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Sample records for altitude training considerations

  1. Altitude and endurance training.

    PubMed

    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 (< 2000-2200 m) and/or too short an altitude training period (<3-4 weeks); (2) the 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.

  2. Altitude and endurance training.

    PubMed

    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 (< 2000-2200 m) and/or too short an altitude training period (<3-4 weeks); (2) the 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

  3. Endurance training at altitude.

    PubMed

    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.

  4. Endurance training at altitude.

    PubMed

    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. PMID:19519223

  5. [High altitude training: sense, nonsense, trends].

    PubMed

    Friedmann, B; Bärtsch, P

    1997-11-01

    Athletes who need high endurance capacity often use training at moderately high altitude (1500-3000 m) to improve oxygen delivery and utilization because of a hypoxia-induced increase of the red blood cell volume and adaptations at the muscular level. As maximal heart rates decrease at high altitude and plasma lactate levels for a given workload change during prolonged exposure to high altitude, it can be difficult to control and adapt the intensity and duration of the work-outs. Furthermore, maximal performance capacity decreases and therefore training intensity at high altitude is usually reduced compared to training at sea level. To avoid these disadvantages at high altitude a concept of living at moderately high altitude and training at lower elevations, termed "live high-train low" evolved, opposing the conventional concept of "live high-train high". A third option using a hypobaric chamber ("live low-train low") is hardly used anymore for training athletes. Studies on the effects of conventional high-altitude training for the improvement of athletic performance often lack a rigorous controlled design and yield controversial results. Regarding the new concept of "live high-train low" there is only one controlled study on college athletes and it shows a minor advantage of this new approach compared to conventional high-altitude training. However, training concepts are especially important for elite competitive athletes, and controlled studies with such individuals are very difficult to perform. Therefore, it appears that today we cannot answer the question of whether altitude-specific physiologic factors or non-altitude-related benefits of training camps account for the success of individual athletes.

  6. Dietary Recommendations for Cyclists during Altitude Training.

    PubMed

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

    2016-01-01

    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. PMID:27322318

  7. Dietary Recommendations for Cyclists during Altitude Training.

    PubMed

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

    2016-01-01

    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.

  8. Dietary Recommendations for Cyclists during Altitude Training

    PubMed Central

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

    2016-01-01

    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. PMID:27322318

  9. Live high, train low at natural altitude.

    PubMed

    Stray-Gundersen, J; Levine, B D

    2008-08-01

    For decades altitude training has been used by endurance athletes and coaches to enhance sea-level performance. Whether altitude training does, in fact, enhance sea level performance and, if so, by what means has been the subject of a number of investigations. Data produced principally by Levine and Stray-Gundersen have shown that living for 4 weeks at 2500 m, while performing the more intense training sessions near sea level will provide an average improvement in sea level endurance performance (duration of competition: 7-20 min) of approximately 1.5%, ranging from no improvement to 6% improvement. This benefit lasts for at least 3 weeks on return to sea level. Two mechanisms have been shown to be associated with improvement in performance. One is an increase in red cell mass ( approximately 8%) that results in an improved maximal oxygen uptake ( approximately 5%). That must be combined with maintenance of training velocities and oxygen flux to realize the improvement in subsequent sea level performance. We find no evidence of changes in running economy or markers of anaerobic energy utilization. Our results have been obtained in runners ranging from collegiate to elite. Wehrlin et al. have recently confirmed these results in elite orienteers. While there are no specific studies addressing the use of living high, training low in football players, it is likely that an improvement in maximal oxygen uptake, all other factors equal, would enhance football performance. This benefit must be weighed against the time away (4 weeks) from home and competition necessary to gain these benefits.

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

    PubMed

    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.

  11. High altitude cerebral oedema during adventure training on Mount Kenya.

    PubMed

    Raitt, S

    2012-09-01

    The trekking ascent to Point Lenana (4,985m) on Mount Kenya is a popular objective for soldiers on adventurous training in Kenya. The standard route previously taken has been the Naro Moru route which involves an ascent rate far in excess of that recommended to avoid altitude illness. This article describes the case of a British soldier who developed high altitude cerebral oedema during an ascent of Point Lenana via the Naro Moro route. Recommendations to reduce the risk of altitude illness on Mount Kenya include alternative and more gradual routes of ascent. Early symptom recognition and descent are vital to prevent clinical deterioration.

  12. Physiological implications of altitude training for endurance performance at sea level: a review.

    PubMed Central

    Bailey, D M; Davies, B

    1997-01-01

    Acclimatisation to environmental hypoxia initiates a series of metabolic and musculocardio-respiratory adaptations that influence oxygen transport and utilisation, or better still, being born and raised at altitude, is necessary to achieve optimal physical performance at altitude, scientific evidence to support the potentiating effects after return to sea level is at present equivocal. Despite this, elite athletes continue to spend considerable time and resources training at altitude, misled by subjective coaching opinion and the inconclusive findings of a large number of uncontrolled studies. Scientific investigation has focused on the optimisation of the theoretically beneficial aspects of altitude acclimatisation, which include increases in blood haemoglobin concentration, elevated buffering capacity, and improvements in the structural and biochemical properties of skeletal muscle. However, not all aspects of altitude acclimatisation are beneficial; cardiac output and blood flow to skeletal muscles decrease, and preliminary evidence has shown that hypoxia in itself is responsible for a depression of immune function and increased tissue damage mediated by oxidative stress. Future research needs to focus on these less beneficial aspects of altitude training, the implications of which pose a threat to both the fitness and the health of the elite competitor. Paul Bert was the first investigator to show that acclimatisation to a chronically reduced inspiratory partial pressure of oxygen (P1O2) invoked a series of central and peripheral adaptations that served to maintain adequate tissue oxygenation in healthy skeletal muscle, physiological adaptations that have been subsequently implicated in the improvement in exercise performance during altitude acclimatisation. However, it was not until half a century later that scientists suggested that the additive stimulus of environmental hypoxia could potentially compound the normal physiological adaptations to endurance

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

    PubMed

    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.

  14. Considerations of high altitude emissions. [from supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Broderick, A. J.; Krull, N. P.

    1976-01-01

    The status of the Federal Aviation Administration's High Altitude Pollution Program is described which was instituted to develop the detailed quantitative information needed to judge whether or not regulatory action to limit such exhaust emissions would be necessary. The complexities of this question and the nature and magnitude of uncertainties still present in our scientific understanding of the potential interactions between aircraft exhaust emissions and stratospheric ozone and climate are reviewed. The direction and scope of future Federal and international activities are described.

  15. Aeroelastic considerations for continuous patrol/high altitude surveillance platforms

    NASA Technical Reports Server (NTRS)

    Turner, C. D.; Rocketts, R. H.

    1983-01-01

    For the last several years, an investigation has been conducted regarding the feasibility of unmanned, airborne, High-Altitude Powered Platforms (HAPP), and High Surveillance Platforms for Over-the-Horizon Targeting (HI-SPOT). These airborne platforms have been proposed as a means of achieving a continuous regional communication-relay or for continuous regional surveillance for use in agricultural research or military applications, i.e., fleet support. These platforms would offer improvements over existing orbiting satellites. These improvements are related to better resolution and increased mission flexibility. The required mission endurance up to six months, would be obtained through the use of either solar power, a cryogenically fueled engine, or microwave-power. Attention is given to airborne platform configuration, structure, structural and aerodynamic modeling, modal analysis, and flutter analysis.

  16. High-altitude paragangliomas diagnostic and therapeutic considerations.

    PubMed

    Rodriguez-Cuevas, H; Lau, I; Rodriguez, H P

    1986-02-01

    Forty-one cervical paragangliomas that occurred in 40 patients born and living in Mexico City, Mexico, were studied. Tumors were most common in women (38/40); were unilateral (39/40), without a side preference; were of the nonhereditary type; and were not malignant. Tumor imaging with radionucleaide angiographic scanning was noninvasive, innocuous, and reliable for screening, whereas selective carotid angiography allowed for definitive diagnosis and clinical stratification of patients. Surgical resection was performed in 29 patients; in 23 cases, en bloc resection was accomplished without a vascular compromise, whereas in 4 patients, a portion of the external carotid artery had to be ligated and resected. Two other patients required a vascular graft to restore blood flow to the internal carotid. Seven patients had postoperative transient cranial nerve palsies, and one had an incomplete hemiplegia. Permanent nerve damage occurred in seven patients. It was concluded that high-altitude paragangliomas are hyperplastic growths that result from adaptation to hypoxia. They are rarely true neoplasm and, in general, are not associated with functional loss. In view of this and of the high morbidity rate associated with surgical removal, it was recommended that these patients be referred to research centers where efforts toward the elucidation of the etiology and pathophysiology of these tumors can be carried out. Surgery should be reserved for symptomatic cases or cases in which the diagnosis remains in doubt. The decision to operate must weigh the following factors: The tumor's benign nature, its slow growth rate, the technical difficulties associated with its resection, the high postoperative morbidity rate, and the general condition of the patient. PMID:3943005

  17. Training Diaries during Altitude Training Camp in Two Olympic Champions: An Observational Case Study

    PubMed Central

    Pugliese, Lorenzo; Serpiello, Fabio R.; Millet, Grégoire P.; Torre, Antonio La

    2014-01-01

    Traditionally, Live High-Train High (LHTH) interventions were adopted when athletes trained and lived at altitude to try maximising the benefits offered by hypoxic exposure and improving sea level performance. Nevertheless, scientific research has proposed that the possible benefits of hypoxia would be offset by the inability to maintain high training intensity at altitude. However, elite athletes have been rarely recruited as an experimental sample, and training intensity has almost never been monitored during altitude research. This case study is an attempt to provide a practical example of successful LHTH interventions in two Olympic gold medal athletes. Training diaries were collected and total training volumes, volumes at different intensities, and sea level performance recorded before, during and after a 3-week LHTH camp. Both athletes successfully completed the LHTH camp (2090 m) maintaining similar absolute training intensity and training volume at high-intensity (> 91% of race pace) compared to sea level. After the LHTH intervention both athletes obtained enhancements in performance and they won an Olympic gold medal. In our opinion, LHTH interventions can be used as a simple, yet effective, method to maintain absolute, and improve relative training intensity in elite endurance athletes. Key Points Elite endurance athletes, with extensive altitude training experience, can maintain similar absolute intensity during LHTH compared to sea level. LHTH may be considered as an effective method to increase relative training intensity while maintaining the same running/walking pace, with possible beneficial effects on sea level performance. Training intensity could be the key factor for successful high-level LHTH camp. PMID:25177197

  18. Training Diaries during Altitude Training Camp in Two Olympic Champions: An Observational Case Study.

    PubMed

    Pugliese, Lorenzo; Serpiello, Fabio R; Millet, Grégoire P; La Torre, Antonio

    2014-09-01

    Traditionally, Live High-Train High (LHTH) interventions were adopted when athletes trained and lived at altitude to try maximising the benefits offered by hypoxic exposure and improving sea level performance. Nevertheless, scientific research has proposed that the possible benefits of hypoxia would be offset by the inability to maintain high training intensity at altitude. However, elite athletes have been rarely recruited as an experimental sample, and training intensity has almost never been monitored during altitude research. This case study is an attempt to provide a practical example of successful LHTH interventions in two Olympic gold medal athletes. Training diaries were collected and total training volumes, volumes at different intensities, and sea level performance recorded before, during and after a 3-week LHTH camp. Both athletes successfully completed the LHTH camp (2090 m) maintaining similar absolute training intensity and training volume at high-intensity (> 91% of race pace) compared to sea level. After the LHTH intervention both athletes obtained enhancements in performance and they won an Olympic gold medal. In our opinion, LHTH interventions can be used as a simple, yet effective, method to maintain absolute, and improve relative training intensity in elite endurance athletes. Key PointsElite endurance athletes, with extensive altitude training experience, can maintain similar absolute intensity during LHTH compared to sea level.LHTH may be considered as an effective method to increase relative training intensity while maintaining the same running/walking pace, with possible beneficial effects on sea level performance.Training intensity could be the key factor for successful high-level LHTH camp.

  19. Training Diaries during Altitude Training Camp in Two Olympic Champions: An Observational Case Study.

    PubMed

    Pugliese, Lorenzo; Serpiello, Fabio R; Millet, Grégoire P; La Torre, Antonio

    2014-09-01

    Traditionally, Live High-Train High (LHTH) interventions were adopted when athletes trained and lived at altitude to try maximising the benefits offered by hypoxic exposure and improving sea level performance. Nevertheless, scientific research has proposed that the possible benefits of hypoxia would be offset by the inability to maintain high training intensity at altitude. However, elite athletes have been rarely recruited as an experimental sample, and training intensity has almost never been monitored during altitude research. This case study is an attempt to provide a practical example of successful LHTH interventions in two Olympic gold medal athletes. Training diaries were collected and total training volumes, volumes at different intensities, and sea level performance recorded before, during and after a 3-week LHTH camp. Both athletes successfully completed the LHTH camp (2090 m) maintaining similar absolute training intensity and training volume at high-intensity (> 91% of race pace) compared to sea level. After the LHTH intervention both athletes obtained enhancements in performance and they won an Olympic gold medal. In our opinion, LHTH interventions can be used as a simple, yet effective, method to maintain absolute, and improve relative training intensity in elite endurance athletes. Key PointsElite endurance athletes, with extensive altitude training experience, can maintain similar absolute intensity during LHTH compared to sea level.LHTH may be considered as an effective method to increase relative training intensity while maintaining the same running/walking pace, with possible beneficial effects on sea level performance.Training intensity could be the key factor for successful high-level LHTH camp. PMID:25177197

  20. The effects of altitude training are mediated primarily by acclimatization, rather than by hypoxic exercise.

    PubMed

    Levine, B D; Stray-Gundersen, J

    2001-01-01

    For training at altitude to be effective, it must provide some advantage above and beyond similar training at sea level. This advantage could be provided by: 1) acclimatization to altitude which improves oxygen transport and/or utilization; 2) hypoxic exercise which "intensifies" the training stimulus; or 3) some combination of both. Controlled studies of "typical" altitude training, involving both altitude acclimatization and hypoxic exercise have never been shown to improve sea level performance. This failure has been attributed to reduced training loads at altitude. One approach developed by Levine and Stray-Gundersen, called "living high-training low" has been shown to improve sea level performance over events lasting 8-20 minutes. This strategy combines altitude acclimatization (2,500 m) with low altitude training to get the optimal effect. The opposite strategy, "living low-training high" is proposed by Dr. Hoppeler in this debate. In defense of the primacy of the altitude acclimatization effect, data will be presented to support the following: 1). Living high-training low clearly improves performance in athletes of all abilities; 2). The mechanism of this improvement is primarily an increase in erythropoietin leading to increased red cell mass, VO2max, and running performance; 3). Rather than intensifying the training stimulus, training at altitude leads to the opposite effect--reduced speeds, reduced power output, reduced oxygen flux--and, following the principal of symmorphosis, is not likely to provide any advantage for a well trained athlete; 4). At the moderate altitudes used by most athletes, resting oxygen delivery to skeletal muscle is well preserved, arguing against any detrimental effect on "protein synthesis"; 5). It is possible however, that at significantly higher altitudes, acclimatization leads to appetite suppression, inhibition of protein synthesis, muscle wasting, excessive ventilatory work, and metabolic compensation that is NOT

  1. Extravehicular activity training and hardware design consideration.

    PubMed

    Thuot, P J; Harbaugh, G J

    1995-07-01

    Preparing astronauts to perform the many complex extravehicular activity (EVA) tasks required to assemble and maintain Space Station will be accomplished through training simulations in a variety of facilities. The adequacy of this training is dependent on a thorough understanding of the task to be performed, the environment in which the task will be performed, high-fidelity training hardware and an awareness of the limitations of each particular training facility. Designing hardware that can be successfully operated, or assembled, by EVA astronauts in an efficient manner, requires an acute understanding of human factors and the capabilities and limitations of the space-suited astronaut. Additionally, the significant effect the microgravity environment has on the crew members' capabilities has to be carefully considered not only for each particular task, but also for all the overhead related to the task and the general overhead associated with EVA. This paper will describe various training methods and facilities that will be used to train EVA astronauts for Space Station assembly and maintenance. User-friendly EVA hardware design considerations and recent EVA flight experience will also be presented. PMID:11541312

  2. Extravehicular activity training and hardware design consideration.

    PubMed

    Thuot, P J; Harbaugh, G J

    1995-07-01

    Preparing astronauts to perform the many complex extravehicular activity (EVA) tasks required to assemble and maintain Space Station will be accomplished through training simulations in a variety of facilities. The adequacy of this training is dependent on a thorough understanding of the task to be performed, the environment in which the task will be performed, high-fidelity training hardware and an awareness of the limitations of each particular training facility. Designing hardware that can be successfully operated, or assembled, by EVA astronauts in an efficient manner, requires an acute understanding of human factors and the capabilities and limitations of the space-suited astronaut. Additionally, the significant effect the microgravity environment has on the crew members' capabilities has to be carefully considered not only for each particular task, but also for all the overhead related to the task and the general overhead associated with EVA. This paper will describe various training methods and facilities that will be used to train EVA astronauts for Space Station assembly and maintenance. User-friendly EVA hardware design considerations and recent EVA flight experience will also be presented.

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

    PubMed

    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.

  4. Military applications of hypoxic training for high-altitude operations.

    PubMed

    Muza, Stephen R

    2007-09-01

    Rapid deployment of unacclimatized soldiers to high mountainous environments causes debilitating effects on operational capabilities (physical work performance), and force health (altitude sickness). Most of these altitude-induced debilitations can be prevented or ameliorated by a wide range of physiological responses collectively referred to as altitude acclimatization. Acclimatization to a target altitude can be induced by slow progressive ascents or continuous sojourns at intermediate altitudes. However, this "altitude residency" requirement reduces their utilization in rapid response military missions that exploit the air mobility capability of modern military forces to quickly deploy to an area of operations on short notice. A more recent approach to induce altitude acclimatization is the use of daily intermittent hypoxic exposures (IHE) in lieu of continuous residence at high altitudes. IHE treatments consist of three elements: 1) IHE simulated altitude (inspired oxygen partial pressure: PIO2), 2) IHE session duration, and 3) total number of IHE sessions over the treatment period. This paper reviews and summarizes the results of 25 published IHE studies. This review finds that an IHE altitude>or=4000 m, and daily exposure duration of at least 1.5 h repeated over a week or more are required to have a high probability of developing altitude acclimatization. The efficacy of shorter duration (<1.5 h) hypoxic exposures at >or=4000 m simulated altitudes, and longer exposures (>4 h) at moderate altitudes (2500-3500 m) is not well documented. The predominate IHE-induced altitude acclimatization response appears to be increased arterial oxygen content through ventilatory acclimatization. Thus, IHE is a promising approach to provide the benefits of altitude acclimatization to low-altitude-based soldiers before their deployment to high mountainous regions.

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

    PubMed

    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.

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

    PubMed

    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.

  7. Altitude training induced alterations in erythrocyte rheological properties: a controlled comparison study in rats.

    PubMed

    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.

  8. Time course of the hemoglobin mass response to natural altitude training in elite endurance cyclists.

    PubMed

    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.

  9. Deep Vein Thrombosis and Pulmonary Embolism in a Mountain Guide: Awareness, Diagnostic Challenges, and Management Considerations at Altitude.

    PubMed

    Hull, Claire M; Rajendran, Dévan; Fernandez Barnes, Arturo

    2016-03-01

    High intensity exercise is associated with several potentially thrombogenic risk factors, including dehydration and hemoconcentration, vascular trauma, musculoskeletal injuries, inflammation, long-distance travel, and contraceptive usage. These are well documented in case reports of venous thrombosis in track and field athletes. For mountaineers and those working at high altitude, additional risks exist. However, despite there being a high degree of vigilance for "classic" conditions encountered at altitude (eg, acute mountain sickness, high altitude pulmonary edema, and high altitude cerebral edema), mainstream awareness regarding thrombotic conditions and their complications in mountain athletes is relatively low. This is significant because thromboembolic events (including deep vein thrombosis, pulmonary embolism, and cerebral vascular thrombosis) are not uncommon at altitude. We describe a case of deep vein thrombosis and pulmonary embolism in a male mountain guide and discuss the diagnostic issues encountered by his medical practitioners. Potential risk factors affecting blood circulation (eg, seated car travel and compression of popliteal vein) and blood hypercoagulability (eg, hypoxia, environmental and psychological stressors [avalanche risk, extreme cold]) relevant to the subject of this report and mountain athletes in general are identified. Considerations for mitigating and managing thrombosis in addition to personalized care planning at altitude are discussed. The prevalence of thrombosis in mountain athletes is uncharted, but lowlanders increasingly go to high altitude to trek, ski, or climb. Blood clots can and do occur in physically active people, and thrombosis prevention and recognition will demand heightened awareness among participants, healthcare practitioners, and the altitude sport/leisure industry at large.

  10. Deep Vein Thrombosis and Pulmonary Embolism in a Mountain Guide: Awareness, Diagnostic Challenges, and Management Considerations at Altitude.

    PubMed

    Hull, Claire M; Rajendran, Dévan; Fernandez Barnes, Arturo

    2016-03-01

    High intensity exercise is associated with several potentially thrombogenic risk factors, including dehydration and hemoconcentration, vascular trauma, musculoskeletal injuries, inflammation, long-distance travel, and contraceptive usage. These are well documented in case reports of venous thrombosis in track and field athletes. For mountaineers and those working at high altitude, additional risks exist. However, despite there being a high degree of vigilance for "classic" conditions encountered at altitude (eg, acute mountain sickness, high altitude pulmonary edema, and high altitude cerebral edema), mainstream awareness regarding thrombotic conditions and their complications in mountain athletes is relatively low. This is significant because thromboembolic events (including deep vein thrombosis, pulmonary embolism, and cerebral vascular thrombosis) are not uncommon at altitude. We describe a case of deep vein thrombosis and pulmonary embolism in a male mountain guide and discuss the diagnostic issues encountered by his medical practitioners. Potential risk factors affecting blood circulation (eg, seated car travel and compression of popliteal vein) and blood hypercoagulability (eg, hypoxia, environmental and psychological stressors [avalanche risk, extreme cold]) relevant to the subject of this report and mountain athletes in general are identified. Considerations for mitigating and managing thrombosis in addition to personalized care planning at altitude are discussed. The prevalence of thrombosis in mountain athletes is uncharted, but lowlanders increasingly go to high altitude to trek, ski, or climb. Blood clots can and do occur in physically active people, and thrombosis prevention and recognition will demand heightened awareness among participants, healthcare practitioners, and the altitude sport/leisure industry at large. PMID:26723546

  11. Considerations for integrating fitness into dance training.

    PubMed

    Rafferty, Sonia

    2010-01-01

    In recent years it has frequently been suggested that dancers may not be sufficiently prepared for the physical demands of dance. The majority of researchers have arrived at the conclusion that there are gaps in the structure of dance training programs that could be filled with the type of physical training that has benefited other elite athletes. This article reviews some recommendations in light of current research for the supplementation of dance training and the inclusion of fitness concepts in traditional dance classes.

  12. Altitude training causes haematological fluctuations with relevance for the Athlete Biological Passport.

    PubMed

    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.

  13. Altitude training causes haematological fluctuations with relevance for the Athlete Biological Passport.

    PubMed

    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. PMID:25545030

  14. Physiological considerations in training young athletes.

    PubMed

    Zauner, C W; Maksud, M G; Melichna, J

    1989-07-01

    Healthy children evidence smaller values of cardiorespiratory function than adults, but these are in proportion to the smaller body size. At birth, the distribution of muscle fibres and the activity of enzymes in muscle are different from in adults, but these differences disappear at about age 6. On the other hand, muscle fibre thickness increases from birth to about 18 years of age and this is concurrent with increases in muscular strength. The increase in maximal oxygen consumption (VO2max) that accompanies growth and maturation in the human has been attributed in the main to appreciating muscle mass. During exercise, heart rate and cardiac output increase in the child as in the adult, but the heart rate in the child is greater and the stroke volume smaller. Furthermore, the arteriovenous difference in oxygen is greater in the exercising child than in the adult. Children also evidence a diminished blood pressure response to exercise. It seems that control of ventilation at exercise is the same in children as in adults, but exercise ventilation has been reported to be less efficient in the child. The young are less capable of regulating core temperature at exercise than adults and are more readily dehydrated. Very limited data suggest that muscle energy substrate storage and utilisation in children are such that they are less capable of anaerobic metabolism than adults. Generally, children respond to aerobic training as do adults, but such training in the first decade of life has been reported to have negligible effects. Blood lipid levels in children seem to be favourably influenced by persistent endurance activity. Ventilatory efficiency of children at exercise is augmented by aerobic training. Maximal values of ventilation and breathing frequency are increased in children and youth by endurance training. Conflicting data exist regarding the influence of training upon the child's vital capacity. Pulmonary diffusion capacity in well trained children has been seen

  15. Load management in elite German distance runners during 3-weeks of high-altitude training.

    PubMed

    Sperlich, Billy; Achtzehn, Silvia; de Marées, Markus; von Papen, Henning; Mester, Joachim

    2016-06-01

    There is a debate on the optimal way of monitoring training loads in elite endurance athletes especially during altitude training camps. In this case report, including nine members of the German national middle distance running team, we describe a practical approach to monitor the psychobiological stress markers during 21 days of altitude training (~2100 m above sea-level) to estimate the training load and to control muscle damage, fatigue, and/or chronic overreaching. Daily examination included: oxygen saturation of hemoglobin, resting heart rate, body mass, body and sleep perception, capillary blood concentration of creatine kinase. Every other day, venous serum concentration of blood urea nitrogen, venous blood concentration of hemoglobin, hematocrit, red and white blood cell were measured. If two or more of the above-mentioned stress markers were beyond or beneath the athlete's normal individual range, the training load of the subsequent training session was reduced. Running speed at 3 mmol L(-1) blood lactate (V3) improved and no athlete showed any signs of underperformance, chronic muscle damage, decrease body and sleep perception as well as activated inflammatory process during the 21 days. The dense screening of biomarkers in the present case study may stimulate further research to identify candidate markers for load monitoring in elite middle- and long-distance runners during a training camp at altitude.

  16. Load management in elite German distance runners during 3-weeks of high-altitude training.

    PubMed

    Sperlich, Billy; Achtzehn, Silvia; de Marées, Markus; von Papen, Henning; Mester, Joachim

    2016-06-01

    There is a debate on the optimal way of monitoring training loads in elite endurance athletes especially during altitude training camps. In this case report, including nine members of the German national middle distance running team, we describe a practical approach to monitor the psychobiological stress markers during 21 days of altitude training (~2100 m above sea-level) to estimate the training load and to control muscle damage, fatigue, and/or chronic overreaching. Daily examination included: oxygen saturation of hemoglobin, resting heart rate, body mass, body and sleep perception, capillary blood concentration of creatine kinase. Every other day, venous serum concentration of blood urea nitrogen, venous blood concentration of hemoglobin, hematocrit, red and white blood cell were measured. If two or more of the above-mentioned stress markers were beyond or beneath the athlete's normal individual range, the training load of the subsequent training session was reduced. Running speed at 3 mmol L(-1) blood lactate (V3) improved and no athlete showed any signs of underperformance, chronic muscle damage, decrease body and sleep perception as well as activated inflammatory process during the 21 days. The dense screening of biomarkers in the present case study may stimulate further research to identify candidate markers for load monitoring in elite middle- and long-distance runners during a training camp at altitude. PMID:27356568

  17. Increases in .VO2max with "live high-train low" altitude training: role of ventilatory acclimatization.

    PubMed

    Wilhite, Daniel P; Mickleborough, Timothy D; Laymon, Abigail S; Chapman, Robert F

    2013-02-01

    The purpose of this study was to estimate the percentage of the increase in whole body maximal oxygen consumption (.VO(2max)) that is accounted for by increased respiratory muscle oxygen uptake after altitude training. Six elite male distance runners (.VO(2max) = 70.6 ± 4.5 ml kg(-1) min(-1)) and one elite female distance runner (.VO(2max)) = 64.7 ml kg(-1) min(-1)) completed a 28-day "live high-train low" training intervention (living elevation, 2,150 m). Before and after altitude training, subjects ran at three submaximal speeds, and during a separate session, performed a graded exercise test to exhaustion. A regression equation derived from published data was used to estimate respiratory muscle .VO(2) (.VO(2RM)) using our ventilation (.VE) values. .VO(2RM) was also estimated retrospectively from a larger group of distance runners (n = 22). .VO(2max) significantly (p < 0.05) increased from pre- to post-altitude (196 ± 59 ml min(-1)), while (.VE) at .VO(2max) also significantly (p < 0.05) increased (13.3 ± 5.3 l min(-1)). The estimated .VO(2RM) contributed 37 % of Δ .VO(2max). The retrospective group also saw a significant increase in .VO(2max) from pre- to post-altitude (201 ± 36 ml min(-1)), along with a 10.8 ± 2.1 l min(-1) increase in (.VE), thus requiring an estimated 27 % of Δ .VO(2max) Our data suggest that a substantial portion of the improvement in .VO(2max) with chronic altitude training goes to fuel the respiratory muscles as opposed to the musculature which directly contributes to locomotion. Consequently, the time-course of decay in ventilatory acclimatization following return to sea-level may have an impact on competitive performance.

  18. Acclimatization to altitude and normoxic training improve 400-m running performance at sea level.

    PubMed

    Nummela, A; Rusko, H

    2000-06-01

    To investigate the benefits of 'living high and training low' on anaerobic performance at sea level, eight 400-m runners lived for 10 days in normobaric hypoxia in an altitude house (oxygen content = 15.8%) and trained outdoors in ambient normoxia at sea level. A maximal anaerobic running test and 400-m race were performed before and within 1 week of living in the altitude house to determine the maximum speed and the speeds at different submaximal blood lactate concentrations (3, 5, 7, 10 and 13 mmol x l(-1)) and 400-m race time. At the same time, ten 400-m runners lived and trained at sea level and were subjected to identical test procedures. Multivariate analysis of variance indicated that the altitude house group but not the sea-level group improved their 400-m race time during the experimental period (P < 0.05). The speeds at blood lactate concentrations of 5-13 mmol x l(-1) tended to increase in the altitude house group but the response was significant only at 5 and 7 mmol x l(-1) (P < 0.05). Furthermore, resting blood pH was increased in six of the eight altitude house athletes from 0.003 to 0.067 pH unit (P < 0.05). The results of this study demonstrate improved 400-m performance after 10 days of living in normobaric hypoxia and training at sea level. Furthermore, the present study provides evidence that changes in the acid-base balance and lactate metabolism might be responsible for the improvement in sprint performance.

  19. Acclimatization to altitude and normoxic training improve 400-m running performance at sea level.

    PubMed

    Nummela, A; Rusko, H

    2000-06-01

    To investigate the benefits of 'living high and training low' on anaerobic performance at sea level, eight 400-m runners lived for 10 days in normobaric hypoxia in an altitude house (oxygen content = 15.8%) and trained outdoors in ambient normoxia at sea level. A maximal anaerobic running test and 400-m race were performed before and within 1 week of living in the altitude house to determine the maximum speed and the speeds at different submaximal blood lactate concentrations (3, 5, 7, 10 and 13 mmol x l(-1)) and 400-m race time. At the same time, ten 400-m runners lived and trained at sea level and were subjected to identical test procedures. Multivariate analysis of variance indicated that the altitude house group but not the sea-level group improved their 400-m race time during the experimental period (P < 0.05). The speeds at blood lactate concentrations of 5-13 mmol x l(-1) tended to increase in the altitude house group but the response was significant only at 5 and 7 mmol x l(-1) (P < 0.05). Furthermore, resting blood pH was increased in six of the eight altitude house athletes from 0.003 to 0.067 pH unit (P < 0.05). The results of this study demonstrate improved 400-m performance after 10 days of living in normobaric hypoxia and training at sea level. Furthermore, the present study provides evidence that changes in the acid-base balance and lactate metabolism might be responsible for the improvement in sprint performance. PMID:10902676

  20. Relationship Between Vertical Jump Height and Swimming Start Performance Before and After an Altitude Training Camp.

    PubMed

    García-Ramos, Amador; Padial, Paulino; de la Fuente, Blanca; Argüelles-Cienfuegos, Javier; Bonitch-Góngora, Juan; Feriche, Belén

    2016-06-01

    García-Ramos, A, Padial, P, de la Fuente, B, Argüelles-Cienfuegos, J, Bonitch-Góngora, J, and Feriche, B. Relationship between vertical jump height and swimming start performance before and after an altitude training camp. J Strength Cond Res 30(6): 1638-1645, 2016-This study aimed (a) to analyze the development in the squat jump height and swimming start performance after an altitude training camp, (b) to correlate the jump height and swimming start performance before and after the altitude training period, and (c) to correlate the percent change in the squat jump height with the percent change in swimming start performance. Fifteen elite male swimmers from the Spanish Junior National Team (17.1 ± 0.8 years) were tested before and after a 17-day training camp at moderate altitude. The height reached in the squat jump exercise with additional loads of 0, 25, 50, 75, and 100% of swimmers' pretest body weight and swimming start performance (time to 5, 10, and 15 m) were the dependent variables analyzed. Significant increases in the jump height (p ≤ 0.05; effect size [ES]: 0.35-0.48) and swimming start performance (p < 0.01; ES: 0.48-0.52) after the training period were observed. The start time had similar correlations with the jump height before training (r = -0.56 to -0.77) and after training (r = -0.50 to -0.71). The change in the squat jump height was inversely correlated with the change in the start time at 5 m (r = -0.47), 10 m (r = -0.73), and 15 m (r = -0.62). These results suggest that altitude training can be suitable to enhance explosive performance. The correlations obtained between the squat jump height and start time in the raw and change scores confirm the relevance of having high levels of lower-body muscular power to optimize swimming start performance.

  1. Athletic altitude training protocols and their application in preparation for mountainous operations.

    PubMed

    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.

  2. Timing of return from altitude training for optimal sea level performance.

    PubMed

    Chapman, Robert F; Laymon Stickford, Abigail S; Lundby, Carsten; Levine, Benjamin D

    2014-04-01

    While a number of published studies exist to guide endurance athletes with the best practices regarding implementation of altitude training, a key unanswered question concerns the proper timing of return to sea level prior to major competitions. Evidence reviewed here suggests that, altogether, the deacclimatization responses of hematological, ventilatory, and biomechanical factors with return to sea level likely interact to determine the best timing for competitive performance.

  3. Altitude training and haemoglobin mass from the optimised carbon monoxide rebreathing method determined by a meta-analysis

    PubMed Central

    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

    2013-01-01

    Objective To characterise the time course of changes in haemoglobin mass (Hbmass) in response to altitude exposure. Methods 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. Results 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%. Conclusions Camps as short as 2 weeks of classic and LHTL altitude will quite likely increase Hbmass and most athletes can expect benefit. PMID:24282204

  4. Rhodiola crenulata- and Cordyceps sinensis-based supplement boosts aerobic exercise performance after short-term high altitude training.

    PubMed

    Chen, Chung-Yu; Hou, Chien-Wen; Bernard, Jeffrey R; Chen, Chiu-Chou; Hung, Ta-Cheng; Cheng, Lu-Ling; Liao, Yi-Hung; Kuo, Chia-Hua

    2014-09-01

    High altitude training is a widely used strategy for improving aerobic exercise performance. Both Rhodiola crenulata (R) and Cordyceps sinensis (C) supplements have been reported to improve exercise performance. However, it is not clear whether the provision of R and C during high altitude training could further enhance aerobic endurance capacity. In this study, we examined the effect of R and C based supplementation on aerobic exercise capacity following 2-week high altitude training. Alterations to autonomic nervous system activity, circulatory hormonal, and hematological profiles were investigated. Eighteen male subjects were divided into two groups: Placebo (n=9) and R/C supplementation (RC, n=9). Both groups received either RC (R: 1400 mg+C: 600 mg per day) or the placebo during a 2-week training period at an altitude of 2200 m. After 2 weeks of altitude training, compared with Placebo group, the exhaustive run time was markedly longer (Placebo: +2.2% vs. RC: +5.7%; p<0.05) and the decline of parasympathetic (PNS) activity was significantly prevented in RC group (Placebo: -51% vs. RC: -41%; p<0.05). Red blood cell, hematocrit, and hemoglobin levels were elevated in both groups to a comparable extent after high altitude training (p<0.05), whereas the erythropoietin (EPO) level remained higher in the Placebo group (∼48% above RC values; p<0.05). The provision of an RC supplement during altitude training provides greater training benefits in improving aerobic performance. This beneficial effect of RC treatment may result from better maintenance of PNS activity and accelerated physiological adaptations during high altitude training.

  5. Electrolyte-carbohydrate beverage prevents water loss in the early stage of high altitude training.

    PubMed

    Yanagisawa, Kae; Ito, Osamu; Nagai, Satsuki; Onishi, Shohei

    2012-01-01

    To prevent water loss in the early stage of high altitude training, we focused on the effect of electrolyte-carbohydrate beverage (EC). Subjects were 16 male university students who belonged to a ski club. They had ski training at an altitude of 1,800 m. The water (WT) group drank only water, and the EC group drank only an electrolyte-carbohydrate beverage. They arrived at the training site in the late afternoon. The study started at 7 pm on the day of arrival and continued until noon of the 4(th) day. In the first 12 hours, 1 L of beverages were given. On the second and third days, 2.5 L of beverages were given. All subjects ate the same meals. Each morning while in fasting condition, subjects were weighed and blood was withdrawn for various parameters (hemoglobin, hematocrit, sodium, potassium and aldosterone). Urine was collected at 12 hour intervals for a total 60 hours (5 times). The urine volume, gravity, sodium and potassium concentrations were measured. Peripheral oxygen saturation and heart rate were measured during sleep with a pulse oximeter. Liquid intakes in both groups were similar, hence the electrolytes intake was higher in the EC group than in the WT group. The total urine volume was lower in the EC group than in the WT group, respectively (p<0.05). Plasma volume decreased in the WT group and increased in the EC group but a significant difference was not observed in the final value. Aldosterone concentration tended to be less in the EC group than in the WT group. Electrolyte-carbohydrate beverage in the early stage of high altitude training may be effective in decreasing urinary output and preventing loss of blood plasma volume.

  6. The Effect of an Altitude Training Camp on Swimming Start Time and Loaded Squat Jump Performance.

    PubMed

    García-Ramos, Amador; Štirn, Igor; Padial, Paulino; Argüelles-Cienfuegos, Javier; De la Fuente, Blanca; Calderón, Carmen; Bonitch-Góngora, Juan; Tomazin, Katja; Strumbelj, Boro; Strojnik, Vojko; Feriche, Belén

    2016-01-01

    This study evaluated the influence of an altitude training (AT) camp on swimming start time and loaded squat jump performance. To accomplish this goal, 13 international swimmers (8 women, 5 men) were allocated to both the control (Sea Level Training, SLT) and experimental conditions (AT, 2320 m above sea level) that were separated by a one year period. All tests (15 m freestyle swimming start and loaded squat jumps with additional loads of 25%, 50%, 75%, and 100% of swimmers' body weight) were performed before and after a concurrent 3-week strength and endurance training program prescribed by the national coach. Following the SLT camp, significant impairments in swimming start times to 10 (+3.1%) and 15 m (+4.0%) were observed (P < 0.05), whereas no significant changes for the same distances were detected following the AT camp (-0.89%; P > 0.05). Trivial changes in peak velocity were obtained during the loaded squat jump after both training periods (effect sizes: < 0.20). Based on these results we can conclude that a traditional training high-living high strategy concurrent training of 3 weeks does not adversely affect swimming start time and loaded squat jump performance in high level swimmers, but further studies are necessary to assess the effectiveness of power-oriented resistance training in the development of explosive actions. PMID:27467760

  7. The Effect of an Altitude Training Camp on Swimming Start Time and Loaded Squat Jump Performance.

    PubMed

    García-Ramos, Amador; Štirn, Igor; Padial, Paulino; Argüelles-Cienfuegos, Javier; De la Fuente, Blanca; Calderón, Carmen; Bonitch-Góngora, Juan; Tomazin, Katja; Strumbelj, Boro; Strojnik, Vojko; Feriche, Belén

    2016-01-01

    This study evaluated the influence of an altitude training (AT) camp on swimming start time and loaded squat jump performance. To accomplish this goal, 13 international swimmers (8 women, 5 men) were allocated to both the control (Sea Level Training, SLT) and experimental conditions (AT, 2320 m above sea level) that were separated by a one year period. All tests (15 m freestyle swimming start and loaded squat jumps with additional loads of 25%, 50%, 75%, and 100% of swimmers' body weight) were performed before and after a concurrent 3-week strength and endurance training program prescribed by the national coach. Following the SLT camp, significant impairments in swimming start times to 10 (+3.1%) and 15 m (+4.0%) were observed (P < 0.05), whereas no significant changes for the same distances were detected following the AT camp (-0.89%; P > 0.05). Trivial changes in peak velocity were obtained during the loaded squat jump after both training periods (effect sizes: < 0.20). Based on these results we can conclude that a traditional training high-living high strategy concurrent training of 3 weeks does not adversely affect swimming start time and loaded squat jump performance in high level swimmers, but further studies are necessary to assess the effectiveness of power-oriented resistance training in the development of explosive actions.

  8. The Effect of an Altitude Training Camp on Swimming Start Time and Loaded Squat Jump Performance

    PubMed Central

    Štirn, Igor; Padial, Paulino; Argüelles-Cienfuegos, Javier; De la Fuente, Blanca; Calderón, Carmen; Bonitch-Góngora, Juan; Tomazin, Katja; Strumbelj, Boro; Strojnik, Vojko; Feriche, Belén

    2016-01-01

    This study evaluated the influence of an altitude training (AT) camp on swimming start time and loaded squat jump performance. To accomplish this goal, 13 international swimmers (8 women, 5 men) were allocated to both the control (Sea Level Training, SLT) and experimental conditions (AT, 2320 m above sea level) that were separated by a one year period. All tests (15 m freestyle swimming start and loaded squat jumps with additional loads of 25%, 50%, 75%, and 100% of swimmers’ body weight) were performed before and after a concurrent 3-week strength and endurance training program prescribed by the national coach. Following the SLT camp, significant impairments in swimming start times to 10 (+3.1%) and 15 m (+4.0%) were observed (P < 0.05), whereas no significant changes for the same distances were detected following the AT camp (-0.89%; P > 0.05). Trivial changes in peak velocity were obtained during the loaded squat jump after both training periods (effect sizes: < 0.20). Based on these results we can conclude that a traditional training high—living high strategy concurrent training of 3 weeks does not adversely affect swimming start time and loaded squat jump performance in high level swimmers, but further studies are necessary to assess the effectiveness of power-oriented resistance training in the development of explosive actions. PMID:27467760

  9. Increased Hypoxic Dose After Training at Low Altitude with 9h Per Night at 3000m Normobaric Hypoxia

    PubMed Central

    Carr, Amelia J.; Saunders, Philo U.; Vallance, Brent S.; Garvican-Lewis, Laura A.; Gore, Christopher J.

    2015-01-01

    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 < 0.05. There was a 3.7% increase in Hbmass in lowHH+NHnight compared with CON (p = 0.02). In comparison to baseline, Hbmass increased by 1.2% (±1.4%) in the lowHH group, 2.6% (±1.8%) in lowHH+NHnight, and there was a decrease of 0.9% (±4.9%) in CON. VO2max increased by ~4% within both experimental conditions but was not significantly greater than the 1% increase in CON. There was a ~9% difference in pre and post-intervention values in time to exhaustion after lowHH+NH-night (p = 0.03) and a ~8% pre to post-intervention difference (p = 0.006) after lowHH only. We recommend low 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 points In some countries, it may not be possible to perform classical altitude training effectively, due to the low elevation at altitude training venues. An

  10. Increased Hypoxic Dose After Training at Low Altitude with 9h Per Night at 3000m Normobaric Hypoxia.

    PubMed

    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 < 0.05. There was a 3.7% increase in Hbmass in lowHH+NHnight compared with CON (p = 0.02). In comparison to baseline, Hbmass increased by 1.2% (±1.4%) in the lowHH group, 2.6% (±1.8%) in lowHH+NHnight, and there was a decrease of 0.9% (±4.9%) in CON. VO2max increased by ~4% within both experimental conditions but was not significantly greater than the 1% increase in CON. There was a ~9% difference in pre and post-intervention values in time to exhaustion after lowHH+NH-night (p = 0.03) and a ~8% pre to post-intervention difference (p = 0.006) after lowHH only. We recommend low 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

  11. Propulsion/airframe integration considerations for high altitude hypersonic cruise vehicles

    NASA Technical Reports Server (NTRS)

    Weidner, J. P.

    1980-01-01

    A study has been conducted to determine the implications of top-mounted inlet nacelles on propulsion performance and cruise range. The top-mounted nacelle would be less visible from ground-based radar below and ahead of the aircraft. For this study, the nacelle is integrated with a high altitude Mach 5 turbojet/ramjet-powered airplane concept requiring a large nacelle. Results of the study suggest nacelle installation advantages and improved inlet mass flow ratio for the top-mounted nacelle, but at the expense of a higher installed drag at transonic and supersonic speeds.

  12. Comparison of Live High: Train Low Altitude and Intermittent Hypoxic Exposure

    PubMed Central

    Humberstone-Gough, Clare E.; Saunders, Philo U.; Bonetti, Darrell L.; Stephens, Shaun; Bullock, Nicola; Anson, Judith M.; Gore, Christopher J.

    2013-01-01

    Live High:Train Low (LHTL) altitude training is a popular ergogenic aid amongst athletes. An alternative hypoxia protocol, acute (60-90 min daily) Intermittent Hypoxic Exposure (IHE), has shown potential for improving athletic performance. The aim of this study was to compare directly the effects of LHTL and IHE on the running and blood characteristics of elite triathletes. Changes in total haemoglobin mass (Hbmass), maximal oxygen consumption (VO2max), velocity at VO2max (vVO2max), time to exhaustion (TTE), running economy, maximal blood lactate concentration ([La]) and 3 mM [La] running speed were compared following 17 days of LHTL (240 h of hypoxia), IHE (10.2 h of hypoxia) or Placebo treatment in 24 Australian National Team triathletes (7 female, 17 male). There was a clear 3.2 ± 4.8% (mean ± 90% confidence limits) increase in Hbmass following LHTL compared with Placebo, whereas the corresponding change of -1.4 ± 4.5% in IHE was unclear. Following LHTL, running economy was 2.8 ± 4.4% improved compared to IHE and 3mM [La] running speed was 4.4 ± 4.5% improved compared to Placebo. After IHE, there were no beneficial changes in running economy or 3mM [La] running speed compared to Placebo. There were no clear changes in VO2max, vVO2max and TTE following either method of hypoxia. The clear difference in Hbmass response between LHTL and IHE indicated that the dose of hypoxia in IHE was insufficient to induce accelerated erythropoiesis. Improved running economy and 3mM [La] running speed following LHTL suggested that this method of hypoxic exposure may enhance performance at submaximal running speeds. Overall, there was no evidence to support the use of IHE in elite triathletes. Key Points Despite a clear 3.2% increase in haemoglobin mass following 17 days of Live High: Train Low altitude training, no change in maximal aerobic capacity was observed. There were positive changes in running economy and the lactate-speed relationship at submaximal running speeds

  13. Position statement--altitude training for improving team-sport players' performance: current knowledge and unresolved issues.

    PubMed

    Girard, Olivier; Amann, Markus; Aughey, Robert; Billaut, François; Bishop, David J; Bourdon, Pitre; Buchheit, Martin; Chapman, Robert; D'Hooghe, Michel; Garvican-Lewis, Laura A; Gore, Christopher J; Millet, Grégoire P; Roach, Gregory D; Sargent, Charli; Saunders, Philo U; Schmidt, Walter; Schumacher, Yorck O

    2013-12-01

    Despite the limited research on the effects of altitude (or hypoxic) training interventions on team-sport performance, players from all around the world engaged in these sports are now using altitude training more than ever before. In March 2013, an Altitude Training and Team Sports conference was held in Doha, Qatar, to establish a forum of research and practical insights into this rapidly growing field. A round-table meeting in which the panellists engaged in focused discussions concluded this conference. This has resulted in the present position statement, designed to highlight some key issues raised during the debates and to integrate the ideas into a shared conceptual framework. The present signposting document has been developed for use by support teams (coaches, performance scientists, physicians, strength and conditioning staff) and other professionals who have an interest in the practical application of altitude training for team sports. After more than four decades of research, there is still no consensus on the optimal strategies to elicit the best results from altitude training in a team-sport population. However, there are some recommended strategies discussed in this position statement to adopt for improving the acclimatisation process when training/competing at altitude and for potentially enhancing sea-level performance. It is our hope that this information will be intriguing, balanced and, more importantly, stimulating to the point that it promotes constructive discussion and serves as a guide for future research aimed at advancing the bourgeoning body of knowledge in the area of altitude training for team sports.

  14. Position statement—altitude training for improving team-sport players’ performance: current knowledge and unresolved issues

    PubMed Central

    Girard, Olivier; Amann, Markus; Aughey, Robert; Billaut, François; Bishop, David J; Bourdon, Pitre; Buchheit, Martin; Chapman, Robert; D'Hooghe, Michel; Garvican-Lewis, Laura A; Gore, Christopher J; Millet, Grégoire P; Roach, Gregory D; Sargent, Charli; Saunders, Philo U; Schmidt, Walter; Schumacher, Yorck O

    2013-01-01

    Despite the limited research on the effects of altitude (or hypoxic) training interventions on team-sport performance, players from all around the world engaged in these sports are now using altitude training more than ever before. In March 2013, an Altitude Training and Team Sports conference was held in Doha, Qatar, to establish a forum of research and practical insights into this rapidly growing field. A round-table meeting in which the panellists engaged in focused discussions concluded this conference. This has resulted in the present position statement, designed to highlight some key issues raised during the debates and to integrate the ideas into a shared conceptual framework. The present signposting document has been developed for use by support teams (coaches, performance scientists, physicians, strength and conditioning staff) and other professionals who have an interest in the practical application of altitude training for team sports. After more than four decades of research, there is still no consensus on the optimal strategies to elicit the best results from altitude training in a team-sport population. However, there are some recommended strategies discussed in this position statement to adopt for improving the acclimatisation process when training/competing at altitude and for potentially enhancing sea-level performance. It is our hope that this information will be intriguing, balanced and, more importantly, stimulating to the point that it promotes constructive discussion and serves as a guide for future research aimed at advancing the bourgeoning body of knowledge in the area of altitude training for team sports. PMID:24282213

  15. Rhodiola crenulata- and Cordyceps sinensis-Based Supplement Boosts Aerobic Exercise Performance after Short-Term High Altitude Training

    PubMed Central

    Chen, Chung-Yu; Hou, Chien-Wen; Bernard, Jeffrey R.; Chen, Chiu-Chou; Hung, Ta-Cheng; Cheng, Lu-Ling; Liao, Yi-Hung

    2014-01-01

    Abstract Chen, Chung-Yu, Chien-Wen Hou, Jeffrey R. Bernard, Chiu-Chou Chen, Ta-Cheng Hung, Lu-Ling Cheng, Yi-Hung Liao, and Chia-Hua Kuo. Rhodiola crenulata- and Cordyceps sinensis-based supplement boosts aerobic exercise performance after short-term high altitude training. High Alt Med Biol 15:371–379, 2014.—High altitude training is a widely used strategy for improving aerobic exercise performance. Both Rhodiola crenulata (R) and Cordyceps sinensis (C) supplements have been reported to improve exercise performance. However, it is not clear whether the provision of R and C during high altitude training could further enhance aerobic endurance capacity. In this study, we examined the effect of R and C based supplementation on aerobic exercise capacity following 2-week high altitude training. Alterations to autonomic nervous system activity, circulatory hormonal, and hematological profiles were investigated. Eighteen male subjects were divided into two groups: Placebo (n=9) and R/C supplementation (RC, n=9). Both groups received either RC (R: 1400 mg+C: 600 mg per day) or the placebo during a 2-week training period at an altitude of 2200 m. After 2 weeks of altitude training, compared with Placebo group, the exhaustive run time was markedly longer (Placebo: +2.2% vs. RC: +5.7%; p<0.05) and the decline of parasympathetic (PNS) activity was significantly prevented in RC group (Placebo: −51% vs. RC: −41%; p<0.05). Red blood cell, hematocrit, and hemoglobin levels were elevated in both groups to a comparable extent after high altitude training (p<0.05), whereas the erythropoietin (EPO) level remained higher in the Placebo group (∼48% above RC values; p<0.05). The provision of an RC supplement during altitude training provides greater training benefits in improving aerobic performance. This beneficial effect of RC treatment may result from better maintenance of PNS activity and accelerated physiological adaptations during high altitude training. PMID

  16. Yin and yang, or peas in a pod? Individual-sport versus team-sport athletes and altitude training.

    PubMed

    Aughey, Robert J; Buchheit, Martin; Garvican-Lewis, Laura A; Roach, Gregory D; Sargent, Charli; Billaut, François; Varley, Matthew C; Bourdon, Pitre C; Gore, Christopher J

    2013-12-01

    The question of whether altitude training can enhance subsequent sea-level performance has been well investigated over many decades. However, research on this topic has focused on athletes from individual or endurance sports, with scant number of studies on team-sport athletes. Questions that need to be answered include whether this type of training may enhance team-sport athlete performance, when success in team-sport is often more based on technical and tactical ability rather than physical capacity per se. This review will contrast and compare athletes from two sports representative of endurance (cycling) and team-sports (soccer). Specifically, we draw on the respective competition schedules, physiological capacities, activity profiles and energetics of each sport to compare the similarities between athletes from these sports and discuss the relative merits of altitude training for these athletes. The application of conventional live-high, train-high; live-high, train-low; and intermittent hypoxic training for team-sport athletes in the context of the above will be presented. When the above points are considered, we will conclude that dependent on resources and training objectives, altitude training can be seen as an attractive proposition to enhance the physical performance of team-sport athletes without the need for an obvious increase in training load.

