been observed in some athletes sleeping at simulated moderate altitude. In this study, we investigated relationships between the HVR of 14 trained male endurance cyclists with variable RDI and sleep quality responses to simulated moderate altitude. Blood oxygen saturation (SpO2%), heart rate, RDI, arousal rate, awakenings, sleep efficiency, rapid eye movement (REM) sleep, non-REM sleep stages 1, 2 and slow wave sleep as percentages of total sleep time (%TST) were measured for two nights at normoxia of 600 m and one night at a simulated altitude of 2,650 m. HVR and RDI were not significantly correlated with sleep stage, arousal rate or awakening response to nocturnal simulated altitude. SpO2 was inversely correlated with total RDI (r = -0.69, P = 0.004) at simulated altitude and with the change in arousal rate from normoxia (r = -0.65, P = 0.02). REM sleep response to simulated altitude correlated with the change, relative to normoxia, in arousal (r = -0.63, P = 0.04) and heart rate (r = -0.61, P = 0.04). When stratified, those athletes at altitude with RDI >20 h(-1) (n = 4) and those with sleep or arousal increase. However, the stratified RDI provides a basis for determining potential sleep disturbance in athletes at simulated moderate altitude.

  8. Erythropoietin, 2,3 DPG, oxygen transport capacity, and altitude training in adolescent Alpine skiers.

    Science.gov (United States)

    Son, Hee Jeong; Kim, Hyo Jeong; Kim, Jin Hae; Ohno, Hideki; Kim, Chang Keun

    2012-01-01

    Rapid growth during adolescence caused by metabolic changes and their metabolic response to anaerobic and aerobic exercise differs considerably from that in adults and this is especially true in the responses to stresses, such as altitude exposure. However, there is little information on the suitability of exercise training at altitude for young athletes. Six male Korean adolescent alpine skiers (13-17 yr), with a skiing career of 3-5 yr, participated in the study. All subjects were exposed to an altitude of 2700 m (8858 ft) for 5 wk and altitude exposure consisted of 6 d/wk of training (4-5 h/d), with living quarters at 2100 m (-6890 ft) (Tignes, France). The 5 wk of ski training at altitude were maintained at the same level (the same number of slalom and giant slalom skiing trials) as at sea level. There was a significant increase in oxygen transport capacity, despite decreased erythropoietin (EPO) production (-31%) after altitude training. Red blood cell (RBC), hemoglobin (Hb), hematocrit (Hct), and 2,3 DPG concentrations increased significantly during altitude exposure and after return to sea level. Results indicate that applying altitude training in adolescent skiers may improve their endurance performance. However, EPO production during altitude training needs to be evaluated in larger future studies.

  9. Moderate altitude but not additional endurance training increases markers of oxidative stress in exhaled breath condensate.

    Science.gov (United States)

    Heinicke, Ilmar; Boehler, Annette; Rechsteiner, Thomas; Bogdanova, Anna; Jelkmann, Wolfgang; Hofer, Markus; Rawlings, Pablo; Araneda, Oscar F; Behn, Claus; Gassmann, Max; Heinicke, Katja

    2009-07-01

    Oxidative stress occurs at altitude, and physical exertion might enhance this stress. In the present study, we investigated the combined effects of exercise and moderate altitude on redox balance in ten endurance exercising biathletes, and five sedentary volunteers during a 6-week-stay at 2,800 m. As a marker for oxidative stress, hydrogen peroxide (H(2)O(2)) was analyzed by the biosensor measuring system Ecocheck, and 8-iso prostaglandin F2alpha (8-iso PGF2alpha) was determined by enzyme immunoassay in exhaled breath condensate (EBC). To determine the whole blood antioxidative capacity, we measured reduced glutathione (GSH) enzymatically using Ellman's reagent. Exercising athletes and sedentary volunteers showed increased levels of oxidative markers at moderate altitude, contrary to our expectations; there was no difference between both groups. Therefore, all subjects' data were pooled to examine the oxidative stress response exclusively due to altitude exposure. H(2)O(2) levels increased at altitude and remained elevated for 3 days after returning to sea level (p altitude, but declined immediately after returning to sea level (p altitude resulted in elevated GSH levels (p altitude (p altitude for up to 6 weeks increases markers of oxidative stress in EBC independent of additional endurance training. Notably, this oxidative stress is still detectable 3 days upon return to sea level.

  10. High-altitude wind resources in the Middle East

    KAUST Repository

    Yip, Chak Man Andrew

    2017-08-23

    In the Middle East, near-surface wind resources are intermittent. However, high-altitude wind resources are abundant, persistent, and readily available and may provide alternative energy resources in this fossil-fuel-dependent region. Using wind field data from the Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2), this study identifies areas favorable to the deployment of airborne wind energy (AWE) systems in the Middle East and computes the optimal heights at which such systems would best operate. AWE potential is estimated using realistic AWE system specifications and assumptions about deployment scenarios and is compared with the near-surface wind generation potential with respect to diurnal and seasonal variability. The results show the potential utility of AWE in areas in the Middle East where the energy demand is high. In particular, Oman and Saudi Arabia have a high level of the potential power generation with low annual variability.

  11. Impact of target altitude restrictions on laser performance

    Energy Technology Data Exchange (ETDEWEB)

    Canavan, G.H.

    1989-01-01

    This report estimates the impact of Raman restrictions and shielding penalties separately and together. Its goal is an overall assessment of likely impact rather than a review of the details of missile trajectories, Raman physics, and shielding techniques, whose individual treatments matter less than their overall integration. Raman scattering could produce a factor of 2-3 reduction on the performance of repetitive pulse lasers with large fluences in each small pulse. Radio-frequency free-electron lasers (RF FELs), which have more frequent pulses with less energy in each, are impacted less. Shielding gives an independent penalty of about a factor of 2, but the combined effect of altitude and shielding penalizes lasers with large pulses by factors of 3-10. Those factors are significantly larger than any other factors differentiating between the two types of FELs. 8 refs., 2 figs.

  12. The High-Altitude Water Cherenkov Observatory: First Light

    Science.gov (United States)

    Weisgarber, Thomas

    2013-04-01

    The High-Altitude Water Cherenkov (HAWC) Observatory is under construction at Sierra Negra in the state of Puebla in Mexico. Operation began in September 2012, with the first 30 out of the final 300 water Cherenkov detectors deployed and in data acquisition. The HAWC Observatory is designed to record particle air showers from gamma rays and cosmic rays with TeV energies. Though the detector is only 10% complete, HAWC is already the world's largest water Cherenkov detector in the TeV band. In this presentation, I will summarize the performance of the detector to date and discuss preliminary observations of cosmic-ray and gamma-ray sources. I will also describe deployment plans for the remainder of the detector and outline prospects for TeV observations in the coming year.

  13. Human physiology at extreme altitudes on Mount Everest.

    Science.gov (United States)

    West, J B

    1984-02-24

    Extreme altitude presents an enormous physiological challenge to the human body because of severe oxygen deprivation. The American Medical Research Expedition to Everest was specifically designed to study man under these conditions, and successfully obtained physiological data above 8000 meters, including a few measurements on the summit itself. The results show that man can tolerate the extreme hypoxia only by an enormous increase in ventilation, which results in an alveolar partial pressure of carbon dioxide of 7.5 torr on the summit and an arterial pH of over 7.7. Even so, the arterial partial pressure of oxygen is apparently less than 30 torr, and maximum oxygen uptake is about 1 liter per minute. Additional measurements of ventilation, blood physiology, and metabolic and psychometric changes clarified how man responds to this hostile environment.

  14. Helicopter Acoustic Flight Test with Altitude Variation and Maneuvers

    Science.gov (United States)

    Watts, Michael E.; Greenwood, Eric; Sim, Ben; Stephenson, James; Smith, Charles D.

    2016-01-01

    A cooperative flight test campaign between NASA and the U.S. Army was performed from September 2014 to February 2015. The purposes of the testing were to: investigate the effects of altitude variation on noise generation, investigate the effects of gross weight variation on noise generation, establish the statistical variability in acoustic flight testing of helicopters, and characterize the effects of transient maneuvers on radiated noise for a medium-lift utility helicopter. This test was performed at three test sites (0, 4000, and 7000 feet above mean sea level) with two aircraft (AS350 SD1 and EH-60L) tested at each site. This report provides an overview of the test, documents the data acquired and describes the formats of the stored data.

  15. Development of High Altitude UAV Weather Radars for Hurricane Research

    Science.gov (United States)

    Heymsfield, Gerald; Li, Li-Hua

    2005-01-01

    A proposed effort within NASA called (ASHE) over the past few years was aimed at studying the genesis of tropical disturbances off the east coast of Africa. This effort was focused on using an instrumented Global Hawk UAV with high altitude (%Ok ft) and long duration (30 h) capability. While the Global Hawk availability remains uncertain, development of two relevant instruments, a Doppler radar (URAD - UAV Radar) and a backscatter lidar (CPL-UAV - Cloud Physics Lidar), are in progress. The radar to be discussed here is based on two previous high-altitude, autonomously operating radars on the NASA ER-2 aircraft, the ER-2 Doppler Radar (EDOP) at X-band (9.6 GHz), and the Cloud Radar System (CRS) at W- band (94 GHz). The nadir-pointing EDOP and CRS radars profile vertical reflectivity structure and vertical Doppler winds in precipitation and clouds, respectively. EDOP has flown in all of the CAMEX flight series to study hurricanes over storms such as Hurricanes Bonnie, Humberto, Georges, Erin, and TS Chantal. These radars were developed at Goddard over the last decade and have been used for satellite algorithm development and validation (TRMM and Cloudsat), and for hurricane and convective storm research. We describe here the development of URAD that will measure wind and reflectivity in hurricanes and other weather systems from a top down, high-altitude view. URAD for the Global Hawk consists of two subsystems both of which are at X-band (9.3-9.6 GHz) and Doppler: a nadir fixed-beam Doppler radar for vertical motion and precipitation measurement, and a Conical scanning radar for horizontal winds in cloud and at the surface, and precipitation structure. These radars are being designed with size, weight, and power consumption suitable for the Global Hawk and other UAV's. The nadir radar uses a magnetron transmitter and the scanning radar uses a TWT transmitter. With conical scanning of the radar at a 35" incidence angle over an ocean surface in the absence of

  16. Large high altitude air shower observatory (LHAASO) project

    International Nuclear Information System (INIS)

    He Huihai

    2010-01-01

    The Large High Altitude Air Shower Observatory (LHAASO) project focuses mainly on the study of 40 GeV-1 PeV gamma ray astronomy and 10 TeV-1 EeV cosmic ray physics. It consists of a 1 km 2 extensive air shower array with 40 000 m 2 muon detectors, 90,000m 2 water Cerenkov detector array, 5 000 m 2 shower core detector array and an air Cerenkov/fluorescence telescope array. Prototype detectors are designed with some of them already in operation. A prototype array of 1% size of LHAASO will be built at the Yangbajing Cosmic Ray Observatory and used to coincidently measure cosmic rays with the ARGO-YBJ experiment. (authors)

  17. The hydration status of backpackers at high altitude.

    Science.gov (United States)

    Rozier, L H

    1998-01-01

    The purpose of the descriptive study was to determine the hydration status of recreational backpackers (n = 201) hiking at altitudes between 7,500 and 14,000 feet. Urine specific gravity was used to document the level of hydration of each subject entering or leaving the Bridger-Teton Wilderness. Demographic, risk, and knowledge factors were also obtained from the sample. Both pre-hike and post-hike subjects were dehydrated; pre-hike mean specific gravity was 1.018, and the post-hike mean was 1.023, showing a significant difference (t = -4.671, p < 0.0000). A small subset group (n = 10) entered both pre- and post-hike data and the findings were similar to the large group, showing a significant increase in specific gravity post-hike (t = -4.881, p < 0.0009). Interestingly, 24% (n = 130) of the post-hike males presented with hematuria.

  18. Registros de mayor altitud para mosquitos (Diptera: Culicidae en Venezuela

    Directory of Open Access Journals (Sweden)

    Juan-Carlos Navarro

    2010-03-01

    Full Text Available Los mosquitos (Diptera: Culicidae son insectos holometábolos con estadios inmaduros acuáticos que utilizan una amplia variedad de hábitats larvales, desde cuerpos de agua en el suelo hasta Fitotelmata (depósitos de agua en las plantas y depósitos artificiales. La disponibilidad de sitios de reproducción a menudo determina el límite superior del ámbito de los mosquitos. Nosotros construimos una base de datos de 9 607 registros, 432 localidades, 19 géneros y 254 especies. La coordillera Andina posee el 77% de los registros con mayor altitud incluyendo Aedes euris con un registro a 3 300 m, seguido por tres especies de Anopheles -subgénero Kerteszia- con una altitud máxima de 2 680 m. Wyeomyia bicornis y Culex daumastocampa a 2 550 m fueron los registros de mayor altitud en la cordillera Costera- Central, mientras que el record más alto en Pantepui fue Wyeomyia zinzala a 2 252 m. El 60% de los registros de máxima altitud están representados por especies asociadas con fitotelmata (Bromeliaceae y Sarraceniaceae. Los límites superiores de Culex quinquefasciatus y Anopheles (Kerteszia podría representar el límite teórico para la transmisión de filariasis o arbovirus, por Culex y malaria por Anopheles (Kerteszia en Venezuela. Del mismo modo, un vector del dengue, Aedes aegypti, no ha sido registrado por encima de 2 000 m.Highest mosquito records (Diptera: Culicidae in Venezuela. Mosquitoes (Diptera: Culicidae are holometabolous insects with aquatic immature stages, which use a broad variety of larval habitats, from ground water bodies to Phytothelmata (water deposits in plants and artificial deposits. The availability of breeding sites often determines the upper limits of mosquito ranges. We built a database with 9 607 records with 432 localities, 19 genera and 254 species. The Andean mountains have 77% of the highest mosquito records including Aedes euris with record at 3 133 m, followed by three species of Anopheles -subgenera

  19. High-Altitude Platforms - Present Situation and Technology Trends

    Directory of Open Access Journals (Sweden)

    Flavio Araripe D'Oliveira

    2016-07-01

    Full Text Available High-altitude platforms (HAPs are aircraft, usually unmanned airships or airplanes positioned above 20 km, in the stratosphere, in order to compose a telecommunications network or perform remote sensing. In the 1990 and 2000 decades, several projects were launched, but very few had continued. In 2014, 2 major Internet companies (Google and Facebook announced investments in new HAP projects to provide Internet access in regions without communication infrastructure (terrestrial or satellite, bringing back attention to the development of HAP. This article aims to survey the history of HAPs, the current state-of-the-art (April 2016, technology trends and challenges. The main focus of this review will be on technologies directly related to the aerial platform, inserted in the aeronautical engineering field of knowledge, not detailing aspects of the telecommunications area.

  20. Detection of EASs at high altitude with ARGO-YBJ

    International Nuclear Information System (INIS)

    Di Sciascio, Giuseppe

    2017-01-01

    The ARGO-YBJ experiment has been in stable data taking for about 5 years at the YangBaJing Cosmic Ray Observatory (Tibet, P.R. China, 4300 m a.s.l., 606 g/cm 2 ). With a duty-cycle greater than 86% the detector collected about 5×10 11 events in a wide energy range, from few hundreds GeV up to about 10 PeV. Exploiting the full coverage approach with a high segmentation of the readout at high altitude, ARGO-YBJ imaged the front of Extensive Air Showers (EAS) with unprecedented resolution and detail. A number of important problems in galactic cosmic ray physics has been faced through different analyses. In this contribution we summarize the latest results in gamma-ray astronomy and in cosmic ray physics. (paper)

  1. Altitude simulation facility for testing large space motors

    Science.gov (United States)

    Katz, U.; Lustig, J.; Cohen, Y.; Malkin, I.

    1993-02-01

    This work describes the design of an altitude simulation facility for testing the AKM motor installed in the 'Ofeq' satellite launcher. The facility, which is controlled by a computer, consists of a diffuser and a single-stage ejector fed with preheated air. The calculations of performance and dimensions of the gas extraction system were conducted according to a one-dimensional analysis. Tests were carried out on a small-scale model of the facility in order to examine the design concept, then the full-scale facility was constructed and operated. There was good agreement among the results obtained from the small-scale facility, from the full-scale facility, and from calculations.

  2. Anthropometric survey of high-altitude Bolivian porters.

    Science.gov (United States)

    Leatherman, T L; Thomas, R B; Greksa, L P; Haas, J D

    1984-01-01

    This paper presents the results of an anthropometric survey of 138 rural Aymaran high-altitude males who were working as porters in La Paz, Bolivia (3700 m). All subjects were measured for stature, weight, upper arm circumference, and triceps skinfolds. The body size and composition of the porters were then compared to an Aymaran rural population from the Bolivian highlands, and urban mestizo labourers from La Paz. The porters were smaller than the urban sample, but appeared to be generally representative of rural Aymaran natives with respect to body size and composition, and nutritional status. It is suggested that towards one extreme of nutritional variability, some degree of undernutrition may be indicated, which should be considered in future studies of adaptation to hypoxia among these Andean highlanders.

  3. Radiation Physics for Space and High Altitude Air Travel

    Science.gov (United States)

    Cucinotta, F. A.; Wilson, J. W.; Goldhagen, P.; Saganti, P.; Shavers, M. R.; McKay, Gordon A. (Technical Monitor)

    2000-01-01

    Galactic cosmic rays (GCR) are of extra-solar origin consisting of high-energy hydrogen, helium, and heavy ions. The GCR are modified by physical processes as they traverse through the solar system, spacecraft shielding, atmospheres, and tissues producing copious amounts of secondary radiation including fragmentation products, neutrons, mesons, and muons. We discuss physical models and measurements relevant for estimating biological risks in space and high-altitude air travel. Ambient and internal spacecraft computational models for the International Space Station and a Mars mission are discussed. Risk assessment is traditionally based on linear addition of components. We discuss alternative models that include stochastic treatments of columnar damage by heavy ion tracks and multi-cellular damage following nuclear fragmentation in tissue.

  4. Analysis of the low-altitude proton flux asymmetry: methodology

    CERN Document Server

    Kruglanski, M

    1999-01-01

    Existing East-West asymmetry models of the trapped proton fluxes at low altitudes depend on the local magnetic dip angle and a density scale height derived from atmospheric models. We propose an alternative approach which maps the directional flux over a drift shell (B sub m , L) in terms of the local pitch and azimuthal angles alpha and beta, where beta is defined in the local mirror plane as the angle between the proton arrival direction and the surface normal to the drift shell. This approach has the advantage that it only depends on drift shell parameters and does not involve an atmosphere model. A semi-empirical model based on the new methodology is able to reproduce the angular distribution of a set of SAMPEX/PET proton flux measurements. Guidelines are proposed for spacecraft missions and data analysis procedures that are intended to be used for the building of new trapped radiation environment models.

  5. Status of the large high altitude air shower observatory project

    Energy Technology Data Exchange (ETDEWEB)

    Zha, Min, E-mail: zham@ihep.ac.cn [Key Laboratory of Astroparticle and Cosmic Ray, Institute of High Energy Physics, YuQuan Road 19 B, 100049 Beijing (China)

    2012-11-11

    The Large High Altitude Air Shower Observatory (LHAASO) project is a multipurpose project. The main scientific tasks can be summarized as follows: (1) searching for galactic cosmic ray origins through gamma ray source detection above 30 TeV; (2) wide field of view survey for gamma ray sources at energies higher than 100 GeV; (3) energy spectrum measurements for individual cosmic ray species from 30 TeV to 10 PeV. To target above tasks, a complex detector array is designed. This paper describes the progress on the research and development of all kind of detectors. Construction and operation of a prototype detector array at Tibet site with 4300 m a.s.l. are also presented.

  6. Thermoelectric Energy Conversion Technology for High-Altitude Airships

    Science.gov (United States)

    Choi, Sang H.; Elliott, James R.; King, Glen C.; Park, Yeonjoon; Kim, Jae-Woo; Chu, Sang-Hyon

    2011-01-01

    The High Altitude Airship (HAA) has various application potential and mission scenarios that require onboard energy harvesting and power distribution systems. The power technology for HAA maneuverability and mission-oriented applications must come from its surroundings, e.g. solar power. The energy harvesting system considered for HAA is based on the advanced thermoelectric (ATE) materials being developed at NASA Langley Research Center. The materials selected for ATE are silicon germanium (SiGe) and bismuth telluride (Bi2Te3), in multiple layers. The layered structure of the advanced TE materials is specifically engineered to provide maximum efficiency for the corresponding range of operational temperatures. For three layers of the advanced TE materials that operate at high, medium, and low temperatures, correspondingly in a tandem mode, the cascaded efficiency is estimated to be greater than 60 percent.

  7. Maximal exercise at extreme altitudes on Mount Everest.

    Science.gov (United States)

    West, J B; Boyer, S J; Graber, D J; Hackett, P H; Maret, K H; Milledge, J S; Peters, R M; Pizzo, C J; Samaja, M; Sarnquist, F H

    1983-09-01

    Maximal exercise at extreme altitudes was studied during the course of the American Medical Research Expedition to Everest. Measurements were carried out at sea level [inspired O2 partial pressure (PO2) 147 Torr], 6,300 m during air breathing (inspired PO2 64 Torr), 6,300 m during 16% O2 breathing (inspired PO2 49 Torr), and 6,300 m during 14% O2 breathing (inspired PO2 43 Torr). The last PO2 is equivalent to that on the summit of Mt. Everest. All the 6,300 m studies were carried out in a warm well-equipped laboratory on well-acclimatized subjects. Maximal O2 uptake fell dramatically as the inspired PO2 was reduced to very low levels. However, two subjects were able to reach an O2 uptake of 1 l/min at the lowest inspired PO2. Arterial O2 saturations fell markedly and alveolar-arterial PO2 differences increased as the work rate was raised at high altitude, indicating diffusion limitation of O2 transfer. Maximal exercise ventilations exceeded 200 l/min at 6,300 m during air breathing but fell considerably at the lowest values of inspired PO2. Alveolar CO2 partial pressure was reduced to 7-8 Torr in one subject at the lowest inspired PO2, and the same value was obtained from alveolar gas samples taken by him at rest on the summit. The results help to explain how man can reach the highest point on earth while breathing ambient air.

  8. Oxidative stress at high altitude: genotype–phenotype correlations

    Directory of Open Access Journals (Sweden)

    Pandey P

    2014-05-01

    Full Text Available Priyanka Pandey,1,2 MA Qadar Pasha1,2 1CSIR-Institute of Genomics and Integrative Biology, Delhi, India; 2Department of Biotechnology, University of Pune, Ganeshkhind, Pune, India Abstract: It has been well-documented that the hypobaric hypoxic environment at high altitude (HA causes stress to both the permanent residents of HA and the sojourners. This oxidative stress primarily disturbs the oxygen-sensing and vascular homeostasis pathways, thereby upsetting normal human physiology, especially in sojourners. These environmental challenges have caused dynamic evolutionary changes within natives of HA, allowing them to develop adaptive plasticity. This review focuses on the genomic and biochemical features of the molecules involved in the oxygen-sensing and vascular homeostasis pathways with respect to HA pulmonary edema (HAPE and adaptation. We review the role of genetic markers such as HIF-prolyl hydroxylase 2, endothelial PAS domain-containing protein 1, endothelial nitric oxide synthase, endothelin 1, cytochrome b-245 alpha polypeptide, and glutathione S-transferase pi 1, as well as three circulatory biomarkers (nitric oxide, endothelin 1, and 8-iso-prostaglandin F2α, by highlighting approaches such as candidate gene and genome-wide, adopted in deciphering the pathways. A disagreement between the two approaches has also been highlighted. In addition, we discuss that an overrepresentation of wild-type alleles in HA natives and mutant alleles of same polymorphisms in HAPE patients implies that the allelic variants at the same locus are involved in adaptation and HAPE, respectively. Moreover, healthy sojourners present a number of genomic features similar to HA natives, further strengthening the concept of genetic predisposition. A trend in correlation between protective and risk alleles and altered levels of circulatory markers clearly documents the phenomenon of genotype–phenotype correlations. We conclude that the genetic and biochemical

  9. Viticultura tropical a gran altitud. Condiciones y expresiones del terroir

    Directory of Open Access Journals (Sweden)

    Marco Quijano Rico

    2009-10-01

    Full Text Available Nuestro proyecto se inició en 1982 en la Loma de Puntalarga, entre 2500 y2600 metros de altitud, a 5,78 ºN y 72,98 ºW, en la cordillera oriental de los Andes. Las variedades más utilizadas actualmente son Pinot noir, Riesling y cruzamientos de Riesling x Silvaner. Desde 1984 se realizan trabajos de investigación sobre temas pertinentes. La baja latitud, la elevada altitud, el volumen de precipitación relativamente modesto y la transparencia del cielo, determinan el flujo de radiación solar incidente y su composición espectral, así como la amplitud del cambio de temperatura entre el día y la noche y las bajas temperaturas nocturnas, que son los rasgos del clima frío imperante en la región. El comportamiento de las cepas y las características del vino indican que las condiciones climáticas locales, pueden considerarse térmicamente equivalentesa las de ciertos territorios tradicionales renombrados. La coexistencia durante el año de todos los estadios de vegetación de la vid y la producción de vendimias con buen contenido de azúcar y niveles suficientes de acidez, hace posible la elaboración de vinos de calidad sobresaliente, de modo secuencial y continuo.En los viñedos del proyecto, las condiciones climáticas anuales son equivalentesa las otoñales, de maduración de las uvas en regiones septentrionales y australes. Al mismo tiempo, el flujo de radiación solar no sufre cambios notables y es rico en las longitudes de onda del ultravioleta B. Los dos factores pueden marcar las características de las uvas, haciendo parte así del efecto terroir.

  10. Hypoxia symptoms during altitude training in professional Iranian fighter pilots.

    Science.gov (United States)

    Alagha, Babak; AhmadBeygi, Shervin; Ahmadbeigy, Shervin; Moosavi, Seyed Ali Javad; Jalali, Seyed Mahmood

    2012-01-01

    Susceptibility to hypoxia is influenced by a multitude of factors, including fatigue, physical activity, illnesses, ambient temperature, rate of ascent, destination altitude, medications, and alcohol. Anecdotally, several reports have been made regarding changes in the form of hypoxia presentation in Iranian fighter pilots in the absence of these factors. This study focused specifically on the effect of pilot age on susceptibility to hypoxia and its initial presentation. We assumed that a pilot's age may increase his susceptibility to hypoxia and consequently reduce the amount of time it takes for hypoxia to present. Because our literature review did not reveal any previous study addressing the possible relationship between age and susceptibility to hypoxia, the purpose of this study is to address and clarify this relationship. In this retrospective study, we collected information from Iranian fighter pilots (n = 30) through an anonymous questionnaire in 2000. The form of hypoxia presentation of each subject was evaluated during five altitude chamber training (ACT) sessions that were conducted routinely from 1972 to 1984. To enhance the accuracy of the study's results, confounding factors such as prior hypoxia experience in an ACT session have been taken into consideration. The results revealed a statistically significant relationship between age and a change in the form of hypoxia presentation in our subjects. Increased age reduced the amount of time before the first individual hypoxia symptom appeared (P < .000002). Although having previous hypoxia experience may help pilots to recognize their symptoms earlier, its effect was not statistically significant (P < .18). A few changes in the nature of individual symptoms were observed; however, we did not find a meaningful statistical correlation between pilot age and change in the nature of symptoms. Susceptibility ot hypoxia increases with pilot age. Copyright © 2012 Air Medical Journal Associates. Published by

  11. Altitude Training and its Influence on Physical Endurance in Swimmers

    Science.gov (United States)

    Strzała, Marek; Ostrowski, Andrzej; Szyguła, Zbigniew

    2011-01-01

    It is possible to plan an altitude training (AT) period in such a way that the enhanced physical endurance obtained as a result of adaptation to hypoxia will appear and can be used to improve performance in competition. Yet finding rationales for usage of AT in highly trained swimmers is problematic. In practice AT, in its various forms, is still controversial, and an objective review of research concentrating on the advantages and disadvantages of AT has been presented in several scientific publications, including in no small part the observations of swimmers. The aim of this article is to review the various methods and present both the advantageous and unfavourable physiological changes that occur in athletes as a result of AT. Moreover, AT results in the sport of swimming have been collected. They include an approach towards primary models of altitude/hypoxic training: live high + train high, live high + train low, live low + train high, as well as subsequent methods: Intermittent Hypoxic Exposure (IHE) and Intermittent Hypoxic Training (IHT). Apnoea training, which is descended from freediving, is also mentioned, and which can be used with, or as a substitute for, the well-known IHE or IHT methods. In conclusion, swimmers who train using hypoxia may be among the best-trained athletes, and that even a slight improvement in physical endurance might result in the shortening of a swimming time in a given competition, and the achievement of a personal best, which is hard to obtain by normal training methods, when the personal results of the swimmer have reached a plateau. PMID:23486564

  12. The HAMMER: High altitude multiple mission environmental researcher

    Science.gov (United States)

    Hayashi, Darren; Zylla, Cara; Amaro, Ernesto; Colin, Phil; Klause, Thomas; Lopez, Bernardo; Williamson, Danna

    1991-01-01

    At the equator, the ozone layer ranges from 65,000 to 130,000+ feet which is beyond the capabilities of the ER-2, NASA's current high altitude reconnaissance aircraft. The Universities Space Research Association, in cooperation with NASA, is sponsoring an undergraduate program which is geared to designing an aircraft that can study the ozone layer at the equator. This aircraft must be able to satisfy four mission profiles. Mission one is a polar mission which ranges from Chile to the South Pole and back to Chile, a total range of 6000 n. mi. at 100,000 feet with a 2500 lb. payload. The second mission is also a polar mission with a decreased altitude of 70,000 feet and an increased payload of 4000 lb. For the third mission, the aircraft will take-off at NASA Ames, cruise at 100,000 feet carrying a 2500 lb. payload, and land in Puerto Montt, Chile. The final mission requires the aircraft to take-off at NASA Ames, cruise at 100,000 feet with a 1000 lb. payload, make an excursion to 120,000 feet, and land at Howard AFB, Panama. All three missions require that a subsonic Mach number is maintained due to constraints imposed by the air sampling equipment. The aircraft need not be manned for all four missions. Three aircraft configurations were determined to be the most suitable for meeting the above requirements. The performance of each configuration is analyzed to investigate the feasibility of the project requirements. In the event that a requirement can not be obtained within the given constraints, recommendations for proposal modifications are given.

  13. Effect of simulated high-altitude hypoxia on Porphyromonas gingivalis

    Directory of Open Access Journals (Sweden)

    Jing-jing HUANG

    2012-04-01

    Full Text Available Objective To investigate the effects of simulated high-altitude hypoxia on the detection rate and endotoxin level of Porphyromonas gingivalis (Pg of subgingival bacterial plagues in rabbit periodontitis models. Methods Forty male rabbits were randomly divided into four groups, namely, normoxia control group (group A1, normoxia experimental group (group A2, hypoxia control group (group B1, and hypoxia experimental group (group B2. Each group included 10 rabbits. Periodontitis models was established in groups A2 and B2 combined by ligating both lower central incisors with steel ligature and feeding periodontitis diets, and then the animals were housed in a hypoxia chamber (simulating 5000m altitude, 23h per day. Groups A1 and A2 were raised normal diet in normoxia environment. After eight weeks, the rabbit periodontitis model was evaluated by observing radiographic features of the X-ray films and histopathologic changes under a light microscope. Subgingival plague sample from periodontal pockets on both lower central incisors were collected for isolation, culture and identification of Pg, and for detection of the endotoxin level. Results The histopathologic observation and X-ray examination results showed that the periodontitis of rabbits in group B2 was significantly more severe than that in group A2. The detection rates of Pg in group A1, A2, B1 and B2 was 0%, 50%, 55% and 95% (P < 0.05. Pg detection rate and endotoxin level were higher in group B2 (95%, 0.46±0.04EU/ml than in group A2 (50%, 0.38±0.02EU/ml, P < 0.05. Conclusions The process speed and damage degree of periodontitis in hypoxic environment is higher than that in normoxic environment. Moreover, the hypoxic environment is more suitable in the colonization of Pg with higher endotoxin level in subgingival plague.

  14. Low-altitude ion heating with downflowing and upflowing ions

    Science.gov (United States)

    Shen, Y.; Knudsen, D. J.; Burchill, J. K.; Howarth, A. D.; Yau, A. W.; James, G.; Miles, D.; Cogger, L. L.; Perry, G. W.

    2017-12-01

    Mechanisms that energize ions at the initial stage of ion upflow are still not well understood. We statistically investigate ionospheric ion energization and field-aligned motion at very low altitudes (330-730 km) using simultaneous plasma, magnetic field, wave electric field and optical data from the e-POP satellite. The high-time-resolution (10 ms) dataset enables us to study the micro-structures of ion heating and field-aligned ion motion. The ion temperature and field-aligned bulk flow velocity are derived from 2-D ion distribution functions measured by the SEI instrument. From March 2015 to March 2016, we've found 17 orbits (in total 24 ion heating periods) with clear ion heating signatures passing across the dayside cleft or the nightside auroral regions. Most of these events have consistent ion heating and flow velocity characteristics observed from both the SEI and IRM instruments. The perpendicular ion temperature goes up to 4.5 eV within a 2 km-wide region in some cases, in which the Radio Receiver Instrument (RRI) sees broadband extremely low frequency (BBELF) waves, demonstrating significant wave-ion heating down to as low as 350 km. The e-POP Fast Auroral Imager (FAI) and Magnetic Field (MGF) instruments show that many events are associated with active aurora and are within downward current regions. Contrary to what would be expected from mirror-force acceleration of heated ions, the majority of these heating events (17 out of 24) are associated with the core ion downflow rather than upflow. These statistical results provide us with new sights into ion heating and field-aligned flow processes at very low altitudes.

  15. Computer vision techniques for rotorcraft low altitude flight

    Science.gov (United States)

    Sridhar, Banavar

    1990-01-01

    Rotorcraft operating in high-threat environments fly close to the earth's surface to utilize surrounding terrain, vegetation, or manmade objects to minimize the risk of being detected by an enemy. Increasing levels of concealment are achieved by adopting different tactics during low-altitude flight. Rotorcraft employ three tactics during low-altitude flight: low-level, contour, and nap-of-the-earth (NOE). The key feature distinguishing the NOE mode from the other two modes is that the whole rotorcraft, including the main rotor, is below tree-top whenever possible. This leads to the use of lateral maneuvers for avoiding obstacles, which in fact constitutes the means for concealment. The piloting of the rotorcraft is at best a very demanding task and the pilot will need help from onboard automation tools in order to devote more time to mission-related activities. The development of an automation tool which has the potential to detect obstacles in the rotorcraft flight path, warn the crew, and interact with the guidance system to avoid detected obstacles, presents challenging problems. Research is described which applies techniques from computer vision to automation of rotorcraft navigtion. The effort emphasizes the development of a methodology for detecting the ranges to obstacles in the region of interest based on the maximum utilization of passive sensors. The range map derived from the obstacle-detection approach can be used as obstacle data for the obstacle avoidance in an automatic guidance system and as advisory display to the pilot. The lack of suitable flight imagery data presents a problem in the verification of concepts for obstacle detection. This problem is being addressed by the development of an adequate flight database and by preprocessing of currently available flight imagery. The presentation concludes with some comments on future work and how research in this area relates to the guidance of other autonomous vehicles.

  16. ATR, Radiation Transport Models in Atmosphere at Various Altitudes

    International Nuclear Information System (INIS)

    1981-01-01

    1 - Description of problem or function: ATR is a user-oriented code for calculating quickly and simply radiation environment problems at all altitudes in the atmosphere. The code is based on parametric models of a comprehensive data base of air transport results which were generated using discrete ordinates transport techniques for infinite homogeneous air. The effects of air-ground interface and non-uniform air density are treated as perturbation corrections on homogeneous air results. ATR includes parametric models for neutrons and secondary gamma rays as a function of space, energy and source- target angle out to angles of 550 g/cm 2 of air. ATR contains parameterizations of infinite medium air transport of neutrons and secondary gamma rays and correction factors for the air-ground interface and high altitude exponential air. It responds to a series of user-oriented commands which specify the source, geometry and print options to output a variety of useful air transport information, including energy-angle dependent fluence, dose, current, and isodose ranges. 2 - Method of solution: The version 3 differs from earlier versions in that version 3 contains the parameterization of the new neutron and secondary gamma rays data base that was calculated using the latest DNA approved cross sections for air. Other improvements to the ATR code include: parameterization and inclusion into ATR of new air- over-ground correction factors, low energy x-rays calculations, new fission source, and new convenience options. 3 - Restrictions on the complexity of the problem: ATR takes approximately 36,000 decimal words of storage. This can be lessened by overlaying different parts of the code

  17. Snow sublimation on a high-altitude Himalayan glacier

    Science.gov (United States)

    Stigter, E.; Litt, M.; Steiner, J. F.; Bonekamp, P. N. J.; Bierkens, M. F.; Shea, J.; Immerzeel, W. W.

    2017-12-01

    Snow sublimation is a loss of water from a snowpack to the atmosphere due to direct phase transition of snow to water vapour. Conditions at high elevations in the Himalaya favour sublimation, i.e. low atmospheric pressure, high wind speed, dry air and high incoming solar radiation. Snow sublimation is a potential important component of the high-altitude water and glacier mass balance, but measurements are non-existent in the Himalaya and models generally ignore this process. Hence, we measured surface latent heat fluxes with an eddy covariance system on Yala Glacier (5350 m a.s.l) in the Nepalese Himalaya to quantify the role snow sublimation plays in the water budget. A one-month data set from October to November 2016 reveals that cumulative sublimation is substantial relative to the dry season precipitation (31 mm for a 32-day period). Sublimation parameterizations of different complexity were subsequently tested against our field measurements to quantify sublimation patterns in space and over longer periods based on nominal meteorological measurements. Results show that a multiple linear regression on wind speed and humidity performed best and this is used to simulate snow sublimation spatially distributed on Yala Glacier for the winter season 2016-2017. Averaged over an entire winter and over the entire glacier surface, sublimation plays a crucial role in the high altitude water balance and in the mass balance of glaciers. Future research should focus on quantifying the role of sublimation at the catchment scale, the development of larger scale parametrizations and efficient measurement strategies to validate the results.

  18. Patterns of genetic variation across altitude in three plant species of semi-dry grasslands.

    Directory of Open Access Journals (Sweden)

    Thomas Hahn

    Full Text Available Environmental gradients caused by altitudinal gradients may affect genetic variation within and among plant populations and inbreeding within populations. Populations in the upper range periphery of a species may be important source populations for range shifts to higher altitude in response to climate change. In this study we investigate patterns of population genetic variation at upper peripheral and lower more central altitudes in three common plant species of semi-dry grasslands in montane landscapes.In Briza media, Trifolium montanum and Ranunculus bulbosus genetic diversity, inbreeding and genetic relatedness of individuals within populations and genetic differentiation among populations was characterized using AFLP markers. Populations were sampled in the Swiss Alps at 1800 (upper periphery of the study organisms and at 1200 m a.s.l. Genetic diversity was not affected by altitude and only in B. media inbreeding was greater at higher altitudes. Genetic differentiation was slightly greater among populations at higher altitudes in B. media and individuals within populations were more related to each other compared to individuals in lower altitude populations. A similar but less strong pattern of differentiation and relatedness was observed in T. montanum, while in R. bulbosus there was no effect of altitude. Estimations of population size and isolation of populations were similar, both at higher and lower altitudes.Our results suggest that altitude does not affect genetic diversity in the grassland species under study. Genetic differentiation of populations increased only slightly at higher elevation, probably due to extensive (historic gene flow among altitudes. Potentially pre-adapted genes might therefore spread easily across altitudes. Our study indicates that populations at the upper periphery are not genetically depauperate or isolated and thus may be important source populations for migration under climate change.

  19. A brief introduction to high altitude nuclear explosion and a review on high altitude nuclear tests of usa and former USSR

    International Nuclear Information System (INIS)

    Sun Jingwen

    1999-11-01

    The author briefly introduces some knowledge about high altitude nuclear explosion (HANE) and presents a general review on high altitude nuclear tests of USA and former USSR. Physical phenomenon generated by HANE is given. The effects of HANE on space flyer, artificial satellite and communication are discussed. Some aspects of a mechanism of antimissile for HANE are described and the effect and role of HANE for USA and USSR are reviewed

  20. Pre-Altitude Serum Ferritin Levels and Daily Oral Iron Supplement Dose Mediate Iron Parameter and Hemoglobin Mass Responses to Altitude Exposure.

    Directory of Open Access Journals (Sweden)

    Andrew D Govus

    Full Text Available To investigate the influence of daily oral iron supplementation on changes in hemoglobin mass (Hbmass and iron parameters after 2-4 weeks of moderate altitude exposure.Hematological data collected from 178 athletes (98 males, 80 females exposed to moderate altitude (1,350-3,000 m were analysed using linear regression to determine how altitude exposure combined with oral iron supplementation influenced Hbmass, total iron incorporation (TII and blood iron parameters [ferritin and transferrin saturation (TSAT].Altitude exposure (mean ± s: 21 ± 3 days increased Hbmass by 1.1% [-0.4, 2.6], 3.3% [1.7, 4.8], and 4.0% [2.0, 6.1] from pre-altitude levels in athletes who ingested nil, 105 mg and 210 mg respectively, of oral iron supplement daily. Serum ferritin levels decreased by -33.2% [-46.9, -15.9] and 13.8% [-32.2, 9.7] from pre-altitude levels in athletes who supplemented with nil and 105 mg of oral iron supplement daily, but increased by 36.8% [1.3, 84.8] in athletes supplemented with 210 mg of oral iron daily. Finally, athletes who ingested either 105 mg or 210 mg of oral iron supplement daily had a greater TII compared with non-supplemented athletes (0 versus 105 mg: effect size (d = -1.88 [-2.56, -1.17]; 0 versus 210 mg: effect size (d = -2.87 [-3.88, -1.66].Oral iron supplementation during 2-4 weeks of moderate altitude exposure may enhance Hbmass production and assist the maintenance of iron balance in some athletes with low pre-altitude iron stores.

  1. Acúmulo de nutrientes em frutos de cafeeiro em duas altitudes de cultivo: micronutrientes Nutrient accumulation in coffee fruits at two at two plantation altitudes: micronutrients

    Directory of Open Access Journals (Sweden)

    Bruno Galvêas Laviola

    2007-12-01

    Full Text Available Dado à importância de se conhecer a exportação de micronutrientes pelos frutos, bem como, as épocas em que são mais demandados pelo cafeeiro, estudou-se o acúmulo de B, Cu, Fe, Mn e Zn em frutos de Coffea arabica L da antese à maturação, em lavouras estabelecidas em duas altitudes. Estudou-se também a variação no teor desses elementos. Estudou-se o acúmulo de B, Cu, Fe, Mn e Zn em frutos de cafeeiro arábico da antese à maturação em duas altitudes, bem como a variação na concentração dos elementos em folhas dos ramos produtivos. O experimento foi constituído da variedade de cafeeiro (Coffea arabica L. Catuaí IAC 44 cultivada a 720 e 950 m de altitude, no município de Martins Soares-MG. O delineamento experimental foi inteiramente ao acaso, com três repetições, usando um esquema de parcela subdividida no tempo. O aumento da altitude influenciou o ciclo reprodutivo do cafeeiro, demandando maior tempo para formação dos frutos. O consumo de nutrientes pelos frutos, assim como o enchimento de grãos, foi mais crítico em condições de menor altitude, já que a planta necessitou completar esses processos em menor espaço de tempo. No estádio de expansão rápida, a percentagem de acúmulo de micronutrientes foi maior na altitude de 720 m, comparada à de 950 m. De modo geral, a altitude influenciou a variação das concentrações foliares de nutrientes, apesar de não se ter observado resposta-padrão da concentração foliar ao aumento da altitude. Conclui-se que a altitude teve influência na extensão do ciclo, bem como no acúmulo de micronutrientes em frutos e na variação, das concentrações foliares destes elementos em folhas de cafeeiro.In view of the importance of knowing fruit micronutrients export from the soil, and the season in which its coffee-plant demand is higher, the accumulation of B, Cu, Fe, Mn and Zn in fruits as well as the variation in the leaf content of the elements in productive branches of

  2. The influence of weather on the flight altitude of nocturnal migrants in mid-latitudes

    NARCIS (Netherlands)

    Kemp, M.U.; Shamoun-Baranes, J.; Dokter, A.M.; van Loon, E.; Bouten, W.

    2013-01-01

    By altering its flight altitude, a bird can change the atmospheric conditions it experiences during migration. Although many factors may influence a bird's choice of altitude, wind is generally accepted as being the most influential. However, the influence of wind is not clearly understood,

  3. Syndrome of Acute Anxiety Among Marines After Recent Arrival at High Altitude

    Science.gov (United States)

    2014-05-01

    initial presentation. Case 4 A male Marine in his late teens was brought to the BAS from a higher altitude because of cotnplaints of acute chest pain...there was no traditional altitude-associated cerebral symptomatology. Upon reporting suicidal ideation and an inability to contract for safety, and

  4. 75 FR 6319 - Proposed Amendment of Low Altitude Area Navigation Route T-254; Houston, TX

    Science.gov (United States)

    2010-02-09

    ... Amendment of Low Altitude Area Navigation Route T-254; Houston, TX AGENCY: Federal Aviation Administration... altitude Area Navigation (RNAV) route T-254 in the Houston, TX, terminal area by eliminating the segment... safety and the efficient use of the navigable airspace in the Houston, TX, terminal area. DATES: Comments...

  5. Update in the understanding of altitude-induced limitations to performance in team-sport athletes.

    Science.gov (United States)

    Billaut, François; Aughey, Robert J

    2013-12-01

    The internationalism of field-based team sports (TS) such as football and rugby requires teams to compete in tournaments held at low to moderate altitude (∼1200-2500 m). In TS, acceleration, speed and aerobic endurance are physical characteristics associated with ball possession and, ultimately, scoring. While these qualities are affected by the development of neuromuscular fatigue at sea level, arterial hypoxaemia induced by exposure to altitude may further hinder the capacity to perform consecutive accelerations (CAC) or sprint endurance and thereby change the outcome of a match. The higher the altitude, the more severe the hypoxaemia, and thus, the larger the expected decline in aerobic endurance, CAC and match running performance. Therefore, it is critical for athletes and coaches to understand how arterial hypoxaemia affects aerobic endurance and CAC and the magnitude of decline they may face at altitude for optimal preparation and increased chances of success. This mini review summarises the effects of acute altitude/hypoxia exposure on aerobic endurance, CAC and activity profiles of TS athletes performing in the laboratory and during matches at natural altitude, and analyses the latest findings about the consequences of arterial hypoxaemia on the relationship between peripheral perturbations, neural adjustments and performance during repeated sprints or CAC. Finally, we briefly discuss how altitude training can potentially help athletes prepare for competition at altitude.

  6. Are UK commercial expeditions complying with wilderness medical society guidelines on ascent rates to altitude?

    Science.gov (United States)

    Shah, Neeraj M; Windsor, Jeremy S; Meijer, Heleen; Hillebrandt, David

    2011-01-01

    The incidence of acute mountain sickness can be reduced by ascending slowly to altitude. We compared a recommended ascent rate with those offered by commercial companies to three of the most popular high-altitude destinations in the world. While the majority complied with the recommended ascent rate, ascents on Kilimanjaro did not. © 2011 International Society of Travel Medicine.

  7. Altitude ammonia-oxidizing bacteria and archaea in soils of Mount Everest.

    Science.gov (United States)

    Zhang, Li-Mei; Wang, Mu; Prosser, James I; Zheng, Yuan-Ming; He, Ji-Zheng

    2009-11-01

    To determine the abundance and distribution of bacterial and archaeal ammonia oxidizers in alpine and permafrost soils, 12 soils at altitudes of 4000-6550 m above sea level (m a.s.l.) were collected from the northern slope of the Mount Everest (Tibetan Plateau), where the permanent snow line is at 5800-6000 m a.s.l. Communities were characterized by real-time PCR and clone sequencing by targeting on amoA genes, which putatively encode ammonia monooxygenase subunit A. Archaeal amoA abundance was greater than bacterial amoA abundance in lower altitude soils (or=5700 m a.s.l.). Both archaeal and bacterial amoA abundance decreased abruptly in higher altitude soils. Communities shifted from a Nitrosospira amoA cluster 3a-dominated ammonia-oxidizing bacteria community in lower altitude soils to communities dominated by a newly designated Nitrosospira ME and cluster 2-related groups and Nitrosomonas cluster 6 in higher altitude soils. All archaeal amoA sequences fell within soil and sediment clusters, and the proportions of the major archaeal amoA clusters changed between the lower altitude and the higher altitude soils. These findings imply that the shift in the relative abundance and community structure of archaeal and bacterial ammonia oxidizers may result from selection of organisms adapted to altitude-dependent environmental factors in elevated soils.

  8. Physiological Changes to the Cardiovascular System at High Altitude and Its Effects on Cardiovascular Disease.

    Science.gov (United States)

    Riley, Callum James; Gavin, Matthew

    2017-06-01

    Riley, Callum James, and Matthew Gavin. Physiological changes to the cardiovascular system at high altitude and its effects on cardiovascular disease. High Alt Med Biol. 18:102-113, 2017.-The physiological changes to the cardiovascular system in response to the high altitude environment are well understood. More recently, we have begun to understand how these changes may affect and cause detriment to cardiovascular disease. In addition to this, the increasing availability of altitude simulation has dramatically improved our understanding of the physiology of high altitude. This has allowed further study on the effect of altitude in those with cardiovascular disease in a safe and controlled environment as well as in healthy individuals. Using a thorough PubMed search, this review aims to integrate recent advances in cardiovascular physiology at altitude with previous understanding, as well as its potential implications on cardiovascular disease. Altogether, it was found that the changes at altitude to cardiovascular physiology are profound enough to have a noteworthy effect on many forms of cardiovascular disease. While often asymptomatic, there is some risk in high altitude exposure for individuals with certain cardiovascular diseases. Although controlled research in patients with cardiovascular disease was largely lacking, meaning firm conclusions cannot be drawn, these risks should be a consideration to both the individual and their physician.

  9. Cosmic Rays with Portable Geiger Counters: From Sea Level to Airplane Cruise Altitudes

    Science.gov (United States)

    Blanco, Francesco; La Rocca, Paola; Riggi, Francesco

    2009-01-01

    Cosmic ray count rates with a set of portable Geiger counters were measured at different altitudes on the way to a mountain top and aboard an aircraft, between sea level and cruise altitude. Basic measurements may constitute an educational activity even with high school teams. For the understanding of the results obtained, simulations of extensive…

  10. User’s Manual For SHARC-4 The Strategic High-Altitude Radiance Code

    Science.gov (United States)

    1997-03-31

    The Strategic High-Altitude Radiance Code, SHARC -4, calculates atmospheric radiance and transmission over a 1 - 40 micrometers spectral region for...the dominant sources at these altitudes. This fourth release of SHARC has been upgraded to model atmospheric structure due to stochastic processes

  11. Study on Oxygen Supply Standard for Physical Health of Construction Personnel of High-Altitude Tunnels

    Directory of Open Access Journals (Sweden)

    Chun Guo

    2015-12-01

    Full Text Available The low atmospheric pressure and low oxygen content in high-altitude environment have great impacts on the functions of human body. Especially for the personnel engaged in complicated physical labor such as tunnel construction, high altitude can cause a series of adverse physiological reactions, which may result in multiple high-altitude diseases and even death in severe cases. Artificial oxygen supply is required to ensure health and safety of construction personnel in hypoxic environments. However, there are no provisions for oxygen supply standard for tunnel construction personnel in high-altitude areas in current tunnel construction specifications. As a result, this paper has theoretically studied the impacts of high-altitude environment on human bodies, analyzed the relationship between labor intensity and oxygen consumption in high-altitude areas and determined the critical oxygen-supply altitude values for tunnel construction based on two different standard evaluation systems, i.e., variation of air density and equivalent PIO2. In addition, it has finally determined the oxygen supply standard for construction personnel in high-altitude areas based on the relationship between construction labor intensity and oxygen consumption.

  12. Effects of Intermittent Altitude Exposures on Acclimatization of 4,300 M

    National Research Council Canada - National Science Library

    Beidleman, Beth

    2001-01-01

    This study examined the effects of 3 wk of intermittent exposures (4 h/d, 5 d/wk) to 4,300 m altitude-equivalent, in combination with either passive sitting or exercise training, on the process of altitude acclimatization...

  13. Metabolic Effects of High Altitude Trekking in Patients With Type 2 Diabetes

    NARCIS (Netherlands)

    de Mol, Pieter; Fokkert, Marion J.; de Vries, Suzanna T.; de Koning, Eelco J. P.; Dikkeschei, Bert D.; Gans, Rijnold O. B.; Tack, Cees J.; Bilo, Henk J. G.

    2012-01-01

    OBJECTIVE-Limited information is available regarding the metabolic effects of high altitude trekking in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS-Thirteen individuals with type 2 diabetes took part, in a 12-day expedition to the summit of Mount Toubkal (altitude, 4,167 m), Morocco,

  14. Effects of repetitive training at low altitude on erythropoiesis in 400 and 800 m runners.

    Science.gov (United States)

    Frese, F; Friedmann-Bette, B

    2010-06-01

    Classical altitude training can cause an increase in total hemoglobin mass (THM) if a minimum "dose of hypoxia" is reached (altitude >or=2,000 m, >or=3 weeks). We wanted to find out if repetitive exposure to mild hypoxia during living and training at low altitude (training camps at low altitude interspersed by 3 weeks of sea-level training and at the same time points in a control group (CG) of 5 well-trained runners. EPO, sTfR and ferritin were also repeatedly measured during the altitude training camps. Repeated measures ANOVA revealed significant increases in EPO- and sTfR-levels during both training camps and a significant decrease in ferritin indicating enhanced erythropoietic stimulation during living and training at low altitude. Furthermore, significant augmentation of THM by 5.1% occurred in the course of the 2 altitude training camps. In conclusion, repetitive living and training at low altitude leads to a hypoxia-induced increase in erythropoietic stimulation in elite 400 m and 800 m runners and, apparently, might also cause a consecutive augmentation of THM.

  15. Metabolic effects of high altitude trekking in patients with type 2 diabetes

    NARCIS (Netherlands)

    Mol, P. de; Fokkert, M.J.; Vries, S.T. de; Koning, E.J. de; Dikkeschei, B.D.; Gans, R.O.; Tack, C.J.J.; Bilo, H.J.

    2012-01-01

    OBJECTIVE Limited information is available regarding the metabolic effects of high altitude trekking in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS Thirteen individuals with type 2 diabetes took part in a 12-day expedition to the summit of Mount Toubkal (altitude, 4,167 m), Morocco,

  16. Threshold altitude for bubble decay and stabilization in rat adipose tissue at hypobaric exposures

    DEFF Research Database (Denmark)

    Randsoe, Thomas; Larsen, Ole Hyldegaard

    2013-01-01

    Bubble formation during altitude exposures, causing altitude decompression sickness (aDCS), has been referred to in theoretical models as venous gas embolisms (VGE). This has also been demonstrated by intravascular gas formation. Previous reports indicate that the formation of VGE and aDCS incide...

  17. Ice Crystal Icing Engine Testing in the NASA Glenn Research Center's Propulsion Systems Laboratory: Altitude Investigation

    Science.gov (United States)

    Oliver, Michael J.

    2014-01-01

    The National Aeronautics and Space Administration (NASA) conducted a full scale ice crystal icing turbofan engine test using an obsolete Allied Signal ALF502-R5 engine in the Propulsion Systems Laboratory (PSL) at NASA Glenn Research Center. The test article used was the exact engine that experienced a loss of power event after the ingestion of ice crystals while operating at high altitude during a 1997 Honeywell flight test campaign investigating the turbofan engine ice crystal icing phenomena. The test plan included test points conducted at the known flight test campaign field event pressure altitude and at various pressure altitudes ranging from low to high throughout the engine operating envelope. The test article experienced a loss of power event at each of the altitudes tested. For each pressure altitude test point conducted the ambient static temperature was predicted using a NASA engine icing risk computer model for the given ambient static pressure while maintaining the engine speed.

  18. High-altitude mountaineering and brain function: neuropsychological testing of members of a Mount Everest expedition.

    Science.gov (United States)

    Jason, G W; Pajurkova, E M; Lee, R G

    1989-02-01

    Concern has been raised regarding the possibility that hypoxic conditions encountered during high-altitude mountaineering may have lasting harmful effects on the human brain. Members of an expedition to Mount Everest completed a series of neuropsychological tests before and after the expedition. Exposure to altitudes above 7,200 m was limited to a maximum of four consecutive nights, separated by rest periods at lower altitudes. No significant decline in performance was observed on any test. The subjects also completed a short series of tests at different altitudes during the expedition. No significant deterioration was observed at altitudes up to 7,500 m. There do not appear to be lasting harmful effects on brain function under these conditions.

  19. Usefulness of training camps at high altitude for well-trained adolescents

    Directory of Open Access Journals (Sweden)

    Jiří Suchý

    2015-03-01

    Full Text Available Objective: Opinions on the suitability of sports training at altitudes of 1800-2200 m above sea level (ASL for increasing performance in youth are not unanimous. The objective of this study was to test the influence of a ten day altitude training camp on performance in well-trained adolescent cross-country skiers. Methods: A running test of 3 × 2 km (aerobic, anaerobic and critical intensity was used with a rest interval of 10 minutes. The test was performed 4 times - an initial test at a lowland (900 m ASL prior to departure for altitude, two tests at altitude (1850 m ASL, a final test ten days after returning to lower altitudes. The aerobic, anaerobic and critical load intensities were set by graded a load test. For all individual tests, the participants maintained the same heart rate individually defined for the various segments using a heart rate monitor. Changes in speed between the tests were compared. The body's internal response was also monitored by the concentration of lactate (2 and 8 minutes after each exertion. Participants: Well-trained adolescent cross-country skiers (N = 11, age: 14.4 ± 1.2 years, weight: 54.4 ± 8.6 kg, height: 170 ± 7 cm, fat: 13 ± 2.6%. Results: The average times attained in the first altitude test for aerobic and anaerobic load were higher (p < .05 than in the entry test at low altitude. In the second altitude test the average times for all intensities were significantly (p < .05 higher than in the first altitude test. In the tests after returning to the lower altitudes the times attained for all intensities were on average higher than at altitude. The average lactate concentration levels following the various intensities were similar (p > .05. The dynamics of the cool-down monitored via the lactate value at the eighth minute after completing the relevant segment showed that at altitude the adolescents cooled down significantly (p < .05 slower rate following the aerobic and anaerobic intensity than at

  20. A 45-year-old man with excessive daytime somnolence, and witnessed apnea at altitude

    Directory of Open Access Journals (Sweden)

    Welsh CH

    2011-04-01

    Full Text Available A sleepy man without sleep apnea at 1609m (5280 feet had disturbed sleep at his home altitude of 3200m (10500 feet. In addition to common disruptors of sleep such as psychophysiologic insomnia, restless leg syndrome, alcohol and excessive caffeine use, central sleep apnea with periodic breathing can be a significant cause of disturbed sleep at altitude. In symptomatic patients living at altitude, a sleep study at their home altitude should be considered to accurately diagnose the presence and magnitude of sleep disordered breathing as sleep studies performed at lower altitudes may miss this diagnosis. Treatments options differ from those to treat obstructive apnea. Supplemental oxygen is considered by many to be first-line therapy.

  1. Effect of Altitude and Aspect on Wood-Water Relations of Beech (Fagus orientalis Lipsky. Wood

    Directory of Open Access Journals (Sweden)

    Elif Topaloğlu

    2013-11-01

    Full Text Available Effects of altitude and aspect on wood-water relations in Oriental beech (Fagus orientalis Lipsky. were studied. Study area divided into five altitude steps and two aspect groups, total of 20 trees were cut off. In order to determine the wood-water relations; volume density value, fiber saturation point, maximum moisture content, and shrinkage and swelling percentages were determined. According to results, with 95% significance level (p<0,05, altitude affects volume density value, shrinkage and swelling percentages, fiber saturation point and maximum moisture content; aspect affects volume density value, tangential and radial shrinkage percentages, volumetric shrinkage percentage, tangential and longitudinal swelling percentages, fiber saturation point and maximum moisture content while it has no effect on longitudinal shrinkage percentage, radial and volumetric swelling percentages. Results demonstrated that northern aspect and first altitude step has the lowest values, thus, this aspect and altitude step making a suitable place for this tree species to be used as solid wood.

  2. Effect of egg composition and oxidoreductase on adaptation of Tibetan chicken to high altitude.

    Science.gov (United States)

    Jia, C L; He, L J; Li, P C; Liu, H Y; Wei, Z H

    2016-07-01

    Tibetan chickens have good adaptation to hypoxic conditions, which can be reflected by higher hatchability than lowland breeds when incubated at high altitude. The objective of this trial was to study changes in egg composition and metabolism with regards the adaptation of Tibetan chickens to high altitude. We measured the dry weight of chicken embryos, egg yolk, and egg albumen, and the activity of lactate dehydrogenase (LDH) and succinic dehydrogenase (SDH) in breast muscle, heart, and liver from embryos of Tibetan chicken and Dwarf chicken (lowland breed) incubated at high (2,900 m) and low (100 m) altitude. We found that growth of chicken embryos was restricted at high altitude, especially for Dwarf chicken embryos. In Tibetan chicken, the egg weight was lighter, but the dry weight of egg yolk was heavier than that of Dwarf chicken. The LDH activities of the three tissues from the high altitude groups were respectively higher than those of the lowland groups from d 15 to hatching, except for breast muscle of Tibetan chicken embryos on d 15. In addition, under the high altitude environment, the heart tissue from Tibetan chicken had lower LDH activity than that from Dwarf chicken at d 15 and 18. The lactic acid content of blood from Tibetan chicken embryos was lower than that of Dwarf chicken at d 12 and 15 of incubation at high altitude. There was no difference in SDH activity in the three tissues between the high altitude groups and the lowland groups except in three tissues of hatchlings and at d 15 of incubation in breast muscle, nor between the two breeds at high altitude except in the heart of hatchlings. Consequently, the adaptation of Tibetan chicken to high altitude may be associated with higher quantities of yolk in the egg and a low metabolic oxygen demand in tissue, which illuminate the reasons that the Tibetan chicken have higher hatchability with lower oxygen transport ability. © 2016 Poultry Science Association Inc.

  3. High Altitude Emissions of Black Carbon Aerosols: Potential Climate Implications

    Science.gov (United States)

    Satheesh, S. K.

    2017-12-01

    Synthesizing a series of ground-based and airborne measurements of aerosols over the Indian region during summer and pre-monsoon seasons have revealed the persistence of elevated absorbing aerosol layers over most of the Indian region; more than 50% of which located above clouds. Subsequent, in situ measurements of black carbon (BC) using high-altitude balloons, showed surprising layers with high concentrations in the middle and upper troposphere even at an altitude of 8 to 10 kms. Simultaneous measurements of the vertical thermal structure have shown localized warming due to BC absorption leading to large reduction in lapse rate and sharp temperature inversion, which in turn increases the atmospheric stability. This aerosol-induced stable layer is conducive for maintaining the black carbon layer longer at that level, leading thereby to further solar absorption and subsequently triggering dry convection. These observations support the `solar escalator' concept through which absorption-warming-convection cycles lead to self-lifting of BC to upper troposphere or even to lower stratosphere under favorable conditions in a matter of a few days. Employing an on-line regional chemistry transport model (WRF-Chem), incorporating aircraft emissions, it is shown that emissions from high-flying aircrafts as the most likely source of these elevated black carbon layers. These in-situ injected particles, produce significant warming of the thin air in those heights and lift these layers to even upper tropospheric/lower stratospheric heights, aided by the strong monsoonal convection occurring over the region, which are known to overshoot the tropical tropopause leading to injection of tropospheric air mass (along with its constituent aerosols) into the stratosphere, especially during monsoon season when the tropical tropopause layer is known to be thinnest. These simulations are further supported by the CALIPSO space-borne LIDAR derived extinction coefficient profiles. Based on

  4. Certification and safety aspects relating to the transport of passengers on high altitude balloons in Europe

    Science.gov (United States)

    Schoenmaker, Annelie

    2014-07-01

    High-altitude balloons typically fly between 25 and 50 km in altitude, which, while below the Karman line of 100 km, is yet far above the altitudes typically flown by aircraft. For example, the highest-flying commercial aircraft - the Concorde - had a maximum cruising altitude of only 18 km. zero2infinity, a Spanish company, is currently developing a pressurized pod named “bloon” which will be capable of lifting six people, including two pilot crew members and four paying passengers, to an altitude of 36 km through the use of high-altitude balloons. The boundary between Airspace and Outer Space has never been legally defined, mostly because of the lack of activities taking place between the altitude where airplanes fly and the lowest orbiting spacecraft. High-altitude balloons do fly at these in-between altitudes and the prospect of commercializing access to these parts of the stratosphere poses some questions in a new light. Given the relatively low altitude at which they fly, it may well be that these types of balloons would be considered to operate exclusively within air space. However, given the technology involved in crewed high altitude balloon flights, which is more similar to spacecraft engineering than to traditional hot-air or gas ballooning, it is necessary to evaluate the various legal regimes, codes, and regulations that would apply to such flights, especially regarding licenses and liabilities. For high altitude balloon flights commencing in Europe, the European Aviation Safety Agency (EASA) would very likely be the competent certification or licensing agency for these flights, although there would likely be input from various national aviation authorities as well. However, because the European Commission (EC) has not yet issued regulations regarding commercial spaceflight, particularly the use of high altitude balloons, new rules and regulations governing such flights may still need to be drafted and promulgated. With the development of

  5. Temporal and spatial changes in Western Himalayan firn line altitudes from 1998 to 2009

    Science.gov (United States)

    Guo, Zhongming; Wang, Ninglian; Kehrwald, Natalie M.; Mao, Ruijuan; Wu, Hongbo; Wu, Yuwei; Jiang, Xi

    2014-07-01

    Understanding changes in glacier mass balance is important because it is indicative of changes in climate and the hydrologic cycle. The latter also has particular influence on people living near glaciers and/or glacier-fed rivers. The Western Himalayas remain one of the regions where recent changes in glacier mass balance are not well-known. The temporal and spatial changes in firn line altitudes are an indicator of equilibrium line altitudes and thus reflect changes in glacier mass balance. Here, we use Himalayan Landsat TM/ETM + data in July and August (the late summer melt season) to quantify changes in firn line altitudes from 1998 to 2009. We produced reflectance maps through radiometric calibration and atmospheric correction and use topographic correction to remove or reduce terrain or shadow effects. The real ‘surface albedo’ is obtained by narrowband-to-broadband (NTB) albedo conversion from the combined solar radiation. The firn line altitude was then extracted by combining the ‘surface albedo’ with pre-registered digital elevation model. The individual firn line altitude varies by region. The Western Himalayas display the largest range of firn line variability, where the firn line altitudes vary from 4840 m a.s.l. to 5770 m a.s.l. The individual glacier mean firn line altitude from 1998 to 2009 rose from 5072 ± 77 m a.s.l. to 5640 ± 74 m a.s.l. in the Western Himalayas. The mean firn line altitude increased from 1998 to 2009. The lowest mean recorded firn line altitude recorded was 5237 ± 166 m a.s.l. in 1998, whereas the highest was 5397 ± 135 m a.s.l. in 2000. We also observed a difference between the changes in fine line altitudes of northern and southern slopes of the western Himalayans, as the northern slope glaciers display a greater increase in firn line altitudes than the southern slope glaciers. In the southern slope, changes in firn line altitudes correlate with NCDC-NOAA temperature and precipitation data. This sustained increase of

  6. Hematocrit and Hemoglobin Levels of Nonhuman Apes at Moderate Altitudes: A Comparison with Humans.

    Science.gov (United States)

    Mortola, Jacopo P; Wilfong, DeeAnn

    2016-12-01

    Mortola, Jacopo P. and DeeAnn Wilfong. Hematocrit and hemoglobin levels of nonhuman apes at moderate altitudes: a comparison with humans. High Alt Med Biol. 17:323-335, 2016.-We asked to what extent the hematologic response (increase in hematocrit [Hct] and in blood hemoglobin concentration [Hb]) of humans to altitude hypoxia was shared by our closest relatives, the nonhuman apes. Data were collected from 29 specimens of 7 species of apes at 2073 m altitude (barometric pressure Pb = 598 mm Hg); additional data originated from apes located at a lower altitude (1493 m, Pb = 639 mm Hg). The human altitude profiles of Hct and Hb between sea level and 3000 m were constructed from a compilation of literature sources that (all combined) comprised data sets of 10,000-12,000 subjects for each gender. These human data were binned for 0-250 m altitude (sea level) and for each 500 m of progressively higher altitudes. Values of Hb and Hct of both men and women were significantly higher than at sea level at the 1500 bin (1250-1750 m); hence, the altitude threshold for the human hematological responses must be between 1000 and 1500 m. In the nonhuman apes, no increase in Hct or Hb was apparent at 1500 m; at 2000 m, the increase was significant only for the Hb of females. At either altitude in the group of nonhuman apes, the increase in Hct was much less than in humans, and that of Hb was significantly less at 1500 m. We conclude that lack of, or minimal, hematopoietic response to moderate altitude can occur in mammalian species that are not genetically adapted to high altitudes. Polycythemia is not a common response to altitude hypoxia and, at least at moderate altitudes, the degree of the human response may represent the exception among apes rather than the rule.

  7. Increasing arboreality with altitude: a novel biogeographic dimension.

    Science.gov (United States)

    Scheffers, Brett R; Phillips, Ben L; Laurance, William F; Sodhi, Navjot S; Diesmos, Arvin; Williams, Stephen E

    2013-11-07

    Biodiversity is spatially organized by climatic gradients across elevation and latitude. But do other gradients exist that might drive biogeographic patterns? Here, we show that rainforest's vertical strata provide climatic gradients much steeper than those offered by elevation and latitude, and biodiversity of arboreal species is organized along this gradient. In Philippine and Singaporean rainforests, we demonstrate that rainforest frogs tend to shift up in the rainforest strata as altitude increases. Moreover, a Philippine-wide dataset of frog distributions shows that frog assemblages become increasingly arboreal at higher elevations. Thus, increased arboreality with elevation at broad biogeographic scales mirrors patterns we observed at local scales. Our proposed 'arboreality hypothesis' suggests that the ability to exploit arboreal habitats confers the potential for larger geographical distributions because species can shift their location in the rainforest strata to compensate for shifts in temperature associated with elevation and latitude. This novel finding may help explain patterns of species richness and abundance wherever vegetation produces a vertical microclimatic gradient. Our results further suggest that global warming will 'flatten' the biodiversity in rainforests by pushing arboreal species towards the cooler and wetter ground. This 'flattening' could potentially have serious impacts on forest functioning and species survival.

  8. Adaptation of an epilithic ecosystem to harsh high altitude environment

    Science.gov (United States)

    de La Torre Noetzel, R.; Horneck, G.; García Sancho, L.; Scherer, K.; Facius, R.; Urlings, T.; Rettberg, P.; Reina, M.; Pintado, A.

    2003-04-01

    Epilithic ecosystems in high mountains are exposed to an extreme microclimate characterized by intense solar UV radiation, high temperature fluctuations and high aridity. Using the epilithic ecosystem Rhizocarpon geographicum, the most abundant lichen at the Plataforma de Gredos (Sierra de Gredos, Central Spain, 1.895 m a.s.l.) as model system, we have investigated whether the cortex protects the photobiont against impacts by this extreme environment. The UV radiation climate was measured optoelectronically as well by use of the biological dosimeter DLR-Biofilm, and the microclimate (temperature, relative humidity, PAR) by a microclimatic station (Squirrel, U.K.). The photosynthetic activity of the lichens was periodically determined by use of a photosynthesis yield analyser MINI PAM. Using lichen samples with- and without cortex during different periods of a growing season, showed a substantial protection by the cortex against environmental stress conditions, especially at summer solstice. Solar UV radiation and desiccation exerted the most damaging effects in lichens without cortex. Because of the high resistance of the intact lichen against the harsh high altitude climate, R. geographicum has been selected as test system for survival studies in space to be performed during the upcoming BIOPAN mission of ESA.

  9. UAV Low Altitude Photogrammetry for Power Line Inspection

    Directory of Open Access Journals (Sweden)

    Yong Zhang

    2017-01-01

    Full Text Available When the distance between an obstacle and a power line is less than the discharge distance, a discharge arc can be generated, resulting in the interruption of power supplies. Therefore, regular safety inspections are necessary to ensure the safe operation of power grids. Tall vegetation and buildings are the key factors threatening the safe operation of extra high voltage transmission lines within a power line corridor. Manual or laser intensity direction and ranging (LiDAR based inspections are time consuming and expensive. To make safety inspections more efficient and flexible, a low-altitude unmanned aerial vehicle (UAV remote-sensing platform, equipped with an optical digital camera, was used to inspect power line corridors. We propose a semi-patch matching algorithm based on epipolar constraints, using both the correlation coefficient (CC and the shape of its curve to extract three dimensional (3D point clouds for a power line corridor. We use a stereo image pair from inter-strip to improve power line measurement accuracy by transforming the power line direction to an approximately perpendicular to epipolar line. The distance between the power lines and the 3D point cloud is taken as a criterion for locating obstacles within the power line corridor automatically. Experimental results show that our proposed method is a reliable, cost effective, and applicable way for practical power line inspection and can locate obstacles within the power line corridor with accuracy better than ±0.5 m.