  17. High altitude headache and acute mountain sickness at moderate elevations in a military population during battalion-level training exercises.

    PubMed

    Norris, Jacob N; Viirre, Erik; Aralis, Hilary; Sracic, Michael K; Thomas, Darren; Gertsch, Jeffery H

    2012-08-01

    Few studies have evaluated high altitude headache (HAH) and acute mountain sickness (AMS) in military populations training at moderate (1,500-2,500 m) to high altitudes (>2,500 m). In the current study, researchers interviewed active duty personnel training at Marine Corps Mountain Warfare Training Center. Participants were asked about HAH and AMS symptoms, potential risk factors, and medications used. In a sample of 192 U.S. Navy and Marine Corps personnel, 14.6% reported AMS (Lake Louise Criteria > or = 3) and 28.6% reported HAH. Dehydration and recent arrival at altitude (defined as data collected on days 2-3) were significantly associated with AMS; decreased sleep allowance was significantly associated with HAH. Although ibuprofen/Motrin users were more likely to screen positive for AMS, among AMS-positive participants, ibuprofen/Motrin users had decreased likelihood of reporting robust AMS relative to non-ibuprofen/Motrin users (p < 0.01). These results suggest that maintenance of hydration and adequate sleep allowance may be critical performance requirements at altitude. Further, ibuprofen/Motrin may be a reasonable treatment for the symptoms of AMS and HAH, although further study is warranted.

  18. Performance changes during a weeklong high-altitude alpine ski-racing training camp in lowlander young athletes.

    PubMed

    Hydren, Jay R; Kraemer, William J; Volek, Jeff S; Dunn-Lewis, Courtenay; Comstock, Brett A; Szivak, Tunde K; Hooper, David R; Denegar, Craig R; Maresh, Carl M

    2013-04-01

    Thousands of youth athletes travel to high altitude to participate in lift-access alpine sports. The purpose of this study was to examine the impact of acute high-altitude exposure on balance, choice reaction time, power, quickness, flexibility, strength endurance, and V[Combining Dot Above]O2max in youth lowlander athletes during a weeklong preseason training camp in Summit County, CO, USA. Eleven youth ski racers (4 boys and 7 girls; age, 13.7 ± 0.5 years; height, 157.2 ± 12.6 cm; weight, 52.4 ± 6.8 kg) with 7.7 ± 2.2 skiing years of experience participated in baseline testing at 160 m one week before the camp and a set of daily tests in the morning and afternoon at 2,828 m and skied between 3,328 and 3,802 m during a 6-day camp. Balance and choice reaction time tests were stagnant or improved slightly during the first 3 days and then improved on days 4 and 6. Vertical jump, flexibility, T-agility test, and push-ups in 1 minute improved on day 6. The number of sit-ups in 1 minute did not improve, and scores on the multistage fitness test decreased 20.34%. There was no effect of Lake Louise acute mountain sickness (AMS) questionnaire scores on performance variables measured. Athletes sojourning to high altitude for ski camps can train on immediate ascent but should slowly increase training volume over the first 3 days. Athletes should expect improvements in balance and reaction time 3-6 days into acclimatization. Coaches and athletes should expect about 20% of youth lowlander athletes to have signs and symptoms of AMS during the first 3 days of altitude exposure for alpine lift access sports at altitudes of up to 3,800 m.

  19. Level III Training Evaluation: Considerations for Today's Organizations.

    ERIC Educational Resources Information Center

    Harrell, Kathleen D.

    2001-01-01

    Discussion of the four-level model of training evaluation focuses on the need for evaluation at level III, to show that training has been effective and that trainees behave differently on the job. Suggests data collection and measurement methods, including pretraining-posttraining evaluation, action plan audits, simulations, and unobtrusive…

  20. Children and Adolescents: Physiological Considerations during Exercise Training

    ERIC Educational Resources Information Center

    Strawbridge, Marilyn

    2013-01-01

    Because children and adolescents are not just miniature adults, it is important to know that children might be vulnerable to injury and may not respond positively to certain types or intensities of training. It is also important to recognize how training can positively affect growth and development, so it can be judiciously applied at critical…

  1. Challenges for an interdisciplinary consideration of cognitive training.

    PubMed

    Birney, Damian Patrick

    2015-01-01

    Whether fluid cognitive functions are malleable has been a topic of ongoing debate for at least the past 100 years. Ever-evolving technology has led to new and diverse fields of investigation entering this debate. There are significant advantages to be gained by integrating different scientific paradigms, but there are also significant challenges. Cross-paradigm differences in levels of analysis, nomenclature, and expectations of training outcomes complicate interpretation of training results. It is argued that further investigations of (a) cross-paradigm intricacies and (b) strategy versus process training, particularly with spatial abilities, are needed.

  2. [Contributions of training in biomedical ethics. Investigations, considerations and prospects].

    PubMed

    Waelchli, M; Foppa, C

    2012-01-01

    The testimonies of healthcare professionals who have received introductory training in biomedial ethics show a perceived improvement in their competence in managing complex situations that involve ethical stakes. The resources acquired in this way should make it possible to prevent and reduce the appearance of moral distress, a phenomenon the consequences and persistence of which can lead to burnout and to giving up the profession. These observations encourage establishments to reinforce the resources intended for ethical awareness courses for their fellow workers.

  3. The effects of altitude/hypoxic training on oxygen delivery capacity of the blood and aerobic exercise capacity in elite athletes – a meta-analysis

    PubMed Central

    Park, Hun-young; Hwang, Hyejung; Park, Jonghoon; Lee, Seongno; Lim, Kiwon

    2016-01-01

    [Purpose] This study was designed as a meta-analysis of randomized controlled trials comparing effectiveness of altitude/hypoxic training (experimental) versus sea-level training (control) on oxygen delivery capacity of the blood and aerobic exercise capacity of elite athletes in Korea. [Methods] Databases (Research Information Service System, Korean studies Information Service System, National Assembly Library) were for randomized controlled trials comparing altitude/hypoxic training versus sea-level training in elite athletes. Studies published in Korea up to December 2015 were eligible for inclusion. Oxygen delivery capacity of the blood was quantified by red blood cell (RBC), hemoglobin (Hb), hematocrit (Hct), erythropoietin (EPO); and aerobic exercise capacity was quantified by maximal oxygen consumption (VO2max). RBC, Hb, Hct, VO2max represented heterogeneity and compared post-intervention between altitude/hypoxic training and sea-level training in elite athletes by a random effect model meta-analysis. EPO represented homogeneity and meta-analysis performed by a fixed effect model. Eight independent studies with 156 elite athletes (experimental: n = 82, control: n = 74) were included in the metaanalysis. [Results] RBC (4.499×105 cell/ul, 95 % CI: 2.469 to 6.529), Hb (5.447 g/dl, 95 % CI: 3.028 to 7.866), Hct (3.639 %, 95 % CI: 1.687 to 5.591), EPO (0.711 mU/mL, 95% CI: 0.282 to 1.140), VO2max (1.637 ml/kg/min, 95% CI: 0.599 to 1.400) showed significantly greater increase following altitude/hypoxic training, as compared with sea-level training. [Conclusion] For elite athletes in Korea, altitude/ hypoxic training appears more effective than sea-level training for improvement of oxygen delivery capacity of the blood and aerobic exercise capacity. PMID:27298808

  4. [Training in digestive endoscopy. Considerations, experiences and methodological contributions].

    PubMed

    Santos Lucero, R; Espiniella, F; Zárate, J O; Tomás, J; Grosso, M

    1986-01-01

    The bibliographical contributions on education in digestive endoscopy and the need of establishing in Argentina a curricular programming for its teaching-learning are considered. The experience of the authors acquired during the giving of eight Basic or initiation Courses and eight Advanced or Improvement Courses is presented. They used in them six didactic simulators and endoscopic cinematography that completed the written simulations. Conceptual and methodological aspects are exposed to perform the curricular programming of training comprising the student from the student of Medicine to the gastroenterologist or surgeon more devoted or specialist in digestive endoscopy. PMID:3661076

  5. The feasibility of a high-altitude aircraft platform with consideration of technological and societal constraints. Thesis - Kansas Univ.

    NASA Technical Reports Server (NTRS)

    Graves, E. B.

    1982-01-01

    The feasibility of remotely piloted aircraft performing year around missions at an altitude of 70,000 feet is determined. Blimp and airplane type vehicles employing solar-voltaic, microwave, or nuclear propulsion systems were considered. A payload weighing 100 pounds and requiring 1000 watts of continuous power was assumed for analysis purposes. Results indicate that a solar powered aircraft requires more solar cell area than is available on conventional aircraft configurations if designed for the short days and high wind speeds associated with the winter season. A conventionally shaped blimp that uses solar power appears feasible if maximum airspeed is limited to about 100 ft/s. No viable airplane configuration that uses solar power and designed to withstand the winter environment was found. Both a conventionally shaped blimp and airplane appear feasible using microwave power. Nuclear powered aircraft of these type are also feasible. Societal attitudes toward the use of solar power in high altitude aircraft appear favorable. The use of microwave power for this purpose is controversial, even though the ground station required would transmit power at levels comparable to existing satellite communications stations.

  6. Adding heat to the live-high train-low altitude model: a practical insight from professional football

    PubMed Central

    Buchheit, M; Racinais, S; Bilsborough, J; Hocking, J; Mendez-Villanueva, A; Bourdon, P C; Voss, S; Livingston, S; Christian, R; Périard, J; Cordy, J; Coutts, A J

    2013-01-01

    Objectives To examine with a parallel group study design the performance and physiological responses to a 14-day off-season ‘live high-train low in the heat’ training camp in elite football players. Methods Seventeen professional Australian Rules Football players participated in outdoor football-specific skills (32±1°C, 11.5 h) and indoor strength (23±1°C, 9.3 h) sessions and slept (12 nights) and cycled indoors (4.3 h) in either normal air (NORM, n=8) or normobaric hypoxia (14±1 h/day, FiO2 15.2–14.3%, corresponding to a simulated altitude of 2500–3000 m, hypoxic (HYP), n=9). They completed the Yo-Yo Intermittent Recovery level 2 (Yo-YoIR2) in temperate conditions (23±1°C, normal air) precamp (Pre) and postcamp (Post). Plasma volume (PV) and haemoglobin mass (Hbmass) were measured at similar times and 4 weeks postcamp (4WPost). Sweat sodium concentration ((Na+)sweat) was measured Pre and Post during a heat-response test (44°C). Results Both groups showed very large improvements in Yo-YoIR2 at Post (+44%; 90% CL 38, 50), with no between-group differences in the changes (−1%; −9, 9). Postcamp, large changes in PV (+5.6%; −1.8, 5.6) and (Na+)sweat (−29%; −37, −19) were observed in both groups, while Hbmass only moderately increased in HYP (+2.6%; 0.5, 4.5). At 4WPost, there was a likely slightly greater increase in Hbmass (+4.6%; 0.0, 9.3) and PV (+6%; −5, 18, unclear) in HYP than in NORM. Conclusions The combination of heat and hypoxic exposure during sleep/training might offer a promising ‘conditioning cocktail’ in team sports. PMID:24282209

  7. High-altitude medicine.

    PubMed

    West, John B

    2012-12-15

    Medical problems occur at high altitude because of the low inspired Po(2), which is caused by the reduced barometric pressure. The classical physiological responses to high altitude include hyperventilation, polycythemia, hypoxic pulmonary vasoconstriction-increased intracellular oxidative enzymes, and increased capillary density in muscle. However, with the discovery of hypoxia-inducible factors (HIFs), it is apparent that there is a multitude of responses to cellular hypoxia. HIFs constitute a master switch determining the general response of the body to oxygen deprivation. The recent discovery of genetic changes in Tibetans has opened up an exciting area of research. The two major human populations that have adapted well to high altitude, the Tibetans and Andeans, have strikingly different phenotypes. Diseases of lowlanders going to high altitude include acute mountain sickness, high-altitude pulmonary edema, and high-altitude cerebral edema. Diseases affecting permanent residents or highlanders include chronic mountain sickness and high-altitude pulmonary hypertension. Important recent advances have been made on mitigation of the effects of the hypoxic environment. Oxygen enrichment of room air is very powerful. Every 1% increase in oxygen concentration reduces the equivalent altitude by about 300 m. This procedure is used in numerous facilities at high altitude and in a Chinese train to Lhasa. An alternative strategy is to increase the barometric pressure as in aircraft cabins. A hybrid approach combining both strategies shows promise but has never been used. Mines that are being developed at increasingly high altitudes pose great medical problems.

  8. Effects of 12-Week Endurance Training at Natural Low Altitude on the Blood Redox Homeostasis of Professional Adolescent Athletes: A Quasi-Experimental Field Trial.

    PubMed

    Tong, Tomas K; Kong, Zhaowei; Lin, Hua; He, Yeheng; Lippi, Giuseppe; Shi, Qingde; Zhang, Haifeng; Nie, Jinlei

    2016-01-01

    This field study investigated the influences of exposure to natural low altitude on endurance training-induced alterations of redox homeostasis in professional adolescent runners undergoing 12-week off-season conditioning program at an altitude of 1700 m (Alt), by comparison with that of their counterparts completing the program at sea-level (SL). For age-, gender-, and Tanner-stage-matched comparison, 26 runners (n = 13 in each group) were selected and studied. Following the conditioning program, unaltered serum levels of thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (T-AOC), and superoxide dismutase accompanied with an increase in oxidized glutathione (GSSG) and decreases of xanthine oxidase, reduced glutathione (GSH), and GSH/GSSG ratio were observed in both Alt and SL groups. Serum glutathione peroxidase and catalase did not change in SL, whereas these enzymes, respectively, decreased and increased in Alt. Uric acid (UA) decreased in SL and increased in Alt. Moreover, the decreases in GSH and GSH/GSSG ratio in Alt were relatively lower compared to those in SL. Further, significant interindividual correlations were found between changes in catalase and TBARS, as well as between UA and T-AOC. These findings suggest that long-term training at natural low altitude is unlikely to cause retained oxidative stress in professional adolescent runners.

  9. Effects of 12-Week Endurance Training at Natural Low Altitude on the Blood Redox Homeostasis of Professional Adolescent Athletes: A Quasi-Experimental Field Trial

    PubMed Central

    Tong, Tomas K.; Kong, Zhaowei; Lin, Hua; He, Yeheng; Lippi, Giuseppe; Shi, Qingde; Zhang, Haifeng

    2016-01-01

    This field study investigated the influences of exposure to natural low altitude on endurance training-induced alterations of redox homeostasis in professional adolescent runners undergoing 12-week off-season conditioning program at an altitude of 1700 m (Alt), by comparison with that of their counterparts completing the program at sea-level (SL). For age-, gender-, and Tanner-stage-matched comparison, 26 runners (n = 13 in each group) were selected and studied. Following the conditioning program, unaltered serum levels of thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (T-AOC), and superoxide dismutase accompanied with an increase in oxidized glutathione (GSSG) and decreases of xanthine oxidase, reduced glutathione (GSH), and GSH/GSSG ratio were observed in both Alt and SL groups. Serum glutathione peroxidase and catalase did not change in SL, whereas these enzymes, respectively, decreased and increased in Alt. Uric acid (UA) decreased in SL and increased in Alt. Moreover, the decreases in GSH and GSH/GSSG ratio in Alt were relatively lower compared to those in SL. Further, significant interindividual correlations were found between changes in catalase and TBARS, as well as between UA and T-AOC. These findings suggest that long-term training at natural low altitude is unlikely to cause retained oxidative stress in professional adolescent runners. PMID:26783415

  10. Effects of 12-Week Endurance Training at Natural Low Altitude on the Blood Redox Homeostasis of Professional Adolescent Athletes: A Quasi-Experimental Field Trial.

    PubMed

    Tong, Tomas K; Kong, Zhaowei; Lin, Hua; He, Yeheng; Lippi, Giuseppe; Shi, Qingde; Zhang, Haifeng; Nie, Jinlei

    2016-01-01

    This field study investigated the influences of exposure to natural low altitude on endurance training-induced alterations of redox homeostasis in professional adolescent runners undergoing 12-week off-season conditioning program at an altitude of 1700 m (Alt), by comparison with that of their counterparts completing the program at sea-level (SL). For age-, gender-, and Tanner-stage-matched comparison, 26 runners (n = 13 in each group) were selected and studied. Following the conditioning program, unaltered serum levels of thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (T-AOC), and superoxide dismutase accompanied with an increase in oxidized glutathione (GSSG) and decreases of xanthine oxidase, reduced glutathione (GSH), and GSH/GSSG ratio were observed in both Alt and SL groups. Serum glutathione peroxidase and catalase did not change in SL, whereas these enzymes, respectively, decreased and increased in Alt. Uric acid (UA) decreased in SL and increased in Alt. Moreover, the decreases in GSH and GSH/GSSG ratio in Alt were relatively lower compared to those in SL. Further, significant interindividual correlations were found between changes in catalase and TBARS, as well as between UA and T-AOC. These findings suggest that long-term training at natural low altitude is unlikely to cause retained oxidative stress in professional adolescent runners. PMID:26783415

  11. Space Station Freedom altitude strategy

    NASA Technical Reports Server (NTRS)

    Mcdonald, Brian M.; Teplitz, Scott B.

    1990-01-01

    The Space Station Freedom (SSF) altitude strategy provides guidelines and assumptions to determine an altitude profile for Freedom. The process for determining an altitude profile incorporates several factors such as where the Space Shuttle will rendezvous with the SSF, when reboosts must occur, and what atmospheric conditions exist causing decay. The altitude strategy has an influence on all areas of SSF development and mission planning. The altitude strategy directly affects the micro-gravity environment for experiments, propulsion and control system sizing, and Space Shuttle delivery manifests. Indirectly the altitude strategy influences almost every system and operation within the Space Station Program. Evolution of the SSF altitude strategy has been a very dynamic process over the past few years. Each altitude strategy in turn has emphasized a different consideration. Examples include a constant Space Shuttle rendezvous altitude for mission planning simplicity, or constant micro-gravity levels with its inherent emphasis on payloads, or lifetime altitudes to provide a safety buffer to loss of control conditions. Currently a new altitude strategy is in development. This altitude strategy will emphasize Space Shuttle delivery optimization. Since propellant is counted against Space Shuttle payload-to-orbit capacity, lowering the rendezvous altitude will not always increase the net payload-to-orbit, since more propellant would be required for reboost. This altitude strategy will also consider altitude biases to account for Space Shuttle launch slips and an unexpected worsening of atmospheric conditions. Safety concerns will define a lower operational altitude limit, while radiation levels will define upper altitude constraints. The evolution of past and current SSF altitude strategies and the development of a new altitude strategy which focuses on operational issues as opposed to design are discussed.

  12. Developing maximal neuromuscular power: part 2 - training considerations for improving maximal power production.

    PubMed

    Cormie, Prue; McGuigan, Michael R; Newton, Robert U

    2011-02-01

    This series of reviews focuses on the most important neuromuscular function in many sport performances: the ability to generate maximal muscular power. Part 1, published in an earlier issue of Sports Medicine, focused on the factors that affect maximal power production while part 2 explores the practical application of these findings by reviewing the scientific literature relevant to the development of training programmes that most effectively enhance maximal power production. The ability to generate maximal power during complex motor skills is of paramount importance to successful athletic performance across many sports. A crucial issue faced by scientists and coaches is the development of effective and efficient training programmes that improve maximal power production in dynamic, multi-joint movements. Such training is referred to as 'power training' for the purposes of this review. Although further research is required in order to gain a deeper understanding of the optimal training techniques for maximizing power in complex, sports-specific movements and the precise mechanisms underlying adaptation, several key conclusions can be drawn from this review. First, a fundamental relationship exists between strength and power, which dictates that an individual cannot possess a high level of power without first being relatively strong. Thus, enhancing and maintaining maximal strength is essential when considering the long-term development of power. Second, consideration of movement pattern, load and velocity specificity is essential when designing power training programmes. Ballistic, plyometric and weightlifting exercises can be used effectively as primary exercises within a power training programme that enhances maximal power. The loads applied to these exercises will depend on the specific requirements of each particular sport and the type of movement being trained. The use of ballistic exercises with loads ranging from 0% to 50% of one-repetition maximum (1RM) and

  13. Living at high altitude in combination with sea-level sprint training increases hematological parameters but does not improve performance in rats.

    PubMed

    Martinez-Bello, Vladimir Essau; Sanchis-Gomar, Fabian; Nascimento, Ana Lucia; Pallardo, Federico V; Ibañez-Sania, Sandra; Olaso-Gonzalez, Gloria; Calbet, Jose Antonio; Gomez-Cabrera, Mari Carmen; Viña, Jose

    2011-06-01

    The regimen of aerobic training at sea level with recovery at high altitude has been used by athletes to improve performance. However, little is known about the effects of hypoxia when combined with sprint interval training on performance. The aim of the present study was to determine the effect of a "living high-sprint training low" strategy on hemoglobin, hematocrit and erythropoietin levels in rats. We also wanted to test whether the addition of a hypoxic stress to the program of daily treadmill running at high speeds induces expressional adaptations in skeletal muscle and affects performance. The protein content of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), cytochrome C, pyruvate dehydrogenase kinase (PDK1), heat shock protein 70 (HSP70), manganese superoxide dismutase (MnSOD) and citrate synthase activity were determined in different muscle fiber types in our animals (red and white gastrocnemius muscle). We also determined the maximal aerobic velocity (MAV) before and after the training period. A total of 24 male Wistar rats (3 month old) were randomly divided into four experimental groups: the normoxic control group (n = 6), the normoxic trained group (n = 6), the hypoxic control group (12 h pO(2) 12%/12 h pO(2) 21%) (n = 6) and the hypoxic trained group (12 h pO(2) 12%/12 h pO(2) 21%). Living in normobaric hypoxia condition for 21 days significantly increased hemoglobin, hematocrit and erythropoietin levels in both the rest and the trained groups. The trained animals (normoxia and hypoxia) significantly increased their maximal aerobic velocity. No changes were found in the skeletal muscle in PGC-1α, cytochrome C, PDK1, HSP70, MnSOD protein content and in the citrate synthase activity in any experimental group. Regardless of whether it is combined with sprint interval training or not, after 21 days of living at high altitude we found a significant increase in the hematological values determined in our study. However, contrary to

  14. Assessment of oxidative stress biomarkers - neuroprostanes and dihomo-isoprostanes - in the urine of elite triathletes after two weeks of moderate-altitude training.

    PubMed

    García-Flores, Libia Alejandra; Medina, Sonia; Cejuela, Roberto; Martínez-Sanz, José Miguel; Oger, Camille; Galano, Jean-Marie; Durand, Thierry; Casas-Pina, Teresa; Martínez-Hernández, Pedro; Ferreres, Federico; Gil-Izquierdo, Ángel

    2016-01-01

    This randomized and controlled trial investigated whether the increase in elite training at different altitudes altered the oxidative stress biomarkers of the nervous system. This is the first study to investigate four F4-neuroprostanes (F4-NeuroPs) and four F2-dihomo-isoprostanes (F2-dihomo-IsoPs) quantified in 24-h urine. The quantification was carried out by ultra high pressure liquid chromatography-triple quadrupole-tandem mass spectrometry (UHPLC-QqQ-MS/MS). Sixteen elite triathletes agreed to participate in the project. They were randomized in two groups, a group submitted to altitude training (AT, n = 8) and a group submitted to sea level training (SLT) (n = 8), with a control group (Cg) of non-athletes (n = 8). After the experimental period, the AT group triathletes gave significant data: 17-epi-17-F2t-dihomo-IsoP (from 5.2 ± 1.4 μg/mL 24 h(-1) to 6.6 ± 0.6 μg/mL 24 h(-1)), ent-7(RS)-7-F2t-dihomo-IsoP (from 6.6 ± 1.7 μg/mL 24 h(-1) to 8.6 ± 0.9 μg/mL 24 h(-1)), and ent-7-epi-7-F2t-dihomo-IsoP (from 8.4 ± 2.2 μg/mL 24 h(-1) to 11.3 ± 1.8 μg/mL 24 h(-1)) increased, while, of the neuronal degeneration-related compounds, only 10-epi-10-F4t-NeuroP (8.4 ± 1.7 μg/mL 24 h(-1)) and 10-F4t-NeuroP (5.2 ± 2.9 μg/mL 24 h(-1)) were detected in this group. For the Cg and SLT groups, no significant changes had occurred at the end of the two-week experimental period. Therefore, and as the main conclusion, the training at moderate altitude increased the F4-NeuroPs- and F2-dihomo-isoPs-related oxidative damage of the central nervous system compared to similar training at sea level.

  15. Design considerations for high-altitude, long-endurance, microwave-powered aircraft. M.S. Thesis - George Washington Univ., Washington, D.C.

    NASA Technical Reports Server (NTRS)

    Nguyen, H. Q.

    1985-01-01

    The sizing and performance analyses have been conducted in the design of long-endurance, high-altitude airplanes. These airplanes receive power either continuously beamed from a phased array transmitter or intermittently beamed from a dish transmitter. Results are presented for the cases of flight in zero wind speed and nonzero wind speed. Sensitivity studies indicate that the vehicle size is relatively insensitive to changes in the transmitter size. Cost estimates were made using models that excluded the airplane cost. Using a reference payload, results obtained from array and dish configurations were compared. Comparisons showed savings in cost as well as smaller vehicle sizes when an array transmitter was used.

  16. Integrating the EMPD with an Alpine altitudinal training set to reconstruct climate variables in Holocene pollen records from high-altitude peat bogs

    NASA Astrophysics Data System (ADS)

    Furlanetto, Giulia; Badino, Federica; Brunetti, Michele; Champvillair, Elena; De Amicis, Mattia; Maggi, Valter; Pini, Roberta; Ravazzi, Cesare; Vallé, Francesca

    2016-04-01

    Temperatures and precipitation are the main environmental factors influencing vegetation and pollen production. Knowing the modern climate optima and tolerances of those plants represented in fossil assemblages and assuming that the relationships between plants and climate in the past are not dissimilar from the modern ones, fossil pollen records offer many descriptors to reconstruct past climate variables. The aim of our work is to investigate the potential of high-altitude pollen records from an Alpine peat bog (TBValter, close to the Ruitor Glacier, Western Italian Alps) for quantitative paleoclimate estimates. The idea behind is that high-altitude ecosystems are more sensitive to climate changes, especially to changes in July temperatures that severely affect the timberline ecotone. Meantime, we met with difficulties when considering the factors involved in pollen dispersal over a complex altitudinal mountain pattern, such as the Alps. We used the EMPD-European Modern Pollen Database (Davis et al., 2013) as modern training set to be compared with our high-altitude fossil site. The EMPD dataset is valuable in that it provides a large geographic coverage of main ecological and climate gradients (at sub-continental scale) but lacks in sampling of altitudinal gradients and high-altitude sites in the Alps. We therefore designed an independent altitudinal training set for the alpine valley hosting our fossil site. 27 sampling plots were selected along a 1700m-elevational transect. In a first step, each plot was provided with (i) 3 moss polsters collected following the guidelines provided by Cañellas-Boltà et al. (2009) and analyzed separately to account for differences in pollen deposition at small scale, (ii) morphometrical parameters obtained through a high-resolution DEM, and (iii) temperature and precipitation were estimated by means of weighted linear regression of the meteorological variable versus elevation, locally evaluated for each site (Brunetti et al

  17. High-altitude-nuclear electromagnetic pulse (HEMP) environment simulation public health and safety considerations. Technical report, 1 Oct 89-31 May 91

    SciTech Connect

    Casey, K.

    1992-03-01

    The existence of electromagnetic fields external to the working volumes of high-altitude nuclear electromagnetic pulse (HEMP) environment simulators has raised both environmental and public-health concerns regarding the safety of HEMP environment simulator operations. This report contains a review of what HEMP is, what its effects on defense systems are, and why and how HEMP environment simulation testing is conducted. The state of present knowledge concerning the external simulator fields and their possible effects on biological and electronic systems is summarized. Research initiatives are identified to aid in answering the most important questions regarding the continued environmental safety of HEMP simulator operations. These initiatives are intended to support (1) development of options for modification and/or relocation of HEMP environment simulator facilities and (2) determination of safe exposure levels for biological and electronic systems. Recommendations for specific DoD actions are given.

  18. PHYSICAL FIDELITY CONSIDERATIONS FOR NRC ADVANCED REACTOR CONTROL ROOM TRAINING SIMULATORS USED FOR INSPECTOR/EXAMINER TRAINING

    SciTech Connect

    Branch, Kristi M.; Mitchell, Mark R.; Miller, Mark; Cochrum, Steven

    2010-11-07

    This paper describes research into the physical fidelity requirements of control room simulators to train U.S. Nuclear Regulatory Commission (NRC) staff for their duties as inspectors and license examiners for next-generation nuclear power plants. The control rooms of these power plants are expected to utilize digital instrumentation and controls to a much greater extent than do current plants. The NRC is assessing training facility needs, particularly for control room simulators, which play a central role in NRC training. Simulator fidelity affects both training effectiveness and cost. Research has shown high simulation fidelity sometimes positively affects transfer to the operational environment but sometimes makes no significant difference or actually impedes learning. The conditions in which these different effects occur are often unclear, especially for regulators (as opposed to operators) about whom research is particularly sparse. This project developed an inventory of the tasks and knowledges, skills, and abilities that NRC regulators need to fulfill job duties and used expert panels to characterize the inventory items by type and level of cognitive/behavioral capability needed, difficulty to perform, importance to safety, frequency of performance, and the importance of simulator training for learning these capabilities. A survey of current NRC staff provides information about the physical fidelity of the simulator on which the student trained to the control room to which the student was assigned and the effect lack of fidelity had on learning and job performance. The study concludes that a high level of physical fidelity is not required for effective training of NRC staff.

  19. Human factors considerations for training astronauts to function effectively in multiple environments

    NASA Technical Reports Server (NTRS)

    Cohen, Malcolm M.

    1991-01-01

    This paper reviews some of the basic issues involved in training individuals to function appropriately under the several conditions that comprise the aerospace environment. The topic of transfer of training is examined in some detail, and the use of high-fidelity simulators in various training programs is discussed. Both current and classical techniques used to train astronauts are noted, and some relatively new and innovative training techniques and methods are described. Particularly, the paper discusses an important aspect of functioning appropriately in a given environment that is based on how well the operator calibrates his motor activity for that specific environment. The role of motor-sensory feedback for the acquisition of motor skills is discussed in the context of training.

  20. Employer Co-Funded Training in the UK: Current Practice and Policy Considerations

    ERIC Educational Resources Information Center

    Thomas, Rhodri; Parsons, David; Barry, John; Rowe, Valerie

    2007-01-01

    Purpose: This paper sets out to examine the contribution of employer co-funding of publicly-funded vocational education and training in the UK (i.e. training initiatives that are available to all qualified applicants but funded jointly by the public and private sectors). Design/methodology/approach: The paper draws on qualitative research…

  1. Altitude preexposure recommendations for inducing acclimatization.

    PubMed

    Muza, Stephen R; Beidleman, Beth A; Fulco, Charles S

    2010-01-01

    For many low-altitude (<1500 m) residents, their travel itineraries may cause them to ascend rapidly to high (>2400 m) altitudes without having the time to develop an adequate degree of altitude acclimatization. Prior to departing on these trips, low-altitude residents can induce some degree of altitude acclimatization by ascending to moderate (>1500 m) or high altitudes during either continuous or intermittent altitude preexposures. Generally, the degree of altitude acclimatization developed is proportional to the altitude attained and the duration of exposure. The available evidence suggests that continuous residence at 2200 m or higher for 1 to 2 days or daily 1.5- to 4-h exposures to >4000 m induce ventilatory acclimatization. Six days at 2200 m substantially decreases acute mountain sickness (AMS) and improves work performance after rapid ascent to 4300 m. There is evidence that 5 or more days above 3000 m within the last 2 months will significantly decrease AMS during a subsequent rapid ascent to 4500 m. Exercise training during the altitude preexposures may augment improvement in physical performance. The persistence of altitude acclimatization after return to low altitude appears to be proportional to the degree of acclimatization developed. The subsequent ascent to high altitude should be scheduled as soon as possible after the last altitude preexposure.

  2. Alternative considerations for environmental oversight training: Results from a needs assessment

    SciTech Connect

    Young, C.; Hensley, J.

    1995-11-01

    For staff to perform their jobs effectively and efficiently, they must be adequately trained. Well-trained staff are also more likely to be satisfied with their jobs and to remain with a given organization. In addition to hiring staff with relevant backgrounds and skills, critical steps in maintaining adequately trained staff are to analyze skill levels needed for the various tasks that personnel are required to perform and to provide training to improve staff s skill base. This first analysis is commonly referred to as a training needs assessment. Training needs are usually determined by defining the tasks required for a particular job and the associated knowledge, skills, and abilities necessary to adequately accomplish these tasks. The Office of Northwestern Area Programs of the U.S. Department of Energy`s (DOE`s) Office of Environmental Management (EM) oversees environmental remediation activities in the Chicago, Idaho, Oakland, and Richland Operations Offices. For this organization to effectively carry out its mission, its staff need to be as proficient as possible in the appropriate knowledge and skills. Therefore, a training needs assessment was conducted to determine staff`s level of knowledge and proficiency in various skills. The purpose of the assessment was to: (1) Examine the types of activities or tasks in which staff are involved, (2) Determine the skills needed to perform relevant tasks, and (3) Assess gaps in knowledge and skills for the tasks performed in order to suggest opportunities for skill development.

  3. Physiological and Neural Adaptations to Eccentric Exercise: Mechanisms and Considerations for Training

    PubMed Central

    Hedayatpour, Nosratollah; Falla, Deborah

    2015-01-01

    Eccentric exercise is characterized by initial unfavorable effects such as subcellular muscle damage, pain, reduced fiber excitability, and initial muscle weakness. However, stretch combined with overload, as in eccentric contractions, is an effective stimulus for inducing physiological and neural adaptations to training. Eccentric exercise-induced adaptations include muscle hypertrophy, increased cortical activity, and changes in motor unit behavior, all of which contribute to improved muscle function. In this brief review, neuromuscular adaptations to different forms of exercise are reviewed, the positive training effects of eccentric exercise are presented, and the implications for training are considered. PMID:26543850

  4. Physiological and Neural Adaptations to Eccentric Exercise: Mechanisms and Considerations for Training.

    PubMed

    Hedayatpour, Nosratollah; Falla, Deborah

    2015-01-01

    Eccentric exercise is characterized by initial unfavorable effects such as subcellular muscle damage, pain, reduced fiber excitability, and initial muscle weakness. However, stretch combined with overload, as in eccentric contractions, is an effective stimulus for inducing physiological and neural adaptations to training. Eccentric exercise-induced adaptations include muscle hypertrophy, increased cortical activity, and changes in motor unit behavior, all of which contribute to improved muscle function. In this brief review, neuromuscular adaptations to different forms of exercise are reviewed, the positive training effects of eccentric exercise are presented, and the implications for training are considered.

  5. Acceleration of Deep Neural Network Training with Resistive Cross-Point Devices: Design Considerations

    PubMed Central

    Gokmen, Tayfun; Vlasov, Yurii

    2016-01-01

    In recent years, deep neural networks (DNN) have demonstrated significant business impact in large scale analysis and classification tasks such as speech recognition, visual object detection, pattern extraction, etc. Training of large DNNs, however, is universally considered as time consuming and computationally intensive task that demands datacenter-scale computational resources recruited for many days. Here we propose a concept of resistive processing unit (RPU) devices that can potentially accelerate DNN training by orders of magnitude while using much less power. The proposed RPU device can store and update the weight values locally thus minimizing data movement during training and allowing to fully exploit the locality and the parallelism of the training algorithm. We evaluate the effect of various RPU device features/non-idealities and system parameters on performance in order to derive the device and system level specifications for implementation of an accelerator chip for DNN training in a realistic CMOS-compatible technology. For large DNNs with about 1 billion weights this massively parallel RPU architecture can achieve acceleration factors of 30, 000 × compared to state-of-the-art microprocessors while providing power efficiency of 84, 000 GigaOps∕s∕W. Problems that currently require days of training on a datacenter-size cluster with thousands of machines can be addressed within hours on a single RPU accelerator. A system consisting of a cluster of RPU accelerators will be able to tackle Big Data problems with trillions of parameters that is impossible to address today like, for example, natural speech recognition and translation between all world languages, real-time analytics on large streams of business and scientific data, integration, and analysis of multimodal sensory data flows from a massive number of IoT (Internet of Things) sensors. PMID:27493624

  6. Acceleration of Deep Neural Network Training with Resistive Cross-Point Devices: Design Considerations.

    PubMed

    Gokmen, Tayfun; Vlasov, Yurii

    2016-01-01

    In recent years, deep neural networks (DNN) have demonstrated significant business impact in large scale analysis and classification tasks such as speech recognition, visual object detection, pattern extraction, etc. Training of large DNNs, however, is universally considered as time consuming and computationally intensive task that demands datacenter-scale computational resources recruited for many days. Here we propose a concept of resistive processing unit (RPU) devices that can potentially accelerate DNN training by orders of magnitude while using much less power. The proposed RPU device can store and update the weight values locally thus minimizing data movement during training and allowing to fully exploit the locality and the parallelism of the training algorithm. We evaluate the effect of various RPU device features/non-idealities and system parameters on performance in order to derive the device and system level specifications for implementation of an accelerator chip for DNN training in a realistic CMOS-compatible technology. For large DNNs with about 1 billion weights this massively parallel RPU architecture can achieve acceleration factors of 30, 000 × compared to state-of-the-art microprocessors while providing power efficiency of 84, 000 GigaOps∕s∕W. Problems that currently require days of training on a datacenter-size cluster with thousands of machines can be addressed within hours on a single RPU accelerator. A system consisting of a cluster of RPU accelerators will be able to tackle Big Data problems with trillions of parameters that is impossible to address today like, for example, natural speech recognition and translation between all world languages, real-time analytics on large streams of business and scientific data, integration, and analysis of multimodal sensory data flows from a massive number of IoT (Internet of Things) sensors. PMID:27493624

  7. Acceleration of Deep Neural Network Training with Resistive Cross-Point Devices: Design Considerations.

    PubMed

    Gokmen, Tayfun; Vlasov, Yurii

    2016-01-01

    In recent years, deep neural networks (DNN) have demonstrated significant business impact in large scale analysis and classification tasks such as speech recognition, visual object detection, pattern extraction, etc. Training of large DNNs, however, is universally considered as time consuming and computationally intensive task that demands datacenter-scale computational resources recruited for many days. Here we propose a concept of resistive processing unit (RPU) devices that can potentially accelerate DNN training by orders of magnitude while using much less power. The proposed RPU device can store and update the weight values locally thus minimizing data movement during training and allowing to fully exploit the locality and the parallelism of the training algorithm. We evaluate the effect of various RPU device features/non-idealities and system parameters on performance in order to derive the device and system level specifications for implementation of an accelerator chip for DNN training in a realistic CMOS-compatible technology. For large DNNs with about 1 billion weights this massively parallel RPU architecture can achieve acceleration factors of 30, 000 × compared to state-of-the-art microprocessors while providing power efficiency of 84, 000 GigaOps∕s∕W. Problems that currently require days of training on a datacenter-size cluster with thousands of machines can be addressed within hours on a single RPU accelerator. A system consisting of a cluster of RPU accelerators will be able to tackle Big Data problems with trillions of parameters that is impossible to address today like, for example, natural speech recognition and translation between all world languages, real-time analytics on large streams of business and scientific data, integration, and analysis of multimodal sensory data flows from a massive number of IoT (Internet of Things) sensors.

  8. Training aircraft design considerations based on the successive organization of perception in manual control

    NASA Technical Reports Server (NTRS)

    Heffley, R. K.; Clement, W. F.; Craig, S. J.

    1982-01-01

    The thesis that pilot skill development in the Navy approach and landing task is very strongly tied to the aircraft closure rate and, therefore, that pilot training for this task should be based on an appropriate progression closure rate is considered. A rational and explicit determination of design point approach speeds as well as other important aerodynamic features for training aircraft is also considered. Two keys are discussed: recognition of the significance of transitioning from a purely compensatory control loop technique to one involving a pursuit crossfeed between throttle and pitch attitude, and addressing the terminal flight path adjustment in terms of range-to-go.

  9. Navigating Social Networking and Social Media in School Psychology: Ethical and Professional Considerations in Training Programs

    ERIC Educational Resources Information Center

    Pham, Andy V.

    2014-01-01

    Social networking and social media have undoubtedly proliferated within the past decade, allowing widespread communication and dissemination of user-generated content and information. Some psychology graduate programs, including school psychology, have started to embrace social networking and media for instructional and training purposes; however,…

  10. Counseling Psychology in the Era of Genetic Testing: Considerations for Practice, Research, and Training

    ERIC Educational Resources Information Center

    Kaut, Kevin P.

    2006-01-01

    The field of genetics and the process of testing for genetic disorders have advanced considerably over the past half century, ushering in significant improvements in certain areas of medical diagnosis and disease prediction. However, genetic discoveries are accompanied by many social, emotional, and psychological implications, and counseling…

  11. Program Design Considerations for Leadership Training for Dental and Dental Hygiene Students

    PubMed Central

    Taichman, Russell S.; Parkinson, Joseph W.; Nelson, Bonnie A.; Nordquist, Barbara; Ferguson-Young, Daphne C.; Thompson, Joseph F.

    2012-01-01

    Since leadership is an essential part of the oral health professions, oral health educators can play an essential role in establishing a culture of leadership and in mentoring students to prepare them for future leadership roles within the profession. However, leadership training for oral health professionals is a relatively new concept and is frequently not found within dental and dental hygiene curricula. The purpose of this article is to propose several models for leadership training that are specific to the oral health professions. The authors hope that providing an overview of leadership programs in academic dental institutions will encourage all U.S. and Canadian dental schools to begin developing a culture that promotes leadership development. PMID:22319084

  12. Training the Developing Brain Part II: Cognitive Considerations for Youth Instruction and Feedback

    PubMed Central

    Kushner, Adam M.; Kiefer, Adam W.; Lesnick, Samantha; Faigenbaum, Avery D.; Kashikar-Zuck, Susmita; Myer, Gregory D.

    2015-01-01

    Growing numbers of youth participating in competitive, organized physical activity has led to a concern for the risk of sports related injuries during important periods of human development. Recent studies have demonstrated the ability of Integrative Neuromuscular Training (INT) to enhance athletic performance and to reduce the risk of sports related injuries in youth. Successful implementation of INT necessitates instruction from knowledgeable and qualified instructors who understand the unique physical, cognitive and psychosocial characteristics of youth to provide appropriate training instruction and feedback. Principles of a classical theory of cognitive development provide a useful context for discussion of developmentally appropriate methods and strategies for INT instruction of youth. INT programs that consider these developmentally appropriate approaches will provide a controlled, efficacious environment for youth to improve athletic performance and to reduce risk of sports related injury; thus, promoting a healthy, active lifestyle beyond an individual’s formative years. PMID:25968858

  13. Automated Disambiguation of Acronyms and Abbreviations in Clinical Texts: Window and Training Size Considerations

    PubMed Central

    Moon, Sungrim; Pakhomov, Serguei; Melton, Genevieve B.

    2012-01-01

    Acronyms and abbreviations within electronic clinical texts are widespread and often associated with multiple senses. Automated acronym sense disambiguation (WSD), a task of assigning the context-appropriate sense to ambiguous clinical acronyms and abbreviations, represents an active problem for medical natural language processing (NLP) systems. In this paper, fifty clinical acronyms and abbreviations with 500 samples each were studied using supervised machine-learning techniques (Support Vector Machines (SVM), Naïve Bayes (NB), and Decision Trees (DT)) to optimize the window size and orientation and determine the minimum training sample size needed for optimal performance. Our analysis of window size and orientation showed best performance using a larger left-sided and smaller right-sided window. To achieve an accuracy of over 90%, the minimum required training sample size was approximately 125 samples for SVM classifiers with inverted cross-validation. These findings support future work in clinical acronym and abbreviation WSD and require validation with other clinical texts. PMID:23304410

  14. High-Altitude Illness

    MedlinePlus

    ... altitude illness: Acute mountain sickness High-altitude pulmonary edema (also called HAPE), which affects the lungs High-altitude cerebral edema (also called HACE), which affects the brain These ...

  15. Clinical management of immuno-suppression in athletes associated with exercise training: sports medicine considerations.

    PubMed

    Hackney, Anthony Carl

    2013-01-01

    The Overtraining Syndrome (OTS) is a physically debilitating medical condition that results in athletes being totally compromised in their capacity to perform and compete. Many physiological systems are affected by the process of overtraining and the development of the OTS which results from it; but one system in particular, the immune, is highly susceptible to degradation resulting in a reduction in overall health and physical performance. The aim of this paper is to review; 1) the evidence-based proactive steps and actions to take to greatly reduce the risk of development of an infection or a compromised immune system in athletes; and 2) the course of action for clinicians to take when they are dealing with an athlete displaying overt signs of an infection and, or inflammation. Evidenced reported here within support that it is essential for clinicians to take practical preventative and management steps - actions with athletes (involved in intensive exercise training) in order to help preserve and maintain a healthy and robust immune system if they are going to perform optimally.

  16. Living altitude influences endurance exercise performance change over time at altitude.

    PubMed

    Chapman, Robert F; Karlsen, Trine; Ge, R-L; Stray-Gundersen, James; Levine, Benjamin D

    2016-05-15

    For sea level based endurance athletes who compete at low and moderate altitudes, adequate time for acclimatization to altitude can mitigate performance declines. We asked whether it is better for the acclimatizing athlete to live at the specific altitude of competition or at a higher altitude, perhaps for an increased rate of physiological adaptation. After 4 wk of supervised 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) where they resided for 4 wk. Daily training for all subjects was completed at a common altitude from 1,250 to 3,000 m. Subjects completed 3,000-m performance trials on the track at sea level, 28 and 6 days before departure, and at 1,780 m on days 5, 12, 19, and 26 of the altitude camp. Groups living at 2,454 and 2,800 m had a significantly larger slowing of performance vs. the 1,780-m group on day 5 at altitude. The 1,780-m group showed no significant change in performance across the 26 days at altitude, while the groups living at 2,085, 2,454, and 2,800 m showed improvements in performance from day 5 to day 19 at altitude but no further improvement at day 26 The data suggest that an endurance athlete competing acutely at 1,780 m should live at the altitude of the competition and not higher. Living ∼300-1,000 m higher than the competition altitude, acute altitude performance may be significantly worse and may require up to 19 days of acclimatization to minimize performance decrements.

  17. Ears and Altitude

    MedlinePlus

    ... Meeting Calendar Find an ENT Doctor Near You Ears and Altitude Ears and Altitude Patient Health Information ... uncomfortable feeling of fullness or pressure. Why do ears pop? Normally, swallowing causes a little click or ...

  18. Fulminant high altitude blindness.

    PubMed

    Mashkovskiy, Evgeny; Szawarski, Piotr; Ryzhkov, Pavel; Goslar, Tomaz; Mrak, Irena

    2016-06-01

    Prolonged altitude exposure even with acclimatization continues to present a physiological challenge to all organ systems including the central nervous system. We describe a case of a 41-year-old Caucasian female climber who suffered severe visual loss that was due to possible optic nerve pathology occurring during a high altitude expedition in the Himalayas. This case is atypical of classic high altitude cerebral oedema and highlights yet another danger of prolonged sojourn at extreme altitudes. PMID:27601532

  19. Operational Physical Performance and Fitness in Military Women: Physiological, Musculoskeletal Injury, and Optimized Physical Training Considerations for Successfully Integrating Women Into Combat-Centric Military Occupations.

    PubMed

    Nindl, Bradley C; Jones, Bruce H; Van Arsdale, Stephanie J; Kelly, Karen; Kraemer, William J

    2016-01-01

    This article summarizes presentations from a 2014 United States Department of Defense (DoD) Health Affairs Women in Combat symposium addressing physiological, musculoskeletal injury, and optimized physical training considerations from the operational physical performance section. The symposium was held to provide a state-of-the-science meeting on the U.S. DoD's rescinding of the ground combat exclusion policy opening up combat-centric occupations to women. Physiological, metabolic, body composition, bone density, cardiorespiratory fitness, and thermoregulation differences between men and women were briefly reviewed. Injury epidemiological data are presented within military training and operational environments demonstrating women to be at a higher risk for musculoskeletal injuries than men. Physical training considerations for improved muscle strength and power, occupational task performance, load carriage were also reviewed. Particular focus of this article was given to translating physiological and epidemiological findings from the literature on these topics toward actionable guidance and policy recommendations for military leaders responsible for military physical training doctrine: (1) inclusion of resistance training with special emphasis on strength and power development (i.e., activation of high-threshold motor units and recruitment of type II high-force muscle fibers), upper-body strength development, and heavy load carriage, (2) moving away from "field expediency" as the major criteria for determining military physical training policy and training implementation, (3) improvement of load carriage ability with emphasis placed on specific load carriage task performance, combined with both resistance and endurance training, and (4) providing greater equipment resources, coaching assets, and increased training time dedicated to physical readiness training. PMID:26741902

  20. Operational Physical Performance and Fitness in Military Women: Physiological, Musculoskeletal Injury, and Optimized Physical Training Considerations for Successfully Integrating Women Into Combat-Centric Military Occupations.

    PubMed

    Nindl, Bradley C; Jones, Bruce H; Van Arsdale, Stephanie J; Kelly, Karen; Kraemer, William J

    2016-01-01

    This article summarizes presentations from a 2014 United States Department of Defense (DoD) Health Affairs Women in Combat symposium addressing physiological, musculoskeletal injury, and optimized physical training considerations from the operational physical performance section. The symposium was held to provide a state-of-the-science meeting on the U.S. DoD's rescinding of the ground combat exclusion policy opening up combat-centric occupations to women. Physiological, metabolic, body composition, bone density, cardiorespiratory fitness, and thermoregulation differences between men and women were briefly reviewed. Injury epidemiological data are presented within military training and operational environments demonstrating women to be at a higher risk for musculoskeletal injuries than men. Physical training considerations for improved muscle strength and power, occupational task performance, load carriage were also reviewed. Particular focus of this article was given to translating physiological and epidemiological findings from the literature on these topics toward actionable guidance and policy recommendations for military leaders responsible for military physical training doctrine: (1) inclusion of resistance training with special emphasis on strength and power development (i.e., activation of high-threshold motor units and recruitment of type II high-force muscle fibers), upper-body strength development, and heavy load carriage, (2) moving away from "field expediency" as the major criteria for determining military physical training policy and training implementation, (3) improvement of load carriage ability with emphasis placed on specific load carriage task performance, combined with both resistance and endurance training, and (4) providing greater equipment resources, coaching assets, and increased training time dedicated to physical readiness training.

  1. High-altitude headache.

    PubMed

    Marmura, Michael J; Hernandez, Pablo Bandres

    2015-05-01

    High-altitude headache is one of many neurological symptoms associated with the ascent to high altitudes. Cellular hypoxia due to decreased barometric pressure seems to be the common final pathway for headache as altitude increases. Susceptibility to high-altitude headache depends on genetic factors, history of migraine, and acclimatization, but symptoms of acute mountain sickness are universal at very high altitudes. This review summarizes the pathophysiology of acute mountain sickness and high-altitude headache as well as the evidence for treatment and prevention with different drugs and devices which may be useful for regular and novice mountaineers. This includes an examination of other headache disorders which may mimic high-altitude headache. PMID:25795155

  2. Effect of altitude on some blood factors and its stability after leaving the altitude.

    PubMed

    Hematy, Yones; Setorki, Mahbubeh; Razavi, Akram; Doudi, Monir

    2014-09-01

    The underlying mechanisms of altitude training are still a matter of controversial discussion. The aim of this study was to compare the hemoglobin concentration, red blood cell count and volume between normal and high altitude situations and their persistence after returning back from higher altitudes. The study population included male students of Ardal Branch, Islamic Azad University. Twelve apparently healthy individual with high level of physical activity, mean age of 22.6 ± 1.50 years were selected through purposive and available sampling method. In this study, blood samples were collected at different time and altitudes in order to compare the changes of Red Blood Cell (RBC), Mean Cell Hemoglobin (MCH), Mean Corpuscular Hemoglobin Concentration (MCHC) and Mean Cell Volume (MCV). The first blood sampling was conducted at the altitude of 1830 m. The subsequent blood samplings were conducted 48 and 72 h after reaching the altitude of 4000 m and 24, 48 and 72 h after returning back to the altitude of 1830 m. The statistical method used in this study was repeated measurement ANOVA. Red Blood Cell (RBC) changes between onset of climbing to 1830 m and 24, 48 and 2 h after sojourn at 1830 m height (after returning from 4000 m altitude) was significant. Mean Cell Hemoglobin (MCH) showed no significant change in any of the altitudes. MCHC changes between onset of moving toward altitude 1830 meters and 24, 48 and 72 h after sojourn at 1830 m height (after returning from 4000 m altitude) was also significant in addition, MCHC showed a significant difference between 24 h staying at 1830 m altitude with 48 and 72 h staying at 4000 m altitude. Mean Cell Volume (MCV) showed no significant difference between 48 and 72 h staying at 4000 m altitude and also between 24, 48 and 72 h staying at 1830 m altitude; however, there was a significant difference between onset of moving toward 1830 m altitude with 24, 48 and 72 h staying at 1830 m altitude and also 48 and 72 h staying at

  3. High altitude reconnaissance aircraft

    NASA Technical Reports Server (NTRS)

    Yazdo, Renee Anna; Moller, David

    1990-01-01

    At the equator the ozone layer ranges from 65,000 to 130,000 plus 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 cruise at 130,000 feet for six hours at Mach 0.7, while carrying 3,000 lbs. of payload. In addition, the aircraft must have a minimum range of 6,000 miles. In consideration of the novel nature of this project, the pilot must be able to take control in the event of unforeseen difficulties. Three aircraft configurations were determined to be the most suitable - a joined-wing, a biplane, and a twin-boom conventional airplane. The performance of each configuration was analyzed to investigate the feasibility of the project.

  4. The Economics of Vocational Training: Past Evidence and Future Considerations. World Bank Staff Working Papers Number 713.

    ERIC Educational Resources Information Center

    Metcalf, David H.

    A partial survey of the literature on the economics of vocational training reveals three important lessons on how evaluations may be undertaken using data on pay, inputs, and outputs. The first lesson is that social, corporate, and private returns to vocational training in developing countries appear to be high enough to justify expanding training…

  5. Is hypoxia training good for muscles and exercise performance?

    PubMed

    Vogt, Michael; Hoppeler, Hans

    2010-01-01

    Altitude training has become very popular among athletes as a means to further increase exercise performance at sea level or to acclimatize to competition at altitude. Several approaches have evolved during the last few decades, with "live high-train low" and "live low-train high" being the most popular. This review focuses on functional, muscular, and practical aspects derived from extensive research on the "live low-train high" approach. According to this, subjects train in hypoxia but remain under normoxia for the rest of the time. It has been reasoned that exercising in hypoxia could increase the training stimulus. Hypoxia training studies published in the past have varied considerably in altitude (2300-5700 m) and training duration (10 days to 8 weeks) and the fitness of the subjects. The evidence from muscle structural, biochemical, and molecular findings point to a specific role of hypoxia in endurance training. However, based on the available performance capacity data such as maximal oxygen uptake (Vo(2)max) and (maximal) power output, hypoxia as a supplement to training is not consistently found to be advantageous for performance at sea level. Stronger evidence exists for benefits of hypoxic training on performance at altitude. "Live low-train high" may thus be considered when altitude acclimatization is not an option. In addition, the complex pattern of gene expression adaptations induced by supplemental training in hypoxia, but not normoxia, suggest that muscle tissue specifically responds to hypoxia. Whether and to what degree these gene expression changes translate into significant changes in protein concentrations that are ultimately responsible for observable structural or functional phenotypes remains open. It is conceivable that the global functional markers such as Vo(2)max and (maximal) power output are too coarse to detect more subtle changes that might still be functionally relevant, at least to high-level athletes.

  6. Tibetans at extreme altitude.

    PubMed

    Wu, Tianyi; Li, Shupin; Ward, Michal P

    2005-01-01

    Between 1960 and 2003, 13 Chinese expeditions successfully reached the summit of Chomolungma (Mt Everest or Sagarmatha). Forty-five of the 80 summiteers were Tibetan highlanders. During these and other high-altitude expeditions in Tibet, a series of medical and physiological investigations were carried out on the Tibetan mountaineers. The results suggest that these individuals are better adapted to high altitude and that, at altitude, they have a greater physical capacity than Han (ethnic Chinese) lowland newcomers. They have higher maximal oxygen uptake, greater ventilation, more brisk hypoxic ventilatory responses, larger lung volumes, greater diffusing capacities, and a better quality of sleep. Tibetans also have a lower incidence of acute mountain sickness and less body weight loss. These differences appear to represent genetic adaptations and are obviously significant for humans at extreme altitude. This paper reviews what is known about the physiologic responses of Tibetans at extreme altitudes.

  7. Training considerations for the intracoelomic implantation of electronic tags in fish with a summary of common surgical errors

    SciTech Connect

    Cooke, Steven J.; Wagner, Glenn N.; Brown, Richard S.; Deters, Katherine A.

    2011-01-01

    Training is a fundamental part of all scientific and technical disciplines. This is particularly true for all types of surgeons. For surgical procedures, a number of skills are necessary to reduce mistakes. Trainees must learn an extensive yet standardized set of problem-solving and technical skills to handle challenges as they arise. There are currently no guidelines or consistent training methods for those intending to implant electronic tags in fish; this is surprising, considering documented cases of negative consequences of fish surgeries and information from studies having empirically tested fish surgical techniques. Learning how to do fish surgery once is insufficient for ensuring the maintenance or improvement of surgical skill. Assessment of surgical skills is rarely incorporated into training, and is needed. Evaluation provides useful feedback that guides future learning, fosters habits of self-reflection and self-remediation, and promotes access to advanced training. Veterinary professionals should be involved in aspects of training to monitor basic surgical principles. We identified attributes related to knowledge, understanding, and skill that surgeons must demonstrate prior to performing fish surgery including a “hands-on” assessment using live fish. Included is a summary of common problems encountered by fish surgeons. We conclude by presenting core competencies that should be required as well as outlining a 3-day curriculum for training surgeons to conduct intracoelomic implantation of electronic tags. This curriculum could be offered through professional fisheries societies as professional development courses.

  8. Thrombosis at mountain altitudes.

    PubMed

    Cucinell, S A; Pitts, C M

    1987-11-01

    Victims of high-altitude pulmonary edema often have clots obstructing the pulmonary vessels. This, together with an apparent high incidence of thrombophlebitis and cerebral emboli at altitude suggests that mountain travel may predispose to hypercoagulability. A critical analysis of the available data suggests that, although thrombosis may be a late event complicating various forms of mountain sickness, the laboratory techniques of characterizing hypercoagulability are not sufficient to define and characterize the mechanism.

  9. Integrating Anatomy Training into Radiation Oncology Residency: Considerations for Developing a Multidisciplinary, Interactive Learning Module for Adult Learners

    ERIC Educational Resources Information Center

    Labranche, Leah; Johnson, Marjorie; Palma, David; D'Souza, Leah; Jaswal, Jasbir

    2015-01-01

    Radiation oncologists require an in-depth understanding of anatomical relationships for modern clinical practice, although most do not receive formal anatomy training during residency. To fulfill the need for instruction in relevant anatomy, a series of four multidisciplinary, interactive learning modules were developed for a cohort of radiation…

  10. Interdisciplinary Doctoral Leadership Training in Early Intervention: Considerations for Research and Practice in the 21st Century

    ERIC Educational Resources Information Center

    Woods, Juliann; Snyder, Patricia

    2009-01-01

    This article examines issues associated with the preparation of doctoral-level personnel to assume interdisciplinary scholarship and leadership roles in early intervention (EI). Following a review of national reports focused on EI doctoral leadership training, the preparation of educational researchers, and interdisciplinary doctoral programs in…

  11. Considerations for the Use of the Observation Experience to Aid in Early Socialization and Retention of Athletic Training Students

    ERIC Educational Resources Information Center

    Mazerolle, Stephanie M.; Dodge, Thomas

    2014-01-01

    Context: Retention of quality students in athletic training programs (ATPs) is important. Many factors contribute to retention of students, including their motivation level, peer support, positive interactions with instructors, clinical integration, and mentorship. Objective: Highlight the use of the observation period for preparatory athletic…

  12. CAT altitude avoidance system

    NASA Technical Reports Server (NTRS)

    Gary, B. L. (Inventor)

    1982-01-01

    A method and apparatus are provided for indicating the altitude of the tropopause or of an inversion layer wherein clear air turbulence (CAT) may occur, and the likely severity of any such CAT, includes directing a passive microwave radiometer on the aircraft at different angles with respect to the horizon. The microwave radiation measured at a frequency of about 55 GHz represents the temperature of the air at an ""average'' range of about 3 kilometers, so that the sine of the angle of the radiometer times 3 kilometers equals the approximate altitude of the air whose temperature is measured. A plot of altitude (with respect to the aircraft) versus temperature of the air at that altitude, can indicate when an inversion layer is present and can indicate the altitude of the tropopause or of such an inversion layer. The plot can also indicate the severity of any CAT in an inversion layer. If CAT has been detected in the general area, then the aircraft can be flown at an altitude to avoid the tropopause or inversion layer.

  13. APOLLO 16 COMMANDER JOHN YOUNG ENTERS ALTITUDE CHAMBER FOR TESTS

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Apollo 16 commander John W. Young prepares to enter the lunar module in an altitude chamber in the Manned Spacecraft Operations Building at the spaceport prior to an altitude run. During the altitude run, in which Apollo 16 lunar module pilot Charles M. Duke also participated, the chamber was pumped down to simulate pressure at an altitude in excess of 200,000 feet. Young, Duke and command module pilot Thomas K. Mattingly II, are training at the Kennedy Space Center for the Apollo 16 mission. Launch is scheduled from Pad 39A, March 17, 1972.

  14. Use of virtual reality technique for the training of motor control in the elderly. Some theoretical considerations.

    PubMed

    de Bruin, E D; Schoene, D; Pichierri, G; Smith, S T

    2010-08-01

    Virtual augmented exercise, an emerging technology that can help to promote physical activity and combine the strengths of indoor and outdoor exercise, has recently been proposed as having the potential to increase exercise behavior in older adults. By creating a strong presence in a virtual, interactive environment, distraction can be taken to greater levels while maintaining the benefits of indoor exercises which may result in a shift from negative to positive thoughts about exercise. Recent findings on young participants show that virtual reality training enhances mood, thus, increasing enjoyment and energy. For older adults virtual, interactive environments can influence postural control and fall events by stimulating the sensory cues that are responsible in maintaining balance and orientation. However, the potential of virtual reality training has yet to be explored for older adults. This manuscript describes the potential of dance pad training protocols in the elderly and reports on the theoretical rationale of combining physical game-like exercises with sensory and cognitive challenges in a virtual environment.

  15. Altitude Modulates Concussion Incidence

    PubMed Central

    Smith, David W.; Myer, Gregory D.; Currie, Dustin W.; Comstock, R. Dawn; Clark, Joseph F.; Bailes, Julian E.

    2013-01-01

    Background: Recent research indicates that the volume and/or pressure of intracranial fluid, a physiology affected by one’s altitude (ie, elevation above sea level), may be associated with the likelihood and/or severity of a concussion. The objective was to employ an epidemiological field investigation to evaluate the relationship between altitude and concussion rate in high school sports. Hypothesis: Because of the physiologies that occur during acclimatization, including a decline in intracranial compliance (a “tighter fit”), increased altitude may be related to a reduction in concussion rates in high school athletes. Study Design: Cohort study; Level of evidence, 3. Methods: Data on concussions and athlete exposures (AEs) between 2005-2006 and 2011-2012 were obtained from a large national sample of high schools (National High School Sports-Related Injury Surveillance System [High School RIO]) and were used to calculate total, competition, and practice concussion rates for aggregated sports and for football only. Results: Altitude of participating schools ranged from 7 to 6903 ft (median, 600 ft), and a total of 5936 concussions occurred in 20,618,915 exposures (2.88 per 10,000 AEs). When concussion rates were dichotomized by altitude using the median, elevated altitude was associated with a reduction in concussion rates overall (rate ratio [RR], 1.31; P < .001), in competition (RR, 1.31; P < .001), and in practice (RR, 1.29; P < .001). Specifically, high school sports played at higher altitude demonstrated a 31% reduction (95% confidence interval [CI], 25%-38%) in the incidence of total reported concussions. Likewise, concussion rates at increased altitude were reduced 30% for overall exposures, 27% for competition exposures, and 28% for practice exposures in football players (P < .001). Conclusion: The results of this epidemiological investigation indicate increased physiological responses to altitude may be associated with a reduction in sports

  16. High Altitude Medical Problems

    PubMed Central

    Hultgren, Herbert N.

    1979-01-01

    Increased travel to high altitude areas by mountaineers and nonclimbing tourists has emphasized the clinical problems associated with rapid ascent. Acute mountain sickness affects most sojourners at elevations above 10,000 feet. Symptoms are usually worse on the second or third day after arrival. Gradual ascent, spending one to three days at an intermediate altitude, and the use of acetazolamide (Diamox) will prevent or ameliorate symptoms in most instances. Serious and potentially fatal problems, such as high altitude pulmonary edema or cerebral edema, occur in approximately 0.5 percent to 1.0 percent of visitors to elevations above 10,000 feet—especially with heavy physical exertion on arrival, such as climbing or skiing. Early recognition, high flow oxygen therapy and prompt descent are crucially important in management. Our knowledge of the causes of these and other high altitude problems, such as retinal hemorrhage, systemic edema and pulmonary hypertension, is still incomplete. Even less is known of the effect of high altitudes on medical conditions common at sea level or on the action of commonly used drugs. ImagesFigure 2. PMID:483805

  17. Speech privacy and annoyance considerations in the acoustic environment of passenger cars of high-speed trains.

    PubMed

    Jeon, Jin Yong; Hong, Joo Young; Jang, Hyung Suk; Kim, Jae Hyeon

    2015-12-01

    It is necessary to consider not only annoyance of interior noises but also speech privacy to achieve acoustic comfort in a passenger car of a high-speed train because speech from other passengers can be annoying. This study aimed to explore an optimal acoustic environment to satisfy speech privacy and reduce annoyance in a passenger car. Two experiments were conducted using speech sources and compartment noise of a high speed train with varying speech-to-noise ratios (SNRA) and background noise levels (BNL). Speech intelligibility was tested in experiment I, and in experiment II, perceived speech privacy, annoyance, and acoustic comfort of combined sounds with speech and background noise were assessed. The results show that speech privacy and annoyance were significantly influenced by the SNRA. In particular, the acoustic comfort was evaluated as acceptable when the SNRA was less than -6 dB for both speech privacy and noise annoyance. In addition, annoyance increased significantly as the BNL exceeded 63 dBA, whereas the effect of the background-noise level on the speech privacy was not significant. These findings suggest that an optimal level of interior noise in a passenger car might exist between 59 and 63 dBA, taking normal speech levels into account.

  18. [Echocardiographic examinations in unsedated racing pigeons (Columbia livia forma domestica) with special consideration for the physical training].

    PubMed

    Krautwald-Junghanns, M E; Pees, M; Schütterle, N

    2002-01-01

    The heart of the bird is characterized by its enormous efficiency. Racing pigeons are bred for a long time for their flight performance. In the present study therefore the heart of 108 racing pigeons of the breed Bricoux were examined by means of echocardiography. The birds were either kept in aviaries (untrained) or as racing birds. The aim was to find out whether differences in the heart dimensions and/or the heart work occur between untrained and trained birds, like it is described already in humans and mammals (so-called athletic's heart). Significant differences between the two groups could be determined with different parameters, in particular with parameters, which affect the heart work. Thus it was for the first time possible to prove the formation of a athletic's heart in birds, and by that the adaptation of the avian heart to appropriate performance requirements. PMID:12058599

  19. Preparation for football competition at moderate to high altitude.

    PubMed

    Gore, C J; McSharry, P E; Hewitt, A J; Saunders, P U

    2008-08-01

    Analysis of approximately 100 years of home-and-away South American World Cup matches illustrate that football competition at moderate/high altitude (>2000 m) favors the home team, although this is more than compensated by the likelihood of sea-level teams winning at home against the same opponents who have descended from altitude. Nevertheless, the home team advantage at altitudes above approximately 2000 m may reflect that traditionally, teams from sea level or low altitude have not spent 1-2 weeks acclimatizing at altitude. Despite large differences between individuals, in the first few days at high altitude (e.g. La Paz, 3600 m) some players experience symptoms of acute mountain sickness (AMS) such as headache and disrupted sleep, and their maximum aerobic power (VO2max) is approximately 25% reduced while their ventilation, heart rate and blood lactate during submaximal exercise are elevated. Simulated altitude for a few weeks before competition at altitude can be used to attain partial ventilatory acclimation and ameliorated symptoms of AMS. The variety of simulated altitude exposures usually created with enriched nitrogen mixtures of air include resting or exercising for a few hours per day or sleeping approximately 8 h/night in hypoxia. Preparation for competition at moderate/high altitude by training at altitude is probably superior to simulated exposure; however, the optimal duration at moderate/high altitude is unclear. Preparing for 1-2 weeks at moderate/high altitude is a reasonable compromise between the benefits associated with overcoming AMS and partial restoration of VO2max vs the likelihood of detraining.

  20. Considerations for design of an e-learning program augmenting advanced geriatric nurse practitioner's clinical skills training.

    PubMed

    Rostad, Hanne M; Grov, Ellen Karine; Moen, Anne

    2014-01-01

    E-learning programs offer learners flexibility, more control over their learning experience, possibilities for repetition and allows for learning to be more individualized compared to traditional teaching methods. This paper presents considerations for an interdisciplinary project to design an e-learning program for graduate students enrolled in a master's program in Advanced Geriatric Nursing. The e-learning program offers new opportunities for learners to apply theoretical knowledge and develop their skills in the process of collaborative knowledge creation. A model based on the systematic development of instruction and learning and a pedagogical framework for e-learning has guided the design process. This paper explains how the e-learning program was created and how content was developed and implemented in an e-learning environment. PMID:24943556

  1. Environmental dynamics at orbital altitudes

    NASA Technical Reports Server (NTRS)

    Karr, G. R.

    1976-01-01

    The influence of real satellite aerodynamics on the determination of upper atmospheric density was investigated. A method of analysis of satellite drag data is presented which includes the effect of satellite lift and the variation in aerodynamic properties around the orbit. The studies indicate that satellite lift may be responsible for the observed orbit precession rather than a super rotation of the upper atmosphere. The influence of simplifying assumptions concerning the aerodynamics of objects in falling sphere analysis were evaluated and an improved method of analysis was developed. Wind tunnel data was used to develop more accurate drag coefficient relationships for studying altitudes between 80 and 120 Km. The improved drag coefficient relationships revealed a considerable error in previous falling sphere drag interpretation. These data were reanalyzed using the more accurate relationships. Theoretical investigations of the drag coefficient in the very low speed ratio region were also conducted.

  2. Athletes at altitude

    PubMed Central

    Pugh, L. G. C. E.

    1967-01-01

    1. Six international middle-distance runners were investigated during 4 weeks in England and during a similar period in Mexico City (2270 m (7450 ft.)) 2. In 3-mile (4828 m) time trials at 2270 m the increase in time taken by four subjects compared with sea level was 8·5% on the 4th day and 5·7% on the 29th day. There was thus a gain of 2·8% or 20 sec in time associated with acclimatization. 3. In 1-mile (1609 m) time trials the times were increased by 3·6% in the first week at altitude and by 1·5% in the 4th week. The improvement amounted to 2·1%, or 4·9 sec. 4. In 5 min maximum exercise on the ergometer maximum O2 intake for six subjects at altitude was reduced by 14·6% on the 2nd day and 9·5% on the 27th. Only one subject showed no change in maximum oxygen intake (V̇O2, max) with time spent at altitude. 5. Although V̇O2, max was persistently reduced at altitude work rates finally exceeded sea-level values, owing to increased over-all efficiency. 6. Forty-minute recovery O2 intakes after 5 min maximum exercise averaged 17·35 l. at sea level and 17·53 l. at altitude. Mean values from 40th to 50th min were within ± 7% of pre-exercise values. 7. Serial tests at increasing loads yielded a straight-line relation between O2 intake and work rate over a wide range of work rates at sea level and at altitude. Heart rate and ventilation for given work intensity were maximal in the first 2-10 days at altitude and thereafter declined. 8. Capillary HbO2 saturation fell from 93% at rest to 87% in maximum exercise. The corresponding alveolar gas tensions were PA, O2 89 mm Hg, PA, CO2 24 mm Hg. About half the total unsaturation in maximum exercise was explained by the Bohr effect. 9. In six of eight pairs of determinations V̇O2, max measured on the ergometer was within ± 0·15 l./min of V̇O2, max measured on the running track. Nevertheless, it was not possible to predict running performance from ergometer measurements. PMID:6058997

  3. Embracing change: practical and theoretical considerations for successful implementation of technology assisting upper limb training in stroke

    PubMed Central

    2012-01-01

    Background Rehabilitation technology for upper limb training of stroke patients may play an important role as therapy tool in future, in order to meet the increasing therapy demand. Currently, implementation of this technology in the clinic remains low. This study aimed at identifying criteria and conditions that people, involved in development of such technology, should take into account to achieve a (more) successful implementation of the technology in the clinic. Methods A literature search was performed in PubMed and IEEE databases, and semi-structured interviews with therapists in stroke rehabilitation were held, to identify criteria and conditions technology should meet to facilitate (implementation of) technology-assisted arm-hand skills training in rehabilitation therapy of stroke patients. In addition, an implementation strategy frequently applied in general health care was used to compose a stepwise guidance to facilitate successful implementation of this technology in therapy of stroke patients. Implementation-related criteria mentioned by therapists during the interviews were integrated in this guidance. Results Results indicate that, related to therapy content, technology should facilitate repetition of task-related movements, tailored to the patient and patient’s goals, in a meaningful context. Variability and increasing levels of difficulty in exercises should be on offer. Regarding hardware and software design of technology, the system should facilitate quick familiarisation and be easily adjustable to individual patients during therapy by therapists (and assistants). The system should facilitate adaptation to individual patients’ needs and their progression over time, should be adjustable as to various task-related variables, should be able to provide instructions and feedback, and should be able to document patient’s progression. The implementation process of technology in the clinic is provided as a stepwise guidance that consists of five

  4. Canadian Academy of Sport and Exercise Medicine position statement: athletes at high altitude.

    PubMed

    Koehle, Michael S; Cheng, Ivy; Sporer, Benjamin

    2014-03-01

    Many sports incorporate training at altitude as a key component of their athlete training plan. Furthermore, many sports are required to compete at high altitude venues. Exercise at high altitude provides unique challenges to the athlete and to the sport medicine clinician working with these athletes. These challenges include altitude illness, alterations in training intensity and performance, nutritional and hydration difficulties, and challenges related to the austerity of the environment. Furthermore, many of the strategies that are typically utilized by visitors to altitude may have implications from an anti-doping point of view.This position statement was commissioned and approved by the Canadian Academy of Sport and Exercise Medicine. The purpose of this statement was to provide an evidence-based, best practices summary to assist clinicians with the preparation and management of athletes and individuals travelling to altitude for both competition and training.

  5. Physiology in medicine: acute altitude exposure in patients with pulmonary and cardiovascular disease.

    PubMed

    Seccombe, Leigh M; Peters, Matthew J

    2014-03-01

    Travel is more affordable and improved high-altitude airports, railways, and roads allow rapid access to altitude destinations without acclimatization. The physiology of exposure to altitude has been extensively described in healthy individuals; however, there is a paucity of data pertaining to those who have reduced reserve. This Physiology in Medicine article discusses the physiological considerations relevant to the safe travel to altitude and by commercial aircraft in patients with pulmonary and/or cardiac disease.

  6. Ear - blocked at high altitudes

    MedlinePlus

    ... ears; Flying and blocked ears; Eustachian tube dysfunction - high altitude ... the middle ear and the back of the nose and upper throat. ... down from high altitudes. Chewing gum the entire time you are ...

  7. Cardiovascular medicine at high altitude.

    PubMed

    Whayne, Thomas F

    2014-07-01

    Altitude physiology began with Paul Bert in 1878. Chronic mountain sickness (CMS) was defined by Carlos Monge in the 1940s in the Peruvian Andes as consisting of excess polycythemia. Hurtado et al performed studies in the Peruvian Andes in the 1950s to 1960s which defined acclimatization in healthy altitude natives, including polycythemia, moderate pulmonary hypertension, and low systemic blood pressure (BP). Electrocardiographic changes of right ventricular hypertrophy (RVH) were noted. Acclimatization of newcomers to altitude involves hyperventilation stimulated by hypoxia and is usually benign. Acute mountain sickness (AMS) in travelers to altitude is characterized by hypoxia-induced anorexia, dyspnea, headache, insomnia, and nausea. The extremes of AMS are high-altitude cerebral edema and high-altitude pulmonary edema. The susceptible high-altitude resident can lose their tolerance to altitude and develop CMS, also referred to as Monge disease. The CMS includes extreme polycythemia, severe RVH, excess pulmonary hypertension, low systemic BP, arterial oxygen desaturation, and hypoventilation.

  8. Lidar Altitude Data Read Routine

    Atmospheric Science Data Center

    2013-03-19

      Lidar Altitude Data Read Routine This routine demonstrates reading the lidar altitude data stored in CALIPSO Lidar Level 1B Profile, Level 2 Aerosol ... Data Language (IDL) and uses HDF routine calls to read the altitude data which are stored in an HDF vdata (table) structure, as described ...

  9. [Altitude adaptation. Biological problems in the context of the environment].

    PubMed

    Eckes, L

    1976-01-01

    The following part of the description of adaptation to high altitude describes the geographical specifities of the relevant regions of the world. There are several factors which require an adaptive answer, such as hypoxia, temperature, terrain, nutrition etc. The terms of genetically determined and of individual adaptation are discussed, with special consideration of a duration of settlement in the main altitude regions of about ten thousand years, as well as the principles of adaptation in general, including the phenomenon of maladaptation. The problem of adaptation of animals to high altitude is reviewed in short especially in regard to mammals. The differential fertility proves to be most important in the survival of a species in high altitude as well as the individual adaptability, is the fitness which makes high altitude tolerable to newcomers.

  10. Satellite altitude determination uncertainties

    NASA Technical Reports Server (NTRS)

    Siry, J. W.

    1972-01-01

    Satellite altitude determination uncertainties will be discussed from the standpoint of the GEOS-C satellite, from the longer range viewpoint afforded by the Geopause concept. Data are focused on methods for short-arc tracking which are essentially geometric in nature. One uses combinations of lasers and collocated cameras. The other method relies only on lasers, using three or more to obtain the position fix. Two typical locales are looked at, the Caribbean area, and a region associated with tracking sites at Goddard, Bermuda and Canada which encompasses a portion of the Gulf Stream in which meanders develop.

  11. Improving oxygenation at high altitude: acclimatization and O2 enrichment.

    PubMed

    West, John B

    2003-01-01

    When lowlanders go to high altitude, the resulting oxygen deprivation impairs mental and physical performance, quality of sleep, and general well-being. This paper compares the effects of ventilatory acclimatization and oxygen enrichment of room air on the improvement of oxygenation as judged by the increase in the alveolar P(O2) and the reduction in equivalent altitude. The results show that, on the average, complete ventilatory acclimatization at an altitude of 5000 m increases the alveolar P(O2) by nearly 8 torr, which corresponds to a reduction in equivalent altitude of about 1000 m, although there is considerable individual variability. By comparison, oxygen enrichment to 27% at 5000 m can easily reduce the equivalent altitude to 3200 m, which is generally well tolerated. Because full ventilatory acclimatization at altitudes up to about 3600 m reduces the equivalent altitude to about 3000 m, oxygen enrichment is not justified for well-acclimatized persons. At an altitude of 4200 m, where several telescopes are located on the summit of Mauna Kea, full acclimatization reduces the equivalent altitude to about 3400 m, but the pattern of commuting probably would not allow this. Therefore, at this altitude, oxygen enrichment would be beneficial but is not essential. At higher altitudes such as 5050 m, where other telescopes are located or planned, the gain in oxygenation from acclimatization is insufficient to produce an adequate mental or physical performance for most work, and oxygen enrichment is highly desirable. Full ventilatory acclimatization requires at least a week of continuous exposure, although much of the improvement is seen in the first 2 days. PMID:14561244

  12. Jupiter's High-Altitude Clouds

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The New Horizons Multispectral Visible Imaging Camera (MVIC) snapped this incredibly detailed picture of Jupiter's high-altitude clouds starting at 06:00 Universal Time on February 28, 2007, when the spacecraft was only 2.3 million kilometers (1.4 million miles) from the solar system's largest planet. Features as small as 50 kilometers (30 miles) are visible. The image was taken through a narrow filter centered on a methane absorption band near 890 nanometers, a considerably redder wavelength than what the eye can see. Images taken through this filter preferentially pick out clouds that are relatively high in the sky of this gas giant planet because sunlight at the wavelengths transmitted by the filter is completely absorbed by the methane gas that permeates Jupiter's atmosphere before it can reach the lower clouds.

    The image reveals a range of diverse features. The south pole is capped with a haze of small particles probably created by the precipitation of charged particles into the polar regions during auroral activity. Just north of the cap is a well-formed anticyclonic vortex with rising white thunderheads at its core. Slightly north of the vortex are the tendrils of some rather disorganized storms and more pinpoint-like thunderheads. The dark 'measles' that appear a bit farther north are actually cloud-free regions where light is completely absorbed by the methane gas and essentially disappears from view. The wind action considerably picks up in the equatorial regions where giant plumes are stretched into a long wave pattern. Proceeding north of the equator, cirrus-like clouds are shredded by winds reaching speeds of up to 400 miles per hour, and more pinpoint-like thunderheads are visible. Although some of the famous belt and zone structure of Jupiter's atmosphere is washed out when viewed at this wavelength, the relatively thin North Temperate Belt shows up quite nicely, as does a series of waves just north of the belt. The north polar region of

  13. Brain Food at High Altitude.

    PubMed

    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.

  14. Brain Food at High Altitude.

    PubMed

    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. PMID:27651260

  15. Can aneroid sphygmomanometers be used at altitude?

    PubMed

    Kametas, N A; McAuliffe, F; Krampl, E; Nicolaides, K H; Shennan, A H

    2006-07-01

    Mercury-independent devices are increasingly being used in clinical practice as mercury will soon be removed from clinical use as a result of environmental, health and safety concerns. The aim of this study was to evaluate the accuracy of a portable aneroid device in an adult population at high altitude by following the part of the protocol of the British Hypertension Society regarding comparison between device and observer. We examined 10 subjects in Cerro de Pasco, Peru, which is situated 4370 m above sea level. The aneroid device was initially calibrated at both high altitude and at sea level to ensure optimal function. Validation of the device was undertaken at high altitude by connecting it in parallel to two mercury sphygmomanometers. Eleven sequential same-arm measurements were taken from each subject by two trained observers, alternating between mercury sphygmomanometry and the aneroid device. Simultaneous mercury readings were also recorded for additional analysis. During calibration, all 60 comparisons between the aneroid and mercury sphygmomanometers were within 3 mm Hg both at sea level and at high altitude. At validation, the device achieved an A grade for both systolic and diastolic pressures and also fulfilled the requirements of the Association for the Advancement of Medical Instrumentation. The mean and standard deviation for systolic and diastolic pressures, respectively, were -1.32 (4.3) mm Hg and 3.7 (4.7) mm Hg in sequential analysis and -0.7 (2.6) mm Hg and -3.3 (2.7) mm Hg in simultaneous analysis. We conclude that the Riester-Exacta portable aneroid device can be recommended for use in an adult population at high altitude.

  16. Infectious Diseases at High Altitude.

    PubMed

    Basnyat, Buddha; Starling, Jennifer M

    2015-08-01

    Travel to elevations above 2,500 m is an increasingly common activity undertaken by a diverse population of individuals. These may be trekkers, climbers, miners in high-altitude sites in South America, and more recently, soldiers deployed for high-altitude duty in remote areas of the world. What is also being increasingly recognized is the plight of the millions of pilgrims, many with comorbidities, who annually ascend to high-altitude sacred areas. There are also 400 million people who reside permanently in high mountain ranges, which cover one-fifth of the Earth's surface. Many of these high-altitude areas are in developing countries, for example, the Himalayan range in South Asia. Although high-altitude areas may not harbor any specific infectious disease agents, it is important to know about the pathogens encountered in the mountains to be better able to help both the ill sojourner and the native high-altitude dweller. Often the same pathogens prevalent in the surrounding lowlands are found at high altitude, but various factors such as immunomodulation, hypoxia, poor physiological adaptation, and harsh environmental stressors at high altitude may enhance susceptibility to these pathogens. Against this background, various gastrointestinal, respiratory, dermatological, neurological, and other infections encountered at high altitude are discussed.

  17. Altitude-related illness in two California national parks.

    PubMed

    Weichenthal, L A; Hendey, G

    1998-01-01

    High-altitude illness encompasses a spectrum of disorders related to the hypoxia experienced by individuals at elevation. Altitude-related illness has been well described in the United States, but there are no studies published in the medical literature looking at the occurrence of high-altitude illness within the US National Parks system. The purpose of this study is to describe the incidence, treatment, and outcomes of visitors to Sequoia and Kings Canyon National Parks who presented to emergency medical services (EMS) personnel with signs and symptoms consistent with high-altitude illness. We conducted a retrospective review of all EMS patient care records (PCRs) from Sequoia and Kings Canyon National Parks during the study period of June 1992 to August 1995. There were 23 cases of altitude-related illness identified by EMS personnel in the parks during the 38-month study period, including five cases of high-altitude pulmonary edema and 19 cases of acute mountain sickness. One patient died, nine patients were transported to local hospitals, nine patients were assisted in their descent and then released from medical care, and four patients were treated and then allowed to continue their travels. There was an average of 5.9 cases per year of high-altitude illness and an incidence of one case per 27 EMS contacts. We conclude that altitude-related illness does occur in Sequoia and Kings Canyon National Parks and, although high-altitude illness accounts for only 4% of EMS contacts, caring for these patients uses a significant amount of national park resources. We suggest continued training of emergency medical technicians and park medics in the recognition and treatment of these disorders. We also support education of hikers to reduce or prevent the morbidity associated with altitude-related illness.

  18. Altitude release mechanism

    DOEpatents

    Kulhanek, Frank C.

    1977-01-01

    An altitude release mechanism for releasing a radiosonde or other measuring instrument from a balloon carrying it up into the atmosphere includes a bottle partially filled with water, a tube sealed into the bottle having one end submerged in the water in the bottle and the free end extending above the top of the bottle and a strip of water-disintegrable paper held within the free end of the tube linking the balloon to the remainder of the package. As the balloon ascends, the lowered atmospheric air pressure causes the air in the bottle to expand, forcing the water in the bottle up the tubing to wet and disintegrate the paper, releasing the package from the balloon.

  19. Cardiovascular medicine at high altitude.

    PubMed

    Whayne, Thomas F

    2014-07-01

    Altitude physiology began with Paul Bert in 1878. Chronic mountain sickness (CMS) was defined by Carlos Monge in the 1940s in the Peruvian Andes as consisting of excess polycythemia. Hurtado et al performed studies in the Peruvian Andes in the 1950s to 1960s which defined acclimatization in healthy altitude natives, including polycythemia, moderate pulmonary hypertension, and low systemic blood pressure (BP). Electrocardiographic changes of right ventricular hypertrophy (RVH) were noted. Acclimatization of newcomers to altitude involves hyperventilation stimulated by hypoxia and is usually benign. Acute mountain sickness (AMS) in travelers to altitude is characterized by hypoxia-induced anorexia, dyspnea, headache, insomnia, and nausea. The extremes of AMS are high-altitude cerebral edema and high-altitude pulmonary edema. The susceptible high-altitude resident can lose their tolerance to altitude and develop CMS, also referred to as Monge disease. The CMS includes extreme polycythemia, severe RVH, excess pulmonary hypertension, low systemic BP, arterial oxygen desaturation, and hypoventilation. PMID:23892441

  20. Cardiovascular physiology at high altitude.

    PubMed

    Hooper, T; Mellor, A

    2011-03-01

    The role of the cardiovascular system is to deliver oxygenated blood to the tissues and remove metabolic effluent. It is clear that this complex system will have to adapt to maintain oxygen deliver in the profound hypoxia of high altitude. The literature on the adaptation of both the systemic and pulmonary circulations to high altitude is reviewed. PMID:21465906

  1. Cardiovascular physiology at high altitude.

    PubMed

    Hooper, T; Mellor, A

    2011-03-01

    The role of the cardiovascular system is to deliver oxygenated blood to the tissues and remove metabolic effluent. It is clear that this complex system will have to adapt to maintain oxygen deliver in the profound hypoxia of high altitude. The literature on the adaptation of both the systemic and pulmonary circulations to high altitude is reviewed.

  2. Medical continuing education: reform of teaching methods about high altitude disease in China.

    PubMed

    Luo, Yongjun; Zhou, Qiquan; Huang, Jianjun; Luo, Rong; Yang, Xiaohong; Gao, Yuqi

    2013-06-01

    The purpose of high altitude continuing medical education is to adapt knowledge and skills for practical application on the plateau. Most trainees have experience with academic education and grassroots work experience on the plateau, so they want knowledge about new advances in the pathogenesis, diagnosis, and treatment of high altitude disease. As such, traditional classroom teaching methods are not useful to them. Training objects, content, and methods should attempt to conduct a variety of teaching practices. Through continuing medical education on high altitude disease, the authors seek to change the traditional teaching model away from a single classroom and traditional written examinations to expand trainees' abilities. These innovative methods of training can improve both the quality of teaching and students' abilities to prevent and treat acute mountain sickness, high altitude pulmonary edema, high altitude cerebral edema, and chronic mountain sickness to increase the quality of high altitude medical care.

  3. Preparing for Hiking and Rock-Climbing At Altitude

    NASA Technical Reports Server (NTRS)

    Greenleaf, John E.

    2002-01-01

    Exposure to altitude with or without exercise usually results in body dehydration. Psychological and physiological preparation for exercise at altitude involves consideration of maintaining body warmth in a cool to cold environment with progressively lower oxygen content (partial pressure) as altitude increases. However, this discussion will focus on altitudes below 14,000 it where supplemental breathing oxygen is not required for sojourns of healthy people. Background information and helpful advice for those who exercise in the cold can be found in selected articles in the 2001 Winter Issue of this Newsletter: M.B. Ducharme, Get ready for outdoor winter play: prepare yourself for the cold; C. O'Brien, Think layers when dressing for exercise in the cold; B.G. Rice and R. Ellis, Let it snow, let it snow, let it snow - but be aware of winter hazards; and L.B. Mayers, Exercise - induced asthma.

  4. Can patients with coronary heart disease go to high altitude?

    PubMed

    Dehnert, Christoph; Bärtsch, Peter

    2010-01-01

    Tourism to high altitude is very popular and includes elderly people with both manifest and subclinical coronary heart disease (CHD). Thus, risk assessment regarding high altitude exposure of patients with CHD is of increasing interest, and individual recommendations are expected despite the lack of sufficient scientific evidence. The major factor increasing cardiac stress is hypoxia. At rest and for a given external workload, myocardial oxygen demand is increased at altitude, particularly in nonacclimatized individuals, and there is some evidence that blood-flow reserve is reduced in atherosclerotic coronary arteries even in the absence of severe stenosis. Despite a possible imbalance between oxygen demand and oxygen delivery, studies on selected patients have shown that exposure and exercise at altitudes of 3000 to 3500 m is generally safe for patients with stable CHD and sufficient work capacity. During the first days at altitude, patients with stable angina may develop symptoms of myocardial ischemia at slightly lower heart rate x  blood-pressure products. Adverse cardiac events, however, such as unstable angina coronary syndromes, do not occur more frequently compared with sea level except for those who are unaccustomed to exercise. Therefore, training should start before going to altitude, and the altitude-related decrease in exercise capacity should be considered. Travel to 3500 m should be avoided unless patients have stable disease, preserved left ventricular function without residual capacity, and above-normal exercise capacity. CHD patients should avoid travel to elevations above 4500 m owing to severe hypoxia at these altitudes. The risk assessment of CHD patients at altitude should always consider a possible absence of medical support and that cardiovascular events may turn into disaster. PMID:20919884

  5. High-Altitude Magnetic Survey Over the United States

    NASA Astrophysics Data System (ADS)

    Hildenbrand, T. G.; Keller, G.; Pellerin, L.; Phillips, J.; Ravat, D.; Sabaka, T.

    2003-12-01

    The year 2004 offers an exciting and cost-effective opportunity to acquire a high-altitude magnetic data set over the U.S. A national mission is presently being planned to collect IFSAR imagery in addition to total and vector magnetic field data at an altitude of about 15 km. High-altitude magnetic data, needed as a reference field to properly level the U.S. low-altitude magnetic data set (0.3 km altitude), will also provide new insights on fundamental tectonic and thermal processes, thereby enabling a new view of the structural and lithologic framework of continental and offshore regions. A correctly merged, low-altitude magnetic database, using high-altitude magnetic data as a reference field, will be one of the most important legacies of a high-altitude magnetic mission, as it will greatly expand the utility of the invaluable U.S. magnetic data. However, the high-altitude data also have considerable independent scientific value. These unique data will bridge the spectral gap between the spectrums of the low-altitude aeromagnetic and satellite magnetic data. Based on our understanding of the magnetic properties of the lithosphere, the high-altitude data will clearly aid in the solution of a broad range of applied Earth science issues related to: the conundrum of long-wavelength magnetic anomalies; geologic and tectonic processes of crustal accretion and evolution; thermal and mechanical properties of the lithosphere; societal concerns including localization of favorable areas for mineral, energy, and thermal resources; and mitigation of earthquake and volcanic hazards. The wavelength band of a high-altitude survey will be particularly helpful in studying the lower crust--its composition, structure, and thermal regime--and large geologic/tectonic structures, such as basement terranes. In addition, these results will provide significant new constraints for geological interpretation of complementary regional topographic, seismic, electromagnetic, gravity, and heat

  6. Lung Disease at High Altitude

    PubMed Central

    Stream, JO; Luks, AM; Grissom, CK

    2016-01-01

    Large numbers of people travel to high altitudes, entering an environment of hypobaric hypoxia. Exposure to low oxygen tension leads to a series of important physiologic responses that allow individuals to tolerate these hypoxic conditions. However, in some cases hypoxia triggers maladaptive responses that lead to various forms of acute and chronic high altitude illness, such as high-altitude pulmonary edema or chronic mountain sickness. Because the respiratory system plays a critical role in these adaptive and maladaptive responses, patients with underlying lung disease may be at increased risk for complications in this environment and warrant careful evaluation before any planned sojourn to higher altitudes. In this review, we describe respiratory disorders that occur with both acute and chronic exposures to high altitudes. These disorders may occur in any individual who ascends to high altitude, regardless of his/her baseline pulmonary status. We then consider the safety of high-altitude travel in patients with various forms of underlying lung disease. The available data regarding how these patients fare in hypoxic conditions are reviewed, and recommendations are provided for management prior to and during the planned sojourn. PMID:20477353

  7. Acute Exposure of College Basketball Players to Moderate Altitude: Selected Physiological Responses.

    ERIC Educational Resources Information Center

    Noble, Bruce J.; Maresh, Carl M.

    1979-01-01

    In general, basketball players with moderately high aerobic power who reside at an altitude of 1,000 m do not display the hypoxic response to an altitude of 2,200 m expected of sea level residents and aerobically trained athletes. (JD)

  8. Psychological testing at high altitudes.

    PubMed

    Nelson, M

    1982-02-01

    Psychological testing was done on 20 subjects at various altitudes (sea level, 3,8,10 m, and 5,000 m) during a 35-d mountaineering expedition to Denali (Mt. McKinley). Intellectual functioning and personality changes were studied. While little variation was noted at the lower altitude, at 5,000 m there was a marked deterioration in cognitive ability. This was accompanied by a sharp increase in paranoia and obsessive-compulsiveness and smaller increases in depression and hostility.

  9. A3 Altitude Test Facility

    NASA Technical Reports Server (NTRS)

    Dulreix, Lionel J.

    2009-01-01

    This slide presentation shows drawings, diagrams and photographs of the A3 Altitude Test Facility. It includes a review of the A3 Facility requirements, and drawings of the various sections of the facility including Engine Deck and Superstructure, Test Cell and Thrust Takeout, Structure and Altitude Support Systems, Chemical Steam generators, and the subscale diffuser. There are also pictures of the construction site, and the facility under construction. A Diagram of the A3 Steam system schematic is also shown

  10. [Altitude adaptation. IV. Fertility and reproduction at high altitudes].

    PubMed

    Eckes, L

    1976-01-01

    High altitude populations have been reproducing for thousands of years. The mean total fertility is comparable to the respective mean values of the whole populations or is even higher. On the other hand, newcomers from sea level seem to have difficulties reproducing in high altitude, especially if they are caucasian. Cattle and other animals fail to reproduce to some extent (due to degeneration of the testes, asoospermia, abortation etc.), which can only be avoided after crossbreeding with aclimatized strains in several generations. But successful gestation in altitudes above 3000 metres is different from sea level gestation in several aspects, which may be important for the survival of mother and child, thus leaving open the question of selective pressure. The mean birth weight of man and animals is reduced, while the mean palcental weight is greater (relatively and absolutely) due to enlargement of the capillary volume. Placenta proves to be on higher risk for developing infarcts (the more in number and extetion, the greater the caucasian admixture). Due to the tendency to a greater extention of the surface, the rate of placenta praevia is extremely high (27%). The lower birth weight corresponds to a higher neonatal mortality, progressing with increasing altitude. Additional to the high altitude stress including the factors to which the newborn are exposed, such as cold, nuturtional deficiencies etc., particular socio-economic conditions influence the differential mortality. In the Bolivian mining-areas, mortality during the first year of life rises to 50%. Only high fertility rates compensate this loss so that high altitude population growth rates do not vary with the altitude.

  11. Aging, Tolerance to High Altitude, and Cardiorespiratory Response to Hypoxia.

    PubMed

    Richalet, Jean-Paul; Lhuissier, François J

    2015-06-01

    Richalet, Jean-Paul, and François J. Lhuissier. Aging, tolerance to high altitude, and cardiorespiratory response to hypoxia. High Alt Med Biol. 16:117-124, 2015.--It is generally accepted that aging is rather protective, at least at moderate altitude. Some anecdotal reports even mention successful ascent of peaks over 8000 m and even Everest by elderly people. However, very few studies have explored the influence of aging on tolerance to high altitude and prevalence of acute high altitude related diseases, taking into account all confounding factors such as speed of ascent, altitude reached, sex, training status, and chemo-responsiveness. Changes in physiological responses to hypoxia with aging were assessed through a cross-sectional 20-year study including 4675 subjects (2789 men, 1886 women; 14-85 yrs old) and a longitudinal study including 30 subjects explored at a mean 10.4-year interval. In men, ventilatory response to hypoxia increased, while desaturation was less pronounced with aging. Cardiac response to hypoxia was blunted with aging in both genders. Similar results were found in the longitudinal study, with a decrease in cardiac and an increase in ventilatory response to hypoxia with aging. These adaptive responses were less pronounced or absent in post-menopausal untrained women. In conclusion, in normal healthy and active subjects, aging has no deleterious effect on cardiac and ventilatory responses to hypoxia, at least up to the eighth decade. Aging is not a contraindication for high altitude, as far as no pathological condition interferes and physical fitness is compatible with the intensity of the expected physical demand of one's individual. Physiological evaluation through hypoxic exercise testing before going to high altitude is helpful to detect risk factors of severe high altitude-related diseases.

  12. General introduction to altitude adaptation and mountain sickness.

    PubMed

    Bärtsch, P; Saltin, B

    2008-08-01

    The key elements in acclimatization aim at securing the oxygen supply to tissues and organs of the body with an optimal oxygen tension of the arterial blood. In acute exposure, ventilation and heart rate are elevated with a minimum reduction in stroke volume. In addition, plasma volume is reduced over 24-48 h to improve the oxygen-carrying capacity of the blood, and is further improved during a prolonged sojourn at altitude through an enhanced erythropoiesis and larger Hb mass, allowing for a partial or full restoration of the blood volume and arterial oxygen content. Most of these adaptations are observed from quite low altitudes [approximately 1000 m above sea level (m a.s.l.)] and become prominent from 2000 m a.s.l. At these higher altitudes additional adaptations occur, one being a reduction in the maximal heart rate response and consequently a lower peak cardiac output. Thus, in spite of a normalization of the arterial oxygen content after 4 or more weeks at altitude, the peak oxygen uptake reached after a long acclimatization period is essentially unaltered compared with acute exposure. What is gained is a more complete oxygenation of the blood in the lungs, i.e. SaO(2) is increased. 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 at altitudes between 2500 and 3000 m a.s.l. Pulmonary edema is rarely seen below 3000 m a.s.l. and brain edema is not seen below 4000 m a.s.l. It is possible to travel to altitudes of 2500-3000 m a.s.l., wait for 2 days, and then gradually start to train. At higher altitudes, one should consider a staged 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

  13. Asteroid airburst altitude vs. strength

    NASA Astrophysics Data System (ADS)

    Robertson, Darrel; Wheeler, Lorien; Mathias, Donovan

    2016-10-01

    Small NEO asteroids (<Ø140m) may not be a threat on a national or global level but can still cause a significant amount of local damage as demonstrated by the Chelyabinsk event where there was over $33 million worth of damage (1 billion roubles) and 1500 were injured, mostly due to broken glass. The ground damage from a small asteroid depends strongly on the altitude at which they "burst" where most of the energy is deposited in the atmosphere. The ability to accurately predict ground damage is useful in determining appropriate evacuation or shelter plans and emergency management.Strong asteroids, such as a monolithic boulder, fail and create peak energy deposition close to the altitude at which ram dynamic pressure exceeds the material cohesive strength. Weaker asteroids, such as a rubble pile, structurally fail at higher altitude, but it requires the increased aerodynamic pressure at lower altitude to disrupt and disperse the rubble. Consequently the resulting airbursts have a peak energy deposition at similar altitudes.In this study hydrocode simulations of the entry and break-up of small asteroids were performed to examine the effect of strength, size, composition, entry angle, and speed on the resulting airburst. This presentation will show movies of the simulations, the results of peak burst height, and the comparison to semi-analytical models.

  14. Key considerations for the experimental training and evaluation of cancer odour detection dogs: lessons learnt from a double-blind, controlled trial of prostate cancer detection

    PubMed Central

    2014-01-01

    Background Cancer detection using sniffer dogs is a potential technology for clinical use and research. Our study sought to determine whether dogs could be trained to discriminate the odour of urine from men with prostate cancer from controls, using rigorous testing procedures and well-defined samples from a major research hospital. Methods We attempted to train ten dogs by initially rewarding them for finding and indicating individual prostate cancer urine samples (Stage 1). If dogs were successful in Stage 1, we then attempted to train them to discriminate prostate cancer samples from controls (Stage 2). The number of samples used to train each dog varied depending on their individual progress. Overall, 50 unique prostate cancer and 67 controls were collected and used during training. Dogs that passed Stage 2 were tested for their ability to discriminate 15 (Test 1) or 16 (Tests 2 and 3) unfamiliar prostate cancer samples from 45 (Test 1) or 48 (Tests 2 and 3) unfamiliar controls under double-blind conditions. Results Three dogs reached training Stage 2 and two of these learnt to discriminate potentially familiar prostate cancer samples from controls. However, during double-blind tests using new samples the two dogs did not indicate prostate cancer samples more frequently than expected by chance (Dog A sensitivity 0.13, specificity 0.71, Dog B sensitivity 0.25, specificity 0.75). The other dogs did not progress past Stage 1 as they did not have optimal temperaments for the sensitive odour discrimination training. Conclusions Although two dogs appeared to have learnt to select prostate cancer samples during training, they did not generalise on a prostate cancer odour during robust double-blind tests involving new samples. Our study illustrates that these rigorous tests are vital to avoid drawing misleading conclusions about the abilities of dogs to indicate certain odours. Dogs may memorise the individual odours of large numbers of training samples rather than

  15. High Altitude Ballooning as a Mechanism for Teaching NGSS-Related Geoscience Content and Classroom Activities for Pre- and In-Service Teachers

    NASA Astrophysics Data System (ADS)

    Urban, M. A.; Kroeger, T.

    2014-12-01

    Training in-service and pre-service K-12 science teachers to understand and structure appropriate instructional opportunities for addressing cross-cutting concepts and engineering design with students in their classrooms is critical given the emphases in the Next Generation Science Standards (NGSS). One mechanism for doing so involves utilizing high altitude ballooning as a tool for providing authentic investigation opportunities in the geosciences. As individual states review and make decisions about what role the NGSS will play in their standards, it is important for college and university science teacher preparation programs to prepare current and future teachers to become more comfortable with designing research investigations, controlling variables, anticipating cross-disciplinary connections, refining and analyzing data, and communicating the findings of real and contrived scientific investigation. Many undergraduate and professional development research possibilities exist through high altitude ballooning, including: microbiological experimentation at high altitudes, microcontroller use for context-specific data collection, near-space system development and design, balloon flight-track modeling, and more. Example projects and findings will be shared. Equally important to creating appropriate learning activities to address NGSS expectations is understanding the context-specific needs and available resources existing in K-12 science classrooms. Findings from semi-structured interviews with a focus group of pre-service and practicing teachers will be presented -- from both participants and non-participants in high altitude ballooning activities -- related to how high altitude ballooning could be (or already is) being used to meet NGSS and state science standards. The two primary outcomes of the presentation are to: 1) inform science teacher preparation programs for purposes of structuring useful and appropriate science methods activities; 2) frame the K-12

  16. High altitude, a natural research laboratory for the study of cardiovascular physiology and pathophysiology.

    PubMed

    Scherrer, Urs; Allemann, Yves; Jayet, Pierre-Yves; Rexhaj, Emrush; Sartori, Claudio

    2010-01-01

    High altitude constitutes an exciting natural laboratory for medical research. Although initially, the aim of high-altitude research was to understand the adaption of the organism to hypoxia and find treatments for altitude-related diseases, during the past decade or so, the scope of this research has broadened considerably. Two important observations led the foundation for the broadening of the scientific scope of high-altitude research. First, high-altitude pulmonary edema represents a unique model that allows studying fundamental mechanisms of pulmonary hypertension and lung edema in humans. Second, the ambient hypoxia associated with high-altitude exposure facilitates the detection of pulmonary and systemic vascular dysfunction at an early stage. Here, we will review studies that, by capitalizing on these observations, have led to the description of novel mechanisms underpinning lung edema and pulmonary hypertension and to the first direct demonstration of fetal programming of vascular dysfunction in humans. PMID:20417338

  17. High altitude, a natural research laboratory for the study of cardiovascular physiology and pathophysiology.

    PubMed

    Scherrer, Urs; Allemann, Yves; Jayet, Pierre-Yves; Rexhaj, Emrush; Sartori, Claudio

    2010-01-01

    High altitude constitutes an exciting natural laboratory for medical research. Although initially, the aim of high-altitude research was to understand the adaption of the organism to hypoxia and find treatments for altitude-related diseases, during the past decade or so, the scope of this research has broadened considerably. Two important observations led the foundation for the broadening of the scientific scope of high-altitude research. First, high-altitude pulmonary edema represents a unique model that allows studying fundamental mechanisms of pulmonary hypertension and lung edema in humans. Second, the ambient hypoxia associated with high-altitude exposure facilitates the detection of pulmonary and systemic vascular dysfunction at an early stage. Here, we will review studies that, by capitalizing on these observations, have led to the description of novel mechanisms underpinning lung edema and pulmonary hypertension and to the first direct demonstration of fetal programming of vascular dysfunction in humans.