  10. Nationwide network of total solar eclipse high altitude balloon flights

    Science.gov (United States)

    Des Jardins, A. C.

    2017-12-01

    Three years ago we envisioned tapping into the strength of the National Space Grant Program to make the most of a rare astronomical event to engage the general public through education and to create meaningful long-lasting partnerships with other private and public entities. We believe strongly in giving student participants career-making opportunities through the use of the most cutting edge tools, resources, and communication. The NASA Space Grant network was in a unique position to engage the public in the eclipse in an awe-inspiring and educational way at a surprisingly small cost. In addition to public engagement, the multidisciplinary project presented an in-depth hands-on learning opportunity for the thousands of student participants. The project used a network of high altitude ballooning teams positioned along the path of totality from Oregon to South Carolina to conduct coordinated collaborative activities during the eclipse. These activities included 1) capturing and streaming live video of the eclipse from near space, 2) partnering with NASA Ames on a space biology experiment, and 3) conducting high-resolution atmospheric radiosonde measurements. This presentation will summarize the challenges, results, lessons learned, and professional evaluation from developing, training, and coordinating the collaboration. Details of the live streaming HD video and radiosonde activities are described in separate submissions to this session.

  11. Fog Chemistry at Different Altitudes in the Swiss Alps

    Science.gov (United States)

    Michna, P.; Eugster, W.; Wanner, H.

    2010-07-01

    During two extended summer seasons in 2006 and 2007, we installed two battery driven versions of the Caltech active strand cloud water collector (MiniCASCC) at the Niesen mountain in the northern Swiss Alps. Along, we measured air temperature, relative humidity, wind, and visibility. During these two field operation phases we gained weekly samples of fogwater, where we analysed the major anions and cations, and the stable water isotopes δD and δ18O. The fog collectors were installed at an altitude of 2300 and 1600 m asl to resolve altitudinal differences in fog chemistry. We found a large variability between the events, but no clear altitudinal gradient. At both sites, the most important ions were nitrate, ammonium, and sulphate. Higher concentrations occured preferably in late spring (start of sampling period) and in autumn (end of sampling). Compared to previous studies at lower elevations in the Swiss Plateau during wintertime, our measurements showed considerable lower ion loads in the fogwater. The combination of these results suggest that lowest ion loads are found in convective clouds with a short lifetime and that the highest ion loads occur during radiation fog events at lower elevations.

  12. Safely Enabling Civilian Unmanned Aerial System (UAS) Operations in Low-Altitude Airspace by Unmanned Aerial System Traffic Management (UTM)

    Science.gov (United States)

    Kopardekar, Parimal Hemchandra

    2015-01-01

    Many UAS will operate at lower altitude (Class G, below 2000 feet). There is an urgent need for a system for civilian low-altitude airspace and UAS operations. Stakeholders want to work with NASA to enable safe operations.

  13. HURRICANE AND SEVERE STORM SENTINEL (HS3) HIGH-ALTITUDE IMAGING WIND AND RAIN AIRBORNE PROFILER (HIWRAP) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Hurricane and Severe Storm Sentinel (HS3) High-Altitude Imaging Wind and Rain dataset was collected from the High-altitude Imaging Wind and Rain Airborne...

  14. GPM GROUND VALIDATION HIGH ALTITUDE IMAGING WIND AND RAIN AIRBORNE PROFILER (HIWRAP) MC3E V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation High Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) MC3E dataset was collected by the High-Altitude Imaging Wind and Rain...

  15. ROCK2 and MYLK variants under hypobaric hypoxic environment of high altitude associate with high altitude pulmonary edema and adaptation

    Directory of Open Access Journals (Sweden)

    Pandey P

    2015-11-01

    Full Text Available Priyanka Pandey,1,2 Ghulam Mohammad,1,3 Yogendra Singh,1,2 MA Qadar Pasha1,2 1Functional Genomics Unit, CSIR-Institute of Genomics and Integrative Biology, Delhi, 2Department of Biotechnology, University of Pune, Ganeshkhind, Pune, Maharashtra, 3Department of Medicine, SNM Hospital, Leh, Ladakh, Jammu and Kashmir, IndiaObjective: To date, a major class of kinases, serine–threonine kinase, has been scantly investigated in stress-induced rare, fatal (if not treated early, and morbid disorder, high altitude pulmonary edema (HAPE. This study examined three major serine–threonine kinases, ROCK2, MYLK, and JNK1, along with six other genes, tyrosine hydroxylase, G-protein subunits GNA11 and GNB3, and alpha1 adrenergic receptor isoforms 1A, 1B, and 1D as candidate gene markers of HAPE and adaptation.Methods: For this, 57 variants across these nine genes were genotyped in HAPE patients (n=225, HAPE controls (n=210, and highlanders (n=259 by Sequenom MS (TOF-based MassARRAY® platform using iPLEX™ Gold technology. In addition, to study the gene expression, quantitative real-time polymerase chain reaction was performed in human peripheral blood mononuclear cells of the three study groups.Results: A significant association was observed for C allele (ROCK2 single-nucleotide polymorphism, rs10929728 with HAPE (P=0.03 and C, T, and A alleles (MYLK single-nucleotide polymorphisms, rs11717814, rs40305, and rs820336 with both HAPE and adaptation (P=0.001, P=0.006, and P=0.02, respectively. ROCK2 88 kb GGGTTGGT haplotype was associated with lower risk of HAPE (P=0.0009. MYLK 7 kb haplotype CTA, composed of variant alleles, was associated with higher risk of HAPE (P=0.0006 and lower association with adaptation (P=1E–06, whereas haplotype GCG, composed of wild-type alleles, was associated with lower risk of HAPE (P=0.001 and higher association with adaptation (P=1E–06. Haplotype–haplotype and gene–gene interactions demonstrated a correlation in working

  16. Variability of Diurnal Temperature Range During Winter Over Western Himalaya: Range- and Altitude-Wise Study

    Science.gov (United States)

    Shekhar, M. S.; Devi, Usha; Dash, S. K.; Singh, G. P.; Singh, Amreek

    2018-04-01

    The current trends in diurnal temperature range, maximum temperature, minimum temperature, mean temperature, and sun shine hours over different ranges and altitudes of Western Himalaya during winter have been studied. Analysis of 25 years of data shows an increasing trend in diurnal temperature range over all the ranges and altitudes of Western Himalaya during winter, thereby confirming regional warming of the region due to present climate change and global warming. Statistical studies show significant increasing trend in maximum temperature over all the ranges and altitudes of Western Himalaya. Minimum temperature shows significant decreasing trend over Pir Panjal and Shamshawari range and significant increasing trend over higher altitude of Western Himalaya. Similarly, sunshine hours show significant decreasing trend over Karakoram range. There exists strong positive correlation between diurnal temperature range and maximum temperature for all the ranges and altitudes of Western Himalaya. Strong negative correlation exists between diurnal temperature range and minimum temperature over Shamshawari and Great Himalaya range and lower altitude of Western Himalaya. Sunshine hours show strong positive correlation with diurnal temperature range over Pir Panjal and Great Himalaya range and lower and higher altitudes.

  17. Exploring the Limits of High Altitude GPS for Future Lunar Missions

    Science.gov (United States)

    Ashman, Benjamin W.; Parker, Joel J. K.; Bauer, Frank H.; Esswein, Michael

    2018-01-01

    An increasing number of spacecraft are relying on the Global Positioning System (GPS) for navigation at altitudes near or above the GPS constellation itself - the region known as the Space Service Volume (SSV). While the formal definition of the SSV ends at geostationary altitude, the practical limit of high-altitude space usage is not known, and recent missions have demonstrated that signal availability is sufficient for operational navigation at altitudes halfway to the moon. This paper presents simulation results based on a high-fidelity model of the GPS constellation, calibrated and validated through comparisons of simulated GPS signal availability and strength with flight data from recent high-altitude missions including the Geostationary Operational Environmental Satellite 16 (GOES-16) and the Magnetospheric Multiscale (MMS) mission. This improved model is applied to the transfer to a lunar near-rectilinear halo orbit (NRHO) of the class being considered for the international Deep Space Gateway concept. The number of GPS signals visible and their received signal strengths are presented as a function of receiver altitude in order to explore the practical upper limit of high-altitude space usage of GPS.

  18. High altitude-related hypertensive crisis and acute kidney injury in an asymptomatic healthy individual.

    Science.gov (United States)

    Gilbert-Kawai, Edward; Martin, Daniel; Grocott, Michael; Levett, Denny

    2016-01-01

    High-altitude exposure causes a mild to moderate rise in systolic and diastolic blood pressure. This case report describes the first documented case of a hypertensive crisis at altitude, as well as the first report of the occurrence of acute kidney injury in the context of altitude-related hypertension. A healthy, previously normotensive 30-year old, embarked on a trek to Everest Base Camp (5300 m). During his 11-day ascent the subject developed increasingly worsening hypertension. In the absence of symptoms, the individual initially elected to remain at altitude as had previously been the plan. However, an increase in the severity of his hypertension to a peak of 223/119 mmHg resulted in a decision to descend. On descent he was found to have an acute kidney injury that subsequently resolved spontaneously. His blood pressure reverted to normal at sea level and subsequent investigations including a transthoracic echocardiogram, cardiac magnetic resonance imaging, renal ultrasound, and urinary catecholamines were normal. This report challenges the view that transient rises in blood pressure at altitude are without immediate risk. We review the evidence that altitude induces hypertension and discuss the implications for the management of hypertension at altitude.

  19. Lipid Profiles, Glycated Hemoglobin, and Diabetes in People Living at High Altitude in Nepal.

    Science.gov (United States)

    Aryal, Nirmal; Weatherall, Mark; Bhatta, Yadav Kumar Deo; Mann, Stewart

    2017-09-10

    This study aimed to describe lipid profiles and the distribution of glycated hemoglobin (HbA1c) in a sample of a high altitude population of Nepal and to explore associations between these metabolic risk variables and altitude. A cross-sectional survey of cardiovascular disease and associated risk factors was conducted among 521 people living at four different altitude levels, all above 2800 m, in the Mustang and Humla districts of Nepal. Urban participants (residents at 2800 m and 3620 m) had higher total cholesterol (TC) and triglyceride (TG) than rural participants. A high ratio of TC to high-density lipoprotein-cholesterol (HDL) (TC/HDL ≥ 5.0) was found in 23.7% (95% CI 19.6, 28.2) and high TG (≥1.7 mmol/L) in 43.3% (95% CI 38.4, 48.3) of participants overall. Mean HbA1c levels were similar at all altitude levels although urban participants had a higher prevalence of diabetes. Overall, 6.9% (95% CI 4.7, 9.8) of participants had diabetes or were on hypoglycaemic treatment. There was no clear association between lipid profiles or HbA1c and altitude in a multivariate analysis adjusted for possible confounding variables. Residential settings and associated lifestyle practices are more strongly associated with lipid profiles and HbA1c than altitude amongst high altitude residents in Nepal.

  20. Altitude training for elite endurance athletes: A review for the travel medicine practitioner.

    Science.gov (United States)

    Flaherty, Gerard; O'Connor, Rory; Johnston, Niall

    2016-01-01

    High altitude training is regarded as an integral component of modern athletic preparation, especially for endurance sports such as middle and long distance running. It has rapidly achieved popularity among elite endurance athletes and their coaches. Increased hypoxic stress at altitude facilitates key physiological adaptations within the athlete, which in turn may lead to improvements in sea-level athletic performance. Despite much research in this area to date, the exact mechanisms which underlie such improvements remain to be fully elucidated. This review describes the current understanding of physiological adaptation to high altitude training and its implications for athletic performance. It also discusses the rationale and main effects of different training models currently employed to maximise performance. Athletes who travel to altitude for training purposes are at risk of suffering the detrimental effects of altitude. Altitude illness, weight loss, immune suppression and sleep disturbance may serve to limit athletic performance. This review provides an overview of potential problems which an athlete may experience at altitude, and offers specific training recommendations so that these detrimental effects are minimised. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Tracking performance with two breathing oxygen concentrations after high altitude rapid decompression

    Science.gov (United States)

    Nesthus, Thomas E.; Schiflett, Samuel G.; Oakley, Carolyn J.

    1992-01-01

    Current military aircraft Liquid Oxygen (LOX) systems supply 99.5 pct. gaseous Aviator's Breathing Oxygen (ABO) to aircrew. Newer Molecular Sieve Oxygen Generation Systems (MSOGS) supply breathing gas concentration of 93 to 95 pct. O2. The margin is compared of hypoxia protection afforded by ABO and MSOGS breathing gas after a 5 psi differential rapid decompression (RD) in a hypobaric research chamber. The barometric pressures equivalent to the altitudes of 46000, 52000, 56000, and 60000 ft were achieved from respective base altitudes in 1 to 1.5 s decompressions. During each exposure, subjects remained at the simulated peak altitude breathing either 100 or 94 pct. O2 with positive pressure for 60 s, followed by a rapid descent to 40000 ft. Subjects used the Tactical Life Support System (TLSS) for high altitude protection. Subcritical tracking task performance on the Performance Evaluation Device (PED) provided psychomotor test measures. Overall tracking task performance results showed no differences between the MSOGS breathing O2 concentration of 94 pct. and ABO. Significance RMS error differences were found between the ground level and base altitude trials compared to peak altitude trials. The high positive breathing pressures occurring at the peak altitudes explained the differences.

  2. Hemosiderin deposition in the brain as footprint of high-altitude cerebral edema.

    Science.gov (United States)

    Schommer, Kai; Kallenberg, Kai; Lutz, Kira; Bärtsch, Peter; Knauth, Michael

    2013-11-12

    Based on recent findings of microhemorrhages (MHs) in the corpus callosum (CC) in 3 individuals after nonfatal high-altitude cerebral edema (HACE), we hypothesized that hemosiderin depositions in the brain after high-altitude exposure are specific for HACE and remain detectable over many years. This was a cross-sectional study involving 37 mountaineers in 4 groups: 10 had experienced HACE, 8 high-altitude pulmonary edema, 11 severe acute mountain sickness, and 8 had climbed to altitudes ≥6,962 m without developing any high-altitude illness. HACE was defined as ataxia necessitating assistance with walking and/or decreased consciousness. Within hemosiderin depositions, which were quantified by a score. Unequivocal MHs located in the splenium of the CC were found in 8 subjects and questionable MHs were found in 2 subjects 1 to 35 months after HACE. They were located outside the CC in 5 more severe cases. MHs remained unchanged in those reexamined after 12 to 50 months. A few unequivocal MHs in the splenium of the CC were found in one subject after severe acute mountain sickness, while one subject with high-altitude pulmonary edema and 2 of the extreme altitude climbers had questionable lesions. In all other subjects, MHs were unequivocally absent. MHs detectable by susceptibility-weighted MRI predominantly in the splenium of the CC are long-lasting footprints of HACE.

  3. Glucose Homeostasis During Short-term and Prolonged Exposure to High Altitudes

    Science.gov (United States)

    Ader, Marilyn; Bergman, Richard N.

    2015-01-01

    Most of the literature related to high altitude medicine is devoted to the short-term effects of high-altitude exposure on human physiology. However, long-term effects of living at high altitudes may be more important in relation to human disease because more than 400 million people worldwide reside above 1500 m. Interestingly, individuals living at higher altitudes have a lower fasting glycemia and better glucose tolerance compared with those who live near sea level. There is also emerging evidence of the lower prevalence of both obesity and diabetes at higher altitudes. The mechanisms underlying improved glucose control at higher altitudes remain unclear. In this review, we present the most current evidence about glucose homeostasis in residents living above 1500 m and discuss possible mechanisms that could explain the lower fasting glycemia and lower prevalence of obesity and diabetes in this population. Understanding the mechanisms that regulate and maintain the lower fasting glycemia in individuals who live at higher altitudes could lead to new therapeutics for impaired glucose homeostasis. PMID:25675133

  4. Altitude effects on growth of indigenous children in Oaxaca, Southern Mexico.

    Science.gov (United States)

    Little, Bertis B; Malina, Robert M; Pena Reyes, Maria Eugenia; Bali Chavez, Guillermo

    2013-09-01

    The effect of altitude of residence on the growth status of 11,454 indigenous school children 6-14 years of age in Oaxaca, southern Mexico, was examined. Indicators of living conditions (human development index [HDI], index of community nutritional risk [INR], index of marginalization [IM], index of relative isolation [II]) were regressed on z-scores for height, weight and BMI, and the residuals were regressed on altitude of residence (km). Independent of other environmental conditions, altitude negatively affected height by approximately -0.07 z-scores per kilometer altitude above sea level. The estimated average decrease in stature was 0.92 cm per kilometer elevation. BMI was significantly increased, 1.2 units per kilometer elevation, consistent with earlier studies of growth status and altitude. In contrast, weight was not affected by altitude of residence. Approximately 36% of the reduction in height and 54% of the increase in BMI were due to altitude effects; the remaining changes in height and BMI were associated with environmental factors reflected in the indices of community well-being considered. Copyright © 2013 Wiley Periodicals, Inc.

  5. Domain specific changes in cognition at high altitude and its correlation with hyperhomocysteinemia.

    Directory of Open Access Journals (Sweden)

    Vijay K Sharma

    Full Text Available Though acute exposure to hypobaric hypoxia is reported to impair cognitive performance, the effects of prolonged exposure on different cognitive domains have been less studied. The present study aimed at investigating the time dependent changes in cognitive performance on prolonged stay at high altitude and its correlation with electroencephalogram (EEG and plasma homocysteine. The study was conducted on 761 male volunteers of 25-35 years age who had never been to high altitude and baseline data pertaining to domain specific cognitive performance, EEG and homocysteine was acquired at altitude ≤240 m mean sea level (MSL. The volunteers were inducted to an altitude of 4200-4600 m MSL and longitudinal follow-ups were conducted at durations of 03, 12 and 18 months. Neuropsychological assessment was performed for mild cognitive impairment (MCI, attention, information processing rate, visuo-spatial cognition and executive functioning. Total homocysteine (tHcy, vitamin B12 and folic acid were estimated. Mini Mental State Examination (MMSE showed temporal increase in the percentage prevalence of MCI from 8.17% on 03 months of stay at high altitude to 18.54% on 18 months of stay. Impairment in visuo-spatial executive, attention, delayed recall and procedural memory related cognitive domains were detected following prolonged stay in high altitude. Increase in alpha wave amplitude in the T3, T4 and C3 regions was observed during the follow-ups which was inversely correlated (r = -0.68 to MMSE scores. The tHcy increased proportionately with duration of stay at high altitude and was correlated with MCI. No change in vitamin B12 and folic acid was observed. Our findings suggest that cognitive impairment is progressively associated with duration of stay at high altitude and is correlated with elevated tHcy in the plasma. Moreover, progressive MCI at high altitude occurs despite acclimatization and is independent of vitamin B12 and folic acid.

  6. Evaluation of transport ventilators at mild simulated altitude: a bench study in a hypobaric chamber.

    Science.gov (United States)

    Boussen, Salah; Coulange, Mathieu; Fournier, Marc; Gainnier, Marc; Michelet, Pierre; Micoli, Christophe; Negrel, Lionel

    2014-08-01

    Previous studies on ventilators used for air transport showed significant effects of altitude, in particular with regard to accuracy of the tidal volume (VT) and breathing frequency. The aim of the study was to evaluate transport ventilators under hypobaric conditions. We conducted a bench study of 6 transport ventilators in a Comex hypobaric chamber to simulate mild altitude (1,500 m [4,920 feet] and 2,500 m [8,200 feet]). The ventilators were connected to a test lung to evaluate their accuracy: (1) to deliver a set VT under normal resistance and compliance conditions at F(IO2) = 0.6 and 1, (2) to establish a set PEEP (0, 5, 10, and 15 cm H2O), and (3) to establish a set inspiratory pressure in pressure controlled mode, (4) at a F(IO2) setting, and (5) and at a frequency setting. Four ventilators kept an average relative error in VT of ventilator was affected by the altitude only at F(IO2) = 1. The Osiris 3 ventilator had > 40% error even at 1,500 m. We found no change in frequency as a function of altitude for any ventilators studied. No clinically important differences were found between all altitudes with the PEEP or inspiratory pressure setting. Although F(IO2) was affected by altitude, the average error did not exceed 11%, and it is unclear whether this fact is an experimental artifact. We have shown that most of the new transport ventilators tested require no setting adjustment at moderate altitude and are as safe at altitude as at sea level under normal respiratory conditions. Older technologies still deliver more volume with altitude in volumetric mode.

  7. Persistent organic pollutants (POPs) as environmental risk factors in remote high-altitude ecosystems.

    Science.gov (United States)

    Kallenborn, Roland

    2006-01-01

    Persistent organic pollutants (POPs), and their transformation products, are the most investigated organic environmental contaminants within the past five decades. Organochlorines have been found in virtually all environmental compartments on the globe. Severe environmental implications have been shown to be associated with the presence of the POP group of contaminants in the environment. However, in the late 1990s, Canadian scientists first pinpointed the implication of POPs for high-altitude environments in a comprehensive way (Blais et al., 1998, Nature 395, 585-588). Under certain meteorological and geographic conditions, high-altitude environments can serve as "cold condensers" for atmospheric POP loadings. Subsequent investigations in high-altitude environments in Asia, Europe, and North and South America have confirmed suspicions that high-altitude mountainous regions have the potential to serve as focus regions for POPs and even for nonpersistent, medium-lived contaminants, such as "currently used pesticides", due to cold condensation and deposition in high altitudes. Although the presence and the altitude-dependent increase of POP levels in mountainous regions are confirmed by many international studies, the ecotoxicological consequences still remain largely unknown. At present, only a few studies have been published describing the biological effects in high-altitude environments due to increased POP exposure. Therefore, in this early stage of the international research effort on the ecotoxicological risk evaluation of persistent contaminants in high-altitude, pristine ecosystems, the present review intends to summarize the current state of research on POPs in high-altitude environments and draw preliminary conclusions on possible consequences of the presence of POPs in mountainous ecosystems based on currently available information from alpine and related Arctic environments.

  8. Iron supplementation at high altitudes induces inflammation and oxidative injury to lung tissues in rats

    Energy Technology Data Exchange (ETDEWEB)

    Salama, Samir A., E-mail: salama.3@buckeyemail.osu.edu [High Altitude Research Center, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); Department of Biochemistry, Faculty of Pharmacy, Al-Azhar University, Cairo 11751 (Egypt); Department of Pharmacology and GTMR Unit, College of Clinical Pharmacy, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); Omar, Hany A. [Department of Pharmacology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514 (Egypt); Maghrabi, Ibrahim A. [Department of Clinical Pharmacy, College of Clinical Pharmacy, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); AlSaeed, Mohammed S. [Department of Surgery, College of Medicine, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); EL-Tarras, Adel E. [High Altitude Research Center, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia)

    2014-01-01

    Exposure to high altitudes is associated with hypoxia and increased vulnerability to oxidative stress. Polycythemia (increased number of circulating erythrocytes) develops to compensate the high altitude associated hypoxia. Iron supplementation is, thus, recommended to meet the demand for the physiological polycythemia. Iron is a major player in redox reactions and may exacerbate the high altitudes-associated oxidative stress. The aim of this study was to explore the potential iron-induced oxidative lung tissue injury in rats at high altitudes (6000 ft above the sea level). Iron supplementation (2 mg elemental iron/kg, once daily for 15 days) induced histopathological changes to lung tissues that include severe congestion, dilatation of the blood vessels, emphysema in the air alveoli, and peribronchial inflammatory cell infiltration. The levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), lipid peroxidation product and protein carbonyl content in lung tissues were significantly elevated. Moreover, the levels of reduced glutathione and total antioxidant capacity were significantly reduced. Co-administration of trolox, a water soluble vitamin E analog (25 mg/kg, once daily for the last 7 days of iron supplementation), alleviated the lung histological impairments, significantly decreased the pro-inflammatory cytokines, and restored the oxidative stress markers. Together, our findings indicate that iron supplementation at high altitudes induces lung tissue injury in rats. This injury could be mediated through excessive production of reactive oxygen species and induction of inflammatory responses. The study highlights the tissue injury induced by iron supplementation at high altitudes and suggests the co-administration of antioxidants such as trolox as protective measures. - Highlights: • Iron supplementation at high altitudes induced lung histological changes in rats. • Iron induced oxidative stress in lung tissues of rats at high altitudes. • Iron

  9. High altitude medicine education in China: exploring a new medical education reform.

    Science.gov (United States)

    Luo, Yongjun; Luo, Rong; Li, Weiming; Huang, Jianjun; Zhou, Qiquan; Gao, Yuqi

    2012-03-01

    China has the largest plateau in the world, which includes the whole of Tibet, part of Qinghai, Xinjiang, Yunnan, and Sichuan. The plateau area is about 257.2×10(4) km(2), which accounts for about 26.8% of the total area of China. According to data collected in 2006, approximately twelve million people were living at high altitudes, between 2200 to 5200 m high, on the Qinghai-Tibetan Plateau. Therefore, there is a need for medical workers who are trained to treat individuals living at high altitudes. To train undergraduates in high altitude medicine, the College of High Altitude Military Medicine was set up at the Third Military Medical University (TMMU) in Chongqing in 1999. This is the only school to teach high altitude medicine in China. Students at TMMU study natural and social sciences, basic medical sciences, clinical medical sciences, and high altitude medicine. In their 5(th) year, students work as interns at the General Hospital of Tibet Military Command in Lhasa for 3 months, where they receive on-site teaching. The method of on-site teaching is an innovative approach for training in high altitude medicine for undergraduates. Three improvements were implemented during the on-site teaching component of the training program: (1) standardization of the learning progress; (2) integration of formal knowledge with clinical experience; and (3) coaching students to develop habits of inquiry and to engage in ongoing self-improvement to set the stage for lifelong learning. Since the establishment of the innovative training methods in 2001, six classes of high altitude medicine undergraduates, who received on-site teaching, have graduated and achieved encouraging results. This evidence shows that on-site teaching needs to be used more widely in high altitude medicine education.

  10. Mechanisms of Memory Dysfunction during High Altitude Hypoxia Training in Military Aircrew.

    Science.gov (United States)

    Nation, Daniel A; Bondi, Mark W; Gayles, Ellis; Delis, Dean C

    2017-01-01

    Cognitive dysfunction from high altitude exposure is a major cause of civilian and military air disasters. Pilot training improves recognition of the early symptoms of altitude exposure so that countermeasures may be taken before loss of consciousness. Little is known regarding the nature of cognitive impairments manifesting within this critical window when life-saving measures may still be taken. Prior studies evaluating cognition during high altitude simulation have predominantly focused on measures of reaction time and other basic attention or motor processes. Memory encoding, retention, and retrieval represent critical cognitive functions that may be vulnerable to acute hypoxic/ischemic events and could play a major role in survival of air emergencies, yet these processes have not been studied in the context of high altitude simulation training. In a series of experiments, military aircrew underwent neuropsychological testing before, during, and after brief (15 min) exposure to high altitude simulation (20,000 ft) in a pressure-controlled chamber. Acute exposure to high altitude simulation caused rapid impairment in learning and memory with relative preservation of basic visual and auditory attention. Memory dysfunction was predominantly characterized by deficiencies in memory encoding, as memory for information learned during high altitude exposure did not improve after washout at sea level. Retrieval and retention of memories learned shortly before altitude exposure were also impaired, suggesting further impairment in memory retention. Deficits in memory encoding and retention are rapidly induced upon exposure to high altitude, an effect that could impact life-saving situational awareness and response. (JINS, 2017, 23, 1-10).

  11. Quantitative changes in the sleep EEG at moderate altitude (1630 m and 2590 m.

    Directory of Open Access Journals (Sweden)

    Katrin Stadelmann

    Full Text Available Previous studies have observed an altitude-dependent increase in central apneas and a shift towards lighter sleep at altitudes >4000 m. Whether altitude-dependent changes in the sleep EEG are also prevalent at moderate altitudes of 1600 m and 2600 m remains largely unknown. Furthermore, the relationship between sleep EEG variables and central apneas and oxygen saturation are of great interest to understand the impact of hypoxia at moderate altitude on sleep.Fourty-four healthy men (mean age 25.0 ± 5.5 years underwent polysomnographic recordings during a baseline night at 490 m and four consecutive nights at 1630 m and 2590 m (two nights each in a randomized cross-over design.Comparison of sleep EEG power density spectra of frontal (F3A2 and central (C3A2 derivations at altitudes compared to baseline revealed that slow-wave activity (SWA, 0.8-4.6 Hz in non-REM sleep was reduced in an altitude-dependent manner (~4% at 1630 m and 15% at 2590 m, while theta activity (4.6-8 Hz was reduced only at the highest altitude (10% at 2590 m. In addition, spindle peak height and frequency showed a modest increase in the second night at 2590 m. SWA and theta activity were also reduced in REM sleep. Correlations between spectral power and central apnea/hypopnea index (AHI, oxygen desaturation index (ODI, and oxygen saturation revealed that distinct frequency bands were correlated with oxygen saturation (6.4-8 Hz and 13-14.4 Hz and breathing variables (AHI, ODI; 0.8-4.6 Hz.The correlation between SWA and AHI/ODI suggests that respiratory disturbances contribute to the reduction in SWA at altitude. Since SWA is a marker of sleep homeostasis, this might be indicative of an inability to efficiently dissipate sleep pressure.

  12. No Change in Running Mechanics With Live High-Train Low Altitude Training in Elite Distance Runners.

    Science.gov (United States)

    Stickford, Abigail S L; Wilhite, Daniel P; Chapman, Robert F

    2017-01-01

    Investigations into ventilatory, metabolic, and hematological changes with altitude training have been completed; however, there is a lack of research exploring potential gait-kinematic changes after altitude training, despite a common complaint of athletes being a lack of leg "turnover" on return from altitude training. To determine if select kinematic variables changed in a group of elite distance runners after 4 wk of altitude training. Six elite male distance runners completed a 28-d altitude-training intervention in Flagstaff, AZ (2150 m), following a modified "live high-train low" model, wherein higherintensity runs were performed at lower altitudes (945-1150 m) and low-intensity sessions were completed at higher altitudes (1950-2850 m). Gait parameters were measured 2-9 d before departure to altitude and 1 to 2 d after returning to sea level at running speeds of 300-360 m/min. No differences were found in ground-contact time, swing time, or stride length or frequency after altitude training (P > .05). Running mechanics are not affected by chronic altitude training in elite distance runners. The data suggest that either chronic training at altitude truly has no effect on running mechanics or completing the live high-train low model of altitude training, where higher-velocity workouts are completed at lower elevations, mitigates any negative mechanical adaptations that may be associated with chronic training at slower speeds.

  13. Cancer protection related to solar ultraviolet radiation, altitude and vitamin D.

    Science.gov (United States)

    Hayes, Daniel P

    2010-10-01

    A whole host of epidemiological studies have reported lower cancer rates and mortality in high-altitude regions. These studies are reviewed and discussed in detail. Evidence for the salutary role of vitamin D in protecting against cancer and other maladies will also be reviewed and discussed. The dependence of vitamin D production on sunlight and its enhancement with altitude will be demonstrated. The hypothesis is advanced and developed that the lower cancer rates observed at high altitudes arise from enhanced sunlight-induced vitamin D production levels. Protective vitamin D mechanisms which support this hypothesis as well as other supportive medical evidence are also presented. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. United States high-altitude test experiences. A review emphasizing the impact on the environment

    International Nuclear Information System (INIS)

    Hoerlin, H.

    1976-06-01

    The US high-altitude nuclear explosions of the 1955-1962 period are listed chronologically; dates, locations, and yields are given. The major physical phases of the interactions of the weapon outputs with the atmosphere are described, such as the formation of fireballs at the low high-altitudes and the partition of energies and their distribution over very large spaces at the higher high-altitudes. The effects of these explosions on the normal activities of populations and the protective measures taken are documented. Many scientific observations, together with their significance and values, are reviewed. 109 refs

  15. Outdoor altitude stabilization of QuadRotor based on type-2 fuzzy and fuzzy PID

    Science.gov (United States)

    Wicaksono, H.; Yusuf, Y. G.; Kristanto, C.; Haryanto, L.

    2017-11-01

    This paper presents a design of altitude stabilization of QuadRotor based on type-2 fuzzy and fuzzy PID. This practical design is implemented outdoor. Barometric and sonar sensor were used in this experiment as an input for the controller YoHe. The throttle signal as a control input was provided by the controller to leveling QuadRotor in particular altitude and known well as altitude stabilization. The parameter of type-2 fuzzy and fuzzy PID was tuned in several heights to get the best control parameter for any height. Type-2 fuzzy produced better result than fuzzy PID but had a slow response in the beginning.

  16. Strategic high-altitude atmospheric radiation code (SHARC) user instructions. Technical report, September 1987-January 1989

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, R.L.; Duff, J.W.; Bernstein, L.S.; Acharya, P.K.; Gruninger, J.H.

    1989-02-03

    This report describes how to implement and use the Strategic High-Altitude Radiance Code (SHARC). SHARC calculates atmospheric radiation for paths from 60 to 300 km altitude in the 2-40 micrometer spectral region. It models radiation due to NLTE (Non-Local Thermodynamic Equilibrium) molecular emissions which are the dominant sources at these altitudes. This initial version of SHARC includes the five strongest IR radiators, CO/sub 2/, NO, O/sub 3/, H/sub 2/O, and CO. The code is available on magnetic tape and can be obtained by written request to AFGL/OPB.

  17. The Strategic High-Altitude Atmospheric Radiation Code (SHARC) user instructions

    Science.gov (United States)

    Sundberg, R. L.; Duff, J. W.; Bernstein, L. S.; Acharya, P. K.; Gruninger, J. H.; Robertson, D. C.

    1989-02-01

    This report describes how to implement and use the Strategic High-Altitude Radiance Code (SHARC). SHARC calculates atmospheric radiation for paths from 60 to 300 km altitude in the 2 to 40 micron spectral region. It models radiation due to NLTE (Non-Local Thermodynamic Equilibrium) molecular emissions which are the dominant sources at these altitudes. This initial version of SHARC includes the five strongest IR radiators, CO2, NO, O3, H2O, and CO. The code is available on magnetic tape and can be obtained by written request to AFGL/OPB.

  18. A Clinician Guide to Altitude Training for Optimal Endurance Exercise Performance at Sea Level.

    Science.gov (United States)

    Constantini, Keren; Wilhite, Daniel P; Chapman, Robert F

    2017-06-01

    Constantini, Keren, Daniel P. Wilhite, and Robert F. Chapman. A clinician guide to altitude training for optimal endurance exercise performance at sea level. High Alt Med Biol. 18:93-101, 2017.-For well over 50 years, endurance athletes have been utilizing altitude training in an effort to enhance performance in sea level competition. This brief review will offer the clinician a series of evidence-based best-practice guidelines on prealtitude and altitude training considerations, which can ultimately maximize performance improvement outcomes.

  19. Iridium: Global OTH data communications for high altitude scientific ballooning

    Science.gov (United States)

    Denney, A.