  18. Solar collector with altitude tracking

    DOEpatents

    Barak, Amitzur Z.

    1977-01-01

    A device is provided for turning a solar collector about an east-west horizontal axis so that the collector is tilted toward the sun as the EWV altitude of the sun varies each day. It includes one or more heat responsive elements and a shading means aligned so that within a range of EWV altitudes of the sun during daylight hours the shading means shades the element or elements while during the rest of the daylight hours the elements or elements are heated by the sun to assume heated, stable states. Mechanical linkage between the collector and the element is responsive to the states of the element or elements to tilt the collector in accordance with variations in the EWV altitude of the sun.

  19. High altitude, prolonged exercise, and the athlete biological passport.

    PubMed

    Schumacher, Yorck O; Garvican, Laura A; Christian, Ryan; Lobigs, Louisa M; Qi, Jiliang; Fan, Rongyun; He, Yingying; Wang, Hailing; Gore, Christopher J; Ma, Fuhai

    2015-01-01

    The Athlete Biological Passport (ABP) detects blood doping in athletes through longitudinal monitoring of erythropoietic markers. Mathematical algorithms are used to define individual reference ranges for these markers for each athlete. It is unclear if altitude and exercise can affect the variables included in these calculations in a way that the changes might be mistaken for blood manipulation. The aim of this study was to investigate the influence of the simultaneous strenuous exercise and low to high altitude exposure on the calculation algorithms of the ABP. 14 sea level (SL) and 11 altitude native (ALT) highly trained athletes participated in a 14-day cycling stage race taking place at an average altitude of 2496 m above sea level (min. 1014 m, max. 4120 m), race distances ranged between 96 and 227 km per day. ABP blood measures were taken on days -1,3,6,10,14 (SL) and -1,9,15 (ALT) of the race. Four results from three samples of two different SL athletes exceeded the individual limits at the 99% specificity threshold and one value at 99.9%. In ALT, three results from three samples of three different athletes were beyond the individual limits at 99%, one at 99.9%. The variations could be explained by the expected physiological reaction to exercise and altitude. In summary, the abnormalities observed in the haematological ABP´s of well-trained athletes during extensive exercise at altitude are limited and in line with expected physiological changes.

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

    PubMed

    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. PMID:22429234

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

    PubMed

    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.

  2. Low-Altitude Exploration of the Venus Atmosphere by Balloon

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.

    2010-01-01

    The planet Venus represents an exciting target for future exploration by spacecraft. One target of scientific interest is the lower atmosphere, which represents an environment of high temperature and moderate to high atmospheric pressure. This represents a considerable challenge to the technical art of ballooning, but one which may be amenable to solution. Several possible designs for low-altitude balloons are discussed. Conceptual design for three mission examples are analyzed: a conventional balloon operating below the cloud level at an altitude of 25 kilometers, a large rigid-envelope balloon operating near the surface at an altitude of 5 kilometers, and a small, technology demonstrator rigid-envelope balloon operating at 5 kilometers.

  3. Threshold altitude resulting in decompression sickness

    NASA Technical Reports Server (NTRS)

    Kumar, K. V.; Waligora, James M.; Calkins, Dick S.

    1990-01-01

    A review of case reports, hypobaric chamber training data, and experimental evidence indicated that the threshold for incidence of altitude decompression sickness (DCS) was influenced by various factors such as prior denitrogenation, exercise or rest, and period of exposure, in addition to individual susceptibility. Fitting these data with appropriate statistical models makes it possible to examine the influence of various factors on the threshold for DCS. This approach was illustrated by logistic regression analysis on the incidence of DCS below 9144 m. Estimations using these regressions showed that, under a noprebreathe, 6-h exposure, simulated EVA profile, the threshold for symptoms occurred at approximately 3353 m; while under a noprebreathe, 2-h exposure profile with knee-bends exercise, the threshold occurred at 7925 m.

  4. Gender not a factor for altitude decompression sickness risk

    NASA Technical Reports Server (NTRS)

    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.

  5. Sleep apneas and high altitude newcomers.

    PubMed

    Goldenberg, F; Richalet, J P; Onnen, I; Antezana, A M

    1992-10-01

    Sleep and respiration data from two French medical high altitude expeditions (Annapurna 4,800 m and Mt Sajama 6,542 m) are presented. Difficulties in maintaining sleep and a SWS decrease were found with periodic breathing (PB) during both non-REM and REM sleep. Extent of PB varied considerably among subjects and was not correlated to the number of arousals but to the intercurrent wakefulness duration. There was a positive correlation between the time spent in PB and the individual hypoxic ventilatory drive. The relation between PB, nocturnal desaturation, and mountain sickness intensity are discussed. Acclimatization decreased the latency toward PB and improved sleep. Hypnotic benzodiazepine intake (loprazolam 1 mg) did not worsen either SWS depression or apneas and allowed normal sleep reappearance after acclimatization.

  6. Development of Aptitude at Altitude

    ERIC Educational Resources Information Center

    Hogan, Alexandra M.; Virues-Ortega, Javier; Botti, Ana Baya; Bucks, Romola; Holloway, John W.; Rose-Zerilli, Matthew J.; Palmer, Lyle J.; Webster, Rebecca J.; Baldeweg, Torsten; Kirkham, Fenella J.

    2010-01-01

    Millions of people currently live at altitudes in excess of 2500 metres, where oxygen supply is limited, but very little is known about the development of brain and behavioural function under such hypoxic conditions. We describe the physiological, cognitive and behavioural profile of a large cohort of infants (6-12 months), children (6-10 years)…

  7. Altitude Testing of Large Liquid Propellant Engines

    NASA Technical Reports Server (NTRS)

    Maynard, Bryon T.; Raines, Nickey G.

    2010-01-01

    The National Aeronautics and Space Administration entered a new age on January 14, 2004 with President Bush s announcement of the creation the Vision for Space Exploration that will take mankind back to the Moon and on beyond to Mars. In January, 2006, after two years of hard, dedicated labor, engineers within NASA and its contractor workforce decided that the J2X rocket, based on the heritage of the Apollo J2 engine, would be the new engine for the NASA Constellation Ares upper stage vehicle. This engine and vehicle combination would provide assured access to the International Space Station to replace that role played by the Space Shuttle and additionally, would serve as the Earth Departure Stage, to push the Crew Excursion Vehicle out of Earth Orbit and head it on a path for rendezvous with the Moon. Test as you fly, fly as you test was chosen to be the guiding philosophy and a pre-requisite for the engine design, development, test and evaluation program. An exhaustive survey of national test facility assets proved the required capability to test the J2X engine at high altitude for long durations did not exist so therefore, a high altitude/near space environment testing capability would have to be developed. After several agency concepts the A3 High Altitude Testing Facility proposal was selected by the J2X engine program on March 2, 2007 and later confirmed by a broad panel of NASA senior leadership in May 2007. This facility is to be built at NASA s John C. Stennis Space Center located near Gulfport, Mississippi. 30 plus years of Space Shuttle Main Engine development and flight certification testing makes Stennis uniquely suited to support the Vision For Space Exploration Return to the Moon. Propellant handling infrastructure, engine assembly facilities, a trained and dedicated workforce and a broad and varied technical support base will all ensure that the A3 facility will be built on time to support the schedule needs of the J2X engine and the ultimate flight

  8. [High altitude medicine is a concern also for Swedish primary care. Knowledge needed to identify high risk patients and provide appropriate advice].

    PubMed

    Kiwanuka, Olivia

    2015-05-26

    With the increasing amount of people traveling to high altitude regions, the number of people at risk of acquiring altitude illness increases. Altitude illness entails three syndromes; acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema. These syndromes are potentially lethal acquired medical conditions that in most cases are preventable. Health care providers need to inform travelers of the risks associated with mountaineering and the prophylactic measures available as well as identify underlying conditions that require specific considerations. This article provides a summary of the pathophysiology, symptoms and treatment of altitude illness and aims to be an orientation for general practitioners.

  9. Hemoglobin Mass and Aerobic Performance at Moderate Altitude in Elite Athletes.

    PubMed

    Wehrlin, Jon Peter; Marti, Bernard; Hallén, Jostein

    2016-01-01

    Fore more than a decade, the live high-train low (LHTL) approach, developed by Levine and Stray-Gundersen, has been widely used by elite endurance athletes. Originally, it was pointed out, that by living at moderate altitude, athletes should benefit from an increased red cell volume (RCV) and hemoglobin mass (Hbmass), while the training at low altitudes should prevent the disadvantage of reduced training intensity at moderate altitude. VO2max is reduced linearly by about 6-8 % per 1000 m increasing altitude in elite athletes from sea level to 3000 m, with corresponding higher relative training intensities for the same absolute work load. With 2 weeks of acclimatization, this initial deficit can be reduced by about one half. It has been debated during the last years whether sea-level training or exposure to moderate altitude increases RCV and Hbmass in elite endurance athletes. Studies which directly measured Hbmass with the optimized CO-rebreathing technique demonstrated that Hbmass in endurance athletes is not influenced by sea-level training. We documented that Hbmass is not increased after 3 years of training in national team cross-country skiers. When athletes are exposed to moderate altitude, new studies support the argument that it is possible to increase Hbmass temporarily by 5-6 %, provided that athletes spend >400 h at altitudes above 2300-2500 m. However, this effect size is smaller than the reported 10-14 % higher Hbmass values of endurance athletes living permanently at 2600 m. It remains to be investigated whether endurance athletes reach these values with a series of LHTL camps. PMID:27343108

  10. Hemoglobin Mass and Aerobic Performance at Moderate Altitude in Elite Athletes.

    PubMed

    Wehrlin, Jon Peter; Marti, Bernard; Hallén, Jostein

    2016-01-01

    Fore more than a decade, the live high-train low (LHTL) approach, developed by Levine and Stray-Gundersen, has been widely used by elite endurance athletes. Originally, it was pointed out, that by living at moderate altitude, athletes should benefit from an increased red cell volume (RCV) and hemoglobin mass (Hbmass), while the training at low altitudes should prevent the disadvantage of reduced training intensity at moderate altitude. VO2max is reduced linearly by about 6-8 % per 1000 m increasing altitude in elite athletes from sea level to 3000 m, with corresponding higher relative training intensities for the same absolute work load. With 2 weeks of acclimatization, this initial deficit can be reduced by about one half. It has been debated during the last years whether sea-level training or exposure to moderate altitude increases RCV and Hbmass in elite endurance athletes. Studies which directly measured Hbmass with the optimized CO-rebreathing technique demonstrated that Hbmass in endurance athletes is not influenced by sea-level training. We documented that Hbmass is not increased after 3 years of training in national team cross-country skiers. When athletes are exposed to moderate altitude, new studies support the argument that it is possible to increase Hbmass temporarily by 5-6 %, provided that athletes spend >400 h at altitudes above 2300-2500 m. However, this effect size is smaller than the reported 10-14 % higher Hbmass values of endurance athletes living permanently at 2600 m. It remains to be investigated whether endurance athletes reach these values with a series of LHTL camps.

  11. Sleep and Breathing at High Altitude.

    PubMed

    Wickramasinghe, Himanshu; Anholm, James D.

    1999-01-01

    Sleep at high altitude is characterized by poor subjective quality, increased awakenings, frequent brief arousals, marked nocturnal hypoxemia, and periodic breathing. A change in sleep architecture with an increase in light sleep and decreasing slow-wave and REM sleep have been demonstrated. Periodic breathing with central apnea is almost universally seen amongst sojourners to high altitude, although it is far less common in long-standing high altitude dwellers. Hypobaric hypoxia in concert with periodic breathing appears to be the principal cause of sleep disruption at altitude. Increased sleep fragmentation accounts for the poor sleep quality and may account for some of the worsened daytime performance at high altitude. Hypoxic sleep disruption contributes to the symptoms of acute mountain sickness. Hypoxemia at high altitude is most severe during sleep. Acetazolamide improves sleep, AMS symptoms, and hypoxemia at high altitude. Low doses of a short acting benzodiazepine (temazepam) may also be useful in improving sleep in high altitude. PMID:11898114

  12. High Altitude Cooking and Food Safety

    MedlinePlus

    ... Where to Place the Food Thermometer Recommended Internal Temperatures Is egg cookery affected at high altitudes? Is ... atmospheric pressure — affects both the time and the temperature of most everything that's cooked. Where the altitude ...

  13. High Altitude Ozone Research Balloon

    NASA Technical Reports Server (NTRS)

    Cauthen, Timothy A.; Daniel, Leslie A.; Herrick, Sally C.; Rock, Stacey G.; Varias, Michael A.

    1990-01-01

    In order to create a mission model of the high altitude ozone research balloon (HAORB) several options for flight preparation, altitude control, flight termination, and payload recovery were considered. After the optimal launch date and location for two separate HAORB flights were calculated, a method for reducing the heat transfer from solar and infrared radiation was designed and analytically tested. This provided the most important advantage of the HAORB over conventional balloons, i.e., its improved flight duration. Comparisons of different parachute configurations were made, and a design best suited for the HAORB's needs was determined to provide for payload recovery after flight termination. In an effort to avoid possible payload damage, a landing system was also developed.

  14. Cognitive impairments at high altitudes and adaptation.

    PubMed

    Yan, Xiaodan

    2014-06-01

    High altitude hypoxia has been shown to have significant impact on cognitive performance. This article reviews the aspects in which, and the conditions under which, decreased cognitive performance has been observed at high altitudes. Neural changes related to high altitude hypoxia are also reviewed with respect to their possible contributions to cognitive impairments. In addition, potential adaptation mechanisms are reviewed among indigenous high altitude residents and long-term immigrant residents, with discussions about methodological concerns related to these studies.

  15. Altitude characteristics of selected air quality analyzers

    NASA Technical Reports Server (NTRS)

    White, J. H.; Strong, R.; Tommerdahl, J. B.

    1979-01-01

    The effects of altitude (pressure) on the operation and sensitivity of various air quality analyzers frequently flown on aircraft were analyzed. Two ozone analyzers were studied at altitudes from 600 to 7500 m and a nitrogen oxides chemiluminescence detector and a sulfur dioxide flame photometric detector were studied at altitudes from 600 to 3000 m. Calibration curves for altitude corrections to the sensitivity of the instruments are presented along with discussion of observed instrument behavior.

  16. [Work at high altitude: concepts of physiopathology, risk factors, health surveillance and criteria for the development of work capacity evaluation criteria].

    PubMed

    Taino, Giuseppe; Giardini, Guido; Pecchio, Oriana; Brevi, Marco; Giorgi, Marco; Verardo, Marina Giulia; Detragiaches, Enrico; Imbriani, Marcello

    2012-01-01

    Work at high altitude (elevation equal to or greater than 3000 m above sea level) results in a physiological adaptation of the human organism to changing environmental conditions. The main problem related to the altitude is represented by the reduction of partial pressure of oxygen (hypoxia) that occurs in proportion to the reduction of barometric pressure. Our study, starting with an analysis of the human body's physiological response to acute hypoxic conditions and acclimatization for reaching protracted stays, takes into consideration all risk factors related to the performance of work at high altitude. We identified risk factors related to physical environment of high altitude and represented by temperature, humidity, latitude, speed wind, atmospheric pressure and hypoxia, risk factors related to the worker and represented by age, sex, state of health and individual susceptibility, degree of training. With reference to the state of health we analyzed the major pathophysiological conditions that can create situations of susceptibility to high altitude. We then analyzed risk factors related to the characteristics of the job that are represented by the degree of physical effort and energy expenditure required, by the personal protective equipment (PPE) used and by the concomitant exposure to other occupational risk factors of physical and chemical nature. It was finally addressed the decision making process related to the formulation of the judgment of suitability for performance of work activities at high altitude. The health protocol proposed requires an accurate anamnestic investigation aimed at gathering information on pre-existing pathophysiological conditions that need, once identified, clinical and instrumental tests specific and targeted. These clinical protocols are analyzed and proposed for the main pathophysiologic conditions that pose a risk to health at high altitude. For workers, in which clinical investigation and medical history has not shown

  17. An altitude-dependent spacecraft charging model

    NASA Technical Reports Server (NTRS)

    Haffner, J. W.

    1977-01-01

    A model for the altitude dependence of the hot plasma parameters responsible for the electrostatic charging of spacecraft was developed. Based upon plasma orbit theory, the directed velocity is a function of the ambient magnetic field flux density. A consequence of this approach is that while the thermal velocity distributions (assumed to be Maxwellian) of the plasma particles are independent of the magnetic field strength (and hence altitude), the particle densities increase with magnetic field strength. Thus, according to this model, while the equilibrium voltage is independent of altitude, the charging current density increases with decreasing altitude. However, the probability of such spacecraft charging decreases with decreasing altitude.

  18. Altitude-Related Illness: Advice to Travellers

    PubMed Central

    Crutcher, Rodney A.

    1990-01-01

    Altitude-related medical problems have received much attention in the recent medical literature. Family physicians must be knowledgeable about these problems so that they can give appropriate advice to travellers. The author, a practising family physician, discusses issues arising from both the modest cabin altitudes experienced in modern-day air travel and the greater altitudes experienced by skiers and trekkers, pilots and mountaineers, and lowland adventurers of all sorts. He reviews the process of acclimatization to altitude and the four principal forms of altitude illness. PMID:21233912

  19. Space Operations Center orbit altitude selection strategy

    NASA Technical Reports Server (NTRS)

    Indrikis, J.; Myers, H. L.

    1982-01-01

    The strategy for the operational altitude selection has to respond to the Space Operation Center's (SOC) maintenance requirements and the logistics demands of the missions to be supported by the SOC. Three orbit strategies are developed: two are constant altitude, and one variable altitude. In order to minimize the effect of atmospheric uncertainty the dynamic altitude method is recommended. In this approach the SOC will operate at the optimum altitude for the prevailing atmospheric conditions and logistics model, provided that mission safety constraints are not violated. Over a typical solar activity cycle this method produces significant savings in the overall logistics cost.

  20. Impact of extreme exercise at high altitude on oxidative stress in humans.

    PubMed

    Quindry, John; Dumke, Charles; Slivka, Dustin; Ruby, Brent

    2016-09-15

    Exercise and oxidative stress research continues to grow as a physiological subdiscipline. The influence of high altitude on exercise and oxidative stress is among the recent topics of intense study in this area. Early findings indicate that exercise at high altitude has an independent influence on free radical generation and the resultant oxidative stress. This review provides a detailed summary of oxidative stress biochemistry as gleaned mainly from studies of humans exercising at high altitude. Understanding of the human response to exercise at altitude is largely derived from field-based research at altitudes above 3000 m in addition to laboratory studies which employ normobaric hypoxia. The implications of oxidative stress incurred during high altitude exercise appear to be a transient increase in oxidative damage followed by redox-sensitive adaptations in multiple tissues. These outcomes are consistent for lowland natives, high altitude acclimated sojourners and highland natives, although the latter group exhibits a more robust adaptive response. To date there is no evidence that altitude-induced oxidative stress is deleterious to normal training or recovery scenarios. Limited evidence suggests that deleterious outcomes related to oxidative stress are limited to instances where individuals are exposed to extreme elevations for extended durations. However, confirmation of this tentative conclusion requires further investigation. More applicably, altitude-induced hypoxia may have an independent influence on redox-sensitive adaptive responses to exercise and exercise recovery. If correct, these findings may hold important implications for athletes, mountaineers, and soldiers working at high altitude. These points are raised within the confines of published research on the topic of oxidative stress during exercise at altitude.

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

    PubMed

    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.

  2. Bioethical considerations.

    PubMed

    Leyser-Whalen, Ophra; Lawson, Erma; Macdonald, Arlene; Temple, Jeff R; Phelps, John Y

    2014-11-01

    The clinical literature notes that pregnancy has become an expected benefit of solid organ transplant. Establishing "best practices" in the management of this particular transplant population requires careful consideration of the ethical dimensions, broadly speaking, of posttransplant pregnancies and these women's lived experiences. In this article, we present the current clinical and social science posttransplant pregnancy research. We specifically address the psychosocial and ethical issues surrounding preconception counseling and posttransplant health quality of life and mothering and suggest areas for future research. PMID:25151472

  3. Intermittent hypoxic training: fact and fancy.

    PubMed

    Levine, Benjamin D

    2002-01-01

    Intermittent hypoxic training (IHT) refers to the discontinuous use of normobaric or hypobaric hypoxia, in an attempt to reproduce some of the key features of altitude acclimatization, with the ultimate goal to improve sea-level athletic performance. In general, IHT can be divided into two different strategies: (1) providing hypoxia at rest with the primary goal being to stimulate altitude acclimatization or (2) providing hypoxia during exercise, with the primary goal being to enhance the training stimulus. Each approach has many different possible application strategies, with the essential variable among them being the "dose" of hypoxia necessary to achieve the desired effect. One approach, called living high-training low, has been shown to improve sea-level endurance performance. This strategy combines altitude acclimatization (2500 m) with low altitude training to ensure high-quality training. The opposite strategy, living low-training high, has also been proposed by some investigators. The primacy of the altitude acclimatization effect in IHT is demonstrated by the following facts: (1) living high-training low clearly improves performance in athletes of all abilities, (2) the mechanism of this improvement is primarily an increase in erythropoietin, leading to increased red cell mass, V(O2max), and running performance, and (3) rather than intensifying the training stimulus, training at altitude or under hypoxia leads to the opposite effect - reduced speeds, reduced power output, reduced oxygen flux - and therefore is not likely to provide any advantage for a well-trained athlete.

  4. The Effect of Residing Altitude on Levels of High-Density Lipoprotein Cholesterol: A Pilot Study From the Omani Arab Population.

    PubMed

    Al Riyami, Nafila B; Banerjee, Yajnavalka; Al-Waili, Khalid; Rizvi, Syed G; Al-Yahyaee, Said; Hassan, Mohammed O; Albarwani, Sulayma; Al-Rasadi, Khalid; Bayoumi, Riad A

    2015-07-01

    Lower mortality rates from coronary heart disease and higher levels of serum high-density lipoprotein cholesterol (HDL-C) have been observed in populations residing at high altitude. However, this effect has not been investigated in Arab populations, which exhibit considerable genetic homogeneity. We assessed the relationship between residing altitude and HDL-C in 2 genetically similar Omani Arab populations residing at different altitudes. The association between the levels of HDL-C and other metabolic parameters was also investigated. The levels of HDL-C were significantly higher in the high-altitude group compared with the low-altitude group. Stepwise regression analysis showed that altitude was the most significant factor affecting HDL-C, followed by gender, serum triglycerides, and finally the 2-hour postprandial plasma glucose. This finding is consistent with previously published studies from other populations and should be taken into consideration when comparing cardiovascular risk factors in populations residing at different altitudes.

  5. Altitude Stress During Participation of Medical Congress.

    PubMed

    Kim, Soon Bae; Kim, Jong Sung; Kim, Sang Jun; Cho, Su Hee; Suh, Dae Chul

    2016-09-01

    Medical congresses often held in highlands. We reviewed several medical issues associated with altitude stress especially while physicians have participated medical congress held in high altitude. Altitude stress, also known as an acute mountain sickness (AMS), is caused by acute exposure to low oxygen level at high altitude which is defined as elevations at or above 1,200 m and AMS commonly occurs above 2,500 m. Altitude stress with various symptoms including insomnia can also be experienced in airplane. AMS and drunken state share many common features in symptoms, neurologic manifestations and even show multiple microbleeds in corpus callosum and white matter on MRI. Children are more susceptible to altitude stress than adults. Gradual ascent is the best method for the prevention of altitude stress. Adequate nutrition (mainly carbohydrates) and hydration are recommended. Consumption of alcohol can exacerbate the altitude-induced impairments in judgment and the visual senses and promote psychomotor dysfunction. For prevention or treatment of altitude stress, acetazolamide, phosphodiesterase inhibitors, dexamethasone and erythropoietin are helpful. Altitude stress can be experienced relatively often during participation of medical congress. It is necessary to remind the harmful effect of AMS because it can cause serious permanent organ damage even though the symptoms are negligible in most cases.

  6. ALT space shuttle barometric altimeter altitude analysis

    NASA Technical Reports Server (NTRS)

    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.

  7. Altitude Stress During Participation of Medical Congress.

    PubMed

    Kim, Soon Bae; Kim, Jong Sung; Kim, Sang Jun; Cho, Su Hee; Suh, Dae Chul

    2016-09-01

    Medical congresses often held in highlands. We reviewed several medical issues associated with altitude stress especially while physicians have participated medical congress held in high altitude. Altitude stress, also known as an acute mountain sickness (AMS), is caused by acute exposure to low oxygen level at high altitude which is defined as elevations at or above 1,200 m and AMS commonly occurs above 2,500 m. Altitude stress with various symptoms including insomnia can also be experienced in airplane. AMS and drunken state share many common features in symptoms, neurologic manifestations and even show multiple microbleeds in corpus callosum and white matter on MRI. Children are more susceptible to altitude stress than adults. Gradual ascent is the best method for the prevention of altitude stress. Adequate nutrition (mainly carbohydrates) and hydration are recommended. Consumption of alcohol can exacerbate the altitude-induced impairments in judgment and the visual senses and promote psychomotor dysfunction. For prevention or treatment of altitude stress, acetazolamide, phosphodiesterase inhibitors, dexamethasone and erythropoietin are helpful. Altitude stress can be experienced relatively often during participation of medical congress. It is necessary to remind the harmful effect of AMS because it can cause serious permanent organ damage even though the symptoms are negligible in most cases. PMID:27621942

  8. Altitude Stress During Participation of Medical Congress

    PubMed Central

    Kim, Soon Bae; Kim, Jong Sung; Kim, Sang Jun; Cho, Su Hee

    2016-01-01

    Medical congresses often held in highlands. We reviewed several medical issues associated with altitude stress especially while physicians have participated medical congress held in high altitude. Altitude stress, also known as an acute mountain sickness (AMS), is caused by acute exposure to low oxygen level at high altitude which is defined as elevations at or above 1,200 m and AMS commonly occurs above 2,500 m. Altitude stress with various symptoms including insomnia can also be experienced in airplane. AMS and drunken state share many common features in symptoms, neurologic manifestations and even show multiple microbleeds in corpus callosum and white matter on MRI. Children are more susceptible to altitude stress than adults. Gradual ascent is the best method for the prevention of altitude stress. Adequate nutrition (mainly carbohydrates) and hydration are recommended. Consumption of alcohol can exacerbate the altitude-induced impairments in judgment and the visual senses and promote psychomotor dysfunction. For prevention or treatment of altitude stress, acetazolamide, phosphodiesterase inhibitors, dexamethasone and erythropoietin are helpful. Altitude stress can be experienced relatively often during participation of medical congress. It is necessary to remind the harmful effect of AMS because it can cause serious permanent organ damage even though the symptoms are negligible in most cases.

  9. Altitude Stress During Participation of Medical Congress

    PubMed Central

    Kim, Soon Bae; Kim, Jong Sung; Kim, Sang Jun; Cho, Su Hee

    2016-01-01

    Medical congresses often held in highlands. We reviewed several medical issues associated with altitude stress especially while physicians have participated medical congress held in high altitude. Altitude stress, also known as an acute mountain sickness (AMS), is caused by acute exposure to low oxygen level at high altitude which is defined as elevations at or above 1,200 m and AMS commonly occurs above 2,500 m. Altitude stress with various symptoms including insomnia can also be experienced in airplane. AMS and drunken state share many common features in symptoms, neurologic manifestations and even show multiple microbleeds in corpus callosum and white matter on MRI. Children are more susceptible to altitude stress than adults. Gradual ascent is the best method for the prevention of altitude stress. Adequate nutrition (mainly carbohydrates) and hydration are recommended. Consumption of alcohol can exacerbate the altitude-induced impairments in judgment and the visual senses and promote psychomotor dysfunction. For prevention or treatment of altitude stress, acetazolamide, phosphodiesterase inhibitors, dexamethasone and erythropoietin are helpful. Altitude stress can be experienced relatively often during participation of medical congress. It is necessary to remind the harmful effect of AMS because it can cause serious permanent organ damage even though the symptoms are negligible in most cases. PMID:27621942

  10. Intermittent altitude exposures reduce acute mountain sickness at 4300 m.

    PubMed

    Beidleman, Beth A; Muza, Stephen R; Fulco, Charles S; Cymerman, Allen; Ditzler, Dan; Stulz, Dean; Staab, Janet E; Skrinar, Gary S; Lewis, Steven F; Sawka, Michael N

    2004-03-01

    Acute mountain sickness (AMS) commonly occurs at altitudes exceeding 2000-2500 m and usually resolves after acclimatization induced by a few days of chronic residence at the same altitude. Increased ventilation and diuresis may contribute to the reduction in AMS with altitude acclimatization. The aim of the present study was to examine the effects of intermittent altitude exposures (IAE), in combination with rest and exercise training, on the incidence and severity of AMS, resting ventilation and 24-h urine volume at 4300 m. Six lowlanders (age, 23 +/- 2 years; body weight, 77 +/- 6 kg; values are means +/- S.E.M.) completed an Environmental Symptoms Questionnaire (ESQ) and Lake Louise AMS Scoring System (LLS), a resting end-tidal partial pressure of CO2 ( PETCO2) test and a 24-h urine volume collection at sea level (SL) and during a 30 h exposure to 4300 m altitude-equivalent (barometric pressure=446 mmHg) once before (PreIAE) and once after (PostIAE) a 3-week period of IAE (4 h.day(-1), 5 days.week(-1), 4300 m). The previously validated factor score, AMS cerebral score, was calculated from the ESQ and the self-report score was calculated from the LLS at 24 h of altitude exposure to assess the incidence and severity of AMS. During each IAE, three subjects cycled for 45-60 min.day(-1) at 60-70% of maximal O2 uptake (VO2 max) and three subjects rested. Cycle training during each IAE did not affect any of the measured variables, so data from all six subjects were combined. The results showed that the incidence of AMS (%), determined from both the ESQ and LLS, increased (P<0.05) from SL (0 +/- 0) to PreIAE (50 +/- 22) at 24 h of altitude exposure and decreased (P<0.05) from PreIAE to PostIAE (0 +/- 0). The severity of AMS (i.e. AMS cerebral symptom and LLS self-report scores) increased (P<0.05) from SL (0.02 +/- 0.02 and 0.17 +/- 0.17 respectively) to PreIAE (0.49 +/- 0.18 and 4.17 +/- 0.94 respectively) at 24 h of altitude exposure, and decreased (P<0.05) from Pre

  11. High-altitude reconnaissance aircraft

    NASA Technical Reports Server (NTRS)

    Yazdi, Renee Anna

    1991-01-01

    At the equator the ozone layer ranges from 65,000 to 130,000+ ft, which is beyond the capabilities of the ER-2, NASA's current high-altitude reconnaissance aircraft. This project is geared to designing an aircraft that can study the ozone layer. The aircraft must be able to satisfy four mission profiles. The first is a polar mission that ranges from Chile to the South Pole and back to Chile, a total range of 6000 n.m. at 100,000 ft with a 2500-lb payload. The second mission is also a polar mission with a decreased altitude and an increased payload. For the third mission, the aircraft will take off at NASA Ames, cruise at 100,000 ft, and land in Chile. The final mission requires the aircraft to make an excursion to 120,000 ft. All four missions require that a subsonic Mach number be maintained because of constraints imposed by the air sampling equipment. Three aircraft configurations were determined to be the most suitable for meeting the requirements. The performance of each is analyzed to investigate the feasibility of the mission requirements.

  12. Rocket Engine Altitude Simulation Technologies

    NASA Technical Reports Server (NTRS)

    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.

  13. Physiological characteristics of elite high-altitude climbers.

    PubMed

    Puthon, L; Bouzat, P; Rupp, T; Robach, P; Favre-Juvin, A; Verges, S

    2016-09-01

    Factors underlying the amplitude of exercise performance reduction at altitude and the development of high-altitude illnesses are not completely understood. To better describe these mechanisms, we assessed cardiorespiratory and tissue oxygenation responses to hypoxia in elite high-altitude climbers. Eleven high-altitude climbers were matched with 11 non-climber trained controls according to gender, age, and fitness level (maximal oxygen consumption, VO2 max ). Subjects performed two maximal incremental cycling tests, in normoxia and in hypoxia (inspiratory oxygen fraction: 0.12). Cardiorespiratory measurements and tissue (cerebral and muscle) oxygenation were assessed continuously. Hypoxic ventilatory and cardiac responses were determined at rest and during exercise; hypercapnic ventilatory response was determined at rest. In hypoxia, climbers exhibited similar reductions to controls in VO2 max (climbers -39 ± 7% vs controls -39 ± 9%), maximal power output (-27 ± 5% vs -26 ± 4%), and arterial oxygen saturation (SpO2 ). However, climbers had lower hypoxic ventilatory response during exercise (1.7 ± 0.5 vs 2.6 ± 0.7 L/min/%; P < 0.05) and lower hypercapnic ventilatory response (1.8 ± 1.4 vs 3.8 ± 2.5 mL/min/mmHg; P < 0.05). Finally, climbers exhibited slower breathing frequency, larger tidal volume and larger muscle oxygenation index. These results suggest that elite climbers show some specific ventilatory and muscular responses to hypoxia possibly because of genetic factors or adaptation to frequent high-altitude climbing.

  14. Endoscopic considerations in children.

    PubMed

    Lobritto, S J

    2001-01-01

    Endoscopy often is required in the management of patients with chronic liver disease. Endoscopy in this pediatric population is a safe and effective diagnostic and therapeutic modality for the appropriate clinical situation. The clear advantage afforded by reduced-sized equipment, new anesthetic agents, better operator training, and specialized pediatric endoscopy units have resulted in better outcomes and reduced risk to the patient. Advances in technical innovations will expand the currently offered diagnostic and therapeutic options for management of pediatric with portal hypertension. This article reviews specific considerations for endoscopy in this demanding patient population. PMID:11175977

  15. Sickness at high altitude: a literature review.

    PubMed

    Brundrett, G

    2002-03-01

    When some individuals spend just a few hours at low atmospheric pressure above 1,500 m (5,000 ft)--such as when climbing a mountain or flying in a plane at high altitude--they become ill. Altitude sickness studies originally concentrated on life-threatening illnesses which beset determined and athletic climbers at extreme altitudes. In recent years, however, research attention is moving towards milder forms of sickness reported by a significant proportion of the growing number of visitors to mountain and ski resorts at more moderate altitude. Some of this research is also relevant in understanding the problems experienced by passengers in newer planes that fly at a significantly higher equivalent cabin altitude, i.e. 2,440 m (8,000 ft), than earlier designs. Engineering solutions--such as enriched oxygen in enclosed spaces at altitude, or in the case of aircraft, lower cabin altitudes--are possible, but for an economic assessment to be realistic an engineer needs to identify the scale of the problem and to understand the factors determining susceptibility. This review concentrates on the problems of mountain sickness in the ordinary population at altitudes of around 3,000 m (10,000 ft); this is a problem of growing concern as ski resorts develop, mountain trekking increases in popularity, and as higher altitude cabin pressures are achieved in aircraft.

  16. Hormonal contraceptives and travel to high altitude.

    PubMed

    Keyes, Linda E

    2015-03-01

    Women frequently ask about the safety and efficacy of using hormonal contraception (HC), either oral contraceptive pills (OC) or other forms, when traveling to high altitude locales. What are the risks and benefits of using HC at high altitude? Does HC affect acclimatization, exercise performance, or occurrence of acute mountain sickness? This article reviews current data regarding the risks and benefits of HC at high altitude, both demonstrated and theoretical, with the aim of helping health care providers to advise women traveling above 2500 meters. Most healthy women can safely use HC when traveling to high altitude, but should be aware of the potential risks and inconveniences.

  17. Werner deconvolution for variable altitude aeromagnetic data

    SciTech Connect

    Ostrowski, J.S. ); Pilkington, M.; Teskey, D.J. )

    1993-10-01

    The standard Werner deconvolution method is extended to include the effects of variable sensor altitude but this leads to a deconvolution algorithm that is unstable for slowly changing flight height. By expressing the sensor altitude as a linear function of horizontal position (within a specified window), the authors show that the numerical instability can be avoided. The subsequent selection and averaging of the raw solutions is controlled by three parameters that can be adjusted to specific survey data characteristics. Results for an aeromagnetic survey over Vancouver Island, British Columbia show that, in comparison with the variable altitude approach, the standard Werner method produces unacceptable errors when applied to variable altitude data.

  18. Hormonal contraceptives and travel to high altitude.

    PubMed

    Keyes, Linda E

    2015-03-01

    Women frequently ask about the safety and efficacy of using hormonal contraception (HC), either oral contraceptive pills (OC) or other forms, when traveling to high altitude locales. What are the risks and benefits of using HC at high altitude? Does HC affect acclimatization, exercise performance, or occurrence of acute mountain sickness? This article reviews current data regarding the risks and benefits of HC at high altitude, both demonstrated and theoretical, with the aim of helping health care providers to advise women traveling above 2500 meters. Most healthy women can safely use HC when traveling to high altitude, but should be aware of the potential risks and inconveniences. PMID:25759908

  19. Prosthodontic considerations.

    PubMed

    Taylor, T D; Belser, U; Mericske-Stern, R

    2000-01-01

    The prosthodontic section of the 1997 ITI Consensus Conference in Vitznau, Switzerland, examined a broad spectrum of issues related to the prosthodontic phase of dental implant therapy. Topics included diagnosis and treatment planning, considerations for the use of ITI prosthodontic components, management of the partially edentulous patient, management of the edentulous patient, implant occlusion, and the use of narrow- and wide-body implants. The management of partially and totally edentulous patients will be discussed in separate papers. This paper is written so that each major consensus point discussed by the prosthodontic section is the first sentence of a paragraph. The remainder of each paragraph serves as background information or justification for the consensus statement. It should be noted that agreement on all points was reached by voting within the prosthodontic section. Many of the consensus statements were reached unanimously, while some were reached through compromise and split vote. Not all of the points presented here were presented to the plenum session on the final day of the conference. PMID:11168260

  20. The high-altitude brain.

    PubMed

    Hornbein, T F

    2001-09-01

    The highest place on our planet, Mount Everest (8850 m), appears to be close to the limit of how high an acclimatized human can go, albeit slowly. In this paper, I will explore the possibility that what limits human performance at such extreme degrees of hypoxia is the availability of oxygen to the brain. Also, one of the known costs of such extreme exposure is residual mild impairment of performance on neuropsychometric tests after return to sea level, implying injury to brain cells. That such injury could occur in the absence of any overt impairment of function, much less without loss of consciousness, is unexpected. I will speculate about physiological mechanisms that might cause or contribute to both decrements in real-time performance while at altitude and residual deficits for a time after return to low elevations; the effects of hypoxia on brain cells are an even greater puzzle at the present time.

  1. Multilayer Perceptron Model for Nowcasting Visibility from Surface Observations: Results and Sensitivity to Dissimilar Station Altitudes

    NASA Astrophysics Data System (ADS)

    Chaudhuri, Sutapa; Das, Debanjana; Sarkar, Ishita; Goswami, Sayantika

    2015-10-01

    The reduction in the visibility during fog significantly influences surface as well as air transport operations. The prediction of fog remains difficult despite improvements in numerical weather prediction models. The present study aims at identifying a suitable neural network model with proper architecture to provide precise nowcast of the horizontal visibility during fog over the airports of three significantly affected metropolises of India, namely: Kolkata (22°32'N; 88°20'E), Delhi (28°38'N; 77°12'E) and Bengaluru (12°95'N; 77°72'E). The investigation shows that the multilayer perceptron (MLP) model provides considerably less error in nowcasting the visibility during fog over the said metropolises than radial basis function network, generalized regression neural network or linear neural network. The MLP models of different architectures are trained with the data and records from 2000 to 2010. The model results are validated with observations from 2011 to 2014. Our results reveal that MLP models with different configurations (1) four input layers, three hidden layers with three hidden nodes in each layer and a single output; (2) four input layers with two hidden layers having one hidden node in the first hidden layer and two hidden nodes in the second hidden layer, and a single output layer; and (3) four input layers with two hidden layers having two hidden nodes in each hidden layer and a single output layer] provide minimum error in nowcasting the visibility during fog over the airports of Kolkata, Delhi and Bengaluru, respectively. The results show that the MLP model is well suited for nowcasting visibility during fog with 6 h lead time, however, the study reveals that the MLP model sensitive to dissimilar station altitudes in nowcasting visibility, as the minimum prediction error for the three metropolises having dissimilar mean sea level altitudes is observed through different configurations of the model.

  2. Cardiovascular effects of chronic carbon monoxide and high-altitude exposure

    SciTech Connect

    McGrath, J.J. )

    1989-07-01

    At higher altitudes, ambient carbon monoxide levels are increasing with the number of residents and tourists and their use of motor vehicles and heating devices (such as fireplaces, furnaces, and stoves). Although chronic exposure to carbon monoxide or high altitude causes pronounced cardiovascular changes in humans as well as in animals, there is little information on the effects elicited by these stressors combined. Data from acute studies and theoretical considerations suggest that carbon monoxide inhaled at altitude may be more detrimental than carbon monoxide inhaled at sea level. It is not known, however, if the cardiovascular system adapts or deteriorates with continuous, concurrent exposure to carbon monoxide and high altitude. Male laboratory rats were exposed for six weeks in steel barometric chambers to altitudes ranging from 3,300 ft (ambient) to 18,000 ft and to concentrations ranging from 0 to 500 parts per million (ppm)2. Carbon monoxide had no effect on body weight at any altitude. There was a tendency for hematocrit to increase even at the lowest concentration of carbon monoxide (9 ppm), but the increase did not become significant until 100 ppm. At 10,000 ft, there was a tendency for total heart weight to increase in rats inhaling 100 ppm carbon monoxide. Although its effects on the heart at altitude are complex, carbon monoxide, in concentrations of 500 ppm or less, had little effect on the right ventricle; it did not exacerbate any effects due to altitude. There was a tendency for the left ventricle weight to increase with exposure to 35 ppm carbon monoxide at altitude, but the increase was not significant until 100 ppm carbon monoxide. Heart rate, blood pressure, cardiac output, and peripheral resistance were unaffected by exposure to 35 ppm carbon monoxide or 10,000-ft altitude singly or in combination.

  3. High Altitude Illnesses in Hawai‘i

    PubMed Central

    2014-01-01

    High Altitude Headache (HAH), Acute Mountain Sickness (AMS), and High Altitude Cerebral Edema (HACE) are all high altitude related illnesses in order of severity from the mildly symptomatic to the potentially life-threatening. High altitude illnesses occur when travelers ascend to high altitudes too rapidly, which does not allow enough time for the body to adjust. Slow graded ascent to the desired altitude and termination of ascent if AMS symptoms present are keys to illness prevention. Early recognition and rapid intervention of AMS can halt progression to HACE. Pharmacologic prophylaxis with acetazolamide is a proven method of prevention and treatment of high altitude illness. If prevention fails then treatment modalities include supplemental oxygen, supportive therapy, hyperbaric treatment, and dexamethasone. Given the multitude of visitors to the mountains of Hawai‘i, high altitude illness will continue to persist as a prevalent local condition. This paper will emphasize the prevention and early diagnosis of AMS so that the illness does not progress to HACE. PMID:25478293

  4. Is Pulse Oximetry Useful for Screening Neonates for Critical Congenital Heart Disease at High Altitudes?

    PubMed

    Hoffman, Julien I E

    2016-06-01

    Now that pulse oximetry is used widely to screen for critical congenital heart disease, it is time to consider whether this screening method is applicable to those who live at high altitudes. Consideration of basic physical principles and reports from the literature indicate that not only is the 95 % cutoff point for arterial oxygen saturation incorrect at high altitudes, but the lower saturations are accompanied by greater variability and therefore there is the possibility of a greater percentage of false-positive screening tests at high altitudes. Because of ethnic differences in response to high altitudes, normative data will have to be collected separately in different countries and perhaps for different ethnic groups.

  5. Aerodynamic characteristics of a hypersonic viscous optimized waverider at high altitudes

    NASA Technical Reports Server (NTRS)

    Rault, Didier F. G.

    1992-01-01

    The present paper addresses the applicability of the basic concept of waveriding at high altitudes, and the extent to which the large viscous forces degrade the aerodynamic performance of waveriders. The waverider under consideration was designed using a continuum flow methodology. It is shown that the lift-to-drag ratio of high-altitude/high-Knudsen-number waveriders can be expected to be significantly lower than their low altitude/low Knudsen number counterparts. The aerodynamic performance of a representative waverider which was optimized for a 90-km, Mach-25 application is studied for altitudes ranging from 97 km to 145 km and incidence angles of 0 to 30 deg. Typical values of the lift-to-drag ratio were computed to be in the range of 0 to 0.3. Friction forces are mostly responsible for this poor performance. Friction forces account for more than 93 percent of the drag and significantly reduce lift.

  6. Turbojet Performance and Operation at High Altitudes with Hydrogen and Jp-4 Fuels

    NASA Technical Reports Server (NTRS)

    Fleming, W A; Kaufman, H R; Harp, J L , Jr; Chelko, L J

    1956-01-01

    Two current turbojet engines were operated with gaseous-hydrogen and JP-4 fuels at very high altitudes and a simulated Mach number of 0.8. With gaseous hydrogen as the fuel stable operation was obtained at altitudes up to the facility limit of about 90,000 feet and the specific fuel consumption was only 40 percent of that with JP-4 fuel. With JP-4 as the fuel combustion was unstable at altitudes above 60,000 to 65,000 feet and blowout limits were reached at 75,000 to 80,000 feet. Over-all performance, component efficiencies, and operating range were reduced considerable at very high altitudes with both fuels.

  7. Developmental functional adaptation to high altitude: review.

    PubMed

    Frisancho, A Roberto

    2013-01-01

    Various approaches have been used to understand the origins of the functional traits that characterize the Andean high-altitude native. Based on the conceptual framework of developmental functional adaptation which postulates that environmental influences during the period of growth and development have long lasting effects that may be expressed during adulthood, we initiated a series of studies addressed at determining the pattern of physical growth and the contribution of growth and development to the attainment of full functional adaptation to high-altitude of low and high altitude natives living under rural and urban conditions. Current research indicate that: (a) the pattern of growth at high altitude due to limited nutritional resources, physical growth in body size is delayed but growth in lung volumes is accelerated because of hypoxic stress); (b) low-altitude male and female urban natives can attain a full functional adaptation to high altitude by exposure to high-altitude hypoxia during the period of growth and development; (c) both experimental studies on animals and comparative human studies indicate that exposure to high altitude during the period of growth and development results in the attainment of a large residual lung volume; (d) this developmentally acquired enlarged residual lung volume and its associated increase in alveolar area when combined with the increased tissue capillarization and moderate increase in red blood cells and hemoglobin concentration contributes to the successful functional adaptation of the Andean high-altitude native to hypoxia; and (e) any specific genetic traits that are related to the successful functional adaptation of Andean high-altitude natives have yet to be identified.

  8. Sleep at high altitude: guesses and facts.

    PubMed

    Bloch, Konrad E; Buenzli, Jana C; Latshang, Tsogyal D; Ulrich, Silvia

    2015-12-15

    Lowlanders commonly report a poor sleep quality during the first few nights after arriving at high altitude. Polysomnographic studies reveal that reductions in slow wave sleep are the most consistent altitude-induced changes in sleep structure identified by visual scoring. Quantitative spectral analyses of the sleep electroencephalogram have confirmed an altitude-related reduction in the low-frequency power (0.8-4.6 Hz). Although some studies suggest an increase in arousals from sleep at high altitude, this is not a consistent finding. Whether sleep instability at high altitude is triggered by periodic breathing or vice versa is still uncertain. Overnight changes in slow wave-derived encephalographic measures of neuronal synchronization in healthy subjects were less pronounced at moderately high (2,590 m) compared with low altitude (490 m), and this was associated with a decline in sleep-related memory consolidation. Correspondingly, exacerbation of breathing and sleep disturbances experienced by lowlanders with obstructive sleep apnea during a stay at 2,590 m was associated with poor performance in driving simulator tests. These findings suggest that altitude-related alterations in sleep may adversely affect daytime performance. Despite recent advances in our understanding of sleep at altitude, further research is required to better establish the role of gender and age in alterations of sleep at different altitudes, to determine the influence of acclimatization and of altitude-related illness, and to uncover the characteristics of sleep in highlanders that may serve as a study paradigm of sleep in patients exposed to chronic hypoxia due to cardiorespiratory disease.

  9. Diving at altitude: from definition to practice.

    PubMed

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

    2014-01-01

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

  10. Diving at altitude: from definition to practice.

    PubMed

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

    2014-01-01

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

  11. High altitude aircraft flight tests

    NASA Astrophysics Data System (ADS)

    Helmken, Henry; Emmons, Peter; Homeyer, David

    1996-03-01

    In order to make low earth orbit L-band propagation measurements and test new voice communication concepts, a payload was proposed and accepted for flight aboard the COMET (now METEOR) spacecraft. This Low Earth Orbiting EXperiment payload (LEOEX) was designed and developed by Motorola Inc. and sponsored by the Space Communications Technology Center (SCTC), a NASA Center for the Commercial Development of Space (CCDS) located at Florida Atlantic University. In order to verify the LEOEX payload for satellite operation and obtain some preliminary propagation data, a series of 9 high altitude aircraft (SR-71 and ER-2) flight tests were conducted. These flights took place during a period of 7 months, from October 1993 to April 1994. This paper will summarize the operation of the LEOEX payload and the particular configuration used for these flights. The series of flyby tests were very successful and demonstrated how bi-directional, Time Division Multiple Access (TDMA) voice communication will work in space-to-ground L-band channels. The flight tests also acquired propagation data which will be representative of L-band Low Earth Orbiting (LEO) communication systems. In addition to verifying the LEOEX system operation, it also uncovered and ultimately aided the resolution of several key technical issues associated with the payload.

  12. Internalized Heterosexism: Clinical Implications and Training Considerations

    ERIC Educational Resources Information Center

    Kashubeck-West, Susan; Szymanski, Dawn; Meyer, Jill

    2008-01-01

    This article focuses on implications of empirical research on the construct of internalized heterosexism (IH) in lesbian, gay, and bisexual (LGB) individuals. First, suggestions for practice with LGB clients are provided using the framework proposed by Goodman et al. for social justice work at micro, meso, and macro levels. Second, ideas for the…

  13. Alternative Considerations for Surgical Training and Funding.

    PubMed

    Martin, Ronald F

    2016-02-01

    Since the late 1880s surgical residency programs have existed in forms that are similar to our current models. Many important variations have been introduced over time. On aggregate this system has worked remarkably well; though as economic, demographic, and cultural changes continue to evolve, one must wonder if we were to change our models how might we do that and what reasoning could we use. This article's focus is to take a stratospheric view of what could be done, particularly in the United States, rather than characterize what happens in other countries with other health economic systems. PMID:26612018

  14. Morphology of the internal organs in the adaptation of animals to high-altitude conditions

    NASA Technical Reports Server (NTRS)

    Rakhimov, Y. A.; Belkin, V. S.; Usmanov, M. U.

    1975-01-01

    Disruption of metabolic processes in the walls of the blood vessels as well as changes in the functional activity of the endocrine glands play an important role in the process of an animal's accommodation to a combination of stress factors. Preliminary training of animals for stays at high-altitude markedly reduces the severity of the morphological picture.

  15. [Sildenafil and exercise performance at altitude].

    PubMed

    Peidro, Roberto M

    2015-01-01

    Barometric pressure and partial oxygen pressure decrease with increasing altitude. Hypobaric hypoxia produced is responsible for altitude-related diseases and it can cause severe decrements in exercise performance. The physiological adaptations to the altitude are multiple and they contribute to alter different athletic qualities. The VO2 worsening could be associated to increased pulmonary vascular resistance and nitric oxide diffusion alteration. Performance impairments at altitude can also be accentuated by hypoxia-induced elevations in pulmonary arterial pressure. Clinical studies have demonstrated the beneficial effects of sildenafil on the treatment of pulmonary hypertension. These effects have led to suggest that its indication for competitions at altitude might improve athletic performance. The investigations demonstrate different results depending on the altitude level and times and intensities of exercise. Some studies show performance improvements, although not in all participants. Individual responses vary widely between different athletes. This presentation examines the effects of altitude on exercise capacity and shows studies about the use of sildenafil to improve sport performance. This text also discusses the possible side effects and implications for the use of sildenafil in athletes, indication that is not the basic one of the drug. The physicians must know in each athlete the individual sildenafil side effects that could arise and that would influence negatively on health and performance.

  16. [Sildenafil and exercise performance at altitude].

    PubMed

    Peidro, Roberto M

    2015-01-01

    Barometric pressure and partial oxygen pressure decrease with increasing altitude. Hypobaric hypoxia produced is responsible for altitude-related diseases and it can cause severe decrements in exercise performance. The physiological adaptations to the altitude are multiple and they contribute to alter different athletic qualities. The VO2 worsening could be associated to increased pulmonary vascular resistance and nitric oxide diffusion alteration. Performance impairments at altitude can also be accentuated by hypoxia-induced elevations in pulmonary arterial pressure. Clinical studies have demonstrated the beneficial effects of sildenafil on the treatment of pulmonary hypertension. These effects have led to suggest that its indication for competitions at altitude might improve athletic performance. The investigations demonstrate different results depending on the altitude level and times and intensities of exercise. Some studies show performance improvements, although not in all participants. Individual responses vary widely between different athletes. This presentation examines the effects of altitude on exercise capacity and shows studies about the use of sildenafil to improve sport performance. This text also discusses the possible side effects and implications for the use of sildenafil in athletes, indication that is not the basic one of the drug. The physicians must know in each athlete the individual sildenafil side effects that could arise and that would influence negatively on health and performance. PMID:26339884

  17. Acclimatization and tolerance to extreme altitude

    NASA Technical Reports Server (NTRS)

    West, J. B.

    1993-01-01

    During the last ten years, two major experiments have elucidated the factors determining acclimatization and tolerance to extreme altitude (over 7000 m). These were the American Medical Research Expedition to Everest, and the low pressure chamber simulation, Operation Everest II. Extreme hyperventilation is one of the most important responses to extreme altitude. Its chief value is that it allows the climber to maintain an alveolar PO2 which keeps the arterial PO2 above dangerously low levels. Even so, there is evidence of residual impairment of central nervous system function after ascents to extreme altitude, and maximal oxygen consumption falls precipitously above 7000 m. The term 'acclimatization' is probably not appropriate for altitudes above 8000 m, because the body steadily deteriorates at these altitudes. Tolerance to extreme altitude is critically dependent on barometric pressure, and even seasonal changes in pressure probably affect climbing performance near the summit of Mt Everest. Supplementary oxygen always improves exercise tolerance at extreme altitudes, and rescue oxygen should be available on climbing expeditions to 8000 m peaks.

  18. High Altitude Launch for a Practical SSTO

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Denis, Vincent

    2003-01-01

    Existing engineering materials allow the construction of towers to heights of many kilometers. Orbital launch from a high altitude has significant advantages over sea-level launch due to the reduced atmospheric pressure, resulting in lower atmospheric drag on the vehicle and allowing higher rocket engine performance. high-altitude launch sites are particularly advantageous for single-stage to orbit (SSTO) vehicles, where the payload is typically 2% of the initial launch mass. An earlier paper enumerated some of the advantages of high altitude launch of SSTO vehicles. In this paper, we calculate launch trajectories for a candidate SSTO vehicle, and calculate the advantage of launch at launch altitudes 5 to 25 kilometer altitudes above sea level. The performance increase can be directly translated in to increased payload capability to orbit, ranging from 5 to 20% increase in the mass to orbit. For a candidate vehicle with an initial payload fraction of 2% of gross lift-off weight, this corresponds to 31 % increase in payload (for 5-km launch altitude) to 122% additional payload (for 25-km launch altitude).

  19. High Altitude Launch for a Practical SSTO

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Denis, Vincent; Lyons, Valerie (Technical Monitor)

    2003-01-01

    Existing engineering materials allow the construction of towers to heights of many kilometers. Orbital launch from a high altitude has significant advantages over sea-level launch due to the reduced atmospheric pressure, resulting in lower atmospheric drag on the vehicle and allowing higher rocket engine performance. High-altitude launch sites are particularly advantageous for single-stage to orbit (SSTO) vehicles, where the payload is typically 2% of the initial launch mass. An earlier paper enumerated some of the advantages of high altitude launch of SSTO vehicles. In this paper, we calculate launch trajectories for a candidate SSTO vehicle, and calculate the advantage of launch at launch altitudes 5 to 25 kilometer altitudes above sea level. The performance increase can be directly translated into increased payload capability to orbit, ranging from 5 to 20% increase in the mass to orbit. For a candidate vehicle with an initial payload fraction of 2% of gross lift-off weight, this corresponds to 31% increase in payload (for 5-km launch altitude) to 122% additional payload (for 25-km launch altitude).

  20. High Altitude Launch for a Practical SSTO

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Denis, Vincent

    2003-01-01

    Existing engineering materials allow the construction of towers to heights of many kilometers. Orbital launch from a high altitude has significant advantages over sea-level launch due to the reduced atmospheric pressure, resulting in lower atmospheric drag on the vehicle and allowing higher rocket engine performance. High-altitude launch sites are particularly advantageous for single-stage to orbit (SSTO) vehicles, where the payload is typically 2 percent of the initial launch mass. An earlier paper enumerated some of the advantages of high altitude launch of SSTO vehicles. In this paper, we calculate launch trajectories for a candidate SSTO vehicle, and calculate the advantage of launch at launch altitudes 5 to 25 kilometer altitudes above sea level. The performance increase can be directly translated into increased payload capability to orbit, ranging from 5 to 20 percent increase in the mass to orbit. For a candidate vehicle with an initial payload fraction of 2 percent of gross lift-off weight, this corresponds to 31 percent increase in payload (for 5-kilometer launch altitude) to 122 percent additional payload (for 25-kilometer launch altitude).

  1. Comparative human ventilatory adaptation to high altitude.

    PubMed

    Moore, L G

    2000-07-01

    Studies of ventilatory response to high altitudes have occupied an important position in respiratory physiology. This review summarizes recent studies in Tibetan high-altitude residents that collectively challenge the prior consensus that lifelong high-altitude residents ventilate less than acclimatized newcomers do as the result of acquired 'blunting' of hypoxic ventilatory responsiveness. These studies indicate that Tibetans ventilate more than Andean high-altitude natives residing at the same or similar altitudes (PET[CO(2)]) in Tibetans=29.6+/-0.8 vs. Andeans=31.0+/-1.0, P<0.0002 at approximately 4200 m), a difference which approximates the change that occurs between the time of acute hypoxic exposure to once ventilatory acclimatization has been achieved. Tibetans ventilate as much as acclimatized newcomers whereas Andeans ventilate less. However, the extent to which differences in hypoxic ventilatory response (HVR) are responsible is uncertain from existing data. Tibetans have an HVR as high as those of acclimatized newcomers whereas Andeans generally do not, but HVR is not consistently greater in comparisons of Tibetan versus Andean highland residents. Human and experimental animal studies demonstrate that inter-individual and genetic factors affect acute HVR and likely modify acclimatization and hyperventilatory response to high altitude. But the mechanisms responsible for ventilatory roll-off, hyperoxic hyperventilation, and acquired blunting of HVR are poorly understood, especially as they pertain to high-altitude residents. Developmental factors affecting neonatal arterial oxygenation are likely important and may vary between populations. Functional significance has been investigated with respect to the occurrence of chronic mountain sickness and intrauterine growth restriction for which, in both cases, low HVR seems disadvantageous. Additional studies are needed to address the various components of ventilatory control in native Tibetan, Andean and other

  2. The effect of altitude on cycling performance: a challenge to traditional concepts.

    PubMed

    Hahn, A G; Gore, C J

    2001-01-01

    Acute exposure to moderate altitude is likely to enhance cycling performance on flat terrain because the benefit of reduced aerodynamic drag outweighs the decrease in maximum aerobic power [maximal oxygen uptake (VO2max)]. In contrast, when the course is mountainous, cycling performance will be reduced at moderate altitude. Living and training at altitude, or living in an hypoxic environment (approximately 2500 m) but training near sea level, are popular practices among elite cyclists seeking enhanced performance at sea level. In an attempt to confirm or refute the efficacy of these practices, we reviewed studies conducted on highly-trained athletes and, where possible, on elite cyclists. To ensure relevance of the information to the conditions likely to be encountered by cyclists, we concentrated our literature survey on studies that have used 2- to 4-week exposures to moderate altitude (1500 to 3000 m). With acclimatisation there is strong evidence of decreased production or increased clearance of lactate in the muscle, moderate evidence of enhanced muscle buffering capacity (beta m) and tenuous evidence of improved mechanical efficiency (ME) of cycling. Our analysis of the relevant literature indicates that, in contrast to the existing paradigm, adaptation to natural or simulated moderate altitude does not stimulate red cell production sufficiently to increase red cell volume (RCV) and haemoglobin mass (Hb(mass)). Hypoxia does increase serum erthyropoietin levels but the next step in the erythropoietic cascade is not clearly established; there is only weak evidence of an increase in young red blood cells (reticulocytes). Moreover, the collective evidence from studies of highly-trained athletes indicates that adaptation to hypoxia is unlikely to enhance sea level VO2max. Such enhancement would be expected if RCV and Hb(mass) were elevated. The accumulated results of 5 different research groups that have used controlled study designs indicate that continuous

  3. High-Altitude Hydration System

    NASA Technical Reports Server (NTRS)

    Parazynski, Scott E.; Orndoff, Evelyne; Bue, Grant C.; Schaefbauer, Mark E.; Urban, Kase

    2010-01-01

    Three methods are being developed for keeping water from freezing during high-altitude climbs so that mountaineers can remain hydrated. Three strategies have been developed. At the time of this reporting two needed to be tested in the field and one was conceptual. The first method is Passive Thermal Control Using Aerogels. This involves mounting the fluid reservoir of the climber s canteen to an inner layer of clothing for better heat retention. For the field test, bottles were mounted to the inner fleece layer of clothing, and then aerogel insulation was placed on the outside of the bottle, and circumferentially around the drink straw. When climbers need to drink, they can pull up the insulated straw from underneath the down suit, take a sip, and then put it back into the relative warmth of the suit. For the field test, a data logger assessed the temperatures of the water reservoir, as well as near the tip of the drink straw. The second method is Passive Thermal Control with Copper-Shielded Drink Straw and Aerogels, also mounted to inner layers of clothing for better heat retention. Braided wire emanates from the inside of the fleece jacket layer, and continues up and around the drink straw in order to use body heat to keep the system-critical drink straw warm enough to keep water in the liquid state. For the field test, a data logger will be used to compare this with the above concept. The third, and still conceptual, method is Active Thermal Control with Microcontroller. If the above methods do not work, microcontrollers and tape heaters have been identified that could keep the drink straw warm even under extremely cold conditions. Power requirements are not yet determined because the thermal environment inside the down suit relative to the external environment has not been established. A data logger will be used to track both the external and internal temperatures of the suit on a summit day.

  4. Multipath study for a low altitude satellite utilizing a data relay satellite system

    NASA Technical Reports Server (NTRS)

    Eggert, D.

    1970-01-01

    Technical considerations associated with a low altitude satellite operating in conjuction with a data relay satellite system are reported. Emphasis was placed on the quantitative characterization of multipath phenomenon and determination of power received via both the direct and earth reflection paths. Attempts were made to develop a means for estimating the magnitude and nature of the reflected power.

  5. Aeronautic Instruments. Section II : Altitude Instruments

    NASA Technical Reports Server (NTRS)

    Mears, A H; Henrickson, H B; Brombacher, W G

    1923-01-01

    This report is Section two of a series of reports on aeronautic instruments (Technical Report nos. 125 to 132, inclusive). This section discusses briefly barometric altitude determinations, and describes in detail the principal types of altimeters and barographs used in aeronautics during the recent war. This is followed by a discussion of performance requirements for such instruments and an account of the methods of testing developed by the Bureau of Standards. The report concludes with a brief account of the results of recent investigations. For accurate measurements of altitude, reference must also be made to thermometer readings of atmospheric temperature, since the altitude is not fixed by atmospheric pressure alone. This matter is discussed in connection with barometric altitude determination.

  6. 75 FR 10995 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-10

    ... ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034; February 26, 1979); and (3) does..., or direct routes for which a minimum or maximum en route authorized IFR altitude is prescribed....

  7. 76 FR 33136 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034; February 26, 1979); and (3) does... airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude...

  8. 77 FR 65256 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-26

    ... ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034; February 26, 1979); and (3) does... airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude...

  9. 78 FR 9583 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... ``significant rule'' under DOT Regulatory Policiesand Procedures (44 FR 11034; February 26, 1979); and (3) does... airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude...

  10. 76 FR 59890 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-28

    ... ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034; February 26, 1979); and (3) does... airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude...

  11. Altitude Testing of Large Liquid Propellant Engines

    NASA Technical Reports Server (NTRS)

    Maynard, Bryon; Raines, Nickey

    2008-01-01

    Altitude Testing of the J2-X engine at 100,000 feet (start capability). Chemical Steam Generation for providing vacuum. Project Started Mar 07. Test Stand Activation around Late 2010. J-2X Testing around early 2011.

  12. The Altitude Effect on Air Speed Indicators

    NASA Technical Reports Server (NTRS)

    Hersey, M D; Hunt, F L; Eaton, H N

    1921-01-01

    The object of this report is to present the results of a theoretical and experimental study of the effect, on the performance of air speed indicators, of the different atmospheric conditions experienced at various altitudes.

  13. Paul Bikle's Record Altitude Sailplane Flight

    NASA Video Gallery

    On a cold and windy February afternoon 50 years ago, the late Paul Bikle, then director of NASA's Flight Research Center, soared into the stratosphere with one goal in mind - a world altitude recor...

  14. Environmental dynamics at orbital altitudes

    NASA Technical Reports Server (NTRS)

    Karr, G. R.

    1976-01-01

    The work reported involved the improvement of aerodynamic theory for free molecular and transition flow regimes. The improved theory was applied to interpretation of the dynamic response of objects traveling through the atmosphere. Satellite drag analysis includes analysis methods, atmospheric super rotation effects, and satellite lift effects on orbital dynamics. Transition flow regimes were studied with falling sphere data and errors resulting in inferred atmospheric parameters from falling sphere techniques. Improved drag coefficients reveal considerable error in previous falling sphere data. The drag coefficient has been studied for the entire spectrum of Knudsen Number and speed ratio, with particular emphasis on the theory of the very low-speed ratio regime.

  15. Python Engine Installed in Altitude Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1949-01-01

    An engine mechanic checks instrumentation prior to an investigation of engine operating characteristics and thrust control of a large turboprop engine with counter-rotating propellers under high-altitude flight conditions in the 20-foot-dianieter test section of the Altitude Wind Tunnel at the Lewis Flight Propulsion Laboratory of the National Advisory Committee for Aeronautics, Cleveland, Ohio, now known as the John H. Glenn Research Center at Lewis Field.

  16. Industrial Training Handbook.

    ERIC Educational Resources Information Center

    Barber, John W., Ed.

    This industrial training handbook covers the following areas: preparatory considerations; training methods and techniques; training for specific functions; and established organizations. Part I examines the extension and re-designing of technical colleges since the 1920's and the present integration of the work of colleges with the needs of…

  17. Early history of high-altitude physiology.

    PubMed

    West, John B

    2016-02-01

    High-altitude physiology can be said to have begun in 1644 when Torricelli described the first mercury barometer and wrote the immortal words "We live submerged at the bottom of an ocean of the element air." Interestingly, the notion of atmospheric pressure had eluded his teacher, the great Galileo. Blaise Pascal was responsible for describing the fall in pressure with increasing altitude, and Otto von Guericke gave a dramatic demonstration of the enormous force that could be developed by atmospheric pressure. Robert Boyle learned of Guericke's experiment and, with Robert Hooke, constructed the first air pump that allowed small animals to be exposed to a low pressure. Hooke also constructed a small low-pressure chamber and exposed himself to a simulated altitude of about 2400 meters. With the advent of ballooning, humans were rapidly exposed to very low pressures, sometimes with tragic results. For example, the French balloon, Zénith, rose to over 8000 m, and two of the three aeronauts succumbed to the hypoxia. Paul Bert was the first person to clearly state that the deleterious effects of high altitude were caused by the low partial pressure of oxygen (PO2), and later research was accelerated by high-altitude stations and expeditions to high altitude. PMID:25762218

  18. Early history of high-altitude physiology.

    PubMed

    West, John B

    2016-02-01

    High-altitude physiology can be said to have begun in 1644 when Torricelli described the first mercury barometer and wrote the immortal words "We live submerged at the bottom of an ocean of the element air." Interestingly, the notion of atmospheric pressure had eluded his teacher, the great Galileo. Blaise Pascal was responsible for describing the fall in pressure with increasing altitude, and Otto von Guericke gave a dramatic demonstration of the enormous force that could be developed by atmospheric pressure. Robert Boyle learned of Guericke's experiment and, with Robert Hooke, constructed the first air pump that allowed small animals to be exposed to a low pressure. Hooke also constructed a small low-pressure chamber and exposed himself to a simulated altitude of about 2400 meters. With the advent of ballooning, humans were rapidly exposed to very low pressures, sometimes with tragic results. For example, the French balloon, Zénith, rose to over 8000 m, and two of the three aeronauts succumbed to the hypoxia. Paul Bert was the first person to clearly state that the deleterious effects of high altitude were caused by the low partial pressure of oxygen (PO2), and later research was accelerated by high-altitude stations and expeditions to high altitude.

  19. Altitude-Test-Chamber Investigation of Mcdonnell Afterburner on J34 Engine

    NASA Technical Reports Server (NTRS)

    Reller, John O.; Dowman, Harry W.

    1949-01-01

    An altitude-test-chamber investigation was conducted to determine the operational and performance characteristics of a McDonnell afterburner with a fixed-area exhaust nozzle on a J34 engine. At rated engine speed, the altitude limit, as determined by combustion blow-out, occurred as a band of unstable operation of about 6000-foot altitude in width with minimum altitude limits from 31,000 feet at a simulated flight Mach number of 0.40 to about 45,500 feet at a simulated flight Mach number of 1.00. Considerable difficulty was experienced in attempting to establish or maintain balanced-cycle engine operation at altitudes above 36,000 feet. The fuel-air ratio for balanced-cycle operation and lean blowout of the afterburner, the augmented-thrust ratio, the total specific fuel consumption, and the afterburner combustion efficiency for balanced-cycle operation are summarized in a table. Satisfactory afterburner ignition was obtained over a range of flight Mach Numbers from 0.32 to 0.60 at altitudes from 10,000 to 30,000 and engine speeds from 10,000 to 12,500 rpm.

  20. The Gravity Field of Mercury After the Messenger Low-Altitude Campaign

    NASA Technical Reports Server (NTRS)

    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.

  1. Intermittent altitude exposures improve muscular performance at 4,300 m.

    PubMed

    Beidleman, Beth A; Muza, Stephen R; Fulco, Charles S; Cymerman, Allen; Ditzler, Dan T; Stulz, Dean; Staab, Janet E; Robinson, Scott R; Skrinar, Gary S; Lewis, Steven F; Sawka, Michael N

    2003-11-01

    Chronic altitude residence improves muscular performance at altitude, but the effect of intermittent altitude exposures (IAE) on muscular performance at altitude has not been defined. The purpose of this study was to determine the effects of 3 wk of IAE, in combination with rest and cycle training, on muscular performance at altitude. Six lowlanders (23 +/- 2 yr, 77 +/- 6 kg; means +/- SE) completed a cycle time trial and adductor pollicis endurance test at sea level and during a 30-h acute exposure to 4,300 m altitude equivalent (barometric pressure = 446 mmHg) once before (pre-IAE) and once after (post-IAE) a 3-wk period of IAE (4 h/day, 5 days/wk, 4,300 m). During each IAE, three subjects cycled for 45-60 min/day at 60%-70% of maximal O2 uptake and three subjects rested. Cycle training during each IAE did not appear to affect muscular performance at altitude. Thus data from all six subjects were combined. Three weeks of IAE resulted in 1) a 21 +/- 6% improvement (P < 0.05) in cycle time-trial performance (min) from pre-IAE (32.8 +/- 3.7) to post-IAE (24.8 +/- 1.2), 2) a 63 +/- 26% improvement (P < 0.05) in adductor pollicis endurance (min) from pre-IAE (9.2 +/- 2.8) to post-IAE (14.8 +/- 4.2), and 3) a 10 +/- 4% increase (P < 0.05) in resting arterial O2 saturation (%) from pre-IAE (82 +/- 2) to post-IAE (90 +/- 1). These improvements in muscular performance after IAE correlated strongly with increases in resting arterial O2 saturation and were comparable to those reported previously after chronic altitude residence. IAE may therefore be used as an alternative to chronic altitude residence to facilitate improvements in muscular performance in athletes, soldiers, mountaineers, shift workers, and others that are deployed to altitude.

  2. Predicted optical performance of the high-altitude balloon experiment (HABE) telescope in an adverse thermal environment

    SciTech Connect

    Akau, R.L.; Givler, R.C.; Eastman, D.R.

    1994-04-01

    The High-Altitude Balloon Experiment (HABE) telescope was designed to operate at an ambient temperature of {minus}55 C and an altitude of 26 km, using a precooled primary mirror. Although at this altitude the air density is only 1.4 percent of the value at sea level, the temperature gradients within the telescope are high enough to deform the optical wavefront. This problem is considerably lessened by precooling the primary mirror to {minus}35 C. This paper describes the application of several codes to determine the range of wavefront deformation during a mission.

  3. Nitric oxide in adaptation to altitude

    PubMed Central

    Laskowski, Daniel; Erzurum, Serpil C.

    2012-01-01

    This review summarizes published information on levels of nitric oxide gas (NO) in the lungs and NO-derived liquid phase molecules in the acclimatization of visitors newly arrived at altitudes of 2500m or more and adaptation of populations whose ancestors arrived thousands of years ago. Studies of acutely exposed visitors to high altitude focus on the first 24–48 hours with just a few extending to days or weeks. Among healthy visitors, NO levels in the lung, plasma and/or red blood cells fell within three hours, but then returned toward baseline or slightly higher by 48 hours, and increased above baseline by 5 days. Among visitors ill with high-altitude pulmonary edema at the time of the study or in the past, NO levels were lower than their healthy counterparts. As for highland populations, Tibetans had NO levels in the lung, plasma and red blood cells that were at least double and in some cases orders of magnitude greater than other populations regardless of altitude. Red blood cell associated nitrogen oxides were more than two hundred times higher. Other highland populations had generally higher levels although not to the degree showed by Tibetans. Overall, responses of those acclimatized and those presumed to be adapted are in the same direction although the Tibetans have much larger responses. Missing are long-term data on lowlanders at altitude showing how similar they become to the Tibetan phenotype. Also missing are data on Tibetans at low altitude to see the extent to which their phenotype is a response to the immediate environment or expressed constitutively. The mechanisms causing the visitors’ and the Tibetans’ high levels of NO and NO-derived molecules at altitude remain unknown. Limited data suggest processes including hypoxic upregulation of NO synthase gene expression, hemoglobin-NO reactions and genetic variation. Gains in understanding will require integrating appropriate methods and measurement techniques with indicators of adaptive function

  4. The ergogenics of hypoxia training in athletes.

    PubMed

    Loffredo, Brett M; Glazer, James L

    2006-06-01

    Hypoxia elicits hematopoiesis, which ultimately improves oxygen transport to peripheral tissues. In part because of this, altitude training has been used in the conditioning of elite endurance athletes for decades, despite equivocal evidence that such training benefits subsequent sea level performance. Recently, traditional live high-train high athletic conditioning has been implicated in a number of deleterious effects on training intensity, cardiac output, muscle composition, and fluid and metabolite balance--effects that largely offset hematopoietic benefits during sea level performance. Modified live high-train low conditioning regimens appear to capture the beneficial hematopoietic effects of hypoxic training while avoiding many of the deleterious effects of training at altitude. Because of the logistical and financial barriers to living high and training low, various methods to simulate hypoxia have been developed and studied. The data from these studies suggest a threshold requirement for hypoxic exposure to meaningfully augment hematopoiesis, and presumably improve athletic performance.

  5. 14 CFR 23.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maximum operating altitude. 23.1527 Section... Information § 23.1527 Maximum operating altitude. (a) The maximum altitude up to which operation is allowed... established. (b) A maximum operating altitude limitation of not more than 25,000 feet must be established...

  6. 14 CFR 23.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maximum operating altitude. 23.1527 Section... Information § 23.1527 Maximum operating altitude. (a) The maximum altitude up to which operation is allowed... established. (b) A maximum operating altitude limitation of not more than 25,000 feet must be established...

  7. 14 CFR 23.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Maximum operating altitude. 23.1527 Section... Information § 23.1527 Maximum operating altitude. (a) The maximum altitude up to which operation is allowed... established. (b) A maximum operating altitude limitation of not more than 25,000 feet must be established...

  8. 14 CFR 23.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum operating altitude. 23.1527 Section... Information § 23.1527 Maximum operating altitude. (a) The maximum altitude up to which operation is allowed... established. (b) A maximum operating altitude limitation of not more than 25,000 feet must be established...

  9. Atmospheric Sampling of Aerosols to Stratospheric Altitudes using High Altitude Balloons

    NASA Astrophysics Data System (ADS)

    Jerde, E. A.; Thomas, E.

    2010-12-01

    Although carbon dioxide represents a long-lived atmospheric component relevant to global climate change, it is also understood that many additional contributors influence the overall climate of Earth. Among these, short-lived components are more difficult to incorporate into models due to uncertainties in the abundances of these both spatially and temporally. Possibly the most significant of these short-lived components falls under the heading of “black carbon” (BC). There are numerous overlapping definitions of BC, but it is basically carbonaceous in nature and light absorbing. Due to its potential as a climate forcer, an understanding of the BC population in the atmosphere is critical for modeling of radiative forcing. Prior measurements of atmospheric BC generally consist of airplane- and ground-based sampling, typically below 5000 m and restricted in time and space. Given that BC has a residence time on the order of days, short-term variability is easily missed. Further, since the radiative forcing is a result of BC distributed through the entire atmospheric column, aircraft sampling is by definition incomplete. We are in the process of planning a more comprehensive sampling of the atmosphere for BC using high-altitude balloons. Balloon-borne sampling is a highly reliable means to sample air through the entire troposphere and into the lower stratosphere. Our system will incorporate a balloon and a flight train of two modules. One module will house an atmospheric sampler. This sampler will be single-stage (samples all particle sizes together), and will place particles directly on an SEM sample stub for analysis. The nozzle depositing the sample will be offset from the center of the stub, placing the aerosol particles toward the edge. At various altitudes, the stub will be rotated 45 degrees, providing 6-8 sample “cuts” of particle populations through the atmospheric column. The flights will reach approximately 27 km altitude, above which the balloons

  10. Patients with Obstructive Sleep Apnea at Altitude.

    PubMed

    Bloch, Konrad E; Latshang, Tsogyal D; Ulrich, Silvia

    2015-06-01

    Bloch, Konrad E., Tsogyal D. Latshang, and Silvia Ulrich. Patients with obstructive sleep apnea at altitude. High Alt Med Biol 16:110-116, 2015.--Obstructive sleep apnea (OSA) is highly prevalent in the general population, in particular in men and women of older age. In OSA patients sleeping near sea level, the apneas/hypopneas associated with intermittent hypoxemia are predominantly due to upper airway collapse. When OSA patients stay at altitudes above 1600 m, corresponding to that of many tourist destinations, hypobaric hypoxia promotes frequent central apneas in addition to obstructive events, resulting in combined intermittent and sustained hypoxia. This induces strong sympathetic activation with elevated heart rate, cardiac arrhythmia, and systemic hypertension. There are concerns that these changes expose susceptible OSA patients, in particular those with advanced age and co-morbidities, to an excessive risk of cardiovascular and other adverse events during a stay at altitude. Based on data from randomized trials, it seems advisable for OSA patients to use continuous positive airway pressure treatment with computer controlled mask pressure adjustment (autoCPAP) in combination with acetazolamide during an altitude sojourn. If CPAP therapy is not feasible, acetazolamide alone is better than no treatment at all, as it improves oxygenation and sleep apnea and prevents excessive blood pressure rises of OSA patients at altitude.

  11. High altitude pulmonary edema in mountain climbers.

    PubMed

    Korzeniewski, Krzysztof; Nitsch-Osuch, Aneta; Guzek, Aneta; Juszczak, Dariusz

    2015-04-01

    Every year thousands of ski, trekking or climbing fans travel to the mountains where they stay at the altitude of more than 2500-3000m above sea level or climb mountain peaks, often exceeding 7000-8000m. High mountain climbers are at a serious risk from the effects of adverse environmental conditions prevailing at higher elevations. They may experience health problems resulting from hypotension, hypoxia or exposure to low temperatures; the severity of those conditions is largely dependent on elevation, time of exposure as well as the rate of ascent and descent. A disease which poses a direct threat to the lives of mountain climbers is high altitude pulmonary edema (HAPE). It is a non-cardiogenic pulmonary edema which typically occurs in rapidly climbing unacclimatized lowlanders usually within 2-4 days of ascent above 2500-3000m. It is the most common cause of death resulting from the exposure to high altitude. The risk of HAPE rises with increased altitude and faster ascent. HAPE incidence ranges from an estimated 0.01% to 15.5%. Climbers with a previous history of HAPE, who ascent rapidly above 4500m have a 60% chance of illness recurrence. The aim of this article was to present the relevant details concerning epidemiology, pathophysiology, clinical symptoms, prevention, and treatment of high altitude pulmonary edema among climbers in the mountain environment.

  12. Wind study for high altitude platform design

    NASA Technical Reports Server (NTRS)

    Strganac, T. W.

    1979-01-01

    An analysis of upper air winds was performed to define the wind environment at potential operating altitudes for high-altitude powered platform concepts. Expected wind conditions of the contiguous United States, Pacific area (Alaska to Sea of Japan), and European area (Norwegian and Mediterranean Seas) were obtained using a representative network of sites selected based upon adequate high-altitude sampling, geographic dispersion, and observed upper wind patterns. A data base of twenty plus years of rawinsonde gathered wind information was used in the analysis. Annual variations from surface to 10 mb (approximately 31 km) pressure altitude were investigated to encompass the practical operating range for the platform concepts. Parametric analysis for the United States and foreign areas was performed to provide a basis for vehicle system design tradeoffs. This analysis of wind magnitudes indicates the feasibility of annual operation at a majority of sites and more selective seasonal operation for the extreme conditions between the pressure altitudes of 100 to 25 mb based upon the assumed design speeds.

  13. Patients with Obstructive Sleep Apnea at Altitude.

    PubMed

    Bloch, Konrad E; Latshang, Tsogyal D; Ulrich, Silvia

    2015-06-01

    Bloch, Konrad E., Tsogyal D. Latshang, and Silvia Ulrich. Patients with obstructive sleep apnea at altitude. High Alt Med Biol 16:110-116, 2015.--Obstructive sleep apnea (OSA) is highly prevalent in the general population, in particular in men and women of older age. In OSA patients sleeping near sea level, the apneas/hypopneas associated with intermittent hypoxemia are predominantly due to upper airway collapse. When OSA patients stay at altitudes above 1600 m, corresponding to that of many tourist destinations, hypobaric hypoxia promotes frequent central apneas in addition to obstructive events, resulting in combined intermittent and sustained hypoxia. This induces strong sympathetic activation with elevated heart rate, cardiac arrhythmia, and systemic hypertension. There are concerns that these changes expose susceptible OSA patients, in particular those with advanced age and co-morbidities, to an excessive risk of cardiovascular and other adverse events during a stay at altitude. Based on data from randomized trials, it seems advisable for OSA patients to use continuous positive airway pressure treatment with computer controlled mask pressure adjustment (autoCPAP) in combination with acetazolamide during an altitude sojourn. If CPAP therapy is not feasible, acetazolamide alone is better than no treatment at all, as it improves oxygenation and sleep apnea and prevents excessive blood pressure rises of OSA patients at altitude. PMID:25973669

  14. Wind study for high altitude platform design

    NASA Technical Reports Server (NTRS)

    Strganac, T. W.

    1979-01-01

    An analysis of upper air winds was performed to define the wind environment at potential operating altitudes for high altitude powered platform concepts. Wind conditions of the continental United States, Pacific area (Alaska to Sea of Japan), and European area (Norwegian and Mediterranean Sea) were obtained using a representative network of sites selected based upon adequate high altitude sampling, geographic dispersion, and observed upper wind patterns. A data base of twenty plus years of rawinsonde gathered wind information was used in the analysis. Annual variations from surface to 10 mb pressure altitude were investigated to encompass the practical operating range for the platform concepts. Parametric analysis for the United States and foreign areas was performed to provide a basis for vehicle system design tradeoffs. This analysis of wind magnitudes indicates the feasibility of annual operation at a majority of sites and more selective seasonal operation for the extreme conditions between the pressure altitudes of 100 to 25 mb based upon the assumed design speeds.

  15. Can High Altitude Influence Cytokines and Sleep?

    PubMed Central

    de Aquino Lemos, Valdir; dos Santos, Ronaldo Vagner Thomatieli; Lira, Fabio Santos; Rodrigues, Bruno; Tufik, Sergio; de Mello, Marco Tulio

    2013-01-01

    The number of persons who relocate to regions of high altitude for work, pleasure, sport, or residence increases every year. It is known that the reduced supply of oxygen (O2) induced by acute or chronic increases in altitude stimulates the body to adapt to new metabolic challenges imposed by hypoxia. Sleep can suffer partial fragmentation because of the exposure to high altitudes, and these changes have been described as one of the responsible factors for the many consequences at high altitudes. We conducted a review of the literature during the period from 1987 to 2012. This work explored the relationships among inflammation, hypoxia and sleep in the period of adaptation and examined a novel mechanism that might explain the harmful effects of altitude on sleep, involving increased Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) production from several tissues and cells, such as leukocytes and cells from skeletal muscle and brain. PMID:23690660

  16. Responses of the autonomic nervous system in altitude adapted and high altitude pulmonary oedema subjects

    NASA Astrophysics Data System (ADS)

    Mathew, Lazar; Purkayastha, S. S.; Jayashankar, A.; Radhakrishnan, U.; Sen Gupta, J.; Nayar, H. S.

    1985-06-01

    Studies were carried out to ascertain the role of sympatho-parasympathetic responses in the process of adaptation to altitude. The assessment of status of autonomic balance was carried out in a group of 20 young male subjects by recording their resting heart rate, blood pressure, oral temperature, mean skin temperature, extremity temperatures, pupillary diameter, cold pressor response, oxygen consumption, cardioacceleration during orthostasis and urinary excretion of catecholamines; in a thermoneutral laboratory. The same parameters were repeated on day 3 and at weekly intervals for a period of 3 weeks, after exposing them to 3,500 m; and also after return to sea level. At altitude, similar studies were carried out in a group of 10 acclimatized lowlanders, 10 high altitude natives and 6 patients who had recently recovered from high altitude pulmonary oedema. In another phase, similar studies were done in two groups of subjects, one representing 15 subjects who had stayed at altitude (3,500 4,000 m) without any ill effects and the other comprising of 10 subjects who had either suffered from high altitude pulmonary oedema (HAPO) or acute mountain sickness (AMS). The results revealed sympathetic overactivity on acute induction to altitude which showed gradual recovery on prolonged stay, the high altitude natives had preponderance to parasympathetic system. Sympathetic preponderance may not be an essential etiological factor for the causation of maladaptation syndromes.

  17. Does heat acclimation improve exercise capacity at altitude? A cross-tolerance model.

    PubMed

    White, A C; Salgado, R M; Schneider, S; Loeppky, J A; Astorino, T A; Mermier, C M

    2014-11-01

    New approaches to inducing altitude acclimation in a relatively short timeframe are needed, as it is not practical for many soldiers and athletes to gain access to specialized training facilities. Acclimation to one environmental stressor could enhance adaptation to various other stressors in animals and humans. This phenomenon has been described as cross-tolerance and involves the activation of common protective pathways. The purpose of this review is to discuss possible mechanisms involved in the cross-tolerance between heat and hypoxia. Future data could potentially support the use of a cross-tolerance model as a means for military personnel to prepare for deployment to high-altitude environments, as well as for athletes competing at high altitude.

  18. [Intermittent hypoxic training--the state of science].

    PubMed

    Schöffel, N; Senff, T; Gerber, A; de Roux, A; Bauer, T T; Groneberg, D A

    2008-05-01

    Intermittent hypoxic training (IHT) plays an important role concerning methods of training. Considering the enormous logistic and pecuniary investments for altitude training, there is a high demand for more efficient concepts. The intermittent hypoxic training is a new, alternative form of altitude training. The idea of IHT is to economise the currently most reliable and evaluated method which is known as "live high - train low" (LHTL). Thus, IHT combines a normal training at sea level with short training sessions in a chamber that creates a hypoxic but normobaric environment. Its aim is to initiate a similar level of erythropoesis as that usually achieved through long stays in high altitude with a minimised effort. This study analyses the results of selected studies that deal with IHT, evaluating the performance improvements in general and possible haematological variances/changes specifically.

  19. Sleep of Andean high altitude natives.

    PubMed

    Coote, J H; Stone, B M; Tsang, G

    1992-01-01

    The structure of sleep in lowland visitors to altitudes greater than 4000 m is grossly disturbed. There are no data on sleep in long-term residents of high altitudes. This paper describes an electroencephalographic study of sleep in high altitude dwellers who were born in and are permanent residents of Cerro de Pasco in the Peruvian Andes, situated at 4330 m. Eight healthy male volunteers aged between 18 and 69 years were studied. Sleep was measured on three consecutive nights for each subject. Electroencephalographs, submental electromyographs and electro-oculograms were recorded. Only data from the third night were used in the analysis. The sleep patterns of these subjects resembled the normal sleep patterns described by others in lowlanders at sea level. There were significant amounts of slow wave sleep in the younger subjects and rapid eye movement sleep seemed unimpaired.

  20. Sonic Thermometer for High-Altitude Balloons

    NASA Technical Reports Server (NTRS)

    Bognar, John

    2012-01-01

    The sonic thermometer is a specialized application of well-known sonic anemometer technology. Adaptations have been made to the circuit, including the addition of supporting sensors, which enable its use in the high-altitude environment and in non-air gas mixtures. There is a need to measure gas temperatures inside and outside of superpressure balloons that are flown at high altitudes. These measurements will allow the performance of the balloon to be modeled more accurately, leading to better flight performance. Small thermistors (solid-state temperature sensors) have been used for this general purpose, and for temperature measurements on radiosondes. A disadvantage to thermistors and other physical (as distinct from sonic) temperature sensors is that they are subject to solar heating errors when they are exposed to the Sun, and this leads to issues with their use in a very high-altitude environment

  1. A neurogenic basis for acute altitude illness.

    PubMed

    Krasney, J A

    1994-02-01

    Acute altitude illnesses include acute mountain sickness (AMS), a benign condition involving headache, nausea, vomiting, irritability, insomnia, dizziness, lethargy, and peripheral edema, and potentially lethal high-altitude cerebral edema and pulmonary edema (HAPE). Recent evidence is summarized that AMS is related to cerebral edema secondary at least in part to hypoxic cerebral vasodilation and elevated cerebral capillary hydrostatic pressure. This results in reduced brain compliance with compression of intracranial structures in the absence of altered global brain metabolism. It is postulated that these primary intracranial events elevate peripheral sympathetic activity that acts neurogenically in the lung possibly in concert with pulmonary capillary stress failure to cause HAPE and in the kidney to promote salt and water retention. The adrenergic responses are likely modulated by striking increases of aldosterone, vasopressin and atrial natriuretic peptide. The effects of exercise on altitude-induced illness and various therapeutic regimens (acetazolamide, CO2 breathing, dexamethasone, and alpha adrenergic inhibitors) are discussed in light of this hypothesis.

  2. The High Altitude Student Platform Status and Future Plans

    NASA Astrophysics Data System (ADS)

    Guzik, T. Gregory; Ellison, Steven B.; Gould, Randy; Granger, Douglas; Smith, Douglas; Stewart, Michael; Wefel, John P.

    The High Altitude Student Platform (HASP) is designed to carry multiple student payloads to an altitude of about 36 kilometers with flight durations of 15 to 20 hours using a small volume, zero pressure balloon. To date HASP has had two successful flights (2006, 2007) and is anticipating a third flight this September (2008). Including the upcoming flight, HASP has supported 29 student payloads from 15 institutions across the United States involving about 110 undergraduate and graduate students. By participating in a HASP flight, students gain practical, real-world experience in the design, fabrication, system testing, operation, data analysis and management of an aerospace payload. Such experiences are very difficult to achieve in a normal classroom setting and play an important role in training new aerospace scientists and engineers. During the flights, the HASP control systems have functioned exceptionally well and the modular electronics design has enabled us to maintain flexibility, improve reliability and decrease flight-line support expenses. These capabilities, plus new advances in miniaturized balloon vehicle control systems, may enable the overall weight of HASP to be significantly reduced potentially reducing launch costs and/or improving the student payload to system mass ratio. During the presentation we will discuss the HASP program, previous flights, science results / lessons learned from the student payloads and plans for improving the efficiency of future flights.

  3. Exercise-Induced Hypoxaemia Developed at Sea-Level Influences Responses to Exercise at Moderate Altitude

    PubMed Central

    Gaston, Anne-Fleur; Durand, Fabienne; Roca, Emma; Doucende, Grégory; Hapkova, Ilona; Subirats, Enric

    2016-01-01

    Purpose The aim of this study was to investigate the impact of exercise-induced hypoxaemia (EIH) developed at sea-level on exercise responses at moderate acute altitude. Methods Twenty three subjects divided in three groups of individuals: highly trained with EIH (n = 7); highly trained without EIH (n = 8) and untrained participants (n = 8) performed two maximal incremental tests at sea-level and at 2,150 m. Haemoglobin O2 saturation (SpO2), heart rate, oxygen uptake (VO2) and several ventilatory parameters were measured continuously during the tests. Results EIH athletes had a drop in SpO2 from 99 ± 0.8% to 91 ± 1.2% from rest to maximal exercise at sea-level, while the other groups did not exhibit a similar decrease. EIH athletes had a greater decrease in VO2max at altitude compared to non-EIH and untrained groups (-22 ± 7.9%, -16 ± 5.3% and -13 ± 9.4%, respectively). At altitude, non-EIH athletes had a similar drop in SpO2 as EIH athletes (13 ± 0.8%) but greater than untrained participants (6 ± 1.0%). EIH athletes showed greater decrease in maximal heart rate than non-EIH athletes at altitude (8 ± 3.3 bpm and 5 ± 2.9 bpm, respectively). Conclusion EIH athletes demonstrated specific cardiorespiratory response to exercise at moderate altitude compared to non-EIH athletes with a higher decrease in VO2max certainly due to the lower ventilator and HRmax responses. Thus EIH phenomenon developed at sea-level negatively impact performance and cardiorespiratory responses at acute moderate altitude despite no potentiated O2 desaturation. PMID:27583364

  4. Progress on low altitude cloud icing research

    NASA Technical Reports Server (NTRS)

    Jeck, R. K.

    1981-01-01

    The icing environment at altitudes below 10,000 feet were studied. The following questions are asked, are: (1) existing aircraft certification criteria applicable; (2) too stringent on icing for helos; (3) based on accurate data; (4) appropriate for low (10,000 ft) altitudes? The research plan is outlined: review historical icing data, obtain new measurements, collect modern icing data from other groups, and recommend LWC, OAT, and MVD criteria for helicopters. Estimated accuracies and known sources of error are included. It is concluded that the net effect of possible sources of error of both signs is uncertain.

  5. [Health status of high-altitude population].

    PubMed

    Okumiya, Kiyoto

    2013-01-01

    The health status of high-altitude population in Qinghai (China), Ladakh (India), and Arunachal (India) was investigated using comprehensive geriatric functional assessment in relation to their recent lifestyle change with the socio-economic globalization. People in urban areas had a higher prevalence of lifestyle-related diseases and poorer geriatric functions, and a lower subjective quality of life (QOL) than people in rural areas. The optimal prevention of lifestyle-related diseases and preservation of a high QOL are important for the people living in each of the above-mentioned areas with a high altitude.

  6. Lead - nutritional considerations

    MedlinePlus

    Lead poisoning - nutritional considerations; Toxic metal - nutritional considerations ... utensils . Old paint poses the greatest danger for lead poisoning , especially in young children. Tap water from lead ...

  7. Variability in low altitude astronomical refraction as a function of altitude.

    PubMed

    Sampson, Russell D; Lozowski, Edward P; Fathi-Nejad, Arsha

    2008-12-01

    Low altitude astronomical refraction (LAAR) of the setting Sun was measured over a sea horizon from a coastal location in Barbados, West Indies. The altitude of the upper limb of the Sun and the apparent horizon were determined using a digital video camera (Canon XL2) and a digital SLR camera (Canon EOS 5D). A total of 14 sunsets were measured between 2005 and 2007. From these measurements LAAR variability was estimated at 14 standard altitudes of the refracted Sun between 0 degrees .01 and 4 degrees .5. The relative variability decreases with increasing altitude from +/- 0.0195 of mean refraction at an altitude of 0 degrees .01 to +/- 0.0142 at 4 degrees .5. If extrapolated to an altitude of 15 degrees , a linear fit to the data produces a relative variability of +/- 0.0038 and an absolute variability of +/- 0(").45. Statistical analysis of the relative variability in LAAR appears to support the decreasing trend. However, error propagation analysis further suggests that the observed values of refraction may exceed the accuracy of the measurement system at altitudes higher than 2 degrees .

  8. Lunar Landing Training vehicle piloted by Neil Armstrong during training

    NASA Technical Reports Server (NTRS)

    1969-01-01

    A Lunar Landing Training Vehicle, piloted by Astronaut Neil Armstrong, goes through a checkout flight at Ellington Air Force Base on June 16, 1969. The total duration of the lunar simulation flight was five minutes and 59 seconds. Maximum altitude attained was about 300 feet.

  9. Study on the radiation property of high temperature gas relation with flight altitude and velocity

    NASA Astrophysics Data System (ADS)

    Meng, Weihua; Xu, Hang; Xiang, Jingbo; Song, Jiangtao

    2013-08-01

    While flying in the aerosphere at high speed, it will form shock wave around the noddle of flight vehicle. The radiation of hot air behind shock wave is a major factor responsible for the infrared signature of the vehicle, and has an important influence on the infrared detection system mounted in it. Calculating the infrared radiation of high temperature gas is significant for selecting an optimal detection band and improving detection capability of the IR system. In this paper, focused on the high-speed flight in typical altitude, the line-by-line method was adopted to calculate the radiation properties of high temperature gas around the noddle of the vehicle to study the relationship with the flight altitude and velocity. At first, based on the flight altitude, the related parameters of the flow, such as pressure, temperature and density, were calculated using the standard atmosphere model. Then, the parameters of the air which had passed through the shock wave were calculated according to the shock wave theory. At last, the line-by-line method had been used to calculate the radiant absorption coefficient of high temperature gas in different velocity and flight altitude. The results of calculation show that in the same velocity, the average absorption coefficient of high temperature gas is smaller while the higher flight altitude; in the same flight altitude, the coefficient is bigger while the higher velocity. And so, while flying in low altitude with high speed, the radiation of the hot air should be taken into consideration more carefully for infrared system design.

  10. Body and organ weights of rats exposed to carbon monoxide at high altitude.

    PubMed

    McGrath, J J

    1988-01-01

    Although chronic exposure to carbon monoxide (CO) or high altitude produces pronounced cardiovascular changes in humans as well as animals, there is little information on the effects elicited by these stressors combined. Theoretical considerations, as well as data from acute studies, suggest that CO inhaled at high altitude may be more detrimental than CO inhaled at low altitude. The purpose of these studies was to construct a system in which CO and altitude could be controlled precisely, and to investigate the effects of continuous exposure to CO and high altitude on body weights and hematocrit ratios, as well as heart, spleen, adrenals, kidneys, and pituitary weights. Male, laboratory rats were exposed for 6 wk in steel barometric chambers to (1) 100 ppm CO, (2) 15,000 ft simulated high altitude (SHA), and (3) CO at SHA. Altitude was simulated by a system of gate valves and a vacuum pump, and measured by an altimeter. CO, from high-pressure cylinders, was introduced into the air supplying each chamber through a mass flow controller and measured by a nondispersive infrared (NDIR) analyzer. Although SHA had no affect on left ventricle plus septum (LV + S), adrenal, spleen, or kidney weights, SHA decreased body weights, and increased hematocrit ratios, as well as right ventricle (RV), total heart (HT), and pituitary weights. CO had no affect on body weights, RV, HT, adrenal, spleen, or kidney weights, but CO increased hematocrit ratios and LV + S weights. There was no significant interaction between SHA and CO on any parameter except kidney weight. These results indicate that, in general, the effects produced by 15,000 ft SHA are not intensified by exposure to 100 ppm CO. PMID:3351978

  11. Butterflies of the high-altitude Atacama Desert: habitat use and conservation

    PubMed Central

    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. PMID:25309583

  12. Butterflies of the high-altitude Atacama Desert: habitat use and conservation.

    PubMed

    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.

  13. Cloud Altitude Determination of Overshooting Tops in Severe Thunderstorms

    NASA Astrophysics Data System (ADS)

    Goldberg, R.; Magee, N. B.

    2011-12-01

    The maximum heights of deep convective clouds and overshooting tops have been analyzed and compared using a combination of space and ground-based measurement systems. Deeply convective cumulonimbus clouds are capable of reaching and penetrating the tropopause. The portions of convective clouds that extend into the stratosphere are known as overshooting tops. Instances of tornado onset have been observed to match or slightly lag the timing of maximum cloud-top altitudes. In addition, precise forecasting and measurement of convective cloud-top heights are of critical importance to the safety and efficiency of commercial aviation flight routings. This study included the use of data from three NASA A-Train satellites, 88-D and TDWR Doppler radar, NAM modeling output, and direct visual sightings. The three polar-orbiting satellites included Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), CloudSat, and Aqua. CALIPSO and CloudSat return a vertical profile of microphysical parameters as their near-nadir beams intersect clouds. CALIPSO uses a lidar instrument (CALIOP), operating at 532 and 1064 nm, that is capable of detecting aerosol and small cloud particles. CloudSat uses a radar system called Cloud Profiling Radar (CPR), operating at 94 GHz (3.2 mm), that can penetrate thicker clouds, including those with precipitation. The Moderate Resolution Imaging Spectroradiometer (MODIS) on board Aqua provided a 250m resolution map view that permitted identification of the unique texture of overshooting tops. Satellite data and ground-based Doppler radar were co-located and used to compare cloud-top and echo-top measurements and products. In addition to co-located observational data, North American Mesoscale (NAM) model output with maximum 6-hour lead time was analyzed for convective cloud top forecasts. Finally, direct sightings of cloud tops were made at the time of CALIPSO overpasses of New Jersey. Using a surveyor's transit, the angle from the

  14. Safely Enabling Low-Altitude Airspace Operations

    NASA Technical Reports Server (NTRS)

    Kopardekar, Parimal

    2015-01-01

    Near-term Goal - Enable initial low-altitude airspace and UAS operations with demonstrated safety as early as possible, within 5 years. Long-term Goal - Accommodate increased UAS operations with highest safety, efficiency, and capacity as much autonomously as possible (10-15 years).

  15. Altitude Adaptation: A Glimpse Through Various Lenses

    PubMed Central

    2015-01-01

    Abstract Simonson, Tatum S. Altitude adaptation: A glimpse through various lenses. High Alt Med Biol 16:125–137, 2015.—Recent availability of genome-wide data from highland populations has enabled the identification of adaptive genomic signals. Some of the genomic signals reported thus far among Tibetan, Andean, and Ethiopian are the same, while others appear unique to each population. These genomic findings parallel observations conveyed by decades of physiological research: different continental populations, resident at high altitude for hundreds of generations, exhibit a distinct composite of traits at altitude. The most commonly reported signatures of selection emanate from genomic segments containing hypoxia-inducible factor (HIF) pathway genes. Corroborative evidence for adaptive significance stems from associations between putatively adaptive gene copies and sea-level ranges of hemoglobin concentration in Tibetan and Amhara Ethiopians, birth weights and metabolic factors in Andeans and Tibetans, maternal uterine artery diameter in Andeans, and protection from chronic mountain sickness in Andean males at altitude. While limited reports provide mechanistic insights thus far, efforts to identify and link precise genetic variants to molecular, physiological, and developmental functions are underway, and progress on the genomics front continues to provide unprecedented movement towards these goals. This combination of multiple perspectives is necessary to maximize our understanding of orchestrated biological and evolutionary processes in native highland populations, which will advance our understanding of both adaptive and non-adaptive responses to hypoxia. PMID:26070057

  16. Sickle Cell Trait, Exercise, and Altitude.

    ERIC Educational Resources Information Center

    Eichner, Edward R.

    1986-01-01

    Sickle cell trait is generally benign and does not shorten life, but it may confer some small risk with extremes of exercise or altitude. Research concerning these risks is presented, and it is concluded sickle cell trait is no barrier to outstanding athletic performance. (Author/MT)

  17. Altitude Adaptation: A Glimpse Through Various Lenses.

    PubMed

    Simonson, Tatum S

    2015-06-01

    Simonson, Tatum S. Altitude adaptation: A glimpse through various lenses. High Alt Med Biol 16:125-137, 2015.--Recent availability of genome-wide data from highland populations has enabled the identification of adaptive genomic signals. Some of the genomic signals reported thus far among Tibetan, Andean, and Ethiopian are the same, while others appear unique to each population. These genomic findings parallel observations conveyed by decades of physiological research: different continental populations, resident at high altitude for hundreds of generations, exhibit a distinct composite of traits at altitude. The most commonly reported signatures of selection emanate from genomic segments containing hypoxia-inducible factor (HIF) pathway genes. Corroborative evidence for adaptive significance stems from associations between putatively adaptive gene copies and sea-level ranges of hemoglobin concentration in Tibetan and Amhara Ethiopians, birth weights and metabolic factors in Andeans and Tibetans, maternal uterine artery diameter in Andeans, and protection from chronic mountain sickness in Andean males at altitude. While limited reports provide mechanistic insights thus far, efforts to identify and link precise genetic variants to molecular, physiological, and developmental functions are underway, and progress on the genomics front continues to provide unprecedented movement towards these goals. This combination of multiple perspectives is necessary to maximize our understanding of orchestrated biological and evolutionary processes in native highland populations, which will advance our understanding of both adaptive and non-adaptive responses to hypoxia.

  18. Sextant measures spacecraft altitude without gravitational reference

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Horizon-sensing sextant measures the altitude of an orbiting spacecraft without gravitational reference by optically measuring the dip angle to the horizon along a line of sight in each of two planes. The sextant scans over a relatively limited field of view.

  19. Insulin secretion at high altitude in man

    NASA Astrophysics Data System (ADS)

    Sawhney, R. C.; Malhotra, A. S.; Singh, T.; Rai, R. M.; Sinha, K. C.

    1986-09-01

    The effect of hypoxia on circulatory levels of insulin, its response to oral glucose administration (100 g) and changes in circadian rhythms of glucose as well as insulin were evaluated in euglycemic males at sea level (SL, 220 m) during their stay at high altitude (3500 m, SJ) and in high altitude natives (HAN). Basal glucose levels were not altered at high altitude but the rise in glucose (δ glucose) after glucose load was significantly higher in SJ and HAN (p<0.01) as compared to SL values. An increase (p<0.01) both in basal as well as glucose induced rise in insulin secretion (δ insulin) was observed at HA. The rise in insulin in SJ was significantly higher (p<0.01) than in HAN. This elevation in glucose and insulin levels was also evident at different times of the day. The circadian rhythmicity of glucose as well as insulin was altered by the altitude stress. The findings of the study show a rise in insulin level at HA but the hyperglycemia in the face of hyper-insulinism require the presumption of a simultaneous and dispropotionate rise of insulin antagonistic hormones upsetting the effect of insulin on glucose metabolism.