    While the scientific community is no stranger to embracing commercially available technologies, the growth and availability of truly affordable cutting edge technologies is opening the door to an entirely new means of global communications. For many years high altitude ballooning has provided science an alternative to costly satellite based experimental platforms. As with any project, evolution becomes an integral part of development. Specifically in the NSBF ballooning program, where flight durations have evolved from the earlier days of hours to several weeks and plans are underway to provide missions up to 100 days. Addressing increased flight durations, the harsh operational environment, along with cumbersome and outdated systems used on existing systems, such as the balloon vehicles Support Instrumentation Package (SIP) and ground-based systems, a new Over-The-Horizon (OTH) communications medium is sought. Current OTH equipment planning to be phased-out include: HF commanding systems, ARGOS PTT telemetry downlinks and INMARSAT data terminals. Other aspects up for review in addition to the SIP to utilize this communications medium include pathfinder balloon platforms - thereby, adding commanding abilities and increased data rates, plus providing a package for ultra-small experiments to ride aloft. Existing communication systems employed by the National Scientific Balloon Facility ballooning program have been limited not only by increased cost, slow data rates and "special government use only" services such as TDRSS (Tracking and Data Relay Satellite System), but have had to make special provisions to geographical flight location. Development of the Support Instrumentation Packages whether LDB (Long Duration Balloon), ULDB (Ultra Long Duration Balloon) or conventional ballooning have been plagued by non-standard systems configurations requiring additional support equipment for different regions and missions along with a myriad of backup for redundancy. Several

  20. Hormona de crecimiento en sujetos varones de diferentes altitudes

    Directory of Open Access Journals (Sweden)

    Elydia Mujica

    2010-07-01

    Full Text Available Objetivos: Determinar los niveles de hormona de crecimiento (GH en sujetos varones adultos, a nivel del mar (Lima, 150 msnm y en la altura (Cajamarca: 2 750 msnm; Huancayo: 3 280 msnm; Morococha: 4 540 msnm. Diseño: Estudio descriptivo, observacional, transversal y prospectivo. Lugar: Ciudades de Lima, Cajamarca, Huancayo y Morococha, Perú. Participantes: Adultos varones, nativos de localidades de diferentes altitudes. Intervenciones: Previo consentimiento informado, a 41 adultos varones nativos de su localidad de origen [12 sujetos alnivel del mar (Lima 150 m, 10 sujetos en Cajamarca (2 750 m, 12 sujetos en Huancayo (3 280 m y 7 sujetos en Morococha (4 540 m] se tomó muestras de sangre en ayunas y en condiciones de reposo. Principales medidas de resultados: Niveles sanguíneos de hormona de crecimiento (GH en sangre. Resultados: La edad promedio de los participantes fue 28 años (rango de 20 a 35 años. Los valores promedios de GH encontrados fueron: a 4 540 m, 3,87 ± 0,16 ng/mL; a 3 280 m, 1,31 ± 0,09 ng/mL; a 2 750 m, 0,63 ± 0,08 ng/mL; y a 150 m, 0,54 ± 0,04 ng/mL. Hubo diferencia significativa (p < 0,05 entre los valores de GH encontrados en la altura a 4 540 m y 3 280 m con respecto al nivel del mar 150 m. No se encontró diferencia significativa entre los valores encontrados a 2 750 m con respecto a 150 m. Conclusiones: Los niveles de GH son mayores en los sujetos nativos a 3 280 m (Huancayo, n=12 y 4 540 m (Morococha, n=7 respecto a los sujetos que viven a 150 m (Lima, n=12.

  1. High Altitude Aerial Natural Gas Leak Detection System

    Energy Technology Data Exchange (ETDEWEB)

    Richard T. Wainner; Mickey B. Frish; B. David Green; Matthew C. Laderer; Mark G. Allen; Joseph R. Morency

    2006-12-31

    The objective of this program was to develop and demonstrate a cost-effective and power-efficient advanced standoff sensing technology able to detect and quantify, from a high-altitude (> 10,000 ft) aircraft, natural gas leaking from a high-pressure pipeline. The advanced technology is based on an enhanced version of the Remote Methane Leak Detector (RMLD) platform developed previously by Physical Sciences Inc. (PSI). The RMLD combines a telecommunications-style diode laser, fiber-optic components, and low-cost DSP electronics with the well-understood principles of Wavelength Modulation Spectroscopy (WMS), to indicate the presence of natural gas located between the operator and a topographic target. The transceiver transmits a laser beam onto a topographic target and receives some of the laser light reflected by the target. The controller processes the received light signal to deduce the amount of methane in the laser's path. For use in the airborne platform, we modified three aspects of the RMLD, by: (1) inserting an Erbium-doped optical fiber laser amplifier to increase the transmitted laser power from 10 mW to 5W; (2) increasing the optical receiver diameter from 10 cm to 25 cm; and (3) altering the laser wavelength from 1653 nm to 1618 nm. The modified RMLD system provides a path-integrated methane concentration sensitivity {approx}5000 ppm-m, sufficient to detect the presence of a leak from a high capacity transmission line while discriminating against attenuation by ambient methane. In ground-based simulations of the aerial leak detection scenario, we demonstrated the ability to measure methane leaks within the laser beam path when it illuminates a topographic target 2000 m away. We also demonstrated simulated leak detection from ranges of 200 m using the 25 cm optical receiver without the fiber amplifier.

  2. Oviposition of aquatic insects in a tropical high altitude stream.

    Science.gov (United States)

    Rios-Touma, Blanca; Encalada, A C; Prat, N

    2012-12-01

    The persistence of aquatic insect populations in streams depends on the recruitment of larval populations from egg masses deposited by adults, especially after disturbance. However, recruitment of aquatic populations by oviposition is a process that remains unstudied in streams and rivers. The objectives of our study were to document flying and oviposition patterns of aquatic insects in a high altitude tropical stream during both dry and wet seasons. In particular we studied 1) richness and abundance of adult forms of aquatic insects flying and ovipositing; 2) number of eggs (oviposition pattern), egg mass identity, and morphology; and 3) substrate preferences by ovipositing females. We found 2,383 aquatic insects corresponding to 28 families, with dipterans representing 89% of total individuals collected. Adult insects had lower richness (28 taxa) than larval diversity (up to 52 taxa) and distinct community composition. Richness and relative abundance of most taxa (adults) were not significantly different between seasons, behaviors, diel period, or all three. During both sampling periods we found females with eggs in a total of 15 different families (13 in the dry season and 14 in the wet season). There were no significant differences in the proportion of females with eggs between seasons, diel periods, or different behaviors (flying versus ovipositing traps) of the different female taxa. Few types of egg masses were found in rocks at the stream during both seasons, and most egg masses found corresponded to families Baetidae and Chironomidae. Finally, we provide the first description of eggs masses (size, shape, color, and number of eggs per female) of gravid females (10 taxa) and those found in the stream substrate (six taxa) of Andean macroinvertebrates. This is the first study reporting oviposition, adult diversity, and oviposition patterns of aquatic insects in the Andean region.

  3. Identification and observations of the plasma mantle at low altitude

    International Nuclear Information System (INIS)

    Newell, P.T.; Meng, Ching-I.; Sanchez, E.R.; Burke, W.J.; Greenspan, M.E.

    1991-01-01

    The direct injection of magnetosheath plasma into the cusp produces at low altitude a precipitation regime with an energy-latitude dispersion-the more poleward portion of which the authors herein term the cusp plume. An extensive survey of the Defense Meteorological Satellite Program (DMSP) F7 and F9 32 eV to 30 keV precipitating particle data shows that similar dispersive signatures exist over much of the dayside, just poleward of the auroral oval. Away from noon (or more precisely, anywhere not immediately poleward of the cusp) the fluxes are reduced by a factor of about 10 as compared to the cusp plume, but other characteristics are quite similar. For example, the inferred temperatures and flow velocities, and the characteristic decline of energy and number flux with increasing latitude is essentially the same in a longitudinally broad ring of precipitation a few degrees thick in latitude over much of the dayside. They conclude that the field lines on which such precipitation occurs thread the magnetospheric plasma mantle over the entire longitudinally extended ring. Besides the location of occurence (i.e., immediately poleward of the dayside oval), the identification is based especially on the associated very soft ion spectra, which have densities from a few times 10 -2 to a few times 10 -1 /cm 3 ; on the temperature range, which is form from a few tens of eV up to about 200 eV; amd on the characteristic gradients with latitude. Further corroborating evidence that the precipitation is associated with field lines which thread the plasma mantle includes drift meter observations which show that regions so identified based on the particle data consistently lie on antisunward convecting field lines. The observations indicate that some dayside high-latitude auroral features just poleward of the auroral oval are embedded in the plasma mantle

  4. Objective Versus Self-Reported Sleep Quality at High Altitude.

    Science.gov (United States)

    Anderson, Paul J; Wood-Wentz, Christina M; Bailey, Kent R; Johnson, Bruce D

    2017-11-27

    Anderson, Paul J., Christina M. Wood-Wentz, Kent R. Bailey, and Bruce D. Johnson. Objective versus self-reported sleep quality at high altitude. High Alt Med Biol. 16:000-000, 2017. Previous studies have found little relationship between polysomnography and a diagnosis of acute mountain sickness (AMS) using the Lake Louise Symptom Questionnaire (LLSQ). The correlation between sleep question responses on the LLSQ and polysomnography results has not been explored. We compared LLSQ sleep responses and polysomnography data from our previous study of workers rapidly transported to the South Pole. Sixty-three subjects completed a 3-hour flight from sea level to the South Pole (3200 m, 9800 ft). Participants completed limited overnight polysomnography on their first night and completed LLSQ upon awakening. We compared polysomnography results at the South Pole with sleep question responses on the LLSQ to assess their degree of correspondence. Twenty-two (30%) individuals reported no sleep problems whereas 20 (32%) reported some problems and 20 (33%) individuals reported poor sleep and 1 reported no sleep (n = 1). Median sleep efficiency was (94%) among response groups and mean overnight oxygen saturation was 81%. Median apnea hypopnea index (AHI; events/hour) was 10.2 in those who reported no problems sleeping, 5.1 in those reporting some problems sleeping, and 13.7 in those who reported poor sleep. These differences were not statistically significant. Self-reported sleep quality varied but there were no associated significant differences in sleep efficiency, overnight oxygen saturation, nor AHI. Studies that explore the role of objective sleep quality in the development of AMS should remove the sleep question on the LLSQ from AMS scoring algorithms.

  5. Characteristics of trapped proton anisotropy at Space Station Freedom altitudes

    Science.gov (United States)

    Armstrong, T. W.; Colborn, B. L.; Watts, J. W.

    1990-01-01

    The ionizing radiation dose for spacecraft in low-Earth orbit (LEO) is produced mainly by protons trapped in the Earth's magnetic field. Current data bases describing this trapped radiation environment assume the protons to have an isotropic angular distribution, although the fluxes are actually highly anisotropic in LEO. The general nature of this directionality is understood theoretically and has been observed by several satellites. The anisotropy of the trapped proton exposure has not been an important practical consideration for most previous LEO missions because the random spacecraft orientation during passage through the radiation belt 'averages out' the anisotropy. Thus, in spite of the actual exposure anisotropy, cumulative radiation effects over many orbits can be predicted as if the environment were isotropic when the spacecraft orientation is variable during exposure. However, Space Station Freedom will be gravity gradient stabilized to reduce drag, and, due to this fixed orientation, the cumulative incident proton flux will remain anisotropic. The anisotropy could potentially influence several aspects of Space Station design and operation, such as the appropriate location for radiation sensitive components and experiments, location of workstations and sleeping quarters, and the design and placement of radiation monitors. Also, on-board mass could possible be utilized to counteract the anisotropy effects and reduce the dose exposure. Until recently only omnidirectional data bases for the trapped proton environment were available. However, a method to predict orbit-average, angular dependent ('vector') trapped proton flux spectra has been developed from the standard omnidirectional trapped proton data bases. This method was used to characterize the trapped proton anisotropy for the Space Station orbit (28.5 degree inclination, circular) in terms of its dependence on altitude, solar cycle modulation (solar minimum vs. solar maximum), shielding thickness

  6. Nutrição para os praticantes de exercício em grandes altitudes Nutritional strategy for exercising in high altitudes

    Directory of Open Access Journals (Sweden)

    Caroline Buss

    2006-02-01

    Full Text Available Quando o atleta ascende a uma grande altitude, ele é exposto a uma pressão barométrica reduzida, e os efeitos fisiológicos que acompanham estas mudanças da pressão atmosférica podem ter grande influência sobre o seu organismo e seu desempenho físico. Acredita-se que a hipóxia seja responsável pelo início de uma cascata de eventos sinalizadores que, ao final, levam à adaptação à altitude. A exposição aguda à hipóxia provoca sonolência, fadiga mental e muscular e prostração. Cefaléia, náusea e anorexia são sintomas provocados pela Doença Aguda das Montanhas, que pode ocorrer nos primeiros dias de permanência na altitude. Uma estratégia nutricional adequada é fundamental para que o organismo não sofra nenhum estresse adicional. O objetivo deste trabalho foi apresentar os principais efeitos da altitude sobre o organismo e sobre o desempenho físico, discutir e/ou sugerir recomendações nutricionais para esta situação e, se possível, apresentar uma orientação nutricional prática para o atleta na altitude. Algumas das principais conclusões encontradas foram: o consumo energético deve ser aumentado; é fundamental monitorar a quantidade de líquidos ingeridos e escolher alimentos agradáveis ao paladar, ricos em energia e nutrientes. Recomenda-se trabalhar com um nutricionista do esporte com antecedência, para que um plano alimentar individual seja elaborado e colocado em prática antes mesmo da viagem à altitude.When athletes are subject to high altitudes, they are exposed to a lower barometric pressure and the physiological effects that accompany these atmospheric pressure changes can have a strong influence on their bodies and performance. Hypoxia is thought to be responsible for triggering a cascade of signaling events that eventually leads to altitude acclimatization. Acute exposure to hypoxia causes sleepiness, mental and muscle fatigue and prostration. Headache, nausea and anorexia are some of the

  7. Scientific Approach for Optimising Performance, Health and Safety in High-Altitude Observatories

    Science.gov (United States)

    Böcker, Michael; Vogy, Joachim; Nolle-Gösser, Tanja

    2008-09-01

    The ESO coordinated study “Optimising Performance, Health and Safety in High-Altitude Observatories” is based on a psychological approach using a questionnaire for data collection and assessment of high-altitude effects. During 2007 and 2008, data from 28 staff and visitors involved in APEX and ALMA were collected and analysed and the first results of the study are summarised. While there is a lot of information about biomedical changes at high altitude, relatively few studies have focussed on psychological changes, for example with respect to performance of mental tasks, safety consciousness and emotions. Both, biomedical and psychological changes are relevant factors in occupational safety and health. The results of the questionnaire on safety, health and performance issues demonstrate that the working conditions at high altitude are less detrimental than expected.

  8. Superpressure Tow Balloon for Extending Durations and Modifying Trajectories of High Altitude Balloon Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation involves the concept of using a Superpressure Tow Balloon (STB) with existing NASA high altitude balloon designs to form a tandem balloon...

  9. The effects of age, sleep deprivation, and altitude on complex performance.

    Science.gov (United States)

    1985-05-01

    Little research has been concerned with the combined effects on performance of age, sleep deprivation, and altitude. This study examined their potential interaction with laboratory tasks measuring aviation-related psychological functions. : Healthy m...

  10. SPLENIC INFARCTION: an intriguing and important cause of pain abdomen in high altitude

    Directory of Open Access Journals (Sweden)

    P. K. Hota

    2015-01-01

    Full Text Available Background: Patients with Sickle cell trait (SCT are usually asymptomatic. They are usually unaware of their condition unless they have a family history. There are specific situations, where these people suffer from the effects of sickle cell trait. Splenic syndrome at high altitude is one of the specific problems. It is usually seen after a patient with SCT has been inducted to high altitude like in case of mountaineers and military personnel deployed in high altitude warfare. Pain abdomen due to splenic infarction in individuals with SCT is one of the manifestations. These patients, if diagnosed in time, they can be spared from unnecessary surgical interventions. We present herewith our experience of splenic infarction due to SCT in high altitude and their management.

  11. Effect of altitude and season on microbial activity, abundance and community structure in Alpine forest soils

    Czech Academy of Sciences Publication Activity Database

    Siles, J. A.; Cajthaml, Tomáš; Minerbi, S.; Margesin, R.

    2016-01-01

    Roč. 92, č. 3 (2016), fiw008 ISSN 0168-6496 Institutional support: RVO:61388971 Keywords : Alpine soil s * forest * altitude Subject RIV: EE - Microbiology, Virology Impact factor: 3.720, year: 2016

  12. Sub-Scale Re-entry Capsule Drop via High Altitude Balloons

    Data.gov (United States)

    National Aeronautics and Space Administration — The project objective is to develop and test a sub-scale version of the Maraia Entry Capsule on a high altitude balloon. The capsule is released at 100,000 ft. The...

  13. Observation of a 27-day solar signature in noctilucent cloud altitude

    Science.gov (United States)

    Köhnke, Merlin C.; von Savigny, Christian; Robert, Charles E.

    2018-05-01

    Previous studies have identified solar 27-day signatures in several parameters in the Mesosphere/Lower thermosphere region, including temperature and Noctilucent cloud (NLC) occurrence frequency. In this study we report on a solar 27-day signature in NLC altitude with peak-to-peak variations of about 400 m. We use SCIAMACHY limb-scatter observations from 2002 to 2012 to detect NLCs. The superposed epoch analysis method is applied to extract solar 27-day signatures. A 27-day signature in NLC altitude can be identified in both hemispheres in the SCIAMACHY dataset, but the signature is more pronounced in the northern hemisphere. The solar signature in NLC altitude is found to be in phase with solar activity and temperature for latitudes ≳ 70 ° N. We provide a qualitative explanation for the positive correlation between solar activity and NLC altitude based on published model simulations.

  14. GRIP HIGH ALTITUDE IMAGING WIND AND RAIN AIRBORNE PROFILER (HIWRAP) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) is a dual-frequency (Ka- and Ku-band) conical scan system, configured with a nadir viewing antenna...

  15. Altitude control performance improvement via preview controller for unmanned airplane for radiation monitoring system

    International Nuclear Information System (INIS)

    Sato, Masayuki; Muraoka, Koji; Hozumi, Koki; Sanada, Yukihisa; Yamada, Tsutomu; Torii, Tatsuo

    2017-01-01

    This paper is concerned with the design problem of preview altitude controller for Unmanned Airplane for Radiation Monitoring System (UARMS) to improve its control performance. UARMS has been developed for radiation monitoring around Fukushima Dai-ichi nuclear power plant which spread radiation contaminant due to the huge tsunamis caused by the Great East Japan Earthquake. The monitoring area contains flat as well as mountain areas. The basic flight controller has been confirmed to have satisfactory performance with respect to altitude holding; however, the control performance for variable altitude commands is not sufficient for practical use in mountain areas. We therefore design preview altitude controller with only proportional gains by considering the practicality and the strong requirement of safety for UARMS. Control performance of the designed preview controller was evaluated by flight tests conducted around Fukushima Sky Park. (author)

  16. Description of the Strategic High-Altitude Atmospheric Radiation Code (SHARC)

    Science.gov (United States)

    Duff, J. W.; Sundberg, R. L.; Gruninger, J. H.; Bernstein, L. S.; Robertson, D. C.; Healey, R. J.

    1990-11-01

    The report describes an upgraded version of the strategic high-altitude radiance code, SHARC-2. The SHARC calculates atmospheric radiance and transmittance over the 2 to 40 micrometer spectral region for arbitrary paths within 50 and 300 km altitude, including space viewing. It models radiation due to non-local thermodynamic equilibrium (NLTE) molecular emissions which are the dominant sources at these altitudes. This new version, which is now ready for distribution, has been upgraded to include a fully integrated auroral model with time-dependent chemistry, extention down to 50 km altitude, and radiation from the minor isotopes of CO2. In addition, there have been numerous internal upgrades to the various modules. These include a Voigt lineshape for the radiative excitation module; embedding of the auroral region into a quiescent atmosphere; and improvements in the radiation transport algorithms.

  17. Using ultrasound lung comets in the diagnosis of high altitude pulmonary edema: fact or fiction?

    Science.gov (United States)

    Wimalasena, Yashvi; Windsor, Jeremy; Edsell, Mark

    2013-06-01

    High altitude pulmonary edema is a life-threatening condition that remains a concern for climbers and clinicians alike. Within the last decade, studies have shown ultrasonography to be valuable in the accurate diagnosis of a variety of lung pathologies, including cardiogenic pulmonary edema, pleural effusion, pneumothorax, and lung consolidation. Recently, studies conducted in remote areas have demonstrated that ultrasound lung comets can be used as a measure of subacute pulmonary edema and high altitude pulmonary edema in climbers ascending to altitude. This clinical review article provides an overview of lung ultrasonography and its relevance as a diagnostic aid to respiratory pathology. In addition, we describe a standardized technique for identifying ultrasound lung comets and its utility in recognizing the presence of extravascular lung water, as well as the results of studies that have used this approach at sea level and high altitude. Copyright © 2013 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  18. Effect of oxygen supplementation in a hatchery at high altitude and ...

    African Journals Online (AJOL)

    PCRT

    2014-11-19

    Visschedijk, 1991). Growth increases the ... supplementation to the hatchery at high altitude resulted in a slightly higher hatching weight of chicks and ... high metabolic rate, both of which require more O2 (Acar et al., 1995). The peak ...

  19. Procedure for altitude compensation for a flame-photometric sulfur analyzer

    International Nuclear Information System (INIS)

    Hales, J.M.; Easter, R.C.; Lee, R.N.

    1979-01-01

    A calibration scheme, which applies to the Meloy-285 sulfur analyzer, is described. This scheme allows reliable instrument calibration, which automatically compensates for variations in instrument response with altitude

  20. Easy-to-Use UAV Ground Station Software for Low-Altitude Civil Operations Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design and develop easy-to-use Ground Control Station (GCS) software for low-altitude civil Unmanned Aerial Vehicle (UAV) operations. The GCS software...

  1. Easy-to-Use UAV Ground Station Software for Low-Altitude Civil Operations, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design and develop easy-to-use Ground Control Station (GCS) software for low-altitude civil Unmanned Aerial Vehicle (UAV) operations. The GCS software...

  2. Thermally Stable Catalytic Combustors for Very High Altitude Airbreathing Propulsion, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Aerospace vehicles operating at high altitudes have the potential to be less expensive and more versatile alternatives to space based systems for earth/space...

  3. Unmanned Aerial Vehicles: Progress Toward Meeting High Altitude Endurance Aircraft Price Goals

    National Research Council Canada - National Science Library

    1998-01-01

    ...) High Altitude Endurance (HAE) Unmanned Aerial Vehicle (UAV) program to determine whether the average flyaway cost for the Global Hawk and DarkStar HAE alr vehicles will be within DOD's cost goal...

  4. High altitude pulmonary edema. Report of a case with familiar history

    International Nuclear Information System (INIS)

    Velasquez, Jurg Niederbacher; Rueda Manrique, Adriana L; Sanabria Pico, Carmen E

    1998-01-01

    We report the case of a ten years old child, who presented a high altitude pulmonary edema. His father had the same disorder ten years ago. In addition we review the physiopathology, diagnosis and management of this disease

  5. Energy and emissions characterization of an eco-efficient biomass cook stove at different altitudes

    International Nuclear Information System (INIS)

    Pérez-Bayer, Juan F.; Graciano-Bustamante, Diana S.; Gómez-Betancur, José A.

    2013-01-01

    Around 2.5 billion people depend on wood as their main fuel for heating and cooking.In this work is studied the effect of altitude (678 and 1976 meters above sea level) on energy performance and emissions of an improved wood stove under standardized cooking tests. The experiments were carried out under the Water Boiling (WBT) and Controlled Cooking (CCT) Tests. The efficiency decreased about 24 % with increasing altitude in WBT, and specific fuel consumption increased 27.3 % due to the air density changes. Regarding the controlled cooking test, the specific fuel consumption and specific emissions increased by 15.3 % and 16 %, respectively. It is highlighted that altitude significantly affects the 'Plancha' wood stove behavior. Specific emissions increased at higher altitudes, so it is necessary to redesign wood stoves according to their geographical location in order to optimize the cooking process. (author)

  6. Response to Comments on ?High Altitude Pulmonary Edema in an Experienced Mountaineer. Possible Genetic Predisposition?

    OpenAIRE

    Whitlow, Kenneth S.

    2015-01-01

    We appreciate the letter to the editor and are pleased to respond regarding our recent case study regarding high altitude pulmonary edema in an experienced mountaineer. The letter raises some valid questions regarding our treatment decisions.

  7. GPM Ground Validation High Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) OLYMPEX V1a

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Altitude Wind and Rain Airborne Profiler (HIWRAP) instrument is a Doppler radar designed to measure tropospheric winds through deriving Doppler profiles...

  8. Monitoring of total body water to examine the progress of acclimatization of runners at varying altitudes

    Directory of Open Access Journals (Sweden)

    Miroslav Semerád

    2017-11-01

    Full Text Available The purpose of our pilot study was to find out if total body water (TBW changes could objectively modify the course of adaptation during training for elite runners at different altitudes. The aim of this pilot study is to summarize the indication of the progress of acclimatization at high altitudes (1000–2700 meters above sea level during alpine conditioning. In three training camps at various altitudes the TBW of elite runners (F = 3, M = 1; n = 4; age 23 } 0.9 was monitored, in order to check the progress of acclimatization. We used BIA measurement methods (Bodystat 1500 at different high altitude running camps at the Czech Republic, Morocco and Ethiopia. Changes in TBW were used to check the progress of acclimatization. We discovered that the retention peaks of TBW corresponded with critical days (p ≤ 0.04; Cohen’s d. The highest measured increases of TBW at an altitude of 1000 m were for runner 1, 1.7 litres and for runner 2, 2.1 litres with retention peaks for both occurring on the 5th day. At an altitude of 1770 m runner 1 reached an increase of TBW of 6.3 litres, with a retention peak on the 11th day, and runner 3 had an increase of 5.1 litres with a peak on the 8th day. In the acclimatization phase we found two critical periods, from the 4th–6th day, and after the 10th–12th day. For runner 4 in altitude 2700m who completed the camp at a higher altitude, the situation is more complicated because there were fluctuations of the content of TBW in the range of 1.25 litres, with the highest depression on the 5th and then again an unsettled rise and reaching a maximum on the 12th, when she nearly returned to the initial value. Detected retention peaks reflected different levels of altitude (5th–12th days.We can conclude that the measuring of changes in TBW during camps at higher altitudes may be one of the biomarkers during acclimatization to altitude.

  9. Update in the understanding of altitude-induced limitations to performance in team-sport athletes

    OpenAIRE

    Billaut, François; Aughey, Robert J

    2013-01-01

    The internationalism of field-based team sports (TS) such as football and rugby requires teams to compete in tournaments held at low to moderate altitude (∼1200–2500 m). In TS, acceleration, speed and aerobic endurance are physical characteristics associated with ball possession and, ultimately, scoring. While these qualities are affected by the development of neuromuscular fatigue at sea level, arterial hypoxaemia induced by exposure to altitude may further hinder the capacity to perform con...

  10. Novel drugs in the management of acute mountain sickness and high altitude pulmonary edema

    OpenAIRE

    Gaurav Sikri, Gaurav; Bhattacharya,Anirban

    2015-01-01

    Gaurav Sikri, Anirban Bhattacharya Department of Physiology, Armed Forces Medical College, Wanowarie, Pune, IndiaWe read with great interest the review article titled “Wilderness medicine at high altitude: recent developments in the field” by Shah et al.1 The authors have comprehensively summarized the recent advances in the field of high altitude medicine relevant to sports and travel medicine. However, Shah et al have described potential drugs for management of high-alti...

  11. Preliminary study on alterations of altitude road traffic in China from 2006 to 2013.

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    Full Text Available Road traffic can play an important role in strengthening regional economic activities, especially at high altitude, and it is necessary to know important traffic-related information. Although previous studies reported on road traffic in China, there has been little research on high-altitude road traffic to date.The annual official census of road traffic safety from 2006 to 2013 was used to obtain data on the general population, registered drivers, registered vehicles, newly built roads, road traffic accidents (RTAs, mortality rate per 100 000 populations and per 10 000 vehicles in high-altitude provinces, including Tibet, Qinghai, Xinjiang, Gansu, Yunnan, Sichuan, and Chongqing. These provincial data were reviewed retrospectively, with the national data as the reference. Statistical analysis (i.e., t test was used to compare the estimated average annual change rate of population, number of registered drivers, registered vehicles, and newly built roads in high-altitude provinces with the national rates.Compared with the national data, there are significantly higher annual rates of population growth in Tibet and Xinjiang, registered drivers in Gansu, registered vehicles in Gansu, Sichuan, and Chongqing, and newly built roads in Tibet and Qinghai. Among the investigated provinces, Tibet, Qinghai, and Yunnan had a higher proportion of the roads with the high class. RTAs and RTA-induced casualties in the high-altitude provinces indicated a decreasing trend. The mortality rate per 10 000 vehicles and per 100 000 populations showed a decreasing trend, while the RTA-related mortality rate in Tibet, Qinghai, Xinjiang and Gansu remained high.Major changes for road traffic in high-altitude provinces have occurred over the past decade; however, the RTA-related mortality rate in high-altitude provinces has remained high. This study furthers understanding about road traffic safety in China; further studies on road traffic safety at high altitude should be

  12. Parasympathetic neural activity accounts for the lowering of exercise heart rate at high altitude

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Calbet, J A; Rådegran, G

    2001-01-01

    In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied.......In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied....

  13. Preliminary study on alterations of altitude road traffic in China from 2006 to 2013

    Science.gov (United States)

    Zhao, Hui; Yin, Zhiyong; Xiang, Hongyi; Liao, Zhikang; Wang, Zhengguo

    2017-01-01

    Introduction Road traffic can play an important role in strengthening regional economic activities, especially at high altitude, and it is necessary to know important traffic-related information. Although previous studies reported on road traffic in China, there has been little research on high-altitude road traffic to date. Method The annual official census of road traffic safety from 2006 to 2013 was used to obtain data on the general population, registered drivers, registered vehicles, newly built roads, road traffic accidents (RTAs), mortality rate per 100 000 populations and per 10 000 vehicles in high-altitude provinces, including Tibet, Qinghai, Xinjiang, Gansu, Yunnan, Sichuan, and Chongqing. These provincial data were reviewed retrospectively, with the national data as the reference. Statistical analysis (i.e., t test) was used to compare the estimated average annual change rate of population, number of registered drivers, registered vehicles, and newly built roads in high-altitude provinces with the national rates. Results Compared with the national data, there are significantly higher annual rates of population growth in Tibet and Xinjiang, registered drivers in Gansu, registered vehicles in Gansu, Sichuan, and Chongqing, and newly built roads in Tibet and Qinghai. Among the investigated provinces, Tibet, Qinghai, and Yunnan had a higher proportion of the roads with the high class. RTAs and RTA-induced casualties in the high-altitude provinces indicated a decreasing trend. The mortality rate per 10 000 vehicles and per 100 000 populations showed a decreasing trend, while the RTA-related mortality rate in Tibet, Qinghai, Xinjiang and Gansu remained high. Conclusions Major changes for road traffic in high-altitude provinces have occurred over the past decade; however, the RTA-related mortality rate in high-altitude provinces has remained high. This study furthers understanding about road traffic safety in China; further studies on road traffic safety at

  14. Altitude mountain sickness among tourist populations: a review and pathophysiology supporting management with hyperbaric oxygen.

    Science.gov (United States)

    Butler, Gleen J; Al-Waili, N; Passano, D V; Ramos, J; Chavarri, J; Beale, J; Allen, M W; Lee, B Y; Urteaga, G; Salom, K

    2011-01-01

    In the mountain climbing community, conventional prevention of altitude mountain sickness (AMS) relies primarily on a formal acclimatization period. AMS symptoms during mountaineering climbs are managed with medication, oxygen and minor recompression (1524-2438 m altitude) using a portable chamber, such as the Gamow Bag. This is not always an acceptable therapy alternative in a predominantly elderly tourist population. The primary problem with reduced pressure at high altitude is hypoxaemia, which causes increased sympathetic activity, induces pulmonary venous constriction, while increasing pulmonary blood flow and regional perfusion. Rapid assents to altitude contribute to an increased incidence of decompression sickness (DCS). The treatment of choice for DCS is hyperbaric oxygenation, thus, treatment of high-altitude induced hypoxaemia using hyperbaric oxygenation (HBO(2)) is logical. Life Support Technologies group and the Center for Investigation of Altitude Medicine (CIMA, in Cusco, Peru) propose a comprehensive and multidisciplinary approach to AMS management. This approach encompasses traditional and advanced medical interventions including the use of a clinical HBO(2) chamber capable of recompression to three times greater than sea level pressure (3 atmosphere absolute (ATA)). The system uses a series of AMS hyperbaric treatment profiles that LST has previously developed to the US military and NASA, and that take greater advantage of vasoconstrictive effects of oxygen under true hyperbaric conditions of 1.25 ATA. These profiles virtually eliminate AMS rebound after the initial treatment often seen in conventional AMS treatment, where the patient is either treated at altitude, or does not recompress back to sea level or greater pressure (1.25 ATA), but returns directly to the same altitude where AMS symptoms first manifested.

  15. Albuminuria and overall capillary permeability of albumin in acute altitude hypoxia

    DEFF Research Database (Denmark)

    Hansen, J M; Olsen, Niels Vidiendal; Feldt-Rasmussen, B

    1994-01-01

    The mechanism of proteinuria at high altitude is unclear. Renal function and urinary excretion rate of albumin (Ualb) at rest and during submaximal exercise and transcapillary escape rate of 125I-labeled albumin (TERalb) were investigated in 12 normal volunteers at sea level and after rapid and p....... The elevated TERalb suggests an overall increase in capillary permeability, including the glomerular endothelium, as the critical factor in high-altitude induced albuminuria....

  16. Increasing alpine transit traffic through Switzerland will considerably enhance high altitude alpine pollutant levels

    Energy Technology Data Exchange (ETDEWEB)

    Prevot, A.S.H.; Dommen, J.; Furger, M.; Graber, W.K. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Within the EU-Project VOTALP (Vertical Ozone Transports in the Alps), we have shown that deep alpine valleys like the Mesolcina Valley very efficiently transport air out of the polluted valley up to altitudes between 2000 and near 4000 m asl (above sea level). Pollutants emitted in these valleys are very efficiently transported up to high altitudes. (author) 2 figs., 1 tab., 2 refs.

  17. Assessment of Aeromedical Evacuation Transport Patient Outcomes With and Without Cabin Altitude Restriction

    Science.gov (United States)

    2017-08-24

    animal studies suggest that altitude exposure may result in adverse physiological effects , but the degree of risk appears unclear and may depend not...and human studies suggest that altitude exposure may result in adverse physiological effects , but the degree of effect remains unclear and may depend...These results prompted a closer look at mechanical ventilation (subset examination). Out of the 100 patients investigated in this study, all were

  18. Assessment of the Brainstem-Mediated Stapedius Muscle Reflex in Andean Children Living at High Altitudes.

    Science.gov (United States)

    Counter, S Allen; Buchanan, Leo H; Ortega, Fernando; Jacobs, Anthony B; Laurell, Göran

    2017-03-01

    Counter, S. Allen, Leo H. Buchanan, Fernando Ortega, Anthony B. Jacobs, and Göran Laurell. Assessment of the brainstem-mediated stapedius muscle reflex in Andean children living at high altitudes. High Alt Med Biol. 18:37-45, 2017.-This study examined the physiological thresholds, amplitude growth, and contraction duration of the acoustic stapedius reflex (ASR) in Andean children aged 2-17 years living at altitudes of 2850 m (Altitude I Group) and 3973 m (Altitude II Group) as part of a general medical assessment of the health status of the children. The brainstem-mediated ASR reveals the integrity of the neuronal components of the auditory reflex arc, including the cochlea receptors, eight cranial nerves, and brainstem neural projections to the cochlear nuclei, bilateral superior olivary nuclei, facial nerve nuclei, and facial nerve and its stapedius branch. Uncrossed (ipsilateral) and crossed (contralateral) ASR thresholds (ASRT), ASR amplitude growth (ASRG) function, and ASR muscle contraction duration (decay/fatigue) (ASRD) were measured noninvasively with 500, 1000 Hz and broadband (bandwidth = 125-4000 Hz) noise stimulus activators using a middle ear immittance system. Oxygen saturation (SaO 2 ) level and heart rate were measured in a subsample of the study group. Statistical analyses revealed that the Altitude I and Altitude II groups had ASRT, ASRG function, and ASRD rates comparable to children at sea level and that the two groups were not significantly different for any of the ASR measures. No significant association was found between SaO 2 or heart rate and ASRT, growth, and muscle fatigue rate. In conclusion, the assessment of the ASR in children in the high-altitude groups revealed normal function. Furthermore, the results indicate no adverse oto-physiological effects of altitude on the brainstem-mediated ASR at elevations between 2850 and 4000 m and suggest normal middle ear and auditory brainstem function.