  20. High Altitude Plasma Instrument (HAPI) data analysis

    NASA Technical Reports Server (NTRS)

    Burch, J. L.

    1994-01-01

    The objectives of the Dynamics Explorer mission are to investigate the coupling of energy, mass, and momentum among the earth's magnetosphere, ionosphere, and upper atmosphere. At launch, on August 3, 1981, DE-1 was placed into an elliptical polar orbit having an apogee of 23,130 km to allow global auroral imaging and crossings of auroral field lines at altitudes of several thousand kilometers. At the same time DE-2 was placed into a polar orbit, coplanar with that of DE-1 but with a perigee altitude low enough (309 km) for neutral measurements and an apogee altitude of 1012 km. The DE-1 High Altitude Plasma Instrument (HAPI) provided data on low and medium energy electrons and ions from August 13, 1981 until December 1, 1981, when a high-voltage failure occured. Analysis of HAPI data for the time period of this contract has produced new results on the source mechanisms for electron conical distributions, particle acceleration phenomena in auroral acceleration regions, Birkeland currents throughout the nightside auroral regions, the source region for auroral kilometric radiation (AKR), and plasma injection phenomena in the polar cusp.

  1. Subsonic Airplane For High-Altitude Research

    NASA Technical Reports Server (NTRS)

    Chambers, Alan; Reed, R. Dale

    1993-01-01

    Report discusses engineering issues considered in design of conceptual subsonic airplane intended to cruise at altitudes of 100,000 ft or higher. Airplane would carry scientific instruments for research in chemistry and physics of atmosphere, particularly, for studies of ozone hole, greenhouse gases, and climatic effects.

  2. Safely Enabling Low-Altitude Airspace Operations

    NASA Technical Reports Server (NTRS)

    Kopardekar, Parimal

    2015-01-01

    Near-term Goal: Enable initial low-altitude airspace and UAS operations with demonstrated safety as early as possible, within 5 years. Long-term Goal: Accommodate increased UAS operations with highest safety, efficiency, and capacity as much autonomously as possible (10-15 years).

  3. High Altitude Synthetic Aperture Imaging of Titan

    NASA Astrophysics Data System (ADS)

    West, Richard; Stiles, B.; Anderson, Y.; Boehmer, R.; Callahan, P.; Gim, Y.; Hamilton, G.; Johnson, W. T.; Kelleher, K.; Wye, L.; Zebker, H.

    2006-09-01

    The Cassini spacecraft has been conducting observations of Titan since July 2004 . Currently, 6 close flyby's have collected synthetic aperture radar (SAR) data giving image resolutions down to 300 - 500 m. About 14 additional close radar imaging passes are planned. To improve radar coverage and increase the synergy with other Cassini imaging instruments such as VIMS and ISS, the radar team has started experimenting with very high altitude SAR imaging where conditions permit. This presentation will examine the performance trade-offs, special processing issues, and science potential of these high altitude SAR observations. These data collections are distinct from the normal Titan SAR images because the range will be much larger (around 20,000 km). To acquire enough signal in these circumstances, the radar operates in the lowest bandwidth scatterometer mode while spacecraft pointing control is used to slowly pan the central beam across a small swath. Due to a lower signal to noise ratio these high altitude images are designed to average together 150-200 independent looks to see features that may lie below the noise floor. So far, three high altitude images have been acquired during Titan flyby's T12, T13, and T15. In T12 imaging was attempted from 37000 km with an effective resolution around 5 km. In T13 the Huygens Probe landing site was imaged from 11000 km with effective resolution of 1 - 2 km. In T15 the Tsegehi area was imaged from 20000 km with effective resolution of 2 - 3 km.

  4. The Power of Aircraft Engines at Altitude

    NASA Technical Reports Server (NTRS)

    Ragazzi, Paolo

    1939-01-01

    The subject of the present paper is confined to the investigations and methods employed by the Fiat company in their studies on the altitude performance of an air-cooled engine of the production type. The experimental set-up as well as test engine data are provided.

  5. The morbid anatomy of high altitude

    PubMed Central

    Heath, Donald

    1979-01-01

    The morbid anatomical changes which take place in man and animals exposed to the chronic hypoxia of residence at high altitude are briefly reviewed. ImagesFig. 1Fig. 2Fig. 3Fig. 5Fig. 4Fig. 6Fig. 7Fig. 8 PMID:493205

  6. A low-altitude satellite interaction study

    NASA Technical Reports Server (NTRS)

    Bienkowski, G. K.; Holman, J. M. L.; Mc Kinley, R. R.; Siskind, S. M.

    1971-01-01

    Two computer programs calculate interaction effects of high speed spacecraft on the environment at altitudes from 90 km to 150 km. EXT program determines fluid field in bodies of arbitrary geometries in transient flow regime. INT program uses EXT output and measures flow conditions inside spacecraft body.

  7. High-altitude solar power platform

    SciTech Connect

    Bailey, M.D.; Bower, M.V.

    1992-04-01

    Solar power is a preeminent alternative to conventional aircraft propulsion. With the continued advances in solar cells, fuel cells, and composite materials technology, the solar powered airplane is no longer a simple curiosity constrained to flights of several feet in altitude or minutes of duration. A high altitude solar powered platform (HASPP) has several potential missions, including communications and agriculture. In remote areas, a HASPP could be used as a communication link. In large farming areas, a HASPP could perform remote sensing of crops. The impact of HASPP in continuous flight for one year on agricultural monitoring mission is presented. This mission provides farmers with near real-time data twice daily from an altitude which allows excellant resolution on water conditions, crop diseases, and insect infestation. Accurate, timely data will enable farmers to increase their yield and efficiency. A design for HASPP for the foregoing mission is presented. In the design power derived from solar cells covering the wings is used for propulsion, avionics, and sensors. Excess power produced midday will be stored in fuel cells for use at night to maintain altitude and course.

  8. Measurement of aircraft speed and altitude

    NASA Technical Reports Server (NTRS)

    Gracey, W.

    1980-01-01

    Problems involved in measuring speed and altitude with pressure-actuated instruments (altimeter, airspeed indicator, true-airspeed indicator, Machmeter, and vertical-speed indicator) are examined. Equations relating total pressure and static pressure to the five flight quantities are presented, and criteria for the design of total and static pressure tubes are given. Calibrations of typical static pressure installations (fuselage nose, wing tip, vertical fin, and fuselage vent) are presented, various methods for flight calibration of these installations are described, and the calibration of a particular installation by two of the methods is described in detail. Equations are given for estimating the effects of pressure lag and leaks. Test procedures for the laboratory calibration of the five instruments are described, and accuracies of mechanical and electrical instruments are presented. Operational use of the altimeter for terrain clearance and vertical separation of aircraft is discussed, along with flight technical errors and overall altitude errors of aircraft in cruise operations. Altitude-measuring techniques based on a variety of properties of the Earth and the atmosphere are included. Two appendixes present airspeed and altitude tables and sample calculations for determining the various flight parameters from measured total and static pressures.

  9. High-altitude physiology: lessons from Tibet

    NASA Astrophysics Data System (ADS)

    Wagner, Peter D.; Simonson, Tatum S.; Wei, Guan; Wagner, Harrieth; Wuren, Tanna; Yan, Ma; Qin, Ga; Ge, Rili

    2013-05-01

    Polycythemia is a universal lowlander response to altitude; healthy Andean high-altitude natives also have elevated [Hb]. While this may enhance O2 transport to tissues, studies have shown that acute isovolumic changes in [Hb] do not affect exercise capacity. Many high-altitude Tibetans have evolved sea-level values of [Hb], providing a natural opportunity to study this issue. In 21 young healthy male Tibetans with [Hb] between 15 and 23 g/dl, we measured VO2MAX and O2 transport capacity at 4200m. VO2MAX was higher when [Hb] was lower (P<0.05), enabled by both higher cardiac output and muscle O2 diffusional conductance, but neither ventilation nor the alveolar-arterial PO2 difference (AaPO2) varied with [Hb]. In contrast, Andean high altitude natives remain polycythemic with larger lungs and higher lung diffusing capacity, a smaller exercising AaPO2, and lower ventilation. The challenges now are (1) to understand the different adaptive pathways used by Andeans and Tibetans, and (2) to determine in Tibetans whether, during evolution, reduced [Hb] appeared first, causing compensatory cardiac and muscle adaptations, or if enhanced cardiac function and muscle O2 transport capacity appeared first, permitting secondary reduction in [Hb]. For (2), further research is necessary to determine the basis of enhanced cardiac function and muscle O2 transport, and identify molecular targets of evolution in heart and muscle. Putative mutations can then be timed and compared to appearance of those affecting [Hb].

  10. 77 FR 3091 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-23

    ... 3091-3098] [FR Doc No: 2012-1046] DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR... airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude is... changeover points (COPs) for Federal airways, jet routes, or direct routes as prescribed in part 95. The...

  11. 76 FR 72094 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-22

    ... airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude is... changeover points (COPs) for Federal airways, jet routes, or direct routes as prescribed in part 95. The Rule... routes, ] ensure navigation aid coverage that is adequate for safe flight operations and free...

  12. 75 FR 24790 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-06

    ... Airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude is... changeover points (COPs) for Federal Airways, jet routes, or direct routes as prescribed in part 95. The Rule... routes, ensure navigation aid coverage that is adequate for safe flight operations and free of...

  13. 76 FR 11675 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-03

    ... airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude is... changeover points (COPs) for Federal airways, jet routes, or direct routes as prescribed in part 95. The Rule... routes, ensure navigation aid coverage that is ] adequate for safe flight operations and free...

  14. 77 FR 50909 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-23

    ... airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude is... changeover points (COPs) for Federal airways, jet routes, or direct routes as prescribed in part 95. The Rule... routes, ensure navigation aid coverage that is adequate for safe flight operations and free of...

  15. 78 FR 20783 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ... airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude is... points (COPs) for Federal airways, jet routes, or direct routes as prescribed in part 95. The Rule The..., ensure navigation aid coverage that is adequate for safe flight operations and free of...

  16. 78 FR 68699 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-15

    ... airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude is... changeover points (COPs) for Federal airways, jet routes, or direct routes as prescribed in part 95. The Rule... routes, ensure navigation aid coverage that is adequate for safe flight operations and free of...

  17. 77 FR 38477 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-28

    ... airways, jet routes, or direct routes for which a minimum or maximum en route authorized IFR altitude is... changeover points (COPs) for Federal airways, jet routes, or direct routes as prescribed in part 95. The Rule... routes, ensure navigation aid coverage that is adequate for safe flight operations and free of...

  18. Estimation of high altitude Martian dust parameters

    NASA Astrophysics Data System (ADS)

    Pabari, Jayesh; Bhalodi, Pinali

    2016-07-01

    Dust devils are known to occur near the Martian surface mostly during the mid of Southern hemisphere summer and they play vital role in deciding background dust opacity in the atmosphere. The second source of high altitude Martian dust could be due to the secondary ejecta caused by impacts on Martian Moons, Phobos and Deimos. Also, the surfaces of the Moons are charged positively due to ultraviolet rays from the Sun and negatively due to space plasma currents. Such surface charging may cause fine grains to be levitated, which can easily escape the Moons. It is expected that the escaping dust form dust rings within the orbits of the Moons and therefore also around the Mars. One more possible source of high altitude Martian dust is interplanetary in nature. Due to continuous supply of the dust from various sources and also due to a kind of feedback mechanism existing between the ring or tori and the sources, the dust rings or tori can sustain over a period of time. Recently, very high altitude dust at about 1000 km has been found by MAVEN mission and it is expected that the dust may be concentrated at about 150 to 500 km. However, it is mystery how dust has reached to such high altitudes. Estimation of dust parameters before-hand is necessary to design an instrument for the detection of high altitude Martian dust from a future orbiter. In this work, we have studied the dust supply rate responsible primarily for the formation of dust ring or tori, the life time of dust particles around the Mars, the dust number density as well as the effect of solar radiation pressure and Martian oblateness on dust dynamics. The results presented in this paper may be useful to space scientists for understanding the scenario and designing an orbiter based instrument to measure the dust surrounding the Mars for solving the mystery. The further work is underway.

  19. Is High Altitude Pulmonary Edema Relevant to Hawai‘i?

    PubMed Central

    2014-01-01

    High altitude clinical syndromes have been described in the medical literature but may be under recognized in the state of Hawai‘i. As tourism increases, high altitude injuries may follow given the easy access to high altitude attractions. Visitors and clinicians should be aware of the dangers associated with the rapid ascent to high altitudes in the perceived comfort of a vehicle. This paper will review the basic pathophysiology, prevention, and treatment of the most serious of the high altitude clinical syndromes, high altitude pulmonary edema. PMID:25478294

  20. Altitude Exposure at 1800 m Increases Haemoglobin Mass in Distance Runners

    PubMed Central

    Garvican-Lewis, Laura A.; Halliday, Iona; Abbiss, Chris R.; Saunders, Philo U.; Gore, Christopher J.

    2015-01-01

    The influence of low natural altitudes (< 2000 m) on erythropoietic adaptation is currently unclear, with current recommendations indicating that such low altitudes may be insufficient to stimulate significant increases in haemoglobin mass (Hbmass). As such, the purpose of this study was to determine the influence of 3 weeks of live high, train high exposure (LHTH) at low natural altitude (i.e. 1800 m) on Hbmass, red blood cell count and iron profile. A total of 16 elite or well-trained runners were assigned into either a LHTH (n = 8) or CONTROL (n = 8) group. Venous blood samples were drawn prior to, at 2 weeks and at 3 weeks following exposure. Hbmass was measured in duplicate prior to exposure and at 2 weeks and at 3 weeks following exposure via carbon monoxide rebreathing. The percentage change in Hbmass from baseline was significantly greater in LHTH, when compared with the CONTROL group at 2 (3.1% vs 0.4%; p = 0.01;) and 3 weeks (3.0% vs -1.1%; p < 0.02, respectively) following exposure. Haematocrit was greater in LHTH than CONTROL at 2 (p = 0.01) and 3 weeks (p = 0.04) following exposure. No significant interaction effect was observed for haemoglobin concentration (p = 0.06), serum ferritin (p = 0.43), transferrin (p = 0.52) or reticulocyte percentage (p = 0.16). The results of this study indicate that three week of natural classic (i.e. LHTH) low altitude exposure (1800 m) results in a significant increase in Hbmass of elite distance runners, which is likely due to the continuous exposure to hypoxia. Key points Two and three weeks of LHTH altitude exposure (1800 m) results in a significant increase in Hbmass LHTH altitude exposure increased Hbmass by 3.1% after 2 weeks, and 3.0% after 3 weeks of exposure LHTH altitude exposure may be a practical method to increase Hbmass in well-trained athletes. PMID:25983592

  1. Effect of moderate altitude on peripheral muscle oxygenation during leg resistance exercise in young males.

    PubMed

    Oguri, Kazuo; Du, Na; Kato, Yoshihiro; Miyamoto, Kei; Masuda, Takahiro; Shimizu, Katsuji; Matsuoka, Toshio

    2004-09-01

    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. Key PointsThe change in muscle oxygenation during the parallel squat at 1800 altitude and near sea level was investigated using near infrared

  2. EXTERIOR VIEW OF AIRLOCK FOR ALTITUDE CHAMBER R, FACING SOUTHEAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR VIEW OF AIRLOCK FOR ALTITUDE CHAMBER R, FACING SOUTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  3. DETAIL OF DOMED BOTTOM, ALTITUDE CHAMBER R, FACING EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF DOMED BOTTOM, ALTITUDE CHAMBER R, FACING EAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  4. VIEW OF PUMP ROOM FOR ALTITUDE CHAMBERS, FACING SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF PUMP ROOM FOR ALTITUDE CHAMBERS, FACING SOUTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  5. INTERIOR OF AIRLOCK FROM INTERIOR OF ALTITUDE CHAMBER R, FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR OF AIRLOCK FROM INTERIOR OF ALTITUDE CHAMBER R, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  6. DETAIL OF THE INTERIOR OF THE DOMED LID, ALTITUDE CHAMBER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF THE INTERIOR OF THE DOMED LID, ALTITUDE CHAMBER R, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  7. DETAIL OF PLATFORM SUPPORT BRACKET, ALTITUDE CHAMBER L, FACING NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF PLATFORM SUPPORT BRACKET, ALTITUDE CHAMBER L, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  8. DETAIL OF WALLMOUNTED STAIRS ON INTERIOR OF ALTITUDE CHAMBER L, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF WALL-MOUNTED STAIRS ON INTERIOR OF ALTITUDE CHAMBER L, FACING SOUTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  9. EXTERIOR OF ALTITUDE CHAMBERS R (TO LEFT) AND L (TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR OF ALTITUDE CHAMBERS R (TO LEFT) AND L (TO RIGHT), FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  10. EXTERIOR OF ALTITUDE CHAMBERS R (TO LEFT) AND L (TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR OF ALTITUDE CHAMBERS R (TO LEFT) AND L (TO RIGHT), FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  11. EXTERIOR AND INTERIOR VIEW OF AIRLOCK FOR ALTITUDE CHAMBER R, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR AND INTERIOR VIEW OF AIRLOCK FOR ALTITUDE CHAMBER R, FACING SOUTH - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  12. BOTTOM LEVEL OF ALTITUDE CHAMBER L, FACING SOUTHWEST Cape ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BOTTOM LEVEL OF ALTITUDE CHAMBER L, FACING SOUTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  13. UPPER HALF OF THE INTERIOR OF ALTITUDE CHAMBER R, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    UPPER HALF OF THE INTERIOR OF ALTITUDE CHAMBER R, LOOKING UP FROM BOTTOM LEVEL, FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  14. INTERIOR OF ALTITUDE CHAMBER R, LOOKING DOWN FROM AIRLOCK, FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR OF ALTITUDE CHAMBER R, LOOKING DOWN FROM AIRLOCK, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  15. VIEW OF THE CONTROL ROOM FOR THE ALTITUDE CHAMBERS, FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF THE CONTROL ROOM FOR THE ALTITUDE CHAMBERS, FACING SOUTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  16. DETAIL OF THE EXTERIOR OF THE DOMED LID, ALTITUDE CHAMBER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF THE EXTERIOR OF THE DOMED LID, ALTITUDE CHAMBER R, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  17. DETAIL OF REPRESSURIZATION AIR PIPE, ALTITUDE CHAMBER L, FACING SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF RE-PRESSURIZATION AIR PIPE, ALTITUDE CHAMBER L, FACING SOUTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  18. INTERIOR OF ALTITUDE CHAMBER L FROM TOP LEVEL OF ACCESS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR OF ALTITUDE CHAMBER L FROM TOP LEVEL OF ACCESS PLATFORMS, FACING WEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  19. DETAIL OF DOMED BOTTOM, ALTITUDE CHAMBER L, FACING NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF DOMED BOTTOM, ALTITUDE CHAMBER L, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  20. LOWER HALF OF THE INTERIOR OF ALTITUDE CHAMBER R, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOWER HALF OF THE INTERIOR OF ALTITUDE CHAMBER R, LOOKING UP FROM BOTTOM LEVEL, FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  1. INTERIOR OF ALTITUDE CHAMBER L, LOOKING UP FROM BOTTOM LEVEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR OF ALTITUDE CHAMBER L, LOOKING UP FROM BOTTOM LEVEL OF INTERNAL PLATFORMS, FACING EAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  2. DETAIL OF VACUUM PIPE OPENING WITHIN ALTITUDE CHAMBER R, FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF VACUUM PIPE OPENING WITHIN ALTITUDE CHAMBER R, FACING SOUTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  3. Make Room for Training.

    ERIC Educational Resources Information Center

    Filipczak, Bob

    1991-01-01

    Discusses audiovisual technology and its place in today's state-of-the-art training classroom. Looks at costs, design considerations, and who really uses the technology. Describes Dow Chemical Company's state-of-the-art training center in Midland, Michigan. (JOW)

  4. Maximum terminal velocity turns at constant altitude

    NASA Astrophysics Data System (ADS)

    Eisler, G. Richard; Hull, David G.

    An optimal control problem is formulated for a maneuvering reentry vehicle to execute a maximum terminal velocity turn at constant altitude to a fixed final position. A control solution technique is devised which uses a Newton scheme to repetitively solve a nonlinear algebraic system for two parameters to provide the on-line guidance. The turn control takes advantage of the high dynamic pressure at the beginning of the flight path; the lift solution acts to null deviations from the prescribed altitude. Control solutions are compared for a continuously updated, approximate physical model, for a simulation of the approximate optimal guidance in a true physical model, and for a parameter optimization solution for the true model. End constraint satisfaction is excellent. Overall trajectory agreement is good, if the assumed atmospheric model is reasonably accurate.

  5. Maximum terminal velocity turns at constant altitude

    SciTech Connect

    Eisler, G.R.; Hull, D.G.

    1987-01-01

    An optimal control problem is formulated for a maneuvering reentry vehicle to execute a maximum terminal velocity turn at constant altitude to a fixed final position. A control solution technique is devised which uses a Newton scheme to repetitively solve a nonlinear algebraic system for two parameters to provide the on-line guidance. The turn control takes advantage of the high dynamic pressure at the beginning of the flight path; the lift solution acts to null deviations from the prescribed altitude. Control solutions are compared for a continuously updated, approximate physical model, for a simulation of the approximate optimal guidance in a true physical model, and for a parameter optimization solution for the true model. End constraint satisfaction is excellent. Overall trajectory agreement is good, if the assumed atmospheric model is reasonably accurate.

  6. Solar radiation monitoring for high altitude aircraft

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1981-01-01

    Ground-based and satellite-based ionizing radiation monitoring systems are considered as alternative methods for ensuring safe radiation levels for high-altitude aircraft. It is found that ground-based methods are of limited accuracy due to insensitivity to solar particles of energies between the riometer upper cutoff of about 50 MeV and the neutron monitor threshold of about 450 MeV. This energy range is demonstrated to be essential for atmospheric radiation monitoring at high altitude, and must be covered by satellite measurement. On the basis of presently available data, the accuracy to which the incident solar particle flux must be measured by satellite-borne detectors is examined and recommendations are made to establish minimum requirements.

  7. Solar radiation monitoring for high altitude aircraft

    NASA Astrophysics Data System (ADS)

    Wilson, J. W.

    1981-10-01

    Ground-based and satellite-based ionizing radiation monitoring systems are considered as alternative methods for ensuring safe radiation levels for high-altitude aircraft. It is found that ground-based methods are of limited accuracy due to insensitivity to solar particles of energies between the riometer upper cutoff of about 50 MeV and the neutron monitor threshold of about 450 MeV. This energy range is demonstrated to be essential for atmospheric radiation monitoring at high altitude, and must be covered by satellite measurement. On the basis of presently available data, the accuracy to which the incident solar particle flux must be measured by satellite-borne detectors is examined and recommendations are made to establish minimum requirements.

  8. The autonomic nervous system at high altitude

    PubMed Central

    Drinkhill, Mark J.; Rivera-Chira, Maria

    2007-01-01

    The effects of hypobaric hypoxia in visitors depend not only on the actual elevation but also on the rate of ascent. Sympathetic activity increases and there are increases in blood pressure and heart rate. Pulmonary vasoconstriction leads to pulmonary hypertension, particularly during exercise. The sympathetic excitation results from hypoxia, partly through chemoreceptor reflexes and partly through altered baroreceptor function. High pulmonary arterial pressures may also cause reflex systemic vasoconstriction. Most permanent high altitude dwellers show excellent adaptation although there are differences between populations in the extent of the ventilatory drive and the erythropoiesis. Some altitude dwellers, particularly Andeans, may develop chronic mountain sickness, the most prominent characteristic of which being excessive polycythaemia. Excessive hypoxia due to peripheral chemoreceptor dysfunction has been suggested as a cause. The hyperviscous blood leads to pulmonary hypertension, symptoms of cerebral hypoperfusion, and eventually right heart failure and death. PMID:17264976

  9. The High Altitude Gamma Ray Observatory, HAWC

    NASA Astrophysics Data System (ADS)

    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.

  10. Dust observations at orbital altitudes surrounding Mars.

    PubMed

    Andersson, L; Weber, T D; Malaspina, D; Crary, F; Ergun, R E; Delory, G T; Fowler, C M; Morooka, M W; McEnulty, T; Eriksson, A I; Andrews, D J; Horanyi, M; Collette, A; Yelle, R; Jakosky, B M

    2015-11-01

    Dust is common close to the martian surface, but no known process can lift appreciable concentrations of particles to altitudes above ~150 kilometers. We present observations of dust at altitudes ranging from 150 to above 1000 kilometers by the Langmuir Probe and Wave instrument on the Mars Atmosphere and Volatile Evolution spacecraft. Based on its distribution, we interpret this dust to be interplanetary in origin. A comparison with laboratory measurements indicates that the dust grain size ranges from 1 to 12 micrometers, assuming a typical grain velocity of ~18 kilometers per second. These direct observations of dust entering the martian atmosphere improve our understanding of the sources, sinks, and transport of interplanetary dust throughout the inner solar system and the associated impacts on Mars's atmosphere.

  11. High altitude plumes at Mars morning terminator

    NASA Astrophysics Data System (ADS)

    Sanchez-Lavega, A.; Garcia Muñoz, A.; Garcia Melendo, E.; Perez-Hoyos, S.; Gomez Forrellad, J. M.; Pellier, C.; Delcroix, M.; Lopez Valverde, M. A.; González Galindo, F.; Jaeschke, W.; Parker, D.; Phillips, J.; Peach, D.

    2015-10-01

    In March and April 2012 two extremely high altitude plumes were observed at the Martian terminator reaching 200 -250 km or more above the surface[1]. They were located at about 195o West longitude and 45o South latitude (at Terra Cimmeria) and extended ˜500 -1,000 km in both North-South and East- West, and lasted for about 10 days. Both plumes exhibited day-to-day variability, and were seen at the morning terminator but not at the evening limb. Another large plume was captured on Hubble Space Telescope images in May 1997 at 99º West longitude and 3º South latitude, but its altitude cannot be pr ecisely determined.Broad-band photometry was performed of both events in the spectral range 255 nm -1052 nm. Based on the observed properties, we discuss different possible scenarios for the mechanism responsible for the formation of these plumes.

  12. Dust observations at orbital altitudes surrounding Mars.

    PubMed

    Andersson, L; Weber, T D; Malaspina, D; Crary, F; Ergun, R E; Delory, G T; Fowler, C M; Morooka, M W; McEnulty, T; Eriksson, A I; Andrews, D J; Horanyi, M; Collette, A; Yelle, R; Jakosky, B M

    2015-11-01

    Dust is common close to the martian surface, but no known process can lift appreciable concentrations of particles to altitudes above ~150 kilometers. We present observations of dust at altitudes ranging from 150 to above 1000 kilometers by the Langmuir Probe and Wave instrument on the Mars Atmosphere and Volatile Evolution spacecraft. Based on its distribution, we interpret this dust to be interplanetary in origin. A comparison with laboratory measurements indicates that the dust grain size ranges from 1 to 12 micrometers, assuming a typical grain velocity of ~18 kilometers per second. These direct observations of dust entering the martian atmosphere improve our understanding of the sources, sinks, and transport of interplanetary dust throughout the inner solar system and the associated impacts on Mars's atmosphere. PMID:26542578

  13. Pulmonary Embolism in Young Natives of High Altitude.

    PubMed

    Singhal, Sanjay; Bhattachar, Srinivasa Alasinga; Paliwal, Vivek; Malhotra, Vineet Kumar; Addya, Kalyani; Kotwal, Atul

    2016-01-01

    Thrombotic events are relatively common in high altitude areas and known to occur in young soldiers working at high altitude without usual risk factors associated with thrombosis at sea-level. However, till now, cases with thrombotic events were reported only in lowlanders staying at high altitude. These two cases of pulmonary embolism demonstrate that thrombotic events can occur in highlanders after a prolonged stay at the extreme altitude. PMID:27512534

  14. Observations from a constant-altitude stratospheric balloon

    NASA Technical Reports Server (NTRS)

    Mollo-Christensen, Erik; Vermillion, Charles H.; Chan, Paul H.; Mcbrien, Gary E.; Ward, William; Coronado, Patrick

    1991-01-01

    The paper describes a constant-altitude stratospheric balloon system, called Earthwinds, designed for high-altitude atmospheric observations. Special attention is given to the balloon's variable ballast system for altitude control; reactions of the balloon system to air motions in a stratified atmosphere; instruments for locating the balloon position, controlling the altitude, and making observations of atmospheric movements; balloon dynamics; and the atmospheric phenomena that will be observed by the balloon instruments.

  15. Pulmonary Embolism in Young Natives of High Altitude

    PubMed Central

    Singhal, Sanjay; Bhattachar, Srinivasa Alasinga; Paliwal, Vivek; Malhotra, Vineet Kumar; Addya, Kalyani; Kotwal, Atul

    2016-01-01

    Thrombotic events are relatively common in high altitude areas and known to occur in young soldiers working at high altitude without usual risk factors associated with thrombosis at sea-level. However, till now, cases with thrombotic events were reported only in lowlanders staying at high altitude. These two cases of pulmonary embolism demonstrate that thrombotic events can occur in highlanders after a prolonged stay at the extreme altitude. PMID:27512534

  16. Physiology studies at high altitude; why and how.

    PubMed

    Mellor, Adrian; Woods, D

    2014-06-01

    The military has always had an important role in high altitude research. This is due to the fact that mountainous regions often span borders and provide a safe haven to enemies. Deploying troops rapidly into high altitude environments presents major problems in terms of the development of high altitude illness. This paper examines the rationale for carrying out research at high altitude and the opportunities within the UK Defence Medical Services for carrying out this research.

  17. Infrared reflectance of high altitude clouds.

    PubMed

    Hovis, W A; Blaine, L R; Forman, M L

    1970-03-01

    The spectral reflectance characteristics of cirrostratus, cirrus clouds, and a jet contrail, in the 0.68-2.4-micro spectral interval, are of interest for remote sensing of cloud types from orbiting satellites. Measurements made with a down-looking spectrometer from a high altitude aircraft show differences between the signatures of naturally formed ice clouds, a fresh jet contrail, and a snow covered surface.

  18. Critique of the equivalent air altitude model.

    PubMed

    Conkin, Johnny; Wessel, James H

    2008-10-01

    The adverse effects of hypoxic hypoxia include acute mountain sickness (AMS), high altitude pulmonary edema, and high altitude cerebral edema. It has long been assumed that those manifestations are directly related to reduction in the inspired partial pressure of oxygen (P(I)O2). This assumption underlies the equivalent air altitude (EAA) model, which holds that combinations of barometric pressure (P(B)) and inspired fraction of O2 (F(I)O2) that produce the same P(I)O2 will result in identical physiological responses. However, a growing body of evidence seems to indicate that different combinations of P(B) and P(I)O2 may produce different responses to the same P(I)O2. To investigate this question with respect to AMS, we conducted a search of the literature using the terms hypobaric hypoxia, normobaric hypoxia, and hypobaric normoxia. The results suggest that the EAA model provides only an approximate description of isohypoxia, and that P(B) has an independent effect on hypoxia and AMS. A historical report from 1956 and 15 reports from 1983 to 2005 compare the same hypoxic P(I)O2 at different P(B) with respect to the development of hypoxia and AMS. These data provide evidence for an independent effect of P(B) on hypoxia and AMS, and thereby invalidate EAA as an ideal model of isohypoxia. Refinement of the EAA model is needed, in particular for applications to high altitude where supplemental O2 is inadequate to prevent hypoxic hypoxia. Adjustment through probabilistic statistical modeling to match the current limited experimental observations is one approach to a better isohypoxic model. PMID:18856188

  19. Mitochondrial function at extreme high altitude.

    PubMed

    Murray, Andrew J; Horscroft, James A

    2016-03-01

    At high altitude, barometric pressure falls and with it inspired P(O2), potentially compromising O2 delivery to the tissues. With sufficient acclimatisation, the erythropoietic response increases red cell mass such that arterial O2 content (C(aO2)) is restored; however arterial P(O2)(P(aO2)) remains low, and the diffusion of O2 from capillary to mitochondrion is impaired. Mitochondrial respiration and aerobic capacity are thus limited, whilst reactive oxygen species (ROS) production increases. Restoration of P(aO2) with supplementary O2 does not fully restore aerobic capacity in acclimatised individuals, possibly indicating a peripheral impairment. With prolonged exposure to extreme high altitude (>5500 m), muscle mitochondrial volume density falls, with a particular loss of the subsarcolemmal population. It is not clear whether this represents acclimatisation or deterioration, but it does appear to be regulated, with levels of the mitochondrial biogenesis factor PGC-1α falling, and shows similarities to adapted Tibetan highlanders. Qualitative changes in mitochondrial function also occur, and do so at more moderate high altitudes with shorter periods of exposure. Electron transport chain complexes are downregulated, possibly mitigating the increase in ROS production. Fatty acid oxidation capacity is decreased and there may be improvements in biochemical coupling at the mitochondrial inner membrane that enhance O2 efficiency. Creatine kinase expression falls, possibly impairing high-energy phosphate transfer from the mitochondria to myofibrils. In climbers returning from the summit of Everest, cardiac energetic reserve (phosphocreatine/ATP) falls, but skeletal muscle energetics are well preserved, possibly supporting the notion that mitochondrial remodelling is a core feature of acclimatisation to extreme high altitude. PMID:26033622

  20. Oxygen affinity of blood in altitude Sherpas.

    PubMed

    Samaja, M; Veicsteinas, A; Cerretelli, P

    1979-08-01

    Oxygen equilibrium curves on blood within 6 h from sampling have been estimated from polarographic measurements of oxyhemoglobin concentration, in 13 male 14- to 50-yr old Sherpas residing at 3,850 m above sea level (Kumjung, Nepal). In samples with red blood cell counts = 4.7 +/- 0.8 (SD) x 10(6)/mm3, total hemoglobin concentration [Hb] = 17.0 +/- 1.9 g/dl, and hematocrit = 53.3 +/- 5.0, the mean oxygen half-saturation of hemoglobin (P50) (pH = 7.4 and PCO2 = 40 Torr) was 27.3 +/- 1.8 Torr. The P50 of altitude Sherpas was not significantly different from that of acclimatized lowlanders (28.2 +/- 1.3; n = 7), sea-level Caucasian residents (26.5 +/- 1.0; n = 17), and Sherpas at sea level (27.1; n = 3). The 2,3-diphosphoglyceric acid-to-hemoglobin concentration ratio ([2,3-DPG]/[Hb]) in altitude Sherpas was 1.22 +/- 0.03, the same as that of acclimatized Caucasians (1.22 +/- 0.10). The Bohr effect measured for the blood of one altitude Sherpas by the ratio deltalog P50/deltapH was -0.32 and -0.45 at PCO2 levels of 40 and 20 Torr, respectively. These values are not significantly different from those found in Caucasians at sea level where deltalog P50/deltalpH was -0.35 and -0.42, respectively. It is concluded that the P50 in native highlanders is not significantly different from that observed in sea-level dwellers. [2,3-DPG]/[Hb] at altitude, both in natives and in newcomers, is 20% higher than in sea-level residents.

  1. Visual control of altitude in flying Drosophila.

    PubMed

    Straw, Andrew D; Lee, Serin; Dickinson, Michael H

    2010-09-14

    Unlike creatures that walk, flying animals need to control their horizontal motion as well as their height above the ground. Research on insects, the first animals to evolve flight, has revealed several visual reflexes that are used to govern horizontal course. For example, insects orient toward prominent vertical features in their environment [1-5] and generate compensatory reactions to both rotations [6, 7] and translations [1, 8-11] of the visual world. Insects also avoid impending collisions by veering away from visual expansion [9, 12-14]. In contrast to this extensive understanding of the visual reflexes that regulate horizontal course, the sensory-motor mechanisms that animals use to control altitude are poorly understood. Using a 3D virtual reality environment, we found that Drosophila utilize three reflexes--edge tracking, wide-field stabilization, and expansion avoidance--to control altitude. By implementing a dynamic visual clamp, we found that flies do not regulate altitude by maintaining a fixed value of optic flow beneath them, as suggested by a recent model [15]. The results identify a means by which insects determine their absolute height above the ground and uncover a remarkable correspondence between the sensory-motor algorithms used to regulate motion in the horizontal and vertical domains.

  2. Use of ultrasound in altitude decompression modeling

    NASA Technical Reports Server (NTRS)

    Olson, Robert M.; Pilmanis, Andrew A.

    1993-01-01

    A model that predicts the probability of developing decompression sickness (DCS) with various denitrogenation schedules is being developed by the Armstrong Laboratory, using human data from previous exposures. It was noted that refinements are needed to improve the accuracy and scope of the model. A commercially developed ultrasonic echo imaging system is being used in this model development. Using this technique, bubbles images from a subject at altitude can be seen in the gall bladder, hepatic veins, vena cava, and chambers of the heart. As judged by their motion and appearance in the vena cava, venous bubbles near the heart range in size from 30 to 300 M. The larger bubbles skim along the top, whereas the smaller ones appear as faint images near the bottom of the vessel. Images from growing bubbles in a model altitude chamber indicate that they grow rapidly, going from 20 to 100 M in 3 sec near 30,000 ft altitude. Information such as this is valuable in verifying those aspects of the DCS model dealing with bubble size, their growth rate, and their site of origin.

  3. Central Sleep Apnea at High Altitude.

    PubMed

    Burgess, Keith R; Ainslie, Philip N

    2016-01-01

    The discovery of central sleep apnea (CSA) at high altitude is usually attributed to Angelo Mosso who published in 1898. It can occur in susceptible individuals at altitude above 2000 m, but at very high altitude, say above 5000 m, it will occur in most subjects. Severity is correlated with ventilatory responsiveness, particularly to hypoxia. Theoretically, it should spontaneously improve with time and acclimatization. Although the time course of resolution is not well described, it appears to persist for more than a month at 5000 m.It occurs due to the interaction of hypocapnia with stages 1 and 2 NREM sleep, in the presence of increased loop-gain. The hypocapnia is secondary to hypoxic ventilatory drive. With acclimatization, one might expect that the increase in PaO2 and cerebral blood flow (CBF) would mitigate the CSA. However, over time, both the hypoxic and hypercapnic ventilatory responses increase, causing an increase in loop gain which is a counteracting force.The severity of the CSA can be reduced by descent, supplemental oxygen therapy, oral or intravenous acetazolamide. Recent studies suggest that acute further increases in cerebral blood flow will substantially, but temporarily, reduce central sleep apnea, without altering acid based balance. Very recently, bi-level noninvasive ventilation has also been shown to help (mechanism unknown). Sleep quality can be improved independent of the presence of CSA by the use of benzodiazepine sedation. PMID:27343103

  4. A Challenge to the Highest Balloon Altitude

    NASA Astrophysics Data System (ADS)

    Saito, Yoshitaka; Akita, Daisuke; Fuke, Hideyuki; Iijima, Issei; Izutsu, Naoki; Kato, Yoichi; Kawada, Jiro; Matsuzaka, Yukihiko; Mizuta, Eiichi; Namiki, Michiyoshi; Nonaka, Naoki; Ohta, Shigeo; Sato, Takatoshi; Seo, Motoharu; Takada, Atsushi; Tamura, Keisuke; Toriumi, Michihiko; Yamagami, Takamasa; Yamada, Kazuhiko; Yoshida, Tetsuya; Matsushima, Kiyoho; Tanaka, Shigeki

    Development of a balloon to fly at higher altitudes is one of the most attractive challenges in scientific balloon technologies. After reaching the highest record setting balloon altitude of 53.0 km using the 3.4 µm film in 2002, a thinner balloon film with a thickness of 2.8 µm using a higher density resin was developed. In 2004, a 5,000 m3 balloon with the film was successfully launched, however, 60,000 m3 balloons launched in 2005, 2006, and 2007, were broken during the ascending phase. The problem was suspected to be due to the properties of the film including the uniformity and the strength, neither of which can be estimated by the conventional tensile test. Thus, we checked the strength of the film with large sample, the bi-axial tensile test properties, the creep properties, and the viscoelasticity, comparing with these to the other thick balloon films. In this conference, we are going to report our new test procedure of the balloon film, results of our current and a new 2.8 µm balloon film, and our future plan to launch the highest altitude balloon.

  5. Trajectory Control For High Altitude Balloons

    NASA Astrophysics Data System (ADS)

    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.

  6. [High-altitude pulmonary edema in Japan].

    PubMed

    Kobayashi, T

    1995-12-01

    To understand the pathophysiology of high-altitude pulmonary edema (HAPE), we examined the pathway of adaptation to high altitude in lifelong of Tibet. The Tibetan natives had higher exercise performance, but lower maximal oxygen uptake and lower blood lactate concentrations than did acclimatized Han newcomers. Clinical and basic studies done to determine the pathophysiologic characteristics of 47 patients with HAPE and of subjects susceptible to HAPE. The altitude of onset was 2,680 m to 3,190 m above sea level. Results of hemodynamic studies and the presence of protein-rich edema fluid indicated that HAPE is noncardiogenic and is a type of increased permeability edema. The levels of IL-1 beta, IL-6, IL-8, and TNF-alpha in bronchoalveolar lavage fluid from subjects with HAPE were high on admission. The subjects susceptible to HAPE had much greater increases in an index of pulmonary vascular resistance than did the controls, which resulted in much higher levels of pulmonary arterial pressure during both acute hypoxia and hypobaria. The subjects susceptible to HAPE also has blunted hypoxic ventilatory drives. We studied whether human leukocyte antigen DR-6 functions as a genetic predisposition to HAPE. The frequency of DR-6 was increased in the subjects susceptible to HAPE, which suggests that they have a constitutional abnormality in the pulmonary circulatory, and ventilatory responses to hypoxia and hypobaria, and that genetic factors may be involved in the development of HAPE.

  7. 14 CFR 91.515 - Flight altitude rules.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Flight altitude rules. 91.515 Section 91... Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.515 Flight altitude rules. (a..., hill, or other obstruction to flight, for day operations; and (2) The altitudes prescribed in §...

  8. 14 CFR 91.177 - Minimum altitudes for IFR operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Minimum altitudes for IFR operations. 91... Instrument Flight Rules § 91.177 Minimum altitudes for IFR operations. (a) Operation of aircraft at minimum altitudes. Except when necessary for takeoff or landing, or unless otherwise authorized by the FAA,...

  9. 14 CFR 27.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Maximum operating altitude. 27.1527 Section 27.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... § 27.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed, as...

  10. 14 CFR 121.661 - Initial approach altitude: Flag operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Initial approach altitude: Flag operations... § 121.661 Initial approach altitude: Flag operations. When making an initial approach to a radio navigation facility under IFR, no person may descend below the pertinent minimum altitude for...

  11. 14 CFR 91.177 - Minimum altitudes for IFR operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Minimum altitudes for IFR operations. 91... Instrument Flight Rules § 91.177 Minimum altitudes for IFR operations. (a) Operation of aircraft at minimum altitudes. Except when necessary for takeoff or landing, or unless otherwise authorized by the FAA,...

  12. 14 CFR 29.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Maximum operating altitude. 29.1527 Section 29.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 29.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed,...

  13. 14 CFR 29.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maximum operating altitude. 29.1527 Section 29.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 29.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed,...

  14. 14 CFR 27.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maximum operating altitude. 27.1527 Section 27.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... § 27.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed, as...

  15. 14 CFR 91.177 - Minimum altitudes for IFR operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Minimum altitudes for IFR operations. 91... Instrument Flight Rules § 91.177 Minimum altitudes for IFR operations. (a) Operation of aircraft at minimum altitudes. Except when necessary for takeoff or landing, or unless otherwise authorized by the FAA,...

  16. 10 CFR 862.6 - Voluntary minimum altitude.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Voluntary minimum altitude. 862.6 Section 862.6 Energy... § 862.6 Voluntary minimum altitude. In addition to complying with all applicable FAA prohibitions or restrictions, aircraft are requested to maintain a minimum altitude of 2,000 feet above the terrain of...

  17. 14 CFR 121.661 - Initial approach altitude: Flag operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Initial approach altitude: Flag operations... § 121.661 Initial approach altitude: Flag operations. When making an initial approach to a radio navigation facility under IFR, no person may descend below the pertinent minimum altitude for...

  18. 14 CFR 91.515 - Flight altitude rules.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Flight altitude rules. 91.515 Section 91... Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.515 Flight altitude rules. (a..., hill, or other obstruction to flight, for day operations; and (2) The altitudes prescribed in §...

  19. VIEW OF THE TOPS OF ALTITUDE CHAMBER R (TO LEFT) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF THE TOPS OF ALTITUDE CHAMBER R (TO LEFT) AND ALTITUDE CHAMBER L (TO RIGHT) FROM THE 42’-0” LEVEL OF ACCESS PLATFORMS, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  20. 14 CFR 121.661 - Initial approach altitude: Flag operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Initial approach altitude: Flag operations... § 121.661 Initial approach altitude: Flag operations. When making an initial approach to a radio navigation facility under IFR, no person may descend below the pertinent minimum altitude for...

  1. 14 CFR 29.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maximum operating altitude. 29.1527 Section 29.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 29.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed,...

  2. 10 CFR 862.6 - Voluntary minimum altitude.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Voluntary minimum altitude. 862.6 Section 862.6 Energy... § 862.6 Voluntary minimum altitude. In addition to complying with all applicable FAA prohibitions or restrictions, aircraft are requested to maintain a minimum altitude of 2,000 feet above the terrain of...

  3. 14 CFR 27.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maximum operating altitude. 27.1527 Section 27.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... § 27.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed, as...

  4. 10 CFR 862.6 - Voluntary minimum altitude.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Voluntary minimum altitude. 862.6 Section 862.6 Energy... § 862.6 Voluntary minimum altitude. In addition to complying with all applicable FAA prohibitions or restrictions, aircraft are requested to maintain a minimum altitude of 2,000 feet above the terrain of...

  5. 14 CFR 135.93 - Autopilot: Minimum altitudes for use.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Autopilot: Minimum altitudes for use. 135... Operations § 135.93 Autopilot: Minimum altitudes for use. (a) Except as provided in paragraphs (b), (c), (d), and (e) of this section, no person may use an autopilot at an altitude above the terrain which is...

  6. 14 CFR 29.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum operating altitude. 29.1527 Section 29.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 29.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed,...

  7. 14 CFR 91.515 - Flight altitude rules.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Flight altitude rules. 91.515 Section 91... Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.515 Flight altitude rules. (a..., hill, or other obstruction to flight, for day operations; and (2) The altitudes prescribed in §...

  8. 14 CFR 91.177 - Minimum altitudes for IFR operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Minimum altitudes for IFR operations. 91... Instrument Flight Rules § 91.177 Minimum altitudes for IFR operations. (a) Operation of aircraft at minimum altitudes. Except when necessary for takeoff or landing, or unless otherwise authorized by the FAA,...

  9. Human Behaviour and Development under High-Altitude Conditions

    ERIC Educational Resources Information Center

    Virues-Ortega, Javier; Garrido, Eduardo; Javierre, Casimiro; Kloezeman, Karen C.

    2006-01-01

    Although we are far from a universally accepted pattern of impaired function at altitude, there is evidence indicating motor, perceptual, memory and behavioural deficits in adults. Even relatively low altitudes (2500 m) may delay reaction time, and impair motor function. Extreme altitude exposure (greater than 5000 m) may result in more pronounced…

  10. 10 CFR 862.6 - Voluntary minimum altitude.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Voluntary minimum altitude. 862.6 Section 862.6 Energy... § 862.6 Voluntary minimum altitude. In addition to complying with all applicable FAA prohibitions or restrictions, aircraft are requested to maintain a minimum altitude of 2,000 feet above the terrain of...

  11. 14 CFR 121.661 - Initial approach altitude: Flag operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Initial approach altitude: Flag operations... § 121.661 Initial approach altitude: Flag operations. When making an initial approach to a radio navigation facility under IFR, no person may descend below the pertinent minimum altitude for...

  12. 14 CFR 27.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum operating altitude. 27.1527 Section 27.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... § 27.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed, as...

  13. 14 CFR 91.515 - Flight altitude rules.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Flight altitude rules. 91.515 Section 91... Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.515 Flight altitude rules. (a..., hill, or other obstruction to flight, for day operations; and (2) The altitudes prescribed in §...

  14. 14 CFR 135.93 - Autopilot: Minimum altitudes for use.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...), and (e) of this section, no person may use an autopilot at an altitude above the terrain which is less... instrument approach facility other than ILS, no person may use an autopilot at an altitude above the terrain... person may use an autopilot with an approach coupler at an altitude above the terrain that is less...

  15. 14 CFR 135.93 - Autopilot: Minimum altitudes for use.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...), and (e) of this section, no person may use an autopilot at an altitude above the terrain which is less... instrument approach facility other than ILS, no person may use an autopilot at an altitude above the terrain... person may use an autopilot with an approach coupler at an altitude above the terrain that is less...

  16. 14 CFR 135.93 - Autopilot: Minimum altitudes for use.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...), and (e) of this section, no person may use an autopilot at an altitude above the terrain which is less... instrument approach facility other than ILS, no person may use an autopilot at an altitude above the terrain... person may use an autopilot with an approach coupler at an altitude above the terrain that is less...

  17. 14 CFR 135.93 - Autopilot: Minimum altitudes for use.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...), and (e) of this section, no person may use an autopilot at an altitude above the terrain which is less... instrument approach facility other than ILS, no person may use an autopilot at an altitude above the terrain... person may use an autopilot with an approach coupler at an altitude above the terrain that is less...

  18. Detection of ocean color changes from high altitudes

    NASA Technical Reports Server (NTRS)

    Hovis, W. A.; Forman, M. L.; Blaine, L. R.

    1973-01-01

    The detection of ocean color changes, thought to be due to chlorophyll concentrations and gelbstoffe variations, is attempted from high altitude (11.3km) and low altitude (0.3km). The atmospheric back scattering is shown to reduce contrast, but not sufficiently to obscure color change detection at high altitudes.

  19. Changes in labial capillary density on ascent to and descent from high altitude

    PubMed Central

    Gilbert-Kawai, Edward; Coppel, Jonny; Phillip, Hennis; Grocott, Michael; Ince, Can; Martin, Daniel

    2016-01-01

    Present knowledge of how the microcirculation is altered by prolonged exposure to hypoxia at high altitude is incomplete and modification of existing analytical techniques may improve our knowledge considerably. We set out to use a novel simplified method of measuring in vivo capillary density during an expedition to high altitude using a CytoCam incident dark field imaging video-microscope. The simplified method of data capture involved recording one-second images of the mucosal surface of the inner lip to reveal data about microvasculature density in ten individuals. This was done on ascent to, and descent from, high altitude. Analysis was conducted offline by two independent investigators blinded to the participant identity, testing conditions and the imaging site.  Additionally we monitored haemoglobin concentration and haematocrit data to see if we could support or refute mechanisms of altered density relating to vessel recruitment. Repeated sets of paired values were compared using Kruskall Wallis Analysis of Variance tests, whilst comparisons of values between sites was by related samples Wilcoxon Signed Rank Test. Correlation between different variables was performed using Spearman’s rank correlation coefficient, and concordance between analysing investigators using intra-class correlation coefficient. There was a significant increase in capillary density from London on ascent to high altitude; median capillaries per field of view area increased from 22.8 to 25.3 (p=0.021). There was a further increase in vessel density during the six weeks spent at altitude (25.3 to 32.5, p=0.017). Moreover, vessel density remained high on descent to Kathmandu (31.0 capillaries per field of view area), despite a significant decrease in haemoglobin concentration and haematocrit. Using a simplified technique, we have demonstrated an increase in capillary density on early and sustained exposure to hypobaric hypoxia at thigh altitude, and that this remains elevated on

  20. The effect of ''living high-training low'' on physical performance in rats

    NASA Astrophysics Data System (ADS)

    Miyazaki, S.; Sakai, A.

    In this research, we hypothesized that, in rats, adaptation to high altitude (2500 m) plus training at low altitude (610 m), ''living high-training low'', improves physical performance at low altitude more than living and training at low altitude (610 m). Rats were divided into four groups: (1) living at low altitude (LL, n=12), (2) living and training at low altitude (LLTL, n=13), (3) living at high altitude (LH, n=12), (4) living at high altitude and training at low altitude (LHTL, n=13). The program for living at high altitude involved raising rats under hypobaric hypoxia (equivalent to 2500 m), and the training program consisted of running on a tread-mill at low altitude. All groups were raised at each altitude and trained to run at 35 m/min for 40 min/day, 6 days/week for 6 weeks. During this program, we measured heart rates both at rest and during exercise, and performed running-time trials. The mean heart rate during exercise was lower in groups with training than in groups without training, and the groups receiving training could run longer than the untrained groups. The LHTL group especially showed the lowest mean heart rate during exercise and the longest running time among all groups. After 6 weeks of the training program, all rats had a catheter implanted into the carotid artery, and the mean systemic arterial pressure was continuously measured during treadmill running. The rate of increase of this pressure as the running intensity increased was lower in groups with training than in groups without training, especially in the LHTL group. Finally, we anesthetized all the rats and extracted both the right and left ventricles, and the triceps surae and liver. Training increased the weight of the left ventricle, triceps surae, and liver. The increase in weight of the left ventricle and triceps surae was higher in the LHTL group than in the LLTL group in particular. It appeared that living high- training low may be an effective strategy to improve performance

  1. White blood cell and hormonal responses to 4300 m altitude before and after intermittent altitude exposure.

    PubMed

    Beidleman, Beth A; Muza, Stephen R; Fulco, Charles S; Cymerman, Allen; Staab, Janet E; Sawka, Michael N; Lewis, Steven F; Skrinar, Gary S

    2006-08-01

    Recent studies have demonstrated that brief daily IAE (intermittent altitude exposure) was equally as effective as continuous altitude residence in inducing physiological adaptations consistent with altitude acclimatization. Although the positive benefits of IAE have been clearly defined, the potential negative consequences of IAE on health, specifically the immune system, remain undefined. The present study determined the effects of IAE on WBC (white blood cell) and hormonal responses during rest and exercise at 4300 m altitude. Six lowlanders (age, 23+/-2 years; body weight, 77+/-6 kg; values are means+/-S.E.M.) completed a VO(2)max (maximal O(2) uptake) and submaximal cycle ergometer test during a 30-h SL (sea level) exposure and during a 30 h exposure to 4300 m altitude-equivalent once before (PreIAE) and once after (PostIAE) a 3-week period of IAE (4 hxday(-1), 5 daysxweek(-1), 4300 m). The submaximal cycle ergometer test consisted of two consecutive 15-min work bouts at 40% and 70% of altitude-specific VO(2)max. Blood samples were obtained at rest and during both exercise work bouts for measurements of WBC count, leucocyte subset counts, cortisol, adrenaline (epinephrine) and noradrenaline (norepinephrine). WBC, neutrophil and lymphocyte counts increased significantly (P<0.05) during rest and exercise from SL to PreIAE and decreased (P<0.05) during rest and exercise from PreIAE to PostIAE. Monocyte counts decreased (P<0.05) during rest and exercise from PreIAE to PostIAE, but eosinophil and basophil counts did not change. Cortisol, adrenaline and noradrenaline did not change during rest or exercise from SL to PreIAE or PostIAE, but all increased significantly (P<0.05) from rest during the two work bouts. In conclusion, this type of IAE stimulus did not induce a hormonal stress response and did no harm in terms of activation of the immune system at altitude, as measured by WBC and leucocyte subset counts. This method of pre-acclimatization can therefore be

  2. Global Trends in Glacial Cirque Floor Altitudes and Their Relationships with Climate, Equilibrium Line Altitudes, and Mountain Range Heights

    NASA Astrophysics Data System (ADS)

    Mitchell, S. G.; Humphries, E.