  19. Preliminary study on alterations of altitude road traffic in China from 2006 to 2013.

    Science.gov (United States)

    Zhao, Hui; Yin, Zhiyong; Xiang, Hongyi; Liao, Zhikang; Wang, Zhengguo

    2017-01-01

    Road traffic can play an important role in strengthening regional economic activities, especially at high altitude, and it is necessary to know important traffic-related information. Although previous studies reported on road traffic in China, there has been little research on high-altitude road traffic to date. The annual official census of road traffic safety from 2006 to 2013 was used to obtain data on the general population, registered drivers, registered vehicles, newly built roads, road traffic accidents (RTAs), mortality rate per 100 000 populations and per 10 000 vehicles in high-altitude provinces, including Tibet, Qinghai, Xinjiang, Gansu, Yunnan, Sichuan, and Chongqing. These provincial data were reviewed retrospectively, with the national data as the reference. Statistical analysis (i.e., t test) was used to compare the estimated average annual change rate of population, number of registered drivers, registered vehicles, and newly built roads in high-altitude provinces with the national rates. Compared with the national data, there are significantly higher annual rates of population growth in Tibet and Xinjiang, registered drivers in Gansu, registered vehicles in Gansu, Sichuan, and Chongqing, and newly built roads in Tibet and Qinghai. Among the investigated provinces, Tibet, Qinghai, and Yunnan had a higher proportion of the roads with the high class. RTAs and RTA-induced casualties in the high-altitude provinces indicated a decreasing trend. The mortality rate per 10 000 vehicles and per 100 000 populations showed a decreasing trend, while the RTA-related mortality rate in Tibet, Qinghai, Xinjiang and Gansu remained high. Major changes for road traffic in high-altitude provinces have occurred over the past decade; however, the RTA-related mortality rate in high-altitude provinces has remained high. This study furthers understanding about road traffic safety in China; further studies on road traffic safety at high altitude should be performed.

  20. Time course of the hemoglobin mass response to natural altitude training in elite endurance cyclists.

    Science.gov (United States)

    Garvican, L; Martin, D; Quod, M; Stephens, B; Sassi, A; Gore, C

    2012-02-01

    To determine the time course of hemoglobin mass (Hb(mass)) to natural altitude training, Hb(mass), erythropoietin [EPO], reticulocytes, ferritin and soluble transferrin receptor (sTfR) were measured in 13 elite cyclists during, and 10 days after, 3 weeks of sea level (n=5) or altitude (n=8, 2760 m) training. Mean Hb(mass), with a typical error of ∼2%, increased during the first 11 days at altitude (mean ± standard deviation 2.9 ± 2.0%) and was 3.5 ± 2.5% higher than baseline after 19 days. [EPO] increased 64.2 ± 18.8% after 2 nights at altitude but was not different from baseline after 12 nights. Hb(mass) and [EPO] did not increase in sea level. Reticulocytes (%) were slightly elevated in altitude at Days 5 and 12 (18.9 ± 17.7% and 20.4 ± 25.3%), sTfR was elevated at Day 12 (18.9 ± 15.0%), but both returned to baseline by Day 20. Hb(mass) and [EPO] decreased on descent to sea level while ferritin increased. The mean increase in Hb(mass) observed after 11 days (∼300 h) of altitude training was beyond the measurement error and consitent with the mean increase after 300 h of simulated live high:train low altitude. Our results suggest that in elite cyclists, Hb(mass) increases progressively with 3 weeks of natural altitude exposure, with greater increases expected as exposure persists. © 2010 John Wiley & Sons A/S.

  1. High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

    Science.gov (United States)

    2008-07-21

    against HEMP effects resulting from a nuclear exchange.40 The Limited Test Ban Treaty of 1963 prohibits nuclear explosions in the atmosphere, in space, and...Order Code RL32544 High Altitude Electromagnetic Pulse ( HEMP ) and High Power Microwave (HPM) Devices: Threat Assessments Updated July 21, 2008 Clay...2008 to 00-00-2008 4. TITLE AND SUBTITLE High Altitude Electromagnetic Pulse ( HEMP ) and High Power Microwave (HPM) Devices: Threat Assessments 5a

  2. Influence the Rubber Seed Type and Altitude on Characteristic of Seed, Oil and Biodiesel

    OpenAIRE

    Salni Salni; Poedji Loekitowati Hariani; Hanifa Marisa Hanifa

    2017-01-01

    This research studies the influence of the type of rubber seed that is superior and local, altitude plant in South Sumatra province to the characteristic of seed, oil and biodiesel (methyl ester). Rubber plants planted from local rubber seed by seeds seedlings and superior rubber seed by selected clones. In the study, rubber plants planted at a different altitude, namely in Banyuasin district (18 m above sea level), Prabumulih District (176 m above sea level) and Lahat District (627 m above s...

  3. Influence of the Rubber Seed Type and Altitude on Characteristic of Seed, Oil and Biodiesel

    OpenAIRE

    Salni, Salni; Hariani, Poedji Loekitowati; Hanifa, Hanifa Marisa

    2017-01-01

    This research studies the influence of the type of rubber seed that is superior and local, altitude plant in South Sumatra province to the characteristic of seed, oil and biodiesel (methyl ester). Rubber plants planted from local rubber seed by seeds seedlings and superior rubber seed by selected clones. In the study, rubber plants planted at a different altitude, namely in Banyuasin district (18 m above sea level), Prabumulih District (176 m above sea level) and Lahat District (627 m above s...

  4. Precision Agriculture: Using Low-Cost Systems to Acquire Low-Altitude Images.

    Science.gov (United States)

    Ponti, Moacir; Chaves, Arthur A; Jorge, Fabio R; Costa, Gabriel B P; Colturato, Adimara; Branco, Kalinka R L J C

    2016-01-01

    Low cost remote sensing imagery has the potential to make precision farming feasible in developing countries. In this article, the authors describe image acquisition from eucalyptus, bean, and sugarcane crops acquired by low-cost and low-altitude systems. They use different approaches to handle low-altitude images in both the RGB and NIR (near-infrared) bands to estimate and quantify plantation areas.

  5. Altitude training causes haematological fluctuations with relevance for the Athlete Biological Passport

    DEFF Research Database (Denmark)

    Bonne, Thomas Christian; Lundby, Carsten; Lundby, Anne Kristine

    2015-01-01

    the ABPS threshold at day +14. In the control group, no values exceeded the individual ABP reference range. In conclusion, LHTH induces haematological changes in Olympic-level elite athletes which can exceed the individually generated references in the ABP. Training at altitude should be considered...... a confounding factor for ABP interpretation for up to four weeks after altitude exposure but does not consistently cause abnormal values in the ABP. Copyright © 2014 John Wiley & Sons, Ltd....

  6. Discrete Neural Altitude Control for Hypersonic Vehicle Via Flight Path Angle Tracking

    OpenAIRE

    Shixing Wang; Bin Xu; Fuchun Sun; Yifu Jiang

    2012-01-01

    In this study, the altitude control is analyzed for the longitudinal dynamics of a generic Hypersonic Flight Vehicle (HFV). By transforming altitude command into the tracking of flight path angle with fast dynamics, the system design is focusing on the control of the attitude subsystem. The virtual control is designed with nominal feedback and Neural Network (NN) approximation via back-stepping. Under the proposed controller, the Semiglobal Uniform Ultimate Boundedness (SGUUB) stability is gu...

  7. WETLAND VEGETATION INTEGRITY ASSESSMENT WITH LOW ALTITUDE MULTISPECTRAL UAV IMAGERY

    Directory of Open Access Journals (Sweden)

    M. A. Boon

    2017-08-01

    Full Text Available The use of multispectral sensors on Unmanned Aerial Vehicles (UAVs was until recently too heavy and bulky although this changed in recent times and they are now commercially available. The focus on the usage of these sensors is mostly directed towards the agricultural sector where the focus is on precision farming. Applications of these sensors for mapping of wetland ecosystems are rare. Here, we evaluate the performance of low altitude multispectral UAV imagery to determine the state of wetland vegetation in a localised spatial area. Specifically, NDVI derived from multispectral UAV imagery was used to inform the determination of the integrity of the wetland vegetation. Furthermore, we tested different software applications for the processing of the imagery. The advantages and disadvantages we experienced of these applications are also shortly presented in this paper. A JAG-M fixed-wing imaging system equipped with a MicaScene RedEdge multispectral camera were utilised for the survey. A single surveying campaign was undertaken in early autumn of a 17 ha study area at the Kameelzynkraal farm, Gauteng Province, South Africa. Structure-from-motion photogrammetry software was used to reconstruct the camera position’s and terrain features to derive a high resolution orthoretified mosaic. MicaSense Atlas cloud-based data platform, Pix4D and PhotoScan were utilised for the processing. The WET-Health level one methodology was followed for the vegetation assessment, where wetland health is a measure of the deviation of a wetland’s structure and function from its natural reference condition. An on-site evaluation of the vegetation integrity was first completed. Disturbance classes were then mapped using the high resolution multispectral orthoimages and NDVI. The WET-Health vegetation module completed with the aid of the multispectral UAV products indicated that the vegetation of the wetland is largely modified (“D” PES Category and that the

  8. Snow chemistry of high altitude glaciers in the French Alps

    Science.gov (United States)

    Maupetit, François; Delmas, Robert J.

    1994-09-01

    Snow samples were collected as snowcores in the accumulation zone of four high altitude glaciers (2980 3540m.a.s.l.) from each of the 4 highest mountain areas of the French Alps, during 3 consecutive years: 1989, 1990 and 1991. Sampling was performed in spring (˜ May), before the onset of late spring summer percolation. The accumulated snow therefore reflects winter and spring conditions. A complementary sampling of fresh-snow was performed on an event basis, on one of the studied glaciers, in 1990 and 1991. All samples were analysed for major ions (but also for total formate and acetate in fresh-snow samples) using ion chromatography. The acidity-alkalinity was accurately determined with a titration technique. The ion balance of alpine snow has been achieved from those analyses. High alpine snow is slightly acid (H+ 3 20 μeq 11), but is episodically affected by alkaline saharan dust events. The different sources (pollution, seasalt and soil dust) affecting the impurity content of snow were identified using principal component analysis. The measured free acidity, mainly from anthropogenic origin, originates from nitric acid scavenging while sulfuric acidity is partially neutralized by atmospheric ammonia and by alkaline soil dust derived species, the contribution of hydrochloric acid being negligible. All ions exhibit higher concentrations in spring than in winter snow, indicating most likely the influence of increased vertical transport from the lower troposphere at this time. The transport of saharan dust is described through three major events reaching the Alps during March 1990 and 1991. Very high concentrations of Ca2+ and HCO3 were measured in corresponding samples, indicating that the solubilisation of CaCO3 represents the major influence of saharan dust on the impurity content of alpine snow, shifting the pH from acid towards alkaline values. Chemical analysis suggests that during their transport, mineral alkaline particles can react through acid

  9. Wetland Vegetation Integrity Assessment with Low Altitude Multispectral Uav Imagery

    Science.gov (United States)

    Boon, M. A.; Tesfamichael, S.

    2017-08-01

    The use of multispectral sensors on Unmanned Aerial Vehicles (UAVs) was until recently too heavy and bulky although this changed in recent times and they are now commercially available. The focus on the usage of these sensors is mostly directed towards the agricultural sector where the focus is on precision farming. Applications of these sensors for mapping of wetland ecosystems are rare. Here, we evaluate the performance of low altitude multispectral UAV imagery to determine the state of wetland vegetation in a localised spatial area. Specifically, NDVI derived from multispectral UAV imagery was used to inform the determination of the integrity of the wetland vegetation. Furthermore, we tested different software applications for the processing of the imagery. The advantages and disadvantages we experienced of these applications are also shortly presented in this paper. A JAG-M fixed-wing imaging system equipped with a MicaScene RedEdge multispectral camera were utilised for the survey. A single surveying campaign was undertaken in early autumn of a 17 ha study area at the Kameelzynkraal farm, Gauteng Province, South Africa. Structure-from-motion photogrammetry software was used to reconstruct the camera position's and terrain features to derive a high resolution orthoretified mosaic. MicaSense Atlas cloud-based data platform, Pix4D and PhotoScan were utilised for the processing. The WET-Health level one methodology was followed for the vegetation assessment, where wetland health is a measure of the deviation of a wetland's structure and function from its natural reference condition. An on-site evaluation of the vegetation integrity was first completed. Disturbance classes were then mapped using the high resolution multispectral orthoimages and NDVI. The WET-Health vegetation module completed with the aid of the multispectral UAV products indicated that the vegetation of the wetland is largely modified ("D" PES Category) and that the condition is expected to

  10. Model of Atmospheric Links on Optical Communications from High Altitude

    Science.gov (United States)

    Subich, Christopher

    2004-01-01

    Optical communication links have the potential to solve many of the problems of current radio and microwave links to satellites and high-altitude aircraft. The higher frequency involved in optical systems allows for significantly greater signal bandwidth, and thus information transfer rate, in excess of 10 Gbps, and the highly directional nature of laser-based signals eliminates the need for frequency-division multiplexing seen in radio and microwave links today. The atmosphere, however, distorts an optical signal differently than a microwave signal. While the ionosphere is one of the most significant sources of noise and distortion in a microwave or radio signal, the lower atmosphere affects an optical signal more significantly. Refractive index fluctuations, primarily caused by changes in atmospheric temperature and density, distort the incoming signal in both deterministic and nondeterministic ways. Additionally, suspended particles, such as those in haze or rain, further corrupt the transmitted signal. To model many of the atmospheric effects on the propagating beam, we use simulations based on the beam-propagation method. This method, developed both for simulation of signals in waveguides and propagation in atmospheric turbulence, separates the propagation into a diffraction and refraction problem. The diffraction step is an exact solution, within the limits of numerical precision, to the problem of propagation in free space, and the refraction step models the refractive index variances over a segment of the propagation path. By applying refraction for a segment of the propagation path, then diffracting over that same segment, this method forms a good approximation to true propagation through the atmospheric medium. Iterating over small segments of the total propagation path gives a good approximation to the problem of propagation over the entire path. Parameters in this model, such as initial beam profile and atmospheric constants, are easily modified in a

  11. Point-of-Care Ultrasound Utility and Potential for High Altitude Crew Recovery Missions.

    Science.gov (United States)

    Galdamez, Laura A; Clark, Jonathan B; Antonsen, Erik L

    2017-02-01

    Flights to high altitude can lead to exposure and unique pathology not seen in normal commercial aviation. This paper assesses the potential for point-of-care ultrasound to aid in management and disposition of injured crewmembers from a high altitude incident. This was accomplished through a systematic literature review regarding current diagnostic and therapeutic uses of ultrasound for injuries expected in high altitude free fall and parachuting. While current research supports its utility in diagnostics, therapeutic procedures, and triage decisions, little research has been done regarding its utility in high altitude specific pathology, but its potential has been demonstrated. An algorithm was created for use in high altitude missions, in the event of an emergency descent and traumatic landing for an unconscious and hypotensive pilot, to rule out most life threatening causes. Each endpoint includes disposition, allowing concise decision-making.Galdamez LA, Clark JB, Antonsen EL. Point-of-care ultrasound utility and potential for high altitude crew recovery missions. Aerosp Med Hum Perform. 2017; 88(2):128-136.

  12. Novel drugs in the management of acute mountain sickness and high altitude pulmonary edema

    Directory of Open Access Journals (Sweden)

    Sikri G

    2015-12-01

    Full Text Available Gaurav Sikri, Anirban Bhattacharya Department of Physiology, Armed Forces Medical College, Wanowarie, Pune, IndiaWe read with great interest the review article titled “Wilderness medicine at high altitude: recent developments in the field” by Shah et al.1 The authors have comprehensively summarized the recent advances in the field of high altitude medicine relevant to sports and travel medicine. However, Shah et al have described potential drugs for management of high-altitude illnesses, such as acute mountain sickness (AMS, high altitude cerebral edema, and high altitude pulmonary edema (HAPE as one group under the section “Novel drug treatment for AMS”. The pathophysiologies of these two sets of diseases (AMS/high altitude cerebral edema as one and HAPE as another set are different2 and hence it would have been nice to have had the novel drugs described separately to elucidate the therapeutic approach for the two different classes of diseases.View original paper by Shah et al.

  13. The performance of Dräger Oxylog ventilators at simulated altitude.

    Science.gov (United States)

    Flynn, J G; Singh, B

    2008-07-01

    Ventilated patients frequently require transport by air in a hypobaric environment. Previous studies have demonstrated significant changes in the performance of ventilators with changes in cabin pressure (altitude) but no studies have been published on the function of modem ventilators at altitude. This experiment set out to evaluate ventilatory parameters (tidal volume and respiratory rate) of three commonly used transport ventilators (the Dräger Oxylog 1000, 2000 and 3000) in a simulated hypobaric environment. Ventilators were assessed using either air-mix (60% oxygen) or 100% oxygen and tested against models simulating a normal lung, a low compliance (Acute Respiratory Distress Syndrome) lung and a high-resistance (asthma) lung. Ventilators were tested at a range of simulated altitudes between sea level and 3048 m. Over this range, tidal volume delivered by the Oxylog 1000 increased by 68% and respiratory rate decreased by 28%. Tidal volume delivered by the Oxylog 2000 ventilator increased by 29% over the same range of altitudes but there was no significant change in respiratory rate. Tidal volume and respiratory rate remained constant with the Oxylog 3000 over the same range of altitudes. Changes were consistent with each ventilator regardless of oxygen content or lung model. It is important that clinicians involved in critical care transport in a hypobaric environment are aware that individual ventilators perform differently at altitude and that they are aware of the characteristics of the particular ventilator that they are using.

  14. Shape memory alloy resistance behaviour at high altitude for feedback control

    Science.gov (United States)

    Ng, W. T.; Sedan, M. F.; Abdullah, E. J.; Azrad, S.; Harithuddin, A. S. M.

    2017-12-01

    Many recent aerospace technologies are using smart actuators to reduce the system's complexity and increase its reliability. One such actuator is shape memory alloy (SMA) actuator, which is lightweight, produces high force and large deflection. However, some disadvantages in using SMA actuators have been identified and they include nonlinear response of the strain to input current, hysteresis characteristic that results in inaccurate control and less than optimum system performance, high operating temperatures, slow response and also high requirement of electrical power to obtain the desired actuation forces. It is still unknown if the SMA actuators can perform effectively at high altitude with low surrounding temperature. The work presented here covers the preliminary process of verifying the feasibility of using resistance as feedback control at high altitude for aerospace applications. Temperature and resistance of SMA actuator at high altitude is investigated by conducting an experiment onboard a high altitude balloon. The results from the high altitude experiment indicate that the resistance or voltage drop of the SMA wire is not significantly affected by the low surrounding temperature at high altitude as compared to the temperature of SMA. Resistance feedback control for SMA actuators may be suitable for aerospace applications.

  15. The effects of classic altitude training on hemoglobin mass in swimmers.

    Science.gov (United States)

    Wachsmuth, N B; Völzke, C; Prommer, N; Schmidt-Trucksäss, A; Frese, F; Spahl, O; Eastwood, A; Stray-Gundersen, J; Schmidt, W

    2013-05-01

    Aim of the study was to determine the influence of classic altitude training on hemoglobin mass (Hb-mass) in elite swimmers under the following aspects: (1) normal oscillation of Hb-mass at sea level; (2) time course of adaptation and de-adaptation; (3) sex influences; (4) influences of illness and injury; (5) interaction of Hb-mass and competition performance. Hb-mass of 45 top swimmers (male 24; female 21) was repeatedly measured (~6 times) over the course of 2 years using the optimized CO-rebreathing method. Twenty-five athletes trained between one and three times for 3-4 weeks at altitude training camps (ATCs) at 2,320 m (3 ATCs) and 1,360 m (1 ATC). Performance was determined by analyzing 726 competitions according to the German point system. The variation of Hb-mass without hypoxic influence was 3.0 % (m) and 2.7 % (f). At altitude, Hb-mass increased by 7.2 ± 3.3 % (p altitude. In conclusion, the altitude (2,320 m) effect on Hb-mass is still present 3 weeks after return, it decisively depends on the health status, but is not influenced by sex. In healthy subjects it exceeds by far the oscillation occurring at sea level. After return from altitude performance increases after a delay of 3 weeks.

  16. Hemoglobin mass after 21 days of conventional altitude training at 1816 m.

    Science.gov (United States)

    Pottgiesser, Torben; Ahlgrim, Christoph; Ruthardt, Sebastian; Dickhuth, Hans-Hermann; Schumacher, Yorck Olaf

    2009-11-01

    The underlying mechanisms of altitude training are still a matter of controversial discussion but erythropoietic adaptations with an increase of total haemoglobin mass (tHb) have been shown in several studies, partly depending on an adequate hypoxic dose. The aim of this retrospective study was to investigate if a 3 weeks sojourn at moderate altitude (1816 m) with conventional training sessions (live and train at moderate altitude), especially under real and uncontrolled conditions, results in an increased tHb. tHb was measured in seven male cyclists competing at elite level (German national cycling team, U23 category) prior to the ascent to altitude and immediately after descent to sea-level. The athletes completed a 21 days altitude training camp living at 1816 m and training at 1800-2400 m during the competitive season. No significant difference was found in tHb after the altitude sojourn (prior 927+/-109g vs. 951+/-113g post, 95% CI -13-61g). Additionally, the analysis of red cell volume, plasma volume and blood volume or haemoglobin concentration [Hb] as well as haematocrit (Hct) did not reveal any significant changes. The data supports the theory that an adequate hypoxic dose is required for adaptations of the erythropoietic system with an increase of tHb and a threshold of approximately 2100-2500 m has to be exceeded.

  17. Monocular Vision System for Fixed Altitude Flight of Unmanned Aerial Vehicles.

    Science.gov (United States)

    Huang, Kuo-Lung; Chiu, Chung-Cheng; Chiu, Sheng-Yi; Teng, Yao-Jen; Hao, Shu-Sheng

    2015-07-13

    The fastest and most economical method of acquiring terrain images is aerial photography. The use of unmanned aerial vehicles (UAVs) has been investigated for this task. However, UAVs present a range of challenges such as flight altitude maintenance. This paper reports a method that combines skyline detection with a stereo vision algorithm to enable the flight altitude of UAVs to be maintained. A monocular camera is mounted on the downside of the aircraft's nose to collect continuous ground images, and the relative altitude is obtained via a stereo vision algorithm from the velocity of the UAV. Image detection is used to obtain terrain images, and to measure the relative altitude from the ground to the UAV. The UAV flight system can be set to fly at a fixed and relatively low altitude to obtain the same resolution of ground images. A forward-looking camera is mounted on the upside of the aircraft's nose. In combination with the skyline detection algorithm, this helps the aircraft to maintain a stable flight pattern. Experimental results show that the proposed system enables UAVs to obtain terrain images at constant resolution, and to detect the relative altitude along the flight path.

  18. Improvement in 100-m Sprint Performance at an Altitude of 2250 m

    Directory of Open Access Journals (Sweden)

    Nicholas P. Linthorne

    2016-05-01

    Full Text Available A fair system of recognizing records in athletics should consider the influence of environmental conditions on performance. The aim of this study was to determine the effect of an altitude of 2250 m on the time for a 100-m sprint. Competition results from the 13 Olympic Games between 1964 and 2012 were corrected for the effects of wind and de-trended for the historical improvement in performance. The time advantage due to competing at an altitude of 2250 m was calculated from the difference between the mean race time at the 1968 Olympic Games in Mexico City and the mean race times at the low-altitude competition venues. The observed time advantage of Mexico City was 0.19 (±0.02 s for men and 0.21 (±0.05 s for women (±90% confidence interval. These results indicate that 100-m sprinters derive a substantial performance advantage when competing at a high-altitude venue and that an altitude of 1000 m provides an advantage equivalent to a 2 m/s assisting wind (0.10 s. Therefore, the altitude of the competition venue as well as the wind speed during the race should be considered when recognizing record performances.

  19. A Novel Approach to Critical Congenital Heart Disease (CCHD Screening at Moderate Altitude

    Directory of Open Access Journals (Sweden)

    Erin Lueth

    2016-07-01

    Full Text Available The American Academy of Pediatrics (AAP has endorsed Critical Congenital Heart Disease (CCHD screening using pulse oximetry nationwide, but, however, acknowledges that altitude may impact failure rates and alternative algorithms may be required at high altitudes. We therefore evaluated a modified screening protocol at an altitude of 6200 feet with the hypothesis that modifications could decrease failure rates. We evaluated 2001 well, newborn infants ≥35 weeks gestation using a modified protocol, which included a lower saturation cutoff for the first screen (85% instead of the AAP recommended 90% and an oxygen hood intervention between the first two screens. Using our modified screening algorithm, we found a 0.3% failure rate, which was similar to the 0.2% sea-level rate and statistically different from the 1.1% rate identified in a recent study at similar altitude. Had the AAP protocol been used, the failure rate would have increased to 0.8%, which is similar to prior reports near this altitude. Echocardiograms were performed on failing newborns with no CCHD identified. A Birth Defects Registry Database review demonstrated one newborn with CCHD was missed after meeting AAP passing criteria. Overall, this study demonstrates that an alternative algorithm can be implemented at moderate altitude with decreased failure rate and comparable false negative rate.

  20. Monocular Vision System for Fixed Altitude Flight of Unmanned Aerial Vehicles

    Directory of Open Access Journals (Sweden)

    Kuo-Lung Huang

    2015-07-01

    Full Text Available The fastest and most economical method of acquiring terrain images is aerial photography. The use of unmanned aerial vehicles (UAVs has been investigated for this task. However, UAVs present a range of challenges such as flight altitude maintenance. This paper reports a method that combines skyline detection with a stereo vision algorithm to enable the flight altitude of UAVs to be maintained. A monocular camera is mounted on the downside of the aircraft’s nose to collect continuous ground images, and the relative altitude is obtained via a stereo vision algorithm from the velocity of the UAV. Image detection is used to obtain terrain images, and to measure the relative altitude from the ground to the UAV. The UAV flight system can be set to fly at a fixed and relatively low altitude to obtain the same resolution of ground images. A forward-looking camera is mounted on the upside of the aircraft’s nose. In combination with the skyline detection algorithm, this helps the aircraft to maintain a stable flight pattern. Experimental results show that the proposed system enables UAVs to obtain terrain images at constant resolution, and to detect the relative altitude along the flight path.

  1. The Gravity Field of Mercury After the Messenger Low-Altitude Campaign

    Science.gov (United States)

    Mazarico, Erwan; Genova, Antonio; Goossens, Sander; Lemoine, Frank G.; Smith, David E.; Zuber, Maria T.; Neumann, Gary A.; Solomon, Sean C.

    2015-01-01

    The final year of the MESSENGER mission was designed to take advantage of the remaining propellant onboard to provide a series of lowaltitude observation campaigns and acquire novel scientific data about the innermost planet. The lower periapsis altitude greatly enhances the sensitivity to the short-wavelength gravity field, but only when the spacecraft is in view of Earth. After more than 3 years in orbit around Mercury, the MESSENGER spacecraft was tracked for the first time below 200-km altitude on 5 May 2014 by the NASA Deep Space Network (DSN). Between August and October, periapsis passages down to 25-km altitude were routinely tracked. These periods considerably improved the quality of the data coverage. Before the end of its mission, MESSENGER will fly at very low altitudes for extended periods of time. Given the orbital geometry, however the periapses will not be visible from Earth and so no new tracking data will be available for altitudes lower than 75 km. Nevertheless, the continuous tracking of MESSENGER in the northern hemisphere will help improve the uniformity of the spatial coverage at altitudes lower than 150 km, which will further improve the overall quality of the Mercury gravity field.

  2. Altitude training and haemoglobin mass from the optimised carbon monoxide rebreathing method determined by a meta-analysis.

    Science.gov (United States)

    Gore, Christopher J; Sharpe, Ken; Garvican-Lewis, Laura A; Saunders, Philo U; Humberstone, Clare E; Robertson, Eileen Y; Wachsmuth, Nadine B; Clark, Sally A; McLean, Blake D; Friedmann-Bette, Birgit; Neya, Mitsuo; Pottgiesser, Torben; Schumacher, Yorck O; Schmidt, Walter F

    2013-12-01

    To characterise the time course of changes in haemoglobin mass (Hbmass) in response to altitude exposure. This meta-analysis uses raw data from 17 studies that used carbon monoxide rebreathing to determine Hbmass prealtitude, during altitude and postaltitude. Seven studies were classic altitude training, eight were live high train low (LHTL) and two mixed classic and LHTL. Separate linear-mixed models were fitted to the data from the 17 studies and the resultant estimates of the effects of altitude used in a random effects meta-analysis to obtain an overall estimate of the effect of altitude, with separate analyses during altitude and postaltitude. In addition, within-subject differences from the prealtitude phase for altitude participant and all the data on control participants were used to estimate the analytical SD. The 'true' between-subject response to altitude was estimated from the within-subject differences on altitude participants, between the prealtitude and during-altitude phases, together with the estimated analytical SD. During-altitude Hbmass was estimated to increase by ∼1.1%/100 h for LHTL and classic altitude. Postaltitude Hbmass was estimated to be 3.3% higher than prealtitude values for up to 20 days. The within-subject SD was constant at ∼2% for up to 7 days between observations, indicative of analytical error. A 95% prediction interval for the 'true' response of an athlete exposed to 300 h of altitude was estimated to be 1.1-6%. Camps as short as 2 weeks of classic and LHTL altitude will quite likely increase Hbmass and most athletes can expect benefit.

  3. White Mountain Research Station: 25 years of high-altitude research. [organization and functions of test facility for high altitude research

    Science.gov (United States)

    Pace, N.

    1973-01-01

    The organization and functions of a test facility for conducting research projects at high altitudes are discussed. The projects conducted at the facility include the following: (1) bird physiology, (2) cardiorespiratory physiology, (3) endocrinological studies, (4) neurological studies, (5) metabolic studies, and (6) geological studies.

  4. Bovine fasciolosis at increasing altitudes: Parasitological and malacological sampling on the slopes of Mount Elgon, Uganda

    Directory of Open Access Journals (Sweden)

    Howell Alison

    2012-09-01

    Full Text Available Abstract Background To clarify the extent and putative transmission zone of bovine fasciolosis on the slopes of Mount Elgon, Uganda, conjoint parasitological and malacological surveys, inclusive of inspection of animals at slaughter, were undertaken at increasing altitudes. Results A total of 239 cattle were sampled across eight locations ranging in elevation from 1112-2072 m. Faecal material was examined for presence of Fasciola eggs and sera were tested by ELISA for antibodies against Fasciola antigens. Bolstering this, 38 cattle at slaughter from 2 abattoir sites at 1150 m and 1947 m were inspected; in addition, wild buffalo stool (n = 10 opportunistically picked within Mount Elgon National Park (MENP at 3640 m was examined. By faecal egg detection, prevalence of Fasciola gigantica at low (1500 m altitude sites was 43.7% (95% CI 35.4-52.2 and 1.1% (95% CI 0.0-6.0, respectively, while by ELISA was much higher, low altitude - 77.9% (95% CI 69.7-85.4 and high altitude - 64.5% (95% CI 51.3-76.3. The decline in prevalence with increasing altitude was corroborated by abattoir sampling. Thirty seven aquatic habitats, ranging from 1139-3937 m in altitude were inspected for freshwater snails, 12 of which were within MENP. At lower altitudes, Lymnaea (Radix natalensis was common, and often abundant, but at higher altitudes became much rarer ceasing to be found above 1800 m. On the other hand, Lymnaea (Galba truncatula was found only at altitudes above 3000 m and within MENP alone. The snail identifications were confirmed by DNA analysis of the ribosomal 18S gene. Conclusions Active infections of F. gigantica in cattle are common in lower altitude settings but appear to diminish with increasing elevation. This is likely due to a growing paucity of intermediate hosts, specifically populations of L. natalensis for which a natural boundary of 1800 m appeared. Although F. hepatica was not encountered, the presence of several

  5. Control of breathing and the circulation in high-altitude mammals and birds.

    Science.gov (United States)

    Ivy, Catherine M; Scott, Graham R

    2015-08-01

    Hypoxia is an unremitting stressor at high altitudes that places a premium on oxygen transport by the respiratory and cardiovascular systems. Phenotypic plasticity and genotypic adaptation at various steps in the O2 cascade could help offset the effects of hypoxia on cellular O2 supply in high-altitude natives. In this review, we will discuss the unique mechanisms by which ventilation, cardiac output, and blood flow are controlled in high-altitude mammals and birds. Acclimatization to high altitudes leads to some changes in respiratory and cardiovascular control that increase O2 transport in hypoxia (e.g., ventilatory acclimatization to hypoxia). However, acclimatization or development in hypoxia can also modify cardiorespiratory control in ways that are maladaptive for O2 transport. Hypoxia responses that arose as short-term solutions to O2 deprivation (e.g., peripheral vasoconstriction) or regional variation in O2 levels in the lungs (i.e., hypoxic pulmonary vasoconstriction) are detrimental at in chronic high-altitude hypoxia. Evolved changes in cardiorespiratory control have arisen in many high-altitude taxa, including increases in effective ventilation, attenuation of hypoxic pulmonary vasoconstriction, and changes in catecholamine sensitivity of the heart and systemic vasculature. Parallel evolution of some of these changes in independent highland lineages supports their adaptive significance. Much less is known about the genomic bases and potential interactive effects of adaptation, acclimatization, developmental plasticity, and trans-generational epigenetic transfer on cardiorespiratory control. Future work to understand these various influences on breathing and circulation in high-altitude natives will help elucidate how complex physiological systems can be pushed to their limits to maintain cellular function in hypoxia. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Difference in blood microcirculation recovery between normal frostbite and high-altitude frostbite

    Directory of Open Access Journals (Sweden)

    Ming-ke JIAO

    2017-02-01

    Full Text Available Objective To determine the difference in blood microcirculation recovery between normal frostbite and high-altitude frostbite during the wound healing. Methods Twenty four male rats were randomly divided into control group (n=8, normal frostbite group (n=8, and high-altitude group (n=8. The normal frostbite group rats were frozen to produce mid-degree frostbite models by controlling the freezing time with liquid nitrogen penetration equipment. The high-altitude frostbite group rats were acclimated to a hypoxic and low-pressure environment for 1 week, and then the high-altitude frostbite models were constructed by the same way with liquid nitrogen penetration apparatus. On days 3, 7, 11, 15, 19, and 23 after modeling, the recovery situation of blood circulation of each group was observed with contrast ultrasonography by injecting SonoVue micro-bubble into rats' tail. Finally, the micro-bubble concentration (MC was calculated to confirm the blood circulation recovery with software Image Pro. Results At different time points, the wound area of the high-altitude frostbite group was bigger than that of the normal frostbite group, and the MC of control group was always about (27±0.2×109/ml. On day 3, 7, 11, 15, 19, and 23, the MC was significantly lower in the high-altitude frostbite group than in the control group and normal frostbite group (P<0.05. The MC of normal frostbite group was significantly lower than that of the control group on day 3, 7, 11, 15 and 19 (P<0.05. In addition, no obvious difference in MC was found between normal group and control group on the 23th day (P<0.05. Conclusion The blood microcirculation recovery after high-altitude frostbite is significantly slower than the normal frostbite. DOI: 10.11855/j.issn.0577-7402.2017.01.13

  7. [Geographic Altitude of Residence and Alcohol Dependence in a Peruvian Population].

    Science.gov (United States)

    Quiñones-Laveriano, Dante Manuel; Espinoza-Chiong, César; Scarsi-Mejia, Ottavia; Rojas-Camayo, José; Mejia, Christian Richard

    2016-01-01

    The aim of this study was to determine the association between alcohol dependence and altitude of residence in 11 villages in two high altitude areas of Peru. An analytical cross-sectional study was performed using a survey conducted by physicians in primary health care in 11 villages until 2013, that were divided into low altitude (≤2500m asl (above sea level)), and high altitude (>2500m asl) areas. The CAGE test for alcoholism (cut point, ≥2) was applied to those who responded positively when asked if they consumed alcohol. Statistical associations were obtained with generalised linear models Of the 737 participants, 51% were women and the median age was 36 years [interquartile range, 25-50], 334 (45%) lived at low altitude, and 113 (15%) had alcohol dependence. The highest frequency of alcoholism was positively associated with being a village considered extremely poor (Likelihood Ratio (LP)=2.42; 95%CI, 1.40-4.19), while being female (LP=0.44; 95%CI, 0.23-0.89) and residing at high altitude (LP=0.15; 95%CI, 0.07-0.31) were negatively associated. These were adjusted for nine socio-occupational and pathological variables. According to these data, there is a higher frequency of alcohol dependence in being, male, extremely poor, and residing at low altitude. These results should be taken into account by professionals who work in primary care and those involved in mental health care, because of their implications in society. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  8. Effects of altitude and water on flowering and fruiting of jatropha curcas l

    International Nuclear Information System (INIS)

    Shiyu, M.A.; Zhou, L.; Guanglan, P.U.; Hou, L.

    2015-01-01

    Field survey was conducted at three different altitudes in the dry-hot valley of Chin-sha River,China. The variances of flowering and fruiting and the quantity of fruit at three different altitudes areas (Low 800m, Middle 1,200m and High 1,700m) were observed and recorded. Data of 100-seeds weight came from 9 experimental groups which classified by three fruiting periods (early, middle and late) at three different altitudes. To ensure single variable, water effect was studied in the cline banks where situated in the 1,200m and controlled by artificial irrigation. The results showed that flowering and fruiting time under different altitude had significant difference, the lower altitude, the earlier flowering. Fruit number in the middle elevation was remarkably higher than the other two altitude areas. Fruit quantity in early and middle fruiting period accounted for 85 percent at 1,200m, which was significantly higher than the late fruiting period. 100-seeds weight between low and middle elevation, early and middle fruiting period had no significant difference respectively, but they were, respectively, higher than the high altitude and late fruiting period. The maximum of the 100-seeds weight was 65.17g while the lightest was only 49.51g. Water promoted flowering earlier, fruiting delayed but open flower and whole fruiting stage extended. Average fruit numbers in the early and middle stages with regularly irrigation were 220.8 per tree and 195.6 per tree respectively, which were 2.26 times as the same period of plant without irrigation. Therefore, in hilly areas, J. curcas optimal elevation is 800 -1,200m and have high demand for water during flowering and fruiting period. (author)

  9. Geographic Variation in Mentally Unhealthy Days: Air Pollution and Altitude Perspectives.

    Science.gov (United States)

    Ha, Hoehun

    2017-09-01

    Ha, Hoehun. Geographic variation in mentally unhealthy days: air pollution and altitude perspectives. High Alt Med Biol. 18:258-266, 2017. Mental health incorporates our emotional, psychological, and social well-being and it is critical at each phase of life, from youth and preadulthood through adulthood. We assessed the association between mentally unhealthy days (MUDs), air pollutant concentrations, and altitude on the basis of cross-county studies. Data on poor mental health days for the United States were based on health-related telephone surveys conducted by the Behavioral Risk Factor Surveillance System (BRFSS). Average annual regional air pollution data were obtained from Center for Disease Control and Prevention (CDC) WONDER Environmental data, and altitude data were collected from the U.S. Geological Survey (USGS). In the data set (across 2589 U.S. counties for 2011), even after accounting for potential confounding variables and multicollinearity, a significant association between altitude, air pollution, and poor mental health days was found, explaining that poor mental health days increase with increasing air pollution concentrations and with decreasing altitude (R 2  = 0.663, p factors did not change these findings. In this study, we found that counties with lower air pollution and higher altitude had significantly lower average number of MUDs reported within the past 30 days. This association has not been reported before in the literature. These findings suggest a need for further investigation into the extent that air quality and altitude may serve as significant factors for mental health and have major implications in our understanding of the etiology of mental health by medical professionals.

  10. The impact of altitude on the sleep of young elite soccer players (ISA3600).

    Science.gov (United States)

    Sargent, Charli; Schmidt, Walter F; Aughey, Robert J; Bourdon, Pitre C; Soria, Rudy; Claros, Jesus C Jimenez; Garvican-Lewis, Laura A; Buchheit, Martin; Simpson, Ben M; Hammond, Kristal; Kley, Marlen; Wachsmuth, Nadine; Gore, Christopher J; Roach, Gregory D

    2013-12-01

    Altitude training is used by elite athletes to improve sports performance, but it may also disrupt sleep. The aim of this study was to examine the effects of 2 weeks at high altitude on the sleep of young elite athletes. Participants (n=10) were members of the Australian under-17 soccer team on an 18-day (19-night) training camp in Bolivia, with six nights at near sea level in Santa Cruz (430 m) and 13 nights at high altitude in La Paz (3600 m). Sleep was monitored using polysomnography during a baseline night at 430 m and three nights at 3600 m (immediately after ascent, 1 week after ascent and 2 weeks after ascent). Data were analysed using effect size statistics. All results are reported as comparisons with baseline. Rapid eye movement (REM) sleep was likely lower immediately upon ascent to altitude, possibly lower after 1 week and similar after 2 weeks. On all three nights at altitude, hypopneas and desaturations were almost certainly higher; oxygen saturation was almost certainly lower; and central apnoeas, respiratory arousals and periodic breathing were very likely higher. The effects on REM sleep were common to all but one participant, but the effects on breathing were specific to only half the participants. The immediate effects of terrestrial altitude of 3600 m are to reduce the amount of REM sleep obtained by young elite athletes, and to cause 50% of them to have impaired breathing during sleep. REM sleep returns to normal after 2 weeks at altitude, but impaired breathing does not improve.

  11. Fatalities in high altitude mountaineering: a review of quantitative risk estimates.

    Science.gov (United States)

    Weinbruch, Stephan; Nordby, Karl-Christian

    2013-12-01

    Quantitative estimates for mortality in high altitude mountaineering are reviewed. Special emphasis is placed on the heterogeneity of the risk estimates and on confounding. Crude estimates for mortality are on the order of 1/1000 to 40/1000 persons above base camp, for both expedition members and high altitude porters. High altitude porters have mostly a lower risk than expedition members (risk ratio for all Nepalese peaks requiring an expedition permit: 0.73; 95 % confidence interval 0.59-0.89). The summit bid is generally the most dangerous part of an expedition for members, whereas most high altitude porters die during route preparation. On 8000 m peaks, the mortality during descent from summit varies between 4/1000 and 134/1000 summiteers (members plus porters). The risk estimates are confounded by human and environmental factors. Information on confounding by gender and age is contradictory and requires further work. There are indications for safety segregation of men and women, with women being more risk averse than men. Citizenship appears to be a significant confounder. Prior high altitude mountaineering experience in Nepal has no protective effect. Commercial expeditions in the Nepalese Himalayas have a lower mortality than traditional expeditions, though after controlling for confounding, the difference is not statistically significant. The overall mortality is increasing with increasing peak altitude for expedition members but not for high altitude porters. In the Nepalese Himalayas and in Alaska, a significant decrease of mortality with calendar year was observed. A few suggestions for further work are made at the end of the article.

  12. Analysis of the variation of the 0°C isothermal altitude during rainfall events

    Science.gov (United States)

    Zeimetz, Fränz; Garcìa, Javier; Schaefli, Bettina; Schleiss, Anton J.

    2016-04-01

    In numerous countries of the world (USA, Canada, Sweden, Switzerland,…), the dam safety verifications for extreme floods are realized by referring to the so called Probable Maximum Flood (PMF). According to the World Meteorological Organization (WMO), this PMF is determined based on the PMP (Probable Maximum Precipitation). The PMF estimation is performed with a hydrological simulation model by routing the PMP. The PMP-PMF simulation is normally event based; therefore, if no further information is known, the simulation needs assumptions concerning the initial soil conditions such as saturation or snow cover. In addition, temperature series are also of interest for the PMP-PMF simulations. Temperature values can not only be deduced from temperature measurement but also using the temperature gradient method, the 0°C isothermal altitude can lead to temperature estimations on the ground. For practitioners, the usage of the isothermal altitude for referring to temperature is convenient and simpler because one value can give information over a large region under the assumption of a certain temperature gradient. The analysis of the evolution of the 0°C isothermal altitude during rainfall events is aimed here and based on meteorological soundings from the two sounding stations Payerne (CH) and Milan (I). Furthermore, hourly rainfall and temperature data are available from 110 pluviometers spread over the Swiss territory. The analysis of the evolution of the 0°C isothermal altitude is undertaken for different precipitation durations based on the meteorological measurements mentioned above. The results show that on average, the isothermal altitude tends to decrease during the rainfall events and that a correlation between the duration of the altitude loss and the duration of the rainfall exists. A significant difference in altitude loss is appearing when the soundings from Payerne and Milan are compared.

  13. Relationship between altitude and the prevalence of hypertension in Tibet: a systematic review.

    Science.gov (United States)

    Mingji, Cuomu; Onakpoya, Igho J; Perera, Rafael; Ward, Alison M; Heneghan, Carl J

    2015-07-01

    Hypertension is a leading cause of cardiovascular disease, which is the cause of one-third of global deaths and is a primary and rising contributor to the global disease burden. The objective of this systematic review was to determine the prevalence and awareness of hypertension among the inhabitants of Tibet and its association with altitude, using the data from published observational studies. We conducted electronic searches in Medline, Embase, ISI Web of Science and Global Health. No gender or language restrictions were imposed. We assessed the methodological characteristics of included studies using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria. Two reviewers independently determined the eligibility of studies, assessed the methodology of included studies and extracted the data. We used meta-regression to estimate the degree of change in hypertension prevalence with increasing altitude. We identified 22 eligible articles of which eight cross-sectional studies with a total of 16 913 participants were included. The prevalence of hypertension ranged between 23% and 56%. A scatter plot of altitude against overall prevalence revealed a statistically significant correlation (r=0.68; p=0.04). Meta-regression analysis revealed a 2% increase in the prevalence of hypertension with every 100 m increase in altitude (p=0.06). The locations and socioeconomic status of subjects affected the awareness and subsequent treatment and control of hypertension. The results from cross-sectional studies suggest that there is a significant correlation between altitude and the prevalence of hypertension among inhabitants of Tibet. The socioeconomic status of the inhabitants can influence awareness and management of hypertension. Very little research into hypertension has been conducted in other prefectures of Tibet where the altitude is much higher. Further research examining the impact of altitude on blood pressure is warranted

  14. "Omics" of High Altitude Biology: A Urinary Metabolomics Biomarker Study of Rats Under Hypobaric Hypoxia.

    Science.gov (United States)

    Koundal, Sunil; Gandhi, Sonia; Kaur, Tanzeer; Mazumder, Avik; Khushu, Subash

    2015-12-01

    High altitude medicine is an emerging subspecialty that has crosscutting relevance for 21(st) century science and society: from sports medicine and aerospace industry to urban and rural communities living in high altitude. Recreational travel to high altitude has also become increasingly popular. Rarely has the biology of high altitude biology been studied using systems sciences and omics high-throughput technologies. In the present study, 1H-NMR-based metabolomics, along with multivariate analyses, were employed in a preclinical rat model to characterize the urinary metabolome under hypobaric hypoxia stress. Rats were exposed to simulated altitude of 6700 m above the sea level. The urine samples were collected from pre- and post-exposure (1, 3, 7, and 14 days) of hypobaric hypoxia. Metabolomics urinalysis showed alterations in TCA cycle metabolites (citrate, α-ketoglutarate), cell membrane metabolism (choline), gut micro-flora metabolism (hippurate, phenylacetylglycine), and others (N-acetyl glutamate, creatine, taurine) in response to hypobaric hypoxia. Taurine, a potential biomarker of hepatic function, was elevated after 3 days of hypobaric hypoxia, which indicates altered liver functioning. Liver histopathology confirmed the damage to tissue architecture due to hypobaric hypoxia. The metabolic pathway analysis identified taurine metabolism and TCA as important pathways that might have contributed to hypobaric hypoxia-induced pathophysiology. This study demonstrates the use of metabolomics as a promising tool for discovery and understanding of novel biochemical responses to hypobaric hypoxia exposure, providing new insight in the field of high altitude medicine and the attendant health problems that occur in response to high altitude. The findings reported here also have potential relevance for sports medicine and aviation sciences.

  15. A multinational Andean genetic and health program. VIII. Lung function changes with migration between altitudes.

    Science.gov (United States)

    Mueller, W H; Yen, F; Soto, P; Schull, V N; Rothhammer, F; Schull, W J

    1979-08-01

    Studies of lung function in high altitude populations have suggested the influence of hypoxic environment on the development of this characteristic independent of confounding variables such as ethnicity and habitual exercise. However, often the effect of altitude on vital capacity is greater in children than adults, suggesting that more than developmental adaptation is operative. Also selective migration could account for the similarity of migrants and permanent residents at a destination altitude. To explore these problems we studied the lung function (FVC, FEV1, PFR) of 377 individuals who had migrated between altitudes in northern Chile. Migrant measurements were adjusted to those of permanent residents of appropriate age, sex and height at the altitudes of origin and destination. The measurements were then related to ethnicity (Spanish-Aymara ancestry), occupation and permanence, the latter combining information on both age at migration to and length of stay at a destination altitude. Upward migration was associated with increased chest depth, FVC and FEV1, but not height or other chest measurements. Downward migration had no significant effect. The flow-dependent test PFR was so sensitive to observer variability and occupation that it was difficult to establish its relationship to permanence. Unlike the body measurements, lung function measurements (especially PFR) tended to deviate from permanent controls at the origin altitude in a direction suggestive of selective migration, nor was permanence itself independent of ethnicity and occupation. Because of these difficulties the question of developmental adaptation in lung function may not be answerable in cross-sectional studies like the present and previous efforts, but rather in longitudinal investigations in which the control is the individual him/herself.

  16. Influence the Rubber Seed Type and Altitude on Characteristic of Seed, Oil and Biodiesel

    Directory of Open Access Journals (Sweden)

    Salni Salni

    2017-06-01

    Full Text Available This research studies the influence of the type of rubber seed that is superior and local, altitude plant in South Sumatra province to the characteristic of seed, oil and biodiesel (methyl ester. Rubber plants planted from local rubber seed by seeds seedlings and superior rubber seed by selected clones. In the study, rubber plants planted at a different altitude, namely in Banyuasin district (18 m above sea level, Prabumulih District (176 m above sea level and Lahat District (627 m above sea level. The results showed that the weight of the flour, the water content and ash content in the local rubber seeds larger than the superior rubber seed for all altitude, but oil content a large in the superior rubber seeds. The major of fatty acids in the rubber seed oil in all types and altitude are a linoleic acid with a different percentage except local rubber seed oil from Lahat district with the large percentage of octadecanoic acid. Free fatty acids in the oil from the superior seeds rubber of 13.897-15.494 % large than local rubber seed oil was found 9.786-10.399 % for all altitude. By esterification process using sulfuric acid catalyst, Free Fatty Acid (FFA can be reduced to ≤ 2 %. The methyl ester made from the transesterification process of rubber seed oil after esterification using methanol and sodium hydroxide as catalyst. Analysis of methyl esters includes cetane index, flash point, kinematic viscosity, carbon residue, density, moisture content, water and sediment content and distillation compared with SNI 7182 and ASTM 6751-02.  The result indicated that the quality of methyl ester from superior rubber seed oil in the Banyuasin and Prabumulih district better than another methyl ester. The types of rubber seed altitude affect the characteristics of the seed, oil and methyl ester  but the altitude are not significantly different. Keywords: rubber seed, type, altitude, oil, biodiesel Article History: Received March 21st 2017; Received in

  17. Effect of altitude on brain intracellular pH and inorganic phosphate levels.

    Science.gov (United States)

    Shi, Xian-Feng; Carlson, Paul J; Kim, Tae-Suk; Sung, Young-Hoon; Hellem, Tracy L; Fiedler, Kristen K; Kim, Seong-Eun; Glaeser, Breanna; Wang, Kristina; Zuo, Chun S; Jeong, Eun-Kee; Renshaw, Perry F; Kondo, Douglas G

    2014-06-30

    Normal brain activity is associated with task-related pH changes. Although central nervous system syndromes associated with significant acidosis and alkalosis are well understood, the effects of less dramatic and chronic changes in brain pH are uncertain. One environmental factor known to alter brain pH is the extreme, acute change in altitude encountered by mountaineers. However, the effect of long-term exposure to moderate altitude has not been studied. The aim of this two-site study was to measure brain intracellular pH and phosphate-bearing metabolite levels at two altitudes in healthy volunteers, using phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS). Increased brain pH and reduced inorganic phosphate (Pi) levels were found in healthy subjects who were long-term residents of Salt Lake City, UT (4720ft/1438m), compared with residents of Belmont, MA (20ft/6m). Brain intracellular pH at the altitude of 4720ft was more alkaline than that observed near sea level. In addition, the ratio of inorganic phosphate to total phosphate signal also shifted toward lower values in the Salt Lake City region compared with the Belmont area. These results suggest that long-term residence at moderate altitude is associated with brain chemical changes. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Angiogenic/lymphangiogenic factors and adaptation to extreme altitudes during an expedition to Mount Everest.

    Science.gov (United States)

    Patitucci, M; Lugrin, D; Pagès, G

    2009-06-01

    To analyse the correlation between production of angiogenic [vascular endothelial growth factor A (VEGF-A) and interleukin 8 (IL-8)] and lymphangiogenic factors (VEGF-C and D) and adaptation to high altitude (>8000 m). Erythropoietin (EPO) served as a positive control. We analysed the percentage of oxygen saturation and the plasmatic contents of VEGF-A, C, D, IL-8 and EPO in seven mountaineers and four Sherpas during an expedition to Mount Everest. Acute mountain sickness was also evaluated using the Lake Louise score. Whereas VEGF-A, IL-8, VEGF-C and EPO were transiently up-regulated at 5000 m and decreased at the highest altitudes, VEGF-D remained elevated throughout the ascent. Sherpas had increased basal levels of VEGF-A, C, IL-8 and EPO and up-regulation of all the tested factors when they passed the altitude at which they lived. Our data suggest that expression of angiogenic and lymphangiogenic factors is up-regulated directly or indirectly by altitude-dependent hypoxia. Both factors could be involved in a mechanism of adaptation to high altitudes.

  19. Using a Convection Model to Predict Altitudes of White Stork Migration Over Central Israel

    Science.gov (United States)

    Shamoun-Baranes, Judy; Liechti, Olivier; Yom-Tov, Yoram; Leshem, Yossi

    Soaring migrants such as storks, pelicans and large birds of prey rely on thermal convection during migration. The convection model ALPTHERM was designed to predict the onset, strength, duration and depth of thermal convection for varying topographies for glider pilots, based on atmospheric conditions at midnight. We tested ALPTHERM predictions as configured for two topographies of central Israel, the Coastal Plains and the Judean and Samarian Mountains in order to predict altitudes of migrating white storks (Ciconia ciconia). Migrating flocks of white storks were tracked with a motorized glider, to measure maximum altitudes of migration during spring 2000. A significant positive correlation was found between the maximum daily altitudes of migration measured and the predicted upper boundary of thermal convection for the Coastal Plains and Samarian Mountains. Thirty-minute predictions for the Coastal Plains and Samarian Mountains correlated positively with measured maximum migration altitudes per thermal. ALPTHERM forecasts can be used to alter flight altitudes in both civil and especially military aviation and reduce the hazard of serious aircraft collisions with soaring migrants.

  20. Breathing patterns and cardiovascular autonomic modulation during hypoxia induced by simulated altitude.

    Science.gov (United States)

    Bernardi, L; Passino, C; Wilmerding, V; Dallam, G M; Parker, D L; Robergs, R A; Appenzeller, O

    2001-05-01

    To assess the influence of different breathing patterns on autonomic cardiovascular modulation during acute exposure to altitude-induced hypoxia. We measured relative changes in minute ventilation (VE), oxygen saturation (%SaO2), spectral analysis of RR interval and blood pressure, and response to stimulation of carotid baroreceptors (neck suction) at baseline and after acute (1 h) hypobaric hypoxia (equivalent to 5,000 m, in a hypobaric chamber). We studied 19 human subjects: nine controls and 10 Western yoga trainees of similar age, while breathing spontaneously, at 15 breaths/min (controlled breathing) and during 'complete yogic breathing' (slow diaphragmatic + thoracic breathing, approximately 5 breaths/min) in yoga trainees, or simple slow breathing in controls. At baseline %SaO2, VE and autonomic pattern were similar in both groups; simulated altitude increased VE in controls but not in yoga trainees; %SaO2 decreased in all subjects (Pbreathing, controlled breathing and yogic or slow breathing, respectively). Simulated altitude decreased RR interval (from 879 +/- 45 to 770 +/- 39, P breathing. No effect of altitude was seen on stimulation of carotid baroreceptors in both groups. Well-performed slow yogic breathing maintains better blood oxygenation without increasing VE (i.e. seems to be a more efficient breathing) and reduces sympathetic activation during altitude-induced hypoxia.

  1. Butterflies of the high-altitude Atacama Desert: habitat use and conservation.

    Science.gov (United States)

    Despland, Emma

    2014-01-01

    The butterfly fauna of the high-altitude desert of Northern Chile, though depauperate, shows high endemism, is poorly known and is of considerable conservation concern. This study surveys butterflies along the Andean slope between 2400 and 5000 m asl (prepuna, puna and Andean steppe habitats) as well as in high and low-altitude wetlands and in the neoriparian vegetation of agricultural sites. We also include historical sightings from museum records. We compare abundances between altitudes, between natural and impacted sites, as well as between two sampling years with different precipitation regimes. The results confirm high altitudinal turnover and show greatest similarity between wetland and slope faunas at similar altitudes. Results also underscore vulnerability to weather fluctuations, particularly in the more arid low-altitude sites, where abundances were much lower in the low precipitation sampling season and several species were not observed at all. Finally, we show that some species have shifted to the neoriparian vegetation of the agricultural landscape, whereas others were only observed in less impacted habitats dominated by native plants. These results suggest that acclimation to novel habitats depends on larval host plant use. The traditional agricultural environment can provide habitat for many, but not all, native butterfly species, but an estimation of the value of these habitats requires better understanding of butterfly life history strategies and relationships with host plants.

  2. Butterflies of the high altitude Atacama Desert: habitat use and conservation

    Directory of Open Access Journals (Sweden)

    Emma eDespland

    2014-09-01

    Full Text Available The butterfly fauna of the high-altitude desert of Northern Chile, though depauperate, shows high endemism, is poorly known and is of considerable conservation concern. This study surveys butterflies along the Andean slope between 2400 and 500 m asl (prepuna, puna and Andean steppe habitats as well as in high and low altitude wetlands and in the neoriparian vegetation of agricultural sites. We also include historical sightings from museum records. We compare abundances between altitudes, between natural and impacted sites, as well as between two sampling years with different precipitation regimes. The results confirm high altitudinal turnover and show greatest similarity between wetland and slope faunas at similar altitudes. Results also underscore vulnerability to weather fluctuations, particularly in the more arid low-altitude sites, where abundances were much lower in the low precipitation sampling season and several species were not observed at all. Finally, we show that some species have shifted to the neoriparian vegetation of the agricultural landscape, whereas others were only observed in less impacted habitats dominated by native plants. These results suggest that acclimation to novel habitats depends on larval host plant use. The traditional agricultural environment can provide habitat for many, but not all, native butterfly species, but an estimation of the value of these habitats requires better understanding of butterfly life-history strategies and relationships with host plants.

  3. Solar Cell Short Circuit Current Errors and Uncertainties During High Altitude Calibrations

    Science.gov (United States)

    Snyder, David D.

    2012-01-01

    High altitude balloon based facilities can make solar cell calibration measurements above 99.5% of the atmosphere to use for adjusting laboratory solar simulators. While close to on-orbit illumination, the small attenuation to the spectra may result in under measurements of solar cell parameters. Variations of stratospheric weather, may produce flight-to-flight measurement variations. To support the NSCAP effort, this work quantifies some of the effects on solar cell short circuit current (Isc) measurements on triple junction sub-cells. This work looks at several types of high altitude methods, direct high altitude meas urements near 120 kft, and lower stratospheric Langley plots from aircraft. It also looks at Langley extrapolation from altitudes above most of the ozone, for potential small balloon payloads. A convolution of the sub-cell spectral response with the standard solar spectrum modified by several absorption processes is used to determine the relative change from AMO, lscllsc(AMO). Rayleigh scattering, molecular scatterin g from uniformly mixed gases, Ozone, and water vapor, are included in this analysis. A range of atmosph eric pressures are examined, from 0. 05 to 0.25 Atm to cover the range of atmospheric altitudes where solar cell calibrations a reperformed. Generally these errors and uncertainties are less than 0.2%

  4. Altitude training induced alterations in erythrocyte rheological properties: a controlled comparison study in rats.

    Science.gov (United States)

    Bor-Kucukatay, Melek; Colak, Ridvan; Erken, Gülten; Kilic-Toprak, Emine; Kucukatay, Vural

    2014-01-01

    Altitude training is frequently used by athletes to improve sea-level performance. However, the objective benefits of altitude training are controversial. This study aimed to investigate the possible alterations in hemorheological parameters in response to altitude training. Sprague Dawley rats, were divided into 6 groups: live low-train low (LLTL), live high-train high (LHTH), live high-train low (LHTL) and their controls live high and low (LHALC), live high (LHC), live low (LLC). LHC and LHTH groups were exposed to hypoxia (15% O2, altitudes of 3000 m), 4 weeks. LHALC and LHTL were exposed to 12 hours hypoxia/normoxia per day, 4 weeks. Hypoxia was maintained by a hypoxic tent. The training protocol corresponded to 60-70% of maximal exercise capacity. Rats of training groups ran on treadmill for 20-30 min/day, 4 days/week, 4 weeks. Erythrocyte deformability of LHC group was increased compared to LHALC and LLC. Deformability of LHTH group was higher than LHALC and LLTL groups. No statistically significant alteration in erythrocyte aggregation parameters was observed. There were no significant relationships between RBC deformability and exercise performance. The results of this study show that, living (LHC) and training at altitude (LHTH) seems more advantageous in hemorheological point of view.

  5. Childhood anemia at high altitude: risk factors for poor outcomes in severe pneumonia.

    Science.gov (United States)

    Moschovis, Peter P; Banajeh, Salem; MacLeod, William B; Saha, Samir; Hayden, Douglas; Christiani, David C; Mino, Greta; Santosham, Mathuram; Thea, Donald M; Qazi, Shamim; Hibberd, Patricia L

    2013-11-01

    Pneumonia is the leading cause of mortality in young children globally, and factors that affect tissue delivery of oxygen may affect outcomes of pneumonia. We studied whether altitude and anemia influence disease severity and outcomes in young children with World Health Organization-defined severe pneumonia. We analyzed data from the SPEAR (Severe Pneumonia Evaluation Antimicrobial Research) study, a World Health Organization- and USAID-sponsored multinational randomized controlled trial of antibiotics for severe pneumonia among children aged 2 to 59 months in resource-poor settings. The trial enrolled 958 children in 8 sites at varying elevations, classified as high (≥ 2000 m) or low (risk: 4.07; 95% confidence interval: 2.60-6.38) but not at low altitude (relative risk: 1.12; 95% confidence interval: 0.96-1.30). Children at high altitude took longer to reach normoxemia than did children at lower altitudes (5.25 vs 0.75 days; P risk of poor outcome when being treated for severe pneumonia. Given the high global prevalence of anemia among young children, prevention and treatment of anemia should be a priority in children living at high altitude and could improve outcomes of pneumonia.

  6. Comparison of muscle force, muscle endurance, and electromyogram activity during an expedition at high altitude

    Science.gov (United States)

    Terasawa, K.; Fujiwara, T.; Sakai, A.; Yanagidaira, N.; Asano, K.; Yanagisawa, K.; Kashimura, N.; Ueda, G.; Wu, T.; Zhang, Y.

    1996-09-01

    Handgrip force (HF), maximal pinch force (MF), muscle endurance (ME), and the median power frequency (MdPF) of the activity shown in the electromyogram (EMG) were studied at various altitudes in eight normal healthy subjects. MF and ME were measured between the index finger and thumb, and all measurements were obtained at altitudes ranging from 610 to 4860 m during an expedition in the Qinghai Plateau in China. With the change in altitude HF, ME, and MF showed no significant change. Compared to the MdPF at 2260 m on ascent, the MdPF at other altitudes showed a significant decrease ( Pmuscle performance (HF, MF, and ME) was not affected by the environment at high altitude. However, MdPF was affected and the mean MdPF at 610 m after the expedition did not recover to initial values of MdPF. We suggest these results may have been affected by fatigue and chronic exposure to the hypobaric hypoxic environment, since the members of the expedition party expressed feelings of sluggishness and fatigue after the expedition.

  7. Natural Selection on Genes Related to Cardiovascular Health in High-Altitude Adapted Andeans.

    Science.gov (United States)

    Crawford, Jacob E; Amaru, Ricardo; Song, Jihyun; Julian, Colleen G; Racimo, Fernando; Cheng, Jade Yu; Guo, Xiuqing; Yao, Jie; Ambale-Venkatesh, Bharath; Lima, João A; Rotter, Jerome I; Stehlik, Josef; Moore, Lorna G; Prchal, Josef T; Nielsen, Rasmus

    2017-11-02

    The increase in red blood cell mass (polycythemia) due to the reduced oxygen availability (hypoxia) of residence at high altitude or other conditions is generally thought to be beneficial in terms of increasing tissue oxygen supply. However, the extreme polycythemia and accompanying increased mortality due to heart failure in chronic mountain sickness most likely reduces fitness. Tibetan highlanders have adapted to high altitude, possibly in part via the selection of genetic variants associated with reduced polycythemic response to hypoxia. In contrast, high-altitude-adapted Quechua- and Aymara-speaking inhabitants of the Andean Altiplano are not protected from high-altitude polycythemia in the same way, yet they exhibit other adaptive features for which the genetic underpinnings remain obscure. Here, we used whole-genome sequencing to scan high-altitude Andeans for signals of selection. The genes showing the strongest evidence of selection-including BRINP3, NOS2, and TBX5-are associated with cardiovascular development and function but are not in the response-to-hypoxia pathway. Using association mapping, we demonstrated that the haplotypes under selection are associated with phenotypic variations related to cardiovascular health. We hypothesize that selection in response to hypoxia in Andeans could have vascular effects and could serve to mitigate the deleterious effects of polycythemia rather than reduce polycythemia itself. Copyright © 2017. Published by Elsevier Inc.

  8. Modeling of occurrence frequencies of ion conics as a function of altitude and conic angle

    Directory of Open Access Journals (Sweden)

    W. Miyake

    Full Text Available The occurrence frequencies of dayside ion conics with various conic angles are obtained as a function of altitude from Exos-D (Akebono observations. We made a model calculation of ion conic evolution to match the observation results. The observed occurrence frequencies of ion conics with 80° to 90° conic angle are used as an input to the model and the occurrence frequencies of ion conics with smaller conic angles are numerically calculated at higher altitudes. The calculated occurrence frequencies are compared with the observed ones of ion conics with smaller conic angles. We take into account conic angle variation with altitude in both adiabatic and non-adiabatic cases, horizontal extension of ion conics due to E×B drift, and evolution to elevated conics and ion beams in the model. In the adiabatic case, the conic angle decreases with increasing altitude much faster than was observed. The occurrence frequency of small-angle conics is much larger than the observed value without E×B drift and evolution to the other UFIs. An agreement is obtained by assuming non-adiabatic variation of conic angles with altitude and an ion E×B drift to gyro velocity ratio of 0.08 to 0.6, depending on geomagnetic activities.

    Key words. Ionosphere (particle acceleration · Magnetospheric physics (auroral phenomena; magnetopause, cusp, and boundary layers.

  9. Air Quality Standards for Particulate Matter (PM) at high altitude cities

    International Nuclear Information System (INIS)

    Bravo Alvarez, H.; Sosa Echeverria, R.; Sanchez Alvarez, P.; Krupa, S.

    2013-01-01

    The Air Quality Standards for Particulate Matter (PM) at high altitude urban areas in different countries, must consider the pressure and temperature due to the effect that these parameters have on the breath volume. This paper shows the importance to correct Air Quality Standards for PM considering pressure and temperature at different altitudes. Specific factors were suggested to convert the information concerning PM, from local to standard conditions, and adjust the Air Quality Standards for different high altitudes cities. The correction factors ranged from: 1.03 for Santiago de Chile to 1.47 for El Alto Bolivia. Other cities in this study include: Mexico City, México; La Paz, Bolivia; Bogota, Cali and Medellin, Colombia; Quito, Ecuador and Cuzco, Peru. If these corrections are not considered, the atmospheric concentrations will be underestimated. - Highlights: ► AQS for particulate matter concentrations adjusted by pressure and temperature. ► Particulate matter concentrations can be underestimated in high altitude Cities. ► Particulate matter concentrations must be compared under the same conditions. - In order to compare high altitude atmospheric PM concentrations with AQS, one must consider T and P of the sampling site.

  10. The Use of Dexamethasone in Support of High-Altitude Ground Operations and Physical Performance: Review of the Literature

    Science.gov (United States)

    2014-12-01

    HAPE), and high-altitude cerebral edema (HACE). Although AMS is short lived and normally subsides within 2 to 7 days, HAPE and HACE are potentially...mountain sickness (AMS) treatment, high-altitude pulmonary edema (HAPE) treatment, and high-altitude cerebral edema (HACE). This review iden- tified...of treating cerebral edema derived from multiple etiologies. It is also used as a potent antiemetic for cancer chemotherapy patients. Several

  11. Transient altitude-induced compartment syndrome associated with fiberglass casts using waterproof cast padding.

    Science.gov (United States)

    Kadzielski, John; Bae, Donald S

    2013-01-01

    Changes in aircraft cabin pressure and its interplay with a fixed diameter fiberglass cylindrical cast and the closed air cells in waterproof cast padding may cause a transient altitude-induced compartment syndrome. In this case series, 2 patients reported transient compartment syndromes that resolved with aircraft decent. As proof of concept, this work displays photographic and video evidence showing the difference in air cell volume from experimental data in a vacuum chamber as well as real-world volume changes at cruise altitude in a commercial airliner. Transient altitude-induced compartment syndromes associated with fiberglass casts using waterproof cast padding are real and surgeons and patients should be advised of this potentially devastating complication.

  12. The High Altitude Water Čerenkov (HAWC) TeV Gamma Ray Observatory

    Science.gov (United States)

    de la Fuente, Eduardo; Oceguera-Becerra, Tomas; García-Torales, Guillermo; García-Luna, José Luis

    The High Altitude Water Čerenkov observatory is a second generation ground based very high-energy γ-ray detector under construction in Sierra Negra, Puebla, México at an altitude of 4,100m. Higher altitude, improved design and a larger physical size used to reject cosmic ray background, make HAWC 10-20 times more sensitive than its predecessor Milagro. HAWC's large field of view (˜2sr) and over 90% duty cycle make it ideal to search for several types of TeV astronomical γ-ray sources, diffuse emission, cosmic anisotropy, and transients. Details and status of HAWC at date, and a galactic star formation application are here presented.

  13. Effects of altitude on atrial natriuretic peptide: the Bicentennial Mount Everest Expedition.

    Science.gov (United States)

    Tunny, T J; van Gelder, J; Gordon, R D; Klemm, S A; Hamlet, S M; Finn, W L; Carney, G M; Brand-Maher, C

    1989-04-01

    1. Overnight recumbent atrial natriuretic peptide levels were significantly elevated in all ten subjects of the Australian Bicentennial Mount Everest Expedition during the first week at 5400 m, during acclimatization. 2. Twenty-four hour urine volume and urine sodium increased markedly at altitude. 3. Plasma renin activity and plasma aldosterone levels decreased significantly at altitude. 4. No significant changes in plasma cortisol, plasma sodium or potassium, body temperature, systolic or diastolic blood pressure or heart rate were observed. 5. Although it was impossible to control or measure salt and water intake during the study, results suggest that atrial natriuretic peptide may be important in the reduction in renin and aldosterone levels and in the diuresis and natriuresis necessary to adapt to hypoxia at altitude.

  14. Unchanged cerebral blood flow and oxidative metabolism after acclimatization to high altitude

    DEFF Research Database (Denmark)

    Møller, Kirsten; Paulson, Olaf B; Hornbein, Thomas F.

    2002-01-01

    . Global cerebral blood flow at rest and during exercise on a bicycle ergometer was measured by the Kety-Schmidt technique. Cerebral metabolic rates of oxygen, glucose, and lactate were calculated by the Fick principle. Cerebral function was assessed by a computer-based measurement of reaction time...... and cerebral metabolic rates of oxygen and glucose also remained unchanged, whereas cerebral metabolic rates of lactate increased slightly but nonsignificantly at high altitude during exercise compared with high altitude at rest. Reaction time was unchanged. The data indicate that cerebral blood flow......The authors investigated the effect of acclimatization to high altitude on cerebral blood flow and oxidative metabolism at rest and during exercise. Nine healthy, native sea-level residents were studied 3 weeks after arrival at Chacaltaya, Bolivia (5,260 m) and after reacclimatization to sea level...

  15. Image Positioning Accuracy Analysis for Super Low Altitude Remote Sensing Satellites

    Directory of Open Access Journals (Sweden)

    Ming Xu

    2012-10-01

    Full Text Available Super low altitude remote sensing satellites maintain lower flight altitudes by means of ion propulsion in order to improve image resolution and positioning accuracy. The use of engineering data in design for achieving image positioning accuracy is discussed in this paper based on the principles of the photogrammetry theory. The exact line-of-sight rebuilding of each detection element and this direction precisely intersecting with the Earth's elliptical when the camera on the satellite is imaging are both ensured by the combined design of key parameters. These parameters include: orbit determination accuracy, attitude determination accuracy, camera exposure time, accurately synchronizing the reception of ephemeris with attitude data, geometric calibration and precise orbit verification. Precise simulation calculations show that image positioning accuracy of super low altitude remote sensing satellites is not obviously improved. The attitude determination error of a satellite still restricts its positioning accuracy.