    2013-12-01

    Glacial erosion at the base of cirque headwalls and the creation of threshold slopes above cirque floors may contribute to the 'glacial buzzsaw' effect in limiting the altitude of some mountain ranges. Since glacial extent and therefore glacial erosion rate depends on the equilibrium line altitude (ELA) of a region, the altitude of cirque formation should be a function of the ELA. Several regional studies have shown that cirque floors form at an altitude approximating average Quaternary ELAs in some mountain ranges, but a global correlation has not yet been demonstrated. We examined the correlation between cirque altitudes and global ELA trends by compiling existing and new cirque altitude and morphometry data from > 30 mountain ranges at a wide range of latitudes. Where available, we calculate or present the average cirque altitude, relief, and latitude. We compared these altitudes to both the global East Pacific ELA and local ELAs where available. For the locations analyzed, the majority of average cirque altitudes fall between the Eastern Pacific modern and LGM ELAs, and mountain range height is typically limited to < 600 m above that altitude. This evidence supports the hypothesis that cirque formation is dependent upon the ELA, and that cirques likely form as a result of average, rather than extreme, glacial conditions. Furthermore, the correlation between cirque altitude and ELA, along with the restricted window of relief, implies that cirque formation is a factor in limiting peak altitude in ranges that rise above the ELA.

  3. New horizons for the national high-altitude photography program

    USGS Publications Warehouse

    Bermel, Peter F.

    1983-01-01

    The National High-Altitude Photography Program (NHAP) is a multi-Federal agency activity to acquire uniform imagery for the establishment of a national high-altitude photographic data base. Federal agencies participating in NHAP have pooled their resources and consolidated photographic requirements in a systematic 6-year effort that will minimize duplication of photographic programs, reduce overall Federal expenditures for aerial photography, and provide imagery for a wide range of public and private users, The U.S. Geological Survey has the lead coordination role and shares, with the other participating agencies, the responsibility for funding the acquisition of photography. Since the inception of NHAP in 1980, black-and-white and color infrared stereoscopic imagery has been acquired for about 50% of the 3,000,000 square miles in the conterminous United States. An additional 40% of the 48-State area is under contract to provide aerial survey firms, and the sixth and final contract to achieve complete once-over coverage will be awarded early in 1985. Extensive use has been made of the newly established data base for mapping, landform studies, land use planning, natural resource inventory, evaluation and management, engineering, and education. In anticipation of the completion of once-over coverage, the participating agencies have begun studies to define the requirements for a maintenance program which would provide cyclic coverage of the conterminous United States and imagery for specific agency needs. Although continued funding at the same level is not assured, under consideration are requirements for new cameras, films, and other remote sensors, photographic parameters, and extension of program coverage to Alaska, Hawaii, and outlying areas. In addition, new applications of the data base to prepare cartographic map and data products are being investigated. It is becoming increasingly clear that some major decision needs to be made soon if a NHAP II is to begin in

  4. The effect of sudden depressurization on pilots at cruising altitude.

    PubMed

    Muehlemann, Thomas; Holper, Lisa; Wenzel, Juergen; Wittkowski, Martin; Wolf, Martin

    2013-01-01

    The standard flight level for commercial airliners is ∼12 km (40 kft; air pressure: ∼ 200 hPa), the maximum certification altitude of modern airliners may be as high as 43-45 kft. Loss of structural integrity of an airplane may result in sudden depressurization of the cabin potentially leading to hypoxia with loss of consciousness of the pilots. Specialized breathing masks supply the pilots with oxygen. The aim of this study was to experimentally simulate such sudden depressurization to maximum design altitude in a pressure chamber while measuring the arterial and brain oxygenation saturation (SaO(2) and StO(2)) of the pilots. Ten healthy subjects with a median age of 50 (range 29-70) years were placed in a pressure chamber, breathing air from a cockpit mask. Pressure was reduced from 753 to 148 hPa within 20 s, and the test mask was switched to pure O(2) within 2 s after initiation of depressurization. During the whole procedure SaO(2) and StO(2) were measured by pulse oximetry, respectively near-infrared spectroscopy (NIRS; in-house built prototype) of the left frontal cortex. During the depressurization the SaO(2) dropped from median 93% (range 91-98%) to 78% (62-92%) by 16% (6-30%), while StO(2) decreased from 62% (47-67%) to 57% (43-62%) by 5% (3-14%). Considerable drops in oxygenation were observed during sudden depressurization. The inter-subject variability was high, for SaO(2) depending on the subjects' ability to preoxygenate before the depressurization. The drop in StO(2) was lower than the one in SaO(2) maybe due to compensation in blood flow. PMID:22879031

  5. The effect of sudden depressurization on pilots at cruising altitude.

    PubMed

    Muehlemann, Thomas; Holper, Lisa; Wenzel, Juergen; Wittkowski, Martin; Wolf, Martin

    2013-01-01

    The standard flight level for commercial airliners is ∼12 km (40 kft; air pressure: ∼ 200 hPa), the maximum certification altitude of modern airliners may be as high as 43-45 kft. Loss of structural integrity of an airplane may result in sudden depressurization of the cabin potentially leading to hypoxia with loss of consciousness of the pilots. Specialized breathing masks supply the pilots with oxygen. The aim of this study was to experimentally simulate such sudden depressurization to maximum design altitude in a pressure chamber while measuring the arterial and brain oxygenation saturation (SaO(2) and StO(2)) of the pilots. Ten healthy subjects with a median age of 50 (range 29-70) years were placed in a pressure chamber, breathing air from a cockpit mask. Pressure was reduced from 753 to 148 hPa within 20 s, and the test mask was switched to pure O(2) within 2 s after initiation of depressurization. During the whole procedure SaO(2) and StO(2) were measured by pulse oximetry, respectively near-infrared spectroscopy (NIRS; in-house built prototype) of the left frontal cortex. During the depressurization the SaO(2) dropped from median 93% (range 91-98%) to 78% (62-92%) by 16% (6-30%), while StO(2) decreased from 62% (47-67%) to 57% (43-62%) by 5% (3-14%). Considerable drops in oxygenation were observed during sudden depressurization. The inter-subject variability was high, for SaO(2) depending on the subjects' ability to preoxygenate before the depressurization. The drop in StO(2) was lower than the one in SaO(2) maybe due to compensation in blood flow.

  6. High altitude pulmonary oedema (HAPE) in an Indian pilgrim.

    PubMed

    Panthi, Sagar; Basnyat, Buddha

    2013-11-01

    Increasing number of Hindu pilgrims visit the Himalayas where some of them suffer from high altitude illness including the life threatening forms, high altitude pulmonary oedema (HAPE) and high altitude cerebral oedema. Compared to tourists and trekkers, pilgrims are usually ignorant about altitude illness. This is a case of a pilgrim who suffered from HAPE on his trip to Kailash-Mansarovar and is brought to a tertiary level hospital in Kathmandu. This report emphasises on how to treat a patient with HAPE, a disease which is increasingly being seen in the high altitude pilgrim population. PMID:24974506

  7. Aerodynamics of heat exchangers for high-altitude aircraft

    NASA Technical Reports Server (NTRS)

    Drela, Mark

    1996-01-01

    Reduction of convective beat transfer with altitude dictates unusually large beat exchangers for piston- engined high-altitude aircraft The relatively large aircraft drag fraction associated with cooling at high altitudes makes the efficient design of the entire heat exchanger installation an essential part of the aircraft's aerodynamic design. The parameters that directly influence cooling drag are developed in the context of high-altitude flight Candidate wing airfoils that incorporate heat exchangers are examined. Such integrated wing-airfoil/heat-exchanger installations appear to be attractive alternatives to isolated heat.exchanger installations. Examples are drawn from integrated installations on existing or planned high-altitude aircraft.

  8. Strength Training and Children's Health.

    ERIC Educational Resources Information Center

    Faigenbaum, Avery D.

    2001-01-01

    Provides an overview of the potential health benefits of strength training for children, discussing the role of strength training in preventing sports-related injuries and highlighting design considerations for such programs. The focus is on musculoskeletal adaptations to strength training that are observable in healthy children. Guidelines for…

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

    PubMed Central

    Taylor, Andrew T.

    2011-01-01

    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. PMID:23908794

  10. Empirical model of the Martian dayside ionosphere: Effects of crustal magnetic fields and solar ionizing flux at higher altitudes

    NASA Astrophysics Data System (ADS)

    Němec, F.; Morgan, D. D.; Gurnett, D. A.; Andrews, D. J.

    2016-02-01

    We use electron density profiles measured by the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument on board the Mars Express spacecraft to investigate the effects of possible controlling parameters unconsidered in the empirical model of Němec et al. (2011, hereafter N11). Specifically, we focus on the effects of crustal magnetic fields and F10.7 proxy of the solar ionizing flux at higher altitudes. It is shown that while peak electron densities are nearly unaffected by crustal magnetic fields, electron densities at higher altitudes are significantly increased in areas of stronger magnetic fields. The magnetic field inclination appears to have only a marginal effect. Moreover, while the N11 empirical model accounted for the variable solar ionizing flux at low altitudes, the high-altitude diffusive region was parameterized only by the solar zenith angle and the altitude. It is shown that this can lead to considerable inaccuracies. A simple correction of the N11 model, which takes into account both the crustal magnetic field magnitude and the effect of F10.7 at higher altitudes, is suggested.

  11. Physiological training in Jordan.

    PubMed

    al-Wedyan, I A; Shahin, B H; Abu Ghosh, H M; al-Aqqad, S S; al-Qura'an, M S

    1996-09-01

    The hypobaric chamber is designed as a teaching aid in providing orientation for some of the physiological stresses in flight. Reactions during chamber training vary from mild ear block to neurocirculatory collapse. This is a retrospective study on reactions from 1986-94 in the hypobaric chamber training unit at King Hussien Medical Centre in Jordan; 39 cases were reported among 705 trainees in a 12-person rectangular hypobaric chamber. We analyzed the various reactions according to type, severity and altitude of occurrence. The most common reactions were found to be ear block (65%) and sinus block (25%). These were treated on the spot and followed for 48 h without sequelae. We did not have any moderate or severe reaction; we found that all reactions were minor, which reflects the efficacy of safety measures taken prior to and during training.

  12. Application of Multilayer Feedforward Neural Networks to Precipitation Cell-Top Altitude Estimation

    NASA Technical Reports Server (NTRS)

    Spina, Michelle S.; Schwartz, Michael J.; Staelin, David H.; Gasiewski, Albin J.

    1998-01-01

    The use of passive 118-GHz O2 observations of rain cells for precipitation cell-top altitude estimation is demonstrated by using a multilayer feed forward neural network retrieval system. Rain cell observations at 118 GHz were compared with estimates of the cell-top altitude obtained by optical stereoscopy. The observations were made with 2 4 km horizontal spatial resolution by using the Millimeter-wave Temperature Sounder (MTS) scanning spectrometer aboard the NASA ER-2 research aircraft during the Genesis of Atlantic Lows Experiment (GALE) and the COoperative Huntsville Meteorological EXperiment (COHMEX) in 1986. The neural network estimator applied to MTS spectral differences between clouds, and nearby clear air yielded an rms discrepancy of 1.76 km for a combined cumulus, mature, and dissipating cell set and 1.44 km for the cumulus-only set. An improvement in rms discrepancy to 1.36 km was achieved by including additional MTS information on the absolute atmospheric temperature profile. An incremental method for training neural networks was developed that yielded robust results, despite the use of as few as 56 training spectra. Comparison of these results with a nonlinear statistical estimator shows that superior results can be obtained with a neural network retrieval system. Imagery of estimated cell-top altitudes was created from 118-GHz spectral imagery gathered from CAMEX, September through October 1993, and from cyclone Oliver, February 7, 1993.

  13. The risk of developing decompression sickness during air travel following altitude chamber flight.

    PubMed

    Rush, W L; Wirjosemito, S A

    1990-11-01

    Approximately 35,000 students are trained annually in United States Air Force (USAF) altitude chambers. Students who depart the training site via aircraft on the same day as their altitude chamber exposure may place themselves at increased risk for decompression sickness (DCS). Air travel as a passenger in the immediate post-chamber flight period is unrestricted by current USAF regulations. A retrospective study was conducted to assess the potential risk involved in such post-chamber flight travel. During the years 1982-87, there were 292 cases of DCS involving altitude chamber students which were subsequently treated with hyperbaric oxygen therapy. Only seven cases were found wherein the student was asymptomatic prior to air travel and subsequently developed DCS. Because the percentage of students who postpone travel is unknown, a precise relative risk could not be determined. Although the number of cases where sequential chamber and aircraft hypobaric exposures has initiated DCS is small, the potential for such occurrences remains a health concern.

  14. Jet engine soot emission measured at altitude

    NASA Technical Reports Server (NTRS)

    Rosen, J. M.; Greegor, R.

    1974-01-01

    The state of knowledge concerning engine design to minimize air pollution is believed to be such that emission products can be reliably predicted while the engine is still on the drawing board. More effort is now being made to measure emission products from engines operating under cruise conditions. The use of an instrumented aircraft to obtain the appropriate data is perhaps a more realistic and less expensive approach. The results of this study taken at face value indicate that the emission index of typical jet engines calculated from the ground level measurements is comparable to the actual in-flight emission index for altitudes up to 30,000 ft.

  15. Aerodynamics of Shuttle Orbiter at high altitudes

    NASA Technical Reports Server (NTRS)

    Rault, Didier F. G.

    1993-01-01

    The high-altitude/high-Knudsen number aerodynamics of the Shuttle Orbiter are computed from Low-Earth Orbit down to 100 km using three-dimensional direct simulation Monte Carlo and free molecule codes. Results are compared with Blanchard's latest Shuttle aerodynamic model, which is based on in-flight accelerometer measurements, and bridging formula models. Good comparison is observed, except for the normal force and pitching moment coefficients. The present results were obtained for a generic Shuttle geometry configuration corresponding to a zero deflection for all control surfaces.

  16. High altitude balloon experiments at IIA

    NASA Astrophysics Data System (ADS)

    Nayak, Akshata; Sreejith, A. G.; Safonova, Margarita; Murthy, Jayant

    Recent advances in balloon experiments as well as in electronics have made it possible to fly scientific payloads at costs accessible to university departments. We have begun a program of high altitude ballooning at the Indian Institute of Astrophysics, Bengaluru. The primary purpose of this activity is to test low-cost ultraviolet (UV) payloads for eventual space flight, but we will also try scientific exploration of the phenomena occurring in the upper atmosphere, including sprites and meteorite impacts. We present the results of the initial experiments carried out at the CREST campus of IIA, Hosakote, and describe our plans for the future.

  17. Regression of altitude-produced cardiac hypertrophy.

    NASA Technical Reports Server (NTRS)

    Sizemore, D. A.; Mcintyre, T. W.; Van Liere, E. J.; Wilson , M. F.

    1973-01-01

    The rate of regression of cardiac hypertrophy with time has been determined in adult male albino rats. The hypertrophy was induced by intermittent exposure to simulated high altitude. The percentage hypertrophy was much greater (46%) in the right ventricle than in the left (16%). The regression could be adequately fitted to a single exponential function with a half-time of 6.73 plus or minus 0.71 days (90% CI). There was no significant difference in the rates of regression for the two ventricles.

  18. The Training Director's Guide. Volume 1. Administration of Training. Volume 2. Instructional Practices.

    ERIC Educational Resources Information Center

    Department of Manpower and Immigration, Ottawa (Ontario).

    This guide to employee development within industry appears in two sections: Volume 1, administrative guidelines for training directors; and Volume 2, instructional practices for training staffs. Considerations in formulating training policies, steps in organizing the training function, identification and analysis of training needs, employee…

  19. Pulmonary function parameters changes at different altitudes in healthy athletes.

    PubMed

    Ziaee, Vahid; Alizadeh, Reza; Movafegh, Ali

    2008-06-01

    Hypoxia and hypocapnia can cause broncho-constriction in human subjects, and this could have a bearing on performance at high altitude. The object of this study was to examine how pulmonary ventilatory functions during high-altitude trekking. This study is a cohort study on spirometric parameters at different altitudes. Fifty six healthy male volunteers from a university student population were enrolled in the study (ages 22.9+/-5.3 years). Pulmonary function was assessed with a Spirolab II in all participants before ascending at baseline (1150 meter), after ascending at different altitudes (2850, 4150 meter), and after descending at sea level during a 3-day trek in Sialan Mount. This study indicates that in an actual trek, ascending results in significant decrease in forced vital capacity (FVC). FVC significantly decreased with increasing altitude from baseline level and at the sea level it was significantly less than baseline level. Peak flow increased with increasing altitude from baseline (1150 m) to 2850 m and decreased with decreasing altitude (p<0.01). Maximal midexpiratory flow rate (FEF 25-75%) and forced expiratory volume in 1 second to forced expiratory volume ratio (FEV1.0%) significantly increased with increasing and decreasing altitude from baseline level (p<0.001). There was no significant change in FEV1. It could be concluded that changes in some pulmonary ventilatory parameters were proportional to the magnitude of change in altitude during a high-altitude trek. These changes are significant at the beginning of ascending.

  20. [Hormonal variation during physical exertion at high altitude].

    PubMed

    Sutton, J; Garmendia, F

    1977-01-01

    The influence of the physical exercise at high altitude on the endocrine function was studied in 8 normal native men of sea level and in 8 natives men of high altitude. The sea level dwellers were studied both, at sea level, during an acute exposure to low barometric pressure and after 3 months of acclimatization to altitudes over 3,500 meters above the sea level. The experiments at high altitude were conducted at an altitude of 4,500 meters above the sea level. Two types of exercise were carried out, sub-maximal and maximal, at fasting state, between 8 and 10 a.m. During an acute exposure to altitude the physical exercise produced a marked rise of glucose, cortisol and growth hormone and a fall in the insulin content of plasma. In the sea level dwellers, acclimatized to altitude during 3 months, an elevation of growth hormone was observed only during maximal physical effort. Marked variation in glucose and cortisol were observed during both types of exercise. This shows that in these subjects some adaptative changes have ocurred but of lesser extent as those observed in altitude natives. In the high altitude native higher basal concentrations of growth hormone and glucagón as well as a lower glucose concentration in blood, were found. During exercise the high altitude dweller showed no significant changes in somatotropin, meanwhile an important elevation of cortisol occurred. These findings indicate that the high altitude native has metabolic and endocrine responses to exercise similar to those found in well fitted atletes of sea level. The exposure to altitude provoked a rise in glucagon concentration directly proportional to the time of exposition ot altitude. The physical exercise did not elucidate any change in the glucagon content of blood. PMID:753199

  1. Flight Dynamics of High Altitude Research Balloons

    NASA Astrophysics Data System (ADS)

    Sohl, Ian

    2010-10-01

    Dramatic motions have been observed by instrumentation loaded in payloads attached to high altitude weather balloons. Several HARBOR flights have been completed with six-axis attitude sensors and a high definition video camera that allowed us to analyze the balloon's motion. Turbulence in the atmosphere, especially near the jet stream, results in dramatic oscillations---sometimes swinging the payload above the balloon. Other unexpected motions include rapid spinning (as in a barrel roll) of the entire package. We are correlating these motions with observed atmospheric conditions and addressing issues related to payload safety, mission tracking, and recovery. Also of interest are the dynamics of balloon rupture at low atmospheric pressure and the response of the parachute recovery system to that environment. HARBOR (High Altitude Reconnaissance Balloon for Outreach and Research) is a program in which scientific payloads are designed, constructed, and flown by students using weather balloons to reach the edge of space. These flights are similar to the hundreds of weather balloons launched twice a day by the National Oceanic and Atmospheric Administration for which very little is actually known about the flight dynamics.

  2. High altitude living: genetic and environmental adaptation.

    PubMed

    Ramirez, G; Bittle, P A; Rosen, R; Rabb, H; Pineda, D

    1999-01-01

    High altitude (HA) living produces physiological changes for adaptation to chronic hypobaric-hypoxemic conditions. Although much is known about these physiologic adaptations, no clear separation has been made regarding what is "native" or "genetic" adaptation and what is "acquired." In this review, we describe the genetic vs. acquired adaptation and only include studies performed in a population native to HA and not in an acclimatized population or trekkers. The changes encountered in animals and humans living at HA in terms of hematology, muscular, respiratory, cerebral, cardiovascular, hormonal, fluid and electrolytes and reproduction, strongly suggest that genetics play a very important role in HA adaptation. Unfortunately, the characteristic physiology of HA natives has not been systematically defined to established specific measurable parameters of adaptation in comparison to the acquired ambient adaptation of the non-native population. Once the parameters are established, we can compare non-native populations exposed to HA that must emulate the HA physiology for a definite adaptation to be present. With measurable parameters, especially in the management of fluids and electrolytes, we can define how long it will take for a sea level native to adapt to an HA altitude. Until these studies are performed, speculation will continue and no rational medical intervention can be offered to HA newcomers who may experience HA difficulties.

  3. Development of the High Altitude Student Platform

    NASA Astrophysics Data System (ADS)

    Guzik, T. G.; Besse, S.; Calongne, A.; Dominique, A.; Ellison, S. B.; Gould, R.; Granger, D.; Olano, D.; Smith, D.; Stewart, M.; Wefel, J. P.

    2008-11-01

    The High Altitude Student Platform (HASP) was originally conceived to provide student groups with access to the near-space environment for flight durations and experiment capabilities intermediate between what is possible with small sounding balloons and low Earth orbit rocket launches. HASP is designed to carry up to twelve student payloads to an altitude of about 36 km with flight durations of 15 20 h using a small zero-pressure polyethylene film balloon. This provides a flight capability that can be used to flight-test compact satellites, prototypes and other small payloads designed and built by students. HASP includes a standard mechanical, power and communication interface for the student payload to simplify integration and allows the payloads to be fully exercised. Over the last two years a partnership between the NASA Balloon Program Office (BPO), Columbia Scientific Balloon Facility (CSBF), Louisiana State University (LSU), the Louisiana Board of Regents (BoR), and the Louisiana Space Consortium (LaSPACE) has led to the development, construction and, finally, the first flight of HASP with a complement of eight student payloads on September 4, 2006. Here we discuss the primary as-built HASP systems and features, the student payload interface, HASP performance during the first flight and plans for continuing HASP flights. The HASP project maintains a website at http://laspace.lsu.edu/hasp/ where flight application, interface documentation and status information can be obtained.

  4. Acclimatization to altitude: effects on arterial oxygen saturation and pulse rate during prolonged exercise at altitude.

    PubMed

    Stoneham, M D; Pethybridge, R J

    1993-01-01

    Changes in the arterial haemoglobin-oxygen saturation (SaO2) of the blood, in the blood pressure and in the heart rate, were monitored in subjects performing static exercise at an altitude of 3,600 metres before and after an acclimatization period of 28 days during an expedition to the Bolivian Andes. It was found that acclimatised subjects could maintain their SaO2 during prolonged exercise better than non-acclimatised subjects. The pulse rate of acclimatised subjects was consistently lower at the same work level than that of non-acclimatised subjects. Acclimatised subjects were able to reach higher levels of exercise than when they had first arrived at altitude. These data imply that acclimatization to altitude improves the delivery of oxygen to the tissues. The mechanism of this is not certain, but it may be concerned with a reduction in the degree of ventilation-perfusion inequality of the lung which occurs on exposure to high altitude.

  5. Retrieval of cirrus cloud optical thickness and top altitude from geostationary remote sensing

    NASA Astrophysics Data System (ADS)

    Kox, S.; Bugliaro, L.; Ostler, A.

    2014-04-01

    A novel approach for the detection of cirrus clouds and the retrieval of optical thickness and top altitude based on the measurements of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) aboard the geostationary Meteosat Second Generation (MSG) satellite is presented. Trained with 8 000 000 co-incident measurements of the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission the new "cirrus optical properties derived from CALIOP and SEVIRI algorithm during day and night" (COCS) algorithm utilizes a backpropagation neural network to provide accurate measurements of cirrus optical depth τ at λ =532 nm and top altitude z every 15 min covering almost one third of Earth's atmosphere. The retrieved values are validated with independent measurements of CALIOP and the optical thickness derived by an airborne high spectral resolution lidar.

  6. Retrieval of cirrus cloud optical thickness and top altitude from geostationary remote sensing

    NASA Astrophysics Data System (ADS)

    Kox, S.; Bugliaro, L.; Ostler, A.

    2014-10-01

    A novel approach for the detection of cirrus clouds and the retrieval of optical thickness and top altitude based on the measurements of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) aboard the geostationary Meteosat Second Generation (MSG) satellite is presented. Trained with 8 000 000 co-incident measurements of the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission the new "cirrus optical properties derived from CALIOP and SEVIRI algorithm during day and night" (COCS) algorithm utilizes a backpropagation neural network to provide accurate measurements of cirrus optical depth τ at λ = 532 nm and top altitude z every 15 min covering almost one-third of the Earth's atmosphere. The retrieved values are validated with independent measurements of CALIOP and the optical thickness derived by an airborne high spectral resolution lidar.

  7. Dressing for Altitude: U.S. Aviation Pressure Suits--Wiley Post to Space Shuttle

    NASA Technical Reports Server (NTRS)

    Jenkins, Dennis R.

    2012-01-01

    Since its earliest days, flight has been about pushing the limits of technology and, in many cases, pushing the limits of human endurance. The human body can be the limiting factor in the design of aircraft and spacecraft. Humans cannot survive unaided at high altitudes. There have been a number of books written on the subject of spacesuits, but the literature on the high-altitude pressure suits is lacking. This volume provides a high-level summary of the technological development and operational use of partial- and full-pressure suits, from the earliest models to the current high altitude, full-pressure suits used for modern aviation, as well as those that were used for launch and entry on the Space Shuttle. The goal of this work is to provide a resource on the technology for suits designed to keep humans alive at the edge of space. Hopefully, future generations will learn from the hard-fought lessons of the past. NASA is committed to the future of aerospace, and a key component of that future is the workforce. Without these men and women, technological advancements would not be possible. Dressing for Altitude is designed to provide the history of the technology and to explore the lessons learned through years of research in creating, testing, and utilizing today s high-altitude suits. It is our hope that this information will prove helpful in the development of future suits. Even with the closeout of the Space Shuttle and the planned ending of the U-2 program, pressure suits will be needed for protection as long as humans seek to explore high frontiers. The NASA Aeronautics Research Mission Directorate is committed to the training of the current and future aerospace workforce. This book and the other books published by the NASA Aeronautics Research Mission Directorate are in support of this commitment. Hopefully, you will find this book a valuable resource for many years to come.

  8. The effect of repeated altitude exposures on the incidence of decompression sickness

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    INTRODUCTION: Repeated altitude exposures in a single day occur during special operations parachute training, hypobaric chamber training, unpressurized flight, and extravehicular space activity. Inconsistent and contradictory information exists regarding the risk of decompression sickness (DCS) during such hypobaric exposures. HYPOTHESIS: We hypothesized that four short exposures to altitude with and without ground intervals would result in a lower incidence of DCS than a single exposure of equal duration. METHODS: The 32 subjects were exposed to 3 different hypobaric exposures--condition A: 2 h continuous exposure (control); condition B: four 30-min exposures with descent/ascent but no ground interval between the exposures; condition C: four 30-min exposures with descent/ascent and 60 min of ground interval breathing air between exposures. All exposures were to 25,000 ft with 100% oxygen breathing. Subjects were observed for symptoms of DCS, and precordial monitoring of venous gas emboli (VGE) was accomplished with a SONOS 1000 echo-imaging system. RESULTS: DCS occurred in 19 subjects during A (mean onset 70+/-29 min), 7 subjects in B (60+/-34 min), and 2 subjects in C (40+/-18 min). There was a significant difference in DCS incidence between B and A (p = 0.0015) and C and A (p = 0.0002), but no significant difference between B and C. There were 28 cases of VGE in A (mean onset 30+/-23 min), 21 in B (41+/-35 min), and 21 in C (41+/-32 min) with a significant onset curve difference between B and A and between C and A, but not between B and C. Exposure A resulted in four cases of serious respiratory/neurological symptoms, while B had one and C had none. All symptoms resolved during recompression to ground level. CONCLUSION: Data indicate that repeated simulated altitude exposures to 25,000 ft significantly reduce DCS and VGE incidence compared with a single continuous altitude exposure.

  9. Unmanned Aerial System (UAS) Traffic Management (UTM): Enabling Low-Altitude Airspace and UAS Operations

    NASA Technical Reports Server (NTRS)

    Kopardekar, Parimal H.

    2014-01-01

    Many civilian applications of Unmanned Aerial Systems (UAS) have been imagined ranging from remote to congested urban areas, including goods delivery, infrastructure surveillance, agricultural support, and medical services delivery. Further, these UAS will have different equipage and capabilities based on considerations such as affordability, and mission needs applications. Such heterogeneous UAS mix, along with operations such as general aviation, helicopters, gliders must be safely accommodated at lower altitudes. However, key infrastructure to enable and safely manage widespread use of low-altitude airspace and UAS operations therein does not exist. Therefore, NASA is exploring functional design, concept and technology development, and a prototype UAS Traffic Management (UTM) system. UTM will support safe and efficient UAS operations for the delivery of goods and services

  10. Current Status of a NASA High-Altitude Balloon-Based Observatory for Planetary Science

    NASA Technical Reports Server (NTRS)

    Varga, Denise M.; Dischner, Zach

    2015-01-01

    Recent studies have shown that progress can be made on over 20% of the key questions called out in the current Planetary Science Decadal Survey by a high-altitude balloon-borne observatory. Therefore, NASA has been assessing concepts for a gondola-based observatory that would achieve the greatest possible science return in a low-risk and cost-effective manner. This paper addresses results from the 2014 Balloon Observation Platform for Planetary Science (BOPPS) mission, namely successes in the design and performance of the Fine Pointing System. The paper also addresses technical challenges facing the new Gondola for High Altitude Planetary Science (GHAPS) reusable platform, including thermal control for the Optical Telescope Assembly, power generation and management, and weight-saving considerations that the team will be assessing in 2015 and beyond.

  11. Experimental Characterization of Gas Turbine Emissions at Simulated Flight Altitude Conditions

    NASA Technical Reports Server (NTRS)

    Howard, R. P.; Wormhoudt, J. C.; Whitefield, P. D.

    1996-01-01

    NASA's Atmospheric Effects of Aviation Project (AEAP) is developing a scientific basis for assessment of the atmospheric impact of subsonic and supersonic aviation. A primary goal is to assist assessments of United Nations scientific organizations and hence, consideration of emissions standards by the International Civil Aviation Organization (ICAO). Engine tests have been conducted at AEDC to fulfill the need of AEAP. The purpose of these tests is to obtain a comprehensive database to be used for supplying critical information to the atmospheric research community. It includes: (1) simulated sea-level-static test data as well as simulated altitude data; and (2) intrusive (extractive probe) data as well as non-intrusive (optical techniques) data. A commercial-type bypass engine with aviation fuel was used in this test series. The test matrix was set by parametrically selecting the temperature, pressure, and flow rate at sea-level-static and different altitudes to obtain a parametric set of data.

  12. Propulsion System for Very High Altitude Subsonic Unmanned Aircraft

    NASA Technical Reports Server (NTRS)

    Bents, David J.; Mockler, Ted; Maldonado, Jaime; Harp, James L., Jr.; King, Joseph F.; Schmitz, Paul C.

    1998-01-01

    This paper explains why a spark ignited gasoline engine, intake pressurized with three cascaded stages of turbocharging, was selected to power NASA's contemplated next generation of high altitude atmospheric science aircraft. Beginning with the most urgent science needs (the atmospheric sampling mission) and tracing through the mission requirements which dictate the unique flight regime in which this aircraft has to operate (subsonic flight at greater then 80 kft) we briefly explore the physical problems and constraints, the available technology options and the cost drivers associated with developing a viable propulsion system for this highly specialized aircraft. The paper presents the two available options (the turbojet and the turbocharged spark ignited engine) which are discussed and compared in the context of the flight regime. We then show how the unique nature of the sampling mission, coupled with the economic considerations pursuant to aero engine development, point to the spark ignited engine as the only cost effective solution available. Surprisingly, this solution compares favorably with the turbojet in the flight regime of interest. Finally, some remarks are made about NASA's present state of development, and future plans to flight demonstrate the three stage turbocharged powerplant.

  13. Oxygen atom reaction with shuttle materials at orbital altitudes

    NASA Technical Reports Server (NTRS)

    Leger, L. J.

    1982-01-01

    Surfaces of materials used in the space shuttle orbiter payload bay and exposed during STS-1 through STS-3 were examined after flight. Paints and polymers, in particular Kapton used on the television camera thermal blanket, showed significant change. Generally, the change was a loss of surface gloss on the polymer with apparent aging on the paint surfaces. The Kapton surfaces showed the greatest change, and postflight analyses showed mass loss of 4.8 percent on STS-2 and 35 percent on STS-3 for most heavily affected surfaces. Strong shadow patterns were evident. The greatest mass loss was measured on surfaces which were exposed to solar radiation in conjunction with exposure in the vehicle velocity vector. A mechanism which involves the interaction of atomic oxygen with organic polymer surfaces is proposed. Atomic oxygen is the major ambient species at low orbital altitudes and presents a flux of 8 x 10 to the 14th power atoms/cu cm sec for reaction. Correlation of the expected mass loss based on ground-based oxygen atom/polymer reaction rates shows lower mass loss of the Kapton than measured. Consideration of solar heating effects on reaction rates as well as the high oxygen atom energy due to the orbiter's orbital velocity brings the predicted and measured mass loss in surprisingly good agreement. Flight sample surface morphology comparison with ground based Kapton/oxygen atom exposures provides additional support for the oxygen interaction mechanism.

  14. 14 CFR 91.119 - Minimum safe altitudes: General.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... than 500 feet to any person, vessel, vehicle, or structure. (d) Helicopters. Helicopters may be... helicopter shall comply with any routes or altitudes specifically prescribed for helicopters by...

  15. A study of altitude-constrained supersonic cruise transport concepts

    NASA Technical Reports Server (NTRS)

    Tice, David C.; Martin, Glenn L.

    1992-01-01

    The effect of restricting maximum cruise altitude on the mission performance of two supersonic transport concepts across a selection of cruise Mach numbers is studied. Results indicate that a trapezoidal wing concept can be competitive with an arrow wing depending on the altitude and Mach number constraints imposed. The higher wing loading of trapezoidal wing configurations gives them an appreciably lower average cruise altitude than the lower wing loading of the arrow wing configurations, and this advantage increases as the maximum allowable cruise altitude is reduced.

  16. Variability of cloudiness at airline cruise altitudes from GASP measurements

    NASA Technical Reports Server (NTRS)

    Jasperson, W. H.; Nastrom, G. D.; Davis, R. E.; Holdeman, J. D.

    1985-01-01

    Additional statistics relating to the climatology of cloud cover at airline cruise altitudes are presented. The data were obtained between 1975 and 1979 from commercial airliners participating in the Global Atmospheric Sampling Program (GASP). The statistics describe the seasonal, latitudinal and altitudinal variation in cloudiness parameters as well as differences in the high-altitude cloud structure attributed to cyclone and convective-cloud generation processes. The latitudinal distribution of cloud cover derived form the GASP data was found to agree with high-altitude satellite observations. The relationships between three different measures of cloudiness and the relative vorticity at high altitudes is also discussed.

  17. ARTEMIS Low Altitude Magnetic Field Measurements

    NASA Astrophysics Data System (ADS)

    Glassmeier, Karl-Heinz; Constantinescu, Dragos; Auster, Hans-Ulrich

    2016-10-01

    Since 2011, two spacecraft of the five THEMIS mission spacecraft are in orbit around the Moon. These two ARTEMIS probes provide for very interesting observations of plasma physical properties of the lunar environment. In particular, the very low periselene of the ARTEMIS probes allows for the detection of crustal magnetic features of our terrestrial companion. Repeated low passes over the same region are used to confirm the crustal origin of the measured magnetic field variations. Using a model for the decay of the magnetic field intensity and measurements at several altitudes, we estimate the magnetic moment and the depth of the equivalent dipole. Some of these magnetic anomalies are strong enough to produce upstream waves due to the interaction with the solar wind with the anomaly driven mini-magnetospheres.

  18. Daytime Aspect Camera for Balloon Altitudes

    NASA Technical Reports Server (NTRS)

    Dietz, Kurt L.; Ramsey, Brian D.; Alexander, Cheryl D.; Apple, Jeff A.; Ghosh, Kajal K.; Swift, Wesley R.

    2002-01-01

    We have designed, built, and flight-tested a new star camera for daytime guiding of pointed balloon-borne experiments at altitudes around 40 km. The camera and lens are commercially available, off-the-shelf components, but require a custom-built baffle to reduce stray light, especially near the sunlit limb of the balloon. This new camera, which operates in the 600- to 1000-nm region of the spectrum, successfully provides daytime aspect information of approx. 10 arcsec resolution for two distinct star fields near the galactic plane. The detected scattered-light backgrounds show good agreement with the Air Force MODTRAN models used to design the camera, but the daytime stellar magnitude limit was lower than expected due to longitudinal chromatic aberration in the lens. Replacing the commercial lens with a custom-built lens should allow the system to track stars in any arbitrary area of the sky during the daytime.

  19. A Daytime Aspect Camera for Balloon Altitudes

    NASA Technical Reports Server (NTRS)

    Dietz, Kurt L.; Ramsey, Brian D.; Alexander, Cheryl D.; Apple, Jeff A.; Ghosh, Kajal K.; Swift, Wesley R.; Six, N. Frank (Technical Monitor)

    2001-01-01

    We have designed, built, and flight-tested a new star camera for daytime guiding of pointed balloon-borne experiments at altitudes around 40km. The camera and lens are commercially available, off-the-shelf components, but require a custom-built baffle to reduce stray light, especially near the sunlit limb of the balloon. This new camera, which operates in the 600-1000 nm region of the spectrum, successfully provided daytime aspect information of approximately 10 arcsecond resolution for two distinct star fields near the galactic plane. The detected scattered-light backgrounds show good agreement with the Air Force MODTRAN models, but the daytime stellar magnitude limit was lower than expected due to dispersion of red light by the lens. Replacing the commercial lens with a custom-built lens should allow the system to track stars in any arbitrary area of the sky during the daytime.

  20. HAWC: The high altitude water Cherenkov observatory

    NASA Astrophysics Data System (ADS)

    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.

  1. Power Budget Analysis for High Altitude Airships

    NASA Technical Reports Server (NTRS)

    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.

  2. Aviation fuel property effects on altitude relight

    NASA Technical Reports Server (NTRS)

    Venkataramani, K.

    1987-01-01

    The major objective of this experimental program was to investigate the effects of fuel property variation on altitude relight characteristics. Four fuels with widely varying volatility properties (JP-4, Jet A, a blend of Jet A and 2040 Solvent, and Diesel 2) were tested in a five-swirl-cup-sector combustor at inlet temperatures and flows representative of windmilling conditions of turbofan engines. The effects of fuel physical properties on atomization were eliminated by using four sets of pressure-atomizing nozzles designed to give the same spray Sauter mean diameter (50 + or - 10 micron) for each fuel at the same design fuel flow. A second series of tests was run with a set of air-blast nozzles. With comparable atomization levels, fuel volatility assumes only a secondary role for first-swirl-cup lightoff and complete blowout. Full propagation first-cup blowout were independent of fuel volatility and depended only on the combustor operating conditions.

  3. Cluster II Mid-Altitude Cusp Observations

    NASA Astrophysics Data System (ADS)

    Winningham, J. D.

    2002-05-01

    Thirty plus years after its discovery the cusp is still an enigma. Questions such as is it open, closed, or mixed; where does it map; what constitutes a cusp etc still abound. Cusps have been defined on the basis of satellite, rocket, and ground based data from single and multiple sensor types. Cartoons and detailed models have been put forward to define what constitutes a cusp. An equal number of questions abound relative to the role the cusp plays in magnetospheric dynamics, mass and momentum transfer, and even energization to populate the rest of the magnetosphere. In a recent series of papers Savin et al have presented both Interball and Prognoz results in the high altitude cusp and sash region. In these papers they divide the high cusp into several new regions. They have an outer throat (OT) exterior to the MP with field lines connected to the earth and heated, stagnant plasma, a turbulent boundary layer (TBL) just at and outside the MP, an outer cusp (OC) that is inside the MP. They state an indentation depth of 1-2 RE. In the TBL large amplitude, low-frequency waves are observed. We will present multi-instrument/satellite Cluster II data that indicates the depth of the OT may be much deeper than thought by Savin. This stems from the higher spatial temporal resolution available from Cluster. Mid altitudes (~5RE) passes will be shown that exhibit the same morphology as Savin. This leads to a new definition of the cusp as the focus of open magnetopause current layer field lines.

  4. High Altitude Supersonic Decelerator Test Vehicle

    NASA Technical Reports Server (NTRS)

    Cook, Brant T.; Blando, Guillermo; Kennett, Andrew; Von Der Heydt, Max; Wolff, John Luke; Yerdon, Mark

    2013-01-01

    The Low Density Supersonic Decelerator (LDSD) project is tasked by NASA's Office of the Chief Technologist (OCT) to advance the state of the art in Mars entry and descent technology in order to allow for larger payloads to be delivered to Mars at higher altitudes with better accuracy. The project will develop a 33.5 m Do Supersonic Ringsail (SSRS) parachute, 6m attached torus, robotic class Supersonic Inflatable Aerodynamic Decelerator (SIAD-R), and an 8 m attached isotensoid, exploration class Supersonic Inflatable Aerodynamic Decelerator (SIAD-E). The SSRS and SIAD-R should be brought to TRL-6, while the SIAD-E should be brought to TRL-5. As part of the qualification and development program, LDSD must perform a Mach-scaled Supersonic Flight Dynamics Test (SFDT) in order to demonstrate successful free flight dynamic deployments at Mars equivalent altitude, of all three technologies. In order to perform these tests, LDSD must design and build a test vehicle to deliver all technologies to approximately 180,000 ft and Mach 4, deploy a SIAD, free fly to approximately Mach 2, deploy the SSRS, record high-speed and high-resolution imagery of both deployments, as well as record data from an instrumentation suite capable of characterizing the technology induced vehicle dynamics. The vehicle must also be recoverable after splashdown into the ocean under a nominal flight, while guaranteeing forensic data protection in an off nominal catastrophic failure of a test article that could result in a terminal velocity, tumbling water impact.

  5. Uav Borne Low Altitude Photogrammetry System

    NASA Astrophysics Data System (ADS)

    Lin, Z.; Su, G.; Xie, F.

    2012-07-01

    In this paper,the aforementioned three major aspects related to the Unmanned Aerial Vehicles (UAV) system for low altitude aerial photogrammetry, i.e., flying platform, imaging sensor system and data processing software, are discussed. First of all, according to the technical requirements about the least cruising speed, the shortest taxiing distance, the level of the flight control and the performance of turbulence flying, the performance and suitability of the available UAV platforms (e.g., fixed wing UAVs, the unmanned helicopters and the unmanned airships) are compared and analyzed. Secondly, considering the restrictions on the load weight of a platform and the resolution pertaining to a sensor, together with the exposure equation and the theory of optical information, the principles of designing self-calibration and self-stabilizing combined wide-angle digital cameras (e.g., double-combined camera and four-combined camera) are placed more emphasis on. Finally, a software named MAP-AT, considering the specialty of UAV platforms and sensors, is developed and introduced. Apart from the common functions of aerial image processing, MAP-AT puts more effort on automatic extraction, automatic checking and artificial aided adding of the tie points for images with big tilt angles. Based on the recommended process for low altitude photogrammetry with UAVs in this paper, more than ten aerial photogrammetry missions have been accomplished, the accuracies of Aerial Triangulation, Digital orthophotos(DOM)and Digital Line Graphs(DLG) of which meet the standard requirement of 1:2000, 1:1000 and 1:500 mapping.

  6. Cloud altitude determination from infrared spectral radiances

    NASA Technical Reports Server (NTRS)

    Smith, William L.; Frey, Richard

    1990-01-01

    The CO2 slicing method is generally recognized as the most accurate means of inferring cloud altitude from passive infrared radiance observations. The method is applicable to semi-transparent and broken clouds. During the cirrus FIRE and COHMEX field experiments, CO2 channel radiance data suitable for cloud altitude specification were achieved from moderate spectral resolution satellite sounders (NOAA-TOVS and GOES-VAS) and from a High spectral resolution Interferometer Spectrometer (HIS) flown on the NASA U2/ER2 aircraft. Also aboard the ER2 was a down-looking active lidar unit capable of providing cloud top pressure verifications with high accuracy. A third instrument, the Multispectral Atmospheric Mapping Sensor (MAMS) provided 50 meter resolution infrared window data which is used wtih radiosonde data to verify the heights of middle and low level clouds. Comparisons of lidar and MAMS/radiosonde ground truth cloud heights are made with those determined from: high resolution (0.5/cm) HIS spectra, HIS spectra degraded to the moderate resolution (15/cm) of the VAS/TOVS instruments, and spectrally averaged HIS radiances for individual pairs of VAS spectral channels. The results show that the best results are achieved from high resolution spectra; the RMS difference with the ground truth is 23 mb. The RMS differences between the infrared radiance determination and ground truth increase by 35 percent when the spectral resolution is degraded to the moderate spectral resolution of the VAS/TOVS instruments and by 52 to 183 percent, depending upon channel combinations, when only two spectral channels at VAS/TOVS spectral resolution are used.

  7. Training of cosmonauts and astronauts

    NASA Technical Reports Server (NTRS)

    Gurovskiy, N. N.; Link, M. M.

    1975-01-01

    The biomedical and preflight training of spacecraft crews is discussed based on a survey of scientific and technical literature in the U.S. and U.S.S.R. Experience gained from high velocity and high altitude aircraft flights, predictions of human reactions and theoretical models of human adaptation to the new environment of space, and actual spaceflight experience provided scientists and specialists with data from which the state of human health in space could be predicted and life support measures developed.

  8. 20 CFR 617.22 - Approval of training.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... skill level than the worker's past adversely affected employment, and wages for such work at not less... training or remedial education and what would be provided by the training program under consideration for... training is reasonably available, first consideration shall be given to training opportunities...

  9. Effects of Ascent to High Altitude on Human Antimycobacterial Immunity

    PubMed Central

    Aldridge, Robert W.; Siedner, Mark J.; Necochea, Alejandro; Leybell, Inna; Valencia, Teresa; Herrera, Beatriz; Wiles, Siouxsie; Friedland, Jon S.; Gilman, Robert H.; Evans, Carlton A.

    2013-01-01

    Background 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. Methods 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. Results 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. Conclusions 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

  10. Ventilation during simulated altitude, normobaric hypoxia and normoxic hypobaria

    NASA Technical Reports Server (NTRS)

    Loeppky, J. A.; Icenogle, M.; Scotto, P.; Robergs, R.; Hinghofer-Szalkay, H.; Roach, R. C.; Leoppky, J. A. (Principal Investigator)

    1997-01-01

    To investigate the possible effect of hypobaria on ventilation (VE) at high altitude, we exposed nine men to three conditions for 10 h in a chamber on separate occasions at least 1 week apart. These three conditions were: altitude (PB = 432, FIO2 = 0.207), normobaric hypoxia (PB = 614, FIO2 = 0.142) and normoxic hypobaria (PB = 434, FIO2 = 0.296). In addition, post-test measurements were made 2 h after returning to ambient conditions at normobaric normoxia (PB = 636, FIO2 = 0.204). In the first hour of exposure VE was increased similarly by altitude and normobaric hypoxia. The was 38% above post-test values and end-tidal CO2 (PET(CO2) was lower by 4 mmHg. After 3, 6 and 9 h, the average VE in normobaric hypoxia was 26% higher than at altitude (p < 0.01), resulting primarily from a decline in VE at altitude. The difference between altitude and normobaric hypoxia was greatest at 3 h (+ 39%). In spite of the higher VE during normobaric hypoxia, the PET(CO2) was higher than at altitude. Changes in VE and PET(CO2) in normoxic hypobaria were minimal relative to normobaric normoxia post-test measurements. One possible explanation for the lower VE at altitude is that CO2 elimination is relatively less at altitude because of a reduction in inspired gas density compared to normobaric hypoxia; this may reduce the work of breathing or alveolar deadspace. The greater VE during the first hour at altitude, relative to subsequent measurements, may be related to the appearance of microbubbles in the pulmonary circulation acting to transiently worsen matching. Results indicate that hypobaria per se effects ventilation under altitude conditions.

  11. Bicarbonate Values for Healthy Residents Living in Cities Above 1500 Meters of Altitude: A Theoretical Model and Systematic Review.

    PubMed

    Ramirez-Sandoval, Juan C; Castilla-Peón, Maria F; Gotés-Palazuelos, José; Vázquez-García, Juan C; Wagner, Michael P; Merelo-Arias, Carlos A; Vega-Vega, Olynka; Rincón-Pedrero, Rodolfo; Correa-Rotter, Ricardo

    2016-06-01

    Ramirez-Sandoval, Juan C., Maria F. Castilla-Peón, José Gotés-Palazuelos, Juan C. Vázquez-García, Michael P. Wagner, Carlos A. Merelo-Arias, Olynka Vega-Vega, Rodolfo Rincón-Pedrero, and Ricardo Correa-Rotter. Bicarbonate values for healthy residents living in cities above 1500 m of altitude: a theoretical model and systematic review. High Alt Med Biol. 17:85-92, 2016.-Plasma bicarbonate (HCO3(-)) concentration is the main value used to assess the metabolic component of the acid-base status. There is limited information regarding plasma HCO3(-) values adjusted for altitude for people living in cities at high altitude defined as 1500 m (4921 ft) or more above sea level. Our aim was to estimate the plasma HCO3(-) concentration in residents of cities at these altitudes using a theoretical model and compare these values with HCO3(-) values found on a systematic review, and with those venous CO2 values obtained in a sample of 633 healthy individuals living at an altitude of 2240 m (7350 ft). We calculated the PCO2 using linear regression models and calculated plasma HCO3(-) according to the Henderson-Hasselbalch equation. Results show that HCO3(-) concentration falls as the altitude of the cities increase. For each 1000 m of altitude above sea level, HCO3(-) decreases to 0.55 and 1.5 mEq/L in subjects living at sea level with acute exposure to altitude and in subjects acclimatized to altitude, respectively. Estimated HCO3(-) values from the theoretical model were not different to HCO3(-) values found in publications of a systematic review or with venous total CO2 measurements in our sample. Altitude has to be taken into consideration in the calculation of HCO3(-) concentrations in cities above 1500 m to avoid an overdiagnosis of acid-base disorders in a given individual.

  12. Bicarbonate Values for Healthy Residents Living in Cities Above 1500 Meters of Altitude: A Theoretical Model and Systematic Review.

    PubMed

    Ramirez-Sandoval, Juan C; Castilla-Peón, Maria F; Gotés-Palazuelos, José; Vázquez-García, Juan C; Wagner, Michael P; Merelo-Arias, Carlos A; Vega-Vega, Olynka; Rincón-Pedrero, Rodolfo; Correa-Rotter, Ricardo

    2016-06-01

    Ramirez-Sandoval, Juan C., Maria F. Castilla-Peón, José Gotés-Palazuelos, Juan C. Vázquez-García, Michael P. Wagner, Carlos A. Merelo-Arias, Olynka Vega-Vega, Rodolfo Rincón-Pedrero, and Ricardo Correa-Rotter. Bicarbonate values for healthy residents living in cities above 1500 m of altitude: a theoretical model and systematic review. High Alt Med Biol. 17:85-92, 2016.-Plasma bicarbonate (HCO3(-)) concentration is the main value used to assess the metabolic component of the acid-base status. There is limited information regarding plasma HCO3(-) values adjusted for altitude for people living in cities at high altitude defined as 1500 m (4921 ft) or more above sea level. Our aim was to estimate the plasma HCO3(-) concentration in residents of cities at these altitudes using a theoretical model and compare these values with HCO3(-) values found on a systematic review, and with those venous CO2 values obtained in a sample of 633 healthy individuals living at an altitude of 2240 m (7350 ft). We calculated the PCO2 using linear regression models and calculated plasma HCO3(-) according to the Henderson-Hasselbalch equation. Results show that HCO3(-) concentration falls as the altitude of the cities increase. For each 1000 m of altitude above sea level, HCO3(-) decreases to 0.55 and 1.5 mEq/L in subjects living at sea level with acute exposure to altitude and in subjects acclimatized to altitude, respectively. Estimated HCO3(-) values from the theoretical model were not different to HCO3(-) values found in publications of a systematic review or with venous total CO2 measurements in our sample. Altitude has to be taken into consideration in the calculation of HCO3(-) concentrations in cities above 1500 m to avoid an overdiagnosis of acid-base disorders in a given individual. PMID:27120676

  13. Aircraft Low Altitude Wind Shear Detection and Warning System.

    NASA Astrophysics Data System (ADS)

    Sinclair, Peter C.; Kuhn, Peter M.