  16. Periodic breathing and oxygen supplementation in Chilean miners at high altitude (4200m).

    Science.gov (United States)

    Moraga, Fernando A; Jiménez, Daniel; Richalet, Jean Paul; Vargas, Manuel; Osorio, Jorge

    2014-11-01

    Our objective was to determine the nocturnal ventilatory pattern and characterize the effect of oxygen enrichment on nocturnal ventilatory pattern and sleep quality in miners exposed to intermittent hypobaric hypoxia at 4200m. A total of 16 acclimatized miners were studied. Nocturnal ventilatory pattern (plethysmographic inductance), arterial oxygen saturation and heart rate (pulse oximetry) were performed in 9/16 subjects. Sleep quality at high altitude was assessed by self-questionnaires in 16/16 subjects. All measurements were performed during at least 7h of sleep. Subjects were studied while sleeping at high altitude without (control, C) and with oxygen supplementation (FiO2=0.25, treated, T). Periodic breathing (%) C: 25±18 vs T: 6.6±5.6 (pbreathing with apneas was present in miners exposed to high altitude for 1 to 4 years and was reduced by treatment with supplementary oxygen. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Oxidative DNA damage and repair in skeletal muscle of humans exposed to high-altitude hypoxia

    DEFF Research Database (Denmark)

    Lundby, Carsten; Pilegaard, Henriette; van Hall, Gerrit

    2003-01-01

    -consuming tissue. Muscle biopsies from seven healthy humans were obtained at sea level and after 2 and 8 weeks of hypoxia at 4100 m.a.s.l. We found increased levels of strand breaks and endonuclease III-sensitive sites after 2 weeks of hypoxia, whereas oxidative DNA damage detected by formamidopyrimidine DNA......) was unaltered by prolonged hypoxia, in accordance with the notion that HO-1 is an acute stress response protein. In conclusion, our data indicate high-altitude hypoxia may serve as a good model for oxidative stress and that antioxidant genes are not upregulated in muscle tissue by prolonged hypoxia despite......Recent research suggests that high-altitude hypoxia may serve as a model for prolonged oxidative stress in healthy humans. In this study, we investigated the consequences of prolonged high-altitude hypoxia on the basal level of oxidative damage to nuclear DNA in muscle cells, a major oxygen...

  18. The evolution of Titan's high-altitude aerosols under ultraviolet irradiation

    Science.gov (United States)

    Carrasco, Nathalie; Tigrine, Sarah; Gavilan, Lisseth; Nahon, Laurent; Gudipati, Murthy S.

    2018-04-01

    The Cassini-Huygens space mission revealed that Titan's thick brownish haze is initiated high in the atmosphere at an altitude of about 1,000 km, before a slow transportation down to the surface. Close to the surface, at altitudes below 130 km, the Huygens probe provided information on the chemical composition of the haze. So far, we have not had insights into the possible photochemical evolution of the aerosols making up the haze during their descent. Here, we address this atmospheric aerosol aging process, simulating in the laboratory how solar vacuum ultraviolet irradiation affects the aerosol optical properties as probed by infrared spectroscopy. An important evolution was found that could explain the apparent contradiction between the nitrogen-poor infrared spectroscopic signature observed by Cassini below 600 km of altitude in Titan's atmosphere and a high nitrogen content as measured by the aerosol collector and pyrolyser of the Huygens probe at the surface of Titan.

  19. Mitochondrial function in human skeletal muscle following high-altitude exposure

    DEFF Research Database (Denmark)

    Jacobs, Robert A; Boushel, Robert; Wright-Paradis, Cynthia

    2013-01-01

    Studies regarding mitochondrial modifications in human skeletal muscle following acclimatization to high altitude are conflicting, and these inconsistencies may be due to the prevalence of representing mitochondrial function through static and isolated measurements of specific mitochondrial...... characteristics. The aim of this study, therefore, was to investigate mitochondrial function in response to high-altitude acclimatization through measurements of respiratory control in the vastus lateralis muscle. Skeletal muscle biopsies were obtained from 10 lowland natives prior to and again after a total of 9......-11 days of exposure to 4559 m. High-resolution respirometry was performed on the muscle samples to compare respiratory chain function and respiratory capacities. Respirometric analysis revealed that mitochondrial function was largely unaffected, because high-altitude exposure did not affect the capacity...

  20. A Robust Photogrammetric Processing Method of Low-Altitude UAV Images

    Directory of Open Access Journals (Sweden)

    Mingyao Ai

    2015-02-01

    Full Text Available Low-altitude Unmanned Aerial Vehicles (UAV images which include distortion, illumination variance, and large rotation angles are facing multiple challenges of image orientation and image processing. In this paper, a robust and convenient photogrammetric approach is proposed for processing low-altitude UAV images, involving a strip management method to automatically build a standardized regional aerial triangle (AT network, a parallel inner orientation algorithm, a ground control points (GCPs predicting method, and an improved Scale Invariant Feature Transform (SIFT method to produce large number of evenly distributed reliable tie points for bundle adjustment (BA. A multi-view matching approach is improved to produce Digital Surface Models (DSM and Digital Orthophoto Maps (DOM for 3D visualization. Experimental results show that the proposed approach is robust and feasible for photogrammetric processing of low-altitude UAV images and 3D visualization of products.

  1. Atmospheric drag model for Cassini orbit determination during low altitude Titan flybys

    Science.gov (United States)

    Pelletier, F. J.; Antreasian, P. G.; Bordi, J. J.; Criddle, K. E.; Ionasescu, R.; Jacobson, R. A.; Mackenzie, R. A.; Parcher, D. W.; Stauch, J. R.

    2006-01-01

    On April 16, 2005, the Cassini spacecraft performed its lowest altitude flyby of Titan to date, the Titan-5 flyby, flying 1027 km above the surface of Titan. This document discusses the development of a Titan atmospheric drag model for the purpose of the orbit determination of Cassini. Results will be presented for the Titan A flyby, the Titan-5 flyby as well as the most recent low altitude Titan flyby, Titan-7. Different solutions will be compared against OD performance in terms of the flyby B-plane parameters, spacecraft thrusting activity and drag estimates. These low altitude Titan flybys were an excellent opportunity to observe the effect of Titan's atmospheric drag on the orbit determination solution and results show that the drag was successfully modeled to provide accurate flyby solutions.

  2. Mass balance, meteorology, area altitude distribution, glacier-surface altitude, ice motion, terminus position, and runoff at Gulkana Glacier, Alaska, 1996 balance year

    Science.gov (United States)

    March, Rod S.

    2003-01-01

    The 1996 measured winter snow, maximum winter snow, net, and annual balances in the Gulkana Glacier Basin were evaluated on the basis of meteorological, hydrological, and glaciological data. Averaged over the glacier, the measured winter snow balance was 0.87 meter on April 18, 1996, 1.1 standard deviation below the long-term average; the maximum winter snow balance, 1.06 meters, was reached on May 28, 1996; and the net balance (from August 30, 1995, to August 24, 1996) was -0.53 meter, 0.53 standard deviation below the long-term average. The annual balance (October 1, 1995, to September 30, 1996) was -0.37 meter. Area-averaged balances were reported using both the 1967 and 1993 area altitude distributions (the numbers previously given in this abstract use the 1993 area altitude distribution). Net balance was about 25 percent less negative using the 1993 area altitude distribution than the 1967 distribution. Annual average air temperature was 0.9 degree Celsius warmer than that recorded with the analog sensor used since 1966. Total precipitation catch for the year was 0.78 meter, 0.8 standard deviations below normal. The annual average wind speed was 3.5 meters per second in the first year of measuring wind speed. Annual runoff averaged 1.50 meters over the basin, 1.0 standard deviation below the long-term average. Glacier-surface altitude and ice-motion changes measured at three index sites document seasonal ice-speed and glacier-thickness changes. Both showed a continuation of a slowing and thinning trend present in the 1990s. The glacier terminus and lower ablation area were defined for 1996 with a handheld Global Positioning System survey of 126 locations spread out over about 4 kilometers on the lower glacier margin. From 1949 to 1996, the terminus retreated about 1,650 meters for an average retreat rate of 35 meters per year.

  3. Different training responses to eccentric endurance exercise at low and moderate altitudes in pre-diabetic men: a pilot study.

    Science.gov (United States)

    Klarod, Kultida; Philippe, Marc; Gatterer, Hannes; Burtscher, Martin

    2017-01-01

    This pilot study aimed (a) to evaluate the effects of eccentric exercise training at low and moderate altitudes on physical fitness in pre-diabetic men and (b) to establish whether or not oxidative stress levels and antioxidant status were associated with performance improvements. In this crossover trial, five pre-diabetic men conducted nine downhill walking sessions (3 days/week, 3 consecutive weeks) at low altitude (from 1360 to 850 m) and one year later at moderate altitude (from 2447 to 2000 m). Exercise testing and the determination of parameters of oxidative stress and antioxidant capacity were performed pre- and post-training. The biological antioxidant activity of plasma (BAP) increased after eccentric training at moderate altitude ( p  training at moderate-altitude training ( p  = 0.009). Maximum power output improved after training at low altitude and the changes were significantly related to baseline BAP/dROMs ratio ( r  = 0.90). No decrease was seen for fasting plasma glucose. Eccentric exercise training in pre-diabetic men improved performance only when performed at low altitude and this improvement was positively related to the baseline BAP/dROMs ratio. In contrast, 3 weeks of eccentric exercise training increased BAP levels and the BAP/dROMs ratio only at moderate altitude without improving the performance. Thus, one might speculate that the BAP/dROMs ratio has to increase before performance improvements occur at moderate altitude.

  4. Increased Hypoxic Dose After Training at Low Altitude with 9h Per Night at 3000m Normobaric Hypoxia.

    Science.gov (United States)

    Carr, Amelia J; Saunders, Philo U; Vallance, Brent S; Garvican-Lewis, Laura A; Gore, Christopher J

    2015-12-01

    This study examined effects of low altitude training and a live-high: train-low protocol (combining both natural and simulated modalities) on haemoglobin mass (Hbmass), maximum oxygen consumption (VO2max), time to exhaustion, and submaximal exercise measures. Eighteen elite-level race-walkers were assigned to one of two experimental groups; lowHH (low Hypobaric Hypoxia: continuous exposure to 1380 m for 21 consecutive days; n = 10) or a combined low altitude training and nightly Normobaric Hypoxia (lowHH+NHnight: living and training at 1380 m, plus 9 h.night(-1) at a simulated altitude of 3000 m using hypoxic tents; n = 8). A control group (CON; n = 10) lived and trained at 600 m. Measurement of Hbmass, time to exhaustion and VO2max was performed before and after the training intervention. Paired samples t-tests were used to assess absolute and percentage change pre and post-test differences within groups, and differences between groups were assessed using a one-way ANOVA with least significant difference post-hoc testing. Statistical significance was tested at p altitude (1380 m) combined with sleeping in altitude tents (3000 m) as one effective alternative to traditional altitude training methods, which can improve Hbmass. Key pointsIn some countries, it may not be possible to perform classical altitude training effectively, due to the low elevation at altitude training venues. An additional hypoxic stimulus can be provided by simulating higher altitudes overnight, using altitude tents.Three weeks of combined (living and training at 1380 m) and simulated altitude exposure (at 3000 m) can improve haemoglobin mass by over 3% in comparison to control values, and can also improve time to exhaustion by ~9% in comparison to baseline.We recommend that, in the context of an altitude training camp at low altitudes (~1400 m) the addition of a relatively short exposure to simulated altitudes of 3000 m can elicit physiological and performance benefits, without compromise to

  5. Effects of antioxidant vitamins on newborn and placental traits in gestations at high altitude: comparative study in high and low altitude native sheep.

    Science.gov (United States)

    Parraguez, Víctor H; Atlagich, Miljenko; Araneda, Oscar; García, Carlos; Muñoz, Andrés; De Los Reyes, Mónica; Urquieta, Bessie

    2011-01-01

    The present study evaluated the hypothesis that the effects of hypoxia on sheep pregnancies at high altitude (HA) are mediated by oxidative stress and that antioxidant vitamins may prevent these effects. Both HA native and newcomer ewes were maintained at an altitude of 3,589 m during mating and pregnancy. Control low altitude (LA) native ewes were maintained at sea level. Half of each group received daily oral supplements of vitamins C (500 mg) and E (350 IU) during mating and gestation. Near term, maternal plasma vitamin levels and oxidative stress biomarkers were measured. At delivery, lambs were weighed and measured, and placentas were recovered for macroscopic and microscopic evaluation. Vitamin concentrations in supplemented ewes were two- or threefold greater than in non-supplemented ewes. Plasma carbonyls and malondialdehyde in non-supplemented ewes were consistent with a state of oxidative stress, which was prevented by vitamin supplementation. Vitamin supplementation increased lamb birthweight and cotyledon number in both HA native and newcomer ewes, although placental weight and cotyledon surface were diminished. Placentas from vitamin-supplemented HA ewes were similar to those from ewes at sea level, making these placental traits (weight, number and diameter of cotyledons) similar to those from ewes at sea level. Vitamin supplementation had no effect on LA pregnancies. In conclusion, supplementation with vitamins C and E during pregnancy at HA prevents oxidative stress, improving pregnancy outcomes.

  6. Proton isotropy boundaries as measured on mid- and low-altitude satellites

    Directory of Open Access Journals (Sweden)

    N. Yu. Ganushkina

    2005-07-01

    Full Text Available Polar CAMMICE MICS proton pitch angle distributions with energies of 31-80 keV were analyzed to determine the locations where anisotropic pitch angle distributions (perpendicular flux dominating change to isotropic distributions. We compared the positions of these mid-altitude isotropic distribution boundaries (IDB for different activity conditions with low-altitude isotropic boundaries (IB observed by NOAA 12. Although the obtained statistical properties of IDBs were quite similar to those of IBs, a small difference in latitudes, most pronounced on the nightside and dayside, was found. We selected several events during which simultaneous observations in the same local time sector were available from Polar at mid-altitudes, and NOAA or DMSP at low-altitudes. Magnetic field mapping using the Tsyganenko T01 model with the observed solar wind input parameters showed that the low- and mid-altitude isotropization boundaries were closely located, which leads us to suggest that the Polar IDB and low-altitude IBs are related. Furthermore, we introduced a procedure to control the difference between the observed and model magnetic field to reduce the large scatter in the mapping. We showed that the isotropic distribution boundary (IDB lies in the region where Rc/ρ~6, that is at the boundary of the region where the non-adiabatic pitch angle scattering is strong enough. We therefore conclude that the scattering in the large field line curvature regions in the nightside current sheet is the main mechanism producing isotropization for the main portion of proton population in the tail current sheet. This mechanism controls the observed positions of both IB and IDB boundaries. Thus, this tail region can be probed, in its turn, with observations of these isotropy boundaries. Keywords. Magnetospheric physics (Energetic particles, Precipitating; Magnetospheric configuration and dynamics; Magnetotail

  7. High altitude bird migration at temperate latitudes: a synoptic perspective on wind assistance.

    Science.gov (United States)

    Dokter, Adriaan M; Shamoun-Baranes, Judy; Kemp, Michael U; Tijm, Sander; Holleman, Iwan

    2013-01-01

    At temperate latitudes the synoptic patterns of bird migration are strongly structured by the presence of cyclones and anticyclones, both in the horizontal and altitudinal dimensions. In certain synoptic conditions, birds may efficiently cross regions with opposing surface wind by choosing a higher flight altitude with more favourable wind. We observed migratory passerines at mid-latitudes that selected high altitude wind optima on particular nights, leading to the formation of structured migration layers at varying altitude up to 3 km. Using long-term vertical profiling of bird migration by C-band Doppler radar in the Netherlands, we find that such migration layers occur nearly exclusively during spring migration in the presence of a high-pressure system. A conceptual analytic framework providing insight into the synoptic patterns of wind assistance for migrants that includes the altitudinal dimension has so far been lacking. We present a simple model for a baroclinic atmosphere that relates vertical profiles of wind assistance to the pressure and temperature patterns occurring at temperate latitudes. We show how the magnitude and direction of the large scale horizontal temperature gradient affects the relative gain in wind assistance that migrants obtain through ascending. Temperature gradients typical for northerly high-pressure systems in spring are shown to cause high altitude wind optima in the easterly sectors of anticyclones, thereby explaining the frequent observations of high altitude migration in these synoptic conditions. Given the recurring synoptic arrangements of pressure systems across temperate continents, the opportunities for exploiting high altitude wind will differ between flyways, for example between easterly and westerly oceanic coasts.

  8. Improved running economy in elite runners after 20 days of simulated moderate-altitude exposure.

    Science.gov (United States)

    Saunders, P U; Telford, R D; Pyne, D B; Cunningham, R B; Gore, C J; Hahn, A G; Hawley, J A

    2004-03-01

    To investigate the effect of altitude exposure on running economy (RE), 22 elite distance runners [maximal O(2) consumption (Vo(2)) 72.8 +/- 4.4 ml x kg(-1) x min(-1); training volume 128 +/- 27 km/wk], who were homogenous for maximal Vo(2) and training, were assigned to one of three groups: live high (simulated altitude of 2,000-3,100 m)-train low (LHTL; natural altitude of 600 m), live moderate-train moderate (LMTM; natural altitude of 1,500-2,000 m), or live low-train low (LLTL; natural altitude of 600 m) for a period of 20 days. RE was assessed during three submaximal treadmill runs at 14, 16, and 18 km/h before and at the completion of each intervention. Vo(2), minute ventilation (Ve), respiratory exchange ratio, heart rate, and blood lactate concentration were determined during the final 60 s of each run, whereas hemoglobin mass (Hb(mass)) was measured on a separate occasion. All testing was performed under normoxic conditions at approximately 600 m. Vo(2) (l/min) averaged across the three submaximal running speeds was 3.3% lower (P = 0.005) after LHTL compared with either LMTM or LLTL. Ve, respiratory exchange ratio, heart rate, and Hb(mass) were not significantly different after the three interventions. There was no evidence of an increase in lactate concentration after the LHTL intervention, suggesting that the lower aerobic cost of running was not attributable to an increased anaerobic energy contribution. Furthermore, the improved RE could not be explained by a decrease in Ve or by preferential use of carbohydrate as a metabolic substrate, nor was it related to any change in Hb(mass). We conclude that 20 days of LHTL at simulated altitude improved the RE of elite distance runners.

  9. Vegetation Carbon Storage, Spatial Patterns and Response to Altitude in Lancang River Basin, Southwest China

    Directory of Open Access Journals (Sweden)

    Long Chen

    2016-01-01

    Full Text Available Vegetation plays a very important role of carbon (C sinks in the global C cycle. With its complex terrain and diverse vegetation types, the Lancang River Basin (LRB of southwest China has huge C storage capacity. Therefore, understanding the spatial variations and controlling mechanisms of vegetation C storage is important to understand the regional C cycle. In this study, data from a forest inventory and field plots were used to estimate and map vegetation C storage distribution in the LRB, to qualify the quantitative relationships between vegetation C density and altitude at sublot and township scale, and a linear model or polynomial model was used to identify the relationship between C density and altitude at two spatial scales and two statistical scales. The results showed that a total of 300.32 Tg C was stored in the LRB, an important C sink in China. The majority of C storage was contributed by forests, notably oaks. The vegetation C storage exhibited nonlinear variation with latitudinal gradients. Altitude had tremendous influences on spatial patterns of vegetation C storage of three geomorphological types in the LRB. C storage decreased with increasing altitude at both town and sublot scales in the flat river valley (FRV region and the mid-low mountains gorge (MMG region, and first increased then decreased in the alpine gorge (AG region. This revealed that, in southwest China, altitude changes the latitudinal patterns of vegetation C storage; especially in the AG area, C density in the mid-altitude (3100 m area was higher than that of adjacent areas.

  10. The influence of altitude and urbanisation on trends and mean dates in phenology (1980-2009).

    Science.gov (United States)

    Jochner, Susanne C; Sparks, Tim H; Estrella, Nicole; Menzel, Annette

    2012-03-01

    Long-term studies on urban phenology using network data are commonly limited by the small number of observation sites within city centres. Moreover, cities are often located on major rivers and consequently at lower altitudes than their rural surroundings. For these reasons, it is important (1) to go beyond a plain urban-rural comparison by taking the degree of urbanisation into account, and (2) to evaluate urbanisation and altitudinal effects simultaneously. Temporal phenological trends (1980-2009) for nine phenological spring events centred on the German cities of Frankfurt, Cologne and Munich were analysed. Trends of phenological onset dates were negative (i.e. earlier onset in phenology) for 96% of the 808 time series and significantly negative for 56% of the total number. Mean trends for the nine phenological events ranged between -0.23 days year(-1) for beech and -0.50 days year(-1) for hazel. The dependence of these trends and of mean dates on altitude and on the degree of urbanisation was explored. For mean dates, we demonstrated an earlier phenological onset at lower altitude and with a higher degree of urbanisation: altitude effects were highly significant and ranged between 1.34 days (100 m)(-1) (beech) and 4.27 days (100 m)(-1) (hazel). Coefficients for the log-transformed urban index were statistically significant for five events and varied greatly between events (coefficients from -1.74 for spruce to -5.08 for hazel). For trends in phenology, altitude was only significant for Norway maple, and no urban effects were significant. Hence, trends in phenology did not change significantly with higher altitudes or urbanised areas.

  11. Pulmonary capillary reserve and exercise capacity at high altitude in healthy humans.

    Science.gov (United States)

    Taylor, Bryan J; Coffman, Kirsten E; Summerfield, Douglas T; Issa, Amine N; Kasak, Alex J; Johnson, Bruce D

    2016-02-01

    We determined whether well-acclimatized humans have a reserve to recruit pulmonary capillaries in response to exercise at high altitude. At sea level, lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (DmCO), and pulmonary capillary blood volume (V c) were measured at rest before maximal oxygen consumption ([Formula: see text]) was determined in seven adults. Then, DLCO, DmCO and V c were measured pre- and post-exhaustive incremental exercise at 5150 m after ~40 days of acclimatization. Immediately after exercise at high altitude, there was an increase in group mean DmCO (14 ± 10%, P = 0.040) with no pre- to post-exercise change in group mean DLCO (46.9 ± 5.8 vs. 50.6 ± 9.6 ml/min/mmHg, P = 0.213) or V c (151 ± 28 vs. 158 ± 37 ml, P = 0.693). There was, however, a ~20% increase in DLCO from pre- to post-exercise at high altitude (51.2 ± 0.2 vs. 61.1 ± 0.2 ml/min/mmHg) with a concomitant increase in DmCO (123 ± 2 vs. 156 ± 4 ml/min/mmHg) and V c (157 ± 3 vs. 180 ± 8 ml) in 2 of the 7 participants. There was a significant positive relationship between the decrease in [Formula: see text] from sea level to high altitude and the change in DLCO and lung diffusing capacity for nitric oxide (DLNO) from rest to end-exercise at high altitude. These data suggest that recruitment of the pulmonary capillaries in response to exercise at high altitude is limited in most well-acclimatized humans but that any such a reserve may be associated with better exercise capacity.

  12. Temperature lidar measurements from 1 to 105 km altitude using resonance, Rayleigh, and Rotational Raman scattering

    Directory of Open Access Journals (Sweden)

    M. Alpers

    2004-01-01

    Full Text Available For the first time, three different temperature lidar methods are combined to obtain time-resolved complete temperature profiles with high altitude resolution over an altitude range from the planetary boundary layer up to the lower thermosphere (about 1–105 km. The Leibniz-Institute of Atmospheric Physics (IAP at Kühlungsborn, Germany (54° N, 12° E operates two lidar instruments, using three different temperature measurement methods, optimized for three altitude ranges: (1 Probing the spectral Doppler broadening of the potassium D1 resonance lines with a tunable narrow-band laser allows atmospheric temperature profiles to be determined at metal layer altitudes (80–105 km. (2 Between about 20 and 90 km, temperatures were calculated from Rayleigh backscattering by air molecules, where the upper start values for the calculation algorithm were taken from the potassium lidar results. Correction methods have been applied to account for, e.g. Rayleigh extinction or Mie scattering of aerosols below about 32 km. (3 At altitudes below about 25 km, backscattering in the Rotational Raman lines is strong enough to obtain temperatures by measuring the temperature dependent spectral shape of the Rotational Raman spectrum. This method works well down to about 1 km. The instrumental configurations of the IAP lidars were optimized for a 3–6 km overlap of the temperature profiles at the method transition altitudes. We present two night-long measurements with clear wave structures propagating from the lower stratosphere up to the lower thermosphere.

  13. Identifying positive selection candidate loci for high-altitude adaptation in Andean populations.

    Science.gov (United States)

    Bigham, Abigail W; Mao, Xianyun; Mei, Rui; Brutsaert, Tom; Wilson, Megan J; Julian, Colleen Glyde; Parra, Esteban J; Akey, Joshua M; Moore, Lorna G; Shriver, Mark D

    2009-12-01

    High-altitude environments (>2,500 m) provide scientists with a natural laboratory to study the physiological and genetic effects of low ambient oxygen tension on human populations. One approach to understanding how life at high altitude has affected human metabolism is to survey genome-wide datasets for signatures of natural selection. In this work, we report on a study to identify selection-nominated candidate genes involved in adaptation to hypoxia in one highland group, Andeans from the South American Altiplano. We analysed dense microarray genotype data using four test statistics that detect departures from neutrality. Using a candidate gene, single nucleotide polymorphism-based approach, we identified genes exhibiting preliminary evidence of recent genetic adaptation in this population. These included genes that are part of the hypoxia-inducible transcription factor ( HIF ) pathway, a biochemical pathway involved in oxygen homeostasis, as well as three other genomic regions previously not known to be associated with high-altitude phenotypes. In addition to identifying selection-nominated candidate genes, we also tested whether the HIF pathway shows evidence of natural selection. Our results indicate that the genes of this biochemical pathway as a group show no evidence of having evolved in response to hypoxia in Andeans. Results from particular HIF -targeted genes, however, suggest that genes in this pathway could play a role in Andean adaptation to high altitude, even if the pathway as a whole does not show higher relative rates of evolution. These data suggest a genetic role in high-altitude adaptation and provide a basis for genotype/phenotype association studies that are necessary to confirm the role of putative natural selection candidate genes and gene regions in adaptation to altitude.

  14. EFFECT OF MODERATE ALTITUDE ON PERIPHERAL MUSCLE OXYGENATION DURING LEG RESISTANCE EXERCISE IN YOUNG MALES

    Directory of Open Access Journals (Sweden)

    Toshio Matsuoka

    2004-09-01

    Full Text Available Training at moderate altitude (~1800m is often used by athletes to stimulate muscle hypoxia. However, limited date is available on peripheral muscle oxidative metabolism at this altitude (1800AL. The purpose of this study was to determine whether acute exposure to 1800AL alters muscle oxygenation in the vastus lateralis muscle during resistance exercise. Twenty young active male subjects (aged 16 - 21 yr performed up to 50 repetitions of the parallel squat at 1800AL and near sea level (SL. They performed the exercise protocol within 3 h after arrival at 1800 AL. During the exercise, the changes in oxygenated hemoglobin (OxyHb in the vastus lateralis muscle, arterial oxygen saturation (SpO2, and heart rate were measured using near infrared continuous wave spectroscopy (NIRcws and pulse oximetry, respectively. Changes in OxyHb were expressed by Deff defined as the relative index of the maximum change ratio (% from the resting level. OxyHb in the vastus lateralis muscle decreased dramatically from the resting level immediately after the start of exercise at both altitudes. The Deff during exercise was significantly (p < 0.001 lower at 1800AL (60.4 ± 6.2 % than at near SL (74.4 ± 7.6 %. SpO2 during exercise was significantly (p < 0.001 lower at 1800AL (92.0 ± 1.7 % than at near SL (96.7 ± 1.2 %. Differences (SL - 1800AL in Deff during exercise correlated fairly strongly with differences in SpO2 during exercise (r = 0.660. These results suggested that acute exposure to moderate altitude caused a more dramatical decrease in peripheral muscle oxygenation during leg resistance exercise. It is salient to note, therefore , that peripheral muscle oxygenation status at moderate altitude could be evaluated using NIRcws and that moderate altitudes might be effectively used to apply hypoxic stress on peripheral muscles.

  15. Reducing body fat with altitude hypoxia training in swimmers: role of blood perfusion to skeletal muscles.

    Science.gov (United States)

    Chia, Michael; Liao, Chin-An; Huang, Chih-Yang; Lee, Wen-Chih; Hou, Chien-Wen; Yu, Szu-Hsien; Harris, M Brennan; Hsu, Tung-Shiung; Lee, Shin-Da; Kuo, Chia-Hua

    2013-02-28

    Swimmers tend to have greater body fat than athletes from other sports. The purpose of the study was to examine changes in body composition after altitude hypoxia exposure and the role of blood distribution to the skeletal muscle in swimmers. With a constant training volume of 12.3 km/day, young male swimmers (N = 10, 14.8 ± 0.5 years) moved from sea-level to a higher altitude of 2,300 meters. Body composition was measured before and after translocation to altitude using dual-energy X-ray absorptiometry (DXA) along with 8 control male subjects who resided at sea level for the same period of time. To determine the effects of hypoxia on muscle blood perfusion, total hemoglobin concentration (THC) was traced by near-infrared spectroscopy (NIRS) in the triceps and quadriceps muscles under glucose-ingested and insulin-secreted conditions during hypoxia exposure (16% O2) after training. While no change in body composition was found in the control group, subjects who trained at altitude had unequivocally decreased fat mass (-1.7 ± 0.3 kg, -11.4%) with increased lean mass (+0.8 ± 0.2 kg, +1.5%). Arterial oxygen saturation significantly decreased with increased plasma lactate during hypoxia recovery mimicking 2,300 meters at altitude (~93% versus ~97%). Intriguingly, hypoxia resulted in elevated muscle THC, and sympathetic nervous activities occurred in parallel with greater-percent oxygen saturation in both muscle groups. In conclusion, the present study provides evidence that increased blood distribution to the skeletal muscle under postprandial condition may contribute to the reciprocally increased muscle mass and decreased body mass after a 3-week altitude exposure in swimmers.

  16. Tropical temperature altitude amplification in the hiatus period (1998-2012

    Directory of Open Access Journals (Sweden)

    Ducić Vladan D.

    2015-01-01

    Full Text Available In the period 1998-2012 there was a stagnation in temperature rise, despite the GHGs radiation forcing is increased (hiatus period. According to Global Circulation Models simulations, expected response on the rise of GHGs forcing is tropical temperature altitude amplification - temperature increases faster in higher troposphere than in lower troposphere. In this paper, two satellite data sets, UAH MSU and RSS, were used to test altitude temperature amplification in tropic (20°N-20°S in the hiatus period. We compared data from satellite data sets from lower troposphere (TLT and middle troposphere (TMT in general and particularly for land and ocean (for UAH MSU. The results from both satellite measurements showed the presence of hiatus, i.e. slowdown of the temperature rise in the period 1998-2012 compared to period 1979-2012 (UAH MSU and temperature fall for RSS data. Smaller increase, i.e. temperature fall over ocean showed that hiatus is an ocean phenomenon above all. Data for UAH MSU showed that temperature altitude amplification in tropic was not present either for period 1979-2012, or 1998-2012. RSS data set also do not show temperature altitude amplification either for longer (1979-2012, or for shorter period (1998-2012. RSS data for successive 15-year periods from 1979-1993 till 1998-2012 does not show tropical temperature altitude amplification and in one case negative trend is registered in TLT and in two cases in TMT. In general, our results do not show presence of temperature altitude amplification in tropic in the hiatus period. [Projekat Ministarstva nauke Republike Srbije, br. III47007

  17. [BEHAVIOR OF HEMOGLOBIN CONCENTRATION, HEMATOCRIT AND OXYGEN SATURATION IN COLOMBIAN UNIVERSITY POPULATION AT DIFFERENT ALTITUDES].

    Science.gov (United States)

    Trompetero González, Andrea Catalina; Cristancho Mejía, Edgar; Benavides Pinzón, William Fernando; Serrato Roa, Mauricio; Landinez Macias, María Paula; Rojas, Joel

    2015-11-01

    the development of this research is base on the growing interest in understanding the adaptations to chronic hipoxia mainly in the range of intermediate altitudes (1 500-3 000 m.s.n.m) and the need to establish parameters of normality in the variables [Hb], Hct and SO2 for diagnostic and characterization of the population purposes. to analyze the behavior of the [Hb], Hct and SaO2 at different intermediate altitudes (970 m.s.n.m, 1 520 m.s.n.m, 1 728 m.s.n.m, 1 923 m.s.n.m, 2 180 m.s.n.m and 2 600 m.s.n.m) in order to contribute to the knowledge of the high altitude physiology and the clinical field to support the diagnosis of anemia. clinically healthy subjects with low levels of physical activity and food consumption report containing iron. Total of 264 participants of both genders between 18 and 30 years. The blood samples were collected from the antecubital vein and the earlobe and analyzed in a radiometer. A non-parametric statistical analysis was performed. with increasing of altitude, [Hb] and Hct values were increased while the SO2 decreased. Men showed higher values than women in [Hb] and Hct, related to lower values of SO2 than women. a threshold variable was not found, perhaps because of the small distance between the altitudes. The values reported were similar but not identical to other studies. This difference could be explained by genetic diversity among populations. this study allows for the first values of characterization of the study population. All altitudes were above the cutoff for the diagnosis of anemia ([Hb] 12 g/dl). Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  18. Altitude-dependent and -independent variations in Plasmodium falciparum prevalence in northeastern Tanzania

    DEFF Research Database (Denmark)

    Drakeley, Chris J; Carneiro, Ilona; Reyburn, Hugh

    2005-01-01

    correlated with parasite prevalence and mean hemoglobin concentration; however, the relationship varied according to ecological setting. Climatological variables alone cannot predict malarial outcomes. Local variations in seasonality of malaria transmission--together with vector species composition......, topography, host and parasite genetics, and socioeconomic factors--may influence malaria prevalence....... of appropriate regression models. RESULTS: Plasmodium falciparum prevalence showed a negative relationship with altitude (19% and 21% decrease/100-m altitude increase, respectively, in children in Kilimanjaro and Tanga) and rainfall during the 3 months before the survey (46% decrease/100-mm rainfall increase...

  19. Coherent Doppler Lidar for Measuring Velocity and Altitude of Space and Arial Vehicles

    Science.gov (United States)

    Amzajerdian, Farzin; Pierrottet, Diego; Hines, Glenn D.; Petway, Larry; Barnes, Bruce W.

    2016-01-01

    A coherent Doppler lidar has been developed to support future NASA missions to planetary bodies. The lidar transmits three laser beams and measures line-of-sight range and velocity along each beam using a frequency modulated continuous wave (FMCW) technique. Accurate altitude and velocity vector data, derived from the line-of-sight measurements, enables the landing vehicle to precisely navigate from several kilometers above the ground to the designated location and execute a gentle touchdown. The same lidar sensor can also benefit terrestrial applications that cannot rely on GPS or require surface-relative altitude and velocity data.

  20. Phenylethanoid glycosides of Pedicularis muscicola Maxim ameliorate high altitude-induced memory impairment.

    Science.gov (United States)

    Zhou, Baozhu; Li, Maoxing; Cao, Xinyuan; Zhang, Quanlong; Liu, Yantong; Ma, Qiang; Qiu, Yan; Luan, Fei; Wang, Xianmin

    2016-04-01

    Exposure to hypobaric hypoxia causes oxidative stress, neuronal degeneration and apoptosis that leads to memory impairment. Though oxidative stress contributes to neuronal degeneration and apoptosis in hypobaric hypoxia, the ability for phenylethanoid glycosides of Pedicularis muscicola Maxim (PhGs) to reverse high altitude memory impairment has not been studied. Rats were supplemented with PhGs orally for a week. After the fourth day of drug administration, rats were exposed to a 7500 m altitude simulation in a specially designed animal decompression chamber for 3 days. Spatial memory was assessed by the 8-arm radial maze test before and after exposure to hypobaric hypoxia. Histological assessment of neuronal degeneration was performed by hematoxylin-eosin (HE) staining. Changes in oxidative stress markers and changes in the expression of the apoptotic marker, caspase-3, were assessed in the hippocampus. Our results demonstrated that after exposure to hypobaric hypoxia, PhGs ameliorated high altitude memory impairment, as shown by the decreased values obtained for reference memory error (RME), working memory error (WME), and total error (TE). Meanwhile, administration of PhGs decreased hippocampal reactive oxygen species levels and consequent lipid peroxidation by elevating reduced glutathione levels and enhancing the free radical scavenging enzyme system. There was also a decrease in the number of pyknotic neurons and a reduction in caspase-3 expression in the hippocampus. These findings suggest that PhGs may be used therapeutically to ameliorate high altitude memory impairment. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Effets cardiovasculaires d'un bloqueur calcique en hypoxie d'altitude

    DEFF Research Database (Denmark)

    Dugas, L; Dubray, C; Herry, J P

    1995-01-01

    High altitude pulmonary oedema can be successfully treated and prevented by calcium channel blockers. Moreover, calcium entering in the cells could explain the congestive phenomena of acute mountain sickness (AMS). These findings led us to study the action of a calcium channel blocker, isradipine...

  2. 75 FR 16336 - Establishment of Low Altitude Area Navigation Route (T-284); Houston, TX

    Science.gov (United States)

    2010-04-01

    ... (T-284); Houston, TX AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action establishes a low altitude area navigation (RNAV) route, designated T-284, in the Houston... navigable airspace in the Houston, TX, terminal area. DATES: Effective date 0901 UTC, July 29, 2010. The...

  3. 75 FR 18047 - Amendment of Low Altitude Area Navigation Route T-254; Houston, TX

    Science.gov (United States)

    2010-04-09

    ...-254; Houston, TX AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action amends low altitude Area Navigation (RNAV) route T-254 in the Houston, TX, terminal area by... Houston, TX, terminal area. DATES: Effective Dates: 0901 UTC, June 3, 2010. The Director of the Federal...

  4. Exercise capacity and selected physiological factors by ancestry and residential altitude

    DEFF Research Database (Denmark)

    Bianba; Berntsen, Sveinung; Andersen, Lars Bo

    2014-01-01

    level) and across ancestry (native Tibetan vs. Han Chinese children living at the same altitude of 3700 m). METHODS: A total of 430 9-10-year-old native Tibetan children from Tingri (4300 m) and 406 native Tibetan- and 406 Han Chinese immigrants (77% lowland-born and 33% highland-born) from Lhasa (3700...

  5. Physical activity at altitude: challenges for people with diabetes: a review

    NARCIS (Netherlands)

    Mol, P. de; Vries, S.T. de; Koning, E.J. de; Gans, R.O.; Bilo, H.J.; Tack, C.J.

    2014-01-01

    BACKGROUND: A growing number of subjects with diabetes take part in physical activities at altitude such as skiing, climbing, and trekking. Exercise under conditions of hypobaric hypoxia poses some unique challenges on subjects with diabetes, and the presence of diabetes can complicate safe and

  6. Present and former equilibrium-line altitudes near Mount Everest, Nepal and Tibet

    Science.gov (United States)

    Williams, V.S.

    1983-01-01

    New information on equilibrium-line altitudes (ELAs) of present and former glaciers in the Mount Everest area of eastern Nepal and southern Tibet has been derived from field mapping and interpretation of topographic maps and Landsat imagery. Present ELAs rise from south to north across the Himalayan Range from 5200 to 5800 m, as indicated by the altitudes of lowest cirque glaciers and highest lateral and medial moraines on valley glaciers. In contrast, ELAs during maximum late Pleistocene glaciation rose in altitude from 4300 to 5500 m across the range, as indicated by altitudes of lowest cirque floors and maximum extent of glacial deposits. Highest ELAs occurred on previously unrecognized ice caps that formerly covered extensive highland areas in Tibet north of the range crest. During four distinct Holocene glacial advances of subequal magnitude, ELAs were depressed about 30% as much as the late Pleistocene maximum depression. Depression of ELAs during the late Pleistocene glaciation was about twice as great south of the range crest (950 m) as north of it (400 m). Although the present northward decrease in precipitation causes ELAs to rise northward for 85 km at 7.1 m km-1, the gradient during maximum late Pleistocene glaciation was 11 m km-1. Such a great contrast in glacier response to climate change over a short distance is remarkable and probably reflects increased aridity on the Tibetan Plateau and increased climatic contrast across the Himalayan Range during glacial ages.

  7. Bird migration flight altitudes studied by a network of operational weather radars.

    Science.gov (United States)

    Dokter, Adriaan M; Liechti, Felix; Stark, Herbert; Delobbe, Laurent; Tabary, Pierre; Holleman, Iwan

    2011-01-06

    A fully automated method for the detection and quantification of bird migration was developed for operational C-band weather radar, measuring bird density, speed and direction as a function of altitude. These weather radar bird observations have been validated with data from a high-accuracy dedicated bird radar, which was stationed in the measurement volume of weather radar sites in The Netherlands, Belgium and France for a full migration season during autumn 2007 and spring 2008. We show that weather radar can extract near real-time bird density altitude profiles that closely correspond to the density profiles measured by dedicated bird radar. Doppler weather radar can thus be used as a reliable sensor for quantifying bird densities aloft in an operational setting, which--when extended to multiple radars--enables the mapping and continuous monitoring of bird migration flyways. By applying the automated method to a network of weather radars, we observed how mesoscale variability in weather conditions structured the timing and altitude profile of bird migration within single nights. Bird density altitude profiles were observed that consisted of multiple layers, which could be explained from the distinct wind conditions at different take-off sites. Consistently lower bird densities are recorded in The Netherlands compared with sites in France and eastern Belgium, which reveals some of the spatial extent of the dominant Scandinavian flyway over continental Europe.

  8. Development of the High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP)

    Science.gov (United States)

    Heymsfield, G. M.; Carswell, J. R.; Li, L.; Schaubert, D.; Heymsfield, J. C.

    2006-12-01

    A dual-wavelength (Ku and Ka band) High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) is under development for measuring tropospheric winds within precipitation regions and ocean surface winds in rain-free to light rain regions. This instrument is being designed for operation on high-altitude manned aircraft and the Global Hawk UAV. Proposed lidar-based systems provide measurements in cloud-free regions globally. Since many of the weather systems are in disturbed regions that contain precipitation and clouds, microwave based techniques are more suitable in these regions. Airborne radars at NASA and elsewhere have shown the ability to measure winds in precipitation and clouds. These radars have not generally been suitable for deriving the full horizontal wind from above cloud systems (high-altitude or space) that would require conical scan. HIWRAP is conical scan radar that uses new technologies that utilize solid state rather than tube based transmitters. The presentation will discuss the motivation for the instrument, key system level technologies, status, and planned flight testing of the prototype sensor on the high-altitude WB-57 aircraft to demonstrate the system level performance of the instrument.

  9. Effect of high altitude on sensitivity to the taste of phenylthiocarbamide

    Science.gov (United States)

    Singh, S. B.; Chatterjee, A.; Panjwani, U.; Yadav, D. K.; Selvamurthy, W.; Sharma, K. N.

    Sensitivity to the taste of phenylthiocarbamide (PTC) was studied using the Harris-Kalmus method in healthy human volunteers at sea level and then subsequently at an altitude of 3500 m over a period of 3 weeks, after which they were brought back to sea level. Blood sugar, insulin and blood cortisol levels were estimated weekly. The results indicated that, out of 51 subjects studied, 26 (55%) were PTC tasters at sea level. Eight of those unable to taste PTC at sea level tested as tasters at high altitude, and 2 of them reverted to being non-tasters on return to sea level. In the blood, an increase in cortisol and blood insulin levels was seen without any significant change in sugar levels. All the changes recorded at high altitude tended to return to basal values after re-induction to sea level. The study suggests that high-altitude hypoxia in some way, possibly involving changes in hormonal profile among other factors, causes an alteration in sensitivity to the taste of PTC, resulting in some of the individuals shifting to lower PTC sensitivity.

  10. Does altitude moderate the impact of lithium on suicide? : The case of Austria

    NARCIS (Netherlands)

    Helbich, M.; Blüml, V.; Leitner, M.; Kapusta, N.

    2013-01-01

    Suicide, the tenth leading cause of death worldwide, is a complex phenomenon. Models aiming to explain the interaction of ambient variables such as socioeconomic factors, lithium content of drinking water and altitude are poorly developed. While controlling for several risk factors, this research

  11. The effect of altitude and climate on the suicide rates in Turkey.

    Science.gov (United States)

    Asirdizer, Mahmut; Kartal, Erhan; Etli, Yasin; Tatlisumak, Ertugrul; Gumus, Orhan; Hekimoglu, Yavuz; Keskin, Sıddık

    2018-02-01

    Suicide is one of the most important public health problems. There was an association between suicide and several factors such as psychiatric diseases and psychological characteristics, somatic illness, cultural, socioeconomic, familial, occupational and individual risk factors. Also, high altitude and climatic factors including high temperature, cloudiness, more sunshine and low rainfalls were defined as some of these risk factors in the literature. In this study, we aimed to investigate correlation between suicide rates and altitudes of all cities in Turkey and between suicide rates and climatic factors including Rainfall Activity Index, Winter Mean Temperatures, Summer Mean Temperatures and Temperature Difference between January and July previously defined by several authors in the broad series in Turkey. In Turkey, 29865 suicidal deaths occurred in 10 years period between 2006 and 2015. Of them, 21020 (70.4%) were males and 8845 (29.6%) were females. In this study, we found that high altitude above 1500 m, winter median temperature lower than -10 °C and hard temperature changes above 25 °C between winter and summer of settlements were important factors that affected on female suicide rates appropriate to knowledge which defined in previous studies. In conclusion, we suggested that the associations among suicide rates with altitudes and climate should be studied in wider series obtained from different countries for reaching more reliable results. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  12. High-altitude hypoxia and periodic breathing during sleep: gender-related differences.

    Science.gov (United States)

    Lombardi, Carolina; Meriggi, Paolo; Agostoni, Piergiuseppe; Faini, Andrea; Bilo, Grzegorz; Revera, Miriam; Caldara, Gianluca; Di Rienzo, Marco; Castiglioni, Paolo; Maurizio, Bussotti; Gregorini, Francesca; Mancia, Giuseppe; Parati, Gianfranco

    2013-06-01

    High-altitude exposure is characterized by the appearance of periodic breathing during sleep. Only limited evidence is available, however, on the presence of gender-related differences in this breathing pattern. In 37 healthy subjects, 23 male and 14 female, we performed nocturnal cardio-respiratory monitoring in the following conditions: (1) sea level; (2) first/second night at an altitude of 3400 m; (3) first/second night at an altitude of 5400 m and after a 10 day sojourn at 5400 m. At sea level, a normal breathing pattern was observed in all subjects throughout the night. At 3400 m the apnea-hypopnea index was 40.3 ± 33.0 in males (central apneas 77.6%, central hypopneas 22.4%) and 2.4 ± 2.8 in females (central apneas 58.2%, central hypopneas 41.8%; P breathing affects males more than females. Females started to present a significant number of central sleep apneas only at the highest reached altitude. After 10 days at 5400 m gender differences in the apnea-hypopnea index similar to those observed after acute exposure were still observed, accompanied by differences in respiratory cycle length. © 2013 European Sleep Research Society.

  13. Colonization of high altitudes by alien plants over the last two centuries

    Czech Academy of Sciences Publication Activity Database

    Pyšek, Petr; Jarošík, Vojtěch; Pergl, Jan; Wild, Jan

    2011-01-01

    Roč. 108, č. 2 (2011), s. 439-440 ISSN 0027-8424 R&D Projects: GA MŠk LC06073; GA ČR GA206/09/0563 Institutional research plan: CEZ:AV0Z60050516 Keywords : altitude * plant invasions * residence time Subject RIV: EF - Botanics Impact factor: 9.681, year: 2011

  14. Genomic analysis of natural selection and phenotypic variation in high-altitude mongolians.

    Science.gov (United States)

    Xing, Jinchuan; Wuren, Tana; Simonson, Tatum S; Watkins, W Scott; Witherspoon, David J; Wu, Wilfred; Qin, Ga; Huff, Chad D; Jorde, Lynn B; Ge, Ri-Li

    2013-01-01

    Deedu (DU) Mongolians, who migrated from the Mongolian steppes to the Qinghai-Tibetan Plateau approximately 500 years ago, are challenged by environmental conditions similar to native Tibetan highlanders. Identification of adaptive genetic factors in this population could provide insight into coordinated physiological responses to this environment. Here we examine genomic and phenotypic variation in this unique population and present the first complete analysis of a Mongolian whole-genome sequence. High-density SNP array data demonstrate that DU Mongolians share genetic ancestry with other Mongolian as well as Tibetan populations, specifically in genomic regions related with adaptation to high altitude. Several selection candidate genes identified in DU Mongolians are shared with other Asian groups (e.g., EDAR), neighboring Tibetan populations (including high-altitude candidates EPAS1, PKLR, and CYP2E1), as well as genes previously hypothesized to be associated with metabolic adaptation (e.g., PPARG). Hemoglobin concentration, a trait associated with high-altitude adaptation in Tibetans, is at an intermediate level in DU Mongolians compared to Tibetans and Han Chinese at comparable altitude. Whole-genome sequence from a DU Mongolian (Tianjiao1) shows that about 2% of the genomic variants, including more than 300 protein-coding changes, are specific to this individual. Our analyses of DU Mongolians and the first Mongolian genome provide valuable insight into genetic adaptation to extreme environments.

  15. Sighting of King Cobra Ophiophagus hannah in Sikkim, India: a new altitude record for the northeast

    Directory of Open Access Journals (Sweden)

    T. Bashir

    2010-06-01

    Full Text Available We report the sighting of Ophiophagus hannah from Yuksam Village bordering Khangchendzonga Biosphere Reserve in Sikkim. The present record signifies a range extention for this species with respect to altitude (1,840m and habitat (temperate forests reported for this state and the northeast India.

  16. Genomic analysis of natural selection and phenotypic variation in high-altitude mongolians.

    Directory of Open Access Journals (Sweden)

    Jinchuan Xing

    Full Text Available Deedu (DU Mongolians, who migrated from the Mongolian steppes to the Qinghai-Tibetan Plateau approximately 500 years ago, are challenged by environmental conditions similar to native Tibetan highlanders. Identification of adaptive genetic factors in this population could provide insight into coordinated physiological responses to this environment. Here we examine genomic and phenotypic variation in this unique population and present the first complete analysis of a Mongolian whole-genome sequence. High-density SNP array data demonstrate that DU Mongolians share genetic ancestry with other Mongolian as well as Tibetan populations, specifically in genomic regions related with adaptation to high altitude. Several selection candidate genes identified in DU Mongolians are shared with other Asian groups (e.g., EDAR, neighboring Tibetan populations (including high-altitude candidates EPAS1, PKLR, and CYP2E1, as well as genes previously hypothesized to be associated with metabolic adaptation (e.g., PPARG. Hemoglobin concentration, a trait associated with high-altitude adaptation in Tibetans, is at an intermediate level in DU Mongolians compared to Tibetans and Han Chinese at comparable altitude. Whole-genome sequence from a DU Mongolian (Tianjiao1 shows that about 2% of the genomic variants, including more than 300 protein-coding changes, are specific to this individual. Our analyses of DU Mongolians and the first Mongolian genome provide valuable insight into genetic adaptation to extreme environments.

  17. Physical Activity at Altitude : Challenges for People With Diabetes A Review

    NARCIS (Netherlands)

    de Mol, Pieter; de Vries, Suzanna T.; de Koning, Eelco J. P.; Gans, Reinold O. B.; Bilo, Henk J. G.; Tack, Cees J.

    BACKGROUND A growing number of subjects with diabetes take part in physical activities at altitude such as skiing, climbing, and trekking. Exercise under conditions of hypobaric hypoxia poses some unique challenges on subjects with diabetes, and the presence of diabetes can complicate safe and

  18. Regulatory changes contribute to the adaptive enhancement of thermogenic capacity in high-altitude deer mice.

    Science.gov (United States)

    Cheviron, Zachary A; Bachman, Gwendolyn C; Connaty, Alex D; McClelland, Grant B; Storz, Jay F

    2012-05-29

    In response to hypoxic stress, many animals compensate for a reduced cellular O(2) supply by suppressing total metabolism, thereby reducing O(2) demand. For small endotherms that are native to high-altitude environments, this is not always a viable strategy, as the capacity for sustained aerobic thermogenesis is critical for survival during periods of prolonged cold stress. For example, survivorship studies of deer mice (Peromyscus maniculatus) have demonstrated that thermogenic capacity is under strong directional selection at high altitude. Here, we integrate measures of whole-organism thermogenic performance with measures of metabolic enzyme activities and genomic transcriptional profiles to examine the mechanistic underpinnings of adaptive variation in this complex trait in deer mice that are native to different elevations. We demonstrate that highland deer mice have an enhanced thermogenic capacity under hypoxia compared with lowland conspecifics and a closely related lowland species, Peromyscus leucopus. Our findings suggest that the enhanced thermogenic performance of highland deer mice is largely attributable to an increased capacity to oxidize lipids as a primary metabolic fuel source. This enhanced capacity for aerobic thermogenesis is associated with elevated activities of muscle metabolic enzymes that influence flux through fatty-acid oxidation and oxidative phosphorylation pathways in high-altitude deer mice and by concomitant changes in the expression of genes in these same pathways. Contrary to predictions derived from studies of humans at high altitude, our results suggest that selection to sustain prolonged thermogenesis under hypoxia promotes a shift in metabolic fuel use in favor of lipids over carbohydrates.

  19. Persistence of chironomids in metal polluted Andean high altitude streams: does melanin play a role?

    NARCIS (Netherlands)

    Loayza Muro, R.A.; Marticorena-Ruíz, J.K.; Palomino, E.J.; Merritt, C.; de Baat, M.L.; van Gemert, M.; Verweij, R.A.; Kraak, M.H.S.; Admiraal, W.

    2013-01-01

    In high altitude Andean streams an intense solar radiation and coinciding metal pollution allow the persistence of only a few specialized taxa, including chironomids. The aim of the present study was therefore to determine the mechanisms underlying the persistence of chironomids under these multiple

  20. Altitude acclimatization improves submaximal cognitive performance in mice and involves an imbalance of the cholinergic system.

    Science.gov (United States)

    Guerra-Narbona, R; Delgado-García, J M; López-Ramos, J C

    2013-06-15

    The aim of this work was to reveal a hypothetical improvement of cognitive abilities in animals acclimatized to altitude and performing under ground level conditions, when looking at submaximal performance, once seen that it was not possible when looking at maximal scores. We modified contrasted cognitive tasks (object recognition, operant conditioning, eight-arm radial maze, and classical conditioning of the eyeblink reflex), increasing their complexity in an attempt to find performance differences in acclimatized animals vs. untrained controls. In addition, we studied, through immunohistochemical quantification, the expression of choline acetyltransferase and acetyl cholinesterase, enzymes involved in the synthesis and degradation of acetylcholine, in the septal area, piriform and visual cortexes, and the hippocampal CA1 area of animals submitted to acute hypobaric hypoxia, or acclimatized to this simulated altitude, to find a relationship between the cholinergic system and a cognitive improvement due to altitude acclimatization. Results showed subtle improvements of the cognitive capabilities of acclimatized animals in all of the tasks when performed under ground-level conditions (although not before 24 h), in the three tasks used to test explicit memory (object recognition, operant conditioning in the Skinner box, and eight-arm radial maze) and (from the first conditioning session) in the classical conditioning task used to evaluate implicit memory. An imbalance of choline acetyltransferase/acetyl cholinesterase expression was found in acclimatized animals, mainly 24 h after the acclimatization period. In conclusion, altitude acclimatization improves cognitive capabilities, in a process parallel to an imbalance of the cholinergic system.

  1. Cardiac adaptation to chronic high-altitude hypoxia: Beneficial and adverse effects

    Czech Academy of Sciences Publication Activity Database

    Ošťádal, Bohuslav; Kolář, František

    2007-01-01

    Roč. 158, 2-3 (2007), s. 224-236 ISSN 1569-9048 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GA305/07/0875 Institutional research plan: CEZ:AV0Z50110509 Keywords : heart * high altitude * adaptation Subject RIV: ED - Physiology Impact factor: 2.202, year: 2007

  2. 14 CFR 91.411 - Altimeter system and altitude reporting equipment tests and inspections.

    Science.gov (United States)

    2010-01-01

    ... RULES Maintenance, Preventive Maintenance, and Alterations § 91.411 Altimeter system and altitude...), appendix E, of part 43 of this chapter; and (3) Following installation or maintenance on the automatic... airframe rating appropriate to the airplane, or helicopter, to be tested; or (3) A certificated mechanic...

  3. Albuminuria and overall capillary permeability of albumin in acute altitude hypoxia

    DEFF Research Database (Denmark)

    Hansen, J M; Olsen, Niels Vidiendal; Feldt-Rasmussen, B

    1994-01-01

    and passive ascent to 4,350 m. The calcium antagonist isradipine (5 mg/day; n = 6) or placebo (n = 6) was administered to abolish hypoxia-induced rises in blood pressure. Lithium clearance and urinary excretion of beta 2-microglobulin were used to evaluate renal tubular function. High altitude increased Ualb...

  4. Aliskiren Trial in Type 2 Diabetes Using Cardio-Renal Endpoints (ALTITUDE): rationale and study design

    DEFF Research Database (Denmark)

    Parving, Hans-Henrik; Brenner, Barry M; McMurray, John J V

    2009-01-01

    of cardiovascular disease and eGFR > or =30 first event for the composite endpoint of cardiovascular death......, resuscitated death, myocardial infarction, stroke, unplanned hospitalization for heart failure, onset of end-stage renal disease or doubling of baseline serum creatinine concentration. Secondary endpoints include a composite CV endpoint and a composite renal endpoint. CONCLUSION: ALTITUDE will determine...

  5. [Adaptive mechanisms and behavioural recommendations: playing football in heat, cold and high altitude conditions].

    Science.gov (United States)

    Born, D-P; Hoppe, M W; Lindner, N; Freiwald, J; Holmberg, H-C; Sperlich, B

    2014-03-01

    Football is played worldwide and players often have to cope with hot and cold temperatures as well as high altitude conditions. The upcoming and past world championships in Brazil, Qatar and South Africa illustrate the necessity for behavioural strategies and adaptation to extreme environmental conditions. When playing football in the heat or cold, special clothing, hydration and nutritional and acclimatisation strategies are vital for high-level performance. When playing at high altitude, the reduced oxygen partial pressure impairs endurance performance and alters the technical and tactical requirements. Special high-altitude adaptation and preparation strategies are essential for football teams based at sea-level in order to perform well and compete successfully. Therefore, the aim of the underlying review is: 1) to highlight the difficulties and needs of football teams competing in extreme environmental conditions, 2) to summarise the thermoregulatory, physiological, neuronal and psychological mechanism, and 3) to provide recommendations for coping with extreme environmental conditions in order to perform at a high level when playing football in the heat, cold and at high altitude. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Predicted Hematologic and Plasma Volume Responses Following Rapid Ascent to Progressive Altitudes

    Science.gov (United States)

    2014-06-01

    composition changes during exposure to altitude. Fed.Proc. 1969, 28:1190- 1194. 20. Jung RC, Dill DB, Horton R, Horvath SM: Effects of age on plasma...Am.J.Physioi.Endocrinoi.Metab. 2009, 296:E1319- E1325. 57. Davidson JM, Chen JJ, Crapo L, Gray GD, Greenleaf WJ, Catania JA: Hormonal function and sexual

  7. Hypoxia augments LPS-induced inflammation and triggers high altitude cerebral edema in mice.

    Science.gov (United States)

    Zhou, Yanzhao; Huang, Xin; Zhao, Tong; Qiao, Meng; Zhao, Xingnan; Zhao, Ming; Xu, Lun; Zhao, Yongqi; Wu, Liying; Wu, Kuiwu; Chen, Ruoli; Fan, Ming; Zhu, Lingling

    2017-08-01

    High altitude cerebral edema (HACE) is a life-threatening illness that develops during the rapid ascent to high altitudes, but its underlying mechanisms remain unclear. Growing evidence has implicated inflammation in the susceptibility to and development of brain edema. In the present study, we investigated the inflammatory response and its roles in HACE in mice following high altitude hypoxic injury. We report that acute hypobaric hypoxia induced a slight inflammatory response or brain edema within 24h in mice. However, the lipopolysaccharide (LPS)-induced systemic inflammatory response rapidly aggravated brain edema upon acute hypobaric hypoxia exposure by disrupting blood-brain barrier integrity and activating microglia, increasing water permeability via the accumulation of aquaporin-4 (AQP4), and eventually leading to impaired cognitive and motor function. These findings demonstrate that hypoxia augments LPS-induced inflammation and induces the occurrence and development of cerebral edema in mice at high altitude. Here, we provide new information on the impact of systemic inflammation on the susceptibility to and outcomes of HACE. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Low-resolution ship detection from high-altitude aerial images

    Science.gov (United States)

    Qi, Shengxiang; Wu, Jianmin; Zhou, Qing; Kang, Minyang

    2018-02-01

    Ship detection from optical images taken by high-altitude aircrafts such as unmanned long-endurance airships and unmanned aerial vehicles has broad applications in marine fishery management, ship monitoring and vessel salvage. However, the major challenge is the limited capability of information processing on unmanned high-altitude platforms. Furthermore, in order to guarantee the wide detection range, unmanned aircrafts generally cruise at high altitudes, resulting in imagery with low-resolution targets and strong clutters suffered by heavy clouds. In this paper, we propose a low-resolution ship detection method to extract ships from these high-altitude optical images. Inspired by a recent research on visual saliency detection indicating that small salient signals could be well detected by a gradient enhancement operation combined with Gaussian smoothing, we propose the facet kernel filtering to rapidly suppress cluttered backgrounds and delineate candidate target regions from the sea surface. Then, the principal component analysis (PCA) is used to compute the orientation of the target axis, followed by a simplified histogram of oriented gradient (HOG) descriptor to characterize the ship shape property. Finally, support vector machine (SVM) is applied to discriminate real targets and false alarms. Experimental results show that the proposed method actually has high efficiency in low-resolution ship detection.

  9. A space weather index for the radiation field at aviation altitudes

    Directory of Open Access Journals (Sweden)

    Meier Matthias M.

    2014-04-01

    Full Text Available The additional dose contribution to the radiation exposure at aviation altitudes during Solar Particle Events (SPEs has been a matter of concern for many years. After the Halloween storms in 2003 several airlines began to implement mitigation measures such as rerouting and lowering flight altitudes in response to alerts on the NOAA S-scale regarding solar radiation storms. These alerts are based on the integral proton flux above 10 MeV measured aboard the corresponding GOES-satellite which is operated outside the Earth’s atmosphere in a geosynchronous orbit. This integral proton flux has, however, been proved to be an insufficient parameter to apply to the radiation field at aviation altitudes without an accompanying analysis of the shape of the energy spectrum. Consequently, false alarms and corresponding disproportionate reactions ensued. Since mitigating measures can be quite cost-intensive, there has been a demand for appropriate space weather information among responsible airline managers for about a decade. Against this background, we propose the introduction of a new Space Weather index D, based on dose rates at aviation altitudes produced by solar protons during solar radiation storms, as the relevant parameter for the assessment of corresponding radiation exposure. The Space Weather index D is a natural number given by a graduated table of ranges of dose rates in ascending order which is derived by an equation depending on the dose rate of solar protons.

  10. The Role Of Changing Diet And Altitude On Goitre Prevalence In ...

    African Journals Online (AJOL)

    Conclusion: Besides low level of iodine intake, cassava consumption and living in high altitude were responsible for the observed variation and severity in goitre rates. IDD affects several dimensions of human life including school enrolment and marriage. Addressing IDD in-terms of salt iodization and training communities ...

  11. Athletic altitude training protocols and their application in preparation for mountainous operations.

    Science.gov (United States)

    Heil, K M; Keenan, A C M

    2014-01-01

    In recent years, small scale counter-insurgency and expeditionary operations have frequently taken place in mountainous, high-altitude areas. Preparation of soldiers for these environments has typically focussed on extended stays at altitude to ensure physiological acclimatisation. However, with the likelihood that future UK deployments may be unpredictable and thus with little time for preparation, is there a means by which the same acclimatisation may be achieved? The field of athletics has been researching such adaptations since the rise of the elite North African long-distance runners in the 1960s. These athletes all lived high above sea level and had become accustomed to performing in the relatively hypoxic environment found at high altitudes. The research has focussed on eliciting physiological acclimatisation in as short a time as possible, while maintaining the ability to train at the correct intensity. In the following review of altitude training we highlight areas for future investigation and assess whether protocols developed for athletes can be applied to military personnel.

  12. Altitude training causes haematological fluctuations with relevance for the Athlete Biological Passport.

    Science.gov (United States)

    Bonne, Thomas Christian; Lundby, Carsten; Lundby, Anne Kristine; Sander, Mikael; Bejder, Jacob; Nordsborg, Nikolai Baastrup

    2015-08-01

    The impact of altitude training on haematological parameters and the Athlete Biological Passport (ABP) was evaluated in international-level elite athletes. One group of swimmers lived high and trained high (LHTH, n = 10) for three to four weeks at 2130 m or higher whereas a control group (n = 10) completed a three-week training camp at sea-level. Haematological parameters were determined weekly three times before and four times after the training camps. ABP thresholds for haemoglobin concentration ([Hb]), reticulocyte percentage (RET%), OFF score and the abnormal blood profile score (ABPS) were calculated using the Bayesian model. After altitude training, six swimmers exceeded the 99% ABP thresholds: two swimmers exceeded the OFF score thresholds at day +7; one swimmer exceeded the OFF score threshold at day +28; one swimmer exceeded the threshold for RET% at day +14; and one swimmer surpassed the ABPS threshold at day +14. In the control group, no values exceeded the individual ABP reference range. In conclusion, LHTH induces haematological changes in Olympic-level elite athletes which can exceed the individually generated references in the ABP. Training at altitude should be considered a confounding factor for ABP interpretation for up to four weeks after altitude exposure but does not consistently cause abnormal values in the ABP. Copyright © 2014 John Wiley & Sons, Ltd.

  13. A comparative analysis of the influence of weather on the flight altitudes of birds

    NARCIS (Netherlands)

    Shamoun-Baranes, J.; van Loon, E.; van Gasteren, H.; van Belle, J.; Bouten, W.; Buurma, L.

    2006-01-01

    Birds pose a serious risk to flight safety worldwide. A Bird Avoidance Model (BAM) is being developed in the Netherlands to reduce the risk of bird-aircraft collisions. In order to develop a temporally and spatially dynamic model of bird densities, data are needed on the flight-altitude distribution

  14. A statistical study of high-altitude electric fields measured on the Viking satellite

    International Nuclear Information System (INIS)

    Lindqvist, P.A.; Marklund, G.T.

    1990-01-01

    Characteristics of high-altitude data from the Viking electric field instrument are presented in a statistical study based on 109 Viking orbits. The study is focused in particular on the signatures of and relationships between various parameters measured by the electric field instrument, such as the parallel and transverse (to B) components of the electric field instrument, such as electric field variability. A major goal of the Viking mission was to investigate the occurrence and properties of parallel electric fields and their role in the auroral acceleration process. The results in this paper on the altitude distribution of the electric field variability confirm earlier findings on the distribution of small-scale electric fields and indicate the presence of parallel fields up to about 11,000 km altitude. The directly measured parallel electric field is also investigated in some detail. It is in general directed upward with an average value of 1 mV/m, but depends on, for example, altitude and plasma density. Possible sources of error in the measurement of the parallel field are also considered and accounted for

  15. Unmanned aerial vehicle: A unique platform for low-altitude remote sensing for crop management

    Science.gov (United States)

    Unmanned aerial vehicles (UAV) provide a unique platform for remote sensing to monitor crop fields that complements remote sensing from satellite, aircraft and ground-based platforms. The UAV-based remote sensing is versatile at ultra-low altitude to be able to provide an ultra-high-resolution imag...

  16. Awareness of altitude sickness among visitors to a North American ski resort.

    Science.gov (United States)

    Hatzenbuehler, John; Glazer, James; Kuhn, Celine

    2009-01-01

    To quantify awareness of acute mountain sickness (AMS) in a sample of visitors to a North American ski resort and to identify strategies and interest for increasing knowledge of AMS in that population. One hundred and thirty visitors to Big Sky Ski Resort, Montana, were surveyed. Demographic data were obtained. Respondents were asked about their current knowledge of AMS and then answered questions designed to quantify their depth of knowledge of the subject. Correct answers were correlated with demographic data. Respondents also answered questions indicating their interest in further education about altitude illness and their preferred modality for obtaining this information. In general, most respondents were young, 18 to 30 years (62.3%), and male (62.5%). Seventy-six percent had at least some college education and more than 5 years of skiing/snowboarding experience. Only 55% of respondents had some knowledge of AMS, but only 30% had knowledge of AMS symptoms using the Lake Louise Scoring System. About 30% knew the lowest altitude this illness can occur. There was a correlation between educational background and improved knowledge of altitude illness. Half of the respondents desired further information about AMS, and the Internet was the preferred source of information. This study suggests that a large population of skiers in North America may be relatively naive to the dangers of AMS. The majority of the respondents were interested in learning more about altitude illness, and the Internet was the most attractive source of information.

  17. Propagation of whistler mode chorus to low altitudes: Spacecraft observations of structured ELF hiss

    Science.gov (United States)

    SantolíK, O.; Chum, J.; Parrot, M.; Gurnett, D. A.; Pickett, J. S.; Cornilleau-Wehrlin, N.

    2006-10-01

    We interpret observations of low-altitude electromagnetic ELF hiss observed on the dayside at subauroral latitudes. A divergent propagation pattern has been reported between 50° and 75° of geomagnetic latitude. The waves propagate with downward directed wave vectors which are slightly equatorward inclined at lower magnetic latitudes and slightly poleward inclined at higher latitudes. Reverse ray tracing using different plasma density models indicates a possible source region near the geomagnetic equator at a radial distance between 5 and 7 Earth radii by a mechanism acting on highly oblique wave vectors near the local Gendrin angle. We analyze waveforms received at altitudes of 700-1200 km by the Freja and DEMETER spacecraft and we find that low-altitude ELF hiss contains discrete time-frequency structures resembling wave packets of whistler mode chorus. Emissions of chorus also predominantly occur on the dawnside and dayside and have recently been considered as a possible source of highly accelerated electrons in the outer Van Allen radiation belt. Detailed measurements of the Cluster spacecraft at radial distances of 4-5 Earth radii show chorus propagating downward from the source region localized close to the equator. The time-frequency structure and frequencies of chorus observed by Cluster along the reverse raypaths of ELF hiss are consistent with the hypothesis that the frequently observed dayside ELF hiss is just the low-altitude manifestation of natural magnetospheric emissions of whistler mode chorus.

  18. Water level changes of high altitude lakes in Himalaya–Karakoram ...

    Indian Academy of Sciences (India)

    2007; Ramanathan and Feng 2009; UNEP 2009;. Singh et al. 2011). Water melts from the Himalayan glaciers and seasonal snow packs are one of the water sources for high altitude wetlands and lakes (Xu et al. 2009) and to Himalayan rivers. (Immerzeel et al. 2010). Several studies have assessed the status of glaciers in ...

  19. Evidence of JEV inCulex tritaeniorhynchusand pigs from high altitude regions of Tibet, China.

    Science.gov (United States)

    Zhang, Hui; Luo, Houqiang; Ur Rehman, Mujeeb; Nabi, Fazul; Li, Kun; Lan, Yanfang; Huang, Shucheng; Zhang, Lihong; Mehmood, Khalid; Shahzad, Muhammad; Li, Jiakui

    2017-01-01

    Culex tritaeniorhynchus is the primary vector of Japanese encephalitis virus (JEV) which is a major threat to animals and humans health. This virus has been reported earlier from low altitude regions of Tibet, in mosquitoes, Tibetan pigs and local Tibetans, but no reports are available for the probable propagation of JE to high altitude regions (3100 m) of Tibet. This study aimed to find the evidence of JEV in Cx. tritaeniorhynchus and pigs from high altitude regions of Tibet, China. In total, 102 porcine serum samples and eight pools of Cx. tritaeniorhynchus were subjected to real-time PCR (RT-PCR) for the amplification of a fragment (~ 420 bp) of the NS1 gene. The resultant amplicons of the genes were subsequently analyzed and sequenced. Overall seroprevalence of JE in Tibetan pigs was 6.86%, while five pools of Cx. tritaeniorhynchus were found positive for JEV. Results showed genotype III as the most prevalent (100%) among JEV positive isolates. Furthermore, phylogenetic analysis of the JEV positive strains showed 98.8-99% similarity to four reference strains from China (JEV-Hubei, Whe, HYZ and CQ11-66). The present study revealed that JEV has extended its geographic range to high altitude regions of Tibet. The factors like increased tourism and transportation might play key role in the transmission of JE that comprises a potential health risk for humans and animals.

  20. The effect of altitude on breaking seed dormancy and stimulation of ...

    African Journals Online (AJOL)

    Persian hogweed is a perennial herb and aromatic plant which has pharmaceutical and fodder values, and the main propagation method of this species is seed. The goal of this study was to investigate the effect of altitude on breaking dormancy and stimulate seed germination of this species. The study was designed and ...