    1991-01-01

    There is now considerable evidence to substantiate the causal relationship between low altitude wind shear (LAWS) and the recent increase in low-altitude aircraft accidents. The National Research Council has found that for the period 1964 to 1982, LAWS was involved in nearly all the weather-related air carrier fatalities. However, at present, there is no acceptable method, technique, or hardware system that provides the necessary safety margins, for spatial and timely detection of LAWS from an aircraft during the critical phases of landing and takeoff. The Federal Aviation Administration (FAA) has addressed this matter and supports the development of an airborne system for detecting hazardous LAWS with at least a one minute warning of the potential hazard to the pilot. One of the purposes of this paper is to show from some of our preliminary flight measurement research that a forward looking infrared radiometer (FLIR) system can be used to successfully detect the cool downdraft of downbursts [microbursts/macrobursts (MB)] and thunderstorm gust front outflows that are responsible for most of the LAWS events. The FLIR system provides a much greater safety margin for the pilot than that provided by reactive designs such as inertial-air speed systems that require the actual penetration of the MB before a pilot warning can be initiated. Our preliminary results indicate that an advanced airborne FLIR system could provide the pilot with remote indication of MB threat, location, movement, and predicted MB hazards along the flight path ahead of the aircraft.In a proof-of-concept experiment, we have flight tested a prototype FLIR system (nonscanning, fixed range) near and within Colorado MBs with excellent detectability. The results show that a minimum warning time of one-four minutes (5×10 km), depending on aircraft speed, is available to the pilot prior to a MB encounter. Analysis of the flight data with respect to a modified `hazard index' indicates the severe hazard

  14. Population Trends of Central European Montane Birds Provide Evidence for Adverse Impacts of Climate Change on High-Altitude Species.

    PubMed

    Flousek, Jiří; Telenský, Tomáš; Hanzelka, Jan; Reif, Jiří

    2015-01-01

    Climate change is among the most important global threats to biodiversity and mountain areas are supposed to be under especially high pressure. Although recent modelling studies suggest considerable future range contractions of montane species accompanied with increased extinction risk, data allowing to test actual population consequences of the observed climate changes and identifying traits associated to their adverse impacts are very scarce. To fill this knowledge gap, we estimated long-term population trends of montane birds from 1984 to 2011 in a central European mountain range, the Giant Mountains (Krkonoše), where significant warming occurred over this period. We then related the population trends to several species' traits related to the climate change effects. We found that the species breeding in various habitats at higher altitudes had more negative trends than species breeding at lower altitudes. We also found that the species moved upwards as a response to warming climate, and these altitudinal range shifts were associated with more positive population trends at lower altitudes than at higher altitudes. Moreover, long-distance migrants declined more than residents or species migrating for shorter distances. Taken together, these results indicate that the climate change, besides other possible environmental changes, already influences populations of montane birds with particularly adverse impacts on high-altitude species such as water pipit (Anthus spinoletta). It is evident that the alpine species, predicted to undergo serious climatically induced range contractions due to warming climate in the future, already started moving along this trajectory.

  15. Population Trends of Central European Montane Birds Provide Evidence for Adverse Impacts of Climate Change on High-Altitude Species

    PubMed Central

    Flousek, Jiří; Telenský, Tomáš; Hanzelka, Jan; Reif, Jiří

    2015-01-01

    Climate change is among the most important global threats to biodiversity and mountain areas are supposed to be under especially high pressure. Although recent modelling studies suggest considerable future range contractions of montane species accompanied with increased extinction risk, data allowing to test actual population consequences of the observed climate changes and identifying traits associated to their adverse impacts are very scarce. To fill this knowledge gap, we estimated long-term population trends of montane birds from 1984 to 2011 in a central European mountain range, the Giant Mountains (Krkonoše), where significant warming occurred over this period. We then related the population trends to several species' traits related to the climate change effects. We found that the species breeding in various habitats at higher altitudes had more negative trends than species breeding at lower altitudes. We also found that the species moved upwards as a response to warming climate, and these altitudinal range shifts were associated with more positive population trends at lower altitudes than at higher altitudes. Moreover, long-distance migrants declined more than residents or species migrating for shorter distances. Taken together, these results indicate that the climate change, besides other possible environmental changes, already influences populations of montane birds with particularly adverse impacts on high-altitude species such as water pipit (Anthus spinoletta). It is evident that the alpine species, predicted to undergo serious climatically induced range contractions due to warming climate in the future, already started moving along this trajectory. PMID:26426901

  16. DOE handbook: Design considerations

    SciTech Connect

    1999-04-01

    The Design Considerations Handbook includes information and suggestions for the design of systems typical to nuclear facilities, information specific to various types of special facilities, and information useful to various design disciplines. The handbook is presented in two parts. Part 1, which addresses design considerations, includes two sections. The first addresses the design of systems typically used in nuclear facilities to control radiation or radioactive materials. Specifically, this part addresses the design of confinement systems and radiation protection and effluent monitoring systems. The second section of Part 1 addresses the design of special facilities (i.e., specific types of nonreactor nuclear facilities). The specific design considerations provided in this section were developed from review of DOE 6430.1A and are supplemented with specific suggestions and considerations from designers with experience designing and operating such facilities. Part 2 of the Design Considerations Handbook describes good practices and design principles that should be considered in specific design disciplines, such as mechanical systems and electrical systems. These good practices are based on specific experiences in the design of nuclear facilities by design engineers with related experience. This part of the Design Considerations Handbook contains five sections, each of which applies to a particular engineering discipline.

  17. 75 FR 30690 - Minimum Altitudes for IFR Operations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-02

    ...: Background On August 18, 1989 (54 FR 34288), the FAA published a final rule that revised 14 CFR part 91. In... Docket No. FAA-18334)] Minimum Altitudes for IFR Operations AGENCY: Federal Aviation Administration (FAA... amended the guidelines for establishing minimum vectoring altitudes. Without this phrase in the...

  18. 14 CFR 135.203 - VFR: Minimum altitudes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false VFR: Minimum altitudes. 135.203 Section 135... Operating Limitations and Weather Requirements § 135.203 VFR: Minimum altitudes. Except when necessary for... above the surface or less than 500 feet horizontally from any obstacle; or (2) At night, at an...

  19. Photocopy of drawing. RIGHT ALTITUDE CHAMBER REACTIVATION. NASA, John F. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing. RIGHT ALTITUDE CHAMBER REACTIVATION. NASA, John F. Kennedy Space Center, Florida. Drawing 82K06032, Boeing, December, 1997. ACCESS PLATFORM DEMOLITION. Sheet S1 - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  20. 14 CFR 135.203 - VFR: Minimum altitudes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false VFR: Minimum altitudes. 135.203 Section 135... Operating Limitations and Weather Requirements § 135.203 VFR: Minimum altitudes. Except when necessary for... above the surface or less than 500 feet horizontally from any obstacle; or (2) At night, at an...

  1. 14 CFR 135.203 - VFR: Minimum altitudes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false VFR: Minimum altitudes. 135.203 Section 135... Operating Limitations and Weather Requirements § 135.203 VFR: Minimum altitudes. Except when necessary for... above the surface or less than 500 feet horizontally from any obstacle; or (2) At night, at an...

  2. Photocopy of drawing, RIGHT ALTITUDE CHAMBER REACTIVATION. NASA, John F. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing, RIGHT ALTITUDE CHAMBER REACTIVATION. NASA, John F. Kennedy Space Center, Florida. Drawing 82K06032, Boeing, December, 1997. ACCESS PLATFORM INSTALLATION. Sheet S2 - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  3. 14 CFR 135.203 - VFR: Minimum altitudes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false VFR: Minimum altitudes. 135.203 Section 135... Operating Limitations and Weather Requirements § 135.203 VFR: Minimum altitudes. Except when necessary for... above the surface or less than 500 feet horizontally from any obstacle; or (2) At night, at an...

  4. Photocopy of drawing. RIGHT ALTITUDE CHAMBER REACTIVATION. NASA, John F. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing. RIGHT ALTITUDE CHAMBER REACTIVATION. NASA, John F. Kennedy Space Center, Florida. Drawing 82K06032, Boeing, December, 1997. 15 FT LEVEL EQUIPMENT LAYOUT. Sheet E13 - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  5. DETAIL OF THE EXTERIOR OF ALTITUDE CHAMBER R FROM THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF THE EXTERIOR OF ALTITUDE CHAMBER R FROM THE 15’-0” LEVEL OF ACCESS PLATFORMS, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  6. Users guide to high altitude imagery of Michigan

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A guide to the high altitude imagery of Michigan outlines the areas of the state covered by selected recent high altitude aircraft and Earth Resources Technology Satellite flights. The types of remote sensing used are described. Maps of the flight coverage areas are included along with price lists of available imagery.

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

    PubMed

    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.

  8. Quadrant to Measure the Sun's Altitude

    ERIC Educational Resources Information Center

    Windsor, A Morgan, Jr.

    2013-01-01

    The changing altitude of the Sun (either over the course of a day or longer periods) is a phenomenon that students do not normally appreciate. However, the altitude of the Sun affects many topics in disciplines as diverse as astronomy, meteorology, navigation, or horology, such as the basis for seasons, determination of latitude and longitude, or…

  9. Perspectives on functional adaptation of the high altitude native.

    PubMed

    Frisancho, A R

    1983-01-01

    The major physiological processes that enable humans to attain a complete acclimatization to high altitude are briefly reviewed. The available data indicate that: (a) complete acclimatization to high altitude is associated with changes of environmentally modifiable functional traits such as lung volume but not associated with the expression of genetically controlled features such as chest size; (b) as judged by measurements of maximal aerobic power, the high altitude native has attained at high altitude an adaptation that is comparable to that attained by the low altitude native at sea level; the available information suggests that such adaptation is acquired through growth and development in an hypoxic environment; at present, however, we do not know the developmental modifications that occur within each component of the oxygen transport system, such as ventilation, pulmonary diffusion, and oxygen transport, that enable a sea level native to attain a complete functional adaptation to high altitude; and (c) at comparable altitudes among high altitude natives, there are some inter-regional differences in hemopoietic response, so that the samples derived from mining regions of the Andes are characterized by higher hemoglobin concentration than those derived from non-mining areas or the Himalayas. The source of these differences remains to be investigated. PMID:6364176

  10. Introductory address: lessons to be learned from high altitude.

    PubMed Central

    Houston, C. S.

    1979-01-01

    A historical account of the important landmarks in man's experience with the high altitude environment is followed by comments on the important stages in the understanding of its physiological effects. The work of The Mount Logan High Altitude Physiology Study on acute mountain sickness is reviewed from its inception in 1967 until the present. PMID:386292

  11. 14 CFR 135.203 - VFR: Minimum altitudes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false VFR: Minimum altitudes. 135.203 Section 135... REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT VFR/IFR Operating Limitations and Weather Requirements § 135.203 VFR: Minimum altitudes. Except when necessary...

  12. 10 CFR 862.6 - Voluntary minimum altitude.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Voluntary minimum altitude. 862.6 Section 862.6 Energy DEPARTMENT OF ENERGY RESTRICTIONS ON AIRCRAFT LANDING AND AIR DELIVERY AT DEPARTMENT OF ENERGY NUCLEAR SITES § 862.6 Voluntary minimum altitude. In addition to complying with all applicable FAA prohibitions or restrictions, aircraft are requested...

  13. Biventricular thrombosis in a structurally normal heart at high altitude.

    PubMed

    Malani, Susheel; Chadha, Davinder; Banerji, Anup

    2014-01-01

    We present a rare case of biventricular thrombus in a young patient with a structurally normal heart at high altitude, complicated with pulmonary embolism. Detailed evaluation revealed him to have protein S deficiency. Altered environmental conditions at high altitude associated with protein S deficiency resulted in thrombus formation at an unusual location; the same is discussed in this case report.

  14. 14 CFR 91.515 - Flight altitude rules.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Flight altitude rules. 91.515 Section 91...) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Large and Turbine-Powered Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.515 Flight altitude rules....

  15. [Respiratory system at high altitude: pathophysiology and novel therapy options].

    PubMed

    Trübsbach, Suzan S; Pircher, Iris; Treml, Benedict; Löckinger, Alex; Kleinsasser, Axel T

    2011-02-01

    This mini-review conveys information on lung function in hypoxia. Included are presentations of shape and layering of the atmosphere, physiologic basics of lung function at high altitude, pathophysiology of high altitude pulmonary edema (HAPE) and of current and potential therapy approaches for HAPE. PMID:21318740

  16. Altitude acclimatization. Citations from the International Aerospace Abstracts data base

    NASA Technical Reports Server (NTRS)

    Mauk, S. C.

    1980-01-01

    This bibliography of citations to the international literature covers aspects of altitude acclimatization. Included are articles concerning high altitude environments, hypoxia, heart function and hemodynamic responses, physical exercise, human tolerances and reactions, physiological responses, and oxygen consumption. This updated bibliography contains 164 citations, 35 of which are new entries to the previous edition.

  17. Low-Altitude Operation of Unmanned Rotorcraft

    NASA Astrophysics Data System (ADS)

    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

  18. AltitudeOmics: Resetting of Cerebrovascular CO2 Reactivity Following Acclimatization to High Altitude.

    PubMed

    Fan, Jui-Lin; Subudhi, Andrew W; Duffin, James; Lovering, Andrew T; Roach, Robert C; Kayser, Bengt

    2015-01-01

    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 5260 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.

  19. AltitudeOmics: Resetting of Cerebrovascular CO2 Reactivity Following Acclimatization to High Altitude

    PubMed Central

    Fan, Jui-Lin; Subudhi, Andrew W.; Duffin, James; Lovering, Andrew T.; Roach, Robert C.; Kayser, Bengt

    2016-01-01

    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 5260 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. PMID:26779030

  20. Helios High Altitude Long Endurance Mission Mishap

    NASA Technical Reports Server (NTRS)

    Henwood, Barton E.

    2009-01-01

    This slide presentation reviews the failure of the Helios solar aircraft failure. Included are pictures of the aircraft, inflight, and after the mishap, analysis of the root causes of the mishap, contributing factors, recommendations and lessons learned in respect to crew training, and assessing the level of risk.

  1. Understanding controls on cirque floor altitudes: Insights from Kamchatka

    NASA Astrophysics Data System (ADS)

    Barr, Iestyn D.; Spagnolo, Matteo

    2015-11-01

    Glacial cirques reflect former regions of glacier initiation, and are therefore used as indicators of past climate. One specific way in which palaeoclimatic information is obtained from cirques is by analysing their elevations, on the assumption that cirque floor altitudes are a proxy for climatically controlled equilibrium-line altitudes (ELAs) during former periods of small scale (cirque-type) glaciation. However, specific controls on cirque altitudes are rarely assessed, and the validity of using cirque floor altitudes as a source of palaeoclimatic information remains open to question. In order to address this, here we analyse the distribution of 3520 ice-free cirques on the Kamchatka Peninsula (eastern Russia), and assess various controls on their floor altitudes. In addition, we analyse controls on the mid-altitudes of 503 modern glaciers, currently identifiable on the peninsula, and make comparisons with the cirque altitude data. The main study findings are that cirque floor altitudes increase steeply inland from the Pacific, suggesting that moisture availability (i.e., proximity to the coastline) played a key role in regulating the altitudes at which former (cirque-forming) glaciers were able to initiate. Other factors, such as latitude, aspect, topography, geology, and neo-tectonics seem to have played a limited (but not insignificant) role in regulating cirque floor altitudes, though south-facing cirques are typically higher than their north-facing equivalents, potentially reflecting the impact of prevailing wind directions (from the SSE) and/or variations in solar radiation on the altitudes at which former glaciers were able to initiate. Trends in glacier and cirque altitudes across the peninsula are typically comparable (i.e., values typically rise from both the north and south, inland from the Pacific coastline, and where glaciers/cirques are south-facing), yet the relationship with latitude is stronger for modern glaciers, and the relationship with

  2. Microgravity combustion experiment using high altitude balloon.

    NASA Astrophysics Data System (ADS)

    Kan, Yuji

    In JAXA, microgravity experiment system using a high altitude balloon was developed , for good microgravity environment and short turn-around time. In this publication, I give an account of themicrogravity experiment system and a combustion experiment to utilize the system. The balloon operated vehicle (BOV) as a microgravity experiment system was developed from 2004 to 2009. Features of the BOV are (1) BOV has double capsule structure. Outside-capsule and inside-capsule are kept the non-contact state by 3-axis drag-free control. (2) The payload is spherical shape and itsdiameter is about 300 mm. (3) Keep 10-4 G level microgravity environment for about 30 seconds However, BOV’s payload was small, and could not mount large experiment module. In this study, inherits the results of past, we established a new experimental system called “iBOV” in order toaccommodate larger payload. Features of the iBOV are (1) Drag-free control use for only vertical direction. (2) The payload is a cylindrical shape and its size is about 300 mm in diameter and 700 mm in height. (3) Keep 10-3-10-4 G level microgravity environment for about 30 seconds We have "Observation experiment of flame propagation behavior of the droplets column" as experiment using iBOV. This experiment is a theme that was selected first for technical demonstration of iBOV. We are conducting the flame propagation mechanism elucidation study of fuel droplets array was placed at regular intervals. We conducted a microgravity experiments using TEXUS rocket ESA and drop tower. For this microgravity combustion experiment using high altitude balloon, we use the Engineering Model (EM) for TEXUS rocket experiment. The EM (This payload) consists of combustion vessel, droplets supporter, droplets generator, fuel syringe, igniter, digital camera, high-speed camera. And, This payload was improved from the EM as follows. (1) Add a control unit. (2) Add inside batteries for control unit and heater of combustion

  3. Archaic inheritance: supporting high-altitude life in Tibet.

    PubMed

    Huerta-Sánchez, Emilia; Casey, Fergal P

    2015-11-15

    The Tibetan Plateau, often called the roof of the world, sits at an average altitude exceeding 4,500 m. Because of its extreme altitude, the Plateau is one of the harshest human-inhabited environments in the world. This, however, did not impede human colonization, and the Tibetan people have made the Tibetan Plateau their home for many generations. Many studies have quantified their markedly different physiological response to altitude and proposed that Tibetans were genetically adapted. Recently, advances in sequencing technologies led to the discovery of a set of candidate genes which harbor mutations that are likely beneficial at high altitudes in Tibetans. Since then, other studies have further characterized this impressive adaptation. Here, in this minireview, we discuss the progress made since the discovery of the genes involved in Tibetans' adaptation to high altitude with a particular emphasis on describing the series of studies that led us to conclude that archaic human DNA likely contributed to this impressive adaptation.

  4. [HIGH ALTITUDE EXPOSURE IN TRAVELERS WITH PREEXISTING MEDICAL CONDITIONS].

    PubMed

    Mintzer, Dalya Navat; Leshem, Eyal; Chazan, Bibiana; Schwartz, Eli

    2015-11-01

    The number of travelers visiting high altitude regions is increasing. High altitude areas have become more accessible in recent years, and reaching areas at altitudes over 3000 meters above sea level has become more common than before. In many circumstances older travelers, who are more likely to have pre-existing chronic diseases and for whom altitude and hypoxic condition might be a risk, reach high altitudes in a fast and tight schedule, therefore having a shorter time for adaptation and acclimatization. Pre-travel consultation, including the discussion of chronic illnesses and medication use, is therefore crucial for the reduction of the risk of acute mountain sickness and preventing the deterioration of their pre-existing medical conditions.

  5. Low altitude dose measurements from APEX, CRRES and DMSP.

    PubMed

    Mullen, E G; Gussenhoven, M S; Bell, J T; Madden, D; Holeman, E; Delorey, D

    1998-01-01

    Dosimeter data taken on the APEX (1994-1996), CRRES (1990-1991) and DMSP (1984-1987) satellites have been used to study the low altitude (down to 350 km) radiation environment. Of special concern has been the inner edge of the inner radiation belt due to its steep gradient. We have constructed dose models of the inner edge of the belt from all three spacecraft and put them into a personal computer utility, called APEXRAD, that calculates dose for user-selected orbits. The variation of dose for low altitude, circular orbits is given as a function of altitude, inclination and particle type. Dose-depth curves show that shielding greater than approximately 1/4 in Al is largely ineffectual for low altitude orbits. The contribution of outer zone electrons to low altitude dose is shown to be important only for thin shields and to have significant variation with magnetic activity and solar cycle.

  6. The effect of high altitude on olfactory functions.

    PubMed

    Altundağ, Aytuğ; Salihoglu, Murat; Çayönü, Melih; Cingi, Cemal; Tekeli, Hakan; Hummel, Thomas

    2014-03-01

    It is known that high-altitude trips cause nasal congestion, impaired nasal mucociliary transport rate, and increased nasal resistance, due to decreased partial oxygen pressure and dry air. It is also known that olfactory perception is affected by barometric pressure and humidity. The aim of the present study was to investigate whether olfactory function changes in relation to high altitude in a natural setting. The present study included 41 volunteers with no history of chronic rhinosinusitis or nasal polyposis. The study group consisted of 31 men (76 %) and 10 women (24 %); the mean age of the study population was 38 ± 10 years. Olfactory testing was conducted using "Sniffin' Sticks" at a high altitude (2,200 ms) and at sea level. Odor test scores for threshold and identification were significantly better at sea level than at high altitude (p < 0.001). The major finding of this investigation was that olfactory functions are decreased at high altitudes.

  7. Optimal birthweights in Peruvian populations at high and low altitudes.

    PubMed

    Beall, C M

    1981-11-01

    This study tests the hypothesis that optimum birthweight for survival is lower among hospital-born infants in Puno, Peru (altitude 3860 m) than that among their counterparts at low altitude in Tacna, Peru (altitude 600 m). The data are derived from hospital birth records for 1971 and 1972 and municipal death records for 1971 through 1973. Linking these records permits analysis of the patterns of mortality in relation to birthweight. Stabilizing selection upon birthweight is operating in both populations. The high altitude population has a lower mean birthweight and a lower optimal birthweight. The Puno population is closer to its optimal birthweight distribution and, as a result of mortality during infancy, is approaching its optimum birthweight distribution for survival more rapidly than the Tacna population. It appears that the high altitude Puno population may well be adapted to its environment in the sense that there is less selective mortality on birthweight phenotypes.

  8. Synthetic Vision Systems - Operational Considerations Simulation Experiment

    NASA Technical Reports Server (NTRS)

    Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

    2007-01-01

    Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents/accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

  9. Synthetic vision systems: operational considerations simulation experiment

    NASA Astrophysics Data System (ADS)

    Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

    2007-04-01

    Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents / accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

  10. Free and total thyroid hormones in humans at extreme altitude

    NASA Astrophysics Data System (ADS)

    Basu, Minakshi; Pal, K.; Malhotra, A. S.; Prasad, R.; Sawhney, R. C.

    1995-03-01

    Alterations in circulatory levels of total T4 (TT4), total T3 (TT3), free T4 (FT4), free T3 (FT3), thyrotropin (TSH) and T3 uptake (T3U) were studied in male and female sea-level residents (SLR) at sea level, in Armed forces personnel staying at high altitude (3750 m) for prolonged duration (acclimatized lowlanders, ALL) and in high-altitude natives (HAN). Identical studies were also performed on male ALL who trekked to an extreme altitude of 5080 m and stayed at an altitude of more than 6300 m for about 6 months. The total as well as free thyroid hormones were found to be significantly higher in ALL and HAN as compared to SLR values. Both male as well as female HAN had higher levels of thyroid hormones. The rise in hormone levels in different ALL ethnic groups drawn from amongst the southern and northern parts of the country was more or less identical. In both HAN and ALL a decline in FT3 and FT4 occurred when these subjects trekked at subzero temperatures to extreme altitude of 5080 m but the levels were found to be higher in ALL who stayed at 6300 m for a prolonged duration. Plasma TSH did not show any appreciable change at lower altitudes but was found to be decreased at extreme altitude. The increase in thyroid hormones at high altitude was not due to an increase in hormone binding proteins, since T3U was found to be higher at high altitudes. A decline in TSH and hormone binding proteins and an increase in the free moiety of the hormones is indicative of a subtle degree of tissue hyperthyroidism which may be playing an important role in combating the extreme cold and hypoxic environment of high altitudes.

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

    PubMed Central

    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

    Purpose 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. Methods 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 1000m (<1000m, 1000–2000, 2000–3000 and >3000m) according to the average altitude of each ride. Mixed linear modelling was used to compare cycling performance data from each altitude bin. Results 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 < 0.001) during racing at moderate-high altitude compared with the race simulation near sea-level. Conclusion A reduction in oxygen availability as altitude increases leads to attenuation of 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. PMID:26629912

  12. Increased oxidative stress following acute and chronic high altitude exposure.

    PubMed

    Jefferson, J Ashley; Simoni, Jan; Escudero, Elizabeth; Hurtado, Maria-Elena; Swenson, Erik R; Wesson, Donald E; Schreiner, George F; Schoene, Robert B; Johnson, Richard J; Hurtado, Abdias

    2004-01-01

    The generation of reactive oxygen species is typically associated with hyperoxia and ischemia reperfusion. Recent evidence has suggested that increased oxidative stress may occur with hypoxia. We hypothesized that oxidative stress would be increased in subjects exposed to high altitude hypoxia. We studied 28 control subjects living in Lima, Peru (sea level), at baseline and following 48 h exposure to high altitude (4300 m). To assess the effects of chronic altitude exposure, we studied 25 adult males resident in Cerro de Pasco, Peru (altitude 4300 m). We also studied 27 subjects living in Cerro de Pasco who develop excessive erythrocytosis (hematocrit > 65%) and chronic mountain sickness. Acute high altitude exposure led to increased urinary F(2)-isoprostane, 8-iso PGF(2 alpha) (1.31 +/- 0.8 microg/g creatinine versus 2.15 +/- 1.1, p = 0.001) and plasma total glutathione (1.29 +/- 0.10 micromol versus 1.37 +/- 0.09, p = 0.002), with a trend to increased plasma thiobarbituric acid reactive substance (TBARS) (59.7 +/- 36 pmol/mg protein versus 63.8 +/- 27, p = NS). High altitude residents had significantly elevated levels of urinary 8-iso PGF(2 alpha) (1.3 +/- 0.8 microg/g creatinine versus 4.1 +/- 3.4, p = 0.007), plasma TBARS (59.7 +/- 36 pmol/mg protein versus 85 +/- 28, p = 0.008), and plasma total glutathione (1.29 +/- 0.10 micromol versus 1.55 +/- 0.19, p < 0.0001) compared to sea level. High altitude residents with excessive erythrocytosis had higher levels of oxidative stress compared to high altitude residents with normal hematological adaptation. In conclusion, oxidative stress is increased following both acute exposure to high altitude without exercise and with chronic residence at high altitude.

  13. Theoretical atmospheric transmission in the mid-and far-infrared at four altitudes.

    PubMed

    Traub, W A; Stier, M T

    1976-02-01

    The ir transmission of the terrestrial atmosphere is calculated at four altitudes of interest: Mauna Kea at 4.2 km (2-1000 microm), aircraft at 14 km (5-1000 microm), and balloon at 28 km and 41 km (10-1000 microm). We show both high resolution spectra (0.05 cm(-1)) and broadband averages. The results are intended to serve both as a detailed guide to the interference that is expected from the atmosphere for astronomical spectroscopy and also as an indicator of the relative change in absorption and emission that can be expected at various observing altitudes. One salient result for the spectral region around 100 microm is that the absorption (and emissivity) of the atmosphere drops by a factor of 10 for each increase in altitude of 15 km throughout the aircraft and balloon range; thus balloon-borne astronomical photometry and spectroscopy should both enjoy a considerable advantage over aircraft observations in the 30-300-microm region. PMID:20164977

  14. Plasma gonadotrophins, prolactin and corticosterone concentrations in male mice exposed to high altitude.

    PubMed

    Rattner, B A; Macmillan, B T; Michael, S D; Altland, P D

    1980-11-01

    Groups of sexually-naive male NFR/N mice were maintained at sea level or exposed to simulated altitudes of 18 000 ft (5486 m) or 22 000 ft (6705 m) for 1, 3, 7, 14 or 28 days. Plasma LH concentrations were slightly but not significantly depressed after 1 day of hypoxia. Plasma FSH values were reduced (P < 0.05) after 1, 7, 14 and 28 days of exposure to 22 000 ft when compared to the values in the other groups. Prolactin concentrations fluctuated considerably, but were not uniformly affected by high altitude exposure. Exposure to 18 000 ft resulted in an elevation of plasma corticosterone concentration (P < 0.05) for 3 days, which was followed by a decline to control group values, whereas at 22 000 ft corticosterone levels remained elevated. These findings indicate that plasma LH values are transiently reduced during the initial 24 h of exposure to high altitude and that plasma FSH concentrations are depressed in a sustained manner during severe hypoxia.

  15. SHARP: Subsonic High Altitude Research Platform

    NASA Technical Reports Server (NTRS)

    Beals, Todd; Burton, Craig; Cabatan, Aileen; Hermano, Christine; Jones, Tom; Lee, Susan; Radloff, Brian

    1991-01-01

    The Universities Space Research Association 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 that ranges from Chile to the South Pole and back to Chile, a total range of 6000 n.mi. at 100,000 ft with a 2500 lb payload. The second mission is also a polar mission, with an altitude of 70,000 ft and an increased payload of 4000 lbs. For the third mission, the aircraft will takeoff at NASA Ames, cruise at 100,000 ft carrying a 2500 lb payload, and land at Puerto Montt, Chile. The final mission requires the aircraft to take off at NASA Ames, cruise at 100,000 ft with a 1000 lb payload, make an excursion to 120,000 ft, and land at Howard AFB, Panama. Three missions require that a subsonic Mach number be maintained due to constraints imposed by the air sampling equipment. The aircraft need not be manned for all four missions. Three aircraft configurations have been determined to be the most suitable for meeting the above requirements. In the event that a requirement cannot be obtained within the given constraints, recommendations for proposal modifications are given.

  16. NASA/USRA high altitude reconnaissance aircraft

    NASA Technical Reports Server (NTRS)

    Richardson, Michael; Gudino, Juan; Chen, Kenny; Luong, Tai; Wilkerson, Dave; Keyvani, Anoosh

    1990-01-01

    At the equator, the ozone layer ranges from approximately 80,000 to 130,000+ feet which is beyond the capabilities of the ER-2, NASA's current high altitude reconnaissance aircraft. This project is geared to designing an aircraft that can study the ozone layer at the equator. This aircraft must be able to cruise at 130,000 lbs. of payload. In addition, the aircraft must have a minimum of a 6,000 mile range. The low Mach number, payload, and long cruising time are all constraints imposed by the air sampling equipment. A pilot must be able to take control in the event of unforseen difficulties. Three aircraft configurations were determined to be the most suitable for meeting the above requirements, a joined-wing, a bi-plane, and a twin-boom conventional airplane. The techniques used have been deemed reasonable within the limits of 1990 technology. 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.

  17. The High-Altitude Water Cherenkov Observatory

    NASA Astrophysics Data System (ADS)

    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.

  18. Dosimetry at aviation altitudes (2006-2008).

    PubMed

    Meier, Matthias M; Hubiak, Melina; Matthiä, Daniel; Wirtz, Michael; Reitz, Günther

    2009-10-01

    Based upon the European Union (EU)-Directive 96/29/EURATOM, legal regulations on the radiation protection of aircrew had to be implemented into the corresponding national law within the member states of the EU by 13 May 2000. In Article 42 the directive stipulates, among other things, that the exposure of the crew concerned shall be assessed. This requirement has been implemented by dose calculations for most aircrew members in the EU. Some airlines and research institutes regularly spot check the calculated doses by measuring flights. The solar minimum is a time period of particular interest since the dose rates at aviation altitudes reach their maximum within the 11-year solar cycle. For this reason, the German Aerospace Center (DLR) performed repeated measuring flights in cooperation with several German airlines during the past solar minimum from March 2006 to August 2008. The measuring devices used consisted of a tissue equivalent proportional counter, various types of Liulin semiconductor detectors and several bubble detectors.

  19. The High Altitude Water Cherenkov (HAWC) Observatory

    NASA Astrophysics Data System (ADS)

    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...

  20. High Altitude Observatory YBJ and ARGO Project

    NASA Astrophysics Data System (ADS)

    Tan, Y.; ARGO Collaboration

    A 5800 m2 RPC (Resistive Plate Chamber) full coverage air shower array is under construction in the YangBaJing Cosmic Ray Observatory, Tibet of China, by the ChinaItaly ARGO Collaboration. YBJ is a large flat grassland with an area 10 × 70 km2 at 4300m altitude, about 90 north west from Lhasa. Its nearby power station, asphalt road to Lhasa, passing railway (will be constructed during the coming 5 years), optical fiber link to the INTERNET, rare snow and other favourable weather conditions are well suitable for setting an Astrophysical Observatory here. The installation of a large area carpet-like detector in this peculiar site will allow one to perform an all-sky and high duty cycle study of high energy gamma rays from 100GeV to 50 TeV as well as accurate measurements on UHE cosmic rays. To insure the stable and uniform working condition of RPCs, a 104 M2 carpet hall was constructed, the RPC installation have be started in it since last November. The natural distribution and daily variation of temperature in the hall, the data concerning the performances of the installed RPCs, have been measured, the results are presented. ce

  1. Skylab medical experiments altitude test crew observations.

    NASA Technical Reports Server (NTRS)

    Bobko, K. J.

    1973-01-01

    The paper deals with the crew's observations during training and the SMEAT 56-day test. Topics covered include the crew's adaptation to the SMEAT environment and medical experiments protocol. Personal observations are made of daily activities surrounding the medical experiments hardware, Skylab clothing, supplementary activities, recreational equipment, food, and waste management. An assessment of these items and their contributions to the Skylab flight program is made.

  2. Facility Design Considerations.

    ERIC Educational Resources Information Center

    Chase, William W.

    1967-01-01

    Increasing need for vocational education under the impetus of federal aid is generating a demand for vocational teaching facilities. Factors to be considered in planning these facilities inclued--(1) site development, (2) program needs, (3) administrative considerations, (4) environmental controls. (5) mechanical systems, and (6) area and space…

  3. HIGH LIFE: High altitude fatalities led to pulse oximetry.

    PubMed

    Severinghaus, John W

    2016-01-15

    In 1875, Paul Bert linked high altitude danger to the low partial pressure of oxygen when 2 of 3 French balloonists died euphorically at about 8,600 m altitude. World War I fatal crashes of high altitude fighter pilots led to a century of efforts to use oximetry to warn pilots. The carotid body, discovered in 1932 to be the hypoxia detector, led to most current physiologic understanding of the body's respiratory responses to hypoxia and CO2. The author describes some of his UCSF group's work: In 1963, we reported both the brain's ventral medullary near-surface CO2 (and pH) chemosensors and the role of cerebrospinal fluid in acclimatization to altitude. In 1966, we reported the effect of altitude on cerebral blood flow and later the changes of carotid body sensitivity at altitude and the differences in natives of high altitude. In 1973, pulse oximetry was invented when Japanese biophysicist Takuo Aoyagi read and applied to pulses a largely forgotten 35-year-old discovery by English medical student J. R. Squire of a method of computing oxygen saturation from red and infrared light passing through both perfused and blanched tissue.

  4. Aging, High Altitude, and Blood Pressure: A Complex Relationship.

    PubMed

    Parati, Gianfranco; Ochoa, Juan Eugenio; Torlasco, Camilla; Salvi, Paolo; Lombardi, Carolina; Bilo, Grzegorz

    2015-06-01

    Parati, Gianfranco, Juan Eugenio Ochoa, Camilla Torlasco, Paolo Salvi, Carolina Lombardi, and Grzegorz Bilo. Aging, high altitude, and blood pressure: A complex relationship. High Alt Biol Med 16:97-109, 2015.--Both aging and high altitude exposure may induce important changes in BP regulation, leading to significant increases in BP levels. By inducing atherosclerotic changes, stiffening of large arteries, renal dysfunction, and arterial baroreflex impairment, advancing age may induce progressive increases in systolic BP levels, promoting development and progression of arterial hypertension. It is also known, although mainly from studies in young or middle-aged subjects, that exposure to high altitude may influence different mechanisms involved in BP regulation (i.e., neural central and reflex control of sympathetic activity), leading to important increases in BP levels. The evidence is less clear, however, on whether and to what extent advancing age may influence the BP response to acute or chronic high altitude exposure. This is a question not only of scientific interest but also of practical relevance given the consistent number of elderly individuals who are exposed for short time periods (either for leisure or work) or live permanently at high altitude, in whom arterial hypertension is frequently observed. This article will review the evidence available on the relationship between aging and blood pressure levels at high altitude, the pathophysiological mechanisms behind this complex association, as well as some questions of practical interest regarding antihypertensive treatment in elderly subjects, and the effects of antihypertensive drugs on blood pressure response during high altitude exposure.

  5. Effects of high altitude and exercise on marksmanship.

    PubMed

    Tharion, W J; Hoyt, R W; Marlowe, B E; Cymerman, A

    1992-02-01

    The effects of exercise and high altitude (3,700 m to 4,300 m) on marksmanship accuracy and sighting time were quantified in 16 experienced marksmen. Subjects dry-fired a disabled rifle equipped with a laser-based system from a free-standing position. The 2.3-cm circular target was at a distance of 5 m. Marksmanship was assessed under the following conditions: 1) at rest at sea level; 2) immediately after a 21-km run/walk ascent from 1,800 m to 4,300 m elevation; 3) at rest during days 1 to 3 at altitude; 4) at rest during days 14 to 16 at altitude; and 5) immediately after a second ascent after 17 d at altitude. Exercise reduced marksmanship accuracy (p less than 0.05) but did not affect sighting time. Acute altitude exposure reduced marksmanship accuracy, and decreased sighting time (p less than 0.05). However, after residence at altitude, accuracy and sighting time at rest returned to sea level values. Exercise and acute altitude exposure had similar but independent detrimental effects on marksmanship. PMID:1546938

  6. Height and altitude distribution of large volcanoes on Venus

    NASA Technical Reports Server (NTRS)

    Keddie, S. T.; Head, J. W.

    1994-01-01

    Magellan data reveal 156 large volcanoes on Venus (greater than 100 km in diameter) which range in height from 300 m to 5.55 km, with an average height of 1.42 km. On the basis of theory it has been predicted that the development of neutral buoyancy zones (NBZ) on Venus and thus the resulting volcanic deposits are strongly influenced by the altitude-controlled variations in surface pressure. The distribution and height of these large volcanoes as a function of altitude was examined to begin to test these predications. Although large volcanoes are relatively uniformly distributed in altitude, there may be a slight paucity of volcanoes at the lowest elevations and a slight surplus at mid-altitudes. In addition, it is observed that the volcanoes at the highest altitudes tend to be the tallest. The observed distributions at low-mid altitudes is consistent with the prediction of NBZ theory. The high altitude distribution and heights, however, emphasize the necessity of considering other factors, such as tectonic setting, edifice age, magma supply, and thermal gradient, in describing the location and development of large volcanoes on Venus.

  7. DLR HABLEG- High Altitude Balloon Launched Experimental Glider

    NASA Astrophysics Data System (ADS)

    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.

  8. [Aspects and necessity of moderate-altitude research].

    PubMed

    Domej, Wolfgang; Schwaberger, Günther; Guger, Christoph; Herfert, Jürgen; Haditsch, Bernd; Földes-Papp, Zeno; Tilz, Gernot P

    2005-04-01

    Alpinism in all its variations is a leading factor in tourism. Within a few decades, alpine sports, even at high altitudes, have become available to a wide range of people. Now, more people than ever before are hiking, trekking, climbing and skiing at moderate and high altitudes. Annually, 40 million people spend time in the Alps and 100 million visit high altitudes worldwide. However, alpine excursions may entail health problems and many aspects of impaired adaptation to altitude remain unstudied. High-altitude research has mainly been associated with expeditions, with moderate altitudes receiving far less attention, though most tourism takes place at that level. The overwhelming numbers of alpine tourists mean that there is urgent need for high- and moderate-altitude medical research, which would also be within the realm of political responsibility in mountainous countries. Research in mountain medicine and dissemination of relevant findings can show how to improve and conserve performance in healthy individuals and could point the way toward new, safe approaches in the rehabilitation of patients with chronic diseases. It is imperative that mountain medicine continues to develop on a scientific basis.

  9. Nutritional Considerations for Performance in Young Athletes.

    PubMed

    Smith, JohnEric W; Holmes, Megan E; McAllister, Matthew J

    2015-01-01

    Nutrition is an integral component to any athletes training and performance program. In adults the balance between energy intake and energy demands is crucial in training, recovery, and performance. In young athletes the demands for training and performance remain but should be a secondary focus behind the demands associated with maintaining the proper growth and maturation. Research interventions imposing significant physiological loads and diet manipulation are limited in youth due to the ethical considerations related to potential negative impacts on the growth and maturation processes associated with younger individuals. This necessary limitation results in practitioners providing nutritional guidance to young athletes to rely on exercise nutrition recommendations intended for adults. While many of the recommendations can appropriately be repurposed for the younger athlete attention needs to be taken towards the differences in metabolic needs and physiological differences. PMID:26464898

  10. Nutritional Considerations for Performance in Young Athletes

    PubMed Central

    Smith, JohnEric W.; Holmes, Megan E.; McAllister, Matthew J.

    2015-01-01

    Nutrition is an integral component to any athletes training and performance program. In adults the balance between energy intake and energy demands is crucial in training, recovery, and performance. In young athletes the demands for training and performance remain but should be a secondary focus behind the demands associated with maintaining the proper growth and maturation. Research interventions imposing significant physiological loads and diet manipulation are limited in youth due to the ethical considerations related to potential negative impacts on the growth and maturation processes associated with younger individuals. This necessary limitation results in practitioners providing nutritional guidance to young athletes to rely on exercise nutrition recommendations intended for adults. While many of the recommendations can appropriately be repurposed for the younger athlete attention needs to be taken towards the differences in metabolic needs and physiological differences. PMID:26464898

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

    NASA Technical Reports Server (NTRS)

    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

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

    NASA Astrophysics Data System (ADS)

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

    1990-10-01

    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

  13. Methods of the international study on soccer at altitude 3600 m (ISA3600)

    PubMed Central

    Gore, Christopher J; Aughey, Robert J; Bourdon, Pitre C; Garvican-Lewis, Laura A; Soria, Rudy; Claros, Jesus C Jimenez; Sargent, Charli; Roach, Gregory D; Buchheit, Martin; Simpson, Ben M; Hammond, Kristal; Kley, Marlen; Wachsmuth, Nadine; Pepper, Mark; Edwards, Alistair; Cuenca, Douglas; Vidmar, Tony; Spielvogel, Hilde; Schmidt, Walter F

    2013-01-01

    Background We describe here the 3-year process underpinning a multinational collaboration to investigate soccer played at high altitude—La Paz, Bolivia (3600 m). There were two main aims: first, to quantify the extent to which running performance would be altered at 3600 m compared with near sea level; and second, to characterise the time course of acclimatisation of running performance and underlying physiology to training and playing at 3600 m. In addition, this project was able to measure the physiological changes and the effect on running performance of altitude-adapted soccer players from 3600 m playing at low altitude. Methods A U20 Bolivian team (‘The Strongest’ from La Paz, n=19) played a series of five games against a U17 team from sea level in Australia (The Joeys, n=20). 2 games were played near sea level (Santa Cruz 430 m) over 5 days and then three games were played in La Paz over the next 12 days. Measures were (1) game and training running performance—including global positioning system (GPS) data on distance travelled and velocity of movement; (2) blood—including haemoglobin mass, blood volume, blood gases and acid–base status; (3) acclimatisation—including resting heart rate variability, perceived altitude sickness, as well as heart rate and perceived exertion responses to a submaximal running test; and (4) sleep patterns. Conclusions Pivotal to the success of the project were the strong professional networks of the collaborators, with most exceeding 10 years, the links of several of the researchers to soccer federations, as well as the interest and support of the two head coaches. PMID:24282214

  14. NAU's High Altitude Balloon Satellite Program for Middle and High School Students

    NASA Astrophysics Data System (ADS)

    Lutz, Barry L.

    2007-10-01

    Northern Arizona University is entering its fourth year of offering a high altitude balloon satellite program designed for middle and high school students. The program, called Changes in Altitudes, was originally piloted by the NAU Space Grant, a member of the Arizona Space Grant Consortium, and is currently being supported by the University of Arizona's Phoenix Mars Mission as a robotics strand of its Education and Public Outreach program. Each year, ten schools from across Arizona, selected on a competitive basis, are invited to form teams of fours student each to design and build payloads that they will fly on a high altitude weather balloon up to 100, 000 ft above sea level. The baseline payload consists of 6-inch cube containing a pressure data logger, a temperature/relative humidity data logger, and a small film camera that is modified to take photographs approximately every three minutes during the flight. The students track the balloon from launch through burst to touch down. They recover their payloads in the field to retrieve the pressure and temperature profiles of the atmosphere and the images of the Earth recorded during the flight. A post-flight debriefing allows students to see and share their data with students from the other schools. Each school is participates in four flights over a period of two years allowing up to 16 students from each school to experience the project. In addition, the teachers are provided a training workshop and launch to prepare them for leading their student teams. In this poster, examples of student data are presented and the failures and successes are discussed, along with the challenges associated with offering such a program at the pre-college level. The handbook used for teacher training will be available, along with words of encouragement to build a similar program in your state.

  15. Turbulent mixing in high-altitude explosions

    SciTech Connect

    Kuhl, A.L.; Bell, J.B. ); Ferguson, R.E. ); White, W.W.; McCartor, T.H. )

    1992-09-01

    Numerical simulations of a high-altitude explosion were performed using a Godunov code with Adaptive Mesh Refinement (AMR). The code solves the two-dimensional (2-D), time-dependent conservation laws of inviscid gas dynamics while AMR is used to focus the computational effort in the mixing regions. The calculations revealed that a spherical density interface embedded in this flow was unstable and rolled up into a turbulent mixing layer. The shape of the interface was qualitatively similar to experimental photographs. Initially, the mixing layer width grew as a linear function of time, but eventually it reached an asymptotically-constant value. The flow field was azimuthally-averaged to evaluate the mean-flow profiles and the R.M.S. fluctuation profiles across the mixing layer. The mean kinetic energy rapidly approached zero as the blast wave decayed, but the fluctuating kinetic energy asymptotically approached a small constant value (a fraction of a percent of the maximum kinetic energy). This represents the rotational kinetic energy driven by the vorticity field, that continued to mix the fluid indefinitely. It was shown that the vorticity field corresponds to a function that fluctuates between plus and minus values -- with a volume-averaged mean of zero. The amplitude of the vorticity fluctuations decayed as t[sup [minus]1]. The corresponding enstrophy increased linearly with time because of a cascade process for the mean-squared vorticity. This result is in good agreement with the 2-D calculations of turbulent flow as reported by G.K. Batchelor. The problem should be recalculated in 3-D to study the decay of turbulent mixing for spherical interfaces.

  16. Turbulent mixing in high-altitude explosions

    SciTech Connect

    Kuhl, A.L.; Bell, J.B.; Ferguson, R.E.; White, W.W.; McCartor, T.H.

    1992-09-01

    Numerical simulations of a high-altitude explosion were performed using a Godunov code with Adaptive Mesh Refinement (AMR). The code solves the two-dimensional (2-D), time-dependent conservation laws of inviscid gas dynamics while AMR is used to focus the computational effort in the mixing regions. The calculations revealed that a spherical density interface embedded in this flow was unstable and rolled up into a turbulent mixing layer. The shape of the interface was qualitatively similar to experimental photographs. Initially, the mixing layer width grew as a linear function of time, but eventually it reached an asymptotically-constant value. The flow field was azimuthally-averaged to evaluate the mean-flow profiles and the R.M.S. fluctuation profiles across the mixing layer. The mean kinetic energy rapidly approached zero as the blast wave decayed, but the fluctuating kinetic energy asymptotically approached a small constant value (a fraction of a percent of the maximum kinetic energy). This represents the rotational kinetic energy driven by the vorticity field, that continued to mix the fluid indefinitely. It was shown that the vorticity field corresponds to a function that fluctuates between plus and minus values -- with a volume-averaged mean of zero. The amplitude of the vorticity fluctuations decayed as t{sup {minus}1}. The corresponding enstrophy increased linearly with time because of a cascade process for the mean-squared vorticity. This result is in good agreement with the 2-D calculations of turbulent flow as reported by G.K. Batchelor. The problem should be recalculated in 3-D to study the decay of turbulent mixing for spherical interfaces.

  17. Syndrome of acute anxiety among marines after recent arrival at high altitude.

    PubMed

    Sracic, Michael K; Thomas, Darren; Pate, Allen; Norris, Jacob; Norman, Marc; Gertsch, Jeffrey H

    2014-05-01

    Management of mental health is critical for maintenance of readiness in austere military environments. Emerging evidence implicates hypoxia as an environmental trigger of anxiety spectrum symptomatology. One thousand thirty-six unacclimatized infantry Marines ascended from sea level to the Marine Corps Mountain Warfare Training Center (2,061-3,383 m) for a 30-day exercise. Within the first 6 days of training, 7 servicemen presented with severe, acute anxiety/panic with typical accompanying signs of sympathetic activation and no classic symptoms of acute mountain sickness (including headache). Four had a history of well-controlled psychiatric diagnoses. Invariably, cardiopulmonary and neurological evaluations were unrevealing, and acute cardiopulmonary events were excluded within limits of expeditionary diagnostic capabilities. All patients responded clinically to oxygen, rest, and benzodiazepines, returning to baseline function the same day. The unexpected onset of 7 cases of acute anxiety symptomatology coincident with recent arrival at moderate-to-high altitudes represents a highly unusual incidence and temporal distribution, suggestive of hypobaric hypoxemia as the proximal cause. We propose acute hypoxic physiological anxiety (AHPA) as a unique member of the spectrum of altitude-associated neurological disorders. Recognition of AHPA is particularly relevant in a military population; warfighters with anxiety spectrum diagnoses may have a recognizable and possibly preventable vulnerability. PMID:24806502

  18. Syndrome of acute anxiety among marines after recent arrival at high altitude.

    PubMed

    Sracic, Michael K; Thomas, Darren; Pate, Allen; Norris, Jacob; Norman, Marc; Gertsch, Jeffrey H

    2014-05-01

    Management of mental health is critical for maintenance of readiness in austere military environments. Emerging evidence implicates hypoxia as an environmental trigger of anxiety spectrum symptomatology. One thousand thirty-six unacclimatized infantry Marines ascended from sea level to the Marine Corps Mountain Warfare Training Center (2,061-3,383 m) for a 30-day exercise. Within the first 6 days of training, 7 servicemen presented with severe, acute anxiety/panic with typical accompanying signs of sympathetic activation and no classic symptoms of acute mountain sickness (including headache). Four had a history of well-controlled psychiatric diagnoses. Invariably, cardiopulmonary and neurological evaluations were unrevealing, and acute cardiopulmonary events were excluded within limits of expeditionary diagnostic capabilities. All patients responded clinically to oxygen, rest, and benzodiazepines, returning to baseline function the same day. The unexpected onset of 7 cases of acute anxiety symptomatology coincident with recent arrival at moderate-to-high altitudes represents a highly unusual incidence and temporal distribution, suggestive of hypobaric hypoxemia as the proximal cause. We propose acute hypoxic physiological anxiety (AHPA) as a unique member of the spectrum of altitude-associated neurological disorders. Recognition of AHPA is particularly relevant in a military population; warfighters with anxiety spectrum diagnoses may have a recognizable and possibly preventable vulnerability.

  19. Long-Term Exposure to High Altitude Affects Conflict Control in the Conflict-Resolving Stage.

    PubMed

    Ma, Hailin; Wang, Yan; Wu, Jianhui; Wang, Baoxi; Guo, Shichun; Luo, Ping; Han, Buxin

    2015-01-01

    The neurocognitive basis of the effect of long-term high altitude exposure on conflict control is unclear. Event related potentials (ERPs) were recorded in a flanker task to investigate the influence of high altitude on conflict control in the high-altitude group (who had lived at high altitude for three years but were born at low altitude) and the low-altitude group (living in low altitude only). Although altitude effect was not significant at the behavioral level, ERPs showed cognitive conflict modulation. The interaction between group and trial type was significant: P3 amplitude was greater in the low-altitude group than in the high-altitude group in the incongruent trial. This result suggests that long-term exposure to high altitude affects conflict control in the conflict-resolving stage, and that attentional resources are decreased to resist the conflict control in the high-altitude group.

  20. Long-Term Exposure to High Altitude Affects Conflict Control in the Conflict-Resolving Stage

    PubMed Central

    Wu, Jianhui; Wang, Baoxi; Guo, Shichun; Luo, Ping; Han, Buxin

    2015-01-01

    The neurocognitive basis of the effect of long-term high altitude exposure on conflict control is unclear. Event related potentials (ERPs) were recorded in a flanker task to investigate the influence of high altitude on conflict control in the high-altitude group (who had lived at high altitude for three years but were born at low altitude) and the low-altitude group (living in low altitude only). Although altitude effect was not significant at the behavioral level, ERPs showed cognitive conflict modulation. The interaction between group and trial type was significant: P3 amplitude was greater in the low-altitude group than in the high-altitude group in the incongruent trial. This result suggests that long-term exposure to high altitude affects conflict control in the conflict-resolving stage, and that attentional resources are decreased to resist the conflict control in the high-altitude group. PMID:26671280